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	claims	1. A slit mechanism apparatus comprising:two slit plates configured to adjust a thickness of X-rays;two slit link bars which are pivotally supported on two ends of each of the two slit plates to interlock the two slit plates;two shafts on which the two slit link bars are respectively mounted to rotate the two slit link bars;two shutter plates configured to block/pass the X-rays; andtwo shutter link bars which are pivotally supported on two ends of each of the two shutter plates to interlock the two shutter plates and are mounted on the two shafts together with the two slit link bars. 2. The apparatus according to claim 1, wherein the shutter link bar has a length longer than that of the slit link bar. 3. The apparatus according to claim 1, wherein the shutter link bar is fixed to the slit link bar at a predetermined intersection angle. 4. The apparatus according to claim 1, wherein the shutter link bar intersects the slit link bar at an angle selected from a range of 50° to 140°. 5. The apparatus according to claim 1, wherein the shutter link bar intersects the slit link bar at an angle of substantially 90°. 6. The apparatus according to claim 1, wherein the shutter link bar is mounted on the shaft at a predetermined distance from the slit link bar so as to prevent the two slit plates from interfering with the two shutter plates. 7. An X-ray computed tomography apparatus comprising an X-ray tube which generates X-rays, an X-ray detector which detects X-rays transmitted through an object, a rotating mechanism which rotates the X-ray tube together with the X-ray detector around the object, and a slit mechanism apparatus which is provided between the X-ray tube and the object to adjust a width of the X-rays,the slit mechanism apparatus comprisingtwo slit plates configured to adjust a width of X-rays,two slit link bars which are pivotally supported on two ends of each of the two slit plates to interlock the two slit plates,two shafts on which the two slit link bars are respectively mounted to rotate the two slit link bars;two shutter plates configured to block/pass the X-rays, andtwo shutter link bars which are pivotally supported on two ends of each of the two shutter plates to interlock the two shutter plates and are mounted on the two shafts together with the two slit link bars. 8. The apparatus according to claim 7, wherein the shutter link bar has a length longer than that of the slit link bar. 9. The apparatus according to claim 7, wherein the shutter link bar is fixed to the slit link bar at a predetermined intersection angle. 10. The apparatus according to claim 7, wherein the shutter link bar intersects the slit link bar at an angle selected from a range of 50° to 140°. 11. The apparatus according to claim 7, wherein the shutter link bar intersects the slit link bar at an angle of substantially 90°. 12. The apparatus according to claim 7, wherein the shutter link bar is mounted on the shaft at a predetermined distance from the slit link bar so as to prevent the two slit plates from interfering with the two shutter plates. 13. A X-rays beam adjusting/blocking apparatus which includes X-rays beam adjustment means comprising an adjustment plate, X-rays blocking means comprising a blocking plate, and switching means and adjusts and blocks a X-rays beam,wherein when the switching means is in a state to block a X-rays beam, the X-rays blocking means blocks X-rays, and when the switching means is in a state to adjust a X-rays beam, a slit which makes a blocking plate of the X-rays blocking means pass a X-rays beam is always larger than a slit which makes an adjustment plate of the X-rays beam adjustment means pass a X-rays beam. 14. The apparatus according to claim 13, whereinthe X-rays beam adjustment means comprises two adjustment plates and adjusts an intensity of a X-rays beam by adjusting a slit between the two adjustment plates, andthe X-rays blocking means comprises two blocking plates and blocks passage of X-rays by reducing a slit between the two blocking plates to 0. 15. The apparatus according to claim 14, whereinthe X-rays blocking means is placed above the X-rays beam adjustment means,the switching means includes two blocking/switching plates and two adjusting/switching plates, and forms two crossbars by installing the two blocking/switching plates and the two adjusting/switching plates so as to make the two blocking/switching plates respectively intersect the two adjusting/switching plates, andtwo ends of each of the two blocking/switching plates are connected to two ends of a corresponding one of the two blocking plates to form a parallelogram, and two ends of each of the two adjusting/switching plates are connected to two ends of a corresponding one of the two adjustment plates to form another parallelogram. 16. The apparatus according to claim 15, wherein a length of the blocking/switching plate is not less than a length of the adjusting/switching plate. 17. The apparatus according to claim 16, wherein an intersection angle between the blocking/switching plate and the adjusting/switching plate is constant. 18. The apparatus according to claim 17, wherein an intersection angle between the blocking/switching plate and the adjusting/switching plate is 50° to 140°. 19. A CT apparatus including X-ray emission means for emitting X-rays, optical adjustment means for filtering X-rays, a bed on which a patient is placed, and detection means for detecting and X-rays and performing signal processing, further comprisinga X-rays beam adjusting/blocking apparatus which includes X-rays beam adjustment means comprising an adjustment plate, X-rays blocking means comprising a blocking plate, and switching means and adjusts and blocks a X-rays beam, the X-rays blocking means blocking X-rays when the switching means is in a state to block a X-rays beam, and a slit which makes a blocking plate of the X-rays blocking means pass a X-rays beam being always larger than a slit which makes an adjustment plate of the X-rays beam adjustment means pass a X-rays beam when the switching means is in a state to adjust a X-rays beam. 20. The apparatus according to claim 19, whereinthe X-rays beam adjustment means comprises two adjustment plates and adjusts an intensity of a X-rays beam by adjusting a slit between the two adjustment plates, andthe X-rays blocking means comprises two blocking plates and blocks passage of X-rays by reducing a slit between the two blocking plates to 0. 21. The apparatus according to claim 20, whereinthe X-rays blocking means is placed above the X-rays beam adjustment means,the switching means includes two blocking/switching plates and two adjusting/switching plates, and forms two crossbars by installing the two blocking/switching plates and the two adjusting/switching plates so as to make the two blocking/switching plates respectively intersect the two adjusting/switching plates, andtwo ends of each of the two blocking/switching plates are connected to two ends of a corresponding one of the two blocking plates to form a parallelogram, and two ends of each of the two adjusting/switching plates are connected to two ends of a corresponding one of the two adjustment plates to form another parallelogram. 22. The apparatus according to claim 21, wherein a length of the blocking/switching plate is not less than a length of the adjusting/switching plate. 23. The apparatus according to claim 21, wherein an intersection angle between the blocking/switching plate and the adjusting/switching plate is constant.
	claims	1. A charged particle beam apparatus for irradiating a sample with a charged particle beam to inspect the sample, the apparatus comprising:a vacuum chamber to enclose the sample;a first column to irradiate the sample with a charged particle beam or light so as to image the sample;a second column to irradiate the sample with a charged particle beam so as to image the sample or process the sample based on the image obtained by the first column;a rotary stage that mounts the sample thereon, which is placed in the vacuum chamber; anda single-shaft transfer mechanism to transfer the rotary stage in the direction of an axis of the single-shaft transfer mechanism in the vacuum chamber,wherein a target portion for the irradiation of the charged particle beam or light from the first column and the charged particle beam from the second column in XY directions on the sample is positioned by combined movement of the rotary stage and the single-shaft transfer mechanism. 2. The charged particle beam apparatus according to claim 1, further comprising:a storage device that stores an image of the sample inspected by one of the first column and the second column and supplementary information as information shared with the first column and the second column. 3. The charged particle beam apparatus according to claim 1, whereininformation on adjustment of a focal point of an electron beam obtained by one of the first column and the second column is used to adjust a focal point of an electron beam emitted by another column. 4. The charged particle beam apparatus according to claim 1, further comprising:a unit for measuring the amount of a rotation of the rotary stage; anda calculator for controlling deflection of a charged particle beam emitted by each of the first column and the second column, based on the measured amount of the rotation of the rotary stage. 5. The charged particle beam apparatus according to claim 1, further comprising:a unit for measuring the amount of a rotation of the rotary stage; anda calculator for controlling a rotation of an image obtained by each of the first column and the second column, based on the measured amount of the rotation of the rotary stage. 6. A charged particle beam apparatus for irradiating a sample with a charged particle beam to inspect the sample, the apparatus comprising:a rotary stage that mounts the sample;a single-shaft transfer stage that moves the sample mounted on the rotary stage, in the direction of an axis of the single-shaft transfer stage;a first column that irradiates the sample with a charged particle beam to detect a defect present on the sample;a second column that detects the defect, based on coordinates of the defect detected by the first column; anda vacuum chamber that mounts the first column and the second column in line with the single-shaft transfer stage, wherein:the vacuum chamber has a smaller and larger dimension on a cross section parallel to a base of the vacuum chamber,the larger length of the vacuum chamber in a direction of the axis of the single-shaft transfer stage is determined by adding a margin to the double of the outer diameter of the sample, andthe smaller length of the vacuum chamber in a direction crossing the axis of the single-shaft transfer stage in a plane is determined by adding a margin to the outer diameter of the sample. 7. The charged particle beam apparatus according to claim 6, wherein:the first and second columns have respective detectors,the detectors have respective surfaces on which charged particle beams are detected,a normal to the surface of the detector of the first column is directed toward the center of the first column anda normal to the surface of the detector of the second column is directed toward the center of the second column. 8. A charged particle beam apparatus for irradiating a sample with a charged particle beam to inspect the sample, the apparatus comprising:a rotary stage that mounts the sample;a single-shaft transfer stage that moves the sample mounted on the rotary stage, in the direction of an axis of the single-shaft transfer stage;a vacuum chamber having the single transfer stage therein;a first column that irradiates the sample with an optical beam to detect a defect present on the sample; anda second column that detects the defect, based on coordinates of the defect detected by the first column, wherein:the vacuum chamber has a smaller and larger dimension on a cross section parallel to a base of the vacuum chamber,the larger length of the vacuum chamber in a direction of the axis of the single-shaft transfer stage is determined by adding a margin to the double of the outer diameter of the sample, andthe smaller length of the vacuum chamber in a direction crossing the axis of the single-shaft transfer stage in plane is determined by adding a margin to the outer diameter of the sample.
052992420	description	DETAILED DESCRIPTION OF THE INVENTION In response to the above needs for space nuclear power, the Small Excore Heat Pipe Thermionic Reactor (SEHPTR) concept was developed. The SEHPTR concept provides an innovative solution to these concerns of potential users of space nuclear power systems. FIG. 1 illustrates the baseline SEHPTR concept, in which a reactor 10 having the control features of the present invention is shown. Heat is generated within a solid annular core 12 at very high temperatures. The core 12 includes tapered hexagonal shaped fuel elements of UO.sub.2 clad in tungsten. The fuel elements are packaged into four fuel bundles which comprise the core. The annular fuel bundles can be removed, allowing for the entire (non-nuclear) power system to be tested with an electrically heated core simulator. Both the inside and outside surfaces of the core radiate the heat to thermionic energy conversion devices 14 which are located around the core 12. The core heat is collected by high temperature annular emitter heat pipes (not shown) that isothermalize the emitter (inside heat pipe) surface both circumferentially and axially. The collector (cold side) is maintained at a constant temperature by molybdenum based sodium heat pipes 18 that run the length of the core and then bend around shield 19 and become an integral part of the radiator 20. In this particular embodiment of the concept, sixty two thermionic heat pipe units are employed to provide redundancy. There are no pumps or circulating core coolant loops associated with this design. The reactor core is designed to operate in the fast neutron energy spectrum, and criticality control is achieved by neutron leakage. Neutrons are reflected back into the core 12 from the periphery by windowed reflectors 22 and 24. This innovation is the subject of the present application and will be explained more fully below. A central poison rod 16 and associated drive mechanism 27 provides a secondary shutdown device at launch and a backup shutdown mechanism after operation begins on orbit. A cross section of the windowed reflector control scheme is depicted in FIG. 2. FIG. 2a shows the reflector control in an operating condition, and FIG. 2b shows the control in a shutdown condition. Movable annular reflector rings 22 and 24 are concentrically assembled and surround the core 12. Reflector 22 is the outer ring while reflector 24 is the inner ring, closest to the core 12. Each reflector ring includes a plurality of reflective portions 26 in an alternating relationship with a plurality of windowed portions 28 spaced around its circumference. The windowed portions 28 of the reflector rings may be simply voids or openings, or may be filled with a non-reflecting material. The core 12 is reflected around the periphery by the reflective portions 26 of the rings 22 and 24. It is preferred that the reflective portions 26 of the rings be BeO. The dual annular reflective rings 22 and 24 control the reactor by rotational movement relative to each other about the core 12. More specifically, reactor control is achieved by allowing neutrons to leak or be reflected by this dual rotating "windowed" reflector. The reactor 10 is shutdown when the inside and outside windowed portions 28 in the reflector rings 22 and 24 are aligned, as shown in FIG. 2b. The openings in each reflector ring are of a size to ensure that when the openings in each reflector are coincident, there is insufficient reflection of neutrons back to the reactor to allow the reactor to attain criticality. The reactor 10 becomes operational as the windowed portions 28 become non-aligned or closed, thus reflecting neutrons back into the core region, as seen in FIG. 2a. The redundant reflector control scheme of the present invention requires that independent drives turn either the inner or outer reflector ring segments in either direction (clockwise or counterclockwise). Referring to FIG. 3, a sectional view of the reactor control and its drive mechanisms is shown. Inner reflector drive shaft 30 is operably connected to inner pinion 32, which turns inner reflector ring gear 34. The ring gear 34 is structurally connected to the annular windowed inner reflector 24. A similar configuration is used for the outer reflector 22. Outer reflector drive shaft 36 is operably connected to outer pinion 38, which turns outer reflector ring gear 40. The ring gear 40 is structurally connected to the annular windowed outer reflector 22. Inner drive shaft 30 and outer drive shaft 36 are each driven by an individual drive motor (not shown). An annular space 42 between the reflectors 22 and 24, and an annular space 44 between the inner reflector 24 and the core 12 minimizes frictional resistance to rotational movement. A torsional spring or other stored energy device may be provided to interconnect the reflector rings 22 and 24. This torsional spring could be used to automatically return each or either reflector to a system unreflected state (i.e. reflector windows 28 aligned one to the other) upon a loss of power to the control drive motors. Fail safe shut down operation of the reactor would thus be achieved with the torsional spring. With the described arrangement, either the inside 24 or outside 22 reflector and its associated drive 30 or 36, respectively, is capable of independently controlling the reactor and providing redundancy. The simplicity of the drive system, the minimum number of moving parts, and the minimal driving distances and torques resulting from the limited rotation needed to form a complete uninterrupted reflector around the core ensures both minimum weight and maximum reliability for the system. To initiate reactor criticality, each reflector is operated independently and rotated in either direction to an extent that the openings in each are no longer aligned. This reduces the leakage of neutrons from the reactor and the reflector functions to reflect the neutrons back to the reactor core where they are used to initiate and sustain the fission process. Only one of the two reflectors need be moved to achieve reflection of the core. The ability to initiate or sustain a critical configuration by movement of either of the reactor reflectors means that two independent means of controlling the reactor reflector are provided, thus greatly enhancing the reliability of the reactor control system. The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described to best explain the principles of the invention and its practical application and thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.
	summary
	abstract	The present invention relates to a method and an apparatus for the testing or inspection of objects, particularly for detecting defects or irregularities therein, by means of X-radiation, where the object to be inspected is brought into different spatial positions and stays there during image detection. For mechanical positioning of the objects, known methods and apparatuses require a relatively long time with limited inspection precision, while having a considerable space requirement. Accompanied by a small size, the invention obviates this problem in that the X-ray components, comprising X-ray tube and X-ray detector, are only moved in translatory manner and the inspection object or part in a gimbal suspension is only moved in rotary manner in at least one axis and a maximum of three axes x, y and z.
	description	The present application is a continuation of, and claims benefit under 35 USC 120 to, international application PCT/EP2014/053657, Feb. 25, 2014, which claims benefit under 35 USC 119 of German Application No. 10 2013 203 035.5, filed Feb. 25, 2013 and under 35 USC 119(e) of U.S. Ser. No. 61/768,652, filed Feb. 25, 2013. The entire disclosure of international application PCT/EP2014/053657 is incorporated by reference herein. The present invention relates to an optical module, an optical imaging device, a method for supporting an optical element, an optical imaging method, and a method for structuring a contact section of an optical module. The invention can be applied in connection with any desired optical devices and optical imaging methods. In particular, it can be used in connection with the micro lithography used in the production of microelectronic circuits. Particularly in the field of microlithography, besides using components configured with the highest possible precision, it is necessary, inter alia, to set the position and geometry of optical modules of the imaging device, that is to say for example of the modules having optical elements such as lens elements, mirrors or gratings but also of the masks and substrates used, during operation as precisely as possible in accordance with predefined desired values or to stabilize such components in a predefined position or geometry, in order to achieve a correspondingly high imaging quality. In the field of microlithography, the accuracy requirements are in the microscopic range of the order of magnitude of a few nanometers or less. They are not least a consequence of the constant need to increase the resolution of the optical systems used in the production of microelectronic circuits, in order to advance the miniaturization of the microelectronic circuits to be produced. With the increased resolution and the generally accompanying reduction of the wavelength of the light used, the requirements made regarding the accuracy of the positioning and orientation of the components used naturally increase. In particular for the short operating wavelengths used in microlithography in the UV range (for example in the range of 193 nm), but in particular in the so-called extreme UV range (EUV) with operating wavelengths of between 5 nm and 20 nm (typically in the region of 13 nm), this of course affects the efforts to be made for complying with the stringent requirements made of the accuracy of the positioning and/or orientation of the components involved. In connection with the abovementioned stabilization of the optical system, dealing with vibrational energy which arises in the system or is introduced into the system from outside proves to be particularly problematic, however. One approach often used for solving this problem consists in actively influencing the position and/or orientation of individual or a plurality of the system components used, in particular optical elements used, in order to hold the relevant component at a predefined position and/or in a predefined orientation. DE 102 05 425 A1 (Holderer et al.), the disclosure of which is incorporated herein by reference, in connection with the defined positioning and orientation of the facet elements of a facet mirror of an EUV system, discloses individually adjusting the facet elements and then holding them in the adjusted state via corresponding fixing forces. Although a misalignment of the facet elements as a result of introduced vibrational energy relative to the carriers thereof can be prevented in this case via correspondingly dimensioned fixing forces, what is problematic is that the carrier itself can be deformed by introduced vibrational energy, such that the facet elements can be deflected from their desired position and/or orientation in the beam path. Moreover, active influencing of the position and/or orientation of individual or a plurality of optical elements of the imaging system is often desired in order to increase the flexibility of the optical system. In this regard, once again in the case of EUV systems, in particular in the illumination device, for flexible pupil formation it is desirable to use facet mirrors having a large number of movable (typically tiltable) micromirrors or facet elements, the respective position and/or orientation of which must then, of course, be set and held in a highly precise manner. Particularly in the case of such EUV systems it is a particular challenge to realize the precise setting of the position and/or orientation of a large number of facet elements in conjunction with very small dimensions of the facet elements. In this regard, in the case of a facet mirror for such a EUV system, the number of facet elements is typically of the order of magnitude of several hundreds of thousands of facet elements, while the diameter of the optically effective surface of the individual facet element is typically of the order of magnitude of a several hundred micrometers. Similar micromirror arrays comprising several hundreds of thousands of micromirrors are also known for example from U.S. Pat. No. 6,906,845 B2 (Cho et al.), the disclosure of which is incorporated herein by reference. Therefore, the present invention is based on the object of providing an optical module comprising an optical element, an optical imaging device, a method for supporting an optical element, an optical imaging method and a method for structuring a contact section of an optical module which do not have the abovementioned disadvantages, or have them at least to a lesser extent, and in particular ensure reliable positioning and/or orientation of an optical element in a simple manner. The present invention is based on the insight that an improved support of an actively settable optical element, in particular even of tiniest facet elements, and thus an improved positioning and/or orientation of the optical element in the respective setting are achieved in a simple manner in an extremely small space if a selectively activatable contacting device is provided, which comprises a contact section which can selectively be brought into contact with a contact section of the optical element in order to exert a contact force thereon. The activated state of the contacting device and, thus, the contact or the contact force is preferably maintained until either a renewed adjustment (carried out for example in the course of a correction) of the position and/or orientation of the optical element becomes necessary or the operation of the optical module ends. This contact force exerted selectively on the optical element makes it possible to hold the optical element in the position and/or orientation respectively set. In this case, the optical element can be fixed substantially rigidly by the contacting device. However, it is likewise also possible, via a correspondingly vibration-damping configuration of at least one damping section (located in the region of the optical element and/or of the contacting device), to achieve a targeted damping of vibrations that were introduced into the optical element, or to reduce, possibly even completely avoid, such introduction of vibrations. In order to produce the contact between the contact section of the contacting device and the contact section of the optical element, either the contact section of the contacting device or the optical element (or both) can be actuated or moved. In this case, the actuation force can be generated in any desired manner according to any desired principle of operation. Preferably, the actuation force is generated in a contactless manner in order to achieve a particularly space-saving configuration. In accordance with a first aspect, therefore, the present invention relates to an optical module, in particular facet mirror, comprising an optical element and a supporting structure for supporting the optical element, wherein the supporting structure comprises a positioning device for actively setting a position and/or orientation of the optical element in at least one degree of freedom. The supporting structure comprises a selectively activatable contacting device having at least one contacting unit having a first contact section, the first contact section, in an activated state of the contacting device, contacting a second contact section of the optical element in order to exert a contact force on the optical element, and the first contact section, in a deactivated state of the contacting device, being removed from the second contact section. In accordance with a further aspect, the present invention relates to an optical imaging device, in particular for microlithography, comprising an illumination device having a first optical element group, a mask device for accommodating a mask comprising a projection pattern, a projection device having a second optical element group, and a substrate device for accommodating a substrate, the illumination device being designed for illuminating the projection pattern, in particular with light in the EUV range, and the projection device being designed for projecting the projection pattern onto the substrate. The illumination device and/or the projection device comprises an optical module according to the invention. In accordance with a further aspect, the present invention relates to a method for supporting an optical element, in particular a facet element of a facet mirror, wherein the optical element is supported by a supporting structure, wherein a position and/or orientation of the optical element are/is set in at least one degree of freedom. A first contact section of a selectively activatable contacting device, in an activated state of the contacting device, is brought into contact with a second contact section of the optical element in order to exert a contact force on the optical element, while the first contact section is removed from the second contact section in a deactivated state of the contacting device. In accordance with a further aspect, the present invention relates to an optical imaging method, in particular for microlithography, wherein an illumination device illuminates a projection pattern, in particular with light in the EUV range, and a projection device projects the projection pattern onto a substrate. An optical element, in particular a facet element of a facet mirror, of the illumination device and/or of the projection device is supported using a method according to the invention. In accordance with a further aspect, the present invention relates to a method for structuring a contact section of an optical module according to the invention, wherein one of the two contact sections, in particular the first contact section, is configured as a structurable contact section at least section-wise comprising a structurable material which is hardenable after structuring, while the other of the two contact sections, in particular the second contact section, is configured as a structuring contact section at least section-wise having a stiffness sufficient for the defined structuring of the structurable contact section. The structurable contact section is structured in its structurable state by the structuring contact section for producing the complementarily structured first and second contact surfaces and is hardened after this structuring. Further preferred configurations of the invention become apparent from the dependent claims and the following description of preferred embodiments, which refers to the accompanying drawings. Any combinations of the features disclosed, regardless of their being mentioned in the claims, belong to the subject matter of the invention. First Embodiment A first embodiment of an optical imaging device 101 according to the invention is described below with reference to FIGS. 1 to 5. In order to simplify understanding of the following explanations, an orthogonal xyz-coordinate system was introduced into the accompanying drawings, in which the z-direction coincides with the direction of the gravitational force. It goes without saying, however, that any other orientation of this xyz-coordinate system or of the components of the optical imaging device in space can also be chosen in other variants of the invention. FIG. 1 is a schematic illustration, not to scale, of the optical imaging device in the form of a microlithography device 101 used for producing microelectronic circuits. The imaging device 101 comprises an illumination device 102 and an optical projection device 103, which is designed to project, in an imaging process, an image of a projection pattern formed on a mask 104.1 of a mask device 104 onto a substrate 105.1 of a substrate device 105. For this purpose, the illumination device 102 illuminates the mask 104.1 with an illumination light beam (not illustrated in more specific detail). The projection device 103 then receives the projection light beam (indicated by the line 101.1 in FIG. 1) coming from the mask 104.1 and projects the image of the projection pattern of the mask 104.1 onto the substrate 105.1, for example a so-called wafer or the like. The illumination device 102 comprises a system (illustrated only highly schematic in FIG. 1) of optical elements 106, the system comprising, inter alia, an optical module 106.1 according to the invention. As will be explained in greater detail below, the optical module 106.1 is configured as a facet mirror. The optical projection device 103 comprises a further system of optical elements 107, which comprises a plurality of optical modules 107.1. Here, the optical modules of the optical systems 106 and 107 are arranged along a folded optical axis 101.1 of the imaging device 101. In the example shown, the imaging device 101 operates with light in the EUV range at a wavelength of between 5 nm and 20 nm, more precisely at a wavelength of approximately 13 nm. Consequently, the optical elements in the illumination device 102 and the projection device 103 are configured exclusively as reflective optical elements. It goes without saying, however, that any desired types of optical elements (e.g. refractive, reflective or diffractive optical elements) can be used in other variants of the invention which operate with other wavelengths, either individually or in any desired combination. Furthermore, the projection device 103 can also comprise a further optical module according to the invention, for example in the form of a further facet mirror. As can be inferred from FIGS. 2 to 5, the facet mirror 106.1 comprises a supporting structure 108, which supports a multiplicity of optical elements in the form of facet elements 109 (only a single one of which is illustrated in FIG. 3). FIG. 2 illustrates only 900 facet elements 109, for reasons of clarity. In reality, however, the facet mirror 106.1 comprises approximately 400,000 facet elements 109, although it goes without saying that, in other variants of the invention, a deviating number of (arbitrary) optical elements can also be supported on a corresponding supporting structure. It should be noted that, in facet devices, preferably as many facet elements as possible are provided in order to achieve homogenization of the light to the greatest possible extent. Particularly in facet devices, therefore, preferably 10,000 to 1,000,000, preferably 50,000 to 600,000, more preferably 200,000 to 500,000, facet elements are provided. In the example shown, the facet elements 109 are arranged in a regular rectangular matrix such that a narrow gap of less than 0.05 mm to 0.02 mm remains between them in order to achieve the least possible loss of radiation power. It goes without saying, however, that any other arrangement of the optical elements supported by the supporting structure 108, depending on the optical requirements of the imaging device, can also be realized in other variants of the invention. As can be inferred from FIGS. 2 to 5, the facet element 109 has a reflective and thus optically effective surface 109.1. The reflective surface 109.1 is formed on a front side of a facet body 109.2 of the facet element 109, the front side facing away from the supporting structure 108 and facing the illumination light beam. The surface area of the optically effective surface 109.1 of the facet element 109 is preferably 0.05 mm2 to 2.0 mm2, more preferably 0.15 mm2 to 0.5 mm2. In the present example, the surface area of the optically effective surface 109.1 is between 0.2 mm2 and 0.3 mm2, namely 0.25 mm2. At the rear side (facing away from the reflective surface 109.1) of the facet body 109.2, there is provided a projection in the form of a columnar coupling element 109.3, via which the facet element 109 is connected to the supporting structure 108 via a connecting device 110. In the present example, the connecting device 110 is configured as an elastic membrane element or leaf spring element which is connected to the coupling element 109.3, on the one hand, and to the supporting structure 108, on the other hand. The supporting structure 108 comprises a positioning device 111 (illustrated only highly schematically in FIG. 3) for actively setting a position and/or orientation of the facet element 109 in at least one degree of freedom. The relevant setting can be performed individually for each facet element 109. Likewise, however, in other variants of the invention, arbitrarily formed groups of facet elements 109 (up to and including all facet elements 109 of the facet mirror 106.1) can, of course, also be set jointly. Via the positioning device 111, it is possible to set as many degrees of freedom as desired up to and including all six degrees of freedom in space. However, for simplification of the apparatus, preferably only those degrees of freedom are taken into account which have a non-negligible influence on the imaging error or the imaging quality of the imaging device 101 or whose influence on the imaging error or the imaging quality cannot be compensated for more simply elsewhere in the beam path. In the present example, via the positioning device 111 it is possible, inter alia, to set the rotational degree of freedom of the facet element 109 about the y-axis, that is to say therefore the tilting of the facet element 109 about the y-axis. This can be used in the present example of an imaging device in the EUV range in the illumination device 102 for example for pupil variation or for a so-called setting change. The positioning device 111 for this purpose is designed to exert an actuation force FS or a corresponding positioning moment MS about the y-axis on the facet element 109 in order to achieve the setting of the facet element 109 in the desired degree of freedom or degrees of freedom. In the present example, this takes place in a contactless manner according to an electrostatic principle of operation. For this purpose, by way of example, positioning electrodes 111.1 can be provided on the supporting structure 108, which electrodes, in a manner controlled by a control device 112 connected to the positioning device 111, in the region of the facet element 109, establish corresponding electric fields in order to generate the positioning force FS or the positioning moment MS on the facet element 109. It goes without saying, however, that, in other variants of the invention, the positioning force FS or the positioning moment MS can also be generated in any other manner desired, via positioning devices which operate in a contactless or alternatively in a tactile manner or are mechanically connected to the facet element 109. The supporting structure 108 furthermore comprises a selectively activatable contacting device 113 having a contacting unit 113.1, which is designed to exert a contact force FK on the facet element 109 in an activated state, while in a deactivated state it does not exert such a contact force FK on the facet element 109 or is not in such mechanical interaction with the facet element 109. For this purpose, the contacting unit 113.1 comprises a first contact section 113.2, which contacts a second contact section 109.4 of the facet element 109 in the activated state of the contacting device 113, such that the contact force FK acts between the two contact partners 113.2 and 109.4 (substantially perpendicularly to the contact surface thereof; see FIGS. 4 and 5). As can be inferred from FIG. 3, the second contact section 109.4 is arranged at the free end (facing away from the facet body 109.2) of the coupling element 109.3. The second contact section 109.4 is arranged adjacent to the first contact section 113.2 in the deactivated state (illustrated in FIG. 3) of the contacting device 113 in such a way that, between a first contact surface 113.3 of the first contact section 113.2 and a second contact surface 109.5 of the second contact section 109.4, there is formed a narrow gap 114 having a minimum gap width Smin (perpendicular to the first contact surface 113.3). In the deactivated state of the contacting device 113, the gap 114 or the minimum gap width Smin is at least just large enough that the positioning device 111 can adjust the facet element 109 without appreciable contact between the first contact surface 113.3 and the second contact surface 109.5 (or appreciable resistance resulting therefrom). In the present example, the minimum gap width Smin is 10 μm. It goes without saying, however, that a different minimum gap width Smin can also be chosen in other variants of the invention. Preferably, the minimum gap width Smin is 0.1 μm to 10,000 μm, preferably 1 μm to 1,000 μm, more preferably 2 μm to 100 μm. If the contacting device 113 is activated in a manner controlled by the control device 112, then the contacting device 113 exerts on the facet element 109 along the z-axis an actuation force FB (see FIG. 3) which moves the facet element 109 in the present example with elastic deformation of the connecting device 110 toward the (substantially stationary) contacting unit 113.1 until the first contact surface 113.3 and the second contact surface 109.5 bear against one another under the contact force FK (as is illustrated in FIGS. 4 and 5 for two different settings of the facet element 109, and indicated in FIG. 3 by the dashed contour 115). The contacting device 113 exerts the actuation force FB in the present example in a contactless manner via an actuation device 113.4, by virtue of the fact that it again operates according to an electrostatic operative principle. For this purpose, by way of example, actuation electrodes 113.5 of the actuation device 113.4 can be provided on the supporting structure 108, which electrodes, in a manner controlled by the control device 112 connected to the contacting device 113, in the region of the facet element 109, establish corresponding electric fields in order to generate the actuation force FB on the facet element 109 or the contact force FK between the first contact section 113.2 and the second contact section 109.4, respectively. It goes without saying, however, that the actuation force FB or the contact force FK, respectively, in other variants of the invention can also be generated in any other desired manner via devices which operate in a contactless or alternatively tactile manner or are mechanically connected to the facet element 109, respectively. In the present example, the first contact surface 113.3 is configured as a substantially planar surface, while the second contact surface 109.5 is configured as an at least singularly curved surface, the one principal curvature axis of which runs substantially parallel to the y-axis (that is to say substantially parallel to the axis of the rotational degree of freedom that can be set). If the facet element 109 is not intended to be set in the rotational degree of freedom about the x-axis, then the second contact surface 109.5 can be a singularly curved surface, that is to say a substantially cylindrical surface. In the activated state of the contacting device 113, a linear contact zone having a greater or lesser area depending on the stiffness of the two contact partners 113.2, 109.4 (and, of course, magnitude of the contact force FK) is then present. However, if a setting of the facet element 109 in the rotational degree of freedom about the x-axis is intended to be possible as well, then the second contact surface 109.5 is a doubly curved, that is to say substantially ellipsoidal or spherical, surface. In the activated state of the contacting device 113, a dot shaped contact zone having a greater or lesser area depending on the stiffness of the two contact partners 113.2, 109.4 (and, of course, magnitude of the contact force FK) is then present. The contact between the first contact section 113.2 and the second contact section 109.4 firstly has the advantage, in principle, that additional dissipation of heat from the facet element 109 into the supporting structure 108 can be achieved by this approach. In this case, the linear contact zone has the advantage owing to its larger spatial extent relative to the dot shaped contact zone that it enables improved heat transfer from the facet element 109 into the supporting structure 108, such that once again increased dissipation of heat from the facet element 109 into the supporting structure 108 can be achieved. Furthermore, in the activated state of the contacting device 113, a frictionally locking connection is achieved in at least one frictionally locking direction parallel to the first contact surface 113.3 (that is to say, in the present example, in the directions parallel to the xy-plane, in particular parallel to the x-axis), as a result of which the facet element 109, in the respective position and/or orientation of the facet element 109 set by the positioning device 111, is held in its position, even under the influence of vibrations introduced into the facet element 109, as long as the vibrational energy does not exceed a specific threshold. The threshold is defined by the present static friction force FHR governed by the present contact force FK and the frictional conditions in the contact zone, in particular the coefficient of friction between the two contact partners 113.2, 109.4. The facet element 109 is deflected only if the force which results from the vibrational energy and which has a dislocating effect on the facet element 109 parallel to the frictionally locking direction exceeds the static friction force (and possibly holding forces of the positioning device 111 that additionally also have an effect). Consequently, the present invention therefore firstly makes it possible to reduce the holding forces of the positioning device 111. Secondly, by virtue of the contact between the two contact partners 113.2, 109.4 and the resultant fixing of the facet element 109 in its respective setting, for the purpose of stabilizing this setting, it is not necessary to provide for the positioning device 111 to be controlled by closed-loop control that compensates for the vibration influences. Even in the case of a high bandwidth of the vibrations that occur during operation, therefore, closed-loop control having a correspondingly high control bandwidth is not required. Rather, simple activation or deactivation of the contacting device 113 by the control device 112 is sufficient after the setting of the facet element 109 has been carried out or before renewed setting of the facet element 109. In this case, only a significantly smaller bandwidth is required for driving the contacting device 113. In the present example, the respective principal curvature of the second contact surface 109.5 is preferably adapted to the positioning movement (generated by the positioning device 111) of the facet element 109 such that the gap 114 or the minimum gap width Smin remains substantially unchanged in each setting. Accordingly, the facet element 109, upon activation of the contacting device 113, is moved toward the contacting unit 113.1 by the same distance in each setting until the first contact surface 113.3 and the second contact surface 109.5 bear against one another under the contact force FK. It goes without saying, however, that the respective principal curvature of the second contact surface 109.5, in other variants of the invention, can also be configured in such a way that the gap 114 or the minimum gap width Smin varies with increasing deflection from the neutral position (illustrated in FIG. 3 and indicated in FIGS. 4 and 5 by the dashed contours 116 and 117, respectively) of the facet element 109 in order to minimize undesired influences of the movement of the facet element 109 on the imaging quality upon activation of the contacting device 113. In this regard, provision can be made, for example, for the gap 114 or the minimum gap width Smin to at least section-wise decrease with increasing deflection from the neutral position (illustrated in FIG. 3) of the facet element 109. Likewise, additionally or alternatively, an at least in section-wise increase with increasing deflection can be provided. It should be mentioned at this point that the configuration chosen in the present example with an exclusively frictionally locking connection in the contact zone between the two contact partners 113.2, 109.4 has the advantage that any desired settings or deflections of the facet element 109 from its neutral position can be performed without an appreciable variation of the fixing effect of the facet element 109 occurring. In the present example, it is furthermore provided that the control device 112 can vary the contact force FK in the activated state of the contacting device 113, such that in the frictionally locking direction a settable static friction force FHR or (once the static friction force FHR has been overcome) a settable sliding friction force FGR acts as an adjusting resistance W against the positioning force FS of the positioning device. It is thereby possible to reduce the adjusting resistance in a setting state of the activated state of the contacting device 113 in such a way that the positioning force FS of the positioning device 111 suffices to perform a setting of the facet element 109 with a frictional relative movement between the two contact surfaces 113.3, 109.5 against the adjusting resistance W. In a fixing state of the activated state of the contacting device 113, the adjusting resistance W can then be increased by the control device 112 relative to the setting state in such a way that the maximum positioning force FSmax of the positioning device 111 no longer suffices to perform a setting of the facet element 109 against the adjusting resistance W. In the present example, the facet element 109 furthermore has at least one first resonant frequency, which is in the range of approximately 600 Hz. For its part, the contacting unit 113.1 has a damping section 113.6, which has a vibration-damping effect in the range of the first resonant frequency in order to minimize the influence of vibrations on the imaging quality precisely in this critical resonance range of the facet element. Furthermore, the arrangement comprising the facet element 109 and the connecting device 110 has at least one second resonant frequency, which is approximately 750 Hz. The damping section 113.6 is configured such that it has a vibration-damping effect in the range of the second resonant frequency, too, in order to minimize the influence of vibrations on the imaging quality also in this critical resonance range of the arrangement comprising the facet element 109 and the connecting device 110. It goes without saying, however, that the facet element 109, in other variants of the invention, can also have one or more other first resonant frequencies and/or one or more other second resonant frequencies, which are preferably 1 Hz to 2,000 Hz, preferably 50 Hz to 1,500 Hz, more preferably 200 Hz to 1,000 Hz. In the present example, the positioning device 111 is furthermore configured such that it can be operated as an active release device which supports the release of the contact between the first contact section 113.2 and the second contact section 109.4 after deactivation of the contacting device 113 by a first release force FL1. In the present example, this occurs by virtue of the fact that a varying, possibly even alternating, positioning force FS is generated via the positioning device 111, that is to say that vibrational energy is thus introduced into the facet element 109 in a defined manner. The first release force FL1 supports the second release force FL2, namely the releasing restoring force from the deformed connecting device 110, and helps to release or overcome restraining surface forces (e.g. van der Waals forces) between the first contact section 113.2 and the second contact section 109.4. It goes without saying here that, in other variants of the invention, additionally or alternatively, provision can also be made for the release process to be supported in some other way after the deactivation of the contacting device 113. In this regard, a corresponding release device which generates a corresponding release force can be provided in the region of the contacting unit 113.1. Likewise, additionally or alternatively, the actuation device 113.4 can generate a corresponding release force. As already mentioned, FIGS. 4 and 5 show the activated state of the contacting device 113 for two different settings of the facet element 109, for example the two opposite extreme deflections of the facet element 109 from its neutral position (see contour 116 in FIG. 4 and contour 117 in FIG. 5, respectively). It goes without saying that, in the present example, depending on the setting resolution of the positioning device 111, as many intermediate states as desired can be realized between these extreme positions, such that a particularly sensitive setting of the facet element 109 is possible. Second Embodiment A further preferred embodiment of the optical module 206.1 according to the invention is described below with reference to FIGS. 1, 2, and 6 to 9. The optical module 206.1 can be used instead of the optical module 106.1 in the imaging device 101. In terms of its fundamental configuration and functioning, the optical module 206.1 corresponds to the optical module from FIGS. 3 to 5, and so only the differences will be discussed here. In particular, identical components are provided with the identical reference signs, while components of the same type are provided with reference signs increased by the value 100. Unless indicated otherwise hereinafter, reference is made to the above explanations in connection with the first embodiment with regard to the features, functions and advantages of the components. The essential difference with respect to the embodiment from FIGS. 3 to 5 consists in the configuration of the contacting device 213, wherein, in the present example, the first contact surface 213.3 of the first contact section 213.2 and the second contact surface 209.5 of the second contact section 209.4 are structured complementarily in such a way that, in the activated state of the contacting device 213, they form a positively locking connection in at least one positively locking direction (in the present example the direction parallel to the x-axis) in the case of the discrete settings illustrated in FIGS. 8 and 9. For this purpose, the first contact surface 213.3 has two corresponding depressions 213.7 and 213.8, into which a complementarily configured projection 209.6 and 209.7, respectively, of the second contact surface 209.5 engages in each case in the respective setting (in the activated state of the contacting device 213). In the present example, the complementary configuration for producing the positively locking connection in the activated state is achieved via mutually correspondingly complementary polygonal sectional contours of the contact surfaces 213.3 and 209.5 in a sectional plane containing a surface normal to the respective contact surface (in the present example the xz-plane). It goes without saying, however, that, in other variants of the invention, any other sectional contour of the contact surfaces 213.3 and 209.5 can also be provided, as long as the latter are configured complementarily with respect to one another in the respective setting in such a way that they engage in one another in the activated state in order to achieve a positively locking connection in a desired positively locking direction. Furthermore, a contact zone having a comparatively large area is achieved as a result of the complementary structuring of the two contact surfaces 213.3 and 209.5. This has the advantage that, relative to the first embodiment, further improved heat transfer from the facet element 209 into the supporting structure 108 results, such that once again increased dissipation of heat from the facet element 209 into the supporting structure 108 can be achieved. The complementary structuring of the two contact surfaces 213.3 and 209.5 is achieved in the present example by the first contact section 213.2 being configured as a structurable contact section. For this purpose, in the region 213.9 situated on that side of the damping section 213.6 which faces the facet element 209, the first contact section 213.2 is formed from a structurable material which is hardenable after structuring. By contrast, the second contact section 209.4 is configured as a structuring contact section having a stiffness sufficient for the defined structuring of the structurable first contact section 213.2. In order to achieve the structuring of the first contact section 213.2, the structurable first contact section 213.2 is structured in its structurable state by the structuring second contact section 209.4 by virtue of the fact that firstly the positioning device 111 brings the facet element 209 into a first setting and then the contacting device 213 is activated, such that the facet element 209 is pressed with its second contact section 209.4 into the structurable first contact section 213.2 until the arrangement illustrated in FIG. 8 is achieved. Afterward, the contacting device 213 is deactivated, the facet element 209 is brought into a second setting by the positioning device 111 and then the contacting device 213 is activated anew, such that the facet element 209 is pressed with its second contact section 209.4 into the structurable first contact section 213.2 until the arrangement illustrated in FIG. 9 is achieved. Afterward, the structurable region 213.9 of the first contact section 213.2 is hardened in order to achieve the structured first contact surface 213.3 illustrated in FIGS. 6 to 9, which has a sufficient stiffness to be able to achieve the above-described positively locking connection in the desired positively locking direction. In order to ensure that the first contact section 213.2 structured in this way maintains its structuring to a sufficient extent during this process, the hardenable material of the structurable region 213.9 has a gel-like or waxy consistency in its structurable state. In this case, the hardenable material of the structurable region 213.9 in the present example has in its structurable state a dimensional stability which suffices to obtain, after the influence of an acceleration corresponding to at least 100%, preferably at least 125%, more preferably substantially 150%, of the acceleration due to gravity, a dimensional fidelity with respect to the structuring contact section of at least 80%, preferably at least 90%, more preferably substantially 100%. Preferably, the dimensional stability of the hardenable material is chosen such that, under all accelerations which can occur during handling until the final hardening of the material, the material maintains a dimensional fidelity with respect to the structuring second contact section 209.4 that suffices for the desired later positively locking connection. The structurable and hardenable material used is preferably at least one material from a material group consisting of a photoresist material, a multi-component adhesive, in particular curable by UV light, and a, in particular thermally curable, powder coating material. The photoresist material used can be, in principle, any desired photoresists such as are used in microsystems engineering, in particular in semiconductor lithography. It goes without saying, however, that the complementary structuring of the two contact surfaces 213.3 and 209.5 can also be carried out in some other way in other variants of the invention. In this regard, by way of example, the roles of the two contact surfaces 213.3 and 209.5 can be interchanged, that is to say, therefore, that the first contact section 213.2 can form the structuring contact section, while the second contact section 209.4 is configured as a structurable contact section. Likewise, of course, mixed forms of these two variants can also be provided, wherein the respective contact section is configured partly as a structurable and partly as a structuring contact section. It likewise goes without saying that the complementary structuring of the two contact surfaces 213.3 and 209.5, in other variants of the invention, can also be produced in each case individually by separate shaping production and/or reworking by any desired primary forming and/or material-removing and/or material-applying methods. In the present example, during the operation of the imaging device 101, the facet element 209 has the two settings illustrated in FIGS. 8 and 9. It is thereby possible to achieve an on/off function, for example, wherein the facet element 209, for example in the setting from FIG. 8, passes on impinging light in such a way that it can be used as used light in the present imaging process, while the impinging light is removed from the used beam path in the setting from FIG. 9. In other variants of the invention in which light losses are avoided, it is also possible to achieve only a deflection to different used regions. Furthermore, it goes without saying that more than two discrete settings can also be provided in other variants of the invention. In this case, of course, a corresponding number of sections of the two contact surfaces 213.3 and 209.5 that correspondingly engage in one another in a positively locking manner (in the activated state of the contacting device 213) is then provided. Third Embodiment A further preferred embodiment of the optical module 306.1 according to the invention is described below with reference to FIGS. 1, 2, and 10 to 12. The optical module 306.1 can be used instead of the optical module 106.1 in the imaging device 101. In terms of its fundamental configuration and functioning, the optical module 306.1 corresponds to the optical module from FIGS. 6 to 9, and so only the differences will be discussed here. In particular, identical components are provided with the identical reference signs, while components of the same type are provided with reference signs increased by the value 100. Unless indicated otherwise hereinafter, reference is made to the above explanations in connection with the second embodiment with regard to the features, functions and advantages of the components. The essential difference with respect to the embodiment from FIGS. 6 to 9 once again consists in the configuration of the contacting device 313. In this regard, in the present example, the contacting unit 313.1 of the contacting device 313 is indeed likewise equipped with a first contact surface 313.3 of the first contact section 313.2, which, in a manner identical to that in the case of the second embodiment, is structured complementarily with respect to the second contact surface 209.5 of the second contact section 209.4 in such a way that, in the activated state of the contacting device 313, they form a positively locking connection in at least one positively locking direction (in the present example the direction parallel to the x-axis) in the case of the two discrete settings illustrated in FIGS. 11 and 12. In this respect, reference should explicitly be made to the above explanations concerning the second embodiment. In the present example, however, the facet element 209 is configured as an element which is substantially stationary in the respective setting (set by the positioning device 111). By contrast, upon the activation of the contacting device 313 (by the control device 112), the actuation device 313.4 exerts on the contacting unit 313.1 along the z-axis an actuation force FB (see FIG. 10), which moves the contacting unit 313.1 in the present example with elastic deformation of the carrier 313.10 of the contacting unit 313.1 toward the (substantially stationary) facet element 109 until the first contact surface 313.3 and the second contact surface 209.5 bear against one another under the contact force FK (as is illustrated in FIGS. 11 and 12 for two different settings of the facet element 209). In the present example, the carrier 313.10 is configured such that it assumes a stable state in the respective setting (via the positioning device 111) in the activated state of the contacting device 313 (see FIGS. 11 and 12) and in the deactivated state of the contacting device 313 (see FIG. 10), from which stable state the carrier can be moved only by a corresponding actuation force FB being applied. For this purpose, the carrier 313.10 is configured as a bistable elastic element (for example as a membrane-like or leaf-spring-like element) having an arcuate or pot-shaped sectional contour. In the present example, the contacting device 313 exerts the actuation force FB once again in a contactless manner via an actuation device 313.4 by virtue of the fact that it once again operates according to an electrostatic operative principle. Likewise, additionally or alternatively it is also possible, of course, to provide actuation mechanisms which operate with a direct mechanical connection to the contacting unit 313.1 or the elastic carrier 313.10. By way of example, corresponding actuators (for example piezo-actuators) can act on the regions of the elastic carrier 313.10 which lie between the contacting unit 313.1 and the supporting structure 108 in order to introduce into the elastic carrier 313.10 corresponding bending moments for changeover between the two stable end positions of the elastic carrier 313.10. This bistable configuration has the advantage that energy has to be applied only for changing over between the two end positions of the elastic carrier 313.10, while no energy need be applied at all other points in time. This is advantageous with regard to the introduction of disturbing thermal energy and thermal energy that then has to be dissipated again, respectively, into the imaging device 101. It goes without saying that such a bistable configuration can, if appropriate, also be realized in the other two embodiments via a corresponding configuration of the connecting device 110. Likewise, it is also possible, of course, in the third embodiment, to provide a conventional configuration of the carrier as a simple membrane-like or leaf-spring-like element, as is indicated by the dashed contour 318 in FIG. 10. In this case, a corresponding actuation force FB must then always be applied in the activated state in order to achieve the contact force FK. In this case, the carrier 318 then exerts a release force which then at least supports the release of the contact between the first contact surface 313.3 and the second contact surface 209.5. Alternatively, it is also possible, of course, to provide a configuration wherein the contact between the first contact surface 313.3 and the second contact surface 209.5 in the activated state is always (i.e. without supply of energy) achieved via a corresponding mechanical prestress of the carrier, while in the deactivated state a corresponding actuation force FB has to be applied in order to release the contact between the first contact surface 313.3 and the second contact surface 209.5 with further elastic deformation of the carrier. The present invention has been described above exclusively on the basis of facet mirrors. It goes without saying, however, that the invention can also be used in connection with any other optical modules and/or optical elements. Furthermore, the present invention has been described above exclusively on the basis of examples from the field of microlithography. It goes without saying, however, that the invention can also be used in connection with any other optical applications, in particular imaging methods at other wavelengths.
	description	The present invention relates to Light Water Reactor (LWR) fuel assemblies. More specifically, the present invention provides a methodology to assess through an index the condition of nuclear reactor fuel rods and assemblies for LWR plants after a given time of operation under a given heat and neutronic flux and a given water chemistry. Light Water Reactor fuel integrity is a critical part of overall nuclear reactor safety. The structural integrity of the fuel constitutes a primary barrier to fission product release to the environment, consequently, compromising the structural integrity of the fuel during a fuel cycle is avoided. Compromising the integrity of the fuel (i.e. failure of fuel rods), is avoided by a number of measures taken by the fuel manufacturer or/and operator such as performing refueling outage visual inspections on the fuel rods with underwater equipment, changing the fuel rods, etc. Fuel rods are also tracked as to their respective position and core residence time such that when a fuel rod has a defined amount of depleted fuel, the affected fuel assembly is removed from further reactor operation. Although best efforts are used to predict fuel rod failure there has been no accurate methodology for prediction of fuel rod failure based upon operating characteristics. Factors such as the extent of use of the fuel rod or the chemistry of reactor water affect the ability of the fuel rod to withstand structural loadings on the rods. Modification of the usage (i.e. using the fuel rod in another position of the reactor) further increases the variability of the fuel rod failure potential. To avoid undesired consequences of fuel rod failure, nuclear plant operators always decide on discharging fuel elements at an earlier time that may present signs of future damage. That decreases economic efficiency for the nuclear power plant. There is also a need to provide a method to predict fuel rod failure in nuclear fuel assemblies. There is also a further need to provide a methodology to assess fuel rod integrity during the lifetime of the fuel at a specific point in time, such as during a refueling outage. It is therefore an objective of the present invention to provide a methodology to assess the significance of plant changes/alterations on fuel rod integrity. It is also a further objective of the present invention to provide a methodology to assess fuel rod integrity during the lifetime of the fuel at a specific point in time, such as during a refueling outage. The objectives of the present invention are achieved as illustrated and described. The present invention provides a method to assess light water reactor fuel integrity, having the steps of granting access in a nuclear reactor fuel pool to at least one of a discharged fuel rod and a nuclear fuel assembly, calculating an operating flux for the at least one fuel rod and the nuclear fuel assembly, measuring a thickness of CRUD on the at least one of the fuel rod and the nuclear fuel assembly, measuring a thickness of oxide on the at least one fuel rod and the nuclear fuel assembly, calculating a maximized flux for the at least one fuel rod and the nuclear fuel assembly for a position of the at least one fuel rod and the nuclear fuel assembly in a nuclear reactor, calculating a maximized deposit for the at least one fuel rod and the nuclear fuel assembly in the nuclear reactor, calculating a maximized oxide thickness for the at least one fuel rod and the nuclear fuel assembly in the nuclear reactor, calculating a fuel condition index of the at least one of the fuel rod and the nuclear fuel assembly, comparing the fuel condition index to an index constant, and removing the at least one of the fuel rod and the nuclear fuel assembly from operation when the fuel condition index is greater than the index constant. The method may also be performed wherein the fuel condition index is calculated as ∑ ( OperatingFlux MaximFlux + OperatingDeposit MaximDeposit + OperatingOxideThickness MaximOxide ⁢ Thickness ) ≤ ⁢ A where A is the index constant. The index constant may have any value lower or equal to 3.0, as a function of the margin considered. For a safety margin of 20%, the index constant is 2.4. The method may also be accomplished such that the fuel condition index is calculated with correction factors, wherein [ ( Peak ⁢ ⁢ Assy ⁢ ⁢ Flux Maximum ⁢ ⁢ Flux ) ⁢ B + ( Operating ⁢ ⁢ Deposit Maximum ⁢ ⁢ Deposit ) ⁢ C + ( Operating ⁢ ⁢ Oxide ⁢ ⁢ Thickness Maximum ⁢ ⁢ Oxide ⁢ ⁢ Thickness ) ⁢ D ] = FCI and ⁢ [ ( Peak ⁢ ⁢ Assy ⁢ ⁢ Flux Maximum ⁢ ⁢ Flux ) ⁢ B + Deposit ⁢ ⁢ Factor + ( Operating ⁢ ⁢ Oxide ⁢ ⁢ Thickness Maximum ⁢ ⁢ Oxide ⁢ ⁢ Thickness ) ⁢ D ] = FCI Where B, C and D are flow, crud and fuel design adjustment factors with values between 0.3 to 1.4 and FCI is the fuel condition index. The application of the fuel condition index may be performed on either boiling water reactor or pressurized water reactor fuel. Referring to FIG. 1, a Venn diagram describing the factors that affect overall fuel integrity of a LWR plant is provided. Three different interrelated factors are used in the methodology of the present invention to determine the likelihood of an integrity breach of fuel rods for a light water nuclear reactor. The material condition 10 of individual fuel rods is used in conjunction with both the duty (amount of use) of the fuel rods 20 and the environment 30 that the fuel rods will or have experienced to determine the overall likelihood of an integrity breach of the fuel rod or assembly in question. In the triple overlap region 35 of the material 10, duty 20 and environment 30, the potential exists for compromised light water reactor fuel rods. In non-triple overlap regions in the Venn diagram 40, the likelihood of structurally compromised light water reactor fuel rods is minimal as the simultaneous occurrence of all of the factors entering a critical region does not occur. Referring to FIG. 2, a method 100 according to the present invention allows for identification of light water reactor fuel rods that have, or that will have a high risk of structural integrity problems during an upcoming fuel cycle or at the time of evaluation. The methodology 100 calculates a fuel condition index 180 that is a measure of the portion of fuel element endurance expended during realistic operating conditions in a most thermally stressed region of the fuel element. The present methodology 100 uses the factors of heat flux of a nuclear fuel rod, the thickness of a Chalk River Unidentified Deposit (CRUD) on a surface of the fuel rod and the oxide thickness of the fuel rod as obtained from the three factors of environment 30, duty 20 and material 10 for the factors described above. The factors of heat flux of a nuclear fuel rod, the thickness of the Chalk River Unidentified Deposit on the surface of the fuel rod and the oxide thickness of the fuel rod are used to determine the likelihood of the fuel rod integrity being compromised as these factors are interrelated. Specifically, the heat flux for a fuel rod affects both the thickness of CRUD on the fuel rod as well as the oxide thickness of the fuel rod. Changes in CRUD properties on a fuel rod (for instance an increase in thickness of the CRUD layer) results in a change in heat flux as well as oxide composition on the fuel rod. The quantification of a fuel condition index 180 allows a fuel rod to be evaluated at a specific point in time, including times throughout a full fuel cycle. The factors of flux of the nuclear fuel rod, the thickness of the CRUD on the surface of the fuel rod and the oxide thickness of the fuel rod are used to determine the likelihood of a fuel rod integrity breach in the methodology of the present invention. Adjustment factors include, for example, the effect of sequence exchange interval, CRUD maturity and feedwater chemistry. The fuel condition index, therefore, as a time dependent variable, is expressed as: ∑ ( OperatingFlux MaximFlux + OperatingDeposit MaximDeposit + OperatingOxideThickness MaximOxide ⁢ Thickness ) ≤ A ( 1 ) As provided in the above equation (1), if the operating flux encountered by the individual fuel rod is equivalent to the maximum possible flux for that rod, the operating deposit (CRUD deposit) is equivalent to the maximum deposit of CRUD for the rod and the measured operating oxide thickness for the fuel element is equivalent to the maximum oxide thickness possible for the element, the value of the fuel condition index constant (A) is three (3). Using the above factors, the fuel condition index 180 is used to indicate at any given moment within a life span of the fuel element the likelihood of an integrity breach of the fuel rod in that the closer the calculated value is to the value 3, the closer the fuel in question is to failure. In an alternative exemplary embodiment of the methodology of the present invention, the fuel condition index 180, is defined to incorporate a factor of safety to ensure the continued integrity of fuel rods in the reactor. To this end, a margin of 20%, for instance, is chosen, thereby allowing the fuel condition index to be calculated as: ∑ ( OperatingFlux MaximFlux + OperatingDeposit MaximDeposit + OperatingOxideThickness MaximOxide ⁢ Thickness ) ≤ 2.4 ( 2 ) In the equations presented above, the effect of time is considered, wherein the maximum flux is considered at a time that is different from the operating time (moment) of interest. When the operating time for the operating components is the same for all three terms of the equations, the maximum flux, maximum deposit and the maximum oxide thickness are obtained all at different moments from the beginning of operation or, if historic fuel data is used, throughout the life of the fuel element. Thus, at each operating point, a different value of the fuel condition index is achieved. Several fuel condition index calculations may be performed to study a trend for the fuel rod or assembly in question. The fuel condition index may also be graphed over time to determine the maximum fuel condition index value for a specific fuel rod or assembly. This data can be used to determine if the fuel rod or assembly should be removed from service. The asynchronos time of maximum values of the three elements contributing to the fuel index is a characteristic of the light water reactor fuel condition index 180 and is therefore useful to not only ascertain the current condition of fuel elements (rods) in a reactor, but to also predict for a next fuel cycle, the integrity of those fuel elements. As obtained through testing of actual fuel elements in nuclear power reactors, nuclear reactor facilities are divided into High, Medium, and Low Risk cycle plants by dividing the expected range of the fuel condition index (1.9-3.6) into thirds to provide index constants. This result produces the following classifications: FCI≧3.0=High Risk Condition FCI 2.4-2.9=Medium Risk Condition FCI<2.4=Low Risk Condition The FCI may be used, but not limited to, conducting a preliminary assessment of operational conditions on fuel (changes, sequence exchange, water chemistry, etc.) prior to (or without) detailed analysis. The fuel condition index may also estimate risks associated with supplying fuel to a plant where there is no previous operating experience. The fuel condition index may also be used to estimate warranty risks for fuel manufacturers associated with operational excursions or if a change operation is needed during a reactor fuel cycle. Operationally, as provided in FIG. 2, the method 100 to assess boiling water reactor fuel integrity, is accomplished by granting access in a nuclear reactor fuel pool to at least one of a discharged fuel rod and a nuclear fuel assembly 110. The at least one fuel rod or nuclear fuel assembly may be a new rod/fuel assembly or a rod/assembly that was previously in use in a reactor. If the fuel rod or the nuclear fuel assembly were previously used, the rod/assembly is segregated from other heating surfaces of the reactor for further processing as described below. If a nuclear fuel assembly is used, the assembly in total may be evaluated, or individual component pieces may be evaluated. The overall intended position of the rod or assembly in the nuclear reactor is then determined/chosen by reactor engineers. Based upon the anticipated (or actual) position of the fuel rod/fuel assembly in the reactor, an operating flux of the fuel rod or fuel assembly is then calculated 120. While the rod or nuclear fuel assembly is segregated, a thickness of CRUD on the at least one of the fuel rod and the nuclear fuel assembly is then measured 130. The measurement is obtained, for example, by scraping the outside of the at least one fuel rod or the nuclear fuel assembly and measuring the thickness of the resulting scrapings in a laboratory in the exemplary methodology described. The measurement can also be obtained through non-destructive examination (e.g. ECT—Eddy current technique). In addition to measuring the thickness of CRUD of the at least one of the fuel rod and the nuclear fuel assembly, a thickness of oxide on the at least one fuel rod and the nuclear fuel assembly is also measured 140 through ECT or through destructive examination in a hot cell. Based upon the anticipated location inside the reactor, a maximized flux for the at least one fuel rod and the nuclear fuel assembly for the specific position of the at least one fuel rod and the nuclear fuel assembly in a nuclear reactor is calculated 150. The maximized flux is calculated along the most thermally stressed portion of the rod or assembly. A maximized deposit that may be achieved for the at least one fuel rod and the nuclear fuel assembly in the nuclear reactor is then calculated 160. The maximized deposit is determined through selection from the data base of the worst known deposition at which the fuel survived through its life. The length of time chosen may be an instantaneous time or an evaluation may take place over a length of a fuel cycle. A maximized oxide thickness that may be achieved during the time frame in question for the at least one fuel rod and the nuclear fuel assembly in the nuclear reactor is obtained 170 as the smaller value between the worst measured oxide thickness at the end of life of the fuel element and the regulatory admitted maximum oxide thickness. The length of time chosen may be an instantaneous time or an evaluation may occur over a length of the fuel cycle. Next, the fuel condition index of the at least one of the fuel rod and the nuclear fuel assembly is then calculated 180. The calculated fuel condition index is then compared to an index constant 190. Lastly, the at least one of the fuel rod and the nuclear fuel assembly is removed from operation 200 when the fuel condition index is greater than an index constant identified as identifying a high risk condition. The present invention provides a methodology that allows quantification of high risk fuel rods/fuel assemblies. The evaluative methodology improves on the existing methods by greatly reducing the probability of leaking fuel. The evaluative methodology also minimizes potential for degradation of reactor water clean up systems. The method according to the present invention also allows for prediction of fuel rod/assembly leakage for future times, different than current visual investigative technologies that have no such capability. The methodology also allows nuclear plant operators to satisfy the requirements of regulatory agencies that require nuclear power plant operators to develop overlapping credible methods to assess fuel rod integrity in light of plant changes conducted during operation. In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense.
	claims	1. An apparatus for processing a dielectric material, the apparatus comprising:a radiation source module comprising a reflector, an ultraviolet radiation source, and a plate transmissive to the wavelengths of about 150 nm to about 300 nm, to define a sealed interior region, wherein the sealed interior region is in fluid communication with a first fluid source;an optical filter comprising a mesh screen having a plurality of openings;a process chamber module coupled to the radiation source module to define a sealed chamber in operative communication with the ultraviolet radiation source, the process chamber comprising a closable opening adapted to receive a substrate, a support adapted to support the substrate, and a gas inlet in fluid communication with a second fluid source, wherein the optical filter is intermediate the radiation source and the substrate; anda loadlock chamber module in operative communication with the process chamber; the loadlock chamber comprising an airlock chamber in fluid communication with a third fluid source and the support. 2. The apparatus of claim 1, wherein the screen comprises an inner zone having a first mesh size, and an outer zone circumferentially disposed about the inner zone having a second mesh size. 3. The apparatus of claim 2, wherein the inner zone is coaxially aligned with the ultraviolet radiation source. 4. The apparatus of claim 1 wherein the sealed interior region of the radiation source module comprises an absorbent gas. 5. The apparatus of claim 1, wherein the ultraviolet radiation source comprises an electrodeless bulb coupled to an energy source. 6. The apparatus of claim 1, wherein the ultraviolet radiation source is a broadband radiation source with a selected wavelength spectrum, adapted to discriminately react with a first set of chemical bonds and functional groups of the dielectric material and is transparent to a second set of selected chemical bonds or functional groups of the dielectric material. 7. The apparatus of claim 1, wherein the ultraviolet radiation source comprises a dielectric barrier discharge device, an arc discharge device, or an electron impact generator. 8. The apparatus of claim 1, wherein the first fluid source comprises an inert gas; an ultraviolet absorbing gas or combinations comprising at least one of the foregoing gases; the second fluid source comprises the inert gas, a reactive gas, the ultraviolet absorbing gas, or a combination comprising at least one of the foregoing gases and the third fluid source comprises the inert gas. 9. The apparatus of claim 1, further comprising a cooling jacket disposed about the reflector in fluid communication with a cooling medium. 10. The apparatus of claim 1, wherein the dielectric material is a low k dielectric material, a premetal dielectric material, oxides, nitrides, oxynitrides, barrier layer materials, etch stop materials, capping layers, high k materials, a shallow trench isolation dielectric material or combinations comprising at least one of the foregoing dielectric materials. 11. The apparatus of claim 1, wherein the process chamber comprises a heat source adapted to heat the substrate. 12. The apparatus of claim 11, wherein the heat source comprises a proximity thermal chuck assembly comprising multiple pins for supporting the substrate and a spring mounted or an embedded thermocouple for measuring a temperature of the substrate. 13. The apparatus of claim 1, wherein the loadlock chamber is adapted to provide an inert condition for the substrate transferred from the process chamber. 14. The apparatus of claim 1, wherein the reflector comprises a reflecting layer formed of an aluminum metal, a dichroic material, or a multilayer coating. 15. The apparatus of claim 14, wherein the reflecting layer further comprises a protective layer comprising at least one of magnesium fluoride, silicon dioxide, aluminum oxide, and combinations thereof 16. The apparatus of claim 1, wherein the ultraviolet radiation source is adapted to emit a broadband radiation pattern comprising wavelengths within a range of about 150 nm to about 300 nm. 17. The apparatus of claim 1, wherein the process chamber further comprises an in situ irradiance probe positioned to measure an intensity of the ultraviolet broadband radiation. 18. The apparatus of claim 1, wherein the sealed interior region of the radiation source module is in fluid communication with an exhaust or vacuum. 19. The apparatus of claim 1, further comprising a preheating station coupled to the process chamber. 20. The apparatus of claim 1, wherein the screen is embedded in the plate and adapted to uniformly disperse the ultraviolet broadband radiation into the process chamber. 21. The apparatus of claim 1, wherein the process chamber further comprises an oxygen sensor. 22. The apparatus of claim 1, wherein the ultraviolet radiation source includes a portion that protrudes into or interfaces with the sealed interior region. 23. The apparatus of claim 22, wherein the portion includes a terminal end formed of a wire mesh. 24. An apparatus for processing a dielectric material, the apparatus comprising:a radiation source module comprising a reflector, an ultraviolet radiation source adapted to emit broadband radiation, a plate transmissive to the wavelengths of about 150 nm to about 300 nm nm, to define a sealed interior region, wherein the sealed interior region is in fluid communication with a first fluid source;an optical filter comprising a mesh screen disposed between the radiation source and a substrate; anda process chamber module coupled to the radiation source module to define a sealed chamber in operative communication with the ultraviolet radiation source, the process chamber comprising a closable opening adapted to receive the substrate, a support adapted to support the substrate, and a gas inlet in fluid communication with a second fluid source. 25. The apparatus of claim 24, wherein the mesh screen comprises an inner zone having a first mesh size, and an outer zone circumferentially disposed about the inner zone having a second mesh size. 26. The apparatus of claim 25, wherein the inner zone is coaxially aligned with the ultraviolet radiation source. 27. The apparatus of claim 25, further comprising at least one additional zone circumferentially about the outer zone and having a mesh size different from the second mesh size. 28. The apparatus of claim 24, wherein the sealed interior region of the radiation source module comprises, an absorbent gas. 29. The apparatus of claim 24, wherein the broadband radiation comprises a pattern of wavelengths within a range of about 150 nm to about 300 nm. 30. A process for treating a dielectric material, comprising:transferring a substrate having a dielectric material thereon from a loadlock chamber into a process chamber, wherein the process chamber is coupled to a radiation source module comprising a reflector, an ultraviolet radiation source, and a plate to define a sealed interior region, wherein the plate is transmissive to wavelengths of about 150 nm to about 300 nmflowing an inert gas into the process chamber and the sealed interior region;heating the substrate to a temperature within a range from 20° C. to 450° C.;generating ultraviolet broadband radiation at wavelengths of about 150 nm to about 300 nm nm and exposing the substrate to the ultraviolet broadband radiation;transferring the heated substrate at an elevated temperature to the loadlock chamber, and cooling the heated substrate while maintaining an inert atmosphere within the loadlock chamber; andperiodically cleaning the process chamber comprising introducing an oxidizing fluid into the process chamber, activating the oxidizing fluid with the ultraviolet broadband radiation, and volatilizing contaminants from the plate and process chamber. 31. The process of claim 30, further comprising flowing a cooling medium about the reflector. 32. The process of claim 30, wherein exposing the substrate to the ultraviolet broadband radiation comprises flowing an ultraviolet absorbing gas into the sealed interior region to remove a portion of the ultraviolet broadband radiation transmitted to the substrate. 33. The process of claim 30, wherein exposing the substrate to the ultraviolet broadband radiation further comprises simultaneously flowing a reactive gas into the process chamber. 34. The process claim 30, wherein periodically cleaning the process chamber comprises detecting a change in transmission of the ultraviolet broadband radiation into the process chamber, wherein when the change exceeds a predetermined threshold value, the cleaning process is triggered. 35. The process of claim 34, wherein the cleaning process is discontinued when a rate of change of transmission falls below a predetermined rate of change or is at about 100% transmission for a predefined wavelength band. 36. The process of claim 30, further comprising filtering a portion of the ultraviolet broadband radiation prior to exposing the substrate. 37. The process of claim 36, wherein filtering the portion of the ultraviolet broadband radiation comprises disposing a coating, an absorbent gas, an absorbent solid material or a combination thereof in a pathway of the ultraviolet broadband radiation. 38. The process of claim 30, wherein exposing the substrate to the ultraviolet broadband radiation comprises disposing a mesh screen between the ultraviolet radiation source and the process chamber, wherein a portion of the ultraviolet broadband radiation transmitted to the substrate is removed by the filter. 39. The process of claim 30, wherein the dielectric material comprises a premetal dielectric material, a low k dielectric material, a barrier layer, and combinations comprising one or more of the foregoing dielectric materials. 40. The process of claim 30, wherein flowing the inert gas into the process chamber comprises a downflow direction. 41. The process of claim 30, wherein flowing the inert gas into the process chamber comprises a crossflow direction. 42. The process of claim 30, wherein generating the ultraviolet broadband radiation comprises exciting a gas fill with an electrodeless bulb coupled to an energy source. 43. The process of claim 42, wherein the energy source is microwave energy, radiofrequency energy, or a combination of the foregoing energy sources. 44. The process of claim 30, further comprising flowing a gas proximal to the plate within the process chamber in an amount and flow rate effective to minimize deposition of a porogen or any outgassed material from a substrate to the plate. 45. The process of claim 30, further comprising flowing a gas proximal to the plate within the process chamber in an amount and flow rate effective to clean the plate, wherein the gas is activated by the ultraviolet broadband radiation. 46. The process of claim 30, further comprising continuously or periodically monitoring an oxygen concentration in the process chamber. 47. The process of claim 46, further comprising maintaining the oxygen concentration in the process chamber to less than 100 parts per million.
	description	The present application claims priority from U.S. Provisional Patent Application Ser. No. 61/638,555, filed Apr. 26, 2012, and incorporated herein by reference. The present invention relates to sources of X-ray radiation, and, more particularly, to an X-ray tube with a rotating anode. X-ray backscatter imaging relies on scanning an object with a well-collimated beam, typically referred to as “pencil beam”. Several approaches for forming the collimated scanning beam have been suggested. Commonly, beam formation and steering relies on an aperture moving in front of a stationary X-ray tube. In most cases the radiation from an X-ray tube is first collimated into a fan beam by a stationary collimator. Then, a moving part with an opening forms a scanning beam. This moving part can be, for example, a rotating disk with radial slits, or a wheel with openings at the perimeter. The rotating disk covers the fan beam and the scanning beam is formed by the radiation emitted through the slits traversing the length of the fan beam opening. This approach is illustrated, e.g., in the U.S. Pat. No. 3,780,291 (to Stein and Swift). In the case of a rotating wheel, a wheel with radial bores spins around the X-ray source. If the source is placed at the center of the wheel (or hub), the scanning beam is emitted in radial direction with the angular speed of the wheel. Alternatively, the source may be placed off-center with respect to the rotating wheel, which changes the beam geometry. In most X-ray tubes, an electron beam impinges upon a stationary target, which, in turn, gives off X-ray radiation produced by stopping the fast electrons, i.e., Bremsstrahlung. Most of the kinetic energy of the electron beam is converted into heat and only a small fraction is given off as X-rays. For imaging purposes, a small electron beam focal spot is desirable, however anode heating limits the acceptable current for a given focal spot size. To allow smaller focal spots, X-ray tubes 100 have been designed to have rotating anodes, as depicted in FIG. 1. X-ray tube 100 represents a typical design, as produced, for example, by Varian Medical Systems. Rotating anode 102 distributes the heat over a larger area and allows a considerably smaller focal spot 104 of electrons 106 emanating from cathode block 107 than would be possible using a stationary anode. Rotating anode 102 is rotated by rigid coupling to rotor 108 which moves relative to stator 110. X-rays 112 are emitted through exit window 114, and they are subsequently collimated by some external collimating structure. In accordance with various embodiments of the present invention, an X-ray tube is provided that both generates and collimates an X-ray beam. The X-ray tube has a vacuum enclosure, a cathode disposed within the vacuum enclosure for emitting a beam of electrons, and an anode adapted for rotation with respect to the vacuum enclosure about an axis of rotation. The X-ray tube also has at least one collimator opening adapted for co-rotation with respect to the anode within the vacuum enclosure. In accordance with other embodiments of the present invention, the collimator opening or openings may be disposed within the anode itself Each collimator opening may be contiguous with a wedge opening in the anode. In accordance with further embodiments of the present invention, the X-ray tube may have an external collimator opening disposed outside the vacuum enclosure. The collimator openings (or opening) may be disposed above a plane transverse to the axis of rotation containing a locus of focal spots of the beam of electrons. In accordance with embodiments of the present invention, described now with reference to FIGS. 2-6, an X-ray tube 200 is provided that uses a rotating anode, not only to distribute the heat, but also to act as a rotating collimator to create a scanning beam. To that end, referring first to FIG. 2, anode 202 is preferably concave, with an electron beam 204 impinging upon focal spot 205 on an inner surface 206 in such a manner that the X-rays 208 are emitted towards the center 210 of anode 202. In the embodiment depicted in FIG. 2, X-rays 208 are emitted perpendicularly to axis of rotation 212 about which anode 202 rotates. The elevated rim 216 of anode 202 may also be referred to herein as an anode “ring” 216. To form a scanning collimated pencil beam 214, anode ring 216 has openings 218 which allow X-rays 208 to be emitted out of the X-ray tube 200. In the depicted embodiment, anode ring 216 has three openings 120° apart creating a scanning beam coverage of approximately 50°. FIG. 3 is a top cross-sectional view of anode 202 of FIG. 2. The circular focal spot path 220 comprises the locus of regions serving as focal spot 205 as anode 202 rotates. Partially collimated pencil beam 214 emerges from wedge opening 230. An external collimator slit 232 may be situated outside glass envelope 234 of the X-ray tube 200. In FIG. 4, rotating anode 202 has been rotated relative to the cathode block 107 in order to illustrate a near-extremal position of the beam span, where the focal spot 205 will fall into the wedge opening 230 just as collimated pencil beam 214 is about to be vignetted by an edge of wedge opening 230. More generally, within the scope of the present invention, opening 218 is to be considered an instance of a collimator aperture which co-rotates with anode 202, whether or not the aperture is integral with the anode. In the embodiment of rotating anode X-ray tube 500, depicted in FIG. 5, X-rays 502 are emitted at a slight angle to clear the height of the slanted anode 504. This eliminates the need to cut openings into the slanted anode area and thus allows for continuous X-ray generation not interrupted by gaps in the anode area. X-rays 502 are emitted, instead, through an aperture 506 above the plane transverse to rotation axis 212 containing the intersection of focal spot 205 with the surface of rotating anode 504. A further advantage of this design is the greater flexibility in choosing the number of apertures. FIG. 6 is a top view of the anode of FIG. 5. The largest possible angular span of the scanning beam depends on the number of apertures in the ring as well as on the ratio of the ring diameter 2R to the distance r between the focal spot and the center of rotation, see FIG. 6. A single aperture 506 theoretically allows for a 360° angular beam span. For two opposite apertures 506, the theoretical beam span is twice the arc tangent of the ratio R/r, where, as shown in FIG. 6, R is the radius of the an anode rim ring wall 602, and r is the radial distance from the axis of rotation 212 to focal spot 205. Using three equally spaced apertures limits the theoretical beam span to twice the arc tangent of the ratio 3 ⁢ R 2 ⁢ r + R .These formulas are exact for a dimensionless focal spot 205 and an infinitesimally thin anode ring wall 602. Assuming the ring wall radius R is 4/3 of the focal spot distance r, two opposite apertures 506 create a span of about 106°; three equally spaced apertures 506 create a span of just over 69°. In preferred embodiments of the present invention, the aperture 506 in the anode ring wall 602 are vertical cuts (parallel to the axis of rotation) and the collimation in the vertical direction is accomplished by an external collimator slit 232 positioned outside the x-ray tube 500. In order for the scanning beam to span a plane without curvature, the external collimator slit 232 should be coplanar with the focal spot 205. X-ray tubes with anodes rotating at up to 10,000 rpm are commercially available. With three openings and 150 rotations per second, X-ray tube 500, in accordance with embodiments of the present invention, creates a scan rate of 450 lines per second, a rate compatible, for example, with typical applications like whole body scanners. Where examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objective of x-ray scanning Additionally, single device features may fulfill the requirements of separately recited elements of a claim. The embodiments of the invention described herein are intended to be merely exemplary; variations and modifications will be apparent to those skilled in the art. All such variations and modifications are intended to be within the scope of the present invention as defined in any appended claims.
	abstract	A method of plasma particle simulation capable of preventing solution divergence. A space within a housing chamber of a plasma processing apparatus is divided into a plurality of cells. A weighting factor corresponding to the number of plasma particles represented by a superparticle is set in each of the divided cells. Superparticles are set in each of the divided cells using plasma particles contained in the divided cell and the set weighting factor. The behavior of the superparticles in each of the divided cells is calculated. The weighting factor becomes smaller as the divided cell is located closer to a solid wall surface of the housing chamber.
	description	The present invention relates to an alignment technique for assembling collimator modules. In the radiography apparatus, as represented by an X-ray CT apparatus or a general imaging apparatus, a collimator unit placed on the detecting surface side of a radiation detector is highly important for preventing degradation of images due to scattered radiation. Conventionally, a collimator unit has a plurality of collimator plates arrayed in one direction. In recent years, because of rising demand of increasing the number of row-detectors, miniaturization and image quality enhancement in the radiation detecting device, a collimator unit having a plurality of collimator plates assembled in lattice-shape for preventing two-dimensionally the scattered radiation entering the detection surface, is proposed. For example, FIGS. 1-7 of JP Unexamined Patent Application No. 2010-127630 disclose such a lattice-shaped collimator unit. Also, another type of the lattice-shaped collimator unit can be considered as below. For example, a lattice-shaped collimator unit includes a plurality of collimator modules. Each of the plurality of collimator modules includes a plurality of first collimator plates arrayed in a first direction, and a plurality of second collimator plates arrayed in a second direction orthogonal to the first direction. Each of the plurality of first collimator plates has multiple slots (long and thin holes) on the plate surface, and each of the plurality of second collimator plates is inserted into the slots. When assembling the above type of collimator unit, in order to insert the second collimator plate smoothly into the slot and place it without bending it, the plurality of first collimator plates is required to be positioned precisely in the second direction. Actually, however, a collimator module or a collimator unit has an enormous number of collimator plates, for example, ranging from several dozens to several hundreds. That makes it difficult to place all collimator plates at correct positions in a precise manner and at low cost. For example, assuming that a collimator unit of the above type is manufactured, the plurality of first collimator plates is supported by two end-blocks having respective grooves for positioning each edge of the first collimator plate in the second direction. In this case, a bottom surface of the groove of the end-block is processed as a reference surface, and the position of the first collimator plate may be aligned by contacting the edge portion of the first collimator to the reference surface. However, even under the present technology, it is difficult to process each groove with required high precision, which worsens yields and increases manufacturing cost. Under such circumstances, low-cost and high precision collimator modules are demanded. In a first aspect, a method for assembling a collimator module is provided, the collimator module including a plurality of first collimator plates arrayed in a first direction, having a plurality of slots formed on each its plate surface, and a plurality of second collimator plates arrayed in a second direction orthogonal to the first direction, each second collimator plate penetrates the respective slots in the first direction so as to form a lattice-shape. The method includes a first step of positioning the plurality of first collimator plates by moving the first collimator plate in one direction of the second direction, so that a side wall of a first cutout formed on an edge of a radiation incident side or a radiation output side of the first collimator plate is contacted to a member extending to the first direction. In a second aspect, the method for assembling the collimator module according to the first aspect is provided, wherein in the first step, the first collimator plate is moved by hooking a springy member on the first cutout and pulling the first collimator plate with a tension. In a third aspect, the method for assembling the collimator module according to the first aspect is provided, wherein in the first step, the first collimator plate is moved by hooking a springy member on a second cutout which is different from the first cutout and is formed on the edge of the first collimator plate, and pulling the first collimator plate with a tension. In a fourth aspect, the method for assembling the collimator module according to the third aspect is provided, wherein the first cutout is formed on one end side of the second direction of the edge, and the second cutout is formed on the other end side of the second direction of the edge. In a fifth aspect, the method for assembling the collimator module according to any one of the second to forth aspects is provided, wherein after the first step, the method includes a second step of inserting the plurality of second collimator plates into the respective slots, and a third step of sandwiching each second collimator plate between the side walls of each slot by hooking the springy member on the first cutouts of part of the plurality of first collimator plates and moving the part of the plurality of first collimator plates in a direction opposite to the one direction. In a sixth aspect, the method for assembling the collimator module according to any one of the second to forth aspects is provided, wherein after the first step, the method includes a second step of inserting the plurality of collimator plates into the respective slots, and a third step of sandwiching each second collimator plate between the side walls of each slot by hooking the springy member on a third cutout which is different from the first cutout and formed on one end side of the second direction of the edge of part of the plurality of first collimator plates and moving the part of the plurality of first collimator plates in a direction opposite to the one direction. In a seventh aspect, the method for assembling the collimator module according to the fifth or sixth aspect is provided, wherein the part of the plurality of first collimator plates are odd or even numbered collimator plates of the plurality of first collimator plates. In an eighth aspect, the method for assembling the collimator module according to any one of the first to seventh aspects is provided, wherein before the first step, the method includes placing a first block and a second block with a space in the second direction, wherein the first and second block have the respective grooves for placing the edges of the plurality of first collimator plates in the second direction, and inserting the plurality of first collimator plates into the respective grooves. In a ninth aspect, the method for assembling the collimator module according to the eighth aspect is provided, further including a fourth step of bonding the plurality of first collimator plates, the plurality of second collimator plates, the first block and the second block. In a tenth aspect, the method for assembling the collimator module according to any one of the first to ninth aspects is provided, wherein the collimator module is used for a radiation tomographic imaging apparatus. In an eleventh aspect, the method for assembling the collimator module according to any one of the first to ninth aspects is provided, wherein the collimator module is used for a radiation projection imaging apparatus. In a twelfth aspect, a first collimator plate having a plurality of slots on its plate surface for inserting a second collimator plate is provided, the first collimator plate including a cutout formed on an edge of a radiation incident side or a radiation output side of the first collimator plate, having side walls used as a reference surface for positioning the first collimator plate in the direction of the edge. In a thirteenth aspect, a collimator module including a first collimator plate is provided, the first collimator plate having a plurality of slots on its plate surface for inserting a second collimator plate, and a cutout formed on an edge of a radiation incident side or a radiation output side of the first collimator plate, the cutout having side walls used as a reference surface for positioning the first collimator plate in the direction of the edge. In a fourteenth aspect, a radiation detecting device including a collimator module including a first collimator plate is provided, the first collimator plate having a plurality of slots on its plate surface for inserting a second collimator plate, and a cutout formed on an edge of a radiation incident side or a radiation output side of the first collimator plate, the cutout having side walls used as a reference surface for positioning the first collimator plate in the direction of the edge. In a fifteenth aspect, a radiography apparatus including a radiation detecting device including a collimator module comprising a first collimator plate is provided, the first collimator plate having a plurality of slots on its plate surface for inserting a second collimator plate, and a cutout formed on an edge of a radiation incident side or a radiation output side of the first collimator plate, the cutout having side walls used as a reference surface for positioning the first collimator plate in the direction of the edge. In a sixteenth aspect, the radiography apparatus according to the fifteenth aspect is provided, wherein the radiography apparatus is used for tomographic imaging. In a seventeenth aspect, the radiography apparatus according to the fifteenth aspect is provided, wherein the radiography apparatus is used for projection imaging. According to the embodiments described herein, a collimator plate suitable for its position alignment is provided, by forming at least one cutout on its edge and processing with high precision at least one side wall of the cutout as a reference surface for positioning. Thus, the precise position alignment of the collimator plate can be accomplished at relatively low cost. Hereinafter, exemplary embodiments will be described. The invention is not limited to the embodiments specifically described herein. FIG. 1 is a perspective view of an exemplary X-ray CT apparatus 100. As shown in FIG. 1, the X-ray CT apparatus includes a scanning gantry 101 for scanning a subject and acquiring a projection data, and a cradle 102 on which the subject is placed and going in to and out of a bore 104 of the scanning gantry 101, which is a scanning area. The X-ray CT apparatus further comprises an operating console 103 for operating the X-ray CT apparatus 100 and reconstructing images based on the acquired projection data. The cradle 102 contains a motor therein for elevating and horizontally moving the cradle 102. The subject is placed onto the cradle 102 and the cradle 102 goes in to and out of the bore 104 of the scanning gantry 101. The operating console 103 has an input device receiving inputs from an operator, and a monitor for displaying images. Also, the operating console 103 has a central processing device for controlling each device to acquire the projection data of the subject or processing three-dimensional image reconstruction, a data acquisition buffer for acquiring obtained data by the scanning gantry 101, and a memory device for memorizing programs, data, and the like. These devices composing the operating console 103 are not shown in FIG. 1. The scanning gantry 101 has an X-ray tube and an X-ray detection device for scanning the subject. FIG. 2 is a perspective view for explaining the X-ray tube and X-ray detection device. Here, as shown in FIG. 2, a rotational axis direction of the scanning gantry 101 (a horizontal moving direction of the cradle 102 or a body axis direction of the subject) is referred as a slice direction (SL direction). A fan angle direction of an X-ray beam 23 is referred as a channel direction (CH direction). Also, the direction perpendicular to the channel direction and slice direction, and directed toward the rotation center, or the scanning center of the scanning gantry 101, is referred as the iso-center direction (I direction). In the channel direction (CH direction), slice direction (SL direction) and iso-center direction (I direction), the direction toward the arrow in FIG. 2 is (+) direction and the opposite direction is the (−) direction. The X-ray detection device 40 has a plurality of X-ray detection modules 50 for detecting the X-ray, a plurality of two-dimension collimator modules 200 for collimating X-ray beams 23 from an X-ray focal point 21 of an X-ray tube 20, and a base 60 for fixing the plurality of X-ray detection modules 50 and the plurality of two-dimension collimator modules 200 in reference positions. The plurality of two-dimension collimator modules 200 is arrayed in the CH direction and forms a two-dimension collimator device. The plurality of X-ray detection modules 50 corresponding to the plurality of two-dimension collimator modules 200 is arrayed in the CH direction. One X-ray detection module 50 corresponds to one collimator module 200. The X-ray detection module 50 is placed on the X-ray output side of the two-dimension collimator module 200. The X-ray detection module 50 detects the X-rays passed through the subject which is put on the cradle 102 and transferred into the bore. The X-ray detection module 50 has a scintillator block, which is not shown in FIG. 2, that emits visible light by receiving X-rays, and a photodiode chip, which is not shown in FIG. 2, having a photodiode for photoelectric conversion arrayed two-dimensionally in the CH direction and SL direction. The X-ray detection module 50 further has a semiconductor chip, which is not shown in FIG. 2, having functions to accumulate outputs from the photodiode chip on the substrate and to switch outputs for changing a slicing thickness. The base 60 is a rectangular frame-shaped having a pair of circular-arc base members 61 and a pair of linear base members 62 connecting the distal ends of each base member 61. Also, positioning pins or positioning holes for positioning the plurality of two-dimension collimator modules 200 are provided on the base side of the base member 61. Regarding the base 60, a length in the SL direction is in a range of 350 mm to 400 mm for example, a thickness is in a range of 35 mm to 40 mm for example and length of an inner space between the base member 61 and 62 is in a range of 300 mm to 350 mm. Also, a width of each two-dimension collimator module 200 in the CH-direction is 50 mm for example. Hereinafter, the two-dimension collimator module 200 will be described. A material of the base 60 can be, for example, an aluminum alloy or a carbon fiber reinforced plastic (CFRP). CFRP is a composite material of a carbon fiber and a thermoset resin. Because the aluminum alloy or CFRP is light in weight and strong and also has a characteristic of high rigidity, the base 60 can be rotated at high speed in the scanning gantry 101 of the X-ray CT apparatus 100 without generating unnecessary centrifugal forces. Additionally, the base 60 and two-dimension collimator modules 200 fixed thereon hardly strains or bends. Although the two-dimension collimator modules 200 drawn in FIG. 2 are simplified, actually several dozens of two-dimension collimator modules 200 may be fixed on one base 60. Hereinafter, a configuration of the two-dimension collimator module will be described further in detail. FIG. 3 is a perspective view of the two-dimension collimator module in this embodiment. FIGS. 4A and 4B are drawings of a first collimator plate and a second collimator plate, respectively, which configures the two-dimension collimator module. As shown in FIG. 3, the two-dimension collimator module 200 has a plurality of first collimator plates 11, a plurality of second collimator plates 12, a top-end block 13 and a bottom-end block 14. For the purpose of explaining the configuration easily, fewer first collimator plates 11 and second collimator plates 12 are drawn in FIG. u3, however, a number of the first collimators plates 11 is ideally between 32 to 64 plates, and a number of the second collimator plates 12 is ideally between 129 to 257 plates. A plurality of first collimator plates 11 is placed so that its plate surfaces are almost parallel to each other and there is an interval in the CH-direction between the first collimator plates. The top-end block 13 and the bottom-end block 14 are placed so that the plurality of first collimator plates 11 is supported by the two end-blocks in the SL-direction. The plurality of second collimator plates 12 is assembled approximately orthogonally to the plurality of first collimator plates 11. Namely, the plurality of first collimator plates 11 and the plurality of second collimator plates 12 are assembled, which forms a lattice-shaped two-dimension collimator portion. A positioning of the top-end block 13, the bottom-end block 14, the plurality of first collimator plates 11 and the plurality of second collimator plates 12 is done by a predetermined method. And these blocks and plates are bonded to each other using adhesive and the like. A configuration of components of the two-dimension collimator module will be described further in detail. As shown in FIG. 4A the first collimator plate 11 has a rectangular-shape or mildly-curved fan-shape. The first collimator plate 11 is made of a heavy-metal having a high X-ray absorption rate, such as molybdenum, tungsten or lead. When the two-dimension collimator modules 200 are mounted onto the base 60, a plate surface of the first collimator plate 11 is parallel to radiating direction of the X-ray beam 23 from the X-ray focal point 21, and the longitudinal direction thereof corresponds to the SL direction or a cone angle direction of the X-ray beam 23. Here, a thickness of the first collimator plate 11 is approximately 0.2 mm. A plurality of slots 111, which are long and thin holes for inserting the second collimator plate 12, are formed on the plate surface of the first collimator plate 11. The plurality of slots 111 is formed so that when the two-dimension collimator module 200 is mounted onto the base 60, each of the plurality of slots 111 is parallel to the radiating direction of the X-ray beam 23 from the X-ray focal point 21. Incidentally, when considering of inserting the second collimator plate 12 into the slot 111 smoothly, in the exemplary embodiment, a width of the slot 111 in the SL-direction is much wider than a plate thickness of the second collimator plate 12. Whereas if the width of the slot 111 is too wide, the rigidity of the first collimator plate 11 becomes low, which causes strain or bend while assembling or scanning. If these are taken into consideration, the thickness of the second collimator plate 12 may be between 0.06 mm to 0.22 mm, the width of the slot 111 in the SL direction may be between 0.1 mm to 0.28 mm, and the width of the slot 111 is wider than thickness of the second collimator plate 12. Also, if the slot 111 is processed by wire electric discharge, a diameter of the wire can be selected from 0.1 mm, 0.2 mm or 0.3 mm; however, considering a balance between the costs and processing precision, in some embodiments, a 0.2 mm diameter wire is utilized. In the exemplary embodiment, the width of the slot 111 in the SL direction is between 0.2 mm to 0.28 mm. Here, the width of the slot 111 in the SL-direction is approximately 0.24 mm and the length of the slot 111 is approximately 15.4 mm. As shown in FIG. 4A, a first cutout 112, a second cutout 113 and a third cutout 114 are formed on an edge of the X-ray incident side of the first collimator plate 11. These cutouts are used during an assembly of the two-dimension collimator module. In this embodiment, these cutouts all have nearly rectangular shapes and have a size between 2 to 5 mm. The cutouts can be processed and formed simultaneously with manufacturing of the first collimator plates 11 by a wire electric discharge processing method or the like. The wire electric discharge processing is a particularly effective method of forming cutouts on the edge of the plate-shaped material, and the method allows a high precision, low cost processing relatively easily. The first cutout 112 is formed at a position closer to the end of the first collimator plate 11 in the +SL-direction. The first cutout 112 is used as a reference for positioning the first collimator plate 11 in the SL-direction. A side wall 112K of the first cutout 112 on the +SL side is processed with a very high precision, and used as a reference surface having a precise positional relationship with the plurality of slots 111 formed on the plate surface. The second cutout 113 is formed at a position closer to the end of the first collimator plate 11 in the −SL-direction. The second cutout 113 is used for moving or sliding the first collimator 11 to the −SL-direction. For example, one end of a springy member, such as a tip of a plate spring bent in arch shape can be hooked on the second cutout 113, and tension is applied in the −SL-direction. The third cutout 114 is formed at a position next to the first cutout 112 in the +SL-direction. The third cutout 114 is used for moving or sliding the first collimator 11 to the +SL-direction. For example, one end of a springy member, such as a tip of a plate spring bent in arch shape can be hooked on the third cutout 114, and tension is applied in the +SL-direction. A method for assembling the two-dimension collimator module using cutouts will be described further in detail afterward. As shown in FIG. 4B a second collimator plate 12 has a fan-shaped main portion 121 and a rectangular-shaped end portion 122. Similar to the first collimator plate 11, the second collimator plate 12 is made of a heavy-metal having a high X-ray absorption rate. When the second collimator module 200 is mounted onto the base 60, the plate surface of the second collimator plate 12 becomes parallel to the radiating direction of the X-ray beam 23 from the X-ray focal point 21, and a curved long-edge direction that forms the fan-shaped main portion 121 matches to the CH-direction. As shown in FIG. 3, the second collimator plate 12 is inserted into the slot 111 so as to penetrate through each row of slots 111 of the plurality of first collimator plates 11 aligned in the CH-direction. The rectangular-shaped end portion of the second collimator plates 12 is wider than the length of the slot 111 in the I-direction. Thus the end portion works as a stopper when inserted to the slot 111. Also, when a plurality of two-dimension collimator modules 200 is mounted onto the base 60, tips of the main portion of the second collimator plates 12 of one two-dimension collimator module 200, and tips of the rectangular portion of the second collimator plates 12 of next one two-dimension collimator module 200, meet each other in the SL-direction, and form a part of the lattice-shaped two-dimension collimator. Incidentally, regarding the second collimator plate 12, a position gap may occur due to heat deformation. Whenever the gap occurs, the shielding condition of the X-ray changes, which causes crosstalk between detected cells and alters the detection property of the X-ray detection device 20. This can be effectively prevented by thinning a plate thickness of the second collimator plate 12. Whereas if the plate thickness is too thin, rigidity of the second collimator plate 12 becomes low, which causes a bend of the second collimator plate 12 during assembling or scanning Considering such conditions, plate thickness of the second collimator plate 12 is may be between 0.06 mm to 0.14 mm, and is more preferable to fall between 0.08 mm to 0.12 mm in one embodiment. In the exemplary embodiment, the plate thickness of the second collimator plate 12 is approximately 0.1 mm. Also, the width of the second collimator plate 12 in the I-direction is approximately 15 mm in the exemplary embodiment. The top-end block 13 and the bottom-end block 14 are made of lightweight metals such as aluminum or plastic. As shown in FIG. 3, the top-end block 13 has a post 13T extending in the I-direction and orthogonal to the CH-direction and SL-direction, and a flange 13F protruding to the −SL-direction and these are formed as one unit. Therefore, the top-end block 13 has opposite “L” shape when viewed from the +CH direction toward the −CH-direction. Similarly, the bottom-end block 14 has a post 14T extending to the I-direction and a flange 14F protruding to the +SL direction and these are formed as one unit. Therefore, the bottom-end block 14 has “L” shape when viewed from the +CH direction toward the −CH direction. Also, as shown in FIG. 3, a positioning hole is formed at the center of the flange 13F, and a positioning pin 135 is inserted into this positioning hole and fixed. Similarly, a positioning hole is formed at the center of the flange 14F, and a positioning pin 145 is inserted into this positioning hole and fixed. When these positioning pins 135, 145 are respectively fixed to predetermined positions, the two-dimension collimator module 200 will be positioned to the reference position on the base 60. Surrounding the positioning pin 135 (145), four positioning holes 136 (146) are formed. These four positioning holes 136 (146) are formed so that the X-ray detection module 50 shown in FIG. 2 can be accurately mounted. As shown in FIG. 3, the surface 13a of the top-end block 13 and the surface 14a of the bottom-end block 14 are facing each other, and a plurality of grooves for inserting the first collimator plates 11 is formed on each surface 13a and 14a. The plurality of grooves is formed so that when the two-dimension collimator module 200 is mounted onto the base 60, the grooves are positioned along the radiating direction of the X-ray beam 23 radiated from the X-ray focal point 21. A plurality of first grooves 131 having nearly constant depth in the SL-direction is formed on the surface 13a of the top-end block 13. Similarly, a plurality of second grooves 141 having nearly constant depth in the SL-direction is formed on the surface 14a of the bottom-end block 14. Here in both the first groove 131 and second groove 141, the depth in the SL-direction is approximately 1 mm and the width in the CH-direction is approximately 0.24 mm. The side wall 111K of the slot 111 in the +SL direction is a reference surface, and is formed so as to have an accurate positional relationship with the side wall 112K of the first cutout 112 of the first collimator plate 11. Both end walls of the first collimator plate 11 in the SL direction does not contact any of the bottom surfaces of the first and second grooves 131, 141. Thus, there is some space between the ends and the bottom surfaces. Among both side walls of the slots 111′ of the odd-numbered first collimator plates 11′ in the SL-direction, the plate surface of the second collimator plate 12 in the +SL-direction contacts only the side wall 111K in the +SL-direction (see FIG. 17). Among both side walls of the slots 111″ of the even-numbered first collimator plates 11″ in the SL-direction, the plate surface of the second collimator plate 12 in the −SL-direction contacts only the side wall 111Z in the −SL-direction (see FIG. 17). Thus, each second collimator plate 12 is sandwiched in between the side walls 111K of the slots 111′ in the +SL direction of the odd-numbered first collimator plates 11′ and the side walls 111Z of the slots 111″ in the −SL direction of the even-numbered first collimator plates 11″. The plurality of first collimator plates 11, the plurality of second collimator plates 12, the top-end block 13 and the bottom-end block 14 are bonded together using adhesive. Hereinafter, a method for assembling the two-dimension collimator module in this embodiment is described. FIG. 5 is a flow-chart showing the method for assembling the two-dimension collimator module in this embodiment. In step S111, as shown in FIG. 6, each of the top-end block 13 and the bottom-end block 14 is positioned at a predetermined position using a jig. In step S112, as shown in FIG. 7, a plurality of first collimator plates 11 is inserted into the respective grooves of the top-end block 13 and bottom-end block 14. In step S113, the plurality of first collimators 11 are coarsely positioned using a jig. For example, as shown in FIG. 12, each top and bottom edge of the first collimator plate 11 is gently nipped in the CH-direction by using aligning members 301, 302 with comb-shaped cutouts. At this point, the first collimator plates 11 can be moved in the SL-direction. In step S114, as shown in FIG. 8 and FIG. 18, a positioning ruler 401 with an plane extending straight in the CH direction is placed accurately at a predetermined position. The predetermined position is a position having a predetermined positional relationship with the top-end block 13 and bottom-end block 14, and is determined so that the plane is located inside the first cutout 112. Also, a tip of a comb-shaped first spring plate 402 is hooked onto a side wall of the second cutout 113. Then, by moving the first spring plate 402 toward the −SL direction, the plurality of first collimator plates 11 is pulled toward the top-end block 13 (in the −SL-direction). As shown in FIG. 13, the side walls 112K of the first cutouts 112 of the first collimator plates 11 contact the plate surface of the positioning ruler 401 in the +SL-direction. As a result, as shown in FIG. 15, each slot 111′ of the odd-numbered first collimator plates 11′ and each slot 111″ of the even-numbered first collimator plates 11″ are aligned in the CH-direction. Thus, the second collimator plates 12 can be easily inserted to the slots 111. In step S115, as shown in FIG. 9, a plurality of second collimator plates 12 is inserted to respective slots 111 until it stops. FIG. 16 shows a positional relationship between the slot 111′ of the odd-numbered first collimator plate 11′, the slot 111″ of the even-numbered first collimator plate 11″ and the second collimator plate 12 at this point. In step S116, as shown in FIG. 10 and FIG. 19, each tip on a comb-shaped second spring plate 403 is hooked onto a said wall of the third cutout 114″ of the even-numbered first collimator plates 11″. Then, by moving the second spring plate 403 toward the +SL direction with a tension stronger than that of the first spring plate 402, the even-numbered first collimator plates 11″ are pulled toward the bottom-end blocks 14 (+SL direction). Then, as shown in FIG. 14, the second collimator plates 12 are sandwiched in between the side walls of the slots 111′ of the odd-numbered first collimator plates 11′ and the side walls of the slots 111″ of the even-numbered first collimator plates 11″. As a result, as shown in FIG. 17, the plate surface of the second collimator plates 12 in the +SL-direction contact the reference surface which is the side wall 111K of the slots 111′ of the odd-numbered first collimator plates 11′ in the +SL-direction, then the second collimator plates 12 are placed at correct positions. In step S117, a plurality of first collimator plates 11 is re-positioned using the jig and the like. Here, by using the jigs (the comb-shaped aligning members 301, 302) shown in FIG. 12, both top and bottom edges of the first collimator plates 11 are firmly nipped in the CH direction. At this point, the first collimator plates 11 are fixed. In step S118, the plurality of first collimator plates 11, the plurality of second collimator plates 12, the top-end block 13 and the bottom-end block 14 are bonded together using adhesive under such a condition. Then, the two-dimension collimator module 200 is assembled. Additionally, in order to increase rigidity of the two-dimension collimator module 200, as shown in FIG. 11, an X-ray transparent fixing sheet 15 can be pasted onto at least one surface of the X-ray incident side and the X-ray output side. The fixing sheet 15 is constituted with, for example, carbon reinforced plastic (CFRP) having high rigidity, light-weight and high X-ray transparency. The fixing sheet 15 can have grooves on its sheet surface, for receiving the top or bottom edges of the first collimator plates 11. As described above, in this embodiment, a two-dimension collimator module can be assembled with high precision at low cost, since the positioning of collimator plates is realized using the cutouts of the collimator plates having high precision and easily processed. Also, the two-dimension collimator module can be easily assembled and has high positioning precision depending on the movement of the first collimator plate 11 in the SL direction, since inserting the second collimator plate 12 into the slot 111 can be made easier by aligning the position of the slot 111, or positioning can be acquired by putting the first collimator plates 11 and second collimator plates 12 on the reference surface. In order to make the insertion of the second collimator plate 12 into the slot 111 easier, the width of the slot 111 needs to have a plenty of width than the plate thickness of the second collimator plate 12. In this case, the looseness becomes large, which normally makes the positioning precision of the second collimator plate 12 worse. On the other hand, if the width of the slot 111 is almost the same of the thickness of the second collimator plate 12, the positioning precision of the second collimator plate 12 improves; however, the insertion of the second collimator plate 12 into the slot 111 becomes not easy, which decreases the assembly productivity. Whereas in the exemplary embodiment, the first collimator plates 11 are moved toward the top-end block 13 so that the position of the slots 111 is aligned, and the second collimator plates 12 are inserted into the slots 111, and some of the first collimator plates 11 is moved toward the bottom-end block 14 so that the second collimator plates 12 are sandwiched in and positioned at correct positions. Therefore, in the exemplary embodiment, even if the width of the slots 111 is relatively large in comparison to the plate thickness of the second collimator plate 12 to make the insertion of the second collimator plate 12 easer, high precision of the positioning can be acquired. This can increase a degree of freedom between the width of the slot 111 and plate thickness of the second collimator plate 12, and both can be made in a relatively good size. Exemplary embodiments are described above; however, it will be obvious to persons who are skilled in the relevant art to modify the embodiments specifically described herein based on this disclosure. For example, in the embodiment above, although the first to third cutouts are formed on the edges of the X-ray incident side of the first collimator 11, however, at least a part of the first to third cutouts can be formed on the edges of the X-ray output side of the first collimator 11. Also, in the embodiment above, the plurality of first collimator plates 11 is moved toward the −SL direction temporarily, the second collimator plates 12 are inserted to the respective slots 111, a part of the first collimator plates 11 is moved toward the +SL direction and the second collimator plates 12 are sandwiched in between side walls of the slots 111. However, when the width of slot 111 is narrowed to the plate thickness of the second collimator plate 12, the positioning of the first collimator plates 11 is necessary for only once. In this case, as shown in FIG. 20, for example, without forming the third cutout 114, the first collimator plate 11 can be positioned by placing a positioning ruler 401 inside the first cutout 112, hooking the first spring plate 402 to the second cutout 113 and pulling the first spring plate 402. Also, as shown in FIG. 21 for example, without forming the second cutout 113 and third cutout 114, the first collimator plate 11 can be positioned by placing the positioning ruler 401 inside the first cutout 112, hooking the first spring plate 402 to the first cutout 112 and pulling the first spring plate 402. In this case, a side wall of the first cutout 112 to contact the positioning ruler 401 is a reference wall for positioning. Also, in the embodiments above, a main portion of the second collimator plate 12 has a fan-shape that fans along the X-ray beam direction; however this can be rectangular shaped. Further, for example, although the embodiments above are explained based on a collimator module that shields the X-ray, the embodiments described herein can be applied to other applications for shielding other radiating beams, such as gamma rays. The present invention not only relates to a collimator module and assembling method thereof. It can also be used for an X-ray detection device having a plurality of collimator modules, a simple roentgenography apparatus having such X-ray detection device and the X-ray CT apparatus.
	claims	1. An apparatus comprising:an extreme ultraviolet radiation source comprising: a first electrode configured to paws current across a region, the first electrode comprising at least one pyrolitic graphite layer disposed adjacent to an outer surface of a first electrode substrate. 2. The apparatus of claim 1, wherein the extreme ultraviolet radiation source further comprises a second electrode configured to receive current from the first electrode. 3. The apparatus of claim 2, wherein at least one of the first electrode and the second electrode comprises substrate nucleated pyrolitic graphite (SN PG). 4. The apparatus of claim 2, wherein at least one of the first electrode and the second electrode comprises continuously nucleated pyrolitic graphite (CN PG). 5. The apparatus of claim 1, wherein the at least one pyrolitic graphite layer disposed adjacent to an outer surface of a first electrode substrate comprises a first pyolitic graphite layer having a c axis oriented substantially perpendicular to the outer surface of the first electrode substrate. 6. The apparatus of claim 1, wherein the first electrode further comprises a diamond coating between the outer surface of the first electrode substrate and the at least one pyrolitic graphite layer. 7. The apparatus of claim 1, wherein the first electrode substrate comprises graphite. 8. The apparatus of claim 1, wherein the first electrode comprises the first electrode substrate, an adhesion layer and the at least one pyrolitic graphite layer, wherein the at least one pyrolitic graphite layer is adjacent to the adhesion layer. 9. The apparatus of claim 1, wherein the apparatus comprises a lithography system. 10. The apparatus of claim 1, further comprising a plurality of optics operable to interact with extreme ultraviolet radiation from the extreme ultraviolet source. 11. The apparatus of claim 1, further comprising a plurality of optics operable to reflect extreme ultraviolet radiation from the extreme ultraviolet source. 12. The apparatus of claim 1, wherein the extreme ultraviolet source is an electric discharge extreme ultraviolet source. 13. The apparatus of claim 1, wherein the extreme ultraviolet source is a dense plasma focus (DPF) electric discharge extreme ultraviolet source. 14. An electrode comprising:a substrate; a first layer on the substrate having a first thermal expansion coefficient; a second layer on the substrate, the second layer comprising a material having a thermal conductivity of about 3.0 to about 4.0 Watts/centimeter*Kelvin and a sputter yield of about 0.2 atoms/ion at 600 eV Ar, the second layer further having a second thermal expansion coefficient substantially matched to the first thermal expansion coefficient. 15. The electrode of claim 14, wherein the substrate comprises a refractory metal. 16. The electrode of claim 14, wherein the first layer is selected from the group consisting of graphite and diamond. 17. A method of making an electrode, the method comprising:forming a substrate to have a pre-determined shape, the substrate having an outer surface; and depositing pyrolitic graphite on a surface of the substrate so that the c axis of the pyrolitic graphite is generally perpendicular to the outer surface, wherein the substrate and the pyrolitic graphite are included in the electrode. 18. The method of claim 17, wherein the substrate comprises a refractory metal, the first layer comprises a plurality of graphite seeds, and the second layer comprises graphite. 19. The method of claim 17, wherein the substrate comprises graphite. 20. The method of claim 17, wherein the pyrolitic graphite comprises substrate nucleated pyrolitic graphite (SN PG). 21. The method of claim 17, wherein the pyrolitic graphite comprises continuously nucleated pyrolitic graphite (CN PG). 22. The method of claim 17, wherein said depositing comprises chemical vapor deposition. 23. The method of claim 17, wherein the pyrolitic graphite is deposited to a thickness of about 1 millimeter or greater. 24. The method of claim 17, further comprising forming an adhesion layer on the substrate.
	abstract	A pattern writing system includes a plurality of control units configured to use different communication standards; a pattern writing unit configured to be controlled by the plurality of control units and write a pattern on a target object by using a charged particle beam; a storage unit configured to receive parameter information from an external slave computer and stores the parameter information; a first interface information circuit group configured to output a received parameter information to at least one of the plurality of control units in conformity with a communication standard on the at least one of plurality of control units; a main computer; and a second interface circuit group configured to receive a request from the main computer, input parameter information been setting in the plurality of control units without passing through the storage unit, convert communication standards of the parameter information input into a communication standard used by the main computer, and output the parameter information whose each communication standard is converted to the main computer.
	description	This application claims the benefit of U.S. Provisional Application No. 60/478,460, filed Jun. 13, 2003, the entire contents of which are incorporated herein by reference. The present invention relates generally to an x-ray optical system for conditioning an x-ray beam. More particularly, the present invention relates to a optical system for reflecting an x-ray beam in two directions. There are a number of x-ray applications that require the use of a two dimensional conditioned x-ray beam. For example, medical radiotherapy systems utilize x-ray beams to destroy cancerous tissue, x-ray diffraction or microdiffraction analysis systems channel x-ray radiation at a sample crystal generating a diffraction pattern indicative of a lattice structure, and x-ray fluorescence and spectroscopy systems employ directed and conditioned x-ray beams. A Kirkpatrick-Baez optical configuration has been proposed to reflect an x-ray beam in two directions independently. In the Kirkpatrick-Baez configuration, at least two optical elements are oriented sequentially so that their meridian axes are perpendicular. Using two parabolic optical elements, a Kirkpatrick-Baez system is capable of capturing radiation from a point source and collimating it into a parallel beam. Equipped with ellipsoidal optics, a Kirkpatrick-Baez system reflects a perfect point image with a point source at its focal point. More recent developments in the fabrication of multilayer reflective optics have led to further developments in the Kirkpatrick-Baez-type optical systems. For example, a modified Kirkpatrick-Baez system, including the use of sequentially ordered multilayer optics, have been proposed for of inertial confinement fusion. Although the use of multilayer mirrors in a Kirkpatrick-Baez configuration provides increased efficiency, this type of system is not optimal because mirrors positioned at different distances from the source have different capture angles (i.e., a mirror positioned further from the source has lower efficiency), and, additionally, the beam convergence and image size are different in two planes, resulting in a phenomenon known as anamorphotism. To improve efficiency and combat anamorphotism, a proposed confocal optical system employs a pair of multilayer mirrors assembled in a side-by-side configuration. The side-by-side Kirkpatrick-Baez multilayer optic is optimal for applications demanding a beam with low convergence. However, there are other applications which tolerate a higher beam convergence or in which convergence is not limited at all. Examples of such applications include micro x-ray fluorescence analysis (MXRF) and medical radiotherapy systems utilizing a convergence x-ray beam to destroy cancerous tissue. These applications demand a high flux, but a multilayer optic has limited capabilities to provide a high capture angle because of its relatively large d-spacing. Crystals are also capable of reflecting x-rays. Their natural periodic structure, as well as that of multilayer structures, diffracts x-ray according to Bragg's equationnλ=2d sin θ, (1)where n is the integral number describing the order of reflection, λ is the wavelength of x-rays, and d is the spatial periodicity of the lattice structure of the diffractive element. A so-called Johansson crystal provides precise focusing in the diffraction plane similar to an elliptically graded d-spacing multilayer. It is noteworthy that crystals have much smaller d-spacing than multilayers. This allows freedom of design on their base x-ray optical elements with a high capture angle. For example, a Johansson crystal may have a theoretical capture angle up to 4θ. However, crystals have several drawbacks that have heretofore limited their application in certain x-ray related fields. The narrow rocking curve (that is, the angular range over which an element can reflect a parallel beam) of a perfect crystal limits the flux the crystal can utilize from a finite size focal spot. Mosaic crystals have a modest reflectivity and a large penetration depth, which is not favorable in applications requiring sharp focusing. Both types of crystals have a limited acceptance in the axial plane (plane perpendicular to the diffraction plane), and this acceptance drops significantly when an x-ray is not parallel to the diffraction plane. This last feature makes optical systems with two diffractive elements with small d-spacing and narrow rocking curve ineffective. These limiting factors have heretofore rendered optics having crystal combinations ineffective in particular x-ray applications. From the above, it is seen that there exists a need for an improved x-ray optical system for conditioning an x-ray beam using crystals. The present invention provides an x-ray beam conditioning system with a Kirkpatrick-Baez (i.e., confocal) diffractive optic including two optical elements, of which at least one of the optical elements is a crystal. The elements are arranged in a side-by-side configuration. The crystal can be a perfect crystal. One or both diffractive elements can be mosaic crystals. One element can be a multilayer optic. For example, the multilayer optic can be an elliptical mirror or a parabolic mirror with graded d-spacing. The graded d-spacing can be either lateral grading or depth grading, or both. Among other advantages, certain implementations of the x-ray optical system may combine a multilayer x-ray optic with a crystal in an orthogonal, confocal arrangement optimized for high-flux operations. Other features and advantages will be apparent from the following description and claims. An analysis of the efficiency of various diffractive x-ray optical elements provides a basis for the understanding of the present invention. For simplicity, consider a single diffractive element with a cylindrical reflecting surface and with a capability to focus x-rays from a point source to the point image in the diffraction plane. Examples of such diffractive elements are Johansson crystals and elliptical multilayers with a proper grading of d-spacing. The capability of these optical elements to accept and redirect x-rays from a monochromatic x-ray source can be described as:ε=f·α·β·R, (2)where f is a factor describing from which portion of the source size a diffractive element can use radiation, α and β are the acceptance angles in the diffraction and axial planes, respectively, and R is the element reflectivity. The efficiency of the source focal spot usage f can be calculated as a convolution of a source spatial intensity distribution and a diffractive element angular acceptance. But in two extreme cases f can be presented as simple analytical expressions. If the angular size of the source γ as seen from the diffractive element is much larger than an angular acceptance δθ, then f can be calculated as: f = δ ⁢ ⁢ θ γ . ( 3 ) However, when the diffractive element angular acceptance δθ is much larger than an angular size of the source γ, f is equal to 1. An angular acceptance of a diffractive element is identical to its rocking curve. The angular size of the source is: γ = F L , ( 4 ) where F is the effective width of the source in the diffraction plane and L is the distance from the source to a diffractive element. The angular acceptance in the diffraction plane a is defined by the diffractive element length l and Bragg's angle θ, namely: α = ( l · sin ⁢ ⁢ θ ) L . ( 5 ) Equation (5) is a suitable expression for both Johansson crystals and elliptical multilayers. Each diffractive element has a limited acceptance in the axial plane as well, which is caused by the change of the incident angle when a ray propagates out of the diffraction plane. A single element optical system 10 shown in FIG. 1 includes a source 12 that emanates x-rays 13 towards an optical element 16, such as, for example, a Johansson crystal, a Johann crystal, or a logarithm spiral crystal. The optical element 16 diffracts the x-rays 13 to a focus 14. The source 12 and the focus 14 are located on a focusing circle 20. A strip 18 on the optical element 16 defines an area within which the incident angle changes less than the half of the optical element rocking curve. The areas below and above this strip 18 do not reflect the beam effectively because a change of the incident angle is too large compared to the rocking curve. This angular acceptance of a diffractive element in the axial plane β can be described as β = ( δθ tan ⁢ ⁢ θ ) 1 2 . ( 6 ) Some other conditions, for instance, an aperture or an angular source distribution may limit the radiation usage in the axial plane. In such cases, β is the smallest of the limitations. The calculated efficiencies of various optical configurations and optical elements for both large and small focal spot of the sources (see, e.g., expressions 3 and 4) are shown below in Table 1. The configurations include a single optical element, a pair of similar optical elements in a side-by-side, confocal configuration (that is, a Kirkpatrick-Baez configuration), and a hybrid pair of optical elements including a multilayer and a crystal element in a side-by-side, confocal configuration. The representative optical elements are a germanium Ge111 crystal, a multilayer with center d-spacing of 20 Angstroms, a lithium fluoride LiF200 crystal, and a pyrolitic graphite C0002 crystal as a single diffractive element. As indicated, pyrolitic graphite provides superior efficiency for both large and small sources, and the multilayer efficiency exceeds the efficiency of the Ge and LiF crystals when the source is large. TABLE 1EFFICIENCY OF OPTICAL CONFIGURATIONSOpticalLithiumPyroliticConfigurationGermaniumMultilayerFluorideGraphiteLarge SourceSingle Element1.3E−051.2E−043.5E−056.2E−03Standard1.8E−138.1E−095.4E−122.9E−05Confocal OpticHybrid2.0E−081.1E−076.8E−06Confocal OpticSmall SourceSingle Element4.8E−034.2E−033.6E−032.1E−02Standard1.4E−065.3E−043.2E−061.9E−02Confocal OpticHybrid6.9E−041.1E−032.2E−−03Confocal Optic To calculate the efficiency of the confocal optical configuration, a capture angle in the diffraction plane for one element is considered the angle of axial acceptance for the second element. However, equation (6) for the angle of axial acceptance is not correct for the confocal arrangement, since it assumes that deviations not in the diffraction plane occur symmetrically in both directions, which is not the case in the confocal arrangement. FIG. 2 is a diagrammatic view of a confocal (or Kirkpatrick-Baez) optical configuration 40 with a first optical element 42 and a second optical element 44 aligned in a side-by-side, orthogonal manner. The first optical element 42 defines a focusing circle 46 and the second optical element 44 defines a focusing ellipse 48. The first and second optical elements 42, 44 are aligned such that the focusing circle 46 intersects the focal points of the focusing ellipse 48 twice, once at the source 50 and once at the image position 52. In one embodiment, the first optical element 42 is a crystal and the second optical element 44 is a multilayer optic. Referring again to FIG. 2, the crystal working surface 54 is vertical and the multilayer working surface 56 is horizontal and positioned below the focusing circle 46. As shown, the crystal Bragg's angle θc defines the axial component of the incident angle of an x-ray from the focus to the mirror surface and vice versa. The cylindrical working surfaces of two optical elements cross, constructing the working corner of the optic, that is, the two strips 58 and 60 shown on the crystal working surface 54 and the multilayer working surface 56, respectively. Note that the axial components for both optical elements are not symmetric with respect to their corresponding diffraction planes. To find the axial acceptance of a diffractive element in these conditions, expression (6) is re-written as: β = ( 2 ⁢ Δθ tan ⁢ ⁢ θ ) 1 2 ( 7 ) or ⁢ ⁢ as ⁢ : Δ ⁢ ⁢ θ = β 2 ⁢ tan ⁢ ⁢ θ 2 . ( 8 ) In equations (7) and (8), β is an angle between the ray and diffraction plane of an element and Δθ is the corresponding deviation of the incident angle from Bragg's angle. To determine the strength of the incident angle change d(Δθ) caused by a small variation of axial angle dβ, equation (8) is differentiated, yielding:d(Δθ)=β·tan θ·dβ. (9) If d(Δθ)=δθ is an element angular acceptance in its diffraction plane, than its axial acceptance at an average axial angle β is: d ⁢ ⁢ β = δ ⁢ ⁢ θ β ⁢ ⁢ tan ⁢ ⁢ θ . ( 10 ) In a confocal optic arrangement the crystal axial angle βc is defined through the mirror Bragg's angle θm as:βc=arc tan(tan θm·cos θc), and (11)βm=arc tan(tan θc·cos θm), (12)where θm and θc are Bragg's angles of the mirror and crystal, respectively. Since the confocal optic acceptance angle in a vertical plane is defined by the mirror capture angle and the crystal axial acceptance angle, the smaller of these two angles is employed for the efficiency calculations. The efficiency of a confocal optic based on similar or different elements in two diffraction perpendicular planes can be calculated on the basis of the above equations. The results of such calculations are also presented in Table 1. Again, it is seen that graphite provides the highest efficiency. However, a nontrivial result of these calculations is that the hybrid optic including a multilayer and either a perfect crystal (Ge) or a mosaic crystal (LiF) provides higher efficiency than a pure confocal optic having two similar components in two planes. For instance, with a large source, a Ge confocal optic has an efficiency of 1.8E-13, compared to an efficiency of 8.1E-9 for a multilayer optic. However, a hybrid optic with a multilayer in one plane and Ge in another plane provides an efficiency of 2.0E-8. This latter configuration is of a special interest because optics based on a multilayer and a Ge crystal can provide precise focusing and high efficiency. The following, among others, are examples of combinations of diffractive elements that provide a high efficiency in the confocal arrangement: two mosaic crystals with a low d-spacing and high mosaicity; a multilayer mirror and a mosaic or a perfect crystal with a low d-spacing; and a mosaic crystal with a high d-spacing with a mosaic or a perfect crystal with low d-spacing. The definitions of low/high d-spacing and low/high mosaicity depend on the particular requirements of the collimated beam. For example, d-spacing above about 10 Angstroms and mosaicity more than about 5 to 10 arcminutes many be considered high d-spacing and high mosaicity, respectively. A confocal optic including a Johansson crystal and an elliptical multilayer mirror with laterally graded d-spacing and depth grading is one preferred configuration. This type of optic is an effective diffractive component to form a convergent focusing beam. One particularly effective implementation of hybrid confocal multilayer/crystal optic is when a highly convergence beam in one plane is desired, for example, for high convergence beam reflectometry. A parabolic multilayer mirror with laterally graded d-spacing and depth grading is an optimal diffractive element to form a parallel beam. A highly asymmetric Johansson crystal may be used to form a quasi parallel beam when the requirements of beam divergence in one plane are stricter than in the other plane. Again, various embodiments of the present invention can utilize many other diffractive optical components to form a quasi parallel beam. The lengths and center positions of two diffractive elements may coincide, or they may be different. Thus, some areas of two diffractive elements are overlapped, creating a side-by-side, confocal optic, in accordance with an embodiment of the present invention. The hybrid confocal optic of the present invention may include two, four or multiple working corners, as described in U.S. Pat. No. 6,014,423, the contents of which is incorporated herein by reference in its entirety. Finally, certain implementations of the x-ray optical system of the present invention may include entrance and exit apertures to clean the x-ray beam and to simplify x-ray shielding. It should be apparent to those skilled in the art that the above-described embodiment is merely illustrative of but a few of the many possible specific embodiments of the present invention. Numerous and various other arrangements can be readily devised by those skilled in the art without departing from the spirit and scope of the invention as defined in the following claims.
043615341	abstract	Neutron activation is used to analyse the silicon and aluminium content of samples of material, such as bauxite ore and coal. The analysis can be performed on bulk samples, on material on a moving conveyor belt, or on the walls of a borehole. The method involves high energy neutron irradiation of the sample, measurement of the thermal neutron flux in the sample, and monitoring the gamma radiation from the sample at energies of (a) 1.78 MeV and (b) 0.844 MeV and/or 1.015 MeV. Such gamma radiation is produced on decay of (a) .sup.28 Al and (b) .sup.27 Mg isotopes, produced by the reactions .sup.28 Si(n,p).sup.28 Al and .sup.27 Al(n,p).sup.27 Mg. A single gamma ray detector is used. The analysis preferably utilizes equations which include terms to compensate for (a) the production of radiation at 1.78 MeV as a result of the production of the isotope .sup.28 Al from .sup.27 Al by the thermal neutron reaction .sup.27 Al(n,.gamma.).sup.28 Al, and (b) the Compton scattering of 1.78 MeV gamma radiation and background.
	claims	1. A system for inspecting a structure, comprising:an interface board;at least one pulser board communicably coupled to said interface board;a plurality of transmit channels communicably coupled to said pulser board;at least one receiver board communicably coupled to said interface board;a plurality of inspection data receive channels communicably coupled to said receiver board, wherein said receiver board is comprising a logarithmic amplifier for processing inspection data signals from said plurality of inspection data receive channels and providing logarithmic amplification to each channel for at least 70 dB of dynamic range. 2. The system of claim 1, wherein said receiver board further comprises a mulitplexer for providing 70 dB of isolation between inspection data receive channels, and wherein said receiver board is capable of processing data from said plurality of inspection data receive channels with 70 dB of isolation provided by said multiplexer and with logarithmic amplification of 70 dB of dynamic range provided by said logarithmic amplifier. 3. The system of claim 1, wherein said multiplexer is a series of multiplexing chips and wherein said 70 dB of isolation is provided by a 60 dB multiplexing chip serially coupled to a 10 dB multiplexing chip of said multiplexer. 4. The system of claim 3, wherein said multiplexing chips are capable of switching between said inspection data receive channels. 5. The system of claim 3, wherein said logarithmic amplifier is capable of logarithmic amplification of −67 dB to +3 dB of dynamic range. 6. The system of claim 3, wherein said multiplexing chips are capable of switching between said receive channels. 7. The system of claim 3, wherein said logarithmic amplifier is capable of logarithmic amplification of −67 dB to +3 dB of dynamic range. 8. The system of claim 1, wherein said receiver board comprises:a plurality of tuned filters, one of said tuned filters communicably coupled to each of said inspection data receive channels;a multiplexer serially coupled to said plurality of tuned filters;a logarithmic amplifier serially coupled to said multiplexer;a linear amplifier serially coupled to said logarithmic amplifier; andan analog-to-digital converter serially coupled to said linear amplifier. 9. The system of claim 8, further comprising an envelope peak detector, serially coupled between said linear amplifier and said analog-to-digital converter, for capturing the voltage peaks of the signal that has been multiplexed, logarithmically amplified, and linearly amplified. 10. The system of claim 9, further comprising a diode, serially coupled between said linear amplifier and said envelope peak detector, for isolating positive voltage from the signal that has been multiplexed, logarithmically amplified, and linearly amplified. 11. The system of claim 10, wherein said 10 dB multiplexing chips are capable of switching up to eight inspection data receive channels. 12. The system of claim 8, wherein said multiplexer comprises a series of multiplexing chips, wherein said 70 dB of isolation between inspection data receive channels is provided by a 60 dB multiplexing chip serially coupled to at least one 10 dB multiplexing chip of said multiplexer, and wherein said multiplexer is capable of switching between said plurality of inspection data receive channels. 13. The system of claim 1, wherein said interface board is capable of transmitting digitized data from said receiver board though a communication channel. 14. The system of claim 13, wherein said communication channel comprises an Ethernet communication channel. 15. The system of claim 13, wherein said communication channel is capable of transmitting scan data at a 12-bit resolution. 16. The system of claim 13, wherein said interface board is further capable of transmitting digitized data form said receiver board through said communication channel in real time. 17. The system of claim 1, wherein said interface board is capable of receiving data provided by encoders. 18. The system of claim 17, further comprising an encoder interface communicably coupled to said interface board for receiving data from said encoders and providing said data to said interface board. 19. The system of claim 18, wherein said encoder interface comprises at least one counter chip communicably coupled to said interface board and said encoders. 20. The system of claim 18, wherein said encoder interface is capable of receiving data selected from the group consisting of position data, speed data, velocity data, and distance data. 21. The system of claim 1, wherein said receiver board comprises a logarithmic amplifier serially coupled to a linear amplifier. 22. The system of claim 21, wherein said logarithmic amplifier is capable of −67 dB to +3 dB of logarithmic amplification. 23. The system of claim 21, wherein said linear amplifier is capable of providing 20 dB of linear amplification. 24. The system of claim 1, comprising:two pulser boards, each coupled to 16 transmit channels; andtwo receiver boards, each coupled to 16 inspection data receive channels. 25. The system of claim 24, wherein each pulser board is a printed circuit board and comprises 16 pulsers communicably coupled to said 16 transmit channels. 26. The system of claim 1, wherein both said receiver board and said interface board are capable of processing inspection data signals from said plurality of inspection data receive channels at a resolution of 12 bits. 27. The system of claim 1, wherein said interface board and said pulser board are capable of communicating data to said transmit channels at a cycling rate of 200 microseconds (μs) per transmit channel, said receiver board is further capable of receiving and processing data from said inspection data receive channels at a cycling rate of 200 microseconds (μs) per receive channel, and said interface board is further capable of communicating data from said receiver board at a cycling rate of 200 microseconds (μs) per inspection data receive channel. 28. The system of claim 1, wherein said receiver board comprises a tuned filter communicably coupled to each of said inspection data receive channels and capable of processing data at a 5 MHz inspection frequency. 29. A 32 channel multiplexing system for inspecting a structure, comprising:thirty-two transmit transducers;thirty-two receive transducers capable of receiving signals emitted by said transmit transducers following propagation of said emitted signals through the structure;thirty-two receive channels coupled to said receive transducers;a multiplexing system coupled to said thirty-two inspection data receive channels and comprising a logarithmic amplifier for processing data from said thirty-two receive transducers transmitted through said thirty-two inspection data receive channels and providing logarithmic amplification to each channel with at least 70 dB of dynamic range. 30. The system of claim 29, wherein said multiplexing system is further adapted to switch between said inspection data receive channels. 31. The system of claim 30, wherein said linear amplification has a 20 dB gain. 32. The system of claim 30, wherein said multiplexing system is further capable of converting from analog to digital said data that has been previously processed with logarithmic amplification and linear amplification. 33. The system of claim 29, wherein said transmit transducers comprise a pulsing sensor and said receive transducers comprise a receiving sensor communicably coupled to a corresponding pulsing sensor, and wherein each pulsing sensor is coupled to a transmit channel and each receiving sensor is coupled to an inspection data receive channel. 34. The system of claim 29, further comprising an interface for remote communication to an analysis computer. 35. The system of claim 29, wherein said multiplexing system is further adapted to filter said data received from said inspection data receive channels before switching and logarithmically amplifying said data. 36. The system of claim 29, wherein said multiplexing system is further capable of linearly amplifying said data that has been previously processed with logarithmic amplification of at least 70 dB of dynamic range. 37. The system of 29, wherein said multiplexing system is further capable of processing data from said thirty-two inspection data receive channels at a cycling rate of 5 kHz to process data from each of said receive channels once every 6.4 milliseconds (ms). 38. The system of claim 29, wherein said multiplexing system is further adapted to convert said data from an analog signal to a digital signal. 39. A method for multiplexing channels of an inspection system comprising repeating the steps of:receiving signals from a plurality of inspection data receive channels; andmultiplexing said received signals, wherein said multiplexing comprises:filtering said received signals;switching between said plurality of inspection data receive channels to select one inspection data receive channel and define a switched received signal;logarithmically amplifying said switched received signal;linearly amplifying said switched, logarithmically amplified received signal; andconverting said switched, logarithmically amplified, linearly amplified received signal from analog to digital;correlating the multiplexed signals to a physical structure of a part under inspection; andpresenting the correlated information on a display for review by a user. 40. The method of claim 37, further comprising the step of transmitting signals to a plurality of transmit channels. 41. The method of claim 40, further comprising the steps of:controlling timing requirements for said step of transmitting signals to a plurality of transmit channels; andtransmitting said multiplexed signals in real time to a remote processor. 42. The method of claim 41, wherein said step of transmitting said mulitpelxed signals in real time to a remote processor comprises the step of transmitting said multiplexed signals from said inspection data receive channels at a cycling rate of 200 microseconds (μs) per inspection data receive channel, and wherein said multiplexed signals are represented by 12 bit signals. 43. The method of claim 40, wherein the step of transmitting signals to a plurality of transmit channels comprises the step of communicating data to said transmit channels at a cycling rate of 200 microseconds (μs) per transmit channel. 44. The method of claim 39, further comprising the step of capturing peak voltage of said switched, logarithmically amplified, and linearly amplified received signal. 45. The method of claim 44, further comprising the step of isolating positive voltage from said switched, logarithmically amplified, and linearly amplified received signal prior to the step of capturing peak voltage. 46. The method of claim 39, wherein the step of logarithmically amplifying said switched received signal comprises providing logarithmic amplification for at least a 70 dB of dynamic range. 47. The method of claim 46, wherein the step of providing logarithmic amplification for at least 70 dB of dynamic range comprises providing amplification from −67 dB to +3 dB. 48. The method of claim 39, further comprising the step of processing said multiplexed signals from said inspection data receive channels at a cycling rate of 200 microseconds (μs) per inspection data receive channel. 49. A system for inspecting a structure, comprising:an interface board;at least one pulser board communicably coupled to said interface board;a plurality of transmit channels communicably coupled to said pulser board;at least one receiver board communicably coupled to said interface board; anda plurality of receive channels communicably coupled to said receiver board, wherein said receiver board is comprising a logarithmic amplifier for processing signals from said plurality of receive channels and providing logarithmic amplification to each channel for at least 70 dB of dynamic range,wherein said receiver board further comprises a mulitplexer for providing 70 dB of isolation between inspection data receive channels, and wherein said receiver board is capable of processing data from said plurality of inspection data receive channels with 70 dB of isolation provided by said multiplexer and with logarithmic amplification of 70 dB of dynamic range provided by said logarithmic amplifier, andwherein said multiplexer is a series of multiplexing chips and wherein said 70 dB of isolation is provided by a 60 dB multiplexing chip serially coupled to a 10 dB multiplexing chip of said multiplexer.
	abstract	A radiation window membrane and for covering an opening in an X-ray device is presented, as well a method for its manufacturing. Said openings are such through which X-rays are to pass. The membrane comprises a window base layer and a pinhole-blocking layer on a surface of said window base layer. Said pinhole-blocking layer comprises graphene.
	summary
051397099	abstract	ADU (ammonium diuranate) is prepared in particle form directly by reacting ammonium gas with liquid droplets of atomized uranyl compound solutions. Generation of liquid filtrate is prevented by using concentrated solutions of uranyl compounds as feed solutions, or drying the wet ADU particles formed before their settlement when a feed of low concentration is used. The ADU particle thus prepared is finely divided and easy-handling. No filtration operation is necessary in the preparation. The UO.sub.2 powder consequently obtained after calcining and reduction has consistent quality from batch to batch and has good pelletizing and sintering properties. Uranium dioxide with low fluorine content can be prepared from uranyl fluoride solution. Gadolinium-uranium oxide can also be prepared with the present method using an aqueous mixture of gadolinium nitrate and uranyl nitrate as a feed solution.
	claims	1. An extreme ultraviolet light generation device for generating extreme ultraviolet light by irradiating a target with a pulse laser beam and thereby turning the target into plasma, comprising:a chamber;a magnet configured to form a magnetic field in the chamber; andan ion catcher including a collision unit disposed so that ions guided by the magnetic field collide with the collision unit, whereinthe collision unit includes a plurality of collision surfaces disposed to be inclined with respect to the magnetic field. 2. The extreme ultraviolet light generation device according to claim 1, further comprisinga collector mirror configured to reflect extreme ultraviolet light generated in the chamber and thereby concentrate the extreme ultraviolet light, whereinthe plurality of collision surfaces are disposed to be inclined toward an upstream side of the extreme ultraviolet light reflected by the collector mirror. 3. The extreme ultraviolet light generation device according to claim 1, whereinthe ion catcher includes a tubular member having a first end and a second end,the first end has an opening in a direction along the magnetic field,the collision unit is disposed between the first end and the second end, andthe collision unit includes first and second collision units disposed near the first end and the second end, respectively. 4. The extreme ultraviolet light generation device according to claim 1, whereinthe ion catcher includes a tubular member having a first end and a second end,the first end has an opening in a direction along the magnetic field,the collision unit is disposed between the first end and the second end, andthe ion catcher is configured to satisfy a relationship L/φ>3.55, where L is the length of the tubular member from the first end to the second end and φ is the maximum diameter of the opening of the tubular member. 5. The extreme ultraviolet light generation device according to claim 1, whereinthe ion catcher includes a tubular member having a first end and a second end,the first end has an opening in a direction along the magnetic field,the collision unit is disposed between the first end and the second end, andthe tubular member has a polygonally-columnar shape. 6. The extreme ultraviolet light generation device according to claim 1, whereinthe ion catcher includes a tubular member having a first end and a second end,the first end has an opening in a direction along the magnetic field,the collision unit is disposed between the first end and the second end,the magnet is an electromagnet including a coil, andat least a part of the tubular member is disposed in a bore of the coil. 7. The extreme ultraviolet light generation device according to claim 1, whereinthe ion catcher includes a tubular member having a first end and a second end,the first end has an opening in a direction along the magnetic field,the collision unit is disposed between the first end and the second end, andat least a part of the tubular member is disposed to project outside from the chamber. 8. An extreme ultraviolet light generation device for generating extreme ultraviolet light by irradiating a target with a pulse laser beam and thereby turning the target into plasma, comprising:a chamber;a magnet configured to form a magnetic field in the chamber; andan ion catcher including a collision unit disposed so that ions guided by the magnetic field collide with the collision unit; andan exhaust pump, whereinthe ion catcher includes a tubular member having a first end and a second end,the first end has an opening in a direction along the magnetic field,the collision unit is disposed between the first end and the second end, andthe exhaust pump is connected between the first end and the second end to exhaust gas out of the tubular member. 9. The extreme ultraviolet light generation device according to claim 8, wherein the collision unit includes conical or polygonally-pyramidal surfaces. 10. The extreme ultraviolet light generation device according to claim 8, whereinthe collision unit includes first and second collision units disposed near the first end and the second end, respectively. 11. The extreme ultraviolet light generation device according to claim 8, whereinthe ion catcher is configured to satisfy a relationship L/φ>3.55, where L is the length of the tubular member from the first end to the second end and φ is the maximum diameter of the opening of the tubular member. 12. The extreme ultraviolet light generation device according to claim 8, whereinthe tubular member has a polygonally-columnar shape. 13. The extreme ultraviolet light generation device according to claim 8, whereinthe magnet is an electromagnet including a coil, andat least a part of the tubular member is disposed in a bore of the coil. 14. The extreme ultraviolet light generation device according to claim 8, whereinat least a part of the tubular member is disposed to project outside from the chamber. 15. An extreme ultraviolet light generation device for generating extreme ultraviolet light by irradiating a target with a pulse laser beam and thereby turning the target into plasma, comprising:a chamber;a magnet configured to form a magnetic field in the chamber; andan ion catcher including a collision unit disposed so that ions guided by the magnetic field collide with the collision unit, whereinthe ion catcher includes a tubular member having a first end and a second end,the first end has an opening in a direction along the magnetic field,the collision unit is disposed between the first end and the second end, andthe tubular member has a tapered shape. 16. The extreme ultraviolet light generation device according to claim 15, whereinthe collision unit includes first and second collision units disposed near the first end and the second end, respectively. 17. The extreme ultraviolet light generation device according to claim 15, whereinthe ion catcher is configured to satisfy a relationship L/φ>3.55, where L is the length of the tubular member from the first end to the second end and φ is the maximum diameter of the opening of the tubular member. 18. The extreme ultraviolet light generation device according to claim 15, wherein the collision unit includes conical or polygonally-pyramidal surfaces. 19. The extreme ultraviolet light generation device according to claim 15, whereinthe magnet is an electromagnet including a coil, andat least a part of the tubular member is disposed in a bore of the coil. 20. The extreme ultraviolet light generation device according to claim 15, whereinat least a part of the tubular member is disposed to project outside from the chamber.
	claims	1. An inspection method in which electron beam is irradiated to a sample to be inspected and image signals obtained by detecting secondary electrons generated by the irradiation are processed, thereby performing an inspection of the sample to be inspected,wherein electrons emitted from an electron source are accelerated to an acceleration voltage,a deceleration voltage is applied to the sample to be inspected to adjust an incident energy of the electron beam, and a control voltage is applied to a control electrode disposed just above the sample, thereby forming an arbitrary field on the sample to be inspected, andthe acceleration voltage, the deceleration voltage, and the control voltage are controlled in conjunction so that the energy which enters the sample, the field formed on the sample, and probe current of the electron beam which enters the sample to be inspected become almost constant. 2. The inspection method according to claim 1,wherein, while the energy which enters the sample, the field formed on the sample, and the probe current of the electron beam which enters the sample to be inspected are maintained constant, the acceleration voltage, the deceleration voltage, and the control voltage are controlled in conjunction so that a probe diameter of the electron beam becomes optimal. 3. The inspection method according to claim 1,wherein the incident energy of the electron beam is controlled to a size at which an emission efficiency of secondary electrons becomes 1 or higher and no damage occurs in the sample to be inspected. 4. The inspection method according to claim 3,wherein surface potential of the sample to be inspected is controlled by difference between the control voltage and the deceleration voltage. 5. The inspection method according to claim 1,wherein the sample is a semiconductor device, and defective shapes and electric characteristic defects of patterns formed on the semiconductor device are detected.
	abstract	Systems and methods for operating, particularly in the field, a Raman spectroscopy device that includes a laser, a spectrograph, an intensified charge coupled device (ICCD), and an autofocus subsystem. Before spectral data acquisition commences a series of ancillary data checks is performed to monitor operating conditions of at least the laser, the ICCD, and the autofocus subsystem. Further, after each Raman spectrum acquisition, a series of data quality checks is performed to enhance confidence in the just collected data. Only spectral data that passes the data quality checks are further processed. However, all spectral data are stored in a log file. When the log file reaches a predetermined capacity, the log file is closed, and a new round of ancillary data checks is performed to again monitor the status of the Raman spectroscopy device.
	description	This application is a division of U.S. patent application Ser. No. 11/839,274 filed on Aug. 15, 2007 now U.S. Pat. No. 7,606,680, which is a continuation of U.S. patent application Ser. No. 11/105,560 filed on Apr. 14, 2005, now U.S. Pat. No. 7,403,873, which is a divisional of U.S. patent application Ser. No. 10/620,358 filed on Jul. 17, 2003, now U.S. Pat. No. 6,937,964, which is a divisional of U.S. patent application Ser. No. 09/725,498 filed on Nov. 30, 2000, now U.S. Pat. No. 6,629,060, which claims priority to Japanese Patent Application No. H11-341,085 filed on Nov. 30, 1999, the entire contents of all of which applications are incorporated herein by reference. 1. Field of the Invention The present invention relates to technology for facilitating support of analyzers. 2. Description of the Related Arts Blood tests and other forms of clinical examination require that samples such as blood and urine be analyzed for a variety of test items. Analyzers that employ assaying methods suited to the characteristics of the analysis items perform sample assays. Analyzers have sophisticated mechanisms that allow them to assay, with a high degree of sensitivity, extremely low concentrations of a substance, and to assay trace amounts of the sample for ten or more items. To maintain the accuracy of the test results, operations in each of the mechanisms are monitored. When problems arise in operation of the mechanisms, the analyzer issues a warning to that effect, alerting the user to the problem in the analyzer. In such cases, a user will deal with the problem by following the operating manual or, for example, by calling a support center, explaining the circumstances, and following the instructions of the technician. When the user cannot take care of it single-handedly, the support center dispatches a technician to do so. Nevertheless, in clinical testing, merely monitoring the analyzer mechanisms is insufficient for governing test results on vital components with satisfactory accuracy. Quality control is therefore performed. Samples identical with the vital components, or samples that are their analogues, are assayed as quality control substances, and the assay results are monitored. Both internal and external methods are utilized for quality control. Internal quality control is a method of assaying identical quality control substances on a daily basis with the same analyzer, and monitoring whether stable assay results are being obtained. External quality control is a method of monitoring whether assay results that are being obtained are the same as the results assayed by an identical analyzer employed outside of those facilities. In order to carry out external quality control, however, the same quality control substance has to be sent from a statistical tallying center to each facility; the quality control substance has to be assayed at each facility; those assay results (“sample data” hereinafter) have to be sent from each facility to the statistics center; and the sample data has to be tallied by the statistics center. This means that the facilities first learn of the external quality control results when the tally is sent back from the statistics center. From the time the quality control substance is sent out until the time the tally is returned routinely takes one to two months. Sometimes it is necessary to wait until the statistics center accumulates a set number of sample data returns. A first issue the invention addresses relates to measures taken when trouble has arisen. Because today's analyzers are operated under the control of sophisticated programs, instances in which users are unable to solve problems by themselves are increasing. In such cases, users have to wait until a technician visits to deal with the problem. The only option is to wait for the technician's visit if a systematic problem can only be resolved by changing out or adjusting an analyzer component. Nevertheless, these are not the only reasons users are unable to repair breakdowns without the assistance of a technician. There appear to be many cases in which users ought to be able to resolve the trouble on their own. In some instances, the trouble in the analyzer is not resolved because the user cannot adequately explain the status of the problem; in others, the user cannot properly carry out the analyzer operations necessary to resolve the trouble. Because assay is not possible while an analyzer is down, patient test results in clinical examination cannot be reported to the diagnosing physician. For samples like blood, which has low preservation stability, delaying the assay by one day would mean lower accuracy in the test results, and therefore blood has to be drawn from the patient again. A second issue the invention addresses is that, with external quality control, as described above, confirmation can be obtained only by waiting for the tally from the statistics center. This normally is done once a year, and at most on the order of only three or four times a year. To raise the reliability of assay data per se, quality control by definition should be carried out and the results checked before each day's sample assays. In other words, if the quality control sample data falls outside a predetermined range, this can mean that something has gone wrong and that the analyzer is not in sufficient working order. Sample assay should be carried out following adjustment of the analyzer to bring the data within the predetermined range. With current external quality control, however, the tally results come back one or two months after assay, and are only used for confirming after-the-fact the status of the device at the time the assay was made. Wherein a substance such as blood that is liable to transform (denature) over time is the assay subject, the freshness of the quality control substance employed in the sample data assay must be at the same level among each of the facilities taking part in external quality control. When quality control substances are sent out to facilities to collect sample data, inevitably the assaying tends to be performed on different days at different facilities. Accordingly, because the freshness of the quality control substances that are the basis for the sample data collected tends to vary, the reliability of the tally results is diminished. It is an object of the present invention to enable rapid, exact resolution of analyzer problems and effective external quality control. To address the foregoing first issue, an aspect of the present invention presents a support method employed in an information terminal connected to analyzers via a network, the support method comprising: collecting from the analyzers via the network predetermined log information indicating the operational history of the analyzers; storing the collected log information for each analyzer; and outputting the collected log information in response to instructions by the operator of the information terminal. Communication between the information terminal and the analyzers is performed through a dedicated telephone line (in Japan, for example, an NTT line), the Internet, or the like. The operational history of each analyzer can be seen by support personnel at, for example, a support center, and this can prevent analyzers from being down and can facilitate repair work. Collecting log information by SMTP (Simple Mail Transfer Protocol) has the advantage of allowing for easy expansion of the system over a network, since SMTP is usually not subject to the restrictions of firewalls and the like. In this information-terminal employed support method, it is preferable to operate the analyzer from the information terminal via a network. Support personnel can operate the analyzer while looking at the analyzer operational history stored on the information terminal. When an analyzer is down, remote support personnel can quickly resolve the trouble without having to travel to the actual site, leading to a significant reduction in down time. Furthermore, good use can be made of a user support method wherein error determination parameters are prepared in advance; predetermined error information is extracted from the log information; error histories are created by consulting (looking up) the error determination parameters; and error histories and the analyzer are correlatively stored. For example, error level is determined based upon how many times the same occurrence occurred in one day. Along with error type, error message, date and time, and other error log information, error levels are correlated with analyzers and used in forecasting and solving trouble. Further to address the first issue noted above, another aspect of the present invention presents a support method employed in an analyzer connected to a predetermined information terminal via a network, wherein predetermined log information showing the operational history of the analyzer is transmitted at a predetermined timing to the information terminal via the network. For example, during the shutdown process for an analyzer, the operational history for that day is sent to the information terminal. The predetermined information terminal performs the same function as the information terminal in the first aspect of the invention mentioned above. In the above support method used in an analyzer, it is preferable to accept operations from a dedicated information terminal via the network. Accepting control operations from an information terminal even when the information terminal is in a distant support center allows for the fast resolution of problems. To address the foregoing second issue, another aspect of the present invention presents a quality control method employed in an information terminal connected to analyzers via a network, wherein: A: sample data on assays made by the analyzers on predetermined quality control substances is received via a network; B: the received sample data is stored; C: the stored sample data is tallied for each analyzer and each quality control substance; and D: the tally results for the received sample data are provided to the analyzers within a predetermined timeframe. Communication between the information terminal and the analyzers is performed through a dedicated NTT line, the Internet, or the like. The analyzers perform a daily assay of quality control substances, such as control blood, and transmit the assay data to the information terminal. The information terminal stores the assay data sent from analyzers and tallies the stored assay data for each analyzer and each quality control substance. Each time the information terminal receives sample data from an analyzer it performs a new tally (statistical calculation). In order that the tally results be on parameters in which the freshness of the quality control substances is alike, the statistical calculations (tallying) may be on sample data assayed within a predetermined timeframe, for example, within twenty-four hours of being received. When an analyzer requests tally results, the latest tally results at that point are provided in real time. In the present invention, communications by SMTP, which are unlikely to be subject to the restrictions of firewalls, are preferable. To address the foregoing second issue, another aspect of the present invention presents a quality control method employed in analyzers connected to a dedicated information terminal via a network, wherein: A: sample data on assays made by the analyzers on predetermined quality control substances is transmitted to the information terminal via the network; B: tally results on the sample data are requested of the information terminal; C: the tally results on sample data the information terminal has collected from the analyzers within a predetermined timeframe are acquired from the information terminal; and D: the tally results are output. Utilizing this method, the results from the information terminal in the above information-terminal which employed quality control method are tallied and output to an analyzer display, printer, or other output device. A user consults the output results to make an analyzer quality control check on his or her own. Another aspect of the present invention also presents a computer-readable storage medium on which a program for executing the foregoing support method employed in an information terminal or analyzer is recorded. Conceivable recording media include floppy disks, hard drives, semiconductor memory, CD-ROMS, DVDs, and MO disks. Another aspect of the present invention also presents a control device connected to analyzers via a network, comprising: reception means for receiving from the analyzers via the network predetermined log information indicating the operational history of the analyzers; storage means for storing log information for each analyzer; and output means for outputting log information in response to instruction by an operator. This has the same operational effect as the aforementioned support method used in an information terminal. Another aspect of the present invention presents an analyzer connected to a dedicated information terminal via a network, comprising transmission means for transmitting predetermined log information showing operational history of the analyzer at a predetermined timing to the information terminal via the network. This has the same operational effect as the aforementioned support method used in an analyzer. Another aspect of the present invention also presents a control device connected to analyzers via a network, comprising: reception means for receiving via the network sample data on assays made by the analyzers on predetermined quality control substances; storage means for storing received sample data; statistical tallying means for tallying the stored sample data for each analyzer and each quality control substance; and provision means for providing the tally results for the received sample data to the analyzers within a predetermined timeframe. This has the same operational effect as the aforementioned support method used in an information terminal. Another aspect of the present invention also presents an analyzer connected to a dedicated information terminal via a network, comprising: transmission means for transmitting to the information terminal via the network sample data on assays made by the analyzers on predetermined quality control substances; request means for requesting of the information terminal tally results on the sample data; acquisition means for acquiring from the information terminal the tally results on sample data the information terminal has collected from the analyzers within a predetermined timeframe; and output means for outputting the acquired tally results. This has the same operational effect as the aforementioned support method used in an analyzer. The support method and quality control method of the present invention will be explained in detail with reference to the figures. This embodiment will be explained using as an example a remote support system that is a realization of the methods of the present invention. This remote support system is constituted by an analyzer owned by a laboratory (i.e., a user) and a control device of the party providing the system, the devices being interconnected by a dedicated network. The analyzer transmits predetermined log information according to a predetermined timing to the control device over the network. Contained in the log information is operational information showing the operational conditions of the analyzer and sample data. The operational information comprises error information, number of times operated, operation program, set-up parameters and the like for each analyzer. The sample data is assay data from a quality control substance. The control device performs a support process by collecting log information from each analyzer, editing the log information for each analyzer according to content, and storing the information, and then performs a quality control (QC) process. A. Support Process The control device edits operational information from collected log information and stores that information. The control device also analyzes error content based on operational information, and if there is a significant error, it displays that error. Because a technician can review at the control device the log information of the analyzer where the error arose, he can sufficiently understand the conditions of the machine without needing a detailed explanation from the user, and can work on finding the cause of the trouble. In addition, the analyzer is provided with the capability to remotely operate the analyzer. Therefore, a technician does not actually have to go to the laboratory, but can work on the analyzer directly from the control device. Furthermore, the control device can analyze error information, predict when an analyzer will have trouble, and take measures to prevent trouble before it occurs. B. QC Process A control device 1 tallies, i.e., makes statistical computations on, sample data from a quality control substance assayed at each analyzer 2 per type of analyzer 2 and per type of quality control substance. Each time the control device 1 receives sample data, it updates the tally results for the same type of sample data at the same type of machines, and provides the latest tally results on a Web page. By accessing this Web page, the analyzer 2 can acquire the latest tally results. When an analyzer attempts to access the Web page, the control device authenticates the authentication information input by the analyzer. In this manner, soon after assaying a quality control substance, a user can confirm in real time the very latest tally results for the quality control substance. Configuration (1) Overall Configuration FIG. 1 is one example of an overall block diagram of a remote support system according to the first embodiment. In the remote support system according to this embodiment, the control device 1 and the analyzers 2 are interconnected over a dedicated network 3. The analyzer 2 is interconnected with the dedicated network 3 via a network communications interface 4. Possible analyzers include hemanalysis and urinalysis devices. Personal computers, workstations and the like can be used as the control device 1. Dial-up routers and modems can be used as the network communications interface 4. One example that could be given of a dedicated network 3 would be a dedicated telephone line that the provider of this system is able to use exclusively, through a contract with the company providing the telephone line. Other types of networks than dedicated networks can be used, such as the Internet and intranets and LANs. (2) Control Device FIG. 2 is a block diagram showing the functions and constitution of the control device and the analyzer. The control device comprises a communications interface 11, a processing unit 12, a user control database 14, an e-mail server 15, a WWW server 16 and a remote control unit (host end) 13. The communications interface 11 establishes a connection with the analyzers. The processing unit 12 performs the support process and QC process, using the user control database 14. The support process displays a predetermined error log at the control device, making it possible to find the cause of the trouble. FIG. 8 through 11 show display examples of the error log output by the processing unit 12. These display examples are shown on the display unit 17. The QC process makes possible real time external quality control at the analyzer. FIGS. 14 and 15 show examples of Web pages for tally results created by the QC process. These examples will be discussed in detail below. The user control database 14 stores at each analyzer error log, the number of times operated, QC data, log information and the like. The e-mail server 15 receives log information and sample data from analyzers through SMTP. The communications protocol is not limited herein to SMTP, but SMTP has the advantage of facilitating future expansion of this system, due to the fact that it is usually not subject to the restrictions of firewalls and the like. The WWW server 16 provides a WWW browser on the analyzer with the Web pages that processing unit 12 has created. The remote control unit (host end) 13, by being linked with the remote control unit (user end) on the analyzer 2, makes possible the remote operation of the analyzer 2. Because the two units are inter-linked, the analyzer can be logged onto remotely, the window displayed at the analyzer is displayed at the remote control unit (host end) 13, and the analyzer can be operated pursuant to the operations input from the remote control unit (host end) 13. (3) Analyzer An analyzer 2 has an analysis unit 21, and a user terminal 22, which has a communications interface 23, an e-mail server 24, a user side remote control unit 25, a WWW browser 26, a patient masking unit 27 and a control unit 28. The analysis unit 21 assays the quality control substances and generates sample data. The communications interface 23, as with the communications interface 11 in the above control device 1, establishes a connection. The e-mail server 24 sends log information showing the operational history of an analysis unit 21 and sample data to the control device using SMTP. The remote control unit (user end) 25, by being inter-linked with the remote control unit (host end) 13, makes possible the operation of the analyzer 2 from the control device 1. The WWW browser 26 acquires Web pages from the control device based on instructions from a user. The patient masking unit 27 ensures that when the analyzer 2 is operated from the control device 1, patient information is not displayed at the control device. The control unit 28 controls the operations of the analysis unit 21 and of the constituent elements of the user terminal 22. Process Flow An explanation will be given of the process performed by the control device and analyzer in a remote support system. (1) Overall System Process Flow An explanation will be made in detail of the process flow of the overall system. FIG. 3 is an explanatory diagram showing an example of the flow of user support in a remote support system. The analyzer 2 performs routine sample assay (#1), and its operational information is transmitted to the control device 1 according to a predetermined timing (#3). The transmission is made in real time if the operational information contains error information or other urgent information. The transmission is made when the analyzer is shutdown if the operational information is not urgent, such as number of times operated and sample assay results. Error information is also displayed at the analyzer 2, and the user discovers that there is trouble at the analyzer 2 (#8). The control device 1 classifies operational information sent from the analyzer 2 according to type and stores this in the user database 14 (#4). When there is major error information in the stored operational information, or when there are other indications that a predetermined major error will occur, such as when there is minor error information, but the error occurs frequently or when error conditions are worsening, the trouble the analyzer is having is detected based on certain settings (#7). When the analyzer 2 assays a quality control substance, unlike routine sample assay results, the sample data is transmitted to the control device 1 in real time (#3). The analyzer 2 reads a barcode affixed to the assay sample container, determines whether that sample is a quality control substance or not, and based on that determination, transmits the sample data. The control device 1 takes the new sample data and updates the tally results (#5). The user, after sample data assay, acquires the tally results that the control device 1 has tallied (#6) and confirms the external accuracy. The control device 1 updates the Web pages in accordance with updates to the tallied data. The analyzer 2 accesses a Web page, and when the access is authorized, the latest tally results and the sample data are provided on the Web page. In this manner, a user can quickly confirm not just internal quality control results, but external quality control results as well, and can discover malfunctions in an analyzer in real time (#8). The control device 1 tallies quality control data. If the quality control results fall outside of a predetermined range, or if a worsening of the quality control data is anticipated, trouble in the analyzer 2 is detected based on predetermined settings (#7). For example, data is trending away from median values. If trouble at the analyzer 2 is detected at the control device 1, the user is notified to that effect (#8). If trouble at the analyzer is discovered (#8), the user carries out processes to resolve the trouble (#10). The control device 1 analyzes the trouble from the edited operational information of that analyzer 2 (#9), and provides the user with the most suitable information for solving the trouble. If it is difficult for the user to resolve the trouble himself, the user activates the remote control unit of the analyzer (#11). A technician at the support center remotely operates the analyzer 2 and performs a task for resolution of the trouble via the remote control unit of the control device (#12). Thereupon the screen of the analyzer and the screen of the control device are linked. In this manner, with regard to problem that can be resolved through operation of the analyzer, even a complicated problem can be resolved through remote operation from the support center (#14). For troubles that cannot be resolved thus, a technician would go and make repairs (#13, #14). (2) Control Device Process Flow Next, the flow of a process that the control device 1 performs in a remote support system will be explained in detail. (2-1) Collection Process FIG. 4 is a flowchart showing one example of the flow of the main process that the control device 1 performs. In the main process, the control device 1 collects log information from the analyzer 2, and if it is operational history, stores it, and if it is sample data, performs the QC process. The following process commences by means of the dial-up router from the analyzer 2. In Step S1, the communications interface 11 performs a connection process to establish a connection with the analyzer 2. In Step S2, the processing unit 12 performs a prescribed authentication process. In other words, it determines whether the authentication information sent from the analyzer 2 matches the user information in the user database. In Step S3, the processing unit 12 performs a process according to the authentication results. If the determination is that the authentication information matches, operation proceeds to Step S4. If it doesn't match, then the connection is cut or another similar process is performed. In Step S4, the e-mail server 15 receives data from the analyzer 2. The processing unit 12 determines whether the received data is predetermined operational information or not. Operational information is predetermined information other than sample data, and includes, for example, error data, number of times operated, program log, and set-up information. If the answer is “yes,” then Step S5 ensues; if “no,” Step S7 ensues. In Step S5, the processing unit 12 temporarily saves the received operational information. This is for use in the support process, which is discussed below. In the support process, for example, operational information from each analyzer 2 until 00:00 midnight, when the date changes, is stored; when the time reaches 00:00, operational history is created based on the operational information received that day. In Step S6, communications interface 11 severs the connection with the analyzer 2. In Step S7, the processing unit 12 determines whether the received data is sample data from the assay of a quality control substance. If the determination is “yes,” then Step S8 ensues, proceeding to the QC process, which is discussed below. In other words, sample data, including received data, is tallied, and the Web page for each analyzer is updated. If the answer is “no,” the above-described Step S6 ensues, and the connection is severed. (2-2) Support Process FIG. 5 is a flowchart showing an example of a support process that the control device 1 performs independently of the main process. Every time the date changes, the control device 1 edits the operational information received that day and writes that to the history database. In Step S21, the processing unit 12 is waiting for a predetermined time, for example, 00:00. In Step S22, the processing unit 12 determines which analyzer 2 among those registered in the user control database 14 is the subject user. In Step S23, the processing unit 12 determines whether it has received operational information showing operating conditions for that date for the subject user. If the determination is “yes,” Step S24 ensues. If the determination is “no,” then Step S25 ensues. In Step S24, the processing unit 12 edits operational information for each analyzer and each subject matter, and writes this to the history database. For example, it edits error information, number of times operated, operation program, and setting parameters, in separate table format with date and time, and writes this to the history database. In Step S25, the processing unit 12 writes to the user control database 14 predetermined error information showing that operational information could not be acquired. Possible examples of error information include analyzer name, date, time, error number showing the error that arose, and error message corresponding to the error number. In Step S26, the processing unit 12 searches for a predetermined error based on the error information of the subject user. For example, using the methods for determination shown in FIG. 12, error levels are decided, as in the example shown in FIG. 13, from error type and the frequency with which the same type of error occurs. In Step S27, the processing unit 12 uses the search results to determine whether or not errors are contained in the operational information of the subject user. Unless the error level is “0,” the determination is “Yes.” If the determination is “Yes,” Step S28 ensues; if “No,” later-described Step S29 ensues. In Step S28, the processing unit 12 writes the determined error level to the user control database 14. In Step S29, the processing unit 12 determines whether Step S23 through Step S28 have been performed for all registered analyzers 2. If “Yes,” operations return to Step S21, and wait for the date to change. If “No,” then operations return to Step S22, and choose another analyzer as the subject user. (2-3) QC Process FIG. 6 is a flowchart showing the flow of the QC process the control device 1 performs. In the above-discussed main process, when the control device 1 receives sample data from any analyzer 2, the control device 1 performs the following QC process. In other words, it tallies sample data including newly received sample data, and updates the Web page for each analyzer using the new tally results. In Step S31, the processing unit 12 tallies sample data, which includes newly received sample data. Multiple varieties of quality control substances, such as those whose value is high and those whose value is low, and those whose value is within a normal range and those whose value is within an abnormal range, are often used in the same assay category. Wherein the quality control substance is from vital components, values from lot to lot—that is, the lot number for each manufacturing instance—will routinely differ. Furthermore, the assaying mode under which the sample data was assayed must be taken into consideration in order to determine correction values for the assayed data. The control substance type, lot number, and assaying mode are reported from the analyzer to the control device in a manner to be described later. Statistical tallying is conducted for each sort of analyzer and for each kind of quality control substance. Because substances like blood, which are liable to change (denature in the case of blood) over time, are used as the quality control substance, tallies are made each assay day to raise the reliability of the tally results. That the latest tally results are presented in real time in the present invention engenders the risk that the reliability of the tally results is not kept up during the early morning hours since the total count of sample data for that day's assays is insufficient. Therefore, the tally for that day's assays is made on sample data received, for example, within the past 24 hours. In this way, sample data from assaying conditions under the same elapsed-time changes can be used, which prevents the total count from fluctuating markedly according to time slot. At the point the date changes, the tally results within the past 24 hours are set as the tally results for that day. To improve the reliability of the tally results, it is preferable that cutoff values of mean plus or minus 3SD be used, and that values far outside the normal range be excluded in the analysis. When the tally results are presented in the form of the average value of the sample data, and there is a very small amount of data for a 24-hour period, it would be better to use the median value in place of the average value. In Step S32, the processing unit 12 updates the Web page for each analyzer based on the new tally results. It then returns to the main process and severs the connection with the user terminal. It should be noted that the timing for updating the tally results is not limited to being based on the time sample data was received, as long as the timing is such that the latest tally results can be presented to the analyzer. For example, one conceivable alternative would be to update the tally results when a Web page has been accessed from an analyzer. Or, the tally results may be updated at a predetermined time interval set in consideration of the load being placed on the analyzer. (2-4) Other Processes The control device 1 performs other processes in addition to the main process, support process, and QC process. For example, the WWW server 16 provides a Web page when the WWW browser on the analyzer has accessed the Web page. On this occasion, it is preferable that the analyzer perform the authentication process in the form of an interface program, such as a library or CGI (Common Gateway Interface) scripts. Also, the processing unit 12, in response to instructions from the operator of the control device 1, displays the error log stored in the user control database 14. (3) Analyzer Process Flow FIG. 7 is a flowchart showing an example of the main process performed by the analyzer. The analyzer 2 transmits error information and sample data in real time, and transmits operational information other than error information when the operations of the analyzer end. FIG. 7 shows only the flow according to the present invention. When the analyzer is activated, the following process commences. In Step S41, the control unit 28 monitors the operational conditions of the analysis unit 21 and determines whether error information has occurred or not. If the determination is “Yes,” then Step S42 ensues. If “No,” then Step S44, explained later, ensues. In Step S42, the control unit 28 acquires error information from the analysis unit 21 and processes it to be data for e-mail. For example, it creates e-mail in which analyzer authentication information and error information is written into the main body of the text. In Step S43, the control unit 28 activates the e-mail server 24 and transmits the created e-mail. Then operations return to Step S41. In Step S44, the control unit 28 determines whether sample data is to be collected. If the determination is “Yes,” then Step S45 ensues. If “No,” later-explained Step S48 ensues. In Step S45, the control unit 28 stands by for termination of the assay. Upon completion, Step S46 ensues. In Step S46, the control unit 28 acquires sample data from the analysis unit 21 and processes it to be data for e-mail. For example, it writes authentication information into the text of the e-mail, and creates an e-mail with the sample data attached as a file attachment. Other information that is needed when analyzing sample data may be included in the file attachment. Such information includes, for example, lot number, type of quality control substance, assay mode, and device ID. Device ID is identification information for the purpose of identifying an analyzer on this system, and is used to prevent sample data from being entered more than once during analysis. In Step S47, the control unit 28 activates the e-mail server 24 and transmits the created email. In Step S48, the control unit 28 awaits for operational information showing the operational conditions of the analysis unit 21 other than error information. Operational information other than error information can include number of times operated, operation program, set-up conditions and the like. When operational information arises, operations proceed to Step S49. In all other cases, the process flow proceeds to Step S50. In Step S49, the control unit 28 saves the new operational information in a log. In Step S50, the control unit 28 determines whether instructions have been given for completion of the analyzer. If the determination is “No,” then the operations return to Step S41. If “Yes,” then Step S51, described later, ensues. In Step S51, the control unit 28 acquires operational information from the log and processes this to be e-mail data. For example, it creates an e-mail message in which analyzer authentication information and operational information are written into the text of an e-mail message. In Step S52, the control unit 28 activates the e-mail server 24 and transmits the created e-mail message. After that, the control unit 28 terminates operations. Specific Example of Operational Information Stored in History Database by Support Process An explanation will be given in detail regarding the operational information stored in the user control database 14 by the support process described above. FIG. 8 through 11 show examples of operational information displayed at the control device 1 when a hemanalyzer has been used as the analyzer. FIG. 8 shows an example of an operational information selection screen, FIG. 9 shows an example of an error log, FIG. 10 shows an example of a program log, and FIG. 11 shows an example of the number of times of operation. The operational information selection screen of FIG. 8 accepts selections for error log, program log, settings, or number of times operated. An operator can use this screen to designate the analyzer and the type of analyzer. FIG. 9 shows an example of a screen displayed when “error log” has been selected on the operational information selection screen of FIG. 8. Error date and time, error message describing error, error code specifying error, and detailed code 1 and detailed code 2 are displayed. This error log displays, for example, the latest month's error log stored in the history database. It is preferable that each field have sorting and filtering settings. It is also preferable that records of abnormalities that have a high possibility of being problematic be displayed in an easily distinguishable reverse display or the like. Records of abnormalities, for example, are records of occurrences where the aforementioned error level is greater than a predetermined value. FIG. 10 shows an example of a screen displayed when “program log” has been selected on the screen of FIG. 8. In this example, the program name of the program operated at the designated analyzer, the version thereof, and the time and date operated are displayed. FIG. 11 shows an example of a screen displayed when “operation count” has been selected on the screen of FIG. 8. In this example, the number of times that a predetermined unit of the analyzer has been operated is displayed along with the operation date and time. Although not shown in the figures, when “settings” is selected on the selection screen of FIG. 8, the setting terms for the analyzer are displayed. Specific Example of Web Page Created by QC Process An explanation will be given of a specific example of a Web page created by the control device 1 using the QC process described above. FIGS. 14 and 15 show examples of Web pages created by the processing unit 12. As before, these are examples of displays of tally results when analyses are made of a quality control substance using the hemanalyzer. When a WWW browser on an analyzer accesses the control device 1, the window shown in the top half of FIG. 14 is displayed. This window allows the selection of a display style for the tally results. Here, an SDI chart has been selected as the “reporting style,” causing the window shown in FIG. 15 to be displayed. In FIG. 15, a predetermined graph is displayed for each blood component. This graph is created for each type of analyzer and each quality control substance. This graph is capable of displaying the past month's daily sample data for the accessing user and reference machine data. The reference machine data is sample data from assaying a predetermined quality control substance taken at an analyzer of the provider of the remote support system. The graph also displays the degree of deviation from the mean value, 1SD (1 standard deviation) by 1 SD. The daily tally results are finalized when the date changes. In terms of internal quality control, displaying these assay values as they are allows confirmation of the fluctuations in sample data from an analyzer. In terms of external quality control, confirmation is possible of the fluctuations in the sample data from an analyzer against the overall average, using the overall average at the time of taking the sample data, as shown in FIG. 15. By changing the display as he sees fit, a user can make a visual comparison to see how much the sample data of the analyzer deviates from the overall average and the reference machine data. Furthermore, the Web pages on FIGS. 14 and 15 are updated immediately after sample data has been submitted. Therefore, a user can perform external quality control of the sample data he has submitted in real time, without a time lag. FIG. 16 is another display example of tally results for a quality control substance. In this example, the assay values for the user's analyzer, overall average value, and reference machine data are displayed individually. Because there are times when the user wants to make direct comparisons between the assay values of his own analyzer and the overall average and reference machine data, it is preferable to make it possible to display individually the values in FIG. 15 that are displayed within a chart. (A) FIGS. 17 and 18 are block diagrams showing other examples of the remote support system. The network linking the user terminal and the analyzer does not necessarily have to be a dedicated network, but may be the Internet or a LAN. However, when the Internet is used, encoding and a stricter authentication system need to be used to heighten security when transmitting information. It is not necessary for there to be just one control device on the system. For example, separate dedicated networks may be connected by the Internet and routers and gateways, and a control device may be provided for each dedicated network. In addition, a control device can collect predetermined information from analyzers of a dedicated network, for example analyzers on the Internet connected via a dedicated network and router, or analyzers connected to a LAN connected to the Internet via a firewall. (B) In the above first embodiment, possible differences in time zones between the control device 1 and the analyzers 2, and among analyzers when the QC process is conducted, are not taken into consideration. Therefore, as the second embodiment, an explanation will be given of the QC process in a remote support system having a control device and analyzers in different time zones. (B-1) System Operation Analysis of sample data is conducted in the following way. In the same manner as the first embodiment, data collected in the past 48 hours is tallied, and those results become real time tally results. Alternatively, the tally results for each day are computed by tallying the data collected in the past 48 hours, including data collected during the previous day. To make it easier for operators of analyzers in each time zone to confirm tally results, tally results are correlated with those time zones (i.e., local time) and so inscribed. However, when the reference time for analysis is set as local time, the reference time will differ from time zone to time zone, and thus analyses have to be conducted for each time zone. This means that there will be 24 different tally results across the world for a single date, making operation of the system complicated. Additionally, there are countries that have more than one time zone, and there are group hospitals that are located across more than one time zone. On the other hand, when one of the time zones is the basis for the analysis reference time, without regard to local time, the difference between the local time and the reference time becomes a problem. For example, confusion will result if the date of the QC process changes in the middle of the analysis of an analyzer. For this reason, to ensure that the tally results for a given day are the same for all time zones, the tally results for that day are computed with sample data having the same assay date (local time) according to each time zone. (B-2) Base In consideration of the above, in this embodiment, the reference time for the control device 1 is made to be the world's most advanced time, namely, GMT (Greenwich Mean Time)+12 hours. In the following explanation, the reference for the time of day is the time of day in the time zone in which the control device 1 is located, in this case, GMT+12. Each analyzer 2 transmits to the control device 1, along with the sample data, the assay time and date in the time zone in which it is located. The control device 1 conducts analysis of the sample data based on sample data having an assay time and date within the past 48 hours. The reason for tallying sample data for the past 48 hours rather than the past 24 hours is to ensure that there will be a sufficient number of sample data sets N that will form the basis of the analyses. FIG. 19 is a conceptual diagram of data transmitted from the analyzer 2 to the control device 1. Included in this data are lot number, type of quality control substance, assay mode, device ID, time zone, time of day, and sample data. Except for time zone and time of day, all other data is the same as in the first embodiment. For time zone, the time zone in which the analyzer 2 is located is given. For time of day, the assay date and time in the time zone in which each analyzer is located is given. The control device 1 conducts the QC process, which will be discussed later, based on sample data having an assay date and time within 48 hours of the time of day in the time zone in which the control device is located. FIG. 20A is an explanatory diagram showing an insufficient number of sample data sets N received in the past 24 hours. To facilitate the explanation, suppose that analyzers A, B, C, D, and E are located in different time zones, and that each analyzer transmits sample data on a daily basis at 00:00 local time, respectively. Analyzer A is in the GMT+12 time zone. Analyzer E is in the GMT−12 time zone, and analyzers B, C, and D are in time zones in between. The control device is in the GMT+12 time zone. In FIG. 20, sample data with a date of X are indicated as Ax, Bx, etc. For example, A1, A2, and A3 represent sample data from analyzer A dated the 1st, 2nd, and 3rd, respectively. Black circles represent sample data that have already been collected, and white circles represent sample data that have not yet been collected. When the time for the control device is 00:00 on the 3rd day (time of day T1), A2, B2, C2, D2 and E2 are included in the sample data from the past 24 hours. However, when a little time passes and the time of day becomes the time of day T2, all that is included in the sample data from the past 24 hours is the data in the shaded triangular region in the figure, that is, only A3. In such a case, the further a time zone is from GMT+12 hours, the greater the possibility that the sample data will not be tallied, meaning that there will be an insufficient number of data sets N and that it will be difficult to always provide reliable tally results. FIG. 20B is an explanatory diagram showing a sufficient number of data sets N when the analysis is based on sample data received in the past 48 hours. When the time for the control devices reaches 00:00 on the 3rd (time of day T1), sample data from analyzers A through E dated the 1st and 2nd (A1, B1, C1, D1, E1; A2, B2, C2, D2, E2) are included within the sample data from the past 48 hours. Next, when a little time passes and the time of day becomes time of day T2, the data within the shaded trapezoidal region in the figure (i.e., A2, B2, C2, D2, and E2) becomes the population for analysis. In actuality, while the assay time differs for each analyzer, by making the analysis population the sample data of the past 48 hours, it is possible to ensure that there is always a number of sample data sets close to the total number of analyzers on the system. If there is a plurality of sample data sets from the same analyzer within the population, all such sets other than the sample data set with the most recent assay time may be excluded from the analysis. It should be noted that the reference time for the control device is not limited to GMT+12. It is also possible to make the period of time subject to analysis longer than 48 hours or shorter than 48 hours; however, 48 hours is expedient in terms of system operations. (B1-3) Process Flow With the exception of the QC process sub-routine (Step S8 in FIG. 4) performed after receipt of sample data, the process performed by the control device 1 relating to this embodiment is the same as in the first embodiment. A detailed explanation of the QC process in this embodiment appears below. The QC process of this embodiment is divided into (1) a current-day's tallying process and (2) the previous day's tallying process. (B-3-1) Conceptual Illustration of a Current-Day's Tallying Process FIG. 21A is a drawing explaining the concept of a current-day's tallying process. In the current-day's tallying process, a first preliminary population made up of sample data dated within the past 48 hours is sequentially created, using the time at the control device 1 as the reference time. Furthermore, sample data analysis is conducted based on the first preliminary population, and the current-day's tally results are updated. In this embodiment, the updating and tallying process of the first preliminary population is conducted every 10 minutes. In FIG. 21(a-1), the shaded trapezoidal region S0 shows the first preliminary population at the current time of day T1 (18:00 on the 2nd). With the passage of time, the trapezoidal region S0 progresses to the right in the figure. That is, the first preliminary population is updated. As the first preliminary population is updated, the tally results for today (i.e., the 2nd) are also updated. At the point of time T2 (00:00 on the 3rd), when the date changes from the 2nd to the 3rd, the previous day's tallying process for finalizing the tally results of the second is activated. In FIG. 21A(a-2), the shaded trapezoidal region, i.e., the sum of regions S1 and S2′, represents the first preliminary population at time of day T2. Region S1 represents the group of sample data sets dated the 1st and region S2′ represents the group of sample data sets dated the 2nd that were obtained at this point in time. Even if the previous day's tallying process has been activated, the current-day's tallying process continues to be conducted in the same manner as described above. The current-day's tallying process, as it continues, updates the tally results of today (i.e., the 3rd) according to a predetermined timing. (B-3-2) Explanation of a Previous Day's Tallying Process FIG. 21B explains a previous day's tallying process. When this process has been activated at 00:00 on the 3rd, the control device 1 creates a second preliminary population. The control device 1 updates the second preliminary population every 10 minutes, and updates the tally results for the previous day (i.e., the 2nd) based on the updated second preliminary population. The creation and update of the second preliminary population is conducted as follows. Every 10 minutes the control device 1 creates a second preliminary population made up of sample data from the past 48 hours. As the time of day progresses from T2 (00:00 on the 3rd), sample data dated today (i.e., the 3rd) that was collected in later time zones is deleted from the created second preliminary population. FIG. 21(b-1) shows a second preliminary population at time of day T3 (10:00 on the 3rd), 10 hours into the day T2. Region S1′ is a group of sample data dated the 1st and having an assay time within 48 hours of T3. Region S2′ is a group of sample data with an assay date of the 2nd that has already been collected. Region S3′ is sample data from the past 48 hours that is dated the 3rd and is to be deleted from the second preliminary population. At time of day T3, the control device computes the tally results for the previous day (the 2nd) based on the sample data from region S1′ and region S2′. FIG. 21(b-2) is the second preliminary population at a point in time of day T4 (00:00 on the 4th), which is 24 hours after the time of day T2. The shaded region S2 indicates the second preliminary population at this point in time. The second preliminary population at this point in time comprises the group of sample data sets dated the 2nd from all the analyzers participating in the remote support system. At this point in time, the control device 1 finalizes the population for the analysis of the day, two days prior (the 2nd). The tally results obtained from this population become the final tally results for the day, two days prior (the 2nd). (B-4) Flowchart In this embodiment, the control device 1 conducts three types of QC process independently: a collection process, the current-day's tallying process, and the previous day's tallying process. (B-4-1) Collection Process FIG. 22 is a sample data collection process that the control device 1 performs. This process commences when Step S8 (QC process sub-routine) ensues in the main process executed by the control device 1 (FIG. 4). In other words, in this embodiment, each time the control device 1 receives sample data, that data is stored in the base database (not shown in the figures). The sample data that the control device 1 receives is stored in this base database without any deletions. (B-4-2) A Current-Day's Tallying Process FIG. 23 is a flowchart of the current-day's tallying process performed by the control device 1. In the explanation below, a buffer 1 is the work area for forming the first preliminary population that will serve as the basis for the current-day's tallying process. Steps S101, S102: The control device 1 determines whether the date has changed (S101). If it has changed, it activates the previous day's process (S102) (refer to FIG. 21(a-2). Steps S103, S104, S105, S106: The control device 1 determines whether a predetermined time, i.e., 10 minutes, has elapsed since the previous analysis (S103). If it hasn't elapsed, operations return to Step S101 without analyses being made. If it has elapsed, the first preliminary population is updated and the current-day's analysis is updated. Specifically, sample data having a time and date within the past 48 hours is first acquired from the base database and is held in the buffer 1 (S104). Next, it is determined whether among the data held in the buffer 1 there is more than one set of data from the same analyzer (S105). If there is, all such data except the most recent is excluded from the buffer 1 (S106) [refer to FIG. 21(a-1)]. Step S107: The control device 1 performs analyses based upon the updated first preliminary population. These tally results will serve as the current-day's tally results for this point in time. The control device 1 performs the above process independently of the sample data collection process, and updates the current-day's tally results every 10 minutes, based on sample data from within the past 48 hours. (B-4-2) A Previous Day's Tallying Process FIG. 24 is a flowchart of the previous day's tallying process that the control device 1 performs. In the explanation below, a buffer 2 shall be the work area for forming the second preliminary population that will serve as the basis for the previous day's tallying process. When operations in the aforementioned current-day's tallying process proceeds to Step S102, the following process is activated. As with FIG. 21 above, we will suppose that this process commenced at time of day T2 (00:00 on the 3rd). Step S111: The control device 1 again determines whether the date has changed; if it has not changed, the process starting with Step S112 is performed. In other words, until the time of day changes from T3 (00:00 on the 3rd) to T4 (00:00 on the 4th), the update of the second preliminary population and the update of the analysis are conducted (S112 to S117, described below). When the time of day reaches 00:00 on the 4th, the tally results of two days prior, that is, the 2nd, are finalized (Steps 118 through 120 described below). Step S112: The control device 1 determines whether 10 minutes have elapsed since the previous analysis. If the determination is “Yes,” then Step S113 ensues, and the second preliminary population is updated. If the determination is “No,” it does not update the preliminary population, and operations return to Step S111. Steps S113, S114, S115, S116: The control device 1 acquires from the base database sample data from within the past 48 hours and holds these in the buffer 2 (S113). Next, the control device 1 deletes data dated today (i.e., the 3rd) from the acquired sample data (S114). Next, it is determined whether among the data held in the buffer 2 there is more than one set of data from the same analyzer (S115). If there is, all such data except the most recent is excluded from the buffer 1 (S116). In this manner, the second preliminary population is updated [refer to FIG. 21(b-1)]. Step S117: The control device 1, based on the updated second preliminary population, newly computes tally results for the previous day, namely, the 2nd. In this manner the tally results for the 2nd (the previous day) are updated every 10 minutes (S112 to S117). Step S118: If it is determined at Step S111 that the date has changed, in other words, that the time of day has become 00:00 on the 4th, the control device 1 finalizes the population that will serve as the basis for the tally results of the 2nd. In other words, the second preliminary population at this point in time becomes the population for the tally results of the day two days prior (i.e., the 2nd). Only sample data dated the 2nd is contained in the finalized population [refer to FIG. 21(b-2)]. Steps S119: The control device 1 computes the tally results for the day two days prior based on the finalized population. The display of the Web page on which the above tally results are posted is executed based on authentication information input from the analyzer. When a Web page is displayed, the control device 1 confirms the time zone of the analyzer. The reason for this is that it is conceivable that the local time in that time zone is a date other than the date in the GMT+12 time zone. In such cases, the control device 1 does not display the current-day's tally results for the GMT+12 time zone, but displays only the tally results of the previous day's tallying process. With the above-described process, based on sample data collected from analyzers located across the world, the current-day's tallying process sequentially updates the current-day's tally results, and the previous day's process updates the previous day's tally results. In addition, the tally results for each day are finalized through the previous day's tallying process. Because the analysis is performed based on at least a certain number of sample data sets, the reliability of the tally results can be improved. Furthermore, because sample data taken from assays in each time zone is reflected in that day's tally results, a user can use this system without being aware of any differences in time zones. (C) Storage media on which is recorded the above-described programs of the present invention are included in the present invention. These media can include, among others, computer-readable floppy diskettes, hard disks, semiconductor memory, CD-ROMs, DVDs, and opto-magnetic disks. (D) Media that transmit the programs of the present invention are also included in the present invention. These transmission media include telecommunication media (optical fibers, wireless networks, inter alia) in computer network systems (LAN, Internet, wireless communication network) for transporting and supplying program information as carrier. Through the use of the present invention, the history of an analyzer is stored in a control device, thus making possible the rapid response to problems arising in the analyzer and shortening the down time of the analyzer. Also, the external control of an analyzer can be performed essentially in real time. While only selected embodiments have been chosen to illustrate the present invention, to those skilled in the art it will be apparent from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing description of the embodiments according to the present invention is provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
	description	This invention relates generally to the field of deposition and etching processes and devices that use ion beams. Direct access storage devices (DASDs) have become part of everyday life, and as such, the capability to manipulate and store larger amounts of data at greater speeds is expected. To meet these expectations, DASDs such as hard disk drives (HDDs) have undergone many changes. The basic hard disk drive model resembles a phonograph. That is, the hard disk drive model includes a storage disk, or hard disk, that spins at a standard rotational speed. An actuator arm with a suspended slider is utilized to reach out over the disk. The arm carries a head assembly that has a magnetic read/write transducer, or head, for writing or reading information to or from a location on the disk. An air bearing surface (ABS) on the slider allows the slider to be flown very close to the surface of a disk. The complete head assembly, e.g., the suspension and head, is called a head gimbal assembly (HGA). Data is recorded onto the surface of a disk in a pattern of concentric rings known as data tracks. One way to increase the amount of data that can be stored on a disk is to make each data track narrower so that the tracks can be placed closer together. But, as tracks are narrowed, the signal-to-noise ratio is worsened, making it more difficult to discern signals from the head. Signal-to-noise ratio can be improved by positioning the head closer to the disk surface. Thus, the height of the slider above the disk (referred to as fly height) can be an important parameter. Another important parameter is the distance between the bottom surface of the head and the bottom surface of the substrate to which the head is attached (referred to as pole tip recession). In general, as the spacing between the head and the disk surface is narrowed, it becomes more important to tightly control the flatness and uniformity of surfaces such as the ABS, in order to reduce the probability of contact between the head and a disk. Ion milling is a popular technique for forming the ABS on a slider. However, with distances and tolerances measured in terms of nanometers, even minute deviations in the topography of a surface can be very significant. In order to achieve the desired surface uniformity, conventional ion milling techniques need to be improved beyond their current capabilities. A shaper for shaping an ion beam is described. The shaper can be used for both deposition and etching. The shaper includes a plate that is placed between an ion beam grid and an ion beam source. The plate covers holes in the grid, and is shaped and dimensioned such that the plate does not partially cover any holes in the grid that are directly adjacent to the plate. A hole is configured to mount the shaper at a center of the grid and at least one other hole is configured to secure the shaper to the grid to prevent the shaper from rotating relative to the grid. A center mount portion covers holes in the grid. The plate has two axes of reflection symmetry. The uniformity of both deposition and etching is improved. Reference will now be made in detail to embodiments of the present invention. While the invention will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, and components have not been described in detail as not to unnecessarily obscure aspects of the present invention. FIG. 1 illustrates an example of an ion beam deposition and etching apparatus 10 that utilizes an ion beam shaper 30 in accordance with embodiments of the present invention. FIG. 1 is not to scale. In the example of FIG. 1, the apparatus 10 includes a grid 15 that is mounted on an ion beam gun, or source, 19. FIG. 1 includes a side view showing grid 15 installed in apparatus 10, and a top view showing an enlarged version of grid 15 (as if grid 15 had been removed from apparatus 10 and rotated for ease of viewing). A specimen 11 is mounted on a table 17 such that the center 23 of the grid 15, the table 17 and the specimen 11 are aligned. Although not shown in FIG. 1, the specimen 11 and the grid 15 may be mounted at an angle relative to one another. That is, the specimen 11 and grid 15 are not necessarily parallel to each other, and therefore the ion beam's angle of incidence may not be perpendicular to the specimen 11. The table 17 and/or the grid 15 can be rotated—in general, the specimen 11 and the grid 15 can be rotated relative to one another. Grid 15 includes a large number of holes, exemplified by hole 21. Grid 15 may also include regions (other than the regions between adjacent holes) that are free of holes. Although not shown in FIG. 1, the holes 21 extend to the periphery of grid 15. As specimen 11 is rotated relative to the grid 15, ion beam source 19 emits an ion beam 25 onto the surface of grid 15. The beam 25 is filtered by grid 15, and relatively small ion “beamlets” 27 are emitted from the grid 15. Using techniques known in the art and so not described in detail herein, the beamlets 27 can be used to deposit material onto specimen 11 or to etch material from specimen 11. It is desirable that ion beam density be uniform across the surface of the specimen 11, so that material is deposited uniformly across the specimen's surface or so that etching is uniform across the specimen's surface. To achieve such uniformity, a shaper 30 is mounted onto either the upper or lower surface of grid 15. In one embodiment, the ion beam source 19 includes a plasma chamber and a set of beam grids. In such an embodiment, the shaper 30 is mounted on the innermost grid (the grid closest to the plasma chamber). Again, FIG. 1 is not to scale. In actuality, the surface area of shaper 30 is relatively small compared to the surface of grid 15. For example, shaper 30 may cover less than about five (5) percent of the grid 15. According to embodiments of the present invention, the shaper 30 is dimensioned and shaped such that it does not partially cover any of the holes 21. That is, in one embodiment, each of the holes 21 in grid 15 is either completely closed by shaper 30 or is completely exposed to an incident ion beam. In operation, as the specimen 11 is rotated beneath the source 19 and grid 15, ion beamlets 27 that are not blocked by shaper 30 are able to reach specimen 11. Empirical results demonstrate that, with the use of shaper 30, deposition and etching are uniform across the entire radius of specimen 11 (see FIG. 4). Significantly, shaper 30 can be used for both deposition and etching and achieves uniform results for both. FIGS. 2 and 3 illustrate ion beam shaper 30 according to one embodiment of the present invention. Shaper 30 is essentially a relatively thin and flat plate formed from a durable material such as molybdenum. In one embodiment, shaper 30 and grid 15 are made of the same material. With reference to FIG. 2, shaper 30 has reflective (bilateral, mirror) symmetry about a first axis 41 and also has reflective symmetry about a second axis 42 that is perpendicular to the first axis. In the present embodiment, shaper 30 includes a hole 34 that is used to mount the shaper at the center of the grid 15 of FIG. 1 (the hole 34 is aligned with the center of the grid 15 and a screw or other type of fastening mechanism is inserted through hole 34 into grid 15). In a similar manner, other holes, such as hole 35, can be used to secure shaper 30 to grid 15 and to prevent the shaper from rotating relative to the grid. A first arm 37, measured from the center mount portion 36, extends radially in one direction (R1) while a second arm 38, also measured from the center mount portion 36, extends radially in the opposite direction (R2). In one embodiment, each of the arms 37 and 38 covers 53 holes in grid 15 (FIG. 1). Additional holes are covered by the center mount portion 36. As shown in FIG. 3, each of the arms 37 and 38 of shaper 30 includes a first portion 51 that is substantially rectilinear in shape. Each arm 37 and 38 also includes a second portion 52 that is wider (W) and longer (L) than first portion 51. The second portion 52 includes a first region 61 that is substantially rectilinear in shape, and a second region 62 that tapers, forming essentially a triangular shape. Each arm 37 and 38 also includes a third portion 53 that is wider than the second portion 52, and is essentially chevron-shaped (V-shaped). Each arm 37 and 38 also includes a fourth portion 54 that is wider than the third portion 53, and that is also essentially chevron-shaped. In general, the width of shaper 30 increases in the radial or lengthwise direction. In one embodiment, shaper 30 has an overall length of about 5 inches and a maximum width of about two (2) inches. With reference again to FIG. 1, before passing through grid 15, some portions of the ion beam 25 will have a greater density of ions than other portions of the beam. The shaper 30 blocks the higher density portions of the beam 25, such that the ion beamlets 27 that reach the specimen 11 are more uniform and thus will produce a more uniform deposition or etch pattern on the surface of the specimen. Because shaper 30 blocks the higher density portions of the ion beam, the overall intensity of the ion beam is reduced, which may result in reduced deposit and etch rates. However, the reduction in these rates is balanced by the advantages that come with improved uniformity. For example, when applied to the fabrication of hard disk drives (HDDs)—specifically, to the fabrication of the air bearing surface (ABS) of a slider—the improved uniformity results in improved ABS topography after deposition and etch, thus allowing the read/write head to be situated closer to the surface of a storage disk without increasing the probability of contact between the head and the disk surface. FIG. 4 is a graph 70 illustrating ion beam density versus radius (e.g., a radius along the surface of a specimen). Curve 1 shows that, using shaper 30 of FIGS. 1-3, the beam density is relatively flat across the surface of a specimen. Significantly, even at the periphery of a specimen, the beam density remains relatively flat, for both deposition and etch. In contrast, as represented by curve 2, beam density is significantly diminished at the periphery of a specimen when a conventional etch or deposition technique is used. Because the beam density remains relatively flat across the surface of a specimen, the amount of material deposited or removed during deposition and etching will be uniform across the surface of the specimen. Indeed, empirical data demonstrates that uniform deposition and etching across the surface of a specimen is realized using shaper 30, over a wide range of operating parameters including beam density, mounting angle (the angle between the specimen and the beam), and beam power, voltage or current. Notably, with shaper 30, both uniform deposition and uniform etching are achieved over the range of operating parameters. Thus, the shaper 30 does not have to be removed and replaced with a different shaper between deposition and etching. In summary, embodiments in accordance with the present invention pertain to an ion beam shaper that can be used during both deposition and etch, and that can improve both deposition and etch uniformity across the entire surface of a specimen. Thus, elements such as the air bearing surface of a slider in an HDD can be made to finer tolerances, which in turn allows a read/write head to be located closer to the surface of a disk, reducing signal-to-noise ratio and allowing more information to be stored on the disk. The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and many modifications and variations are possible in light of the above teaching. The embodiments described herein were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
043361030	description	Referring now to the drawing and first, particularly, to FIGS. 1 and 2 thereof, there are shown two cross-sectional views of a fuel element pit 1, mutually disposed at an angle of 90.degree. relative to one another. The work to be performed therein is able to be effected from a movable operating bridge 11 under visual observation. In these diagrammatic illustrations of FIGS. 1 and 2, only those tools and fixtures are shown diagrammatically as are required for performing the method of the invention. Thus, there are located at one side wall of the pit 1, a tilting device 12 for a fuel element receiving basket or cage 51, and also a storage container 13 for defective fuel rods, a supply storage 14 for new fuel rods as well as a so-called Sipping test device 19 for checking entire fuel elements for defective fuel rods that might be contained therein. A container 16 for disassembled fuel-element base or foot members, a fuel-rod exchanging tool 2 as well as a tool 18 for loosening the fuel-element foot members and a tool 17 for checking each individual fuel rod for possible damage are additionally provided. The operating sequence for the method of the invention is as follows: Each fuel element taken from the reactor core is initially introduced into the Sipping test device 19 and is examined there for possible damage to individual fuel rods. Should a fuel element 5 received therein be perceived to be defective, that fuel element 5 is placed in the receiving basket 51 of the tilting device 12. This receiving basket 5 is closable at both ends thereof. The fuel element 5, with this receiving basket 51, is then turned through 180.degree., so that the foot or base end of the fuel element 5 points upwardly. After the receiving basket 51 is opened at an end thereof, the base or foot member of the fuel element 5 is disassembled therefrom by means of the remotely activated tool 18 and is deposited in the storage container 16. The ends of the fuel rods in the fuel element 5, which are now freely accessible at the top of the latter, as viewed in FIG. 1, for example, are individually examined by means of the device 17, which is operatable, ultrasonically (German Published Non-Prosecuted Application DT-OS No. 2 414 650.1), for example, to detect any water leakage into the fuel rods. In this manner, the defective fuel rods are determined and can be removed from the fuel element 5. To this end, the centering plate 4, shown in top plan view in FIG. 4, is initially disposed above the fuel elements 5, the bore holes 42 of the centering plate 4 permitting accurate travel of the fuel-rod exchanging tool 2 to the respective fuel rods located underneath. This situation is schematically represented in FIG. 3. The fuel rod 52 perceived to be defective is withdrawn into the interior of the tool 2, through which water flows continuously during this operation, being drawn into the lower end of the tool 2 through a line 31 under the action of a pump 32. This measure provides the advantage that, in the case of fuel rods with cladding-tube damage that is so extensive that fission gases can escape, the escaping gases can be entrained by this flow of water upwardly within the tool 2, and the thus entrained gases can then be separated from the water in the gas separator 33 and fed to the purification and waste-gas collecting system 35. Thereafter, the defective fuel rod which is gripped and enclosed by the tool 2 is moved away by and with the latter and deposited in the container 13 for defective fuel rods. For this purpose, the pulling or drawing mechanism inside the tool 2, which may be of the rack-and-pinion type, for example, is switched over so that it then pushes the rod into the container 13, which is advantageously connected to a circulatory loop of water all its own, since it must be expected that the fuel rods stored therein give off radio-active fission gases and fission products. Then, a new fuel rod or another replacement rod can be taken from the store 14 of new fuel rods; in principle, this corresponds to the operation of removing the fuel rod from the fuel element. Thereafter, this new fuel rod is introduced into the vacated position in the fuel element 5. After the fuel-rod exchange operation is completed, the fuel element 5, which is now usable again, is temporarily deposited in a fuel-element storage rack 15 until it can be reinserted into the reactor core with the aid of the fuel-element loading machine. As mentioned hereinbefore, the centering plate 4 is an essential element of the fuel-rod exchanging device 2. This plate is shown in a top plan view in FIG. 4 and in a side elevational view in FIG. 5. The intersections of the coordinates a and b with A and B, respectively, represent corresponding fuel rod positions of a fuel element or fuel assembly. From FIG. 4 and also from FIG. 5 it is clearly evident that the fuel rods 52 are disposed very closely together. For this reason, it is not possible to provide centering holes in the centering plate 4 for each individual fuel rod position so that the fuel-rod exchanging tool 2 may be applied to the respective fuel rod. This difficulty is circumvented accordingly by providing that the centering holes 42 be assigned only to each fuel rod which corresponds to the coordinate intersections a, A. In order that all of the fuel-rod positions may be reached, this centering plate 4 is raised, turned through 90.degree. and replaced; then, the centering holes 42 correspond to fuel rod positions of the coordinate intersections a, B. A repeated similar shift through 90.degree. permits all of those fuel rods which are located at the coordinate intersections b, B to be covered and after turning once again through 90.degree., those fuel rods at the coordinate intersections b, A. The illustrted bores 43 are provided for receiving the threaded bolts or pins of the control rod guide tubes 53 and, likewise, illustrated connecting breakthroughs are provided between pairs of adjacent centering holes. The latter measure is necessary so that the threaded bolts or pins of the control rod guide tubes 53 are not in the way when the centering plate 4 is put in place after having been turnably shifted through 90.degree.. The position of the centering plate 4 per se must depend upon the fuel element or the receiving basket or cage 51 therefor. For this purpose, the centering plate 4 is provided with four spacer posts or pins 41 which carry the centering frame 44 proper that surrounds the wall of the receiving basket or cage 51. In this manner, assurance is provided that each centering hole 42 of the plate 4 is associated with one fuel-rod end in accordance with the coordinate scheme shown and described herein. These fuel rod ends, as shown, are provided with a mushroom-shaped head, which is surrounded by the gripper 61 as shown in FIG. 5. This gripper 61 is attached to a moving linkage 6 and thereby permits the withdrawal of the respectively gripped fuel rod 52, as shown in FIG. 5. An eddy current test probe 23 is built into the lower part 21 of this fuel rod exchanging tool 2, so that the exact location of any damage to this fuel rod 52 is immediately ascertainable as the fuel rod is being pulled through the tool 2 upon its removal from the fuel element 5. The fuel rod exchanging tool 2 per se is diagrammatically shown in FIG. 6. On the face of it, the tool 2 is formed of a lower part which is enclosed by an outer support tube 22 and of an upper part which is surrounded by a large guide tube 26. The length of the support tube 22 is somewhat greater than the length of the fuel rod 52 to be drawn in, and the length of the large guide tube 26 is of the same order of magnitude. At the end of this large guide tube 26 there is a console or bracket carrying a driving device 27 formed, for example, of a gear drive and a hand crank. This gear drive 27 meshes with a rack 65a, which is connected to an upper withdrawal tube 65. This tube 65 is connected to the moving linkage 6 proper, which extends through the support tube 22 and into the large guide tube 26 through a seal 25. At the lower end of the support tube 22, the moving linkage 6 extends advantageously through a closure member 21 of the suport tube 22 as well as through the eddy current measuring probe 23 installed therein. On the moving linkage 6, there is located the gripper 61 proper for the respective fuel rod head; it is slotted two to three times radially and is formed of springy or resilient material. As shown, the inner contour of the gripper 61 is matched to the conventional mushroom-shaped head of the fuel-rod end cap. After being placed on this cap, the gripper 61 is clamped to the cap by a locking or coupling rod 63 in a manner that it cannot be loosened from the fuel rod head, as the locking rod 63 is pushed downwardly. The rod 63 extends through the entire tool and is provided at the upper end thereof, as shown in FIG. 6, with a thread which threadedly engages in an adjusting nut 64. This adjusting nut 64 is virtually braced against the pulling tube 65 or the end closure thereof, which is provided with a hook for connecting a lifting tool or device thereto. The end 63a of the rod 6 is provided with two markings which indicate the upper and the lower position of this rod 6 and thereby also the inwardly driven and the outwardly driven conditions of the gripper 61. In the inwardly driven condition, the gripper 61 is closed and is locked against opening. In the outwardly driven condition, and upper conical member 62 at the locking or coupling rod 63 opens the gripper 61 by making contact with a slotted opposing cone or countercone 61a. In this manner, the gripping tool releases the fuel rod; is retractible and proceeds to another fuel rod. The hereinbefore described part of the fuel rod exchanging tool 2 exhibits the function thereof of pulling a fuel rod 52 out of a fuel element 5. For pushing a fuel rod 52 into a fuel element 5, however, it is necessary that the new fuel rod be kept free of any bending or buckling stress. For this purpose, an inner support tube 24 is provided, wherein the moving linkage 6 and, consequently, also the inwardly driven fuel rod 52 are guided. This guide tube 24 also ensures that, when the fuel rod 52 contained in this tool is pushed into the fuel element 5 or into the storage container 13 for the fuel rods 2, also, that no lateral movement of the relatively thin fuel rod 52 and consequent bending or buckling of the latter is possible due to the thrust or push exerted by the gripper head 61. Assurance is provided, in this manner, that a new fuel rod 52 can be reloaded without damage into a vacated fuel-rod position. Buckling or bending in the fuel element per se of the fuel rods 52 that are being inserted is prevented by the mesh of the spacers that are disposed at different levels of the fuel element. Instead of performing the raising and lowering operations manually, a motor drive may also be used, of course, however, it would appear that manual operation is preferable so that possible disturbances during the feed of the fuel rod 52 into and out of the fuel element 5 can be felt more readily. As already mentioned hereinbefore, the placing of the fuel rod exchanging tool 2 onto the centering plate 4 is controlled from above by visual observation. The tool 2 is suspended for this purpose from a suitably drivable lifting device. To provide weight relief, it is advantageous to provide the tool further with a float at an upper part thereof, as shown diagrammatically in FIG. 3 in the interest of clarity. It should not be left unmentioned that this special fuel-rod exchanging tool 2 is usable also for performing other operations in the fuel-element pit, such as for examining the individual fuel rods 52, for example, by so-called gamma scanning, to determine the burnt-off condition thereof, by leading them past an appropriate measuring head.
052951669	abstract	A start-up range neutron monitor system for monitoring neutrons generated from a neutron source comprises a neutron detector disposed in a non-earthed state and adapted to detect neutrons generated from the neutron source, a coaxial cable for externally transmitting a detection signal from the neutron detector, the coaxial cable being composed of a core and an outer sheath, a preamplifier incorporated on a way of the coaxial cable for amplifiying the detection signal, and a signal processing unit connected to the preamplifier through the coaxial cable to process the amplified detection signal amplified. The coaxial cable is composed of a first cable portion connecting the neutron detector and the preamplifier on an input side thereof and a second cable portion connecting the preamplifier and the signal processing unit on an output side of the preamplifier. A cable shield is further disposed so as to cover the first cable portion of the coaxial cable, wherein an earth side circuit on the signal processing unit is earthed and the cable shield is connected to an earth side circuit of the preamplifier, thus constituting the entire system as one point earth structure. A coil assembly including including first and second coils are also incorporated in the core and outer sheath of the first cable portion of the coaxial cable respectively alone or together with the cable shield. The first and second coils have the same inductance and are arranged so as to generate magnetic fluxes in directions reverse to each other.
	abstract	A method and system is disclosed for directing charged particles on predetermined areas on a target semiconductor substrate. After aligning a wafer mask with a semiconductor wafer, with the wafer mask having one or more mask patterns thereon, the charged particles are directed to pass through the mask patterns to land on one or more selected areas on the semiconductor wafer.
	description	This application is a continuation of application Ser. No. 11/323,331, filed Dec. 30, 2005, now abandoned, which was a continuation-in-part of application Ser. No. 11/233,921, filed Sep. 22, 2005 now abandoned. This invention concerns the absorption of radiation, such as x-ray radiation, using a flexible shield. Particularly, the invention is concerned with a lightweight, very thin and flexible non-lead radiation shield, worn against a patient while radiation therapy is administered internally to the patient, and with protection against the effects of backscatter radiation on the patient. Shields for protection of patients and medical workers against excessive doses of radiation, particularly in dentists' offices and other x-ray imaging or therapy situations, are well known. Heavy and relatively stiff lead shields have been typical for this purpose. Shields of lighter weight and greater flexibility have also been used. U.S. Pat. Nos. 4,938,233, 6,048,379 and 6,674,087 disclose various radiation shields, some of which employ tungsten or other heavy metal particles suspended in a polymeric flexible medium, such as silicone. Experimental results have indicated that radiation at, for example, 50 kVp, absorbed in a shield formed of such heavy metal particles, generates an undesirable backscattered radiation dose. For the situation where radiation is administered from a source within the patient, the backscattered radiation dose is absorbed in adjacent tissue, particularly the patient's skin adjacent to the shield. The current disclosure includes improvements to the flexible absorber design to minimize this undesirable and potentially damaging effect. The invention now described encompasses a lightweight, very thin and flexible radiation shield which includes, in flexible media, a layer including high atomic number particles and a layer including mid atomic number particles. Measurements indicate that backscattered radiation is largely limited to low-energy photons. The invention includes the incorporation of a thin layer or layers of solid mid atomic number absorber particles carried in a polymer incorporated into the patient side of the absorber panel. In use, impinging high energy x-ray photons pass into the absorber through the thin layer of mid atomic number particles. Backscattered radiation from this thin layer is minimal. As x-rays pass into the heavy atomic number absorber, they are absorbed, and any backward-emitted low energy backscatter radiation is in turn largely absorbed by the mid atomic number layer or layers of the invention. A preferred embodiment of the invention involves the use of a first, patient-adjacent layer with a thin silicone polymer carrier that is loaded with fine metal particles. Ideally these metal particles have significant content of the mid atomic number elements Fe, Co, or Ni due to their inherent radiation absorption edges. As the layer should also remain non-toxic, food grade Fe, Fe oxides, and/or stainless steel powders are ideal. The powders are mixed with liquid silicone rubber, and applied to the absorber device in a thin film. A second layer more remote from contact with the patient includes high atomic number particles, such as tungsten, again in a flexible medium such as silicone. The entire composite of multiple layers, in a preferred embodiment, is not greater than about 2 mm in thickness. In one specific embodiment of the invention the flexible shield is used in conjunction with one or more dosimeters, placed adjacent to the patient's skin. The dosimeters can be incorporated into the shield, at or very close to the patient side of the shield. These dosimeters can provide feedback for verification of dose at the skin, and for control of the dose. It is thus among the objects of this invention to improve in the convenience of use and in the performance and effectiveness of non-lead flexible radiation shields, particularly for the case where radiation is administered inside the patient and backscatter is an important concern. These and other objects, advantages and features of the invention will be apparent from the following description of preferred embodiments, considered along with the drawings. In the drawings, FIG. 1 shows a radiation attenuating shield 10 of the invention, comprising a flexible, flimsy and thin sheet of material, preferably about 2 mm maximum in thickness, for laying against a patient experiencing internal radiation therapy, such as using an x-ray source within a cavity or lumen of the body. The sheet 10 is flexible and conformable enough, and heavy enough in weight, such that it readily conforms to the body when placed against the skin. FIG. 2 is a schematic view in cross-section showing an example of preferred construction for the sheet of material 10. The flexible radiation shield 10 preferably has an outer skin 12 of a fabric material, which may be a woven fabric material. In a preferred embodiment this material is stretchable, and the material may be any of several known stretchable elastic fabrics such as LYCRA. This outer skin fabric layer 12 is adhered to the outer surface of a layer 14, which is in turn secured to or integral with a layer 16, the latter being the side of the shield 10 that is placed directly against the patient. The layer 16 can be called a first layer or patient-adjacent layer, and the layer 14 can be called a second layer or patient-remote layer. Although the two layers 14 and 16 have different composition, they act essentially as a single layer. In one preferred implementation the overall thickness t of the flexible radiation shield 10 is no more than about 2 mm, and can be even less. Of the two layers 14 and 16, these in one preferred embodiment are both soft silicone, such as very soft Shore A5 medical grade silicone. In one preferred embodiment the layer 14, more remote from the patient, is filled with ninety percent by weight tungsten powder, carried in the silicone host. The tungsten powder in one embodiment is minus 100 mesh sintered tungsten metal, mixed with the liquid silicone and molded into sheets or shapes suitable for the absorber application. Breast shapes, i.e. cup shapes, have also been produced of this material. Such a layer alone, only about 1 millimeter in thickness, has been shown to attenuate x-rays of 45 kVp by a factor of greater than ten thousand. Because a single layer such as the layer 14 described above tends to generate an undesirable backscatter radiation dose to adjacent tissue when x-rays at about 45 to 50 kVp are primarily being absorbed, the flexible radiation shield of the invention includes the layer 16, also preferably a layer with a soft silicone host. The layer 16 comprises at least one layer having solid mid-atomic number absorber particles, and this layer (or layers) 16 is placed against the patient. In one preferred embodiment the mid-atomic number particles comprise about fifty percent by weight of the entire layer, the balance being the same soft medical grade silicone described above relative to the layer 14. The mid-atomic number particles preferably are at least as small as minus 100 mesh (149 microns in diameter), and more preferably about 400 mesh (37 microns). A preferred size range is about 35 to about 150 microns. They may be, for example, any of the following metals alone or in mixtures, including compounds of any of the metals: iron, nickel and cobalt and other elements of similar atomic number. Iron, nickel and cobalt match have absorption that matches the absorption and re-emission of characteristic lines and radiation of tungsten. Since the layer should remain non-toxic, food grade iron oxides and/or stainless steel powders are advantageously used. These powders are mixed with liquid silicone rubber, and can be applied against the layer 14 in a thin film, essentially integrating the two silicone layers together. Alternatively, the layer 14 can be applied against a previously produced layer 16. Tests of a composite flexible radiation absorber shield 10, produced in accordance with the example given above, revealed, at 50 kVp radiation, a significant reduction of backscatter. Most of the x-ray radiation at 50 kVp appears to pass through the patient-adjacent layer 16, and of the radiation which does, nearly all is absorbed in the layer 14 (with greater than 10,000 to 1 reduction based on radiation which is able to transmit through the entire shield 10). As noted above, a small percentage of the radiation striking the high molecular weight layer 14 is backscattered back toward the patient, and nearly all of this backscatter is absorbed as it travels back through the mid-molecular weight layer 16 adjacent to the patient. Backscattered radiation from the mid-molecular weight layer 16, from the initially impinging radiation, is minimal. In other embodiments other polymers can be used as carriers or hosts for the layers of high molecular weight and mid-molecular weight absorber materials. Wax layers have been produced, for disposable use and preferably shaped to the patient's breasts or other organ or body feature where radiation is being internally administered. This type of shield is castable to the shape desired and produces a semi-hard absorber structure, of relatively low cost. Also, shields can be produced with much lower proportions of radiation attenuating metals, and these structures may be used in contrast enhancing, marker or filter applications. The absorber 10 constructed as in FIG. 2, with layers 12, 14 and 16 and the described very soft silicone host material, is very flimsy, easily trimmable, and conformal enough such that it forms itself around most anatomic structures (breasts, ribs and torso, shoulders, hands, face, etc.) This conformability is consistent with the material's ability to stretch, in a preferred embodiment, up to 200% elongation and to elastically return to shape. The material is cleanable, and suitable for reusable article service, although it can be disposable if desired and in many cases it will be cut by the surgeon and in such cases will be used only once. In another embodiment, the flexible radiation shield structure 10 shown in FIG. 2, with silicone composite layers, can be a portion of a further liquid silicone rubber overmolded structure used selectively to shield (or to irradiate) specific parts of anatomy. The overmolding can be in the form of a colored cover, as in a tinted silicone coating, rather than the stretchable elastic fabric. A graded absorber shield structure may be produced for certain applications. In this form the shield is created with co-bonded regions that have tungsten filler adjacent to regions that have no filler. The result is an absorber with selective absorption which may be of value in certain radiation treatment applications. Functionally composite structures including adhesives can form an integral part of the shield. For example, adhesive (covered by a releasable backing sheet) can be in selected areas of the skin side of the shield, where the surgeon is likely to cut the shield to make the patient incision. The adhesive helps permit closure of any gaps. FIG. 3 illustrates schematically an embodiment of the invention wherein a flexible radiation absorption shield 20, constructed in the manner described above, incorporates one or more dosimeters 22 in the shield. The flexible radiation shield for the breast application covers the breast and reduces the dose leaving the patient during the treatment. This shield will allow the doctor, attending staff and friends to be with the patient during treatment. The shield has features that reduce the secondary scattering dose at the interface between the high Z material absorber and the patient's skin. Placing a miniature dosimeter on the patient's skin over the applicator will allow a verification of the dose delivered and especially the dose to the skin. Due to the backscatter dose that is developed because of the high Z shield, obtaining an accurate dose at the skin surface depends on how the x-rays interact with the dosimeter. Having optimized low and intermediate Z materials surrounding the detector is critical to achieving accurate dosimetry; the dosimeter(s) can be shielded from receiving backscatter. The miniature dosimeter 22 or dosimeters can be integrated into the flexible shield so that they are one component, as shown in FIG. 3, or they can be separate, contained in a separate mat or sheet similar to what is shown in FIG. 3, but usually smaller than the shield itself, which will lie over (outside) the detector sheet. The detector sheet can include shielding of the dosimeters against backscatter from the shield. If the dosimeter is integrated into the skin side of the shield as preferred, the path of the dosimeter cable can be marked with a bright contrasting color line printed on the shield, as along the lines 24 seen in FIG. 3. The detector active area can be positioned precisely and also marked on the absorber (at locations 22). To further avoid damage to the sensor and/or its cable 24 a stripe of protection (indicated partially at 26) can be added on or built in so that it protects the components from cutting in preparation for surgery. This protection stripe or shield (or several of them) could be made from Kevlar, for example. More than one detector can be installed in the shield, as indicated in FIG. 3, to further verify the delivered skin dose from the primary radiation. The dosimeters on the surface, between the skin and shield, can also be used for mapping and feedback control. In the mapping mode the x-ray source or sources can be run at their intended high voltage but at a reduced source current, to reduce the dose, but to indicate the dose that would be delivered at full source current. The sources would be run as indicated at all dwell positions and the total delivered dose would be recorded. This mode can accurately predict the total dose that will be delivered at the skin at selected locations when the source or sources are run at full power, time and dwell positions. In the feedback control mode, the dosimeter readings can be used in real time to control the source's output to achieve a desired total dose. When the dose at a given dosimeter reaches the desired level, the source can be changed in current or position. FIG. 3 indicates schematically a treatment planning system 28 (including a computer and programming), which can be connected by wire to the wire leads 24 of the dosimeters, or, as indicated at 30, which can be in wireless communication with the dosimeters 22, without the need for the wires 24. The initial plan delivered from the TPS 28 can be modified by the readings at the dosimeters as follows. The TPS will predict the dose to be received by the dosimeters 22 as well as optimizing the dwell positions, dwell times and x-ray source voltages. This optimized plan, sometimes called a reverse plan, will predict the dose at the dosimeters. When the trial dose is delivered (or the real dose in real time), then the predicted dose at dosimeters (either after all the dose at a dwell point is delivered or after only one dwell point or after only a partial dwell point, which may be the first or any other dwell point) can be compared to the detected dose, and differences detected and the treatment plan changed accordingly, either in a preliminary step or during the actual treatment. The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.
	summary
	summary
	description	This application is a continuation-in-part of U.S. patent application Ser. No. 15/167,617 filed May 27, 2016, which is: a continuation-in-part of U.S. patent application Ser. No. 15/152,479 filed May 11, 2016, which: is a continuation-in-part of U.S. patent application Ser. No. 14/216,788 filed Mar. 17, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 13/087,096 filed Apr. 14, 2011, which claims benefit of U.S. provisional patent application No. 61/324,776 filed Apr. 16, 2010; and which is a continuation-in-part of U.S. patent application Ser. No. 13/788,890 filed Mar. 7, 2013; is a continuation-in-part of U.S. patent application Ser. No. 14/952,817 filed Nov. 25, 2015, which is a continuation-in-part of U.S. patent application Ser. No. 14/293,861 filed Jun. 2, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 12/985,039 filed Jan. 5, 2011, which claims the benefit of U.S. provisional patent application No. 61/324,776, filed Apr. 16, 2010; is a continuation-in-part of U.S. patent application Ser. No. 14/860,577 filed Sep. 21, 2015, which is a continuation of U.S. patent application Ser. No. 14/223,289 filed Mar. 24, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 14/216,788 filed Mar. 17, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 12/985,039 filed Jan. 5, 2011, which claims the benefit of U.S. provisional patent application No. 61/324,776, filed Apr. 16, 2010; and is a continuation-in-part U.S. patent application Ser. No. 15/073,471 filed Mar. 17, 2016, which claims benefit of U.S. provisional patent application No. 62/304,839 filed Mar. 7, 2016, is a continuation-in-part of U.S. patent application Ser. No. 14/860,577 filed Sep. 21, 2015, which is a continuation of U.S. patent application Ser. No. 14/223,289 filed Mar. 24, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 14/216,788 filed Mar. 17, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 13/572,542 filed Aug. 10, 2012, which is a continuation-in-part of U.S. patent application Ser. No. 12/425,683 filed Apr. 17, 2009, which claims the benefit of U.S. provisional patent application No. 61/055,395 filed May 22, 2008, now U.S. Pat. No. 7,939,809 B2; all of which are incorporated herein in their entirety by this reference thereto. Field of the Invention This invention relates generally to treatment of solid cancers. More particularly, the invention relates to redundant measures of charged particle beam state, such as charged particle position, direction, intensity, density, energy, and/or distribution. Discussion of the Prior Art Cancer Treatment Proton therapy works by aiming energetic ionizing particles, such as protons accelerated with a particle accelerator, onto a target tumor. These particles damage the DNA of cells, ultimately causing their death. Cancerous cells, because of their high rate of division and their reduced ability to repair damaged DNA, are particularly vulnerable to attack on their DNA. Patents related to the current invention are summarized here. Proton Beam Therapy System F. Cole, et. al. of Loma Linda University Medical Center “Multi-Station Proton Beam Therapy System”, U.S. Pat. No. 4,870,287 (Sep. 26, 1989) describe a proton beam therapy system for selectively generating and transporting proton beams from a single proton source and accelerator to a selected treatment room of a plurality of patient treatment rooms. Imaging P. Adamee, et. al. “Charged Particle Beam Apparatus and Method for Operating the Same”, U.S. Pat. No. 7,274,018 (Sep. 25, 2007) and P. Adamee, et. al. “Charged Particle Beam Apparatus and Method for Operating the Same”, U.S. Pat. No. 7,045,781 (May 16, 2006) describe a charged particle beam apparatus configured for serial and/or parallel imaging of an object. K. Hiramoto, et. al. “Ion Beam Therapy System and its Couch Positioning System”, U.S. Pat. No. 7,193,227 (Mar. 20, 2007) describe an ion beam therapy system having an X-ray imaging system moving in conjunction with a rotating gantry. C. Maurer, et. al. “Apparatus and Method for Registration of Images to Physical Space Using a Weighted Combination of Points and Surfaces”, U.S. Pat. No. 6,560,354 (May 6, 2003) described a process of X-ray computed tomography registered to physical measurements taken on the patient's body, where different body parts are given different weights. Weights are used in an iterative registration process to determine a rigid body transformation process, where the transformation function is used to assist surgical or stereotactic procedures. M. Blair, et. al. “Proton Beam Digital Imaging System”, U.S. Pat. No. 5,825,845 (Oct. 20, 1998) describe a proton beam digital imaging system having an X-ray source that is movable into a treatment beam line that can produce an X-ray beam through a region of the body. By comparison of the relative positions of the center of the beam in the patient orientation image and the isocentre in the master prescription image with respect to selected monuments, the amount and direction of movement of the patient to make the best beam center correspond to the target isocentre is determined. S. Nishihara, et. al. “Therapeutic Apparatus”, U.S. Pat. No. 5,039,867 (Aug. 13, 1991) describe a method and apparatus for positioning a therapeutic beam in which a first distance is determined on the basis of a first image, a second distance is determined on the basis of a second image, and the patient is moved to a therapy beam irradiation position on the basis of the first and second distances. Problem There exists in the art of charged particle irradiation therapy a need to know and/or control position, direction, energy, intensity, and/or cross-sectional area or shape of the charged particle beam, where the controls are individualized to individual patients and/or individual tumor shapes. The invention comprises a control system using redundant systems to determine charged particle position, direction, energy, and/or intensity in a charged particle cancer therapy system. Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that are performed concurrently or in different order are illustrated in the figures to help improve understanding of embodiments of the present invention. The invention relates generally to use of redundant systems to determine charged particle beam position, shape, direction, energy, and/or intensity in a charged particle cancer therapy system and/or imaging system. In one example, charged particle state in a charged particle beam is determined using one or more elements of: an extraction system from a synchrotron, a beam transport system from the extraction system to a nozzle, and/or one or more photon emitting sheets, such as in a charged particle cancer treatment system and method of operation thereof. A tomography system is optionally used in combination with the charged particle state determination system. For example, knowledge of state of an applied radio-frequency field in an extraction system is used to determine beam energy and/or intensity; an applied magnetic field strength is used to calculate charged particle energy in the beam transport system, one or more detectors imaging photons emitted from coated layers, also referred to as imaging sheets or layers, are used to determine one or more point positions and/or vectors of the charged particle beam, and/or a scintillation detector of a tomography system is used to determine beam intensity, position, direction, and/or energy. Combining the point positions yields localized vectors pinpointing the charged particle beam position, such as entering a patient and/or exiting the patient. Any of the charged particle state determination systems are optionally and preferably used with any of the remaining charged particle state determination systems to yield redundant information on the state of the charged particles in the charged particle beam, where redundancy functions as a safety feature as well as a basis for reducing beam state error, enhancing precision, and enhancing accuracy of the charged particle cancer therapy and/or imaging system. In another embodiment, the charged particle state determination system using one or more coated layers is used in conjunction with a scintillation detector or a tomographic imaging system at time of tumor and surrounding tissue sample mapping and/or at time of tumor treatment. In still another embodiment, common synchrotron, beam transport, and/or nozzle elements are used for both tomographic imaging and cancer treatment. In another embodiment, the charged particle tomography apparatus is used in combination with a charged particle cancer therapy system. For example, tomographic imaging of a cancerous tumor is performed using charged particles generated with an injector, accelerator, and guided with a delivery system. The cancer therapy system uses the same injector, accelerator, and guided delivery system in delivering charged particles to the cancerous tumor. For example, the tomography apparatus and cancer therapy system use a common raster beam method and apparatus for treatment of solid cancers. More particularly, the invention comprises a multi-axis and/or multi-field raster beam charged particle accelerator used in: (1) tomography and (2) cancer therapy. Optionally, the system independently controls patient translation position, patient rotation position, two-dimensional beam trajectory, delivered radiation beam energy, delivered radiation beam intensity, beam velocity, timing of charged particle delivery, and/or distribution of radiation striking healthy tissue. The system operates in conjunction with a negative ion beam source, synchrotron, patient positioning, imaging, and/or targeting method and apparatus to deliver an effective and uniform dose of radiation to a tumor while distributing radiation striking healthy tissue. In another embodiment, a treatment delivery control system (TDCS) or main controller is used to control multiple aspects of the cancer therapy system, including one or more of: an imaging system, such as a CT or PET; a positioner, such as a couch or patient interface module; an injector or injection system; a radio-frequency quadrupole system; a ring accelerator or synchrotron; an extraction system; an irradiation plan; and a display system. The TDCS is preferably a control system for automated cancer therapy once the patient is positioned. The TDCS integrates output of one or more of the below described cancer therapy system elements with inputs of one or more of the below described cancer therapy system elements. More generally, the TDCS controls or manages input and/or output of imaging, an irradiation plan, and charged particle delivery. In yet another embodiment, one or more trays are inserted into the positively charged particle beam path, such as at or near the exit port of a gantry nozzle in close proximity to the patient. Each tray holds an insert, such as a patient specific insert for controlling the energy, focus depth, and/or shape of the charged particle beam. Examples of inserts include a range shifter, a compensator, an aperture, a ridge filter, and a blank. Optionally and preferably, each tray communicates a held and positioned insert to a main controller of the charged particle cancer therapy system. The trays optionally hold one or more of the imaging sheets configured to emit light upon transmission of the charged particle beam through a corresponding localized position of the one or more imaging sheets. Charged Particle Beam Therapy Throughout this document, a charged particle beam therapy system, such as a proton beam, hydrogen ion beam, or carbon ion beam, is described. Herein, the charged particle beam therapy system is described using a proton beam. However, the aspects taught and described in terms of a proton beam are not intended to be limiting to that of a proton beam and are illustrative of a charged particle beam system, a positively charged beam system, and/or a multiply charged particle beam system, such as C4+ or C6+. Any of the techniques described herein are equally applicable to any charged particle beam system. Referring now to FIG. 1A, a charged particle beam system 100 is illustrated. The charged particle beam preferably comprises a number of subsystems including any of: a main controller 110; an injection system 120; a synchrotron 130 that typically includes: (1) an accelerator system 132 and (2) an internal or connected extraction system 134; a beam transport system 135; a scanning/targeting/delivery system 140; a patient interface module 150; a display system 160; and/or an imaging system 170. An exemplary method of use of the charged particle beam system 100 is provided. The main controller 110 controls one or more of the subsystems to accurately and precisely deliver protons to a tumor of a patient. For example, the main controller 110 obtains an image, such as a portion of a body and/or of a tumor, from the imaging system 170. The main controller 110 also obtains position and/or timing information from the patient interface module 150. The main controller 110 optionally controls the injection system 120 to inject a proton into a synchrotron 130. The synchrotron typically contains at least an accelerator system 132 and an extraction system 134. The main controller 110 preferably controls the proton beam within the accelerator system, such as by controlling speed, trajectory, and timing of the proton beam. The main controller then controls extraction of a proton beam from the accelerator through the extraction system 134. For example, the controller controls timing, energy, and/or intensity of the extracted beam. The controller 110 also preferably controls targeting of the proton beam through the scanning/targeting/delivery system 140 to the patient interface module 150. One or more components of the patient interface module 150, such as translational and rotational position of the patient, are preferably controlled by the main controller 110. Further, display elements of the display system 160 are preferably controlled via the main controller 110. Displays, such as display screens, are typically provided to one or more operators and/or to one or more patients. In one embodiment, the main controller 110 times the delivery of the proton beam from all systems, such that protons are delivered in an optimal therapeutic manner to the tumor of the patient. Herein, the main controller 110 refers to a single system controlling the charged particle beam system 100, to a single controller controlling a plurality of subsystems controlling the charged particle beam system 100, or to a plurality of individual controllers controlling one or more sub-systems of the charged particle beam system 100. Referring now to FIG. 7, a first example of the charged particle beam state determination system 750 is illustrated using two cation induced signal generation surfaces, referred to herein as the first sheet 760 and a third sheet 780. Each sheet is described below. Still referring to FIG. 7, in the first example, the optional first sheet 760, located in the charged particle beam path prior to the patient 730, is coated with a first fluorophore coating 762, wherein a cation, such as in the charged particle beam, transmitting through the first sheet 760 excites localized fluorophores of the first fluorophore coating 762 with resultant emission of one or more photons. In this example, a first detector 812 images the first fluorophore coating 762 and the main controller 110 determines a current position of the charged particle beam using the image of the fluorophore coating 762 and the detected photon(s). The intensity of the detected photons emitted from the first fluorophore coating 762 is optionally used to determine the intensity of the charged particle beam used in treatment of the tumor 720 or detected by the tomography system 700 in generation of a tomogram and/or tomographic image of the tumor 720 of the patient 730. Thus, a first position and/or a first intensity of the charged particle beam is determined using the position and/or intensity of the emitted photons, respectively. Still referring to FIG. 7, in the first example, the optional third sheet 780, positioned posterior to the patient 730, is optionally a cation induced photon emitting sheet as described in the previous paragraph. However, as illustrated, the third sheet 780 is a solid state beam detection surface, such as a detector array. For instance, the detector array is optionally a charge coupled device, a charge induced device, CMOS, or camera detector where elements of the detector array are read directly, as does a commercial camera, without the secondary emission of photons. Similar to the detection described for the first sheet, the third sheet 780 is used to determine a position of the charged particle beam and/or an intensity of the charged particle beam using signal position and/or signal intensity from the detector array, respectively. Still referring to FIG. 7, in the first example, signals from the first sheet 760 and third sheet 780 yield a position before and after the patient 730 allowing a more accurate determination of the charged particle beam through the patient 730 therebetween. Optionally, knowledge of the charged particle beam path in the targeting/delivery system 740, such as determined via a first magnetic field strength across the first axis control 142 or a second magnetic field strength across the second axis control 144 is combined with signal derived from the first sheet 760 to yield a first vector of the charged particles prior to entering the patient 730 and/or an input point of the charged particle beam into the patient 730, which also aids in: (1) controlling, monitoring, and/or recording tumor treatment and/or (2) tomography development/interpretation. Optionally, signal derived from use of the third sheet 780, posterior to the patient 730, is combined with signal derived from tomography system 700, such as the scintillation plate 710, to yield a second vector of the charged particles posterior to the patient 730 and/or an output point of the charged particle beam from the patient 730, which also aids in: (1) controlling, monitoring, deciphering, and/or (2) interpreting a tomogram or a tomographic image. For clarity of presentation and without loss of generality, detection of photons emitted from sheets is used to further describe the charged particle beam state determination system 750. However, any of the cation induced photon emission sheets described herein are alternatively detector arrays. Further, any number of cation induced photon emission sheets are used prior to the patient 730 and/or posterior to the patient 730, such a 1, 2, 3, 4, 6, 8, 10, or more. Still further, any of the cation induced photon emission sheets are place anywhere in the charged particle beam, such as in the synchrotron 130, in the beam transport system 135, in the targeting/delivery system 140, the nozzle 146, in the gantry room, and/or in the tomography system 700. Any of the cation induced photon emission sheets are used in generation of a beam state signal as a function of time, which is optionally recorded, such as for an accurate history of treatment of the tumor 720 of the patient 730 and/or for aiding generation of a tomographic image. Referring now to FIG. 1B, an example of a charged particle cancer therapy system 100 is provided. A main controller receives input from one, two, three, or four of a respiration monitoring and/or controlling controller 180, a beam controller 185, a rotation controller 147, and/or a timing to a time period in a respiration cycle controller 148. The beam controller 185 preferably includes one or more or a beam energy controller 182, the beam intensity controller 340, a beam velocity controller 186, and/or a horizontal/vertical beam positioning controller 188. The main controller 110 controls any element of the injection system 120; the synchrotron 130; the scanning/targeting/delivery system 140; the patient interface module 150; the display system 160; and/or the imaging system 170. For example, the respiration monitoring/controlling controller 180 controls any element or method associated with the respiration of the patient; the beam controller 185 controls any of the elements controlling acceleration and/or extraction of the charged particle beam; the rotation controller 147 controls any element associated with rotation of the patient 830 or gantry; and the timing to a period in respiration cycle controller 148 controls any aspects affecting delivery time of the charged particle beam to the patient. As a further example, the beam controller 185 optionally controls any magnetic and/or electric field about any magnet in the charged particle cancer therapy system 100. One or more beam state sensors 190 sense position, direction, intensity, and/or energy of the charged particles at one or more positions in the charged particle beam path. A tomography system 700, described infra, is optionally used to monitor intensity and/or position of the charged particle beam. Referring now to FIG. 2, an illustrative exemplary embodiment of one version of the charged particle beam system 100 is provided. The number, position, and described type of components is illustrative and non-limiting in nature. In the illustrated embodiment, the injection system 120 or ion source or charged particle beam source generates protons. The injection system 120 optionally includes one or more of: a negative ion beam source, an ion beam focusing lens, and a tandem accelerator. The protons are delivered into a vacuum tube that runs into, through, and out of the synchrotron. The generated protons are delivered along an initial path 262. Focusing magnets 230, such as quadrupole magnets or injection quadrupole magnets, are used to focus the proton beam path. A quadrupole magnet is a focusing magnet. An injector bending magnet 232 bends the proton beam toward a plane of the synchrotron 130. The focused protons having an initial energy are introduced into an injector magnet 240, which is preferably an injection Lamberson magnet. Typically, the initial beam path 262 is along an axis off of, such as above, a circulating plane of the synchrotron 130. The injector bending magnet 232 and injector magnet 240 combine to move the protons into the synchrotron 130. Main bending magnets, dipole magnets, turning magnets, or circulating magnets 250 are used to turn the protons along a circulating beam path 264. A dipole magnet is a bending magnet. The main bending magnets 250 bend the initial beam path 262 into a circulating beam path 264. In this example, the main bending magnets 250 or circulating magnets are represented as four sets of four magnets to maintain the circulating beam path 264 into a stable circulating beam path. However, any number of magnets or sets of magnets are optionally used to move the protons around a single orbit in the circulation process. The protons pass through an accelerator 270. The accelerator accelerates the protons in the circulating beam path 264. As the protons are accelerated, the fields applied by the magnets are increased. Particularly, the speed of the protons achieved by the accelerator 270 are synchronized with magnetic fields of the main bending magnets 250 or circulating magnets to maintain stable circulation of the protons about a central point or region 280 of the synchrotron. At separate points in time the accelerator 270/main bending magnet 250 combination is used to accelerate and/or decelerate the circulating protons while maintaining the protons in the circulating path or orbit. An extraction element of an inflector/deflector system is used in combination with a Lamberson extraction magnet 292 to remove protons from their circulating beam path 264 within the synchrotron 130. One example of a deflector component is a Lamberson magnet. Typically the deflector moves the protons from the circulating plane to an axis off of the circulating plane, such as above the circulating plane. Extracted protons are preferably directed and/or focused using an extraction bending magnet 237 and extraction focusing magnets 235, such as quadrupole magnets along a positively charged particle beam transport path 268 in a beam transport system 135, such as a beam path or proton beam path, into the scanning/targeting/delivery system 140. Two components of a scanning system 140 or targeting system typically include a first axis control 142, such as a vertical control, and a second axis control 144, such as a horizontal control. In one embodiment, the first axis control 142 allows for about 100 mm of vertical or y-axis scanning of the proton beam 268 and the second axis control 144 allows for about 700 mm of horizontal or x-axis scanning of the proton beam 268. A nozzle system 146 is used for imaging the proton beam, for defining shape of the proton beam, and/or as a vacuum barrier between the low pressure beam path of the synchrotron and the atmosphere. Protons are delivered with control to the patient interface module 150 and to a tumor of a patient. All of the above listed elements are optional and may be used in various permutations and combinations. Proton Beam Extraction Referring now to FIG. 3, both: (1) an exemplary proton beam extraction system 300 from the synchrotron 130 and (2) a charged particle beam intensity control system 305 are illustrated. For clarity, FIG. 3 removes elements represented in FIG. 2, such as the turning magnets, which allows for greater clarity of presentation of the proton beam path as a function of time. Generally, protons are extracted from the synchrotron 130 by slowing the protons. As described, supra, the protons were initially accelerated in a circulating path, which is maintained with a plurality of main bending magnets 250. The circulating path is referred to herein as an original central beamline 264. The protons repeatedly cycle around a central point in the synchrotron 280. The proton path traverses through a radio frequency (RF) cavity system 310. To initiate extraction, an RF field is applied across a first blade 312 and a second blade 314, in the RF cavity system 310. The first blade 312 and second blade 314 are referred to herein as a first pair of blades. In the proton extraction process, an RF voltage is applied across the first pair of blades, where the first blade 312 of the first pair of blades is on one side of the circulating proton beam path 264 and the second blade 314 of the first pair of blades is on an opposite side of the circulating proton beam path 264. The applied RF field applies energy to the circulating charged-particle beam. The applied RF field alters the orbiting or circulating beam path slightly of the protons from the original central beamline 264 to an altered circulating beam path 265. Upon a second pass of the protons through the RF cavity system, the RF field further moves the protons off of the original proton beamline 264. For example, if the original beamline is considered as a circular path, then the altered beamline is slightly elliptical. The frequency of the applied RF field is timed to apply outward or inward movement to a given band of protons circulating in the synchrotron accelerator. Orbits of the protons are slightly more off axis compared to the original circulating beam path 264. Successive passes of the protons through the RF cavity system are forced further and further from the original central beamline 264 by altering the direction and/or intensity of the RF field with each successive pass of the proton beam through the RF field. Timing of application of the RF field and/or frequency of the RF field is related to the circulating charged particles circulation pathlength in the synchrotron 130 and the velocity of the charged particles so that the applied RF field has a period, with a peak-to-peak time period, equal to a period of time of beam circulation in the synchrotron 130 about the center 280 or an integer multiple of the time period of beam circulation about the center 280 of the synchrotron 130. Alternatively, the time period of beam circulation about the center 280 of the synchrotron 130 is an integer multiple of the RF period time. The RF period is optionally used to calculated the velocity of the charged particles, which relates directly to the energy of the circulating charged particles. The RF voltage is frequency modulated at a frequency about equal to the period of one proton cycling around the synchrotron for one revolution or at a frequency than is an integral multiplier of the period of one proton cycling about the synchrotron. The applied RF frequency modulated voltage excites a betatron oscillation. For example, the oscillation is a sine wave motion of the protons. The process of timing the RF field to a given proton beam within the RF cavity system is repeated thousands of times with each successive pass of the protons being moved approximately one micrometer further off of the original central beamline 264. For clarity, the approximately 1000 changing beam paths with each successive path of a given band of protons through the RF field are illustrated as the altered beam path 265. The RF time period is process is known, thus energy of the charged particles at time of hitting the extraction material or material 330, described infra, is known. With a sufficient sine wave betatron amplitude, the altered circulating beam path 265 touches and/or traverses a material 330, such as a foil or a sheet of foil. The foil is preferably a lightweight material, such as beryllium, a lithium hydride, a carbon sheet, or a material having low nuclear charge components. Herein, a material of low nuclear charge is a material composed of atoms consisting essentially of atoms having six or fewer protons. The foil is preferably about 10 to 150 microns thick, is more preferably about 30 to 100 microns thick, and is still more preferably about 40 to 60 microns thick. In one example, the foil is beryllium with a thickness of about 50 microns. When the protons traverse through the foil, energy of the protons is lost and the speed of the protons is reduced. Typically, a current is also generated, described infra. Protons moving at the slower speed travel in the synchrotron with a reduced radius of curvature 266 compared to either the original central beamline 264 or the altered circulating path 265. The reduced radius of curvature 266 path is also referred to herein as a path having a smaller diameter of trajectory or a path having protons with reduced energy. The reduced radius of curvature 266 is typically about two millimeters less than a radius of curvature of the last pass of the protons along the altered proton beam path 265. The thickness of the material 330 is optionally adjusted to create a change in the radius of curvature, such as about ½, 1, 2, 3, or 4 mm less than the last pass of the protons 265 or original radius of curvature 264. The reduction in velocity of the charged particles transmitting through the material 330 is calculable, such as by using the pathlength of the betatron oscillating charged particle beam through the material 330 and/or using the density of the material 330. Protons moving with the smaller radius of curvature travel between a second pair of blades. In one case, the second pair of blades is physically distinct and/or is separated from the first pair of blades. In a second case, one of the first pair of blades is also a member of the second pair of blades. For example, the second pair of blades is the second blade 314 and a third blade 316 in the RF cavity system 310. A high voltage DC signal, such as about 1 to 5 kV, is then applied across the second pair of blades, which directs the protons out of the synchrotron through an extraction magnet 292, such as a Lamberson extraction magnet, into a transport path 268. Control of acceleration of the charged particle beam path in the synchrotron with the accelerator and/or applied fields of the turning magnets in combination with the above described extraction system allows for control of the intensity of the extracted proton beam, where intensity is a proton flux per unit time or the number of protons extracted as a function of time. For example, when a current is measured beyond a threshold, the RF field modulation in the RF cavity system is terminated or reinitiated to establish a subsequent cycle of proton beam extraction. This process is repeated to yield many cycles of proton beam extraction from the synchrotron accelerator. In another embodiment, instead of moving the charged particles to the material 330, the material 330 is mechanically moved to the circulating charged particles. Particularly, the material 330 is mechanically or electromechanically translated into the path of the circulating charged particles to induce the extraction process, described supra. In this case, the velocity or energy of the circulating charged particle beam is calculable using the pathlength of the beam path about the center 280 of the synchrotron 130 and from the force applied by the bending magnets 250. In either case, because the extraction system does not depend on any change in magnetic field properties, it allows the synchrotron to continue to operate in acceleration or deceleration mode during the extraction process. Stated differently, the extraction process does not interfere with synchrotron acceleration. In stark contrast, traditional extraction systems introduce a new magnetic field, such as via a hexapole, during the extraction process. More particularly, traditional synchrotrons have a magnet, such as a hexapole magnet, that is off during an acceleration stage. During the extraction phase, the hexapole magnetic field is introduced to the circulating path of the synchrotron. The introduction of the magnetic field necessitates two distinct modes, an acceleration mode and an extraction mode, which are mutually exclusive in time. The herein described system allows for acceleration and/or deceleration of the proton during the extraction step and tumor treatment without the use of a newly introduced magnetic field, such as by a hexapole magnet. Charged Particle Beam Intensity Control Control of applied field, such as a radio-frequency (RF) field, frequency and magnitude in the RF cavity system 310 allows for intensity control of the extracted proton beam, where intensity is extracted proton flux per unit time or the number of protons extracted as a function of time. Still referring FIG. 3, the intensity control system 305 is further described. In this example, an intensity control feedback loop is added to the extraction system, described supra. When protons in the proton beam hit the material 330 electrons are given off from the material 330 resulting in a current. The resulting current is converted to a voltage and is used as part of an ion beam intensity monitoring system or as part of an ion beam feedback loop for controlling beam intensity. The voltage is optionally measured and sent to the main controller 110 or to an intensity controller subsystem 340, which is preferably in communication or under the direction of the main controller 110. More particularly, when protons in the charged particle beam path pass through the material 330, some of the protons lose a small fraction of their energy, such as about one-tenth of a percent, which results in a secondary electron. That is, protons in the charged particle beam push some electrons when passing through material 330 giving the electrons enough energy to cause secondary emission. The resulting electron flow results in a current or signal that is proportional to the number of protons going through the target or extraction material 330. The resulting current is preferably converted to voltage and amplified. The resulting signal is referred to as a measured intensity signal. The amplified signal or measured intensity signal resulting from the protons passing through the material 330 is optionally used in monitoring the intensity of the extracted protons and is preferably used in controlling the intensity of the extracted protons. For example, the measured intensity signal is compared to a goal signal, which is predetermined in an irradiation of the tumor plan. The difference between the measured intensity signal and the planned for goal signal is calculated. The difference is used as a control to the RF generator. Hence, the measured flow of current resulting from the protons passing through the material 330 is used as a control in the RF generator to increase or decrease the number of protons undergoing betatron oscillation and striking the material 330. Hence, the voltage determined off of the material 330 is used as a measure of the orbital path and is used as a feedback control to control the RF cavity system. In one example, the intensity controller subsystem 340 preferably additionally receives input from: (1) a detector 350, which provides a reading of the actual intensity of the proton beam and/or (2) an irradiation plan 360. The irradiation plan provides the desired intensity of the proton beam for each x, y, energy, and/or rotational position of the patient/tumor as a function of time. Thus, the intensity controller 340 receives the desired intensity from the irradiation plan 350, the actual intensity from the detector 350 and/or a measure of intensity from the material 330, and adjusts the amplitude and/or the duration of application of the applied radio-frequency field in the RF cavity system 310 to yield an intensity of the proton beam that matches the desired intensity from the irradiation plan 360. As described, supra, the protons striking the material 330 is a step in the extraction of the protons from the synchrotron 130. Hence, the measured intensity signal is used to change the number of protons per unit time being extracted, which is referred to as intensity of the proton beam. The intensity of the proton beam is thus under algorithm control. Further, the intensity of the proton beam is controlled separately from the velocity of the protons in the synchrotron 130. Hence, intensity of the protons extracted and the energy of the protons extracted are independently variable. Still further, the intensity of the extracted protons is controllably variable while scanning the charged particles beam in the tumor from one voxel to an adjacent voxel as a separate hexapole and separated time period from acceleration and/or treatment is not required, as described supra. For example, protons initially move at an equilibrium trajectory in the synchrotron 130. An RF field is used to excite or move the protons into a betatron oscillation. In one case, the frequency of the protons orbit is about 10 MHz. In one example, in about one millisecond or after about 10,000 orbits, the first protons hit an outer edge of the target material 130. The specific frequency is dependent upon the period of the orbit. Upon hitting the material 130, the protons push electrons through the foil to produce a current. The current is converted to voltage and amplified to yield a measured intensity signal. The measured intensity signal is used as a feedback input to control the applied RF magnitude or RF field. An energy beam sensor, described infra, is optionally used as a feedback control to the RF field frequency or RF field of the RF field extraction system 310 to dynamically control, modify, and/or alter the delivered charge particle beam energy, such as in a continuous pencil beam scanning system operating to treat tumor voxels without alternating between an extraction phase and a treatment phase. Preferably, the measured intensity signal is compared to a target signal and a measure of the difference between the measured intensity signal and target signal is used to adjust the applied RF field in the RF cavity system 310 in the extraction system to control the intensity of the protons in the extraction step. Stated again, the signal resulting from the protons striking and/or passing through the material 130 is used as an input in RF field modulation. An increase in the magnitude of the RF modulation results in protons hitting the foil or material 130 sooner. By increasing the RF, more protons are pushed into the foil, which results in an increased intensity, or more protons per unit time, of protons extracted from the synchrotron 130. In another example, a detector 350 external to the synchrotron 130 is used to determine the flux of protons extracted from the synchrotron and a signal from the external detector is used to alter the RF field, RF intensity, RF amplitude, and/or RF modulation in the RF cavity system 310. Here the external detector generates an external signal, which is used in a manner similar to the measured intensity signal, described in the preceding paragraphs. Preferably, an algorithm or irradiation plan 360 is used as an input to the intensity controller 340, which controls the RF field modulation by directing the RF signal in the betatron oscillation generation in the RF cavity system 310. The irradiation plan 360 preferably includes the desired intensity of the charged particle beam as a function of time and/or energy of the charged particle beam as a function of time, for each patient rotation position, and/or for each x-, y-position of the charged particle beam. In yet another example, when a current from material 330 resulting from protons passing through or hitting material is measured beyond a threshold, the RF field modulation in the RF cavity system is terminated or reinitiated to establish a subsequent cycle of proton beam extraction. This process is repeated to yield many cycles of proton beam extraction from the synchrotron accelerator. In still yet another embodiment, intensity modulation of the extracted proton beam is controlled by the main controller 110. The main controller 110 optionally and/or additionally controls timing of extraction of the charged particle beam and energy of the extracted proton beam. The benefits of the system include a multi-dimensional scanning system. Particularly, the system allows independence in: (1) energy of the protons extracted and (2) intensity of the protons extracted. That is, energy of the protons extracted is controlled by an energy control system and an intensity control system controls the intensity of the extracted protons. The energy control system and intensity control system are optionally independently controlled. Preferably, the main controller 110 controls the energy control system and the main controller 110 simultaneously controls the intensity control system to yield an extracted proton beam with controlled energy and controlled intensity where the controlled energy and controlled intensity are independently variable and/or continually available as a separate extraction phase and acceleration phase are not required, as described supra. Thus the irradiation spot hitting the tumor is under independent control of: time; energy; intensity; x-axis position, where the x-axis represents horizontal movement of the proton beam relative to the patient, and y-axis position, where the y-axis represents vertical movement of the proton beam relative to the patient. In addition, the patient is optionally independently translated and/or rotated relative to a translational axis of the proton beam at the same time. Beam Transport The beam transport system 135 is used to move the charged particles from the accelerator to the patient, such as via a nozzle in a gantry, described infra. Charged Particle Energy The beam transport system 135 optionally includes means for determining an energy of the charged particles in the charged particle beam. For example, an energy of the charged particle beam is determined via calculation, such as via equation 1, using knowledge of a magnet geometry and applied magnetic field to determine mass and/or energy. Referring now to equation 1, for a known magnet geometry, charge, q, and magnetic field, B, the Larmor radius, ρL, or magnet bend radius is defined as: ρ L = v ⊥ Ω c = 2 ⁢ Em qB ( eq . ⁢ 1 ) where: v⊥ is the ion velocity perpendicular to the magnetic field, ΩC is the cyclotron frequency, q is the charge of the ion, B is the magnetic field, m is the mass of the charge particle, and E is the charged particle energy. Solving for the charged particle energy yields equation 2. E = ( ρ L ⁢ qB ) 2 2 ⁢ m ( eq . ⁢ 2 ) Thus, an energy of the charged particle in the charged particle beam in the beam transport system 135 is calculable from the know magnet geometry, known or measured magnetic field, charged particle mass, charged particle charge, and the known magnet bend radius, which is proportional to and/or equivalent to the Larmor radius. Nozzle After extraction from the synchrotron 130 and transport of the charged particle beam along the proton beam path 268 in the beam transport system 135, the charged particle beam exits through the nozzle system 146. In one example, the nozzle system includes a nozzle foil covering an end of the nozzle system 146 or a cross-sectional area within the nozzle system forming a vacuum seal. The nozzle system includes a nozzle that expands in x/y-cross-sectional area along the z-axis of the proton beam path 268 to allow the proton beam 268 to be scanned along the x-axis and y-axis by the vertical control element and horizontal control element, respectively. The nozzle foil is preferably mechanically supported by the outer edges of an exit port of the nozzle 146. An example of a nozzle foil is a sheet of about 0.1 inch thick aluminum foil. Generally, the nozzle foil separates atmosphere pressures on the patient side of the nozzle foil from the low pressure region, such as about 10−5 to 10−7 torr region, on the synchrotron 130 side of the nozzle foil. The low pressure region is maintained to reduce scattering of the circulating charged particle beam in the synchrotron. Herein, the exit foil of the nozzle is optionally the first sheet 760 of the charged particle beam state determination system 750, described infra. Charged Particle Control Referring now to FIG. 4A, FIG. 4B, FIG. 5, FIG. 6A, and FIG. 6B, a charged particle beam control system is described where one or more patient specific beam control assemblies are removably inserted into the charged particle beam path proximate the nozzle of the charged particle cancer therapy system 100, where the patient specific beam control assemblies adjust the beam energy, diameter, cross-sectional shape, focal point, and/or beam state of the charged particle beam to properly couple energy of the charged particle beam to the individual's specific tumor. Beam Control Tray Referring now to FIG. 4A and FIG. 4B, a beam control tray assembly 400 is illustrated in a top view and side view, respectively. The beam control tray assembly 400 optionally comprises any of a tray frame 410, a tray aperture 412, a tray handle 420, a tray connector/communicator 430, and means for holding a patient specific tray insert 510, described infra. Generally, the beam control tray assembly 400 is used to: (1) hold the patient specific tray insert 510 in a rigid location relative to the beam control tray 400, (2) electronically identify the held patient specific tray insert 510 to the main controller 110, and (3) removably insert the patient specific tray insert 510 into an accurate and precise fixed location relative to the charged particle beam, such as the proton beam path 268 at the nozzle of the charged particle cancer therapy system 100. For clarity of presentation and without loss of generality, the means for holding the patient specific tray insert 510 in the tray frame 410 of the beam control tray assembly 400 is illustrated as a set of recessed set screws 415. However, the means for holding the patient specific tray insert 510 relative to the rest of the beam control tray assembly 400 is optionally any mechanical and/or electromechanical positioning element, such as a latch, clamp, fastener, clip, slide, strap, or the like. Generally, the means for holding the patient specific tray insert 510 in the beam control tray 400 fixes the tray insert and tray frame relative to one another even when rotated along and/or around multiple axes, such as when attached to a charged particle cancer therapy system 100 dynamic gantry nozzle 610 or gantry nozzle, which is an optional element of the nozzle system 146, that moves in three-dimensional space relative to a fixed point in the beamline, proton beam path 268, and/or a given patient position. As illustrated in FIG. 4A and FIG. 4B, the recessed set screws 415 fix the patient specific tray insert 510 into the aperture 412 of the tray frame 410. The tray frame 410 is illustrated as circumferentially surrounding the patient specific tray insert 510, which aids in structural stability of the beam control tray assembly 400. However, generally the tray frame 410 is of any geometry that forms a stable beam control tray assembly 400. Still referring to FIG. 4A and now referring to FIG. 5 and FIG. 6A, the optional tray handle 420 is used to manually insert/retract the beam control tray assembly 400 into a receiving element of the gantry nozzle or dynamic gantry nozzle 610. While the beam control tray assembly 400 is optionally inserted into the charged particle beam path 268 at any point after extraction from the synchrotron 130, the beam control tray assembly 400 is preferably inserted into the positively charged particle beam proximate the dynamic gantry nozzle 610 as control of the beam shape is preferably done with little space for the beam shape to defocus before striking the tumor. Optionally, insertion and/or retraction of the beam control tray assembly 400 is semi-automated, such as in a manner of a digital-video disk player receiving a digital-video disk, with a selected auto load and/or a selected auto unload feature. Patient Specific Tray Insert Referring again to FIG. 5, a system of assembling trays 500 is described. The beam control tray assembly 400 optionally and preferably has interchangeable patient specific tray inserts 510, such as a range shifter insert 511, a patient specific ridge filter insert 512, an aperture insert 513, a compensator insert 514, or a blank insert 515. As described, supra, any of the range shifter insert 511, the patient specific ridge filter insert 512, the aperture insert 513, the compensator insert 514, or the blank insert 515 after insertion into the tray frame 410 are inserted as the beam control tray assembly 400 into the positively charged particle beam path 268, such as proximate the dynamic gantry nozzle 610. Still referring to FIG. 5, the patient specific tray inserts 510 are further described. The patient specific tray inserts comprise a combination of any of: (1) a standardized beam control insert and (2) a patient specific beam control insert. For example, the range shifter insert or 511 or compensator insert 514 used to control the depth of penetration of the charged particle beam into the patient is optionally: (a) a standard thickness of a beam slowing material, such as a first thickness of Lucite, (b) one member of a set of members of varying thicknesses and/or densities where each member of the set of members slows the charged particles in the beam path by a known amount, or (c) is a material with a density and thickness designed to slow the charged particles by a customized amount for the individual patient being treated, based on the depth of the individual's tumor in the tissue, the thickness of intervening tissue, and/or the density of intervening bone/tissue. Similarly, the ridge filter insert 512 used to change the focal point or shape of the beam as a function of depth is optionally: (1) selected from a set of ridge filters where different members of the set of ridge filters yield different focal depths or (2) customized for treatment of the individual's tumor based on position of the tumor in the tissue of the individual. Similarly, the aperture insert is: (1) optionally selected from a set of aperture shapes or (2) is a customized individual aperture insert 513 designed for the specific shape of the individual's tumor. The blank insert 515 is an open slot, but serves the purpose of identifying slot occupancy, as described infra. Slot Occupancy/Identification Referring again to FIG. 4A, FIG. 4B, and FIG. 5, occupancy and identification of the particular patient specific tray insert 510 into the beam control tray assembly 400 is described. Generally, the beam control tray assembly 400 optionally contains means for identifying, to the main controller 110 and/or a treatment delivery control system described infra, the specific patient tray insert 510 and its location in the charged particle beam path 268. First, the particular tray insert is optionally labeled and/or communicated to the beam control tray assembly 400 or directly to the main controller 110. Second, the beam control tray assembly 400 optionally communicates the tray type and/or tray insert to the main controller 110. In various embodiments, communication of the particular tray insert to the main controller 110 is performed: (1) directly from the tray insert, (2) from the tray insert 510 to the tray assembly 400 and subsequently to the main controller 110, and/or (3) directly from the tray assembly 400. Generally, communication is performed wirelessly and/or via an established electromechanical link. Identification is optionally performed using a radio-frequency identification label, use of a barcode, or the like, and/or via operator input. Examples are provided to further clarify identification of the patient specific tray insert 510 in a given beam control tray assembly 400 to the main controller. In a first example, one or more of the patient specific tray inserts 510, such as the range shifter insert 511, the patient specific ridge filter insert 512, the aperture insert 513, the compensator insert 514, or the blank insert 515 include an identifier 520 and/or and a first electromechanical identifier plug 530. The identifier 520 is optionally a label, a radio-frequency identification tag, a barcode, a 2-dimensional bar-code, a matrix-code, or the like. The first electromechanical identifier plug 530 optionally includes memory programmed with the particular patient specific tray insert information and a connector used to communicate the information to the beam control tray assembly 400 and/or to the main controller 110. As illustrated in FIG. 5, the first electromechanical identifier plug 530 affixed to the patient specific tray insert 510 plugs into a second electromechanical identifier plug, such as the tray connector/communicator 430, of the beam control tray assembly 400, which is described infra. In a second example, the beam control tray assembly 400 uses the second electromechanical identifier plug to send occupancy, position, and/or identification information related to the type of tray insert or the patient specific tray insert 510 associated with the beam control tray assembly to the main controller 110. For example, a first tray assembly is configured with a first tray insert and a second tray assembly is configured with a second tray insert. The first tray assembly sends information to the main controller 110 that the first tray assembly holds the first tray insert, such as a range shifter, and the second tray assembly sends information to the main controller 110 that the second tray assembly holds the second tray insert, such as an aperture. The second electromechanical identifier plug optionally contains programmable memory for the operator to input the specific tray insert type, a selection switch for the operator to select the tray insert type, and/or an electromechanical connection to the main controller. The second electromechanical identifier plug associated with the beam control tray assembly 400 is optionally used without use of the first electromechanical identifier plug 530 associated with the tray insert 510. In a third example, one type of tray connector/communicator 430 is used for each type of patient specific tray insert 510. For example, a first connector/communicator type is used for holding a range shifter insert 511, while a second, third, fourth, and fifth connector/communicator type is used for trays respectively holding a patient specific ridge filter insert 512, an aperture insert 513, a compensator insert 514, or a blank insert 515. In one case, the tray communicates tray type with the main controller. In a second case, the tray communicates patient specific tray insert information with the main controller, such as an aperture identifier custom built for the individual patient being treated. Tray Insertion/Coupling Referring now to FIG. 6A and FIG. 6B a beam control insertion process 600 is described. The beam control insertion process 600 comprises: (1) insertion of the beam control tray assembly 400 and the associated patient specific tray insert 510 into the charged particle beam path 268 and/or dynamic gantry nozzle 610, such as into a tray assembly receiver 620 and (2) an optional partial or total retraction of beam of the tray assembly receiver 620 into the dynamic gantry nozzle 610. Referring now to FIG. 6A, insertion of one or more of the beam control tray assemblies 400 and the associated patient specific tray inserts 510 into the dynamic gantry nozzle 610 is further described. In FIG. 6A, three beam control tray assemblies, of a possible n tray assemblies, are illustrated, a first tray assembly 402, a second tray assembly 404, and a third tray assembly 406, where n is a positive integer of 1, 2, 3, 4, 5 or more. As illustrated, the first tray assembly 402 slides into a first receiving slot 403, the second tray assembly 404 slides into a second receiving slot 405, and the third tray assembly 406 slides into a third receiving slot 407. Generally, any tray optionally inserts into any slot or tray types are limited to particular slots through use of a mechanical, physical, positional, and/or steric constraints, such as a first tray type configured for a first insert type having a first size and a second tray type configured for a second insert type having a second distinct size at least ten percent different from the first size. Still referring to FIG. 6A, identification of individual tray inserts inserted into individual receiving slots is further described. As illustrated, sliding the first tray assembly 402 into the first receiving slot 403 connects the associated electromechanical connector/communicator 430 of the first tray assembly 402 to a first receptor 626. The electromechanical connector/communicator 430 of the first tray assembly communicates tray insert information of the first beam control tray assembly to the main controller 110 via the first receptor 626. Similarly, sliding the second tray assembly 404 into the second receiving slot 405 connects the associated electromechanical connector/communicator 430 of the second tray assembly 404 into a second receptor 627, which links communication of the associated electromechanical connector/communicator 430 with the main controller 110 via the second receptor 627, while a third receptor 628 connects to the electromechanical connected placed into the third slot 407. The non-wireless/direct connection is preferred due to the high radiation levels within the treatment room and the high shielding of the treatment room, which both hinder wireless communication. The connection of the communicator and the receptor is optionally of any configuration and/or orientation. Tray Receiver Assembly Retraction Referring again to FIG. 6A and FIG. 6B, retraction of the tray receiver assembly 620 relative to a nozzle end 612 of the dynamic gantry nozzle 610 is described. The tray receiver assembly 620 comprises a framework to hold one or more of the beam control tray assemblies 400 in one or more slots, such as through use of a first tray receiver assembly side 622 through which the beam control tray assemblies 400 are inserted and/or through use of a second tray receiver assembly side 624 used as a backstop, as illustrated holding the plugin receptors configured to receive associated tray connector/communicators 430, such as the first, second, and third receptors 626, 627, 628. Optionally, the tray receiver assembly 620 retracts partially or completely into the dynamic gantry nozzle 610 using a retraction mechanism 660 configured to alternatingly retract and extend the tray receiver assembly 620 relative to a nozzle end 612 of the gantry nozzle 610, such as along a first retraction track 662 and a second retraction track 664 using one or more motors and computer control. Optionally the tray receiver assembly 620 is partially or fully retracted when moving the gantry, nozzle, and/or gantry nozzle 610 to avoid physical constraints of movement, such as potential collision with another object in the patient treatment room. For clarity of presentation and without loss of generality, several examples of loading patient specific tray inserts into tray assemblies with subsequent insertion into an positively charged particle beam path proximate a gantry nozzle 610 are provided. In a first example, a single beam control tray assembly 400 is used to control the charged particle beam 268 in the charged particle cancer therapy system 100. In this example, a patient specific range shifter insert 511, which is custom fabricated for a patient, is loaded into a patient specific tray insert 510 to form a first tray assembly 402, where the first tray assembly 402 is loaded into the third receptor 628, which is fully retracted into the gantry nozzle 610. In a second example, two beam control assemblies 400 are used to control the charged particle beam 268 in the charged particle cancer therapy system 100. In this example, a patient specific ridge filter 512 is loaded into a first tray assembly 402, which is loaded into the second receptor 627 and a patient specific aperture 513 is loaded into a second tray assembly 404, which is loaded into the first receptor 626 and the two associated tray connector/communicators 430 using the first receptor 626 and second receptor 627 communicate to the main controller 110 the patient specific tray inserts 510. The tray receiver assembly 620 is subsequently retracted one slot so that the patient specific ridge filter 512 and the patient specific aperture reside outside of and at the nozzle end 612 of the gantry nozzle 610. In a third example, three beam control tray assemblies 400 are used, such as a range shifter 511 in a first tray inserted into the first receiving slot 403, a compensator in a second tray inserted into the second receiving slot 405, and an aperture in a third tray inserted into the third receiving slot 407. Generally, any patient specific tray insert 510 is inserted into a tray frame 410 to form a beam control tray assembly 400 inserted into any slot of the tray receiver assembly 620 and the tray assembly is not retracted or retracted any distance into the gantry nozzle 610. Tomography/Beam State In one embodiment, the charged particle tomography apparatus is used to image a tumor in a patient. As current beam position determination/verification is used in both tomography and cancer therapy treatment, for clarity of presentation and without limitation beam state determination is also addressed in this section. However, beam state determination is optionally used separately and without tomography. In another example, the charged particle tomography apparatus is used in combination with a charged particle cancer therapy system using common elements. For example, tomographic imaging of a cancerous tumor is performed using charged particles generated with an injector, accelerator, and guided with a delivery system that are part of the cancer therapy system, described supra. In various examples, the tomography imaging system is optionally simultaneously operational with a charged particle cancer therapy system using common elements, allows tomographic imaging with rotation of the patient, is operational on a patient in an upright, semi-upright, and/or horizontal position, is simultaneously operational with X-ray imaging, and/or allows use of adaptive charged particle cancer therapy. Further, the common tomography and cancer therapy apparatus elements are optionally operational in a multi-axis and/or multi-field raster beam mode. In conventional medical X-ray tomography, a sectional image through a body is made by moving one or both of an X-ray source and the X-ray film in opposite directions during the exposure. By modifying the direction and extent of the movement, operators can select different focal planes, which contain the structures of interest. More modern variations of tomography involve gathering projection data from multiple directions by moving the X-ray source and feeding the data into a tomographic reconstruction software algorithm processed by a computer. Herein, in stark contrast to known methods, the radiation source is a charged particle, such as a proton ion beam or a carbon ion beam. A proton beam is used herein to describe the tomography system, but the description applies to a heavier ion beam, such as a carbon ion beam. Further, in stark contrast to known techniques, herein the radiation source is preferably stationary while the patient is rotated. Referring now to FIG. 7, an example of a tomography apparatus is described and an example of a beam state determination is described. In this example, the tomography system 700 uses elements in common with the charged particle beam system 100, including elements of one or more of the injection system 120, accelerator 130, targeting/delivery system 140, patient interface module 150, display system 160, and/or imaging system 170, such as the X-ray imaging system. One or more scintillation plates, such as a scintillating plastic, are used to measure energy, intensity, and/or position of the charged particle beam. For instance, a scintillation plate 710 is positioned behind the patient 730 relative to the targeting/delivery system 140 elements, which is optionally used to measure intensity and/or position of the charged particle beam after transmitting through the patient. Optionally, a second scintillation plate or a charged particle induced photon emitting sheet, described infra, is positioned prior to the patient 730 relative to the targeting/delivery system 140 elements, which is optionally used to measure incident intensity and/or position of the charged particle beam prior to transmitting through the patient. The charged particle beam system 100 as described has proven operation at up to and including 330 MeV, which is sufficient to send protons through the body and into contact with the scintillation material. Particularly, 250 MeV to 330 MeV are used to pass the beam through a standard sized patient with a standard sized pathlength, such as through the chest. The intensity or count of protons hitting the plate as a function of position is used to create an image. The velocity or energy of the proton hitting the scintillation plate is also used in creation of an image of the tumor 720 and/or an image of the patient 730. The patient 730 is rotated about the y-axis and a new image is collected. Preferably, a new image is collected with about every one degree of rotation of the patient resulting in about 360 images that are combined into a tomogram using tomographic reconstruction software. The tomographic reconstruction software uses overlapping rotationally varied images in the reconstruction. Optionally, a new image is collected at about every 2, 3, 4, 5, 10, 15, 30, or 45 degrees of rotation of the patient. In one embodiment, a tomogram or an individual tomogram section image is collected at about the same time as cancer therapy occurs using the charged particle beam system 100. For example, a tomogram is collected and cancer therapy is subsequently performed: without the patient moving from the positioning systems, such as in a semi-vertical partial immobilization system, a sitting partial immobilization system, or the a laying position. In a second example, an individual tomogram slice is collected using a first cycle of the accelerator 130 and using a following cycle of the accelerator 130, the tumor 720 is irradiated, such as within about 1, 2, 5, 10, 15 or 30 seconds. In a third case, about 2, 3, 4, or 5 tomogram slices are collected using 1, 2, 3, 4, or more rotation positions of the patient 730 within about 5, 10, 15, 30, or 60 seconds of subsequent tumor irradiation therapy. In another embodiment, the independent control of the tomographic imaging process and X-ray collection process allows simultaneous single and/or multi-field collection of X-ray images and tomographic images easing interpretation of multiple images. Indeed, the X-ray and tomographic images are optionally overlaid to from a hybrid X-ray/proton beam tomographic image as the patient 730 is optionally in the same position for each image. In still another embodiment, the tomogram is collected with the patient 730 in the about the same position as when the patient's tumor is treated using subsequent irradiation therapy. For some tumors, the patient being positioned in the same upright or semi-upright position allows the tumor 720 to be separated from surrounding organs or tissue of the patient 730 better than in a laying position. Positioning of the scintillation plate 710 behind the patient 730 allows the tomographic imaging to occur while the patient is in the same upright or semi-upright position. The use of common elements in the tomographic imaging and in the charged particle cancer therapy allows benefits of the cancer therapy, described supra, to optionally be used with the tomographic imaging, such as proton beam x-axis control, proton beam y-axis control, control of proton beam energy, control of proton beam intensity, timing control of beam delivery to the patient, rotation control of the patient, and control of patient translation all in a raster beam mode of proton energy delivery. The use of a single proton or cation beamline for both imaging and treatment facilitates eases patient setup, reduces alignment uncertainties, reduces beam sate uncertainties, and eases quality assurance. In yet still another embodiment, initially a three-dimensional tomographic proton based reference image is collected, such as with hundreds of individual rotation images of the tumor 720 and patient 730. Subsequently, just prior to proton treatment of the cancer, just a few 2-dimensional control tomographic images of the patient are collected, such as with a stationary patient or at just a few rotation positions, such as an image straight on to the patient, with the patient rotated about 45 degrees each way, and/or the patient rotated about 90 degrees each way about the y-axis. The individual control images are compared with the 3-dimensional reference image. An adaptive proton therapy is subsequently performed where: (1) the proton cancer therapy is not used for a given position based on the differences between the 3-dimensional reference image and one or more of the 2-dimensional control images and/or (2) the proton cancer therapy is modified in real time based on the differences between the 3-dimensional reference image and one or more of the 2-dimensional control images. Charged Particle State Determination/Verification/Photonic Monitoring Still referring to FIG. 7, the tomography system 700 is optionally used with a charged particle beam state determination system 750, optionally used as a charged particle verification system. The charged particle state determination system 750 optionally measures, determines, and/or verifies one of more of: (1) position of the charged particle beam, (2) direction of the charged particle beam, (3) intensity of the charged particle beam, (4) energy of the charged particle beam, and (5) a history of the charged particle beam. For clarity of presentation and without loss of generality, a description of the charged particle beam state determination system 750 is described and illustrated separately in FIG. 8 and FIG. 9; however, as described herein elements of the charged particle beam state determination system 750 are optionally and preferably integrated into the nozzle system 146 and/or the tomography system 700 of the charged particle treatment system 100. More particularly, any element of the charged particle beam state determination system 750 is integrated into the nozzle system 146, the dynamic gantry nozzle 610, and/or tomography system 700, such as a surface of the scintillation plate 710 or a surface of a scintillation detector, plate, or system. The nozzle system 146 or the dynamic gantry nozzle 610 provides an outlet of the charged particle beam from the vacuum tube initiating at the injection system 120 and passing through the synchrotron 130 and beam transport system 135. Any plate, sheet, fluorophore, or detector of the charged particle beam state determination system is optionally integrated into the nozzle system 146. For example, an exit foil of the nozzle 610 is optionally a first sheet 760 of the charged particle beam state determination system 750 and a first coating 762 is optionally coated onto the exit foil, as illustrated in FIG. 7. Similarly, optionally a surface of the scintillation plate 710 is a support surface for a fourth coating 792, as illustrated in FIG. 7. The charged particle beam state determination system 750 is further described, infra. Referring now to FIG. 7, FIG. 8, and FIG. 9, four sheets, a first sheet 760, a second sheet 770, a third sheet 780, and a fourth sheet 790 are used to illustrated detection sheets and/or photon emitting sheets upon transmittance of a charged particle beam. Each sheet is optionally coated with a photon emitter, such as a fluorophore, such as the first sheet 760 is optionally coated with a first coating 762. Without loss of generality and for clarity of presentation, the four sheets are each illustrated as units, where the light emitting layer is not illustrated. Thus, for example, the second sheet 770 optionally refers to a support sheet, a light emitting sheet, and/or a support sheet coated by a light emitting element. The four sheets are representative of n sheets, where n is a positive integer. Referring now to FIG. 7 and FIG. 8, the charged particle beam state verification system 750 is a system that allows for monitoring of the actual charged particle beam position in real-time without destruction of the charged particle beam. The charged particle beam state verification system 750 preferably includes a first position element or first beam verification layer, which is also referred to herein as a coating, luminescent, fluorescent, phosphorescent, radiance, or viewing layer. The first position element optionally and preferably includes a coating or thin layer substantially in contact with a sheet, such as an inside surface of the nozzle foil, where the inside surface is on the synchrotron side of the nozzle foil. Less preferably, the verification layer or coating layer is substantially in contact with an outer surface of the nozzle foil, where the outer surface is on the patient treatment side of the nozzle foil. Preferably, the nozzle foil provides a substrate surface for coating by the coating layer. Optionally, a binding layer is located between the coating layer and the nozzle foil, substrate, or support sheet. Optionally, the position element is placed anywhere in the charged particle beam path. Optionally, more than one position element on more than one sheet, respectively, is used in the charged particle beam path and is used to determine a state property of the charged particle beam, as described infra. Still referring to FIG. 7 and FIG. 8, the coating, referred to as a fluorophore, yields a measurable spectroscopic response, spatially viewable by a detector or camera, as a result of transmission by the proton beam. The coating is preferably a phosphor, but is optionally any material that is viewable or imaged by a detector where the material changes spectroscopically as a result of the charged particle beam hitting or transmitting through the coating or coating layer. A detector or camera views secondary photons emitted from the coating layer and determines a current position of the charged particle beam 269 or final treatment vector of the charged particle beam by the spectroscopic differences resulting from protons and/or charged particle beam passing through the coating layer. For example, the camera views a surface of the coating surface as the proton beam or positively charged cation beam is being scanned by the first axis control 142, vertical control, and the second axis control 144, horizontal control, beam position control elements during treatment of the tumor 720. The camera views the current position of the charged particle beam 269 as measured by spectroscopic response. The coating layer is preferably a phosphor or luminescent material that glows and/or emits photons for a short period of time, such as less than 5 seconds for a 50% intensity, as a result of excitation by the charged particle beam. The detector observes the temperature change and/or observe photons emitted from the charged particle beam traversed spot. Optionally, a plurality of cameras or detectors are used, where each detector views all or a portion of the coating layer. For example, two detectors are used where a first detector views a first half of the coating layer and the second detector views a second half of the coating layer. Preferably, at least a portion of the detector is mounted into the nozzle system to view the proton beam position after passing through the first axis and second axis controllers 142, 144. Preferably, the coating layer is positioned in the proton beam path 268 in a position prior to the protons striking the patient 730. Referring now to FIG. 1 and FIG. 7, the main controller 110, connected to the camera or detector output, optionally and preferably compares the final proton beam position 269 with the planned proton beam position and/or a calibration reference to determine if the actual proton beam position 269 is within tolerance. The charged particle beam state determination system 750 preferably is used in one or more phases, such as a calibration phase, a mapping phase, a beam position verification phase, a treatment phase, and a treatment plan modification phase. The calibration phase is used to correlate, as a function of x-, y-position of the glowing response the actual x-, y-position of the proton beam at the patient interface. During the treatment phase, the charged particle beam position is monitored and compared to the calibration and/or treatment plan to verify accurate proton delivery to the tumor 720 and/or as a charged particle beam shutoff safety indicator. Referring now to FIG. 10, the position verification system 172 and/or the treatment delivery control system 112, upon determination of a tumor shift, an unpredicted tumor distortion upon treatment, and/or a treatment anomaly optionally generates and or provides a recommended treatment change 1070. The treatment change 1070 is optionally sent out while the patient 730 is still in the treatment position, such as to a proximate physician or over the internet to a remote physician, for physician approval 1072, receipt of which allows continuation of the now modified and approved treatment plan. Referring now to FIG. 8, a second example of the charged particle beam state determination system 750 is illustrated using three cation induced signal generation surfaces, referred to herein as the second sheet 770, the third sheet 780, and the fourth sheet 790. Any of the second sheet 770, the third sheet 780, and the fourth sheet 790 contain any of the features of the sheets described supra. Still referring to FIG. 8, in the second example, the second sheet 770, positioned prior to the patient 730, is optionally integrated into the nozzle 146, but is illustrated as a separate sheet. Signal derived from the second sheet 770, such as at point A, is optionally combined with signal from the first sheet 760 and/or state of the targeting/delivery system 140 to yield a first vector, v1a, from point A to point B of the charged particle beam prior to the sample or patient 730 at a first time, t1, and a second vector, v2a, from point F to point G of the charged particle beam prior to the sample at a second time, t2. Still referring to FIG. 8, in the second example, the third sheet 780 and the fourth sheet 790, positioned posterior to the patient 730, are optionally integrated into the tomography system 700, but are illustrated as a separate sheets. Signal derived from the third sheet 780, such as at point D, is optionally combined with signal from the fourth sheet 790 and/or signal from the tomography system 700 to yield a first vector, v1b, from point C2 to point D and/or from point D to point E of the charged particle beam posterior to the patient 730 at the first time, t1, and a second vector, v2a, such as from point H to point I of the charged particle beam posterior to the sample at a second time, t2. Signal derived from the third sheet 780 and/or from the fourth sheet 790 and the corresponding first vector at the second time, t2, is used to determine an output point, C2, which may and often does differ from an extension of the first vector, v1a, from point A to point B through the patient to a non-scattered beam path of point C1. The difference between point C1 and point C2 and/or an angle, α, between the first vector at the first time, v1a, and the first vector at the second time, v1b, is used to determine/map/identify, such as via tomographic analysis, internal structure of the patient 730, sample, and/or the tumor 720, especially when combined with scanning the charged particle beam in the x/y-plane as a function of time, such as illustrated by the second vector at the first time, v2a, and the second vector at the second time, v2b, forming angle β and/or with rotation of the patient 730, such as about the y-axis, as a function of time. Still referring to FIG. 8, multiple detectors/detector arrays are illustrated for detection of signals from multiple sheets, respectively. However, a single detector/detector array is optionally used to detect signals from multiple sheets, as further described infra. As illustrated, a set of detectors 810 is illustrated, including a second detector 814 imaging the second sheet 770, a third detector 816 imaging the third sheet 780, and a fourth detector 818 imaging the fourth sheet 790. Any of the detectors described herein are optionally detector arrays, are optionally coupled with any optical filter, and/or optionally use one or more intervening optics to image any of the four sheets 760, 770, 780, 790. Further, two or more detectors optionally image a single sheet, such as a region of the sheet, to aid optical coupling, such as F-number optical coupling. Still referring to FIG. 8, a vector of the charged particle beam is determined. Particularly, in the illustrated example, the third detector 816, determines, via detection of secondary emitted photons, that the charged particle beam transmitted through point D and the fourth detector 818 determines that the charged particle beam transmitted through point E, where points D and E are used to determine the first vector at the second time, v1b, as described supra. To increase accuracy and precision of a determined vector of the charged particle beam, a first determined beam position and a second determined beam position are optionally and preferably separated by a distance, d1, such as greater than 0.1, 0.5, 1, 2, 3, 5, 10, or more centimeters. A support element 752 is illustrated that optionally connects any two or more elements of the charged particle beam state determination system 750 to each other and/or to any element of the charged particle beam system 100, such as a rotating platform 756 used to co-rotate the patient 730 and any element of the tomography system 700. Still referring to FIG. 9, a third example of the charged particle beam state determination system 750 is illustrated in an integrated tomography-cancer therapy system 900. Referring to FIG. 9, multiple sheets and multiple detectors are illustrated determining a charged particle beam state prior to the patient 730. As illustrated, a first camera 812 spatially images photons emitted from the first sheet 760 at point A, resultant from energy transfer from the passing charged particle beam, to yield a first signal and a second camera 814 spatially images photons emitted from the second sheet 770 at point B, resultant from energy transfer from the passing charged particle beam, to yield a second signal. The first and second signals allow calculation of the first vector, v1a, with a subsequent determination of an entry point 732 of the charged particle beam into the patient 730. Determination of the first vector, v1a, is optionally supplemented with information derived from states of the magnetic fields about the first axis control 142, the vertical control, and the second axis control 144, the horizontal axis control, as described supra. Still referring to FIG. 9, the charged particle beam state determination system is illustrated with multiple resolvable wavelengths of light emitted as a result of the charged particle beam transmitting through more than one molecule type, light emission center, and/or fluorophore type. For clarity of presentation and without loss of generality a first fluorophore in the third sheet 780 is illustrated as emitting blue light, b, and a second fluorophore in the fourth sheet 790 is illustrated as emitting red light, r, that are both detected by the third detector 816. The third detector is optionally coupled with any wavelength separation device, such as an optical filter, grating, or Fourier transform device. For clarity of presentation, the system is described with the red light passing through a red transmission filter blocking blue light and the blue light passing through a blue transmission filter blocking red light. Wavelength separation, using any means, allows one detector to detect a position of the charged particle beam resultant in a first secondary emission at a first wavelength, such as at point C, and a second secondary emission at a second wavelength, such as at point D. By extension, with appropriate optics, one camera is optionally used to image multiple sheets and/or sheets both prior to and posterior to the sample. Spatial determination of origin of the red light and the blue light allow calculation of the first vector at the second time, V1b, and an actual exit point 736 from the patient 730 as compared to a non-scattered exit point 734 from the patient 730 as determined from the first vector at the first time, V1a. Still referring to FIG. 9, the integrated tomography-cancer therapy system 900 is illustrated with an optional configuration of elements of the charged particle beam state determination system 750 being co-rotatable with the nozzle 146 of the cancer therapy system 100. More particularly, in one case sheets of the charged particle beam state determination system 750 positioned prior to, posterior to, or on both sides of the patient 730 co-rotate with the scintillation plate 710 about any axis, such as illustrated with rotation about the y-axis. In various cases, co-rotation is achieved by co-rotation of the gantry of the charged particle beam system and a support of the patient, such as the rotatable platform 756, which is also referred to herein as a movable or dynamically positionable patient platform, patient chair, or patient couch. Mechanical elements, such as the support element 752 affix the various elements of the charged particle beam state determination system 750 relative to each other, relative to the nozzle 146, and/or relative to the patient 730. For example, the support elements 752 maintain a second distance, d2, between a position of the tumor 720 and the third screen 780 and/or maintain a third distance, d3, between a position of the third screen 780 and the scintillation plate 710. More generally, support elements 752 optionally dynamically position any element about the patient 730 relative to one another or in x,y,z-space in a patient diagnostic/treatment room, such as via computer control. System Integration Any of the systems and/or elements described herein are optionally integrated together and/or are optionally integrated with known systems. Treatment Delivery Control System Referring now to FIG. 10, a centralized charged particle treatment system 1000 is illustrated. Generally, once a charged particle therapy plan is devised, a central control system or treatment delivery control system 112 is used to control sub-systems while reducing and/or eliminating direct communication between major subsystems. Generally, the treatment delivery control system 112 is used to directly control multiple subsystems of the cancer therapy system without direct communication between selected subsystems, which enhances safety, simplifies quality assurance and quality control, and facilitates programming. For example, the treatment delivery control system 112 directly controls one or more of: an imaging system, a positioning system, an injection system, a radio-frequency quadrupole system, a linear accelerator, a ring accelerator or synchrotron, an extraction system, a beam line, an irradiation nozzle, a gantry, a display system, a targeting system, and a verification system. Generally, the control system integrates subsystems and/or integrates output of one or more of the above described cancer therapy system elements with inputs of one or more of the above described cancer therapy system elements. Still referring to FIG. 10, an example of the centralized charged particle treatment system 1000 is provided. Initially, a doctor, such as an oncologist, prescribes 1010 or recommends tumor therapy using charged particles. Subsequently, treatment planning 1020 is initiated and output of the treatment planning step 1020 is sent to an oncology information system 1030 and/or is directly sent to the treatment delivery system 112, which is an example of the main controller 110. Still referring to FIG. 10, the treatment planning step 1020 is further described. Generally, radiation treatment planning is a process where a team of oncologist, radiation therapists, medical physicists, and/or medical dosimetrists plan appropriate charged particle treatment of a cancer in a patient. Typically, one or more imaging systems 170 are used to image the tumor and/or the patient, described infra. Planning is optionally: (1) forward planning and/or (2) inverse planning. Cancer therapy plans are optionally assessed with the aid of a dose-volume histogram, which allows the clinician to evaluate the uniformity of the dose to the tumor and surrounding healthy structures. Typically, treatment planning is almost entirely computer based using patient computed tomography data sets using multimodality image matching, image coregistration, or fusion. Forward Planning In forward planning, a treatment oncologist places beams into a radiotherapy treatment planning system including: how many radiation beams to use and which angles to deliver each of the beams from. This type of planning is used for relatively simple cases where the tumor has a simple shape and is not near any critical organs. Inverse Planning In inverse planning, a radiation oncologist defines a patient's critical organs and tumor and gives target doses and importance factors for each. Subsequently, an optimization program is run to find the treatment plan which best matches all of the input criteria. Oncology Information System Still referring to FIG. 10, the oncology information system 1030 is further described. Generally, the oncology information system 1030 is one or more of: (1) an oncology-specific electronic medical record, which manages clinical, financial, and administrative processes in medical, radiation, and surgical oncology departments; (2) a comprehensive information and image management system; and (3) a complete patient information management system that centralizes patient data; and (4) a treatment plan provided to the charged particle beam system 100, main controller 110, and/or the treatment delivery control system 112. Generally, the oncology information system 1030 interfaces with commercial charged particle treatment systems. Safety System/Treatment Delivery Control System Still referring to FIG. 10, the treatment delivery control system 112 is further described. Generally, the treatment delivery control system 112 receives treatment input, such as a charged particle cancer treatment plan from the treatment planning step 1020 and/or from the oncology information system 1030 and uses the treatment input and/or treatment plan to control one or more subsystems of the charged particle beam system 100. The treatment delivery control system 112 is an example of the main controller 110, where the treatment delivery control system receives subsystem input from a first subsystem of the charged particle beam system 100 and provides to a second subsystem of the charged particle beam system 100: (1) the received subsystem input directly, (2) a processed version of the received subsystem input, and/or (3) a command, such as used to fulfill requisites of the treatment planning step 1020 or direction of the oncology information system 1030. Generally, most or all of the communication between subsystems of the charged particle beam system 100 go to and from the treatment delivery control system 112 and not directly to another subsystem of the charged particle beam system 100. Use of a logically centralized treatment delivery control system has many benefits, including: (1) a single centralized code to maintain, debug, secure, update, and to perform checks on, such as quality assurance and quality control checks; (2) a controlled logical flow of information between subsystems; (3) an ability to replace a subsystem with only one interfacing code revision; (4) room security; (5) software access control; (6) a single centralized control for safety monitoring; and (7) that the centralized code results in an integrated safety system 1040 encompassing a majority or all of the subsystems of the charged particle beam system 100. Examples of subsystems of the charged particle cancer therapy system 100 include: a radio frequency quadrupole 1050, a radio frequency quadrupole linear accelerator, the injection system 120, the synchrotron 130, the accelerator system 132, the extraction system 134, any controllable or monitorable element of the beam line 268, the targeting/delivery system 140, the nozzle 146, a gantry 1060 or an element of the gantry 1060, the patient interface module 150, a patient positioner 152, the display system 160, the imaging system 170, a patient position verification system 172, any element described supra, and/or any subsystem element. A treatment change 1070 at time of treatment is optionally computer generated with or without the aid of a technician or physician and approved while the patient is still in the treatment room, in the treatment chair, and/or in a treatment position. Safety Referring now to FIG. 11, a redundant safety system 1100 is described. In one optional and preferred embodiment, the charged particle beam system 100 includes redundant systems for determination of one or more of: (1) beam position, (2) beam direction, (3) beam intensity, (4) beam energy, and (5) beam shape. The redundant safety system 1000 is further described herein. Beam Position A beam positioning system 1110 or beam position determination/verification system is linked to the main controller 100 or treatment delivery control system 112. The beam positioning system 1110 includes any electromechanical system, optical system, and/or calculation for determining a current position of the charged particle beam. In a first case, after calibration, the scanning/targeting/delivery system 140 uses x/y-positioning magnets, such as in the first axis control 142 and the second axis control 144, to position the charged particle beam. In a second case, a photonic emission position system 1114 is used to measure a position of the charged particle beam, where the photonic emission system 1114 uses a secondary emission of a photon upon passage of the charged particle beam, such as described supra for the first sheet 760, the second sheet 770, the third sheet 780, and the fourth sheet 790. In a third a case, a scintillation positioning system 1116, such as via use of a detector element in the tomography system 700, is used to measure a position of the charged particle beam. Any permutation or combination of the three cases described herein yield multiple or redundant measures of the charged particle beam position and therefrom one or more measures of a charged particle beam vector during a period of time. Beam Intensity A beam intensity system 1120 or beam intensity determination/verification system is linked to the main controller 100 or treatment delivery control system 112. Herein, intensity is a number of positively charged particles passing a point or plane as a function of time. The beam intensity system 1110 includes any electromechanical system, optical system, and/or calculation for determining a current intensity of the charged particle beam. In a first case, the extraction system 134 uses an electron emission system 1122, such as a secondary emission of electrons upon passage of the charged particle beam through the extraction material 330, to determine an intensity of the charged particle beam. In a second case, the duration of the applied RF-field and/or a magnitude of the RF-field applied in the RF-cavity system 310 is used to calculate the intensity of the charged particle beam, as described supra. In a third case, a photon emission system 1124, such as a magnitude of a signal representing the emitted photons from the photonic emission system 1114, is used to measure the intensity of the charged particle beam. In a fourth case, a scintillation intensity determination system 1126 measures the intensity of the charged particle beam, such as with a detector of the tomography system 700. Beam Energy A beam energy system 1130 or beam energy determination/verification system is linked to the main controller 100 or treatment delivery control system 112. Herein, energy is optionally referred to as a velocity of the positively charged particles passing a point, where energy is dependent upon mass of the charged particles. The beam energy system 1110 includes any electromechanical system, optical system, and/or calculation for determining a current energy of the charged particle beam. In a first case, an RF-cavity energy system 1132 calculates an energy of the charged particles in the charged particle beam, such as via relating a period of an applied RF-field in the RF-cavity system 310 to energy, such as described supra. In a second case, an in-line energy system 1134 is used to measure a value related to beam energy, such as described above in equations 1 and 2. In a third case, a scintillation energy system 1136 is used to measure an energy of the charged particle beam, such as via use of a detector in the tomography system 700. Optionally and preferably, two or more measures/determination/calculations of a beam state property, such as position, direction, shape, intensity, and/or energy yield a redundant measure of the measured state for use in a beam safety system and/or an emergency beam shut-off system. Optionally and preferably, the two or more measures of a beam state property are used to enhance precision and/or accuracy of determination of the beam state property through statistical means. Optionally and preferably, any of the beam state properties are recorded and/or used to predict a future state, such as position, intensity, and/or energy of the charged particle beam, such as in a neighboring voxel in the tumor 720 adjacent to a currently treated voxel in the tumor 720 of the patient 730. Still yet another embodiment includes any combination and/or permutation of any of the elements described herein. Herein, any number, such as 1, 2, 3, 4, 5, is optionally more than the number, less than the number, or within 1, 2, 5, 10, 20, or 50 percent of the number. The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the present invention in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in a practical system. In the foregoing description, the invention has been described with reference to specific exemplary embodiments; however, it will be appreciated that various modifications and changes may be made without departing from the scope of the present invention as set forth herein. The description and figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the generic embodiments described herein and their legal equivalents rather than by merely the specific examples described above. For example, the steps recited in any method or process embodiment may be executed in any order and are not limited to the explicit order presented in the specific examples. Additionally, the components and/or elements recited in any apparatus embodiment may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present invention and are accordingly not limited to the specific configuration recited in the specific examples. Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problems or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components. As used herein, the terms “comprises”, “comprising”, or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same. Although the invention has been described herein with reference to certain preferred embodiments, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention. Accordingly, the invention should only be limited by the Claims included below.
	description	Referring now to the drawing figures, particularly to FIG. 1, there is illustrated a nuclear fuel bundle, generally designated 10. Bundle 10 includes an outer channel 12 surrounding an upper tie plate 14 and a lower tie plate 16. A plurality of fuel rods 18 are disposed in a matrix within the fuel bundle 10 and pass through a plurality of spacers 20 vertically spaced one from the other maintaining the fuel rods in the predetermined matrix thereof. In the illustrated form of FIG. 1, the matrix is a 10xc3x9710 array. A pair of water rods 22 and 24 are disposed in the fuel rods between the lower tie plate 16 and the upper tie plate 14. The water rods serve to transfer moderator fluid from the lower regions of the nuclear fuel bundle to the upper regions, where the water is dispersed through openings in the water rod for flow into the bundle in and about the fuel rods as illustrated in FIG. 1A, the lower tie plate 16 receives end plugs 26 formed on the lower ends of the water rods. The lower ends of the water rods have openings 28 for receiving moderator fluid for flow upwardly within the water rod through passages 30 for flow into passageways 32 formed by the tubular portions of the water rod 22. As illustrated in FIG. 1A, the spacer 20 is bounded by a pair of radially directed flanges 34 and 36 which lie on opposite sides of the spacer 20, maintaining the spacer at the desired elevation along the water rod. Referring now to FIG. 1B, at least one and preferably a pair of water rods 40 are illustrated passing through vertically adjacent spacers 42 and 44. The upper ends of the water rods 40 terminate in end guides which are received in the upper tie plate 45 of the fuel bundle. The spacers 42 and 44 comprise two of a plurality of spacers, typically between five and seven spacers, spaced along the entire length of the fuel bundle for maintaining the fuel rods in the desired array thereof. The spacers 42 and 44 useful with the present invention may comprise any type of spacers, for example, ferrule-type spacers or spacers of the type described and illustrated in U.S. Pat. No. 5,209,899 In the present invention, however, and instead of forming a unitary water rod throughout its entire height between the upper and lower tie plates, the water rod may be formed of two or more water rod segments. For example, and referring to FIG. 2, the water rods 40 may comprise a series of water rod segments interconnected one to the other at adjoining ends. For example, as illustrated in FIG. 2, a water rod segment 46 may have an upper end joined to the lower end of the next-adjacent upper water rod segment 48. The upper end of segment 48 may be joined to the lower end of an additional water rod segment. The process may be repeated until eventually the upper end of the final water rod segment is secured to the upper tie plate. The joints between the adjoining segments are disposed within the openings provided in the spacer through which the water rod extends. For example, the upper end of the segment 46 terminates in a female threaded nipple 50 which may be formed integrally with the segment 46 or formed separately and secured thereto as by threading or welding. The nipple 50 includes an axial passage therethrough in communication with the interior passage 51 of the underlying water rod segment 46. The adjoining upper water rod segment 48 has a male threaded plug 52 on its lower end for threaded engagement with the female threaded nipple 50. Like the nipple 50, the male plug has a central passage 54 through which moderator may flow from the lower segment to the upper segment. In the illustrated form of the present invention, the water rod segments 46 and 48 capture the spacer, for example, spacer 44, therebetween. To accomplish this capture, the segments 46 and 48 have elements, e.g., capture flanges, which project laterally beyond the peripheral confines of the opening in the spacer through which the water rod extends. Thus, for example, the diameter of the overlying and underlying water rod segments 48 and 46, respectively, may be larger than the diameter of the opening through the spacer. By employing a threaded connection between the adjoining two segments, the spacer can be assembled onto the water rods by inserting the nipple 51 and male plug 52 through the opening and threading the segments one to the other. The enlarged diameter portions of the upper and lower segments thus lie in registry with portions of the spacer laterally of the spacer opening and capture the spacer therebetween. Preferably, a small clearance 56 is provided between the enlarged diameter portions and the spacers to accommodate thermal expansion and contraction of the spacer relative to the water rod. In a preferred form of the present invention, the capture flanges may comprise terminal portions of swirler vanes 60 extending externally about the water rod segments 46 and 48. As illustrated in FIG. 2, the swirler vanes form a double helix about the water rod segments, although a single helix or helices in excess of two helices may be used. Ends of the swirler vanes extend beyond the lateral confines of the opening of the spacer, e.g., spacer 44, and on opposite sides thereof to capture the spacer. With a double helix, the ends of the vanes are diametrically opposite and form diametrically opposite stops or flanges 55 engageable by the captured spacer. Where a single helix is employed, only one stop is used, although an additional tab or stop can be used, preferably diametrically opposite the end of the swirler vane. It will be appreciated that the swirler vanes about the water rods serve to deflect moderator onto the adjacent fuel rods and into interstices thereof. In a preferred embodiment of the present invention, a separate segment is provided for each axial spacer-to-spacer region above a lower segment, which may be of a standard water rod configuration and extend through the first two or more spacers in the lower region of the bundle. For example, a third segment 70 above segment 48 is illustrated at FIG. 2. Segment 70 preferably includes a swirler vane(s) 72 terminating at its lower end in stops engageable with the spacer 74. Openings 76 are also provided in the uppermost water rod segment, e.g., segment 70, to flow water from the lower region of the bundle via an interior passage 78 to the upper region of the bundle against and into the interstices between the fuel rods. By using the segmented water rod of the present invention, the water rod tabs previously used to capture the spacer are entirely eliminated. Moreover, the present invention provides an installation whereby damage, marring or scratching of the spacers and water rods is minimized or eliminated. It will be appreciated that with elongated water rods, the spacers are typically displaced along the water rods to their desired location in the bundle. In that displacement, there is potential for damaging the contacting parts of the spacer and water rod. However, in the present invention, the threaded couplings between the water rod segments within the openings of the spacers afford a construction which virtually eliminates any sliding action of the water rod and spacers relative to one another, hence eliminating the potential for damage to one or the other, or both, of the spacers and water rods. In short, the spacer cannot be dislodged from its location along the water rod. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
	claims	1. The scattered radiation shielding grid comprising a plurality of tiles, each tile replicated from a prototile comprising a radiation absording material arranged in a motif, the motif of radiation absorbing material comprising a plurality of non-overlapping linear segments of radiation absorbing material, wherein the segments have an equal length; wherein the prototile comprising a width W(p), a length and the motif solely within the prototile, wherein the prototile width W(p)=W/(Ixc2x1Mxe2x97xafI) and W(p)xe2x89xa0W+D, where W is a radiation sensitive area width of a radiation sensor of a radiation detection panel comprising a plurality of equal size radiation sensors separated by interstitial spaces having a width D, over which the grid is positioned, I is an integer and M is a non-integer. 2. The scattered radiation shielding grid of claim 1 wherein M is less than 0.10. claim 1 3. The scattered radiation grid according to claim 1 wherein W(p)=W/I. claim 1 4. A method for designing a scattered radiation shielding grid comprising a pattern of radiation absorbing material for a radiation detection panel comprising an array of a plurality of sensors each having a radiation sensitive area having a width and a length, the sensors arrayed so that each radiation sensitive area is separated by each adjacent radiation sensitive area by an interstitial space having a width D, the method comprising: a) determining a sensor width W corresponding to the width of the radiation sensitive area of the sensor; b) creating a prototile having a width W(p)=W/(Ixc2x10.10I), W(p)xe2x89xa0W+D and wherein I is an integer; c) producing within the prototile a pinwheel motif of radiation absorbing material; and d) tiling a plurality of tiles replicated from said prototile to produce a pattern comprising a combination of the pinwheel motifs of the tiled tiles. 5. The method according to claim 4 wherein in step (b) the prototile width W(p)=W/I. claim 4 6. A method for generating a radiogram with an exposure system comprising radiation source, and a radiation detection panel, wherein said radiation detection panel comprises an array of a plurality of sensors each having a radiation sensitive area having a width W and a length, the sensors arrayed so that each radiation sensitive area is separated by each adjacent radiation sensitive area by an interstitial space having a width D, the method comprising: positioning between the radiation source and the panel a grid comprising a radiation absorbing material formed in a pattern comprising a combination of a plurality of substantially identical tiled tiles replicated from a prototile, said prototile comprising a width W(p), a length and a pinwheel motif of the radiation absorbing material, the pinwheel motif contained solely within the prototile, wherein the prototile width W(p)=W/I where I is an integer. 7. A scattered radiation shielding grid comprising a radiation absorbing material, and a radiation detection panel over which said grid is positioned comprising a plurality of equal size radiation sensors having a radiation sensitive area width W, separated by radiation insensitive interstitial spaces having a width D, and wherein said grid radiation absorbing material forms a pattern, the pattern comprising a combination of a plurality of substantially identical tiles, each tile replicated from a prototile comprising: (a) a width W(p)=W/I, wherein I is an integer; (b) a length; and (c) a pinwheel motif of the radiation absorbing material contained solely within the prototile. 8. The scattered radiation grid and detection panel according to claim 7 further comprising a pixel gain correction circuit associated with said further detection panel and wherein W(p)=W/(I xc2x10.10I) and W(p)xe2x89xa0W+D. claim 7 9. The scattered radiation grid and detection panel according to claim 8 further comprising a radiation source, wherein said grid is positioned between said panel and said radiation source at a fixed, known distance from said panel, wherein said prototile width W(p) is a projected prototile width on said panel. claim 8 10. A method for designing a pattern for absorption material for a scattered radiation shielding grid for a radiation detection panel comprising an array of a plurality of sensors each having a radiation sensitive area having a width W and a length, the sensors arrayed so that each radiation sensitive area is separated by each adjacent radiation sensitive area by an interstitial space having a width D, the method comprising: a) determining the width of the radiation sensitive area W of the sensor; b) creating a prototile having a width W(p)=W/I wherein I is an integer; c) producing within the prototile a pinwheel motif of the radiation absorbing material; and d) tiling a plurality of tiles replicated from the prototile to produce the pattern, the pattern comprising a combination of the pinwheel motifs of the tiled tiles.
	description	This application claims priority from U.S. provisional application No. 60/781,335 filed Mar. 13, 2006 entitled System and Method for Automatic Measurements and Calibration of Computerized Magnifying Instruments. The invention relates to automatic measurements, calibration and validation of computerized magnifying instruments. Magnifying systems such as microscopic imaging systems are commonly used for conducting research, quantitative characterization and screening in various applications, such as semi-conductors fabrication, pharmaceutical research, biomedical and biotechnology laboratories, aerospace and automotive parts manufacturing. The measurements of attributes characterizing the elements present in microscopic images, finds applications in materials science and in pharmaceutical and biotechnological research. In order to compute accurately and precisely such attributes that accurately and truly reflect the spatial properties of the elements being imaged, a microscopic imaging system must be calibrated beforehand. This process establishes calibration parameters by measuring a reference object image having known attributes such as its physical dimension and shape. The nature of the calibration parameters can be quite complex, as their purpose is to compensate for all types of deformations and inhomogeneities induced by the entire imaging system, including non-linear effects due to all the optical/photoelectronic sub-components. A typical calibration method requires the user to measure on a computer screen, using interactive image processing software tools, the distances between various elements of the image of a reference calibration pattern, as well as to compute other image characteristics using these same tools. This process is repeated for each magnification of the imaging system and requires each time from the user new adjustments of the microscope, photoelectronic sensor and the digital acquisition parameters. The calibration process generally requires the user to precisely identify the position of sharp edges, a task that is inherently subjective and that provides highly variable results between individuals, and also from the same individual at different times. The accuracy and precision of the measurements of a microscopic imaging system are directly affected by the variability of the calibration process. Attempts to reduce this variability and uncertainties include restricting the performance of the calibration steps to a few trained users that thoroughly understand the details of the calibration methods, and averaging calibration results obtained at different times in order to reduce variability. The complexity of these procedures is a factor that prevents a broader adoption of computerized magnifying measurement systems, as they are still considered as complex and sophisticated tools that require a dedicated technical expertise to be properly operated. Thus better calibration and measurement methods are needed, as well as improved ways to characterize and validate the calibration results. The present invention aims at overcoming some of the drawbacks of present magnifying measurement systems such as microscopic imaging systems by providing systems and methods where calibration and specimen analysis is performed automatically, without user intervention. The present invention also automatically validates its own calibration, also without user intervention. This additional validation steps makes the method more robust and less prone to errors. The benefits of the present invention are the automatic production of repeatable and less variable calibration parameters, a simplification of the calibration process for the user, a reduction, and possibly elimination, of the number of specimen slide manipulations. The method minimizes the uncertainties of the calibration procedure and therefore improves the reliability of quantitative magnifying imaging systems used as digital measurement instruments. These are all elements that are expected to lead to a broader adoption and a wider use of computerized quantitative magnifying measurement systems. Thus in one embodiment there is provided a computer-implemented method for automatic calibration of a magnifying measurement system the method comprising: obtaining, an optimized digital image of a reference object comprising at least one standardized landmark feature identifiable by pattern recognition; and establishing calibration parameters based on one or more measured attribute of the at least one standardized landmark features, image acquisition settings and image characteristics. In another embodiment there is provided a computer-implemented method for automatic validation of a calibration of a magnifying measurement system, the method comprising: providing calibration parameters; obtaining a digital image of one or more object comprising one or more attribute of known value; measuring the one or more attribute to generate a measured value; comparing the measured value with the known value; and wherein the system is validated when the measured value is within a predetermined range comprising the known value. In yet another embodiment there is provided a computer implemented method for automatic measurement of an attribute of one or more object using a magnifying measurement system, the method comprising: retrieving calibration parameters: acquiring a digital image of the object in accordance with the calibration parameters; and measuring the attribute. In another aspect of the invention there is provided an automatized magnifying measurement system comprising: a stage to position a sample; image acquisition settings controller image acquiring means for acquiring a magnified digital image of the sample; and data processing module to measure one or more attributes of the sample. In the present description by the term magnifying measurement system it is meant instruments used for magnifying objects such as microscopes and stereoscopes. All types of such instruments are included in the definition such as but not limited to light microscopes, scanning electron microscopes, transmission electron microscopes and the likes. By attributes it is meant characteristics of an object such as its size, shape, texture and the like. By digital image characteristics (or image characteristics) it is meant parameters affecting aspects of the image such as but not limited to contrast, color, intensity, magnification, resolution, background uniformity, chromatic aberrations, optical distortion. By settings or system settings it is meant system configuration including but not limited to settings of the magnifying components such as focal plane and objective power, camera parameters (shutter speed, white balance, digital gamma correction, etc . . . ), illuminating system (lamp voltage), digital shading correction for illuminating inhomogeneity and the like. By automatic (automatically, automatized) it is meant substantially without user intervention. The present invention relates to a method and apparatus for measurements of objects attributes using a computerized magnifying measurement system such as a microscope. In one aspect of the invention the system is calibrated automatically, that is to say substantially without user intervention thereby eliminating calibration errors introduced by user manipulations and subjectivity. The calibration begins by obtaining an optimized digital image of an object comprising standardized landmark features. The dimensions of the standardized landmark features on a reference slide, traceable to real physical dimensions obtained from a standardized external measurement process, are archived in a database. The database contains an entry for each unique reference slide identified by a unique Serial Number. The serial number itself is recognized by the computerized imaging system to ensure the traceability of the calibration process The digital image is then automatically processed to locate and identify the landmark features and to measure selected attributes of the features. In a preferred embodiment, in order to acquire precise measurements of the landmark features, the settings of the system and the characteristics of the image are adjusted until the digital image allows for accurate and precise recognition of the landmark features using a pattern recognition algorithm thereby allowing precise and accurate measurements of the features to be obtained. The uncertainties of that process are also estimated. The measurements of the attributes of the standardized features are preferably performed when the image has been optimized to allow a desired degree a precision and accuracy. It will be appreciated that adjustment of the digital image may be an iterative process involving the interdependent adjustment of digital image characteristics and image acquisition settings at several different magnifications. From measurements of the attributes and from known values of the standardized landmark features, calibration parameters are established and can be retrieved when measuring actual sample. The calibration parameters are dependent on and therefore comprise the acquisition image settings with which the digital image of the standardized features has been acquired, the correction parameters applied to the characteristics of the digital image and the actual measurements of the attributes. In a preferred embodiment all the steps involved in the calibration are automatic in that they do not require input from the user. In this respect, the object comprising the standardized landmarks features (the “standard”) should preferably allow calibration of all attributes that will be measured in the actual samples at all acquisition settings. It will be appreciated however that several standards each comprising different features with different attributes can also be used. The object comprising the standardized features is preferably suitable to perform calibration at several image acquisition settings including several magnification powers. Thus, the standard should comprise different features that are preferably recognized by pattern recognition tools at different magnifications. The ability of the system to calibrate and measure at different magnifications enables measurements at different degrees of precision, accuracy and resolution. In another aspect of the invention the system also allows for automatic validation of the calibration. Objects representative of typical quantitative measurement application, with attributes of known values are provided and measured. In a preferred embodiment a statistically significant number of objects are measured. The statistical distributions of the measured attribute values are compared with the known distribution of values, obtained from an external and standardized measurement process, to determine the validity of the calibration. If the measured values of the attributes fall within the acceptance range, determined by the estimated overall uncertainties the calibration is considered valid. The validation may also comprise different reference standard slide with several objects. The analysis generates a statistical distribution of sizes and shapes for a large population of known physical objects. Auto-verification of the performance of the imaging system and possible auto-detection of a false erroneous calibration parameters. Since the reference slide of known objects have been independently measured and certified with a traceable method, a prior erroneous calibration parameters can be automatically detected as the statistical size distribution depends on them. The comparison of the measured distribution and the corresponding one retrieved from the traceable database will allow such validation scheme. The system also provides for automatic image acquisition processing and measurement of samples. The procedure comprises acquisition of digital images of the sample which can be analyzed to measure attributes of different objects in the sample. Measurement of the samples relies on calibration parameters that are used to acquire the image and obtain the measurements of the attributes (size and shape). The method also encompasses an embodiment in which the calibration, validation and measurement are automatically performed in sequence without user input. Alternatively only the calibration or validation may be performed in combination with the measurement of the sample (or samples). It will be appreciated that all results of calibration and measurements may be expressed with an associated estimated uncertainties whenever a quantitative measure is obtained. It will be appreciated that all events occurring as a calibration or validation procedure is performed is automatically logged into the computerized system in order to allow audits and traceability. The system of the invention is generally described in FIG. 1 wherein object or sample 10 to be analyzed is positioned such as to be coupled with the magnifying components of magnifying instrument 12 which produce an image detected by imaging device such as camera 14 and digitized and sent to digital image buffer 16. The digital image data can be stored in data storage module 18. Processing of the data to establish calibration parameters are performed by data processing module 20 which comprises the necessary modules to process the data as will be described below. The system also comprises camera control 22, magnifying components control 24 and stage control 26. Control module 28 provides overall control of the system components and software and is linked to user interface 30. As shown in FIG. 2 the characteristics of the image (image quality factors) can be analyzed and adjusted by a digital image characteristics adjuster/analyzer 32. The acquisition of images with a desired degree of accuracy requires adjustments of the settings of the system including the magnifying components 34, imaging component 36 and stage position 38. Modules 22, 24 and 26 can adjust these settings taking into account digital image characteristics. An attribute measurements module is provided at 40 to perform attributes measurements on the features of the object using a digital image. There is also provided an accuracy/precision estimator 42 to provide calculations/estimations of statistics related to the attributes measurements and accuracy of the measurements. The accuracy/precision estimator can also be involved in the auto-validation process as described above to compare measured attributes values with known values. There is now provided a description of an embodiment of the method and apparatus of the invention in which the magnifying subcomponent is a microscope system. The optical element with the desired magnification factor as well as other microscope/camera configuration parameters can be selected, either manually by the user using the microscope interface, either semi-automatically with the user supervising the control module 28. In a preferred embodiment the control module 28 automatically configures the microscopic imaging system. In practice, the control module 28 can issue commands to control any aspect of the system. The data communication is bilateral, as the controls 22, 24 and 26 also send back data to the control module 28, to provide information on the current status and settings of the imaging microscope and on the progress of commands issued by the control module 28. When object 10 contains a reference calibration pattern, the pattern image is formed by magnifying instrument 12, and the light from this image is transformed into a digital image by camera 14, which can comprise for instance electronic components such as a CCD (Charge Coupled Device) or a CMOS matrix. The digital image thus formed can be a grey-level image, a color image, or any other type of image, and its size can vary depending on specific applicative needs. Once the imaging microscope has reached a state that corresponds to the commands sent by the control module 28, the control module 28 issues commands to transfer the digital image to the image buffer 16. Upon reception of these commands the transfer of the digital image from the CCD matrix to the image buffer 16 is initiated and finally to the data storage module 18. In order to facilitate subsequent processing by the data processing module 20, information sent or received by the control module 28 about the status and the settings of the imaging microscope are also stored in the data storage module 18, along with the corresponding digital image. The data processing module 20 accesses data from the data storage module 18 and automatically computes, according to the present invention, calibration parameters can be stored back to the data storage module 18. It will be appreciated that the system operations described above can be automatically repeated (that is to say without substantial user intervention) for each configuration of the imaging microscope for which calibration parameters are desired. The calibration parameters thus obtained are stored to the data storage module 18, along with parameters describing the microscopic imaging system configuration and digital image characteristics to which they correspond. In order to calibrate the system, a calibration slide containing a reference calibration pattern, such as the one illustrated in FIG. 3, is calibrated beforehand by an external calibration process that provides traceable values of attributes of the features such as distances between landmark features of the pattern within a known global estimated uncertainty. In practice, the external calibration process provides measurement values that are sufficiently accurate to be considered as accurate and precise and traceable to a reference system independently calibrated. External calibration can be performed, for instance, by an accredited organization that provides measurements that are obtained by performing standardized and well-recognized measurement methods, in a controlled environment, based on a measurement gold standard. The values obtained from the external calibration process can be stored in the data storage module 18, to be later used by the data processing module 20 for the computation of calibration parameters. Each reference slide externally calibrated is uniquely recognized by a serial number automatically read by the calibration procedure. The reference calibration slide of FIG. 3 may comprise a unique identifier (serial number). The identification code can take any form that guarantees uniqueness, but preferably takes a form that can easily and automatically be detected by a computer, such as a bar code. The purpose of this identifier is to uniquely associate traceable values from the external calibration process to the appropriate calibration slide. One can consider a situation where, for instance a research laboratory possesses more than one microscopic imaging system, and also possesses more than one calibration slide. It is not very difficult to imagine a situation where a user enters, through the user interface module 30, the traceable values obtained from the external calibration of one of the two slides, while erroneously uses the other calibration slide for calibrating the microscopic imaging system. An embodiment of the present invention advantageously prevents this situation by explicitly storing the unique identifier of the calibration slide with the traceable values from the external calibration process, and by implementing a verification routine that automatically detects the identification code in the image of the calibration reference pattern and verifies that it corresponds to the one associated with the traceable values from external calibration. It is an object of the present invention to teach a method for the automatic computation of calibration parameters, it is a further object of the present invention to disclose a magnifying imaging system that implements a method for the automatic computation of calibration parameters. The first step of the method, performed by the data processing module 20, is to load the image of the reference calibration pattern from the data storage module 18. The data processing module 20 at this step also retrieves information associated with the reference calibration pattern such as traceable distances obtained from the external calibration process and stored in the data storage module 18. Alternatively, the image and the traceable distance values can be provided to the data processing module 20 by the user, using the user interface module 30. The user interface module 30 can take numerous forms, including well-known computer interfaces to enter numerical values, or it can take the form of selection lists, sliders, checkboxes, or any other type of software user interface component. The user interface module 30 can also comprise file browsers that allow the user to navigate on its local computer or on a computer network to locate and select computer files that may contain configuration parameters, calibration values, images, or any other type of information. It is an object of the present invention to encompass all combinations of user interfaces 30 and of computer networks that can be used to provide data to the data processing module 20, to the data storage module 18 and to the control module 28. The following step of the method applies image processing routines to automatically identify landmark features in the image of the reference calibration pattern. These routines implements image processing algorithms such as edge detection and shape detection algorithms at a subpixel level. The landmark features in the image are identified by identification features that are recognized by pattern recognition. Finally the calibration parameters can be stored to the data storage module 18. The steps are repeated for each configuration of the microscopic imaging systems for which calibration parameters are required, thus providing to the data storage module 18 a set of pre-computed calibration parameters for each configuration of interest of the microscopic imaging system. A further embodiment of the present invention includes the storage of a unique identifier for the microscopic (or magnifying) imaging system along with the calibration parameters. This unique identifier can take for instance the form of the serial number of the microscope of the imaging system. This information is transmitted to the control module 28 and is stored to the data storage module 18. The verification of the correspondence of the microscopic imaging system identifier with the one stored with the calibration parameters prevents the erroneous use of inappropriate correction parameters. The computation of the calibration parameters can be made more robust by incorporating error detection steps, where the image of the reference calibration pattern is automatically analyzed by image processing algorithms that are designed to detect error conditions, such as for instance, the use of an empty slide, the use of any slide that do not contain the appropriate reference calibration pattern, the presence of blurring or of non uniform lighting conditions over the image, the absence of sharp contrasts defining the features, the presence of a scratch or of some dust on the reference slide. Another embodiment of the present invention is to provide automatic sample analysis methods using magnifying imaging systems. A further embodiment of the present invention is to disclose microscopic imaging systems that implement these methods. Once the establishment of the calibration parameters is completed, the magnifying imaging system configuration is adjusted, in accordance to the calibration parameters which are selected based on the features that are to be measured in the sample, either manually by the user, either in a semi automated manner where the user supervises the operations of the control module 28, or in a completely automated manner where the control module 28 automatically configures the microscopic imaging system. Thus for the measurements of the features, the data processing module 20 accesses the data storage module 18 to obtain the appropriate calibration parameters, the ones corresponding to the instrument configuration when the image was acquired. These calibration parameters are taken into account during the measurements of the features. Alternatively, the data processing module 20 can access the calibration parameters from the data storage module 18 once all features are measured, and apply the calibration parameters to the originally computed parameters in order to form calibration-corrected parameters. The automatic sample analysis method can include a verification step where the serial number of the imaging microscope, or any other means for the unique identification of the imaging microscope, is compared with the serial number or the other identification means that is associated with the calibration parameters that correspond to the imaging microscope configuration. One skilled in the art can appreciate that the automatic sample analysis method of the present invention can also be used for the calibration of reference calibration pattern slides. This particular embodiment of the present invention is particularly advantageous for instance, for a manufacturer of microscopic imaging system that would provide to each customer a reference calibration pattern slide with each system that is delivered. For various technical and commercial reasons, this manufacturer may not necessarily want to rely on another corporate entity to perform external calibration of each reference calibration slide. With the present invention, the manufacturer only needs one “gold standard” reference calibration pattern slide that has been externally calibrated. He can then calibrate all other reference calibration pattern slides with respect to this “gold standard” by applying the automatic sample analysis method of the present invention. An embodiment of the automatic validation of the invention is described in FIGS. 4 and 5. With reference to FIG. 4 auto-calibration may optionally precede the auto-validation step which includes the acquisition of an image of a reference slide having objects of known size and shape. Attributes of the features of the objects are automatically measured and compare to the known stored values of the attributes. Measurements of real samples can then proceed. The system may be fully automated by providing a sample manipulator (robot) which can process batch of samples without user intervention. This feature is particularly advantageous when the samples are toxic or otherwise dangerous to manipulate or are easily contaminated. The autovalidation may be based on statistical measurements of the attributes (FIG. 5). The data processing module 20 can measure the attributes using appropriate statistical models. The results can then be compared with known statistically measured values 50 using statistical comparator 52. The assessment of the validation 54 is then performed and if the measured value are within a predetermined range the system is validated. If not corrective measures such as repeating the calibration step can be performed. While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosures as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features herein before set forth, and as follows in the scope of the appended claims.
	abstract	An apparatus and method for an X-ray dosimeter support, comprises of a material-poor support-layer, held by a frame elevated by at least one foot, comprising optimization for low back-scatter, high measurement-repeatability and ease of assembly and disassembly.
	claims	1. A construction layout for caverns of an underground nuclear power plant in a mountain having a longitudinal direction, the construction layout comprising: two primary caverns accommodating nuclear reactor powerhouses, combined caverns, electric powerhouse caverns, pressure relief caverns, a first primary traffic tunnel, a second primary traffic tunnel, a third primary traffic tunnel, a top adit system, and a ground adit system;whereina connecting line of medial axes of the two primary caverns accommodating nuclear reactor powerhouses is perpendicular to the longitudinal direction of the mountain;each combined cavern is disposed on one side of each of the two primary caverns along the longitudinal direction of the mountain; each electric powerhouse cavern and each pressure relief cavern are disposed on two sides of each of the two primary caverns perpendicular to the longitudinal direction of the mountain; each electric powerhouse cavern is perpendicular to the longitudinal direction of the mountain;the first primary traffic tunnel and the third primary traffic tunnel are disposed along the longitudinal direction of the mountain on outer sides of the two combined caverns, respectively; the second primary traffic tunnel is disposed along the longitudinal direction of the mountain between the two combined caverns; one end of each of the first primary traffic tunnel, the second primary traffic tunnel, and the third primary traffic tunnel communicates with a ground surface;the two primary caverns, the combined caverns, the electric powerhouse caverns, and the pressure relief caverns form a cavern group of a nuclear island powerhouse of the underground nuclear power plant; anda skewback or an endwall of an arch crown of each cavern of the cavern group communicates with the ground surface via the top adit system; and a bottom of a sidewall or a bottom of an endwall of each cavern of the cavern group communicates with the first primary traffic tunnel, the second primary traffic tunnel, and the third primary traffic tunnel via the ground adit system. 2. The layout of claim 1, whereinthe top adit system comprises: a first primary adit, a first top adit of a first primary cavern, a second top adit of a second primary cavern, a second primary adit, a third primary adit, third top adits of end parts of the combined caverns, fourth top adits of the electric powerhouse caverns; fifth top adits of middle sections of the combined caverns, a sixth top adit of a first pressure relief cavern, and a seventh top adit of a second pressure relief cavern;the first primary adit, the second primary adit, and the third primary adit are arranged along the longitudinal direction of the mountain and communicate with the ground surface; an elevation of the first primary adit is higher than an elevation of the second primary adit and an elevation of the third primary adit;the first primary adit communicates with skewbacks of arch crowns of the two primary caverns via the first top adit and the second top adit, respectively;one end of the second primary adit and one end of the third primary adit communicate with the endwall of the arch crown of one end of a first combined cavern and the endwall of the arch crown of one end of a second combined cavern, respectively; a middle section of the second primary adit communicates with the endwall of the arch crown of the other end of the first combined cavern via one of the third top adits; a middle section of the third primary adit communicates with the endwall of the arch crown of the other end of the second combined cavern via the other of the third top adits;middle sections of the third top adits communicate with endwalls of arch crowns of one ends of the electric powerhouse cavern via the fourth top adits of the electric powerhouse caverns, respectively;the middle section of the second primary adit communicates with the skewback of the arch crown of a middle section of the first combined cavern via one of the fifth top adits;the middle section of the third primary adit communicates with the skewback of the arch crown of a middle section of the second combined cavern via the other of the fifth top adits; andthe sixth top adit and the seventh top adit are disposed on the middle section and the end of the third primary adit to communicate with the skewback of the arch crown of the first pressure relief cavern and the skewback of the arch crown of the second pressure relief cavern, respectively. 3. The layout of claim 2, wherein each top adit of the top adit system has a longitudinal slope smaller than 12%. 4. The layout of claim 2, whereinthe ground adit system comprises: first bottom adits of the two primary caverns, second bottom adits of first end parts of the combined caverns, third bottom adits of the electric powerhouse caverns, fourth bottom adits of second end parts of the combined caverns, and fifth bottom adits of the pressure relief caverns;the second primary traffic tunnel communicates with the bottom of the sidewall of the first primary cavern and a bottom of the first pressure relief cavern via one of the first bottom adits and one of the fifth bottom adits, respectively; the third primary traffic tunnel communicates with the bottom of the sidewall of the second primary cavern and a bottom of the second pressure relief cavern via the other of the first bottom adits and the other of the fifth bottom adit, respectively;the first primary traffic tunnel communicates with the bottom of the endwall of one end of the first combined cavern via one of the second bottom adit; the second primary traffic tunnel communicates with the bottom of the endwall of one end of the second combined cavern via the other of the second bottom adits;each of the second bottom adits communicates with the bottom of the endwall of corresponding electric powerhouse cavern via each third bottom adit connected; andthe other end of the second primary traffic tunnel communicates with the bottom of the endwall of the other end of the first combined cavern via one of the fourth bottom adits; the other end of the third primary traffic tunnel communicates with the bottom of the endwall of the other end of the second combined cavern via the other of the fourth bottom adits. 5. The layout of claim 4, wherein each bottom adit of the ground adit system has a longitudinal slope smaller than 12%. 6. The layout of claim 4, whereineach of the combined caverns comprises: a first safe powerhouse cavern, a nuclear fuel powerhouse cavern, a second safe powerhouse cavern, and a nuclear auxiliary powerhouse cavern longitudinally connected in series;each of the second bottom adits communicates with a bottom of an endwall of the first safe powerhouse cavern;each of the fourth bottom adits communicates with a bottom of an sidewall of the nuclear auxiliary powerhouse cavern;one ends of the second primary adit and the third primary adit communicate with endwalls of arch crowns of outer end faces of corresponding nuclear auxiliary powerhouse cavern;each of the third top adits of the end parts of the combined caverns communicates with an endwall of an arch crown of an outer end face of the first safe powerhouse cavern; andeach of the fifth top adits of the middle sections of the combined caverns communicates with a skewback of an arch crown of the second safe powerhouse cavern. 7. The layout of claim 1, wherein each of the two primary caverns communicates with a corresponding electric powerhouse cavern via a primary steam channel communicating with the ground surface; and the two primary caverns are provided with corresponding apparatus conveying channels communicating with the ground surface. 8. The layout of claim 2, wherein each of the two primary caverns communicates with a corresponding electric powerhouse cavern via a primary steam channel communicating with the ground surface; and the two primary caverns are provided with corresponding apparatus conveying channels communicating with the ground surface. 9. The layout of claim 3, wherein each of the two primary caverns communicates with a corresponding electric powerhouse cavern via a primary steam channel communicating with the ground surface; and the two primary caverns are provided with corresponding apparatus conveying channels communicating with the ground surface. 10. The layout of claim 4, wherein each of the two primary caverns communicates with a corresponding electric powerhouse cavern via a primary steam channel communicating with the ground surface; and the two primary caverns are provided with corresponding apparatus conveying channels communicating with the ground surface. 11. The layout of claim 5, wherein each of the two primary caverns communicates with a corresponding electric powerhouse cavern via a primary steam channel communicating with the ground surface; and the two primary caverns are provided with corresponding apparatus conveying channels communicating with the ground surface. 12. The layout of claim 6, wherein each of the two primary caverns communicates with a corresponding electric powerhouse cavern via a primary steam channel communicating with the ground surface; and the two primary caverns are provided with corresponding apparatus conveying channels communicating with the ground surface.
	summary
	abstract	Design and making methods of a neutrons generating target are described. In some embodiments, a surface of a target substrate can be modified to form one or more surface features. In some embodiments, a neutron source layer can be disposed on the surface of the target substrate. In some embodiments, the neutron source layer and the target substrate can be heated to an elevated temperature to form a bond between the two. In some embodiments, the surface modification of the target substrate can reduce blistering and material exfoliation in the target. The target can be used in boron neutron capture therapy.
	abstract	An X-ray imaging system is disclosed which can effect positioning of an X-ray irradiator and an X-ray receiver in an adaptive manner. The X-ray imaging system uses an X-ray irradiator and an X-ray receiver opposed to each other through a space to radiograph a subject positioned between the two and comprises radiographing device having the X-ray irradiator and the X-ray receiver, optical radiographing device for picking up an optical image of the subject, specifying device for analyzing the optical image and specifying physical characteristics of the subject, and positioning device for positioning the X-ray irradiator and the X-ray receiver of the radiographing device on the basis of the specified physical characteristics and a portion to be radiographed of the subject.
	abstract	A channel type heterogeneous reactor core for a heavy water reactor for burnup of thorium based fuel is provided. The heterogeneous reactor core comprises at least one seed fuel channel region comprising seed fuel channels for receiving seed fuel bundles of thorium based fuel; and at least one blanket fuel channel region comprising blanket fuel channels for receiving blanket fuel bundles of thorium based fuel; wherein the seed fuel bundles have a higher percentage content of fissile fuel than the blanket fuel bundles. The seed fuel channel region and the blanket fuel channel region may be set out in a checkerboard pattern or an annular pattern within the heterogeneous reactor core. Fuel bundles for the core are also provided.
	abstract	The invention refers to a device and a method for handling a fuel assembly (3), which comprises a number of fuel rods extending between a lower part and an upper part of the fuel assembly, a debris filter located in the lower part of the fuel assembly and a casing surrounding the fuel rods. The device comprises a lifting device (15) for engaging, during a lifting operation, a fuel assembly located in a reactor vessel (1) and lifting the fuel assembly upwards and out from the reactor vessel. A conduit member is connected to the upper part of the fuel assembly. A pump (32) creates a flow of water through the conduit member and the fuel assembly during the lifting operation. The flow has such a size that possible debris particles contained in and/or immediately beneath the debris filter at least are retained in and/or immediately beneath the debris filter during the lifting operation.
	description	The present invention relates to the radiation detecting technical field, and more particularly, to a collimator for adjusting X-ray beam. In some radiation detecting systems, such as CT imaging systems, X-ray tubes are used to generate X-ray. The X-ray is usually emitted in a conical shape from a focal spot. Since application modes of X-ray are diversified, it is required to employ a collimator to define profiles of X-ray. In the conventional techniques, a linear collimator, a rectangular collimator, or combination thereof is employed to define profiles of X-ray. The conventional collimator has a large volume and a complicated structure, in which an upper sliding stop and a lower sliding stop can only be opened or closed simultaneously when adjustment is performed, and a left stop and a right stop are usually stationary and are not adjustable. If target points of an X-ray generator are not symmetrically formed between the upper and lower sliding stops, it is required to adjust the position of one of the upper and lower sliding stops and the target points of the X-ray generator, in order to ensure an effective adjustment of the upper and lower sliding stops. Thus, the conventional collimator is disadvantageous in that a larger space is occupied and the adjustment precision is low. Accordingly, in order to overcome the defects in the prior art, an object of this invention is to provide a collimator for adjusting X-ray beam. The collimator can symmetrically perform adjustments along an up-and-down direction and along a left-and-right direction around target points of a fixed X-ray generator, so that X-ray beams with different field angles can be obtained. An object of the invention is to provide an adjustment device for adjusting a collimator that can separately adjust respective sliding stops of the collimator. In order to achieve the above object of the invention, one aspect of this invention provides a collimator for adjusting X-ray beam, comprising: an up-and-down adjustment mechanism; a left-and-right adjustment mechanism; a supporting member; and an adjusting plate connected with the supporting member, wherein: the up-and-down adjustment mechanism comprises upper and lower first rotating nuts, upper and lower moving leading screws threadedly connected with the upper and lower first rotating nuts, and upper and lower sliding stops located in the supporting member, wherein each of the upper and lower leading screws is connected with the upper and lower sliding stops to drive the upper and lower sliding stops, respectively, to vertically move; and the left-and-right adjustment mechanism comprises left and right second rotating nuts, left and right horizontally moving leading screws connected with the second rotating nuts, and left and right sliding stops located in the supporting member, wherein each of the horizontally moving leading screws is connected with the left and right sliding stops to drive the left and right sliding stops, respectively, to horizontally move. The up-and-down adjustment mechanism further comprises first upper and lower limiting gland covers, and the first upper and lower limiting gland covers are fixed to upper and lower wall surfaces of the supporting member and confine the respective first rotating nuts to rotate within the respective first limiting gland covers. With the above arrangement, symmetrical adjustments along an up-and-down direction and along a left-and-right direction can be obtained. With rotating nuts, the leading screws move linearly rather than rotate, so that X-ray beams with different field angles can be obtained. Preferably, the left-and-right adjustment mechanism further comprises left and right second limiting gland covers. The second limiting gland covers are fixed to left and right wall surfaces of the supporting member and confine the respective second rotating nuts to rotate within the respective second limiting gland covers. Preferably, each of the up-and-down moving leading screws is provided at ends thereof with opening grooves. The opening grooves are connected with the upper and lower sliding stops provided in a longitudinal sliding slot of the supporting member. Preferably, the horizontally moving leading screw is provided at ends thereof with abutting surfaces. The abutting surfaces are connected with left and right sliding stops provided in the supporting member. Preferably, the first rotating nut and the second rotating nut are marked with scales and numerals. Preferably, the up-and-down moving leading screw and the horizontally moving leading screw are marked at ends thereof with scales and numerals corresponding to the first rotating nut and the second rotating nut. Preferably, a fixed stop is provided behind the upper and lower sliding stops in the supporting member. Preferably, the upper and lower sliding stops and the left and right sliding stops are made of tungsten alloy or lead alloy. In order to achieve the above objects of the invention, another aspect of this invention provides an adjustment device for adjusting collimator, comprising: an up-and-down adjustment mechanism; a left-and-right adjustment mechanism; and a supporting member; wherein: an up-and-down adjustment mechanism; a left-and-right adjustment mechanism; and a supporting member, wherein: the up-and-down adjustment mechanism comprises upper and lower first rotating nuts, up-and-down moving upper and lower leading screws threadedly connected with the upper and lower first rotating nut, and upper and lower sliding stops located in the supporting member, wherein each of the upper and lower leading screws are connected with the upper and lower sliding stops to drive the upper and lower sliding stops, respectively, to vertically move; and the left-and-right adjustment mechanism comprises left and right second rotating nuts, horizontally moving left and right leading screws connected with the rotating nuts, and left and right sliding stops located in the supporting member, wherein each of the horizontally moving leading screws are connected with the left and right sliding stops to drive the left and right sliding stops, respectively, to horizontally move. The up-and-down adjustment mechanism further comprises first upper and lower limiting gland covers, and the first upper and lower limiting gland covers are fixed to upper and lower wall surfaces of the supporting member and confine the respective first rotating nuts to rotate within the first limiting gland covers. With the above technical schemes, the following benefits are achieved: 1) The value of field angle of ray beam can be effectively controlled; 2) The width of ray beam can be optionally adjusted; 3) Each adjustment unit on the collimator can be separately adjusted, so that the collimator can be applied to various radiation imaging systems. A preferred embodiment of the present invention will be described herein below with reference to the accompanying drawings. It is to be understood that the following preferred embodiment is only illustrative and will not intend to limit the protection scope of the present invention. Referring to FIGS. 1-4, the collimator according to this invention comprises an up-and-down adjustment mechanism 11, a left-and-right adjustment mechanism 21, a supporting member 15 and an adjusting plate 17 connected with the supporting member 15. Upper and lower sliding stops 18 and left and right sliding stops 25 are made of tungsten alloy or lead alloy. In the preferred embodiment, the up-and-down adjustment mechanism 11 comprises a first limiting gland cover 14, a first rotating nut 13, a leading screw threadedly connected with the first rotating nut 13, such as a T-type leading screw 12 as shown in FIG. 4, and the upper and lower sliding stops 18. The first limiting gland cover 14 is fixed to an upper wall surface and a lower wall surface of the supporting member 15, and confines the first rotating nut 13 to rotate within the first limiting gland cover 14. A certain gap is formed between the first rotating nut 13 and the first limiting gland cover 14 so as to form a clearance fit therebetween. Clearance fit also can be formed at a position where the T-type leading screw 12 goes through the supporting member 15. The T-type leading screw 12 is provided on ends thereof with opening grooves. The upper and lower sliding stops 18 provided in a longitudinal sliding slot 19 of the supporting member 15 are inserted into the opening grooves 30 of the T-type leading screw 12 vertically moved up and down, and are fixed by screws 31. With rotation of the first rotating nut 13, the T-type leading screw 12 is driven to longitudinally and linearly move, so that a slit formed between the upper and lower sliding stops 18 can be adjusted. A fixed stop 16 provided behind the upper and lower sliding stops 18 is used to shield slits exposed from upper and lower ends when the upper and lower sliding stops 18 are adjusted to be closed. The left-and-right adjustment mechanism 21 comprises a second limiting gland cover 24, a second rotating nut 23, a horizontally and left-and-right moving leading screw 22 threadedly connected with the second rotating nut 23, and left and right sliding stops 25. The second limiting gland cover 24 is fixed to a left wall surface and a right wall surface of the supporting member 15, and confines the second rotating nut 23 to rotate within the second limiting gland cover 24. The horizontally moving leading screw 22 linearly moves by the second rotating nut 23. The horizontally moving leading screw 22 is provided in the inner ends thereof with abutting surfaces. The abutting surfaces are connected with the left and right sliding stops 25 provided in the supporting member 15. The horizontally moving leading screw 22 brings the left and right sliding stops to move along a left-to-right direction (a horizontal direction). Furthermore, in order to observe the adjustment amount of the upper and lower sliding stops 18 and the left and right sliding stops 25, scales and numerals are marked on the first rotating nut 13 and the second rotating nut 23. Scales and numerals readable and corresponding to the first rotating nut 13 and the second rotating nut 23 are marked on the ends of the T-type leading screw 12 and the horizontally moving leading screw 22. While the invention has been shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
062460633	description	[EXAMPLE 1] (I) Production of Radiation Image Storage Panel 1) 200 g of stimulable phosphor (BaFBr.sub.0.85 I.sub.0.15 :0.001 Eu.sup.2+), 8.0 g of polyurethane resin (Pandex T5265M, trade name, available from Dainippon Ink & Chemicals, Inc.), and 2.0 g of epoxy resin (anti-yellowing agent, Epikote 1001, trade name, available from Yuka Shell Epoxy Kabushiki Kaisha) were added to methyl ethyl ketone, and mixed by means of a propeller mixer to prepare a coating liquid having a viscosity of 30 PS (at 25.degree. C.). The prepared coating liquid was applied onto a temporary support (polyethylene terephthalate sheet having a surface beforehand coated with silicone-releasing agent) of 150 .mu.m thickness, and dried to form a phosphor layer. The phosphor layer thus formed was then peeled off from the temporary support to give a stimulable phosphor sheet (thickness: 430 .mu.m). 2) Independently, 90 g (in terms of solid content of soft acrylic resin and 50 g of nitrocellulose were added to methyl ethyl ketone, and mixed to prepare a coating dispersion for subbing layer [viscosity at 25.degree. C.: 3-6 PS]. On a glass plate, a film of polyethylene terephthalate (support) was placed. The dispersion was then coated on the polyethylene terephthalate film by means of a doctor blade to form a layer of 15 .mu.m thick, and gradually heated from 25.degree. C. to 100.degree. C. Thus, the coated layer was dried to form a subbing layer on the support. 3) The above-prepared phosphor sheet was placed on the subbing layer, and then continuously pressed with heating by means of a calender roll under a pressure of 500 kgw/cm.sup.2 (temperature of the upper and lower rolls: 45.degree. C., moving speed: 0.3 m/minute). By this pressing procedure, the phosphor sheet was fixed onto the transparent support via the subbing layer. Thus, a stimulable phosphor layer (thickness: 230 .mu.m) is formed. 4) 70 g of fluorocarbon resin (copolymer of fluoro-olefin and monovinyl ether, Lumiflon LF504X, trade name, available from Asahi Glass Co., Ltd.), 5.2 g of isocyanate (crosslinking agent, Sumidule N3500, trade name, available from Sumitomo Bayer Urethane Co., Ltd.), 6.7 g of silicon resin (lubricating agent, X-22-2809, trade name, available from The Shin-Etsu Chemical Co., Ltd.), 0.3 g of dibutyltin laurate (catalyst, KS-1269, trade name, available from Kyodo Chemical Co., Ltd.), 2.8 g of light-scattering particles (anatase type titanium dioxide, A220, trade name, available from Ishihara Industries Co., Ltd., mean particle size: 0.15 .mu.m, refractive index: about 2.6) and 0.12 g of titanate type coupling agent (Plane-act AL-M, trade name, available from Ajinomoto Co., Inc.) were added to methyl ethyl ketone, and mixed to prepare a coating liquid (solid content: 12%). The coating liquid was then applied onto the phosphor layer by means of a doctor blade, and dried to form a surface protective film of approximately 7 .mu.m thick. The content of titanium dioxide in the protective film was found to be 3 wt. %. (II) Calculation of Scattering Length and Absorption Length of Surface Protective Film The coating liquid of the 4) above was applied onto a transparent support (thickness: 180 .mu.m) so that the formed layer might have a thickness of 5 to 50 .mu.m. The diffuse transmittance (%) of the formed layer was measured at wavelength of 400 nm (which corresponds to the main peak of the stimulated emission which was emitted from the aforementioned BaFBR.sub.0.85 I.sub.0.15 :0.001Eu.sup.2+ phosphor), by means of an automatic recording spectrophotometer (U-3210, manufactured by HITACHI, Ltd.) equipped with integrating sphere of 150 .phi. (150-0910). The results are set forth in Table 1. TABLE 1 thickness (.mu.m) 7 11 24 40 diffuse 70.3 62.6 48.4 40.2 transmittance (%) In accordance with the aforementioned formulas, the values of K and S were calculated from the data shown in Table 1. From the calculated values of K and S, the scattering length and the absorption length were calculated to be 23 .mu.m (scattering length=1/S) and 10,000 .mu.m (absorption length=1/K), respectively. [EXAMPLE 2] The procedures of Example 1 were repeated except that 0.9 g of titanium dioxide was added to the coating liquid for the preparation of a protective film, to prepare a radiation image storage panel of the invention. [EXAMPLE 3] (I) Production of Radiation Image Storage Panel A radiation image storage panel was prepared in the manner as described in Example 1, except that the protective film was replaced with the following two-layered protective films. 1) Lower protective film (Protective film I) 70 g of fluorocarbon resin (copolymer of fluoro-olefin and monovinyl ether, Lumiflon LF504X, trade name, available from Asahi Class Co., Ltd.), 5.2 g of isocyanate (crosslinking agent, Sumidule N3500, trade name, available from Sumitomo Bayer Urethane Co., Ltd.), 0.3 g of dibutyltin laurate (catalyst, KS-1269, trade name, available from Kyodo Chemical Co., Ltd.), 2.8 g of light-scattering particles (anatase type titanium dioxide, A220, trade name, available from Ishihara Industries Co., Ltd., mean particle: 0.15 .mu.m, refractive index: about 2.6) and 0.12 g of titanate type coupling agent (Plane-act AL-M, trade name, available from Ajinomoto Co., Inc.) were added to methyl ethyl ketone, and mixed to prepare a coating liquid (solid content: 12%). The coating liquid was then applied onto the phosphor layer by means of a doctor blade, and dried to form a protective film I of approximately 2 .mu.m thick. 2) Upper protective film (Protective film II) 50 g of fluorocarbon resin (copolymer of fluoro-olefin and vinyl ether, Lumiflon LF100, trade name, available from Asahi Glass Co., Ltd., 50 wt. % xylene solution), 5 g of isocyanate (crosslinking agent, Colonate HX, trade name, available from Nippon Polyurethane Co., Ltd.), 0.5 g of silicon resin (lubricating agent, X-22-2809, trade name, available from The Shin-Etsu Chemical Co., Ltd., solid content: 66 wt. %), 0.0004 g of dibutyltin laurate (catalyst, KS-1260, trade name, available from Kyodo Chemical Co., Ltd.), 6 g of light-scattering particles (benzoguanamine resin particles, Epostar s6, trade name, available from Japan Catalyst Co., Ltd.; mean particle size: 6, refractive index: about 1.6), and 0.1 g of titanate type coupling magnet (Plane-act AL-M, trade name, available from Ajinomoto Co., Inc.) were added to methyl ethyl ketone, and mixed to prepare a coating liquid. The coating liquid was then applied onto the protective film I by means of a doctor blade, and heated to 120.degree. C. for 20 minutes to dry and thermally treat the coated liquid to form a protective film II of approximately 7 .mu.m thick. Accordingly, the combination of the protective film I and the protective film II (total thickness: 9 .mu.m was provided on the phosphor layer. (II) Calculation of Scattering Length and Absorption Length of Combined Protective Films The coating liquid for the protective film II was applied onto each of the transparent supports having protective films of different thickness (which were prepared in Example 1-(II), to have 2 .mu.m thick. The diffuse transmittance (%) of the formed layer was measured in the same manner as described in Example 1-(II). [COMPARISON EXAMPLE 1] The procedures of Example 1 were repeated except that titanium dioxide and the coupling agent were not added to the coating liquid for protective film, to prepare a radiation image storage panel for comparison having a protective film of approximately 7 .mu.m thick. [COMPARISON EXAMPLE 2] The procedures of Example 1 were repeated except that titanium dioxide and the coupling agent were not added to the coating liquid for protective film, to prepare a radiation image storage panel for comparison having a protective film of approximately 3.5 .mu.m thick. [EVALUATION OF RADIATION IMAGE STORAGE PANEL] With respect to sensitivity, sharpness and durability, each radiation image storage panel prepared above was evaluated in the following manners. (1) Measurement of sensitivity After the sample storage was exposed to X-rays (generated under 80 kVp), the stimulable phosphor was excited with He-Ne laser (wavelength: 632.8 nm). The stimulated emission produced from the panel was detected, and the sensitivity was evaluated from the relative intensity of the emission. (2) Measurement of sharpness After the sample storage panel was exposed to X-rays (generated under 80 kVp) through an MTF chart, the stimulable phosphor was excited with He-Ne laser (Wavelength: 632.8 nm). The stimulated emission produced from the storage panel was detected by a photomultiplier tube (S-5) to convert into electric signals. On the basis of the obtained signals, the radiographic image was reproduced on a display of an image-reproducing apparatus. The MTF (modulation transfer function) of the reproduced radiographic image was determined (spatial frequency: 2 cycle/mm). (3) Measurement of durability The storage panel was cut into pieces (size: 100 mm .times.250 mm), and one of them was repeatedly subjected to the durability test [described in Japanese Patent Provisional Publication No. 8(1996)-36099] until cracks appeared on the surface of the protective film. From the repeated number of the test, the durability of the panel was evaluated. The results are set forth in Table 2. TABLE 2 panel Ex. 1 Ex. 2 Ex. 3 C. Ex. 1 C. Ex. 2 particles 3 1 3 (20) 0 0 (wt. %) film 7 7 2 (7) 7 3.5 thickness (.mu.m) scattering 23 50 49 >200 >200 length (.mu.m) relative 99 100 98 100 100 sensitivity sharpness 38.0 36.9 37.1 36.5 38.2 (%) durability >4,000 >4,000 >4,000 >4,000 2,000 (times) Remarks: The value in the parenthesis of Ex. 3 is the value of the protective film II. The results set forth in Table 2 indicate the following facts. The radiation image storage panels of the invention (Examples 1, 2 and 3) give images of high sharpness while they have almost the same sensitivity and durability as the conventional radiation image storage panel (Comparison Example 1). Further, the conventional storage panel having a thin protective film (Comparison Example 2) gives high sharpness but shows apparently poor durability.
	claims	1. An apparatus for supplying a target material to a target location, the apparatus comprising:a reservoir that holds a target mixture that includes the target material and non-target particles;a supply system that receives the target mixture from the reservoir and that supplies the target mixture to the target location, the supply system including comprising:a capillary tube, anda nozzle at an output of the capillary tube that defines an orifice through which the target mixture is passed; anda filter inside the capillary tube through which the target mixture is passed. 2. The apparatus of claim 1, wherein the filter is a sintered filter. 3. The apparatus of claim 1, wherein the filter and the tube are arranged so that the target mixture passes through the filter. 4. The apparatus of claim 3, wherein the filter includes pores through which the target material passes. 5. The apparatus of claim 4, wherein the size of the pores within the filter is determined by the size of the nozzle and orifice. 6. The apparatus of claim 5, wherein the size of the nozzle and orifice is determined by the size of the target material. 7. The apparatus of claim 3, wherein the filter pores are uniformly sized. 8. The apparatus of claim 3, wherein the filter pores are non-uniformly sized. 9. The apparatus of claim 1, further comprising a second filter that is upstream of the supply system. 10. The apparatus of claim 9, wherein the filter has a coarser porous structure than the second filter. 11. The apparatus of claim 9, wherein the filter has a finer porous structure than the second filter. 12. The apparatus of claim 9, wherein the second filter is a sintered filter. 13. The apparatus of claim 1, wherein one or more of the filter, the tube, and the nozzle are made of glass. 14. The apparatus of claim 13, wherein the glass is fused silica or fused quartz. 15. The apparatus of claim 1, wherein the filter is integrated with the tube. 16. The apparatus of claim 15, wherein the filter is bonded to the internal wall of the tube. 17. The apparatus of claim 1, wherein the filter is a porous fritted filter. 18. The apparatus of claim 1, wherein the filter is placed within the tube adjacent the nozzle. 19. The apparatus of claim 1, wherein the filter is made of a material that does not chemically react with the target mixture. 20. The apparatus of claim 1, wherein the filter is made of ceramic. 21. A method for supplying a target material to a target location, the method comprising:heating a bulk substance of a target mixture until the bulk substance becomes a fluid of the target mixture, the target mixture including target material and non-target particles;holding the target mixture fluid within a reservoir;passing the target mixture fluid through a nozzle capillary tube of a supply system;filtering at least some of the non-target particles from the target mixture fluid as the target mixture fluid passes through the supply system nozzle capillary tube; andsupplying the filtered target mixture fluid to the target location including passing the filtered target mixture through an orifice of a nozzle defined at the end of the nozzle capillary tube. 22. An apparatus for supplying a target material to a target location, the apparatus comprising:a supply system that is configured to receive a target mixture from a reservoir and to supply the target mixture to a target location, the supply system including a capillary tube defining an internal passageway and a nozzle at an end of the capillary tube, the nozzle defining an orifice; anda filter inside of the internal passageway of the capillary tube and integrated with the capillary tube such that the target material passes through pores within the filter while traveling through the capillary tube. 23. An extreme ultraviolet light system comprising:an apparatus for supplying a target material to a target location, the apparatus comprising:a reservoir that holds a target mixture that includes the target material and non-target particles;a supply system that receives the target mixture from the reservoir and that supplies the target mixture to the target location, the supply system including a capillary tube and a nozzle at an output of the capillary tube that defines an orifice through which the target mixture is passed; anda filter inside the capillary tube through which the target mixture is passed;a light source that supplies an amplified light beam; anda beam delivery system at the output of the light source for directing the amplified light beam along a beam path toward the target location to irradiate the supplied target material with the amplified light beam to thereby produce extreme ultraviolet light.
	claims	1. An optical collector (15) for collecting extreme ultraviolet radiation or EUV light (18) generated at a central EUV production site (20), the collector (15) comprising:a reflective shell (25) including means for compensating thermally induced deformations of the reflective shell (25), wherein the reflective shell (25) is of near ellipsoidal shape and axisymmetric with respect to an axis (30);a support structure (24) supporting the reflective shell (25), such that a cooling channel (29) is established between a back side of the reflective shell (25) and the support structure (24), wherein the reflective shell (25) has a thickness, such that convective heat transfer between the back side of the reflective shell (25) and a cooling medium (26) flowing through the cooling channel (29) dominates the process of removing heat from the reflective shell (25) with respect to heat conduction, and wherein the cooling channel (29) is funnel-shaped with respect to the axis (30); anda cooling circuit (33) connected to the cooling channel (29) to supply a cooling medium (26) to the cooling channel (29) with a controlled coolant pressure and/or mass flow and/or temperature. 2. An optical collector according to claim 1, wherein the cooling channel (29) is connected to the cooling circuit (33) through a plurality of inlet ports (27) and exit ports (32). 3. An optical collector according to claim 2, wherein volutes (28, 31) are provided between the inlet ports (27) and the cooling channel (29) and the exit ports (32) and the cooling channel (29). 4. An optical collector according to claim 1, wherein the cooling medium (26) enters the cooling channel (29) near the axis (30) and exits the cooling channel (29) far from the axis (30). 5. An optical collector according to claim 1, wherein flow disturbing means (36) are provided at predetermined locations within the cooling channel (29). 6. An optical collector according to claim 5, wherein the flow disturbing means comprise a plurality of obstacles which are mounted on a side of the cooling channel (29) opposite to the back side of the reflective shell (25) and/or on the back side of the reflective shell (25). 7. An optical collector according to claim 1, wherein the cooling circuit (29) is a closed circuit comprising a heat exchanging means (34), a compressor (35) and a control valve (41), and a control (40) for controlling the compressor (35) and/or the control valve (41) and/or the heat exchanging means (34). 8. An optical collector according to claim 6, wherein the obstacles comprise a plurality of turbulators (36), which are mounted on a side of the cooling channel (29) opposite to the back side of the reflective shell (25) and/or on the back side of the reflective shell (25). 9. A EUV source (10) comprising:a target delivery system (17), which emits a chain of droplets (19) of a target material, a high power drive laser (12), which ignites the target material at a EUV production site (20); andan optical collector (15), which collects the EUV light (18) generated at the EUV production site (20), wherein the optical collector (15) is a collector according to claim 1. 10. A method for operating an optical collector for collecting extreme ultraviolet radiation or EUV light (18) generated at a central EUV production site (20), comprising: compensating thermally induced deformations of a reflective shell (25) using pressure and/or mass flow and/or temperature of a cooling medium (26) flowing through a cooling channel (29) to compensate for thermally induced deformations of the reflective shell (25), wherein the reflective shell (25) is of near ellipsoidal shape and axisymmetric with respect to an axis (30), and the cooling channel (29) is funnel-shaped with respect to the axis (30), wherein the collector comprises: a reflective shell (25), a support structure (24) supporting the reflective shell (25), such that a cooling channel (29) is established between a back side of the reflective shell (25) and the support structure (24), wherein the reflective shell (25) has a thickness, such that convective heat transfer between the back side of the reflective shell (25) and a cooling medium (26) flowing through the cooling channel (29) dominates the process of removing heat from the reflective shell (25) with respect to heat conduction; and a cooling circuit (33) connected to the cooling channel (29) to supply a cooling medium (26) to the cooling channel (29) with a controlled coolant pressure and/or mass flow and/or temperature. 11. The method according to claim 10, wherein the pressure and/or the mass flow and/or the temperature of the cooling medium (26) is controlled in dependence of an input signal (42) being characteristic of a deformation of the reflective shell (25). 12. The method according to claim 10, wherein a gas is used as the cooling medium. 13. The method according to claim 12, wherein the gas is one of the gases including hydrogen, helium, argon, neon, krypton, xenon, chlorine, nitrogen, fluorine, bromine, and iodine, or a mixture of two or more of said gases.
	description	The present invention relates to a natural-circulation boiling water reactor improved in safety by securing preferable natural-circulation characteristics. In the natural-circulation boiling water reactor (referred hereunder to as the natural-circulation BWR), in order to secure a natural circulation flow rate, a pressure vessel of the reactor is arranged with an axial long length and a reactor core is arranged at a relatively lower position within the pressure vessel of the reactor so as to form a large free space called a chimney over the reactor core. The natural-circulation BWR does not include a re-circulation pump inside the reactor (internal pump) and a reactor re-circulation system (including a re-circulation pump outside the reactor and a jet pump) unlike a forced-circulation boiling water reactor (BWR), so that the fluid within a reactor pressure vessel is not to be forced-circulated by the recirculation pump inside the reactor. In the natural-circulation BWR, the natural circulation flow rate is determined in accordance with the balance of a density difference between a downcomer part and the reactor core, that is, the pressure difference between vapor/liquid two-phase flow in the reactor core, and liquid flow in the downcomer. This natural circulation flow rate is ensured by increasing the water-level (head) of the downcomer part by elevating the reactor pressure vessel as well as by forming a chimney, which is a large free space, above the reactor core so as to reduce the pressure drop of the vapor/liquid two-phase flow in the chimney for reducing the water-head and to increase the water-head difference (head difference) due to the density difference between the inside and the outside of the shroud. The chimney formed above the reactor core of a large-scale natural-circulation BWR is a very large free space with a radius of about 5 m and a height of about 10 m (see Patent Document 1: Japanese Unexamined Patent Application Publication No. HEI 02-80998, for example). When the free space is formed above the reactor core and the vapor/liquid two-phase flow discharged from the reactor core passes therethrough, a multi-dimensional flow is generated in the large space (chimney), which may prevent the natural re-circulation flow, providing a problem in the development of the natural-circulation BWR. The phenomenon of the multi-dimensional flow has been confirmed in the Russian natural-circulation BWR Vk-50. Further, in order to figure out the behavior of the thermal flow in the chimney formed above the reactor core, a test of the vapor/liquid two-phase flow within the so-called large caliber vertical piping was performed in Ontario Hydro Technologies Canada. This vapor/liquid two-phase flow test is a high-temperature and -pressure test using the vertical piping with a diameter of about 60 cm. From this test, it has been understood that the flow within the vertical piping with a diameter of about 60 cm is not a multi-dimensional but a one-dimensional stable flow. On the basis of the result from the Canadian vapor/liquid two-phase flow behavior test, in a large-scale natural-circulation boiling water reactor, such as an SBWR, for ensuring the vapor/liquid two-phase stable flow in a chimney region, which is a large free space, a rectangular-columnar divided chimney composed of a plurality of square lattices is adopted. The divided chimney is about 60 cm square in size, and in the rectangular-columnar divided chimney with this size, the vapor/liquid two-phase stable flow is ensured like in the test in Ontario Hydro Technologies Canada. In the natural-circulation BWR, by adopting the divided chimneys, the flow in each divided chimney is not the multi-dimensional flow, but it becomes a one-dimensional stable flow, enabling the stable natural circulation flow rate to be secured. A natural-circulation reactor adopting the divided chimneys includes the technique disclosed in Patent Document 2 (Japanese Unexamined Patent Application Publication No. H04-259894). This natural-circulation reactor ensures preferable natural-circulation characteristics as well as suppresses the transient reduction in water level by adopting the divided chimneys. In the natural-circulation reactor adopting the divided chimneys, the chimney is vertically divided into two sections so that the flow-path sectional area of the upper divided chimney is smaller than that of the lower divided-chimney. By adopting the divided chimneys in that a divided-chimney region is vertically divided into two sections so as to make flow-path sectional areas different from each other, the stable natural circulation flow rate can be secured while the stability may deteriorate. In general, the stability of the natural-circulation BWR is said to be weak. In view of the stability, the stability of a boiling water reactor (BWR) includes channel stability, reactor core stability, and region stability. Among them, the channel stability is the thermal hydraulic stability concerning the flow rate changes by the feed back via the changes in pressure drop within a fuel channel (a channel box). The reactor core stability and the region stability mean the nuclear thermal hydraulic stability due to the nuclear feed back via changes in reactivity due to void changes in the reactor core. Furthermore, the reactor core stability is the stability in a basic mode of the neutron flux, in which the output of the entire reactor core integrally changes, while the region stability is stability in a higher mode of the neutron flux in accompany of space changes in reactor core output. In a conventional BWR, the reactor core consists of a number of fuel assemblies (fuel channels), and on the top and bottom of the reactor core, plenums are provided in common to form a parallel passage system. When the parallel passage system is formed of a number of the fuel channels, even when flow fluctuations are generated in a specific fuel channel, the pressure drop between the plenums on top and bottom of the reactor core is maintained constant due to the presence of the large majority of the other stable fuel channels. In the reactor core of the parallel passage system, even when flow fluctuations are generated in a specific fuel channel so that the pressure drop is to be changed, a force is applied to the fluid for returning this pressure drop to a predetermined value. The channel stability is stability of a single fuel channel under a boundary condition in that the upper plenum and the lower plenum function as a common pressure boundary of the reactor core so as to maintain the pressure drop of the fuel channel constant. The fuel channel of the BWR forms a vertical heating passage, and the fluid flowing into the reactor core generates a void due to boiling. The vapor/liquid two-phase flow void-fraction distribution in the reactor core axial direction is like that the void-fraction distribution increases toward the top of the reactor core. Thereby, in accordance with the change in reactor-core inlet flow, the pressure drop of the vapor/liquid two-phase part varies with a time-lag along with the transport lag of the void. In the vertical heating passage having the vapor/liquid two-phase flow like the reactor core of the BWR, in accordance with the change in inlet flow, the pressure drop of the vapor/liquid two-phase part varies with a time-lag along with the transport lag of the void. This pressure drop of the vapor/liquid two-phase flow with a time-lag becomes a feed back amount of the feed back loop of the channel stability. Generally, with increasing pressure drop through the vapor/liquid two-phase flow, or with increasing time-lag, the channel stability deteriorates. In the case of the natural-circulation BWR, unlike the reactor core of the BWR, the pressure boundary on the top of the reactor core becomes the outlet of the divided chimney. If the combination of the fuel channel with the divided chimneys is assumed to be an imaginary fuel channel, the region of the vapor/liquid two-phase flow is elongated longer in comparison with the case without the chimneys so that the transport lag of the void is added in the chimneys. Thus, the pressure drop and the time-lag of the vapor/liquid two-phase flow are increased, so that the stability of the imaginary fuel channel may deteriorate. In the natural-circulation BWR with the divided chimneys, there is no prior art aimed at the improvement in fuel channel stability. In the natural-circulation BWR with the divided chimney, the multi-dimensional flow is suppressed, so that the flow becomes stable one-dimensional flow to secure the natural-circulation flow rate; however, if the combination of the fuel channel with the divided chimneys is assumed to be an imaginary fuel channel, the region of the vapor/liquid two-phase flow is elongated in the axial direction of the reactor core, so that the transport lag of the void is added in the chimney, which may result in the deterioration in stability of the imaginary channel. In a conventional BWE, as shown in FIG. 13, the channel stability is evaluated under the condition that the pressure drop Δp in each fuel assembly 1 of the whole reactor core is unified in the upper plenum 2 of the reactor core outlet. In a reactor core 3 of the conventional BWR, several hundreds of the fuel assemblies 1 are arranged, and the nuclear fuel assemblies 1 are loaded in the reactor core 3 to form a parallel passage. In the reactor core 3 forming the parallel passage, even when fluid vibration is generated in a specific fuel assembly (fuel channel) 1, the vibration is absorbed by a number of fuel channels in its vicinity, so that a feed back effect, in which each channel pressure difference Δp (Δp1 to ΔpN) between the upper plenum 2 and a lower plenum 4 of the reactor core is maintained substantially constant, acts on the channel flow rate. In the acting process of the feed back effect maintaining the channel pressure difference Δp constant, since the fuel channel is in the vapor/liquid two-phase state, the time-lag from flow rate change to pressure change is generated, so that the fuel channel may be instabilized under a certain vapor/liquid two-phase condition. In a low flow rate and a long passage, in which the time-lag is large due to the change in pressure drop of the vapor/liquid two-phase state, or when the change in pressure drop of the vapor/liquid two-phase flow has large gain, the stability may be more deteriorated. In the natural-circulation BWR with the divided chimneys, as shown in FIG. 14, pressures of the fuel channels flowing in divided chimneys 6 are once unified (unified in “N” fuel channels 1 with pressure differences ΔpC1 to ΔpCN), and then, the whole fuel assemblies 1 are unified at the outlet of the chimneys 6 (unified in the “k” divided chimneys 6 with pressure differences ΔpCM1 to ΔpCMk). Thus, if the combination of the fuel assemblies 1 with the divided chimneys 6 is assumed to be an imaginary fuel channel, in the imaginary fuel channel, the region of the vapor/liquid two-phase flow is elongated by the length of the divided chimneys in the axial direction in comparison with the fuel assemblies 1 of the reactor core of the conventional BWR, so that the transport lag of the void is added in the divided chimneys. Accordingly, in the natural-circulation BWR, the stability, such as the channel stability of the imaginary fuel channel, may be deteriorated. The present invention has been made in view of the circumstances mentioned above, and it is an object thereof to provide a natural-circulation boiling water reactor in which preferable natural-circulation characteristics are ensured and the stability is improved. A natural-circulation type water boiling nuclear reactor according to the present invention includes a plurality of divided chimneys provided above a reactor core and is charged with a number of fuel assemblies in the reactor core, in which a pressure equalization structure is provided on a divided chimney portion of rectangular-columnar lattice plates of the divided chimneys arranged at an outlet of the reactor core for equalizing pressures in divided chimney parts, in which the pressures of the divided chimney portions are equalized by the pressure equalization structure. Furthermore, a natural-circulation type boiling water reactor according to the present invention includes a plurality of divided chimneys provided above a reactor core and is charged with a number of fuel assemblies in the reactor core, in which a region of the divided chimneys is divided into a plurality of regions in a chimney height direction and a cross sectional area of rectangular-columnar lattice plates of an upper group of the divided chimneys is configured to be larger than that of the rectangular-columnar lattice plates of a lower group of the divided chimneys so as to equalize the pressures of the fuel assemblies arranged in an intermediate section in the chimney height direction. Furthermore, a natural-circulation type boiling water reactor according to the present invention includes a plurality of divided chimneys provided above a reactor core and is charged with a number of fuel assemblies in the reactor core, in which a region of the divided chimneys is divided into a plurality of groups in a chimney height direction, and a central position of rectangular-columnar lattice plates of an upper divided chimney group is laterally shifted from that of the rectangular-columnar lattice plates of a lower divided chimney group so as to equalize the pressures of the fuel assemblies in an intermediate portion of the divided chimneys in the divided-chimney height direction. According to the natural-circulation type boiling water reactor of the present invention, the pressures of the divided chimney portions or the fuel assemblies can be equalized on the upstream side from the outlet of the divided chimneys, so that the position of the pressure boundary of the upper part of the reactor core, which is important for the stability, can be lowered. The vapor/liquid two-phase flow region can be reduced, eliminating the transport lag within the divided-chimneys, so that the stability can be improved. Furthermore, the present invention will become apparent as the following description proceeds with reference to the accompanying drawings. Embodiments of a natural-circulation boiling water nuclear reactor according to the present invention will be described with reference to the attached drawings. FIG. 1 is a conceptual structure drawing of a natural-circulation boiling water reactor (hereunder referred to a natural-circulation BWR) according to a first embodiment of the present invention. In the natural-circulation BWR10, a reactor core shroud 12 is provided in a reactor pressure vessel 11, and several hundreds of many fuel assemblies 13, about 800 fuel assemblies, for example, are charged into the reactor core shroud 12 to form a reactor core 14. The reactor core 14 is provided in a lower portion of the reactor core shroud 12, and a plurality of rectangular-columnar divided-chimneys 15 are provided above the reactor core 14. A plurality of the divided chimneys 15 are combined into a group of the divided chimneys 15. A plurality of the divided chimneys 15 are summarized into a chimney 16, and each of the divided chimneys 15 is provided with a free space formed inside. In the reactor core 14, a number of the fuel assemblies 13 are aligned in a tetragonal lattice arrangement to form a parallel passage in the reactor core. The reactor core 14 includes the group of the divided chimneys 15 arranged in its upper portion to form a parallel passage system having common plenums 17 and 28 arranged in upper and lower portions of the group of the divided chimneys 15. On the outlet side of the chimney 16, the upper plenum 17 of the reactor core is formed, which is covered with a shroud head 18. On the shroud head 18, a number of steam separators 19 are arranged in a bristling state, and on the steam separators 19, a steam dryer 20 is provided. The steam dryer 20 removes the wet humidity from the steam separated by the steam separators 19 to thereby form dry steam by drying the steam, which is then supplied to a steam turbine (not shown) as main steam from a main steam pipe 21. The main steam pipe 21 constitutes a main steam system 22. The steam is expanded due to the working in the steam turbine for generating electric power and is discharged to a condenser (not shown). In the condenser, the steam condenses (is cooled) into condensate. This condensate passes through a condensate feeding system 24 so as to be fed back into the reactor pressure vessel 11 via feed piping 25 as feed water. The feed water fed back into the reactor pressure vessel 11 is mixed with the water (returned water), which is separated from steam in steam condenser separators 19 and is led to a downcomer part 27. The downcomer part 27 is a sleeve-like or cylindrical annular space formed between the reactor pressure vessel 11 and the reactor core shroud 12, and the mixed flow of the feed water with the coolant for reactor water is lowered by natural circulation using the water head difference between upper and lower portions of the downcomer part 27, and is led to a lower reactor-core plenum 28 on the bottom side of the reactor core 14. The mixed flow that has fallen through the downcomer part 27 is inverted by the lower reactor-core plenum 28 to become an ascending flow and is led to an inlet of the reactor core in its lower portion. The mixed flow is heated during the passing through the reactor core 14 due to the nuclear heating effect to become a vapor/liquid two-phase flow and enter the divided chimneys 15. Then, the vapor/liquid two-phase flow rises through an upper reactor-core plenum 17 so as to be led to the steam separators 19 for being separated from the steam. On the other hand, the reactor core 14 is structured in the lower portion of the reactor core shroud 12 and is accommodated within the reactor pressure vessel 11, the reactor core 14 having a number of the fuel assemblies 13 loaded therein. The rectangular-columnar divided chimneys 15 are provided above the reactor core 14, and the divided-chimney 15 is formed of lattice plates 30 in a rectangular-columnar shape to form a free space inside. The divided-chimney 15 is connected to the neighboring divided-chimney via a pressure equalization tube 31, so that the pressure of the divided chimneys 15 adjacent to each other is equally adjusted due to the pressure equalization tube 31. The pressure equalization tube 31 is located at a position lower than the intermediate height region of the divided chimneys 15 in its axial direction so as to form a pressure equalization structure of the divided chimneys 15. The rectangular-columnar divided-chimney 15 has a size of about 60 cm square and a height in the axial direction from several meters to ten and several meters, 10 meters, for example. The chimney 16 has a whole diameter of about 5 meters, which is the sum of the diameters of the divided chimneys 15, and a height in the axial direction of 10 meters, for example. Furthermore, in the fuel assemblies 13 constituting the reactor core 14, a number of fuel rods are accommodated in a rectangular-columnar channel box 33 in a tetragonal lattice arrangement. Control rods 34 are charged in and out between a number of the fuel assemblies 13 by a control rod drive unit (not shown) so as to adjust the reactor output. The control rod 34 has a cruciform cross-section and is charged in out between combinations of four fuel assemblies 13 for adjustment controlling. In the divided chimneys 15 adjacent to each other arranged above the reactor core 14, as shown in FIG. 2, the space pressure in a divided-chimney 15 is equalized to that of the neighboring divided-chimney 15 due to the pressure equalization tube 31 connected therebetween. That is, referring to FIG. 2, according to the present invention, the relationship between the reactor core height and the pressure is shown by a solid line, while according to the conventional example, the relationship varies between dotted lines. In the pressure equalization structure for equalizing pressures of the divided chimneys 15, instead of the pressure equalization tube 31, connection holes 35 may be formed on the divided-chimney 15 in the vicinity of its inlet as shown in FIG. 3. The shape of the connection holes 35 may include a circle, ellipse, oblong and rectangle. The connection holes 35 are formed on each plate surface of the lattice plates 30 provided in the inlet of the rectangular-columnar divided chimneys 15, respectively. In the natural-circulation BWR10 according to the embodiment, a number of the fuel assemblies 13 are accommodated within the reactor pressure vessel 11 to form the reactor core 14 in a lower portion of the reactor core shroud 12, and the divided chimney group is provided on the outlet side of each fuel assembly 13 by bundling the divided chimneys 15. In the divided chimneys 15 adjacent to each other, the pressures of the divided chimneys can be equalized by the pressure equalization tube 31 or the connection holes 35 formed on each divided-chimney 15. That is, the pressures of the whole fuel assemblies 13 can be equalized in the divided chimneys provided at the outlets of the fuel assemblies 13 constituting the reactor core 14. Accordingly, the pressure boundary in an upper portion of the reactor core, which is important for the channel stability of the fuel channels, is shifted from the outlet of the divided chimneys 15 to the connection holes 35 or the pressure equalization tube 31 on the inlet side of the divided chimneys 15 so as to reduce the vapor/liquid two-phase flow region, eliminating or largely improving the transport lag within the divided chimneys 15, thereby improving the stability. FIG. 4 shows a first modification of the first embodiment of the natural-circulation BWR according to the present invention. Since divided chimneys 15A of the first modification are different from the divided chimneys 15 shown in FIGS. 2 and 3, and other configurations and effects are the same as those of the natural-circulation BWR10 shown in FIG. 1, like reference characters designate like components common thereto, and the duplicated drawings and description thereof are eliminated herein. In the divided chimneys 15A shown in FIG. 4, a plurality of connection holes 36a and 36b are formed in the vertical direction at the lower portions of each plate surface of each of the rectangular-columnar lattice plates 30. FIG. 5 shows a second modification of the first embodiment of the natural-circulation BWR according to the present invention. In divided chimneys 15B of the second modification, a slit 37 extending in the chimney axial direction is formed on each of the rectangular-columnar lattice plates 30. In FIG. 5, the vertical slit 37 is formed, but alternatively, horizontal slits may also be formed on the rectangular-columnar lattice plates 30 in a multiple column in the chimney axial direction. Furthermore, FIG. 6 shows a third modification of the first embodiment of the natural-circulation BWR according to the present invention. In the natural-circulation BWR10 of the third modification, instead of forming the connection holes 35, 36a and 36b or the slit 37 on each of the divided chimneys 15, a clearance 38 is formed between the top of the fuel assemblies 13 constituting the reactor core 14 and the inlet (bottom) of the divided chimneys 15. In the natural-circulation BWR10, the divided chimneys 15 provided above the group of the fuel assemblies 13 are provided with the pressure equalization tube 31 so as to communicate the divided chimneys 15, 15 adjacent to each other, or by providing at least one connection hole 35, 36a and 36b or the slit 37 on the rectangular-columnar lattice plate 30 of each of the rectangular-columnar divided chimneys 15, or by furthermore forming the clearance 38 between the top of the group of the fuel assemblies 13 and the bottom of the group of the divided chimneys 15, the pressures of the whole fuel assemblies 13 can be equalized in the divided chimneys provided at the outlet of the fuel assemblies 13. A plurality of the connection holes 36a and 36b are formed on the divided chimneys 15 on the lower side in the chimney axial direction. On the other hand, the slit 37 is formed to range from the bottom of the intermediate portion of the lattice plate 30 toward the lower portion thereof. The slit 37, instead of forming in the vertical direction, may also be formed in the horizontal direction (width direction) in one or more columns. By equalizing the pressures of the whole fuel assemblies 13 and 13 at the divided chimneys 15, the pressure boundary in an upper portion of the reactor core, which is important for the channel stability of the fuel channels, can be shifted in the lower direction from the outlet of the divided chimneys 15 to the inlet side of the divided chimneys 15 so as to reduce the vapor/liquid two-phase flow region to thereby eliminate the transport lag in the group of the divided chimneys 15, so that the stability, such as channel stability, can be improved. FIGS. 7 and 8 are drawings showing a natural-circulation BWR according to a second embodiment of the present invention. FIG. 7 is a schematic elevational sectional view of the natural-circulation BWR according to the second embodiment and FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. 7. In a natural-circulation BWR10A according to the second embodiment, like reference characters designate like components common to the natural-circulation BWR 10 according to the first embodiment, and the duplicated description is omitted herein. In the natural-circulation BWR 10A shown in FIG. 7, above the group of the fuel assemblies 13 constituting the reactor core 14, a plurality of the rectangular-columnar divided chimneys 15 are provided by bundling them to form the chimney 16 composed of the group of the divided chimneys 16. In the divided chimneys 15 constituting the chimney 16, at least one connection hole 41 is formed on rectangular-columnar lattice plates 40 of the divided chimneys 15 arranged in an outermost circumferential region. The connection hole 41 on each lattice plate 40 of the divided chimneys 15 adjacent to each other arranged in the outermost circumferential region is formed larger in diameter than at least one connection hole 44 on each lattice plate 43 of the divided chimneys 15 arranged in the central regions other than the outermost circumferential region so that the pressures of the fuel assemblies 13 arranged in the peripheral section, where the channel flow rate is small and the reactor output is increased, are equalized. In the natural-circulation BWR 10A according to the second embodiment, the pressures of the fuel assemblies 13 as well as the fuel assemblies 13 arranged in the peripheral section about the reactor core 14 in the reactor pressure vessel 11, where the reactor output is largely different, can be equalized. As a result, the position of the pressure boundary of the upper part of the reactor core, which is important for the stability, can be lowered to positions of the connection holes 41 and 44 of the divided chimneys 15 so as to reduce the vapor/liquid two-phase flow region, eliminating the transport lag in the divided-chimneys 15, thus improving the stability. In the connection holes 41 and 44 formed on the divided chimneys 15, the connection hole 41 of the divided chimneys 15 arranged on the outermost circumferential region corresponding to the peripheral section of the fuel assemblies 13 is formed larger in diameter than the connection hole 44 of the residual divided chimneys 15. One or more of the connection holes 41 and 44 may be formed at an appropriate position of the lattice plates 40 and 43. The shape of each of the connection holes 41 and 44 may include a circle, rectangle, ellipse, oblong, and slit. The connection holes 41 and 44 on the divided chimneys 15 may be preferably formed so as to correspond to the lower side rather than the central region in the chimney axial direction. Each of the connection holes 41 and 44 may be formed at an appropriate position of the rectangular-columnar lattice plates 40 and 43 of the divided chimneys 15, but alternatively, a plurality of the holes may be formed on the whole plate surface of the lattice plates 40 and 43 along the vertical direction. In any case, in the connection holes 41 and 44 formed on the divided chimneys 15, it is taken into consideration that at least one hole of the respective holes is formed in the vicinity of the outlet of the group of the fuel assemblies 13 so that the pressure boundary of the upper part of the reactor core is formed at a position lower than the reactor-core upper plenum 17. FIGS. 9 and 10 are drawings showing a natural-circulation BWR according to a third embodiment of the present invention. FIG. 9 is a schematic elevational sectional view of the natural-circulation BWR 10B according to the third embodiment and FIG. 10 is an enlarged drawing of B portion of FIG. 9 as well as showing the relationship between the height of the reactor core and the divided chimneys 15 in the axial direction and the reactor pressure. In the natural-circulation BWR 10B according to the third embodiment, like reference characters designate like components common to the natural-circulation BWR 10 according to the first embodiment, and the duplicated description is omitted herein. In the natural-circulation BWR 10B shown in FIG. 9, divided chimney regions 50 and 51 are divided into a plurality of regions in the height direction in the chimney 16 formed in the upper portion of the reactor core 14 in the reactor pressure vessel 11. In FIG. 9, the divided chimney regions 50 and 51 are vertically divided into two in the axial direction of the chimney 16. A rectangular-columnar divided chimney group 52 corresponding to the upper divided chimney region 50 has divided-chimney lattice plates 54 smaller in the number of plates than divided-chimney lattice plates 55 of a rectangular-columnar divided chimney group 53 corresponding to the lower divided chimney region 51, so that the cross-sectional area of the upper divided chimney 52 is substantially equalized to the sum of the cross-sectional areas of a plurality, four for example, of the lower divided chimneys 53. In the chimney 16 on a plan view, it is established that the cross-sectional area of the upper divided chimney 52 is substantially the same as the sum of the cross-sectional areas of a plurality, four for example, of the lower divided chimneys 53, and the boundary position of the upper and lower divided chimneys 52 and 53 is set lower than the position of the outlet of conventional divided chimneys. The upper and lower divided chimney regions 50 and 51 are divided into a plurality of regions in the chimney height direction (chimney axial direction), and the cross-sectional area of the upper divided chimney 52 is equalized to the sum of the cross-sectional areas of a plurality of the lower divided chimneys 53, so that on the upstream side of the divided chimneys 52 and 53, as shown in FIG. 10, the pressures of the fuel assemblies 13 (reactor pressures) is equalized. As a result, the pressure boundary in an upper portion of the reactor core, which is important for the stability, can be lowered in position. The pressure boundary position in the upper portion of the reactor core can be lowered more than the position of the outlet of the divided chimneys of a conventional natural-circulation BWR so as to reduce the vapor/liquid two-phase flow region to thereby eliminate the transport lag in the divided chimneys so as to improve the stability such as channel stability. FIGS. 11 and 12 are drawings showing a modification of the third embodiment of the natural-circulation BWR. FIG. 11 is a schematic elevational sectional view of the natural-circulation BWR 10B of the modification of the third embodiment and FIG. 12 is an enlarged perspective view of C portion of FIG. 11. Upon describing the modification, like reference characters designate like components common to the natural-circulation BWR 10B according to the third embodiment, and the duplicated description is omitted herein. In the natural-circulation BWR 10B of the modification, a vertically divided structure of the chimney 16 provided above the reactor core 14 differs from that of the chimney shown in FIGS. 9 and 10. In the natural-circulation BWR 10B of the modification, divided chimney regions 56 and 57 formed above a plurality of the fuel assemblies 13 are also divided into a plurality, two for example, of divided chimney regions in a chimney height direction. The central position of the rectangular-columnar upper divided chimneys is shifted from that of the similar rectangular-columnar lower divided chimneys in the radial direction of the reactor core 14, specifically in the horizontal direction. The shift amount in the core radial direction is appropriately set within the range of the width size of one chimney of divided chimneys 59. In the natural-circulation BWR 10B of the modification, by shifting the central position of rectangular-columnar lattice plates 60 of upper divided chimneys 58 from that of the rectangular-columnar lattice plates 61 of lower divided chimneys 59, the pressures of the fuel assemblies 13 can be equalized on the upstream side from the outlet of the upper divided chimneys 58. In such a manner, since the pressures of the fuel assemblies 13 can be equalized on the upstream side from the outlet of the chimney 16, the pressure boundary in the upper portion of the reactor core, which is important for the stability, can be lowered so as to reduce the vapor/liquid two-phase flow region. Thus, the transport lag can be eliminated within the divided chimneys 58 and 59, so that the stability can be improved.
	description	This application claims priority to U.S. Provisional Application No. 62/852,720, filed May 24, 2019, the entire disclosure of which is incorporated by reference herein. The presently-disclosed invention relates generally to systems and methods of use thereof for controlling reactor power levels in nuclear thermal propulsion space reactors and, more specifically, to systems and methods of use thereof for control rod drive mechanisms for nuclear thermal propulsion space reactors. In terrestrial pressurized water reactors (PWRs) 10, which constitute the majority of the world's nuclear power plants, the PWR 10 is primarily controlled by the insertion of internal control rods 12 that are located above the reactor core 14, as shown in FIG. 1. Note, the addition of neutron poisons into the coolant water can also be used to control reactors, but will not be addressed in this disclosure. Most control rod systems consist of three items: (1) a control rod drive motor (CRDM) 16 used to move the corresponding control rods 12 into and out of the reactor core 14 by rotating a roller nut 18 (FIG. 2) attached to a threaded drive shaft 20; (2) a threaded drive shaft 20 connected to the top of the control rod 12 and latched at the top of the control rod 12 by the CRDM's roller nut 18 (the threaded drive shaft 20 is driven into and out of the reactor core 14 by the CRDM 16); and (3) a control rod 12 (usually a cylindrical neutron absorbing poison) that travels into and out of the reactor core 14. The neutron poison in the control rods 12 absorbs the neutrons that are used to provide criticality in nuclear reactors. The poison material in the control rods 12, when placed within the reactor core 14, absorbs enough neutrons to shut down the PWR 10. To control the PWR's power, the control rods 12 are removed axially in incremental steps in order to absorb only enough neutrons to maintain the PWR's criticality. During certain upset conditions, the PWR 10 performs an emergency shutdown, or SCRAM. During a SCRAM, the neutron-absorbing control rods 12 are inserted quickly into the reactor core 14. As stated above, in PWRs 10 the CRDMs 16 are located above the reactor core 14. During a SCRAM, the roller nuts 18 that secure to the threaded drive shafts 20 to the CRDMs 16 are mechanically or magnetically decoupled from the CRDMs 16, as shown in FIG. 2B. This allows the threaded drive shafts 20 and corresponding control rods 12 to drop by gravity into the reactor core 14, thereby stopping the chain reaction. In terrestrial boiling water reactors (BWRs) 22, the second most common type of reactor in nuclear power plants, the reactor power is controlled by either changing the water flow through the BWR 22, changing neutron absorbing chemistry in the coolant water, or inserting or withdrawing control rods 24. For both BWRs 22 and PWRs 10, coolant water enters the core 26 and 14, respectively, from the bottom and exits from the top of the core. BWR control rods 24, located below the reactor core 26, are inserted from below, as shown in FIG. 3. In a BWR 22, the reactor coolant is heated as it flows upward through the reactor core 26. The water boils in the region at the top of the reactor core 26 making it less dense and, therefore, less efficient in thermalizing neutrons. Thermalized neutrons are required to sustain the fission process. The denser water at the bottom of the reactor core 26 results in a higher concentration of neutrons, which in turn makes the control rods 24 more efficient in being able to affect the fission process, or control reactivity. Therefore, in BWRs 22, the control rods 24 are inserted upwards from below the core. During a SCRAM of a BWR 22, gravity counteracts insertion of the control rods 24. The BWR control rods 24 are inserted by a high pressure hydraulic source 28, such as shown in FIG. 4. The reactivity of a nuclear space reactor 30 (FIG. 7) is controlled by either exterior or interior control systems and cannot benefit from the use of gravity. The majority of exterior control systems for space reactors are controlled by rotating control drums 32, or barrels, that are located on the exterior of the reactor core 34, as shown in FIG. 5. Each rotating control drum 32 has both reflector material 36 and neutron absorbing material 38 within the drum 32, as shown in FIG. 6. During normal operations, the control drums 32 are positioned such that the reflecting material 36 is pointing towards the core 34, thereby directing the neutrons back into the reactor core 34, as shown on the left side of FIG. 6. During shutdown, the control drums 32 are positioned so that the neutron absorbing material 38 is pointing toward the reactor core 34, thereby absorbing enough neutrons to shutdown the reactor core 34, as shown on the right side of FIG. 6. There at least remains a need, therefore, for systems and methods for controlling reactor power levels in nuclear space reactors. One embodiment of the present invention provides a control rod assembly for a nuclear reactor having a reactor core and a pressurized fluid source, including a control rod disposed within a control rod sleeve, a lead screw that is selectively secured to the control rod, a trip latch that is secured to a bottom end of the lead screw, the trip latch being selectively securable to a top end of the control rod, a control rod drive motor that is operably connected to the lead screw, and a valve that is in fluid communication with the pressurized fluid source of the nuclear reactor and is movable between a first position in which the pressurized fluid source is isolated from the control rod sleeve and a second position in which the pressurized fluid source is in fluid communication with the control rod sleeve, wherein in the first position of the gas valve the trip latch is in a closed position and in the second position of the gas valve the trip latch is in an open position. Another embodiment of the present invention provides a nuclear reactor having a reactor core, a pressurized fluid source, and a control rod assembly including a control rod disposed within a control rod sleeve, a lead screw, a trip latch that is secured to a bottom end of the lead screw, the trip latch being selectively securable to a top end of the control rod, a control rod drive motor that is operably connected to the lead screw, and a valve that is in fluid communication with the pressurized fluid source of the nuclear reactor and is movable between a first position in which the pressurized fluid source is isolated from the control rod sleeve and a second position in which the pressurized fluid source is in fluid communication with the control rod sleeve, wherein in the first position of the gas valve the trip latch is in a closed position and in the second position of the gas valve the trip latch is in an open position. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention. Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention according to the disclosure. Reference will now be made to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. The present invention is related to the use of interior control rods in nuclear space reactors as either the primary control system and/or only as the reactor shutdown system. Interior control rods may also be used as an independent, alternative shutdown system separate from the primary control drum (barrel) control system. As a secondary shutdown system, the backup control rods could be inserted into the reactor core during launch of the space vehicle for additional shutdown capability in case of a launch failure in which the core becomes submerged in water. After a successful launch and obtaining a safe orbit, the secondary interior control rods would be driven from the reactor core and the reactor startup/control would be governed entirely by the exterior rotating control drums. As the secondary shutdown system, the interior control rods would only be used to shut down the reactor if the primary control system fail. Of note for the present invention, when a nuclear space reactor is in space, gravity cannot assist in re-inserting interior control rods as with the previously discussed PWRs. Various advantages of a space reactor gas assist control rod release mechanism (CRRM) are as follows: the disclosed CRRM allows the control rods to be rapidly inserted into the core without the assistance of gravity; no additional high pressurant is required beyond the normal nuclear thermal reactor space craft pressurized gas; there is no affect with regard to changing the control rod arrangement within the reactor core; valves within the system may be arranged to allow for multiple control rods to be activated from a single gas valve; and the system may be used for terrestrial gas reactors. Before discussing a preferred embodiment of a space reactor gas assist CRRM in accordance with the present invention, a discussion of the basic principles of nuclear thermal propulsion space reactors is presented. Referring now to FIG. 7, the basic principle of a nuclear thermal propulsion space reactor 30 is to heat coolant, usually hydrogen gas, to high temperatures by the nuclear reactor and expel the gas through a rocket nozzle 31 to create thrust. Nuclear thermal propulsion space reactors (here and after referred to as NSRs) are pressure-fed engines requiring pressurized coolant 33 to overcome the coolant pressure drop that occurs in the narrow coolant passageways throughout the reactor. Pressure-fed systems consist of either a tank pressure-fed system, pump-fed system, or a combination of both. In tank pressure-fed systems, the high pressure fuel tank drives the coolant directly through the reactor. A pump-fed system is illustrated in FIG. 7. With pump-fed systems, a turbo-compressor pump 35a/35b takes heated coolant HC that was previously used to cool the reactor components to drive a turbine 35a whose shaft is directly coupled to a compressor pump 35b. It is this pressurized gas, either from the compressor or from the turbo pump, that is used to supply the present CRRM. In space, at initial startup of liquid fueled rockets, the fuel or coolant that is stored within a fuel tank can have a sloshing effect within the tank due to the zero-gravity environment. This sloshing fuel can disrupt the required supply of fuel to the compressor resulting in compressor damage. A method to eliminate fuel sloshing is placing a diaphragm 21 within the fuel tank 23 so that it is disposed between a pressurization gas 25 and the fuel 27, as shown in FIG. 8. The pressurized gas 25 pushes the diaphragm 21 and fuel 27 so as to provide a continuous fuel flow to the turbo-compressor pump 35a/35b (FIG. 7). Note, once the acceleration force from the rocket exhaust begins, the acceleration of the space craft forces the fuel to settle at the bottom of the fuel tank 23 and provides a continuous fuel supply to the turbo-compressor pump intake. The pressurized gas source utilized to prevent the sloshing of fuel may also be used to supply pressurized gas to the present CRRM, as discussed in greater detail below. Referring now to FIG. 9, a CRRM 40 in accordance with the present invention provides a way to SCRAM control rods 42 (FIG. 10) into a reactor core 44 that is in space, without the assistance of gravity. As shown, the control rod 42 is made to act as a piston 46 within a cylinder 48, with pressurized gas from the fuel tank 23 (FIG. 8), or turbo-compressor 35a/35b (FIG. 7), utilized to drive the control rod(s) 42 rapidly into the reactor core 44. Preferably, a piston 46 or enlarged portion of the control rod 42, forms a gas-tight seal (at 51) so that the pressurized gas drives the corresponding control rod 42 into the reactor core 44 when acting on the piston 46. Referring now to FIGS. 10A through 10E, an operation sequence of the CRRM 40 during an emergency (SCRAM) shutdown in a space nuclear reactor is shown. As shown in FIG. 10A, the control rod 42 is in the retracted position outside of the reactor core 44. The control rod 42 is positioned by the CRDM 43, and the gas valve 50 of the pressurized gas source is closed. An optional O-ring seal 52 for forming a gas-tight seal around the control rod 42 is shown in FIG. 10B. Referring now to FIG. 10C, upon the initiation of a SCRAM sequence, the gas valve 50 opens, thereby allowing pressurized gas from the fuel tank 23 (FIG. 8), or turbo-compressor pump 35a/35b (FIG. 7), to enter the control rod enclosure 53. The high pressure gas trips the trip latch 60 open that selectively attaches the control rod 42 to threaded drive shaft 41, as best seen in FIGS. 11A and 11B. Optionally, the trip latch 60 may be activated by deactivating a magnetic latch or activated mechanically by an electrical signal (not shown). As shown in FIG. 10D, with the trip latch 60 open, the pressurized gas drives the control rod 42 into the reactor core 44, where it absorbs neutrons and shuts down the core's reactivity. As shown in FIG. 10E, to restart the reactor, the control rod trip latch 60 is closed by removing gas pressure therefrom. Next, the CRDM 43 is activated and drives the trip latch 60 down the threaded drive shaft 41 where it re-attaches to the control rod 42. The gas valve 50 is closed and the gas within the control rod enclosure 53 is vented. The CRDM 43 retracts the control rod 42 based upon the reactor's start up sequence. Various gas delivery systems may be used to supply the high-pressure gas to the space reactor gas assist CRRM 40. For example, pressurized gas sources may include, but are not limited to, a dedicated control rod shutdown gas supply tank, high pressure thrust exhaust gas exiting the nuclear thermal rocket nozzle, fuel tank pressurant gas, high-pressure gas from the turbo-compressor system, and high-pressure hydraulic supply systems may be used. While one or more preferred embodiments of the invention are described above, it should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit thereof. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents.
	description	This is a Continuation-In-Part application of application Ser. No. 14/109,072, filed Dec. 17, 2013, entitled FLOATING NUCLEAR POWER REACTOR WITH A SELF-COOLING CONTAINMENT STRUCTURE. 1. Field of the Invention This invention relates to a floating nuclear power reactor and more particularly to a floating nuclear power reactor wherein the containment structure of the reactor is self-cooling. More particularly, this invention relates to a floating nuclear power reactor wherein the containment structure is comprised of multiple components. Even more particularly, the reactor includes an automatic radiation scrubbing system. 2. Description of the Related Art In most nuclear power reactors, a primary electrically operated water pump supplies cooling water to the reactor. In many cases, a secondary or back-up water pump is provided in case the primary water pump becomes inoperative. However, should the electrical power source for the water pump or water pumps be disrupted such as in a tsunami, a typhoon or an earthquake, the water pumps are not able to pump cooling water to the reactor which may result in a dangerous meltdown. Further, in some situations, the pipes supplying cooling water to the reactor may fail due to natural causes or a terrorist attack. Currently, there are land based reactor cooling systems available which store water in a tank above the level of the reactor which will passively feed the reactor in case of pump or electricity failure. These tanks are designed to have enough water to cool the system for three days until help can arrive and more water can be pumped in from outside. The problem is that water stored in these tanks is of finite quantity. The tanks will work in case of an emergency shut down like in Fukushima, Japan, but will not work in the case of a pipe breakdown leaking a huge amount of water to the exterior. The reactor core will heat the water supplied from the tank and steam will escape via the pipe breakdown and the water will run out. Once the water runs out, the reactor core will melt due to overheating and explode. It is therefore necessary to be able to supply an infinite amount of water to compensate for lost water via a leaking pipe. Further, current day reactors are protected by huge containment structures but this is not the answer to pipe breakdown outside or inside the containment chambers. A terrorist attack on the turbine room outside the containment structure is probably more dangerous than an attack on the containment structure since such an attack would result in multiple pipes breaking down, thereby breaking the water circuit between the reactor, turbine and condenser. Such an attack could also result in a breakdown of electrical control systems. This would result in the loss of circulating water to the reactor with the emergency stored water being unable to compensate for all the leaking pipes. In such a situation, the reactor will overheat without heat removal and explode. The containment structures of the prior art nuclear power reactors normally include a thick outer containment structure which is comprised of concrete. The thick outer concrete containment structure is somewhat difficult to construct and even more difficult to demolish when the reactor is being replaced. Additionally, the prior art does not provide an efficient automatic radiation scrubbing system. The invention of the co-pending parent application represents a major improvement in the art. The instant invention represents a further improvement in the art. This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter. A floating nuclear power reactor is disclosed. A nuclear power reactor is mounted or positioned on a floating barge-like vessel with the barge-like vessel having an upper end positioned above the water level of a body of water and a lower end positioned beneath the water level of the body of water. Side walls extend between the lower and upper ends of the floating vessel. The nuclear power reactor is positioned on the bottom of the barge-like vessel. The nuclear power reactor includes a first concrete containment member having a lower end, an upstanding sidewall, and an upper end. A cover closes the upper end of the first containment member. A second concrete containment member is positioned in the interior of the first containment member in a spaced-apart relationship so that the inner side of the first containment member is spaced from the outer side of the second containment member to define a first space between the walls thereof. The first space is filled with sand to define a third containment member. The relationship of the first containment member, the second containment member, and the cover define a vent chamber. The vent chamber is filled with a filter material such as stones or rocks, chemicals and water. One or more steam exhaust pipes extend outwardly from the upper end of the vent chamber through the cover to the atmosphere. A reactor vessel, having upper and lower ends, is positioned in the interior compartment of the second containment member with the reactor vessel being positioned below the water level of the body of water. The reactor vessel includes an interior compartment having upper and lower ends. One or more steam exhaust pipes extend through the second containment member so that one end thereof is in communication with the upper end of the interior compartment thereof and so that the other end thereof is in communication with the vent chamber. One or more steam return pipes are associated with the reactor vessel so that one end thereof is in communication with the upper end of the interior compartment of the reactor vessel and so that the other end is in communication with the lower end of the interior compartment of the reactor vessel. In the preferred embodiment, one of the return pipes is of the closed loop type. In the closed loop return pipe structure, the return pipe is filled with a coolant. A portion of the closed loop return pipe is positioned in the interior compartment of the second containment member. The return pipes form a heat exchanger system. A steam exhaust pipe extends from the upper end of the interior compartment of the reactor vessel outwardly through the second and first containment members to a turbine. At least one first water passageway, having inner and outer ends, extends through the bottom of the vessel and the bottom of the second containment member with the outer end of the first water passageway being in fluid communication with the body of water. The inner end of the first water passageway is in fluid communication with the interior compartment of the second containment member. A spring-loaded first hatch is movably mounted in the first water passageway. The first hatch is movable between a closed position and an open position. The first hatch, when in its closed position, closes the outer end of the first water passageway. The first hatch, when in its open position, permits water from the body of water to flow inwardly through the first water passageway into the interior compartment of the second containment member to cool the reactor vessel. A first latching means is associated with the first hatch with the first latching means being movable between a latched position and an unlatched position. The first latching means, when in its latched position, maintains the first hatch in its closed position. The first latching means, when in its unlatched position, permits the first hatch to move from its closed position to its open position. A first condition responsive actuator is associated with the first latching means and the interior compartment of the second containment member to move the first latching means from its latched position to its unlatched position upon the condition, either temperature or pressure, in the interior compartment of the second containment member reaching a predetermined level. At least one second water passageway, having inner and outer ends, extends through the bottom of the vessel into the interior of the reactor vessel. A second hatch is movably mounted in the second water passageway. The second hatch is movable between a closed position and an open position. The second hatch closes the outer end of said second passageway when in its closed position. The second hatch, when in its open position, permits water from the body of water to flow inwardly into the interior of the reactor vessel to cool the reactor vessel. A second latching means is associated with the second hatch which is movable from a latched position to an unlatched position. The second latching means, when in its latched position, maintains the second hatch in its closed position. The second latching means, when in its unlatched position, permits the second hatch to move from its closed position to its open position. A condition, either temperature or pressure, responsive actuator is associated with the second latching means and the interior compartment of the reactor vessel to move the second latching means from its latched position to its unlatched position upon the condition within the interior compartment of the reactor vessel reaching a predetermined level. One or more steam exhaust pipes are also provided which extend from the upper end of the interior compartment of the second containment member to the lower end of the vent chamber. One or more steam exhaust pipes extend outwardly from the upper end of the vent chamber through the cover to the atmosphere. A steam exhaust pipe extends from the upper end of the interior compartment of the reactor vessel, outwardly through the interior compartment of the second containment member, thence through the space between the second and first containment members, thence through the first containment member to a turbine. A normally open valve is positioned in the steam exhaust pipe, which extends to the turbine. One or more steam by-pass pipes extend from the steam exhaust pipe which extends to the turbine. The steam by-pass pipe communicates with the lower interior of the vent chamber. A normally closed valve is imposed in each of the steam by-pass pipes. Although the hatch latching means and condition responsive actuators are described in detail, the hatches could be opened by other means such as mechanical or electrical devices. It is therefore a principal object of the invention to provide an improved floating nuclear power reactor. A further object of the invention is to provide a floating nuclear power reactor which is self-cooling upon the temperature or pressure reaching a predetermined level in the inner containment member or reactor vessel of the nuclear power reactor. A further object of the invention is to provide a self-cooling nuclear power reactor. A further object of the invention is to provide a self-cooling nuclear power reactor including an automatic radiation scrubbing containment structure. A further object of the invention is to provide a self-cooling nuclear power reactor which has an unlimited or infinite supply of cooling water, even in the event of a break in the steam line which extends to the turbine. A further object of the invention is to provide an invention of the type described including at least one and preferably multiple, return lines associated with the reactor vessel and the interior compartment of the second containment member. A further object of the invention is to provide a cooling mechanism for a floating nuclear power reactor which does not require electrical power to operate. A further object of the invention is to provide an invention of the type described wherein the outer confinement structure is comprised of multiple components. These and other objects will be apparent to those skilled in the art. Embodiments are described more fully below with reference to the accompanying figures, which form a part hereof and show, by way of illustration, specific exemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense in that the scope of the present invention is defined only by the appended claims. The numeral 10 refers to a floating vessel such as a barge as shown in the co-pending application Ser. No. 14/109,072, filed Dec. 17, 2013, entitled FLOATING NUCLEAR POWER REACTOR WITH A SELF-COOLING CONTAINMENT STRUCTURE. Barge 10 could be a ship hull or other floating structure. The detail of the barge 10 will not be disclosed other than to say that the barge 10 includes a bottom 12, upstanding ends, and upstanding sides. One of the sides 14 of the barge is shown in the drawings. Barge 10 may be constructed of any suitable material such as steel, concrete, etc. Barge 10 is shown as floating in a body of water 16 such as a lake, ocean, sea, etc. For reference purposes, the body of water 16 will be described as having a water level 18. As seen, the upper end 20 of barge 10 is positioned above the water level 18 with a majority of the barge 10 being submerged in the body of water 16. A nuclear power reactor 22 is positioned on the barge 10 as shown in the drawings. Normally, a second nuclear power reactor would also be positioned on the barge 10 such as shown in the co-pending application. Further, there could be several nuclear power reactors positioned on the barge. Reactor 22 includes a containment member 26 which is cylindrical in shape and which is preferably constructed of concrete. Containment member 26 could be constructed of other materials such as metal, etc. A cover or lid 28 closes the upper end of containment member 26. Reactor 22 includes an upstanding containment member 30 constructed of concrete and which includes a bottom 32, an upstanding side wall 34 and an upper end 36 which defines a sealed interior compartment 38. Usually, containment member 30 will have a greater thickness than containment member 26. A reactor vessel 40 is positioned in compartment 38 and includes an open bottom 42, side wall 44, and upper end 46 which define a sealed interior compartment 48. As seen, the bottom 42 of reactor vessel 40 is positioned on the upper end of bottom 32 of containment structure 30. The reactor vessel 40 also functions as a containment member for the core of the reactor. Containment member 30 is spaced inwardly of containment member 26 as seen in FIG. 1. The lower portion of the space between containment member 26 and the side wall 34 of containment member 26 is filled with sand 50. The space above the upper end of sand 50 is designated by the reference numeral 52 and defines a vent chamber 54. Vent chamber 54 is filled with a combination of rocks, or stones, chemicals and water to create a radiation scrubbing containment structure. The containment members 26, 30 and the space therebetween which is filled with sand 50 combine to create a very strong outer containment structure with the reactor vessel 40 forming an inner containment structure. The numeral 60 refers to a steam exhaust pipe comprised of pipe sections 62 and 64. As seen, pipe portion 62 has its inner end in communication with the upper portion of compartment 38. Pipe portion 64 extends downwardly from pipe portion 62 at 66. The lower end of pipe portion 62 is in communication with the lower end of vent chamber 54. The shape of the pipe 60 permits the pipe 60 to function as an anti-siphon exhaust pipe. A second steam exhaust pipe 68 comprised of pipe sections 70 and 72 will now be described. As seen, pipe section 70 extends upwardly and outwardly from the upper end of compartment 38 to 74 where pipe portion 72 extends downwardly and outwardly therefrom. The lower end of pipe portion 74 is in communication with the lower end of chamber 54. The inner end of pipe portion 70 is in communication with the upper end of compartment 38 as seen in the drawings. The shape of the pipe 70 permits the pipe 70 to function as an anti-siphon exhaust pipe. The numeral 76 refers to a return pipe or line having pipe portions 78, 80, 82 and 84. Pipe portion 78 extends outwardly from compartment 48 adjacent the upper end of wall 44. Pipe portion 80 extends downwardly from the outer end of pipe portion 78, as seen in the drawings. Pipe portion 82 extends inwardly from the lower end of pipe portion 80, through side wall 44, into compartment 48 at the lower end thereof. Pipe portion 84 extends between the inner ends of pipe portions 78 and 82 to provide a closed loop return pipe. The return pipe 76 is filled with a liquid coolant such as sodium, water, etc. As seen, pipe portion 80 and a portion of pipe portions 78 and 82 are in interior compartment 38. Although a single return pipe 76 is shown, additional return pipes could be utilized. The return pipe 76 functions as a heat exchange structure. The numeral 86 refers to a steam return pipe having pipe portions 88, 90 and 92. Pipe portion 88 extends outwardly from compartment 48 adjacent the upper end of side wall 44. Pipe portion 90 extends downwardly from the outer end of pipe portion 88. Pipe portion 92 extends inwardly from the lower end of pipe portion 90 through side wall 44 into compartment 48 at the lower thereof. Although one steam return pipe 86 is shown and described, any number of the steam return pipes 86 could be utilized. The return pipe 86 functions as a heat exchange structure. A water passageway 94 extends upwardly through bottom 12 of barge 10 and through bottom 32 of containment member 30. The inner end of passageway 94 communicates with a larger water passageway 96, which communicates with the interior compartment 38 of containment member 30. A spring-loaded latch 98, which is identical to that shown and described in the co-pending application, is positioned in water passageway 96 to close water passageway 94. Hatch 98 includes a spring (not shown) which urges hatch 98 to its open position. A latching means (not shown), which is identical to that shown in the co-pending application, is associated with the hatch 98 with the latching means being movable between a latched position and an unlatched position as described in the co-pending application. The latching means, when in its latched position, maintains the hatch 98 in its closed position. The latching means, when in its unlatched position, permits the hatch 98 to move from its closed position to its open position. A condition responsive actuator 100, identical to that shown and described in the co-pending application, is associated with the latching means to move the latching means from its latched position to its unlatched position upon the condition, either pressure or temperature, in the interior compartment 38 of containment member 30 reaching a predetermined level. Any number of the water passageways 94 and 96 and the associated structure could be utilized. A water passageway 102 extends upwardly through bottom 12 of barge 10 and through bottom 32 of containment member 30. The inner end of passageway 102 communicates with a larger passageway 104, which communicates with the interior compartment 48 of reactor vessel 40. A spring loaded hatch 106, which is identical to that shown in the co-pending application, is positioned in the water passageway 104 to close water passageway 102. Hatch 106 includes a spring (not shown), which urges hatch 106 to its open position. A latching means, identical to that shown in the co-pending application, is associated with the hatch 106 with the latching means being movable between a latched position and an unlatched position. The latching means, when in its latched position, maintains the hatch 106 in its closed position. The latching means, when in its unlatched position, permits the hatch 106 to move from its closed position to its open position. A condition responsive actuator 107, which is identical to that shown and described in the co-pending application, is associated with the latching means to move the latching means from its latched position to its unlatched position, upon the condition, either temperature or pressure, in the interior compartment 48 of reactor vessel 40 reaching a predetermined level. The numeral 108 refers to a steam exhaust pipe which extends from the upper end of interior compartment 48 of reactor vessel 40 to a conventional turbine. As seen, steam pipe 108 extends outwardly through side wall 44 of reactor vessel 40, through interior compartment 38, through containment member 30, and through containment member 26. One or more steam by-pass pipes 110 extend upwardly from steam exhaust pipe 108 and pass into vent chamber 54 as seen in the drawings. A normally closed valve 112 is imposed in by-pass pipe 110. A normally open valve 114 is imposed in steam exhaust pipe 108 as seen in the drawings. The valves 112 and 114 will be of the remote control electrically operated type. Thus, if pipe 108 should be broken outwardly of containment member 26, valve 114 will be closed to prevent steam from leaking from pipe 108. In that case, the valve 112 will be opened so that steam from pipe 108 will pass upwardly through pipe 110 into the vent chamber 54 wherein radiation in the steam will be scrubbed therefrom before exiting to the atmosphere by way of the pipes 56 and 58. The instant invention functions as will be described. FIG. 1 illustrates the instant nuclear power reactor in its normal operating mode. In that mode: (1) hatches 98 and 106 are closed; (2) the return pipes 76 and 86 will not be functioning since pipe portions 80 and 90 are not being cooled by any surrounding coolant (water) and will stay at the same temperature as the reactor coolant; (3) valve 114 will be open and valve 112 will be closed; (4) steam exhaust pipes 56 and 58 will be inactive; (5) and the core of the reactor vessel will heat the water in the interior compartment thereof so that steam is created and passed to the turbine through steam exhaust pipe 108. The condition responsive actuator 100, upon sensing a predetermined level of pressure or temperature in interior compartment 38, will unlatch the latching means associated with hatch 98, to open hatch 98 thereby creating a temporary pool of water in interior compartment 38 of containment member 30. The temporary pool of water in interior compartment 38 surrounds reactor vessel 40 to cool reactor vessel 40. Reactor vessel 40 is further cooled by the return pipe 76. As the coolant material in pipe portion 84 is heated by the core of the reactor vessel 40, the coolant material will rise in pipe portion 84 and will pass outwardly through pipe portion 78 and thence downwardly through pipe portion 80. The coolant material in pipe portion 80, as it moves downwardly in pipe portion 80, will be cooled since pipe portion 80 is surrounded by the flood water in interior compartment 38. The cooled coolant material will then pass from the lower end of pipe 80 into the interior compartment 48 of reactor vessel 40 by way of pipe portion 82. The cooled material in pipe portion 84 cools the core of the reactor vessel. As the material in pipe portion 84 is heated, the material will rise upwardly through pipe portion 84 and thence again move outwardly through pipe portion 78. The heating and cooling of the material in return pipe 76 causes a continual flow of the coolant material through the heat exchanger system created by return pipe 76. The return pipe 86 functions similarly to return pipe 76 except that return pipe 86 is an open return system rather than a closed loop system as is pipe 76. Steam from interior compartment 48 exits outwardly therefrom by way of pipe portion 88. The steam then passes downwardly through pipe portion 90 which is cooled by the flood water in interior compartment 38. As the steam moves downwardly in pipe portion 72, it is cooled and turns to liquid, with the cooled liquid being returned to the interior compartment 48 of reactor vessel 40 to cool the reactor vessel. The water in interior compartment 38 gets hot in this process and evaporates or turns into steam. This heated water has not been in contact with radioactive material. However, to be safe, the steam in interior compartment 38 is vented into vent chamber 54 and is filtered and scrubbed by the filter material in vent chamber 54 and is passed to the atmosphere by way of the steam exhaust pipes 56 and 58. This process is continued until the temperature in the reactor vessel 40 comes down. The trigger point set to open hatch 98 will be much lower than the trigger point set to open the hatch 106. In this way, there is no sea water entry into the reactor vessel. In the very unlikely scenario that the above described process is unable to cool the core of the reactor vessel 40, and the temperature in the reactor vessel rises, the trigger point to open the hatch 106 would become operational (at the upper safety margins). When water enters reactor vessel 40, it will evaporate and steam goes into steam exhaust pipe 108 and to the turbine. By opening valve 112, steam passes into the vent chamber 54 where it is filtered and then vented to the atmosphere by way of steam exhaust pipes 56 and 58. The filter material in vent chamber 54 and the venting of the steam therefrom functions as a filtered containment venting system. In the event that there is a pipe breakage or leakage in pipe 108 downstream of the reactor, valve 114 may be closed and valve 112, in each of the steam by-pass pipes 110, opened so that the steam from the upper end of interior compartment 114 will be vented through pipes 110 and passed through the filter material in vent chamber 54 and thence to the atmosphere by way of steam exhaust pipes 56 and 58. Although the foregoing description explains the hatches and the actuation of those hatches in detail, it should be noted that the hatches could be opened by means other than that shown. For example, the hatches could be operated by electrical means or by other mechanical means. Further, the barge could be submerged so that the bottom thereof rests on the floor of the body of water. In that case, the hatches would be formed in the side of the barge as disclosed in the co-pending application. Thus it can be seen that the invention accomplishes at least all of its stated objectives. Although the invention has been described in language that is specific to certain structures and methodological steps, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed invention. Since many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
041749995	claims	1. Apparatus for locating an inspection device within a nuclear reactor vessel for volumetric examination thereof, the vessel having an external flange having located thereon a plurality of guide studs extending upwardly therefrom defining a generally circular path, an internal locating element the exact position of which is known and an internal circumferential flange, said apparatus comprising: (a) a support ring generally sized to relate to the path defined by the position of the guide studs; (b) a plurality of guide stud bushings, equal in quantity to the number of guide studs, said bushings being larger in internal diameter than the outer diameter of the guide studs; (c) first clamping means for movably mounting said bushings on said support ring to enable, when loosened, alignment of each of said bushings with one of said guide studs; (d) at least three support legs, all but one of said support legs including means for adapting said legs to contact and rest upon the internal circumferential vessel flange, the remaining support leg including means for adapting said leg to engage the internal locating element; and (e) second clamping means for mounting said support legs to said support ring at a point thereon which insures that the internal circumferential vessel flange and the internal locating element are simultaneously and respectively contacted and engaged. 2. The apparatus according to claim 1 wherein said support ring includes means for positively engaging said first and second clamping means in a predetermined alignment and said first and second clamping means include means for accepting said positive engagement with said support ring. 3. The apparatus according to claim 2 wherein said support ring means for positively engaging comprises an annular longitudinal key running about its periphery and said first and second clamping means for engagement comprises a keyway sized to accept said support ring key. 4. The apparatus according to claim 1 wherein said remaining support leg means for adapting includes a keyed plate mounted to said remaining leg when the core barrel of the reactor vessel remains in place. 5. The apparatus according to claim 1 wherein said remaining support leg means for adapting includes a locating key mounted to said remaining leg when the core barrel of the reactor vessel is removed. 6. The apparatus according to claim 2 wherein said remaining support leg means for adapting includes a keyed plate mounted to said remaining leg when the core barrel of the reactor vessel remains in place. 7. The apparatus according to claim 2 wherein said remaining support leg means for adapting includes a locating key mounted to said remaining leg when the core barrel of the reactor vessel is removed. 8. The apparatus according to claim 1 wherein said support legs include means for extending said legs radially with respect to said support ring. 9. The apparatus according to claim 1 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings. 10. The apparatus according to claim 8 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings. 11. The apparatus according to claim 2 wherein said support legs include means for extending said legs radially with respect to said support ring. 12. The apparatus according to claim 2 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings. 13. The apparatus according to claim 12 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings. 14. The apparatus according to claim 4 wherein said support legs include means for extending said legs radially with respect to said support ring. 15. The apparatus according to claim 4 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings. 16. The apparatus according to claim 14 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings. 17. The apparatus according to claim 5 wherein said support legs include means for extending said legs radially with respect to said support ring. 18. The apparatus according to claim 5 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings. 19. The apparatus according to claim 17 wherein said first clamping means is adapted to clamp said guide stud bushings at varying radial distances from said support rings.
048760730	claims	1. A generator of short-lived radionuclides, comprising a column containing a silica gel support impregnated with a long chain quaternary ammonium ion exchange agent having the formula (R.sub.3 N.sup.+ CH.sub.3)Cl.sup.- wherein the R group is C.sub.8 -C.sub.12 alkyl or at least one of the R groups is phenyl and the remaining groups are C.sub.8 -C.sub.10 alkyl, a complex of a parent radionuclide .sup.191 Os being sorbed on said support in an amount sufficient to maintain the parent radionuclide in steady state equilibrium with its short-lived daughter radionuclide .sup.191m Ir, said complex having been produced by: dissolving radioactive osmium metal in a hypochlorite/hydroxide solution; acidifying the mixture; extracting OsO.sub.4 with an organic solvent; washing the organic phase; adding an aqueous base to complex and extract the osmium from the organic phase; adding a reducing agent and acidifying the mixture to form an osmium complex selected from the group consisting of Na.sub.2 (OsO.sub.2 Cl.sub.4) and Na.sub.2 (OsO.sub.2 (OH).sub.2 Cl.sub.2); the daughter radionuclides being selectively eluted from the column by elution with physiological saline having a pH of about 1. dissolving radioactive osmium metal in a hypochlorite/hydroxide solution; acidifying the mixture; extracting OsO.sub.4 with an organic solvent; washing the organic phase; adding an aqueous base to complex and extract the osmium from the organic phase; adding a reducing agent and acidifying the mixture to form an osmium complex selected from the group consisting of Na.sub.2 (OsO.sub.2 Cl.sub.4) and Na.sub.2 (OSO.sub.2 (OH).sub.2 Cl.sub.2); applying said complex to a finely divided silica gel carrier having a quaternary ammonium salt anionic ion exchange agent having the formula (R.sub.3 N.sup.+ CH.sub.3)Cl.sup.- , wherein R is C.sub.8 -C.sub.12 alkyl or at least one of the R groups is phenyl and the remaining groups are C.sub.8 -C.sub.10 alkyl, sorbed thereon. 2. The short-lived radionuclide generator of claim 1, wherein the osmium is sorbed on the silica gel in an amount of from about 4 to 15 milligrams per gram of silica gel. 3. The short-lived radionuclide generator of claim 1, wherein the quaternary ammonium compound is methyl tricaprylyl ammonium chloride. 4. The short-lived radionuclide generator of claim 1, comprising a further column containing an osmium scavenger selected from the group consisting of 2,3-hydroxy-benzoic acid and 3,4,5-trihydroxy benzoic acid. 5. A process for the preparation of a radionuclide generator, which comprises the steps of: 6. The process of claim 5, wherein the quaternary ammonium salt is methyl tricaprylyl ammonium chloride. 7. The process of claim 5, wherein the organic solvent is chloroform or carbon tetrachloride, the reducing agent is formaldehyde and the osmium is sorbed on the silica gel in an amount of from about 5 to 15 milligrams per gram of the silica gel. 8. A process for obtaining a solution of .sup.191m Ir suitable for injection into a human, which comprises eluting the column of claim 1 with an aqueous solution having a low pH, and admixing same with saline. 9. A process for obtaining an injectable solution of .sup.191m Ir, which comprises eluting the column of claim 8 with an aqueous solution having a pH of 1, and admixing same with saline to produce an intravenously administrable solution having a pH of about 3.5.
	abstract	A method for fabricating a semiconductor device and an equipment for fabricating the semiconductor device are described.
050892177	claims	1. A chemical decontamination clean-up system for use on-line in a nuclear reactor primary system comprising: a back-flushable filter; means within the nuclear reactor primary system for pumping primary system fluids from the nuclear reactor primary system downstream to the back-flushable filter and thereafter through the decontamination system; a plurality of demineralizer banks arranged in parallel, each demineralizer bank comprising one or more demineralizers arranged in parallel wherein primary system fluids are demineralized; means for selectively directing the pumped primary system fluids from the back-flushable filter to a particular demineralizer bank; and means for returning primary system fluids from the demineralizer banks to the primary system. one or more post-filters arranged in parallel capable of removing smaller particulates from the primary system fluids than the back-flushable filter is capable of removing; and means for selectively directing the pumped primary system fluids from the back-flushable filter through one or more of the post-filters positioned upstream of the means for selectively directing the pumped primary system fluids to a particular demineralizer bank. one or more resin fines filters arranged in parallel; and means for selectively directing the pumped primary system fluids from the demineralizers through one or more of the resin fines filters positioned upstream of the means for returning primary system fluids from the demineralizer banks to the primary system. a back-flushable filter that uses nitrogen gas for back-flushing; a filtrate collection tank connected to the back-flushable filter to receive back-flushed particulates; means within the nuclear reactor primary system for pumping primary system fluids from the nuclear reactor primary system to the back-flushable filter and thereafter through the decontamination system; a plurality of post-filters arranged in parallel capable of removing smaller particulates from the primary system fluids than the back-flushable filter is capable of removing; means for selectively directing the pumped primary system fluids from the back-flushable filter through one or more of the post-filters; a plurality of demineralizer banks arranged in parallel, each demineralizer bank comprising a plurality of demineralizers arranged in parallel wherein primary system fluids are demineralized; means for selectively directing the pumped primary system fluids from the post-filters to a particular demineralizer bank; a plurality of resin fines filters arranged in parallel; means for selectively directing the pumped primary system fluids from the demineralizers through one or more of the resin fines filters; and means for returning the primary system fluids from the resin fines filters to the primary system. a back-flushable filter; means within the nuclear reactor primary system for pumping primary system fluids from the nuclear reactor primary system downstream to the back-flushable filter and thereafter through the decontamination system; a plurality of demineralizer banks arranged in parallel, each demineralizer bank comprising one or more demineralizers arranged in parallel wherein primary system fluids are demineralized; means for selectively directing the pumped primary system fluids from the back-flushable filter to a particular demineralizer bank; and means for returning primary fluids from the demineralizer banks to the primary system. one or more post-filters arranged in parallel capable of removing smaller particulates from the primary system fluids than the back-flushable filter is capable of removing; and means for selectively directing the pumped primary system fluids from the back-flushable filter through one or more of the post-filters positioned upstream of the means for selectively directing the pumped primary system fluids to a particular demineralizer bank. one or more resin fines filters arranged in parallel; and means for selectively directing the pumped primary system fluids from the demineralizers through one or more of the resin fines filters positioned upstream of the means for returning primary system fluids from the demineralizer banks to the primary system. pumping primary system fluids containing suspended solids, dissolved solids, or both, to a back-flushable filter for removal of suspended solids; selectively feeding the filtered primary system fluids to one of a plurality of banks of demineralizers arranged in parallel, each such bank of demineralizers comprising one or more demineralizers arranged in parallel; demineralizing the primary system fluids in the selected bank of demineralizers; and returning the filtered and demineralized primary system fluids to the nuclear reactor primary system. 2. The chemical decontamination clean-up system of claim 1 further comprising: 3. The chemical decontamination clean-up system of claim 1 wherein the back-flushable filter utilizes nitrogen gas for back-flushing. 4. The chemical decontamination clean-up system of claim 1 further comprising: 5. The chemical decontamination clean-up system of claim 1 further comprising a filtrate collection tank connected to the back-flushable filter to receive back-flushed particulates. 6. A chemical decontamination clean-up system for on-line use in a nuclear reactor primary system comprising: 7. A nuclear reactor having a primary system wherein the primary system has an on-line chemical decontamination clean-up sub-system comprising: 8. The nuclear reactor of claim 7 wherein the chemical decontamination clean-up sub-system further comprises: 9. The nuclear reactor of claim 7 wherein the back-flushable filter utilizes nitrogen gas for back-flushing. 10. The nuclear reactor of claim 7 wherein the chemical decontamination clean-up sub-system further comprises: 11. The nuclear reactor of claim 7 wherein the chemical decontamination clean-up sub-system further comprises a filtrate collection tank connected to the back-flushable filter to receive back-flushed particulates. 12. A method of removing suspended and dissolved solids for use in on-line chemical decontamination clean-up of nuclear reactor primary systems comprising the steps of: 13. The method of removing suspended and dissolved solids for use in chemical decontamination clean-up of nuclear reactor primary systems of claim 12 further comprising the step of directing the filtered primary system fluids from the back-flushable filter to one or more of a plurality of post-filters arranged in parallel for removal of smaller particulates than the back-flushable filter has removed prior to selectively feeding the filtered primary system fluids to one of the plurality of banks of demineralizers. 14. The method of removing suspended and dissolved solids for use in chemical decontamination clean-up of nuclear reactor primary systems of claim 12 further comprising the step of back-flushing the back-flushable filter periodically. 15. The method of removing suspended and dissolved solids for use in chemical decontamination clean-up of nuclear reactor primary systems of claim 14 wherein the step of back-flushing uses nitrogen gas. 16. The method of removing suspended and dissolved solids for use in chemical decontamination clean-up of nuclear reactor primary systems of claim 14 further comprising the step of collecting the back-flushed particulates in a filtrate collection tank connected to the back-flushable filter. 17. The method of removing suspended and dissolved solids for use in chemical decontamination clean-up of nuclear reactor primary systems of claim 12 further comprising the step of selectively directing the demineralized primary system fluids from the demineralizers to one or more resin fines filters arranged in parallel prior to returning the filtered and demineralized primary system fluids to the nuclear reactor primary system.
	abstract	A metal cooling tube of a water-cooled nuclear reactor, having an inner surface thereof exposed to an aqueous cooling medium containing hydrogen peroxide. The cooling tube has its inner surface coated with matter selected from the group consisting of the element manganese, molybdenum, zinc, copper, cadmium for absorbing such hydrogen peroxide and then affecting decomposition of the hydrogen peroxide in the aqueous medium. In preferred embodiment such coating is manganese and oxides thereof. A method for lowering the electrochemical corrosion potential of a metal allow cooling tube exposed to an aqueous medium in a water-cooled nuclear reactor is also disclosed. Such method comprises the step of coating an inner surface of such tube with matter selected from the group of elements comprising manganese, molybdenum, zinc, copper, cadmium, so as to permit absorption and hydrogen peroxide in such aqueous medium and effect decomposition of hydrogen peroxide in such aqueous medium.
046860770	description	Referring to FIG. 1, the nuclear reactor installation includes a nuclear heating reactor 1 for producing hot water used for heating in a residential area near the installation. Because of the proximity of the installation to a residential area, the reactor safety requirements are very stringent. As indicated, the reactor 1 has a double-walled pressure vessel 2 containing treated demineralized water which fills the interior of the pressure vessel 2 up to a level 3. The vessel 2 also receives a reactor core 4 which is constructed mainly of vertical channel-like cylindrical fuel elements 5 which are filled with fissile material (not shown). Referring to FIGS. 2 and 3, the reactor core 4 also includes vertically movable control rods 6 which are located between the fuel elements 5 and to which vertical absorber rods 7 are secured between the fuel elements 5. As indicated in FIGS. 1 and 2, the fuel elements 5 are carried by a core support plate 8 which bears on a vertical cylindrical casing 9 extending around the support plate 8. This casing 9 is open at the top and bears at the bottom on a base of the pressure vessel 2. Immediately above the plate 8, the casing 9 is formed with bores which are distributed uniformly about the circumference of the casing 9. In addition, two heat exchanger surfaces 20 extend around the top part of the casing 9. The top of the pressure vessel 2 is closed by a double-walled cover 10 which can be opened to give access to the pressure vessel interior. The spaces or chambers between the double walls of the vessel 2 and the cover 10 are interconnected and, in known manner, are sealed off from the outside by means of sealing means (not shown). The pressure vessel 2 has vertical ribs 11 which are connected to a bottom horizontal base plate 12. These ribs form a crushable zone in order to protect the reactor against external mechanical influences and a heat exchanger surface for emergency removal of decay heat. The base plate 12 is carried on the base of a containment 30 which protects the reactor 1 against external mechanical influence including earthquakes and aircraft crashes while also protecting the environment against radiation from the reactor. The containment is in the form of a water-filled pool which has a top cover 31. The pool water serves as an additional radiation protection for the environment even when the cover 31 is open while also acting as a heat sink for emergency removal of afterheat from the reactor 1. In such an emergency, the chambers in the double walls of the pressure vessel 2 and cover 10 which are normally filled with air, a good heat insulant, are flooded with pool water which is a good heat conductor via suitable means (not shown) so that the heat from the inside of the pressure vessel 2 is removed to the pool water with the further assistance of the ribs 11. Means are provided for circulating water through the heat exchanger surfaces 20 as a secondary coolant. This means includes a hot line 21 and a cold line 22 connected at opposite ends of each heat exchanger surface 20, which lines extend through the covers 10, 31 to a secondary heat exchanger 23. As indicated, each cold line 22 includes a pump 24 for pumping the water into the respective heat exchanger surface 20. Another pump 25 is provided in a feed line 26 for delivering heating water. As indicated, the feed line 26 has a pair of valves 27 located before and after the pump 25, respectively. In addition, a pair of parallel branch lines 26' diverge, one through each of the secondary heat exchangers 23, to communicate with a heating water line 28 which conveys heat for heating to a load (not shown). A conveying means is also provided for conveying coolant from within the pressure vessel 2 through the reactor core 4. This conveying means includes a control pump 40 which is connected on the intake side by way of an intake line 41 to an intake in the form of a venturi inlet 42 disposed in the pressure vessel 2 immediately below the coolant level 3. The pump 40 delivers to a control line 43 which extends through the cover 31 and vessel 2 and is connected to a horizontal system of bores in the plate 8 (see FIG. 2). The pump 40 is speed controlled for pumping coolant to the plate 8 and is connected in parallel with a bypass line 44. As indicated in FIG. 1, the intake and delivery sides of the pump 40 are interconnected by way of the bypass line 44 while a control valve 45 is disposed in the bypass line 44. In addition, a controller 46 is connected by means of signal lines 47' to temperature detectors 47 disposed one in each of the hot lines 21 and acts in known manner to control, by way of signal lines 48, 49 and in accordance with the cooling water temperature measured in the hot lines 21, the speed of the control pump 40 (coarse adjustment) or the opening of the control valve 45 (fine adjustment). The control pump 40 is so connected by way of signal lines 50 to the pumps 24 in the lines 21 in known manner that the pump 40 can operate only when at least one of the two pumps 24 is operating. A degassing line 15 which extends through the cover 10 and the cover 31 connects the top zone of the vessel 2 to atmosphere, if required by way of a radioactive gas cleaning and decontamination facility (not shown). Lifting tackle which is known but not shown serves for manipulation of the moving components of the installation, for example, in connection with the opening and closing of the cover 10 and cover 31 and the loading and unloading of the fuel elements 5 in assembly and inspection work. The installation shown in FIG. 1 operates as follows: In normal operation, the control rods 6 and the absorber rods 7 connected thereto are disposed at a predetermined position above the plate 8, such position depending upon the pressure or upon the throughflow of the water which the pump 40 intakes through the venturi inlet 42 and intake line 41 from inside the pressure vessel 2 and delivers through line 43 to the plate 8. A proportion of the water, corresponding to the setting of the valve 45, returns through the bypass line 44 from the delivery side of the pump 40 to the intake side to provide fine control of the water throughflow in the line 43. Coarse adjustment of the water throughflow in the line 43 is provided by adjustment of the speed of the pump 40. The nuclear reaction between the fuel elements 5 occurs mainly in the core zone left free by the absorber rods 7. The resulting heat is transmitted to the water in the pressure vessel 2. The heated water rises in the cylindrical casing 9, reverses to flow downwardly at the top end thereof and yields heat to the heat exchanger surfaces 20. The water continues to flow down and returns through the casing bores above the plate 8 into the core 4 where the cycle recommences. The secondary cooling water is heated in the surfaces 20 and conveys the heat taken up along the hot lines 21 to the secondary heat exchangers 23, where the heat is yielded again and the cooled cooling water returns through lines 22 and pumps 24 to the surfaces 20. The pump 25 delivers heating water through the feed line 26 and branch lines 26' to the secondary heat exchangers 23, in which the water is heated, and to the heating water line 28, through which the heated heating water goes to loads (not shown). In certain circumstances, the heating water may advantageously be circulated in a closed circuit. The valves 27 are normally open and are closed only for assembly and repair work on the additional pump 25. Provided that the secondary cooling water temperature remains stable, the controller 46 maintains the speed of the control pump 40 and the flow cross-section of the valve 45 constant. If, for example, the cooling water temperature rises as indicated by temperature sensors 47 and transmitted by way of signal lines 47' to controller 46, the latter acts by way of the signal line 49 to open the control valve 45 and thus reduce the cooling water throughflow through the control line 43. Consequently, and in a manner to be described hereinafter, the control rods 6 and absorber rods 7 drop so that less heat is produced in the reactor core 4. If the set-value or reference temperature of the cooling water cannot be maintained even with the valve 45 fully open, the controller 46 acts by way of the signal line 48 to reduce the speed of the pump 40. In the event of the cooling water temperature in the hot line 21 decreasing, the controller 46 reacts oppositely to what has just been described. The cooling water temperature set value is adjusted in dependence upon the required temperature and throughflow of heating water in the heating line 28. In the event of the coolant level 3 in the vessel 2 dropping, vapor bubbles form in the venturi inlet 42 so that the pump 40 ceases to deliver cooling water. As a result, in a manner to be described hereinafter, the control rods 6 move automatically by their own weight into their safety position and interrupt reactor operation. Gases are, of course, evolved by radiation inside the pressure vessel 2 and are removed conventionally through the vent line 15. Referring to FIGS. 2-5, each control rod 6 takes the form of a vertical cylindrical tube provided with four radial absorber rods 7 disposed uniformly around the circumference of the control rod 6. Each control rod 6 extends coaxially around a tubular guide rod 60 with the interposition of an annular gap or chamber 100 which extends over the whole length of the control rod 6. The guide rods 60 are about twice as long as the control rods 6 and have smaller inner and outer diameters in their top half than in their bottom half. Each guide rod 60 has an external screwthread near the bottom end to enable threading, into a sleeve 61 and a bore in the plate 8 to which the sleeve 61 is connected. Each bore extends vertically as far as a horizontal bore 8' inside the plate 8. A plug 62 engaged in the vertical bore serves as an abutment for the guide rod 60 and is pierced coaxially to the horizontal bore 8' completely, and coaxially to the vertical bore at the top half-way. Thus, the interior of the guide rod 6 communicates with the horizontal bore 8'. All the horizontal bores 8' are interconnected and combined to form a system which is connected to the control line 43 (see FIG. 1). As FIG. 3 shows, each absorber rod 7 separates two adjacent fuel elements 5. The absorber rods 7 are made of a material which absorbs the atomic particles, neutrons in the present example, responsible for producing the nuclear reaction. Each guide rod 60 is formed in the bottom half with horizontal communicating bores 63 which are disposed in pairs one above another at a 90.degree. offset from one another and which connect the interior of the guide rod 60 to the gap 100. The distance between two consecutive pairs of bores 63 decreases with increasing height. In the transition zone between the large and small diameter halves of the rod 60, six vertical and radial strengthening ribs 64 are distributed uniformly over the guide rod circumference. These ribs 64 serve as a means for the engagement of a tool for screwing the guide rod 60 in and out, the guide rod 60 being adapted to be fitted and demounted independently of the associated control rod 6. Inclined communicating bores 65 are disposed between every two adjacent ribs 64 and, starting from the inside of the bottom half of the guide rods 60, extend upwardly. Immediately above, two additional horizontal and relatively large communicating bores 66 connect the interior of the top half of the guide rod 60 in a zone between two reinforcing ribs 64 to the gap 100. Referring to FIGS. 4 and 5, a vertical cylindrical valve rod 67 which also has a cylindrical head is slidingly engaged from below in a bore at the top end of the bottom half of the guide rod 60 to act as a restrictor. When in the top position, the cylindrical head abuts a shoulder in the inside of the guide rod 60 to provide considerable restriction of the communicating bores 66, whereas when the valve rod 67 is in the bottom position, in engagement with a horizontal retaining pin 68 pushed through the guide rod 60, the bores 66 are opened to the vertical continuous bore. The top end of each control rod 6 has a screwed-on externally hexagonal guide cap 16 which co-operates with the top half of the guide rod 60 to form a restrictor 17. This restrictor 17 provides substantially laminar flow conditions and is much smaller than a bottom restrictor 18 at the other end of the control rod 6 in every position of this rod 6. The top half of the guide rod 60 has the shape of a cone which narrows slightly upwardly so that the restricting cross-section of the top restrictor 17 becomes greater as the control rod 6 rises. Referring to FIG. 4, an adjusting cap 70 is screwed on to the top of the top end of each guide rod 60 and is formed with a vertical continuously hexagonal central aperture or opening 71. The opening 71 serves as a connection between the inside of the guide rod 60 and the inside of the pressure vessel 2 and as a means for engaging a tool to turn the cap 70. Two oppositely disposed horizontal through bores 69 which extend from the vertical bore in the top half of the guide rod 60 to the exterior, i.e. into the interior of the pressure vessel 2 gradually become covered as the cap 70 is turned downwardly. Referring to FIG. 2, a guide lattice 80 is rigidly connected to the casing 9 to support the guide rods 60 against vibration and/or hunting. The arrangement shown in FIGS. 2-5 operates as follows: When the control pump 40 is running at a constant speed and the flow cross-section of the valve 45 remains constant, the throughflow through the control line 43 remains constant. Consequently, a constant quantity of coolant flows through the bores 8' of the plate 8, the coolant passing through the bores in the plug 62 into the interior of the guide rod 60 and through the communicating bores 63,65 into the annular gap or chamber 100. Some of the coolant flows therefrom into the inside of the pressure vessel 2 by way of the communicating bores 66 restricted by the valve rod 67 (see FIG. 4), the central aperture 71 and the through bores 69. Another proportion of coolant issues from the space or chamer 100 through the top restrictor 17 and a third proportion of the quantity of coolant flows through the bottom restrictor 18 into the interior of the pressure vessel 2. Because of its shaping, the guide cap 16 ensures the maintenance of a substantially laminar uniformly distributed flow through the top restrictor 17, thus ensuring reliable centering of the control rod 6. When the speed of the pump 40 rises or the flow cross-section of the valve 45 decreases, the throughflow through the route described and, therefore, the pressure upstream of the guide cap 16 increase. Consequently, the cap 16, control rod 6 and absorber rods 7 rise. The bottom communicating bores 63 therefore cease to be covered by the control rod 6 and the coolant flowing through them flows directly--i.e., not through the annular chamber 100--into the pressure vessel interior. Since this coolant does not have to flow through the bottom restrictor 18, the coolant can issue from the guide rod 60 more rapidly. The pressure below the guide cap 16 therefore decreases increasingly until a state of equilibrium is reached between the forces acting on the control rod 6 and the absorber rods 7 and the movement stops. When the pressure below the guide cap 16 drops in response to a speed decrease of the pump 40 and/or an increase in the flow cross-section of the valve 45, the control rod 6 and the absorber rods 7 drop until a new equilibrium condition has been reached. In the event of an abrupt interruption of cooling water supply to the horizontal bores 8' of the plate 8, the pressure below the cap 16 drops very rapidly and, therefore, so does the pressure below the valve rod 67 (FIG. 4), so that the rod 67 drops by gravity onto the retaining pin 68 and opens the full cross-sections of the bores 66. The low-pressure cooling water can then flow without restriction through the bores 66, the inside of the top half of the guide rod 60, the bores 69 and the central aperture 71 into the inside of the pressure vessel 2. The control rod 6 and the absorber rods 7 can then drop down into their safety position. Due to the vertical distribution of the communicating bores 63, each passage of the bottom edge of a control rod 6 past a bore 63 produces a relatively large variation in the quantity of the cooling water circulating through the guide rod 60. The result is that the control rod 6 takes up a number of preferred heights which are consecutive in stepped fashion and which greatly simplify the coarse adjustment of the control. The fact that the spacing between the bores 63 decreases with increasing height allows for control requirements on high-load operation. Also, because of the conical shape of the top half of the guide rod 60, the gradual variation in the top restrictor 17 in response to variations in control rod position serves for fine adjustment of the control. Because each control rod 6 and the associated absorber rods 7 may vary in shape and weight because of unavoidable manufacturing tolerances, the adjusting caps 70 can provide a further advantage. That is, each cap 70 can be turned to adjust the flow cross-sections of the bores 69 and thus provide individual compensation of the variations between the control rods 6, so that the control rods 6 are at substantially the same height in any operative state of the installation. The guide lattice 80 obviates vibrations and/or hunting movements of the guide rods 60 without impairment of the adjustability of the caps 70 and therefor contributes substantially to the general safety of the installation. Accidential displacements of the caps 70 are therefore prevented as well. As an alternative to the feature shown, for example, the coolant can be introduced at the top end of a guide rod 60 and the descent of the control rod into a safety position can be spring-assisted. Referring to FIG. 6, the guide rod 60' may be constructed to be tubular only in the bottom half, the top half being cylindrical and of smaller diameter than the outer diameter of the bottom half. As above, six strengthening ribs 64 are disposed at the transition between the larger diameter and the small diameter halves and the communicating bores 65 extend to between the ribs 64. Unlike the embodiment of FIG. 2, the bores 63 are disposed only in the top half of the bottom half of the guide rods 60', the diameter of the various bores 63 increasing with increasing height. The vertical separation between the bores 63 is constant. The bores 65 connect the inside of the guide rod 60' to a widened part 100' of the annular chamber 100 which part extends between the cap 16 and the ribs 64. The inside surface of the control rod 6' is formed with horizontal or transverse annular grooves 80 whose height is equal to the axial distance between the top boundary of a bore 63 and the bottom boundary of the adjacent bore 63 disposed on the same generatrix of the guide rod 60'. In addition, two stabilizing apertures 81, in the form of horizontal cylindrical bores, are disposed about halfway up the height of each groove 80 and connect the chamber 100 to the inside of the pressure vessel, the diameter of the apertures 81 decreasing upwardly. The apertures 81 are disposed in the bottom half of the control rod 6'. The axial separation between two adjacent grooves 80 is very small. Consequently, annular separating webs 82 remain between the grooves 80, the axial width of the webs 82 being approximately equal to the greatest diameter of the bores 63. The position of the control rod 6' is stabilized as follows: Assuming a constant pressure or constant delivery of cooling water supplied to the interior of the guide rod 60', the control rod 6'0 takes up a particular position, the cooling water flowing from the inside of the guide rod 60' through the bores 63, 65 into the chamber 100 or 100' and into the pressure vessel interior. The quantity of cooling water conveyed into the chambers 100, 100' issues therefrom by way of the bottom restrictor 18, the top restrictor 17 and the stabilizing bores or apertures 81. Because of the pressure distribution in the control rod 6', at least one web 82 restricts the top zone of a bore 63 so that some of the cooling water, instead of flowing through the bottom restrictor 18 and the bores 81, flows to the bores 65 or to the top restrictor 17 and to bores 63 which may not have been covered by the control rod 6'. Provided that cooling water pressure and delivery remain constant, there is equilibrium between the weight of the control rod 6' and of the absorber rods (not shown) secured thereto, the hydrodynamic forces which the cooling water flowing in the pressure vessel applies to the control rod and absorber rods, and the forces arising because of the pressure differences inside and outside the control rod 6'. Any vertical shift of the control rod 6' results in a change in cooling water throughput through the restrictor bores 63 and, therefore, a variation in the distribution of cooling water flow in the guide rod 60' and annular chambers 100, 100'. The pressure difference operative on the control rod 6' therefore changes substantially. The stabilizing bores 81 have a multiplier effect on these pressure differences since in the event of a change in the restriction provided by the bores 63, the resulting change in the quantity of cooling water flowing through the stabilizing bores 81 is several times greater than the corresponding change of the quantity of cooling water flowing just through the bottom restrictor 18. For example, in response to an upwards movement of the control rod 6', the restrictive effect of the webs 82 on the bores 63 decreases. Thus, more cooling water issues from the guide rod 60' and the pressure below the cap 16 drops. The control rod 6' then drops down back into its original position. However, in the event of a downwards movement of the rod 6', the webs 82 provide increased restriction of the bores 63 and more cooling water is retained in the guide rod 60', so that the pressure below the cap 16 rises and pushes the control rod 6' up back into its original position. Those positions of the control rod 6' in which the bores 63 are disposed exactly opposite bores 81 are very stable since, in this case, small displacements produce relatively substantial restrictions of the bores 63. The flow cross-section of the bores 63, 81 can be considerably increased if required if more than two such bores are disposed at one vertical position. Increased flow-cross-sections can also be provided by special shaping of the bores 63, 81, as illustrated for a stabilizing bore in FIG. 7, in the form of an axial slot 81' extending lengthwise of the control rod 6', and in FIG. 8, the slot 81" being disposed transversely to the longitudinal direction of the control rod 6'. Referring to FIG. 9, the guide rod 60" may have a tubular cylindrical bottom half, as in FIG. 6, but a slightly conical top half which narrows upwardly. The maximum diameter of the top half of the guide rod 60" is less than the outer diameter of the bottom half. The six inclined communicating bores 65 which extend between the ribs 64 connect the guide rod interior to the annular chambers 100, 100', the bottom half of the guide rod being devoid of communicating bores. The top conical half of the guide rod 60" is formed with uniformly distributed horizontal annular grooves 80' separated vertically from one another by conical webs 84. In contrast to the control rod 6' of FIG. 6, the control rod 6" is devoid of stabilizing bores. Instead, the guide cap 16 screwed onto the top end has three annular horizontal projections 85 which extend towards the conical part of the guide rod 60" and which cooperate therewith to form three annular top restrictors 17. Disposed at the bottom end of the control rod 6" is the annular bottom restrictor (not shown) which is identical to the bottom restrictor 18 of FIG. 6. The three projections 85 are tangential to a hypothetical conical surface extending parallel to the conical top half of the guide rod 60"; the projections are equidistant from one another as are the top edges of two adjacent webs 84. The restrictors 17 stabilize the vertical position of the control rods 6" as follows: The position which is shown in FIG. 9 and in which the projections 85 of the control rods project above the top edges of the adjacent webs 84, is a preferred stable position. A very reduced upwards movement of the rod 6" caused by a brief increase in cooling water pressure leads to a substantial increase in the flow cross-section of the restrictors, so that the pressure drops immediately and the control rod drops back into its stable position. Consequently, for a particular constant pressure, a position is always taken up in which the projections 85 are disposed a little above the top edge of the webs 84. A single projection 85 can provide the same effect as the three projections 85 of FIG. 9; however, the provision of a number of projections 85 ensures that the installation will continue to operate satisfactorily even should two of the projections be damaged. As an alternative to the example shown in FIG. 9, the projections can be disposed in the bottom restrictor, in which event the bottom half of the guide rod 60' must be formed with the annular grooves. The webs 84 can each be reduced just to an edge. The cross-section of the grooves 80, 80' can have a shape other than the shapes illustrated and can, for example, extend helically. Also, it may be required to provide position sensors indicating the vertical position of the control rods or absorber rods to observers outside the pressure vessels 2. Sensors of this kind can take the form, for instance, of sonar devices which ascertain the vertical position of the control rods from the core support plate 8 and provide information outside by way of radio. The sensors can also be magnetic sensors connected by way of signal lines to a control room of the installation. For the sake of simplicity, only the effect of the temperature on the controller 46 was shown in the embodiment described. Conventionally, at least the pressure in the pressure vessel 2 and the neutron radiation in the core, as measured by a neutron flux meter, act on the controller 46. The invention thus provides a nuclear reactor installation with a relatively simple means for moving the control rods of a reactor core. Further, the invention provides a relatively simple guide rod arrangement for a movable control rod which is relatively easy to service and maintain.
	description	The present application claims priority from Japanese application JP 2007-199488 filed on Jul. 31, 2007, the content of which is hereby incorporated by reference into this application. 1. Field of the Invention The present invention relates to a scanning electron microscope (SEM) alignment method and a scanning electron microscope. 2. Description of the Related Art One factor used to describe capabilities of an SEM is a resolving power. The resolving power indicates the minimum distance between two distinguishable points. For the purpose of acquiring an image with a higher resolving power, it is necessary to align the optical axis of the SEM. The optical axis of the SEM is aligned chiefly through axis alignment and astigmatism correction. Both the axis alignment and the astigmatism correction are performed on a standard sample installed in the specimen stage, or on an observation target sample, for the purpose of reducing work of the operator. Recently-emerging technologies enable an SEM to perform automatic axis alignment and astigmatism correction through its self-evaluation of an optimal condition of its own. For example, Japanese Patent Application Publication No. 2003-22771 (corresponding to U.S. Pat. No. 6,864,493) describes a technology for automatic axis alignment which uses an image processing technology. In addition, Japanese Patent Application Publication No. 2000-195453 describes a technology for detecting misalignment of the optical axis on the basis of change in the path of an electron beam while the electron beam is scanned. Indeed, the alignment methods respectively described by Japanese Patent Application Publications Nos. 2003-22771 and 2000-195453 each allow an SEM to accurately identify conditions of the SEM itself, and to perform an automatic alignment on the basis of the identified conditions of the SEM with higher accuracy. However, the following alignment error factors stemming from conditions of the samples remain unresolved. (1) In a case where an automatic axis alignment is performed by use of both the standard sample and the observation target sample, the difference in height between the two samples makes the two samples have different optimal values for the axis alignment and different optimal values for the astigmatism correction.(2) In the case of the axis alignment performed on the observation target sample, the irradiation of an electron beam contaminates the observation target sample.(3) A shape suitable for the axis alignment does not always exist on the observation target sample. Descriptions will be provided hereinbelow for an axis alignment method and an astigmatism correction method capable of preventing an alignment error and a correction error from occurring particularly due to conditions of a sample, as well as for an SEM for implementing these methods. A first aspect employed to achieve the foregoing object is to obtain the difference between the optimal value acquired from a result of an automatic axis alignment performed on a standard sample and the optimal values respectively acquired from result of automatic axis alignment performed on a observation target sample, and subsequently to correct the optimal value of the standard sample on which automatic axis alignment is performed by use of one of the differences thus found. The above-described scanning electron microscope alignment method includes the steps of: performing an axis alignment by use of a standard sample provided on a specimen stage, and thus acquiring an optimal control value for an alignment deflector; performing axis alignments respectively at multiple measurement locations different in height on an observation sample held on the specimen stage, and thus acquiring information on pair each consisting of the height of the measurement location and the optimal control value for the alignment deflector at the measurement location, respectively; and storing a correction curve representing relationships between the heights of the measurement locations and the differences between the optimal control value acquired for the alignment deflector by use of the standard sample and the optimal control values acquired for the alignment deflector by use of the observation sample. This correction curve is previously obtained before an actual specimen is observed. At the time of observing a specimen, the scanning electron microscope alignment method includes the steps of: performing an axis alignment by use of the standard sample provided on a specimen stage, and thus acquiring the optimal control value for the alignment deflector; measuring the height of the specimen to be observed; acquiring the difference of the optimal control values corresponding to the measured height from the previously stored correction curve; and setting, at the alignment deflector, a value obtained by adding the difference between the optimal control values acquired from the correction curve to the optimal control value acquired for the alignment deflector by use of the standard sample. The alignment deflector may be a deflector for correcting the misalignment of the optical axis of the objective lens, or a deflector for correcting the misalignment of the optical axis of the astigmatism correction coil. In addition, the correction curve is obtained for each of observing conditions (for example, a condition for an accelerating voltage and an optical condition). Another scanning electron microscope alignment method includes the steps: performing an astigmatism correction by use of a standard sample provided on a specimen stage, and thus acquiring an optimal control value for an astigmatism correction coil; performing astigmatism corrections respectively at multiple measurement locations different in height on an observation sample held on the specimen stage, and thus acquiring information on pair each consisting of the height of the measurement location and the optimal control value for the astigmatism correction coil at the measurement location, respectively; and storing a correction curve representing relationships between the heights of the measurement locations and the differences between the optimal control value acquired for the astigmatism correction coil by use of the standard sample and the optimal control values acquired for the astigmatism correction coil by use of the observation sample. This correction curve is previously obtained before an actual specimen is observed. At the time of observing the specimen, the scanning electron microscope alignment method includes the steps of: performing an axis alignment by use of the standard sample provided on the specimen stage, and thus acquiring the optimal control value for the astigmatism correction coil; measuring the height of the specimen to be observed; acquiring the difference between the optimal control values corresponding to the measured height from the previously stored correction curve; and setting, at the astigmatism correction coil, a value obtained by adding the difference between the optimal control values acquired from the correction curve to the optimal control value acquired for the astigmatism correction coil by use of the standard sample. The correction curve is obtained for each of observing conditions (for example, a condition for an accelerating voltage and an optical condition). In addition, a second aspect employed to achieve the foregoing object is to acquire an optimal stigmator value (or an astigmatism correction signal) by use of the standard sample, to store the optimal stigmator value as a default value, to add the default value depending on the height of a pattern of a observation target sample, and accordingly to perform an astigmatism correction on the basis of a stigmator value obtained by adding the default value. The above-described axis alignment method enables an automatic axis alignment to be accurately performed by use of only the standard sample, and thus needs no observation target sample for the axis alignment. For this reason, the axis alignment method can always keep the state of the optical axis alignment optimal and stable, that is, keep the apparatus exhibiting its highest resolving power with the apparatus performance being fully demonstrated. In addition, the above-described astigmatism correction method makes it possible for an astigmatism correction to be performed stably by use of the standard sample regardless of variations such as the height of a specimen. FIG. 1 is a schematic diagram of a scanning electron microscope. A voltage is applied between a cathode 1 and a first anode 2 by a high-voltage controlling power supply 20 controlled by a computer 40. Thus, with a predetermined emission current, a primary electron beam 4 is emitted from the cathode 1. An accelerating voltage is applied between the cathode 1 and a second anode 3 by the high-voltage controlling power supply 20 controlled by the computer 40. Thereby, the primary electron beam 4 emitted from the cathode 1 is accelerated, and travels to the rear-stage lens system. The primary electron beam 4 is converged by a converging lens 5 controlled by a lens controlling power supply 21. Subsequently, a diaphragm 8 removes unnecessary ranges from the primary electron beam 4. Thereafter, the resultant primary electron beam 4 is converged into a minute spot on a specimen 10 held on a specimen stage 15 by a converging lens 6 controlled by a lens controlling power supply 22, and by an objective lens controlled by an objective-lens controlling power supply 23. Various types such as an in-lens type, an out-lens type and a snorkel type (or a semi-in-lens type) may be chosen for the objective lens 7. Furthermore, a retarding type for decelerating a primary electron beam by applying a voltage to a specimen can be also chosen. Moreover, each lens may be constructed by use of an electrostatic lens made of multiple electrodes. A standard sample 16 on which a pattern is formed for axis alignment is provided on the specimen stage 15. The primary electron beam 4 is two-dimensionally scanned over the specimen 10 by scanning coils 9. The scanning coils 9 are controlled by a scanning-coil controlling power supply 24. A secondary signal 12, such as secondary electron, is generated from the specimen 10 on which the primary electron beam is irradiated. The secondary signal 12 thus generated travels upward through the objective lens 7. Thereafter, the secondary signal 12 is separated from the primary electron by a secondary signal separation cross-electromagnetic field (EXB) generator 11, and the resultant secondary signal 12 is detected by a secondary signal detector 13. The signal detected by the secondary signal detector 13 is amplified by a signal amplifier 14. Thereafter, the amplified signal is transferred to an image memory 25. The transferred signal is displayed as an image of the specimen on an image display device 26. A single-stage deflection coil 51 (as an objective lens aligner) is arranged in a vicinity of, or in the same location as the scanning coil 9, and operates as an aligner for correcting the misalignment of the optical axis of the objective lens 7. In addition, an astigmatism correction coil 52, made of multiple electrodes, for correcting astigmatism in the X-axis and Y-axis directions is arranged between the objective lens 7 and the diaphragm 8. An aligner 53 (or an astigmatism correction coil aligner) for correcting the misalignment of the optical axis in an astigmatism correction coil is arranged in a vicinity of, or in the same location as the astigmatism correction coil 52. The astigmatism correction coil 52 controlled by the astigmatism-correction-coil controlling power supply 32. An objective lens aligner 51 is controlled by an objective-lens-aligner controlling power supply 31. The astigmatism correction coil aligner 53 is controlled by an astigmatism-correction-coil-aligner controlling power supply 33. An image processing unit 27, a storage 41 and an input device 42 are also connected to the computer 40. In addition, the scanning electron microscope shown in FIG. 1 is provided with a specimen height measuring sensor (or a z-sensor), which is not illustrated. For example, the z-sensor includes: a light-emitting element for generating a laser beam; a first collective lens for collecting a laser beam emitted from the light-emitting element into a predetermined location (or the location on which the primary electron beam is irradiated) on the specimen; a second collective lens for collecting the laser beam reflected off the specimen; and a position sensor for receiving the laser beam collected by the second collective lens. The height of the specimen is monitored with the use of change in the position on which the position sensor receives the reflected laser beam. Information on the height of the specimen is transferred to the computer 40. Descriptions will be provided hereinbelow for how to acquire a correction curve necessary for realizing the axis alignment using a flowchart shown in FIG. 2. First of all, an automatic axis alignment is performed by use of the standard sample 16 provided on the specimen stage 15 (in step S11). Thereby, the optimal values of the objective lens aligner 51 in the respective X and Y (A1X1, A1Y1) directions, the optimal values of the astigmatism correction coil aligner 53 in the respective XX, XY, YX and YY (StA1XX1, StA1XY1, StA1YX, StA1YY1) directions, as well as optimal values of the astigmatism correction coil in the respective X and Y (Stx1, StY1) directions are acquired (in step S12). The automatic axis alignment method is described, for example, in Japanese Patent Application Publication No. 2003-22771. Subsequently, automatic axis alignments are performed at multiple measurement locations 56 by an observation sample 54 on the specimen stage 15 (in step S13). As shown in FIG. 5, the multiple measurement locations 56 are arranged in a line in an inclination direction on the observation sample 54. As shown in FIG. 4, the heights respectively of the multiple measurement locations 56 are unidirectionally changed. After performing the automatic axis alignments, the optimal values of the objective lens aligner 51 in each of the X and Y (A1X2, A1Y2) directions, the optimal values of the astigmatism correction coil aligner 53 in each of the XX, XY, YX and YY (StA1XX2, StA1XY2, StA1YX2, StA1YY2) directions, the optimal values of the astigmatism correction coil 52 in each of the X and Y (StX2, StY2) directions, as well as the heights at which the respective automatic axis alignments are performed are acquired with the use of current value of objective lens (in steps S14 and S15). Thereafter, for each aligner, the differences between the optimal value acquired by use of the standard sample 16 and the optimal values acquired by use of the observation sample 54 are acquired as offset values. For example, an offset value of the objective lens aligner 51 in the X direction is expressed withDiffA1X=A1X1−A1X2.Subsequently, by use of the differences (or the offset values)(for example, DiffA1X) thus acquired and their associated heights acquired from the information on the heights corresponding to the multiple measurement values, a curve is generated as a correction curve (in step S16). FIG. 6 shows examples of the correction curve. A correction curve is acquired for each of the observation conditions (for example, a used condition for an accelerating voltage and a used optical condition). A correction curve is generated for each of the X and Y directions of the objective lens aligner 51, each of the XX, XY, YX and YY directions of the astigmatism correction coil aligner 53, as well as each of the X and Y directions of the astigmatism correction coil 52. This makes it possible to always keep the state of the optical axis alignment optimal and stable. FIG. 3 shows an axis alignment sequence when performing a correction by use of the correction curves while a sample is observed. An automatic axis alignment is performed in advance by use of the standard sample, and thereby the optimal values of each aligner are acquired (in step S21). Subsequently, the observation specimen is placed into a specimen chamber (in step S22). When the observation specimen is placed therein, the height of the observation specimen is measured by use of the height measuring sensor (or the z-sensor) using a laser beam (in step S23). Thereafter, for each of the aligners, the offset values are calculated from the correction curves generated in advance on the basis of the used observation condition and the height measured (in step S24). After that, for each of the aligners, the offset values are added to the optimal value previously acquired for the aligner by use of the standard sample, and the aligner are set at a value obtained through this addition (in step S25). For example, in the case of the X direction of the objective lens aligner, DiffA1X corresponding to the observation specimen is found from the correction curve, and DiffA1X is added to A1X1 acquired in advance by the standard sample. Thereby, the objective lens aligner is set at a value thus obtained as the optimal value in the X direction. As the individual optimal value, a value of Diff is calculated for each of the X and Y directions of the objective lens aligner, each of the XX, XY, YX and YY directions of the astigmatism correction coil aligner, as well as each of the X and Y directions of the astigmatism correction coil. The foregoing work carried out before placing the specimen in the SEM makes it possible to start to observe the specimen with an accurate axis alignment being completed, and accordingly with the apparatus performance being fully demonstrated after placing the specimen therein (in step S26). FIG. 7 is a flowchart showing of the steps carried out to generate a correction curve used for performing an astigmatism correction. By use of a standard sample (or a sample for apparatus alignment), optimal stigmator values corresponding to the height of the standard sample (or results of sensing the sample with the z-sensor) are acquired in advance, and are registered as default values. For each focusing condition, these optimal stigmator values are stored as the default values (respectively for the 0°, 45°, 90° and 135° directions) by being uniformly associated with the results of sensing the standard sample with the z-sensor (or LSB values). In the case of the octuple lens obtained by combining two quadruple lens into a single unit, an astigmatism correction is performed on the octuple lens by use of a current I1 supplied to one quadruple lens and a current I2 supplied to the other quadruple lens. For this reason, for each focusing condition, conditions for the currents I1 and I2 (or current values) can be stored in advance as default values. For each focusing condition, the default values for each direction in which the stigmator is adjusted may be acquired through intentionally varying the heights of the measurement locations different from one another by doing things such as sloping the observation sample as shown in FIGS. 4 and 5. Otherwise, for each focusing condition, the default values may be collected through measuring the heights of the multiple measurement locations on a test sample or the like which is not sloped. Correction means is designed to add the default values on the actual adjustment values for the stigmator depending on the current values (or the LSB values) of the OBJ (objective lens) which is moved to a desirable location for observation on the wafer. In the case where the objective lens is an electrostatic lens, the voltage values are used instead of the current values. In the case of the foregoing example, with the addition of the stigmator values previously acquired depending on the height of the sample, the astigmatism correction is capable of being performed even in an region where there is no suitable pattern (such as circular or square shape from which components can be easily extracted in each direction) available for the stigmator adjustment. In a region where there exists the above-mentioned pattern, automatic astigmatism correcting functions (for example, AST and high-speed AST), which are termed as recipes, while a wafer is automatically observed and measured, are effective. For this reason, use of the correction means and the automatic astigmatism correcting functions in its proper way makes it possible to correct the stigmator values more effectively. Particular in a vicinity of an edge of a wafer, there is sometimes no suitable pattern available, for astigmatism correction, having edge orthogonal to the 0°, 45°, 90° or 135° direction although there is a line pattern to be measured. In other words, in some cases, it is desirable that an astigmatism correction should be performed by using a pattern for stigmator adjustment in a region away from an edge of a wafer to some extent, whereas an astigmatism correction should be performed on the basis of the above-described height measurement or the amount of focus control within a range away from the edge of the wafer by a predetermined distance. In such cases, arrangements should be made for the stigmator to be automatically adjusted on the basis of the height of the sample or the like within a range away from the edge of the wafer by the predetermined distance, and for a field of view to be selected for the stigmator adjustment in the vicinity of each measurement location outside the range. More specifically, when a recipe in which measurement conditions for the scanning electron microscope is recorded is intended to be set up, the stigmator adjustment method is automatically set up as described above in a case where measurement points (MPs) are located within the range away from the edge of the wafer by the predetermined distance, whereas a setup screen is displayed to request an operator to set up locations in the stigmator to be adjusted in a case where the operator intends to set up the MPs outside the range. This configuration makes it possible to reduce work for the operator to perform at the time of setting up the recipe. In addition, in a case where the observation specimen is a semiconductor device, reference to design data on the semiconductor device makes it possible to determine whether or not there is a suitable pattern available for the stigmator adjustment in a vicinity of each MP depending on where the MP is set up, because the information about each pattern formed on the specimen is registered in design data. When there is a suitable pattern available, the pattern should be displayed as a candidate pattern for the adjustment. When there is no suitable pattern available, it should be displayed that the selection is made for the stigmator adjustment on the basis of the above-described height measurement or the like. In a case where a pattern for the stigmator adjustment is intended to be selected on the basis of the design data, determination of the selection is made on the basis of whether or not there is a closed pattern satisfying a predetermined condition, and whether or not there are line segments satisfying a predetermined condition, in a field of view (or FOV) which is set up for the SEM with a predetermined magnification being set up therein (or with a magnification needed for the stigmator adjustment being set up therein) within a range away from each MP by a predetermined distance (for example, within a range in which image shift can be performed on the primary electron beam by the deflector). More specifically, determination of the selection is made whether or not each FOV for the SEM includes a closed pattern (for example, an octagon) having line segments orthogonal to the lines extending in the directions at angles of 0°, 45°, 90° and 135° around the center of the field of view thereof, or whether or not the FOV thereof includes line segments equivalent to those which the closed pattern has. The foregoing configuration makes it possible to automatically or semi-automatically select the fields of view for the stigmator adjustment without forcing the operator to select the fields of view for the stigmator adjustment in each MP. Descriptions will be provided hereinbelow of an example for how the stigmator is adjusted on the basis of the measurement of the height of a measurement target wafer. Specifically, first of all, the height of the standard sample is measured by use of the z-sensor. In a case where the height of the standard sample is registered in advance, this step can be omitted. Subsequently, by use of the standard sample, the stigmator is adjusted. Adjustment values obtained through the stigmator adjustment are stored as I10 and I20. It is desirable that the standard sample used at this time should include a pattern, an octagon for example, whose sharpness can be sufficiently evaluated in the 0°, 45°, 90° and 135° directions. Even if the standard sample is not an octagon, a pattern including line segments equivalent to those of an octagon and a pattern, such as a complete round, whose sharpness can be evaluated in the above-mentioned directions may be substituted for the octagon. After, as described above, the astigmatism correction is performed by use of the standard sample, an observation target wafer is placed into the specimen chamber. Note that the default value can be acquired by use of the standard sample even after the observation target wafer is placed in the specimen chamber. Subsequently, the height of the sample of the observation target wafer is measured by use of the z-sensor (or the height measuring sensor). Thereafter, an offset amount (LSB value) as the difference between the optimal stigmator value of the standard sample and that of the observation target wafer are calculated on the basis of the measured height of the sample. Subsequently, the offset amount is added on the optimal stigmator value. For example, in the case of the correction coil of the stigmator in the X direction, an offset amount (Diff StigmaX) for the observation target wafer is calculated, and the offset amount (Diff StigmaX) is added on the default value (StigmaX) beforehand acquired. A value obtained through this addition is set up as an optimal stigmator value. This operation is carried out for the correction coil of the stigmator for the Y direction as well. The foregoing operation is carried out for each of the heights of the respective measurement locations on the sample, and the operation continues to be carried out until the correction curves as shown in FIG. 6 can be generated. Once the correction curves are completed, data on the correction curves is registered in the storage 41. Subsequently, the astigmatism correction is performed on the basis of the data thus registered. Through carrying out the above-described operation, the optimal stigmator values are set up even when observing and measuring a wafer edge in which astigmatism is apt to shift, or even when observing and measuring a wafer whose height is nonuniform in the surface (for example, a wafer which is so warped with a convex portion or a concave portion being present in the middle of the wafer that the astigmatism and the optical axis shift depending on the measurement location, and a specimen locally or globally charged). This makes it possible to observe the observation target wafer with the apparatus performance being fully demonstrated. In addition, if the astigmatism correction method is designed to cause the operator to determine, on the basis of the design data of the device or the like, whether to adjust the stigmator on the basis of sharpness of an image or on the basis of the measurement of the height of the specimen, after the sharpness of the image is measured in the four directions, this design makes it possible to set up stigmator conditions for each of the multiple measurement points with ease. 1. cathode 2. first anode 3. second anode 4. primary electron beam 5. first converging lens 6. second converging lens 7. objective lens 8. diaphragm 9. scanning coil 10. specimen 11. secondary-signal separating cross-electromagnetic field (EXB) generator 12. secondary signal 13. secondary signal detector 14a. signal amplifier 15. stage 16. axis alignment pattern 20. high-voltage controlling power supply 21. first-converging-lens controlling power supply 22. second-converging-lens controlling power supply 23. objective-lens controlling lens 24. scanning-coil controlling power supply 25. image memory 26. image displaying device 27. image processing unit 31. objective-lens-aligner controlling power supply 32. astigmatism-correction-coil controlling power supply 33. astigmatism-correction-coil aligner controlling power supply 40. computer 51. objective-lens aligner 52. astigmatism correction coil 53. astigmatism correction coil aligner 54. observation sample 55. specimen stage
	abstract	A device for preparing radioactive solutions, in particular radiopharmaceutical solutions, including: a movable support block with at least two cells capable of accommodating a vial; and a shielded covering, including a side wall surrounding the periphery of the support block and an upper wall covering the upper face of the support block, an opening being provided in the upper wall of the covering. A means for driving the support block is configured to selectively displace the support block into positions, referred to as working positions, in which a given cell is aligned with the opening to allow access to the cell from the outside of the covering. The support block is configured such that it can be further brought to a position, referred to as closing position, in which the opening is sealed by a shielded element carried by the support block.
	description	In the present invention, magnetic clamps are inserted between the individual lenses in a magnetic doublet lens system. In the embodiment of the present invention wherein the magnetic doublet lens system with the magnetic claims is inserted into an electron beam lithography tool, an apertured scatter filter is inserted in an essentially field-free space between the two lenses, wherein the essentially field-free space is provided by the magnetic clamps. The essentially field-free space is obtained by using the magnetic clamps to effect substantial separation of the magnetic fields of the two lenses. By substantially separating the magnetic fields, doublet compound aberrations, total blur growth and projection magnification changes attributable to magnetic field overlap are avoided. For example, magnetic lenses have a spherical aberration co-efficient (Csph) that is proportional to the integral of the magnetic field flux density first derivative squared (dB/dz)2dz. This is characterized by the following formula: Csphxe2x88x92∫(dB/dz)2dz. Other aberrations and distortions depend on the field distribution B(z) in the same way. Any distortion in the magnetic field is likely to add aberrations and distortions into the final image. In the present invention, magnetic clamps are designed to prevent distortions in the magnetic field that are caused by overlap of the magnetic fields in the magnetic doublet lens system. However, the magnetic clamps are also designed and placed to preserve the symmetry of the magnetic doublet lens. As one skilled in the art is aware, symmetry is required to maintain beam rotation and related anisotropic aberrations within the limits required for acceptable imaging. A schematic of one embodiment of the present invention is illustrated in FIG. 4. FIG. 4 illustrates a cross-section of a magnetic lens doublet system 100. The magnetic lens doublet system has a first lens 110 and a second lens 120. Lens 110 is equipped with magnetic clamp 111. Lens 120 is equipped with magnetic clamp 121. Magnetic clamps 111 and 121 are a ferromagnetic material, such as soft iron or ferrite. The size, configuration and location of the magnetic clamps are determined by a number of factors. The first factor is that the magnetic clamps prevent the fields from lenses 110 and 120 from substantially penetrating into the region 125 between the magnetic clamps. In the embodiment of the present invention wherein the lens system is placed in an electron beam lithography tool, the apertured scatter filter 130 is placed in region 125. The second factor is that the magnetic clamps must be configured so as not to interfere with the radiation transmitted through the lens system. The third factor is that the magnetic clamps must be sized to preserve the symmetry of the doublet. That relationship is reflected by symmetry of the doublet about the common focal plane of the lens. As previously noted, the desired symmetry of the axial magnetic field of a lens is not preserved when the magnetic fields of the two lenses in the magnetic doublet lens system overlap. Also, if the magnetic doublet lens system provides for a 4:1 image reduction, the magnetic lenses must have a size and a placement along the lens system focal length that preserves that relationship. Another embodiment of the present invention is illustrated in FIG. 5. In this embodiment, each lens, 210 and 220 of magnetic doublet lens 200 has two magnetic clamps. Lens 210 is equipped with lenses 211 and 212. Lens 220 is equipped with clamps 221 and 222. As in the previous embodiment, an apertured scatter filter 230 is placed in the field-free space 225 between lens 210 and lens 220. The doublet of the projection lens system of the present invention is described with reference to FIG. 6. The lens 310 of doublet lens 300 generates a field 315 (drawn as a series of lines). The field 315 is contained by magnetic clamp 311. Similarly, the lens 320 of doublet lens 300 generates a field 325 (drawn as a series of lines). The field 325 is contained by magnetic clamp 321. As illustrated in FIG. 6, the magnetic field lines 315 and 325 do not extend into the space 330 that contains the apertured scatter filter 335. Lens 310 is connected to magnetic clamp 311 via connector 339. Lens 320 is connected to magnetic clamp 321 via connector 340. Connectors 339 and 340 are a magnetic material such as ferrite or soft iron. The following example is described with reference to FIG. 7. FIG. 7 is a schematic of a magnetic doublet lens system placed in an electron beam lithography tool. The tool 400 has an optical axis 405. The magnetic doublet lens system 410 is placed between the mask plane 411 and the image plane 412. The magnetic doublet lens system 410 has a first lens 415 and a second lens 420. Both lenses 415 and 420 have wound cores and soft iron bodies. First lens 415 is coupled to a first magnetic clamp 416. Second lens 420 is coupled to a second magnetic clamp 421. The clamps are the same material as the body of the lens (soft iron). An apertured scatter filter 425 is placed between the first magnetic clamp 416 and the second magnetic clamp 421. The lens system 410 is configured to demagnify an image of the mask 411. The degree of demagnification is 0.25 (i.e., an image reduction of 4:1). The demagnified image is transmitted into an energy sensitive material on a wafer in image plane 412. The distance between the mask plane 411 and the apertured scatter filter is 320 mm. The distance between the image plane 412 and the apertured scatter filter 425 is 80 mm. The lens system 410 is centered about the optical axis 405. Using the position of the apertured scatter filter 425 on the optical axis 405 as the zero reference point, the focal length of the first lens is xe2x88x92160 mm. The focal length of the second lens is 40 mm. The focal length of lens 415 is illustrated by the distance from the point Z1A to the apertured scatter filter 425 along the optical axis 405. The focal length of lens 420 is illustrated by the distance from the point Z1B to the apertured scatter filter 425 along the optical axis 405. Lens 415 defines an opening DA that is 120 mm. The Internal length GA of lens 415 is also 120 mm. Lens 420 defines an opening DB that is 30 mm. The internal length GB of lens 420 is also 30 mm. First magnetic clamp 416 defines an opening DCA that is 40 mm. The first magnetic clamp 416 is a distance SCA (80 mm) in a direction parallel to the optical axis. Second magnetic clamp 421 defines an opening DCB that is 10 mm. The second magnetic clamp 421 is a distance SCB (20 mm) from lens 420 in a direction parallel to the optical axis. Thus the 4:1 image reduction is achieved by a 4:1 relationship between the first lens 415 and the second lens 420. The performance of the above described lens system was modeled. The performance of a system without the first and second magnetic clamps 416 and 421 (but otherwise identical) was also modeled. The performance of the two systems was then compared. The modeling was performed using second-order finite element modeling software from Munro""s Electron Beam Software Ltd. of London, England. The comparative results are summarized in the following table. The comparison provided in Table 1 demonstrates the benefits of magnetic clamps. Specifically, the system without clamps had a much lower rotation angle in the region in which the apertured scatter filter was located compared to the system without clamps. This demonstrates that the field effects in the apertured scatter filter region were much lower in the system without clamps compared to the system with clamps. Furthermore, this improvement was obtained without an adverse effect on magnification, landing angle or beam blur. Also, as demonstrated by the reduction in lens excitation for the lens system with clamps, the lens system of the present invention is more efficient than a lens system without such clamps. Although the present invention has been described in terms of numerous examples, one skilled in the art will appreciate that numerous other embodiments are within the scope of the following claims. Consequently, the preceding examples should not be construed as limiting the present invention in any way, except in a manner that is consistent with the following claims.
	summary
	abstract	A method for constructing an error map for a lithography process, by constructing a first error map using spatial error data compiled on a lithography tool used in the lithography process, and constructing a second error map using spatial error data compiled on a mask used in the lithograph process, and then combining the first error map and the second error map to produce an overall error map for the lithography process. In this manner, the spatial error is determined prior to committing product to the process, and excessive error can be corrected or otherwise resolved prior to such commitment. In various embodiments, the spatial error data includes lens error data and stage movement error data. In some embodiments the spatial error data compiled on the mask is constructed by comparing mask pattern placement data to mask pattern source files. Some embodiments include the step of adjusting process variables to reduce errors represented in the overall error map.
	claims	1. An arrangement for collimating electromagnetic radiation, comprising:a macrocollimator which defines at least two cutouts, the macrocollimator defining a plurality of parallel notches on opposite faces of each of the cutouts; andmicrocollimator structures which are positioned in the cutouts of the macrocollimator and have lamellae that absorb electromagnetic radiation, so that collimator channels are formed which in each case extend such that they are transparent in a transmission direction, ends of at least some of the lamellae being received in the macrocollimator notches. 2. An arrangement as claimed in claim 1, wherein the lamellae of the microcollimator structures define a plurality of closed collimator channels and along opposite sides define open collimator channels which perpendicular to the transmission direction are not completely enclosed by lamellae, lamellae of the open collimator channels beign received in the macrocollimator notches and the enclosure is completed by walls of the macrocollimator. 3. An arrangement as claimed in claim 1, wherein the cutouts are arranged in a focusing manner. 4. An X-ray detector unit comprising an arrangement as claimed in claim 1. 5. An X-ray detector unit as claimed in claim 4, wherein at least one of the microcollimator structures is integrally provided with elements of the X-ray detector unit. 6. An X-ray device comprising an arrangement as claimed in claim 1. 7. A method of producing an arrangement for collimating electromagnetic radiation, said method comprising the following steps:manufacturing a macrocollimator which has at least two cutouts,manufacturing microcollimator structures which have lamellae that absorb electromagnetic radiation,inserting the microcollimator structures in the cutouts so that collimator channels are formed which in each case extend such that they are transparent in a transmission direction. 8. A method as claimed in claim 7, wherein at least one of the microcollimator structures has been produced in a casting or injection molding method. 9. A method as claimed in claim 7 wherein the macrocollimator is manufactured in a process separate from the microcollimators and subsequent to their manufacture the microcollimators are frictionally received within cutouts defined by the macrocollimator. 10. A method as claimed in claim 7 wherein the macrocollimator and microcollimators are manufactured separately. 11. A collimator having precise collimation channels for collimating electromagnetic radiation comprising:a macrocollimator encircling and defining a plurality of cutouts which are large relative to the collimator channels;a plurality of microcollimators having lamellae which define the collimator channels, the microcollimators each conforming to a size of the cutouts and being configured to be inserted into and received by one of the cutouts such that the macrocollimator guiding the received microcollimators into an orientation in which the collimator channels extend in an electromagnetic radiation transmission direction. 12. The collimator as claimed in claim 11, wherein the microcollimator defines positioning structures on a surface of each of the cutouts, the positioning structures interacting with the microcollimator structures during insertion to position the microcollimator structures relative to the macrocollimator. 13. The collimator as claimed in claim 12, wherein the positioning structures include guides extending along surfaces of the macrocollimator which define the cutouts. 14. The collimator according to claim 13, wherein the guide structures includes notches or channels which extend parallel to the electromagnetic radiation transmission direction. 15. The collimator as claimed in claim 11, wherein the lamellae are made of an electromagnetic radiation absorbent material, and further including:a material which is only slightly electromagnetic radiation absorbent relative to the material of the lamellae which fills the collimator channels.
053435052	summary	DESCRIPTION The invention relates to a recovery device for a nuclear reactor molten core. Certain accidents in the recent past have demonstrated that the molten core dropping onto the foundation or floor was able to have such an action thereon as to penetrate the same, so that the material might then spread in the neighbouring soil with difficulty forecastable consequences and only limited possibilities of reacting thereto. This is why a recovery device located under the core is proposed, which is designed in such a way as to vigorously cool the core when it has melted as a result of an accident and has dropped, while preventing the advance thereof towards the floor. In its most general form the device comprises vertical partitions defining separate volumes, certain of these volumes being empty, whereas the other volumes are filled with coolant. The latter volumes are surmounted by a refractory material layer. Therefore the molten material mass flows into the empty volumes, but the latter are sufficiently numerous and narrow to decelerate said flow, whose viscosity is also rapidly reduced by the coolant surrounding the empty volumes. The molten material is in heat exchange relationship with the coolant, from which it is only separated by the partitions, which conduct heat and are normally relatively thin. Therefore it is to be expected that the dropping of the molten core will be greatly slowed down and will be forced to solidify before reaching the actual floor. It is advantageous for the partitions to be parallel, so that the coolant-filled volumes form channels in which the coolant can effectively flow in a substantially horizontal direction. Under these conditions, the channels can extend between a slightly raised coolant source and a vaporized coolant outlet. Therefore the coolant replenishment is automatic and is due to the hydrostatic pressure as soon as the vaporization reduces the coolant height on one side of the channels. However, the channels can be separated from the source by a valve or any other isolating device, but a valve or automatic opening device is provided when the coolant is heated. It is also advantageous that the empty and the coolant-filled volumes are surmounted by a continuous heat absorption material layer, which surmounts the refractory material layer so as to reduce the mechanical and thermal shocks if an accident occurs. This avoids the risk of the destruction of the refractory material layer and the partitions by a core having an excessive temperature. It is pointed out in this connection that only the destruction of large portions of partitions could modify the process, but small size destructions during normal operation of the device would not have dangerous consequences, because the material which would penetrate the coolant-filled channels would be subject to an even more vigorous cooling and would therefore rapidly solidify.
	description	This application is a continuation of, and claims priority under 35 USC 120 to, U.S. Ser. No. 14/523,291, filed Oct. 24, 2014, which is a continuation of U.S. application Ser. No. 14/105,396, filed Dec. 13, 2013, now U.S. Pat. No. 8,894,225, which is a continuation of U.S. Ser. No. 13/676,152, filed Nov. 14, 2012, now U.S. Pat. No. 8,632,194, which is a continuation of U.S. Ser. No. 13/268,303, filed Oct. 7, 2011, now U.S. Pat. No. 8,328,374, which is a continuation of, and claims priority under 35 USC 120 to, U.S. Ser. No. 12/755,193, filed Apr. 6, 2010, now U.S. Pat. No. 8,057,053, which is a continuation of, and claims priority under 35 USC 120 to, international application Serial No. PCT/EP2008/008428, filed Oct. 7, 2008, which claims benefit of U.S. Ser. No. 60/978,565, filed Oct. 9, 2007, the disclosure of each of these applications is incorporated herein by reference in its entirety. The disclosure relates to a device for controlling temperature of an optical element provided in a vacuum atmosphere. The disclosure also relates to a method for controlling temperature of an optical element located in a vacuum atmosphere using such a device, an illumination system having such a device for controlling temperature, and a microlithography projection optics having such a device for controlling temperature. In certain applications, it is very desirable to maintain the temperature or the temperature profile of an optical mirror device on a given and in particular on a constant level. Examples for such applications are in particular EUV (Extreme Ultra Violet) illumination and projection optics operating with illumination light wavelengths, in particular in the range between 10 nm and 30 nm. These optics generally have to operate in ultra high vacuum environment since the EUV photons are absorbed by atmospheric gases. Reflective and diffractive elements are generally the only possible optical elements to form and to guide EUV radiation since there is no transparent material available for this wavelength. Since it is very difficult to produce reflective coatings for mirror elements having a reflectivity close to 1 as a rule a portion of light hitting a mirror surface will be absorbed by the optical coating and/or the mirror substrate underneath. This absorbed radiant power in turn heats up the mirror substrates and, due to thermal expansion, changes the surface figure and consequently the optical properties of the mirror which is undesirable. In particular regarding EUV wavelengths this residual absorption leads to absorbed radiant powers which are not at all negligible. Temperature stabilization for high-quality optical mirrors faces several drawbacks since the surface figures of high quality optical mirrors are sensitive to parasitic forces and thus the mirror holding and suspension design has to be optimized for minimum parasitic forces and torques. Minimizing stiffness for appropriate force and torque directions often goes along with reducing cross-sections available for heat conduction. Therefore, a good holding structure in terms of minimum parasitic forces always is a bad thermal conductor raising thermal load problems on the mirror. Since in particular in EUV illumination systems the mirrors are held under vacuum, no gases can be used for mirror cooling purposes. Water cooling of a mirror substrate is problematic since water flowing through channels and tubes always gives rise to dynamic excitation of structural eigen-modes and therefore gives undesired vibrations. Ultra low expansion ceramics as the materials Zerodur made by Schott or ULE made by Corning which tolerate temperature changes to a certain amount are expensive and not easy to manufacture. US 2004/0035570 A1 and US 2004/0051984 A1 show a mirror cooling method involving on radiation heat transfer. These mirror cooling systems involve on a controlled cooling of a heat sink. A rising thermal load on the mirror can be compensated by lowering the temperature of a cold surface of the heat sink. The disclosure provides a device for controlling temperature of an optical element provided in a vacuum atmosphere which in particular can be used for controlling temperature of an optical element, e.g. a mirror, in a EUV microlithography tool leading to a stable performance of the optical element. The device for controlling temperature can includes two controllable thermalization parts. On the one hand, there is a radiational cooling part, which may be realized as a heat sink which surface has a controllable temperature being lower than that of the optical element. On the other hand, there is a heating part for direct or indirect heating of the optical element. The heating part may be a heating mechanism including contact heating e.g. via a heating fluid or as a non-contact heating mechanism relying e.g. on radiation heat transfer, e.g. transfer of infrared radiation. Via controllable heating on the one hand and controllable heat transfer to the radiational cooling part on the other, a very flexible approach is realized regarding control of a given temperature profile of the optical element. Undesired changes of surface figures caused by thermal expansion due to residual absorption of illumination light can be eliminated for example in a first part of the optical mirror via additional heating with the help of the heating part, in a second part of the optical element via selectively controlled radiation transfer to the radiational cooling part, and in a third part of the optical element via a combination of heating on the one hand and selective radiation transfer to the cooling part on the other. This combined and flexible approach leads to the possibility to obtain for example a homogeneous temperature profile within the optical element or helps to obtain a temperature profile with a given symmetry helping to reduce respective wave-front errors. Compared to non-radiational cooling parts, relying e.g. on contact cooling of the optical element itself via the flow of a cooling medium, the radiational cooling part according to the present disclosure avoids a vibrational disturbance of the optical element. The disclosure provides a temperature stabilization that can help to prevent thermal drift effects. The disclosure provides a controller that can equalize changes which normally would occur as a result of a change of the amount of working radiation impinging on the mirror. Such an illumination change for example may be introduced by changing an illumination setting of an illumination system, the optical element being part of this illumination system. The disclosure provides a temperature sensor that can give a good control over the temperature of the optical element. The temperature sensor may be located in the vicinity of an absorbing or reflecting surface of the optical element. In that case, the temperature is measured at the relevant location and therefore gives a direct measure. The temperature sensor may be designed as a non-contact temperature sensor. This avoids disturbance of the structural integrity of the optical element. Regarding a non-contact design of the temperature sensor, this sensor may include a thermal imaging system. The disclosure provides a cooling arrangement that can lead to an efficient cooling of the radiational cooling part. The same holds for the heating arrangement disclosed herein. The disclosure provides a radiational shielding that can avoid an undesired disturbance of the radiational cooling part via members other than the optical element. This leads to a good control of a surface temperature of the radiational cooling part irrespective of an arrangement of members other than the optical element, the temperature of which is to be controlled via the device. The disclosure provides a radiational shielding that can avoid a disturbance of neighboring components, e.g. neighboring optical components or neighboring holding structures. The disclosure provides a Peltier element that can lead to an efficient cooling of the radiational cooling part. The disclosure provides a heat-receiving plate that can lead to a radiational cooling part having well-adjustable thermalization properties. Adjustment of these thermalization properties can be done via the material properties, in particular the thermal conductivity, of the materials constituting the heat-receiving plate on the one hand and the cooling member on the other. In addition, adjustment of the thermalization properties is possible via the thickness of the heat-receiving plate or the cooling member or via the shape of these components which may for example be complementary to that of the optical element. The disclosure provides a cooling part that can avoid a vibrational disturbance of the cooling part due to vibrations induced by the flow of the cooling fluid through the conduit. Due to the gap, the conduit is vibrationally decoupled from the body of the cooling part. Thus, also a disturbance of the optical element is avoided. The disclosure provides a radiational cooling part that can enable a selective heat transfer from the optical element to the radiational cooling part. This gives a radiational heat transfer profile across a surface of the optical element facing the radiational cooling part. Such a profile may be matched to an illumination intensity profile or may be matched to a heating profile, respectively, for illuminating illumination induced wave-front aberrations. The advantages of a heating part disclosed herein can correspond to that of the cooling part disclosed herein. In some cases, the mirror body in case of the device disclosed herein is not disturbed via vibrations induced by the heating fluid flowing through the conduit. The disclosure provides a surface arrangement of the cooling part that can efficiently cools the reflecting surface via radiational heat transfer. The disclosure provides a spacer that can stabilize the run of the fluid conduit within the channel. The spacer can include a spring member and/or a damping member to eliminate transfer of conduit vibrations to the inner wall. The advantages of a method for controlling temperature of an optical element disclosed herein are those already discussed with respect to the device itself. The same holds for an illumination system disclosed herein and for a microlithography projection optics disclosed herein. The disclosure relates further to a device for controlling temperature of an optical mirror device having an optical mirror having a reflecting surface. Further, the disclosure relates to a method for controlling temperature of such an optical mirror device, a microlithography illumination optics having such a device for controlling temperature, an illumination system having such a microlithography illumination optics, a microlithography projection optics having such a device for controlling temperature, a microlithography tool having at least one mirror device being equipped with such a device for controlling temperature and a method for production of a microstructured component using such a microlithography tool. Further, the disclosure relates to a system having a temperature stabilized element. The disclosure provides a device for controlling temperature of an optical mirror device having an optical mirror having a reflecting surface which in particular can be used for controlling temperature of a mirror device in a EUV microlithography tool leading to a stable performance of the optical mirror irrespective of the heat load on the mirror due to residual absorption of reflected light. A device for controlling temperature of an optical element, in particular of an optical mirror device having an optical mirror having a reflective surface, can include at least one heat sink to receive thermal radiation from a mirror heat transfer area of the optical mirror, a heating device to heat the mirror heat transfer area, a control device being in signal connection with the heating device and controlling the heating device such that in steady state a total mirror heat load on the optical mirror resulting from heat received from the heating device, heat received from an illuminating light source whose illuminating light impinges on the mirror which mirror is designed to guide the usable illumination light of the illumination light source, is maintained constant. The inventors found something that is somewhat paradox: They realized that the aforementioned problems can be solved by adding additional heat to the system. With the additional heating device a steady state of temperature profiles can be achieved which is practically no more disturbed by the heat arising from residual absorption of reflected light. If such residual absorption occurs, the heating power of the heating device is lowered in a controlled manner such that the total heat load remains constant. Thus, if any, only small changes of the total thermal behavior of the system which uses the optical mirror device having the device for controlling temperature according to the present disclosure occur. The absolute temperature of the mirror device remains more or less constant. Unwanted thermal expansion leading to disturbances of the optical performance of the mirror device do not occur. Since heating can take place with low response time, the thermal stabilization is done with low time constant and so controlling temperature within a small temperature range is possible. For instance, a given mirror substrate material having a coefficient of thermal expansion of 10−6 l/K and a given thermal expansion limit on the optical surface of 0.2 nm, a temperature control leading in steady state to a temperature profile which is maintained constant on a scale of 0.02 K is to be realized. In general, using temperature stabilization according to the disclosure, temperature profiles can be achieved being constant in time on a scale of 0.1 K or even on a scale of 0.01 K or better. The disclosure is not limited to EUV applications since residual absorptions in reflecting mirrors occur practically at all wavelengths and therefore, in demanding applications, temperature profile of such mirrors also has to be kept constant. The mirror heat transfer area may be a part of the optical mirror. This leads to a direct impact of the heating device on the reflecting surface and therefore gives a direct control of the mirror temperature. The mirror heat transfer area may be a substrate of the mirror. A diffractive element used in a reflection mode also is an example of an optical mirror whose temperature can be controlled via the device according to the disclosure. In practice, the optical mirror device may be a structured reflecting component, e.g. a reticle used in lithographic projection exposure to produce integrated microelectronic circuits. A heat sink that is not in mechanical contact with the mirror heat transfer area ensures that no mechanical stress is introduced to the mirror surface via the heat sink. A temperature sensor to measure the temperature of the mirror heat transfer area and in signal connection with the control device gives a good control over the mirror temperature to be kept constant in steady state. The at least one temperature sensor may be located in the vicinity of the reflecting surface of the optical mirror. In that case, the temperature is measured at the relevant location and therefore gives a direct measure. The temperature sensor may be designed as a non-contact temperature sensor. This avoids disturbance of the structural integrity of the optical mirror device. Regarding a non-contact design of the temperature sensor, this sensor may include a thermal imaging system. Such a thermal imaging system gives the possibility of a direct thermal measurement of the reflecting surface permitting optimum control of its temperature. By having a control device which is in signal connection or is part of a control device of an illumination system including the illumination light source control is possible even without a temperature sensor, only by checking the status of the illumination device. The control device may be in signal connection with a cooling device of the heat sink of the device. Such a control device in particular care for a constant temperature of the heat sink. When the optical mirror device whose temperature is maintained with the device according to the disclosure is used in an optical system having different operating modes, each of these modes can have a different temperature of the heat sink which can be chosen via the control device. Examples for such different operating modes are different illumination settings. A heat sink structured such that thermal radiation transfer from the heat transfer area to the heat sink varies with respect to different parts of the reflecting surface gives the possibility of adapting the heat transfer to the geometry of the heat load due to the residual absorption of the reflected light. The heat sink may be arranged such that portions of the optical mirror having a higher amount of residual absorption also have a higher heat transfer to the heat sink. The heat sink may include at least two sections having different distances to the reflecting surface. Such a heat sink is a design example for a heat sink with varying heat transfer. The heat sink may include at least two heat sink fingers pointing towards to the reflecting surface. Such heat sink fingers can be adapted to a desired heat transfer geometry. The heat sink may have multiple heat sink fingers arranged in a hexagonal field structure. Such a heat sink structure can be adapted to complex heat transfer patterns. The length of the at least two heat sink fingers of a heat sink having a respective design may be equal. Such heat sink fingers are easy to manufacture. Alternatively, the heat sink fingers may have different lengths. Such heat sink fingers provide the possibility to manufacture a heat sink with varying heat transfer or the possibility to manufacture a heat sink following the curvature of a bended reflecting surface. The length of the heat sink fingers follows the curvature of the reflecting surface. Such a heat sink gives, taking into account the heat sink fingers, a uniform heat transfer even over a curved reflecting surface. A heating device structured such that the heat transfer from the heat transfer area to the reflective surface varies with respect to different parts of the reflective surface gives the possibility to adapt the heating by the heating device to the heating by residual absorption to give for example a constant heating over the whole reflecting surface. In particular, the heating device is structured to give the possibility of a heating pattern which is complementary to the heating pattern by residual absorption. A heating device including at least two heating zones which are controllable individually via the control device gives the possibility to produce different heating patterns and therefore to adapt two different illumination patterns of the optical mirror. This in particular is advantageous in case of an illumination system for a microlithography tool having different illumination settings. Heating zones arranged to give a heat receiving distribution of the reflective surface of annular, quadrupole or dipole symmetry can be adapted according to respective illumination settings of an illumination device giving a respective illumination pattern on the mirror device. Resistance wires are an inexpensive way to produce a heating device. An arrangement of the resistance wires according to which the resistance wires are embedded in a substrate of the optical mirror leads to an efficient heat transfer into the optical mirror device. An arrangement of the resistance wires according to which the resistance wires are embedded directly underneath an optical coating of the reflecting surface gives a direct heat transfer to the reflecting surface. The heat sink may include at least two heat sink fingers pointing towards the reflecting surface. Recesses receiving the heat sink fingers result in a good heat transfer between the substrate and the heat sink fingers. The disclosure is not limited to cases where the heat transfer area is part of the optical mirror itself. The heat transfer area may be a heat receiving structure neighboring the optical mirror. In that case, in steady state a constant temperature profile is maintained at the heat receiving structure. A mirror holding structure may serve as the heat receiving structure. In that case, a thermal equilibrium is maintained at the mirror holding structure which in most cases is sufficient to stabilize the optical properties of an illumination optics including optical mirrors held with the help of this structure. This relaxes the desired properties for the coefficient of thermal expansion of the structure material while controlling the dimensional stability of the structure. For example, metals could be used while providing a device for controlling temperature according to the disclosure instead of low-expansion ceramics which is beneficial in terms of material and machine costs, joining technology and handling. Further, the thermal conductivity of metals is in general much better than the thermal conductivity of ceramics with low coefficient of thermal expansion which helps to keep the temperature distribution of the optical mirrors uniform under non-uniform thermal loads. The advantages of the method for controlling temperature of an optical mirror device having an optical mirror having a reflecting surface including the steps of heating the mirror device via a heating device, controlling the mirror device heating such that in steady state a total mirror device heat load resulting from heat received from the heating device on the one hand and heat received from an illumination light source whose illumination light impinges on the mirror on the other which mirror is designated to guide the usable illumination light of the illumination light source is maintained constant, are those already discussed with respect to the device itself. The mirror device heating may be controlled via measuring the temperature of the optical mirror. The mirror device heating may be controlled via measuring the temperature of a mirror holding structure. The mirror device heating may be controlled via checking the status of an illumination light source. The same advantages hold for an illumination system having an illumination light source and a microlithography illumination optics having a plurality of optical mirrors, at least one of which being equipped with a device for controlling temperature according to the disclosure, and for a microlithography projection optics having a plurality of optical mirrors, at least one of which being equipped with a device for controlling temperature according to the disclosure. The illumination light source may be an EUV-source, emitting light in particular in a wavelength region between 5 nm and 30 nm. The advantages of a system having a cooling device, a cooled surface of a cooling element being cooled by the cooling device to establish a first thermal radiation body, a heating device being connected to the temperature stabilized element to establish a heated surface of a second thermal radiation body, a control unit being in signal connection with the cooling device and the temperature stabilized element, wherein the temperature stabilized element is part of a EUV projection exposure apparatus, having a projection light bundle having a wavelength between 5 nm and 100 nm for imaging at least one object into at least one image, wherein at least a part of the cooled surface is distant from a surface area of the temperature stabilized element, wherein a temperature gradient directed towards the surface area of the temperature stabilized element is temporally adjustable via the control unit in absolute value and in direction, and wherein in particular the temperature stabilized element is an optical element for guiding the light bundle or is part of the holding structure of the projection exposure apparatuscorrespond to that already discussed with respect to the device. Adjustment of the temperature gradient in absolute value and in direction leads to the possibility to guide controlled temperature transients through the temperature stabilized element. This opens the door for sophisticated control schemes including feedforward-control and model-base-control. FIG. 1 shows schematically the general components of a microlithography tool 1 which is used for the production of microstructured components such as semiconductor microchips. The microlithography tool 1 has an illumination light source 2 emitting a bundle 3 of illumination light. In FIG. 1, only a chief ray of the illumination light bundle 3 is depicted. The illumination light source 2 is for example an extreme ultraviolet (EUV) light source emitting radiation having a wavelength between 5 nm and 30 nm. Advantageously, the illumination light source 2 is a plasma EUV light source. After being emitted from the illumination light source 2, the illumination light bundle 3 is formed and guided by the help of an illumination optics 4. The illumination light source 2 and the illumination optics 4 are part of an illumination system of the microlithography tool 1. The illumination optics 4 includes several optical mirrors which are not shown in FIG. 1. The illumination optics 4 serves for the provision of a specific illumination of an object field lying in an object plane 5. The specific illumination is also known as illumination setting, meaning that the light bundle 3 has a specific predetermined intensity distribution, a specific predetermined angular distribution and, such as, a specific predetermined polarization distribution in the object plane 5. A reticle 6 which is held by a reticle stage 7 is arranged such that a master surface of the reticle 6 lies in the object field. The reticle 6 is a reflecting reticle. A projection optics 8 images the illuminated object field in the object plane 5 into an image field in an image plane 9. To this end, the projection optics 8 receives an illumination light bundle 10 reflected from the reticle 6 and directs an illumination light bundle 11, formed from the incoming illumination light bundle 10 within the projection optics 8 to the image field. The projection optics 8 also includes several optical mirrors being reflective for the illumination light. These mirrors also are not shown in FIG. 1. A surface of a wafer 12 is arranged in the image field. The wafer 12 is held by a wafer stage 13. The microlithography tool 1 may be operated as a stepper or as a scanner system. Both system types are well-known to the expert. FIG. 2 shows a device 14 for controlling temperature of an optical mirror device 15. The mirror device 15 as shown in FIG. 2 can be part of the projection optics 8, can be part of the illumination light source 2, e.g. a collector thereof, or can be part of the illumination optics 4 of the microlithographic tool 1. The optical mirror device 15 includes a mirror holding structure, holding points 16 of which are indicated in FIG. 2 as triangles. The holding structure may include flexible supports corresponding to those described e.g. with respect to FIGS. 19 and 22 in US 2004/0051984 A1. Further, the optical mirror device 15 includes an optical mirror 17 having a mirror substrate or body 18 carrying a reflecting surface 19 being designed as an optical surface with a reflective coating. The optical mirror 17 and all the other components of the illumination optics 4 and the projection optics 8 guiding the illumination light bundle 3 are provided in a vacuum atmosphere. The device 14 may include a diffractive optical element which thereafter also is referred to as the optical mirror 17. Such a diffractive optical element is able to diffract light from the illumination light bundle 3. The optical mirror 17 is shown as a concave mirror. The reflecting surface 19 serves to reflect light from the illumination light bundle 3 which is depicted schematically in FIG. 2. Depending on the illumination setting, more or less the whole reflecting surface 19 may be illuminated by light from the illumination light bundle 3. Alternatively, only parts of the reflecting surface 19 can be illuminated by light from the illumination light bundle 3, depending on the position of the mirror device 14 within the lithography tool 1, e.g. in or near a pupil plane or a field plane of the optics 4, 8 and depending on the illumination setting. Part of the temperature controlling device 14 is at least one heat sink 20, one of which is shown in FIG. 2. The heat sink 20 serves as a radiational cooling part of the temperature controlling device 14. The heat sink 20 includes a heat-receiving plate. The heat sink 20 includes a cold surface 21 facing the mirror substrate 18 opposite of the reflecting surface 19. The temperature of the cold surface 21 is maintained via adequate an control mechanism on a constant temperature level which in all cases is below the temperature of the mirror substrate 18. In operation, the heat sink 20, i.e. the cold surface 21, receives thermal radiation from the mirror substrate 18 which in the embodiment of FIG. 2 serves as a mirror heat transfer area of the optical mirror 17. The temperature of the cold surface 21 may be maintained on a predetermined temperature profile. This temperature profile is given by the temperature distribution of the cold surface 21 in space and time coordinates. This temperature profile may be controlled regarding these coordinates. In general, the cold surface 21 may have an arbitrary spatial shape. The heat sink 20 is not in mechanical contact with the mirror substrate 18 to reduce mechanical stress on the mirror substrate 18 caused due to the presence of the heat sink 20. The heat sink 20 in addition may be arranged at the periphery of the optical mirror 17, i.e. facing the side surfaces of the mirror substrate 18. The heat sink 20 is made of a metal or of a ceramic material. The cold surface 21 may be processed to increase a heat absorption efficiency of the surface compared to an otherwise similar non-processed surface. The cold surface 21 may provide a ceramic, oxide-, carbide- or nitrite-containing coating on the surface. The cold surface 21 for example may be processed to provide an increased surficial roughness or surficial irregularity resulting in an increased heat-absorption area of the surface. The cold surface 21 may include spatially distributed structures to provide an increased heat-absorption efficiency from the rear surface 21a of the mirror body 18. Heating device 22 are also part of the temperature controlling device 14. In the embodiment of FIG. 2, the heating device 22 are designed as surface heating device heating a rear surface 21a of the mirror substrate 18, i.e. the mirror backside, facing towards the cold surface 21 of the heat sink 20. The surface 21a may be processed or may provide a coating or may include spatially distributed structures as described above with reference to the cold surface 21 of the heat sink 20. The heating device 22 includes resistance wires 23 which in FIG. 2 are shown in cross-section. The resistance wires 23 are arranged at the surface 21a. Alternatively, as indicated in FIG. 2, heating device 24 may be provided as resistance wires being embedded in the mirror substrate 18. The resistance wires 23 may be electrically connected as one single electrical circuit, e.g. forming a parallel or serial connection controlled by at least one control circuit regarding their electrical power. Alternatively, as indicated in FIG. 2, the resistance wires 23 are connected electrically as being part of different electrical circuits controlled by different controllers regarding their electrical power. FIG. 2 shows two groups 25, 26 of resistance wires 23 belonging to different electrical circuits. These groups 25, 26 define two heating zones which are controllable individually via a controller 27. Via lines 28, 29 and power amplifiers 30, 31, the controller 27 is connected to the groups 25, 26 of the resistance wires 23. Instead of or in addition to the groups 25, 26 of the resistance wires 23, heating zones may be defined by fluid channels 31a for heating fluid. Examples of these fluid channels 31a are shown as dashed lines in cross-section in FIG. 2. These fluid channels 31a are arranged within the mirror substrate 18 at a given distance to the reflecting surface 19. In a plane being parallel to the rear surface 21a of the mirror substrate 18, the heating fluid channels 31a are equally distributed. Typical arrangements of fluid channels are disclosed in US 2004/0035570 A1. The flow of heating fluid through those channels 31a in case of this further embodiment is controlled via a valve being in signal connection with the controller 27. In a further embodiment, the heat sink 20 may be divided into a heat-receiving plate 31b facing towards the rear surface 21 of the mirror substrate 21a and a cooling plate 31c arranged such that the heat receiving plate 31b is located in-between the rear surface 21a of the mirror substrate 18 and the cooling plate 31c. Such a design for the heat sink is described in US 2004/0051984 A1. The cooling plate 31c serves as a cooling part to remove heat from the heat receiving plate 31b. Arrangements, materials and surface processing of the heat receiving plate may be those described in US 2004/0051984 A1. The heat receiving plate may be arranged conformably to at least a portion of the rear surface 21a of the optical mirror 17. In the embodiment of FIG. 2, the heating zones, i.e. the groups 25, 26, are arranged to give a heat receiving distribution of the mirror substrate 18 of dipole symmetry. Depending on the arrangement of resistance wire groups, it clearly can be seen that other heat receiving distributions of for example annular, quadrupole or multipole symmetry can be realized. The wires 23 or in general the heating device 22, 24 may be controlled individually regarding their electrical power. Further, the heating device 22, 24 may include Peltier elements. In that case, in addition to the control of the electrical power also the direction of an electrical direct-current or a direct-current component of the electrical power may be controlled for the individual heating device 22, 24 or for a group of them. Due to the separation into individually controllable groups 25, 26 of resistance wires 23 or heating device, the heat transfer from the mirror substrate 18 to the reflective surface 19, shown by arrows 32, 33, varies with respect to different parts, i.e. in FIG. 2 a left part and a right part of the reflective surface 19. The controller 27 controls the heating device 22 such that a total mirror heat load resulting from the heat 32, 33 received from the heating device 22 and heat 34 received from the illumination light source 2 via partial absorption of the illumination light bundle 3 in steady state is maintained constant. The heat 34, i.e. the power absorbed from the not reflected quantity of the illumination light bundle 3, is shown schematically in FIG. 2 as the arrow 34. Via a line 35 the controller 27 is connected with a temperature sensor 36. The temperature sensor 36 is embedded in the mirror substrate 18 and measures the temperature of the mirror substrate 18. In the embodiment of FIG. 2, another temperature sensor is provided which is not shown. In general, the number of temperature sensors being provided at least equals the number of separately controllable groups of resistance wires. All of the temperature sensors provided are in signal connection with the controller 27 via lines or wireless. In general, the temperature sensor 36 is located in the vicinity of the reflecting surface 19 of the optical mirror 17. As an alternative to a contact temperature sensor like the temperature sensor 36 or as an additional sensor, a non-contact temperature sensor 37 may be provided. An embodiment of such a non-contact temperature sensor 37 is shown in FIG. 2 and includes an imaging optics 38 making a thermal image of the reflecting surface 19 on a receiving thermal imaging array 39, e.g. a CCD array. As indicated in FIG. 2, the controller 27 may be in signal connection with a control device 40 of the illumination system, in particular of the illumination light source 2 of the microlithography tool 1. This signal connection is schematically shown via a communication connection or a line 41. Further, via a communication connection or a line 42 the controller 27 may be in signal connection with a control device 43 for cooling device 43a of the heat sink 20. The controller 27 and the control devices 40, 43 may be part of an integrated control apparatus of the microlithography tool 1. The cooling device 43a may be a Peltier cooling device or a cooling device with controlled coolant flow. Examples for such cooling devices and for control of these cooling devices are given in US 2004/0035570 A1 the contents of which is incorporated herein by reference. The temperature of the optical mirror 17, in particular of the reflecting surface 19, is maintained via the following method: At first, the optical mirror device 15 is heated via the heating device 22. The mirror device heating is controlled such that a total mirror device heat load resulting from the heat 32, 33 received from the heating device 22 and the heat 34 received from absorption of the illumination light bundle 3 impinging on the reflecting surface 19 is maintained constant in steady state. In the embodiment of FIG. 2, the temperature of the reflecting surface 19 is measured for example with the temperature sensor 36. As long as no illumination light bundle 3 impinges on the reflective surface 19, the temperature of the mirror substrate 18 underneath the reflecting surface 19 is relatively low, in particular below a first threshold. When the reflecting surface 19 is heated via absorption of the illumination light bundle 3, the temperature of the reflective surface 19 rises above this temperature threshold. Then, via the controller 27, heating of the mirror substrate 18 via the heating device 22 is reduced such that in general after a transient effect within a response time the sum of heat transfer 32 to 34 is maintained constant in steady state. In that case, a radiation heat transfer 44 from the optical mirror device 15 to the heat sink 20 is kept constant. Such a transient effect may be introduced via thermal absorption of energy from the illumination light bundle 3 impinging on the reflecting surface 19 as the microlithography tool starts to operate. In addition, such transient effects may be introduced via the controller 27 and the heating device 22 for control of a temperature gradient directed towards the surface area of the reflecting surface 19 of the mirror substrate 18. Such temperature gradient may be controlled via the controller 27 in absolute value and in direction. Temperature control of the reflecting surface 19 results from heating control of the optical mirror device. During this temperature control, the temperature of the cold surface 21 of the heat sink 20 advantageously is kept constant in steady state, at least as long as the illumination of the reflecting surface 19 is done by one and the same operation mode of the illumination light source 2. In an alternative mode of operation to achieve temperature control of the reflecting surface 19, in addition the temperature of the cold surface 21 of the heat sink 20 may be varied. For example, heating via the heating device 22 or 24 may be accomplished with constant heating energy and temperature control of the reflecting surface 19 may be done via controlling the temperature of the cold surface 21. In practice, the temperature of the heat sink 20 always is lower than that of the mirror substrate 18. As long as the reflecting surface 19 is not heated via residual absorption of the illumination light bundle 3, the temperature of the reflecting surface 19 is somewhat lower than that of the rear surface 21a of the mirror substrate. When the main heat load results from residual absorption of the illumination light bundle 3, the reflecting surface 19 has a temperature which is higher than that of the rear surface 21a of the mirror substrate. In an embodiment of the temperature controlling device 14 not shown in FIG. 2, temperature sensors may be omitted. The heating of the mirror device 15 then is controlled via checking the status of the illumination system, in particular of the illumination light source 2, via the control device 40. For example, when the power of the illumination light source 2 is increased, the controller 27 receives a respective information from the control device 40 and, in response thereto, reduces the heating via the heating device 22 respectively. Such control may be realized via establishing a look-up table or via a model-based or feedforward-control. FIG. 3 shows another embodiment of a heat sink and an optical mirror of a temperature controlling device. Components corresponding to that which have been already discussed with respect of FIGS. 1 and 2 are designated with the same reference numbers and are not described in detail below. In the embodiment of FIG. 3, the optical mirror 17 is shown as a convex mirror. Heating device 45 of the temperature controlling device 46 of FIG. 3 are resistance wires 23 which are embedded directly underneath an optical coating of the reflecting surface 19. Due to this arrangement of the heating device 45, the heat produced via the heating device 45 is generated in the same mirror area where also residual absorption of the illumination light bundle 3 takes place. This facilitates equalization of the sum of the heat loads 32, 33 and 34 in steady state. A heat sink 47 of the temperature controlling device 46 is structured such that thermal radiation transfer from the mirror substrate 18 to the heat sink 47 varies with respect to different parts of the reflecting surface 19. To this end, the heat sink 47 includes seven heat sink fingers 48, 49, 50, 51, 52, 53, 54, numbered in FIG. 3 from left to right. These heat sink fingers 48 to 54 are parallel to each other and are connected via a heat sink main body 55. Neighboring heat sink fingers 48 to 54 are equally spaced apart. All heat sink fingers 48 to 54 point towards the reflecting surface 19. Perpendicular to a longitudinal axis 56, the heat sink fingers 48 to 54 may have a circular cross-section, i.e. the heat sink fingers 48 to 54 may have a cylindrical shape with the longitudinal axis 56 as axis of rotational symmetry. Alternatively, the cross-sections of the heat sink fingers 48 to 54 may be quadratical or rectangular or for example hexagonal. In a plane perpendicular to the axis 56, the heat sink fingers 48 to 54 are arranged in a hexagonal field structure, i.e. as an array with hexagonal symmetry. Alternatively, the heat sink fingers 48 to 54 may be arranged in a rectangular matrix array structure or may be arranged in at least one row. The symmetry of the arrangement of the heat sink fingers 48 to 54 is adapted to the symmetry of the heat receiving distribution of the heating zones of the heating device 55 and/or is adapted to the symmetry of the heat receiving distribution which the reflecting surface 19 receives via absorption of the illumination light bundle 3. Tips 57 of the heat sink fingers 48 to 54 constitute a first section of the heat sink 47 having a first, minor distance to the reflecting surface 19. Gaps 58 between the heat sink fingers 48 to 54 constitute a second section of the heat sink 47 having a second, major distance to the reflecting surface 19. The heat sink fingers 48 to 54 have a different length. The length of the heat sink fingers 48 to 54 follows the curvature of the reflecting surface 19. In case of the convex reflecting surface 19 of FIG. 3, the middle heat sink finger 51 and its neighbors 50 and 52 are the longest fingers. The heat sink fingers 49 and 53 are shorter than the heat sink fingers 50 to 52 but longer than the outer heat sink fingers 48 and 54. The heat sink fingers 48 to 54 are received in recesses 59 of the mirror substrate 18. FIG. 4 shows another embodiment of a temperature maintenance device 60 with a heat sink and an optical mirror device. Components corresponding to that which have been already discussed with respect to FIGS. 1 to 3 are designated with the same reference numbers and are not described in detail below. Heating device 61 are provided as resistance wires 23 which are embedded in a plane in the mirror substrate 18. In FIG. 4, the reflecting surface 19 is a convex surface. As the heating wires 23 are located in a plane, they do not follow the curvature of the reflecting surface 19 in contrast to the embodiment of FIG. 3. A heat sink 62 of the temperature controlling device 60 resembles the heat sink 47 of the temperature maintenance device 46. In contrast to the temperature controlling device 46 of FIG. 3, heat sink fingers 63 are all of the same length. The tips 57 of the heat sink fingers 63 are equally spaced apart from the plane where the resistance wires 23 of the heating device 61 are embedded. The heat sink fingers 63 are received in recesses 63a of the mirror substrate 18. FIG. 5 shows the net radiation heat exchange over a small gap between a mirror heat transfer area, e.g. between the mirror substrate 18, and the cold surface 21 of the heat sink 20 or 47 or 62. This net radiation heat exchange is shown as a function of the cold surface temperature. The cold surface temperature is given in units [K]. The net radiation heat exchange or transfer is given in units [W/m2]. Assuming a maximum heat load of the reflecting surface 19 of the optical mirror 17 of 4 W and a heat transfer area on the mirror, in case of the embodiments of FIGS. 2 to 4 on the mirror back side, of 0.02 m2 and a reference temperature of the mirror substrate 18 of 295 K, it can be seen from FIG. 5 that a surface temperature of the cold surface 21 of about 250K is involved to generate a sufficient cooling power bias. Cooling of the cold surface 21 via the cooling device 43 may take place by thermal electric cooling (TEC), by expansion methods, i.e. refrigerator principle, or by cooling by cold gases or liquids like for example liquid nitrogen. FIG. 6 shows a part of the illumination optics 4 or of the projection optics 8 of the microlithography tool 1 of FIG. 1. Components corresponding to that which have been already discussed are designated with the same reference numbers and are not described in detail below. This part of the optics of the microlithographic tool 1 includes a mirror holding structure 64. This holding structure 64 is realized as a mechanical structure and/or as a metrology frame. The holding structure 64 is a cellular structure having a mesh of carrier bars 64a which are arranged trapezoidal. Four optical mirrors 65 to 68 are carried by the holding structure 64 via posts 69 and carrying plates 70. The mirrors 65 to 68 are numbered in FIG. 6 from above to below. The mirrors 65, 66 are arranged in a first cell of the holding structure 64 and the mirrors 67, 68 are arranged in a second cell of the holding structure 64. The mirrors 65 to 68 have a typical diameter of 100 mm. The holding points 16, where the backsides of the mirror substrates 18 come into contact with the carrier plates 70 are designed as mirror position actuators so that tuning of the illumination light bundle forming and guiding function of the illumination and/or projection optics shown in FIG. 6 is possible. Three of the mirrors 65 to 67 are active mirrors whose position is controlled via mirror position sensors 71 which are carried by the carrier plate 70. The mirror 68 is a passive mirror having no position sensor. A temperature controlling device 72 uses the mirror holding structure 64 as heat receiving structure. The mirror holding structure 64 is heated by heating device 73 with groups 74 to 77 of resistance wires 23. The groups 74 to 77 are in contact with the outer surfaces of the carrier bars 64a of the holding structure. The number of groups 74 to 77 of resistance wires 23 of the heating device 73 equals the number of mirrors 65 to 68. This ensures individual heating of the mirrors 65 to 68 via the groups 74 to 77. Temperature sensors 78 are in contact with those carrier bars 64a which are in contact with the resistance wires 23. In FIG. 6, only one of the temperature sensors 78, namely that being in contact with the carrier bar 64a belonging to the group 77 of resistance wires 23 is shown. Each of the other groups 74 to 76 has its own temperature sensor 78. The temperature controlling device 72 has heat sinks 79, each being arranged in the vicinity of those carrier bars 64a being equipped with the groups 74 to 77 of heating resistance wires 23. Each heat sink 79 is spaced apart from its respective carrier bar 64a by a gap such that each heat sink 79 is not in mechanical contact with the carrier bar 64a. The heat sinks 79 are located outside the cells of the cellular holding structure 64. In the case of the embodiment of FIG. 6, the controller 27 controls the heating device 73 such that a total heat load on the mirror holding structure 64, the posts 69 and the carrying plates 70 and, as a further effect, a total heat load on each of the optical mirrors 65 to 68 resulting from the heat received from the groups 74 to 77 of the heating device 73 on the one hand and the heat received via residual absorption of the illumination light bundle 3 by the reflecting surfaces 19 on the other is maintained constant in steady state. Groups 74 to 77 are connected to the controller 27 in the same way as the group 77. This is not shown in FIG. 6. This temperature control works according to the principles outlined above with respect to the embodiment of FIG. 2. When the illumination light source 2 is shut off, the reflecting surfaces 19 of the mirrors 65 to 68 receive heat only via the heating device 73. When an illumination light bundle 3 is reflected via the reflecting surfaces 19 of the mirrors 65 to 68, heat is absorbed by those reflecting surfaces 19. The heating device 73 are then controlled such that the heat transfer from the groups 74 to 77 with respect to the reflecting surfaces 19 of the mirrors 65 to 68 is lowered with the result that the total mirror heat load is kept constant in steady state. Instead of four groups 74 to 77, a higher number of groups of resistance wires 23 of the heating device 73 may be provided. This gives the possibility of generating different heating zones for one and the same reflecting surface 19 which in turn gives the possibility to heat the reflecting surfaces 19 with a heat distribution e.g. of annular, quadrupole or dipole symmetry. In the production of a microstructured component using the microlithography tool 1, at first the reticle 6 and the wafer 12 are provided on the reticle stage 7 and the wafer stage 13. Then, the reticle structure is projected as an illumination microstructure onto a wafer layer which is sensitive for the illumination light of the microlithography tool 1. Then, the microstructured component is generated from the illumination microstructure via development of the wafer layer. FIG. 7 shows another embodiment of a device 14 for controlling temperature of an optical mirror device which can be part of an illumination optics of an illumination system of the microlithography tool of FIG. 1. Components corresponding to those which have been already discussed with respect to FIGS. 1 to 6 are designed with the same reference numbers and are not described in detail below. The device 14 for controlling temperature of the optical mirror device shown in FIG. 7 in addition has a radiation shielding 80 including a heating device 81 and a further heat sink 82. The radiation shielding 80 serves to reduce a possible thermal influence of the device 14 for controlling temperature on the wafer 12, on the reticle 6 or on another heat-sensitive component of the microlithography tool 1. An example for such a radiation shielding or heat-proofing device is described with reference to FIGS. 3 and 7 in US 2004/0051984 A1. For thermalization of a gap between the heat sink 20 and the mirror substrate 18, gas may be supplied to this gap and after passage through this gap may be evacuated via a suction device. The flow of such a gas in FIG. 7 is indicated by arrows 82a. Such a gas supply is described in US 2004/0051984 A1 e.g. with respect to FIG. 11. FIG. 8 shows another embodiment of a part of the illumination optics 4 of the microlithography tool 1 of FIG. 1. Components corresponding to those which have been already discussed with respect to FIGS. 1 to 7 are designated with the same reference numbers and are not described in detail below. FIG. 8 shows radiation shieldings 83 and 84 between the temperature controlled holding structure 64 and the wafer 12 which is schematically depicted with broken lines. The radiation shielding 83 is located between the groups 76, 77 of resistance wires 23 and the wafer 12. The radiation shielding 84 is located between the groups 74 and 75 of resistance wires 23 and the wafer 12. The radiation shieldings 83, 84 serve to reduce the thermal influence of the thermalization of the holding structure 64 on the wafer 12. The radiation shieldings 83, 84 each include a further heating device 81 and a further heat sink 82 as described above with reference to FIG. 7. FIG. 9 shows another embodiment of a device 14 for controlling temperature of an optical mirror device. Components corresponding to those which have been already discussed with respect to FIGS. 1 to 8 are designated with the same reference numbers and are not described in detail below. Instead of a heating device including groups of resistance wires or heating fluid channels, the embodiment of FIG. 9 has an infrared radiation source 85 for heating the rear surface 21a of the mirror substrate 18. Further, in the embodiment of FIG. 9, the heat sink 20 is connected to an actuator 86 being able to move the heat sink 20 relative to the mirror substrate 18 in order to adjust the gap between the heat sink 20 and the mirror substrate 18 and to produce fine positioning of the heat sink 20 relative to the mirror substrate 18 with respect to a gap width and/or a tilt angle and further with respect to an overlap of the heat sink 20 and the mirror substrate 18. Actuator 86 is in signal connection with the controller 27 via a signal line which is not depicted in FIG. 9. If, e.g. via thermal sensing with the help of a plurality of temperature sensors 36, certain e.g. non-symmetric temperature patterns within the mirror substrate 18 arise, such a non-symmetric pattern may be eliminated via respective movement of the heat sink 20 relative to the mirror substrate 18 via controlled movement of the actuator 86 via the controller 27. For detection of the relative positions of the heat sink 20 to the mirror substrate 18, a position sensor may be present which is not depicted in FIG. 9. Via a signal line this position sensor is connected to the controller 27. FIG. 10 shows another embodiment of a device 14 for controlling temperature of an optical mirror device. Components corresponding to those which have been already discussed with respect to FIGS. 1 to 9 are designated with the same reference numbers and are not described in detail below. In the embodiment of FIG. 10 cooling of the cold surface 21 of the heat sink 20 is realized via cooling channels 87 being arranged in a body of the heat sink 20. Cross-sections of these channels 87 are indicated in FIG. 10 as broken lines. In a plane being parallel to the cold surface 21 and being arranged in the body of the heat sink 20, the cooling channels 87 are equally distributed. FIG. 11 shows a representative cross-section of the cooling channel 87. A conduit 88 is arranged inside the channel 87 and is configured to distribute a cooling fluid 89 through the channel 87. Between the conduit 88 and an inner wall 90 of the channel 87 a gap 91 is formed. This gap 91 is filled with a heat conducting gas. The gap 91 is configured to be maintained at a pressure sufficiently low to prevent or to substantially prevent distortion of a surface figure of the cold surface 21 of the heat sink 20. Details of a cooling means having such cooling channels with inner conduits spaced apart from the inner channel walls by a gap are described in EP 1 376 185 A2, the contents of which is incorporated by reference. In a further embodiment, the channels 87 may be arranged in a plane of the cooling plate 31c according to the respective embodiment described above with reference to FIG. 2. In a further embodiment, heating of the mirror body 18 may be accomplished via heating channels 92 having a similar arrangement to the one of the cooling channels 87 described above. Such heating channels 92 are shown in FIG. 10 as cross-sections within the mirror body 18 in broken lines and in more detail in FIG. 12. Inside the heating channels 92 a conduit 93 is arranged to distribute a heating fluid 94 through the heating channel 92. Between an inner wall 95 of the heating channel 92 and the conduit 93 a gap 96 is formed being filled with a heat conducting gas. The heat conductive gas in the gap 96 is maintained at a pressure sufficiently low to substantially prevent distortion of the reflective surface 19 of the mirror 17. Vibrations induced by the flow of the fluid through the conduits 88, 93 are not transferred to the inner walls 90, 95 of the channels 87, 92. The thermalization fluids 89, 94 and the heat conductive gas in the gaps 91, 96 are provided via sources which are not shown and which are controlled via the controller 27. In the embodiment of FIG. 10 using the heating channels 92, heating via resistance wires 23 may be omitted. Within the gaps 91, 96 spacers 97 may be arranged to maintain a given width of the gaps 91, 96 around the periphery of the conduits 88, 93. Throughout all the embodiments of FIGS. 1 to 10, combined thermalization of the optical mirror 17 via absorption of the illumination light bundle 3, i.e. the working radiation, via heating of a heating part, e.g. heating via the resistance wires 23 or via the heating channels 92, and cooling via a radiation cooling part, i.e. via the cold surface 21 of the heat sink 20, is controlled via the controller 27 such that this combined thermalization leads to temperature stabilization of the optical element. To achieve an adequate temperature control, the heat sink 20 may be equipped with a temperature sensor 97a or with a plurality of such temperature sensors 97a being distributed within the body of the heat sink 20 and being in signal connection with the controller 27. FIG. 10 shows in addition an optional radiation shielding 98 surrounding all surfaces of the heat sink 20 besides the cold surface 21 thus preventing the heat sink 20 from absorbing heat from a member other than the optical mirror 17. To block transmission of vibration and positional changes, components of the device for controlling temperature may be connected via spring members. Examples for this are given with respect to FIGS. 8, 12 and 13 in US 2004/0051984 A1. The optical system of the microlithography tool including the device 14 for controlling temperature has an overall wave-front error which is less or equal to 0.5 nm. The several embodiments for the device 14 for controlling temperature allow a thermally induced surface figure correction in a wave-front range up to 2 nm. Temperature profile shapes over the thermally controlled optical surfaces according to the symmetries in particular of the Zernike polynoms Z6 to Z16 may be introduced via these embodiments of the device 14 for controlling temperature. Accordingly, these devices 14 for controlling temperature address wave-front errors in the symmetry range of the Zernike polynoms Z5 and higher. The Zernike polynoms, for example in the fringe notation are known from mathematical and from optical literature. These devices 14 allow compliance of the surface figures with a profile resolution (wave-front) of 0.2 nm rms, an accuracy (wave-front) of 0.1 nm and a maximal drift (wave-front) of 0.1 nm per 20 minutes. The devices 14 for controlling temperature described above allow for a typical temperatures control a setting time of 10 s. All embodiments of the device 14 for controlling temperature comply with ultra-high vacuum (UHV) conditions.
	summary
052326586	abstract	A fuel assembly for a boiling water reactor includes an elongated box extending between a top part and a bottom part, having box walls with flat outer surfaces defining a polygonal outer cross section with rounded corners, an interior and a longitudinal axis. A bundle of fuel rods is disposed in the box and aligned parallel to one another and to the longitudinal axis of the box. The fuel rods are disposed beside one another in rows parallel to the box walls. The box walls have reinforcements protruding into the interior in the vicinity of the rounded corners defining a relatively increased wall thickness, and the box walls have a relatively reduced wall thickness between the reinforcements.
	summary
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	claims	1. A nuclear reactor comprising a concrete reactor vault, at least one primary vessel located in said reactor vault and coupled to a reactor shield deck, and a heat removal system, each primary vessel substantially surrounded by a containment vessel in a spaced apart relationship, and comprising a reactor core submerged in a pool of liquid metal coolant, said heat removal system comprising: at least one guard vessel, each guard vessel substantially surrounding a corresponding containment vessel in a spaced apart relationship, and comprising a support skirt configured to rest on a base mat of said reactor vault, each said guard vessel coupled to and supporting said reactor shield deck; at least one inlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; at least one outlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; a first fluid flow heat transferring flowpath for the passage of air coolant from the ambient atmosphere outside said nuclear reactor, said flowpath comprising said at least one inlet conduit, the space intermediate said guard vessel of each primary vessel and said containment vessel of each primary vessel, and said at least one outlet conduit; and at least one regenerative heat exchanger in said first flowpath to elevate the temperature of said air coolant so that the temperature remains above the dew point temperature as said air coolant flows through said first flowpath, said at least one regenerative heat exchanger located upstream of the space intermediate said guard vessel and said containment vessel. 2. A nuclear reactor in accordance with claim 1 wherein said at least one heat exchanger in said first flowpath comprises at least one corrosion resistant gas-to-gas heat exchanger. claim 1 3. A nuclear reactor in accordance with claim 1 wherein said at least one regenerative heat exchanger in said first flowpath comprises said outlet conduit positioned inside said inlet conduit, and coaxial with said inlet conduit, said outlet conduit comprising an outer wall, said outlet conduit outer wall transferring heat to said air coolant flowing through said inlet conduit to heat said air coolant above the dew point temperature. claim 1 4. A nuclear reactor in accordance with claim 1 wherein said heat removal system further comprises a cylindrical baffle wall substantially encircling each said containment vessel in a spaced apart relationship, and said first flowpath comprises said at least one inlet conduit, the space intermediate said guard vessel of each primary vessel and said cylindrical baffle wall, the space intermediate said cylindrical baffle wall and said containment vessel of each primary vessel, and said at least one outlet conduit. claim 1 5. A nuclear reactor in accordance with claim 1 wherein said heat removal system further comprises a second fluid flow heat transferring flowpath for the passage of air coolant from the ambient atmosphere outside said nuclear reactor into and out of said reactor vault, said second flowpath comprising at least one vault inlet conduit, the space intermediate said guard vessel and said concrete reactor vault, at least one vault outlet conduit, and at least one regenerative heat exchanger in said second flowpath to elevate the temperature of said air coolant so that the temperature remains above the dew point temperature as said air coolant flows through said second flowpath. claim 1 6. A nuclear reactor in accordance with claim 5 wherein said at least one heat exchanger in said second flowpath comprises at least one corrosion resistant gas-to-gas heat exchanger. claim 5 7. A nuclear reactor in accordance with claim 5 wherein said at least one regenerative heat exchanger in said second flowpath comprises said vault outlet conduit positioned inside said vault inlet conduit, and coaxial with said vault inlet conduit, said vault outlet conduit comprising an outer wall, said vault outlet conduit outer wall transferring heat to said air coolant flowing through said vault inlet conduit to heat said air coolant above the dew point temperature. claim 5 8. A nuclear reactor in accordance with claim 1 further comprising at least one primary heat transferring liquid metal coolant loop, said coolant loop comprising a pump component housed in a vessel, a heat exchanger component housed in a vessel and a plurality of top entry loop conduits connecting in series said primary vessel, said pump component vessel, and said heat exchanger vessel, each said component vessel substantially surrounded by a containment vessel in a spaced apart relationship. claim 1 9. A nuclear reactor in accordance with claim 8 wherein said heat removal system further comprises a guard vessel substantially surrounding each said primary heat transferring liquid metal coolant loop component vessel. claim 8 10. A nuclear reactor in accordance with claim 9 wherein said first flowpath further comprises a space intermediate said guard vessel of each component vessel and said containment vessel of each component vessel. claim 9 11. A nuclear reactor in accordance with claim 9 wherein said second flowpath further comprises a space intermediate said guard vessel of each component vessel and said concrete reactor vault. claim 9 12. A nuclear reactor in accordance with claim 1 wherein said heat removal system further comprises a damper in each said inlet conduit and each said outlet conduit. claim 1 13. A nuclear reactor comprising a concrete reactor vault, at least one primary vessel located in said reactor vault and coupled to a reactor shield deck, and a heat removal system, each primary vessel substantially surrounded by a containment vessel in a spaced apart relationship, and comprising a reactor core submerged in a pool of liquid metal coolant, said heat removal system comprising: a cylindrical baffle wall substantially encircling each said containment vessel in a spaced apart relationship; at least one guard vessel, each guard vessel substantially surrounding a corresponding containment vessel and cylindrical baffle in a spaced apart relationship, each said guard vessel in fluid communication with an adjacent guard vessel, each said guard vessel comprising a support skirt configured to rest on a base mat of said reactor vault, each said guard vessel coupled to and supporting said reactor shield deck; at least one inlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; at least one outlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; a first fluid flow heat transferring flowpath for the passage of air coolant from the ambient atmosphere outside said nuclear reactor, said first flowpath comprising said at least one inlet conduit, the space intermediate said guard vessel of each primary vessel and said cylindrical baffle wall, the space intermediate said cylindrical baffle wall and said containment vessel of each primary vessel, and said at least one outlet conduit; and at least one regenerative heat exchanger in said first flowpath to elevate the temperature of said air coolant so that the temperature remains above the dew point temperature as said air coolant flows through said first flowpath, said at least one regenerative heat exchanger located upstream of the space intermediate said guard vessel and said cylindrical baffle wall, and the space intermediate said cylindrical baffle wall and said containment vessel. 14. A nuclear reactor in accordance with claim 13 wherein said at least one heat exchanger in said first flowpath comprises at least one corrosion resistant gas-to-gas heat exchanger. claim 13 15. A nuclear reactor in accordance with claim 13 wherein said at least one regenerative heat exchanger in said first flowpath comprises said outlet conduit positioned inside said inlet conduit, and coaxial with said inlet conduit, said outlet conduit comprising an outer wall, said outlet conduit outer wall transferring heat to said air coolant flowing through said inlet conduit to heat said air coolant above the dew point temperature. claim 13 16. A nuclear reactor in accordance with claim 13 wherein said heat removal system further comprises a second fluid flow heat transferring flowpath for the passage of air coolant from the ambient atmosphere outside said nuclear reactor into and out of said reactor vault, said second flowpath comprising at least one vault inlet conduit, the space intermediate said guard vessel and said concrete reactor vault, at least one vault outlet conduit, and at least one regenerative heat exchanger in said second flowpath to elevate the temperature of said air coolant so that the temperature remains above the dew point temperature as said air coolant flows through said second flowpath. claim 13 17. A nuclear reactor in accordance with claim 16 wherein said at least one heat exchanger in said second flowpath comprises at least one corrosion resistant gas-to-gas heat exchanger. claim 16 18. A nuclear reactor in accordance with claim 16 wherein said at least one regenerative heat exchanger in said second flowpath comprises said vault outlet conduit positioned inside said vault inlet conduit, and coaxial with said vault inlet conduit, said vault outlet conduit comprising an outer wall, said vault outlet conduit outer wall transferring heat to said air coolant flowing through said vault inlet conduit to heat said air coolant above the dew point temperature. claim 16 19. A nuclear reactor in accordance with claim 13 wherein said heat removal system further comprises a damper in each said inlet conduit and each said outlet conduit. claim 13 20. A nuclear reactor comprising a concrete reactor vault, at least one primary vessel located in said reactor vault and coupled to a reactor shield deck, and a heat removal system, each primary vessel substantially surrounded by a containment vessel in a spaced apart relationship, and comprising a reactor core submerged in a pool of liquid metal coolant, said heat removal system comprising: a cylindrical baffle wall substantially encircling each said containment vessel in a spaced apart relationship; at least one guard vessel, each guard vessel substantially surrounding a corresponding containment vessel and cylindrical baffle in a spaced apart relationship, each said guard vessel in fluid communication with an adjacent guard vessel, each said guard vessel comprising a support skirt configured to rest on a base mat of said reactor vault, each said guard vessel coupled to and supporting said reactor shield deck; at least one inlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; at least one outlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; a first fluid flow heat transferring flowpath for the passage of air coolant from the ambient atmosphere outside said nuclear reactor, said flowpath comprising said at least one inlet conduit, the space intermediate said guard vessel of each primary vessel and said concrete reactor vault, and said at least one outlet conduit; and at least one regenerative heat exchanger in said first flowpath to elevate the temperature of said air coolant so that the temperature remains above the dew point temperature as said air coolant flows through said first flowpath, said at least one regenerative heat exchanger located upstream of the space intermediate said guard vessel and said concrete reactor vault. 21. A nuclear reactor in accordance with claim 20 wherein said at least one heat exchanger in said first flowpath comprises at least one corrosion resistant gas-to-gas heat exchanger. claim 20 22. A nuclear reactor in accordance with claim 20 wherein said at least one regenerative heat exchanger in said first flowpath comprises said outlet conduit positioned inside said inlet conduit, and coaxial with said inlet conduit, said outlet conduit comprising an outer wall, said outlet conduit outer wall transferring heat to said air coolant flowing through said inlet conduit to heat said air coolant above the dew point temperature. claim 20 23. A nuclear reactor comprising a concrete reactor vault, at least one primary vessel located in said reactor vault and coupled to a reactor shield deck, and a heat removal system, each primary vessel substantially surrounded by a containment vessel in a spaced apart relationship, and comprising a reactor core submerged in a pool of liquid metal coolant, said heat removal system comprising: at least one inlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; at least one outlet conduit in fluid communication with the ambient atmosphere outside said nuclear reactor; a first fluid flow heat transferring flowpath for the passage of air coolant from the ambient atmosphere outside said nuclear reactor, said flowpath comprising said at least one inlet conduit, the space intermediate said containment vessel of each primary vessel and said primary vessel, and said at least one outlet conduit; and at least one regenerative heat exchanger in said first flowpath to elevate the temperature of said air coolant so that the temperature remains above the dew point temperature as said air coolant flows through said first flowpath, said at least one regenerative heat exchanger located upstream of the space intermediate said containment vessel and said primary vessel.
	description	This application is a filing under 35 U.S.C. 371 of international application number PCT/GB02/05613, filed Dec. 11, 2002, which claims priority to application number 0208354.1 filed Apr. 11, 2002, in Great Britain the entire disclosure of which is hereby incorporated by reference The present invention relates to a radioisotope generator of the type commonly used to generate radioisotopes such as metastable technetium-99m (99mTc). The diagnosis and/or treatment of disease in nuclear medicine constitute one of the major applications of short-lived radioisotopes. It is estimated that in nuclear medicine over 90% of the diagnostic procedures performed worldwide annually use 99mTc labelled radio-pharmaceuticals. Given the short half-life of radio-pharmaceuticals, it is helpful to have the facility to generate suitable radioisotopes on site. Accordingly, the adoption of portable hospital/clinic size 99mTc generators has greatly increased over the years. Portable radioisotope generators are used to obtain a shorter-lived daughter radioisotope which is the product of radioactive decay of a longer-lived parent radioisotope, usually adsorbed on a bed in an ion exchange column. Conventionally, the radioisotope generator includes shielding around the ion exchange column containing the parent radioisotope along with means for eluting the daughter radioisotope from the column with an eluate, such as saline solution. In use, the eluate is passed through the ion exchange column and the daughter radioisotope is collected in solution with the eluate, to be used as required. In the case of 99mTc, this radioisotope is the principle product of the radioactive decay of 99Mo. Within the generator, conventionally the 99Mo is adsorbed on a bed of aluminium oxide and decays to generate 99mTc. As the 99mTc has a relatively short half-life it establishes a transient equilibrium within the ion exchange column after approximately twenty-four hours. Accordingly, the 99mTc can be eluted daily from the ion exchange column by flushing a solution of chloride ions, i.e. sterile saline solution through the ion exchange column. This prompts an ion exchange reaction, in which the chloride ions displace 99mTc but not 99Mo. In the case of radio-pharmaceuticals, it is highly desirable for the radioisotope generation process to be performed under aseptic conditions i.e. there should be no ingress of bacteria into the generator. Moreover, due to the fact that the isotope used in the ion exchange column of the generator is radioactive, and is thereby extremely hazardous if not handled in the correct manner, the radioisotope generation process also should be performed under radiologically safe conditions. Therefore, current radioisotope generators are constructed as closed units with fluid inlet and outlet ports providing external fluid connections to the inner ion exchange column. U.S. Pat. No. 3,564,256 describes a radioisotope generator in which the ion exchange column is in a cylindrical holder which is located within two box-shaped elements that are in turn located within appropriate radiation shielding. The holder is closed by rubber plugs at both ends, and the box-shaped elements have passages opposite each of the rubber plugs in which respective needles are located. At the outermost ends of the needles quick-coupling members are provided to enable a syringe vessel containing a saline solution to be connected to one of the needles and to enable a collection vessel to be connected to the other of the two needles. This document acknowledges that as the two syringes form a closed system there is no need for air to be withdrawn or added. U.S. Pat. No. 4,387,303 describes a radioisotope generator in which air is introduced to the eluate conduit via a branched pipe so that the hollow spike used to delivery the eluate to be collected has a single bore as the air is introduced into the fluid upstream. U.S. Pat. No. 4,801,047 describes a dispensing device for a radioisotope generator in which the vial containing the saline solution that will be used to flush out the desired radioisotope from the ion exchange column, is mounted in a carrier that is moveable relative to the hollow needle used to pierce the seal of the vial and to extract the saline solution. The drawings of this document clearly illustrate two separate spaced apart hollow needles one to deliver air and one to collect fluid. The dispensing device is intended to penetrate an elastic stopper and so presents the problem that any rotational movement of the eluant container will result in tearing of the stopper which in turn destroys the aseptic environment through the uncontrolled introduction of air into the system. A similar dual needle system is illustrated in U.S. Pat. No. 5,109,160. Although piercing devices are known that employ a single spike with two channels such as that illustrated in U.S. Pat. No. 4,211,588 such piercing devices have been restricted in their application in general to intravenous systems. The present invention seeks to provide a radioisotope generator that is simple in construction but which ensures the necessary degree of sterility and radiological protection is maintained during use. In accordance with the present invention, there is provided a device for producing a fluid containing a radioactive constituent, the device comprising: a shielded chamber within which is located an isotope container housing a radioactive isotope, the shielded chamber including first and second fluid connections to opposing ends of the isotope container and a fluid conduit extending from each of the first and second fluid connections to a fluid inlet and a fluid outlet respectively characterised in that the fluid inlet comprises a single spike having a substantially circular cross-section, the spike being adapted to penetrate the rubber seal of a vial and the spike having two bores, the first bore extending from a first aperture adjacent the tip of the spike to a fluid connection with the fluid conduit and the second bore extending from a second, separate aperture in the spike to a filtering air inlet. Thus, with the present invention rotational movement of a vial penetrated by the spike would not result in tearing of the rubber seal in a manner that would result in the ingress of unfiltered air. Thus, this construction of radioisotope generator ensures that the aseptic conditions of the generator are maintained during use. FIG. 1 illustrates a radioisotope generator 1 comprising an outer container 2, a top plate 3 which is sealingly secured to the outer container 2, and a separate top cover 4 which is secured to the outer container 2 over the top plate 3. Inside the outer container 2 an inner shielded container 5, providing shielding against radiation, is located which is preferably, but not exclusively, made from either lead or a depleted uranium core within a stainless steel shell. The shielded container 5 surrounds a tube 6 containing an ion exchange column 7. The ion exchange column 7 preferably consists of a mixture of aluminium and silica, onto which molybdenum in the form of its radioactive isotope, 99Mo is adsorbed. The tube 6 containing the ion exchange column has frangible rubber seals 8 and 9 at opposing ends 10 and 11 which, as illustrated, when in use are pierced by respective hollow needles 12 and 13. Each of the hollow needles 12 and 13 is in fluid communication with a respective fluid conduit 14, 15 that are in turn in fluid communication respectively with an eluent inlet 16 and an eluate outlet 17. The fluid conduits 14, 15 are preferably flexible plastics tubing. The tubing 14, extending from the hollow needle 12, passes through a channel in a container plug 18, that closes the upper opening 19 to the shielded container 5, and then extends from the container plug 18 to the eluent inlet 16. The tubing 15, extending from the hollow needle 13, passes through a channel in the shielded container 5 to the eluate outlet 17. The inner shielded container 5 is smaller than the outer container 2 and so there is a free space 20 within the outer container 2 above the shielded container 5. This free space 20 accommodates part of the tubing 14, 15 extending from the hollow needles to the eluent inlet and eluate outlet as the lengths of the tubing 14, 15 are both much greater than the minimum length required to connect the hollow needles 12, 13 with the respective eluent inlet 16 and eluate outlet 17. The top plate 5 of the radioisotope generator 1 has a pair of apertures 21 through which respective eluent inlet and outlet components project. The eluent inlet and eluate outlet components are each hollow spikes 22 though in the case of the inlet component the hollow spike has two holes, one for the passage of fluid and one that is connected to a filtered air inlet. This is more clearly illustrated in FIG. 2 and shall be described in greater detail below. The hollow spike 22 consists of an elongate, generally cylindrical, spike body 23 and an annular retaining plate 24 which is attached to or is moulded as a single part with one end of the spike body 23. The opposing end of the spike body 23 is shaped to a point and has an aperture communicating with the interior of the spike body adjacent the point. This pointed end of the spike body 23 is shaped so that it is capable of piercing a sealing membrane of the type commonly found with sample vials. The annular retaining plate 24 forms a skirt projecting outwardly from the spike body 23 and may be continuous around the spike body or discontinuous in the form of a plurality of discrete projections. The top cover 4 of the radioisotope generator 1 also includes a pair of apertures 25 arranged so as to align with the apertures 21 in the top plate 3 and shaped to allow through passage of the spike body 23. Thus, each of the hollow spikes 22 is arranged to be held and supported by its annular retaining plate 24 by component supports 26 provided on the inside of the top plate 3 whilst the hollow spike body 23 projects through the apertures in both the top plate 3 and the top cover 4 to the exterior of the outer container 2. Each one of the apertures 25 in the top cover 4 is located at the bottom of a well 27 that is shaped to receive and support either an isotope collection vial or a saline supply vial. Thus, both vials are housed outside of the outer container 2 and are not exposed to radiation from the ion exchange column 7. In order to supply the ion exchange column with the chloride ions required for elution of the radioisotope, saline solution is drawn through the ion exchange column 7, by establishing a pressure differential across the ion exchange column. This is accomplished by connecting a saline supply vial to the eluent inlet 16 which is in fluid communication with the top end 10 of the ion exchange column 7 via the tubing 14 and hollow needle 12 and connecting an evacuated collection vial to the eluate outlet 17 which is in fluid communication with the bottom end 11 of the ion exchange column 7 via the tubing 15 and hollow needle 13. The pressure differential is established by virtue of the fluid pressure of the saline in the supply vial and the extremely low pressure in the evacuated collection vial. This urges passage of the saline solution through the ion exchange column 7 to the collection vial carrying with it the daughter radioisotope. As shown in FIG. 2 the hollow spike 22 of the eluent inlet 16 is a single body 28 which is substantially circular in cross-section and has two bores 29, 30 leading to opposed apertures in the sharpened point of the spike. The first of the bores 29 is a eluate bore and communicates directly with the outlet fluid connection of the spike which is, in turn, connected to the tubing 14. The second of the two bores 30 is an air bore and leads to a filter chamber 31 and an air hole 32. Although the two apertures in the spike, as illustrated, are both adjacent the tip of the spike, this is not necessary in all cases. The aperture for the air bore may be located lower down the body of the spike. The filter chamber 31 preferably contains a filter disk 33 of a material suitable for extracting bacteria from indrawn air such as PTFE (polytetrafluoroethylene) and PVDF (polyvinylidenefluoride). This construction of fluid inlet ensures that the saline solution can be withdrawn from the vial without air, which is necessary to equalize the pressure within the vial, entering the fluid flow. More importantly, as a single spike of substantially circular cross-section is employed to penetrate the seal of the saline vial, rotational movement of the vial within the well 27 does not result in tearing or other damage to the seal which might permit the ingress of unfiltered air and a breach of the aseptic conditions under which the radioisotope is harvested. Thus, the embodiment of the radioisotope generator described above, provides a more reliable and effective device for the collection of radioisotopes under aseptic conditions. Further and alternative features of the radioisotope generator and of the process of construction of the generator are envisaged without departing from the scope of the present invention as claimed in the appended claims.
	description	This application is a continuation of U.S. patent application Ser. No. 17/159,517 filed on Jan. 27, 2021, which is a divisional of U.S. patent application Ser. No. 16/030,734 filed on Jul. 9, 2018, which claims the benefit of U.S. Provisional Application Ser. No. 62/535,211, filed on Jul. 20, 2017. The complete disclosures of the above applications are hereby incorporated by reference for all purposes. This invention relates to a process and apparatus for growing agricultural products with a reduced abundance of carbon-14 (14C) by employing centrifugal separation of atmospheric gases to remove carbon dioxide (CO2) with radioactive 14C. Agricultural products with reduced 14C content can be grown in controlled environments for the benefit of reducing harmful damage to human DNA that is unavoidable with our current food chain, due to the natural abundance of 14C in atmospheric gases. Radioactive 14C decay to nitrogen-14 with the release of 156 KeV has long been known to have biological effects (Purdom, C. E.). Sequencing of the human genome has identified 6.1 billion base pairs in human DNA, with 119 billion carbon atoms in the DNA of each nucleated cell (Lander, E. S., and Genome Reference Consortium (GRC) Human Genome Assembly build 38 (GRCh38)). Recent quantitative analysis of human tissues has estimated 3 trillion nucleated cells in the human body (Sender, R., Fuchs, S., & Milo, R.). Given the natural abundance and half-life of 14C and composition of our genome (i.e., a mean of roughly 6.0×109 base pairs with 19.5 carbon atoms each), in the average human this decay is occurring once per second in human DNA, resulting in potential bond ruptures, DNA strand breakage, and nitrogen substitution in canonical bases (Sassi, M., et. al.). This cumulative damage has been positively correlated to cancer diagnoses (Patrick, A. D., & Patrick, B. E.), and may have other yet-to-be-quantified effects on human tissues as we age. In fact, no mammal has yet lived without this cumulative damage, so the qualitative benefits of precluding this genetic alteration are yet-to-be-quantified. To preclude this cumulative damage and genetic alteration, it is necessary to perform isotope separation on large volumes of atmospheric gases to remove 14C from agricultural products and their derivatives in the food chain. This requires an economical means for the filtration of atmospheric gases and the growth of agricultural products in controlled environments. In commercial applications, isotope separation has most commonly been applied to uranium isotopes utilizing a centrifugal separation process. The helikon vortex has been applied to uranium isotope enrichment in South Africa utilizing a multi-stage cascade design (Feiverson, H. A., Glaser, A., Mian, Z., & Von Hippel, F. N., and Moore, J. D. L.), but has not been applied to the selective isotope separation of CO2 from atmospheric gases in prior art. Turner, et al., in U.S. Pat. No. 8,460,434, shows that a helikon vortex can be utilized as a centrifugal separator in a multi-stage cascade design as one part of a process to separate methane from landfill gas. Although the multi-stage cascade design of the helikon vortex can separate gases by molecular density, it was developed for the separation of uranium isotopes, which are very heavy and differ in mass by a small amount (i.e., 235U and 238U, which differ in mass by 1.3%), which is one of the most challenging applications for centrifugal separation. Due to this multi-stage cascade design, it is very energy intensive to operate, and although it can be applied to the separation other gases by molecular density, it is uneconomical for the filtration of atmospheric gases on a large-scale for agricultural production. Shacter, in U.S. Pat. No. 3,925,036, shows a method for cycling gases through a cascade of multiple stages to achieve the separation other gases by molecular density. This multi-stage cascade design was also intended for the separation of uranium isotopes, and due to the reasons noted above is very energy intensive to operate, and although it can be applied to the separation other gases by molecular density, it is uneconomical for the filtration of atmospheric gases on a large-scale for agricultural production. Steimel, in U.S. Pat. No. 3,004,158, shows that a gas centrifuge can separate molecules of different masses by applying extremely high velocities while utilizing ionization of the gas with electric currents and the control of magnetic fields around the gas chamber. Although this process is effective for the separation of isotopes of heavy elements, such as uranium (i.e., 235U and 238U, which differ in mass by 1.3%), it is very energy intensive to operate and the apparatus itself is complex to construct, including a large electromagnet, electrodes, and controlling mechanisms. While all of this may be essential for the difficult and energy intensive separation of heavy isotopes from each other (e.g., 235U and 238U), the separation of carbon isotopes (e.g., 12C and 14C, which differ in mass by 16.7%) is much less energy intensive, due to the relatively large mass difference between isotopes. Being more energy intensive than necessary for the desired application, this process is uneconomical for the filtration of atmospheric gases on a large-scale for agricultural production. Gerber, in U.S. Pat. No. 3,594,573, shows that heavy and light isotopes can be separated from a fluid by applying a rotating electric field and ionization of the liquid with electrodes or a radioactive source. Although this process may have economical applications for liquids at atmospheric pressures, utilization of this process for the separation of CO2 with 14C from atmospheric gases would first require the separation of CO2 from other atmospheric gases, the liquification of the removed CO2, and then the application of the described process. After this, the CO2 without 14C would need then to be re-combined with atmospheric gases without CO2. Together, with the added complexity of removing CO2 from atmospheric gases, liquification of this gas, application of the described process, and then recombination of gases, this approach is uneconomical for the filtration of atmospheric gases on a large-scale for agricultural production. Janes, in U.S. Pat. No. 3,939,354, shows that ions can be separated from a plasma source utilizing mass acceleration. Similarly, Drummond, et al., in U.S. Pat. No. 3,942,975, shows that matter can be converted by an arc heater into an ionized plasma in excess of 5,000° K and stabilized with magnetic fields. Although this process was developed for the separation of rare valuable elements, such as metals, these could be adapted to separate carbon isotopes from sources of carbon. Utilization of these methodologies for the separation of CO2 with 14C from atmospheric gases would first require the separation of CO2 from other atmospheric gases, then application of the described process to the removed CO2 (or conversion of some other carbon source to plasma) and then removal of 14C. After this, the carbon without 14C would need to be combined with oxygen to produce CO2, which would then need to be mixed with the atmospheric gases that had the CO2 removed earlier. Together, with the added complexity of removing CO2 from atmospheric gases, application of the described process, conversion of carbon to CO2, and then recombination of gases, this appears to be an uneconomical alternative for the filtration of atmospheric gases on a large-scale for agricultural production. McKinney, et al., in U.S. Pat. No. 3,421,334, shows that isotopes of helium can be separated while in liquid form by exploiting unique physical properties of different isotopes. Although the claim was limited for use with helium, a similar approach could exploit the physical properties of CO2 in a liquid state. This approach would be complicated by the fact CO2 is a compound rather than an element and that there are three stable isotopes of oxygen (i.e., 16O, 17O, and 18O) that are naturally found in combinations with three naturally occurring isotopes of carbon (i.e., 12C, 13C, and 14C). Even so, exploiting the unique molecular weight of 12C16O2 in a liquid state would require the removal of all CO2 from atmospheric gases, application of this new process, and then recombination of the CO2 without 14C with the atmospheric gases without CO2. Altogether, even if this claim were modified for this application, it would also appear to be an uneconomical alternative for the filtration of atmospheric gases to remove 14C on a large-scale for agricultural production. Russ, Fischer, and Crawford, in U.S. Pat. No. 7,332,715 (2008), shows that gas at an atmospheric pressure can be passed through an ionization chamber with an electrode that generates ions, which pass through an ion filter apparatus with voltage differentials, thereby performing mass spectrometry, which demonstrates one form of isotope separation. Although this process is useful for the identification and measurement of the molecular and isotopic constituents of a gas, it is not readily extensible or adaptable to the removal of one isotopic component of atmospheric gases on a large scale, since each molecule of atmospheric gas needs to be ionized prior to filtration. Lashoda, et al, in U.S. Pat. No. 4,584,073, shows that isotopes of an element in a compound can be separated utilizing a laser when the compound is deposited in a monolayer on small glass beads. Although this process has useful applications, utilization of this process for separation of CO2 with 14C from atmospheric gases would first require the separation of CO2 from all other atmospheric gases, the liquification of the removed CO2, and then the application of the described process. After this, the CO2 without 14C would then need to be re-combined with atmospheric gases without CO2. Together, with the added complexity of removing CO2 from atmospheric gases, liquification of the removed CO2 gas, application of the described process, and then recombination of gases, this approach is uneconomical for the filtration of atmospheric gases on a large-scale for agricultural production. Several instances of prior art utilize condensation of gases or condensates as part of a system or method to remove isotopes. Redmann, in U.S. Pat. No. 4,638,674, shows that isotopes can be removed from a continuous stream of gas through condensation, although the claims are limited to gas streams from a nuclear plant rather than atmospheric gases. Similarly, Schweiger in U.S. Pat. No. 4,816,209, shows that radioactive tritium isotopes can be removed from gas from a nuclear reactor by utilizing condensation. These claims are also limited to gases from nuclear reactors. Janner, et al., in U.S. Pat. No. 4,311,674, shows that one isotope component of gases can be selectively excited from a condensate using radiation from a laser. Utilization of this process for separation of CO2 with 14C from atmospheric gases would first require the condensation of CO2 from all other atmospheric gases by increasing the pressure of the gases to exceed 5.1 bars, and then application of the described process. After this, the CO2 without 14C would then need to be re-combined with atmospheric gases without CO2. Together, with the added complexity of removing CO2 from atmospheric gases, liquification of the removed CO2 gas, application of the described process, and then recombination of gases, this approach is uneconomical for the filtration of atmospheric gases on a large-scale for agricultural production. Wikdahl, in U.S. Pat. No. 4,070,171, shows that gas mixtures can be separated by molecular or atomic weight by centrifugal force in a vortex. The described apparatus utilizes velocities exceeding the speed of sound and has been utilized for uranium isotope separation, which is among the most technically difficult isotope separation applications. This apparatus could be adapted for the less rigorous application of 14C separation, although the small diameter limits the utility for the filtration of atmospheric gases on a large-scale for agricultural production, and effective 14C separation can be achieved at lower velocities than those required for more demanding applications. Therefore, this apparatus would be less economical than an alternative that does not require such extremely high velocities, which limits efficiency, and such a small diameter, which limits the volume of throughput. Mangadoddy, et al., in U.S. Pat. No. 9,579,666 B2, shows that dense medium can be separated by centrifugal force in a vortex. Although this apparatus appears very similar to Wikdahl's apparatus, as noted above, it has a larger diameter, is intended for the separation of particles rather than molecules, and is functional at lower velocities. Although this apparatus was not intended for isotope separation, and that subject is outside the scope of the claims, it could be modified and adapted for the application of separating CO2 with 14C from atmospheric gases. In conclusion, no method or process has been formerly developed for maintaining a controlled environment from which CO2 with 14C has either been removed or reduced to a lower level than the natural abundance of 14C, as required for growing agricultural products with reduced 14C content. Similarly, no apparatus has been formerly developed with the specific intent to efficiently and economically remove CO2 with 14C from atmospheric gases with a single filtration pass, as required for large scale agricultural production. A process to grow agricultural products with a reduced abundance of radioactive 14C will have health benefits by reducing harmful damage to human DNA, which has been correlated to cancer. Other benefits of reduced cumulative genetic damage over long periods of time have yet to be quantified. To-date, removal of 14C from agricultural products on a large scale has not been possible due to a lack of an economical means to remove 14C from CO2 on a scale sufficient for agricultural production. Such agricultural products can be grown in a large variety of controlled environments so long as they are airtight, such as a sealed container, greenhouse, or building, and provided the other requirements for agricultural growth are also satisfied, such as light, water, and micronutrients. The controlled environment must be airtight so that the gases therein can be controlled and constitute filtered atmospheric gases from which CO2 with 14C has been removed. With the proper sensors, control valves, and control systems, 1) the abundance of CO2 in the controlled environment can be automatically maintained by circulating atmospheric gases through the filtration system, operating control valves, and circulation of fresh filtered air through the controlled environment, 2) to ensure the quality of the agricultural products, the control system can also ensure the filtration system is effective prior to routing filtered atmospheric gases into the controlled environment, and 3) the air pressure inside the controlled environment can be maintained at a positive pressure with respect to the external atmospheric air pressure, to prevent any leakage that could contaminate the controlled environment. Together with hydroponic growing methodologies, this process enables the complete automation of large scale agricultural production with reduced 14C. The bilateral and unilateral compression helikon vortex designs provide efficient, single-pass systems for the effective filtration of 14C from CO2 that is suitable for the filtration of large quantities of atmospheric gases as required for agricultural production (Patrick, A. D., & Patrick, B. E.). These designs are effective due to the relatively large mass difference between stable carbon and unstable carbon isotopes (i.e., 12C and 14C, which differ in mass by 16.7%), which is much less energy intensive to separate than the typical subjects of nuclear isotope separation, i.e., the heavy element isotopes of uranium, such as 235U and 238U, which differ in mass by 1.3% and require much more energy to separate. The designs also benefit from the fact unlike uranium, which is a scarce resource and cannot be wasted, atmospheric gases are relatively abundant and available for filtration at no material cost. Therefore, if a portion of perfectly usable air is lost as “waste” from the filtration process, there is no material cost for the separation process, and consequently, the filtration process does not require a high level of material efficiency to be successful or effective at removing 14C. The designs are simple without requiring electromagnets or electrodes for the ionization of gas, like some isotope separation methodologies. Also, many of the designs that utilize or require the ionization of gas are more complex and resource intensive to construct and operate. The single-pass system designs are also efficient without requiring a multi-stage cascade design, which requires many more resources to build than a single-pass filtration system, as well as much more energy to operate. The designs are more efficient in both design and operation than any of the designs that require liquification of the gases, or ionization of liquified gases, which introduce the process complexities of liquifying atmospheric gases, the maintenance hazards of operating with highly pressurized systems, and the recombination of filtered gases after liquification. The designs are also more efficient and economical than processes that would require converting CO2 to plasma and stabilizing ionized plasma with magnetic fields. Since the designs only require the acceleration of atmospheric gases, they are also more efficient than processes that require ionization and processing of each molecule of gas in mixtures of gases being separated. Since the designs utilize atmospheric gases directly, they do not require condensation of gases from nuclear power plants or require the excitation of condensates by lasers, which would only add inefficiencies. The designs do not require the acceleration of gases to velocities exceeding the speed of sound, which is required for centrifugal gas separation methodologies applied to more technically difficult isotope separation applications. The designs also do not require the very small diameter of apparatus required by centrifugal gas separation systems intended for more technically challenging isotope separation applications. Since the designs are effective at lower velocities and larger diameters, they are more efficient and well suited for the high throughput of atmospheric gases volumes required for large scale agricultural production applications. The designs are not constrained by particulate separation, only the densities of atmospheric gases, and any particulates that enter the designs would generally be discarded with the high-density atmospheric gases, including the CO2 with 14C. The designs are intended to efficiently and economically remove CO2 with 14C from atmospheric gases with a single-pass filtration, as required for large scale agricultural production. FIG. 1. is a flow diagram for the separation of atmospheric gases to remove CO2 with 14C in accordance with the process, control system, and Helikon Vortex Bilateral and Unilateral Compression designs within the invention. The Helikon Vortex 1 (see FIGS. 2A-2D or FIGS. 3A-3D for details) constitutes a means to remove CO2 with 14C from the atmospheric gases 2. Several alternative processes or apparatus could substitute 1 in this flow diagram, with respective losses of efficiency as described in the background section, and constitute an alternative means to remove CO2 with 14C from 2. The atmospheric pressure p1 of the atmospheric gases 2 is measured by pressure sensor 3 and CO2 abundance c1 in the atmospheric gases 2 is measured by CO2 sensor 4, both of which are monitored by a control system 13. A commercial high-speed air blower 5, which can be activated by the control system 13, accelerates the atmospheric gases to velocity v and volume V0 per second which is output directly into an airflow adapter 6 which is connected to the vortex chamber 7, into which the air is injected tangentially to maximize centrifugal acceleration. A cone 8 which is aligned with the vortex chamber 7 by the vortex exhaust/cone alignment base 9. The position of the cone 8 can be raised or lowered relative to the vortex chamber 7 to reduce or widen the gap between the vortex chamber 7 and the cone 8. The positioning of the cone 8 to achieve the desired separation is hereafter referred to as calibration. Dense molecular gas 10 is forced to the outside of the vortex chamber 7 by centrifugal acceleration a and exits the vortex chamber 7 through the gap near the cone 8, where it is exhausted to the atmosphere, reentering the atmospheric gases 2. Low density molecular gas 11 with reduced 14C content is slowed by the cone 8 and exits the vortex chamber opposite the cone at the top. The calibration (or cone position) can be adjusted by an electrical motor 12 which can raise or lower the cone 8 position relative to the vortex chamber 7 through axial rotation. Low density molecular gas 11 can exit through either manual or solenoid operated electrical control valves 14 and 17, which can be controlled by the control system 13. Control valve 14 is a relief valve which opens and releases gases while the high-speed blower 5 is starting, while the vortex chamber is pressurizing, or while the cone position is changing during calibration. CO2 abundance c2 of the relief valve gas output 15 is measured at CO2 sensor 16 and monitored by the control system 13. Once the vortex chamber 7 is pressurized and CO2 separation is adequate per the helikon vortex calibration, relief control valve 14 is closed and the vortex chamber control valve 17 is simultaneously opened by the control system 13. CO2 separation is adequate when CO2 sensor calibration adjusted measurements c2/c1<S, where the required separation S<1, and S is dependent on the efficiency of the helikon vortex. While the vortex chamber control valve 17 (i.e., the control valve for gaseous input to the controlled environment) is open, the CO2 abundance c3 of the vortex chamber control valve output 18 is monitored by CO2 sensor 19 to ensure CO2 separation is adequate, per the helikon vortex calibration, and proper operation of the vortex. CO2 separation is adequate when CO2 sensor calibration adjusted measurements c3/c1<S. The vortex chamber control valve output 18 passes directly into a controlled environment 20 which can be used for applications requiring CO2 with reduced 14C content (e.g., agricultural production applications). The pressure p2 of gases inside the controlled environment 20 is measured by a pressure sensor 21 and monitored by the control system 13 with to ensure a positive pressure (i.e., p2>p1) is maintained inside the controlled environment 20 to preclude contamination with CO2 containing 14C in the event of a leak or rupture. Control valve 22 remains closed while p2<p1 when 17 is open until 20 has a positive pressure differential over the atmospheric pressure (as determined by comparing pressure sensors 3 and 21), or p2>p1+p0, where p0 is the minimum additional pressure required by 20, to ensure atmospheric gases 2 do not enter 20 through 22. When control valve 17 is open and a sufficient positive pressure exists in the controlled environment 20, or p2>p1+p0, control valve 22 will be opened by the control system 13, allowing controlled environment gases 23 to exit through 22, where it is exhausted to the atmosphere, reentering atmospheric gases 2. Control valve 22 may also be opened by 13 when atmospheric pressure p1 decreases so that p2>p1+2*p0, as an emergency relief, to ensure the pressure in 20 is not so high that controlled environment gases 23 do not enter 7 through 17 when 17 is opened. When p1 is rising, 13 can also turn on 5 to increase p2 to maintain a positive pressure in 20; as described above, 5 pressurizes 7, whereby 17 is opened, increasing p2. When CO2 abundance decreases in 20 due to utilization or consumption by applications, as measured by c3, and c3<c0, where c0 is the minimum CO2 abundance required by 20, 13 will turn on 5 to replace the controlled environment gases in 20. In this manner, 13 can regulate both the pressure and CO2 abundance in the controlled environment 20 as the natural atmospheric pressure p1 of 2 fluctuates and CO2 with reduced 14C content is utilized in 20. The control system 13 can either be programmed or configured to operate 5, 14, 17, and 22 utilizing electronic controls or switches with digital or analog signals, constituting a means to operate the blower and control valves. Similarly, 13 can either be programmed or configured to monitor digital or analog signals from 3, 4, 16, 19, and 21, constituting a means to monitor the sensors. FIGS. 2A-2D are various views of a Bilateral Compression Helikon Vortex Overview, with a front view (FIG. 2A), top view (FIG. 2B), and right-side view (FIG. 2C), and cross-section of the tangential airflow stabilizer (FIG. 2D). This assembly is one instantiation of the helikon vortex 1 in FIG. 1, and several components from FIG. 1 are recognizable here, including the airflow adapter 6, helikon vortex chamber 7, cone 8, and helikon vortex exhaust/cone alignment base 9. The vortex output adapter 24 is where CO2 with reduced 14C content is output, and this is attached to the narrow vortex chamber cap/outlet 25, which is on top of 7. The vortex chamber consists of the upper narrow vortex chamber 26, extends through the center of the upper lateral vortex chamber adapter 27, the center of the airflow adapter 6, the center of the lower lateral vortex chamber adapter 32, and the lower narrow vortex chamber 33. The upper and lower narrow vortex chambers have an interior radius of r1 and combined height of h1, where the height of 26 is less than or equal to half the height of 33. The airflow adapter 6 consists of several components identifiable here, including the blower input connector 28, radial to tangential airflow adapter 29, tangential airflow stabilizer 30, and the wide vortex chamber with tangential input 31. The wide vortex chamber has an interior radius of r2 and height of h2, and is connected to the narrow vortex chambers 26 and 33 of interior radius r1 by 27 and 32, each with a height h3. The blower input connector 28 is a circular adapter with an interior radius of r0 and thickness of t0 for an exterior radius of r0+t0, providing a cross-section area of πr02 for V0 per second of input from the high-speed blower 5. The radial to tangential airflow adapter 29 changes the radial airflow at 28 to a vertical stream at the tangential airflow stabilizer 30 with an interior stream height of h0, a maximum width of w0 where πr02≥h0w0. The stream cross-section 34 can be compressed to increase pressure in the vortex chamber or to achieve a higher input velocity based on the performance of 5. The stream can also be tapered or shaped at the top and bottom excluding wedges from the tangential airflow 35 of height h4 and width w1 from the tangential edge closest to the center of the vortex chamber (See FIG. 2D), where h4≤h0/2 and w1<w0, yielding a cross section area of h0w0−h4w1≤πr02, to evenly distribute pressure in 31 as gases are compressed in 27 and 32. Below the vortex chamber 7, the cone 8 is held in a position aligned with the center of 7 by the helikon vortex exhaust/cone alignment base 9 which is attached to the bottom of 33. The position of 8 can be adjusted for calibration of the helikon vortex while remaining in alignment with the lower narrow vortex chamber 33. The top view (FIG. 2C) obstructs components below 31, but shows reinforcement for the tangential airflow 36, which is also visible on the right-side view (FIG. 2C). The interior volume of the Bilateral Compression Helikon Vortex as defined isV=πr12h1+πr22h2+2π(r12+r1r2+r22)h3/3. FIGS. 3A-3D are various views of a Unilateral Compression Helikon Vortex Overview, with a front view (FIG. 3A), top view (FIG. 3B), and right-side view (FIG. 3C), and cross-section of the tangential airflow stabilizer (FIG. 3D). This assembly is one instantiation of the helikon vortex 1 in FIG. 1, and several components from FIG. 1 are recognizable here, including the airflow adapter 6, helikon vortex chamber 7, cone 8, and helikon vortex exhaust/cone alignment base 9. The vortex output adapter 24 is where CO2 with reduced 14C content is output, and this is attached to the wide vortex chamber cap/outlet 37, which is on top of 6. The vortex chamber consists of the lower narrow vortex chamber 33, and extends through the lower lateral vortex chamber adapter 32, and the center of the airflow adapter 6. The lower narrow vortex chamber has an interior radius of r1 and height of h1. The airflow adapter 6 consists of several components that are identifiable here, including the blower input connector 28, radial to tangential airflow adapter 29, tangential airflow stabilizer 30, and the wide vortex chamber with tangential input 31. The wide vortex chamber has an interior radius of r2 and height of h2, and is connected to the narrow vortex chamber 33 of interior radius r1 by 32, with a height h3. The blower input connector 28 is a circular adapter with an interior radius of r0 and thickness of t0 for an exterior radius of r0+t0, providing a cross-section area of r02 for V0 per second of input from the high-speed blower 5. The radial to tangential airflow adapter 29 changes the radial airflow at 28 to a vertical stream at the tangential airflow stabilizer 30 with an interior stream height of h0, a maximum width of w0 where πr02≥h0w0. The stream cross-section 34 can be compressed to increase pressure in the vortex chamber or to achieve a higher input velocity based on the performance of 5. The stream can also be tapered or shaped at the bottom excluding a wedge from the tangential airflow 35 of height h4 and width w1 from the tangential edge closest to the center of the vortex chamber (See FIG. 3d), where h4≤h0/2 and w1<w0, yielding a cross section area of h0w0−h4w1/2≤πr02, to evenly distribute pressure in 31 as gases are compressed in 32. Below the vortex chamber 7, the cone 8 is held in a position aligned with the center of 7 by the helikon vortex exhaust/cone alignment base 9 which is attached to the bottom of 33. The position of 8 can be adjusted for calibration of the helikon vortex while remaining in alignment with the lower narrow vortex chamber 33. The top view (FIG. 3B) obstructs components below 31, but shows reinforcement for the tangential airflow 36, which is also visible on the right-side view (FIG. 3C). The interior volume of the Unilateral Compression Helikon Vortex as defined isV=πr12h1+πr22h2+π(r12+r1r2+r22)h3/3. FIGS. 4A-4D are Perspective Views of a Bilateral Compression Helikon Vortex (FIG. 4A) and a Unilateral Compression Helikon Vortex (FIG. 4B). FIGS. 5A-5D are various views of a Wide Vortex Chamber with Tangential Input Overview, with a front view (FIG. 5A), back view (FIG. 5B), top view (FIG. 5C), and right-side view (FIG. 5D). On all four views, the blower input connector 28, the radial to tangential airflow adapter 29, and the wide vortex chamber with tangential input 31 are visible. On all but the right-side view, the tangential airflow stabilizer 30 is visible. Cross-sections of 30 are provided in FIGS. 2D and 3D, detailing the interior cross-section area of the tangential airflow stabilizer 34 and variable exclusion wedges 35 detailed above, as related to the radius r0 of 28. The outer reinforcement for the tangential airflow 39 are clearly seen on FIG. 5B, FIG. 5C, and FIG. 5D. These are evenly spaced vertically and centered around the input axis of 28, providing reinforcement for both 30 and 31 near the tangential input. The inner reinforcement for the tangential airflow 40 are seen on FIG. 5C and FIG. 5D, and are also evenly spaced vertically and centered around the input axis of 28, providing reinforcement for both 30 and 31 near the tangential input. FIG. 6 is a Perspective View of a Wide Vortex Chamber with Tangential Input. From this front-upper perspective view the tangential airflow vent 41 is visible inside 31, which was not visible from any of the four views on FIGS. 5A-5D. As illustrated in FIG. 6, 41 has tangential dimensions with a height of h0 and width of w0 and is configured for either a bilateral or unilateral helikon vortex configuration with h4=0 and w1=0, omitting any exclusion wedges (i.e., 35) from the tangential airflow. The airflow adapter 6, as seen on FIGS. 1, 2, and 3, utilizes 28, 29, 30, and 35, as seen on FIGS. 2A-2D and 3A-3D, to constitute a means to stabilize and shape the airflow of said atmospheric gases 2 into 34, as seen on FIGS. 2A-2D and 3A-3D, prior to passing through 41 into 31, as seen here on FIG. 6. FIGS. 7A-7C are various views of a Lateral Vortex Chamber Adapter Overview, with a front view (FIG. 7A), upper-front perspective view (FIG. 7B), and lower-front perspective view (FIG. 7C). The lateral vortex chamber adapter is utilized twice in the bilateral compression helikon vortex configuration 27 and 32, and once in the unilateral compression helikon vortex configuration 32. The lateral adapter 44 connects to a wide vortex chamber 32 with a wide vortex chamber connector 42 and connects to a narrow vortex chamber to a narrow vortex chamber 26 or 33 with a narrow vortex chamber connector 43. As illustrated in FIG. 7B, the interior of the narrow vortex chamber connector 45 has a radius equal to the outside radius of the narrow vortex chamber (See FIGS. 8A-8C). The interior of the lateral adapter 47 is a smooth surface in the shape of a truncated cone and has a radius of r1 at the minimum radius at the edge shared with 45. The interior of the wide vortex chamber connector 46 has a radius equal to the outside radius of the wide vortex chamber 31. The maximum radius of 47 is equal to r2 at the edge shared with 46. Thereby, 47 provides a smooth surface inside the vortex chamber of height h3 between 45 and 46 for the compression of gases for separation by centrifugal acceleration while connecting wide and narrow vortex chamber components. FIGS. 8A-8C are various views of a Narrow Vortex Chamber Overview, with a front view (FIG. 8A), top view (FIG. 8B), and upper-front perspective view (FIG. 8C). The narrow vortex chamber is utilized twice in the bilateral compression helikon vortex configuration 26 and 33, and once in the unilateral compression helikon vortex configuration 33. To reduce helikon vortex manufacturing costs, commercial pipe with standard inner and outer diameters can be utilized for narrow vortex chambers by sizing the connectors on all connecting components, including 9, 25, 27, and 32, to match the outer and inner diameters of standard commercial pipe(s). For instance, the interior diameter of narrow vortex chamber connector 45 must match the outer diameter of the exterior of the narrow vortex chamber 49, and the minimum interior diameter of 47 must match the interior diameter of 48. An example of adapting a commercial pipe would be a 3 inch Schedule 40 PVC pipe, in which case the outer diameter of 49 would be 88.9 mm and the interior diameter of 48 would be 76.2 mm. Any commercial pipes must be cleaned with solvents and in the case of plastic or related synthetic polymers (e.g., polyvinyl chloride), they must be rigid and the interior of the narrow vortex chamber 48 must be coated with an antistatic treatment prior to utilization. FIGS. 9A-9B are various views of a Narrow Vortex Chamber Cap/Outlet Overview, with a front view (FIG. 9A), top view (FIG. 9B), top upper-front perspective view (FIG. 9C), and lower-front perspective view (FIG. 9D). The narrow vortex chamber cap/outlet 25 is utilized in the bilateral compression helikon vortex, and the vortex output adapter 24 is visible in FIG. 9A, FIG. 9B, and FIG. 9C. The top of the narrow vortex chamber cap 50 is visible on FIG. 9B and FIG. 9C. To reduce helikon vortex manufacturing costs, the interior dimensions of the vortex output adapter 24 are intended to connect to commercial pipe with standard inner and outer diameters. The interior of vortex output adapter 51, visible in FIG. 9B, FIG. 9C, and FIG. 9D, has a diameter matching the outer diameter of a commercial pipe, while the vortex chamber cap outlet 52, visible in FIG. 9B and FIG. 9B, has a diameter matching the interior diameter of the same matching commercial pipe. E.g., when connecting 24 to a ½ inch Schedule 40 PVC pipe, the matching dimensions for 51 would be a diameter of 21.33 mm and 52 would be a diameter of 15.80 mm. The bottom of 50 is visible in FIG. 9D, which must be a smooth anti-static surface, like the other interior components of the helikon vortex. FIGS. 10A-10D are various views of a Wide Vortex Chamber Cap/Outlet Overview, with a front view (FIG. 10A), top view (FIG. 10B), top upper-front perspective view (FIG. 10C), and lower-front perspective view (FIG. 10D). The wide vortex chamber cap/outlet 37 is utilized in the unilateral compression helikon vortex, and the vortex output adapter 24 is visible in FIG. 10A, FIG. 10B, and FIG. 10C. The top of the wide vortex chamber cap 53 is visible on FIG. 10B and FIG. 10C. To reduce helikon vortex manufacturing costs, the interior dimensions of the vortex output adapter 24 are intended to connect to commercial pipe with standard inner and outer diameters. The interior of vortex output adapter 51, visible in FIG. 10B, FIG. 10C, and FIG. 10D, has a diameter matching the outer diameter of a commercial pipe, while the vortex chamber cap outlet 52, visible in FIG. 10B and FIG. 10D, has a diameter matching the interior diameter of the matching commercial pipe. E.g., when connecting 24 to a ½ inch Schedule 40 PVC pipe, the matching dimensions for 51 would be a diameter of 21.33 mm and 52 would be a diameter of 15.80 mm. The bottom of 53 is visible in FIG. 10D, which must be a smooth anti-static surface, like the other interior components of the helikon vortex. FIGS. 11A-11C are various views of a Manually Calibrated Helikon Vortex Cone Overview, with a front view (FIG. 11A), top view (FIG. 11B), and lower-front perspective view (FIG. 11C). The manually calibrated helikon vortex cone is one instantiation of 8 which can be utilized in either Bilateral or Unilateral Helikon Vortex configurations. The effective surface of the cone 54 is visible in FIG. 11A, FIG. 11B, and FIG. 11C. This surface must be a smooth anti-static surface, like the other interior components of the helikon vortex. The base of the cone 55 is visible in FIG. 11A and FIG. 11C. In the center of the base of the cone is the threaded core of the cone 56 which is visible in FIG. 11C. To reduce helikon vortex manufacturing costs, the threads are industry standard fine thread count and diameter so that the manually calibrated helikon vortex cone can be used with industry standard bold sizes. E.g., an industry standard ⅜″ bolt size has a fine thread count of 24 threads per inch (TPI). FIGS. 12A-12B are various cross-sectional views of the Manually Calibrated Helikon Vortex Cone, with a Vertical Cross-Section View (FIG. 12A) and a Horizontal Cross-Section View (FIG. 12B). The effective surface of the cone 54 is visible in FIG. 12A on the upper external surface of the vertical cross-section, while the base of the cone 55 is visible on the bottom. The effective surface of the cone 54 is visible in FIG. 12B on the outer circumference of the horizontal cross-section. The threaded core of the cone 56 is visible on FIGS. 12A and 12B. To reduce helikon vortex manufacturing costs, the interior of the cone 57 is hollow, as seen on FIGS. 12A and 12B, precluding the utilization of unnecessary materials. The base of the cone is reinforced in three ways. First, a thick area of material reinforcement for the threaded core 58 is provided around 56, as seen on FIGS. 12A and 12B. Second, radial reinforcement structures 59 and 60 extend from 58 (i.e., near the center of the cone) to 54 (i.e., the outside of the cone), as seen on FIG. 12B. Third, and finally, a circular reinforcement structure 61 goes around the base of the cone and 56, as seen on FIGS. 12A and 12B, connecting the inner radial reinforcement structures 59 to the outer reinforcement structures 60. The inner and outer reinforcement structures, 59 and 60, are distributed at even intervals of angles around the central axis of the cone, but the angles separating structures for 59 and 60 are not necessarily equal, as seen on FIG. 12B, where six 59 are connected to 61 and eight 60 structures are connected to 61. Larger cones may have multiple circular reinforcements 61, in concentric circles, each connected by radial reinforcement structures, such as 59 or 60, while smaller cones may not require a circular reinforcement structure 61 and only a single set of radial reinforcement structures, such as 59, which would then directly connect 58 to 54. FIGS. 13A-13C are various views of an Alternative Threaded Cone Overview, with a front view (FIG. 13A), bottom view (FIG. 13B), and lower-front perspective view (FIG. 13C). The alternative threaded cone differs from the manually calibrated helikon vortex cone in FIGS. 11A-11C in that it has no threaded core 56 and instead has a single threaded extrusion 62 and multiple axial alignment extrusions 63, as seen on FIGS. 13A, 13B, and 13C. The extrusions 62 and 63 are aligned with the central axis of the cone, with 62 being on the central axis as seen from the bottom view in FIG. 13B. One or more axial alignment extrusions, 63, appear around the central axis, with four visible on FIGS. 13B and 13C. The alternative threaded cone is intended for use with an electric motor 12 and the vortex exhaust/alternative threaded cone alignment base on FIGS. 15A-15B and 16A-16B. FIGS. 14A-14C are various views of a Vortex Exhaust/Cone Alignment Base Overview, with a front view (FIG. 14A), top view (FIG. 14B), and bottom view (FIG. 14C). The vortex exhaust/cone alignment base 9 is utilized with the cone 8 illustrated in FIGS. 11A-11C and has several critical functions. First, the bottom of the base 64, visible on FIGS. 14A, 14B and 14C, is held perpendicular to the central axis of the lower vortex chamber 7 via the connector to the vortex chamber 65, visible on FIGS. 14A and 14B, which attaches to the lower narrow vortex chamber 33. The inner diameter of 65 matches the outer diameter of 33 for alignment, and is large enough for the base of the cone 8 to be lowered into 9. Second, two or more vertical vent fins 66, visible on FIGS. 14A, 14B, and 14C, are symmetrically distributed around the central axis of 9, connecting 64 to 65, while being tangential to airflow from 33. The gaps between 66 permit exhaust to exit from the vortex chamber 9. Third, the bottom of the base 64 is structurally reinforced to hold the cone 8 in alignment with the central axis of the lower vortex chamber 7 with one or more circular reinforcements 67, visible on FIGS. 14A and 14B, symmetrically distributed radial reinforcements 68, visible on FIG. 14B, and a central reinforcement 69, visible on FIG. 14B, around the center of 64. The structural reinforcements 67, 68, and 69 support the alignment of the cone 8 while precluding the utilization of unnecessary materials. At the top of the base, 65 is contoured to maximize surface area with 66 to add structural strength. The cone is held in place by a commercial hex that is inserted from the bottom of 64 into the cylindrical hollow central shaft of the base 70, visible on FIGS. 14B and 14C. The hex head of the bolt fits into the base hex nut intrusion 71 which is visible on FIG. 14C. Therefore, the manually calibrated helikon vortex cone 8, in FIGS. 11A-11C, can be attached to this vortex exhaust/cone alignment base 9, in FIGS. 14A-14C, with a commercial hex bolt. The cone can be lowered by turning it clockwise, from the top view, down onto the threaded bolt, and raised by turning it counter-clockwise. When the cone is in a lower position there is a larger gap between the cone 8 and the lower narrow vortex chamber 33, allowing a larger volume of atmospheric gases to exhaust out of 7. These exhaust gases, which exit below 65 on FIG. 14A between the vent fins 66, are the densest atmospheric gases, being on the outside perimeter of 7 while under centrifugal acceleration. FIGS. 15A-15B are various Perspective Views of the Vortex Exhaust/Cone Alignment Base, with an upper-front perspective view (FIG. 15A) and a lower-front view perspective view (FIG. 15B). All the reference numerals in FIGS. 14A-14C are visible in FIGS. 15A-15B. On FIG. 15A, the circular and radial structural supports 67 and 68 can be seen to rise above the base 64, providing reinforcement to 69. The outermost circular structural support 67 also provides more surface area and structural support for 66 to attach to the base 64. The intrusion for the hex bolt 71 can be clearly seen on FIG. 15B in the center of the base 64. The variable outer diameter of 65 can also be seen on FIG. 15B, reducing materials required for construction while enhancing the surface are and structural support for 66 to attach to the connector 65. The vortex exhaust/cone alignment base 9 utilizes a hex bolt held stationary in axial alignment by 69, 70, and 71, and held in alignment with the lower narrow vortex chamber 33, as seen on FIGS. 2A-2D and 3A-3D, by 65 and a plurality of 66, while said hex bolt is threaded into cone 8 holding 8 in axial alignment by 56 and 58, which are reinforced by 61 and a plurality of 59 and 60, as seen on FIGS. 12A-12B, while 8 can be rotated clockwise and counter-clockwise to raise and lower position of 8 inside 33, constitutes a means to position said cone 8 inside said lower narrow vortex chamber 33. FIGS. 16A-16B are various views of a Vortex Exhaust/Alternative Threaded Cone Alignment Base Overview, with a top view (FIG. 16A), and bottom view (FIG. 16B). The vortex exhaust/alternative cone alignment base 9 is utilized with the alternative threaded cone 8 illustrated in FIGS. 13A-13C and differs by the vortex exhaust/cone alignment base 9 illustrated in FIGS. 14A-14C in a few ways. First, instead of a smooth hollow central shaft 70, this base has a threaded central shaft 72, as seen on FIGS. 16A and 16B. Second, instead of the central reinforcement 69 being immediately around 70, there is a circular central shaft 73 that can rotate clockwise and counter-clockwise, as seen on FIGS. 16A and 16B. Third, the central reinforcement for the base 69 goes around 73 in this configuration, as seen on FIG. 16A. Fourth, there are axial alignment shafts 74 which extend through the radial reinforcements 68 and the base 64, as seen on FIGS. 16A and 16B. The front view of this configuration of 9 appears to be the same as FIG. 14A. The axial alignment extrusions 63 on the alternative threaded cone 8 extend through the axial alignment shafts 74 as the threaded extrusion 62 is threaded into 72. Together, the alignment extrusions 62 and shafts 74 align the cone 8 with the vortex chamber 7, as the cone position is raised and lowered by rotating 73 clockwise and counter-clockwise. Fifth, an axial alignment shaft reinforcement 75 is around each shaft 74 to reinforce the radial reinforcements 68, as seen on FIG. 16A. Finally, there is a motor attachment mount 76 on the bottom of 73, as seen on FIG. 16B. This is where an electrical motor 12 can be attached to rotate 73 to raise and lower the cone 8 via a control system 13 to automate the calibration process. FIGS. 17A-17B are Perspective Views of the Vortex Exhaust/Alternative Threaded Cone Alignment Base, with an upper-front perspective view (FIG. 17A) and a lower-front view perspective view (FIG. 17B). All the reference numerals in FIGS. 16A-16B are visible in FIGS. 17A-17B. On FIG. 17A, the axial alignment shaft reinforcement 75 can be seen having a similar height to the radial, circular, and central reinforcement structures 67, 68, and 69. The circular central shaft 73 can be seen extending from the center of 69 in FIG. 17A to the center of 64 on FIG. 17B, where the motor attachment mount 76 is located. The other functions of 64, 65, 66, 67, 68, and 69 identified on FIGS. 15A-15B above are applicable here. The vortex exhaust/alternative threaded cone alignment base 9 utilizes a threaded central shaft 72 that is held in axial alignment by 69 and 73, and reinforced by a plurality of 68, and held in alignment with the lower narrow vortex chamber 33, as seen on FIGS. 2A-2D and 3A-3D, by 65 and a plurality of 66, while 72 is threaded onto 62 of cone 8, as seen on FIGS. 13A-13C, holding 8 in axial alignment by a plurality of extrusions 63 which are inserted into 74, which are reinforced by 68 and 75, while 76 can be rotated clockwise and counter-clockwise manually or by an electric motor 12 to raise and lower the position of 8 inside 33, constitutes a means to position said cone 8 inside said lower narrow vortex chamber 33. 1 helikon vortex 2 atmospheric gases 3 pressure sensor for atmospheric gases 4 CO2 sensor for atmospheric gases 5 high-speed blower 6 airflow adapter 7 helikon vortex chamber 8 helikon vortex cone 9 helikon vortex exhaust/cone alignment base 10 dense molecular gas (vortex chamber exhaust) 11 low density molecular gas (vortex chamber product) 12 electrical motor 13 control system 14 relief control valve 15 relief valve gas output 16 relief valve output CO2 sensor 17 vortex chamber control valve or controlled environment gaseous input control valve 18 vortex chamber control valve output 19 vortex chamber control valve output CO2 sensor 20 controlled environment 21 pressure sensor for controlled environment 22 controlled environment gaseous output control valve 23 controlled environment exhaust 24 vortex output adapter 25 narrow vortex chamber cap/outlet 26 upper narrow vortex chamber 27 upper lateral vortex chamber adapter 28 blower input connector 29 radial to tangential airflow adapter 30 tangential airflow stabilizer 31 wide vortex chamber with tangential input 32 lower lateral vortex chamber adapter 33 lower narrow vortex chamber 34 interior cross-section area of tangential airflow stabilizer 35 excluded wedge from tangential airflow 36 reinforcement for the tangential airflow 37 wide vortex chamber cap/outlet 39 outer reinforcement for the tangential airflow 40 inner reinforcement for the tangential airflow 41 tangential airflow vent 42 narrow vortex chamber connector 43 wide vortex chamber connector 44 lateral adapter 45 interior of narrow vortex chamber connector 46 interior of wide vortex chamber connector 47 interior of lateral adapter 48 interior of narrow vortex chamber 49 exterior of narrow vortex chamber 50 narrow vortex chamber cap 51 interior of vortex output adapter 52 vortex chamber cap outlet 53 wide vortex chamber cap 54 effective surface of cone 55 base of cone 56 threaded core of cone 57 hollow interior of cone 58 reinforcement for threaded core of cone 59 inner radial reinforcement structure for cone 60 outer radial reinforcement structure for cone 61 circular reinforcement for cone 62 threaded extrusion 63 axial alignment extrusion 64 bottom of base 65 connector to vortex chamber 66 vent fin 67 circular reinforcement for base 68 radial reinforcement for base 69 central reinforcement for base 70 hollow central shaft 71 base hex nut intrusion 72 threaded central shaft 73 circular central shaft 74 axial alignment shaft 75 axial alignment shaft reinforcement 76 motor attachment mount The operation for growing agricultural products with reduced 14C content requires a controlled environment 20 with filtered atmospheric gases 2 from which CO2 with 14C has been removed. 1. A filtration system comprising a blower 5 and a helikon vortex 1 constitutes a means to remove CO2 with 14C from atmospheric gases 2; blower 5 output velocity of 322 km per hour or greater is required for effective filtration with helicon vortex 1; 2. Control valves 17, 22 are required to control the flow of gases entering and exiting the controlled environment 20; 3. When the CO2 sensor 19 inside the controlled environment 20 detects a CO2 abundance lower than a predetermined amount, the said filtration system is turned on by the control system 13 and the relief control valve 14 is opened; 4. The CO2 sensor 16 at the relief output is monitored and compared to the CO2 sensor 4 for atmospheric gases 2 outside the controlled environment to ensure said filtration system removal of CO2 with 14C from atmospheric gases 2 is effective by detecting a predetermined delta which can be determined by said filtration system efficiency;5. Once effective filtration is verified, the control system 13 closes the relief control valve 14 and opens control valves 17, 22 which are connected to the controlled environment 20;6. When the CO2 sensor 19 inside the controlled environment 20 detects a CO2 abundance above a predetermined amount, the said filtration system is turn off and the control valves 17, 22 are closed by the control system 13;7. When the controlled environment input control valve 17 is open, the output control valve 22 is only opened by the control system 13 when the air pressure inside the controlled environment 20 as measured by the air pressure sensor 21 exceeds the atmospheric gas air pressure outside of the controlled environment by a predetermined amount as measured by air pressure sensor 3;8. Operation of said filtration system is initially required for a duration sufficient to replace the entire volume of air inside the controlled environment 20. Thereafter, continuous, periodic, or intermittent operation as determined by CO2 sensor 19, as detailed above, may be used to determine periods of operation for the filtration system to maintain sufficient CO2 levels inside the controlled environment 20;9. The control system 13 can either be programmed or configured to operate 5, 14, 17, and 22 utilizing electronic controls or switches with digital or analog signals, constituting a means to operate the blower and control valves. Similarly, 13 can either be programmed or configured to monitor digital or analog signals from 3, 4, 16, 19, and 21, constituting a means to monitor the sensors.10. Helikon vortex 1 above may comprise either a bilateral compression helikon vortex or a unilateral compression helikon vortex as detailed below; effective filtration has been demonstrated with centrifugal acceleration exceeding 16,000 g, a maximum narrow vortex chamber radius of 5.08 cm, and a maximum height of 1.94 m.11. Bilateral compression helikon vortex (FIG. 2) consists of an airflow adapter 6 (consisting of blower input connector 28, radial to tangential airflow adapter 29, tangential airflow stabilizer 30, and exclusion wedge 35), vortex chamber 7 (consisting of a wide vortex chamber 31, upper narrow vortex chamber 26, lower narrow vortex chamber 33, upper lateral adapter 27, and lower lateral adapter 32), cone 8, exhaust/cone alignment base 9, vortex output adapter 24, and narrow vortex chamber cap/outlet 25;12. Unilateral compression helikon vortex (FIG. 3) consists of an airflow adapter 6 (consisting of blower input connector 28, radial to tangential airflow adapter 29, tangential airflow stabilizer 30, and exclusion wedge 35), vortex chamber 7 (consisting of a wide vortex chamber 31, lower narrow vortex chamber 33, and lower lateral adapter 32), cone 8, exhaust/cone alignment base 9, vortex output adapter 24, and wide vortex chamber cap/outlet 37;13. During operation, the atmospheric gases 2 are accelerated by blower 5 and enter the airflow adapter 6 were they are stabilized and shaped prior to tangential injection into the wide vortex chamber 31; Centrifugal acceleration occurs while the atmospheric gases are separated by molecular density in vortex chamber 7; after separation, the high-density gases exit 7 between 33 and 8, while low-density gases exit 7 through 24;14. Calibration of the helikon vortex is essential prior to operation and this is accomplished by adjusting the position of the cone 8 inside the narrow vortex chamber 33 to ensure effective separation of CO2 with 14C. For manual calibration, the vortex exhaust/cone alignment base 9 utilizes a hex bolt held stationary in axial alignment by 69, 70, and 71 (FIG. 15), while cone 8 can be rotated clockwise and counter-clockwise to raise and lower the position of 8 inside 33. Alternatively, the calibration process can be automated with an electric motor 12. The vortex exhaust/alternative threaded cone alignment base 9 utilizes a threaded central shaft 72 that is held in axial alignment by 69 and 73 (FIG. 16), holding 8 in axial alignment by a plurality of extrusions 63 (FIG. 13) which are inserted into 74, while 76 can be rotated clockwise and counter-clockwise by an electric motor 12 to raise and lower the position of 8 inside 33. U.S. Patent Documents 3,004,158October 1961 Steimel, K.3,421,334January 1969 McKinney, et al. . . . 62-283,594,573July 1971 Gerber, H.3,925,036December 1975 Shacter, J. . . . 55/1583,939,354February 1976 Janes, G. S. . . . 250/4843,942,975March 1976 Drummond, et al. . . . 75/10 R4,070,171January 1978 Wikdahl . . . 55/4194,311,674January 1982 Janner, et al. . . . 204/157.224,584,073April 1986 Laboda, et al. . . . 204/157.24,638,674October 1983 Redmann . . . 73/863.124,816,209July 1986 Schweiger . . . 376/3097,332,715 B2February 2008 Russ, et al. . . . 250/2888,460,434June 2013 Turner, et al. . . . 95/1179,579,666 B2February 2013 Mangadoddy, et al. . . . B040C 5/04 Feiverson, H. A., Glaser, A., Mian, Z., & Von Hippel, F. N., Unmaking the Bomb: A Fissile Material Approach to Nuclear Disarmament and Nonproliferation, The MIT Press, Cambridge, Mass., London, England (2014). Genome Reference Consortium (GRC) Human Genome Assembly build 38 (GRCh38), 24 Dec. 2013. Lander, E. S. et al., Initial sequencing and analysis of the human genome, Nature 409, 860-921 (2001). Moore, J. D. L., South Africa and Nuclear Proliferation, Palgrave Macmillan, New York, N.Y. (1987). Patrick, A. D., & Patrick, B. E., Carbon 14 decay as a source of somatic point mutations in genes correlated with cancer diagnoses, Stable Isotope Foundation, Grants Pass, Oreg., USA (2017). Purdom, C. E., Biological hazards of carbon-14, New Sci. 298, 255-257 (1962). Sassi, M., et. al., Carbon-14 decay as a source of non-canonical bases in DNA, Biochimica et Biophysica Acta 1840 526-534 (2014). Sender, R., Fuchs, S., & Milo, R., Revised estimates for the number of human and bacteria cells in the body, PLoS Biol 14(8): e1002533 (2016).
	claims	1. A defect imaging device, comprising:an energy beam system having an output of photons directed at a device under test and producing a positron instantaneously by electron-positron pair production in the device under test, wherein the output has a maximum energy above an electron-positron pair production threshold but below a neutron emission threshold;a detector receiving an annihilation photon from the annihilation of the positron and determining a momentum of an electron forming an annihilation photon. 2. The device of claim 1, further including an imaging system receiving an electrical output from the detector. 3. The device of claim 1, wherein the energy beam system includes an electron accelerator having an output directed at a bremsstrahlung converter. 4. The device of claim 3, further including a collimator at an output of the bremsstrahlung converter. 5. The device of claim 1, wherein the detector is a high purity germanium detector. 6. The device of claim 5, further including a sodium iodide detector.
063079135	description	DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, a shaped plasma discharge system is provided. A shaped radiation source 5 emits radiation 50 at a desired frequency (.lambda..sub.2) and in a desired shape, as illustrated in FIG. 1A. In a preferred embodiment, a plasma generating target is excited to emit the radiation 50 at the desired frequency (.lambda..sub.2) and in the desired shape. The radiation 50 of the plasma discharge is preferably directed to provide the illumination in a photolithography system. Exemplary plasma discharge shapes are an arc, line, circle, ellipse or an array of small discs filling such shapes, or any combination of these shapes. As illustrated in FIG. 1B, a laser source 10 is provided in a laser-based embodiment. Any suitable laser source 10 may be used that can provide light at a desired wavelength, power level and beam quality. Regarding the power level, it is preferred that the laser source 10 provides an output beam 20 with an intensity that is sufficient to generate a desired radiation emission from target 45, for example in an intensity in a range of 10.sup.11 and 10.sup.15 watts per square centimeter may be selected. The output beam 20 preferably is shaped using shaping optics 30 to provide a shaped output laser beam 40 to the target 45, the shaped output laser beam 40 having a cross-sectional illumination field profile. Any shaped illumination field 35 may be created using the shaping optics 30 as long as a shaped beam 40 having a sufficient intensity level is provided to the target 45. A shaped plasma source is created at target 45, which emits the shaped radiation field 50 having wavelength .lambda..sub.2. Condenser 55 preferably collects as much of the radiation 50 as possible and directs it to a reflective or transmissive object 60 to be illuminated by radiation 50. Preferably object 60 is a mask. Condenser 55 optimally directs the radiation on the object 60 in a desired shape, such as illustrated in FIGS. 2-4 or 8, although any desired shape may be selected. The fact that radiation comes from a shaped radiation source optimizes the process so that condenser 55 relays the shape of the source onto the object 60. The camera 70 uses the shaped radiation field (.lambda..sub.2) to image the structure of the object 60 onto the recording medium 80. Preferably the recording medium 80 is a photoresist coated wafer, although any suitable recording medium may be used. The camera 70 is preferably constructed of a plural mirrors and/or lenses. For short wavelengths, such as extreme ultraviolet or x-ray radiation, the camera 70 preferably includes mirrors and the shape of the radiation illumination field (at a wavelength .lambda..sub.2) selected is preferably an arc type of shape since that shape tends to be easier to image with currently widely known camera mirrors, although it is understood any shape may be selected. The radiation field preferably is scanned across the object 60. Alternatively, the object 60 can be moved, or a combination of movement of object 60 and scanning of the radiation field to completely illuminate the object 60 with the radiation and to completely image it on the wafer 80. The wafer 80 may also be moved during illumination to fully project the object 60 on the wafer 80. Preferably the camera 70 is a reduction camera. In a photolithography process, the wafer 80 is preferably covered with a photosensitive material onto which the reduced image of the mask 60 is exposed. After exposure, the photoresist is "developed" so that the image of the mask creates the desired microcircuits on the wafer 80, which preferably is a silicon based wafer. Thus, in an exemplary (but not limiting) embodiment, the shaped radiation field 50 illuminating the mask 60 is imaged by the camera 70 onto the wafer 80. The shaped radiation field in this example is maintained in a given position at the mask 60, and its image through the camera 70 is also maintained at a given position. Both the mask 60 and the wafer 80 are simultaneously moved relative to the shaped radiation field. The movements of the mask 60 and the wafer 80 are preferably set to obtain a complete image of the mask 60 on the wafer 80. Using a pulsed output beam 20, it is possible to operate at a relatively low energy level while achieving a desired level of intensity at the target 45, for a short duration, as demonstrated by the known equation for laser intensity: ##EQU1## The intensity is equal to the energy in each laser pulse (Energy/pulse), divided by the illumination area (A) and the pulse duration (T/pulse). A preferred laser source 10 is a short pulse laser, as described in commonly assigned, co-pending U.S. patent application Ser. No. 09/058,274, now U.S. Pat No. 6,016,324 entitled "Short Pulse Laser System" and U.S. Pat. No. 5,742,634, entitled "Picosecond Laser", both of which are referred to and incorporated herein by reference. However, it should be understood that these particular laser sources are mentioned as examples and any laser source generating a beam 20 providing sufficient intensity at the target 45 can be used. In an exemplary embodiment, a beam intensity of between 10.sup.11 and 10.sup.12 watts per square centimeter (cm..sup.2) at the target 45 is preferred to generate a sufficiently hot plasma for exciting target emissions in the x-ray, soft x-ray, extreme UV and deep UV spectral regions. However, it should be understood that any beam intensity suitable for generating a laser plasma at the target 45 that is suitable in imaging systems (i.e. lithography systems used in imprinting photoresist coated wafers, such as in integrated circuit manufacture) can be used, for example in a range of 10.sup.11 and 10.sup.15 watts per square centimeter at the target 45 or any other suitable intensity. As an example, laser source 10, as described above, can provide output beam 20 having 500 to 1000 pulses per second of, for example 100 or 800 picosecond duration, and 100 to 500 milliJoules/pulse. Another example has a laser source providing an output beam 20 having between 1 and 100,000 milliJoules/pulse. Exemplary wavelengths are in the range of 0.2 micron to 1 micron, although it should be understood that any wavelength for the output beam 20 may be used that can generate the desired intensity level and excite the target material to produce the desired radiation wavelength (.lambda..sub.2). In one embodiment, if an illumination area of approximately 0.005 cm..sup.2 on the target 45 is desired an intensity within the desired range can be achieved. Any shape illumination field may be created using the shaping optics 30 as long as a shaped beam 40 having a sufficient intensity level is provided to the target 45. It should be appreciated that although this discussion has been directed to the shape of the illumination field created in the embodiment where a shaped laser beam is provided, this discussion equally applies to other embodiments of the invention in which the plasma discharge is shaped. Thus, the shapes illustrated in FIGS. 2-4 and 8 illustrate both desired shapes for an illumination field in a shaped laser source embodiment, as well as desired plasma radiation field shapes, both in embodiments where some shaping is imparted by the laser source as well as embodiments discussed in greater detail below in which the plasma discharge is shaped. In a preferred embodiment, an arc shaped illumination field (or plasma radiation field) 35 is provided, as illustrated in FIG. 2. In an alternative embodiment, a ring shaped illumination field (or plasma discharge) 35 is provided, as illustrated in FIG. 3. As illustrated in FIG. 3, the illumination field (or plasma discharge) 35 includes plural segments making up the ring. For example, four arc shaped segments covering approximately 90.degree. (or optionally less or more in each segment) each may be used to create an approximately 360.degree. annular illumination field or a quadruple illumination field. In another example illustrated in FIG. 4, two stacked arcs are provided as the illumination field. It should readily be appreciated that FIGS. 2-4 also illustrate exemplary shaped radiation sources and radiation field shapes for use in accordance with the present invention. Continuing with the discussion of the shaped laser source embodiment, in another more preferred embodiment, the shaping optics 30 include a series of shaping apparatus, represented using reference numerals 115, 120, 130, which receive the output beam 20, flatten it to create a more uniform profile, and shape it to produce the shaped output beam 40, as illustrated in FIG. 6. In this embodiment, the uniformity of the beam is preferably first increased. Generally speaking, the output beam 20 may have a non-uniform distribution profile, such as a gaussian profile. A uniformizing lens 115, such as a gaussian to flat top lens, or alternatively a series of optics, are used to flatten the profile, such as to create a flat top profile. Preferably a stop lens 120 receives the beam and creates a desired shape to be received in the shaping lens or lenses 130. For example a pie-, or wedge-shaped profile may be imparted. The shaping lens 130 may include a single lens, or multiple components, such as plural lenses or mirrors, or combinations of lenses or mirrors. In one embodiment, an ogival aspheric lens 130 (or mirror) is used. An example using shaping mirrors is illustrated in FIG. 7. In that example, one or more shaping mirrors is used, such as mirrors incorporating a shaping curvature. As illustrated in FIG. 7, two shaping mirrors 150, 160 and a shaping lens 110 are used. In an alternative embodiment, the uniformity of the shaped output beam 40 is adjusted, such as by using a random phase plate 135. This example of uniformizing (i.e. flattening) the field is illustrated in FIG. 5, although it should be understood that flattening may be performed at any point in the optical processing upstream of the target 45. In an embodiment where it is desired to create an arc-shaped laser beam cross-section, both cylindrical and cubic aspheric optics are preferably used. In an embodiment where it is desired to create a generally line shaped laser beam cross-section, a cylindrical or cubic aspheric optic preferably is used. In an embodiment where it is desired to create a laser beam cross-section having an array of focused spots, it is preferred that an array of minilenses, a prism array or a grating be used. It should be appreciated that the shaping components can be selected with varying properties to produce the desired shaped illumination field 35. Likewise, a compound, or holographic lens can be used for any of the shaping lenses 110, 135. Such a lens has a varying diffractive pattern within the lens, which can be used to shape the laser light into any desired pattern. Such a lens also is well suited to produce an illumination field 35 having plural components, such as the illumination field 35 illustrated in FIG. 3. A preferred holographic illumination field (or radiation source) is illustrated in FIG. 8 in which an arc is composed of three overlapping segments 170, 180, 190. A multi-segment illumination field (and hence a multi-segment plasma radiation source) also can be used by providing more than one laser output beam 20. By way of example, any number of laser sources 10 can be used, each producing an output beam 20. This example is illustrated in FIG. 9. In the illustrated example, three laser sources 10 are provided, each producing an output beam 20. Each output beam 20 goes to shaping optics 30. Any form of shaping optics 30 can be used that can produce the desired illumination field. In the illustrated embodiment, separate shaping optics 30 are provided for each output beam. The respective shaped output beams 40 then proceed to the target 45. They may either go directly from the shaping optics 30 to the target 45, or may be directed by directing optics to the target 45. It should be understood that the output beams may also be directed to a single shaping optics system 30, as illustrated in FIG. 10. Directing optics 200 receive the respective output beams 20 and direct them such as by the use of mirrors or directing lenses to a desired transmission vector. Alternatively one or more of the laser sources 10 directs their respective output beam 20 directly to the shaping optics 30. In an alternate embodiment, as illustrated in FIG. 11, a single laser source 10 is used and the output beam 20 is split into plural output beams. A splitter 205 can split the beam in any number of ways. Likewise, plural splitters may be used. In the illustrated example, a first splitter splits the output beam 20 into two beams 21, 22. Second and third splitters 207, 208 in turn split each of beams 21 and 22 into two beams. Beams 23 and 24 exit splitter 207 and beams 25 and 26 exit splitter 208. These beams 23 through 26 are received in shaping optics 30, generating a shaped laser beam field 40. Further directing optics (not shown) also may be provided to direct segments of the output beam as desired. These output of splitters 205, 207, 208 split beams 21, 22, 23, 24, 25 and 26 are referred to as split beams or secondary output beams for discussion purposes. The laser source 10 may include various configurations. One example is shown in FIG. 12. A master oscillator and power amplifier 191 provides, for example, a series of laser pulses with, for example, a 700 picosecond or a 400 picosecond pulse duration with a 20 millijoules pulse energy. The laser beam is split using a splitter 193 and the two split beams go from the splitter to respective amplifiers 194 and 195. The amplifiers boost the pulse energy to 250 millijoules, although any suitable energy level may be selected. The amplified beams are combined, such as using a dichroic mirror 196 to produce a single pulse output beam 20 having a pulse energy of 500 millijoules. A single amplifier, or other combinations of amplifiers also may be used. Another example of the laser source is illustrated in FIG. 13. In that example, the laser source 10 provides two output beams 20, each of which is separately processed into a shaped output beam 40. It should be appreciated that in this embodiment, any number of output beams 20 may be created, resulting in a like number of shaped output beams 40. In the illustrated configuration, a master laser oscillator 310 provides a beam of pulses of 1 millijoule energy, for example to the power amplifier 320, which raises the power level to 120 millijoules, the resulting output is split four ways, such as by using a single splitter 325, or any suitable combination of splitting components. The split beams are further amplified, such as to 250 millijoules or any other suitable power level, in each of amplifiers 330, 340, 350, 360. The outputs of amplifiers 330 and 340 are combined into a single output beam 20, such as a beam having 500 millijoules laser pulses. Likewise, the outputs of amplifiers 330 and 340 are combined into a single output beam 20, such as a beam having 500 millijoules laser pulses. Optionally the two output beams 20 proceed to separate shaping optics 30, or alternatively are processed by a shaping optics system, either way, creating shaped output beam 40. The illumination field 35 of the shaped output beam 40 may have any desired pattern to excite any desired plasma radiation from target 45. An alternative embodiment of the system is provided in FIG. 14. In that embodiment a pulse generator 410 provides, for example, timing pulses at a 1 kHz. repetition rate. Delays 415 are used to create a pulse train to plural laser generators 420. In the illustrated example, each of the delays 415 is a 0.2 millisecond delay and the laser generators 420 each operate at a 1 kHz. repetition rate, although it should be understood that any repetition rate can be selected that is consistent with the delays 415 and pulse generator 410. The respective output beams 20 of the laser generators 410 are shaped in shaping optics 30. Alternatively, a single shaping optics system can be used. The shaped output beams 40 then illuminate the target 45. The multi-segment illumination fields may be in any desired shape or pattern. In one example, plural arcs are created, which are combined to form the ring field pattern in FIG. 3 or dual arc pattern in FIG. 4. Any of the above described examples, illustrated in FIGS. 9-14 may be used to produce such a segmented pattern. By way of illustration, the embodiment illustrated in FIG. 11 can be used, wherein each of the split beams 23 through 26 are used to generate a single arc field pattern (such as illustrated in FIG. 2). In combination, they can form the ring field pattern illustrated in FIG. 3. In another example, the embodiment illustrated in FIG. 13 is used to create the illumination field 35 illustrated in FIG. 4. Likewise, the output of amplifier 320, shown in FIG.13, may be further split to create more complex geometries, or the outputs of any of amplifiers 330, 340, 350 or 360 can be further split and amplified to create more complex geometries. The shaped laser beam 40 (as depicted in FIG. 1B) hits the target 45 producing radiation 50 in the wavelength (.lambda..sub.2) desired for imprinting the wafer 80 (and preferably in the desired shape, as described herein). The target 45 is selected for efficient conversion of the shaped output laser beam 40 (of wavelength .lambda..sub.1) to an output radiation field 50 at the appropriate wavelength (.lambda..sub.2) and being shaped in a shape corresponding to the shape of the illumination field 35. For example, if an arc-shape illumination field 35 is provided, the radiation field 50 (from the plasma source 45) is also arc shaped. Any size of target may be used, such as a stream of liquid (discussed in greater detail below), a gas, or a solid target (also discussed in greater detail below) which can be stationary or moving. The target 45 is also selected to generate minimal debris, which may degrade any of the components, such as mirrors or lenses in the system. It is also preferred that the target generate radiation 50 at a wavelength (.lambda..sub.2) that is well reflected by mirrors which may need to reflect it, such as an optional condenser 55 or camera 70. The target material also preferably produces peak radiation at the desired wavelength. The target material may be selected from solids, liquids or gasses, although gases generally are less preferred because of their lower densities. Examples of solid target materials include solid metals, solid xenon and ice. Ice is considered a good extreme ultraviolet target material because its emission spectrum peaks at wavelengths that may be desired in the extreme ultraviolet spectrum. An ice emission spectrum is illustrated in FIG. 15. As seen there, ice produces emission peaks at approximately 11.4 nm., 13 nm., and 15 nm. and 17.2 nm. which are at, or close to wavelengths that have been useful in producing integrated circuits, namely 11.4 nm. and 13.5 nm. These are desired wavelengths because high reflectively multilayer mirrors, such as Mo/Si mirrors, typically have maximum reflectivity at approximately 13.5 nm. and Be/Si mirrors have maximum reflectivity at approximately 11.4 nm. One or more of such mirrors can be used as components of a condenser 55 and/or the projection camera 70, as is well known in the art. In one embodiment the emission wavelengths of the ice target are shifted by controlling the temperature of the plasma produced. An exemplary target 45 using ice as the target material is illustrated in FIG. 16. The target 45 includes a block of ice 210, preferably in the form of a very thin sheet, which has an advantage of minimizing debris formation. However, any shape or thickness of ice 210 may be used. The ice preferably is cooled, such as by using a heat pump or liquefied gas, such as liquefied nitrogen. Cooling the ice serves to inhibit heat degradation and to minimize contamination of other components of the system by reducing the vapor pressure, thereby reducing debris. In one embodiment, a cooling material 220 is located in close proximity to the ice 210. By way of example, the cooling material 220 can be shaped like the ice 210 and superimposed upon it, such as in a stacked relationship, as illustrated. In a preferred embodiment, the cooling material 220 is a liquefied gas, such as liquid nitrogen. The liquid cooling material 220 is received in reservoir 230 which is in proximity to (or touching) the ice 210. The ice target 210 is preferably rotated in use so that the illumination field 35 progressively. strikes different portions of the ice target 210, avoiding excessive degradation of the ice target 210 at any particular location. An optional restoration unit 240 is provided to restore the ice, such as by shaving and/or re-freezing. Rotation shaft 250 provides the rotational force from a motor (not shown) so as to rotate the ice target 210. Other examples of suitable solid target materials are copper and tin. In an alternate embodiment, metallic strip 255, such as a strip, band or foil is used as the target material. In the embodiment illustrated in FIG. 17, the metallic strip 255 is in the form of a rollable web that is provided on a spool 260. In operation a take-up spool 265 operates to translate the strip 255 from spool 260, across the shaped output beam 40. In another embodiment, a liquid target is provided, as illustrated in FIG. 18. In this embodiment, a nozzle 270, connected to reservoir 280 emits a liquid clusters 290, for example xenon, in a stream. It should be understood that any nozzle 270 and reservoir source 280 arrangement can be used. For example, a supply line (not shown) may connect the source 280 with the nozzle, allowing for greater physical separation of the source 280 and the nozzle. Any reservoir 280 may be used, for example a gas canister (if a gaseous target is used) or a bin or hopper may be used. Any suitable nozzle 270 can be used. For example a jet-type nozzle may supply a jet or droplets. One example of the nozzle, as illustrated, is a two-dimensional nozzle, providing a three-dimensional cluster (or micropellet) field as the target. The shaped laser light 40 hits the clusters causing radiation emission in the desired spectrum, such as the extreme UV spectrum. In one embodiment, the liquid is a liquefied gas, such as xenon, or other inert gas. In such an embodiment, a diffuser 300 optionally is provided to collect the gas that forms as the clusters 290 exit the nozzle 270, thereby reducing gas emission. The liquid target material may optionally be treated with additives to control the emission spectrum. By way of example, zinc chloride may be used as additives. Alternatively, instead of droplets, clusters or a jet 290 as the target, solid micropellets can be provided in a gas jet (for example, helium or krypton) such as via a suitable nozzle 270, and are positioned as illustrated with reference number 290. Examples of suitable materials for the micropellets are tin and copper. A water emission spectrum is illustrated in FIG. 15 (above the ice emission spectrum discussed earlier). It is seen that the water emission spectrum includes emission peaks, for example, at approximately nm., 13 nm. and 14.5 nm. In one embodiment, the emission wavelengths of the water target are shifted by controlling the temperature of the plasma produced. In another embodiment, electric energy is applied to the target material after the application of the shaped laser beam. First, the shaped laser beam forms an ionized channel of energized target material. Then, electrical energy is applied to further energize the target material. Because the electrical current will tend to travel through the path of ionized material created by the laser beam, the laser beam determines and stabilizes the position, shape, and volume of the plasma discharge. With the application of the electrical discharge, the same power radiation field 50 (of wavelength .lambda..sub.2) can be produced with a lower intensity laser input, or higher power radiation field 50 can be achieved with the same laser source. An alternative example in which the plasma radiation is shaped near the target is illustrated in FIG. 19. As in other embodiments, shaped optics 30 optionally may be provided to produce a shaped laser output beam 40. Alternatively, shaping optics 30 to shape the laser output beam 40 are not provided. The output beam 40 (either shaped or not shaped) creates an illumination field at a plasma generating target material 690. The laser output beam 40 energizes the target material 690 within the illumination field, and some of this material may form plasma. Additional energy also is provided, as described in greater detail below, to energize the target material 690 within the shaped illumination field, resulting in a more powerful radiation field 50 (of wavelength .lambda..sub.2). In the present embodiment, the additional energy is provided by an electrical discharge. The shaped laser output beam 40 creates a stable channel of ionized matter within target material 690. An electrical current will tend to flow through the ionized channel because abundance of free charge particles in this channel. As illustrated in FIG. 19, laser source 10 is connected to a delay mechanism 610 and a switch 530 by a power line 600. Activation of the laser source 10 sends a signal through power line 600 directing to switch 530 to activate a power source 520. The delay mechanism 610 creates a pause that allows the laser output beam 40 to form an ionization channel prior to the electric discharge. The delay mechanism 610 is any sort of timer or device that delays the signal to switch 530 to create a pause between the application of the laser discharge 40 and the electrical discharge. For example, the delay mechanism 610 may be a computer programmed to idle for several processor cycles. After the pause caused by the delay mechanism 610, a signal reaches the switch 530 to activate electric power source 520. The switch 530 may be any type of device to control the power source 520. In a preferred embodiment, a solid state electronic switch is used. Power source 520 may be any controllable source of electrical power sufficiently strong to produce the arc discharge. For example, power source 520 may be some type of battery or electrical generator. In a preferred embodiment, power source 520 is an electrical energy source combined with a capacitor bank to increase the peak power of the electrical energy source. The capacitor bank stores electricity from the electrical power source when the switch 530 is open (creating an open circuit) and dispenses electricity when the switch 530 is closed (creating a closed circuit). Power source 520 is connected to two electrodes so that a current is passed through a target material located between the two electrodes. In a preferred embodiment illustrated in FIG. 19, the target material 690 is contained within plasma focus tube 680. Plasma focus tube 680 has a coaxial structure formed by an interior cylinder electrode 650, an exterior cylinder electrode 660, and a non-conductive base 640 which connects interior and exterior cylinder electrodes, respectively 650 and 660. Power source 520 is connected by an outside power line 630 to exterior cylinder electrode 660. Power source 520 is also connected to interior cylinder electrode 650 by an inside power line 620. While FIG. 19 illustrates interior cylinder electrode 650 connected to the positive terminal of power source 520 and exterior cylinder electrode 660 connected to the negative terminal, this configuration could be reversed without effecting the device. Once the external electric energy source 520 is activated by switch 530 after delay mechanism 610, electrical power is applied to the plasma focus tube 680, and a potential difference forms between internal cylinder electrode 650 and external electrode 660. As a result of this potential difference, a current 670 flows within the target material 690. As previously discussed, the current 670 tends to flow through the ionization channel formed above the end of the inner electrode by the illumination field of the shaped laser output beam 40 (.lambda..sub.1). Therefore, the shape of the plasma field may be highly regulated by the shape laser output beam 40. The target material 690 effected by the shaped illumination field will remain energized as long as shaped laser output beam 40 is applied. Therefore, the ionized channel created by the shaped laser output beam 40 is stable. The target material 690 is preferably a gas at low pressure (about 1 torr), and the particular gas to be used depends on the radiation output desired. For example, the use of hydrogen would result UV radiation, while lithium vapor, xenon and helium would produce, respectively, EUV, EUV and X-Ray radiation. However, it should be appreciated that various target materials may be employed, as previously discussed in other embodiments. It should also be appreciated that the electrical discharge may be applied prior to the laser pulse. In this embodiment, an electrical discharge is triggered, then a delay mechanism postpones the laser pulse. As a result of this sequencing, the electrical discharge first energizes the target material, then the shaped laser pulse 40 provides additional energy to form plasma within the illumination field. Thus the laser energy continues to regulate the shape and size of the plasma field. FIG. 20 diagrammatically illustrates an alternative system to form radiation field 50 without a laser input. The target 45 is replaced by a shaped radiation device 700 (the shaped radiation device is also diagrammatically illustrated in FIG. 1A as shaped radiation source 5). In a preferred embodiment, the shaped radiation device 700 has an electrical discharge that creates the shaped plasma discharge emitting radiation 50. When a continuous electrical current is passed through a target material between two electrodes, an arc discharge is formed by an electrical charge transfer along a narrow channel of high ion density. An electrical current with a sufficiently high power level will form plasma along the path of the current. Since plasma will only form along the path of the current, the arc discharge shapes the radiation field, such as discussed already regarding other embodiments of the invention. The electrical current can flow through a non-solid target material or along the surface of a solid target material. As in other embodiments of the invention, varying the target materials will vary the wavelength of the radiation output (.lambda..sub.2) FIG. 21 illustrates an exemplary embodiment that uses electrical energy to form the plasma in the target material. Switch 530 activates power source 520 to initiate the electrical discharge. Power source 520 is connected to electrodes 500 and 510 by power lines 540 and 550. While FIG. 21 shows power line 540 connected to a positive terminal of power source 520 and power line 550 connected to a negative terminal, this configuration is merely to illustrate the application of electrical power by power source 520 and not a requirement of the embodiment. The illustrated configuration could be reversed to show power line 540 attached to the negative terminal of power source 520 and power line 550 attached to the positive terminal. When switch 530 activates power source 520, a current flows between electrodes 500 and 510. Any type of electrodes may be used to form electrodes 500 and 510. Preferably, electrodes 500 and 510 are metallic pin electrodes that focus the electrical power into small points at the tips. These pin electrodes are widely commercially available. The current flows through a target material 560 between electrodes 500 and 510 to form an arc discharge 570. The shape and width of arc discharge 570 is influenced by many factors including the spacing of electrodes 500 and 510, the amount of power provided by power source 520, and the type of target material 560. In one preferred embodiment, electrodes 500 and 510 are 5 mm apart, and the width of the arc discharge 570 is 100 to 400 .mu.m. Arc discharge 570 can occur within a nonsolid material or along the surface of a solid material. Target material 560 is selected to produce the desired radiation output, as previously discussed in other embodiments. In one embodiment plasma radiation is created by arc discharge 570 through Li vapor, Xe or He gas at 1 to 260 Torr. In another embodiment, the arc discharge 570 passes along the surface of a solid material such as tin or copper. It should be appreciated that other target materials may used to achieve the desired radiation output. The arc can be formed, for example, by a laser pre-pulse for use as an arc 35 between the electrodes, as discussed in the previous embodiment. FIG. 22 illustrates preferred embodiment of a radiation device 700 and plasma focus 710 that functions without laser input. In this embodiment, shaped radiation device 700 has inner cylinder electrode 650 and outer cylinder electrode 660, and the target material 690 is positioned between the inner and outer cylinder electrodes, respectively 650 and 660. When electrical energy is applied to the radiation device 700, electric current 670 flows through the target material 690. The electrical current also generates a magnetic field, which in turn interacts with the electrical current to produce a force that serves to push the current sheet and ionized gas towards the open end of the coaxial electrodes. Eventually this ionized gas collapses into a very hot plasma formed in front of the inner electrode, forming the plasma focus 710. It can be appreciated from the previous discussions that various target materials 690 may be employed to achieve desired radiation outputs. FIG. 22 illustrates the inner cylinder electrode 650 with a positive charge and the outer cylinder electrode 660 with a negative charge. This configuration leads to the electric current 670 flowing from the inner cylinder electrode 650 to the outer cylinder electrode 660. Alternatively, the relative charges can be reversed so that the electrical current 670 will flow through target materials 690 from the outer cylinder electrode 660 to the inner cylinder electrode 650. This change will not effect the creation a plasma discharge or the resulting shaped radiation output 50. With sufficient power, electric current 670 generates a plasma focus 710. This plasma focus 710 forms in a straight line or has an elliptical or football shape. The shape of the plasma field is influenced by several factors, including the shape and size of inner and outer cylinder electrodes 650 and 660, the attributes of the target materials and the power of the electrical discharge. When viewed from the tip or short end, the plasma focus 710 forms a point focus that emits point radiation 51. Alternately, the plasma focus 710 forms a line or arc focus when viewed from the long side. The shaped radiation output 50 is taken from discharge viewed from the long side. The output radiation 50 of wavelength .lambda..sub.2 proceeds to illuminate the wafer. Various intermediary components preferably are provided between the target material and the wafer 80, although it should be understood that any apparatus (sometimes characterized as a condenser and camera) may be used that provides the output radiation 50 to the wafer 80 in a way that the wafer 80 (coated with photoresist) is imprinted with a pattern provided by a mask 60. As illustrated in FIGS. 1A, 1B and 20, a condenser 55 collects the output radiation 50. Any condenser optics or arrangement may be used that suitably directs the output radiation 50 to the mask 60 in the desired illumination pattern. Preferably the output radiation is shaped to be optimized for optical coupling with the condenser optics. Preferably, the condenser 55 is used to magnify the illumination pattern. In one embodiment, the condenser optics scan the output radiation to progressively illuminate the entire mask. Any form of mask may be used, such as a reflective or pass-through mask, as is known in the art. Optionally, imaging optics 70 may be provided between the mask 60 and the wafer 80, such as a photolithography camera arrangement. Thus, it is seen that a system for directing emitted radiation to a wafer is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the preferred embodiments which are presented in this description for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow. It is noted that equivalents for the particular embodiments discussed in this description may practice the invention as well.
053965264	claims	1. An apparatus for removing a plurality of keys from a grid of a fuel assembly after inserting fuel rods in said grid, which is formed by a plurality of straps of a thin longitudinal strip form intersecting at right angles to each other to form a plurality of grid cells, and having dimples formed on one adjacent pair of walls of said grid cells and springs formed on opposing pair of walls of said grid cells, said grid having an arrangement of said dimples and springs which are rotationally symmetrical in four quadrants in a whole plan view, wherein said keys are inserted in said grid in a longitudinal direction of said straps through opening sections formed near intersections of said plurality of straps, said apparatus comprising: (a) at least one key rotation means, which rotates one half set of said plurality of keys in one rotational direction about a key axis, and the other half set of said plurality of keys in an opposite rotational direction; and (b) at least one key moving means, for moving said plurality of keys in the direction of the key axis. 2. An apparatus as claimed in claim 1, wherein said key rotation means is a key rotation device comprising: a plurality of engaging members for engaging with ends of said keys; link members at right angles to said key axis operatively connected to said engaging members; and rotation devices for operating said link members to rotate said engaging members; and said key moving means is a key moving device comprising: a plurality of pairs of openable or closable clamping members for clamping said keys; link members disposed on said clamping members at right angles to the key axis; closing/opening devices for opening or closing said clamping members by operating said link members; and driving devices for moving said clamping members in the direction of the key axis. 3. An apparatus as claimed in claim 1, wherein said key rotation means is a key rotating device comprising: a plurality of engagement members for engaging with ends of said keys; at least one belt means engaging with said engaging members; and rotating motor means for operating said belt means to rotate said engaging members; and said key moving means comprises: a plurality of pairs of openable or closable clamping members for clamping said keys; link members disposed on said clamping members at right angles to the key axis; closing/opening devices for opening or closing said clamping members by operating said link members; and driving devices for moving said clamping members in the direction of the key axis. 4. An apparatus as claimed in claim 3, wherein said key rotating device comprises: two of said belt means for engaging with a set of eight of said engaging members and with a remaining set of eight of said engaging members; two unidirectional clutches, one of said unidirectional clutches having a clockwise rotational direction and the other one of said unidirectional clutches having a counter clockwise rotational direction for engaging with each of said belt means; a driving shaft attached to said two unidirectional clutches; and said rotating motor means for operating said driving shaft in clockwise and counter clockwise directions. 5. An apparatus as claimed in claim 1, wherein said key rotating device comprises: a plurality of engagement members for engaging with ends of said keys; at least one belt means engaged with said engaging members; rotating motor means for operating said belt members to rotate said engaging members; and said key moving means is a key mover device comprising: a pair of revolving rollers disposed opposite to and at right angles to the key axis so as to clamp said keys and move said keys in the key axis direction; and reciprocating cylinder means for moving said revolving rollers toward each other or away from each other. 6. An apparatus as claimed in claim 5, wherein said key rotating device comprises: two of said belt means for engaging with a set of eight of said engaging members and with a remaining set of eight of said engaging members; two unidirectional clutches, one of said unidirectional clutches having a clockwise rotational direction and the other one of said unidirectional clutches having a counter clockwise rotational direction for engaging with each of said belt means; a driving shaft attached to said two unidirectional clutches; and said rotating motor means for operating said driving shaft in clockwise and counter clockwise directions. 7. An apparatus as claimed in claim 1, wherein said key rotation device comprises: a plurality of engaging members for engaging with ends of said keys; link members disposed at right angles to said key axis operatively connected to said engaging members; and rotation devices for operating said link members to rotate said engaging members; and said key mover device comprises a pair of revolving rollers disposed opposite to and at right angles to the key axis so as to clamp said keys and move said keys in the key axis direction; and reciprocating cylinder means for moving said revolving rollers toward each other or away from each other. 8. An apparatus as claimed in claim 1, wherein said apparatus comprises: a main post having a U-shaped receptor for holding said grid; and a closure member for firmly holding said grid in said U-shaped receptor; wherein said key rotation means is disposed on each of moving blocks provided on four edges defined by three edges of the main post and one edge of the closure member and said key moving means is disposed on each of moving blocks disposed adjacent to two edges of said four edges. 9. An apparatus as claimed in claim 1, wherein said apparatus comprises: a main post having a U-shaped receptor for holding said grid; and a closure member for firmly holding said grid in said U-shaped receptor; wherein said key rotation means is disposed on each of moving blocks provided on four edges defined by three edges of the main post and one edge of the closure member. 10. An apparatus as claimed in claim 5, wherein said key mover device is provided with an engaging device which pulls out inner keys of said plurality of keys by engaging with one end of said inner keys and moving together with said moving block for a specific distance. 11. An apparatus as claimed in claim 7, wherein said key mover device is provided with an engaging device which pulls out inner keys of said plurality of keys by engaging with one end of said inner keys and moving together with said moving block for a specific distance.
048667447	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 4, X-ray beam 34 emitted from X-ray tube 30 has its opposite edges defined by upper and lower collimators 32 and 38, respectively, to provide a fan-shaped beam pattern having a somewhat small width in slice direction 1 as indicated by dash-dot lines. X-ray beam 34 is input to X-ray detector 40 where the intensity of the X-ray beam is converted to an electric signal. Between X-ray tube 30 and X-ray detector 40 a bed, not shown, is located which extends in slice direction 1 and on which patient 36 lies. X-ray tube 30 and X-ray detector 40 are each located opposite to the patient such that they are rotated around rotation axis 3 with the patient as a center, noting that the rotation axis through the patient is parallel to the slice direction. In X-ray detector 40, as shown in FIGS. 5 and 6, plate-like electrodes 42 are arranged, as an array of detection elements, in a parallel fashion, such that they are located in a direction substantially parallel to slice direction 1 and rotation axis 3. Electrodes 42 are disposed in closed housing 44 where, for example, an xenon gas is sealed. Upon the entry of an X-ray into an area between the adjacent electrodes, the xenon gas is ionized to yield xenon ions and electrons. The resultant ion current is detected by the electrodes where the incident X-ray is converted to an electric signal. Window 46 is provided on an X-ray entrance surface of detector 40 and is arcuately curved in fan-out direction 2 with the focus of X-ray tube 30 at its center. The detection signals of X-ray detector 40, after having been converted to a digital signal, are input to an image processing device, not shown, to reconstruct a tomographic image This reconstruction may be implemented by a known method. This method is disclosed, for example, in U.S. Pat. Nos. 4,206,359, 4,212,062 or 4,219,876. Scattering beam eliminating member 50 is comprised of plate-like grids 52 and X-ray transmission (penetrating) areas 54, each of which is located between the grids. Grids 52 are made of an X-ray absorbing metal, i.e., X-ray transmission inhibiting metal, such as lead, molybdenum or tungsten X-ray transmission areas 54, on the other hand, are made of an X-ray transmitting metal, such as aluminum. Scattering beam eliminating member 50 can be formed as follows: For example, lead and aluminum plates are stacked as a 20- to 30-layered structure and mutually bonded to provide a block. In order for the respective plates to be arcuately curved in the width direction with the focus of X-ray tube 30 at its center, the aforementioned block is bent such that the outer arcuate surface 56 is formed with the same curvature as that of window 46 of X-ray detector 40. Scattering beam eliminating member 50 is fixedly bonded to X-ray detector 40 with the outer arcuate surface face 56 placed in intimate contact with window 46 of X-ray detector 40. In this way, the X-ray exit surface (outer arcuate surface 56) of scattering beam eliminating member 50 is curved with substantially the same curvature as that of window 46 (X-ray entrance surface) of X-ray detector 40 and bonded to window 46 of X-ray detector 40 to provide an integral structure. As a result, no displacement due to, for example, oscillation, occurs at that bonded area, whereby it is possible to prevent a variation in sensitivity characteristics at the respective cell of X-ray detector 40, energy characteristics or channel characteristics such as linearity. Scattering beam eliminating member 50 is, for example, 2 to 3 mm in height in the X-ray irradiation direction, 20 to 30 mm in width in slice direction 1 and 600 to 1000 mm in length in fan-out direction 2. Grids 52 are 30 to 80 .mu.m each in thickness and arranged at a pitch of 100 to 200 .mu.m which is a thickness of the X-ray transmission area 54. The operation of the device so arranged will be described below. X-ray 34 from X-ray tube 30 is narrowed through upper collimator 32 to a predetermined width (slice width S) and irradiated onto patient 36. The direct component of the X-ray beam transmitted through patient 36 passes through X-ray transmission areas 54 between grids 52 into X-ray detector 40. However, a scattering beam portion (see scattering beam 26 in FIG. 3) produced in slice direction 1 of X-ray beam 34 at the location of patient 36 impinges onto grids 52 and is absorbed there, since the scattering beam portion is never parallel to grids 52, so that it cannot therefore enter into X-ray detector 40 through grids 52. For this reason, even if the slice width S of X-ray 34 is adequately narrowed the amount of scattering beam incident to X-ray detector 40 will not be increased. The tomographic image of patient 36 which has been reconstructed based on transmission X-ray information so detected by X-ray detector 40 is free from any influence from the scattering beam, thus adequately improving a spatial resolution. It is therefore possible to obtain an image very useful for medical diagnosis. In this embodiment, grids 52 are arranged in only slice direction 1, not in fan-out direction 2, the reason for which is as follows. In fan-out direction 2, the channel spacing of X-ray detector 40 is about 1 mm and, according to the current grid array technique, it is possible to insert about 50 plate-like grids for that spacing of 1 mm. If one of the plate-like grids is missing in any one of a plurality of channels of X-ray detector 40, then a variation of 1/50 (2%) in uniformity occurs among all the channels. In the so-called third generation X-ray CT apparatus, a interchannel uniformity of below 0.05 to 0.2% is required and thus a variation of 2% fails to satisfy the aforementioned requirement. The presence of such a defect necessarily produces an artifact on the image. In the slice direction, on the other hand, the beam width on the X-ray entrance surface of the X-ray detector for a slice width of 10 mm is about 20 mm within which about 1000 plate-like grids are arranged. In this case, a variation in the aforementioned uniformity corresponding to one plate-like grid is 0.1%, an allowable value range. A plurality of grids is adequately implementable only in the slice direction without impairing the interchannel uniformity. This offers an effective means for enhancing a spatial resolution on the image. Needless to say, this invention can also be applied to a solid-state X-ray detector, not to mention a gas detector. In an X-ray CT apparatus employing such a solid-state X-ray detector an array of scintillation elements are located in a fan-out direction and a collimator plate made of a material which permits no ready transmission of an X-ray is located between the respective scintillation elements. The X-ray penetrating the patient is converged by the collimator plates and incident to the scintillation elements. Upon the incidence of the X-ray to the scintillation element, light is induced and converted to an electric signal by a corresponding diode in an array of photodiodes. The scattering beam eliminating device of this invention can be intimately bonded to the X-ray entrance surface of the solid-state detector, whereby it is possible to eliminate the scattering beam.
055106650	summary	TECHNICAL FIELD The present invention pertains to the field of optoelectronic devices. In particular, this invention pertains to an optoelectronic element comprised of a light source means, an optical control means and a photocell means intimately coupled together so that the optoelectronic element behaves like an active circuit element, such as a transistor or a diode. BACKGROUND ART It is well known that optical energy can be absorbed in a semiconductor material if the photon energy is greater than the band-gap energy of the semiconductor material. This phenomenon, known as the photovoltaic or photoconductive effect, occurs when the photons absorbed by the semiconductor material generate electron-hole pairs that produce a potential difference or increased conductance across the p-n junction of the semiconductor. The phenomenon has been used in the prior art to create a variety of hybrid optical/electrical devices. For a more detailed explanation of this phenomenon and its application, reference is made to J. Wilson and J. Hawkes, Optoelectronics: An Introduction, pgs. 286-327, Prentice Hall (1983). Most well known among the uses of the photovolatic/photoconductive effect is the use of a photodiode for generating electrical power, e.g., solar cells converting sunlight to electricity. Other variations of the basic photodiode include the avalanche photodiode and the phototransistor, both of which internally amplify the current flow across the p-n junction of the photodiode. The photodiode is also used as a photodetector for detecting the presence or absence of optical energy, e.g. the light beam switch in an elevator door or a photochopper wheel. Optoisolators make use of the photodiode and a photoemmissive device (e.g., a light emitting diode or LED) to convert electrical energy to photon energy and back again for the purpose of decoupling a power source or an electrical signal. For example, U.S. Pat. No. 4,695,120 shows the combined use of optoisolators to electrically isolate all of the signals to an integrated circuit and a photodiode to provide the electrical power for the integrated circuit. A detailed description of the various types of optoelectronic devices that are available in the prior art is provided in Optoelectronics Fiber-Optic Applications Manual, Hewlett Packard (1981), and Optoelectronics: Theory and Practice, Texas Instruments (1978). Another phenomenon that has been put to use in optical and hybrid optical/electrical circuit devices is the atomic level relationship between electrical fields and optical transmisivity, sometimes referred to as photorefractivity. Photorefractive substances exhibit a change in their index of refraction in response to the application of an electrical field. The most well known of photorefractive materials is the liquid crystal display or LCD. For a more detailed explanation of this phenomenon and its application, reference is made to Photorefractive Materials and Their Applications, Topics in Applied Physics, Vols. 61 and 62, Gunter, P. and Huignard, J. (eds.) (1989). For purposes of understanding the wide variety of electrical/optical devices that are available in the prior art with respect to the present invention, it is helpful to categorize present hybrid electrical/optical circuit devises based upon the nature of their inputs and outputs. Primary electrical/optical devices convert photon energy (input) to electrical energy (output) or vice-versa. Examples of primary types of hybrid electrical/optical devices include the photodiode (optical input/electrical output), the light emitting diode (electrical input/optical output) and the semiconductor laser (electrical input/optical output). Intermediary or secondary electrical/optical devices have a common input and output, but use either photon energy or electrical energy as part of an intermediary step internal to the device. Examples of intermediary or secondary types of hybrid electrical/optical devices include solid state image intensifiers and electroluminiscient devices (optical input/output, electrical intermediary) and photoisolators and optocouplers (electrical input/output, optical intermediary). Of interest for purposes of the present invention are those secondary or intermediary hybrid electrical/optical devices that utilize photorefractive materials as part of the intermediary step. Prior art application of photorefractive materials to hybrid electrical/optical devices has been limited to secondary devices having optical inputs and outputs with an electrical intermediary. The most prevalent uses of photorefractive materials include optical amplifiers, waveguides and light valves, such as liquid crystal light valves, which are used as part of an optical computing network. For example, U.S. Pat. No. 4,764,889 describes the use of optically nonlinear self electro-optic effect devices as part of an optical logical arrangement. U.S. Pat. No. 4,818,867 describes the use of an optical shutter on the output of an optical logic element. An overview of the various types of hybrid electrical/optical devices used in connection with prior art optical computing networks is provided in Feitelson, D., Optical Computing (1988). Although the use of photorefractive materials is well known as part of the intermediary step for electrical/optical hybrid devices having optical inputs and outputs with an electrical intermediary, photorefractive materials have not been used in connection with other types of electrical/optical hybrid devices having electrical inputs and outputs with an optical intermediary. The optical intermediaries of photoisolators and optocouplers are designed for the optimum transfer of photon energy between the photoemissive device and the photovoltaic/photoconductive element and, hence, there is no need for intermediary optical control in such devices. Accordingly, it would be desirable to provide an optoelectronic device that makes use of photorefractive materials as part of an optical intermediary for electrical/optical hybrid devices having electrical inputs and outputs that could take advantage of a modulated transfer function of the photon energy in such a device. SUMMARY OF THE INVENTION In accordance with the present invention, an optoelectronic active circuit element is comprised of a light source means, a photocell means and an optical control means. The light source means has at least one light emitting surface for emitting light energy in a specified frequency bandwidth and the photocell means also has at least one light collecting surface for absorbing light energy. The optical control means is intimately interposed between the light emitting surface of the light source means and the light collecting surface of the photocell means for controlling the emitted light energy that may be absorbed by the photocell means in response to an input signal. The light optical means is capable of either frequency or amplitude modulation of the emitted light energy as a result of changes in the indices of refraction and/or polarization of a photorefractive material. In the preferred embodiment, the photorefractive material is a liquid crystal display material or a lead lantium zirconium titinate material capable of fast switching speeds in response to small changes in an electrical input signal. In the preferred embodiment of the present invention, the light source means is self-powered by the use of a light emitting polymer as the light source means. The light emitting polymer is comprised of a tritiated organic polymer to which at least one organic phosphor or scintillant is bonded. Because the electrical energy generated by the preferred embodiment is dependent upon the rate of emission of photons from the light emitting polymer (which is in turn dependent upon the rate of beta-emissions from the radioisotope used to activate the light emitting polymer), the amount of photon energy available is essentially constant and determinable and is isolated from any electrical noise in the system. In addition to providing a unique source of electrical energy, as well as electrical signals, for CMOS, NMOS and other low power types of electronic circuitry, the output stability and isolation of the present invention makes it ideally suited for applications that require a voltage or current sources that have high signal to noise ratios. Accordingly, a primary objective of the present invention is to provide an optoelectronic active circuit element that includes an optical control means for controlling the amount of electrical energy generated by a photovoltaic cell by controlling the amount of light that is received by a photovoltaic cell from a light source. Another objective of the present invention is to provide an optoelectronic device that makes use of photorefractive materials as part of an optical intermediary for electrical/optical hybrid devices having electrical inputs and outputs and takes advantage of a modulated transfer function of the photon energy in such a device. A further objective of the present invention is to provide an optoelectronic active circuit element wherein the light source means is self-powered by the use of a light emitting polymer as the light source means. Still another objective of the present invention is to provide an optoelectronic active circuit element that includes an optical control means capable of both amplitude and frequency modulation of the photon energy transmitted through the optical control means. A still further objective of the present invention is to provide an optoelectronic active circuit element having an optical control means comprised of an interference filter means and a photorefractive material in combination. These and other objectives of the present invention will become apparent with reference to the drawings, the detailed description of the preferred embodiment and the appended claims.
	abstract	An embodiment of the invention relates to a radiation detector which includes a plurality of radiation detector modules arranged adjacent to one another with in each case one scintillation element with a radiation inlet surface aligned transversely with respect to a main direction of a radiation, and light detector arrangements arranged transversely with respect to the radiation inlet surfaces of the scintillation elements. In the process of at least one embodiment, one light detector arrangement is arranged between two scintillation elements and has two light inlet surfaces which point away from one another, of which one is associated with a first scintillation element and one is associated with a second scintillation element. Furthermore, at least one embodiment of the invention relates to a light detector arrangement, a production method for a radiation detector according to at least one embodiment of the invention and/or an imaging system.
	description	The present invention relates to an ion implanting apparatus and an ion implanting method. Conventionally, when manufacturing a semiconductor device or the like, there has been widely used an ion implanting technique as a method for introducing impurities into a semiconductor substrate, a semiconductor layer, or the like. In a conventional ion implanting technique, in order to implant desired atoms/molecules with a predetermined concentration into a target object such as a semiconductor substrate or a semiconductor layer, a positively charged ion beam is irradiated onto a desired spot of the target object. Accordingly, positively charged ions are irradiated onto the target object and secondary electrons are emitted from the target object, so that the target object is largely charged up and thus charge-up damage may occur thereon. For example, if ions are irradiated onto a polysilicon gate electrode layer on a gate insulating film in order to dope impurities into the polysilicon gate electrode layer, a large quantity of secondary electrons are emitted from the polysilicon layer and positive charges are accumulated on a surface of the polysilicon layer, and positive charges of the implanted ions are added thereon, whereby a large quantity of negative charges are accumulated on the gate insulating film. Meanwhile, if ions are implanted into a n-well in order to form a p-type source/drain region, a large quantity of positive charges are accumulated on a surface of the n-well for the same reason, thereby causing a breakdown of the gate insulating film. Therefore, product failure has often occurred in a p-channel MOS transistor. Meanwhile, disclosed in Patent Document 1 is an ion implanting apparatus including a processing chamber having a plurality of exhaust ports; a holding table installed within the processing chamber, for holding a target object; a shower plate disposed to face the target object and having a plurality of gas discharge holes; and a microwave antenna. Patent Document 1: Japanese Patent Laid-open Publication No. 2005-196994 Patent Document 1 does not disclose a charge-up damage occurring in a target object, particularly product failure occurring in a p-channel MOS transistor. Accordingly, a technical object of the present invention is to provide an atom/molecule implanting technique capable of preventing charge-up damage, and an object of the present invention is to provide an ion implanting apparatus and an ion implanting method capable of suppressing charge-up damage. In accordance with a first aspect of the present invention, there is provided an ion implanting apparatus including: a depressurizable processing chamber; a plasma excitation unit for exciting plasma within the processing chamber; a holding table installed in the processing chamber, for holding a target substrate; a conductive member disposed so as to face the holding table in the processing chamber, having a portion through which the plasma is transmitted toward the holding table; and an RF power application unit for applying RF power for substrate bias onto the target substrate held by the holding table, and the conductive member is electrically grounded with respect to a frequency of the RF power. In accordance with a second aspect of the present invention, in the first aspect, the plasma excitation unit may include a unit for supplying plasma excitation power to an inside of the processing chamber and a unit for supplying a plasma excitation gas to the inside of the processing chamber. In accordance with a third aspect of the present invention, in the second aspect, the plasma excitation gas may include a source gas for ions to be implanted into the target substrate. In accordance with a fourth aspect of the present invention, in the second or the third aspect, a frequency of the plasma excitation power may be in a range of a frequency of a microwave. In accordance with a fifth aspect of the present invention, in any one of the second to the fourth aspects, the unit for supplying the plasma excitation power to the inside of the processing chamber may includes a microwave source; a flat plate antenna; and a unit for transmitting a microwave from the microwave source to the antenna, and the antenna may be disposed to face the holding table with a dielectric plate therebetween, and the microwave radiated from the antenna may propagate through the dielectric plate and irradiate the plasma excitation gas in the processing chamber so as to generate plasma. In accordance with a sixth aspect of the present invention, in any one of the second to the fifth aspects, the unit for supplying the plasma excitation gas may include a plurality of gas paths for discharging the plasma excitation gas into the processing chamber via a gas supply port and an inside of the dielectric plate, and the plasma may be generated in a space where the plasma excitation gas is discharged into the processing chamber from the dielectric plate or in its vicinity. In accordance with a seventh aspect of the present invention, in any one of the second to the fifth aspects, in the processing chamber, an electron density of the plasma in a space opposite to the holding table with respect to the conductive member may be higher than a cut-off density determined by ω2m∈0/e2 where an angular frequency of the plasma excitation power is ω, a permittivity in vacuum is ∈0, mass of an electron is m, and an elementary electric charge is e. In accordance with an eighth aspect of the present invention, in the fourth or the sixth aspect, the plasma excitation gas may include a fluoride gas, and a pressure within the processing chamber may be set such that an electron density of the plasma in a space opposite to the holding table with respect to the conductive member is maintained higher than a cut-off density determined by ω2m∈0/e2 where an angular frequency of the microwave is ω, a permittivity in vacuum is ∈0, mass of an electron is m, and an elementary electric charge is e. In accordance with a ninth aspect of the present invention, in the sixth aspect, within the processing chamber, an electron density of the plasma in a space opposite to the holding table with respect to the conductive member and at a position where the plasma is in contact with the dielectric plate at a side of the conductive member with a plasma sheath therebetween may be higher than a cut-off density determined by ω2m∈0/e2 where an angular frequency of the microwave supplied to the antenna is ω, a permittivity in vacuum is ∈0, mass of an electron is m, and an elementary electric charge is e. In accordance with a tenth aspect of the present invention, in the sixth or the ninth aspect, the formula 1 may be expressed as follow:√{square root over (ne2/(m∈0))} [Formula 1] When a plasma angular frequency determined by the formula 1 (where, n is an electron density of plasma at a position where the plasma is in contact with the dielectric plate at a side of the conductive member with a plasma sheath therebetween, ∈0 is a permittivity in vacuum, m is mass of an electron, and e is an elementary electric charge) is ωpe and an angular frequency of the microwave supplied to the antenna is ω, a distance between the dielectric plate, the formula 2 may be expressed as follow:c/√{square root over (ωpe2−ω2)} [Formula 2] A distance between the dielectric plate and the conductive member may be longer than a microwave penetration depth determined by the formula 2 (here, c is speed of light in vacuum). In accordance with an eleventh aspect of the present invention, in the sixth, the ninth or the tenth aspect, the formula 3 may be expressed as follow:√{square root over (ne2/(m∈0))} [Formula 3] When a plasma angular frequency determined by the formula 3 (where n is an electron density of plasma at a position where the plasma is in contact with the dielectric plate at a side of the conductive member with a plasma sheath therebetween, ∈0 is a permittivity in vacuum, m is mass of an electron, and e is an elementary electric charge) is ωpe and an angular frequency of the microwave supplied to the antenna is ω, the formula 2 may be expressed as follow:c/√{square root over (ωpe2−ω2)} [Formula 4] A distance between the dielectric plate and the conductive member may be three or more times longer than a microwave penetration depth determined by the formula 4 (here, c is speed of light in vacuum). In accordance with a twelfth aspect of the present invention, in any one of the fifth to the eleventh aspects, the antenna may be a radial line slot antenna. In accordance with a thirteenth aspect of the present invention, in any one of the first to the twelfth aspects, the conductive member may be electrically grounded with respect to a direct current. In accordance with a fourteenth aspect of the present invention, in any one of the first to the thirteenth aspects, at least a portion of inner walls of the processing chamber in contact with the plasma and a surface of the conductive member may be coated with at least one of metal oxide and metal nitride. In accordance with a fifteenth aspect of the present invention, in any one of the first to the fourteenth aspects, the conductive member may include therein a unit through which a temperature control medium flows. In accordance with a sixteenth aspect of the present invention, in any one of the first to the fifteenth aspects, a period of the frequency of the RF power may be longer than a time during which implantation atom ions or implantation molecule ions released from the plasma toward a plasma sheath formed on a surface of the target substrate reaches the target substrate. In accordance with a seventeenth aspect of the present invention, in the sixth aspect and any one of the ninth to the sixteenth aspects, a porous ceramic member may be installed at each gas discharge position of the plurality of gas paths, and the plasma excitation gas may be introduced into the processing chamber from the porous ceramic member. In accordance with an eighteenth aspect of the present invention, in the sixth aspect and any one of the ninth to the seventeenth aspects, each gas discharge hole of the plurality of gas paths may have a diameter two or less times larger than a thickness of a sheath formed between the dielectric plate and the plasma, and the plasma excitation gas may be introduced into the processing chamber from the gas discharge hole. In accordance with a nineteenth aspect of the present invention, in any one of the first to the eighteenth aspects, the ion implanting apparatus may further include a unit for cooling the holding table. In accordance with a twentieth aspect of the present invention, in any one of the first to the nineteenth aspects, the holding table may include therein a unit through which cooling medium flows. In accordance with a twenty-first aspect of the present invention, in any one of the first to the twentieth aspects, there is provided an ion implanting method for performing an ion implantation by using the ion implanting apparatus. In accordance with a twenty-second aspect of the present invention, in the twenty-first aspect, the ion implantation may be performed plural times by applying the RF power in the form of pulses. In accordance with a twenty-third aspect of the present invention, in the twenty-second aspect, the pulse may have a predetermined width and interval and the interval of the pulse may be longer than the product of a reciprocal of a ratio of the number of electrons to the total number of ion electric charges in the plasma for a unit volume, a coefficient of secondary electrons emitted from the target substrate and the width of the pulse. In accordance with a twenty-fourth aspect of the present invention, in any one of the twenty-first to the twenty-third aspects, a plasma excitation gas may be a fluoride gas of atom ions to be implanted or a mixed gas made by diluting the fluoride gas of the atom ions to be implanted with a rare gas. In accordance with a twenty-fifth aspect of the present invention, in any one of the twenty-first to the twenty-fourth aspects, a plasma excitation gas may be a gas selected from BF3, PF3 and AsF3 or a mixed gas made by diluting a gas selected from BF3, PF3 and AsF3 with at least one kind of rare gas selected from Ar, Kr and Xe. In accordance with a twenty-sixth aspect of the present invention, in the twenty-fourth or the twenty-fifth aspect, the target substrate may include silicon and the target substrate may be cooled to a temperature lower than a volatilization temperature of a silicon fluoride under a pressure of the processing chamber. In accordance with a twenty-seventh aspect of the present invention, there is provided a semiconductor device manufactured by using the ion implanting apparatus as described in any one of the first to the twentieth aspects. In accordance with a twenty-eighth aspect of the present invention, there is provided a semiconductor device manufactured by using the ion implanting method as described in any one of the twenty-first to the twenty-sixth aspects. In accordance with a twenty-ninth aspect of the present invention, there is provided a semiconductor device manufacturing method including a process for performing ion implantation according to the ion implanting method as described in any one of the twenty-first to the twenty-sixth aspects. In accordance with the present invention, an ion implanting apparatus and an ion implanting method capable of suppressing charge-up damage can be obtained. In particular, in accordance with the present invention, product failure which may occur in manufacturing a p-channel MOS transistor may be greatly reduced and thus production yield can be improved. 101: Exhaust port 102: Processing chamber 103: Target substrate 104: Holding table 105: Gas discharge hole 106: Shower plate 107: Seal ring 108: Cover plate 109: Seal ring 117: Plasma excitation gas supply port 118: Supply hole 110: Space 111: Slot plate 112: Wavelength shortening plate 113: Coaxial waveguide 123: Metal plate 114: Cooling path 115: Ground plate 120: Medium path 121: Transmission window 122: RF power supply 124: Porous ceramic layer 125: Ring-shaped insulating member Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a microwave plasma ion implanting apparatus in accordance with a first embodiment of the present invention. The illustrated microwave plasma ion implanting apparatus includes a processing chamber 102 for exhausting gases via a plurality of exhaust ports 101 and a holding table 104 for holding a target substrate 103 in the processing chamber 102. The processing chamber 102 is manufactured by using wall members made of an Al alloy (Al containing Zr and Mg). It is desirable to form a firm protective film on inner surfaces of the wall, particularly on a portion exposed to plasma since the portion can be damaged by a large quantity of ions irradiated thereto from the plasma. In the present embodiment, the wall surfaces are coated with a dense nonporous Al2O3 protective film having a thickness of 0.5 μm formed by anodic oxidation using a non-aqueous solution. The protective film is not limited thereto, so it may be, e.g., a thermally sprayed film of Y2O3, a film formed by a sol-gel method, or an Al2O3 protective film on which an Y2O3 film is additionally formed. In order to exhaust the processing chamber 102 uniformly, the processing chamber 102 includes a ring-shaped space around the holding table 104 and the plurality of exhaust ports 101 are axial-symmetrically arranged at an equal distance with respect to the target substrate so as to communicate with the ring-shaped space. With the arrangement of the exhaust ports 101, it is possible to exhaust a gas of the processing chamber 102 via the exhaust ports 101 uniformly. Installed at an opening in the top part of the processing chamber 102 is a plate-shaped shower plate 106 made of a dielectric alumina having a dielectric constant of about 9.8 and a low microwave dielectric loss (a dielectric loss of about 1×10−4 or less) and provided with a number of openings (e.g., about 230 openings), i.e., gas discharge holes 105 via a seal ring 107 so as to face the target substrate 103 on the holding table 104. Further, on an outer side of the shower plate 106, i.e., on the opposite side of the holding table 104 with respect to the shower plate 106, there is disposed a cover plate 108 made of alumina via another seal ring 109. These shower plate 106 and cover plate 108 constitute a part of an outer wall of the processing chamber 102. Formed between the top surface of the shower plate 106 and the cover plate 108 are spaces 110 which are charged up with a plasma excitation gas supplied through a supply hole 118 opened in the shower plate 106 from a plasma excitation gas supply port 117 and communicating with the spaces 110. In other words, there are formed grooves at positions in the cover plate 108 each corresponding and connected to the gas discharge holes 105 of the shower plate 106, and the spaces 110 are formed between the shower plate 106 and the cover plate 108. The gas discharge holes 105 are disposed to be connected with the spaces 110. Provided on outlets of the gas discharge holes 105 at the side of the processing chamber 102 is a porous ceramic layer 124. When the plasma excitation gas is introduced into the processing chamber 102, since the gas is discharged from a large area, the porous ceramic layer 124 functions to reduce a gas flow rate and enable a gas to uniformly flow without disturbing a flow of the gas. Furthermore, in the present embodiment, though the porous ceramic layer 124 is installed on the entire surface, except an outer peripheral portion, of the shower plate 106 facing the target substrate 103, it is possible to reduce the gas flow rate by installing the porous ceramic layer 124 only locally on the outlets of the gas discharge holes 105. On the top surface of the cover plate 108, a slot plate 111 of a radial line slot antenna having a plurality of open slots for radiating a microwave, a wavelength shortening plate 112 for propagating the microwave in a diametric direction, and a coaxial waveguide 113 for introducing the microwave to the antenna are installed. Moreover, the wavelength shortening plate 112 is interposed between the slot plate 111 and a metal plate 123. Provided in the metal plate 123 are cooling paths 114. The microwave radiated from the slot plate 111 is transmitted to the cover plate 108 and the shower plate 106; is introduced into a upper space of the processing chamber 102; and ionizes the plasma excitation gas discharged from the porous ceramic layer 124 in the upper space, whereby high density plasma is generated at a region of several mm directly under the porous ceramic layer 124. The generated plasma reaches the target substrate 103 by diffusion. The illustrated shower plate 106 has a diameter of about 400 mm and its outer peripheral portion has a thickness of about 35 mm. In a diameter range of from about 155 mm to about 165 mm, a taper portion is formed, and the shower plate in a range having a diameter less than about 155 mm has a thickness of about 25 mm. In this example, the angle of the taper portion is about 45°, but not limited thereto. Further, it is desirable to round off corners of the taper portion so as to suppress electric field concentration. In addition, a heat flux introduced by exposing the shower plate 106 to the high density plasma is discharged out by a coolant such as water flowing through the cooling path 114 via the slot plate 111, the wavelength shortening plate 112 and the metal plate 113. In the plasma ion implanting apparatus illustrated in FIG. 1, a ground plate 115 is installed within the processing chamber 102. The ground plate 115 is disposed between the shower plate 106 and the holding table 104 for mounting the target substrate 103 thereon; made of semiconductor such as an aluminum alloy; provided with a transmission window 121 through which the plasma generated right under the shower plate 106 can propagate by diffusion; and electrically grounded. Illustrated in FIG. 2 is a plane view of the ground plate 115, in particular, a shape of the transmission window. The transmission window 121 may be divided by grid pattern members to form a matrix shape as indicated by a reference numeral 201 in FIG. 2(a) or may be formed in a ring shape as indicated by a reference numeral 202 in FIG. 2(b). By varying a ratio of an opening area in the transmission window 121, plasma transmittance can be controlled. The ground plate 115 functions to provide a fixed potential to the inside of the processing chamber 102, in addition to this, it may have a temperature control function, particularly, a cooling function. When implanting the ions, it is necessary to provide energy to the ions reaching the target substrate 103. In order to do so, an electrode installed within the holding table 104 is connected with an RF power supply 122 via a condenser and an RF power is applied thereto, so that a self-bias voltage is generated on the target substrate 103. In this case, since the ground plate 115 becomes a ground surface when the RF power is applied to the electrode for the target substrate 103, a negative self-bias voltage can be generated on the surface of the target substrate 103 while hardly increasing a time-averaged plasma potential. If the plasma potential is increased, the energy of the ions irradiated onto the inner wall of the processing chamber 102 increases, thereby causing contamination. As long as the ground plate 115 is grounded at a high frequency with respect to an RF frequency, an increase in the plasma potential can be prevented, so that the ground plate 115 is not necessarily grounded with respect to a direct current. Therefore, for example, by applying a negative DC potential to the ground plate 115, it may be possible to use the ground plate 115 as a means for supplying electrons to the plasma by using secondary electrons emitted by ions. If a radio frequency is low, sheath impedance increases and thus a high self-bias voltage is generated. Therefore, it is desirable to set a frequency to be as relatively low as, e.g., about 1 MHz or less. In the present embodiment, an RF power having a frequency of 400 kHz is applied from the RF power supply 122 to the target substrate 103. Further, in order to perform a temperature control (in particular, cooling) of the target substrate 103, a path 16 through which a temperature control medium flows is provided in the holding table 104. Furthermore, in order to hold and fix the target substrate 103, a non-illustrated electrostatic chuck electrode is provided in the holding table 104. In the example of FIG. 1, the holding table 104 is made of a conductor to serve as an electrode for the target substrate 103 as well, and in order to surround its periphery (in this example, to surround the periphery of the target substrate 103), a ring-shaped insulating member 125 is installed as a part of the wall member of the processing chamber 102. Though the ring-shaped insulating member 125 can be made of a conductor, it may be eroded by high energy ions irradiated thereon, which may cause contamination of the target substrate 103 or deterioration of reproducibility. Accordingly, it is desirable to make the insulating member 125 by using ceramic such as Al2O3 or Y2O3 having excellent plasma resistance or an insulating member or a conductive member of which a surface is coated with a film made of ceramic. Otherwise, it is also desirable to use the same material as that of the target substrate 103, e.g., silicon or the like, as a constituent material or a coating material. Further, instead of installing the ring-shaped insulating member 125 illustrated in FIG. 1, it may be possible, as illustrated in FIG. 9, to fasten a supporting table 902 made of an insulating member having the same diameter as that of a target substrate 903 and an RF electrode 901 directly onto a wall member (not illustrated) of the processing chamber. In addition, in this case, it is desirable to form an insulating protective layer 904 with a thickness of, e.g., about 1 μm by thermally spraying ceramic such as Al2O3, Y2O3 having excellent plasma resistance such that the RF electrode 901 is prevented from being exposed to a side surface of the holding table. Alternatively, as illustrated in FIG. 10, it is effective to limit a region on which high energy ions are irradiated substantially only to a target substrate 1003 by making a holding table 1002 by using ceramic such as Al2O3, Y2O3 having excellent plasma resistance and making a diameter of an RF electrode 1001 equal to or smaller than a diameter of the target substrate 1003. Alternatively, as illustrated in FIG. 11, it may be also possible to make a holding table 1102 by using an insulating member whose diameter is smaller than that of a target substrate 1103 but equal to that of the RF electrode 1001. In this case, it is also desirable to form a protective layer 1104 with a thickness of, e.g., about 1 μm on a side surface of the holding table by thermally spraying ceramic such as Al2O3 or Y2O3 having excellent plasma resistance in order for the RF electrode 1101 not to be exposed to the side surface. Further, the holding tables 1002 and 1102 illustrated in FIGS. 10 and 11 are installed by fastening them directly to a wall member (not illustrated) of the processing chamber. Referring back to FIG. 1, it is desirable to make the ground plate 115 by using a material having high thermal conductivity and low resistivity in order to prevent the temperature from being excessively increased due to plasma heat. Used in the present embodiment is an Al alloy (Al containing Zr and Mg). It is desirable to form a strong protective film on a plasma-exposed surface of the ground plate 115 since a large quantity of ions are irradiated thereon from plasma. Formed in the present embodiment is an Al2O3 protective film with a thickness of about 0.5 μm by anodic oxidation using a non-aqueous solution. The protective film is not limited thereto, so it may be, e.g., a thermally sprayed film of Y2O3, a coating film formed by a sol-gel method, or an Al2O3 protective film on which the thermally sprayed film of Y2O3 or the sol-gel coating film is additionally formed thereon. Further, it is desirable to make a temperature control medium flow through the inside of the ground plate 115 in order to quickly remove a heat flux generated by an ion-electron recombination on a surface of the ground plate 115 and perform an accurate temperature control (in particular, cooling) on the ground plate 115. In the present embodiment, the temperature is controlled to 150° C. by providing a medium flow path 120, through which a medium (in particular, a cooling medium such as a He gas, water, or other coolant having a high heat capacity) flows, within the ground plate 115. By controlling temperature of the ground plate 115 accurately, an increase in the temperature of the surrounding space or the target substrate 103 can be suppressed. When a protective film is formed on the ground plate 115, an uppermost surface functions as an insulator. In case its thickness is thinner enough than a thickness of a sheath formed between the ground plate 115 and the plasma, sheath impedance generated between the plasma and the conductive portion of the ground plate 115 is not readily increased as compared to a case where there is no protective film, so that the ground plate 115 fully functions as a ground of the RF power. Detailed explanation will be provided below. A thickness d of the sheath formed on a surface of an object in contact with the plasma is determined by the following formula 5. d = 0.606 ⁢ ⁢ λ D ⁡ ( 2 ⁢ ⁢ V 0 T e ) 3 / 4 [ Formula ⁢ ⁢ 5 ] Here, V0 is a potential difference between the plasma and the object (unit: V), Te is an electron temperature (unit: eV), and λD is a Debye length which is determined by the following formula 6. λ D = ɛ 0 ⁢ kT ɛ n ɛ ⁢ e 2 = 7.43 × 10 3 ⁢ T e ⁢ [ eV ] n e ⁢ [ m - 3 ] ⁢ [ m ] [ Formula ⁢ ⁢ 6 ] Here, ne is an electron density of the plasma. According to this formula, if the plasma having a density of about 1012 cm−3 is excited, the thickness of the sheath is about 40 μm as shown in FIG. 3. In order to efficiently generate a self-bias on a wafer without increasing a plasma potential, it is necessary to lower the impedance between the ground plate 115 and the plasma at the RF power frequency. This impedance Z (an absolute value of impedance) can be determined by an equation Z=1/(2πfC) (f is a frequency of power) where a capacity between the ground plate 115 and the plasma is expressed in terms of C. Accordingly, since Z is in inverse proportion to C, it is good to increase C as high as possible. If the thickness of the sheath is expressed in terms of d; the thickness of the protective film is expressed in terms of t; and a dielectric constant of the protective film is expressed in terms of ∈s, the capacity C between the ground plate 115 and the plasma is determined by the following formula 7. C = ( d ɛ 0 ⁢ S + t ɛ 0 ⁢ ɛ s ⁢ S ) - 1 = ɛ 0 ⁢ S ( d + t ɛ s ) [ Formula ⁢ ⁢ 7 ] In the present embodiment, d is 40 μm, t is 0.5 μm, and ∈s is 9, so that a decrement of C is at most 1%. Therefore, the increase in the plasma potential caused by a formation of the protective film can be almost negligible. Further, it can be seen from the above formula that the increase in the plasma potential can be almost negligible even if the protective film with a thickness of several μm is formed. Directly under the shower plate 106 as illustrated in FIG. 1, the high density plasma with a low electron temperature is generated by 2.45 GHz microwave supplied from the radial line slot antenna 111. In order to prevent the microwave from penetrating into the plasma, it is desirable to set a microwave power such that a cut-off density ω2m∈0/e2 corresponding to the 2.45 GHz frequency can be equal to or more than 7.5×1010 cm−3. Here, an angular frequency of the microwave is denoted by ω, permittivity in vacuum by ∈0, mass of an electron by m, and an elementary electric charge by e. Accordingly, the plasma in a surface wave mode is stably excited. Furthermore, in order to prevent the ground plate 115 from being heated by a microwave electric field and excite the plasma more stably, it is desirable to generate a microwave electric field in the plasma as weakly as possible. A penetration depth of the microwave electric field into the plasma is characterized as a penetration length of the microwave into the plasma which is determined by the following formula 9 using an angular frequency ωpe of the plasma which is determined by the following formula 8, when a speed of light in vacuum is denoted by c and electron density is denoted by n.√{square root over (ne2/(m∈0))} [Formula 8]c/√{square root over (ωpe2−ω2)} [Formula 9] Since the angular frequency of the plasma is increased in proportion to the root of the electron density, by increasing the electron density, the penetration length becomes short; the ground plate 115 can be prevented from being over-heated; and the plasma can be maintained more stably. That is, it would be better that a distance between the shower plate 106 and the ground plate 115 is longer than the penetration length. In particular, if the distance is about three times or more as long as the penetration length, the microwave power applied to the ground plate 115 is about 1% or less of input power, and thus the plasma can be maintained more stably. In the present embodiment, the distance between the shower plate 106 and the ground plate 115 is set to be about 50 mm. Accordingly, it is good to excite plasma with an electron density of about 1.8×1011 cm−3 or more. Hereinafter, an ion implanting method will be explained in sequence. For example, an ion implantation into a source/drain region of a MOS transistor is performed by generating ions such as BF2+ for forming a p+ layer and AsF2+ or PF2+ for forming an n+ layer by plasma excitation and by accelerating the ions by a self-bias voltage generated on a surface of a wafer (target substrate 103) so as to implant them onto the wafer. For this reason, used as a plasma excitation gas supplied to the processing chamber 102 from the plasma excitation gas supply port 117 is a fluoride gas such as BF3, AsF3 or PF3. It is not desirable to use, for example, a hydride gas such as diborane (B2H6) because when the plasma is excited, light ions such as H+ ions are formed and implanted into a deep region of the wafer, thereby generating a large quantity of defects. Further, it is possible to perform plasma excitation with only the fluoride gas. However, if the plasma is excited with the fluoride gas, F— ions are generated, so that the plasma contains a small quantity of electrons therein. Therefore, it is efficient to dilute it with Ar ions in order to generate electrons. However, in this case, after Ar implantation, it is necessary to completely separate the implanted Ar ions by an annealing process. When the fluoride gas is added, it can be seen that as explained above, the plasma electron density becomes low to be equal to or less than a cut-off density. For example, the plasma was excited with 1.6 kW/cm2 power of 2.45 GHz microwave at a 200 sccm total flow rate of an Ar/NF3 mixed gas and the plasma density was measured 75 mm below the shower plate. At this time, the electron density was maintained higher than about 7.5×1010 cm−3 when a ratio of the NF3 in the mixed gas was in the range from about 0% to about 10%. However, when a pressure of the chamber was about 400 mTorr and the ratio was higher than 10% or when the pressure was about 300 mTorr and the ratio was higher than 20%, the electron density became equal to or lower than the cut-off density of about 7.5×1010 cm−3. Accordingly, the plasma was unstably excited in a chamber, so that the microwave was not reflected from the plasma but penetrated through the plasma to reach the target substrate, thereby damaging the substrate. However, it has been found that even in case that the pressure in the processing chamber was lowered to about 100 mTorr and the ratio of the fluoride gas was increased to about 80% or even in case that the pressure in the processing chamber was lowered to about 50 mTorr and the ratio of the fluoride gas was increased to about 100%, the electron density is not readily decreased and can be maintained equal to or higher than the cut-off density. Further, in case that the plasma was excited with the microwave power of about 1.6 kW/cm2 or more at a NF3 ratio of about 100% and under the pressure of about 100 mTorr and the plasma density was measured 75 mm below the shower plate, it has been found that the electron density is surely higher than the cut-off density (about 1.4×1011 cm−3 at about 2.5 kW power) and the electron temperature is lowered (about 1.3 eV at about 2.5 kW power), so that the plasma is excited stably and the ion implantation can be performed without charge-up damage. Furthermore, when the plasma is excited with a fluoride gas such as BF3 or the like, generated is F radical which reacts with Si of the target substrate, and resultantly formed is SiF4. Since SiF4 is volatile at a normal temperature and thus, the silicon wafer serving as the target substrate is etched. A volatilization temperature of SiF4 is about −160° C. under a pressure of about 76 mTorr, so that in case that the pressure within the processing chamber is about 76 mTorr, it is possible to suppress such an etching by lowering the temperature of the target substrate to about −160° C. or less. Even in case the pressure is about 76 mTorr or less, it is possible to suppress the radical etching by cooling the substrate with liquid nitrogen since the temperature (−196° C.) of the liquid nitrogen is equal to or less than the volatilization temperature. Accordingly, it is desirable to make the liquid nitrogen flow through a temperature control medium path 116 in a holding table 104. By the ion implantation, ions with positive charge are implanted into an ion implantation region of the target substrate and secondary electrons with negative charge are emitted, so that the ion implantation region is positively charged. In case the ions are implanted to form the source/drain region, it is needed to implant the ions with a dosage in a range from about 1×1015 cm−2 to about 5×1015 cm−2. About ten secondary electrons are emitted per an ion impact, so that positive charges in a range from about 1×1016 cm−2 to about 5×1016 cm−2 are accumulated. In order to reduce an electric field intensity generated in a gate insulating film by the ion implantation, ion doses are divided and provided one thousand times. That is, while the microwave plasma is excited, the RF power is applied onto the target substrate in pulse mode. Only if the RF power is on, the self-bias voltage is generated and the ion implantation is performed. When the RF power is off, the charging of the target substrate is eliminated by the electrons in the plasma. Since the dosed ions are about 5×1015 cm−2 in total, a dosage is about 5×1012 cm−2 at one time. An implanted energy is set to be about 1.5 keV, i.e., the self-bias voltage generated by applying the RF power is set to be about 1.5 kV. In this case, a traveling distance of B within the Si is about several nm or less, so that a very thin p+/n junction can be formed. However, if ions having such an energy range are implanted into Si, about ten secondary electrons per ion are emitted, so that positive charges are accumulated about ten times as much as total amount of electric charges implanted by the implantation of the plasma ions. Meanwhile, when the plasma is excited with the Ar and the BF3, a ratio of the electrons to F— ions is about 10%. Therefore, in order to neutralize the electric charges positively charged on the wafer by electrons at one-time pulse, a pulse interval needs to be about one hundred times longer than a pulse width. It is set that a sheet of wafer is processed per minute, a pulse width for applying a substrate bias is about 0.6 ms and a neutralization time by electrons is about 50.4 ms. That is, a 400 kHz RF power is applied at intervals of about 50.4 ms for a pulse width of about 0.6 ms. About one third of ions irradiated onto the wafer are BF2+ (the rest is Ar+), so that a required ion current density J is determined by the following formula 10. J = ⁢ 3 × 5 × 10 12 ⁢ ⁢ ( cm - 2 ) × 1.6 × 10 - 19 ⁢ ( Q ) 0.6 × 10 - 3 ⁢ ⁢ ( s ) = ⁢ 4 × 10 - 3 ⁢ ⁢ A ⁢ / ⁢ cm 2 [ Formula ⁢ ⁢ 10 ] Since the current density is proportional to the plasma density, it is controlled by varying the plasma density with the microwave power for exciting the plasma. An RF non-application time is about one hundred times longer than an RF application time, so that the ion implantation can be performed without charging. In a more general way, the required ion current density J is determined as shown in the following formula 11. J = De α ⁢ ⁢ N ⁢ ⁢ Δ ⁢ ⁢ t [ Formula ⁢ ⁢ 11 ] Here, D is a dosage, e is an elementary electric charge, α is a ratio of implanted ions to plasma ions, N is the number of pulses, and Δt is a pulse width. Further, though the implanted ion is ionized to have a valence number 1 in this case, if there exist polyvalent ions, the elementary electric charge e is multiplied by a valence number and a current density for each ion having the valence number is calculated and then the sum of them is determined as a current density. With reference to FIGS. 4 to 8, there will be explained an example of a device manufactured by using an ion implanting method of the present invention as a second embodiment of the present invention. Further, the same parts as described in the first embodiment are omitted. FIG. 4 illustrates a PMOS transistor 400 manufactured by using the ion implanting method of the present invention. FIGS. 5 to 8 illustrate a manufacturing process. FIG. 5 is a cross-sectional view when a gate electrode 511 is formed on a gate insulating film 512. The gate electrode 511 is made of polysilicon. Above all, in order to form a light doped drain region, BF2+ is implanted into an n-well 513 in a p-type silicon substrate 401 by using the ion implanting method of the present invention. A BF3 gas diluted with Ar is introduced into the processing chamber 102 illustrated in FIG. 1 so as to excite plasma. A pulse width for applying a substrate bias is set to be about 0.6 ms, a neutralization time by electrons to be about 50.4 ms and a dosage to be about 2×1014 cm−2. Therefore, an ion current is determined by the following formula 12. J = ⁢ 3 × 5 × 10 11 ⁢ ⁢ ( cm - 2 ) × 1.6 × 10 - 19 ⁢ ( Q ) 0.6 × 10 - 3 ⁢ ⁢ ( s ) = ⁢ 4 × 10 - 4 ⁢ ⁢ A ⁢ / ⁢ cm 2 [ Formula ⁢ ⁢ 12 ] The substrate bias is set to be about 0.7 kV. Since an RF power frequency of the RF power supply 122 is set to be about 400 kHz, the period is longer than a sheath pass time of BF2+. Therefore, since the BF2+ completely follows the RF frequency, the maximum energy becomes about 1.4 kV which is twice the substrate bias, so that ion energy can be obtained efficiently. Further, liquid nitrogen is allowed to flow through the temperature control medium path 116 of the holding table 104. As a result, as indicated by a reference numeral 501 in FIG. 5, the BF2+ is implanted up to a region with a thickness of about 5 nm in a depth direction. Thereafter, an activation annealing is performed at a temperature of about 600° C. for about 30 minutes, thereby forming a p-type high concentration layer having a carrier concentration of 1019 cm−3 as indicated by a reference numeral 601 in FIG. 6. At the same time, implanted F and Ar are separated by such an annealing. Subsequently, as illustrated in FIG. 7, after a sidewall 711 made of SiO2 is formed at a side wall of the gate electrode 511, ions with a dosage of 5×1015 cm−2 are implanted again in order to form a high concentration source/drain layer, in the same manner as in forming the light doped drain layer. At this time, ion current is determined by the following formula 13 and the substrate bias is set to be about 1.6 kV. J = ⁢ 3 × 5 × 10 12 ⁢ ⁢ ( cm - 2 ) × 1.6 × 10 - 19 ⁢ ( Q ) 0.6 × 10 - 3 ⁢ ⁢ ( s ) = ⁢ 4 × 10 - 3 ⁢ ⁢ A ⁢ / ⁢ cm 2 [ Formula ⁢ ⁢ 13 ] In this case too, since the BF2+ completely follows the RF frequency, the maximum energy becomes about 3.2 kV which is twice the substrate bias, so that ion energy can be obtained efficiently. As a result, as indicated by a reference numeral 701 in FIG. 7, the BF2+ is implanted into a region with a thickness of about 8 nm in a depth direction. Thereafter, an activation annealing is performed at a temperature of about 600° C. for about 30 minutes, thereby forming a p-type high concentration source/drain layer having a carrier concentration of 2×1020 cm−3 as indicated by a reference numeral 801 in FIG. 8. Subsequently, as illustrated in FIG. 4, by forming a contact silicide of the source/drain 801, an interlayer insulating film 411, a contact opening and a wiring 412, the PMOS transistor 400 is manufactured. Since the charge-up damage is completely removed when the ions are implanted, a transistor having a high mobility with a low leakage current can be implemented. The present invention is not limited the above-described embodiments, so the target object may be other semiconductor substrates or made of other materials in need of ion implantation other than the silicon substrate, and the ion source gas may be other gases for generating ions required for implanting. The plasma excitation gas is not limited to Ar but may be other rare gases or other kinds of gases. Further, in the above-described example, the ion source gas has been used together with the plasma excitation gas as well or introduced into the processing chamber 102 through the shower plate 106 from the gas supply port 117 together with the plasma excitation gas, but ion source gas may be introduced into the processing chamber 102 through a different route from that of the plasma excitation gas. As stated above, the present invention has been explained with reference to the embodiments, but the present invention is not limited to configurations or numbers described in the embodiments. For example, the frequency of the microwave is not limited to 2.45 GHz but may be, e.g., 915 MHz, and the plasma excitation gas is not limited to a mixed gas of Ar and fluoride (BF3, AsF3 or the like) but may be fluoride gas (one or more gases of BF3 and AsF3) only. To be brief, the present invention is characterized by including a depressurizable processing chamber, a plasma excitation unit for exciting plasma within the processing chamber, a holding table installed in the processing chamber for holding a target substrate, a conductive member disposed so as to face the holding table in the processing chamber and having a portion through which the plasma is transmitted toward the holding table, and an application unit for applying a substrate bias RF power onto the target substrate held by the holding table, wherein the conductive member is electrically grounded with respect to a frequency of the RF power. Furthermore, it is desirable that the plasma excitation unit includes an RLSA antenna for radiating microwave from a microwave source uniformly and a shower plate for discharging a plasma excitation gas into the processing chamber uniformly manner. Further, it is important to obtain an electron density in the plasma surely exceeding a cut-off density by setting a pressure in the processing chamber to be about 100 mTorr or less; to neutralize the substrate by electrons in the plasma during a non-application period by intermittently supplying the RF bias power with a frequency of about 400 kHz to the substrate; and to surely generate a self-bias with a voltage from about 1 kV to about 5 kV on the substrate without increasing a plasma potential by grounding a ground plate with respect to a RF power frequency of the substrate bias. An application of the ion implanting apparatus and the ion implanting method in accordance with the present invention, in which charge-up damage is rarely occur, is not limited to the PMOS transistor of the embodiments but can be another semiconductor device, LSI, or other electronic devices in need of ion implantation.
	claims	1. A radiation detector, comprising:a plurality of radiation detector modules arranged adjacent to one another, each of the plurality of radiation detector modules including one detector unit, the detector unit including,two scintillation elements with a radiation inlet surface aligned transversely with respect to a main direction of a radiation, anda light detector between the two scintillation elements arranged transversely with respect to the radiation inlet surfaces of the two scintillation elements, the light detector including a first light inlet surface associated with a first scintillation element of the two scintillation elements and a second light inlet surface associated with a second scintillation element of the two scintillation elements, the first light inlet surface and the second light inlet surface pointing away from each other. 2. The radiation detector as claimed in claim 1, wherein the scintillation elements are formed by a homogeneous scintillation layer. 3. The radiation detector as claimed in claim 1, wherein at least the light detector and the detector unit is arranged on a support. 4. An imaging system comprising the radiation detector as claimed in claim 1. 5. The imaging system as claimed in claim 4, wherein the radiation detector extends along a circular or arced path running around an axis of rotational symmetry. 6. The imaging system as claimed in claim 5, wherein a row of detector units of the radiation detector is arranged on a light detector bar structured in a direction parallel to the axis of rotational symmetry. 7. The imaging system as claimed in claim 6, wherein planes of light detector arrangements of the radiation detector are aligned in a direction which is parallel to the axis of rotational symmetry. 8. The imaging system as claimed in claim 6, wherein a light detector arrangement is arranged between every second scintillation element in at least one of the direction parallel to the axis of rotational symmetry and the angular direction of the radiation detector. 9. The imaging system as claimed in claim 5, wherein planes of detector units of the radiation detector are aligned in a direction which is parallel to the axis of rotational symmetry. 10. The imaging system as claimed in claim 9, wherein a light detector arrangement is arranged between every second scintillation element in at least one of the direction parallel to the axis of rotational symmetry and the angular direction of the radiation detector. 11. The imaging system as claimed in claim 5, wherein a support unit is arranged between every second scintillation element in at least one of the direction parallel to the axis of rotational symmetry and the angular direction of the radiation detector. 12. A light detector arrangement for a radiation detector comprising:a light detector including,a first light inlet surface associated with a first scintillation element including a first radiation inlet surface aligned transversely with respect to a main direction of a radiation, anda second light inlet surface associated with a second scintillation element, the first light inlet surface and the second light inlet surface pointing away from each other and the second scintillation element including a second radiation inlet surface aligned transversely with respect to the main direction of a radiation. 13. A radiation detector comprising the light detector arrangement of claim 12. 14. A method for producing a radiation detector, comprising:providing a detector blank with a number of scintillation elements arranged adjacent to one another with a radiation inlet surface aligned transversely with respect to a main direction of a radiation;providing a light detector including two light inlet surfaces which point away from one another;applying one light detector between two of the scintillation elements such that one of the two light inlet surfaces is associated with a first scintillation element and another of the two light inlet surfaces is associated with a second scintillation element, whereinthe light inlet surfaces of the detector are arranged transversely with respect to the radiation inlet surfaces of the scintillation elements. 15. The method as claimed in claim 14 wherein the two light inlet surfaces are back-to-back and have been adhesively bonded or polymer- or fusion bonded.
050162675	abstract	In one embodiment, an x-ray neutron instrument includes an x-ray or neutron lens (10) disposed in a path for x-rays or neutrons in the instrument. The lens (10) comprises multiple elongate open-ended channels (12) arranged across the path to receive and pass segments of an x-ray or neutron beam (14). The channels (12) have side walls reflective to x-rays or neutrons of the beam incident at a grazing angle less than the critical grazing angle for total external reflection of the x-rays or neutrons, whereby to cause substantial focusing or collimation and/or concentration of the thus reflected x-rays or neutrons. In a different embodiment, a condensing-collimating channel-cut monochromator comprises a channel (22) in a perfect-crystal or near perfect-crystal body (20). This channel (22) is formed with lateral surfaces (24, 26) which multiply reflect, by Bragg diffraction from selected Bragg planes, an incident beam (28) which has been collimated at least to some extent. The lateral surfaces (24, 26) are at a finite angle to each other whereby to monochromatize and spatially condense the beam (28) as it is multiply reflected, without substantial loss of reflectivity or transmitted power.
059848537	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic physical principle behind the radiation source is well known from the literature of modern physics. When high energy electrons are retarded by nuclei having a large atomic weight, electromagnetic radiation is emitted. The primary radiation, denoted "bremsstrahlung", has a continuous spectrum with a peak corresponding to a given fraction of the electron energy. The emitted radiation can have an energy peak from a few electron volts (eV) to several million electron volts (MeV) depending on the energy of the incident electrons. In terms of wavelength, this corresponds to a range from ultraviolet light (10-4000 .ANG.) via X-rays (0.1-100 .ANG.) to gamma radiation (<0.10 .ANG.). Thus, by varying the energy of the electrons, the wavelength peak can be displaced accordingly. In addition to bremsstrahlung, which basically has a continuous spectrum, absorption or emission peaks corresponding to atomic electron transition may be embedded in the spectrum, depending on the materials contained in the transmission medium. The details of the radiation source and its function will be described with reference to FIGS. 1 and 2. Basically, the source is built up from two plates 2, 3 with a recessed region forming a microcavity 1 at one or several localities. An anode material 5 and a cathode 4 with extremely small dimensions, and having the form of a sharp tip 10 are located within this microcavity. The radius of curvature of the tip 10 of the cathode is preferably in the nanometer range. If a voltage is applied between the anode 5 and cathode 4, the electric field strength will be extremely high at the cathode. A positive voltage on the anode will cause electrons to be emitted from the cathode by the phenomenon known as field emission. Alternatively, the cathode may be heated to high temperatures, giving rise to thermal emission of electrons. This will be further discussed below with reference to FIG. 6. The electrons are accelerated by the electric field, until they are retarded by the impact at the anode. The anode 5 preferably consists of a metal having a high atomic weight, corresponding to an atomic number exceeding 50. In a preferred embodiment, the anode 5 is made of tungsten which is an endurable metal that can be deposited in the form of thin films either by physical or chemical deposition techniques. Other metals include cobalt, molybdenum and aluminium. The cathode preferably consists of a thin deposited film of a material having a low work function, i.e. the energy required for an electron to be emitted from the surface into the ambient. Materials with this property are oxides of metals from Groups I and II in the periodic table, including cesium, barium and magnesium. The anode 5 and cathode 4, may be connected to a voltage source by electrically conducting leads 6, 7, which may, at least partly, be an integral part of the plates 2, 3. This can be achieved by deposition of stripes by evaporation, sputtering or chemical vapor deposition. Alternatively, if the plates 2, 3 are semiconductors, the leads 6, 7 may be doped regions according to well-known technology. In a preferred embodiment, a third electrode 11 is also present within the microcavity 1. This electrode 11 acts as a gate, controlling the electron current emitted toward the anode 5. The gate electrode has a separate lead 12, enabling a separate voltage source to be connected. According to the well-known theory of vacuum tubes, the anode current is controlled by the gate voltage. This will directly influence the intensity of the emitted radiation which is approximately proportional to the anode current. The emitted dose is simply the time integral of this intensity. By separate and independent control of the gate and anode voltages, it is thus possible to independently control the emitted dose and energy, respectively. The leads 6, 7 and 12 must be properly isolated to avoid short circuit or current leakage. If the plate materials by themselves are not isolating themselves, passivating films may be necessary to ensure proper isolation. Furthermore, the lateral location of the leads is preferably chosen to minimize the electric field across material barriers. The voltage to the anode and cathode should preferably be in the kV range in order to obtain radiation of sufficient energy. With reference to FIG. 6, there is schematically shown an implementation wherein the thermionic emission principle is employed. Through a thin wire 601 or filament disposed in a microcavity 602, such as the one disclosed above, a current I is passed. The temperature will be so high that electrons will be emitted and accelerated by an electronic voltage imposed across the filament 601 and an anode 603, also disposed in microcavity 602. There are two principally different ways of fabricating the radiation source according to the invention. One way is to use two separate solid substrates and define the structures containing the cathode 4, the gate 11, with their leads 7 and 12, and the recess or microcavity 1 in one substrate. The anode 5 and its lead 6 are defined in the second substrates. Lithographic techniques according to well-known art are preferably used in defining these structures. Then finally the two substrates, corresponding to plates 2 and 3, are bonded together, using techniques such as solid-state bonding. If the bonding is performed in a vacuum, the microcavity 1 will remain evacuated, since the bonded seal is almost perfectly hermetic, provided that no organic materials are used. Absolute vacuum is not a necessity, but the density of gas molecules inside the microcavity must not be so high that the accelerating electrons are excessively impeded. A requirement for successful bonding is that the bonded surfaces 8 and 9 are flat and smooth with a precision corresponding to a few atomic layers. A second requirement is that all structures are able to withstand a relatively high annealing temperature, approximately 600-1000.degree. C., without damage. This first fabrication technique is basically known as bulk micromachining, in contrast to its alternative, surface micromachining. According to this, all structures are formed by depositions on one single substrate, again using lithography to define the two-dimensional pattern on the surface. The microcavity 1 is formed by first depositing a sacrificial layer which is etched away after the uppermost layers have been deposited. Closing the microcavity can be done by depositing a top layer, covering openings which are required for the etching of the sacrificial layer. Both described methods of fabrication are feasible and lead to similar device performance. Indeed, from examining a final device, it may be difficult or even impossible to conclude which fabrication procedure has been used. An important characteristic of the proposed fabrication techniques is that the manufacturing cost per unit becomes very small when the source elements are fabricated in large numbers. This is due to the fact that batch fabrication with thousands of units per batch is feasible. In FIG. 3 an embodiment is shown where the source and its leads 6, 7 are mounted inside a tubular element, such as a cannula 100, consisting of a material which is transparent to the emitted radiation. Preferably, the tubular element (or the hollow portion where the source is mounted in the case of a needle), is made from elements having a low atomic number. As shown in the cross section A--A the leads 6, 7 are connected to wires 101, 102 having isolated mantles 103, 104. In a preferred embodiment, the outer diameter of the tubular element is smaller than 2 mm. The cannula is then sufficiently small to penetrate tissue in order to reach a certain location where radiation therapy is required. FIG. 4 shows a further embodiment where the source 200 is located near the distal end of a wire 201, having high bending flexibility in order to prevent organs and tissue from perforation or penetration by mistake. Instead, the wire 201 can be guided to the tissue where radiation therapy is required by insertion through a catheter which has previously been inserted in the tissue by well-known techniques. A cross section B--B of the wire 201 shows that it consists of a tubular member 202, and power transmitting leads 203, 204. The leads 203, 204 are proximally connectable to an external power source by connecting elements 205, 206. Geometrically, the connecting elements 205, 206 have a diameter approximately equal to the diameter of the wire to allow insertion of the wire into a catheter. Referring now to FIG. 7a and b, other vehicles for the radiation source are conceivable, e.g a needle 700 with a solid distal portion 701 having a sharp tip for the easy penetration of soft and hard tissue, and a hollow portion 702, proximal to the solid tip, wherein the radiation source 703 is mounted. In still another embodiment the radiation source may be mounted in a tube 704, the distal end of which, 705, has been bevelled to render it sharp enough for penetration purposes. The open end of the tube may be plugged at 706 so that the interior of the tube housing the source will not be soiled by tissue. The power leads supplying power to the radiation source can either be electrical or fiberoptic leads, according to well-known technology. In the case of optical power transmission, it is necessary to convert the optical power into electrical voltage to provide voltage supply to the source. This may be done by providing optical energy through the fiberoptic leads and letting the light impinge onto a photodiode which converts the light into a voltage. FIG. 5 shows an electronic circuit element M capable of multiplying an input voltage 305 to its output terminals 307, 308 by a factor of approximately two. The circuit operates with two switching elements, for example diodes 301, 302, and two capacitors 303, 304. If two circuit elements as that shown in FIG. 5 are cascaded, the input voltage will be multiplied by a factor of approximately four. Even larger multiplication factors are possible by cascading more circuit elements of a similar type. The diodes 301, 302 may be replaced by other switching elements, such as transistors. Preferably, electronic circuitry M such as that shown in FIG. 5 may be integrated with one of the plates 2, 3 accommodating the source (schematically shown in FIG. 8a). Alternatively, the circuitry consists of a separate electronic chip located close to the source (schematically shown it FIG. 8b). The high voltage generation may of course alternatively be disposed outside the body, e.g in the external power supply. The method of providing a controlled dose of radiation is carried out as follows. The physician localizes the region of interest, e.g. a tumor to be treated. Depending on the site and type of tissue, various vehicles for the radiation source may be employed, e.g. a needle for penetrating through soft tissue, or a guide wire possibly in combination with a catheter, or the insertion may be made through blood vessels or other body channels, such as intestines. When the radiation source has been correctly located inside the body, the radiation source is activated and the required dose is given. The device is switched off and the source is withdrawn from the patient. This procedure may be repeated frequently until the desired clinical result has been achieved. While several embodiments of the invention have been described, it will be understood that it is capable of further modifications, and this application is intended to cover any variations, uses, or adaptations of the invention, following in general the principles of the invention and including such departures from the present disclosure as to come within knowledge or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and falling within the scope of the invention or the limits of the appended claims.
	description	This application claims priority to currently pending U.S. patent application Ser. No. 16/737,216, filed on Jan. 8, 2020 and entitled, “System and Method for General Data Protection Regulation (GDPR) Compliant Hashing in Blockchain Ledgers”, which claims prior to U.S. Provisional Patent Application No. 62/925,546, filed on Oct. 24, 2019 and entitled, “System and Method for General Data Protection Regulation (GDPR) Compliant Hashing in Blockchain Ledgers”, the entirety of which are both incorporated herein by reference. The present invention relates to computer architectures and methods that automatically comply with data security regulations using immutable audit ledgers, such as blockchains. In particular, the invention provides a computer system and method that effectively complies with data processing regulations, including, but not limited to, the European Union's General Data Protection Regulation (GDPR). In accordance with GDPR, Personal Identifiable Information (PII), such as an individual's name, phone number, address, etc. are protected by law and these laws often include the so-called “right to be forgotten”. In most of the current blockchain technologies, one cannot delete information from a blockchain ledger because it is tamper-proof. However, in certain geographical regions having GDPR laws, the inability to delete PII stored in a blockchain ledger may lead to a violation of these data privacy laws, and in particular, a violation of the right to be forgotten. In general, personally identifiable information (PII) is any data that can be used to identify a specific individual. Social Security numbers, mailing or email address, and phone numbers have most commonly been considered PII. However, PII may also include an IP address, login IDs, social media posts, or digital images. Geolocation, biometric, and behavioral data can also be classified as PII. A common mitigating solution to complying with GDPR laws is to store a) hash value, rather than the actual personal data (message), in the blockchain ledger, which makes it difficult to reconstruct the original personal data, especially if the message is padded prior to hashing. However, storing only the hash values of the personal data may not be enough, because it is still possible to draw conclusions on the personal data based upon the stored hash value and as such the personal data is not considered to have been deleted from the blockchain ledger. For example, knowing the hash function used for a given message m, it is possible for one to exhaust, by brute force, the padding space and see which hash values v are obtained in this way because, if a given hash v is not obtained then it can be concluded that m was not the message. For example, a hash value may be mapped to data of any size and together with cryptographic functionality can be used to confirm a data fingerprint (SHA-1, SHA-256. MD-5 etc.). While prior art methods are known which utilize a Merkle Tree function to generate the hash value, the resulting “hash” is still a data point and therefore can be challenged with GDPR compliance. As such, in order to be GDPR compliant, a hash value must not be attributed to the PII and must be proven as such. Additionally, assuming that personal identifiable information (PII) is encrypted rather than hashed before it is written to a blockchain, destroying the cryptographic key renders the stored data unreadable. However, again it is still possible to draw conclusions based on the encrypted message by exhausting the cryptographic keys. As a result, one could launch a challenge against an enterprise employing blockchain technology as to whether or not the enterprise is in compliance with GDPR. Accordingly, there is a strong but, heretofore, unresolved need in the art for a system and method for ensuring GDPR compliance by enterprises that utilize blockchain technology. In various embodiments, the present invention provides a system and method employing a new family of hash functions, rather than a single function, that obviates instantiation of data between source and destination that results in a new hash value which does not include information on the original data. In one embodiment, the present invention provides a computer implemented method for providing general data protection regulation (GDPR) compliant hashing in blockchain ledgers. The method includes, receiving a first message from a user at a blockchain gateway device, wherein the first message comprises personal identification information (PII) and performing, at the blockchain gateway device, a first hashing function on the first message to obtain a hash value of the first message. The method further includes, storing the hash value of the first message in a blockchain ledger, storing the first hashing function in an off-chain database and storing the first message in the off-chain database. When a user of the blockchain desires to be forgotten, the method further includes, receiving a request to delete the first message, arbitrarily selecting a second message that is different than the first message and calculating a second hashing function using the second message, wherein the second hashing function results in the same hash value. The method further includes, replacing the first message in the off-chain database with the second message and replacing the first hashing function in the off-chain database with the second hashing function. In an additional embodiment, the present invention provides a blockchain gateway device for providing general data protection regulation (GDPR) compliant hashing in blockchain ledgers. The blockchain gateway device includes, a processor and one or more memory devices storing computer-executable instructions that, when executed with the processor, cause the system to at least, receive a first message from a user, wherein the first message comprises personal identification information (PII) and perform a first hashing function on the first message to obtain a hash value of the first message. The device is further configured to store the hash value of the first message in a blockchain ledger, store the first hashing function in an off-chain database and store the first message in the off-chain database. The blockchain gateway device is further configured to receive a request to delete the first message, arbitrarily select a second message that is different than the first message, calculate a second hashing function using the second message, wherein the second hashing function results in the same hash value, replace the first message in the off-chain database with the second message and replace the first hashing function in the off-chain database with the second hashing function. In an additional embodiment, the present invention provides one or more non-transitory computer-readable media having computer-executable instructions for performing a method of running a software program on a computing device for providing general data protection regulation (GDPR) compliant hashing in blockchain ledgers. In the present invention, the personal identification information (PII) of the user may include one or more of, social security numbers, mailing addresses, email addresses, phone numbers, IP addresses, login IDs, social media posts, digital images, geolocation data, biometric data, and behavioral data. Accordingly, in various embodiments, the present invention provides a system and method for ensuring GDPR compliance by enterprises that utilize blockchain technology. With reference to FIG. 1, the present invention provides a GDPR-Blockchain Compliant Architecture 100 comprising a blockchain or distributed ledger technology (DLT) 110 and one or more off-chain databases 150. User data under GDPR directive 105, such as PII 112, which may include email addresses, social security number, social media posts, etc., are provided by the user. Hashed data pointers 130 are generated for the GDPR sensitive data, which are then stored in the blockchain ledger 110. Hashed data pointers 130 for public keys 120 and other data 125 may additionally be stored in the blockchain ledger 110. Hashed data pointers 132 from data, other than the user's data 105, such as other non-GDPR sensitive data 134, may additionally be stored in the blockchain ledger 110. Both off-chain 140 and on-chain databases 135 may be used to store the hashed values 132 for the data other than the GDPR sensitive data. In the present invention, in order to comply with the GDPR “right to be forgotten”, the GDPR-Blockchain Compliant architecture 100 further includes an off-chain or cloud database for the GDPR sensitive data 150. The use of the off-chain database 150 for the storage of the hashed values of the GDPR sensitive data 130 in accordance with the present invention to ensure GDPR compliance is described in further detail below. The present invention provides a system and method employing a new family of hash functions that obviates instantiation of data between source and destination by structuring a proof algorithm that results in a new GDPR-PII Hash value “X-Proved”. The resulting hash value does not include information on the original data. In the present intention, a new value of “X-Proved GDPR Compliant” message is generated where “hash” is outside the data block itself and is triggered by an event of “z” to prove GDPR compliance. The use of hashing functions are foundational to the inventive method, but only in the development of a new value of “X-Proved GDPR Compliant” message which could be posted to the blockchain, wherein the resulting value is no longer related to the original data value, thereby complying with GDPR regulations. In various embodiments, the present invention provides a system and method for referencing personal data in a blockchain ledger without being able to draw conclusions on the data itself. The inventive concept is achieved by applying a family of hash functions h_s to the message m such that for any given hash value v and message m there is a function h_s in the family which, when applied to m gives exactly the value v. In one embodiment, in a first step of the present invention, message m is hashed to the value v=h_s(m) and v is stored in the blockchain ledger and s and m are stored outside the blockchain ledger (off-chain). In a next step, if m needs to be deleted upon request, then an arbitrary pseudonym m′ is selected to calculate a new s′ to obtain the same hash v=s′m′. At a next step, m and s are deleted from the off-chain database and replaced with m′, s′, thereby resulting in a proper anonymization while still providing the correct reference. In another embodiment, the method may begin when an enterprise or service provider triggers the GDPR proof of compliance process. In response to the trigger, the method proceeds to iterate pre-hash proof states as part of the hash process, wherein a value of t can be inserted for time=milliseconds. When the hash process has completed, GDPR-Hash Value “X-Proved GDPR Compliant Message”, wherein X can be an arbitrary numerical value, can be generated. This value-proof can then be sequentially timestamped based on t and posted on a public blockchain ledger. Exemplary embodiments for generating the “X-Proved GDPR Compliant Message” are described in the following paragraphs. In an exemplary embodiment for calculating a new s′ to obtain the same hash, multiplication in a finite field K may be performed. Herein, let m, v and s be simply represented by elements of the field K. The mapping h_s: K--->K is given by m is mapped to v=ms. If v, m is given, s=v/m results. In a specific embodiment, the method of the present invention may include: 1. Select a prime number p and a primitive root g mod p. Both can be made public. 2. Let the privacy information (message) be represented by a residue m mod p and freely select another residue s mod p. Both, the residues of m and s are stored outside of the blockchain ledger (off-chain). The blockchain ledger just stores the residue v≡ms mod p. 3. If a request is received to delete the residue of m (outside the ledger), an arbitrary new substitute mnew mod p is chosen and snew:≡vmnew mod p is calculated and m outside the ledger is replaced by mnew and s by snew. Then, mnew·snew≡ms=v mod p, and m, s are then deleted from the off-chain database. In a specific exemplary embodiment of the above described method of the present invention: 1. Assuming, p=29 and g=10. 2. Let the privacy information be represented by m≡13≡102 mod 29. Then s is arbitrarily chosen to be s≡24≡104 mod 29 and ms≡g6≡22 mod 29 is stored in the blockchain ledger. 3. When removal of data is requested, m≡13 is replaced by an arbitrary value mnew, say mnew≡17, then snew≡vmnew−1=g27=3 mod 29 is calculated and 13, 24 are deleted from the off-chain database and replaced by 17, 3. FIG. 2 illustrates a swim diagram of an exemplary process 200 for providing GDPR blockchain hashing compliance, in accordance with an embodiment of the present invention. For example, the process 200 can be implemented using a blockchain gateway device 210, controlled by a user 205, to store messages and hashing functions in an off-chain database 215 and to store hashed values in a blockchain ledger 220. The process 200 provides GDPR compliance when queried by a data controller 225. In operation, a user 205 of the GDPR compliant blockchain system 200 provides a first message including personal identity information (PII) to a blockchain gateway 210. The blockchain gateway 210 then generates a hash value of the first message using a first hashing function 235 and then stores the hash value in the off-chain database 215. The hash value is also stored 245 in the blockchain ledger 220. The user 205 may be providing their PII to a data controller 225 to be used for verification of the user's identity, however no PII is stored in the blockchain ledger 220. In order to comply with GDPR requirements, “The Right to Be Forgotten” must be adhered to by the blockchain gateway 210, wherein the blockchain gateway 210 must guarantee that the stored hash value cannot to attributed to user data. As such, when the blockchain gateway 220 receives a request to delete the first message, the blockchain gateway 220 arbitrarily selects a second message that is different than the first message 255. The blockchain gateway 220 then calculates a second hashing function using the second message that results in the same hash value 260. The blockchain gateway then replaces the first message with the second message and replaces the first hashing function with the second hashing function 265 in the off-chain database 215. In response, an X-proved GDPR compliant hash value of the message is generated 270 by the blockchain gateway 210, which is then stored 275 in the blockchain ledger 220. When the data controller 225 checks for GDPR compliance 280 with the execution of the right to be forgotten requested by the user 205, the X-proved GDPR compliant message 275 is provided to the data controller 225, thereby verifying GDPR compliant anonymization while still referencing the same hash value. FIG. 3 illustrates a computer implemented method 300 for providing general data protection regulation (GDPR) compliant hashing in blockchain ledgers in accordance with the present invention. Step 305 includes, performing a hashing function on a first message to obtain a hash value of the first message. At step 310, the hash value is stored in the blockchain ledger and at step 315, the first hashing function and the first message are stored in the off-chain database. At step 320, upon receiving a request to delete the first message from the blockchain ledger, the method continues at step 325 by arbitrarily selecting a second message. At step 330, the method continues by calculating a second hashing function using the second message, wherein the second hashing function results in the same hash value. At step 335 the first message in the off-chain database is replaced by the second message and the first hashing function in the off-chain database is replaced by the second hashing function, thereby providing GDPR compliant anonymization while still referencing the same hash value. As such, in various embodiments, the present invention provides a system a method for automatically ensuring GDPR compliance when utilizing blockchain technology. While the inventive concept has been described based upon GDPR compliance, this is not intended to be limiting and compliance with various other data regulations are within the scope of the present invention. FIG. 4 is a block diagram 400 illustrating the components of an exemplary blockchain gateway device, in accordance with the present invention. As shown in FIG. 4, the blockchain gateway device includes a processor 420 and one or more memory devices 430 storing computer-executable instructions that, when executed with the processor, cause the system to at least, receive a first message from a user, wherein the first message comprises personal identification information (PII) and perform a first hashing function on the first message to obtain a hash value of the first message. The processor 420 is further configured to store the hash value of the first message in a blockchain ledger, store the first hashing function in an off-chain database and store the first message in the off-chain database. The processor 420 is further configured to receive a request to be forgotten from the user, arbitrarily select a second message that is different than the first message, calculate a second hashing function using the second message, wherein the second hashing function results in the same hash value, replace the first message in the off-chain database with the second message, replace the first hashing function in the off-chain database with the second hashing function and store a GDPR compliant hash value of the message in the blockchain ledger. In some implementations, a blockchain gateway device 400 for implementing the GDPR-blockchain compliant architecture shown in FIG. 1, may include one or more the components of the blockchain gateway device 400. As shown in FIG. 4, the blockchain gateway device 400 may include a bus 410, a processor 420, a memory 430, a storage component 440, an input component 450, an output component 460, and a communication interface 470. Bus 410 may include circuitry that permits communication among the components of the blockchain gateway device 400. Processor 420 may be implemented in hardware, firmware, or a combination of hardware and software. Processor 420 may be a central processing unit (CPU), a graphics processing unit (GPU), an accelerated processing unit (APU), a microprocessor, a microcontroller, a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or another type of processing component. In some implementations, processor 420 includes one or more processors capable of being programmed to perform a function. Memory 430 may include a random-access memory (RAM), a read only memory (ROM), and/or another type of dynamic or static storage device (e.g., a flash memory, a magnetic memory, and/or an optical memory) that stores information and/or instructions for use by processor 420. Storage component 440 may be configured for storing information and/or software related to the operation and use of the blockchain gateway device 400. For example, storage component 440 may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optic disk, and/or a solid state disk), a compact disc (CD), a digital versatile disc (DVD), a floppy disk, a cartridge, a magnetic tape, and/or another type of non-transitory computer-readable medium, along with a corresponding drive. Input component 450 may include circuitry that allows the blockchain gateway device 400 to receive information, such as via user input, such as, a touch screen display, a keyboard, a keypad, a mouse, a button, a switch, and/or a microphone. Output component 460 may include a component that provides output information from the blockchain gateway device 400, such as a display or a speaker. Communication interface 470 may include a transceiver circuitry that allows the blockchain gateway device 400 to communicate with other devices, such as via a wired connection, a wireless connection, or a combination of wired and wireless connections. Communication interface 470 may allow device 400 to receive information from another device and/or provide information to another device. For example, communication interface 470 may include an Ethernet interface, an optical interface, a coaxial interface, an infrared interface, a radio frequency (RF) interface, a universal serial bus (USB) interface, a Wi-Fi interface, a cellular network interface, and/or the like. The blockchain gateway device 400 may perform one or more processes described herein. The blockchain gateway device 400 may perform these processes based on the processor 420 executing software instructions stored by a non-transitory computer-readable medium, such as a memory 430 and/or storage component 440. The specific arrangement of components shown in FIG. 4 are provided as an exemplary embodiment. In practice, the blockchain gateway device 400 may include additional components, fewer components, different components, or differently arranged components than those illustrated in FIG. 4. The present invention may be embodied on various computing platforms that perform actions responsive to software-based instructions and most particularly on touchscreen portable devices. The following provides an antecedent basis for the information technology that may be utilized to enable the invention. The computer readable medium described in the claims below may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any non-transitory, tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. However, as indicated above, due to circuit statutory subject matter restrictions, claims to this invention as a software product are those embodied in a non-transitory software medium such as a computer hard drive, flash-RAM, optical disk or the like. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wire-line, optical fiber cable, radio frequency, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, C#, C++, Visual Basic or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. While methods, apparatuses, and systems have been described in connection with exemplary embodiments of the various figures, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments for performing the same function without deviating therefrom. Therefore, the invention should not be limited to any single embodiment, but rather should be construed in breadth and scope in accordance with the appended claims.
	claims	1. A method for manufacturing a boron-lined neutron detector having a cathode and an anode, the cathode being sensitive to neutron impingement to cause current at the anode that provides for neutron detection, the method including:providing a boron-containing material;providing water;mixing the boron-containing material into the water to create a water-based liquid mixture;providing a substrate of the cathode of the neutron detector;applying the water-based liquid mixture to the substrate of the cathode at a location for neutron impingement to cause the current at the anode that provides for neutron detection;removing water from the water-based liquid applied to the substrate to leave a boron-containing layer upon the substrate that is sensitive to the neutron impingement to cause the current at the anode. 2. A method as set forth in claim 1, wherein the step of providing a boron-containing material includes providing the material to include B-10. 3. A method as set forth in claim 1, wherein the step of providing a boron-containing material includes providing the material to include at least one binder. 4. A method as set forth in claim 1, wherein the step of providing a boron-containing material includes providing the material to include at least one thickener. 5. A method as set forth in claim 1, wherein subsequent to the step of removing water the method further includes the step of drying the layer. 6. A method as set forth in claim 5, wherein subsequent to the step of drying the layer, the substrate and the layer are baked. 7. A method as set forth in claim 1, wherein the step of providing a substrate includes providing the substrate as a hollow cylindrical with an interior so that the hollow cylinder can receive the anode therein, and the step of applying the water-based liquid mixture to the substrate of the cathode at a location for neutron impingement to cause the current at the anode that provides for neutron detection includes applying the mixture to the interior of the hollow cylinder so as to face the anode received within the hollow cylindrical. 8. A method as set forth in claim 1, wherein the step of providing a boron-containing material includes providing the material to include B-10, and the steps of providing a boron-containing material including B-10 and removing water from the water-based liquid applied to the substrate to leave a boron-containing layer are such that a loading of B-10 is between about 0.1 mg/cm2 and about 1.0 mg/cm2 within the boron-containing layer upon the substrate. 9. A method as set forth in claim 8, wherein the loading of B-10 is between about 0.2 mg/cm2 and about 0.6 mg/cm2. 10. A method as set forth in claim 9, wherein the loading of B-10 is between about 0.35 mg/cm2 and about 0.4 mg/cm2. 11. A method for manufacturing a boron-lined neutron detector having a cathode and an anode, the cathode being sensitive to neutron impingement to cause current at the anode that provides for neutron detection, the method including:providing a B-10 containing material;providing water;mixing the B-10 containing material into the water to create a water-based liquid mixture;providing a substrate of the cathode of the neutron detector;applying the water-based liquid mixture to the substrate of the cathode at a location for neutron impingement to cause the current at the anode that provides for neutron detection;removing water from the water-based liquid applied to the substrate to leave a B-10 containing layer upon the substrate that is sensitive to the neutron impingement to cause the current at the anode. 12. A method as set forth in claim 11, wherein the step of providing a B-10 containing material includes providing the material to include boron that contains at least 90% B-10. 13. A method as set forth in claim 11, wherein the step of providing a B-10 containing material includes providing the material to include at least one binder. 14. A method as set forth in claim 11, wherein the step of providing a boron-containing material includes providing the material to include at least one thickener. 15. A method as set forth in claim 11, wherein subsequent to the step of removing water the method further includes the step of drying the layer. 16. A method as set forth in claim 15, wherein subsequent to the step drying the layer, the substrate and the layer are baked. 17. A method as set forth in claim 11, wherein the step of providing a substrate includes providing the substrate as a hollow cylindrical with an interior so that the hollow cylinder can receive the anode therein, and the step of applying the water-based liquid mixture to the substrate of the cathode at a location for neutron impingement to cause the current at the anode that provides for neutron detection includes applying the mixture to the interior of the hollow cylinder so as to face the anode received within the hollow cylindrical. 18. A method as set forth in claim 11, wherein the steps of providing a B-10 containing material and removing water from the water-based liquid applied to the substrate to leave a B-10 containing layer are such that a loading of B-10 is between about 0.1 mg/cm2 and about 1.0 mg/cm2 within the B-10 containing layer upon the substrate. 19. A method as set forth in claim 18, wherein the loading of B-10 is between about 0.2 mg/cm2 and about 0.6 mg/cm2. 20. A method as set forth in claim 19, wherein the loading of B-10 is between about 0.35 mg/cm2 and about 0.4 mg/cm2.
	description	This application is a National Stage of International Application No. PCT/CA2012/050218 filed Apr. 5, 2012, which claims the benefit of priority of U.S. Provisional Patent Application No. 61/472,388 filed Apr. 6, 2011. PCT/CA2012/050218 and 61/472,388 are incorporated herein by reference, in their entirety. The present disclosure relates generally to nuclear reactors. More particularly, the present disclosure relates to molten salt nuclear reactors. Molten Salt Nuclear reactors have been proposed in several different forms but two main areas differentiate their use. First is how the fissile and fertile materials are carried. Second is whether extra bulk moderator is employed (graphite is typically specified). The first factor sees three potential designs, which are described below. Single Fluid reactor design: One single salt that contains both fertile (e.g., thorium and/or U238) and fissile material (e.g., U233 and/or Pu239, U235 etc). The benefit of this mode of operation is that typically, the core design is quite simple. The drawbacks include: (1) difficult fission product removal chemistry (as thorium is chemically virtually identical to rare earth fission products) and (2) possibility of a large leakage of neutrons which both lowers the potential breeding ratio and may cause neutron induced damage on the reactor vessel. Examples of single fluid reactors include the circa 1970 Molten Salt Breeder Reactor (MSBR) of Oak Ridge National Laboratories (ORNL) and MOSART of Russia. Two Fluid reactor design: There are separate carrier salts for the fertile (typically thorium) and fissile material (typically U233). The two main benefits are simpler fission product removal chemistry and greatly reduced leakage of neutrons since they are absorbed in the surrounding fertile blanket. The main drawbacks are: (1) a potentially more complex core, (2) the need for a barrier material between the two salts that can retain strength in a strong neutron flux, and (3) somewhat decreased proliferation resistance understood by those trained in the field since a “blanket” is employed. As an example, a two fluid reactor design was studied by ORNL from 1960 to 1968. 1 and ½ Fluid reactor design (one and a half fluid reactor design): A hybrid design in which a central fuel salt containing both fertile and fissile material is surrounded by a fertile only blanket salt. This has the advantage of decreased leakage of neutrons but fission product removal remains difficult and there is still a barrier material needed between the central region and the blanket region, albeit potentially in a weaker neutron flux than the Two Fluid design. There is also the blanket salt proliferation issue. Examples include ORNL 1954 to 1960, and the French TMSR/MSFR 2005 to present. In the prior art, the use of a bulk moderator throughout the core (neutron moderator material formed throughout the volume of the nuclear core) can affect reactor design in many ways. Graphite has been by far the most commonly proposed moderator in the core but clad beryllium and/or heavy water has also been investigated. The main effect of having a moderator is a softening of the neutron spectrum, which can allow operation with far less fissile material. A second very important ability enabled by the use of bulk moderator is that it limits neutron leakage by a method referred to as an under moderated outer zone, which is described below. A Single Fluid design has the drawback that significant numbers of neutrons can be lost to leakage and these same neutrons can damage the outer vessel (typically a nickel alloy such as Hastelloy N). Adding reflector material between the core and vessel wall (i.e., adding a graphite lining to the vessel wall) has only a limited effect as would be understood by workers in the field. With graphite or other moderator throughout the core, Oak Ridge National Labs proposed an under moderated outer zone in the mid 1960s. They first calculated the ideal ratio of fuel salt to graphite for an infinite core (i.e., no worry of leakage). This led to a specific neutron spectrum, softened by the graphite, which implies that a particular ratio of fertile (typically thorium) to fissile (typically U233) will make the reactor critical. This salt to graphite ratio (typically about 13% salt in most ORNL work) is employed only for the central core. In a thin outer zone (typically about a meter or less in thickness) they used a much higher ratio of salt to graphite (37% in ORNL work). This results in a harder neutron spectrum in this zone and, as would be understood by workers in the field, leads to a much greater absorption of neutrons in the fertile (thorium) versus production in fissile (U233). For an example, see Nuclear Applications & Technology, Vol. 8, February 1970, page 210, FIG. 1. In reactor physics terms this means the inner core has a K infinity of greater than one (net producers of neutrons) while the outer zone has K infinity much less than one (net absorber). The overall combination is a K effective of just over 1.0 as required to maintain criticality. Three cases relating to an unreflected core, a reflected core and a core with an under moderated outer zone core are shown in FIGS. 1 and 2, which are meant only to show differences in neutron flux profiles for different types of single fluid reactors. In FIG. 1, plot 1 shows the neutron flux for a single fluid molten salt nuclear core being free of any neutron reflector at the periphery of the nuclear core vessel (i.e., in the absence of reflector 4), and plot 2 shows the neutron flux for a nuclear core having a 40 cm-thick neutron reflector 4 at the periphery of the nuclear core vessel. Also shown at FIG. 1 is a wall 3 of the reflector 4. FIG. 2 shows a neutron flux plot 5 (neutron flux profile) for a single fluid molten salt reactor core without a reflector but with an under moderated outer zone 6. As shown in FIG. 2, the neutron flux at the outer periphery (˜200 cm) is greatly reduced in comparison to the unreflected “bare core” plot 1 of FIG. 1. There are significant drawbacks to using bulk graphite or other moderators (clad beryllium, heavy water). For example, graphite is known to have a limited lifetime in the core which has forced designers to either propose very low power density and thus very large cores or to plan for periodic graphite replacement which is a difficult challenge. As well, the overall safety of Molten Salt Reactors is outstanding but the potential fire hazard of graphite cannot be ignored. Finally graphite use represents a significant disposal. With clad beryllium used throughout the core, the losses of neutrons to the cladding are excessive. Thus it has long been a desire to be able to design a practical Single Fluid reactor that does not employ bulk moderators such as graphite. However, without an under moderated outer zone, the issue of neutron leakage and damage to the outer vessel have always curtailed these efforts. As well, the less moderated neutron spectrum means a shorter prompt neutron lifetime which has negative implications on reactor control as would be known by those trained in the field. As an example, in the MOSART design of Russia which is a Single Fluid transuranic waste burner, they felt the need to propose two thick layers, a layer of graphite facing the salt to slow neutrons down and reflect some neutrons and then of steel blocks to absorb the unreflected neutrons. This 20 tonne liner of graphite would still require periodic replacement which limits the design's utility. Finally, as would be known by those trained in the art, a graphite reflector can in many cases actually increase the overall leakage of neutrons due to a fission power peaking from more thermalized neutrons re-entering the core salt from the graphite reflector. Therefore, improvements in molten salt nuclear reactors are desirable. In a first aspect, the present disclosure provides a single fluid molten salt nuclear reactor that comprises: a vessel having a central region and a vessel wall; a support structure; a neutron moderator secured to the support structure and located in the central region of the vessel, the neutron moderator having at least one through hole defined therein; and a pump to circulate a molten salt in the vessel, the support structure, the neutron moderator, and the pump being arranged to circulate the molten salt through the at least one through hole of the neutron moderator and between the neutron moderator and the vessel wall. In a second aspect, the present disclosure provides a single fluid molten salt nuclear reactor that comprises: a vessel having a central region and a vessel wall; two opposite walls disposed at opposite ends of the vessel; a support structure; a neutron moderator secured to the support structure and located in the central region of the vessel; a molten salt inlet formed on one of the two opposite walls; a molten outlet formed on the other of the two opposite walls; and a pump operationally connected to the molten salt inlet and to the molten salt outlet, the pump to circulate a molten salt in the vessel. Other aspects and features of the present disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures. The present disclosure provides an improved Single Fluid Molten Salt Nuclear Reactor (also referred to as a Single Fluid Reactor). In some embodiments, the core diameter of the Single Fluid Reactor can range from 2 to 4 meters. The Single Fluid Reactor has an inner zone that includes a solid neutron moderator, which can have salt coolant channels (through holes) defined therein. In some embodiments, the solid neutron moderator can be replaced when required. This solid neutron moderator can have a relatively small diameter, which can range, in some embodiments, from less than one meter to about 1.5 meter. The solid neutron moderator effectively creates an inner zone with a neutron spectrum (profile) that is far more thermalized than if the solid neutron moderator were absent. The surrounding layer of salt surrounding this modest sized inner zone (the inner zone can also be referred to as a central zone) will have a much harder neutron spectrum. The inner zone to which the present disclosure refers is the volume of the solid neutron moderator plus the volume of any through holes or apertures defined by the solid neutron moderator. By choosing a single fuel salt with an appropriate ratio of fertile (e.g., thorium or U238) to fissile (e.g., U233, U235, or Pu) one can assure that the inner zone has a k infinity of much greater than 1.0 and the outer layer of pure salt a K infinity of less than 1.0, and that overall the k effective is the needed value of just over 1.0 as would be understood by a worker skilled in the art. FIG. 3 shows two plots of the neutron flux for a Single Fluid Reactor. Plot 7, labeled “no central zone”, is when no central moderated zone (no neutron moderator at the central region) is present in the Single Fluid Reactor. As shown by plot 7, in this situation there is still significant neutron flux at the outer edge of the core which is the vessel wall 8. The neutron flux at the wall 8 can lead to potential damage and to loss of neutrons to leakage. Plot 9, labeled “Two Zone Profile”, is with the central moderated zone 10 present and, as the outer zone (the zone outside the moderated zone 10) is under-moderated this leads to a much more rapid decline in the neutron flux and effectively a much lower neutron flux at the outer vessel wall. Plot 9 shows that a Single Fluid Reactor, in accordance with the present disclosure, can lead to significantly less damage at the wall 8 of the vessel containing the fuel salt. FIG. 4 shows a generalized depiction of an embodiment of a Single Fluid Reactor of the present disclosure. The Single Fluid Reactor includes an outer vessel 20, a central moderator 22 that defines through holes 24 (salt channels) to allow passage of molten salt (fertile/fissile salt) therethrough. The molten salt traverses the channels 24 in the direction of the arrow 26. The volume comprised between the central moderator 22 and the outer vessel 20 includes a salt zone 28, free of bulk solid moderator, in which the fissile/fertile salt also flows in the direction of the arrow 26. For clarity purposes, FIG. 4 does not show entry and exit ports for the salt, or other ancillary elements. The presence of the central neutron moderator 22 can result in a similar under moderated outer zone like the 1970 single fluide MSBR and will result in the salt zone 28 being a net absorber of neutrons (more absorbed by the fertile elements (Th and/or U238) versus produced by the fissile elements (U233, Pu239 etc). As a result, the power and neutron flux distribution should follow that shown in plot 9 of FIG. 3 and lead to a greatly reduced leakage of neutrons and reduced neutron induced damage to the outer vessel wall. As will be understood by the skilled worker, the dimensions of the vessel and of the neutron moderator can be determined in accordance with constituents of the molten salt to maintain a flux of neutrons at the vessel wall below a pre-determined neutron flux, such as to avoid damage to the vessel wall. This reduced neutron flux at the wall (periphery) of the outer vessel 20 resulting from the present disclosure will allow a practical reactor without a graphite reflector. This significantly reduces the complexity of design and operation as there is not any graphite liner replacement required. Further, as there are essentially no neutrons reflected (there is no graphite reflector), there is no issue of power peaking due to the graphite reflector thermalizing neutrons. Having a simple steel liner as a reflector/absorber before the final outer vessel wall is optional. The reduced neutron flux at the wall (periphery) also means far fewer neutrons lost to leakage and a resultant improvement in the conversion and/or breeding ratio. This reduced neutron flux at the outer periphery of the reactor core (reduced neutron flux at the wall of the vessel 20) can have a significant benefit on reactor control. As is known in the art, if a reactor has a mix of thermal and fast fissions, with at least 5% of fissions coming from the thermal spectrum, then these reactions that stem from the thermal spectrum, with their longer prompt neutron lifetime, will regulate the reactor, which improves reactor control. Different embodiments beyond the above generalized depiction of FIG. 4 are described below. Another embodiment of the present invention is shown in FIG. 5, where a rigid support structure 40 that is connected to, and extends down from, the top 21 of the outer vessel 20. The embodiment of FIG. 5 addresses the physical stability of the central zone, which includes the central moderator 22. The rigid support structure 40 can be made of material that includes, but is not limited to, graphite, molybdenum or Hastelloy N. In addition to being supported at the top of the outer vessel 20, the rigid support structure 40 can also be connected to any other suitable portion of the outer vessel to ensure that the central moderator 22 inserted in the support structure 40 does not move with respect to the outer vessel 20. Any suitable connection means between the outer vessel 20 and the support structure are within the scope of the present disclosure. Although not shown in FIG. 5, the rigid support structure 40 can have openings defined therein to allow passage of molten salt through the rigid support structure and through the central moderator 22. In FIG. 5, the salt flow from the top 21 of the vessel, in the direction indicated by arrows 23. In the embodiment of FIG. 5, the flow of salt through the through holes 24 of the central moderator 22 will be limited as most salt will follow the path of least resistance around the core. However, it can be advantageous to physically direct a greater volume of salt flow in the direction of the central moderator 22 and its through holes 24. The embodiment of the present disclosure shown at FIG. 6 addresses this issue. To direct a higher salt flow through the central moderator 22, a salt flow guide structure 60 can be used. The salt flow guide structure 60 can be tube shaped (cylinder shaped) and can extend from the bottom (bottom wall 2000) to the top (top wall 2002, opposite the bottom wall) of the outer vessel 20 (the bottom wall and top wall are disposed at opposite ends of the vessel 20). The outer vessel 20 has salt inlet ports 62 that can be configured (sized) to force a higher relative percentage of salt through the salt flow guide structure 60 and through the central moderator 22. Although not shown in FIG. 6, the salt inlet ports 62 are connected to a pump system that pumps a molten fuel salt through the salt inlet ports 62. The pump system can be arranged to have a different pump rate for different salt inlet ports 62. The fuel salt having entered by the inlet ports 62 leaves the outer vessel 20 through salt exit ports 64 to then travel on to the primary heat exchangers (not shown). The salt flow guide structure 60 can include, for example, a simple tube of graphite itself or Molybdenum and/or Molybdenum alloy such as TZM or Hastelloy N. Arrows 23 indicate the direction of molten salt flow. In some embodiments, the salt flow guide structure 60 can also be used as a guide for control rod or rods (an option not depicted). Control or shutdown rods are often considered optional but this new core feature may allow them to function practically. As would be understood by a skilled worker, control rods have much greater net worth in a softer neutron spectrum and are a challenge to provide enough neutron absorption for faster neutron spectrums. In the case of the present disclosure, a control rod can be inserted into the central core zone where the spectrum is softer or more thermalized. Another embodiment of the present disclosure is shown at FIG. 7, which shows salt entry and exit being accomplished from the top 21 of the outer vessel 20. The incoming cooler salt enters the reactor core through a salt flow guide structure 80 leading to the central core after which the salt loops back to exit tubes (salt exit piping 82) on the top of the vessel, for example, adjacent the periphery of the outer vessel 20. The now hotter fuel salt exits the reactor core through salt exit piping 82 and apertures 25, and travels to the primary heat exchanger (not depicted). Although not shown in the Figure, salt exit piping 82 can be present at all apertures 25. The molten salt flow direction is indicated by arrows 23. Although not shown, the flow direction of the molten salt could be reversed from that shown in FIG. 7. That is, the molten salt could enter from piping 82 (in this embodiment the piping would be referred to as salt inlet piping) and exit through the guide structure 80. Regardless of the flow direction of the molten salt, in the embodiment of FIG. 7, the molten salt circulates through the holes of the central moderator 22 (neutron moderator) and between the central moderator and the vessel wall of the vessel 20. Another embodiment to discuss is the moderator itself. Graphite is a possible choice of material for the central moderator 22. Graphite is known to expand beyond its original dimensions after a certain amount of fast neutron flux. Such expansion may prove allowable although in some cases, a graphite central moderator will require periodic replacement. The small size of the central moderator 22 can facilitate this replacement during for example, planned shutdowns for general maintenance or inspection. Alternatively, Beryllium compounds such as, for example, Beryllium Oxide and Beryllium Fluoride, powdered graphite, or any other suitable moderator material could be used within a cladding without departing from the scope of the present disclosure. Cladding could include but not be limited to, Molybdenum, TZM or Hastelloy N. The combination of molybdenum and beryllium compound for example could be such that very long core residency times could be reached as both materials are expected to have a very long potential residency time, potentially a full reactor lifetime of 30 to 60 years. The support structure 40 (FIG. 5), the guide structure 60 (FIG. 6), and the guide structure 80 (FIG. 7) can also be made from the same list of potential cladding materials. As any cladding or support structure is only a minor fraction of the overall core, the neutron losses to this material should not be significant and there is the option of using isotopically enriched materials to further reduce losses as would be understood by someone trained in the art. The embodiments shown at FIGS. 4, 5, 6 and 7 are meant as generalized depictions uncomplicated by the associated components needed outside the reactor core. FIG. 8 represents another embodiment showing a more detailed system. The bottom portion of FIG. 8 is similar to the generalized depiction of FIG. 7. The central moderator 22 is held in place by the salt flow guide structure 80, which passes through an aperture in a top reflector 100 that connects to the output of the primary heat exchanger (PHX) 102. The top reflector 100 can limit or prevent neutrons from reaching the primary heat exchanger. As an example, stainless steel 316 SS can be used as a material for the top reflector 100. The PHX 102 can be, but is not limited to, a tube within shell heat exchanger. The salt is driven through the PHX 102 by a main pump 104. The fuel salt thus travels through the PHX 102, through the salt flow guide structure 80, through the central moderator 22, and then loops back along the periphery of the outer vessel 20 outside the PHX 102 to just above the PHX where it is then pumped back through the PHX 102. The molten salt flow direction is indicated by arrows 23. The outer vessel 20 is connected to a reactor lid 110 by connecting bolts 114. Inlet coolant salts enter through piping 106 to the PHX 102 and then exit through piping 108. This coolant salt delivers the usable heat to an Intermediate Heat Exchanger (not depicted) which heats a turbine working media (Steam, He, Supercritical CO2, N2, Air etc). Small extra penetrations include helium gas bubbling tube(s) 116 and exit plenum gas tube(s) 118. As understood by those in the field, this system is to help remove fission gases Xenon and Krypton along with other volatile and noble fission products. Finally, at the bottom of the core is a drain line 120 leading to a freeze plug and decay heat tanks as is standard in molten salt reactor design. Although not shown, the main pump 104 could be arranged such that the flow direction of the molten salt could be reversed from that shown in FIG. 8. In the embodiment of FIG. 8, the guide structure 80, the central moderator 22, and the main pump 104 are arranged to circulate the molten salt through the through holes of the central moderator 22 and between the central moderator 22 and the vessel wall of the vessel 20. In the embodiments presented herein, the guide structures 60 and 80 can also be referred to as support and guide structures, as they also support the central moderator 22. The support structure 40 of FIG. 5 can also be referred to as a support and guide structure, as is also guides molten salt towards the central moderator 22. In the embodiments presented herein, the central moderator is shown as being cylindrical with cylindrical through holes parallel to the height of the cylinder. However, as will be understood by the skilled worker, any other suitable shape of central moderator and through holes is also within the scope of the present disclosure. Further, even though the central moderators depicted herein define through holes, this need not be the case. To give examples of sizes, the entire reactor vessel may be some 7.5 meters in height and 3.5 meters in diameter. The central moderator 22 can have a diameter of the order of one meter. The top reflector 100 can have 50 cm of thickness and the PHX 102 can be 3 meters tall and 3 meters in diameter. Such a PHX 102 could provide approximately 21 cubic meters of heat exchanger and adequate for 2250 MWth and thus roughly 1000 MWe. The active fuel salt volume in the lower core region would be a cylinder roughly 3.5 m high and 3.5 m in diameter or roughly 34 cubic meters. A further 16 cubic meters of fuel salt may be found in the outer periphery around the PHX 102, the top collection plenum and within the PHX 102. A total salt volume of 50 cubic meters gives a quite conservative power density within the core (other prior art ranged from a fuel salt volumes of 15 to 100 cubic meters per 1000 MWe). The advantages of this integrated system include the fact that the entire primary fuel loop is within the primary reactor vessel. After disconnecting coolant salt entry 106 and exit 108 piping and unfastening the bolted 114 reactor lid 110, the entire assembly of pump, PHX, reflector, guide structure and inner core can be removed for inspection and/or maintenance by an overhead crane (not depicted). Again, as a reminder, without the central moderator 22 modifying the neutron flux profile and greatly lowering the neutron flux at the outer vessel wall 20 and internal reflector 100 such a reactor could not expect any significant lifetime out of the Hastelloy N components. As well, leakage of neutrons would both greatly lower the conversion or breeding ratio. As such, the present disclosure provides a practical Single Fluid Molten Salt Nuclear Reactor without any bulk moderator material. The following presents modeling results of embodiments of the present disclosure. The modeling was done using Monte-Carlo N-Particle (MNCP) code. The modeling was focused on systems with U235 as the primary fissile (as it would be a likely startup fissile material) and U238 as the primary fertile material. The modeled reactor geometry shown is that of FIG. 9. FIG. 9 shows a top down view that shows the outer reactor vessel wall 900 of diameter D 902 and having a central moderator 904 with salt flow channels (through holes) of diameter d 910 and pitch L 908. The central moderator zone being a distance S 906 from the outer vessel wall with the space between being filled with fuel salt. FIG. 10 shows a side view of the system modeled. The outer vessel wall 900 has a thickness t 918. The inner moderator core 904 has a width w 912 and a height h 916 and is centered such that the distance H 914 from the top and bottom of the vessel are the same. FIG. 11 shows a top down view of the moderator core itself which has a radius R 920 and a minimum spacing r 922 from the outer most salt channel to the outside of the moderator core. For initial modeling runs a wall thickness t 918 of 1 cm of Hastelloy N (high nickel alloy) is used and the reactor vessel 904 is a right cylinder of 4 meters inside diameter and 4 meters in height. Several diameters and heights of the inner moderator zone 904 have been modeled, all with the same arrangement of nineteen salt channels with a 20 cm pitch L. For simulation purposes, the diameter W and height h have been kept equal and values of 1 meter, 1.5 meter and 2.0 meters have been modeled. Nuclear grade graphite is assumed for these models and a temperature of about 650° C. assumed for the molten salt temperature. As discussed below, the modeling of embodiments of the present disclosure shows an increased benefit from the fast neutrons and, a decrease of neutron flux at the vessel wall. Modeling results also indicate that, in some cases, a low ratio of fissile to fertile material can achieve criticality. This is especially important when starting reactors on Low Enriched Uranium where up to 20% U235 enrichment is possible on proliferation grounds but above 5% enrichment is more difficult to obtain commercially. Results of three modeling runs are as follow. The first modeling run involved a simple 1 meter diameter (w 912, FIG. 10) by 1 meter high (h 916, FIG. 10) cylindrical graphite core with 19 channels of 10 cm diameter d (910, FIG. 9), a minimum spacing r (922, FIG. 11) of 5 cm, and a pitch L (908, FIG. 10) for a salt flow giving a salt to graphite ratio of approximately 19% in the central core. Fuel salt was a 73% LiF-27% UF4 eutectic with a 470° C. melting point. Just under 12% U235 enrichment was required to be critical. This initial modeling attempt was not ideal as the calculated (modeled) leakage of neutrons was still relatively high at 4% but this is already a large improvement over what would be expected without the central core. The modeling results included a very large fast fission bonus from U238 of 7.23% of all fissions. As well, parasitic losses of neutrons to the enriched lithium (0.09%), fluorine (1.2%), carbon atoms (0.04%) and the outer vessel wall were very low, totaling 1.4% of absorptions. Just over 5% of fissions came from neutrons of thermal energy (below 0.625 eV). In a second modeling run, the same inner core arrangement of 19 fuel salt channels was used as in the first modeling run described above. That is, the interspacing (or pitch L 908) of the through holes and the diameter of the through holes was unchanged. However, the diameter w and the height h of the moderator core 904 were increased to 2 meters each, and the minimum spacing r (922, FIG. 11) was increased to 55 cm. The results of this second modeling run show quite high losses to graphite (3.4%) which is not surprising as the pure graphite radial layer is 55 cm thick. The results of the second modeling run also show a lowering of losses to neutron leakage to 1.0% as well as having a surprisingly low requirement of U235 enrichment of only 3.2% (lower than current light water reactors). Most fissions in the second modeling run were thermal (68%) and the fast fission bonus dropped to 5.2%. In a third modeling run, the same inner core arrangement of 19 fuel salt channels was used as in the first and second modeling runs described above. That is, the interspacing of the through holes and the diameter of the through holes was unchanged. However, the diameter w and the height h of the moderator core 904 were set to 1.5 meter each, and the minimum spacing r (922, FIG. 11) was set to 30 cm. The modeling results show a somewhat higher U235 enrichment (4.44%) than in the second modeling run, a 5.63% U238 fast fission bonus, losses to graphite of 1.2% and neutron leakage of only 0.74% of neutrons (lower than any molten salt reactor design work of ORNL, even including their Two Fluid studies which had 0.8% lost to neutron leakage and reflector loses, (e.g., see ORNL 4528)). FIG. 12 shows plots of relative neutron flux as a function of neutron energy, the plots resulting from the third modeling run described above. Plot 1000 represent the aforementioned flux at the center of the central moderator 904 and the plot 1002 represents the neutron flux at the wall of the nuclear reactor. As evidenced by FIG. 12, there is a decrease in relative neutron flux from the center to the outer periphery (wall) as it drops by 3 to 4 orders of magnitude. These combinations of very low parasitic losses and substantial U238 fast fission bonus result in an initial conversion ratio of 0.90 which is much higher than the initial ratio of roughly 0.80 that ORNL modeled for the denatured molten salt reactor (DMSR) described in ORNL TM 7207 that started on a mix of 20% LEU and thorium but with bulk graphite throughout the core. As well, there was almost no fast fission bonus of U238 in the DMSR study. Thermal fissions accounted for 55% of all fissions. For the 1.5 m by 1.5 meter third modeling run, comparing parasitic absorptions to other reactors (not including fission products or nonfertile and nonfissile actinides such as U236 and Np237) there is a total of just over 3% loses. Compared to this is 4.8% in the DMSR (ORNL TM 7207) and 5.5% in the MSBR (ORNL 4541). Much higher of course are conventional reactors with 11.7% in heavy water CANDUs and roughly 22% in Light Water Reactors. The latter reactors are predominantly in control poisons not required in MSR designs. The most recent modeling returned to the small 1 m diameter w by 1 m high h core but changed to smaller channel diameter d of 8 cm. The higher ratio of graphite to fuel salt had the desired effect of increasing the k inf in the inner core and greatly decreasing neutron leakage from the vessel while retaining more benefits of the fast spectrum. For criticality the needed enrichment of U235 was 9.9%. The leakage was a very low 0.66% and reactor vessel wall absorptions only 0.14% (with now a more practical wall thickness t of 5 cm). Carbon absorptions were only 0.12% and total parasitic absorptions the lowest to date at 2.4%. The fast fission bonus remained a very high 7.1% of all fissions. In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that these specific details are not required. The above-described embodiments are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope, which is defined solely by the claims appended hereto.
	summary
047180765	claims	1. An X-ray imaging apparatus comprising: means for generating X-rays, including electron gun means for emitting an electron beam, anode target means for receiving the electron beam emitted by said electron gun means, and for irradiating X-rays at an X-ray focal spot on said anode target means, and means for moving said X-ray focal spot in a first direction by a first distance on said anode target means; a slit plate, separated from said X-ray generator means by a second distance, and disposed substantially parallel to said first direction in which said X-ray focal spot moves, said slit plate formed with a plurality of elongated slits which allow X-rays to pass therethrough, and which are arranged side-by-side, each extending in a second direction substantially perpendicular to said first direction in which the X-ray focal spot moves on said anode target means, said slits being adjacent to each other and separated from each other by a third distance; means for detecting X-rays, having a two-dimensional input plane, including a projected area, arranged opposite to said slit plate, so as to accommodate a subject to be imaged between said slit plate and said detcting means, said X-ray detecting means being separated from said slit plate by a fourth distance, said X-ray detecting means for detecting X-rays having passed through said slits and the subject and impinged on said two-dimensional input plane, and converting said X-rays into electrical signals indicative thereof, the detected x-rays being comprised of scattered components and fundamental components, where the fundamental components comprise x-rays which pass directly through the subject without scattering, said first, second, third and fourth distances having a relation such that, when the X-ray focal spot moves on said anode target by said first distance, those areas on said two-dimensional input plate of said X-ray detecting means, on which X-rays having passed through adjacent slits impinge, partially overlap; data processing means for processing said electrical signals converted by said X-ray detecting means, said data processing means providing processed electrical signals corresponding to said fundamental components of the X-rays having passed through said slits and the subject, including: (1) means for dividing said projected area into a plurality of portions which extend parallel to said second direction in which said slits extend, and (2) means for acquiring electrical signals corresponding to the fundamental components from each of said portions, said fundamental components being those of the X-rays which impinge onto that area on said two-dimensional input plate which are projected from said x-ray focal spot through said slits, said data processing means comprises means for reconstructing an X-ray image based on said electrical signals corresponding to said fundamental components; and image display means for displaying the image reconstructed by said data processing means. generating X-rays using an electron gun which emits an electron beam at an anode target to an X-ray focal spot thereupon; collimating said X-rays by providing a slit plate separated from the electrion gun, said slit plate formed with a plurality of elongated slits which allow X-rays to pass therethrough and which extend in a first direction; detecting X-rays with detector means, which have passed through said slit plate and a subject to be X-rayed, the detected x-rays being comprised of scattered components and fundamental components, where the fundamental components comprise x-rays which pass directly through the subject without scattering, moving x-ray focal spot on said anode target in a second direction which is perpendicular to said first direction, so as to form a plurality of x-rays which scan several areas on said detector means, where the scanned areas formed by x-rays passing through adjacent slits partially overlap, converting said detected x-rays to electrical signals; processing said electrical signals by providing processed electrical signals corresponding to fundamental components of the X-rays having passed through said slits and said subject, said processing occurring by dividing a projected area into a plurality of continuous portions, each of which extend parallel to said first direction in which the slits extend, and acquiring first electrical signals corresponding to said fundamental components from each of the portions; reconstructing an X-ray image based on said first electrical singals; and displaying the reconstructed image. 2. An x-rays imaging apparatus according to claim 1 in which said X-ray detecting means comprises an X-ray image intensifier. 3. An X-ray imaging apparatus according to claim 1 in which said X-ray detecting means comprises a camera tube. 4. An X-ray imaging apparatus according to claim 1, in which said data processing means picks up the electrical signals corresponding to said fundamental components and electrical signals corresponding to scattered components appearing on an area outside, but near said projected area on said two-dimensional input plane, said data processing means comprises mean for processing said signals to eliminate the scattered signals. 5. An X-ray imaging apparatus according to claim 1 in which said data processing means comprises means for storing both the electrical signals corresponding to said fundamental components and the electrical signals corresponding to scattered components appearing on an area outside said projected area on said two-dimensional input plate, and comprises further processing means to remove the electrical signals corresponding to scattered components appearing on said outside area so that only the electrical signals corresponding to said fundamental components are provided to said data processing means. 6. An X-ray imaging apparatus according to claim 1, in which said slit plate is a lead plate having through-holes forming said slits. 7. An X-ray imaging apparatus according to claim 1, in which said means for moving the X-ray focal spot is for reciprocally moving said focal spot in a third direction parallel to said first direction in which said focal spot moves, a first frequency, by which said focal spot reciprocally moves in said fist direction, being higher than a second frequency, by which said focal spot moves in said third direction. 8. An X-ray imaging apparatus according to claim 1 wherein said data processing means has means for dividing said projected are into a plurality of continuous portions. 9. A method for perofrming X-ray imaging, comprising the steps of:
052415783	summary	BACKGROUND OF THE INVENTION The present invention relates to a grid alignment system for portable radiography. Portable radiography accounts for an increasing proportion of x-ray examinations performed in hospitals. In the University of Chicago hospitals, approximately 50% of all chest radiographs are obtained at the bedside with portable radiographic apparatus. Though the clinical importance of these examinations is beyond question, the image quality is generally inferior to that obtained with fixed radiographic apparatus in an x-ray department. The inferior image quality obtained using portable radiography apparatus is widely recognized, and is a source of concern to radiologists and clinicians. This poor image quality is commonly attributed to intrinsic limitations of portable radiography apparatus, however, it is in fact mainly due to uncontrolled scattered radiation, which fogs the radiograph, reducing contrast and obscuring diagnostic information. Use of an accurately aligned anti-scatter grid can provide consistently high image quality, but precise alignment of the grid relative to the x-ray source is essential for good results. Such precise alignment is difficult to achieve with conventional manual or "eye-ball" techniques. For portable radiography, excellent results can be achieved with a 6:1 or 8:1 anti-scatter grid, provided that the x-ray beam energy is no greater than 90 KV, and provided that the anti-scatter grid is accurately aligned with respect to the x-ray source. Referring to FIG. 1, accurate alignment of portable radiographic machine 20 relative to anti-scatter grid 21 and x-ray film 22 is illustrated in position A, while inaccurate alignment is illustrated in position B. In the case of a conventional lead strip linear anti-scatter grid, alignment is critical only in one dimension, that is, across the grid lines. Moderate angulation error along the direction of the grid lines does not significantly impair image quality. In other words, referring again to FIG. 1, moderate misalignment about a horizontal axis lying within the plane of the page is not so critical, whereas alignment about an axis perpendicular to the plane of the page is critical. Further, with a focused grid, it is also necessary for central x-ray beam 23 of portable x-ray machine 20 to be centered accurately with respect to anti-scatter grid 21. Further, variations in focus distance are important, but mainly affect film density, provided that the portable x-ray machine 20 is properly centered and aligned relative to anti-scatter grid 21. In the case of a two dimensional grid, for example a cross-hatch grid or pinhole grid, alignment is critical in two dimensions. A system that addresses this alignment problem is presented in U.S. Pat. No. 4,752,948, issued Jun. 21, 1988, and assigned to the same assignee as the present application. The disclosure of U.S Pat. No. 4,752,948 is expressly incorporated herein by reference. While adequately addressing the problem of alignment between x-ray beam and anti-scatter grid in a portable x-ray apparatus, this patented device presents a mechanical system which has proven somewhat difficult to retrofit to existing portable x-ray apparatus, or to use with very ill patients who are unable to cooperate. Therefore, a need exists for a simple alignment system which can be easily retrofitted to existing portable x-ray apparatus, and which can be used in the most difficult clinical situations. Commercially available grid cassettes (x-ray film holders incorporating anti-scatter grids) include a 14.times.17 inch (35.6.times.43.2 cm) lead strip grid encased in nylon/plastic material. These grid cassettes are relatively crudely manufactured and are heavy and cumbersome to handle. When the grid lines are oriented vertically, the total transverse dimension of the grid is 14 inches (35.6 cm). Therefore, in heavy-set broad patients, it is necessary to rotate the grid cassette 90.degree. so that the grid lines run transversely, orienting the longer dimension of the grid horizontally. This maneuver, which has been found to be necessary in between 25% and 50% of portable chest radiographs, frequently results in severe misalignment. This is so because the necessary vertical adjustments which must be performed accurately to align the x-ray beam with the grid are more difficult to judge accurately when the grid is transversely oriented In addition, transversely orienting the grid requires the x-ray source and collimator to be rotated, an additional adjustment step. Therefore, it would also be desirable to maintain the anti-scatter grid orientation in a vertical direction for all patients, while permitting the x-ray film to be oriented either vertically or horizontally facilitating the accommodation of heavy-set broad patients. SUMMARY OF THE INVENTION The present invention in large part avoids the above-noted problems of the prior approaches to alignment between a portable x-ray apparatus and an anti-scatter grid by providing a simple grid alignment system, which can be retrofitted to existing equipment. In addition, the invention provides a new grid cassette which facilitates the horizontal or vertical orientation of x-ray film in portable radiography, while permitting the anti-scatter grid to maintain a single orientation. To facilitate accurate alignment and centering of the central x-ray beam with a focused grid in a clinical setting, the present invention employs a light projector, specifically, a laser light projector, and a unique compact reflector element. The projector is mounted in or on the collimator housing of a portable x-ray machine, and can be powered from the collimation light circuit or from a separate battery. The light projector is positioned so that a light line or spot is projected parallel to the central x-ray beam of the x-ray source. An opaque line on the transparent front surface of the collimator housing appears as a dark shadow within the field projected by the collimation light. The coincidence of this dark shadow with the laser light is indicative of placement of the grid cassette at the proper focal distance from the x-ray source. Angulation errors between the x-ray source and grid cassette are indicated by a compact reflector element which either temporarily attaches to or is formed integrally with the grid cassette. The front of the reflector element is covered by an imaging surface, and a reflecting surface is located behind the imaging surface. The incident light line or spot creates an image on the imaging surface, and the light line or spot reflected from the reflecting surface also forms an image on the imaging surface. The amount of separation between the two images on the imaging surface is indicative of the magnitude of angulation alignment error between the grid cassette and the x-ray source. When alignment is accurate, the incident light line or spot and reflected light line or spot are superimposed on the imaging surface. To confirm the accuracy of beam alignment, the present invention contemplates at least one pair of small radiopaque markers which are inserted into the front and rear surfaces of the grid cassette. Each pair of markers is positioned so that when the x-ray beam is perfectly aligned and centered, the images produced by the markers on the x-ray film are substantially superimposed. Misalignment or decentering of the x-ray beam results in misregistration of the markers, and the amount of misalignment can be quantified by assessing the amount of misregistration. The present invention also contemplates a grid cassette which is capable of accommodating either vertically or horizontally oriented film cassettes without requiring reorientation of the grid cassette. This allows accommodation of broad, heavyset patients without the misalignment errors that typically occur when the grid cassette is reoriented. The grid cassette also includes an integrally formed hand hold for easy portability and to facilitate placing the grid cassette behind a patient. These and other features and advantages of the present invention will become apparent to one of skill in this art with reference to the drawings and following detailed description of the preferred embodiments.
055966128	claims	1. Testing arrangement (14) for materials testing at a lead-through (4) in a nuclear reactor, said lead-through (4) comprising a first tube (6) welded into an opening in a reactor cap (1) and a second tube (8) inserted in the first tube (6), whereby the first tube (6) and the second tube (8) are sealingly joined at a common upper end and whereby the second tube (8) projects further under the reactor cap (1) than the first tube (6), said testing arrangement comprising a probe-equipped sword (85) arranged for insertion into an annular gap (20) that is present between both the tubes and for scanning a testing area which extends around said gap, whereby a manipulator (10) is arranged to position the testing arrangement opposite to the lead-through (4), the testing arrangement (14) comprising a pinching arrangement (32), which applies a pinching force between a point at the outer surface of the first tube (6) and an opposite point at the outer surface of a projecting part of the second tube (8), in order to widen the gap (20) at the side of the second tube (8) at which the pinching force is applied, a sword guiding arrangement (74) cooperating with the pinching arrangement (32) to guide the sword (85) into the widened part of the gap (20), a first lifting arrangement (24,40,42,44) for bringing the pinching arrangement on a level with the lower part of the outer tube, a second lifting arrangement (82,83,84) for inserting the sword (85) into the gap (20), and a turning arrangement for displacing, in cooperation with the pinching arrangement (32), the widened part of the gap along the inner periphery of the first tube (6) and for displacing in connection therewith the sword in the gap through the testing area, wherein the testing arrangement (14) is attachable to the above mentioned manipulator, and wherein the testing arrangement (14) is dockable at a chosen lead-through (4) by means of the manipulator (10), wherein the lifting arrangements are arranged at the turning arrangement and wherein the pinching arrangement (32) is arranged at the first lifting arrangement (24,40,42,44), and the sword guiding arrangement (74) carrying the sword (85) is arranged at the second lifting arrangement (82,83,84), both lifting arrangements being linearly movable in the axial direction of the tubes. 2. Testing arrangement according to claim 1, wherein the sword guiding arrangement (74) is pivotable between a position enabling passage for the sword (85) past an end piece (9) arranged at the lower end of the inner tube (8) and a position above said end section (9), close to or against the outer surface of said inner tube (8). 3. Testing arrangement according to claim 1, wherein the sword guiding arrangement (74) is provided with a detector for detecting, in connection with the lifting movement of the first lifting arrangement, the fact that said sword guiding arrangement is in contact with or is close to contact with the lower part of the first tube (6). 4. Probe sword (85) for insertion into an annular gap (20) between two concentrically arranged tubes (6,8) and for displacement as well in the axial direction of the tubes as around said annular gap (20), wherein the probe sword (85) comprising a probe end, an elastic sword blade with an essentially U-shaped cross section, a connection means (96) at the end opposite to the probe end and a probe (100) mounted at the probe end, the sword further comprising at least one conduit (98), running along an edge of the sword, for conveyance of a fluid to the probe end, and at least one electric wire (97), running along an edge of the sword, for the connection to the probe, and wherein the connection means (96) comprises means for attachment to a sword actuator (82,83,84) and for connection of inlet conduits for fluid and of an electric input wire and/or output wire. 5. Probe sword (85) according to claim 4, wherein the probe (100) is attached to a holder (106) which is attached to the probe end of the sword, the holder (106) being resilient in a transverse direction. 6. Probe sword (85) according to claim 4, wherein said sword is provided with a through aperture in which the probe (100) is mounted. 7. Probe sword (85) according to claim 4, wherein said probe (100) is a cleaning probe (104) comprising at least one brush (108), adapted to clean a gap into which the sword is inserted in cooperation with a fluid being conveyed to the probe end through the mentioned conduit (98). 8. Probe sword (85) according to claim 4, wherein the probe (100) is an electrically actuatable probe for testing. 9. Probe sword (85) according to claim 4, wherein the sword blade on a part of its length has slightly U-shaped cross section with thickened legs and a thin bottom, in order to give a high moment of inertia about the longitudinal plane of symmetry of the sword blade by virtue of the thickened legs as well as to provide a place for said conduit (98) and wire (97), and to provide, by virtue of the thin bottom, a resilient bendability around a center of curvature that is situated on the convex side of the U-shaped cross section. 10. Method for materials testing of a lead-through in a reactor cap, the lead-through having a first tube, the first tube passing through an opening provided in the reactor cap and being joined to the reactor cap by a weld, and a second tube being inserted essentially coaxially in the first tube, the first and the second tube having a substantially annular gap therebetween, comprising the steps of: applying a first force on a peripheral surface of the first tube and a second force on a peripheral surface of the second tube substantially opposed to the first force, thereby widening a part of the gap; inserting a probe into a widened part of the gap between the first and the second tubes; and scanning the area within the gap by means of the probe. displacing at least one of the points of application of the forces along the peripheral surface of at least one of the tubes, thereby displacing the widened part of the gap around the approximate axis of symmetry of the lead-through; and displacing the probe with the widened part of the gap around said approximate axis of symmetry of the lead-through. 11. Method according to claim 10, comprising the steps of: 12. Method according to claim 10, comprising the step of lifting the second tube, thereby increasing its lateral mobility. 13. Method according to claim 10, wherein the probe is applied to a sword which is flexible in a first transverse direction and is stiff in a second transverse direction perpendicular to the first transverse direction. 14. Method according to claim 13, further comprising the step of inserting the probe-equipped sword into the widened part of the gap past an end piece mounted on the second tube, whereby the sword by flexing adapts to the geometry of the first tube and the second tube.
	claims	1. A nuclear plant, comprising:a containment shell;a shut-off valve disposed outside of said containment shell;at least one pressure relief line passing out of said containment shell and sealed by said shut-off valve, and through said pressure relief line a pressure relief flow can flow during relief operation when said shut-off valve is open, said pressure relief line having an inlet mouth;a gas flow treatment device, disposed within said containment shell, and disposed upstream from said pressure relief line on an inlet side, said gas flow treatment device having a lateral casing and a chimney-shaped flow duct, enclosed by said lateral casing, and having a lower inflow opening and an upper inflow and outflow opening formed therein, said gas flow treatment device disposed upstream from said shutoff valve; anda first group of catalytic elements for eliminating at least one of hydrogen or carbon monoxide disposed in said chimney-shaped flow duct above or in a region of said lower inflow opening, and said inlet mouth of said pressure relief line disposed above said first group of catalytic elements and below said upper inflow and outflow opening in said lateral casing such that in an event of a critical fault or emergency with release of at least one of the hydrogen or the carbon monoxide in said containment shell, during convection operation preceding the relief operation, when said shut-off valve is closed said chimney-shaped flow duct is flowed through from bottom to top by a gas mixture present in said containment shell by a principle of natural convection, and during the relief operation the gas mixture flows into said chimney-shaped flow duct from below and from above by a principle of forced overflow and flows away via said pressure relief line as the pressure relief flow. 2. The nuclear plant according to claim 1, further comprising a second group of catalytic elements for eliminating at least one of the hydrogen or the carbon monoxide in said chimney-shaped flow duct and disposed above said inlet mouth of said pressure relief line and below or in a region of said upper inflow and outflow opening of said chimney-shaped flow duct. 3. The nuclear plant according to claim 2, further comprising a through-flow limitation device disposed in said pressure relief line, and adjusted in relation to a power of said first and second group of catalytic elements such that during the relief operation a concentration of at least one of the hydrogen or the carbon monoxide in a region of said inlet mouth of said pressure relief line is less than 50% of a corresponding concentration in the region of said lower inflow opening of said chimney-shaped flow duct. 4. The nuclear plant according to claim 3, wherein said through-flow limitation device is adjusted and a shape of said chimney-shaped flow duct selected in such a way that a mass flow occurring in said pressure relief line during the relief operation is at most 100% of a mass flow in said chimney flow duct during the convection operation. 5. The nuclear plant according to claim 3, wherein said through-flow limitation device is adjusted and a shape of said chimney-shaped flow duct selected in such a way that a flow speed onto said first and second groups of catalytic elements during the relief operation is less than 5 m/s. 6. The nuclear plant according to claim 2, wherein said first and second groups of catalytic elements are configured in such a way, as regards an operating temperature thereof during the relief operation, that said first and second groups of catalytic elements act as igniters at a hydrogen concentration of more than 7 vol. % in an incoming gas mixture. 7. The nuclear plant according to claim 1, wherein said gas flow treatment device is disposed in a lower third, in relation to a total height of said containment shell. 8. The nuclear plant according to claim 1, wherein said gas flow treatment device is disposed set apart from primary convection paths in a region of low hydrogen concentration in partially enclosed spaces. 9. The nuclear plant according to claim 7,wherein said gas flow treatment device is one of a plurality of gas flow treatment devices for the pressure relief flow, disposed in the lower third in relation to the total height of said containment shell;further comprising a plurality of catalytic recombiners, disposed positioned above and not acting directly on the pressure relief flow, for eliminating at least one of the hydrogen or the carbon monoxide; andwherein said gas flow treatment devices together bring about less than 20% of a total available recombination power. 10. The nuclear plant according to claim 1, wherein an air exchange number in said containment shell of L <0.3 h is achieved during the convection operation. 11. The nuclear plant according to claim 1, further comprising a cooling device, disposed inside said containment shell, for the pressure relief flow and is connected into said pressure relief line. 12. The nuclear plant according to claim 11, wherein said cooling device is configured for convective re-cooling by way of the gas mixture located in said containment shell and/or by evaporation cooling. 13. The nuclear plant according to claim 11, wherein said cooling device is configured, in terms of cooling power thereof, to cool the pressure relief flow from an input temperature in a range of approximately 400 to 500 ° C. to an output temperature in a range of approximately 150 to 300 ° C. 14. The nuclear plant according to claim 1, wherein said containment shell has a lead-through and said pressure relief line has a thermal protection cladding in a region of said lead-through through said containment shell. 15. The nuclear plant according to claim 1, wherein said first group of catalytic elements is constructed from palladium, on metal substrates having a ceramic coating, and said first group of catalytic elements contain a precious metal proportion of more than 0.2 wt. % based on said substrates. 16. The nuclear plant according to claim 1, further comprising at least one of filters or scrubbers for purifying the pressure relief flow and for activity re-cooling and disposed in a portion of said pressure relief line disposed outside of said containment shell. 17. The nuclear plant according to claim 2, further comprising a through-flow limitation device disposed in said pressure relief line, and adjusted in relation to a power of said first and second group of catalytic elements such that during the relief operation a concentration of at least one of the hydrogen or the carbon monoxide in a region of said inlet mouth of said pressure relief line is less than 30% of a corresponding concentration in the region of said lower inflow opening of said chimney-shaped flow duct. 18. The nuclear plant according to claim 3, wherein said through-flow limitation device is adjusted and a shape of said chimney-shaped flow duct selected in such a way that a mass flow occurring in said pressure relief line during the relief operation is less than 80% of a mass flow in said chimney-shaped flow duct during convection operation. 19. The nuclear plant according to claim 1, wherein an air exchange number in said containment shell of L <0.1 h is achieved during the convection operation. 20. The nuclear plant according to claim 1, wherein said first group of catalytic elements is constructed from palladium on metal substrates having a ceramic coating, and said first group of catalytic elements contain a precious metal proportion of more than 0.5 wt. % based on said substrates. 21. The nuclear plant according to claim 1, wherein said first and second groups of catalytic elements are constructed from at least one precious metal selected from the group consisting of palladium, platinum, and vanadium on at least one of ceramic substrates or on metal substrates having a ceramic coating, and said first and second groups of catalytic elements contain a precious metal proportion of more than 0.2 wt. % based on said substrates. 22. The nuclear plant according to claim 1, wherein said first and second groups of catalytic elements are constructed from at least one precious metal selected from the group consisting of palladium, platinum, and vanadium on at least one of ceramic substrates or on metal substrates having a ceramic coating, and said first and second groups of catalytic elements contain a precious metal proportion of more than 0.5 wt. % based on said substrates.
047568712	abstract	For safety in storage and transport of nuclear fuel elements outside a nuclear reactor core, they are provided with a coating of a neutron-absorbing substance from a liquid phase, e.g. by immersion, spraying or pouring, utilizing a melt, a solution or immersion so that the possibility of critical mass attainment is eliminated or minimized.
	claims	1. An electron energy loss spectral observation apparatus comprising:a transmission or scanning transmission electron microscope;an electron spectrometer having a plurality of lenses; andan electron spectrometer controller for controlling the electron spectrometer,wherein the electron spectrometer controller includes:simulation means based on a parameter design method using, as parameters, exciting current values of the individual lenses or values set on the basis of the exciting current values, for simulating fluctuation of electron energy loss spectral data when a plurality of parameters of the individual lenses are fluctuated simultaneously and conditions of the individual lenses are decided by calculation values based on the simulation result. 2. The electron energy loss spectral observation apparatus according to claim 1, wherein the simulation means is configured to implement functions, including functions to:allot the parameters to a orthogonal array;acquire electron energy loss spectral data in accordance with individual conditions based on the orthogonal array;prepare a factor effect table on the basis of electron energy loss spectral data corresponding to the individual conditions; andcalculate optimum parameters from the factor effect table. 3. An electron microscope comprising:an electron spectrometer having a plurality of lenses and adapted to perform energy spectroscopy; anda lens adjustment system for adjusting the lenses,wherein the lens adjustment system controls conditions of the individual lenses based on a simulation of fluctuation of electron energy loss spectral data when a plurality of exciting currents or values set on the basis of the exciting currents are fluctuated simultaneously. 4. The electron microscope according to claim 3,wherein the lens adjustment system sets conditions of the individual lenses through simulation based on a parameter design method using, as parameters, exciting currents or values set on the basis of the exciting currents. 5. The electron microscope according to claim 4, wherein the lens adjustment system is configured to perform implement functions, including functions to:read input values of the parameters;allot the parameters to an orthogonal array;acquire spectral data corresponding to conditions based on the orthogonal array;prepare a factor effect table from the acquired spectral data;calculate conditions of exciting currents of the individual lenses from the factor effect table: andcontrol the exciting currents of the individual lenses on the basis of the calculated exciting current values of the individual lenses. 6. The electron microscope according to claim 4, further comprising:an image display unit for displaying spectral data of the electron microscope, wherein:the image display unit displays a lens adjustment button for starting adjustment of lens conditions on the image display screen, andthe lens adjustment system is started in accordance with a command via the lens adjustment button. 7. The electron microscope according to claim 4, wherein:at least any one of the parameters is a fixed value set during production of the apparatus or installation thereof,at least any one of the other parameters is a variable value to be set during adjustment, andthe lens adjustment system adjusts a lens corresponding to the variable value. 8. A lens adjustment method including simulation means configured to implement functions, including functions to:adjust optimum conditions of a plurality of lenses, wherein exciting currents of the individual lenses or values set on the basis of the exciting currents are used as parameters; andcarry out simulation based on a parameter design method, wherein:conditions of exciting currents of the individual lenses are set on the basis of calculation values based on the simulation. 9. A lens adjustment method comprising steps of:adjusting optimum conditions of a plurality of lenses of an electron spectrometer attached to an electron microscope and adapted to perform energy spectroscopy, wherein exciting currents of the individual lenses or values set on the basis of the exciting currents are used as parameters; andcarrying out simulation based on a parameter design method, whereinconditions of exciting currents of the individual lenses are set on the basis of calculation values based on simulation of fluctuation of electron energy loss spectral data for fluctuation of parameters of the individual lenses. 10. The lens adjustment method according to claim 9, wherein the step of carrying out simulation comprises:reading parameters of each lens,allotting the parameters to an orthogonal array,acquiring spectral data in accordance with conditions based on the orthogonal array,preparing a factor effect table from the acquired data, andcalculating conditions of exciting currents of the individual lenses on the basis of the factor effect table. 11. A lens adjustment system for adjusting conditions of a plurality of lenses of an electron spectrometer, the system comprising:simulation means based on a parameter design method using, as parameters, exciting current values of the individual plural lenses or values set on the basis of the exciting current values, wherein:of a group of the lenses, the simulation means sets a lens with fixed parameters and sets another lens is set with unfixed parameters, and during lens condition adjustment, andconditions of the lens for which the parameters are unfixed are adjusted on the basis of calculation values based on simulation of fluctuation of electron energy loss spectral data for fluctuation of parameters of the individual lenses by the simulation means. 12. A lens adjustment method comprising steps of:adjusting exciting current values of individual lenses of an electron spectrometer by setting at least three parameters based on exciting current values for each lens and a number of simulation operations; andconducting simulation on the basis of the set values, wherein the simulation includes:inserting three parameters based on the exciting current values, as parameters of the individual lenses, to an orthogonal array;measuring a zero-loss spectrum under the individual conditions based on the orthogonal array;calculating a half-width of the measured zero-loss spectrum;preparing a factor effect table from the half-width corresponding to each calculated condition;acquiring a relational expression between the exciting current value of each lens and the half-width from the factor effect table; andcalculating the exciting current value of each lens from the relational expression,wherein the simulation is repeated in accordance with a frequency of the simulation by using the calculated exciting current value as an initial value. 13. A controlling apparatus for an electron spectrometer comprising a plurality of lenses, wherein:the apparatus is configured to adjust exciting current values of individual lenses of the electron spectrometer including a plurality of lenses, the exciting current values of individual lenses of the electron spectrometer being adjusted by the apparatus through simulation based on at least three parameters based on exciting current values for each lens and the number of simulation operations, wherein the simulation includes the functions to:insert three parameters based on the exciting current values, as parameters of the individual lenses, to an orthogonal array;measure a zero-loss spectrum under the individual conditions based on the orthogonal array;calculate a half-width of the measured zero-loss spectrum;prepare a factor effect table from the half-width corresponding to each calculated condition;acquire a relational expression between the exciting current value of each lens and the half-width from the factor effect table; andcalculate the exciting current value of each lens from the relational expression,the controlling apparatus being further configures to set the exciting current value of each lens by repeating the simulation in accordance with a frequency of the simulation by using the calculated exciting current value as an initial value. 14. The controlling apparatus according to claim 13, further comprising:a storing apparatus for storing at least one of the initial value and the calculated exciting current value by the simulation. 15. An electron microscope comprising the controlling apparatus according to claim 14. 16. An electron energy loss spectral observation apparatus comprising the controlling apparatus according to claim 14. 17. An electron microscope comprising the controlling apparatus according to claim 13. 18. An electron energy loss spectral observation apparatus comprising the controlling apparatus according to claim 13.
	description	This application is a continuation in part of U.S. patent application Ser. No. 14/318,246, filed Jun. 27, 2014, which claims the benefit of (i) U.S. provisional application Ser. No. 61/840,428 having a filing date of Jun. 27, 2013; (ii) U.S. provisional application Ser. No. 61/925,114 filed Jan. 8, 2014; (iii) U.S. provisional application Ser. No. 61/925,131 filed Jan. 8, 2014; (iv) U.S. provisional application Ser. No. 61/925,122 filed Jan. 8, 2014; (v) U.S. provisional application Ser. No. 61/925,148 filed Jan. 8, 2014; (vi) U.S. provisional application Ser. No. 61/925,142 filed Jan. 8, 2014; (vii) U.S. provisional application Ser. No. 61/841,834 filed Jul. 1, 2013; (viii) U.S. provisional application Ser. No. 61/843,015 filed Jul. 4, 2013; U.S. patent application Ser. No. 14/318,246 is also a continuation-in-part of U.S. patent application Ser. No. 14/205,339 filed Mar. 11, 2014, now U.S. Pat. No. 9,245,654 issued Jan. 26, 2016, which claims benefit of U.S. provisional application Ser. No. 61/776,592 filed Mar. 11, 2013; and U.S. patent application Ser. No. 14/205,339 is a continuation-in-part of U.S. application Ser. No. 12/850,633 filed Aug. 5, 2010. The entire disclosures of each of these priority applications are incorporated herein by reference for all purposes. Some aspects of the disclosed subject matter and the claimed invention may have been made by or on behalf of Alpha Ring International, Ltd. of Monterey, CA and Nonlinear Ion Dynamics, LLC of Monterey, CA, under a joint research agreement titled “JOINT RESEARCH AND DEVELOPMENT AGREEMENT.” The subject matter disclosed was developed and the claimed invention was made by, or on behalf of, one or both parties to the joint research agreement that was in effect on or before the effective filing date of the claimed invention, and some aspects of the claimed invention may have been made as a result of activities undertaken within the scope of the joint research agreement. The present disclosure relates to inter-nuclear reactions and reactors for initiating and maintaining these reactions. Since the 1950s, the science and technology communities have been striving to achieve controlled and economically viable fusion. Fusion is an appealing energy source for many reasons, but after billions of dollars and decades of research, to most, the idea of a sustainable fusion source for clean energy has become a pipe dream. The challenge has been to find a way to sustain a fusion reaction in a way that is economical, safe, reliable, and environmentally sound. This challenge has proved to be extraordinarily difficult. The commonly held belief in the art is that another 25-50 years of research remain before fusion is a viable option for power generation—“As the old joke has it, fusion is the power of the future—and always will be” (“Next ITERation?”, Sep. 3, 2011, The Economist). Prior efforts in large-scale fusion research have primarily focused on two methods of creating conditions for fusion ignition: inertial confinement fusion (ICF) and magnetic confinement fusion. ICF attempts to initiate a fusion reaction by compressing and heating fusion reactants such as a mixture of deuterium and tritium in the form of a small pellet about the size of a pinhead. The fuel is energized by delivering high-energy beams of laser light, electrons, or ions to the fuel target, causing the heated outer layer of the target fuel to explode and produce shockwaves that travel inward through the fuel pellet compressing and heating the fusion reactants, thereby initiating a fusion reaction. At the time of this filing, the most successful ICF program is the National Ignition Facility (NIF) which was constructed at the cost of nearly 3.5 billion dollars and completed in 2009. NIF reached a milestone by causing a fuel pellet to give off more energy than was applied to it, but as of 2015, the NIF experiments were only able to reach about ⅓ of the energy levels needed for ignition. Regarding a sustainable reaction, the longest reported ICF fusion reaction was on the order of 150 picoseconds. Even if ICF efforts achieve ignition conditions, there are still many obstacles to making it a viable energy source. For example, solutions are needed to remove heat from the reaction chamber without interfering with the fuel targets and driver beams, and solutions are needed to mitigate the short lifetime of fusion plants due to the radioactive byproducts of the fusion reactants: deuterium and tritium reactions produce neutrons. The second major research direction, magnetic confinement fusion, attempts to induce fusion by using magnetic fields to confine hot fusion fuel in the form of a plasma. This method seeks to lengthen the time that ions spend close together and increase the likelihood that they fuse. Magnetic fusion devices apply a magnetic force on charged particles in a manner that, when balanced with centripetal force, causes the particles to move in circular or helical path within the plasma. The magnetic confinement prevents the hot plasma from contacting the walls of its reactor. In magnetic confinement, fusion occurs entirely within the plasma. Most of the research in magnetic confinement is based on the tokamak design in which hot plasma is confined within a toroidal magnetic field. The Tokamak Fusion Test Reactor (TFTR) at Princeton, N.J. is world's first magnetic fusion device to perform extensive scientific experiments with plasmas composed of 50/50 deuterium/tritium. Built in 1980, it was hoped that TFTR would finally achieve fusion energy, but it never achieved this goal and was shut down in 1997. To date, the longest plasma duration time of any tokamak is 6 minutes and 30 seconds, held by the Tore Supra tokamak in France. Current efforts in magnetically confined fusion are focused on the International Thermonuclear Experimental Reactor (ITER), a Tokamak reactor that began construction in 2013. As of June 2015, the building costs have exceeded $14 billion, and construction of the facility is not expected until 2019 with full deuterium-tritium experiments starting in 2027. The current estimate for the cost of the project is over $50 billion, and it is likely the costs will continue to rise. Recently, the Energy and Water Development Subcommittee of the Senate Appropriations Committee released a recommendation that the U.S. withdraw from the ITER project. Due to market realities, and the inherent limitations of the tokamak design for fusion power, many analysts doubt that fusion reactors such as ITER will become commercially viable. An alternative form of magnetic confinement is being studied by the Maryland Centrifugal Experiment (MCX), at the University of Maryland. It will test the concepts of centrifugal confinement and velocity shear stabilization. In this experiment, capacitors are discharged from a cylindrical cathode through hydrogen gas to a surrounding vacuum chamber in the presence of a magnetic field. The orthogonal electric and magnetic fields (represented as J×B) produce a force that drives hot ionized plasma (>105 K) into rotation around the discharge electrodes. Due to the significant change in temperatures at the plasma boundary, there inevitably exists cold neutral species that significantly affect plasma flows. Studies have focused on the effect of neutrals and as they have thought to “impede the required plasma rotation” needed for fusion conditions. “Neutral species” or simply “neutrals” are atoms or molecules with a neutral charge, i.e., they have the same number of electrons and protons, the atomic number in the case of an atom. An ion or ionized atom or other particle has a charge, i.e., it has at least one more electron than proton or at least one more proton than electron. Rotating plasma devices that do not employ highly ionized plasmas have been considered for fusion research, but the neutrals have always been seen as a problem for reaching fusion conditions. Due to limiting effects including neutral drag and instabilities, one researcher in the field considered that while “not quite impossible [it is] still unlikely that rotating plasmas alone would lead to the realization of a self-sustained fusion reactor.” (Review Paper: ROTATING PLASMAS″, Lehnart, Nuclear Fusion 11 (1971)). All credible prior approaches have all faced confinement and engineering issues. A gross energy balance for a fusion reactor, Q, is defined as:Q=Efusion/Ein, where Efusion is the total energy released by fusion reactions, and Ein is the energy used to create the reactions. The goal is to exceed a Q of one or “unity” toward the end of creating a viable energy source. Officials of the Joint European Torus (JET) claim to have achieved Q≈0.7 and the US National Ignition Facility recently claims to have achieved a Q>1 (ignoring the very substantial energy losses of its lasers). The condition of Q=1, referred to as “breakeven,” indicates that the amount of energy released by fusion reactions is equal to the amount of energy input. In practice, a reactor used to produce electricity should exhibit a Q value significantly greater than 1 to be commercially viable, since only a portion of the fusion energy can be converted to a useful form. Conventional thinking holds that only strongly ionized plasmas that do not have significant quantities of neutrals present have the potential of achieving Q>1. These conditions limit the particle densities and energy confinement times that can be achieved in a fusion reactor. Thus, the field has looked to the Lawson criterion as the benchmark for controlled fusion reactions—a benchmark, it is believed, that no one has yet achieved when accounting for all energy inputs. The art's pursuit of the Lawson criterion, or substantially similar paradigms, has led to fusion devices and systems that are large, complex, difficult to manage, expensive, and, as yet, economically unviable. A common formulation of the Lawson criterion, known as the triple product, is as follows: nT ⁢ ⁢ τ E > 12 ⁢ ⁢ k B E ch ⁢ T 2 〈 συ 〉 While the Lawson criterion will not be discussed in detail here; in essence, the criterion states that the product of the particle density (n), temperature (T), and confinement time (τE) must be greater than a number dependent on the energy of the charged fusion products (Ech), the Boltzmann constant (kB), the fusion cross section (σ), the relative velocity (ν), and temperature in order for ignition conditions to be reached. For the deuterium-tritium reaction, the minimum of the triple product occurs at T=14 keV and the number for the triple product is about 3×1021 keV s/m3 (J. Wesson, “Tokamaks”, Oxford Engineering Science Series No 48, Clarendon Press, Oxford, 2nd edition, 1997.) In practice, this industry-standard paradigm suggests that temperatures in excess of 150,000,000 degrees Centigrade are required to achieve positive energy balance using a D-T fusion reaction. For proton-boron 11 fusion, the Lawson criterion suggests that the required temperature must be yet substantially higher. More specifically, nτ˜1016 s/cm3, which is ˜100× greater than required for D-T fusion [from Inertial Electrostatic Confinement (IEC) Fusion: Fundamentals and Applications by George H. Miley and S. Krupaker Murali]. An aspect of the Lawson criterion is based on the premise that thermal energy must be continually added to the plasma to replace lost energy, maintain the plasma temperature, and keep it fully or highly ionized. In particular, a major source of energy loss in conventional fusion systems is radiation due to electron bremsstrahlung and cyclotron motion as mobile electrons interact with ions in the hot plasma. The Lawson criterion was formulated for fusion methods where electron radiation loss is a significant consideration due to the use of hot, heavily ionized plasmas with highly mobile electrons. Because the conventional thinking holds that high temperatures and a strongly-ionized plasma, absent of the presence of a significant presence of neutrals, are required, it was further believed that inexpensive physical containment of the reaction was impossible. Accordingly, the methods that have been most heavily pursued are directed to complex and expensive schemes to contain the reaction, such as those used in magnetic confinement systems (e.g., the ITER tokamak) and in inertial confinement systems (e.g., NIF laser). In fact, at least one source acknowledges the believed impossibility of containing a fusion reaction with a physical structure: “The simplest and most obvious method with which to provide confinement of a plasma is by a direct-contact with material walls, but is impossible for two fundamental reasons: the wall would cool the plasma and most wall materials would melt. We recall that the fusion plasma here requires a temperature of ˜108 K while metals generally melt at a temperature below 5000 K.” (“Principles of Fusion Energy,” A. A. Harms et al.). The need for extremely high temperatures is premised on the belief that only highly energized ions with charge can fuse, and that the coulombic repulsion force limits the fusion events. The present teaching in the field relies on this basic assumption for the vast majority of all research and projects. In rare instances, researchers have considered methods for reducing the Coulombic barrier or repulsion force, which repels interacting positive nuclei, in order to reduce the required energy to initiate and maintain fusion. Such methods have largely been disregarded as infeasible with the methods described above. In the 1950's the concept of muon-catalyzed fusion was studied by Luis Alvarez using a hydrogen bubble chamber at the University of California at Berkeley. Alverez's work (“Catalysis of Nuclear Reactions by μ Mesons.” Physical Review. 105, Alvarez, L. W.; et al. (1957)) demonstrated nuclear fusion taking place at temperatures significantly lower than the temperatures required for thermonuclear fusion. In theory, it was proposed that fusion could occur even at or below room temperature. In this process, a negatively charged muon replaces one of the electrons in a hydrogen molecule. Since the mass of a muon is 207 greater than an electron, the hydrogen nuclei are consequently drawn 207 times closer together than in a normal molecule. When the nuclei are this close together, the probability of nuclear fusion is greatly increased, to the point where a significant number of fusion events can happen at room temperature. While muon-catalyzed fusion received some attention, efforts to make a muon-catalyzed fusion source have not been successful. Current techniques for creating large numbers of muons require significant amounts of energy that exceed the energy produced by the catalyzed nuclear fusion reactions, thus precluding breakeven or Q>1. Moreover, each muon has about a 1% chance of “sticking” to the alpha particle produced by the nuclear fusion of a deuteron (the nucleus of deuterium atom) with a triton (the nucleus of tritium atom), removing the “stuck” muon from the catalytic cycle. This means that each muon can only catalyze at most a few hundred deuterium-tritium nuclear fusion reactions. Thus, these two factors—muons being too expensive to make and then sticking too easily to alpha particles—limit muon-catalyzed fusion to a laboratory curiosity. To create useful muon-catalyzed fusion, reactors would need a cheaper, more efficient muon source and/or a way for each muon to catalyze many more fusion reactions. To date, none have been found or even theorized. In March of 1989, Martin Fleischmann and Stanley Pons submitted a paper to the Journal of Electroanalytical Chemistry reporting that they had discovered a method of reducing the Coulombic barrier by a method that is now commonly referred to as “cold fusion.” Fleishmann and Pons believed they had observed nuclear reaction byproducts and a significant amount of heat generated by a small tabletop experiment involving electrolysis of heavy water on the surface of palladium electrodes. One explanation for cold fusion considered that hydrogen and its isotopes could be absorbed in certain solids, such as palladium, at high densities. The absorption of hydrogen creates a high partial pressure, reducing the average separation of hydrogen isotopes and thus lowering the potential barrier. Another explanation was that electron screening of the positive hydrogen nuclei in the palladium lattice was sufficient for lowering the barrier. While the Fleischmann-Pons findings initially received significant press, the reception by the scientific community was largely critical as a group at Georgia Tech University quickly found problems with their neutron detector, and Texas A&M University discovered bad wiring in their thermometers. These experimental mistakes, along with many failed attempts to replicate the Fleischmann-Pons experiment by well-known laboratories, lead most in the scientific community to conclude that any positive experimental results should not be attributed to “fusion.” Due in part to the publicity received, the United States Department of Energy (DOE) organized a special panel to review cold fusion theory and research. First in November of 1989, and again 2004, the DOE concluded that results thus far did not present convincing evidence that useful sources of energy would result from the phenomena attributed to “cold fusion.” Another attempt to reduce the Coulombic barrier employs electron screening in a solid matrix. Electron screening has first been observed in stellar plasmas where it was determined to change the fusion rate by five orders of magnitude if the screening factor changes by only a few percent (Wilets, L., et al. “Effect of screening on thermonuclear fusion in stellar and laboratory plasmas.” The Astrophysical Journal 530.1 (2000): 504.). According to Wilets, “[t]he rate of thermonuclear fusion in plasmas is governed by barrier penetration. The barrier itself is dominated by the Coulomb repulsion of the fusing nuclei. Because the barrier potential appears in the exponent of the Gamow formula, the result is very sensitive to the effects of screening by electrons and positive ions in the plasma. Screening lowers the barrier and thus enhances the fusion rate; the greater the nuclear charges, the more important it becomes.” One example that tries to make use of this electron screening effect to create ignition conditions is presented in US Patent Publication No. US2005/0129160A1 by Robert Indech. In this application, Indech describes the electron shielding of the positively-charged repulsive forces between two deuterons located near the tip of a microscopic cone structure when electrons concentrate at the top of the cone structure due to an applied potential. As disclosed, these cones were arrayed on a surface measuring 3 cm by 3 cm. While Indech and others have realized the potential electron screening to lower the Coulombic barrier for fusion reactors, it is doubtful any efforts have been successful. At most these efforts appear to propose methods for ignition and not a sustained and controlled fusion reaction. Despite efforts in ICF, magnetic confinement fusion, and various methods of reducing the Coulombic barrier, there is currently no commercially feasible fusion reactor design that exists. One aspect of the present disclosure relates to an apparatus having features (a)-(f). Feature (a) is a first electrode having a substantially cylindrical inner surface that has an axis and forms at least a portion of a confining wall, where the confining wall at least partially encloses a confinement region. Feature (b) is a second electrode located within a region interior to the first electrode and separated from the first electrode by at least the confinement region. Feature (c) includes at least one magnet configured to provide a magnetic field through the confinement region such that at least a portion of the magnetic field in the confinement region is substantially parallel to the axis of the substantially cylindrical inner surface of the first electrode. Feature (d) is an inlet to the confinement region for permitting introduction of neutrals to the confinement region. Feature (e) is a control system including a voltage and/or current source for applying a potential between the first electrode and the second electrode sufficient to produce an electrical current from the second electrode toward the first electrode in the confinement region, where the first and second electrodes, the at least one magnet, and/or the control system are configured to induce rotational movement of ions and the neutrals in the confinement region. Figure (f) is a reactant attached to or embedded in the confining wall such that, during operation, repeated collisions between the neutrals and the reactant produce an interaction with the reactant that gives off energy and produces a product having a nuclear mass that is different from a nuclear mass of any of the nuclei of the neutrals and the reactant. In some cases, the control system may be configured to control the magnetic field in the confinement region and/or control a supply of neutrals to the confinement region via the inlet. The first and second electrodes, the at least one magnet, and/or the control system of the apparatus may sometimes be configured to induce the rotational movement of the neutrals in the confinement region at an average velocity of at least about 50,000 m/s in the confinement region. In some embodiments, the at least one magnet includes at least one permanent magnet having opposite magnetic poles offset from one another in the direction of the axis of the substantially cylindrical inner surface of the first electrode. In some embodiments, the at least one magnet includes two permanent magnets separated from one another by at least the confinement region and in the direction of the axis of the substantially cylindrical inner surface of the first electrode. In some embodiments, the at least one magnet includes two permanent magnets radially separated from one another by at least the confinement region. In some embodiments, the at least one magnet includes an electromagnet. An electromagnet may be in, e.g., a superconducting magnet. In some embodiments, at least a portion of the confining wall is separable from the remainder of apparatus to allow replacement. In some embodiments, the confining wall includes a refractory metal and/or a stainless steel. In some embodiments, the confining wall includes a layered structure in which at least one the layers includes the first electrode. A layered structure may include an electron emitter and/or the reactant attached to or embedded in the confining wall. In some embodiments, the nuclear mass of the product is greater than the nuclear mass of any of the nuclei of the neutral particles and the reactant. In some cases, the interaction is a fusion reaction, and in some cases the fusion reaction is an aneutronic fusion reaction. In some embodiments, the reactant attached to or embedded in the confining wall includes boron-11 and/or the neutrals include neutral hydrogen, deuterium, and/or tritium. In some embodiments, during operation, the neutrals in the confinement region proximate the confining wall may have a concentration of at least about 1020/cm3. In some embodiments, the apparatus also has one or more electron emitters configured to emit, during operation, electrons into a region adjacent to the confining wall. The electron emitters may be attached to or embedded in the confining wall and may include boron or a boron-containing material. In some embodiments, during operation of the apparatus, the confinement region proximate the confining wall may include an electron-rich region having an excess of electrons over positively charged particles of at least about 106/cm3. This electron-rich region may extend from the confining wall into the confinement region by a distance of between about 50 nanometers and about 50 micrometers. In some cases, the electron-rich region may have an electric field strength of at least about 106 V/m and in some cases, the neutrals in the electron-rich region have an energy of, on average, of between about 0.1 eV and 2 eV. Another aspect of this disclosure pertains to a method that includes operations (a)-(d). Operation (a) consists of introducing neutrals to a confinement region. Operation (b) includes applying an electrical potential difference between a first electrode and a second electrode to produce an electrical current from the second electrode toward the first electrode, where the first electrode has a substantially cylindrical inner surface that has an axis and forms at least a portion of a confining wall that at least partially encloses the confinement region. The confining wall at least partially encloses the confinement region and has a a reactant attached to it or embedded in it. The second electrode is also located within a region interior to the first electrode and separated from the first electrode by at least the confinement region. Operation (c) includes applying a magnetic field, from at least one magnet, through the confinement region such that at least a portion of the magnetic field in the confinement region is substantially parallel to the axis of the substantially cylindrical inner surface of the first electrode, where the magnetic field and the electrons driven from the first electrode to the second electrode induce rotational movement of ions and the neutrals in the confinement region. Operation (d) includes maintaining rotational movement of the neutrals to promote repeated collisions between the neutrals and the reactant to thereby produce a reaction between the reactant and the neutrals that gives off energy and produces a product having a nuclear mass that is different from a nuclear mass of any of the nuclei of the neutrals and the reactant. In some cases, when performing this method, neutrals travel in the confinement region at an average velocity of at least about 50,000 m/s. In some cases, the at least one magnet includes at least one permanent magnet having opposite magnetic poles offset from one another in the direction of the axis of the substantially cylindrical inner surface of the first electrode. In some cases, the at least one magnet includes two permanent magnets separated from one another by at least the confinement region and in the direction of the axis of the substantially cylindrical inner surface of the first electrode. In some cases, the at least one magnet includes two permanent magnets radially separated from one another by at least the confinement region. In some cases, the at least one magnet includes an electromagnet, and in some cases, the electromagnet is a superconducting magnet. In some cases, the the confining wall has a substantially cylindrical shape, and in some cases, the method includes separating at least a portion of the confining wall from the remainder of apparatus to allow replacement. In some cases, the confining wall includes a refractory metal and/or a stainless steel. In some cases, the confining wall includes a layered structure in which at least one of the layers includes the first electrode. The layered structure may include an electron emitter and/or the reactant attached to or embedded in the confining wall. In some cases, the method produces a product having a nuclear mass that is greater than the nuclear mass of any of the nuclei of the neutral particles and the reactant. In some cases, the reaction is a fusion reaction, and in some cases the reaction is an aneutronic fusion reaction. In some cases, when the reactant attached to or embedded in the confining wall includes boron-11, and in some cases, the neutrals include neutral hydrogen, deuterium, and/or tritium. In some cases, the method is performed so that neutrals in the confinement region proximate the confining wall have a concentration of at least about 1020/cm3. In some cases, the confining wall includes one or more electron emitters that are configured to emit, during operation, electrons into a region adjacent to the confining wall. These electron emitters may be attached to or embedded in the confining wall, and in some cases, the electron emitters include boron or a boron-containing material. In some cases, while maintaining the rotational movement of the neutrals, the confinement region proximate the confining wall includes an electron-rich region having an excess of electrons over positively charged particles of at least about 106/cm3. This electron-rich region may extend from the confining wall into the confinement region by a distance of between about 50 nanometers and 50 micrometers. In some cases, the electron-rich region may have an electric field strength of at least about 106 V/m and in some cases, the neutrals in the electron-rich region have an energy of, on average, of between about 0.1 eV and 2 eV. Introduction Various embodiments disclosed herein pertain to reactors and methods of operating those reactors under conditions that induce a reaction between two or more nuclei in a manner that produces more energy than is input to the reactor. This disclosure refers to such reactions as nuclear fusion reactions or simply fusion reactions, although aspects of the reaction may be quantitatively or qualitatively different from aspects of reactions conventionally characterized as nuclear fusion. Therefore when the term fusion is used in the remainder of this disclosure, the term does not necessarily connote all the features conventionally ascribed to nuclear fusion. In some embodiments disclosed herein, a reactor may generate a sustained fusion reaction making it suitable as a viable energy source. As described herein, a sustained fusion reaction refers to a fusion reaction in which reactor may continuously operate above unity for a period of about a second. In various embodiments, the reactor in which the fusion reaction occurs is designed or configured to constrain or confine rotating species including, typically, one or more of the nuclei participating in a fusion reaction. Various structures may be provided for confining the rotating species. Typically, though not necessarily, these structures define a solid physical enclosure. As explained more fully elsewhere herein, the enclosed structure may have many shapes such as a generally cylindrical shape. Examples of suitable structures that may be used for a physical enclosure are depicted in FIGS. 1, 7, and 6. Regardless of any other functions, the wall of the reactor typically serves to confine species rotating in the region adjacent to and internal to the wall. The wall is confining in the sense that it confines the rotating species to remain within the reactor. As described herein, this wall of the reactor is referred to as the wall, the confining wall, or the shroud. In various embodiments, the wall also serves other functions: notably as an electrode, as a magnet, as a source of fusion reactants (e.g., boron compounds), and/or as an electron emitter. Because the wall constrains the reactants species physically rather than by a magnetic field or a pressure wave—as are done in conventional approaches to fusion—it is unlike any conventional fusion reactor designs. Its other functions, such as being an electrode for imparting a voltage difference, being a magnet, being a source of reactant material, and being an electron emitter, provide additional distinctions from conventional fusion reactor designs. In certain embodiments, the reactor contains a wall, as described, and a space interior to the wall (which may be annular in shape) where reactant species, including a substantial fraction or percentage of neutrals, rotate and repeatedly impinge on the surface of the reactor wall and sometimes fuse with species present in the wall. When accounting for the energy input to the reactor, the resulting reaction can breakeven and result in Q>1. To ensure that the fusion reaction is sustainable over a period required by particular energy-generation applications, the ratio of energy out to energy in should be significantly greater than 1. This accounts for inherent inefficiencies in using energy generated by a fusion reaction to sustain the conditions that allow fusion to occur (e.g., particular plasma densities in the confinement region). In certain embodiments, the ratio should be at least about 1.2. In certain embodiments, the ratio should be at least about 1.5. In certain embodiments, the ratio should be at least about 2. In certain embodiments, the reactor is continuously operated under sustainable conditions for at least about fifteen minutes, or at least about one hour. In one example, hydrogen atoms rotate in the reactor and impinge on boron or lithium atoms in the reactor wall to undergo fusion. In some embodiments, the reactor includes one or more electron emitters that produce an electron flux that, during operation, produce a strong field that reduces the Coulombic repulsion between interacting nuclei. The reactants can be any species that can support a fusion reaction in the space interior to the confining wall of the reactor. In various embodiments, at least one of the reactants is a species that is rotating within the reactor interior region. In some cases, both of the reactants are rotating species. In some cases, one of the reactants is a rotating species and the other is a species that is held stationary, such as when a reactant is embedded in a part of the reactor wall that confines the rotating species. In some cases, there is some combination of reactants that are rotating and stationary such that fusion may occur between rotating species or between a rotating species and a stationary species. In cases where the reacting species are predominantly rotating species, the physical structure of the reactor may be configured such that the rotating species need not substantially impinge on the inner surface of a wall of the reactor to support a fusion reaction. In some designs, the rotating species are constrained by a force such as a force that prevents them from substantially striking the reactor wall. In such designs, two rotating species fuse in the region interior to the confining wall (e.g., the confinement region) or along the surface of the wall. In some designs, a rotating species may fuse with a stationary species (e.g., a target material) located within the confinement region. In certain embodiments, the reactants are species that react aneutronically. In other embodiments, the reactants are species that react neutronically. One or both of the reactants may also be a neutral, or uncharged, species. Sometimes the species present in the reactor are referred to as “particles.” However, such species are only particles at the molecular or atomic scale. The disclosed small-scale, e.g., table-top, aneutonic reactors require relatively little or no biological shielding from neutron radiation. Fusion reactions in reactors described herein may be characterized as “warm fusion,” e.g., where fusion occurs in the temperature range of about 1000 K to 3000 K, and as such are much easier to handle compared to “hot fusion reactors” (e.g. those in tokamak reactors). Since the fusion is substantially aneutronic and “warm,” materials and thus costs associated with “warm fusion” reactors may be significantly reduced. For instance, in some cases, a prototype reactor has been built for less than $50,000. Since radiation shielding and the industrial-grade hardware commonly used for hot plasma reactors may not be required, the disclosed small-scale reactors may also have a small weight and footprint. The rotational motion of the species in the reactor may be imparted by a number of mechanisms. One mechanism imparts rotation via the application of interacting electric and magnetic fields. The interaction is manifest as a Lorentzian force that acts on charged particles in the reactor. Examples of reactor designs that can produce a Lorentzian force to act on charged species are depicted in FIGS. 1a-c and 6. FIGS. 1a-c depict a Lorentzian driven reactor where the reactor has inner electrode 120, and where the shroud (confining wall) is an outer electrode 110. An electric field 144 between the electrodes in the presence of an applied magnetic field 146, having a perpendicular component, causes a Lorentzian force on charge particles or charged species traveling in between the electrodes. This force drives them azimuthally into rotation as indicated in FIG. 1c. In another class of reactor design, rotational motion is imparted to charged species by applying a potential or a change in potential sequentially to a plurality of electrodes arranged azimuthally around a wall of the reactor. An example of a suitable reactor design is shown in FIG. 7. In many implementations, the reactor is operated in a manner such that the rotating charged species interact with neutral species and impart angular momentum to those neutral species, thereby setting up rotational motion of the neutral species as well as the charged species within the reactor. In many implementations, the majority of rotating species are neutrals and the charged species are ionized particles such as a proton (p+). As described herein, this process may be referred to as ion-neutral coupling. FIG. 2a schematically illustrates the ion-neutral coupling process in which a few charged particles 204 of a first reactant impart motion to the surrounding neutral particles 206 of the first reactant. In various embodiments, the reactor is designed to emit electrons in an internally localized region of the reactor where fusion events are expected to occur. Referring again to FIG. 2a, these electrons may form an electron-rich region 232 near the confining wall 210. The presence of excess electrons lowers the Coulomb barrier and thereby increases the probability of fusion. As explained elsewhere herein, emitting electrons in this manner can produce an electron-rich region that reduces the intrinsic Coulombic repulsion between two positively charged nuclei, which are candidates for fusion. In certain embodiments, the electron emission occurs at or adjacent to the wall that confines the rotating species within the reactor. In one example, electron emission is provided by passive structures such as boron-containing coupons or strips embedded in or attached to the confining wall of the reactor. Such passive structures emit electrons when the localized temperatures increase during operation of the reactor. In other embodiments, electron emission is implemented using active structures that are controlled independently of the heating produced during normal operation of the reactor. An example of an active structure for electron emission is depicted in FIGS. 21a and 21b and includes separately controlled resistive elements for heating the individual electron emitters. Another aspect of this disclosure relates to structures or systems for capturing and converting energy produced by a fusion reaction within the reactor. One class of energy capture systems provides for direct capture of electrical energy produced by traveling alpha particles generated by the fusion reaction. This may be done by generating an applied electric field in the path of emitted alpha particles which causes the alpha particles to decelerate and generates an electric current in a circuit connected to the electrodes used to produce the electric field. Another class of energy capture systems provides for energy capture using heat engines such as those including a turbine, heat exchanger, or other conventional structure employed to convert thermal energy produced from the fusion reaction into mechanical energy. These and other energy capturing mechanisms will be discussed later in this disclosure. Interactions by Neutrals with the Wall Neutral species interacting with the wall of a reactor provide a different type of interaction than has been employed in conventional fusion studies. The repeated interactions take place over a relatively large volume, which may be the annular space next to the inner wall of or the inner surface of the confinement wall. Because the rotating neutrals frequently interact elastically with the wall at a shallow angle, e.g., at a glancing or grazing angle, they may immediately leave the wall and reenter the interior space with much of the energy they had upon entry. FIG. 2b illustrates an example trajectory path a neutral 206 may have as it moves along the surface of the confinement wall 210. When a rotating neutral particle enters or strikes the wall, it typically encounters a potential fusion partner with which it may react or not. When it does not react, it re-enters the interior space where it continues on its rotational journey. In this manner, it repeatedly interacts with the surface of the wall, and in each such elastic collision little to no energy is lost. Some particle-wall interactions that do not result in fusion are illustrated schematically in FIGS. 3a-d. While the figures depict interactions with boron11 and/or titanium, these interactions may also occur when other reactant materials are used in the confinement wall. As illustrated in FIG. 3a, in some fraction of the neutral-wall interactions, the neutral particle 206 of the first reactant experiences an elastic collision with a nucleus 308 of a second reactant in the wall (in the illustrated example, the second reactant boron11), and the rebounding neutral maintains most of the energy it had going into the interaction. Of all neutral-wall interactions, elastic collisions typically have that highest occurrence. In a much smaller fraction of the collisions, depicted in FIG. 3b, the nucleus of the neutral particle 206 of the first reactant comes sufficiently close to the nucleus 308 that the collision becomes inelastic as a result of tunneling that occurs when the two nuclei come into very close proximity. FIG. 3c depicts yet another interaction that may occur; in this case, a neutral penetrates into the wall. This type of collision may occur somewhat frequently when the confinement surface contains a material such as titanium or palladium that may absorb hydrogen molecules. FIG. 3d depicts an inelastic collision of a charged particle, e.g., a proton, with the confining wall. This situation contrasts with the frequent elastic collisions that neutrals such as atomic hydrogen have with the confining wall (previously depicted in FIG. 3a). When a charged particle approaches and departs from the confining wall, the particle may experience Bremsstrahlung energy loss. This energy loss is caused by electrostatic interaction between the charged particle and electrons in the electron-rich region. As a result of the electrostatic forces, some kinetic energy is lost, and high energy electromagnetic radiation such as x-rays are emitted. In conventional fusion reactors that focus on trying to fuse ionized particles, Bremsstrahlung radiation may result in significant energy loss. By using a weakly ionized plasma having a high proportion of neutrals to ions, these losses are largely avoided. In a certain fraction of tunneling interactions between the neutral nucleus in motion and the nucleus of an atom in the wall, fusion may occur. FIG. 4a depicts the stages of the aneutronic fusion reaction that occurs when a hydrogen atom or proton fuses with a boron 11 atom. First, in 482, a proton traveling at high velocity collides with a boron 11 atom, and the two nuclei fuse to form an excited carbon nucleus, depicted in 483. The excited carbon nucleus is short-lived, however, and decomposes into a beryllium nucleus and an alpha particle that is emitted having a kinetic energy of 3.76 MeV, as seen in 484. Finally, in 485, the newly formed beryllium nucleus almost immediately decomposes into two more alpha particles, each having a kinetic energy of 2.46 MeV. FIGS. 4b-e depict the various stages of the same proton-boron 11 fusion reaction shown in FIG. 4a in relation to the surface of the confining wall 412. FIG. 4a depicts a proton traveling at high velocity towards a surface of boron 11 atoms on the confining wall. As the neutral hydrogen atom approaches the confining wall it passes through and the electron-rich region 432, which partially screens the repulsive force between the two positively charged nuclei. FIG. 4c depicts the stage at which the neutral hydrogen has fused with a boron atom to form a carbon nucleus. In FIG. 4d, the carbon nucleus has decomposed into a beryllium nucleus one alpha particle. Lastly, in FIG. 4e, the beryllium nucleus decomposes, emitting two additional alpha particles. Because the potential reactants are neutral species rather than ions, most of their interactions with atoms in the surface of the confinement wall are elastic collisions. In contrast, a positively charged particle entering the wall will be deflected by electrostatic repulsive forces at a distance from other nuclei in the wall. These electrostatic interactions cause the charged particle to lose energy; i.e., the collisions are inelastic. A neutral particle, which has a positively charged nucleus screened to a degree by the orbital electrons, does not experience the same repulsive force. As a consequence, the neutral is more likely to directly impact another atom in the wall. The use of neutrals rather than ions, therefore, increases the likelihood of a fusion reaction, and when a fusion reaction does not occur, the neutral is more likely to rebound elastically with a higher energy than a corresponding ion. Overall, the rotating neutral particles undergo many repeated interactions with the wall and those that are unproductive in producing a fusion reaction elastically rebound with relatively little energy loss. As mentioned, the neutrals tend to reemerge from the wall and with sufficient energy that they can enter into a next interaction with the wall which might be productive in creating a fusion reaction. Each of the interactions with the wall has a probability of resulting in a fusion reaction between the neutral nucleus and the nucleus of an atom in the wall. Where the reactants are different species (e.g., 11B and p+), the rate of fusion per unit volume is given bydN/dT=n1n2σν where n1 and n2 are the densities of the respective reactants, σ is the fusion cross section at a particular energy, and ν is the relative velocity between the two interacting species. For a system in which at least one species rotates in a confinement region and repeatedly strikes a confining wall containing a second species, the values of the densities of the species may be on the order of 1020 cm−3 for the rotating species and 1023 cm−3 for the immobilized species (e.g., boron), the values of the fusion cross section may be on the order of 10−32 cm2, and the relative velocity of the interacting species may be on the order of 103 m/s. By comparison, for a tokamak reactor, the values of the density of each of the species is on the order of 1014 cm−3, the values of the fusion cross section are on the order of 10−28 cm2, and the relative velocity of the interacting species is on the order of 106 m/s. (Based on information provided in “Inertial Confinement Fusion.pdf” by M. Ragheb dated on Jan. 14, 2015.) Clearly, systems employing neutral species, like those described herein, have a strong advantage by virtue of their higher densities. The rate of fusion energy per unit volume for such systems exceeds that of tokamak and inertial confinement systems by at least about eight orders of magnitude. Thus, a system as disclosed herein can achieve a defined rate of energy production in about one-hundred-millionth of the volume of a tokamak or internal confinement system. Coulombic Barrier Reduction As explained, credible, prior approaches to nuclear fusion have energized fusion reactants and the supporting environment to extremely high temperatures, on the order of at least 150,000,000 K (13000 eV). This is done to impart sufficient kinetic energy to the fusion reactants to overcome their natural electrostatic repulsion. In this environment, each reactant is a nucleus having an intrinsic positive charge which must first be overcome to allow some probability of a fusion reaction. Certain embodiments of the present disclosure employ much lower temperatures; e.g., on the order of 2000 K (0.17 eV) in fusion reactions. These embodiments employ neutral species as one or more reactants and/or modify the reaction environment to reduce the strong Coulombic repulsive force between reactant nuclei. Reduction of the Coulombic force may be accomplished in various ways including, for example, (i) providing an electron rich field in the region of the reaction and/or (ii) aligning the quantum mechanical spins of reactant nuclei. Depending on the structure of the reactor, the apparatus and methods for reducing Coulombic repulsion may take many forms. The following description assumes that the reactor includes an annular space with an outer confining wall or shroud. Other reactor structures can likewise produce reduced Coulombic repulsion environments that support fusion, but they may accomplish this in manners different than the one that follows. The following is provided as one possible explanation of the environment near the inner surface of a confining electrode and should not be construed as a limitation on the practice of the disclosed embodiments. In this explanation, reactant species, particularly neutrals, rotate at high velocity and strike the inner surface of the electrode. Concurrently, electrons are emitted from or near the confining wall. The rapidly rotating neutrals have high angular velocity and therefore exert extreme pressure on the inner surface of the confining wall through an associated centrifugal force. Electrons emitted from the inner surface of the wall oppose this force. The emitted electrons will diffuse away from the location where they are emitted, e.g., away from the wall and toward an interior space. However, the centrifugal force of the neutrals constrains the electrons to the region near the inner surface of the outer electrode. A resulting thin region of balanced forces adjacent to the inner surface of the electrode possesses a strong field that reduces the Coulombic repulsion between reactant nuclei. The force balance may be expressed mathematically as the equilibrium of (i) the gradient (in a direction away from the wall surface in which electrons are emitted) of the product of the temperature and the density of electrons and neutrals, and (ii) the centrifugal force exerted toward the inner surface. The centrifugal force is proportional to the product of the neutrals' density, the radial position, and the square of their angular velocity. ∂ ∂ 𝓇 ⁢ ( n e ⁢ KT e + n 0 ⁢ KT 0 ) = n 0 ⁢ m 0 ⁢ ω 2 ⁢ 𝓇 In this expression, r is the radial direction away from the inner surface of the confining electrode, K is the Boltzmann constant, Te and T0 are the electron and neutral temperatures in Kelvin, ne and n0 are the densities of electrons and neutrals, n0 is the density of neutral species, m0 is the mass of one rotating neutral species (e.g., a hydrogen atom), and ω2 is the square of the angular velocity of the rotating neutral species. In a thin region next to the surface from which the electrons are emitted (e.g., the inner surface of the confining wall), the free electrons create a strong electrical field (see the schematic representation of electron-rich region 232 adjacent confining wall 210 in FIGS. 2a-b). The high concentration of neutrals limits the mean free path of the electrons, preventing them from following ballistic trajectories and thus obtaining sufficient kinetic energy to significantly ionize the neutrals. Also, there are relatively few positive ions available for recombination because the neutrals have a significantly higher density than the ions. For example, the prevalence of ions to neutrals may be in the ranges of less than about 1:10, less than about 1:100, less than about 1:1000, or less than about 1:10000. Hence the neutrals are frequently positioned between the electrons and positive ions. This set of conditions produces a high concentration of excess electrons near the confining wall's inner surface and hence a strong electric field. The combination of a large excess of electrons (over ions) in a very thin region (e.g., next to the inner surface of the electrode) and in the presence of a high concentration of neutrals produces a very strong electric field. In this region, the strong field reduces the Coulombic repulsion of interacting positively charged nuclei. Hence, the probability of two positively charged nuclei coming in close proximity is significantly increased. Additionally, as mentioned, rotating particles impinging on the inner surface of the confining wall produce repeated opportunities for interacting fusion reactants. Neutrals repeatedly pass through the electron-rich layer and strike the inner surface of the confining wall or shroud and reenter the interior space of the reactor. This impingement on the wall represents the radial component of centrifugal force produced by particles rotating in a constrained environment (e.g., the inner surface of the confining wall). The repeated collisions, contact, or strikes increase the probability of a fusion reaction in a given area over a given period of time. The repetition replaces the need for a long confinement time and addresses the concerns that led to Lawson's criterion for characterizing prior approaches to fusion reactions. In simple terms, the overall probability of a fusion reaction is increased significantly. As an example, the electron-rich region may be characterized by any combination of the following parameter values: Density of free electrons: about 1023/cm3 Density of neutrals: about 1020/cm3 Density of positive ions: about 1015-1016/cm3 (about 10−5 to 0.01% of neutrals) Difference in densities of electrons and positive ions: about 106 to 108/cm3 Thickness (radial) of free electron-rich region (region where most of the electron density gradient exists): about 1 micrometer Electric field strength in the electron-rich region: about 106 to 108 V/m Electron temperature: about 1800-2000 K. (about 0.15 to 0.17 eV) Centripetal acceleration: about 109 g's (where g is the acceleration due to gravity=9.8 ms−2) The free electrons in such systems may be viewed as collectively catalyzing the fusion reaction of two nuclei. By analogy, one or more muons in association with protons and deuterons are sometimes described as catalyzing the fusion of hydrogen and deuterium atoms. Just as muons catalyze the fusion by allowing two fusing nuclei to get closer to one another, the free electrons in the vicinity of fusing nuclei catalyze fusion reactions described herein. Effectively, the electrons reduce the energy barrier that prevents the two reactants from coming close enough to react. This is very similar to the action of any catalyst in a chemical or physical context. Both muons and electrons increase the rate of reaction but do not actually participate in the reaction; they simply reduce the energy barrier required to bring the reactants in close enough proximity to react. However, muon and electron catalysis have few other similarities. Muon catalyzed fusion is not commercially viable for various reasons. Notably, muons have a much greater mass than electrons and hence producing them is much more energetically expensive. Further, only relatively few of them can be produced at any instant in time, which means the breakeven requirement for fusion is not attainable. For the proton-boron-11 reaction, breakeven fusion may require approximately 1017 successful fusion interactions per cubic centimeter per second. Only a few nuclei in a large pool would be able to benefit from muon catalyzed fusion, nowhere near the level needed to support fusion. In contrast, electrons can be easily produced, and in high density. For example, in accordance with the techniques disclosed herein, electrons can be generated at densities of approximately 1020 per cubic centimeter or greater. With such high densities, the electrons act collectively to produce a high electric field, which over a relatively large volume reduces the Coulombic barrier to interaction between approaching nuclei. Such a relatively large volume permits the needed interactions to breakeven, i.e. at least about 1017 successful fusion interactions per cubic centimeter per second. Terminology A “reactor” is an apparatus in which one or more reactants react to produce one or more products, often with an accompanying release of energy. The one or more reactants are provided in a reactor by continuous delivery, intermittent delivery, and/or a one-time delivery. They may be provided in the form of gasses, liquids, or solids. In some cases, a reactant is provided as a component of a reaction; for example, it may be included in a structure of the reactor such as a wall. Boron 11, lithium 6, carbon 12, and the like may be provided in a confining wall of a reactor. In some cases, a reactant is provided from an external source such as from a gas supply tank. In certain embodiments, the reactor is configured to promote a nuclear fusion reaction having a Q>1. A reactor may have components for removal of products and/or energy produced during the reaction. Product removal components may be ports, passages, getters, and the like. Energy removal components may be heat exchangers and the like for removing thermal energy, inductors and similar structures for directly removing electrical energy, etc. The reactor components may permit products and energy to be removed continuously or intermittently. In certain embodiments, a reactor has one or more confining walls that contain the reactants, and in some cases, provides a source of reactant, an electrical field, etc. As illustrated throughout this disclosure, reactors suitable for providing a sustained fusion reaction may have many different designs. A “rotor” is a reactor or reactor component in which one or more reactant or product species (particles) rotates in a space. The space may be defined at least in part by a confining wall as described herein. In some cases, the rotation is induced by a magnetic force, an electrical force, and/or a combination of the two, as in the case of a Lorentz force. In certain embodiments, the rotation is induced by applying an electrical and/or magnetic force to electrically charged particles in a manner that causes them to rotate in a confinement region; the rotating charged particles collide with neutrals to cause the neutrals to likewise rotate in the confinement region, a phenomenon sometimes called ion-molecule coupling. Because the neutrals are not affected by the electrical and/or magnetic force, they would not rotate in the confinement region absent the interaction with the charged particles. The confining wall or other outer structure of the rotor may have many closed shapes as described herein. In some embodiments, the outer structure has a generally or substantially circular or cylindrical shape. In such cases, the shape need not be geometrically exact, but may exhibit certain variations such as eccentricity around an axis of rotation, non-continuous curvature such as vertices, and the like. In some cases, the confinement region of a rotor has an interior rod or other structure arranged concentrically with respect to the confining wall. In such cases, the rotor has an “annular space” where the particles rotate. When used herein, an “annular space” refers to a confinement region wherein the region is substantially ring-shaped. It should be understood that some rotors do not have an interior rod or other structure to define an annular space. In such cases, the confinement region of the rotor is simply a hollow structure. While an annular space may have a generally cylindrical shape, such a shape may exhibit certain variations such as eccentricity around an axis of rotation, non-continuous curvature such as vertices, and the like. The “Lorentz force” is provided by a combination of electric and magnetic forces on a charge due to the resulting electromagnetic fields. The magnitude and direction of the force is given by the cross product of the electric and magnetic fields; hence the force is sometimes referred to as J×B. When the electric and magnetic fields have orthogonal directions, the force applied to a charged particle has a rotational direction that may be represented by the right-hand rule mnemonic. In fusion reactions, participating reactants and products, which may include protons, alpha particles, and boron (11B), are not necessarily present in complete purity. To the extent that any such reactant, product, or other component of a reaction is presented herein, such component is understood to be substantially present. In other words, the component need not be present at the level of 100% but may be present at a lower level, e.g., about 95% by mass or about 99% by mass. An aneutronic reaction is conventionally understood to be a fusion reaction in which neutrons carry no more than 1% of the total released energy. As used herein, an aneutronic reaction or a substantially aneutronic reaction is one that meets this criterion. Examples of aneutronic reactions include: p+B11→3He4+8.68 MeV D+He3→He4+p+18.35 MeV p+Li6→He4+He3+4.02 MeV p+Li7→2He4+17.35 MeV p+p→D+e++v+1.44 MeV D+p→He3+γ+5.49 MeV He3+He3→He4+2p+12.86 MeV p+C12→N13+γ+1.94 MeV N13→C13+e++v+γ+2.22 MeV p+C13→N14+γ+7.55 MeV p+N14→O15+γ+7.29 MeV O15→N15+e++v+γ+2.76 MeV p+N15→C12+He4+4.97 MeV C12+C12→Na23+p+2.24 MeV C12+C12→Na20+He4+4.62 MeV C12+C12→Mg24+γ+13.93 MeVExamples of neutronic reactions include D+T→He4+n+17.59 MeV D+D→He3+n+3.27 MeV T+T→He4+2n+11.33 MeV The coulombic repulsion force is the electrostatic force experienced by two or more particles of the same charge. For two interacting particles, it is proportional to the reciprocal of the square of the separation distance (Coulomb's law). Thus, the repulsion becomes significantly stronger as charged particles approach one another. The repulsive force experienced by a charged particle in an electric field produced by multiple charged particles is given by the superposition of the contributions of all charged particles in the vicinity. Lowering the coulombic barrier means that the commonly known and understood coulombic repulsion force typically calculated or experienced between two isolated particles is “lowered” or reduced by some calculable degree when the particles are in some proximity to a sufficient number of electrons or other charged particles to reduce the repulsive force that isolated particles would otherwise experience. As an example, the presence of excess electrons at a density of XX reduce the coulombic repulsive force between two positively charged YY particles in the domain of the electrons by ZZ %. Lorentzian Rotor Embodiments First Embodiment FIGS. 1a-c depict a first embodiment of a reactor in which charged particles, charged species, or ions are rotated by the Lorentz force. FIG. 1a is a cross-section view of a reactor, while FIG. 1b provides an isometric cutout view of the same reactor along of section A-A from FIG. 1a. Unless stated otherwise, directionality using the r, Θ, and z coordinates pertains to a cylindrical coordinate system as shown in FIG. 1b. In the depicted embodiment, a Lorentzian driven rotor has outer wall 110, which also serves as the outer electrode, and concentric inner electrode 120, sometimes referred to as a discharge rod, that is separated from the outer electrode by annular space 140. An electric field is formed across the annular space by applying an electric potential between the inner electrode 120 and the shroud 140. When a sufficient electric potential is applied between the electrodes, a portion of the gas in the annular space is ionized, and a radial plasma current across the annular space is generated. In various embodiments, the inner electrode is held at a high positive potential while the shroud is grounded such that the electric field, and the flow of current, is substantially in the positive r-direction. FIG. 1c depicts how the Lorentzian force is used to drive charged particles azimuthally within the confining wall 110. In FIG. 1c, the discharge rod has been removed and the axis has translated in the z-direction to improve clarity. While not shown, a magnet such as a permanent magnet or a superconducting magnet is used to generate an applied magnetic field that is substantially parallel to the z-axis (substantially axial direction) within the annular space. The magnetic field is substantially perpendicular to the direction of the electrical current causing the moving charged particles, charged species, and ions to experience a Lorentz force in the azimuthal (or Θ) direction. For example, consider the case in which the discharge rod has a positive potential vis-à-vis the outer electrode (e.g., the discharge rod has an applied positive potential while the outer electrode is grounded), thereby producing an electric field in the r-direction (144). In this configuration positively charged ions will move in the r-direction towards the outer electrode through the annular space 140. If a magnetic field concurrently points in the z-direction (146), the ions will experience a Lorentz force in the −Θ direction, or clockwise direction as viewed from the perspective shown in FIGS. 1b and 1c. In some cases the electric field and magnetic field may be at an angle that differs from the perpendicular yet is not parallel, such that perpendicular components, to a lesser or greater extent, are present in sufficient strength to create a sufficiently strong azimuthal Lorentz force. This azimuthal force acts on charged particles, charged species, and ions, which in turn couple with neutrals such that neutrals in the annular space between the central discharge rod and outer electrode also are made to move at high rotational velocity. The lack of any moving mechanical parts means that there is little limitation to the speed at which rotation can occur, thus providing rotation rates of neutrals and charged particles that are in excess of, for example, 100,000 RPS. Reverse Electrical Polarity Embodiment FIGS. 5a-d depict another embodiment in which a reactor may utilize a Lorentzian force to drive ions and neutrals, through ion-neutral coupling, into rotation. Reactors configured for reverse electrical polarity differ from the reactors depicted in FIGS. 1a-c in that the electric field, and the flow of current (by convention in the direction of positive charge movement), is substantially in the negative r-direction. FIG. 5a is a cross-section view of a reactor, while FIG. 5b provides an isometric cutout view of the same reactor along of section A-A from FIG. 5a. A reverse electrical polarity rotor has outer electrode 510 and concentric inner electrode 520 that is separated from the outer electrode by annular space 540, sometimes referred to herein as a confinement region. A radial electric field directed towards the inner electrode may be formed in the annular space by applying an electric potential to the inner electrode and/or the outer electrode. When a sufficient electric potential is applied between the electrodes, a portion of the gas in the annular space is ionized, and a radial plasma current across the annular space is generated. FIG. 5c depicts how the Lorentzian force is used to drive charged particles azimuthally within the reactor. In FIG. 5c, the inner electrode has been removed from view, and the depicted axis has been translated in the z-direction to improve clarity. While not shown, a magnet such as a permanent magnet or a superconducting magnet is used to generate an applied magnetic field that is substantially parallel to the z-axis (i.e., in a substantially axial direction) within the annular space. The magnetic field is substantially perpendicular to the direction of the electrical current causing the moving charged particles, charged species, and ions to experience a Lorentz force in the azimuthal (or Θ) direction. For example, consider the case in which the inner electrode has an applied negative potential while the outer electrode is grounded (or held at a positive potential) producing an electric field in the negative r-direction (544). In this configuration, positively charged ions will move in the negative r-direction towards the inner electrode through the annular space 540. If a magnetic field concurrently points in the z-direction (546), the ions will experience a Lorentz force in the +Θ direction or counterclockwise direction as viewed from the perspective shown in FIGS. 5b and 5c. In some cases, the electric field and magnetic field may be at an angle that differs from the perpendicular yet is not parallel, such that perpendicular components, to a lesser or greater extent, are present in sufficient strength to create a sufficiently strong azimuthal Lorentz force. This azimuthal force acts on charged particles, charged species, and ions, which in turn couple with neutrals such that neutrals in the annular space are also made to move at high rotational velocity. The lack of any moving mechanical parts means that there is little limitation to the speed at which rotation can occur, thus providing rotation rates of neutrals and charged particles that are in excess of, for example, 100,000 RPS. Reverse Fields Embodiment FIGS. 6a-d depict multiple views of another reactor embodiment that utilizes a Lorentzian force to drive ions and neutrals, through ion-neutral coupling, into rotation. The reactor of this embodiment operates using a reverse fields configuration. Reactors having this configuration differ from the reactors depicted in FIGS. 1a-c and FIGS. 5a-d in that the orientation of the electric field and the magnetic field within the confinement region are reversed. In this configuration, the magnetic field, instead of being substantially parallel to the z-axis, is directed radially in the positive or negative r-direction. Similarly, the electric field, rather than being directed radially, is substantially parallel to the z-axis. FIG. 6a is an isometric view of the reactor, FIG. 6b is a view of the reactor in the z-direction, FIG. 6c is an isometric section view of the reactor (corresponding to line A-A in FIG. 6b), and FIG. 6d provides a side view of the reactor. The depicted embodiment includes an inner ring magnet 626 and a concentric outer ring magnet 616 that also serves as the confining wall. The ring magnets have their poles oriented in the same direction, such that corresponding surfaces of the inner and outer ring magnets are the same. In this case, the exterior surface is a north pole 658, and the interior surface is a south pole 659. In some embodiments, there may be one or more additional layers of material on the interior surface of magnet 658 such that the confining surface material is different from the magnetic material. The region between concentric magnets forms the annular space 640 which is bound in the z-direction by electrodes on one end of the confinement region 660a and electrodes on the other end of the confinement region 660b. Generally, all the electrodes on either side of the confinement region (corresponding to electrodes 660a or to electrodes 660b) are given a similar electric potential. Unlike in the depicted hybrid reactor, electrodes 660a (or to electrodes 660b) may be a single contiguous electrode forming, for example, a ring or a disk shape. If electrodes 660a are grounded and electrodes on the other side of the annular space 660b are given a positive potential then an electric field is applied through the confinement region in the positive z-direction. If the magnetic field points in the r-direction (as depicted) the orthogonal electric and magnetic fields cause ions to rotate azimuthally in the Θ direction (see, e.g., FIG. 6c). Alternatively, if an electric field was pointed in the negative z-direction by applying a positive potential to electrodes 660a while grounding electrodes 660b, ions would rotate in the −Θ direction. Wave-Particle Embodiments A second embodiment of a controlled fusion device is shown in FIGS. 7a and 7b in which ions rotate as a result of oscillating electrostatic fields. In this embodiment ions are accelerated azimuthally by electric fields produced from multiple discrete wall electrodes 714 located on, or forming, an outer ring, optionally in combination with interior electrodes 724 located on, or forming, an inner ring to generate localized, azimuthally-varying electric fields within an annular space 740. In some cases, the wall electrodes collectively form the confining wall, and in some cases, the wall electrodes may be disposed on or within a portion of a confining wall or scaffold. The electric field advances azimuthally in a controlled sequence such that the electrostatic force applied to ions proceeds sequentially in a substantially azimuthal direction (in the Θ or −Θ direction). In this way, charged species are accelerated akin to a Maglev train that is propelled by oscillating magnetic fields along a train track. An oscillatory potential may be applied to the electrodes. The oscillations may vary in phase or other parameter from one electrode to the next to induce or maintain rotational movement of ions. Ions present in the annular space experience an electrostatic force as a result of electric fields, and only a relatively small number or percentage of ions are needed to drive large numbers or percentages of neutrals through the principle of ion-neutral coupling. Ions used to drive the neutrals into rotation may be generated by any suitable mechanism such as inductive or capacitive coupling. In some embodiments, ions are generated when an RF charge sequence is applied to the wall and/or interior electrodes. In some embodiments the wall and/or interior electrodes may first undergo an initial charge sequence to ionize some of the neutral gas in the annular space and then transition to a different charge sequence that drives the rotation of ions. For example, a charge profile used to ionize a gas might simply involve grounding the confining wall electrodes 714 while applying a high potential to the interior electrodes 724. In some embodiments, a gas that is already partially ionized may be introduced into the annular space 740. While FIGS. 7a and 7b depict two binary charge profiles that may be used to drive ion rotation in the annular space, many alternative charge sequences are possible. In some charge sequences, an electrode may be, for instance, held at a ground potential for a duration of time or may have a charge sequence that is asymmetrical (e.g., a positive potential is held for twice the duration of a negative potential). In certain embodiments, this system does not require a magnetic field such as an axial static magnetic field. FIG. 7a depicts an example of this embodiment taken at a first point in in time when the electrodes are provided with a first potential profile such that ions (e.g., a cloud or a grouping of ions) 704 experiences a force in the −Θ^ direction. FIG. 7b depicts the embodiment of FIG. 7a at a later point in time when the electrodes are provided with a different potential profile such that ions 704 continue to experience an azimuthal force in the −Θ direction. Hybrid Embodiments In certain embodiments a reactor includes features for producing both Lorentzian force and an oscillating electrostatic field to drive ions and neutrals, through ion-neutral coupling, into rotation. At any stage of operation, the reactor may use one or both of these mechanisms. FIGS. 6a-f depict an example reactor suitable for such operation. FIG. 6a is an isometric view of the reactor, FIG. 6b is a view of the reactor in the z-direction, FIG. 6c is an isometric section view of the reactor (corresponding to line A-A in FIG. 6b), FIG. 6d provides a side view of the reactor, and FIGS. 6e and 6f are section views (corresponding to line B-B in FIG. 6d) at different points in time. The depicted embodiment includes an inner ring magnet 626 and a concentric outer ring magnet 616 that also serves as the confining wall. The ring magnets have their poles oriented in the same direction, such that corresponding surfaces of the inner and outer ring magnets are the same. In this case, the exterior surface is a north pole 658, and the interior surface is a south pole 659. In some embodiments, there may be one or more additional layers of material on the interior surface of magnet 658 such that the confining surface material is different from the magnetic material. The region between concentric magnets forms the annular space 640 which is bound in the z-direction by one or more pairs of electrodes 660a and 660b. When electrode pairs 660a and 660b are given different potentials, an electric field substantially parallel to the z-direction is generated in the annular space, for example, by applying a positive potential to electrodes 660a while grounding electrodes 660b. When ions are generated in the annular space, the orthogonal electric and magnetic fields cause them to rotate azimuthally in the −Θ direction (see, e.g., FIG. 6c). If a positive potential were applied to electrodes 660b while electrodes 660a were grounded, ions would rotate in the Θ direction. In some embodiments, as depicted in FIGS. 6a-e, a plurality of electrodes 660a and 660b are distributed radially along the annular space. In such cases, the reactor may be driven in a fashion similar to that of the reactor in FIGS. 7a and 7b. During operation, each electrode pair is driven with a substantially similar electric potential that differs from the potential of an adjacent electrode pair such that a localized electric field is generated in the Θ direction. As depicted in FIGS. 6d and 6e, the voltages applied to electrode pairs can be modulated in a controlled sequence so that the electrostatic force applied to ions presents a substantially continuous azimuthally (in the Θ or −Θ direction) varying component. In some configurations, a reactor may be configured to operate in a manner that initially drives ions and neutrals by a Lorentzian force and then transitions to driving ions and neutrals using the just described alternating electrostatic fields. 6. Reactor Types (Sizes) In one aspect, reactors may be classified into groups by the power output they provide. In this manner reactors of the present disclosure are, for purposes of this discussion, divided into small, medium and large scale reactors. Small scale reactors are typically capable of generating between about 1-10 kW of power. In some embodiments, these reactors are used for personal applications such as powering automobiles or providing power to a household. The next classification is medium scale reactors which typically deliver between about 10 kW-50 MW of power. Medium scale reactors may be used for larger applications such as server farms, and large vehicles such as trains, and submarines. Large scale reactors are reactors that are designed to output between about 50 MW-10 GW of power and may be used for large operations such as powering portions of a power grid and/or industrial power plants. While these three general classifications provide practical categories to which the present disclosure may relate, reactors disclosed herein are not tied to any of these categories. The surface area (product of the perimeter and axial direction) of a shroud or confining wall typically limits the maximum power that may be generated by a reactor. A shroud having a large surface area supports fusion reactions over the large area of an interior surface (e.g., 122 in FIG. 1a). For small scale reactors, the radius of the interior surface of the shroud is typically about 1 centimeter to about 2 meters and the surface area of the interior surface is typically between about 5 cm3 and 20 cm3. For a medium scale reactor, the radius of the interior surface of the shroud is typically about 2 m to about 10 m and the surface area of the interior surface is typically between about 25 m3 and 150 m3. For a large scale reactor, the radius of the interior surface of the shroud is typically about 10 meters to about 50 meters and the surface area of the interior surface is typically between about 125 m3 and 628 m3. In some cases the radius of the interior surface may be on the order of kilometers, having a similar footprint to the Large Hadron Collider (LHC) run the CERN laboratory in Switzerland. Each of the above values assumes a single reactor that stands alone or is part of a contiguous stack of reactors (described below). First Embodiment FIGS. 1a-c depict the structure of a reactor having concentric electrodes that utilizes a Lorentzian rotor to drive charged particles and fusion reactants into rotation. This embodiment has an inner electrode 120, an outer electrode 110, and an annular space 140 between the two electrodes. During operation, an applied potential between these electrodes creates an electric field 144 that is substantially in the r-direction. While not shown, this embodiment also includes permanent magnets or an electromagnet (e.g., a superconducting magnet) that generates a magnetic field 146 in the z-direction between the inner and outer electrodes. As depicted in FIG. 1c, charged particles moving between the electrodes experience an azimuthally directed force, or a Lorentzian force, as a result of the radial electric field and the axial magnetic field. As shown, the reactor depicted in FIG. 1a has a gap 142 that radially separates the outer surface of the inner electrode 112 and the interior surface of the outer electrode 122. While the surface areas of the facing surfaces of the inner and outer electrodes may dictate the scale of a reactor, the radial gap may remain relatively constant across a wide range of applications. In some cases, the upper limit of a gap may be limited by the power available to ionize gas in the annular space and generate a plasma current, while the lower limit of the gap may be limited to manufacturing tolerances. When a gap is very small, e.g. less than 0.1 mm, any misalignment between the electrodes may cause the electrodes to touch creating a short circuit. Of course, as manufacturing tolerances allow greater precision, smaller gaps may be feasible. In some embodiments, the gap may be between about 1 mm and about 50 cm, and in some embodiments, the gap may be between about 5 cm and about 20 cm. In some cases, the gap may vary along the r-direction and/or the z-direction of a reactor. For example, the radius of the inner electrode may vary as a function of position along the z-axis while the radius of the inner surface of the outer electrode is constant. The length in the z-direction of the confining wall created by the outer electrode may be determined by the radial dimensions and the power generation requirements of the reactor. In some embodiments, the length of the outer electrode in the z-direction may be limited by the type and configuration of magnets used to create the magnetic field. For example, if permanent magnets are placed on either end of the annular space along the z-direction (as depicted in FIG. 11), the outer electrode may be limited to about 5 or about 10 cm in the z-direction. If, however, the magnetic field is generated using multiple permanent ring magnets, as shown in FIGS. 16 and 17, or an electromagnet or a superconducting magnet, as shown in FIG. 10, the length of the outer electrode in the z-direction may be much longer. For example, the outer electrode may be between about 1 meter and about 10 meters. Generally, the outer electrode 110 is of a similar length to the inner electrode 120, however, this need not always be the case. In some embodiments, the inner electrode may extend beyond the outer electrode in one or both directions. In some embodiments, the length of the outer electrode may exceed the length of the inner electrode such that the outer electrode extends beyond the inner electrode in one or both directions. While FIGS. 1a-1b depict one configuration in which a solid, circular inner electrode is used in conjunction with circular outer electrodes, there are many permutations of electrode shapes that may be used in this configuration. Several non-limiting examples of alternate embodiments will be apparent to those of skill in the art and are discussed with reference to FIGS. 8a-b and FIGS. 9a-c. While several illustrative examples are provided, one can easily understand how many additional electrode shapes are feasible. As depicted in FIG. 8a, in some embodiments the inner electrode 820 may be a ring-like structure that is not solid all the way through. Providing a cavity or an open space within the inner electrode may be useful for heat dissipation, the use of internal magnets such shown in FIGS. 17a-c, or the use of other components within the reactor. In some cases, the radius of the inner and outer electrodes may vary along the z-direction of a reactor. For example, as shown in FIG. 8a, an inner electrode 820 may have a larger circumference at some locations along the z-direction, reducing the gap 842 at those locations. Conversely, a uniform inner electrode may be used with an outer electrode having an inner radius that changes or even fluctuates along the z-direction. In some instances, such as the embodiment depicted in FIG. 8b, both the radius of the inner electrode 820 and the radius on the inner surface of the outer electrode 810 vary in the z-direction such that the gap 842 is maintained along the z-direction of the reactor. FIGS. 9a-c depict cross sections of reactors that have non-circular cross sections. As depicted, in some embodiments, the inner electrode 920, and the outer electrode 910 may have a radius that varies azimuthally, i.e., in the Θ direction. In some cases, the surfaces of the inner and outer electrodes (912 and 922) may have an elliptical cross section as shown in FIG. 9a. In some cases, the major and minor axis of an ellipse-shaped cross section electrode may only be off by a small percentage, for example, less than 1%. In some embodiments surface 912 and/or 922 may form a polygonal cross section, such as the reactor shown in FIG. 9b having a cross section that forms a heptagon. In some embodiments surfaces 912 and 922 may have 4 or more sides; in some embodiments more than 8 sides, and in some embodiments more than 16 sides. Having corners on surface 912 may be advantageous in certain situations; for example, rotating particles may have an increased rate of collisions with target materials at corner locations resulting in an increased rate of fusion. In some embodiments, such as in the reactor configuration depicted in FIG. 9c, the radius of the inner or outer electrodes, defined by surfaces 912 and 922, may vary in the Θ direction such that the cross section of either surface has a patterned edge; e.g., an edge that is sinusoidal, saw-tooth shaped, or square-wave shaped. While the inner and outer electrodes in the depicted embodiments are co-axial, in some embodiments the axes of the inner and outer electrodes are offset, e.g., the annular space is eccentric, such that the inner and outer electrodes have z-direction axes that are substantially parallel but not collinear. Materials for inner and outer electrodes may depend on the reactor size, selected fusion reactants, and other parameters that govern the operation of a fusion reactor. In general, there are many trade-offs such as ranges in cost, thermal properties, and electrical properties that determine which materials are selected for reactors. Refractory metals (e.g., tungsten and tantalum) may be chosen for small scale reactors because of their extremely high melting points and relatively high electrical conductivity at high temperatures; however using these materials in a large scale reactor may significantly increase the cost of a reactor. In certain embodiments, the electrode materials have a sufficiently high melting temperature to withstand the thermal energy released during operation of the reactor. For the outer electrode, forming the confining wall on which fusion reactions may occur, the thermal energy release is often great. To withstand regular use, the material of the outer electrode should have a melting temperature that is in excess of temperatures reached by the electrodes during operation of the reactor. In some cases the material chosen for an electrode is greater than about 800° C., in some cases the melting temperature of an electrode is greater than about 1500 C, and in other cases the melting temperature is greater than about 2000° C. In many embodiments, it is beneficial for the electrode material to have a high thermal conductivity. If heat can be extracted from an electrode (e.g., using a heat exchanger) at an equivalent rate to which heat is introduced to the electrode during steady state conditions, then a reactor may be suitable for continuous operation. When an electrode material has a high thermal conductivity, the rate at which heat be extracted may be improved and concerns of overheating are reduced. In some cases the thermal conductivity is greater than about 10 ⁢ W m°K ,in some cases the thermal conductivity is greater than about 100 ⁢ W m°K ,and in some cases the thermal conductivity is greater than about 200 ⁢ W m°K . In certain cases, such as when a reactor is configured for pulsed operation, it may be beneficial for the electrode material to have a high heat capacity. By having a high heat capacity, an electrode increases in temperature at a slower rate during operation of the reactor. When used in a pulsed operation, the generated thermal energy may continue to be dissipated through the electrodes between pulses, preventing the electrodes from reaching their melting temperature. In some cases the specific heat of the electrode should be higher than about 0.25 J/g/° C., in some cases, the specific heat should be greater than about 0.37 J/g/° C., in other cases, the specific heat should be higher than about 0.45 J/g/° C. In certain embodiments, the electrode material has a relatively small coefficient of thermal expansion. In some cases, by having a low coefficient of thermal expansion a reactor may have improved performance over a greater range of temperatures. For example, if a reactor has a gap that is about 1 millimeter at room temperature, the gap may be proportionally much smaller during steady state operation due to the expansion of the inner and/or outer electrodes. If a thermal coefficient is too high, the outer and inner electrodes may touch causing a short circuit. Alternatively, if a reactor is designed to have a certain gap at operating temperatures, the gap may be larger than desired when a reactor is first turned on. In some cases the linear coefficient of thermal expansion of an electrode material is less than about 4.3×10−6° C.−1, in some cases the linear coefficient of thermal expansion of an electrode material is less than about 6.5×10° C.−1, and in other cases the linear coefficient of thermal expansion of an electrode material is less than about 17.3×10−6° C.−1. To facilitate reactor operation, the electrodes may be designed to have mechanical properties such as resistance to degradation during thermal cycling. Under certain conditions, some materials, e.g. stainless steels, become brittle and eventually experience fatigue as a result of thermal cycling. If a reactor operates in pulsed operation and an electrode is rapidly heated and cooled, internal stress may develop. In some cases, the effects of thermal loading cycles may be reduced by using an electrode having a single bulk material, or by using two or more materials having similar coefficients of expansion. Certain materials may experience deformation due to creep at high temperatures. Thus electrode materials may be chosen to maintain their strength at elevated temperatures. Electrode materials may be chemically inert and not significantly affected by oxidation, corrosion, or other chemical degradation over the lifetime of a reactor. Another consideration for electrode materials is whether or not they are ferromagnetic. In some cases, if ferromagnetic materials are used, internal localized magnetic fields are created that may interfere with establishment or maintenance of the intended magnetic field within the annular space. In a Lorentzian driven reactor having concentric electrodes, the inner and outer electrodes may be made from a material that is sufficiently conductive such that, during operation, an electric potential is evenly applied over the surfaces of the electrodes. In certain embodiments, at room temperature, the resistivity of the inner or outer electrode material is less than about 7×10−7 Ωm, and in some cases less than about 1.68×10−8 Ωm. In addition to being conductive at room temperate, when a reactor is not in operation, the inner and outer electrodes may be conductive at higher operating temperatures. During operation the inner or outer electrode may reach temperatures of between about 600° C. to about 2000° C. During operation, the resistivity of the outer electrode material should be no greater than about 1.7E-8 Ωm, and in some cases no greater than about 1E-6 Ωm. In cases where reactants or by-products include hydrogen or helium, consideration may be given to a material's resistance to hydrogen embrittlement. Hydrogen embrittlement is a process by which metals such as stainless steel become brittle and in some cases fracture due to the introduction and subsequent diffusion of hydrogen atoms or molecules into the metal. Since the solubility of hydrogen increases at higher temperatures, the diffusion of hydrogen into the electrode material may increase during operation of the reactor. When assisted by a concentration gradient in which there is significantly more hydrogen outside the metal than inside, e.g., caused by the centrifugal densification of hydrogen atoms that impinge on the confining wall, the diffusion rates may be increased further. Individual hydrogen atoms within the metal gradually recombine to form hydrogen molecules, creating an internal pressure in the metal. Additionally, or alternatively, entrained hydrogen molecules themselves create internal pressure. This pressure can increase to levels where the metal has reduced ductility, toughness, and tensile strength, up to the point where cracks form and the electrode fails. In some cases, in which a metal contains carbon (e.g. carbonized steel) an electrode may be susceptible to a process known as hydrogen attack in which hydrogen atoms diffuse into the into the steel and recombine with carbon to form methane gas. As methane gas collects within the metal, it generates internal pressure that may lead to mechanical failure of the device. While methods for reducing the effects of the hydrogen embrittlement are described elsewhere herein, in general, a material's susceptibility to embrittlement is considered when designing electrodes. In some cases, electrodes may include platinum, platinum alloys, and ceramics such as boron nitride, each of which resist hydrogen embrittlement. In some cases, the metallurgical structure may be modified so that the effect of hydrogen in the lattice of a metal is less detrimental. For example, in some cases a metal or metal alloy may undergo a heat treatment to achieve a desired metallurgical structure. In various embodiments, the inner and outer electrodes are primarily constructed of metals and metal alloys. In some embodiments, the inner and/or outer electrode is made at least in part from a refractory metal having a high melting temperature. Refractory metals are known for being chemically inert, suitable for fabrication using powder metallurgy, and are stable against creep at very high temperatures. Examples of suitable refractory metals include niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium and iridium. In one example, at least the outer electrode includes tantalum. In some embodiments, one or both electrodes are made using stainless steel. Benefits of stainless steel include its machinability and resistance to corrosion. In some cases, electrodes are made at least in part from a non-carbon based stainless steel, such as Incoloy, which may be more resistant than carbonized stainless steels to hydrogen embrittlement. In some cases, an electrode may be made at least in part of a nickel alloy that maintains its strength at very high temperatures such as Inconel, Monel, Hastelloys, and Nimonic. In some cases, electrodes are made at least in part from copper or a copper alloy. In some cases, an electrode is configured with one or more channels for internal cooling to extract heat, such that materials with lower resistance to extreme temperatures may be used. While absorption of a small atom fusion reactant such as hydrogen, deuterium, or helium may lead to a mechanical failure of an electrode, under some operating conditions, deleterious embrittlement effects may be reduced or eliminated for certain materials. For example, under some conditions hydrogen absorbing materials such as palladium-silver alloys appear to be impervious to hydrogen embrittlement (Jimenez, Gilberto, et al. “A comparative assessment of hydrogen embrittlement: palladium and palladium-silver (25 weight % silver) subjected to hydrogen absorption/desorption cycling” (2016), which is incorporated herein by reference in its entirety). In such cases, absorption of a fusion reactant may increase the rate of a fusion reaction, for example, a rotating gas reactant such as hydrogen may collide with a fixed hydrogen atom fixed on the outer electrode (or the confining wall). In some cases, reactants are provided to the reactor by diffusing reactants through the inner and/or the outer electrode. In some cases, an electrode may include titanium, palladium, or a palladium alloy for the purpose of delivering fusion reactants or increasing the rate of collisions between fusion reactants. In some cases, as discussed elsewhere herein, an outer or inner electrode may include an electron emitting material having a high electron emissivity. In some cases, an outer electrode may include a target material that includes a fusion reactant. In some cases, the target material is consumed during operation as a result of a fusion reaction. For example, in some cases, lanthanum hexaboride is used as a target material, and boron-11 atoms are consumed during a proton-boron reaction. First Embodiment—Electrodes: In some embodiments the outer electrode is monolithic, being made from a single material, and in other embodiments, the outer electrode has a layered or segmented structure including two or more materials. In some embodiments, the interior surface of the outer electrode, the confining wall, includes a target material (a material containing a fusion reactant), or an electron emitting material. In some cases, a target material or an electron emitter may cover the entire surface area of the confinement wall, and in some cases, a target material or electron emitter is located at one or more discrete locations along the confinement wall (e.g., as depicted by the electron emitters in FIGS. 21a-b). In some cases, an inner layer of the outer electrode provides one property while a more exterior layer provides a different property. For example, an interior layer that forms the surface of the confinement wall may have a high melting temperature, while an exterior layer may have a superior thermal conductivity or electrical conductivity. In some cases, an electrode may include a layer of material forming the confinement wall that has a higher resistance to hydrogen embrittlement than the rest of the electrode. In some cases, an electrode includes a ceramic coating that can prevent hydrogen atoms from penetrating into the lattice of the outer electrode or provide thermal insulation of the bulk electrode material. In some embodiments, an outer electrode may have a layer of aluminum nitride, aluminum oxide, or boron nitride. Some materials that have a low electrical conductivity at room temperature (e.g. boron nitride) may be heat treated to improve their electrical conductivity. In some cases, an electrode may undergo a surface treatment that adds material to the electrode surface and reduces hydrogen embrittlement. For example, when an electrode is made out of a material that is susceptible to hydrogen embrittlement (e.g., tantalum), embrittlement may be reduced by adding minor amounts of a noble metal to the electrode surface. In some cases, the noble metal may only cover a small portion of the electrode surface. For example, the noble metal may cover less than about 50%, less than about 30%, or less than 10% of the electrode surface while providing a significant reduction of hydrogen embrittlement to the electrode. In some cases, small amounts of platinum, palladium, gold, iridium, rhodium, osmium, rhenium, and ruthenium may be added to an electrode surface to reduce hydrogen embrittlement. In some cases, small spots (e.g., about 0.5 inches in diameter) of noble metal may be riveted or welded to the electrode surface. In some cases, a noble metal powder may be added to a reactor, and during normal operation, the powder is sputtered onto the electrode surface. In some cases, a nobel metal may be periodically added to the surfaces of electrodes, e.g., after reactor has operated for a predetermined amount of time. In some cases, a sleeve is attached to the interior surface of the outer electrode, such that the interior surface of the sleeve forms the confinement wall. In some cases, a sleeve may be used to, e.g., provide a target material, provide an electron emitter, provide a barrier for hydrogen penetration into the outer electrode, and/or provide thermal protection to the outer electrode. In some cases, a sleeve is consumable and/or replaceable. For example, if the sleeve contains a target material that is consumed, the sleeve may eventually be replaced. In other cases, a sleeve acts as a sacrificial layer that protects the outer electrode from hydrogen embrittlement. In situations where the sleeve itself fails due to hydrogen embrittlement, it may be replaced at a much lower cost than the entire outer electrode. In some embodiments, the outer electrode may have a porous or mesh-like structure that allows high energy charged particles to pass through the electrode while still confining rotating neutrals within the annular space. Charged particles that pass through the outer electrode may be guided by magnetic fields of an exterior magnet. In some cases, escaping alpha particles are redirected towards hardware (discussed elsewhere herein) capable of converting the kinetic energy of alpha particles into electrical energy. In some cases, the pore size in and our electrode may be less than about 100 microns, in some cases, and in some cases, less than about 1 micron. In general, the construction of the inner electrode may be similar to that of the outer electrode. As with the outer electrode, the inner electrode may be made of a single material, or it may have a layered or segmented structure being made of two or more materials. In some embodiments, the inner electrode may be a solid body, and in other embodiments, the inner electrode has an interior space. In some cases, the inner electrode may include one or more pathways for internal cooling. In various embodiments, the inner electrode is connected to a power supply that provides a current that passes from the inner electrode out to a grounded outer electrode. Materials for the outer electrode are generally also suitable for the inner electrode, although, in certain embodiments, an inner electrode does not include target materials or electron emitting materials. First Embodiment—Magnets FIGS. 10a-d depict a first embodiment in which an axial magnetic field is applied by an electromagnet such as a superconducting magnet. FIG. 10a shows an isometric view of a superconducting magnet that surrounds the outer electrode of the reactor. As depicted, the magnet includes an enclosure 1056. FIG. 10b provides the same perspective as FIG. 10a, with the enclosure 1056 of the superconducting magnet removed revealing the superconductive coil windings 1054. FIG. 10c provides a perspective of the reactor as viewed along the z-axis and FIG. 10d is an isometric section view corresponding to the section lines, A-A, shown in FIG. 10c. As shown, the reactor has outer electrode 1010, inner electrode 1020, and a gap 10 that defines the annular space 1040 between the two electrodes. An electrical current (as depicted by arrows in FIG. 10a) passes through superconductive coil windings 1054 that wrap around the reactor, creating an applied magnetic field that is substantially in the z-direction through the annular space. In some embodiment, a superconducting magnet is used to generate an applied magnetic field that passes through the annular space that is between about 1-20 Tesla. In some cases, the applied magnetic field is between 1-5 Tesla. Coil windings are placed in an insulated enclosure 1056 positioned around the reactor that is kept at low-temperature (e.g., less than −180° C.) and low-pressure. The enclosure 1056 may be cooled by, for example, adiabatic expansion of gas (e.g., He), or a cryogenic liquid such that the temperature of the superconductive coil is kept below its critical temperature. In some cases, the enclosure may be cooled mechanically, avoiding any need for liquid cryogens. The coil windings may be made from superconducting materials such as niobium-titanium, or niobium-tin, Bismuth strontium calcium copper oxide (BSCC), or Yttrium barium copper oxide (YBCO). Coil windings may take the form of a wire or a tape that may be wrapped in an insulating material. In some cases, the coil windings include any of the aforementioned superconducting materials placed in a copper matrix to provide mechanical stability. In some embodiments, commercially sold superconducting magnets may be from vendors such as Cryomagnetics, Inc., or manufactures of Magnetic Resonance Imaging devices. In some cases, a superconducting magnet such as or similar to the AMS-02 superconducting magnet used for the Alpha Magnetic Spectrometer Experiment may be used. When a superconducting magnet is used to provide the axial magnetic field, the radius of the confining wall is typically smaller than the radius of the superconducting magnet, for example, in some cases, the radius may be limited to about 20 meters. When an electromagnet or superconducting magnet is placed around the outer electrode, there may be spacing between the outer electrode 1010 and the enclosure of the magnet 1056. This spacing may be used reduce heat transfer to the magnet. In some cases, a heat exchanger may be placed between the outer electrode 1010 and a magnetic enclosure. When the outer electrode has a porous or mesh-like structure, there may be a spacing between the outer electrode and the enclosure of a magnet that allows for charged particles that pass through the outer electrode. Charged particles, e.g., alpha particles, passing through the outer electrode may be constrained in the r-direction by ion cyclotron motion so that they do not collide with the enclosure 1056. In some cases, the spacing between the outer electrodes is between about 3 cm to about 6 cm, and in some cases, between about 6 cm and about 10 cm. Charged particles may then travel in the z-direction towards energy conversion means for generating electrical energy as described elsewhere herein. FIGS. 11a-b depict a reactor in which permanent disk-shaped magnets 1150 are placed on either end of the annular space 1140 to generate an applied magnetic field that is substantially axially directed, i.e., it points in the z-direction. FIG. 11a provides a perspective viewed along the z-direction, while FIG. 11b provides an isometric section view that corresponds to the indicated section lines in FIG. 11a. As depicted in FIG. 11b, the reactor has an inner electrode 1120, an outer electrode 1110 forming the confinement wall 1112, and an annular space between the inner and outer electrodes. Magnets 1150 are placed on either side of the annular space and have the same magnetic orientation. For example, both magnets may have a north pole facing in the positive z-direction, or both magnets may have a north pole facing in the negative z-direction. While not depicted, in some embodiments the magnets 1150 may be ring-shaped such that the magnet is in proximity to the annular space 1140 and provides a substantially uniform magnetic region along the inner surface of the outer electrode 1112. The ring-shaped magnets have the same pole orientation as the disk-shaped magnets depicted in FIG. 11. FIGS. 12a-b depict another embodiment in which a plurality permanent magnets 1250 having the same polarity in the z-direction (e.g., the same orientation as the disk-shaped magnets depicted in FIG. 11), are placed on either side of the annular space 1240 to generate an applied magnetic field in the z-direction along the inner surface of the outer electrode 1212. FIG. 12a provides a perspective in the z-direction, while FIG. 12b provides an isometric section view that corresponds to the indicated section lines, A-A, in FIG. 12a. Some features are labeled in an enlarged view 1201, which depicts how the annular space is bound by the inner electrode 1220, the outer electrode 1210, and permanent magnets 1250. Using a plurality of smaller magnets may be useful to reduce costs and physical constraints associated with larger monolithic magnets for large-scale reactors. The arrangement of magnets 1250 shown in FIGS. 12a and 12b may be viewed as effectively creating two facing ring magnets. While not shown, in some embodiments a combination of different magnet shapes is used to generate the axial magnetic field. For example, a ring magnet may be used on one side of the annular space while a plurality of bar magnets may be used on the other. FIGS. 13a-c depict an embodiment in which a reactor 1300 with a single inner electrode 1320 has multiple annular spaces 1340 separated by permanent magnets 1350 that are arrayed along the z-direction. As depicted, the reactor has inner electrode 1320, a plurality of outer electrodes 1310 that form the confinement wall 1312, which is a combination of wall segments, and an annular space 1340 between each outer electrode and the inner electrode. FIG. 13a provides a perspective viewed along the z-direction, while FIGS. 13b and 13c provide a section view and an isometric section view, respectively, that correspond to the indicated section lines in FIG. 13a. When permanent magnets are placed on either end of the annular space, the length of the annular space in the z-direction may be limited by the strength of the magnetic field that can be generated by permanent magnets. In some cases, the annular space may be limited to, for example, about 5 or 10 cm. By arraying magnets 1350 in the z-direction between a plurality of annular spaces 1340, the total surface area on the confinement wall 1312 of the outer electrode 1310 may be increased. As with previous embodiments, each magnet 1350 has the same orientation along the z-axis. This design efficiently uses the permanent magnets between the annular spaces, as each magnetic pole contributes to shaping the magnetic field that is applied to a bordering annular space. While the depicted embodiment is shown using ring-shaped magnets, many other shapes may be used; for example, each magnet bordering an annular space may be made of many smaller magnets that collectively form a ring-like structure (see FIGS. 12a-b). In some embodiments, the outer electrode 1310 may be segmented into physically distinct parts that are electrically isolated. In some embodiments, the outer electrode may be monolithic or otherwise electrically connected, for example, such that each outer electrode segment corresponding to each annular space 1340 is grounded. FIGS. 14a-c depict an embodiment in which a single reactor structure 1400 has multiple annular spaces 1440 separated by permanent magnets 1450 that are arrayed along the z-direction. As depicted, the reactor has a plurality of inner electrodes 1420 and a plurality of outer electrodes 1410 forming the confinement wall 1412 for the annular space 1440 between each set of electrodes. FIG. 14a provides a perspective in the z-direction, while FIGS. 14b and 14c provide a section view and an isometric section view that correspond to the indicated section lines in FIG. 14a. Rather than employing ring-shaped magnets and a single inner electrode, as depicted in the embodiments of FIGS. 13a-c, the embodiments of FIGS. 14a-c employ disc-shaped magnets and multiple inner electrode segments. The description of corresponding features from FIGS. 13a-c pertains to the embodiment of FIG. 14a-c. In some embodiments, a reactor as shown may operate using only a subset of the available annular spaces depending on energy demands. For example, in some embodiments fusion reactants are only introduced into one annular space and a voltage potential is only applied to the inner electrode adjacent to that annular space. In this manner, the energy output of a reactor may be controlled to meet energy demands, even in real time if necessary. Therefore, in some embodiments, individual inner electrodes 1420 and/or outer electrodes 1410 are independently controllable. FIGS. 15a-15c illustrate the magnetic field generated by a series of ring that magnets 1550 are that substantially coaxial and have the same orientation. FIG. 15a is an isometric view of three magnets, FIG. 15b depicts a view along the magnet's shared axis, and FIG. 15c is a section view corresponding to the line A-A in FIG. 15b. While previous embodiments have made use of magnets that are offset from the annular space in the z-direction, magnets may also be offset from the annular space radially in r-direction. As illustrated by the dashed lines in FIG. 15c, each ring magnet, when considered individually, generates a magnetic field 1545 originating at its north pole and ending at its south pole. When multiple ring magnets are placed next to each other, the net effect can be a combined magnetic field that is a superposition of the individual magnet fields and substantially pointed along the shared axis as indicated by the solid magnetic field lines 1546. This magnet configuration may be used to extend the feasible length of an annular space of a reactor while using permanent magnets. FIGS. 16a-16c illustrate an embodiment using radially offset ring magnets 1650 to generate an axial magnetic field through the annular space. As depicted, the reactor has a single inner electrode 1620 and a single outer electrode 1610 that forms the confinement wall 1612 for the annular space 1640 between the electrodes. FIG. 16a provides a perspective of the reactor as viewed along the z-direction, while FIGS. 16b and 16c provide a section view and an isometric section view that correspond to the indicated section line in FIG. 16a. Each of the magnets 1650 has the same polarity along the z-direction. For example, as depicted, each of the magnets 1650 has its south pole facing in the positive z-direction. This embodiment allows for an extended annular space in the z-direction, creating a larger surface area on the confining wall 1610 and allowing for a greater power output potential. Overlapping features from corresponding embodiments of FIGS. 13 and 14 may apply to the embodiments of FIGS. 16a-c. FIGS. 17a-17c illustrate an embodiment using radially offset magnets (1750, 1752) to generate an axial magnetic field through a single annular space. As depicted, the reactor has a single inner electrode 1720 and a single outer electrode 1710 that forms the confinement wall 1712 for the single annular space 1740 between the electrodes. FIG. 17a provides a perspective of the reactor as viewed in the z-direction, while FIGS. 17b and 17c provide a section view and an isometric section view that correspond to the indicated section line in FIG. 17a. The embodiment of FIGS. 17a-c goes beyond the embodiment described with relation to FIGS. 16a-c in that additional magnets 1752 are placed in the interior region of the inner electrode 1620. As depicted, the additional magnets 1752 have the same orientation along the z-direction as the exterior magnets 1750. In some embodiments, as depicted in FIGS. 17b and 17c, the inner ring magnets 1752 are aligned with the outer ring magnets 1750 in the z-direction. In some embodiments, the inner ring magnets may be offset from the outer ring magnets, or the spacing between magnets may differ from the spacing of the outer magnets. In some embodiments, the interior magnets may take a different shape than the exterior magnets, e.g. the interior magnets may be bar magnets. In some embodiments, permanent magnets are made from rare earth elements or alloys of rare earth elements. Examples of suitable magnets include samarium-cobalt magnets and neodymium magnets. Other strong magnets known now or later developed may be suitable for use. In some embodiments permanent magnets may be used to generate a field that that is between about 0.1 and 1.5 about Tesla in the annular space; in some embodiments, permanent magnets may generate a magnetic field between about 0.1 and about 0.5 Tesla in the annular space. Not all reactors require permanent magnets. Some employ electromagnets or superconducting magnets as explained with reference to FIGS. 10a-d. Some reactors employ a combination of two or more of a permanent magnet and an electromagnet. FIGS. 18a-d depict a first embodiment in which an axial magnetic field is applied by an electromagnet. As depicted, the reactor has an inner electrode 1820 and an outer electrode 1810 that forms the confinement wall 1812 for the annular space 1840 between the electrodes. FIG. 18a shows an isometric view of an electromagnet that is placed over the reactor. FIG. 18b provides a perspective of the reactor as along the z-axis and FIGS. 18c and 18d depict a section view and an isometric section view corresponding to the section lines shown in FIG. 18b. An electrical current is passed through coil windings 1854 that wrap around reactor in the z-direction to create an applied magnetic field that is substantially in the z-direction through the reactor as depicted by the magnetic field lines in FIG. 18c. The electrical current through the electroconductive coil may be provided by an AC or a DC power supply. In cases where the electroconductive coil is driven by an AC power supply, the inner electrode and/or outer electrode may also be driven by an AC power supply at the same frequency. This is done such that the rotation of charged particles is maintained in the same direction, rather than in alternating directions as would occur if the alternating polarity of the magnetic field was not synchronized with the electric field. The coil may be made from a conductive material such as copper, aluminum, gold, or silver. In some embodiments, the coil takes the form of a wire that is wrapped around the outer electrode, in some embodiments the coil is placed in a separate enclosure that may be placed around the outer electrode. Reverse Electrical Polarity Embodiment A reverse electrical polarity rotor was previously described in FIGS. 5a to 5c. Generally, unless stated otherwise, the structure of electrodes corresponding to the first embodiment are also descriptive of a reverse electrical polarity rotor. For example, materials for inner and outer electrodes, the gap between electrodes (542 in FIG. 5a), and the configurations of magnets used to produce a magnetic field in the z-direction may be the same as described for the concentric electrode reactors. However, as explained below, some embodiments employ different structural configurations and/or different materials (e.g., different materials on the inner electrode). FIG. 5d depicts a cross selection of a reverse electrical polarity rotor. An electric field may be applied in the negative r-direction by applying a negative voltage to the inner electrode and grounding the outer electrode, by grounding the inner electrode and applying a positive potential to the outer electrode, or by applying a more negative potential to the inner electrode than is applied to the outer electrode. When an electric field is generated by applying an electric potential to the inner and/or outer electrode, positively charged particles in the annular space 540 are drawn towards the inner electrode 520. As the charged particles move inward, a Lorentz force azimuthally accelerates the particles which may result in a spiraled trajectory as illustrated by path 503. Through ion-neutral coupling, neutrals in the annular space are co-rotated along with the positively charged particles. Due to the potential difference between the inner and outer electrodes, a surplus of electrons on the inner electrode forms an electron-rich region 532 proximate to the electrode surface that rotates in the same direction as the positively charged particles due to the Lorenz force. As discussed elsewhere, this electron-rich region may reduce the Coulombic barrier between fusing nuclei. In some cases, this electron-rich region may extend out about 100 um to about 3 mm from the surface of the inner electrode. In some cases, when positively charged particles move inward, recombination of charged species occurs when a positively charged particle contacts the inner electrode or when a positively charged particle encounters a free electron in the electron-rich region. In some cases, a positively charged particle may orbit the inner electrode at a Larmor radius 502. In some embodiments, the concentration of positively charged particles may vary in the radial direction. For example, there may be a higher concentration of positively charged particles circling the annular space at a Larmor radius, than near the outer electrode. This gradient of charged particles may result in a velocity distribution within the annular space with particles tending to move more slowly near the outer wall where there is a higher concentration of neutrals due to a centrifugal force and fewer positively charged particles to drive the neutrals into motion. In some configurations, an inner electrode is constructed from a single material such as tantalum, tungsten, copper, carbon, or lanthanum hexaboride. In some cases, an inner electrode has a conductive core 520a that is coated with an electron emitting and/or target material 520b. For example, the inner electrode may have a core made from a conductive and heat resistant material, e.g., tungsten, which is coated with lanthanum hexaboride, boron nitride, or another boron-containing material. In some cases, the inner electrode has a diameter that is between about 1 cm and about 3 cm, and in some cases, between about 4 cm and about 6 cm. In some cases, the inner electrode has a tiny cross-section, for example, it may be a filament or wire. In such embodiments, the inner electrode may have a diameter less than about 0.5 mm, less than about 0.1 mm, or less than about 0.05 mm. In some cases, the inner electrode may extend between about 3 cm and about 10 cm in length in the z-direction. In some cases, the inner electrode may be small in the z-direction, e.g., less than about 3 cm, or less than about 1 cm. In some embodiments, the inner electrode may be much longer in the z-direction, e.g., longer than about 20 cm. In some cases, the confinement region in the z-direction for a reverse electrical polarity reactor (the length that the inner and outer electrodes overlap) may be limited by the power source that applies a charge to the inner and/or outer electrode. In some cases, the length in z-direction may depend on the gas pressure within the confinement region. In some cases, the power needed to generate a plasma within the annular space may be reduced if the gas pressure is reduced to a very low pressure allowing for an increased length in the z-direction. FIG. 19a depicts several methods by which the inner electrode may be actively cooled. In some cases, inner electrode 1910 has an internal pathway 1928 through which a passing fluid removes heat. For example, water may be pumped through the internal pathways to remove heat from the inner electrode. In some cases, an inner electrode may be joined to a ceramic block 1923 that is thermally conductive and electrically insulating. A ceramic block may be made of materials such as aluminum oxide. Heat is dissipated through the ceramic block, removing heat from the end of the inner electrode to which it is connected. In some cases, a ceramic block contains an opening or hole to support the inner electrode. In some cases, an inner electrode is fixed to the ceramic using a set screw. In some cases, the heat conducted through the ceramic block is used to generate electrical power, e.g., via thermoelectric generators or heat exchangers that are coupled to the ceramic block. In some cases, the inner electrode may be replaced if the target material is consumed or if the electrode is damaged. For example, a boron coated filament that is used as an inner electrode may be replaced when the boron coating is consumed or when the filament breaks. In certain embodiments, the length of the inner electrode extends beyond the annular space (as defined by the z-direction edges of the outer electrode). In some cases, the position of the inner electrode is adjusted in the z-direction, e.g., via a linear actuator. For example, if the inner electrode is a wire, the wire may be drawn through the annular space during operation of the reactor to prevent the inner electrode from melting, or to replace a section of the wire where a target material (e.g., a boron coating) has been consumed. In some cases, the width of the inner electrode may vary in the z-direction. FIG. 19b depicts a configuration in which the inner electrode 1920 extends beyond the outer electrode 1910 and is held in place by a sleeve 1921, that may act as an extension of the inner electrode. Sleeve 1921 may be made from conductive materials such as copper, stainless steel, and tantalum. In some cases, a potential may be applied to the inner electrode through the sleeve; this may reduce resistive heating to inner electrodes that have a small diameter. In some cases, the diameter of the sleeve may be much greater than that of the inner electrode. For example, the diameter of the sleeve may be greater than about 10 cm while the diameter of the inner electrode is less than about 0.5 mm. In some configurations, the inner electrode may be fixed to the sleeve using set screws. In some embodiments, the sleeve may be threaded directly into the sleeve. These and other attachment mechanisms may allow the inner electrode 1920 to be replaceable, while the sleeve 1921 is permanent. In some cases, the sleeve may be coated with a target material such as boron. In some cases, a sleeve may be internally cooled as discussed in FIG. 19a. As with the reactors of the first embodiment, the gap between the inner and outer electrode may be limited by a power supply's ability to generate a plasma in the confinement region. In some cases, the outer electrode may be similar in construction to the outer electrode described for the first embodiment. In some cases, the outer electrode may have an exterior insulating layer. This may be useful, e.g., if an alternating signal is applied the electrodes of a reactor, or if the reverse electrical polarity reactor is part of a modular unit consisting of additional reactors that need to be electrically isolated from one another. In general, the supporting structure of both the inner and outer electrode may include electrically insulating materials insulate the electrodes from the housing of the reactor, and prevent alternative current paths between the electrodes. In some cases, the outer electrode is a metallic sheet (e.g., a copper sheet) that is confined to a cylindrical shape by being placed within a quartz tube. In some cases, an outer electrode is a solid tubular structure that is placed within an insulating structure. In another embodiment, the electrode is made by coating the interior surface of a quartz tube with a metallic conductive coating. As discussed elsewhere, only a small number of ions or positively charged particles are needed to drive many neutral particles into rotation. Due to the confining wall associated with the outer electrode, the concentration of neutrals increases in the radial direction. Rotating neutrals, however, are unaffected by the radial electric field or the axial magnetic field. Due to randomized collisions with the outer wall and other particles, neutrals may be deflected into the electron-rich region, and in some cases, neutrals may impact a target material on the inner electrode resulting in fusion events. Likewise, in some cases, positively charged particles may also be deflected into the inner electrode producing a fusion reaction, e.g., a proton-boron11 fusion reaction. In some cases, a reverse electrical polarity reactor is operated at a constant voltage. For example, a voltage supply may apply a potential to the inner electrode and/or outer electrode so that a constant or substantially constant potential difference between the electrodes is maintained during operation of the reactor. In another mode of operation, a reverse electrical polarity reactor is operated at a constant current. Operating at constant current may be beneficial when the inner electrode is small and susceptible to failure due to resistive heating. In some cases, a reactor is initially operated using constant voltage and then transitioned to a constant current mode of operation. In some configurations, an energy storage device such as a capacitor or a battery is used to apply a potential to the inner electrode and/or outer electrode to initiate a fusion reaction. In some cases, circuitry regulates the current and/or voltage supplied by the energy storage device. In some cases, an energy device (e.g., a capacitor) is connected to the inner electrode and/or outer electrode and discharged until the energy storage device is no longer capable generating an electric field strong enough to support a fusion reaction. In some cases, a reactor is configured with an additional energy storage device that is charged by electrical energy generated from the fusion reaction while the first energy storage device is discharged. A controller may then operate a switch that that alternates the energy storage devices between charging and discharging modes, so that a fusion reaction may be maintained. In some cases, a power supply is disconnected from either the inner and/or outer electrode, and a fusion reaction may continue to occur for a period (e.g., about 10 seconds) before the potential difference between the electrodes is no longer sufficient to sustain the fusion reaction. When the electric field becomes too small to sustain fusion, the voltage or current source may again be reconnected to apply a negative potential to the inner electrode. Before the operation of a reverse polarity reactor, the gas in the annular space may be at be at a pressure of about 1 atm or higher. In some cases, such as when the inner electrode is long in the z-direction, an inner electrode may have a low pressure to reduce the power needed to initiate a fusion reaction. In some cases, the pressure within the annular space may be reduced to less than about 1 Torr or less than about 10 mTorr before operating the reactor. In some cases, the pressure within the annular space may be adjusted through inlet and outlet valves to control the rate of a fusion reaction. For a reverse electrical polarity reactor, the magnetic field in the confinement region is sometimes greater than about 0.5 Tesla, and sometimes greater than about 1 Tesla, and sometimes greater than about 3 Tesla. In some embodiments of a reverse electrical polarity reactor, the magnetic field is not substantially perpendicular to the electric field between the inner and outer electrodes. In some embodiments, the magnetic field is not uniform through the confinement region. The magnetic field in the confinement region may be tuned by adjusting the placement and orientation of magnets and/or electrodes. In some cases, a non-uniform magnetic field may increase the rate at which ions and neutrals collide with the inner electrode. In general, the applied magnetic field and/or the potential applied to electrodes may vary depending on the geometry of a reactor, the reactant gas composition, and the reactant gas pressure. During operation, the concentration of particles, particularly higher mass particles, is greater near the outer wall due to the centrifugal force. This may be helpful in extracting fusion products, which have a higher mass than the rotating reactants, from the annular space. For example, when alpha particles are produced by a fusion reaction involving a rotating hydrogen species, alpha particles may be concentrated near the outer wall where they may then be removed through an outlet valve. In some cases, fusion products may be pumped into another reactor in which the fusion products are used as reactants. For example, alpha particles or helium atoms produced in a reverse electrical polarity reactor may be moved to another reactor configured to support a helium-helium fusion reaction. Reverse Fields Reactor Embodiments Another reactor embodiment has a reverse fields configuration was described previously with relation to FIGS. 6a-d. This configuration employs a Lorentzian rotor to impart and maintain rotational movement of particles in an annular space. Generally, many of the reactors described herein may be reconfigured to apply reverse fields, albeit with the orientation of the magnetic field and electric field transposed. A magnetic field in the radial direction may be applied using permanent magnets (616, and 626) made from a magnetic material such as those described in relation to the first embodiment. In some cases, permanent magnets may be replaced with a plurality of azimuthally offset electromagnets having radially orientated axes, such that a magnetic field, oriented substantially in the r-direction, is applied throughout the annular space. In some cases, the surface of the confining wall may include one or more layers that protect a magnetic material. For example, a layer of aluminum or tantalum may provide protection to either an exterior or interior magnet. In some cases, a protective layer may include a target material containing a fusion reactant or an electron emitter. In some cases, a confining wall may have an internal cooling system to keep material below its melting temperature and prevent magnets from demagnetizing. In concentric electrode embodiments, the gap between the inner electrode and the outer electrode is sometimes constrained by the available power to ionize gas in the annular space. Similarly, in a reverse fields configuration the confinement region in the z-direction that separates electrodes 660a and 660b may be constrained. For example, in some cases, the spacing between electrodes is in the range of about 1 mm to about 50 cm, and in some cases, the spacing is between electrodes is in the range of about 5 cm to about 20 cm. In concentric electrode embodiments, the length of the annular space in the z-direction may sometimes be limited by the strength of permanent magnets. Similarly, in a reverse fields configuration, the gap in the r-direction may sometimes be limited by the need to create a strong magnetic field near the surface of the confinement wall. In some cases, the radial gap may be limited to, for example, about 10 cm or less, or about 5 cm or less. In some cases, as when magnet 616 provides sufficiently strong magnetic field near the confinement surface by itself, the gap may be larger; for example, in some cases, the gap may be larger than about 10 cm. In some cases, the interior magnet may not be necessary. Wave-Particle Reactor Embodiments An alternative reactor configuration, sometimes referred to as the wave-particle embodiment, was briefly described previously and is depicted in FIGS. 7a and 7b. In a wave-particle embodiment, charged particles are driven into rotation by oscillating electrostatic fields. The neutral species are pushed along by the charged particles. Electric fields are created by applying charge to azimuthally separated electrodes located on the confinement wall, an interior wall, or another structure in communication with the confinement region. Since this embodiment does not require a magnetic field, the structural limitations imposed by using magnets do not apply. For example, the radius of the reactor may be larger than what is feasible for ring or disk-shaped magnets. Further, because the embodiment does not require current flow between an inner and an outer electrode, structural limitations imposed by concentric electrodes do not apply. In some embodiments of a wave-particle design, the radius of a confinement wall may be greater than about 2 meters, in some cases greater than about 10 meters, and in some cases greater than about 50 meters. In contrast to some implementations of a Lorentzian rotor, the length of a reactor in the z-direction is not limited by the strength of permanent magnets as may sometimes be the case in concentric electrode embodiments. In some embodiments, a confinement region (e.g., an annular region) may have a length in the z-direction that is greater than about 1 meter, in some cases, greater than about 10 meters, and in some cases greater than about 100 meters. In one embodiment there is a curvature in the z-direction of a reactor so that that the confinement wall forms a torus or torus-like shape. In general, the size limitations of a reactor may be governed energy demands of the reactor and costs associated with production. In a wave-particle embodiment, a degree of control over the rotating species may be set by defining the number and size of the azimuthally offset electrodes impacting the confinement region. A relatively greater number of electrodes along the confinement wall allows the electric field lines to be more finely modulated, which can improve the efficiency at which the electric field is used to move charged particles. In some cases this is because the dynamically changing electric field drives particles points primarily in the azimuthal direction rather than the radial direction. Generally, a reactor will have at least three azimuthally separated electrodes. Some reactors may have at least five azimuthally spaced electrodes, some reactors may have more than about 50 azimuthally spaced electrodes. In some designs, the number of electrodes scales with a size of a reactor. For example, a reactor having a radius of about 1 meter may have between about 20 and about 40 azimuthally spaced electrodes along the confinement wall while a reactor having a radius of about 2 meters may have about 40 to about 80 azimuthally spaced electrodes. In some cases, the ratio of a reactor's circumference, in meters, to the number of azimuthally spaced inner or outer electrodes is between about 3 and about 150, and in some cases the ratio is between about 20 and 100. In some cases, the electrodes are separated by an electrically insulating material such as aluminum nitride or boron nitride. The insulating material may be sufficiently thick so that the material does not experience electrical breakdown. The minimum thickness may be determined by the dielectric strength of the insulating material and the voltage applied to electrodes. In some cases, an electrically insulating material contains a target material (fusion reactant such as boron-11) and/or an electron emitter. In some cases, the width of an electrode in the azimuthal direction is less than about 10 cm, in some cases less than about 5 cm, and in some cases less than about 2 cm. The electrodes may have any of various shapes. For example, they may be circular or polygonal. In some cases, they are rectangular. In some embodiments, a reactor utilizes azimuthally separated electrodes only along the confinement wall. Alternatively, in some embodiments, a reactor utilizes electrodes only along an inner wall, or only electrodes that bound the confinement region in the z-direction (e.g., electrode placement may correspond to electrodes 660a and 660b of the reverse fields embodiment depicted in FIG. 6c). In cases where electrodes do not themselves define the confinement wall, the surface of the confinement wall may be made of another material such as a target material or an electron emitter. For example, the electrodes may be separated from the confinement region by a sleeve that contains coupons made from lanthanum hexaboride. In some cases, the confinement-wall wall is configured with a thermal management component such as a heat exchanger (e.g., a cooling jacket). A heat exchanger can be used to prevent electrodes from overheating and/or supply to provide heated fluid to a heat engine for generating electrical or heat energy. In some cases, heat may be dissipated from a reactor by passing a fluid such as water through passageways in the confinement wall. For example, insulating material separating azimuthally separated electrodes may have internal passages through which fluid is passed. In concentric electrode embodiments, the gap between an inner electrode and outer electrode is sometimes constrained due to the limited power available to ionize gas in the confinement region. In a wave-particle configuration, the gap between adjacently located electrically isolated electrodes may also be constrained. For example, in some cases, the spacing between electrodes is, on average, in the range of about 1 mm to about 50 cm, and in some case, the spacing is between electrodes is, on average, in the range of about 5 cm to about 20 cm. In some cases, a wave-particle reactor has more than one mode of operation. For example, a first phase may be employed to initiate or strike a plasma and a later phase may be used drive ions (and indirectly neutrals) in a rotational direction. For example, an RF electric field may be applied radially between the inner electrodes and the outer electrodes to generate a weakly ionized plasma prepare a reactor for operation. Once the plasma has been generated between the inner and outer electrodes, the reactor may transition to a mode where drive signals are sequentially applied to the azimuthally distributed electrodes to drive charged particles and neutrals into rotation. Oscillating signals applied to azimuthally distributed electrodes to drive rotation of ions and neutrals may be provided over a wide range of frequencies chosen based on the reactor configuration and the desired rotational velocity. For example, the drive signals may be applied at a frequency in the range of about 60 kHz to 1 THz, and in some cases in the range of about 60 kHz and 1 GHz. In some cases, the frequency of a drive signal may begin low and then increase, gradually or abruptly. For example, the drive signal may start at a relatively low frequency, e.g. 60 kHz and eventually ramp up to a much higher frequency, e.g., 100 Mhz. In some cases, a drive signal applies charge using a controlled voltage. To avoid arcing between electrodes electrodes, charge is ideally applied a high voltage and low current, rather than high current at low voltage. In some cases, a drive signal applies between about 1 kV and about 100 kV to azimuthally separated electrodes. In some cases, a drive signal may apply more than 100 kV to electrodes. Using electrostatic forces, a wave-particle embodiment may induce rotational velocities that exceed that typically found in Lorentzian driven reactor having a similar reactor configuration (e.g., a similar confinement radius). In some cases, an electrostatically driven reactor may drive rotation of a gaseous species at a rate of at least about 1000 RPS, or in some cases at least about 100,000 RPS. In a wave-particle embodiment, a control system may be used to direct how charges are applied to the electrodes. In some cases, a control system uses a detected velocity, determined using a high-speed camera or another sensor, as feedback to adjust a charge sequence that is applied to the electrodes. In general, azimuthally separated electrodes may have similar structural considerations and may be made from similar materials to those described in relation to the above embodiments that employ magnetic fields. Hybrid Reactor Embodiments Another general reactor configuration, which may be referred to as a hybrid reactor configuration, was briefly described with relation to FIGS. 6a to 6f. This configuration employs both a Lorentzian rotor and a wave-particle driver to impart and maintain rotational movement of particles in an annular space. When operating a Lorentzian rotor in a hybrid reactor, some aspects of the above-description of the reverse fields embodiment may apply. Similarly, when operating using azimuthally spaced electrodes of the hybrid reactor, some aspects of the above-description of the wave-particle embodiment may apply. As in the reverse fields embodiments, a magnetic field in the radial direction may be applied using permanent magnets (616, and 626) which may be made from magnetic materials such as those described in relation to the first embodiment. In some cases, permanent magnets may be replaced with a plurality of azimuthally offset electromagnets having radially orientated axes, such that a magnetic field, oriented substantially in the r-direction, is applied throughout the confinement region. In some cases, the surface of the confining wall may include one or more layers that protect a magnetic material. For example, a layer of aluminum or tantalum may provide protection to either an exterior or interior magnet. In some cases, a protective layer may include a target material containing a fusion reactant or an electron emitter. In some cases, a confining wall may have an internal cooling system to keep material below its melting temperature and prevent magnets from demagnetizing. In concentric electrode embodiments, the gap between the inner electrode and the outer electrode is sometimes constrained by the available power to ionize gas in the annular space. Similarly, in a hybrid reactor configuration the confinement region or annular space in the z-direction that separates electrodes 660a and 660b may be constrained. For example, in some cases, the spacing between electrodes is in the range of about 1 mm to about 50 cm, and in some cases, the spacing is between electrodes is in the range of about 5 cm to about 20 cm. In concentric electrode embodiments, the length of the annular space in the z-direction may sometimes be limited by the strength of permanent magnets. Similarly, in a hybrid configuration, the gap in the r-direction may sometimes be limited by the need to create a strong magnetic field near the surface of the confinement wall. In some cases, the radial gap may be limited to, for example, about 10 cm or less, or about 5 cm or less. In some cases, as when magnet 616 provides sufficiently strong magnetic field near the confinement surface by itself, the gap may be larger; for example, in some cases, the gap may be larger than about 10 cm. In some cases, the interior magnet may not be necessary. In a hybrid embodiment, a control system may be used to direct how control signals are applied to the azimuthally separated electrodes. In some cases, a control system may receive feedback from sensors to adjust a charge sequence that is applied to the electrodes. In general, electrodes (660a and 660b) may have similar structural considerations and may be made from materials described as being suitable for electrodes in the first embodiment. In some configurations, a hybrid reactor is configured to transition between operating modes while conducting a fusion reaction or just prior to conducting a fusion reaction. For example, the reactor may operate initially using a Lorentzian rotor before transitioning to a wave-particle driver to maintain particle rotation. Under certain conditions, a Lorentzian driven rotor may be more efficient at initiating rotation of particles in the annular space. Once particles within the annular space have reached a critical state of rotation within the reactor in which the benefit of using a Lorentzian rotor is no longer seen, the reactor may switch to a wave-particle drive mode of operation. In some cases, by transitioning to a wave-particle driving mode of operation, greater particle velocities and thus greater energy production may be achieved. In some cases, by transitioning to a wave-particle driving mode of operation, energy production may be modulated with greater precision by adjusting the sequence of drive signals that are applied to the azimuthally distributed electrodes (660a and 660b). In some embodiments that use electromagnets to generate an electric field, a current supply used to control the magnetic field may be terminated when the reactor enters a wave-particle mode of operation. This may be useful to prevent a Lorentzian force from acting on charged particles in the z-direction. Electron Emitters As described elsewhere herein, a confining wall is sometimes made at least in part of an electron emitting material, referred to herein as an electron emitter. These materials may emit electrons via thermionic emission above a certain temperature. For example, some boron based electron emitters have an emission temperature that is in the range of about 1500 K to about 2500 K. In some cases, an electron emitter may be in the form of a powder that is compacted, sintered, or otherwise converted to a form suitable for placement within the annular space. In some cases, an electron emitting material may be sintered or deposited using physical vapor deposition onto the confining wall of a reactor. In other cases, an electron emitter may be forged into a continuous structure that forms part of the confining wall or is attached to the confining wall. Some electron emitters are materials having a low work function that do not degrade when exposed to the thermal and other conditions within a reactor. Examples of electron emitters include oxides and borides such as barium oxide, strontium oxide, calcium oxide, aluminum, oxide, thorium oxide, lanthanum hexaboride, cerium hexaboride, calcium hexaboride, strontium hexaboride, barium hexaboride, yttrium hexaboride, gadolinium hexaboride, samarium hexaboride, and thorium hexaboride. In some cases, emitters may be carbides and borides of transition metals, e.g. zirconium carbide, hafnium carbide, tantalum carbide, and hafnium diboride. In some cases, emitters may serve as a reactant of a fusion reaction such as 6Li, 15N, 3He, and D. In some cases, an electron emitter may be a compound that includes a fusion reactant. For example, lanthanum hexaboride may act as both an electron emitter and a target material for proton-11B fusion. In some cases, a fusion reaction product may serve as an electron emitter. In some cases, an electron emitter may be a composite of two or more materials, where at least one material has a low work function and emits electrons during operation. In some cases, an electron emitter is attached as a solid element in the confinement wall of a reactor. In some embodiments, electron emitters, which may be provided in the form of coupons, have a thin or flat structure and are attached to the confining wall without protruding significantly into the annular space. FIG. 20a depicts several illustrative cross-sections of electron emitters. In some embodiments, these electron emitters may be attached to the surface of the confining wall using a mechanical fastener such as a clip, or a screw. In some cases, an electron emitter is configured to slide into a slot within the confinement wall and is held in place by, at least partially, friction. For example, a slot may have grooves or a clamping mechanism for holding an electron emitter in place. In some cases, emitters are attached to the confining wall by heat, adhesive, or another process. In some cases, the emitter structures have a thickness that is less than about 1.2 cm, in some cases less than about 6 mm, and in some cases less than about 3 mm. The dimensions of an electron emitter in the azimuthal direction or the z-direction may be limited by the physical dimensions of a reactor. FIG. 20b depicts several configurations in which electron emitters 2036 may be distributed symmetrically along the surface of the confining wall 2010, however in some configurations electron emitters may be positioned in only a few select regions. In certain embodiments when emitters are disposed on the surface of the confining wall, they are heated by frictional and/or plasma heat that is intrinsic to the operation of the reactor. In some cases, an additional method may be used to add energy to an electron emitter to increase the rate of electron emission. An additional method may be used to heat an emitter during initial operation of a reactor when it is still relatively cool. In some cases, additional methods of increasing electron emission may be used to control the rate of a fusion reaction. In some embodiments, an electron emitter on the confining wall is electrically connected to a power supply to enhance electron emission. For example, in some embodiments, a current is passed through a filament within an electron emitting material to provide Joule heating. In some cases, a filament is made of a refractory metal such as tungsten. In some cases, such as when the confining wall is grounded, the electron emitter may be separated from a grounded portion of the confining wall by an electrically insulating material. In some cases, a direct current is applied to a filament. In some cases, electron emission is further improved or controlled by applying an alternating current to an electron emitter; for example, a current having an RF or microwave signal. FIGS. 21a-b depict an example in which Joule heating may be used to control electron emission in a reactor having concentric electrodes. FIG. 21a provides a view in the z-direction of the reactor having an inner electrode 2120, an outer electrode 2110 separated from the inner electrode by the confinement region (e.g., an annular space) 2140, and electron emitting modules 2136 placed along the confining wall 2112 that are powered by a power supply 2135. FIG. 21b provides an enlarged view of an electron emitting module located on the confining wall. An electron emitting module includes an electron emitter material 2130, such as lanthanum hexaboride, that is heated by a filament 2134. In some cases, the module may include insulating layers, depicted as 2137 and 2138, which may provide electrical and/or thermal isolation from the outer electrode and/or confining wall (assuming they are different). These insulating layers may be made out of ceramic materials such as zirconium oxide, aluminum oxide, zinc nitride, and magnesium oxide. In some embodiments, the position of the electron emitting modules may be adjusted during operation of the reactor. For example, to increase electron emission caused by frictional heating of the rotating species, a module may be moved radially inward into the confinement region using an actuator. Alternatively, to limit a reaction, a module may be pulled out of the confinement region in order to limit the electrons being released. In some embodiments, electron emitters may have a sharp point or a cone shaped structure at one end for improved field electron emission. For example, when an electron emitter is supplied with an electric potential, a strong electric field occurring near the point as a result of the narrowing geometry may cause field electron emission focused at the location of the point. In some embodiments, one or more lasers are used to increase or otherwise control electron emission from an emitter. As depicted in FIG. 22, a reactor 2200 may be configured with a laser 2231 to direct light within the confinement region 2240 onto an electron emitter 2230. As depicted, light from a laser may be optically directed through or along an inner electrode 2220 via an insulated optical fiber 2239. While lasers may be directed at emitters that are used for thermionic emission, they may also be directed at other materials such as titanium on the confinement wall that may exhibit the photoelectric effect. For example, metals and conductors may exhibit the photoelectric effect when impinging photons create a charge imbalance that is not neutralized by current flow. While FIG. 22 depicts a first embodiment, in a reverse electrical polarity embodiment, a laser may be directed towards the inner, negatively charged electrode, to increase electron emission. Gas Delivery System A reactor may have one or more gas valves that for introducing fusion reactants and removing fusion product. In some cases, standardized gas valves may be used. For example, gas valves used for low-pressure deposition and etching chambers may be suitable for the reactor. In some cases, a gas reactant is released into the confinement region at a location interior location; for example, a reactant species may be routed through an inner electrode. In some cases, a gas valve may be located at one end of the confinement region or annular space in the z-direction, and in other cases a gas reactant species is introduced into the confinement region through a valve located within the confining wall. Outlet valves for fusion products may be placed at similar locations to the inlet valves. When fusion products are removed during operation of a reactor, outlet valves may be located on the confinement wall or at a location adjacent to the confinement wall, but offset from the confinement region in the z-direction. In some cases, an inlet and outlet valves may need to be electrically insulated from an electrode so as not to cause an electrical short to ground. Inlet and outlet valves may also be accompanied with vacuum or pump systems to aid in the transport of gas species into and out of a reactor. In some cases, valves may include flow meter that controls the amount of gas species added into or removed from a reactor. In some cases, a flowmeter may be connected to a control system of the reactor to carefully limit the amount of hydrogen, or reactant species that is put into the chamber. In some cases, a gas inlet introduces neutrals near the confinement region and a gas outlet removes neutrals that have migrated beyond where fusion is occurring in the z-direction of a reactor. In some cases, a pumping system that controls the distribution of neutrals along the z-direction of a reactor is used to remove neutrals that might otherwise reduce the efficiency of converting the kinetic energy of fusion products (e.g., alpha particles) into electrical energy. While the embodiments discussed describe gas species, in other embodiments fusion reactants are introduced into the confinement region in liquid form. In some cases, rather than filling the confinement region with a fusion reactant in the form of a gas, the confinement region may be filled or partially filled with a liquid fuel. For example, liquids containing available or easily releasable hydrogen such as liquid hydrogen, ammonia, alkanes such as butane or methane, and liquid hydrides may be used in place of gaseous hydrogen. In some cases, a liquid fuel is provided in a manner that quickly vaporizes after entering a chamber. In some cases, adding a liquid fuel to a reactor is used to control the pressure within the reactor. For example, by using temperature differentials and the known volume of the confinement region, the pressure within the confinement region may be back-calculated using the ideal gas law. In some cases, the gas reactant pressure within a reactor may be carefully monitored so that a high neutral density is maintained and yet the structural integrity of the reactor is not compromised. When a reactor is a Lorentzian rotor, liquid fuel may be added in sufficient quantity or under thermal conditions that the liquid does not immediately evaporate upon entering the confinement region. In such cases, a current may be passed through the liquid fuel by applying a potential between electrodes. In some cases, a liquid seeded with charged particles such as potassium. In the presence of a magnetic field, the Lorentzian force drives the charged and neutral components of the liquid fuel into rotation. As the kinetic energy of the rotating column increases, the liquid near the boundary layer along the confining wall may vaporize, releasing hydrogen gas or another reactant gas that may fuse with a target material on the confining wall. For example, proton-11B fusion may occur when hydrogen gas is released from the liquid fuel, and the confining wall contains lanthanum hexaboride. In some cases, the gaseous layer which develops between the rotating liquid and the confining wall may create a slip layer that allows the liquid in the confinement region to rotate even faster by decreasing the drag imposed by the liquid-wall interface. In some cases, a liquid may absorb heat and may reduce concerns of melting the electrodes. Since liquids may have high densities of the fusion reactant compared to gasses, the liquid may be used for extended periods without needing replacement. While not limited to embodiments which use liquid fuel, in some cases a reactor may have a safety valve to release gas from a reactor if the pressure exceeds a threshold value. In some cases, such as in transportation applications, a fusion reactant may be stored in liquid form and delivered to a reactor as a liquid or vaporized prior to delivery. By storing fusion reactants in a liquid form, a fuel supply may be small and compact. In some cases, a liquid fuel may be supplied to a reactor by pressurized tank. In some cases, a fusion reactant (e.g. hydrogen) may be may be contained in small capsules that are provided to a reactor. For example, hydrogen may be stored in glass capsules that are provided to a reactor through a port in the confinement wall. In some cases, hydrogen may be provided in a pressurized form (e.g., at a pressure of at several atmospheres) and in some cases, hydrogen may be provided in liquid form. In cases where the reactor is already in operation, the temperature within the reactor may melt the capsule container material, allowing the fuel to be released, immediately or over a delayed period (e.g., minutes). In some cases, such as when a reactor is cool from not being in operation, a laser (e.g., as depicted in FIG. 22) may be directed at a fuel capsule to break down the capsule material and release the reactant or fuel. In cases such as automotive applications, storing small amounts of a fusion reactant such as hydrogen in capsules may add convenience by reducing or eliminating hardware (e.g., pressurized tanks) that might otherwise be required to store reactants safely. In some cases, a fusion reactant such as hydrogen may be introduced into the reactor as a solid compound. For example, polymer fuel pellets made of polyethylene or polypropylene may be provided to a reactor through a port in the confinement wall as hydrogen fuel is consumed in a reactor. Once inside a reactor, high temperatures caused by operation of the reactor or the energy of a laser (e.g., the laser as depicted in FIG. 22), may be sufficient to decompose the polymer and release hydrogen gas. In some embodiments, ammonia borane (also known as borazane) may be used as a hydrogen fuel. When a reactor reaches a temperature greater than about 100° C., the ammonia borane releases molecular hydrogen and gaseous boron-nitrogen compounds. In some cases, ammonia borane or the boron-nitrogen compounds may act as electron emitters, and in some cases, boron atoms from the ammonia borane may undergo a fusion reaction with hydrogen atoms during operation of a reactor. In many applications (e.g., automotive applications), solid fuels may add convenience by reducing or eliminating hardware that might otherwise be required to store gas fuels or liquid fuels safely. Cooling System In some cases, to enable sustained operation of the reactor, the reactor must be cooled to prevent electrodes, magnets, and/or other components from overheating. In some embodiments, a reactor may be cooled by full emersion in a liquid bath. In some embodiments, a reactor includes a heat sink that draws heat away from the reactor via conduction and transfers it to a fluid medium such as air or liquid coolant. As an example, a heat exchanger may be used. A fan or a pump may be used to control the flow conditions and aid in carrying away heat that is transferred to the fluid medium. Depending on the monitored temperatures within the reactor, the fluid velocity may be adjusted, such that fluid flow is modulated between laminar and turbulent flow. In some embodiments, fluid is passed through a cooling jacket on the outside of a reactor and in some cases cooling tubes may be used to cool components within the reactor. As described elsewhere herein, a heat sink may be a used to transfer heat to working fluid that is used by a heat engine for producing electrical energy. Examples of liquids that may be used as working fluids for for cooling a reactor include water, liquid lead, liquid sodium, liquid bismuth, molten salts, molten metals, and various organic compounds including some alcohols, hydrocarbons, and halocarbons. Power Supply Reactors may include one or power supplies that are used to supply electrical current to electrodes, electromagnets, and other electrical components that needed to operate a reactor. The power supply may control current and/or voltage between two terminals (e.g., concentric electrodes). In some embodiments, a power supply is capable of supplying a maximum voltage of about 200 volts to about 1000 volts. For example, in some embodiments, a power supply can provide up to 600 volts to an electrode. In some embodiments, a small scale reactor may be able to provide about 0.1 A to about 100 A of current and/or deliver at least about 1 kW of power. In some medium scale embodiments, a reactor may be able to provide about 1 A to about 1 kA of current and/or deliver at least about 5 kW of power. In some large scale in embodiments, a reactor may be able to provide about 1 A to about 10 kA of current and/or deliver at least hundreds of kilowatts of power. Depending on the operating mode of the reactor, a power supply may be used to provide direct current or an alternating current. In some embodiments, an alternating current is applied to electrodes to strike a plasma. In some cases, the voltage required to strike a plasma in the confinement region may be reduced by more than about 10% compared to when a direct current is used to strike a plasma. In cases where an AC signal is used to strike a plasma, a power source may deliver an alternating current or voltage signal at frequencies greater than about 1 kHz, or in some cases, greater than about 1 Mhz. In some configurations, such as when an electromagnet is used to provide an axial magnetic field, and alternating current may be applied to both the electromagnet and the electrodes. In some cases, alternating signals may be applied to the electrodes and an electromagnet that have the same frequency but are out of phase. In some cases, a power supply may apply a current or voltage signal to an electrode or an electromagnet that is greater than about 500 Hz, or greater than about 1 kHz. In some cases, an electromagnet is operated as the same frequency that an alternating current is applied to electrodes so that the rotation of particles may be maintained. In some cases, a commercially available power supply may be used to apply a current or voltage signal to the electrodes of a reactor or an electromagnet. Examples of vendors of suitable power supplies include Advanced Energy Industries and TDK-Lambda American Inc. Sensors When operating a reactor, a variety of parameters may be monitored to control the rate of energy output, improve efficiency, prevent failure of components, and the like. For example, the temperature of a reactor may be monitored to ensure that the components of the reactor do not exceed defined maximum temperature values. If a permanent magnet gets too hot, it may demagnetize, and if an electrode or any other component gets too hot, it may yield or melt. In some cases, the operation of a reactor requires a relatively high temperature. For example, some electron emitters must acquire a sufficient thermal energy before electrons are released into the confinement region. Temperatures within a reactor may be monitored using sensors such as thermocouples, inferred imagery, and thermistors. In some cases, temperatures at locations within a reactor may be inferred by measuring temperatures at other locations within the reactor. For example, the temperature at the interior surface of an outer electrode may be inferred by monitoring the temperature at the exterior surface of the outer electrode. In some cases, by measuring temperatures indirectly from an exterior location, low-cost temperature sensors, such as silicon bandgap temperature sensors may be used. In some embodiments, the gas pressures within the reactor may be monitored. By monitoring the pressure in front of an electron emitter, information may be gained about the density of electrons as they are pressed tightly against the confining wall. Pressure measurements from within the chamber may be used by a controller to regulate the flow rates of gas species entering and exiting the confinement region. In some embodiments, rotational speeds within the confinement region or annular space may be monitored using a camera that captures hundreds or thousands of images per second. In some cases, measuring the rotation of species within a reactor may be aided by introducing species that will fluoresce or have a detectable optical signature such as argon or quantum dots. In some embodiments, the gas composition with the confinement region may be monitored for fusion products such as 4He and 3He or for low quantities Deuterium within a reactant gas. In some embodiments, the detection of fusion products and reactants may be performed using an in situ mass spectrometer (e.g., a qRGA from Hiden Analytical that is capable of detecting low quantities of Deuterium in a gas sample), optical spectroscopy, or an NMR sensor. In some embodiments, a reactor may be equipped with Geiger counters to detect levels of radiation. FIGS. 23a-c depict an example of how nuclear magnetic resonance sensing may be used to determine the composition of gas reactants in a concentric electrode embodiment. FIG. 23a depicts a reactor having inner electrode 2320, outer electrode 2310, and a substantially uniform and time-invariant magnetic field the z-direction 2391 that passes through the confinement region. The axially applied magnetic field may be used to align the nuclear spins of the rotating species and may be applied by a superconducting magnet as described elsewhere herein. In some cases, an axial magnetic field is greater than about 0.1 Tesla, in some cases, an axial magnetic field is greater than about 0.5 Tesla, and in some cases, an axial magnetic field is greater than about 2 Tesla through the confinement region. When detection is desired, the nuclear spins of rotating species within the confinement region are perturbed by applying an RF pulse in the azimuthal direction. FIG. 23b depicts how an azimuthally, time-varying magnetic field 2392 is generated by applying an alternating current in the z-direction of the inner electrode. In some embodiments, the alternating current passing through the center electrode has a frequency of between about 60 Hz to about 1 MHz, and in some cases about 1 MHz to about 1 GHz. After perturbing the alignment of species with the time-varying magnetic field, the rate at which the nuclear spins of species are realigned is then monitored using a detection coil as depicted in FIG. 23c. A detection coil 2390 is substantially perpendicular to the major axis (the z-axis) of the reactor and monitors current passing through the coil as a result of the electromagnetic radiation that was absorbed and re-emitted by the rotating species. In some cases, detection coils similar to that used in a medical NMR system may be used. Control System Monitored parameters may be provided as inputs to a control system that operates the reactor in a regime that maintains system component integrity and supports fusion. The control system may control any and all parameters of the fusion reaction, and in some cases other operations such as heat energy gathering or utilization processes and conversion to electrical or other useful forms of energy. In certain embodiments, the control system maintains a balance between heat generation and heat extraction. Thus, for example, to maintain this predetermined and preselected balance, the control system may control application of electrical energy to electrodes in the reactor (e.g., by modulating electrical pulses, e.g., lengthening or shortening the time period between each pulse and/or changing the voltage applied to create the plasma), changing the magnetic field, for example, with an adjustable magnet in conjunction with a superconducting magnet, and changing the density of the reactants. As discussed elsewhere herein, some parameters may need to fall within a defined process window such that both of these conditions are met. In some cases, a control system receives information that identifies an energy demand and adjusts process conditions accordingly. A control system may also have a criterion, which when met, initiates an automated shutdown process to prevent damage to the reactor or nearby operators. For example, if the temperature of the confining wall exceeds a certain threshold, or radiation thresholds are reached, a reactor may quench the fusion reaction. A control system may quench a reactor by, for example, grounding all electrodes, closing gas input valves, and/or introducing an inert gas species such as nitrogen. In some cases, a control system may provide closed-loop feedback as shown, for example, in FIG. 24. Based upon measured input parameters from sensors 2460 and a desired energy output signal 2461, a control system 2462 may send control signals 2463 to adjust the various parameter settings of the reactor 2464 as necessary to control the energy output 2465 or meet other specifications. Input parameters that are used by a controller may include parameters such as temperature, pressure, flow rates, gas composition fractions (e.g., partial pressures), particle velocities, current discharge between electrodes, and voltage. In some cases, the control system utilizes historical data of one or more parameters. For example, while it may be important to know a particular temperature value, it may also be important to understand the rate and/or magnitude at which temperature is fluctuating. Examples of reactor settings that may be adjusted by the controller include applied currents, applied voltages, applied magnetic field strength (in the case of an electromagnet), and gas flow rates (e.g., hydrogen flow rates). Typically, the controller passes a control signal to a reactor component responsible for the associated setting. For example, a control signal may be passed to a power supply to instruct the power supply to apply a specified voltage. In some cases, a setting may also be an input parameter to the control system. For example, in determining what voltage should be applied, a controller may account for the current and/or voltage presently applied to the electrodes. In some cases, a controller may use machine learning to improve its decisions so that a reactor may become more efficient over time, resistant to physical changes in the device (e.g., when a part fails and is replaced), or anticipate energy demand. Certain operational features of a reactor may be independently controlled. For example, the flow rate of a cooling fluid may be controlled using a system that is independent of the control system responsible for adjusting the primary operating inputs of a reactor, such as current and gas flow rates. In another example, electron emitting modules, e.g. as depicted in FIG. 21a, may have an associated controller that receives a measured temperature of the electron emitter and determines what current should be applied to a filament to provide Joule heating. The control system described above may be implemented in the form of control logic using computer software in a modular or integrated manner. There are many possible ways to control operation. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate how to implement the control functions using hardware and/or a combination of hardware and software. In some cases, a control system may be implemented as software code to be executed by a processor using any suitable computer language such as, for example, Java, LabVIEW, MATLAB, C++, or Python using, for example, conventional or object-oriented techniques. The software code may be stored as a series of instructions, or commands on a computer-readable medium, such as a random access memory (RAM), a read-only memory (ROM), a magnetic medium such as a hard-drive or a floppy disk, or an optical medium such as a CD-ROM. In some cases, a control system may be tested and designed using a FPGA (Field Programmable Gate Array), and then later manufactured through an ASIC process. In some cases, a controller may be a single chip that can securely store and execute the control logic. Any such computer readable medium may reside on or within a single computational apparatus and may be present on or within different computational apparatuses within a system or network. For example, the control system may be implemented using one or more processors, PLCs, computers, processor-memory combinations, and variations and combinations of these. The control system may be a distributed control network, a control network, or other types of control systems known to those of skill in the art for controlling large plants and facilities, and individual apparatus, as well as combinations and variations of these. Radiation Shield In some embodiments, such as when a reactor supports an aneutronic or substantially aneutronic reaction, the reactor may require little if any shielding to reduce radiation exposure. When there is a concern of neutronic radiation, the reactor may be outfitted with appropriate shielding. Neutrons readily pass through most material but interact enough to cause biological damage. In some cases, a reactor may be placed in an enclosure that absorbs neutrons. In some cases, the confinement wall of a reactor may include an external layer for absorbing neutrons. In some cases, shielding layers may be made of concrete having a high water content, polyethylene, paraffin, wax, water, or other hydrocarbon materials. In some cases, a shielding layer may include a lead or boron as a neutron absorber. For example, boron carbide may be used as a shielding layer where concrete would be cost prohibitive. In some embodiments, the ends of a reactor in the z-direction may include a material such as boron nitride that not only absorbs neutrons but is thermally and electrically insulating. In some cases, an electron emitter, such as lanthanum hexaboride, serves the additional function of providing shielding from neurotic radiation. In some cases, such as large scale reactors, tanks of water, oil, or gravel, may be placed over a reactor to provide effective shielding. The thickness of a shielding layer depends in part of what materials are used, where the reactor is located, the type of fusion reaction, and the size of the reactor. In some embodiments a shielding layer is greater than about 10 centimeters, in some cases, a shielding layer is greater than about 100 centimeters, and in some cases, a shielding layer is greater than about 1 meter. Replaceable Components Due to the aggressive nature of the plasma and fusion products within a reactor, electrodes may become damaged, distorted, embrittled, etc. Under normal operating conditions, some components of a reactor may eventually fail and need to be replaced. Further, when operating conditions exceed certain thresholds (e.g., high temperatures, pressures, plasma potentials, or reactant concentrations), components may be damaged or wear out more quickly. In cases where hydrogen is used as a reactant, electrodes may, over time, suffer from hydrogen embrittlement. If an embrittled electrode is not replaced, it is possible for the electrode to convert into a powder. In some cases, a reactor may be inadvertently operated outside its normal operating conditions resulting in increased wear or structural damage to one or more electrodes or other components. For example, if a cooling system malfunctions, the temperature of an electrode may near its melting temperature causing the electrode to deform. In some cases, thermal stresses may cause micro-fractures to appear on or within an electrode. If an electrode has an internal cooling system that breaches to allow water vapor to enter into the confinement region, the reactor may experience a spike in the pressure. Fusion reactors as described herein may be highly configurable and modular. In certain embodiments, one or more components may be replaced and/or interchanged. Some components are permanent and are designed to not wear out during a reactor's lifetime, and some components are expected to be replaced after a certain number of operation cycles or time in operation. For each replaceable component, there may be a designated procedure for the removal, handling, refurbishment, and/or replacement of the component. In addition, there may be one or more indicators and field-implementable diagnostics that indicated and/or anticipate the degradation of the component. Examples of replaceable components include one or more electrodes in the reactor, fusion reactants, containers fusion reactants (e.g. hydrogen gas canisters), and energy conversion devices associated with the reactor. Examples of indicators that a component should be replaced include a decrease in electrical conductivity of an electrode, the time the component has been in operation, and the optical properties of the component (e.g., changes to the surface of a component may be detected optically). Mechanical failure may be determined by visual inspection, or in some cases, by monitoring measured parameters such as temperature, pressure, and conductivity of the electrodes. In some cases, a control system contains logic for determining a mechanical failure of an electrode or other component. In some cases, the conductivity and/or conductance of electrodes may decrease over time. Due to the volatile nature of plasma, there can be an electrically insulative dielectric coating that forms on the electrode. If the conductivity and/or conductance of an electrode is reduced, the reactor may become less efficient and/or require excess amounts of power. If nothing is done to mitigate the declining conductance and/or conductivity of a reactor, the reactor may become an electrical and/or thermal hazard. While much of the discussion herein concerns determining an electrode's conductivity and/or conductance, it should be understood that conductivity may vary from position-to-position in an electrode. For example, the conductivity of the reaction-facing surface of an electrode may be much lower, after a long period of operation, than the conductivity of an interior portion of the electrode. As another example, the conductivity of the original material in an electrode may remain largely unchanged during operation, but a dielectric film formed on the reaction-facing surface of the electrode may significantly degrade the overall conductance of the electrode. Resistivity and/or resistance can be determined in lieu of conductivity and/or conductance. Various techniques may be employed to monitor electrode conductivity and/or conductance or determine that electrode conductivity or conductance has reached a level that requires attention or replacement. In one example, using the electrode's geometry, the conductivity of the electrode may be determined by measuring the resistance between two points on the electrode surface when the reactor is not in operation. This measurement may be performed manually during a routine system check, e.g., by using a multimeter. In some cases, a reactor is configured with measurement circuitry that automatically measures the resistance of an electrode between operation cycles. In some cases, a reactor's control system may be configured to automatically determine the conductance of an electrode from a measured resistance. Another way an electrode's conductance may be determined is by performing a diagnostic cycle in which a gaseous reactant in the confinement region is replaced with another gas, and a plasma is generated within the confinement region. For example, hydrogen gas may be replaced with argon gas, neon gas, or nitrogen gas. A control system may then monitor the electrical behavior of the plasma measuring the voltage of the electrodes and the current passing through the electrodes. Based upon the electrical behavior of the argon plasma, the conductivity of an electrode may be determined. For example, the conductivity of each electrode may be determined by comparing the measured electrical behavior of the argon plasma (or another plasma) to an expected electrical behavior. In some cases, the expected electrical behavior of a plasma, such as an argon plasma, may be determined via simulation, or by measuring the electrical behavior on a new reactor that does not have a dielectric coating. A reactor electrode may be assigned a predetermined threshold of low conductivity or conductance value that triggers service or replacement of an electrode. For example, if the conductivity of an electrode falls below about 80% of its expected value, the electrode may be replaced or treated to restore conductivity to an appropriate level. In some embodiments, when an electrodes conductivity or conductance falls below and acceptable level, a cleaning cycle is performed. For example, a cleaning cycle may involve introducing a cleaning gas, e.g. argon, into the confinement region and operating the reactor to generate a plasma that removes some or all of the dielectric coating. In some cases, a weakly ionized plasma may be sufficient to remove the dielectric coating. In some cases, the argon gas may be fully ionized during a cleaning cycle. Depending on the chemical nature of the degradation, a chemically restorative treatment may be employed. For example, if the electrode degradation results from the formation of a hydride or other form of hydrogen-mediated reduction, the compromised electrode may be treated with an oxidizing agent, such as an oxygen-containing plasma. In some cases, if the conductivity or conductance of an electrode falls below a designated level (e.g., about 50% of its expected value), the reactor may be determined to be unsafe to operate. This may be indicative that a thick dielectric film has formed and the reactor will require dangerous levels of power from a power source. In some cases, a control system or associated safety system may shut down operation until replacement or restoration of an affected electrode. In some cases, a reactor's control system contains logic for determining a mechanical failure of an electrode or other component and then triggering an alert or automatic shutdown of the reactor. In some embodiments, one or more of the electrodes or magnets in a reactor include a protective or sacrificial layer. In some cases, this sacrificial layer is a sleeve (e.g., a sleeve that forms the interior surface of the confining wall) that may be replaced at scheduled intervals. In some embodiments, a metal component such as an electrode or a sleeve may be removed to undergo a restorative process, e.g. an annealing process to remove internal stresses that may have arisen due to thermal cycling. In some cases, e.g., when component experiences hydrogen embrittlement, the component may be removed and the material of the component may be reprocessed to make a new part. In some cases, an embrittled component, e.g. a tantalum electrode, may be restored to a ductile condition by annealing under a vacuum. For example, in some cases, an embrittled component may be restored by annealing at around 1200° C. under a vacuum. Target materials (fusion reactants) may eventually be consumed and need to be replaced. For example, some embodiments employ lanthanum hexaboride which contains boron-11 as a reactant required for a proton-boron-11 fusion reaction. Once depleted, this material needs to be replaced. Due to thermal cycling, lanthanum hexaboride may also become brittle and fail. Destruction or degradation of lanthanum hexaboride will reduce the fusion reaction output. In some cases, a control system may notify an operator of a power drop-off that would correspond to a target material being depleted or moved out of the confinement region. In some cases, a control system may alert an operator when a consumable material like lanthanum hexaboride had reached a predetermined use limit and should be replaced. The following non-limiting examples represent a few embodiments that may be practiced in accordance with the broader principles described herein. 1.) Negative Electrode (Outer Electrode) The outer electrode, sometimes called the “shroud” includes a cylindrical metal ring with multiple points of attachment for the lanthanum hexaboride or other target material. The composition of the shroud is typically a refractory metal, such as tantalum (Ta) or tungsten (W), due to the high thermal resistance of refractory metals; however, certain embodiments of the reactor use lower temperature metals such as Alloy 316 Stainless Steel. These embodiments may include a liquid cooling circuit that prevents the shroud from reaching the critical melting temperature of the composition metal. As explained, the outer electrode may be either the more negative or the more positive electrode. Electrical Conductivity The plasma in the reactor is struck between the positive electrode and the negative electrode by utilizing electrical power from an external power supply. This event is mediated by the electrical voltage across the two electrodes and the electrical current traveling through the electrodes and the plasma. The voltage required to strike the plasma and initiate the fusion process may be directly related to the electrical conductivity of the two electrodes. As mentioned, there can be a dielectric (electrically insulative) coating that builds up on the negative electrode, thus affecting the electrical conductivity of the electrode. A field-implementable diagnostic for determining conductivity of the outer electrode is a resistance measurement between two points using a digital multimeter. In some implementations, once the resistance is measured, its value is entered into QA software, which will indicate the conductivity and operational status of the outer electrode. A second diagnostic for determining conductivity would involve the striking of an glow discharge argon plasma in the reactor. This is done via control software, which will subsequently monitor the electrical behavior of the argon plasma (voltage and current). By an automatic comparison to an internal calibration, the control software can determine the conductivity of the electrode and send the data to QA software. If the QA software indicates that the electrical conductivity falls below 80% of the standard conductivity rating of the composition metal, then the AR unit is said to be outside of the optimal operation regime and into the non-optimal operation regime. If the conductivity falls below 50% of the standard rating, then the AR unit is said to be in the unsafe operation regime, as this will draw too much power from the power supply and provide a potential electrical and thermal hazard. If the conductivity is 0%, this indicates that a complete insulative layer has formed on the negative electrode and the system is non-operational. Operation: Continue operating unit normally. Non-optimal operation: Run Argon Cleaning Cycle on AR unit using provided control software. Repeat until conductivity enters ‘optimal operation’ zone. If conductivity does not improve, perform the ‘unsafe operation’ below. Unsafe operation: The outer electrode should be cleaned. Structural Integrity It is possible for the mechanical structure of the shroud to become damaged, distorted, or embrittled. This can occur due to a number of different reasons. A failure in the cooling system, or improper operation of the cooling system, can lead to extreme temperatures inside the reactor that are beyond the safe operating parameters. These extreme temperatures can lead to thermal shock, causing micro-fractures to appear on or within the shroud. Additionally, if these extreme temperatures approach the melting point of the shroud composition material, the shroud itself will begin to distort and melt. A field-implementable diagnostic for detecting defects in structural integrity is visual inspection prompted by an abnormal temperature alert from the control software. The control software may monitor the temperature of several different components of the unit, and check that each component remains within safe operating parameters. If the temperature of any such component travels outside the safe operating parameters, it may trip a temperature indicator alarm. In extreme cases (such as a prolonged duration of an overheated component), the system may shut itself down and require a mandatory visual inspection of the integrity of the shroud. If the shroud is damaged, it may be sent to a QA team for inspection and analysis. 2.) Positive Electrode (Inner Electrode) The inner electrode may includes a cylindrical metal disk and hollow metal cylinder attached to a high-voltage ceramic feedthrough on the back of the chamber. These two components are known as the ‘head’ and the ‘rod.’ The composition of the center electrode head is typically a refractory metal, such as tantalum (Ta) or tungsten (W), due to the high thermal resistance of refractory metals; however, different embodiments of the reactor use lower temperature metals such as Alloy 316 Stainless Steel. Higher-temperature center heads will operate longer and thus will warrant replacement less frequently. The center electrode rod is typically made of Alloy 316 Stainless Steel, since it does not experience the same extreme temperatures as the head. In some embodiments, the center electrode rod is cooled with liquid water to prevent overheating. In embodiments utilizing a high-temperature head, the head is attached to the rod with a Molybdenum (Mo) set screw. In embodiments utilizing a low-temperature head, the head is also water cooled, and it is welded or soldered to the rod such that the cooling circuit is continuous. Electrical Conductivity As in the case for the outer electrode, the electrical conductivity of the inner electrode mediates the electrical behavior of the plasma. A change in the conductivity will result in the change of the voltage required to strike and sustain the plasma for the fusion reaction. As mentioned above, the volatile nature of the plasma and fusion reactions taking place inside the reactor can lead to the build-up of a dielectric coating on the surface of the inner electrode, thus affecting its electrical conductivity. The standard field-implementable diagnostics for determining the electrical conductivity of the center electrode (with respect to the various operational regimes outlined above) are identical to those for the inner electrode. Structural Integrity The inner electrode has the same operational risks as the outer electrode (or shroud) with regards to the structural integrity of the component. It can be damaged, distorted, or embrittled; however, since there is a liquid cooling channel inside the inner electrode, there are additional methods for failure detection other than the thermal monitoring of specific components by the control system. If the temperature of the center electrode rod (or the temperature of the liquid-cooled center electrode head described above as an alternate embodiment) approaches the melting temperature of the composition material, the outer surface of the rod (or head) may be breached, allowing a combination of water vapor and liquid water into the vacuum chamber. This can occur due to a failure of or improper use of the cooling system, as well as the appearance of a sustained plasma arc on the center electrode rod (or head) itself. Once this occurs, there will be an instantaneous rise in pressure due to the preponderance of water vapor entering the chamber through the breach. The control system will detect this pressure rise and immediately shut the system down with an error fault that warrants an immediate and required visual inspection. 3.) Lanthanum Hexaboride Target Lanthanum Hexaboride, commonly referred to as LaB6, is a refractory ceramic material that is used in the scientific industry as an electron emitter due to its low work function. In a reactor, the LaB6 is attached to the negative electrode via uniformly distributed attachment points along the inner wall. The LaB6 contains the solid boron fuel required for a fusion reaction, and will need to be replaced once the fuel is depleted. Boron Isotope Composition There are two main isotopes (atoms of same number of protons and different number of neutrons) of boron found in nature, , and . The most abundant of these two isotopes is , as 80% of all Boron is found in this form. Since this is also the isotope required for the fusion reaction to take place, it may be necessary to know the relative concentration of this particular isotope present in the LaB6 fuel. There are various methods for detective this concentration, including inductively coupled plasma optical emission spectrometry (ICP-OES), thermal ionization mass spectrometry (TIMS), secondary ion mass spectrometry (SIMS), inductively coupled plasma mass spectrometry (ICP-MS), among others. In some embodiments, there is not field-implementable diagnostic that is able to measure the boron isotope composition of the LaB6, as these are techniques that require the sample to be sent to a third-party analytical diagnostics lab. Structural Integrity Due to the ceramic nature of this compound, it is extremely brittle, and is extremely susceptible to thermal stress. The volatile reactions occurring inside the reactor, as well as the rapid rates of heating and cooling present in various components such as the center electrode and the shroud, can cause the structural integrity of the LaB6 to break down. It has been observed in several embodiments of the reactor that the LaB6 fuel will tend to break apart over time, which warrants the need for replacement. One field-implementable diagnostic for determining the structural integrity (and lack thereof) of the LaB6 fuel is by visual inspection. There are certain indicators provided by the control software that warrant the need for a visual inspection of the LaB6. Because the fusion reactions occur at the LaB6 sites, the entirety of the output power (as measured by the control software) is extracted from these sites. If the steady-state power output of the reactor drops by more than 20%, it could indicate a problem with one of the LaB6 pieces and trip a power indicator alarm on the software. This type of alarm would warrant the need for a visual inspection of the LaB6 pieces. Energy Conversion Hardware Reactors as described herein produce energy in one or more forms; typically they produce multiple forms of energy simultaneously. When operating, most reactors produce thermal energy. They may also produce radiant energy over a broad or narrow range of frequencies. For example, excited species within the reactor (e.g., electronically excited hydrogen atoms) emit radiation in one or more frequency bands. Often the reactor operates in modes that require plasma and/or produce a plasma, and when the plasma exists it produces radiant energy. Still further, many reactions produce charged species (e.g., ions such as alpha particles) with high levels of kinetic energy. Reactors may also produce mechanical energy through pressure variations or oscillations. Any one or more of these energy forms may be converted to different energy forms usable for particular applications. Therefore, in certain embodiments, an energy conversion device or component is coupled to an associated reactor. In some cases, the energy conversion device converts thermal energy from the reactor to electrical energy (e.g., a thermoelectric device). In some cases, the energy conversion device converts thermal energy from the reactor to mechanical energy (e.g., a heat engine). In some cases, the energy conversion device converts electromagnetic radiation from the reactor to electrical energy (e.g., a photovoltaic device). In some cases, the energy conversion device converts the kinetic energy of charged reaction products (e.g., alpha particles) or ionized fusion reactants (e.g., protons) to electrical energy. In some cases, the energy conversion device converts mechanical energy from the reactor to electrical energy (e.g., a piezoelectric device). Various energy conversion devices may be used to convert thermal energy produced by reactor into mechanical and/or electrical energy. For example, a thermoelectric generator may be thermally coupled to a reactor to generate electrical energy. A thermoelectric generator may be thermally coupled to the reactor by, for example, being placed on the confinement wall of the reactor or having thermal energy from the reactor delivered via a heat transfer device such as a heat pipe. In another example, a reactor may convert thermal energy into mechanical energy (e.g., a moving piston or a rotating crankshaft) via a heat engine. In some embodiments, a reactor is outfitted with a Stirling engine. In some embodiments, the reactor may be outfitted with a heat engine, e.g., a heat engine that uses the Rankine cycle, where the working fluid experiences cyclic phase changes. If electrical energy is desired, a heat engine may be configured with an electric generator that converts, for example, a rotating crankshaft or an oscillating piston into electrical energy. Some energy conversion devices may convert electromagnetic radiation or radiant energy produced by reactor into electrical energy. For example, a reactor may have photovoltaic cells on either end of the confinement region to convert radiant energy into electrical energy. In some cases, the reactor may include a transparent barrier to provide thermal protection and/or optical devices to concentrate the radiant energy onto a photovoltaic cell. In some cases, a photovoltaic cell may have a tuned bandgap corresponding to a narrowband wavelength of radiant energy (e.g., corresponding to hydrogen) emitted from the reactor. The reactor may also be configured with components that convert the kinetic energy of charged particles emitted from a reactor into electrical energy. For example, positively charged particles (e.g. alpha particles) may be forced to travel through an opposing electric field generated by one or more electrodes that slow their travel. As the particles decelerate, an electric current is generated in an electrical circuit connected to the positively charged electrode(s). In some cases, alpha particles emitted from the reactor may be directed towards such electrodes via applied magnetic fields. In some cases, the reactor may be configured with a magnetohydrodynamic generator (MHD generator) that converts the kinetic energy of a plasma generated as a result of a nuclear reaction into electrical energy. In some cases, the reactor may use a single energy conversion device (or energy conversion modules) to convert energy produced by the reactor into mechanical and/or electrical energy. In some embodiments, the reactor may use a plurality of energy conversion devices (or energy conversion modules) to convert energy produced by the reactor into mechanical and/or electrical energy. Since the reactor may produce various forms of energy, different types of energy conversion devices may be combined to increase the total mechanical and/or electrical energy that is generated. In some cases, the addition of a second energy conversion device may not reduce the energy output of a first energy conversion device because the energy conversion devices convert different forms of energy produced by the reactor. For example, in some embodiments, the reactor may generate electrical energy from both a photovoltaic cell which converts radiant energy and a thermoelectric generator which converts thermal energy. In this example, the presence of a photovoltaic cell may not diminish the electrical energy produced by the thermoelectric generator and vice versa. In some embodiments, a reactor may be outfitted with multiple energy conversion devices that convert the same type of energy produced by the reactor. For example, in some cases, a reactor may be outfitted with a Stirling engine as well as a thermoelectric generator both of which make use of thermal energy. In this example, a thermoelectric generator may simply capture the thermal energy that was not converted to mechanical and/or electrical energy by the Stirling engine. In general, any combination of energy conversion devices or modules described in herein may be used to generate mechanical and/or electrical energy from a reactor. Enclosure While not depicted, a reactor may include an enclosure that walls off the confinement region from the ambient environment. In some cases, the dimensions of an enclosure are governed in part by the outer dimensions of a confining wall. In some embodiments, the confining wall defines the boundary of the enclosure in the r-direction, and the confinement region is isolated from the external environment using flanges on both ends of the confinement wall in the z-direction. In some embodiments, an entire system including control systems, power supplies, magnets, and energy conversion apparatuses is placed within an enclosure. Materials chosen for an enclosure may depend on the enclosure's intended purpose. For example, enclosures may be needed to provide biological shielding, thermal isolation, and/or to enable low-pressure operating conditions. In some cases, an enclosure may have a layered structure in which each layer provides a different function. For example, an enclosure may include a hydrocarbon material for biological shielding and a ceramic layer to provide thermal insulation. In some cases, more than one enclosure may be used. For example, a first enclosure may include flanges that seal off the confinement region in the z-direction creating a vacuum chamber while a second, exterior enclosure encompasses the entire reactor. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will know and appreciate ways and/or methods to implement an enclosure to that meets the needs of a reactor's application. Process Conditions Multistage Operations and/or Reactions In some cases, the energy output or efficiency of a reactor is improved when operated in multiple stages. In some cases, a reactor may have one or more preparatory stages that prime the conditions within a reactor for conducting a fusion reaction. For example, preparatory stages in a multistage process may be used to increase the temperature of electron emitters, cool the temperature of a confining wall, generate a plasma within the confinement region, or modify the gas pressure within the confinement region. FIG. 25 depicts an example of a multistage process flow that may be used to operate a reactor. In a first operation, 2501, electron emitters are heated until they reach a prescribed temperature for emitting electrons. After heating the electron emitters in 2501, an alternating current is applied between the electrodes of the reactor to strike a weakly ionized plasma. Immediately after initiating a plasma in the confinement region, the reactor may transition to a stage used to rotate charged particles in the reactor and sustain a fusion reaction. In some Lorentzian rotors, this may mean applying a direct current to the electrodes when a uniform magnetic field is applied. Alternatively, in embodiments in which an alternating magnetic field is applied in the z-direction of a reactor, this may mean applying an alternating current to the electrodes at the same frequency that the magnetic field oscillates. In some cases, an alternating magnetic field may be applied by applying an alternating current to an electromagnet (e.g. a superconducting magnet) or physically moving permanent magnets by, e.g., by having rotors having magnets with alternating magnetic orientations on either side of the confinement region. In some cases, the rotation of neutrals and charged particles is maintained in the same direction by alternating the electric field and the magnetic field at the same frequency. For example, in some cases, the both the electric and magnetic field may be oscillated at a frequency that is between about 0.1 Hz and 10 Hz, in some cases, about 10 Hz to about 1 kHz, and in some cases greater than 1 kHz. In a wave-particle embodiment, a sequence of electrode charges, or a drive signal, may be applied to the electrodes bordering the confinement region to initiate rotation. For example, a drive signal may be started a low frequency, e.g. about 60 Hz and then ramp up to a higher frequency e.g. about 10 MHz. In some cases, a reactor may include a similar multistage process for terminating a fusion reaction. In some cases, a reactor may have an idle stage of operation that occurs between when fusion reaction is halted and then resumed. During operation of a reactor, the parameters may be closely monitored. In a reactor that makes use of a Lorentz force to rotate charges species, the current density in the confinement region or annular space near the confining wall may be in the range of about 150 A/m2 to about 10 kA/m2, e.g., about 150 A/m2 to about 9 kA/m2. In some cases, the current density near a confining wall may be in the range of about 150 A/m2 to about 700 kA/m2, and in some cases in the range of about 400 A/m2 to about 6000 kA/m2. In some cases a reactor is operated to maintain a sufficient electric field near the confining wall. For example, in some cases the electric field is greater than about 25 V/m, in some cases greater than about 40 V/m, and in some case greater than about 30 V/m. In some multistage operations, a reactor may periodically alternate the direction in which charged particles are rotated. In some cases, by alternating the direction that charged particles rotate, the rate of collisions between two rotating fusion reactants may be increased. In some cases, the direction of rotation may be alternated to increase or control the rate of fusion in a reactor. In some embodiments, by alternating the direction of rotation the rate of fusible events on a confinement wall may be reduced due to fusible events occurring within the annular space rather than on the confinement surface. This may be beneficial to, for instance, reduce heat imparted to a confinement wall if the confinement wall becomes too hot. In the cases of Lorentzian rotors, the direction of rotation may be alternated by alternating an applied electric field and/or magnetic field. For example, if the magnetic field is alternated while an electric field is maintained, the Lorentzian force on charged particles will also alternate directions. In some cases, an applied electric field and or an applied magnetic field is alternated at a frequency between about 0.1 Hz to about 10 Hz, in some cases, about 10 Hz to about 1 kHz, and in some cases greater than about 1 kHz. This may have the effect of concentrating electrons in the electron-rich region, concentrating rotating particles in close proximity, and in some cases, increasing the number of fusion reactions. Gas Conditions In cases where gas is introduced into the confinement region, e.g. a hydrogen or helium reactant gas, it may be beneficial for the reactant gas to have certain purity. In some cases, impurities in a reactant gas volume may decrease the rate of fusion and the overall energy output. In cases where a reactant gas is readily available in a pure form, a reactant gas having a purity of of at least about 99.95% by volume or at least about 99.999% by volume. This means there are fewer than 10 vpm (volume per million) impurities in the cylinder. In some cases, deuterium, a naturally occurring isotope of hydrogen, may be found within a hydrogen reactant gas. For example, deuterium may be present within the impurities of a hydrogen tank, and as such, present a potential hazard when present in sufficient quantities within the reactant gas. If there is too much deuterium in the fuel, fusion reactions other than proton-boron11 may occur within the reactor. In some instances, these other reactions may emit radioactive byproducts. To monitor the amount of deuterium in a reactant gas, a reactor may be equipped with sensors, such as the qRGA from Hiden Analytical mass spectrometer, for monitoring the amount of deuterium within a hydrogen reactant gas. Prior to ignition, a reactor may contain a mole fraction of ions to neutrals that is close to 0%. After striking a plasma, the reactor may be operated having a mole fraction of ions to neutrals in the rotating gas species that is about 1:1000 to about 1:1,000,000. In some cases, the mole fraction of ions to neutrals in a reactant gas may vary depending on the particular stage of a multistage process flow. For example, in the process flow of FIG. 25, a gas may have a higher mole fraction of ions to neutrals after initiating a plasma in stage 2502 than while the reactor is operating at steady state in stage in 2503. As described elsewhere, reactors may be equipped with gas inlet and exit valves. In principle, the flow through a gas inlet valve and/or a gas outlet valve may be controlled to maintain a desired gas composition or gas pressure within the confinement region. In some cases, the gas volume in the confinement region may be replaced at a rate that is less than about once a minute, or about once an hour. In many embodiments, gas valves may be sealed, so there is no fluid flow during operation of the reactor. In some cases, a reactant gas is maintained at standard temperature and pressure before generating a plasma in the confinement region. In some cases, such as when a vacuum enclosure is used, a vacuum pump may be used to lower the pressure to less than about 1×10−2 Torr, and in some cases less than about 1×10−6 Torr prior to striking a plasma in the confinement region. In some cases, to increase the density of neutrals a reactant gas feedline may increase the pressure within a reactor to more than about 0.1 Torr, and in some cases more than about 10 Torr before striking a plasma in the confinement region or during operation of a reactor. During operation of the reactor, particles may experience a centripetal acceleration that is on the order of a billion times that of the gravitational acceleration on the surface of the earth. In some cases, the gas pressure and/or density along the confinement wall may be monitored during operation of the reactor. If the pressure induced the rotating species is not sufficient near the confining wall, the electron rich region may diffuse farther into the confinement region and not provide the desired electron screening effect. In some cases, the gas pressure near the confinement wall may be monitored in real time. Prior to initiating a plasma the temperature of a gas may be approximately at room temperature, in some cases a gas is initially heated. In some cases, the gas is heated to greater than about 1,800° C., and in some cases the gas is heated to greater than about 2,200° C. During steady operation of the reactor the gas temperature may me heated such that the gas in the confinement region is in the range of about 400° C. to about 800° C., and in some cases in the range of about 900° C. to about 1,500° C. As discussed elsewhere, a reactant gas may be delivered into a reactor by a variety of mechanisms. In cases in which as inlet valve is used, a gas reactant may be delivered from a gas canister or pressurized tank. In some embodiments, a reactant gas such as hydrogen may be delivered into the confinement region by being out-diffused from the confinement wall or a hydrogen absorbing material such as titanium or palladium. Operating Conditions for Reducing Coulombic barrier As described elsewhere herein, the rate of fusion per volume per unit time may be expressed bydN/dT=n1n2σν where n1 and n2 are the densities of the respective reactants, σ is the fusion cross section at a particular energy, and ν is the relative velocity between the two interacting species. The product (σ ν) may be increased by reducing the coulombic barrier. In some cases the fusion cross section may be between about 10−30 cm2 and about 10−48 cm2, and in some cases about 10−28 cm2 and about 10−24 cm2. In some cases the relative velocity is between 104 m/s and 106 m/s, and in some cases between about 103 m/s and about 104 m/s. In some cases, a reduction to the coulombic barrier may result in a reaction rate that is about 1017 to about 1022 fusion reactions per second per cubic centimeter along the confinement wall. As discussed elsewhere, an electron-rich region may be formed near the confinement wall to provide a screening effect between colliding nuclei. In some cases, electron emitters may be used to provide free electrons to this region. Emitters may be energized optically (e.g., using a laser), by frictional heating of the rotating particles, and/or by Joule heating. Within the electron-rich region, the density of electrons may be on order of about 1010 cm−3 to about 1023 cm−3, and in some cases, the density of electrons is on the order of about 1023 cm−3 within this region. In some embodiments, the density of neutrals in the electron-rich region may be about 1016 cm−3 to about 1018 cm−3, and in some cases, the neutrals density within the confinement region is on the order of about 1020 cm−3. Positive ions may be found at a much lower density than neutrals within the electron-rich region. In some cases, the density of positive ions is about 1015 cm−3 to about 1016 cm−3. In some cases the ratio of electrons to positive ions within the electron-rich region is in the range of about 106:1 to about 108:1. The radial thickness of the electron-rich region may be characterized as the region in where most of the electron gradient exists. In some cases, the electron-rich region is in the range of about 50 nm to about 50 um, in some cases, the electron rich is about 500 nm to about 1.5 um. Within the electron-rich region, e.g. about 1 um away from the confining wall, there may be a strong electric field. In some cases, the electric field within the electron-rich region (or confinement region) is greater than 106 V/m, and in some cases, the electric field is greater than about 108 V/m. In some cases, the temperature of electrons in this region is about 10,000 K to about 50,000 K, and in some cases about 15,000 K to about 40,000 K. In some cases, if one parameter is constrained by a physical limitation, that parameter may end up being a driving parameter that affects other parameters within the electron-rich region. For example, the Lawson criterion involves a balance of parameters. In some cases, the parameters of the electron-rich region may depend in part on the fusion reaction that is targeted. For example, the parameter ranges are different in a p+11B reaction vs. a D+D reaction. Another approach to increasing the probability of fusion events is by aligning the spin of the fusion reactants. The nuclear force has a spin-dependent component. When spins are aligned, between two nuclei, e.g., those of a deuteron and a deuteron, the coulombic barrier is reduced. Nuclear magnetic moments play a role in quantum tunneling. Specifically, when the magnetic moments of two nuclei are parallel, an attractive force between the two nuclei is created. As a result, the total potential barrier between two nuclei with parallel magnetic moments is lowered, and a tunneling event is more likely to occur. The reverse is true when two nuclei have antiparallel magnetic moments, the potential barrier is increased, and tunneling is less likely to occur. When the magnetic moment of a particular type of nucleus is positive, the nucleus tends to align its magnetic moment in the direction of an applied magnetic field. Conversely, when the moment is negative, the nucleus tends to align antiparallel to an applied field. Most nuclei, including most nuclei which are of interest as potential fusion reactants, have positive magnetic moments (p, D, T, 6Li, 7Li, and 11B all have positive moments; 3He and 15N have negative moments). In certain embodiments, a magnetic field is provided that aligns the magnetic moments in approximately the same direction at every point within the device where a magnetic field is present. This results in a reduction of the total potential energy barrier between nuclei when the first and second working materials have nuclear magnetic moments which are either both positive or both negative. It is believed that this leads to an increased rate of tunneling and a greater occurrence of fusion reactions. This effect may also be referred to as spin polarization or magnetic dipole-dipole interaction. In addition, the gyration of a nucleus about a magnetic field line also contributes to determining the total angular momentum of the nucleus. So when the cyclotron motion of the nucleus produces additional angular momentum in the same direction as the polarization of the nuclear magnetic moment, the Coulomb barrier is further reduced. In some cases, the spin states of fusion reactants (e.g., 1H and 11B) in the confinement region and along the confining wall may be aligned by applying a magnetic field in the range of 1-20 T. In cases in which a magnetic field is used to provide a Lorentzian force, the magnetic field may also align the spin states of the fusion reactants. The combination of a reduced coulombic barrier through, e.g., electron screening and a spin polarization (enabled by a strong magnetic field acting on the reactant nuclei) may produce a significant enhancement in the rate fusion. The electrostatic attraction between two nuclei includes a spin-dependent term that becomes dominate at short distances (e.g., less than 1 fm). Applications Fusion reactors as described herein have abundant applications that may resolve many societal issues such dependence on fossil fuels. In some cases, the use of fusion reactors may make feasible and/or practical energy intensive applications that were not feasible or practical with conventional power generation methods. A few applications of fusion reactors are now briefly discussed. In some cases, fusion reactors may be used to retrofit a fossil fuel power plant such as a power plant which burns coal, natural gas, or petroleum to produce electricity. In some cases, fusion reactors described herein may be used to retrofit a fission power plant. When retrofitting a power plant, in some cases, it may only be necessary to replace or update the portions of the power plant where energy is produced. This makes power plant retrofits simple and cost efficient as turbines, generators, cooling towers, connections to a power distribution network, and other infrastructure may be reused. For example, a coal power plant may be retrofitted by replacing a coal-fired boiler with a fusion boiler that utilizes a reactor described herein. Similarly, a fission power plant may be retrofitted by replacing the control rods and uranium fuel with a fusion reactor as described herein. In some cases, a fusion reactor has a modular design that employs a plurality of smaller reactors. By having a plurality of reactors, the power output of a plant may be modulated to meet energy demand by varying the number of reactors in operation. Additionally, if individual reactors can be serviced or replaced while other reactors remain operable, the overall power output of the plant may not be significantly affected. In some cases, a fusion reactor may be used as a heating interface for industrial processes such as fiberglass manufacture. In some cases, a reactor is configured as the heat source for a steam generator (e.g., a steam generator used for steam cleaning or metal cutting). In some cases, a reactor is used as a source of helium where helium is produced as a result of a fusion reaction (e.g., when the reactor conducts proton-boron-11 fusion). In some cases, the reactor may be used as part of a water heater, such as a home-sized water heater. For example, the reactor may be placed within a water tank or may be thermally coupled to a water tank such that heat emanating from the reactor is used to heat water. In some cases, a fusion-based water heater may be paired with a water radiator to provide indoor heating. In some cases, a fusion reactor is used for transportation applications. For example, a fusion reactor may be used to power and automobiles, planes, trains, and boats. An automobile, for instance, may be outfitted with a reactor having one or more energy conversion modules configured to generate electrical and/or mechanical energy. In an electric car, electrical energy produced by a reactor may be used to charge a battery or capacitor which is used to provide power to an electric motor. For example, a reactor may be operated to charge a car battery whenever the battery's state of charge falls below a certain threshold value. In some cases, mechanical energy is produced by, for example, a Stirling engine which is used to provide the driving power for a car. In some cases, a fusion reactor may be used to provide power to outer space vehicles. Some designs for outer space vehicles use a fission reactor such as a radioisotope thermoelectric generator. Such designs suffer from use and generation radioactive isotopes. They also require carrying relatively large amounts of radioactive fuel. Since reactors described herein may be aneutronic or substantially aneutronic, these reactors may be much more preferable for spacecraft designed to carry human occupants. Additionally, the energy densities of fusion reactants used for reactors described herein are significantly higher than fuels required by a fission reaction or a chemical reaction to produce the same amount of energy. The claim elements that do not recite “means” or “step” are not in “means plus function” or “step plus function” form. (See, 35 USC §112(f)). Applicant's intend that only claim elements reciting “means” or “step” be interpreted under or in accordance with 35 U.S.C. § 112(f). The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
052531864	abstract	A system for a process facility monitors the execution of a procedure in which steps are defined with associated conditions. Each condition is one of an initial condition, sequential condition or constraining condition. While constraining conditions are checked for violations during several steps, sequential conditions are checked only during an associated step. The sequential conditions may be transformed into constraining conditions for subsequent steps by setting a transform flag either prior to execution of the procedure or during execution of the procedure in response to an operator request. Once a transformable sequential condition has been met or the step associated therewith has been completed, an enable flag is set making the sequential condition a transformed condition which is checked at the same time as the predefined constraining conditions.
	abstract	A boiling water reactor includes a reactor pressure vessel having a feedwater inlet for the introduction of recycled steam condensate and/or makeup coolant into the vessel, and a steam outlet for the discharge of produced steam for appropriate work. A fuel core is located within a lower area of the pressure vessel. The fuel core is surrounded by a core shroud spaced inward from the wall of the pressure vessel to provide an annular downcomer forming a coolant flow path between the vessel wall and the core shroud. A probe system that includes a combination of conductivity/resistivity probes and/or one or more time-domain reflectometer (TDR) probes is at least partially located within the downcomer. The probe system measures the coolant level and flow velocity within the downcomer.
	description	This Application is a Section 371 National Stage Application of International Application No. PCT/EP2007/004625, filed May 24, 2007 and published as WO 2008/141667 A1 on Nov. 27, 2008, the content of which is hereby incorporated by reference in its entirety. The present invention relates to collimation apparatus for radiotherapy. The technique of radiotherapy involves directing a beam of harmful high-energy radiation towards a tumour. The radiation causes damage to the tumour cells which, over time, destroys the cancer. As the beam is harmful, it is necessary to limit the radiation dose that is applied to the healthy tissue, whilst at the same time maintaining the dose delivered to the tumour. Accordingly, some means needs to be provided to de-limit the radiation beam so that its size is no larger than is necessary or achievable. Early radiotherapy machines used a collimation system as shown schematically (along the beam's eye view) in FIG. 1, in which two sets of moving shielding blocks (known as diaphragms) move in mutually perpendicular directions x and y, both axes being perpendicular to the radiation beam (z). Thus, a first pair of blocks 10, 12 move in an x direction to the limit the transverse width of the beam (as viewed in FIG. 1). A second pair of blocks 14, 16 move in the y direction so as to de-limit the width of the beam in that axis. In this way, a beam of any chosen rectangular size up to a maximum achievable size could be used. Tumours are not generally rectangular, however. As a result, it is now common to use a so-called “multi leaf collimator”, which is made up of individual thin “leaves” of a high atomic number material such as tungsten, each of which can move independently in and out of the beam path in order to block the beam. FIG. 2 shows a generalised multi-leaf collimator which replaces the y collimators 14, 16 of FIG. 1. The x collimators 10 and 12 remain. Thus, the multi-leaf collimator 16 consists of a first bank 18 and a second bank 20, each comprising a large number of thin leaves 22, narrow in the x direction transverse to the beam and relatively long in the y direction transverse to the beam and the z direction parallel to the beam. Their length in the z direction allows sufficient opacity to the x-ray or other beam to achieve an effective shielding effect, and their length in the y direction allows them to be extended into and out of the beam in that direction so as to define any chosen shape. In some cases, as shown in FIG. 3, the remaining pair of diaphragms 10, 12 are dispensed with altogether, and the leaves are made sufficiently long to shut off the beam completely by overlapping or passing right across the beam as shown in the case of (for example) leaf 24. The join between opposing leaves 24, 26 can either be placed underneath an offset blocking strip 28 (as shown in FIG. 3) or can be achieved by placing the leaves at different points along the z axis so that the two leaves 24, 26 can overlap when viewed in the z direction. This arrangement does, however, mean that the width of the beam in the x direction can only be one of an integer number times the width of the leaves. The arrangement shown in FIG. 2 allows any dimension of a beam width since the x collimators 10, 12 can be moved as desired. Prior to the development of the MLC, beams were de-limited to the shape of the tumour insofar as existing collimation arrangements permitted. When the multi-leaf collimator became available, novel forms of treatment were made possible such as conformal arc radiotherapy, in which the shape of the beam conforms at all times to the projected shape of the tumour along the instantaneous axis of the beam. This minimises radiation dose to healthy tissue either side of the tumour, and in combination with a rotating source that is able to direct a beam towards the patient from a range of different directions, can result in a very high dose within the tumour and a very small dose outside the tumour. Conformal arc therapy can, however, only deliver a convex-shaped dose, i.e. one in which the dose steadily decreases away from the dose centre. Further developments in the use of multi-leaf collimators have included techniques such as intensity modulated radiotherapy (IMRT) and other techniques in which more complex shapes created by the multi-leaf collimator allow non-convex dose distributions to be built up over time. Generally, the MLC does not irradiate the entire tumour continuously in such techniques, and otherwise difficult but useful dose shapes can be developed such as a cylindrical dose conforming to the shape of a patient's hip in which (for example) a bone tumour is irradiated leaving the sensitive organs within the hip largely unirradiated. These can result in a need for an off-centre radiation field, as shown schematically in FIG. 4; the radiation field 30 is displaced from the beam's central axis 32, and in order to do this one x collimator 12 is extended across the beam beyond the central axis 32. Assuming that the beam aperture is 40 cm at the collimators, beam shapes such as those shown in FIG. 2 require the x collimators 10, 12 to traverse from a fully withdrawn (or “20 cm open”) position to a 0 cm position at which they extend to the central axis of the beam. In order to provide beam shapes such as that shown in FIG. 4, a further 15 cm or so of extension also is required. This will not translate into a complete blocking of the beam by one diaphragm only, but generally this is not clinically required. A 15 cm offset beyond the beam's central axis will suffice for most clinically useful shapes. It should be remembered however that in order to shield the full beam, the diaphragms are required to be of the order of 8 cm thick solid tungsten material. That additional 15 cm of 8 cm thick tungsten imposes a significant weight burden on the diaphragms. Correspondingly, the mechanism required to move a significantly greater mass of diaphragm will be correspondingly heavier itself. Both of these increase the overall mass of the treatment head, which in turn causes the apparatus structure to deflect more, resulting in a less accurate treatment. It should be borne in mind that most clinical accelerators place the treatment head at the end of a long arm which is mounted on a rotatable support so that the treatment head can be rotated around the patient. Additional mass at the end of that arm causes the arm to deform in a direction which will vary (relative to the treatment head) as the treatment head traverses in an arc around the patient. The present invention therefore seeks to provide a diaphragm which is able to offer the necessary blocking of the radiation beam over a large proportion of the aperture (if necessary), whilst having minimal mass. The present invention therefore provides a radiotherapy apparatus comprising a means for producing a beam of radiation directed along a beam axis and having a width in first and second directions transverse to the beam axis, a multi-leaf collimator for selectively limiting the width of the beam in at least the first direction, a block collimator for selectively limiting the width of the beam in at least the second direction, the block collimator comprising a diaphragm moveable into and out of the beam and having a thickness in the direction of the beam axis that varies. The diaphragm can have a front edge of greater thickness than at least one region behind the front edge. It can also have a spine region extending from a rear part thereof towards the front edge that is greater thickness than at least one region displaced laterally with respect thereto. Together, these can cover the areas that will not be fully shadowed by a dynamically moving MLC. A control means for the multi-leaf collimator can be arranged to extend leaves of the multi-leaf collimator to shadow regions of the beam that are blocked by a relatively thinner section of the diaphragm. This is made easier if the spine region extends from the rearmost part of the diaphragm, the spine region extends to the front edge of the diaphragm, the spine region is straight, the spine region is a central region of the diaphragm, and if the width of the spine region increases towards the front edge of the diaphragm. Generally, the first and second directions will be mutually transverse. The present invention also relates to a radiotherapy apparatus comprising a multi-leaf collimator and a block collimator, the block collimator comprising a diaphragm with variable thickness. In a further aspect, the present invention provides a block collimator for use in radiotherapy apparatus comprising a diaphragm moveable into and out of a beam, and having a thickness in the direction of the beam axis that varies. In a still further aspect, the present invention provides a radiotherapy apparatus comprising a means for producing a beam of radiation directed along a beam axis and having a width in first and second directions transverse to the beam axis, a multi-leaf collimator for selectively limiting the width of the beam in at least the first direction, a block collimator for selectively limiting the width of the beam in at least the second direction, the block collimator comprising a diaphragm moveable into and out of the beam and having a width that varies transverse to the direction of movement. Thus, parts of the diaphragm can be essentially reduced to zero thickness, leaving a central spine region and a wider front edge that preferably extends across substantially the entire width of the beam in the first direction. Referring to FIG. 5, showing the view along the beam axis 100, a diaphragm 102 is moveable in and out along an X axis 104 so as to selectively shield the beam to a desired degree. Only the right-hand diaphragm 102 is shown in FIG. 5; there will be a corresponding left-hand diaphragm on the other side which, in this embodiment, is of like construction although it need not be. A multi-leaf collimator 106 operates in the Y axis. The multi-leaf collimator 106 (MLC) comprises a number of individual leaves 108 which can be extended into and out of the beam along a y axis perpendicular to the diaphragm axis 104. Each leaf can be selectively moved by a desired distance so as to shape the beam to a chosen curved outline such as that shown at 110. The extremity 112 of the curve 110 in the x axis is then met by the diaphragm 102. This both covers the inevitable small degree of leakage between the leaves 108, and allows for the possibility that the extremity 112 does not coincide with a leaf edge. Normally, leaves 108 that are behind the front edge 114 of the diaphragm 102 are redundant and can be withdrawn (as shown in FIG. 4). The diaphragm 102 of FIG. 5 comprises a central spine region 116 and a front edge 118. The spine region 116 is shown as being centrally located on the diaphragm 102. This is an arrangement which is straightforward and offers a balanced diaphragm, but which is not essential. Both the spine 116 and the front edge 118 are of a relatively increased thickness, to the full thickness normally associated with a diaphragm for a block collimator. Typically, this is of the order of 8 cm thick. The central spine region 116 extends from a rearmost edge 120 of the diaphragm along its central axis 104 until it reaches the front edge 118 of the diaphragm. Approximately half way along the length of the diaphragm, the spine region 116 begins to widen at 122, becoming steadily wider until it is approximately 80-90 percent of the width of the diaphragm at the point where it meets the thicker front edge 118. This thickened “Y”-shaped region of the diaphragm 102 is bounded on either side by generally thinner regions 124, 126. These generally thinner regions are only a fraction of the thickness of the spine and front edge, typically 1-3 cm and preferably about 2 cm. Whilst this is not thick enough to block the therapeutic beam entirely, it is thick enough to cover leakage between MLC leaves adequately. Accordingly, under the control of a suitable control means integrated within the radiotherapy apparatus, the leaves 108 of the MLC are advanced so as to cover the regions 124, 126 of the diaphragm that are of lesser thickness and (as shown) overlap slightly with the spine region 116. Accordingly, an adequate shadow is cast in the beam over all of the areas to be collimated out. The widening portion 122 of the spine 116 allows for the MLC leaves 108 to “catch up” as the diaphragm 102 moves forward. Generally, leaves 108 will be withdrawn to a greater extent in front of the diaphragm 102, and therefore as the diaphragm 102 moves forward to extend beyond a complete leaf, then that leaf will have a reasonable traverse distance in order to reach the central axis 104 of the block collimator. This traverse will take some time, and therefore the relatively greater width of the spine in 116 in the region 122 allows for this, as can be seen in FIG. 5. Meanwhile, the thinner portions 124, 126 are of greatly reduced weight, thereby reducing the weight of the diaphragm to an acceptable level yet still permitting extension of the diaphragm significantly beyond the central axis 100 of the beam. FIG. 6 shows a section along the beam axis along the lines VI-VI on FIG. 5. The leaves 108 of the multi-leaf collimator extend so as to collimate the beam 128 down to a narrower section 130 which corresponds (in this embodiment) to the minimum approach distance of the opposing leaves. Leaves are not permitted to move more closely, in order to prevent them from touching and being damaged. This narrow section 130 is then entirely within the spine section 116 of the block collimator 102. The thinner regions 124, 126 are entirely within the shadow of the MLC leaves 108. FIG. 7 shows the diaphragm 102 in a perspective view. A curved front edge 114 allows for a minimum penumbra regardless of the position of the diaphragm 102 (and hence the incident angle of the radiation) in a generally known manner. Other arrangements are however possible that employ a flat front face; either the penumbra is accepted, or the diaphragm follows an arcuate path so that the front face remains aligned with the beam direction. The thickened front edge 118 extends across the full width of the diaphragm 102, and the spine region 106 extends in a straight line from the rear of the diaphragm 102 to the front edge 114 along the central axis of the diaphragm 102. Approximately half way along the diaphragm 102, it widens in the region 122 in a linear manner so that by the point where the spine 106 reaches the thickened front edge 118, it is approximately 80-90 percent of the width of the diaphragm. Thinner regions 124, 126 either side of the central spine region 106 allow for considerable weight reduction. FIG. 8 shows an alternative design. This relies on the fact that many MLC systems support the leaves 108 in a carriage 132, which extends above and below the leaves and supports the upper and lower edges thereof. The carriage 132 does not itself extend to the centre of the beam, although it may move into and out of the beam field in order to carry the leaves forward and permit a greater extension of the leaves into and/or across the field. The carriage does however have a defined thickness in the beam direction 134, which means that there is a corresponding spacing 136 between the upper edge of the leaves 108 and the lower face of the diaphragm 102. As the carriages 132 do not extend to the centre of the field, however, this spacing 136 is unnecessary in the region beneath the spine 116 if the latter is centrally located. If the spine 116 is not central with respect to the diaphragm, then the availability of space will depend on where the spine is located relative to the position or range of movement of the carriages 132. Accordingly, in this embodiment the spine 116 also projects below the lower face of the diaphragm at 138. This means that more material can be placed in the spine region, improving the opacity of the diaphragm system. Alternatively, a corresponding amount of material can be removed from the upper edge of the spine, thereby reducing the overall depth of the collimator system and hence the radiation head, and improving the flexibility of the apparatus as a whole. FIG. 9 shows a perspective view from beneath of the diaphragm of FIG. 8. The lower projection 138 of the spine 116 can clearly be seen, extending rearwardly from the curved front face 114 of the diaphragm to the rear edge beneath the spine 116. The lower projection could also include an additional section partly or fully corresponding to the widening region 122, depending on the location and any range of movement of the MLC carriages 132. FIG. 10 shows a further embodiment. The purpose of the thinner regions 124, 126 either side of the spine 116 is to provide a back-up shield behind the extended MLC leaves 108. This caters for concerns that there may be some transmission through the MLC leaves, for example between leaves. Efforts are however made to eliminate such sources of leakage, and it may be that such backup is considered unnecessary. In that case, further weight saving can be achieved by eliminating the thinner regions completely and adopting a design as shown in FIG. 10. The diaphragm 102 consists simply of a front edge 118 and a spine 116, with the widening portion 122 between thereby defining a Y-profile when viewed along the beam axis. If the speed of movement of the MLC leaves is felt to be sufficient, or if the intended speed of the diaphragm is low enough, the widening portion 122 can be omitted leaving, potentially, a simple T-profile diaphragm. Only a single spine is shown in the accompanying figures. However, it is possible to envisage a diaphragm having a plurality of spines, which would offer a choice of locations as to where to park opposing leaves. This additional flexibility may be useful in clinical situations, although it will reduce slightly the weight savings obtainable through the present invention. It will of course be understood that many variations may be made to the above-described embodiment without departing from the scope of the present invention. Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
056235267	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 3 and 4 show a first embodiment of the invention. In this arrangement, straps 100 which are made of the same material as the shroud 14, for example stainless steel 304, are, in this embodiment, fastened to the shroud using so called "P-bolts" 102. While it is to be specifically noted that the invention is not limited to the use of these so called "P-bolts", this particular type of fastening technique is preferred in connection with this embodiment. With the illustrated straps, the H5 to H8 welds are spanned or covered. A plurality of straps 100, for example four or more straps, can be used; however, they need not necessarily be uniformly arranged at 90 degree intervals and the spacing is determined on a case-by-case basis depending on the reinforcement which is required and the space which is available. Prior to being submerged, each strap 100 is mounted on a delivery fixture and fitted with three (by way of example only) EDM heads (not shown) which are positioned at the sites where the "P-bolt" connections are required. Each of the straps is then lowered down through the annulus 104 defined between the shroud 14 and inner wall of the pressure vessel 16, using a so called "rigid pole" system. When each of the straps 100 is maneuvered into the desired position, the EDM tool heads cut the appropriately shaped holes through the wall of the shroud. The EDM heads are then remotely released and removed while the strap is maintained in position. The "P-bolts" 102 are then lowered into position, slid into the strap, threaded in and expanded. Each "P-bolt" 102 is then crimped to lock it in place. In the illustrated embodiment, the strap has an L-shape and the lower end or foot 100f fastened to a shroud support plate 30. The EDM process is carried out in a manner wherein the tooling loads are negligible and no chips are produced during each cut. The fines which are produced during the cutting operation are flushed out by water which is directed through the electrode by flushing pumps which take suction on the shroud and pass the water through filters. The filters in this instance are 0.8 micron and capture 99.9% of the fines in the water which is pumped through the area of the EDM electrodes. An alternative to the above "pre-mounting" technique resides in the strap being placed in position and the EDM cutting tools, which are supported at the ends of a delivery mast, then delivered into position in the annulus between the shroud and the pressure vessel using the above mentioned rigid pole system. Tool fixtures including alignment features and positioning clamps can be used to secure the mast and the tool head at the proper location for the respective cuts. It will be noted that the shroud 14, to which the strap according to the first embodiment of the invention is applied, has eight welds H1 to H8; and that the strap 100 illustrated in FIG. 3 is such as to span welds H5 to H8. This strap is able to withstand bend, and shear in addition to tension, and thus, when fastened to the shroud in the illustrated position, is able to securely support the shroud against bending and shearing forces as well as tension, and thus can be expected to increase the strength and resistance of the shroud to forces produced by seismic activity and the like for both horizontal and vertical welds. For further disclosure pertaining to the above mentioned "P-bolts", reference may be had to U.S. Pat. No. 5,065,490 issued to Wivagg et al. on Nov. 19, 1991. The disclosure of this patent is hereby incorporated by reference. It will be noted that FIG. 4 shows a variant of the first embodiment. That is to say, in this figure, an opening 106 is formed in the shroud 14 immediately above the top of the strap 100 and a flange section 100a is formed at the upper end of the illustrated strap 100. The flange 100a is arranged to project through the hole 106 into the interior of the shroud 14 where it can be connected to an internal tie rod or the like type of structure. FIGS. 5 and 6 show a second embodiment of the invention. This embodiment features a strap 100' which has an angled foot section 100f' and which is adapted for use with a shroud having a skirt portion 14a'. This embodiment is essentially similar to the first with this latter mentioned exception. FIG. 6 shows the strap of FIG. 5 in enlarged form. In this drawing the use of "P-bolt" type fasteners is shown. It will be noted that the length of the straps shown in FIGS. 3 to 6 is not limited to that shown in the drawings and can be of any suitable length. For example, it is clearly within the scope of the invention to make the straps long enough as to extend along a substantial portion of the height of the shroud and to span welds H4 to H8 for example. It will be further noted that the upper ends of the straps can be formed with outwardly extending flanges which are adapted to be connected to an external support structure such as a tie rod or the like, and thus cooperate with this additional structure in a manner which will extend the supportive effect of the straps over the full length of the shroud. Alternatively, a hole can be formed in the shroud which allows an inwardly extending flange to be fitted through the hole and to be connected to an internally disposed support structure. As will be appreciated, in the event that a hole is formed in the shroud for the purposes of allowing a flange or projection to pass through into the interior of the shroud, the hole and the projection member should have very similar dimensions so that a relatively snug fit is achieved and the amount of water which can flow through any remaining gaps is minimized to the maximum possible degree. Although the present invention has been described with reference to only two basic embodiments, it will be appreciated that a number of variations and modification are possible without departing from the scope of the invention and that the scope of the invention is determined only by the appended claims.
048790869	abstract	A neutron reactivity control system for a LWBR incorporating a stationary seed-blanket core arrangement. The core arrangement includes a plurality of contiguous hexagonal shaped regions. Each region has a central and a peripheral blanket area juxapositioned an annular seed area. The blanket areas contain thoria fuel rods while the annular seed area includes seed fuel rods and movable thoria shim control rods.
	abstract	Aimed at providing an ion implantation apparatus elongated in period over which failure of a target work, due to deposition and release of ion species typically to and from the inner surface of a through-hole shaping a beam shape of ion beam, may be avoidable, reduced in frequency of exchange of an aperture component, and consequently improved in productivity, an aperture component shaping a beam shape has a taper opposed to the ion beam, in at least a part of inner surface of at least the through-hole, and has a thick thermal-sprayed film formed so as to cover the inner surface and therearound of the through-hole.
	summary
044906161	summary	BACKGROUND OF THE INVENTION Various diagnostic and therapeutic procedures have been developed utilizing X-ray or other types of radiation. These procedures include utilizing X-rays for determining the presence of various conditions as well as techniques for treating malignancies. However, the unnecessary and uncontrolled subjection of the human body, or portions thereof, to radiation can have many deleterious effects. The medical and dental professions have accordingly taken steps attempting to reduce, as far as possible, the subjection of patients to this harmful radiation, occurring either inadvertently or during intended treatment to various parts of the body, or resulting from stray, scattered and surplus rays. It has been found that even very limited amounts of exposure to radiation, especially in children, occasionally causes damage to such glands as the pituitary and thyroid. In efforts to avoid such problems, techniques and apparatuses have been developed which attempt to absorb or shield various body areas of the patient from undesired exposure or from stray or scattered X-rays such as those which normally tend to scatter from the principal stream of X-rays. Preferably, the only X-rays allowed to contact human tissue are those necessary for the specific procedure. U.S. Pat. Nos. 2,962,589, issued to Dlouhy; 3,304,523, issued to Medwedeff; 4,223,229, issued to Persico et al; and 4,286,170, issued to Moti are examples of different devices used to protect a patient during a radiation procedure. The patent to Dlouhy describes a diagnostic chair which includes a radiation shield directly attached to the chair. The shield contains a block which is slid into position against the patient's neck. A thumb screw is loosened in order for the shield to be pivoted and lie flat against the neck area. The patent to Persico et al illustrates an oral radiation protector for protecting teeth, gingiva, peridontal bones, salivary glands, and adjacent body areas against the effects of radiation therapy. The protector consists of an intraoral shield which is placed in the patient's mouth. The shield portion is generally curvilinear in shape and is attached to encompass the lower front portion of the head. However, neither of these references describes a device which protects the head during a cephalometric diagnostic procedure. SUMMARY OF THE INVENTION The present invention is directed to a shield which is used to protect various portions of a patient's head, neck, and skull which need not be subjected to radiation during a cephalometric diagnostic procedure utilizing X-ray or similar radiation. The shield consists of a relatively planar piece of material which is impervious to X-rays. This planar portion can be utilized in conjunction with a cephalometric head holder to insure that the cephalometric shield is properly positioned with respect to the X-ray machine. Additionally, a screw, brad, staple or the like is used in conjunction with the cephalometric head holder to insure that the shield is properly held immobile. Furthermore, since radiation is reduced to a smaller portion of the patient's face and skull, the size of the film which is utilized in the cephalometric procedure can be reduced. Additionally, an alternate embodiment utilizes a removable shield in conjunction with the shield and cephalometric head holder to vary the portion of the face which is subjected to X-rays. The above and other features of the present invention will be more fully understood when considered in connection with the following description of a typical device embodying the invention as shown in the accompanying drawings.
045377413	claims	1. In combination with a length of tubular fuel cladding for a nuclear reactor, in which the cladding has an open axial end; a funnel mounted to the open axial end of the cladding, said funnel having an enlarged outer open end leading to a reduced diameter neck that is at least partially inserted within the open axial end of the cladding as a coaxial outwardly protruding attachment; and a continuous length of tubing shrunk about both the cladding and funnel to grip and maintain them as a unit during handling of the unfilled cladding and reception of fuel into the cladding through the attached funnel. a cylindrical ring coaxially fitted about the cladding and covered by said tubing, said ring having a rear annular shoulder facing opposite to the open end of the funnel and adapted to be engageable for pulling the ring, tubing and funnel from the cladding. a funnel mounted to the open axial end of the cladding, said funnel having a neck with an outside diameter complementary to the inner diameter of the cladding and a coaxial enlarged open end adapted to facilitate reception of fuel, the funnel neck being at least partially inserted within the open axial end of the cladding as a coaxial outwardly protruding attachment; and a continuous length of shrink tubing tightly encircling and gripping both the cladding and funnel adjacent the open axial end of the cladding to maintain them as a unit during handling of the unfilled cladding and reception of fuel into the cladding through the attached funnel. a cylindrical ring coaxially positioned about the cladding at a location inwardly adjacent its open axial end and covered by said tubing, said ring having a rear annular shoulder facing opposite to the open end of the funnel and adapted to be engageable for pulling the ring, tubing and funnel from the cladding. a cylindrical ring coaxially positioned about the cladding at a location inwardly adjacent its open axial end and covered by said tubing, said ring having a rear annular shoulder facing opposite to the open end of the funnel and adapted to be engageable for pulling the ring, tubing and funnel from the cladding; said ring having an inner cylindrical surface slidably fitted about the cladding. rear annular shoulder means along the length of shrink tubing facing opposite to the open end of the funnel for engagement during removal of the tubing and funnel from the cladding. 2. The combination of claim 1, further comprising: 3. The combination of claim 1, wherein the length of tubing is composed of plastic resin capable of being shrunk diametrically by application of heat. 4. In combination with a length of nuclear fuel cladding having an inner cylindrical diameter and an outer cylindrical diameter, in which the cladding is partially pre-assembled for loading of fuel pellets through an open axial end; 5. The combination of claim 4, further comprising: 6. The combination of claim 4, further comprising: 7. The combination of claim 4, further comprising:

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