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	description	This application is a 35 U.S.C. §371 of and claims priority to PCT International Application Number PCT/EP 03/003616, which was filed 08 Apr. 2003 (08.04.03), and was published in German which was based on German Patent Application No. 102 19 514.5 which was filed 30 Apr. 2002 (30.04.02) and the teachings of which are incorporated herein by reference. The invention relates to a lighting system, in particular for extreme ultraviolet (EUV) lithography, comprising a projection objective for producing semiconductor elements for wavelengths ≦193 mm, a light source, an object plane, an exit pupil, the first optical element having first grid elements for producing optical channels and the second optical element having second grid elements, each optical channel which is formed by one of the first grid elements of the first optical element being assigned a grid element of the second optical element, it being possible for grid elements of the first optical element and of the second optical element to be configured in such a way or arranged in such a way that the result for each optical channel is a continuous beam course from the light source as far as the object plane. The invention also relates to a projection exposure installation having such a lighting system. In order to reduce the structure widths of electronic components, in particular of semiconductor components, the wavelength for the light used for the microlithography should be reduced further and further. At present, wavelengths of ≦193 nm are already used in lithography. Here, a lighting system suitable for EUV Lithography should illuminate the field predefined for the EUV lithography, in particular the annular field of an objective, homogeneously, that is to say uniformly, with as few reflections as possible. In addition, the pupil of the objective should be illuminated independently of the field as far as a specific filling level σ, and the exit pupil of the lighting system should lie in the entry pupil of the objective. With regard to the general prior art, reference is made to U.S. Pat. Nos. 5,339,346, 5,737,137, 5,361,292 and 5,581,605. EP 0 939 341 shows a lighting system for the EUV range having a first optical integrator, which has a large number of first grid elements, and a second optical integrator, which has a large number of second grid elements. In this case, the distribution of the illumination in the exit field is controlled via a stop wheel. However, the use of a stop wheel entails considerable light losses. Further solutions proposed, such as a quadrupole illumination distribution and illumination systems that can be used differently via interchangeable optics are, however, firstly very complex and secondly restricted to specific types of illumination. DE 199 03 807 A1 describes an EUV lighting system which, inter alia, comprises two mirrors having grid elements. Systems of this type are also designated double-facetted EUV lighting systems. The illumination of the exit pupil is in this case determined by the arrangement of the grid elements on the second mirror. The illumination in the exit pupil or an illumination distribution is in this case defined. In the earlier German patent application 100 53 587.9 a lighting system is described, it being possible for a predefined illumination pattern to be set in the exit pupil of the lighting system by means of appropriate associations between the grid elements of the first and of the second optical element. Using a lighting system of this type, the field in the reticle plane can be illuminated homogeneously and with a partially filled aperture, and also the exit pupil of the lighting system can be illuminated in a variable manner. The variable setting of any desired illumination distribution in the exit pupil is in this case carried out largely without light losses. The present invention is based on the object of providing a lighting system with which the basic idea of the earlier patent application can be implemented in practice by means of constructional solutions. According to the invention, this object is achieved in that the angles of the first grid elements of the first optical element can be adjusted in order to modify a tilt. In addition, the location and/or angle of the second grid elements of the second optical element can also be adjusted individually and independently of one another, in order, by means of displacing and/or tilting the first and second grid elements, to implement a different assignment of the first grid elements of the first optical element to the second grid elements of the second optical element. By means of appropriate displacement and/or tilting of the grid elements, optical channels in variable configurations can now be achieved. In order that the individual bundles of rays of field honeycombs as grid elements in the field overlap again, pupil honeycombs as grid elements can be inclined or tilted appropriately in relation to a pupil honeycomb plate or the mirror support of the latter. Mirror facets are particularly suitable as field honeycombs and as pupil honeycombs. If, in this case, the system is built up as a system having real intermediate images of the light source after the field honeycomb plate or the mirror support of the first optical element, then the pupil honeycombs can be used at the same time as field lenses for the coupled projection of the light source into the entry pupil of the lithography objective or projection objective. If, in an advantageous refinement of the invention, the number M of second grid elements (pupil honeycombs) of the pupil honeycomb plate or the mirror support is always greater than N, where N is the number of channels, which is determined by the number of illuminated first grid elements (field honeycombs), variable illumination patterns can be presented in the exit pupil. In other words: in this case, more pupil honeycombs or mirror facets will be provided on the second optical element than would be necessary for the number of optical channels produced by the first grid elements of the first optical element. Given a specific setting with a specific field honeycomb having N channels, in each case only some of the pupil honeycombs are thus illuminated. This therefore leads to segmented or parceled illumination of the pupil honeycombs. FIG. 1 shows in a general illustration an EUV projection lighting installation having a complete EUV lighting system comprising a light source 1, for example a laser-plasma, plasma or pinch-plasma source or else another EUV light source, and a projection objective 25 illustrated merely in principle. Apart from the light source 1, there are arranged in the lighting system a collector mirror 2 which, for example, can comprise a plurality of shells arranged in one another, a planar mirror 3 or reflective spectral filter, an aperture stop 4 with an image of the light source (not designated), a first optical element 5 having a large number of facet mirrors 6 (see FIGS. 2 and 3), a second optical element 7 arranged thereafter and having a large number of grid elements 8 in the form of facet mirrors, and two projection mirrors 9a and 9b. The projection mirrors 9a and 9b are used to project the facet mirrors 8 of the second optical element 7 into an entry pupil of the projection objective 25. The reticle 12 can be moved in the y direction as a scanning system. The reticle plane 11 also simultaneously constitutes the object plane. In order to provide different optical channels for adjusting the setting in the bean path of the lighting system, for example there is a larger number M of mirror facets 8 of the second optical element 7 than corresponds to the number N of the mirror facets 6 of the first optical element 5. In FIG. 1, the mirror facets are not illustrated, for reasons of clarity. The angles of the mirror facets 6 of the first optical element 5 can in each case be adjusted individually, while both the angles and the locations of the mirror facets 8 of the second optical element 7 can be adjusted. In FIGS. 7 to 14, explained in the following text, details relating to this are described and illustrated. As a result of the tiltable arrangement and the ability to displace the mirror facets 6 and 8, different beam paths and thus different optical channels can be created between the first optical element 5 and the second optical element 7. The following projection objective 25 can be constructed as a six-mirror projection objective. A wafer 14 is located on a carrier unit 13 as the object to be exposed. As a result of the ability to adjust the mirror facets 6 and 8, different settings can be implemented in an exit pupil 15 of the lighting system which, at the same time, forms an entry pupil of the projection objective 25. In FIGS. 2 and 3, optical channels which are different in principle are illustrated by means of different layers and angles of the mirror facets 6 and 8 of the two optical elements 5 and 7. The lighting system is in this case indicated in simplified form as compared with the illustration in FIG. 1 (for example with respect to the position of the optical elements 5 and 7 and with only one projection mirror 9). In this case, the illustration in FIG. 2 shows a greater filling factor σ. For σ=1.0, the objective pupil is filled completely; σ=0.6 accordingly denotes underfilling. In FIGS. 2 and 3, the beam path from the light source 1 via the reticle 12 as far as the exit pupil 15 is illustrated. FIG. 4 shows a plan view of a mirror support 16 of the first optical element 5 having a large number of grid elements in the form of mirror facets 6. The illustration shows 142 individually adjustable mirror facets 6 as field honeycombs in rectangular form, which are arranged in blocks in a region illuminated by the nested collector mirror 2. The angles of the mirror facets 6 can in each case be adjusted individually. The facets 8 of the second optical element 7 can additionally be displaced among themselves and, if required, also independently of one another. FIG. 5 shows a plan view of a mirror support 16 or pupil honeycomb plate of the second optical element 7, the optical channels resulting in a circular setting. FIG. 6 shows a plan view of a mirror support 16 of the second optical element 7 having mirror facets in an annular setting. A further possibility consists in a known quadrupole setting (not illustrated). In FIGS. 5 and 6, the illuminated mirror facets are in each case illustrated dark. FIG. 7 shows a plan view of the mirror support 16 of the second optical element 7, the mirror support 16 being formed as a guide disk. The mirror support 16 or the guide disk is provided with a large number of guide grooves (only one guide groove 17 is illustrated in FIG. 7, for reasons of clarity), in which a circular mirror facet 8 is guided in each case. The guide groove 17 runs essentially radially or in slightly curved form for this purpose. The course of the guide grooves 17 depends on the respective application and on the desired displacement direction of the mirror facets 8. Underneath the mirror support 16 or the guide disk, parallel to and resting thereon, there is arranged a control disk 18, which is likewise provided with a number of control grooves 19 corresponding to the guide grooves 17 and therefore to the mirror facets 8. Each mirror facet 8 is thus guided in a guide groove 17 and in a control groove 19. If the control disk 18 is moved in the direction of the arrow 20 in FIG. 7 by means of a drive device, not illustrated, then the mirror facets 8 are moved radially inward or outward along the guide groove 17. As a result of this displacement, the assignments of the optical channels and therefore the illumination change. This means that, by rotating the control disk 18 relative to the guide disk 16, the associated mirror facet 8 at the point of intersection of the two grooves 17 and 19 is displaced along the associated guide groove 17. FIGS. 9 and 10 show a refinement for the displacement of the mirror facets 8 of the second optical element 7 respectively in a guide groove 17 of the mirror support 16, in each case a drive device 21 being provided (illustrated only in principle and dashed in FIGS. 9 and 10). In this case, each mirror facet 8 has its own drive in the associated guide groove 17, it being possible for the drive to be provided, for example, in accordance with the known piezoelectric inch-worm principle. Of course, for this purpose, other drive devices by means of which the mirror facets 8 can be adjusted individually in each case are also possible. Instead of arranging the drive device in each case directly in a guide groove 17, if required these can of course also be arranged independently thereof underneath or behind the mirror support 16. FIGS. 11 and 12 illustrate in section and in plan view an enlarged illustration of a mirror facet 6 of the first optical element 5, which is connected to the mirror support 16 of the first optical element 5 by a joint 22, which is formed as a solid body joint. In this case, all the parts can be in one piece or each mirror facet 6 has a central web as a joint 22, via which the connection is made to the mirror support 16 located underneath. By means of actuators 23, not specifically illustrated, which are located between the mirror support 16 and the underside of each mirror facet 6, each mirror facet 6 can be tilted with respect to the mirror support 16. The plan view according to FIG. 12 reveals that tilting possibilities in both directions are provided by an actuator 23 which is located on the y axis and a further actuator 23 which is located on the x axis. In this case, the two actuators 23 are in each case located on the axis assigned to them outside the point of intersection of the axes. Since the adjustment or tilting of each mirror facet 6 is carried out only to a very small extent, piezoceramic elements, for example, can be used as actuators 23. FIGS. 13 and 14 illustrate a refinement by means of which larger tilts for the mirror facets 6 are made possible. As can be seen from FIG. 13, in this case there is a central tilting joint or tilting bearing 24 between the mirror facet 6 and the mirror support 16. Here, too, actuators 23 ensure that the mirror facets 6 are tilted both in the x direction and in the y direction. For this purpose, in this case there are two actuators 23 arranged at a distance from each other on the y axis outside the point of intersection of the two axes, and two further actuators 23 outside the y axis on both sides at the same distance from the x axis (see FIG. 14). By means of the tilting devices illustrated in FIGS. 11 to 14, t is possible to adjust not only the mirror facets 6 of the first optical element 5 but also the mirror facets 8 of the second optical element 7 as desired and independently of one another. As distinct from the mirror facets 6 of the first optical element 5, which have an elongated or narrow rectangular form, the mirror facets 8 of the second optical element 7 have a circular form. However, this difference has no influence on the type or mode of action of the tilting devices illustrated in FIGS. 11 to 14. In principle, the mirror facets 6 of the first optical element can likewise be displaced in the same way as illustrated in FIGS. 7 to 10 but, in practice, this will generally not be necessary; instead, pure tilting adjustments will as a rule be sufficient. Actuating elements that can be activated magnetically or electrically are also possible as actuators 23. The actuators 23 can in this case adjust the mirror facets 6 and 8 continuously via a control loop (not illustrated). Likewise, it is also possible for the actuators to define end positions, with which in each case two exact tilted positions are predefined for the mirror facets 6 and 8.
044329326	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a modular reactor head shielding system embodying the invention is designated generally by the reference numeral 10. The modular reactor head shielding system or reactor shield 10 is shown operatively in place mounted on a reactor head 12. The reactor head 12 includes a top 14 from which extends control rods or a control rod cover 16. The reactor head 12 includes a plurality of vent ports 18 each of which is shown with a cover plate 20 of the reactor shield 10. The reactor head 12 includes a generally cylindrical side 22 from which extends the vent ports 18 and which may have various shapes depending upon the manufacturer of the reactor head and may be tapered from the top 14 down to a bottom flange 24 which forms the bottom of the reactor head cover. The top 14 is typically secured to the side 22 by a plurality of bolts 26. The reactor head 12 is secured to a reactor base 28 by a plurality of studs 30 onto which are mounted nuts 32. The reactor base 28 typically is situated in a well 34 which may include a shoulder 36 as illustrated or may be substantially upstanding around the whole reactor head 12. The nuts 32 can be removed with the shield 10 in place. The reactor shield 10 includes a plurality of pads 38 which are hung by mounting plates 40 from the reactor top 14 such as from the bolts 26. Shorter pads 38' are hung below the vents 20 by chains or straps 39. The pads 38 and 38' interleave with one another such that there are no radiation paths between adjacent pads. The pads are secured to one another by straps 42 which can have a hook or loop of synthetic material which adheres to a mating piece 44 on the adjacent pad 38 when pressed together (such as that sold under the trademark "Velcro"). The interleaving or overlap of the pads 38 and 38' is best illustrated in FIG. 2. Each of the pads 38 or 38' includes a pair of outer covers or sleeves 46 and 48 which are secured together offset from one another at a seam 50. Each sleeve 46 or 48 includes a pair of blankets 52 and 54. The manufacture of the blankets 52 and 54 and pads 38 or 38' is best described with reference to FIGS. 3 and 4. One blanket 52 is illustrated in FIG. 3. The blanket 52 includes a cover 56, such as nylon which can be plastic coated to prevent the lead from oxidizing. The cover 56 is filled with lead wool, as for example with 10 pounds per square foot. The cover 56 is then stitched with a grid type pattern 58 to secure the lead wool so that it does not shift within the blanket 52. The blanket 52 is sealed at its top and bottom ends 59 and 60 such as by sewing. Referring to FIG. 4, the covers or sleeves 46 and 48 of one pad 38 are best illustrated, each with a pair of blankets 52 and 54 inserted therein. Each of the blankets has a lead core interior 62 formed from the stitched lead wool. Each pair of blankets 52 and 54 are secured to one another such as by glueing along a common seam 64 prior to insertion into the sleeves 46 and 48. Each pair of blankets 52 and 54 is then glued to a sleeve wall 66 and 68, respectively, adjacent to the seam 50 to provide a very strong but flexible pad 38. The outer cover or sleeves 46 and 48 can be made from nylon or reinforced polyvinyl chloride (PVC) or other suitable material preferably having a tear strength of at least 300 pounds since the total weight of each pad 38 may be on the order of 300 to 350 pounds. The shorter pads 38' weigh less than the pads 38. The assembly of the hanging plates 40 for the pads 38 and 38' is best illustrated in FIGS. 5 through 7. The plates 40 include a large innerplate 70 with a plurality of bolt holes 72 therethrough. A mating outer plate 74 has a plurality of bolt holes 76 which match with the holes 72 in the innerplate 70. Each of the sleeves 46 and 48 has a top portion 78 and 80, respectively, folded over upon itself above the tops of the inner blankets 52 and 54 to provide a secure mounting pad for the plates 70 and 74. The top portion 78 and 80 are sandwiched between the plates 70 and 74 utilizing a plurality of bolts 82 and nuts 84. As best seen in FIG. 7 the sandwiched portion 78 has an outer end 85 which flares out further ensuring the secure mounting of the pads 38. The bolts or studs 26 on the reactor top 14 include a nut 86 which are removed to secure a mounting arm 88 thereon. The arm 88 includes a plate 90 and a stud hole or aperture 92 which is mounted on the stud 26 and secured by the nut 86. The outer end of the mounting arm 88 includes a retaining post or pin 94. Each of the mounting plates 40 includes a projecting mounting ear 96 at each end, which overlap one another behind the retaining post 94. The plates 40 preferably include a lifting aperture 98 into which can be placed a hook or other mechanical means to lift the pads 38 into position on the reactor head 12 or on a frame if desired. The plates 70 and 74 preferably have a shape to fit the outside of the reactor head 12. The resulting pad assembly 38 provides a flexible shield covering which will not injure the reactor side 22 and provides a reactor head shield 10 which is easily placed around the reactor head 12 while the nuts 32 are being removed and replaced and maybe left on the reactor head throughout the work outage. The pads 38' may have the chains 41 attached to their outer bolts 82 in the plate or clamp 40. The resulting shielding with the quaddruple lead wool blankets saves approximately 25 to 30 man rems per outage which is a reduction in exposure factor of magnitudes less than that otherwise required during a refueling outage. Many modifications and variations of the present invention are possible in light of the above teachings. The vent covers 20 can also be blankets or can be lead plates or lead poured into a frame. The scale and shape of each reactor head 12 of different manufacturers or different models would be somewhat different; however, the shaping of the pads 38 and 38' is easily accomplished within the teachings of the invention. The pads 38 and 38' preferably are tapered to fit the curvature of the reactor head 12, but also could be straight with some filler pads in between. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
	abstract	A dynamic neutron reflector assembly for a “breed-and-burn” fast reactor incrementally adjusts neutron spectrum and reactivity in a reactor core. The composition of materials in the dynamic neutron reflector may be adjusted to change neutron reflectivity levels, or to introduce neutron moderating or absorption characteristics. The dynamic neutron reflector may contain a flowing reflecting liquid of adjustable volume and/or density. Submergible members may be selectively inserted into the flowing reflecting liquid to alter its volume and introduce other neutron modifying effects such as moderation or absorption. Selective insertion of the submergible members allows for concentration of the neutron modifying effects in a selected portion of the reactor core. The flowing reflecting liquid may also act as a secondary coolant circuit by exchanging heat with the molten fuel salt.
	abstract	A nuclear reactor module includes a reactor core and a reactor housing that surrounds the reactor core about its sides, wherein the reactor housing is configured to direct coolant through the reactor core. A neutron reflector is located between the reactor core and the reactor housing, wherein the neutron reflector has a plurality of inlet ports facing the reactor core. The neutron reflector also has a plurality of outlet ports fluidly connected to the inlet ports to direct a portion of the coolant through the neutron reflector.
	summary
	summary
061335789	abstract	For measuring basis weight of a moving web in the cross direction scanner of a paper-making machine, an encapsulated nuclear source of Promethium 147 is used because of its wide area of emission. To conserve space it is mounted on a vertical axis. The source in a horizontal plane parallel to the moving web from a stowed position where the source is shielded to an active position where the source emits through an aperture, through the moving web, and to a detector. The x-y array planar type detector uses four detector segments symmetrically arranged around a center and compensates for belt direction misalignment (the belt driving the cross direction scanners) by mathematically manipulating the electrical signals from each detector to eliminate the error term.
	description	The invention relates to an apparatus for restoring a tight fitup provided against an adjacent structure and, more particularly, to a compact remotely installable jet pump piping support device that restores the tight and rigid fitup originally provided between the inlet mixer and the adjacent restrainer bracket in a boiling water nuclear reactor jet pump. In a boiling water nuclear reactor (BWR), hollow tubular jet pumps positioned within the shroud annulus provide the required reactor core flow. The upper portion (inlet mixer) is laterally positioned and supported against two opposing rigid set screw contacts within restrainer brackets by a gravity actuated wedge, intended to assure clearances do not occur at the supports. The flow through and outside the jet pumps contains pressure fluctuations from various sources in the reactor system. The pressure fluctuations can have frequencies close to one or more natural vibration modes of the jet pump piping, which depend on the tight fitup of the restrainer bracket contacts, which support the inlet mixer from the jet pump riser pipe. Operating thermal gradients, component alignment changes, hydraulic loads, and fluctuations in these loads can overcome the lateral support provided by the gravity wedge. These effects and/or loosening of the set screws due to failure of their securing tack welds can cause clearances to develop at the opposing two fixed set screw contacts. This loss of contact can change the jet pump natural frequency to match some excitation frequency in the system, causing vibration of the piping and exerting increased loads which have caused cyclic fatigue cracking and wear of the supports and their welded attachments. This can result in degradation from wear and fatigue at additional jet pump structural supports, to a degree which may require plant shutdown. The apparatus described herein is intended for BWR/6 reactor designs, where the available installation clearance access can be as small as 0.25 inches in width, and where disassembly of the inlet mixer to allow wedge installation is to be avoided. Over the last 19 years, General Electric has designed and installed both gravity and spring actuated wedge supports at locations where clearances have developed in restrainer bracket contacts. The gravity wedges (see, e.g., U.S. Pat. No. 6,052,425) employed a tapered sliding wedge and a fixed bracket mount which engaged the jet pump restrainer bracket. The earlier types of these designs required disassembly of the jet pumps to allow access for their installation, which was an undesirable expense and extension of the reactor outage time. The gravity wedges were applicable to restrainer bracket/inlet mixer gap widths from about 1.0 to 2.0 inches, as space was required for a wedge with sufficient weight to give the required support load. General Electric also implemented spiral spring actuated wedge repairs (see, e.g., U.S. Pat. No. 6,490,331) for BWR/4 reactor designs, where the available installation clearance access can be as small as 0.60 inches in width, and where disassembly of the inlet mixer to allow wedge installation was avoided. While it was initially intended that this prior design would also be installable in the smaller access space for BWR/6 reactors, without disassembly of the inlet mixers, this proved too difficult. Another solution which had limited application was to reinforce the welded attachment of the two fixed contacts to the restrainer bracket, then reseat the inlet mixer against the fixed contacts when the jet pump was reassembled. In an exemplary embodiment of the invention, a vertical spring wedge restores a tight fitup against an adjacent structure, such as between an inlet mixer and an adjacent restrainer bracket in a boiling water nuclear reactor jet pump. The vertical spring wedge includes a U-shaped bracket including a pair of guiding portions and a pair of bracket holes. A pair of wedge assemblies are coupled with the bracket, each of the wedge assemblies including a wedge segment attached to a spring-loaded guide rod. The guide rods are displaceable in the bracket holes between a retracted position and an extended position. The wedge segments engage the guiding portions, and a combination of the bracket and wedge assemblies have a first width when the guide rods are in the retracted position and have a second width wider than the first width when the guide rods are in the extended position. In another exemplary embodiment of the invention, a method of restoring a tight fitup between an inlet mixer and an adjacent restrainer bracket in a boiling water nuclear reactor jet pump includes the steps of pulling the guide rods against the spring-load to the retracted position; inserting the vertical spring wedge into a gap between the inlet mixer and the restrainer bracket; and releasing the guide rods, wherein the spring-load urges the guide rods toward the extended position. The vertical spring wedge 10 described herein generally includes a pair of tapered wedge segments 12 attached to respective guide rods 14 with pre-load springs 16, all of which are mounted within a U-shaped bracket 18. The assembly 10 has a compact configuration to fit within the limited radial space between an inlet mixer IM and a restrainer bracket RB in a boiling water nuclear reactor jet pump (see FIG. 7). As shown, the springs 16 are mounted on the guide rods 14 between the bracket 18 and the wedge segment 12. With the guide rods 14 in a retracted position (FIGS. 1 and 2), a pre-load force of the springs acts to drive the guide rods 14 toward an extended position (FIGS. 3 and 4). The springs 16 are preferably helical coil springs. The spring pre-load provides wedge segment seating force, as was previously provided by the weight of the larger wedge in previous gravity wedge designs. As a result, when the wedge assembly is installed in the nominal aligned position, each spring 16 is compressed to provide about six pounds pre-load to force the mating wedge segments 12 into engagement. The spring pre-load of the wedge acting across the shallow angled wedge surfaces maintains rigid contact between the inlet mixer and the restrainer bracket. The wedge also takes up the clearance from wear during operation. The vertical legs of the bracket 18 include tapered guiding portions 20 as shown in FIG. 2. The guiding portions 20 guide and react against the wedge segments 12, wherein the wedge segments 12 and the guiding portions 20 are tangentially offset to minimize a tool radial thickness of the assembly. With reference to FIGS. 7 and 8, the bracket 18 is open in its center to fit around the existing restrainer bracket set screw and guide ear features, which also maintain the vertical orientation of the wedge 10. Additionally, the bracket 18 has a relief slot 24 at the top that straddles the restrainer bracket guide ear, and projecting lips 28 (FIG. 1) that engage the bottom of the restrainer bracket to further assure that the vertical orientation of the assembly is maintained. The wedge segments 12 are machined with a 10° slope angle between their sliding surfaces, which is consistent with the previous gravity wedges described above. This angle has been found by testing and operating experience to provide a tightly sealed fitup that gives a rigid load path between the parts, without being so shallow that friction results in self-locking of the wedge adjusted motion. The guiding portions 20 of the bracket 18 preferably include 10° sloped guide slots to which the wedge segments 12 seat against. The guide rods 14 are preferably attached to the wedge segments 12 by a threaded engagement, oriented parallel to the 10° wedge surfaces. A portion of the upper length of each guide rod 14 has a square cross section and fits within a mating square hole 22 in the top or cross member of the bracket 18. The guide rod 14 and wedge segments 12 are locked against rotation at assembly by inserting a pin into a hole drilled in both parts to assure that no parts can become loose. The sliding fit between the guide rods 14 and the bracket holes 22 and between the wedge segments 12 and the mating bracket surfaces or guiding portions 20 guide the wedges within the bracket along the 10° sloped axis. The sliding fitup also maintains relative alignment of the parts during handling, until the wedge is installed. From the retracted position as shown in FIGS. 1 and 2, as the wedges are displaced downward by action of the springs 16, the combined width of the wedge segments and bracket 18 increases to thereby tighten within the space between the inlet mixer and the restrainer bracket. The initial wedge thickness is machined before assembly, based on inspection measurements of the existing set screw protrusion, to assure that the wedge is installed with a useful operating pre-load range. The gravity wedges typically weighed 5-10 pounds, so an initial twelve pound total spring force on a 10° slope reacts against the projecting lips to allow the wedges to compensate for an increase in the gap of about 0.12 inches while maintaining the minimum pre-load previously used. Preferably, the wedge assembly 10 is installed using a collet tool, which grips the tops of the wedge guide rods 14. The tool pulls the guide rods 14 upward against the bracket 18, compressing the springs 16. As the wedge is displaced upward, the combined width of the wedge segment 12 and bracket 18 decreases, such as to allow installation clearance in the space between the inlet mixer and the restrainer bracket. The assembly is lowered into the restrainer bracket/inlet mixer gap, and the collet tool is released. The wedge segments 12 locate against either side of the set screw at installation, keeping the wedge assembly in position. The vertical spring wedge described herein restores the tight and rigid fitup originally provided between the inlet mixer and the adjacent restrainer bracket in a boiling water nuclear reactor jet pump, replacing the support function of an existing screw type contact. It provides continuous adjustment for possible alignment variation of the mixer, and compensates for possible wear after installation. The device is remotely installable in a clearance width as small as 0.25 inches and requires minimum installation time, without disassembly of the jet pump. It is also configured with a minimum of weight and height to be supported above the engagement between the inlet mixer and the restrainer bracket, which assures that the vibration frequencies of the assembly are enough higher than the jet pump excitation frequencies that resonance and fatigue failure are avoided. Provision of two independently pre-loaded wedges provides tight fitup on both sides of the set screw to compensate for the positioning of the inlet mixer within the restrainer bracket, which is generally not symmetrical. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
	abstract	According to an aspect of the invention, there is provided an electron beam lithography apparatus including a first setting unit configured to set a drawing position on a semiconductor substrate based on layout information of the semiconductor substrate, a second setting unit configured to set a valid range on the semiconductor substrate based on shape information of the semiconductor substrate, a determination unit configured to determine whether or not the drawing position falls within the valid range, and an irradiation unit configured to irradiate the semiconductor substrate with an electron beam when the determination unit determines that the drawing position falls within the valid range.
	description	This application claims the benefit of U.S. provisional patent application No. 60/873,726 filed on Dec. 7, 2006 and U.S. provisional patent application No. 60/860,538 filed on Nov. 21, 2006, each of which is incorporated herein by reference in their entirety and for all purposes. The present invention relates generally to the field of steam generators used in nuclear power plants. More specifically, the present invention relates to improved nozzle dams for hot and cold legs of a steam generator, as well as methods for installing and removing such improved nozzle dams. The present invention also includes methods and apparatus for the pressurization and control of steam generator nozzle dam seals. Nuclear power plants are routinely shut down for refueling, maintenance, inspection, and testing. FIG. 1 shows a simplified diagram of a typical nuclear power plant 10 which includes a steam generator 12, a reactor pressure vessel 14 holding a reactor core 16 in a core support barrel 18, and a refueling pool 20. When refueling a nuclear power plant or servicing the reactor core 16, the reactor pressure vessel 14 and refueling pool 20 are flooded with water. However, when the reactor pressure vessel 14 and refueling pool 20 are flooded, water will typically enter the steam generator 12 preventing maintenance, inspection and testing of the steam generator 12 during refueling or servicing of the reactor core 16. In order to simultaneously service both the reactor core 16 and the steam generator 12, some form of temporary seal must be installed in the piping 22 connecting the reactor pressure vessel 14 with the generator 12 in order to isolate the reactor core 16 and refueling pool 20 from the steam generator 12, thus permitting simultaneous testing and inspection of the generator components. This seal is achieved by installing what is known in the industry as a “nozzle dam” in the nozzles of the steam generator primary head. A cutaway view of the nozzle 24 of the steam generator 12 is shown in FIG. 1A. The nozzle dam 26 is designed to be carried through a small manway 28 in the generator head and assembled by hand. As the nozzle dam installer is subject to radiation exposure inside the steam generator 12, the nozzle dam 26 must be installed as quickly as possible in order to minimize the radiation exposure. The nozzle dam 26 also must effect a reliable water-tight seal able to withstand high water pressures without compromising the structural integrity of the nozzle wall or steam generator wall. FIG. 2 shows a cutaway view of a typical prior art nozzle dam 26. Such nozzle dams 26 used to seal the nozzles 24 of nuclear power plant steam generators typically use aluminum structures supporting a rubber diaphragm 30 with pneumatic seals (e.g., a dry seal 32, a wet seal 36, and an annulus 34 between the wet seal 36 and dry seal 32), as shown in FIG. 2. Two variations of nozzle dam attachment are currently in use. FIGS. 3 and 3A show cutaway views which depict the nozzle dam 26 attached to the nozzle 24 utilizing radial pins 38 interfacing with holes 40 on the interior of the steam generator nozzle 24 or interfacing with welded hold-down rings. As shown in FIG. 4, another common attachment method uses a flange 42 at the top of the nozzle dam 26 bolted to a ring 44 that has been welded to the steam generator bowl at the junction of the nozzle 24 and the body of the steam generator 12. The inside diameter of the welded ring 44 may also serve as a sealing surface for the pneumatic seals. Other examples of prior art nozzle dams are described in U.S. Pat. No. 4,667,701 and U.S. Pat. No. 4,957,215. Such prior art nozzle dam designs were designed as retrofits for pre-existing steam generators and were thus constrained by the pre-existing design of the steam generator nozzles. Accordingly, these prior art nozzle dams were limited in terms of placement position in the nozzle, attachment points and supports, unknown sealing surfaces of the nozzles, and limited manway openings. Further, such prior art nozzle dam installation technicians are subject to radiation exposure level limitations. These constraints resulted in nozzle dams that were large in size, heavy in weight, difficult and time consuming to install and remove, had unknown sealing surfaces, expensive to manufacture, comprised of multiple moving components such as structural bolts, pins or other locking mechanisms each of which had the potential for failure, and not readily adapted for remote installation or removal. With the advent of new nuclear power plant designs, such as Westinghouse's new AP1000 nuclear power plant design and the supply of new replacement stream generators, an opportunity exists for overcoming most, if not all, the limitations of prior art nozzle dam designs by working with the steam generator manufacturer to ensure standardized steam generator nozzles with uniform sealing surfaces. It would therefore be advantageous to provide a nozzle dam design for steam generators of newly designed nuclear power plants and for replacement steam generators, which when compared to the prior art nozzle dams are lighter in weight, smaller in size, simpler and quicker to install, have a known sealing surface, are economical to manufacture, are designed without multiple moving components such as bolts, pins, or other locking mechanisms having the potential for failure, minimize radiation exposure, and are adaptive to remote installation and removal. The methods and apparatus of the present invention provide the foregoing and other advantages. The present invention relates to nozzle dams for nuclear power plant steam generators, and methods for installing and removing nozzle dams. The present invention includes an apparatus for watertight sealing of a steam generator nozzle. In one example embodiment, the apparatus comprises a nozzle dam, a nozzle dam attachment ring designed to accept the nozzle dam, and a seal. The attachment ring is provided in an interior of the nozzle and has a plurality of retaining tabs and a nozzle dam landing. The nozzle dam is adapted for insertion into the attachment ring and abutment against the nozzle dam landing. The nozzle dam has a plurality of radial protrusions adapted to interlock with the retaining tabs for fixing the nozzle dam in the attachment ring upon rotation of the nozzle dam in the attachment ring. The seal covers at least one side of the nozzle dam for effecting a watertight seal between the nozzle dam and the attachment ring. In a further example embodiment, the nozzle dam and seal form a nozzle dam assembly. The nozzle dam may be disc-shaped and divided into two disc segments. The seal may form a hinge connecting the two disc segments, enabling the nozzle dam assembly to be folded in half. A center locking mechanism may be provided for locking the two disc segments together in an unfolded state of the nozzle dam. Further, a rotation limiting mechanism may be provided on the nozzle dam to prevent over-rotation of the nozzle dam assembly in the attachment ring. In addition, a locking mechanism may be provided for locking the nozzle dam into the attachment ring. The locking mechanism may comprise a locking pin, a locking tab, or the like. In another example embodiment, cladding may be fitted into the interior of the nozzle and the attachment ring may be fixed in the cladding (e.g., by welding). Alternatively, the attachment ring may be machined from cladding provided in the interior of the nozzle. The seal may extend over one side of the nozzle dam at over at least a portion of the nozzle dam edge. Alternatively, the seal may extend over one side of the nozzle dam and beyond the edges of the nozzle dam. In one example embodiment, the seal may comprise an inflatable seal. The seal may be pressurized remotely after interlocking of the nozzle dam in the attachment ring. A computerized pressurization control and monitoring station may be provided for controlling and monitoring the remote pressurization of the seal. The seal may comprise a segmented seal having a diaphragm extending over one side of the nozzle dam and at least one pneumatic seal extending around a circumference of the nozzle dam. For example, two pneumatic seals may be provided with an annulus arranged therebetween. The segments of the seal may be adapted to be pressurized and monitored independently by the pressurization control and monitoring station. The diaphragm may comprise a mechanical seal which is activated by the flow of water. The present invention is also directed towards a nozzle dam assembly for a nozzle of a steam generator. In one example embodiment, the nozzle dam assembly may comprise a disc-shaped nozzle dam which is divided into two segments and a seal covering at least one side of the nozzle dam. The seal may form a hinge connecting the two disc segments and enabling the nozzle dam assembly to be folded in half. A plurality of radial protrusions may extend from the nozzle dam which are adapted to interlock with corresponding retaining tabs on an attachment ring in an interior of the nozzle upon rotation of the nozzle dam assembly in the attachment ring. The nozzle dam assembly of the present invention may also include additional features of the nozzle dam and seal mentioned above. The present invention is also directed towards an attachment ring for accepting a nozzle dam assembly for a nozzle of a steam generator. In one example embodiment, the attachment ring comprises a plurality of retaining tabs and a plurality of receiving slots positioned between the retaining tabs for accepting radial protrusions of a nozzle dam of the nozzle dam assembly. A nozzle dam landing is provided for supporting the nozzle dam assembly. The retaining tabs interlock with the radial protrusions of the nozzle dam upon rotation of the nozzle dam assembly once the nozzle dam assembly is positioned in the attachment ring abutting the nozzle dam landing. The present invention also includes methods for installing a nozzle dam assembly into an interior of a steam generator nozzle. In order to install the nozzle dam prior to maintenance of the steam generator, the nozzle dam assembly is folded in half and passed through the manway to an installer who has climbed into the steam generator through the manway after removal of a manway cover. The nozzle dam assembly comprises a disc-shaped nozzle dam and a seal, the nozzle dam being divided into two disc segments with the seal forming a hinge connecting the two disc segments. The nozzle dam assembly can then be unfolded into an open position. The nozzle dam assembly can be locked in the open position with a center locking mechanism locking the two disc segments together. The nozzle dam assembly can then be inserted into an attachment ring in the nozzle interior. The nozzle dam assembly can then be rotated so that radial protrusions extending from the nozzle dam interlock with corresponding retaining tabs on the attachment ring. The nozzle dam assembly can then be secured to the attachment ring in an interlocked position using a locking mechanism, which is adapted to prevent the nozzle dam assembly from rotating in either direction. Once the locking mechanism is set, the installer exits the manway. The inflatable seal can then be pressurized to effect a watertight seal between the attachment ring and the nozzle dam. Removal of the nozzle dam is simply the reverse of the installation procedure. The time required for installation or removal of the nozzle dam assembly is estimated at approximately 30 seconds, which is considerably faster than prior art nozzle dams that require the manipulation of multiple bolts or pins during installation and removal. The present invention also provides methods and apparatus for the pressurization and control of steam generator nozzle dam seals. The ensuing detailed description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing detailed description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an embodiment of the invention. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims. The present invention relates to improved nozzle dams for hot and cold legs of a steam generator, as well as methods for installing and removing such an improved nozzle dams. As shown in FIGS. 5-19B, the present invention includes various example aspects and embodiments of a nozzle dam system that includes a nozzle dam assembly and a nozzle dam attachment ring designed to accept the nozzle dam assembly. In the example embodiment shown in FIGS. 6A-6C, the nozzle dam assembly 60 comprises a nozzle dam 62 and an inflatable seal 64. The nozzle dam 62 is disk shaped and consists of two segments 62a and 62b joined by the seal 64. The seal 64 may extend over one side of the nozzle dam 60 and at least a portion of the nozzle dam edge. Optionally the inflatable seal 64 may extend over one side of the nozzle dam 62 beyond the edges of the nozzle dam 62. The nozzle dam assembly 60 may be folded in half (i.e., along joint line 63), with the inflatable seal 64 acting as a hinge connecting the two segments 62a and 62b. As shown in FIGS. 6A and 14C, the nozzle dam 62 may include a plurality of equally spaced-apart radial protrusions 66 extending from the disk segments 62a and 62b. These radial protrusions 66 may be used to secure the nozzle dam 62 to the nozzle dam attachment ring 50 (FIG. 5). A center locking unit 68 may be provided for locking the two segments 62a and 62b of the nozzle dam together, as shown in FIGS. 14A-14E. FIG. 14D shows a cross-section of the center locking unit 68 in a locked in position (e.g., with a locking disc 69 rotated to extend across the joint line 63) preventing folding of the two segments 62a and 62b. FIG. 14E shows a cutaway view of the center locking mechanism 68. In a further example embodiment, a locking mechanism may be provided for locking the nozzle dam 62 in position in the attachment ring 50. For example, as shown in FIGS. 6A-6C, a flip-type locking tab 70 may also be provided for locking the nozzle dam 62 into the attachment ring 50 and preventing rotation in either direction. Alternatively, as shown in FIGS. 14B-16, a locking pin 72 may be used to secure the nozzle dam 62 to the attachment ring 50 and prevent rotation. Other types of locking mechanism which can be adapted for use with the present invention will be apparent to those skilled in the art. In addition, a rotation limiting mechanism may be provided on the nozzle dam 62. For example, as shown in FIGS. 6A-6C, rotation limiting mechanism may comprise a rotation limiting protrusion or tab 74 provided on a side of one or more radial protrusions 66 that prevents over-rotation of the nozzle dam assembly 60 in the attachment ring 50 during installation. The rotation limiting tab 74 also ensures proper alignment of the retaining tabs 52 of the attachment ring 50 and the radial protrusions 66. In a further example embodiment, a spring-loaded pin may be provided on the nozzle dam 62 which automatically interlocks with a corresponding slot or opening in the attachment ring 50. Such a spring-loaded pin may serve to prevent over-rotation of the nozzle dam 62 in the attachment ring 50 and to lock the nozzle dam 62 in position on the attachment ring preventing rotation in either direction (thus providing the function of the rotation limiting mechanism and the locking mechanism). The spring-loaded pin may be provided on an edge of the nozzle dam 62 between the radial protrusions 66. A release mechanism may be provided for retracting the spring-loaded pin from the attachment ring to enable removal of the nozzle dam 62 from the attachment ring 50. As shown in FIG. 5, the nozzle dam attachment ring 50 is adapted to be fitted inside a nozzle 24 of a steam generator 12 (FIG. 1). FIG. 7 shows an example of a prior art cold leg nozzle 24. With the present invention, as shown in the example embodiment of FIG. 8A, the inside 81 of the nozzle 80 may be machined to close tolerances to accept cladding sized to accept the attachment ring. FIG. 8B shows the machined cold leg nozzle 80 with cladding 82 installed in accordance with an example embodiment of the present invention. The hot leg nozzle of a steam generator 12 is of a slightly different shape. An example of a prior art hot leg nozzle 84 is shown in FIG. 17. A machined hot leg nozzle 86 in accordance with an example embodiment of the present invention is shown in FIG. 18A. Although the hot and cold leg nozzles are of slightly different shape, the example embodiments of the present invention described below in connection with a cold leg nozzle are equally applicable to a hot leg nozzle, with minor modifications to the dimensions of the nozzle dam, attachment ring, and cladding that would be apparent to one skilled in the art. The cladding 82 may be welded into the machined interior 81 of the nozzle 80 and machined in place. The attachment ring 50 may then be inserted into the cladding 82 and welded in place (see welds 88), as shown in FIGS. 9, 9A, and 10A (cold leg) and FIG. 18B (hot leg). The cladding 82 may extend above and below the attachment ring 50, as shown for example in FIG. 10A. The cladding 82 and the attachment ring 50 may be made of the same material, such as Inconel 690 or similar material, to preclude weld damage from differing thermal expansion characteristics of dissimilar material. Alternatively, the attachment ring 50 may be welded directly to the machined base metal of the nozzle 80 and the cladding 82 may be applied after the attachment ring 50 is installed, as shown in FIG. 12. Alternatively, as shown in FIG. 10B, cladding 82 may be applied to the machined interior of the nozzle 80 and the attachment ring 50 may be machined directly from the cladding 82 once the cladding 82 is secured in place. The attachment ring 50 may be provided with a temporary protective shield (not shown) to preclude weld splatter and/or other damage to the attachment ring 50 during installation in the nozzle 80. As can be seen in FIGS. 5 and 15, a top portion of the ring 50 includes a plurality of equally spaced apart nozzle dam retaining tabs 52 extending towards the center of the ring 50 that serve to retain the radial protrusions 66 on the nozzle dam 62. The number of retaining tabs 52 on the attachment ring 50 corresponds to the number of radial protrusions 66 on the nozzle dam 62. Receiving slots 54 are formed between the retaining tabs 52. As shown in FIG. 5, a lower portion of the inner surface of the ring comprises a machined sealing surface 56 for forming a seal with the inflatable seal 64 of the nozzle dam assembly 60. A nozzle dam landing 58 is provided in the inner surface of the ring 50 above the machined sealing surface 56 for accepting the nozzle dam assembly 60. FIGS. 11 and 19 show the basic geometry of a cold and hot leg of an attachment ring 50, respectively, in accordance with example embodiments of the present invention. FIGS. 11A and 19A show a section through a portion of the attachment ring 50 in the area of the receiving slots 54, and FIGS. 11B and 19B show a section through a portion of the attachment ring 50 in the area of the retaining tabs 52. As can be seen in FIG. 1B, a slot 59 is formed between the bottom portion of retaining tab 52 and the nozzle dam landing 58 which is adapted to accept the radial protrusions 66 of the nozzle dam 62. FIG. 13 shows a top view of the attachment ring 50. FIG. 13A shows a side view of the attachment ring 50 and FIG. 13B shows a cross section of the attachment ring 50. In one example embodiment, the seal 64 may comprise an inflatable seal. The seal 64 may be pressurized remotely after interlocking of the nozzle dam 62 in the attachment ring 50. A computerized pressurization control and monitoring station may be provided for controlling and monitoring the remote pressurization of the seal. Methods and apparatus for pressurizing the seal and controlling and monitoring the seal pressure are discussed below in connection with FIGS. 21-24. In one example embodiment, the seal 64 may comprise a segmented seal having a diaphragm 30 extending over one side of the nozzle dam 62 and at least one pneumatic seal 32, 36 extending around a circumference of the nozzle dam 62. For example, two pneumatic seals 32, 36 may be provided with an annulus 34 arranged therebetween, as shown in FIG. 2. The seal 64 may surround the edge of the nozzle dam 62 and provide sealing between the side of the nozzle dam 62 and the attachment ring 50 fixed to the steam generator nozzle wall, which is typically cylindrical in shape. The segments of the seal 64 may be adapted to be pressurized and monitored independently by a pressurization control and monitoring station 100, as discussed in detail in connection with FIG. 21 below. Each of these seal regions 32, 34, 36 may be independently energized with compressed air from a main supply. An emergency back-up supply of bottled gas is typically provided in case of failure of the main supply. Flexible air lines connect the nozzle dam assembly 62, air supplies and the pressurization control and monitoring station 100. The wet seal 36 and dry seal 32 effect a seal between the nozzle dam 62 and the attachment ring 50 fixed to the steam generator nozzle wall, while the annulus 34 is pressurized to monitor the integrity of the seals 32, 36 while in operation. The diaphragm 30 may comprise a mechanical seal in the area of either the wet seal 36 or the dry seal 32 which is activated by the flow of water being retained by the nozzle dam 62 in the unlikely event that the inflatable seals 32, 34, 26 are compromised. In order to install the nozzle dam assembly 60 prior to maintenance of the steam generator 12, the nozzle dam assembly 60 is folded in half and passed through the manway 28 (FIG. 1A) to an installer who has climbed into the steam generator 12 through the manway 28. The nozzle dam assembly 60 can then be opened from the folding position. The two segments 62a and 62b can optionally be locked together using the center locking unit 68. The nozzle dam assembly 60 may then be set into the attachment ring 50. The radial protrusions 66 of the nozzle dam 62 can then be aligned with the receiving slots 54 in the attachment ring 50 and the nozzle dam assembly 60 can then be lowered (e.g., via handles 67) until the nozzle dam 62 rests against the nozzle dam landing 58, as shown in FIGS. 6A-6B and FIGS. 15A-15B. The nozzle dam assembly 60 can then be rotated so that the radial protrusions 66 slide into the slot 59 formed between the corresponding retaining tabs 66 and the nozzle dam landing 58, interlocking the nozzle dam 62 with the attachment ring 50, as shown in FIGS. 6C and 16. In an example embodiment shown in FIGS. 5-6C where a rotation limiting tab 74 is provided on a radial protrusion 66, the nozzle dam assembly 60 is rotated until the rotation limiting tab 74 abuts against a corresponding retaining tab 52, as shown in FIG. 6C. The nozzle dam assembly 60 may thereafter optionally be secured in this interlocked position using a locking tab 70 (FIG. 6C) or locking pin 72 (FIG. 16), which is adapted to prevent the nozzle dam assembly 60 from rotating in either direction. Once the locking tab 70 or locking pin 72 is set, the installer exits the manway 28. The inflatable seal 64 can then be pressurized to effect a watertight seal between the attachment ring 50 and the nozzle dam 62. Inflation of the seal 64 is controlled remotely. Therefore, the seal 64 can be pressurized as soon as the nozzle dam 62 is secured in the attachment ring 50 or anytime after the installer exits the manway 28. Removal of the nozzle dam assembly 60 is simply the reverse of the installation procedure. The time required for installation or removal of the nozzle dam assembly 60 is estimated at approximately 30 seconds, which is considerably faster than prior art nozzle dams (FIGS. 3 and 4) that require the manipulation of multiple bolts or pins during installation and removal. In a typical steam generator 12, the nozzle 24, 84 widens at the junction of the nozzle and the body of the steam generator 12. For example, this junction may be funnel shaped, as shown in FIG. 17. By machining the interior surface of the nozzle and providing cladding 82 for accepting the attachment ring 50 in accordance with the present invention, the attachment ring 50 can be placed at a point in the nozzle 86 having a smaller diameter than could be achieved with prior art nozzle dam retrofit designs. Thus, the nozzle dam assembly 60 in accordance with the various embodiments of the present invention has a smaller diameter than prior art nozzle dam designs. It should be appreciated that the water pressure forces increase substantially as the radius of the nozzle increases (i.e., by the square of the diameter). By placing the nozzle dam assembly 60 in the nozzle 86 at a location having a smaller diameter than prior art designs, the forces which the nozzle dam 62 of the present invention will be subjected to will be much less than compared to prior art designs. Therefore, due to the smaller size of the nozzle dam assembly 60 and the lower forces, the nozzle dam assembly 60 of the present invention is smaller, lighter, and easier to handle as compared to prior art designs, and can thus be installed quicker and with less effort. Further, since the nozzle dam assembly 60 is secured against linear movement in the nozzle due to the interlocking of the radial protrusions 66 and retaining tabs 52, multiple screws or pins are not required to secure the nozzle dam in place. A simple rotation of the nozzle dam assembly 60 in the attachment ring 50 secures the nozzle dam assembly 60 against linear movement. Only a simple locking mechanism 70, 72 is required to secure the nozzle dam assembly 60 against rotational movement, as the installed nozzle dam assembly 60 is not subject to any significant rotational forces. Further, the nozzle dam assembly 60 of the present invention is less prone to failure than prior art designs due to the reduced number of movable parts. In particular, multiple bolts and pins are not required to secure the nozzle dam assembly 60 in place. The drawings show example embodiments of the present invention in which the nozzle dam 62 has eight radial protrusions 66 and the attachment ring 50 has eight corresponding retaining tabs 52. However, one skilled in the art should appreciate that the present invention may be implemented with a varying number of radial protrusions 66 and corresponding retaining tabs 52. It should be appreciated that the present invention can be used in a nozzle of both a hot or cold leg of a steam generator, or in any other nozzle where sealing against water pressure is required, such as in the petrochemical industry or the like. The present invention also provides methods and apparatus for the pressurization and control of steam generator nozzle dam seals. An example of a prior art nozzle dam support console 90 is shown in FIG. 20. This support console 90 is connected to the seal regions 32, 34, 36 via air lines (connected via air line connectors 93) and serves as the pneumatic distribution center to each of the seal regions 32, 34, 36, and also monitors the air flow in each region. Such prior art consoles 90 are typically constructed with analog pneumatic devices, (i.e. valves 92, regulators 94, pressure gauges 96, and flow indicators 98), which make the unit cumbersome, requires extensive maintenance, and requires a highly trained operator for its operation. Monitoring air flow in the seal regions, as well as providing regulated air pressure, is a major function of the nozzle dam console 90. If an air flow condition exists during operation, an alarm will sound to alert the operator, and other personnel in the immediate area, of a potential reactor water leak or air pressure loss at the nozzle dam. The operator must then determine the source of the problem. With prior art systems, the operator must typically refer to an extensive manual to determine an appropriate corrective response, which is time consuming and may lead to errors. As shown in FIGS. 21-23B, the present invention provides a computerized nozzle dam support console 100 (also referred to herein as a pressurization control and monitoring station) for pressurization and control of a nozzle dam seal 64 that is simple to use, small in size, automatically identifies corrective actions to be taken, and can be remotely monitored and controlled. In one example embodiment of the present invention, as shown in FIG. 21, the nozzle dam support console 100 utilizes a computer 102 to digitally interface with an analog pneumatic distribution system, which includes air supplies and flexible air lines connecting the seal regions to the air supplies and the console. FIG. 22 shows an example embodiment of a distribution system 120 in accordance with the present invention. The distribution system 120 may include, for each seal region 32, 34, and 36, a flow switch 122, valve 124, digital pressure transducer 126, and regulator 128 connected to flexible air lines for delivering and controlling the air supply and pressure to each seal region (dry seal 32, wet seal 36, and annulus 34). The distribution system 120 may be included within the console 100, which is provided with air-line connections 105 to the distribution system 120 for accepting air lines from the seal regions 32, 34, 36. A data acquisition module 130 receives information from the digital pressure transducers 126 and flow switches 122, and communicates this information to the nozzle dam support console computer 102. The information received from the data acquisition module 130 may be displayed on a console display 104 and monitored by a processor of the computer 102. The system may also be monitored remotely. It should be appreciated that the example embodiment shown in FIG. 21 is an air distribution system 120 for use with two nozzle dam assemblies (e.g., one for the hot leg and one for the cold leg of the steam generator 12). The console 100 and distribution system 120 may be adapted to support three nozzle dam assemblies for steam generators having one hot leg nozzle and two cold leg nozzles with respective nozzle dam assemblies. Those skilled in the art will appreciate that several nozzle dam air distribution systems 120 may be ganged together so that the seals of multiple nozzle dams can be monitored and controlled by a single support console. FIG. 23A shows a detailed view of a display 104 for the nozzle dam support console 100 shown in the FIG. 21 example embodiment, while FIG. 23B shows a detailed view of a control panel 106 of the console 100 shown in the FIG. 21 example embodiment. As shown in FIG. 23A, the display 104 may be configured to monitor and control the seal regions of two nozzle dams, one section 104a of the display 104 for the hot leg of a steam generator and another section 104b of the display 104 for the cold leg of a steam generator. As discussed above in connection with FIG. 22, in such an example embodiment there will be separate air distribution systems 120 for each nozzle dam seal (e.g., hot leg seal and cold leg seal), which may be ganged together and connected to a single data acquisition module. Alternatively, the air distribution system 120 for each nozzle dam seal may be connected to a separate data acquisition module 130, and each such data acquisition module 130 may communicate data from each distribution system 120 to the console 100 separately. As shown in FIG. 23A, the display 104 may include separate pressure gauges 108 and flow indicator lights 110 for the wet seal 36, dry seal 32, and annulus 34 for each nozzle dam seal 64. The display may also include an inlet pressure gauge 112 and inlet flow indicator light 114. The display 104 also includes an area 116 for displaying instructions or corrective actions. During installation of the nozzle dam assembly 60, a seal activation sequence may be displayed on the console display 104 indicating the sequence in which the seal regions 32, 34, 36 should be pressurized and the final pressure of each such region. As shown in FIG. 23B, the console control panel 106 may include, for each seal region, a valve switch 130 for remotely opening and closing the respective valve 124 and a pressure regulator control 132 for remotely controlling the respective regulator 128. The console control panel 106 may also include a valve switch 134 for opening or closing a valve of the inlet air supply and a pressure regulator control 136 for remotely controlling a pressure regulator for the inlet air supply and/or a backup air supply. While the prior art seals typically utilize three seal segments as shown in the FIG. 2, those skilled in the art will readily appreciate that the present invention can be used to pressurize and control a nozzle dam seal 64 having more or less than three seals. FIG. 24 shows a block diagram of an example embodiment of a system 140 for pressurizing and controlling the nozzle dam seals in accordance with the present invention. In addition to the elements shown in FIG. 22, the distribution system as shown in FIG. 22 may also include a flow indicator 142, regulator 144, valve 146, and pressure transducer 148 positioned between the inlet air supply 150 (or backup air supply 153) and the data acquisition module 130. The data acquisition module 130 may continually provide updated pressure and flow readings for the various seal regions 32, 34, 36, as well as for the inlet air supply 150. Once the nozzle dam seal regions 32, 34, 36 are initially pressurized, software running on a processor (CPU) 152 in the computer 102 will monitor the data obtained from the pressure transducers 126, 148 and flow switches 122, 142 by the data acquisition module 130. The software running on the processor may comprise a program 154 written using Lab View or other appropriate software. The pressure and flow information for each seal region 32, 34, 36 and for the inlet air supply 150 is communicated to the display 104 and displayed using respective pressure gauges and flow indicators as discussed above in connection with FIG. 23A. The processor 152 may sound an alarm in the event that the pressure falls below a preset minimum pressure or rises above a preset maximum pressure, or if air flow is detected in a seal region. Event alarms may be audible and/or visual. The visual alarm indicators may identify if a particular seal or the inlet air supply is the cause for the alarm, and whether the problem relates to an overpressure, underpressure, or a flow condition for the particular seal or inlet air supply. The visual alarm may comprise an intermittent flashing of a pressure gauge bezel 108, 112 for the corresponding seal region at issue or the inlet air supply in the event of a high or low pressure condition. The visual alarm may also comprise intermittent flashing of a flow monitor 110, 114 for the corresponding seal region or the inlet air supply at issue in the event of a flow condition. Multiple audible and/or visual alarms may sound simultaneously or sequentially in the event of multiple events relating to pressure and flow conditions for one or more of the seal regions 32, 34, 36 or the inlet air supply 150. The present pressures for the seal regions and the inlet air supply may be stored in a database 158 of the control console 100. In addition to sounding an audible and/or visual alarm in the event the processor 152 determines that the pressure exceeds the maximum or minimum limit for a particular region or for the inlet air supply 150, or detects a flow condition, the processor 152 will determine appropriate corrective action instructions. The corrective action instructions can then be displayed on the console display screen 104 should an event occur that requires the attention of the operator (e.g., in screen section 116 shown in FIG. 23A). The corrective action instructions may be stored on the database 158. The processor 152 may select the appropriate corrective action from the database 158 based on a pre-stored set of logic rules which depend on the pressure reading, flow condition, and/or whether one or more particular seal regions or the inlet air supply is at issue. The corrective action instructions may include detailed information to enable the operator to resolve the event at issue. As an example, in the event air flow is detected in the cold leg dry seal, the dry seal flow indicator light for the cold leg may flash and/or an audible alarm may sound. In addition, the following corrective action may be displayed on section 116 of the console display screen 104: AIR FLOW IN COLD LEG DRY SEAL HAS BEEN DETECTED 1. Ensure that the hose connections at the back of the Monitor Case and Nozzle Dam are properly connected 2. If properly connected, then the dry seal is leaking air. Notify the control room immediately. 3. If the operating pressure in the seal cannot be maintained, turn the Dry Seal and Annulus valves to the OFF position. 4. It is recommended that the cavity be drained down and this seal be replaced Notify the control room. As shown in the example embodiment of FIG. 24, the air distribution system 120, including the pressure transducers 126, 148, regulators 128,144, valves 124, 146, flow indicators 122, 142 and data acquisition module 130 may be included as a part of the nozzle dam support console 100. Alternatively, the air distribution system 120 may be remote from the computer 102 and display 104 and connected thereto via a wired or wireless data connection. The system may also be monitored and/or controlled remotely using, for example, a laptop or second support console via a connection 160, such as a wired or wireless direct connection or a wired or wireless network connection to either the data acquisition module 130 or the on-site nozzle dam support console 100. The nozzle dam support console 100 may also be adapted to automatically carry out corrective actions in certain circumstances (within appropriate limits), such as emergency shutdown of one or more seal region valves in the event of an air leak at a particular valve, automatic adjustment of the inlet air pressure, automatic adjustment of air pressure to a particular seal region, activation of a back-up air supply in the event of failure of the main air supply, or the like. In addition, the nozzle dam support console 100 may be adapted to keep a log of any such automatic corrective actions it has carried out, and this log may be displayed on the console display, printed out at an associated printer, or accessed remotely. It should now be appreciated that the present invention provides advantageous embodiments of a nozzle dam assembly and methods for installing and removing such a nozzle dam assembly, as well as advantageous methods and apparatus for pressurizing and controlling nozzle dam seals. Although the invention has been described in connection with various illustrated embodiments, numerous modifications and adaptations may be made thereto without departing from the spirit and scope of the invention as set forth in the claims.
046613064	claims	1. In a spectral shift pressurized water nuclear reactor employing a low neutron moderating fluid for the spectral shift including a reactor pressure vessel, a core comprising a plurality of fuel assemblies, a core support plate, apparatus comprising means for penetrating the reactor vessel for introducing said moderating fluid into said reactor vessel, means associated with the core support plate for directly distributing said moderating fluid to and from said fuel assemblies comprising at least one inlet flow channel in said core plate; a plurality of branch inlet feed lines connected to said inlet flow channel in said core plate; a plurality of vertical inlet flow lines flow connected to said branch inlet feed lines; each vertical flow line communicating with a fuel assembly; said distribution means further comprising a plurality of lines serving as return flow lines, each of which is connected to one of said fuel assemblies; a plurality of branch exit flow lines in said core plate flow connected to said return flow lines of the fuel assembly; and at least one outlet flow channel flow connected to said branch exit flow lines; and a flow port interposed between said penetration means and said distribution means for flow connecting said penetration means with said distribution means. 2. The apparatus of claim 1, including at least two separate flow regions associated with said core support plate with each region including an inlet channel, a branch inlet feed line, a vertical flow line from the core support plate to a fuel assembly, a return flow line from the fuel assembly to the core support plate, a branch exit flow line, and an outlet flow channel in the core support plate. 3. The apparatus of claim 1, wherein said means for penetrating the reactor vessel comprises a pipe passing through the wall of said reactor vessel, said pipe being seal welded to said reactor vessel, the end of said pipe within said reactor vessel having a flange thereon. 4. The apparatus of claim 3, wherein said penetration means includes a venturi orifice within said pipe. 5. The apparatus of claim 1, wherein said flow port comprises an elongated hollow pipe fixedly connected at one end to said pentration means, and fixedly connected at the second end thereof to the core support plate, said flow port having means between said ends for sealingly varying the length of said flow port between said ends. 6. The apparatus of claim 5, wherein said flow port comprises a first member attached to said core support plate, a second member attached to said penetration means and said sealing means comprises a bellows fixedly connected at one end to said first member and fixedly connected at its other end to said second member. 7. The apparatus of claim 6, wherein the unconnected ends of said first and second members are telescopically arranged with a slideable seal therebetween. 8. The apparatus of claim 7, wherein the unconnected ends of said first member comprises an elongated hollow tube portion, a flow channel is formed in the core support plate which communicates with said elongated hollow tube, with said elongated hollow tube partially closed at its end by an elongated solid rod portion connected thereto, at the intersection of the elongated hollow tube and the solid rod portion; a shank at the intersection of said elongated hollow tube and said solid rod portion extending into said flow channel of said core support plates, said shank having at least one hole therethrough which provides flow communication between the elongated hollow tube and the flow channel in said core support plate. 9. In a spectral shift pressurized water nuclear reactor employing a low neutron moderating fluid for the spectral shift including a reactor pressure vessel, a core comprising a plurality of fuel assemblies, a core support plate; at least one means for penetrating the reactor vessel and for introducing said moderating fluid into said reactor vessel; means associated with the core support plate for directly distributing said moderating fluid to and from said fuel assemblies comprising at least one inlet flow channel in said core plate; a plurality of branch inlet feed lines connected to said inlet flow channel in said core plate; a plurality of vertical flow lines flow connected to said branch inlet feed lines, each vertical flow line communicating with a fuel assembly; said distribution means further comprising a plurality of lines serving as return flow lines, each of which is connected to one of said fuel assemblies; a plurality of branch exit flow lines in said core plate flow connected to said return flow lines of the fuel assembly; and at least one outlet flow channel flow connected to said branch exit flow lines; and a flow port interposed between each said penetration means and said distribution means for flow connecting said penetration means with said distribution means.
	summary
	abstract	A dental radiology apparatus includes: a generator (18) emitting X-radiation provided with a collimation device collimating the radiation in an appropriate manner using several forms of collimation slits, at least one radiation sensor (20a, 20b) including a first, a second and a third image acquisition surface which are each positioned opposite an appropriate form of slit in order to use the apparatus in panoramic mode, cone beam tomographic mode and mode determining a trajectory which will be used in panoramic mode respectively. In the third mode a form of slit elongated along a plane P is arranged opposite the third surface corresponding to a part of the second surface along a Z-axis perpendicular to the plane P and the assembly is driven in rotation about an axis parallel to the Z-axis.
059563818	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a preferred embodiment of a first configuration la for detecting the dropping of a control element 3 into a non-illustrated reactor core. Detectors Dl to Dn are disposed in positions X1 to Xn at predetermined distances along a fall path F of the control element 3 (or of a control element group). The number of detectors D1 to Dn and the distances between them depend essentially on the desired detection accuracy and on the acceptable level of expense. For the sake of simplicity, only three detectors D1, D2 and Dn are shown in the figures. The procedure is discussed herein, purely by way of example, with reference to the example of one control element 3. However, it can be applied logically to a plurality of control elements 3 or for all of the control elements 3 of a reactor core. The detectors D1 to Dn can be constructed in a wide variety of ways. They may, for example, respond to radioactivity, heat, electromagnetic effects or other physical effects. It is essential in the present case that the detectors detect the dropping of the respective control element 3 at the place where they are installed, through a physical effect and a corresponding signal. In particular, the following detector types that are known from the art are usable: neutron flux, gamma, beta, alpha detectors and measuring sensors or thermocouples for the local coolant temperature. It is expedient for the detectors D1 to Dn which are in any case disposed in or outside the reactor core, to be used for the present function. They may, for example, be detectors D1 to Dn for determining power density. In the figures, reference symbols S1 to Sn denote signals that are respectively output by the detectors D1 to Dn. When the control element 3 drops downward, the detectors D1 to Dn in each case successively produce the signals S1 to Sn with signal edges, as the control element 3 goes past. The edges (rising edges) of the signals S1 to Sn thus occur one after the other with a time delay. The representation of the signal edges of the signals S1 to Sn which is shown in the figures is chosen according to their time delay on a time axis t (indicated by dashes). In the present case, it is assumed that the detectors D1 to Dn each output a constant signal. The signals S1 to Sn which are shown are therefore, for example, formed as constant signals with rising edges. Other types of signals, for example alternating signals, are likewise conceivable. The signals S1 and S2 are then subsequently delayed, using delay components V1 and V2, in such a way that their edges are approximately simultaneous with the edge of the signal Sn. A relative delay with respect to the signal Sn thus takes place. If n detectors Dn are provided, the detectors D1 to Dn-1 (non-illustrated) have a delay component V1 to Vn-1 (non-illustrated). An adder component 9 is provided, so that a sum signal Sx is obtained which has a large steep rising edge. In order to make the sum signal Sx more readily processable, it may be subsequently further fed through a differentiating component DGS, so as to yield a pulse sum signal Sy which is then fed to a monitoring device 12. The monitoring device 12 is used, for example, for the detection, processing or signaling of faults, or for data transmission and is constructed according to the generally known prior art. It may initiate further reactions to the drop of the control element and is incorporated in a drive or control system of the reactor. The approximate addition of the respective signals S1 to Sn produces a considerable increase in the useful signal component in comparison with the interference signals, which provides better evaluation. Noise components in the interference signal in this case are at least partly eliminated, so that it is easier for the downstream monitoring device 12 to detect the drop. The delay time in the delay components V1, V2 may be fixed in advance according to the sites where the detectors D1 to Dn are installed. The delay times may then be determined by trials or on the basis of theoretical considerations. This procedure can, for example, be carried out by using an analog or digital circuit, in particular a computer. However, the signals S1 to Sn may also be respectively stored firstly. The respective delay time is then given from the difference between the occurrence of the respective signal S1 to Sn and the last signal Sn. This procedure is suitable, in particular, for digital signal processing using a computer. The delay times of the respective delay components V1 to Vn-1 (non-illustrated) can be calculated according to the following relationship: EQU Ti=Xn/v-Xi/v. In this equation, I=1, . . . , n-1: Xi and Xn indicate the positions of the respective detectors D1 and Dn along the fall path F of the control element 3, PA1 Ti indicates the delay times of the respective signals S1 to Sn from the detectors D1 to Dn at the positions Xi and Xn, and PA1 v indicates the fall rate of the respective control element 3. FIG. 2 shows a second variant, in which a configuration 1b has differentiation components DG1 to DGn that are connected downstream of the respective detectors D1 to Dn, in each signal path of the detectors D1 to Dn. The edges of the signals from the detectors D1 to Dn are thereby converted into pulses I1 to In which are well-suited to signal processing. The addition produces a sum pulse Is. A configuration 1c according to FIG. 3 has thresholding components GG1 to GGn connected downstream of the differentiation components DG1 to DGn. In this way, only signals which have a predetermined amplitude are evaluated and delayed. In this case the amplitude is dependent on the dropping rate. A control rod driven slowly into the reactor core therefore does not lead to a detected signal. The embodiment of the configuration lc according to FIG. 3 may also be realized in such a way that the thresholding components GG1 to GGn output binary signals. After the binary signals have been delayed by the delay components V1 and V2, the binary signals are then fed to a coincidence monitoring device 9a. The latter then performs a logical check of the binary signals, through the use of which the dropping of the control element 3 is detected. The coincidence monitoring device 9a then outputs a fault detection signal at its output 10, which is fed to the monitoring device 12 already described above. The embodiment of the configuration 1c is suitable, in particular, for digital signal processing, in which the outputs of the detectors D1 to Dn are connected to inputs of an automation device which has a computer. The signal processing components referred to are then constructed in the form of software or programs. In individual cases, and under certain conditions, a simple detection according to FIG. 4 may also be sufficient. In this case, pulse signals I1 to In are firstly added and then integrated with respect to time using an integrator 15. This produces a sum pulse Is which also leads directly to improved evaluation and detection in comparison with the prior art. This signal may then optionally be subsequently fed to a differentiation stage DS, with the result of providing a characteristic pulse which has a good signal-to-noise ratio. It is also conceivable for the signals to be checked by using logic before they are processed further, in order to detect certain fault situations or in order to stop further processing on the grounds of false information. This type of logical check for the signals is also suitable for an embodiment involving a computer. Any desired combinations of the above-mentioned features are, of course, conceivable within the knowledge of the person skilled in the art, without departing from the fundamental concept of the present invention.
	description	This application is a continuation application of PCT/JP2014/78044 having an international filing date of Oct. 22, 2014, which claims priority to JP2013-253450 filed Dec. 6, 2013, the entire contents of both of the application are incorporated herein by reference. The present invention relates to a containment cask (container) for radioactive material such as spent nuclear fuel discharged from a nuclear power plant or the like, the cask being able to hold the spent fuel for the purpose of storage or for the purpose of transport. A cask used, for example, when transporting a radioactive material such as a spent nuclear fuel, must have a structure that efficiently dissipates heat generated by the radioactive material stored inside the cask to the outside, and that also shields gamma rays and neutrons emitted from the radioactive material so that they do not escape to the outside. According to Patent Reference 1, for example, there is disclosed a prior art cask for transporting radioactive material that has a lead layer serving as a gamma ray shielding material interposed between a stainless steel inner shell and a steel intermediate shell disposed on the outer side of the inner shell. The cask according to Patent Reference 1 is also filled with a silicone rubber that serves as a neutron shield and is interposed between the intermediate shell and a steel outer shell disposed on the outer side of the intermediate shell. Typically, such a multilayer lead cask is a cylinder with a three-layer structure (in the following, the structure on the innermost side is referred to as an “inner shell”; the structure on the outermost side is referred to as an “outer shell”; and the structure between the “inner shell” and the “outer shell” is referred to as an “intermediate shell”). A lead layer with outstanding gamma ray shielding properties is formed between the metallic inner shell and the metallic intermediate shell by pouring molten lead between the inner shell and the intermediate shell, and allowing the lead to solidify. This ensures a shielding capability against gamma rays, while forming an enclosure that is as thin as possible. The prior art technology according to Patent Reference 1 is an example of a method of forming a lead layer in a casting process involving a pouring of molten lead. However, when a lead layer is formed between the steel shells of a two-layer structure, voids readily form at the boundary between the inner shell and the poured lead, or at the boundary between the intermediate shell and the poured lead, simply by pouring molten lead between the inner shell and the intermediate shell. If gases are present inside these voids, there are some cases in which the state is nearly that of a virtual vacuum, but in any case, when such voids (referred to below as “void layers,” irrespective of the presence or absence of gases) exist, the heat-dissipating effect of the cask is significantly reduced. For this reason, if the cask is used without removing such void layers, the internal temperature of the cask exceeds a hypothetically allowable temperature, resulting in a hazardous state. Patent Reference 2 was proposed to prevent the formation of such void layers, by employing what is generally referred to as a “homogenization treatment” before pouring the molten lead between the inner shell and the intermediate shell, so as to enhance adhesion between the lead layer and the steel shells. In the past, homogenization treatment was employed by heating lead with a burner to melt it so as to create an alloy layer, while causing the lead layer to adhere more closely to the alloy layer and successively increase the thickness. However, the object of the manufacturing method disclosed in Patent Reference 2 was to improve the adhesion obtained in homogenization treatment by forming a vitrifiable lead-tin based thin-film. Specifically, the homogenization treatment according to Patent Reference 2 was implemented with the following sequence of steps: (1) A washing treatment step in which adhering matter, greasy components, and the like are removed from the external surface of the inner shell by degreasing, to produce a clean state; (2) A solvent application step in which the steel sheet surface is heated with a burner to a temperature on the order of 230-270° C., and after the surface reaches a specified temperature, a flux which is a solvent that improves wettability is applied; (3) A vitrifiable material application step in which the vitrifiable lead-tin based material is uniformly applied to the surface by dissolving it and dropping it onto the surface immediately after solvent application; and (4) A thin-film formation step in which the system is cooled for a while after solvent application, the inner surface (the side that holds the radioactive material) of the inner shell is reheated with a burner, the temperature is raised to 180-250° C., and the floating vitrifiable material is wiped off with a heat-resistant cloth, forming a thin-film of vitrifiable material on the exterior surface of the inner shell. However, homogenization treatment that requires steps such as (1) to (4) has a problem in that because it is accomplished almost entirely by manual labor performed by highly experienced and highly skilled workers, it is very inefficient, it takes an extended period of time to manufacture the cask, and the manufacturing cost is high. In addition, due to the fact that it is not possible to always prevent the formation of void layers when the above-described homogenization treatment is employed, there is a need to inspect the cask after it is manufactured to see whether or not there are void layers, and the inspection process itself takes a lot of work. The present invention was devised with consideration given to the above-described problem of the formation of void layers at the boundary between the inner shell and the poured lead, or at the boundary between the intermediate shell and the poured lead. The object of the present invention is to provide a containment cask for radioactive material that makes it possible to shorten the manufacturing time and to reduce the manufacturing cost by completely eliminating homogenization treatment, or, even if homogenization treatment is employed, to reduce the scope of its use by half. Patent Reference 1: Japanese Patent Application Kokai Publication No. S61-198099 Patent Reference 2: Japanese Patent Application Kokai Publication No. H07-27896 The problems that the present invention aims to solve are that because prior art containment casks for radioactive material assumed the use of homogenization treatment, an extended period of time was needed to manufacture the cask, and the manufacturing cost also increased. The present invention solves these problems by providing a containment cask for a radioactive material comprising: a metallic inner shell; a metallic intermediate shell disposed on an outer side of the inner shell; an outer shell disposed so as to cover an outer side of the intermediate shell; lead solidified from a molten lead poured between the inner shell and the intermediate shell to serve as a gamma ray shielding material; and a low melting point metal filled in either one or both of (i) a first void layer formed at a boundary between the inner shell and the solidified lead or (ii) a second void layer formed at a boundary between the intermediate shell and the solidified lead. According to the construction of the present invention, the void layers that prevent the cask from dissipating heat are filled with a low melting point metal that has a thermal conductivity surpassing that of air that is present in the void layers, for example. In other words, the concept of the present invention is to provide the cask with a good heat-dissipating effect, and to prevent the temperature within the cask from rising. This is achieved by filling the void layers with a low melting point metal in a closely adhering state after the void layers are formed. The containment cask for radioactive material according to the present invention is able to shorten the manufacturing time and to reduce the manufacturing cost by eliminating homogenization treatment altogether, or, if homogenization treatment is used, to employ it only on the outer surface of the inner shell or only on the inner surface of the intermediate shell. In the present invention, the term “low melting point metal” refers not only to a pure metal formed from a single metallic element, but also includes alloys. Use of alloys is not limited to alloys formed from a plurality of metallic elements, but also metal-like compounds formed from metallic elements and non-metallic elements. Several embodiments of the containment cask for radioactive materials according to the present invention (referred to below simply as a “cask”) are described in detail with reference to the appended drawings. A cask according to Example 1 illustrated in FIGS. 1A and 1B has the following construction. A cask 1 is a cylindrical container that is able to hold a radioactive material such as a spent nuclear fuel for the purpose of storage or for the purpose of transport. The cask 1 has a cylindrical inner shell 2, a cylindrical intermediate shell 3 disposed on an outer side of the inner shell 2, as well as an outer shell 4 disposed so as to cover an outer side of the intermediate shell. The inner shell 2, the intermediate shell 3, and the outer shell 4 are arranged so that the centers of each of the cylindrical shells are positioned coaxially. Heat radiating fins (not pictured) are attached to the outer shell 4. A lead layer 5b is formed as a gamma ray shielding material in a space between the inner shell 2 and the intermediate shell 3, to prevent gamma rays emitted from a radioactive material from escaping to outside of the cask 1. In addition, a space between the intermediate shell 3 and the outer shell 4 is filled with a neutron shielding material 6 formed from a material such as silicone rubber, for example. A cover 7 that freely opens and closes is provided at the upper end of the cask 1. A holding member 2a that is able to hold radioactive material is provided inside the inner shell 2. The lower end of the cask 1 is sealed shut with a bottom plate 8. According to the cask 1 which has the above-described construction, gamma rays and neutrons emitted from the radioactive material held in the holding member 2a are shielded by the lead layer 5b and the neutron shielding material 6. The cut-away portion of FIG. 1B is a sectional view along the line A-A′ as seen from a lateral orientation (this also applies to FIG. 3B and FIG. 6B described below). FIGS. 2A and 2B are enlarged views of the rectangular portion marked by the dashed line B in the cut-away portion shown in FIG. 1B (this also applies to FIGS. 4A and 4B, FIGS. 5A and 5B, and FIGS. 7A and 7B described below). Following is a description of the method of manufacturing the cask 1 according to Example 1. The cask 1 according to Example 1 has a lead layer 5b with excellent gamma ray shielding properties formed between the inner shell 2 made from a metal (e.g., a stainless steel such as SUS) and the intermediate shell 3 which is also made also made from a metal (e.g., a stainless steel such as SUS), by pouring molten lead into a space between the inner shell 2 and the intermediate shell 3, and cooling the poured lead 5a to solidify it. Thus, as shown in FIG. 2A, immediately after the poured lead 5a cools and solidifies, the resulting state is such that a first void layer 9a is formed at the boundary between the inner shell 2 and the poured lead 5a, and a second void layer 9b is formed at the boundary between the intermediate shell 3 and the poured lead 5a. A gas such as air, for example, that is present inside the first void layer 9a and the second void layer 9b has a thermal conductivity that is poorer than metal, so this portion forms a heat-insulating layer, causing a reduced heat-dissipating effect in the cask 1. Accordingly, the method of manufacturing the cask 1 of Example 1 involves pouring a molten lead between the inner shell 2 and the intermediate shell 3 to serve as a gamma ray shielding material, and then using a low melting point metal 10 to fill the first void layer 9a formed at the boundary between the inner shell and the poured lead 5a, and/or a second void layer 9b formed at the boundary between the intermediate shell and the poured lead 5a. In the example shown in FIGS. 2A and 2B, when the molten lead is poured and cooled, not only is the first void layer 9a formed, but also the second void layer 9b is formed, so the low melting point metal 10 fills both the first void layer 9a and the second void layer 9b. However, when the molten lead is poured, it is not always the case that the first void layer 9a and the second void layer 9b are both formed, but instead, there are cases in which only one or the other is formed. In such cases, the low melting point metal 10 should be caused to fill whichever one of the void layers is formed, whether that be the first void layer 9a or the second void layer 9b. The present invention places no particular restrictions on the type of low melting point metal 10. However, Al, Pb, Sn, and Zn, or alloys containing these metals can be used, for example. The low melting point metal 10 that is selected should have a melting point lower than the melting point of lead, so that when the low melting point metal 10 flows in a molten state into the first void layer 9a and/or the second void layer 9b, it does not cause the solidified lead 5a, which has already cooled after being poured, to return to a molten state. If a metal or alloy having a melting point lower than the melting point of lead (327.5° C.) is used as the low melting point metal 10, it is possible for the low melting point metal 10 to flow into the first void layer 9a and the second void layer 9b at a temperature lower than the melting point of lead. A soldering alloy can, for example, be used as a low melting point metal 10 having a melting point lower than the melting point of lead. If an Sn—Pb soldering alloy is used, for example, the solidus curve temperature and the liquidus curve temperature vary according to the compounding ratio of Sn, but any of these temperatures are lower than the melting temperature of lead. In particular, if the compounding ratio of Sn in the Sn—Pb soldering alloy is 20% or higher, the solidus curve temperature and the liquidus curve temperature are both lower than 280° C. If a eutectic solder (e.g., Sn 63%-Pb 37%) is used, the solidus curve temperature and the liquidus curve temperature can both be set at 183° C. In the present invention, it is even more advantageous for the low melting point metal 10 that is selected to have a melting point lower than an allowable temperature of the cask 1 (which is often designed so that the temperature is typically on the order of 150° C., for example). If the melting point of the low melting point metal 10 is set below the allowable temperature of the cask 1, a portion of the low melting point metal 10 can become molten and liquefied, and in a state in which it can typically be used with ensured safety. If the low melting point metal 10 has a melting point lower than an allowable temperature of the cask 1, it is possible to have a portion of the low melting point metal 10 be in a liquefied state when the cask 1 starts to be used, holding the radioactive material in the holding member 2a. Accordingly, if the low melting point metal 10 has a melting point lower than the allowable temperature of the cask 1, then it also becomes possible to absorb slight deformations that result from differences in the thermal expansion ratio of the inner shell 2, the intermediate shell 3, and a lead layer 5. This makes it possible to further increase the adhesion between the inner shell 2 and the lead layer 5, or between the intermediate shell 3 and the lead layer 5, so as to support a state of firm adhesion. This also makes it possible to further enhance the heat-dissipating effect of the cask 1. In detail, a low melting point solder can be used, for example, as the low melting point metal 10 that has a melting point lower than the allowable temperature (e.g., 150° C.) of the cask 1. For example, if an Sn—Pb—Bi low melting point solder (28.5 Sn—Pb-28.5 Bi) is used, the solidus curve temperature is 99° C. and the liquidus curve temperature is 139° C. It is also advantageous for the low melting point metal 10 to be a metal or alloy that is a liquid at a normal temperature. If the low melting point metal 10 is a liquid at a normal temperature, then a portion of the low melting point metal 10 will always be in a liquid state, regardless of whether or not the holding member 2a contains a radioactive material. Consequently, there is always a high adhesion between the shell 2 and the lead layer 5, or between the intermediate shell 3 and the lead layer 5. In addition, the heat-dissipating effect of the cask 1 is further enhanced, because it is possible to absorb slight deformations that result from differences in the thermal expansion ratio of the inner shell 2, the intermediate shell 3, and a lead layer 5. A specific example of a metal that can be used as the low melting point metal 10 is silver, which is a liquid at a normal temperature. In this context, the term “normal temperature” follows the definition given in JIS Z 8703, wherein a normal temperature is in a range of 20° C.±15° C. (i.e., 5° C. to 35° C.). Homogenization treatment, which involves inefficient manual labor, is not used at all in the cask 1 of Example 1, so the cask manufacturing time can be shortened and the manufacturing cost can be reduced. Following is a description of the construction of a cask 21 according to Example 2 shown in FIGS. 3A and 3B, with a focus on the points that differ from Example 1. As shown in FIGS. 3A and 3B, the cask 21 according to Example 2 has a cylindrical inner shell 22, a cylindrical intermediate shell 23 disposed so as to cover an outer side of the inner shell 22, as well as an outer shell 24 disposed so as to cover an outer side of the intermediate shell 23. A holding member 22a that is able to hold radioactive material is provided inside the inner shell 22. A cover 27 that freely opens and closes is provided at the upper end of the cask 21. The lower end of the cask 21 is sealed shut with a bottom plate 28. A lead layer 25b is formed as a gamma ray shielding material formed between the inner shell 22 made from a metal (e.g., a stainless steel such as SUS) and the intermediate shell 23 which is also made from a metal (e.g., a stainless steel such as SUS). A neutron shield material 26 (e.g., silicone rubber) fills a space between the intermediate shell 23 and the outer shell 24. These points are the same as in the cask 1 of Example 1. The point of difference between Example 1 and the manufacturing method of cask 21 according to Example 2 is that in the cask 21 according to Example 2, before pouring molten lead between the inner shell 22 and the intermediate shell 23, a homogenization treatment is performed on only one of either an outer surface of the inner shell 22 or on an inner surface of the intermediate shell 23. It should be noted that FIGS. 3A and 3B illustrates an example in which homogenization treatment is performed on only an outer surface the inner shell 22. In the above example, as shown in FIG. 4A, a void layer is not present at the boundary between the inner shell 22 and a poured lead 25a when the poured lead 25a has solidified, because the adhesion is increased due to the effect of a homogenization-treated portion 31. Accordingly, in producing the cask 21 of Example 2, a manufacturing method is employed in which homogenization treatment is performed on only one of either the outer surface of the inner shell 22 or on the inner surface of the intermediate shell 23, and molten lead is poured between the inner shell 22 and the intermediate shell 23 as a gamma ray shielding material, and then the led is allowed to cool. After that, as shown in FIG. 4B, a void layer 29 is filled with a low melting point metal 30 in a closely adhering state, the void being formed at a boundary between the outer surface of the inner shell 22 or the inner surface of the intermediate shell 23, whichever surface is not homogenization treated (the inner surface of the intermediate shell 23 in the above example). In contrast to the above example, if homogenization treatment is performed only on the inner surface of the intermediate shell 23, as shown in FIGS. 5A and 5B, a void layer 29 is formed only at the boundary between the inner shell 22 and the poured lead 25a. Consequently, in this case, only the void layer 29 formed on the side of the inner shell 22 is filled with the low melting point metal 30 in a closely adhering state. The description of the low melting point metal 30 does not particularly differ from that of Example 1, so it is omitted. Even if the cask 21 of Example 2 undergoes homogenization treatment, void layers are prevented only on one of either the outer surface of the inner shell 22 or the inner surface of the intermediate shell 23. Therefore, the cask manufacturing time and the manufacturing cost can be reduced to a certain extent, but not to the extent as in the cask 1 of Example 1. Following is a description of the construction of a cask 41 according to Example 3 shown in FIGS. 6A and 6B, with a focus on the points that differ from Example 2. As shown in FIGS. 6A and 6B, the cask 41 also has a cylindrical inner shell 42, a cylindrical intermediate shell 43 disposed so as to cover an outer side of the inner shell 42, as well as an outer shell 44 disposed so as to cover an outer shell of the intermediate shell 43. A holding member 42a that is able to hold radioactive material is provided inside the inner shell 42, a cover 7 that freely opens and closes is provided at the upper end of the cask 41, the lower end of the cask 41 is sealed shut with a bottom plate 48, and a neutron shield material 46 (e.g., silicone rubber) fills a space between the intermediate shell 43 and the outer shell 44. These points are the same as in Examples 1 and 2. The method of manufacturing the cask 41 according to Example 3 differs from that of Example 1 and Example 2 in that in manufacturing the cask 41 according to Example 3, instead of pouring molten lead, a plurality of lead bodies 45, formed beforehand into any desired shape and size, are inserted into a space between the inner shell 42 made from a metal (e.g., SUS) and the intermediate shell 43 which is also made from a metal (e.g., SUS), to serve as a gamma ray shielding material. FIGS. 6A and 6B shows an example in which spherical lead bodies 45 are inserted into the space. In the above example, as shown in FIG. 7A, immediately after inserting the spherical lead bodies 45 into the space between the inner shell 42 and the intermediate shell 43, the state is such that a void layer 49 is present among the lead bodies 45. Accordingly, the method of manufacturing the cask 41 of Example 3 involves inserting a plurality of lead bodies 45, formed beforehand into any desired shape and size, into a space between the inner shell 42 and the intermediate shell 43, to serve as a gamma ray shielding material, and then filling the void layer 49 formed between the lead bodies 45 with a low melting point metal 50. The description of the low melting point metal 50 does not particularly differ from that of Examples 1 and 2, so it is omitted. The formed lead bodies inserted between the inner shell 42 and the intermediate shell 43 are not restricted to the spherical shape of the lead bodies 45 shown in FIGS. 7A and 7B. The lead bodies 45 may, for example, be granular, round bar-shaped, regular hexahedral, in the shape of a rectangular parallelepiped, or the like. If bar-shaped lead bodies are used, they may be inserted in a mutually parallel orientation in the space between the inner shell 42 and the intermediate shell 43, or they may be inserted in blocks arranged in a mutually intersecting orientation. In Example 3, the void layer 49 formed among the lead bodies 45 may be filled with a good thermal conductivity oil, instead of using the low melting point metal 50. Grease is an example of a good thermal conductivity oil. Homogenization treatment, which involves inefficient manual labor, is not used at all in the cask 41 of Example 3, so the cask manufacturing time can be shortened and the manufacturing cost can be reduced. It should be noted that if Example 1 and Example 2 are compared, the volume of the void layer 49 becomes large, and it is sufficient to fill the void layer 49 only with the low melting point metal 50 or the good thermal conductivity oil. This means that there is no particular advantage for the void layer 49 to have a large volume. In addition, the cask 41 of Example 3 has good heat dissipating properties. The above-described casks 1, 21, and 41 that correspond respectively to the inventions according to the claims are able to enhance the heat-dissipating effect of the casks, and can prevent the temperature within the casks from rising. This is achieved by filling the void layers that develop during the manufacturing process with a low melting point metal or a good thermal conductivity oil in a closely adhering state during the latter stages of the manufacturing process. The following manufacturing method has also been conceived of as a means for making it possible to achieving another construction. In contrast to Example 3 described above, this manufacturing method involves first using the low melting point metal 50 or a good thermal conductivity oil to fill the space between the inner shell 42 and the intermediate shell 43, and then inserting the lead bodies 45. Even a manufacturing method that reverses this sequence is thought to make it possible to insert the lead bodies 45 into the space between the inner shell 42 and the intermediate shell 43, without utilizing the viscosities of the low melting point metal 50 and the good thermal conductivity oil. A manufacturing method that reverses this sequence is able to utilize the low melting point metal 50, which has a melting point lower than lead, to obtain adhesion within the low melting point metal 50, without melting the lead bodies 45. The present invention is not limited to the above-described example, and the preferred embodiment may, of course, be advantageously modified within the scope of the technical ideas recited in the claims. For example, the above embodiments disclose examples in which the inner shell, the intermediate shell, and the outer shell are formed from cylinders, but the inner shell, the intermediate shell, and the outer shell are not limited to this shape, and may be in the shape of a rectangular parallelepiped, for example.
	claims	1. A liquid radioactive waste treatment system, the system comprising:a housing which comprises an external wall, the wall being able to be penetrated by sunlight and being comprised of a transparent material;an evaporation unit which is located in the housing, and comprises an evaporation plate having an uneven surface on which the liquid waste flows; anda liquid waste dispersing unit which is located above the evaporation plate and disperses the liquid waste; anda heat collector plate which is mounted on an upper wall of the housing and stores solar heat, wherein the liquid waste which passes the evaporation plate moves to the heat collector plate, is heated, and moves to the evaporation plate again to circulate. 2. The system of claim 1, wherein a plurality of evaporation plates are provided, and each of the evaporation plates are stacked to be spaced apart from each other by an equal distance. 3. The system of claim 1, wherein a guide plate is perpendicularly attached to the evaporation plate at each side of the evaporation plate. 4. The system of claim 1, wherein a lower end of the evaporation plate is formed to be inclined into a single direction, to enable the liquid waste flow in the direction. 5. The system of claim 1, wherein the evaporation plate is positioned to be inclined at a predetermined angle. 6. The system of claim 1, wherein the evaporation plate is made of a stainless steel. 7. The system of claim 1, further comprising:an inlet fan and an exhaust fan which are mounted on the external wall of the housing,wherein air which is flowed inside of the housing from the inlet fan, passes over the evaporation plate, and is discharged to an outside of the housing via the exhaust fan. 8. The system of claim 1, wherein the external wall of the housing is made of a glass. 9. A liquid radioactive waste treatment system, the system comprising:a housing which is covered with a glass;an evaporation module where an evaporation plate, having an uneven surface in the housing, and a guide plate, which is perpendicularly attached to the evaporation plate at each side of the evaporation plate, are stacked, and each of the evaporation plates are spaced apart from each other by an equal distance;a liquid waste dispersing unit, is located above the plurality of evaporation modules, and disperses the liquid waste; anda heat collector plate which is mounted on a upper wall of the housing and stores solar heat, wherein the liquid waste which passes the evaporation plate moves to the heat collector plate, is heated, and moves to the evaporation plate again to circulate. 10. The system of claim 9, wherein a lower end of the evaporation plate is formed to be inclined into a direction, to enable the liquid waste flow in the direction. 11. The system of claim 9, wherein the evaporation plate is positioned to be inclined at a predetermined angle. 12. The system of claim 9, wherein the evaporation plate is made of a stainless steel. 13. The system of claim 9, further comprising:an inlet fan and an exhaust fan, which are mounted on the external wall of the housing,wherein air which is flowed inside of the housing from the inlet fan passes over the evaporation plate, and is discharged to outside of the housing via the exhaust fan after monitoring system.
	summary
	claims	1. A method of repairing a bottom-mounted instrumentation nozzle for an irradiated reactor vessel that is filled with water and has the reactor internals removed and an in-core instrument tube connected to the bottom-mounted instrumentation nozzle below the reactor vessel, comprising the steps of:installing a plug within or over the bottom-mounted instrumentation nozzle in a manner that prevents the water in the reactor vessel from leaking to any significant extent through the bottom-mounted instrumentation nozzle;severing the bottom-mounted instrumentation nozzle from the in-core instrument tube below the plug;sealing an external container over the bottom-mounted instrumentation nozzle and against an underside of the reactor vessel to create a substantially leak tight seal between the external container and a bottom of the reactor vessel;removing at least a portion of a weld between the reactor vessel and the bottom-mounted instrumentation nozzle;applying an upward force on the bottom-mounted instrumentation nozzle to remove the bottom-mounted instrumentation nozzle from a thru-opening in the bottom of the reactor vessel;inserting a new bottom-mounted instrumentation nozzle through the thru-opening in the bottom of the reactor vessel or a new bottom-mounted instrumentation nozzle plug into the thru-opening in the bottom of the reactor vessel; andsealably attaching the new bottom-mounted instrumentation nozzle or the bottom nozzle instrumentation plug to the bottom of the reactor vessel. 2. The method of repairing the bottom-mounted instrumentation nozzle of claim 1 wherein the bottom-mounted instrumentation nozzle is being replaced with the new bottom-mounted instrumentation nozzle including the step of attaching the in-core instrument tube to a bottom end of the new bottom-mounted instrumentation nozzle. 3. The method of repairing the bottom-mounted instrumentation nozzle of claim 1 wherein the new bottom-mounted instrumentation nozzle or the bottom nozzle instrumentation plug is constructed with an integral shoulder that is configured to be welded to the bottom of the reactor vessel. 4. The method of repairing the bottom-mounted instrumentation nozzle of claim 3 wherein either an upper surface on the bottom of the reactor vessel surrounding the thru-opening or the shoulder on the new bottom-mounted instrumentation nozzle or bottom nozzle instrumentation plug is machined to match the contour of the other of either the upper surface on the bottom of the reactor vessel surrounding the thru-opening or the shoulder on the new bottom-mounted instrumentation nozzle or bottom nozzle instrumentation plug. 5. The method of repairing the bottom-mounted instrumentation nozzle of claim 1 wherein the step of sealing an external container over the bottom-mounted instrumentation nozzle includes pressuring a seal on a lip of the external container against the bottom of the reactor vessel by leveraging the external container off of a structural member in a bottom of a reactor cavity in which the reactor vessel is supported or off of other bottom-mounted instrumentation nozzles. 6. The method of repairing the bottom-mounted instrumentation nozzle of claim 5 wherein the seal comprises a double concentric O-ring seal that comprises two O-ring gaskets. 7. The method of repairing the bottom-mounted instrumentation nozzle of claim 6 including a leak-off line between the O-ring gaskets to monitor for leaks. 8. The method of repairing the bottom-mounted instrumentation nozzle of claim 1 wherein the external container includes a drain. 9. The method of repairing the bottom-mounted instrumentation nozzle of claim 1 wherein the external container includes a mechanical or hydraulic jack supported within the interior of the external container and configured to apply the upward force to the bottom-mounted instrumentation nozzle or the bottom nozzle instrumentation plug. 10. The method of repairing the bottom-mounted instrumentation nozzle of claim 9 wherein the mechanical or hydraulic jack is remotely operated. 11. A method of repairing a sealed penetration through a pressure vessel filled above the penetration with a liquid comprising the steps of:installing a plug within or over the penetration in a manner that prevents the liquid in the pressure vessel from leaking to any significant extent through the penetration;sealing an external container over the penetration and against an outside of the pressure vessel to create a substantially leak tight seal between the external container and outside of the pressure vessel;removing at least a portion of a weld between the pressure vessel and the penetration;applying a force on the penetration to remove the penetration from a thru-opening in the pressure vessel;inserting a new penetration through the thru-opening in the pressure vessel or a plug into the thru-opening in the pressure vessel; andsealably attaching the new penetration or plug to the pressure vessel. 12. The method of claim 11 wherein the step of applying the force removes the penetration from the thru-opening into the pressure vessel. 13. The method of claim 11 wherein the new penetration or plug is constructed with an integral shoulder that is configured to be welded to the pressure vessel. 14. The method of claim 13 wherein either a mating surface on the pressure vessel surrounding the thru-opening or a mating surface on the shoulder is machined to match the contour of the other. 15. The method of claim 11 wherein the step of sealing an external container over the penetration includes pressuring a seal on a lip of the external container against the bottom of the reactor vessel by leveraging the external container off of an adjacent structural member. 16. The method of claim 15 wherein the seal comprises a double concentric O-ring seal that comprises two O-ring gaskets. 17. The method of claim 16 including a leak-off line between the O-ring gaskets to monitor for leaks. 18. The method of claim 11 wherein the external container includes a drain. 19. The method of claim 11 wherein the external container includes a mechanical or hydraulic jack supported within the interior of the external container and configured to apply the force to the penetration. 20. The method of claim 19 wherein the mechanical or hydraulic jack is remotely operated.
062122525	abstract	An X-ray mask which is provided with an alignment mark and a transfer circuit pattern having a high position accuracy can be manufactured through a simplified manufacturing process.. A membrane allowing passage of X-rays is formed on a substrate. A X-ray absorber intercepting transmission of X-rays is formed on the membrane. The substrate includes a window exposing the membrane. The X-ray absorber includes a transfer circuit pattern and an alignment mark formed in a region not overlapping with the window in a plan view.
	summary
	description	1. Field of the Invention The present invention relates to a charged-particle beam writing method and a charged-particle beam writing apparatus. More specifically, the present invention relates to the calculation and correction of a position displacement amount of a charged-particle beam due to a charging effect of a sample. 2. Background Art With the introduction of a double patterning technique, there has been a demand for enhancement of position accuracy of a photomask. With its demand, there has been a demand for an improvement in pattern placement accuracy in the photomask. It has, however, been known that when a pattern of the photomask is written by an electron beam writing apparatus, a beam irradiation position is displaced or shifted due to a resist charging effect. As one method for correcting this beam irradiation position displacement, there has been known a method for forming a charge dissipation layer (CDL) on a resist layer and preventing the charging of a resist surface. Since, however, the charge dissipation layer basically has an acid characteristic, it is incompatible with a chemical amplification resist. There is also a need to provide a new facility in order to form the charge dissipation layer, thus causing a further increase in the manufacturing cost of a photomask. Therefore, it is desirable to perform charging effect correction (CEC) without using the charge dissipation layer. A writing apparatus for calculating a correction amount of a beam irradiation position, based on electric field strength and applying a beam based on the correction amount has been proposed in Japanese Patent Application Laid-Open No. 2007-324175. According to the writing apparatus, a position displacement amount distribution is calculated from an irradiation amount or exposure distribution through a linear response function assuming that a linear proportional relationship is established between the exposure distribution and a charge amount distribution. According to further discussions of the present inventors, however, it has been found out that the position displacement amount distribution cannot be calculated with satisfactory accuracy assuming that the linear proportional relationship is established between the exposure distribution and the position displacement amount distribution. Therefore, the need for establishing a new model to determine the position displacement amount distribution with high accuracy without using such a linear proportional relationship has arisen. An object of the present invention is to provide a charged-particle beam writing method and apparatus capable of calculating a distribution of a beam displacement amount due to a charging effect with satisfactory accuracy in terms of the above problems. According to one aspect of the present invention, in a charged-particle beam writing method, a charged-particle beam is deflected and each pattern is written onto a sample placed on a stage. In the charged-particle beam writing method, a charge amount distribution in an irradiation region of the charged-particle beam and a charge amount distribution in a non-irradiation region thereof are calculated, using an exposure distribution of the charged-particle beam applied onto the sample, and a fogging electron amount distribution. Then, a distribution of a position displacement amount of the charged-particle beam on the sample is calculated, based on the charge amount distributions in the irradiation and non-irradiation regions. Then, the charged-particle beam is deflected, based on the distribution of the position displacement amount and writing each pattern onto the sample. According to another aspect of the present invention, a charged-particle beam writing apparatus deflects a charged-particle beam by a deflector and writes each pattern onto a sample placed on a stage. The charged-particle beam writing apparatus comprises position displacement amount distribution calculating means for calculating a distribution of a position displacement amount of the charged-particle beam lying on the sample, based on a charge amount distribution in an irradiation region of the sample irradiated with the charged-particle beam, and a charge amount distribution in a non-irradiation region unirradiated therewith. And the charged-particle beam writing apparatus comprises deflector control means for controlling the deflector based on the distribution of the position displacement amount. Another object and an advantage of the present invention are apparent from the following description. FIG. 1 is a schematic configuration diagram of an electron beam writing apparatus 100 according to the present embodiment. The electron beam writing apparatus 100 of variable-shaped beam system shown in FIG. 1 is equipped with a writing section 1. An XY stage 3 for holding a mask corresponding to a sample 2 is accommodated within the writing section 1. The mask corresponding to the sample 2 is one formed by sequentially laminating a chromium oxide film and a resist layer over a glass substrate. The XY stage 3 is configured so as to be movable in X and Y directions by stage driving means 46 to be described later. The position of movement of the XY stage 3 is detected by stage position detecting means 45 to be described later, based on the output of a laser interferometer 4. An electron gun 5 corresponding to a source for the generation of an electron beam 6 is disposed above the XY stage 3. An illuminating lens 7, an S1 aperture (first aperture) 8, a projection lens 9, a shaping deflector 10, an S2 aperture (second aperture) 11, an objective lens 12 and an objective deflector 13 are disposed between the electron gun 5 and the XY stage 3. The electron beam writing apparatus 100 is also equipped with a control section 20 and a memory or storage device 21 connected to the control section 20. The storage device 21 stores therein layout data, a position displacement amount distribution (called also “position displacement amount map”) and optical system error distribution (called also “optical system error map”) or the like to be described later. As the storage device 21, there may be mentioned, for example, a magnetic disk device, a magnetic tape device, an FD or a semiconductor memory or the like. The control unit 20 is equipped with a preprocessing calculation unit 30. The preprocessing calculation unit 30 includes pattern density calculating means 31, dose distribution calculating means 32, exposure distribution calculating means 33, fogging electron amount distribution calculating means 34, charge amount distribution calculating means 35 and position displacement amount distribution calculating means 36. The pattern density distribution calculating means 31 calculates distributions of pattern densities set every mesh region with respect to respective frames virtually divided or partitioned in mesh form with predetermined dimensions, based on graphic data contained in the layout data read from the storage device 21. The dose distribution calculating means 32 calculates a distribution of dose using a proximity effect correction equation of backscattered electrons to be described later. The exposure distribution calculating means 33 calculates an exposure distribution (irradiation amount distribution) of an electron beam applied to the sample, based on the pattern density distributions and the dose distribution. The fogging electron amount distribution calculating means 34 calculates a distribution of a fogging electron amount, based on the exposure distribution and a function descriptive of the spread of fogged electrons. The charge amount distribution calculating means 35 calculates a charge amount distribution of an irradiation region to which the electron beam is applied, and a charge amount distribution of a non-irradiation region to which no electron beam is applied, in accordance with a method to be described later. The position displacement amount distribution calculating means 36 calculates a distribution of a position displacement amount of the electron beam on the sample, based on the charge amount distribution calculated by the charge amount distribution calculating means 35. The control section 20 has shot data generating means 41, grid matching control means 42, shaping deflector control means 43, objective deflector control means 44, the above-described stage position detecting means 45 and stage driving means 46 in addition to the preprocessing calculation unit 30. The shot data generating means 41 creates or generates writing data, based on the layout data read from the storage device 21 and creates shot data, based on the writing data. The grid matching control means 42 controls the objective deflector control means 44 based on the position displacement amount distribution calculated by the position displacement amount distribution calculating means 36. The shaping deflector control means 43 controls the position of the shaping deflector 10 in such a manner that an S2 aperture image having a desired size and shape (rectangle or triangle) is obtained. The objective deflector control means 44 controls the position of the objective deflector 13 in such a manner that the electron beam 6 is applied onto a desired position of the sample 2. A general writing operation of the electron beam writing apparatus 100 will next be explained. The electron beam 6 emitted from the electron gun 5 is illuminated onto the entire S1 aperture 8 having a rectangular opening or aperture by the illuminating lens 7. The electron beam 6 of the S1 aperture image transmitted through the S1 aperture 8 is projected onto the S2 aperture 11 having a key-type opening by the projection lens 9. The position of the first aperture image on the S2 aperture 11 is deflected by the shaping deflector 10. Thus, the corresponding image is formed to a desired beam shape and size. The electron beam 6 of the S2 aperture image penetrated through the S2 aperture 11 is focused by the objective lens 12 and deflected by the objective deflector 13, which in turn is applied onto a desired position of the sample 2 placed on the XY stage 3. The sample 2 is moved as shown in FIG. 2 with the continuous movement of the XY stage 3 upon pattern writing. FIG. 2 is a diagram showing the direction of movement of the sample 2 at the pattern writing. A writing region R of the sample 2 is virtually divided or partitioned into a plurality of strip-like stripe regions SR. The electron beam 6 is applied onto one stripe region SR in the X direction. That is, the shot position (irradiation region) of the electron beam 6 is also caused to follow the movement of the stage while the XY stage 3 is being continuously moved in the X direction. When the writing of one stripe region is completed, the XY stage 3 is step-fed in the Y direction. The electron beam 6 is applied onto the next stripe region in the X direction. At this time, the XY stage 3 is continuously moved in the opposite X direction. Incidentally, it has been known that when the electron beam is applied onto the resist layer of the sample 2 as described above, the position of beam irradiation is shifted or displaced due to a resist charging effect. Thus, in the present embodiment, the writing of each pattern having considered a position displacement amount in the electron beam writing apparatus 100 is performed in accordance with such a flow as shown in FIG. 3A. FIG. 3A is a flow chart for describing a writing method according to the present embodiment. According to the flow shown in FIG. 3A, the layout data stored in the storage device 21 is first read by the pattern density calculating means 31. Based on graphic data contained in the layout data, a pattern density is calculated with respect to each of frames (hereinafter called “mesh regions”) virtually partitioned in mesh form with predetermined dimensions (grid dimensions) (Step S100). In this Step S100, a distribution ρ(x,y) of pattern density for every mesh region is calculated. Next, a distribution D(x,y) of dose for every mesh region is calculated using the pattern density distribution ρ(x,y) calculated in step S100 referred to above (Step S102). In this Step S102, the dose distribution D(x,y) is calculated in accordance with the following proximity effect correction equation (1) of backscattered electrons:D=D0×{(1+2×η)/(1+2×ηρ)} (1) (where D0 indicates a reference dose, and η indicates a backscattered ratio) These reference dose D0 and backscattered ratio η are set by a user of the charged-particle beam writing apparatus 100. The backscattered ratio η can be set in consideration of an acceleration voltage of the electron beam 6, a resist film thickness of the sample 2, the type of base substrate, process conditions (such as a PEB condition and a development condition), etc. Next, an exposure distribution E(x,y) (called also “exposure intensity distribution”) for every mesh region is calculated by multiplying the pattern density distribution ρ(x,y) calculated in above Step S100 and the dose distribution D(x,y) calculated in above Step S102 by each other (Step S104). And then a fogging electron amount distribution F(x,y,σ) is calculated in accordance with a method to be described later (Step S106). A charge amount distribution C(x,y) is calculated by the charge amount distribution calculating means 35 in accordance with a method to be described later (Step S108). Incidentally, the pre-calculated pattern density distribution ρ(x,y), dose distribution D(x,y), exposure distribution E(x,y), fogging electron amount distribution F(x,y,σ) and charge amount distribution C(x,y) are stored in the storage device 21. They may be read and obtained from the storage device 21 in steps respectively. Next, a position displacement amount distribution ρ(x,y) is calculated based on the charge amount distribution C(x,y) calculated by the position displacement amount distribution calculating means 36 in above Step S108 (Step S110). In this Step S110, the position displacement amount distribution p(x,y) is calculated by convolution integral of the charge amount distribution C(x,y) and a response function r(x,y) for converting the amount of charge to a position displacement error. Then, grid matching is executed based on the position displacement amount distribution p(x,y) calculated in above Step S110 (Step S112). After the control of the objective deflector 13 has been conducted in this Step S112 as described later, the electron beam 6 is applied onto the sample 2 to write a pattern (Step S114). Incidentally, the writing may be conducted in accordance with a flow shown in FIG. 3B as an alternative to the flow shown in FIG. 3A. FIGS. 3A and 3B are different in Steps S102 and 103 and identical in other Steps. In step S102 of FIG. 3A, the dose distribution D(x,y) is calculated based on the pattern density distribution ρ(x,y), whereas in step S103 of FIG. 3B, the fixed dose distribution D(x,y) is obtained without reference to the pattern density distribution ρ(x,y). In step S104 of FIG. 3B, the fixed dose distribution D(x,y) obtained in step S103 and the pattern density distribution ρ(x,y) calculated in step S100 are multiplied by each other to determine the exposure distribution E(x,y). Thus, the exposure distribution E(x,y) may be calculated using the fixed dose distribution D(x,y) without depending on the pattern density distribution ρ(x,y). In FIG. 4, ♦ indicates a dose that changes according to a pattern density ρ, and □ indicates a dose (21 μC/cm2) fixed regardless of the pattern density. The flow of the grid matching executed in above Step S112 will next be explained with reference to FIG. 5. As shown in FIG. 5, the position displacement amount distribution calculated by the position displacement amount distribution calculating means 36 is stored in the storage device 21. Thereafter, the position displacement amount distribution stored in the storage device 21 and the optical system error distribution created in advance and stored in the storage device 21 are read by the grid matching control means 42. The grid matching control means 42 combines each data of the position displacement amount distribution for every mesh and each data of the optical system error distribution for every mesh and outputs the combined data to the objective deflector control means 44. The objective deflector control means 44 controls the position of deflection of the electron beam 6, based on the inputted data. That is, the position of the objective deflector 13 is controlled to a correction position where the position displacement amount distribution and the optical system error distribution have been taken into consideration. In order to improve the accuracy of placement of each pattern on the sample, there is a need to perform grid matching with satisfactory accuracy. To this end, there is a need to calculate the position displacement amount distribution p(x,y) (called also “position shift amount distribution”) with high accuracy. A method for calculating the position displacement amount distribution p(x,y) will next be explained. A position displacement amount distribution calculating method according to a comparative example with respect to the present embodiment will first be described with reference to FIG. 6. Assumes that a function g′(x,y) descriptive of a spread distribution of electrons (charge amount) exists with respect to a given exposure distribution E(x,y) in the present comparative example. As this function g′(x,y), a model of a Gaussian distribution positively charged in an electron beam irradiation region and negatively charged in a non-irradiation region as shown in FIG. 7, for example, can be used. A charge amount distribution C(x,y) is determined by convolution integral of the exposure distribution E(x,y) and the spread distribution function g′(x,y). Next imagine a response function r(x,y) for converting the charge amount distribution C(x,y) to the position displacement amount distribution p(x,y). Since the position displacement of the beam can be expressed as a function of distance between a beam irradiation position (x,y) and a charging position (x′,y′) here, the response function can be described like “r(x-x′,y-y′)”. FIG. 8 is a diagram showing a model assumed to calculate the response function r(x,y). As shown in FIG. 8, two parallel flat plates 51 and 52 both earthed to 0 V are disposed with being spaced a distance L away from each other. The upper flat plate 51 corresponds to a wall surface of the writing section 1, specifically, a block of the objective lens 12, and the lower flat plate 52 corresponds to a chrome layer of a photomask. The two flat plates 51 and 52 are considered as complete conductors. A point charge source 55 is disposed at the surface of a resist 53 having a thickness h. Since the conductive chrome layer 52 can be assumed to be a mirror upon static potential calculations, a mirror image charge 54 is positioned below the chrome layer 52 by an equal distance “−h”. Actual electrostatic charge 55 and mirror charge 54 act as a dipole 56 in pairs. Since the conductive upper flat plate 51 can also be taken as a mirror, one pair of an infinite number of dipoles 56 is disposed at a pitch of “2L”. Upon actual calculations, the number of the dipoles 56 is cut off to a given actual limit. A trajectory of each electron 57 accelerated at 50 keV is calculated by solving a motion equation. Thus, the final shift or displacement of the position of each electron at the time that it reaches the surface of the resist 53, is obtained as a beam position error relative to a given incident position. According to this assumption, the position displacement amount distribution p(x,y) is determined by convolution integral of the response function r(x,y) and the charge amount distribution C(x,y). That is, the position displacement amount distribution p(x,y) is determined by convolution integral of the response function r(x,y), the charge distribution function g′(x,y) and the exposure distribution E(x,y). Assuming now that a linear proportional relationship is established between the exposure distribution E(x,y) and the position displacement amount distribution p(x,y), the position displacement amount distribution p(x,y) can be determined by convolution integral of the linear response function R(x,y) and the exposure distribution E(x,y) as shown in FIG. 6. Namely, according to the present comparative example, the calculation of the charge amount distribution C(x,y) can be skipped because the position displacement amount distribution p(x,y) is directly introduced from the exposure distribution E(x,y) via the linear response function R(x,y). According to the discussions of the present inventors, however, it has been found out that the position displacement amount distribution p(x,y) determined by the comparative example is different from the results of experiments. The method for calculating the position displacement amount distribution according to the comparative example will be verified with reference to FIGS. 9A, 9B and 10. Upon the verification of the position displacement amount distribution calculating method according to the comparative example, a linear step function was first given as an exposure distribution e(x) as shown in FIG. 9A. According to the present function, the amount of irradiation in an irradiation region is 1 and the amount of irradiation in a non-irradiation region is 0. In the comparative example, the position displacement amount distribution p(x) is determined by convolution integral of the exposure distribution e(x) and the linear response function R(x) as shown in FIG. 9B. Thus, the linear response function R(x) can be determined by differentiation of the position displacement amount distribution p(x). It has been understood that as shown in FIG. 10, the linear response function R1(x) determined by differentiation of the position displacement amount distribution p(x) is different from a desired response function R2(x) and is rotationally unsymmetric at the boundary between the irradiation and non-irradiation regions. It has thus been understood that the assumption of the linear proportional relationship in the comparative example is not established. Therefore, the present inventors have found out a new model for calculating a position displacement amount distribution without using the linear response function R(x). The present inventors have first measured a resist charging effect. FIG. 11 is a diagram showing a test layout used to measure the resist charging effect. Incidentally, the contents of respective parts are shown on a changed scale to make it easier to understand the contents of the respective parts. The test layout TL shown in FIG. 11 is obtained by writing first box arrays 62 on a grid (81×81 grids) 60, whose pitch L1 is 1 mm and whose length L2 of one side is 80 mm, at the amount of irradiation of 12 μC/cm2; then writing an irradiation pad 63, whose length L3 of one side is 40 mm and whose pattern density is 100%, at the center of the layout TL at the amount of irradiation of 21 μC/cm2; and further writing second box arrays 64 on the same grid 60 as the first box arrays 62 at the amount of irradiation of 12 μC/cm2. As shown in enlarged form in FIG. 12, the first box array 62 is of a square pattern whose length L4 of one side is 4 μm, for example. The second box array 64 is of a frame-shaped pattern whose length L5 of one side is 14 μm and whose center has been cut off in a size larger than that of the first box array 62. Here, the pattern density of the irradiation pad 63 was changed like 100%, 75%, 50% and 25% to form the test layouts TL respectively. FIGS. 13A through 13D respectively show irradiation pads 63A, 63B, 63C and 63D whose pattern densities are 100%, 75%, 50% and 25% respectively. The irradiation pad 63A shown in FIG. 13A is comprised of a plurality of rectangular patterns 630 spaced away from one another by a distance L6. The distance L6 is 20 μm, for example. The irradiation pad 63B shown in FIG. 13B is comprised of a plurality of patterns 631 spaced away from one another by the distance L6. Each of the patterns 631 is one formed by causing a plurality of line patterns 631a whose length L7 of short side is 4 μm, for example to intersect one another. The irradiation pad 63C shown in FIG. 13C is comprised of a plurality of patterns 632 spaced away from one another by the distance L6. Each of the patterns 632 has a plurality of square patterns 632a. The length L8 of one side of the pattern 632a is 4 μm, for example. The irradiation pad 63D shown in FIG. 13D is comprised of a plurality of patterns 633 spaced away from one another by the distance L6. Each of the patterns 633 is one in which the number of the patterns 632a constituting the pattern 632 is reduced to half. The positions of the written first and second box arrays 62 and 64 were respectively measured using a resist image measuring method. A position displacement of the irradiation pad 63 due to a charging effect can be measured by subtracting the position of each first box array 62 from the position of each second box array 64. In the present embodiment, the position displacements of the two box arrays 62 and 64 written on the 2 mm-pitched 41×41 grids of the 81×81 grids shown in FIG. 11 were measured to shorten their measurement times. Here, in the present embodiment, the pattern density is changed to 100%, 75%, 50% and 25% as described above with respect to four types of chemical amplification resists A through D where as shown in FIG. 4, the dose D is fixed (21 μC/cm2) regardless of the pattern density ρ and the dose D is changed according to the pattern density ρ, thereby forming test layouts TL respectively. Then, position displacements thereof were measured for every test layout. Measured results of position displacements due to charging effects are shown in FIGS. 14A through 14C. FIGS. 14A through 14C respectively schematically show a position displacement in the vicinity of a boundary between irradiation and non-irradiation regions and a position displacement in the outer periphery of the non-irradiation region with respect to three types of resists A, B and C where a dose D is fixed. As shown in FIGS. 14A through 14C, similar position displacements 71A, 71B and 71C occur so as to expand outside in the outer periphery of the non-irradiation region even with respect to any of the three types of resists A, B and C. On the other hand, both position displacements 70A and 70B occur toward the inside of the irradiation region in the neighborhood of the boundary between the irradiation region and the non-irradiation region in the case of the resists A and B as shown in FIGS. 14A and 14B. These position displacements 70A and 70B differ from each other in that the position displacement 70A in the case of the resist A is approximately symmetric from right to left and up and down, whereas the position displacement 70B in the case of the resist B is asymmetric up and down. Unlike these resists A and B, the position displacement 70C in the case of the resist C shows little position displacement toward the inside of the irradiation region as shown in FIG. 14C. FIGS. 15A through 15D, FIGS. 16A through 16D and FIGS. 17A through 17D are respectively diagrams showing X-direction position displacements each related or corresponding to the average of 11 rows where the dose is constant (21 μC/cm2) without depending on the pattern density with respect to three types of resists A, B and C. These FIGS. 15A through 17D are respectively ones in which X-direction position displacement amounts each corresponding to the average of 11 rows equivalent to thirty-first row through fifty-first row in every other pitch of 81×81 grids are plotted. FIGS. 15A, 16A and 17A respectively show position displacement amounts where the pattern density of the irradiation pad 63 is 25%, FIGS. 15B, 16B and 17B respectively show position displacement amounts where the pattern density of the irradiation pad 63 is 50%. FIGS. 15C, 16C and 17C respectively show position displacement amounts where the pattern density of the irradiation pad 63 is 75%, and FIGS. 15D, 16D and 17D respectively show position displacement amounts where the pattern density of the irradiation pad 63 is 100%. According to the results shown in FIGS. 15A through 17D, it has been understood that each of the position displacement amounts increases as the pattern density becomes higher, and the position displacement amounts are different from one another where the type of resist differs even in the same pattern density. On the other hand, FIG. 18 shows together the X-direction position displacement amount where the pattern density ρ is 25% and the dose D is fixed to 21 μC/cm2 in the case of the resist A, and the X-direction position displacement amount where the pattern density ρ is 100% and the dose D is 5.25 μC/cm2 in the case of the resist A. Since the exposure E is determined by multiplying the pattern density ρ and the dose D by each other as described above here, these two cases are identical in exposure E. Therefore, these two cases are considered to be equal in position displacement amount, but differ from each other in position displacement amount as shown in FIG. 18. This is considered to occur due to the difference between the case in which the dose D is fixed to 21 μC/cm2 without depending on the pattern density ρ and the case in which the dose is changed according to the pattern density ρ (5.25 μC/cm2). Thus, there is a need to enhance the accuracy of calculation of the exposure distribution for the purpose of calculating the position displacement amount distribution with satisfactory accuracy. To this end, the dose distribution D(x,y) is preferably calculated according to the pattern density ρ as executed in step S102 of FIG. 3A. A method of calculating the fogging electron amount distribution F(x,y,σ) executed in step S106 shown in each of FIGS. 3A and 3B to calculate the position displacement amount distribution that enables the description of the above measured results will next be explained. Assume that a function g(x,y) descriptive of a spread distribution of fogged electrons exists with respect to an exposure distribution E(x,y) firstly in above Step S106. This function g(x,y) is a model of a Gaussian distribution such as shown in FIG. 7 in a manner similar to the comparative example and can be expressed like the following equation (2):g(x,y)=(1/πσ2)×exp{−(x2+y2)/σ2} (2) The fogging electron amount distribution (called also “fogging electron amount intensity”) F(x,y,σ) is determined as expressed in the following equation (3) by convolution integral of the spread distribution function g(x,y) and the exposure distribution E(x,y).F(x,y,σ)=∫∫g(x-x″,y-y″)E(x″,y″)dx″dy″ (3) The calculation of the charge amount distribution C(x,y) executed in step S108 shown in each of FIGS. 3A and 3B will next be explained. Assume that a function C(E,F) for determining the charge amount distribution C(x,y) from the exposure distribution E(x,y) and the fogging electron amount distribution F(x,y,σ) exists firstly in above Step S108. The so-assumed function C(E,F) is separated into a variable CE(E) to which irradiation or exposure electrons contribute and a variable CF(F) to which fogging electrons contribute, as expressed in the following equation (4):C(E,F)=CE(E)+CF(F) (4) Further, the function for the irradiation region has been assumed to be the variable CF(F)=0, i.e., C(E,F)=CE(E). On the other hand, the function for the non-irradiation region has been assumed to be the variable CE(E)=0, i.e., C(E,F)=CF(F). As shown in FIG. 19A, the electrons are electrostatically charged uniformly within the irradiation region, that is, the variable was assumed to be CE(E)=co. This co is a constant, e.g., 1. In the non-irradiation region as shown in FIG. 19B, the charge CF(F) is saturated as the fogging electron amount intensity F becomes larger. Therefore, the variable CF(F) in the non-irradiation region will be expressed like the following equation (5):CF(F)=−c1×Fα (5) α in the above equation (5) satisfies a condition of 0<α<1. According to the experiments of the present inventors, it has been found out that α becomes closest to the result of experiments when α is greater than or equal to 0.3 and is smaller than or equal to 0.4, and is suitable. This suitable range of a can be varied according to the used electron beam writing apparatus. The reason why the function CF(F) is defined as expressed in the above equation (5) will be explained here. The measured results of position displacements are obtained with respect to the four types of pattern densities (100%, 75%, 50% and 25%) as shown in FIGS. 15A through 17D. Assuming that the fogging electron amount intensity F at the pattern density of 100% is F100, the fogging electron amount intensities at the respective pattern densities are respectively brought to F100, 0.75×F100, 0.5×F100 and 0.25×F100 in proportion to the pattern density. However, CF(F) is an unknown function. Therefore, there is a possibility that CF(F100), CF(0.75×F100), CF(0.5×F100) and CF(0.25×F100) will not be proportional in intensity and differ from one another in distribution form at the respective pattern densities. When the distribution forms at the respective pattern densities differ in this way, CF(F) must be defined for every pattern density, thus resulting in inconvenience in terms of analysis. Therefore, such a function CF(F) that distribution forms of similar figures are obtained even if the pattern density changes, was defined with respect to a given F. That is, the function CF(F) was defined so as to satisfy the relationship of the following equation (6). a in the following equation (6) indicates a pattern density, and A is a constant.CF(aF)/CF(F)=A (6) If a function related to similar figures is taken, then the distribution form remains unchanged even if CF(F) is not proportional in its entire intensity. The intensity can be adjusted by a combination of the parameters c0 and c1. Thus, there is no need to define CF(F) for every pattern density and one CF(F) may simply be defined with respect to one σ. Therefore, the analysis can be simplified. The optimum combination of the parameters c0, c1 and σi is next determined with reference to FIG. 20. Here, the unit of the parameters c0 and c1 is [μC/cm2], and unit of the parameter σ is [mm]. A step-shaped charge amount distribution CE(E) having a magnitude of c0 is assumed to exist in an irradiation region as shown in FIG. 20. A position displacement amount p0(x) is calculated by convolution integral of the charge amount distribution CE(E) and the pre-calculated response function r(x) (Step S200). In a non-irradiation region, CF(F) is calculated assuming that given α and a fogging electron spread radius (hereinafter called “fog radius”) σ are given (Step S202). The CF(F) is determined with respect to a plurality of fog radii σ. For example, the fog radius σ is assumed to be defined at 1 mm intervals between 1 mm and 24 mm. Then, position displacement amounts p1(x) through pi(x) are determined using the charge amount distribution CF(F) and the response function r relative to the fog radii σ1 through σi. Combining the position displacement amounts p(x) in these irradiation and non-irradiation regions, p(x) is expressed like the following equation (7) (Step S204):p(x)=c0×p0(x)+c1×pi(x) (7) Combinations of parameters c0, C1 and σ at which the above equation (7) is fit best for the result of experiments (fitting) are determined. FIGS. 21A through 21D, FIGS. 22A through 22D and FIGS. 23A through 23D are respectively diagrams showing fitting results about the resists A, B and C. FIGS. 21A, 22A and 23A respectively show fitting results where the pattern density of the irradiation pad 63 is 25%. FIGS. 21B, 22B and 23B respectively show fitting results where the pattern density of the irradiation pad 63 is 50%. FIGS. 21C, 22C and 23C respectively show fitting results where the pattern density of the irradiation pad 63 is 75%. FIGS. 21D, 22D and 23D respectively show fitting results where the pattern density of the irradiation pad 63 is 100%. Using the results shown in FIGS. 21A through 23D, position displacement amount distributions can be determined with satisfactory accuracy as compared with the comparative example. FIGS. 24A through 24C are respectively diagrams showing the optimum combinations of parameters c0, c1 and σ determined by fitting with respect to the resists A, B and C. On the other hand, it has been found out that even when the same kind of resists are used, they are different in optimum fog radius σ when different in pattern density as shown in FIGS. 24A through 24C. It is desired that the fog radius σ does not change depending on the pattern density physically. Although the satisfactory fitting result is obtained with respect to the resist A, the fitting results more satisfactory than the resist A were not obtained with respect to the resists B and C. According to the discussions of the present inventors, these results are considered to be due to the fact that the charge in the irradiation region is assumed to be flat as CE(E)=c0. Therefore, the present inventors have modified the model in such a manner that the influence of fogging electrons is described even in the charge amount distribution in the irradiation region. In such a model, the charge amount distribution in the irradiation region was represented like the following equation (8). However, the charge amount distribution in the non-irradiation region was set in a manner similar to the above model.C(E,F)=CE(E)+CFe(F)=c0−c1×Fα (8) Combinations of parameters c0, c1 and σ determined as to the modified model are shown in FIGS. 25A and 25B. FIGS. 25A and 25B respectively show the combinations of the parameters c0, c1 and σ about the resists B and C. As shown in FIGS. 25A and 25B, the modified model still has dependence of the fog radius σ on the pattern density. Further, it has been found out that although c1 determined by fitting must be convolved or overlaid on the curved line of the equation (4), it has not been overlaid thereon. Therefore, the present inventors have constructed a new generalized model for solving these. The relationship between the charge amount distribution CF(F) in the non-irradiation region and the fogging electron amount intensity F was first represented by a polynomial function like the following equation (9). In the following equation (9), f1, f2 and f3 are constants respectively.CF(F)=f1×F+f2×F2+f3×F3 (9)Next, charge amount distributions C(x,0) at y=0 were calculated for the respective pattern densities using parameter groups shown in FIGS. 24A through 25B. The calculated charge amount distributions C(x,0) are shown in FIG. 26. The reason why the parameter groups shown in FIGS. 24A through 25B are used is that although each optimum fog radius σ changes depending on the pattern density, the distribution form at each pattern density is proper. Incidentally, the accuracy of fitting to be executed below can be improved by calculating the charge amount distribution C(x,y) on a two-dimensional basis without making a limit to y=0. Such an optimum fog radius σ that the charge amount distribution C(x,0) in the non-irradiation region shown in FIG. 26 and CF(F) of the above equation (9) are most fit is then determined. Satisfactory fitting results cannot be obtained where the fog radius σ is excessively small as shown in FIG. 27A and the fog radius σ is excessively large as shown in FIG. 27C. Namely, since data about respective pattern densities are separated from one another when the fog radius σ becomes excessively small or large, the above parameters f1, f2 and f3 cannot be determined. On the other hand, when a satisfactory fitting result is obtained where the optimum fog radius σ is determined as shown in FIG. 27B, and hence the above parameters f1, f2 and f3 can be determined. Next, the fogging electron amount distribution F in the irradiation region is determined using the determined optimum fog radius σ. The charge amount distribution C(E,F) in the irradiation region was represented by a polynomial function like the following equation (10) using the exposure distribution E and the fogging electron amount distribution F determined in the above equation (9). The charge amount distribution CFe(F) to which the fogging electrons contribute is considered in the following equation (10): C ⁡ ( E , F ) = ⁢ C E ⁡ ( E ) + C Fe ⁡ ( F ) = ⁢ ( d 0 + d 1 × ρ + d 2 × D + d 3 × E ) + ⁢ ( e 1 × F + e 2 × F 2 + e 3 × F 3 ) ( 10 ) Then, such parameters d0, d1, d2, d3, e1, e2 and e3 that the charge amount distribution C(x,0) in the irradiation region shown in FIG. 26 and the charge amount distribution C(E,F) of the above equation (10) are most fit, are determined. Here, a fitting result is shown in FIG. 28. The optimum combinations of the parameters d0, d1, d2, d3, e1, e2, e3, f1, f2, f3 and σ determined by fitting of the charge amount distributions in these irradiation and non-irradiation regions are shown in FIG. 29. Here, the unit of the parameters d0 and d1 is [nC/cm2]. The unit of the parameters d2, d3, e1 and f1 is [(nC/cm2)/(μC/cm2)] or [ 1/1000] or [‰]. The unit of the parameters e2 and f2 is [(nC/cm2)/(μC/cm2)2]. The unit of the parameters e3 and f3 is [(nC/cm2)/(μC/cm2)3]. As shown in FIG. 29, the optimum fog radius σ is selected from a range of 8 mm to 16 mm according to the type of resist. This generalized model is different from the model using the above function related to the similar figures and remains unchanged in the optimum fog radius σ even if the pattern density changes. Incidentally, it has been found out that as to the resists A of the same type as shown in FIG. 29, the optimum fog radius σ (=13 mm) taken where the dose D is fixed without depending on the pattern density ρ, and the optimum fog radius σ (=8 mm) taken where the dose D is changed in accordance with the proximity effect correction equation (1) of the backscattered electrons depending on the pattern density ρ are different from one another. Incidentally, since the optimum fog radius σ are different where the resists differ in thickness, the optimum fog radii σ may be individually determined in accordance with the above method with the resists different in thickness as different resists. A position displacement amount distribution p(x,y) is calculated using the so-determined charge amount distribution C(x,y) in step S110 shown in each of FIGS. 3A and 3B. FIGS. 30A through 30C are respectively diagrams showing fitting results between the position displacement amount distributions determined in the generalized model according to the present embodiment and experimental data with respect to resists A, B and C. In the figures, the position displacement amount distributions determined in the generalized model are shown in solid lines and the experimental data are shown in broken lines, respectively. FIGS. 30A through 30C also schematically show position displacements in the neighborhood of a boundary between irradiation and non-irradiation regions, and position displacements in the outer periphery of the non-irradiation region in a manner similar to FIGS. 14A through 14C. In each of the resists A, B and C, the determined position displacement amount distribution and the experimental data approximately coincide with each other. Determining the position displacement amount distributions using the generalized model established by the present inventors as shown in FIGS. 30A through 30C enables the calculation of the position displacement amount distributions with satisfactory accuracy. A beam position displacement due to charging effects is corrected by performing the grid matching as shown in FIG. 5 using the position displacement amount distributions. FIG. 31 is a diagram showing beam irradiation position displacement amounts prior and subsequent to the grid matching. As shown in oblique lines in FIG. 31, each of the beam irradiation position displacement amounts that remain after the grid matching is reduced to a level equivalent to one in the case in which a charge dissipation film or layer is used. On the other hand, it has been found out that satisfactory fitting results are obtained by bringing a contribution of fog electrons in a charge amount distribution for an irradiation region to CFe(F)=0 in a certain kind of resist as in the resists A and D. This is understood even from the parameters e1=e2=e3=0 related to the resists A and D shown in FIG. 29. The generalized model constructed by the present inventors can be adapted even to this type of resists A and D. A physical effect referred to as EBIC (electron beam induced conductivity) at which each resist has conductivity only for a moment by irradiation of an electron beam has been known. The above generalized model is adaptable even to the EBIC. Namely, since the EBIC is of a phenomenon that occurs only by the irradiation of the electron beam, electrical charges are accumulated as a non-irradiation region until the electron beam is applied. The so-accumulated electrical charges escape to the base due to the irradiation of the electron beam. Therefore, CFe(F) based on fog electrons is temporarily reset and starts to be accumulated from zero. Further, once the electron beam is applied, there is a case in which conductivity slightly remains. In this case, the charge amount of fog electrons is reduced after the irradiation of the electron beam as compared with before the irradiation of the electron beam. The generalized model can adapt to such a reduction in charge amount by shifting the parameters f1, f2 and f3 descriptive of the non-irradiation region to the parameters e1, e2 and e3 descriptive of the irradiation region. Incidentally, the present invention is not limited to the above embodiment and can be modified in various ways within the scope not departing from the gist of the invention. For example, although the electron beam is used in the present embodiment, the present invention is not limited to it, but also applicable to a case in which other charged-particle beams such as ion beams are used. The features and advantages of the present invention may be summarized as follows. According to one aspect of the present invention, charge amount distributions in irradiation and non-irradiation regions are calculated using an exposure distribution and a fogging electron amount distribution instead of directly obtaining a position displacement amount distribution from the exposure distribution through a linear response function, and the position displacement amount distribution is calculated based on the charge amount distributions. It is therefore possible to calculate a position displacement of a beam lying on a sample, which has not been calculated where a linear proportional relationship has been taken into consideration. Thus, a beam position displacement due to a charging effect can be corrected with satisfactory accuracy. According to another aspect of the present invention, a distribution of a position displacement amount of a charged-particle beam lying on a sample is calculated based on charge amount distributions in irradiation and non-irradiation regions, and a deflector is controlled based on the position displacement amount distribution. It is therefore possible to correct a beam position displacement due to a charging effect with satisfactory accuracy. Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. The entire disclosure of a Japanese Patent Applications No. 2008-077008, filed on Mar. 25, 2008 and No. 2008-331585, filed on Dec. 25, 2008 including specification, claims, drawings and summary, on which the Convention priority of the present application is based, are incorporated herein by reference in its entirety.
	description	This application claims priority from U.S. Provisional Application No. 61/789,605, filed on Mar. 15, 2013, the entirety of which is hereby fully incorporated by reference herein. This disclosure is related to nuclear reactor plants, and specifically nuclear reactor plants that are configured to have a primary containment that is configured to be separable for ease of refueling, inspection, and maintenance. A first representative embodiment of the disclosure is provided. The embodiment includes a system for refueling a nuclear reactor. The system includes a lower reactor vessel comprising a plurality of fuel rods and a plurality of control rods disposed therein, the lower reactor vessel further comprises an upper flange. An upper reactor vessel comprises a steam generator and pressurizer disposed therein. The upper reactor vessel further comprises a lower flange that matingly engages the upper flange of the lower reactor vessel. A transporter surrounds an outer surface of the upper reactor vessel. The transporter is configured to translate the upper reactor vessel vertically toward and away from the lower reactor vessel and also to translate the upper reactor vessel horizontally toward or away from alignment with the lower reactor vessel. Another representative embodiment of the disclosure is provided. The embodiment includes providing a nuclear reactor primary plant within a stationary lower reactor vessel that encloses a plurality of fuel rods and a plurality of control rods, the lower reactor vessel comprising an open top defined by a first flange. The method further includes providing a movable upper reactor vessel that encloses a steam generator and pressurizer, the upper reactor vessel comprising an open bottom defined by a second flange that matingly engages the first flange during normal operation of the nuclear reactor. The method additionally includes providing a transporter further comprising at least first and second sets of rollers mounted upon respective first and second horizontal tracks that are disposed upon opposite sides of the upper reactor vessel. The method further includes providing one or more lifts disposed between the collar and the first and second sets of rollers, wherein operation of the lifting mechanism changes the vertical position of the upper reactor vessel with respect to the horizontal tracks. Another representative embodiment of the disclosure is provided. The embodiment provides a method of refueling a nuclear reactor. The method includes shutting down and cooling down the nuclear reactor, establishing a long term decay heat removal system in thermal communication with the nuclear reactor, and isolating a reactor vessel from a steam system and a feedwater system connected to the nuclear reactor during normal operation of the nuclear reactor. The method further comprises disconnecting a lower reactor vessel enclosing nuclear fuel and a plurality of control rods from an upper reactor vessel enclosing a steam generator and a pressurizer disposed above the lower reactor vessel. The method further includes lifting the upper reactor vessel upwardly from the lower reactor vessel and sliding the upper reactor vessel away from the lower reactor vessel, to allow access to the lower reactor vessel to remove used or spent nuclear fuel and/or add new nuclear fuel, wherein the upper reactor vessel is surrounded by a transporter, the transporter is slidably connected to first and second rails disposed upon opposite sides of the upper reactor vessel, and the transporter further comprises one or more lifts to upwardly translate the upper reactor vessel away from the lower reactor vessel. Advantages of the present disclosure will become more apparent to those skilled in the art from the following description of the preferred embodiments of the disclosure that have been shown and described by way of illustration. As will be realized, the disclosed subject matter is capable of other and different embodiments, and its details are capable of modification in various respects. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive. Turning now to FIGS. 1-10, a nuclear reactor 10 is shown. The nuclear reactor 10 may be a pressurized water reactor (PWR), boiling water reactor (BWR), or other types of reactor plants known in the art, such as various types of light water reactors. While one of ordinary skill in the art will appreciate upon detailed review of the subject specification and figures that the disclosed subject matter is applicable to a multitude of different types of nuclear plant designs, the subject specification is described herein with reference to a pressurized water reactor, and more specifically, a small modular reactor. With specific reference to FIG. 1, the nuclear reactor 10 includes a lower reactor vessel 20 and an upper reactor vessel 50 disposed above the lower reactor vessel 20. The lower reactor vessel 20 encloses the nuclear fuel, normally disposed within a plurality of fuel rods 5, and a plurality of control rods (depicted as disposed within control rod guide frames 6) that are slidingly disposed in conjunction with the plurality of fuel rods 5 to control the operation of the nuclear reactor (in conjunction with other portions of the power plant). The lower reactor vessel 20 is maintained full of subcooled primary coolant that is circulated therethrough and through the upper reactor vessel 50, which may be disposed directly above the lower reactor vessel 20. The upper reactor vessel 50 encloses a steam generator 60 and a pressurizer 90 that is normally disposed within the very top portion of the upper reactor vessel 50. The steam generator 60 is configured to receive the hot primary coolant (which flows from the lower reactor vessel 20 normally through an inner central riser 64), through a plurality of parallel reactor coolant pumps 85, and with parallel flow through a plurality of steam generator tubes 68 disposed outboard of the central riser 64. The steam generator 60 includes a secondary portion that receives an input of feedwater through a feed input 72. The feedwater flows around the outside of the plurality of heat tubes 68 and boils to steam due to heat transfer from the hot primary coolant flowing through the heat tubes 68. The steam created within the steam generator 60 (which may be high quality steam, or in other embodiments superheated steam) leaves the steam generator 60 through one or more steam outlets 74. The steam leaving the steam generator 60 is piped to a plurality of turbines (not shown, which may be within or outside of the containment 1, shown in FIGS. 3 and 4) to generate electrical power. The steam powering the turbines is condensed and pumped back to steam generator 60 as feedwater to continue the cycle. The upper reactor vessel 50 may further include a pressurizer 90, which is fluidly connected to the primary coolant system, such as in direct fluid communication with the primary coolant within the upper reactor vessel 50, such as in the central riser 64 or the primary tube sheet 82. The pressurizer 90 includes a plurality of heaters that are constantly and/or cyclically operated to increase the temperature of the water therein to saturation temperature of the primary coolant for the given pressure of the primary coolant within the pressurizer 90. By forming a steam “bubble” within the top of the pressurizer, the remainder of the primary coolant, which is at a lower temperature, but the same pressure as the coolant within the pressurizer 90 remains a subcooled liquid, as necessary for removing sufficient heat from the fuel rods to remove the heat produced within the lower reactor vessel 20. The flow of primary coolant through the upper and lower reactor vessels 20, 50 is urged by a plurality of reactor coolant pumps 85, which are normally disposed within the upper reactor vessel 50, and specifically may take suction from or propel primary coolant into the tube sheet 82 of the steam generator 60, such that heated primary coolant is urged into parallel flow through the plurality of tubes 68 in the steam generator 60. As best shown in FIG. 1, the lower reactor vessel 20 forms a primary containment for the nuclear fuel and the primary coolant disposed within the lower reactor vessel 20 during normal operation of the reactor 10. In some embodiments, the lower reactor vessel 20 is formed to minimize the number of penetrations through the side walls thereof, for various purposes such as to limit or eliminate the potential for a loss of coolant from the nuclear reactor 10. The top of the lower reactor vessel 20 is open with an upper flange 21 disposed around the opening 22 into the lower reactor vessel 20. The upper reactor vessel 50 may be disposed directly above the lower reactor vessel 20, with the upper reactor vessel 50 including a lower flange 51 that matingly engages the upper flange 21 of the lower reactor vessel 20. The upper reactor vessel 50 includes an opening 52 that allows for primary coolant flow from the lower reactor vessel 20 and into the upflow portion 64, and flow from the plurality of parallel tubes 68 to return to the lower reactor vessel 20. As appreciated with review of FIG. 1, the respective openings 22, 52 of the lower and upper reactor vessels 20, 50 are in communication with each other when the upper flange 21 and lower flange 51 of the lower reactor vessel 20 and upper reactor vessel 50, respectively, are coupled or fixed together. In some embodiments, the upper flange 21 and lower flange 51 of the lower reactor vessel 20 and upper reactor vessel 50, respectively, may be fixed together with a plurality of fasteners 24 that extend above the lower flange 51 and connect either through the upper and lower flanges 21, 51, or alternatively are received within a respective threaded aperture in the upper flange 21. A shown in FIGS. 2-4, a transporter 100 may be disposed around the upper reactor vessel 50 and connectable therewith to cause one or both of vertical translation of the upper reactor vessel 50 away from the lower reactor vessel 20 and horizontal translation of the upper reactor vessel 50 away from the lower reactor vessel 20. The transporter 100 may be removably connectable to the upper reactor vessel 50, such that during normal operation of the nuclear reactor 10 the transporter does not make contact with the upper reactor vessel 50. The transporter 100 is maintained in place surrounding portions of the upper reactor vessel 50 such that the transporter 100 may quickly and conveniently be configured to contact and vertically translate (with one or more lifts 120, discussed below) and/or horizontally translate the upper reactor vessel 50 (including all components disposed therein) to allow for convenient refueling of the lower reactor vessel 20 and convenient inspection and/or maintenance of the upper reactor vessel 50. As best shown in FIGS. 5-6, the transporter 100 may include a platform 163 that surrounds all or a portion of an outer circumference of the upper reactor vessel 50. In some embodiments, the platform 163 may be disposed just below the tube sheet portion 82a of the upper reactor vessel 50, which encloses the primary tube sheet 82. The tube sheet portion 82a is formed within the upper reactor vessel 50 with a larger diameter than the diameter of the upper reactor vessel 50 below the tube sheet portion 82a, which surrounds the portion enclosing the plurality of primary tubes 84 that are disposed outboard of the upflow portion 64. The tube sheet portion 82a of the upper reactor vessel 50 defines a ledge 82b that extends radially outward from the portion of the upper reactor vessel 50 that defines the tube sheet portion 82a. In some embodiments, a lift 120, or in some embodiments, a plurality of lifts 120 are disposed upon the platform 163 (or upon another suitable structure of the transporter 100 for interaction with the upper reactor vessel 50) and are positioned to be clear of the tube sheet portion 82a (and the upper reactor vessel 50 overall) during normal operations of the reactor plant 10, but during shutdown conditions, the plurality of lifts 120 may be operated to extend upward to contact the ledge 82b and (once the upper reactor vessel 50 is decoupled from the lower reactor vessel 20) lift the upper reactor vessel 50 off of the lower reactor vessel 20. FIG. 7 provides a side view of the upper reactor vessel 50 lifted vertically off of the lower reactor vessel 20. The plurality of lifts 120 may be hydraulically or electrically operated and are configured to expand, and with sufficient force to translate the upper reactor vessel 50 upward. In some embodiments, four or another suitable number of lifts 120 may be positioned about the platform 163 and in some embodiments, the plurality of lifts 120 may be configured to simultaneously operate to maintain the upper reactor vessel 50 in a vertical orientation along its length (i.e. with the exposed surface of the lower flange 51 of the upper reactor vessel 50 in a horizontal planar alignment). In some embodiments, the plurality of lifts 120 may be disposed at equal spacing along the circumference of the ledge 82b, while in other embodiments, the plurality of lifts 120 may be otherwise staggered as appropriate for consistent lifting and support of the upper reactor vessel 50 both in static and dynamic conditions (i.e. when the upper reactor vessel 50 is slid horizontally as discussed below). FIGS. 5-6 schematically depict lifts 120 with a scissor mechanism to increase the working height of the lifts 120, although one of ordinary skill in the art will appreciate that other designs of hydraulic or electric lifts (or even other types of suitable lifts) may be provided. In some embodiments, the lifts 120 (and/or the platform 163) may include structure that engages the tube sheet portion 82a of the upper reactor vessel 50 (or vice versa) when the upper reactor vessel 50 has been lifted vertically by the plurality of lifts 120. The engagement between the upper reactor vessel 50 and the lifts 120 and/or platform 163 may also provide the system with increased support and stability in seismic conditions. The engagement between the tube sheet portion 82a of the upper reactor vessel 50 and the platform 163 or lifts 120 (which in some embodiments are fixed to the platform 163) may be with one or more male portions that are fixed to one of the components and one or more respective female portions that are fixed to the other of the components, with the male and female portions automatically engaging when the lifts 120 vertically raise the upper reactor vessel 50 to a certain height above the lower reactor vessel 20. In other embodiments, other automatic structures could be used, potentially in combination with a manual attachment system (which in some embodiments may be the sole attachment system between the platform 163 and upper reactor vessel 50). As shown in FIGS. 9 and 10, the lifts may include two or more flanges 1200 that are configured to selectively engage the ledge 82b of the tube sheet 82 (or another convenient surface) of the upper reactor vessel 50. The flanges 1200 may be normally positioned outboard of the upper reactor vessel 50 such that the flanges do not contact the upper reactor vessel 50 during normal operations of the plant. The flanges 1200 may each be connected to a hydraulic actuator, such as a ram (not shown, but conventional) at one or more locations upon the respective flange 1200, such as one or both end portions 1202. The end portions 1202 of the flange 1200 may be connected to the respective hydraulic ram with bolted connections (such as through the holes 1203 depicted in the figures, or through another connection. The hydraulic ram may be supported by the transporter 100, and specifically by one of the plurality of platforms (such as platform 160) supported upon the transporter. The hydraulic rams may be configured to move the respective flanges 1200 laterally toward and away from the upper reactor vessel 50, to allow the flanges 1200 (and in some embodiments via the seat 1221 upon the plurality of supports 1220, or a removable shim 1209, each discussed below) to engage the ledge 82a of the upper reactor vessel 50 when the transporter 100 moves vertically. In some embodiments, the amount of initial vertical motion of the transporter 100 with respect to the (stationary) upper reactor vessel 50 may be limited to avoid any stress on piping and connections that extends from the transporter 100 to the upper reactor vessel 50, and to minimize the amount of disconnection of piping and connections that is needed to lift the transporter 100 with respect to the upper reactor vessel 50. The flanges 1200 may each include a plurality of supports 1220 that extend from the upper surface 1208 of the flange 1200. The supports 1220 may each include a seat 1221 which contacts the ledge 82b of the upper reactor vessel 50 when so engaged, and a back 1222 that extends upwardly from the seat 1221 and may be a short distance (such as 0.5, 1.0, or 1.5 inches) from the side of the tube sheet portion 82a when the flange 1200 engages the upper reactor vessel 50. The plurality of backs 1222 are each and collectively configured to provide lateral support for the upper reactor vessel 50, such as for seismic concerns, and the plurality of backs 1222 upon each of the flanges 1200 collectively provide lateral support in various lateral directions. In some embodiments, the flange 1200 may include a plurality of backs 1222 disposed upon the top surface 1208 of each flange, but the top surface 1208 of the flange is configured to engage the ledge 82b, with the backs 1222 each providing lateral support when the flanges 1200 engage and lift the upper reactor vessel 50. FIG. 9 depicts two flanges 1200 disposed upon opposite sides of the upper reactor vessel 50 and positioned in a normal position, each aligned radially outward from the upper reactor vessel 50, and specifically from the tube sheet 82a. FIG. 10 depicts the two flanges 1200 disposed in registry and under the ledge 82, with the flanges 1200 raised (normally by the transporter 100, or alternatively by a separate lifting mechanism) to provide contact between the seats 1221 (with or without the optional shim 1209) and the ledge 82b, with the backs 1222 each positioned with respect to the upper reactor vessel 50 to provide lateral support thereto in various lateral directions. As best shown in FIGS. 2-4, the transporter 100 may be mounted upon (and hanging by) two or more horizontal rails 202, 204 which are mounted within the containment vessel 1 for the nuclear reactor system 10. In some embodiments, the first and second horizontal rails 202, 204 may be mounted such that they extend across opposite sides of the outer surface of the upper reactor vessel 50, and in some embodiments across a mid-portion of the height of the upper reactor vessel 50. The transporter 100 may include two horizontal cranes 112, 114 (which may the same or similar to structures known as “gantry” cranes) which extend between the first and second horizontal rails 202, 204 with opposite ends of each crane 112, 114 being rollably mounted thereon. The opposite ends of each crane 112, 114 may be rollably mounted upon the respective horizontal track with a motorized roller 116, with one or more wheels 117 that rolls upon the track. The roller 116 may be electric, hydraulic or powered through another energy source or source of torque. In some embodiments, the wheels 117 of the roller 116 may be selectively locked in a fixed position (operationally when the nuclear plant 10 is aligned for normal operation) to avoid unwanted movement of the rollers 116. In some embodiments, the rollers 116 may each include one or more wheels 117 that rest upon an upper surface of the respective track 202, 204, and in some embodiments may include other wheels (or alignment structures) that engage side portions of the track (normally the outboard side of the track that faces away from the upper reactor vessel 50) for additional alignment between the roller 116 and the track. As will be understood, the rollers 116 may be operated in unison such that the first and second cranes 112, 114 move in unison and in the same direction, to appropriately support the upper reactor vessel 50 while moving horizontally. As depicted in FIG. 2, each of the first and second cranes 112, 114, may support cross members 113, 115, which are disposed upon opposite sides of the upper reactor vessel 50 and extend between the first and second cranes 112, 114. Each of the cross members 113, 115 may be fixed to both cranes 112, 114 such that the system (i.e. the first and second cranes 112, 114 and the first and second cross members 113, 115) disposed therebetween) defines a rigid support structure, or collar, that fully surrounds the outer circumference of the upper reactor vessel 50. The cranes 112, 114 and/or the cross member 113, 115 (or other structures within the transporter 100 that are ultimately mounted to the cranes 112, 114 and/or cross members 113, 115), may rigidly support a plurality of vertical support members 130 that extend along a portion of the height of the upper reactor vessel 50 and in parallel with the vertical longitudinal axis of the upper reactor vessel 50. The vertical support members 130 are configured to support a plurality of spaced apart platforms 160 (generally as shown in FIG. 2) 161, 162, 163 (specific potential locations depicted in FIGS. 3-4) that are disposed around the circumference of the upper reactor vessel 50 at locations proximate to the upper reactor vessel 50 where either frequent inspections must occur, or in locations where support for various accessories, cables, and pipes associated with the various systems within the upper reactor vessel 50 must be supported. In some embodiments, the platforms 160 may be disposed with respect to the upper reactor vessel 50 such that no structure of the platform 160 (and in some embodiments the entire transporter system 100) contacts the upper reactor vessel 50 (or insulation or lagging applied to the outer surface of the upper reactor vessel 50) during normal operation of the reactor plant 10, to prevent any conduction heat transfer from the upper reactor vessel 50 to the transporter 100, which could decrease the thermal efficiency of the system. A method of preparing a nuclear reactor for refueling is now described. Initially, the nuclear reactor 10 is aligned for normal operation with the upper reactor vessel 50 fixed above the lower reactor vessel 20, with primary coolant flowing therethrough. When shutdown and refueling operations are necessary, the reactor is shut down as is known generally in the art, such as by translating the control rods 6 downward with respect to the fuel rods 5, either gradually, or by a scram (step 400) during a rapid shutdown of the reactor 5 (i.e., placing the reactor 5 in a subcritical condition). After the reactor 5 is shut down, the temperature and pressure of the primary coolant is reduced according to processes known generally in the art. Next, or in parallel, decay heat removal may be intiated to continue to remove decay heat from the reactor during shut down operations (step 410), by, for example, establishing a long-term decay heat removal system (not shown) in thermal communication with the nuclear reactor 5. After the ability to remove decay heat from the reactor is verified, the primary coolant is drained from the overall reactor plant, such that level of primary coolant is preferably just below the top of the flange 21 of the lower reactor vessel 20 (step 420). Next, the steam piping is disconnected from the one or more steam outlets 74 on the upper reactor vessel 50, and feed piping disconnected from the one or more feedwater inlets 72, and any other fluid connections with the upper reactor vessel 50 (such as, for example, a pressure relief system) are disconnected therefrom. Finally, any electrical connections with the upper reactor vessel 50 are removed (as needed to vertically and horizontally translate the upper reactor vessel 50) (step 430). Next, upper and lower reactor vessels 50, 20 are disconnected (step 440) by removing or withdrawing a plurality of fasteners 24 from at least the lower vessel flange 21, and potentially from both flanges 21, 51. In some embodiments, the fasteners 24 may be removed from the upper reactor vessel 50, while in other embodiments, the fasteners 24 may be stowed in a fixed position upon the upper reactor vessel 50. Once the fasteners 24 are withdrawn, the plurality of lifts 120 are operated, upon the platform 163 or upon another convenient surface of the transporter 100, to engage the upper reactor vessel 50, such as the ledge 82b upon the tube sheet portion 82a of the upper reactor vessel 50 (step 450). In some embodiments, the lifts 120 are simultaneously operated and at the same speed such that each lift 120 engages the upper reactor vessel 50 at substantially the same time and at substantially the same speed to maintain the vertical alignment of the upper reactor vessel 50 as it is lifted vertically off of the lower reactor vessel 20. In embodiments where the upper reactor vessel 50 and lifts 120 (and/or platform 163) including the self-engagement structures or mechanisms (or are configured to receive the manual engagement structures described above), these self-engagement structures or mechanisms (or the manual engagement structures) are implemented to fix the upper reactor vessel 50 ultimately to the transporter. The upper reactor vessel 50 is lifted vertically by the plurality of lifts 120 until there is a sufficient space between the upper and lower reactor vessels 20, 50. In some embodiments, the lifts may lift the upper reactor vessel 50 a distance within a range of up to about one foot (inclusive of all distances below one foot). In some embodiments, the upper reactor vessel 50 may be lifted six inches. In still other embodiments, the upper reactor vessel 50 may be lifted a larger distance as needed, such as between one and five feet (inclusive of all distances therewithin). The plurality of lifts 120 may be configured to lift the upper reactor vessel 50 a suitable distance to allow it to clear all components associated with the lower reactor vessel 20, such that the upper reactor vessel 50 can be translated horizontally away from alignment with the lower reactor vessel 20. Once the upper reactor vessel 50 is lifted, the transporter 100 is energized to horizontally translate the upper reactor vessel away from alignment with the lower reactor vessel 20 (step 460). The transporter 100 causes the plurality of rollers 116 that rest upon the first and second tracks 202, 204 (and may be connected one of the first or second cranes 112, 114, or other support structure forming the collar or the transporter 100) to roll upon the tracks 202, 204 to translate the upper reactor vessel 50 away from alignment with the lower reactor vessel 20. When the transporter 100 and upper reactor vessel 50 reach the final location for maintenance and inspection, in some embodiments, the plurality of lifts 120 may lower the upper reactor vessel 50 to its normal height, to obtain additional stability and minimize the operation of the plurality of lifts 120 (step 470). In some embodiments, additional automatic or manual systems may be implemented to fix the transporter 100 (or various components of the transporter 100) to the upper reactor vessel 50 for support to the upper reactor vessel 50. In some embodiments, the containment 1 may include a lower vessel compartment 300 and one or more auxiliary compartments 240 located outboard of the lower vessel compartment 300. In these embodiments, transporter 100 rolls the upper reactor vessel 50 out of the lower vessel compartment 300 and to one of the auxiliary compartments 240, where inspection of the inner volume of the upper reactor vessel 50 can occur without interfering with refueling operations of the lower reactor vessel 20 within the lower vessel compartment 300. In some embodiments, the lower vessel compartment 300 and the auxiliary compartment 240 may be separated with a movable panel or door 242 (FIG. 4) or other structure that selectively separates the two compartments, both to minimize radiation exposure within the auxiliary compartment, as well to provide a water seal between the compartments in situations where the lower vessel compartment 300 is flooded for decay heat removal or for use in refueling activities. Once the refueling and inspection work is completed (step 480), the upper reactor vessel 50 is returned to alignment with the lower reactor vessel 20 by operating the plurality of rollers 116, cranes 202, 204 or other structure of the transporter 100 (step 490). In embodiments where the upper reactor vessel 50 was lowered prior to maintenance and inspection, the plurality of lifts 120 again raise to the upper reactor vessel 50 to the lifted height to allow for clearance of the upper reactor vessel 50 above the lower reactor vessel 20. Upon proper alignment of the upper reactor vessel 50 above the lower reactor vessel 20, the plurality of lifts 120 are lowered to lower the upper reactor vessel 50 upon the flange 21 of the lower vessel 20 (step 500). The plurality of fasteners 24 are placed to compress the opposite flanges 21, 51 together (step 510), and the reactor and steam plant is restored for proper operation (i.e. by restoring steam and feed piping, electrical connections, etc.) and the plant is restored for operation (step 520). In embodiments where the nuclear plant 10 is operated with dual operating nuclear reactor plants, which may be designed to operate simultaneously (with the same or different turbines) together, or independently, the first and second rails 202, 204 may extend through the containment 1 to interact with a second transporter system (not shown) that surrounds the other reactor vessel (not shown), to allow for separation and movement of the upper reactor vessel of the other reactor vessel (either to the same auxiliary compartment 240, or a different auxiliary compartment (not shown)) from the other plant for refueling, inspection and/or maintenance. In some embodiments, a transporter may be provided in conjunction with different types of nuclear reactor plants, such as other types of PWRs or BWRs. By way of example, in PWR designs where the pressurizer and steam generator are fluidly connected to the reactor vessel, but are mounted externally of the reactor vessel, a transporter may be provided to selectively engage and lift a reactor vessel head (which normally supports external control rod drive mechanisms as well as other components or structures of a reactor plant) to allow the vessel head to be moved away and returned to the reactor vessel as needed for refueling and maintenance operations. The transporter may be configured to constantly surround (but in some embodiments to not make contact in a normal operational configuration) the reactor vessel for convenient engagement and movement of the reactor vessel head, such that operations to move the reactor vessel head play only a minimal role in the overall time needed to perform certain maintenance and refueling activities where access to the internals of the reactor vessel is necessary. One of ordinary skill in the art would understand how to modify the transporter 100 and its associated structure disclosed above with respect to the nuclear reactor 10 in order to operate with respect other types of reactor designs with a thorough review of this disclosure. While the preferred embodiments of the disclosure have been described, it should be understood that the disclosure is not so limited and modifications may be made without departing from the disclosure. The scope of the invention is defined by the appended claims, and all devices, structures, systems, and methods that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.
	claims	1. A gantry type particle beam irradiation system which comprises a gantry and is configured such that a particle beam is extracted from a circular accelerator, in a case where a direction in a circular track plane of the circular accelerator is defined as X direction in a plane which is perpendicular to a travelling direction of the particle beam at an extraction position of the circular accelerator, and the direction which is perpendicular to X direction in a plane which is perpendicular to the travelling direction of the particle beam is defined as Y direction, the particle beam has small emittance in X direction and large emittance in Y direction, and the particle beam which is transported by a particle beam transportation unit is irradiated from an irradiation nozzle installed in the gantry to an irradiation target,wherein the irradiation nozzle has a ridge filter,an angle of the gantry, with which the particle beam is transported so as for emittance in X direction and emittance in Y direction at the extraction position of the circular accelerator to be separated and to maintain each emittance at a position where the particle beam is incident on the irradiation nozzle, is defined as a reference angle, in the state where the gantry is the reference angle the ridge filter is installed so as for the direction in which emittance in X direction is maintained is tilted to the direction which is perpendicular to a ridge of the ridge filter by a predetermined angle. 2. The particle beam irradiation system according to claim 1, wherein the predetermined angle is in a range of 20 degrees to 70 degrees. 3. The particle beam irradiation system according to claim 1, wherein the predetermined angle is 45 degrees. 4. The particle beam irradiation system according to claim 1, wherein the ridge filter has a rectangular base, and a direction which is perpendicular to a ridge of the ridge filter is tilted to a direction to which one side of the base extends by a predetermined angle. 5. The particle beam irradiation system according to claim 1,wherein the gantry has the configuration in which a plane which is formed by a center line of the particle beam which is deflected in the gantry is a flat plane, at an angle of the gantry in which the flat plane is perpendicular to the circular track plane of the circular accelerator, a direction in which emittance in the X direction of the particle beam in the irradiation nozzle is maintained is defined as a reference axis and the ridge filter is installed by tilting a direction which is perpendicular to a ridge of the ridge filter to a direction of the reference axis. 6. A particle beam therapy system comprising a circular accelerator, a particle beam transportation unit for transporting a particle beam which is extracted from the circular accelerator, a treatment table for laying a patient and a gantry-type particle beam irradiation system according to claim 1.
	claims	1. A method for evaluating the presence of a pharmaceutical material in a pharmaceutical process, comprising:providing the pharmaceutical material to a processing structure, the processing structure including at least one of a vessel or a pipe,removing at least part of the pharmaceutical material from said processing structure,transmitting at least one signal to be propagated in said processing structure,receiving the thus propagated signal,comparing at least one parameter value of the received signal with a reference value, andevaluating, based on the comparison of said values, if there is any remaining pharmaceutical material in the processing structure. 2. The method as claimed in claim 1, comprisingusing said processing structure as a waveguide, wherein transmitting a signal comprises transmitting at least one electromagnetic wave to be propagated in said processing structure, and wherein receiving the signal comprises receiving the thus propagated electromagnetic wave,wherein comparing at least on parameter value of the received signal comprises comparing at least one parameter value related to the received electromagnetic wave with said reference value. 3. The method as claimed in claim 2, wherein said electromagnetic wave has a frequency in the range of about 300 MHz to about 300 GHz. 4. The method as claimed in claim 2, wherein said received electromagnetic wave is a reflected wave received at substantially the same location from where it was transmitted, wherein the transmission and reception are preferably performed by means of a single antenna. 5. The method as claimed in claim 2, wherein a first antenna is used for transmitting the electromagnetic wave and a second antenna is used for receiving the propagated electromagnetic wave. 6. The method as claimed in claim 2, comprising receiving said at least one electromagnetic wave at two or more locations by at least two antennas. 7. The method as claimed in claim 2, comprising transmitting electromagnetic waves from two or more locations by at least two antennas. 8. The method as claimed in claim 2, comprising at least one of transmitting and receiving at least one electromagnetic wave from at least one of an array of transmitters and an array of receivers provided on a common module. 9. The method as claimed in claim 1, wherein the signal is transmitted in a direction substantially parallel to a direction of flow of the pharmaceutical material. 10. The method as claimed in claim 9, wherein the direction of signal transmission is with the direction of flow of the pharmaceutical material. 11. The method as claimed in claim 9, wherein the direction of signal transmission is against the direction of flow of the pharmaceutical material. 12. The method as claimed in claim 1, wherein transmitting a signal comprises transmitting at least one acoustic wave to be propagated in said processing structure, and wherein receiving the signal comprises receiving the thus propagated acoustic wave,wherein comparing at least one parameter value of the received signal comprises comparing at least one parameter value related to the received acoustic wave with said reference value. 13. The method as claimed in claim 1, comprising determining the reference value by, when a known amount of material is present in processing structure, transmitting at least one signal to be propagated in said processing structure, receiving the propagated signal, and determining the value of at least one parameter related to the received signal. 14. The method as claimed in claim 1, wherein said at least one parameter is selected from the group consisting of an amplitude, a phase, a power, and a frequency of the received signal. 15. The method as claimed in claim 1, comprising using at least one reflector in the propagation path of the transmitted signal in order to at least partially block the propagation of the transmitted signal and at least partially reflect the transmitted signal. 16. The method as claimed in claim 1, comprising adjusting the frequency of the signal to be transmitted so that a resonance will occur in the processing structure, wherein measurements are performed in a resonance mode of operation. 17. The method as claimed in claim 1, wherein said pharmaceutical material is a powder. 18. The method as claimed in claim 1, wherein the signal is transmitted into an input end of the processing structure. 19. A method for evaluating a processing structure used in a pharmaceutical process, the processing structure comprising a lumen adapted to receive materials, the method comprising:providing the processing structure,using the processing structure as a waveguide by transmitting at least one signal in the form of at least one electromagnetic wave to be propagated along a longitudinal axis of the lumen and guided by the processing structure,receiving the propagated electromagnetic wave;comparing at least one parameter value of the received electromagnetic wave with a reference value related to a reference state of the interior of the processing structure; andevaluating, based on the comparison of said values, if the present state of the interior of the processing structure is different from said reference state. 20. The method as claimed in claim 19, wherein said states are related to material content in the processing structure, wherein the processing structure contains a first amount of material in the reference state and a second amount of material in the present state, wherein the method comprises evaluating, based on the comparison of said values, whether said second amount is different from said first amount. 21. The method as claimed in claim 20, wherein said first amount is substantially zero and the method comprises evaluating whether there is any material in the processing structure. 22. The method as claimed in claim 20, wherein said first amount is a non-zero amount of material and the method comprises determining whether a certain filling level has been reached. 23. The method as claimed in claim 20, further comprising changing the amount of material inside the processing structure based on the evaluation of whether the second amount is different from the first amount. 24. The method as claimed in claim 19, further comprising controlling the pharmaceutical process based on said at least one parameter, wherein the action of controlling comprises at least stopping the pharmaceutical process and continuing the pharmaceutical process. 25. The method as claimed in claim 19, wherein at least the transmitting, receiving, and evaluating are performed continuously for monitoring the progress of the pharmaceutical process. 26. The method as claimed in claim 19, wherein said states are related to the internal geometry of the processing structure, the processing structure has a first internal geometry in the reference state at a first point of time and a second internal geometry in the present state at a second point of time, and the method comprises evaluating, based on the comparison of said values, if a geometrical change on the interior of the processing structure has occurred between said first and second points of time. 27. A method for evaluating a solid material in a pharmaceutical process, comprising:providing a waveguide configured for directing the propagation of electromagnetic waves,providing the solid material in said waveguide,transporting at least part of the solid material in said waveguide,removing at least part of the solid material from said waveguide,transmitting at least one signal, in the form of an electromagnetic wave, to be propagated in said waveguide,receiving the propagated electromagnetic wave, andusing at least one parameter related to the received electromagnetic wave to evaluate an amount of the solid material remaining in the waveguide. 28. A method of monitoring a process of transporting an amount of material through a pharmaceutical processing structure, the pharmaceutical processing structure comprising at least one of a vessel or a pipe, comprising:using the processing structure as a waveguide by transmitting signals in the form of a plurality of electromagnetic waves to be propagated along and guided by the processing structure,receiving the propagated plurality of electromagnetic waves;comparing at least one parameter value of the received plurality of electromagnetic waves with a reference value that is indicative of a reference state of the interior of the processing structure before said amount of material has been introduced into the processing structure; wherein when said amount of material is introduced into the processing structure, said parameter value will become different from said reference value, and when said amount of material has been transported through the processing structure, said parameter value will about equal said reference value.
	claims	1. A method for supersonic lean fuel combustion comprising the steps of:providing an apparatus comprising:a plasma arc torch comprising:a cylindrical vessel having a first end and a second end,a tangential inlet connected to or proximate to the first end of the cylindrical vessel,a tangential outlet connected to or proximate to the second end of the cylindrical vessel,an electrode housing connected to the first end of the cylindrical vessel such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, anda hollow electrode nozzle connected to the second end of the cylindrical vessel such that a center line of the hollow electrode nozzle is aligned with the longitudinal axis of the cylindrical vessel,a cyclone combustor connected to the hollow electrode nozzle of the plasma arc torch, wherein the cyclone combustor has a tangential entry, a tangential exit, and an exhaust outlet, anda turbocharger having a turbine connected to a compressor via a shaft, wherein a turbine entry is connected to the tangential exit of the cyclone combustor, a compressor exit is connected to the tangential entry of the cyclone combustor;generating a vortex within the cylindrical vessel of the plasma arc torch by injecting a gas, fluid or steam into the tangential inlet of the plasma arc torch such that a portion of the gas, fluid or steam discharges out of the tangential outlet of the plasma arc torch;creating an electric arc between the electrode and the hollow electrode nozzle to generate a plasma that is confined by the vortex and is discharged through the hollow electrode nozzle into the cyclone combustor;generating a combustion air whirl flow within the cyclone combustor by injecting a compressed air into the tangential entry of the cyclone combustor;converting a fuel to one or more hot gases using the plasma; andextracting a rotational energy from at least a portion of the one or more hot gases that pass from the tangential exit of the cyclone combustor into the turbine entry using the turbine of the turbocharger. 2. The method as recited in claim 1, further comprising a first valve disposed between the tangential exit of the cyclone combustor and the turbine entry. 3. The method as recited in claim 1, further comprising a compressor inlet valve connected to a compressor entry of the compressor. 4. The method as recited in claim 3, wherein the compressor inlet valve comprises:a volute with a tangential entry;a cone-shaped reducer connected to the volute;a linear actuator connected to the volute,a cone-shaped stopper disposed within the cone-shaped reducer and operably connected to the linear actuator;a controller connected to the linear actuator; andadjusting a gap between the cone-shaped stopper and the cone-shaped reducer using the controller to increase or decrease a mass flow while maintaining a whirl velocity to closely match a compressor tip velocity. 5. The method as recited in claim 1, further comprising:a first stage recuperator connected to a discharge exhaust of the turbine and the compressor exit;a second stage recuperator connected to a discharge exhaust of the cyclone combustor;heating a compressed air from the compressor using the one or more hot gases within first stage recuperator and the second stage recuperator; andintroducing the compressed air into the cyclone combustor via the tangential entry of the cyclone combustor. 6. The method as recited in claim 5, further comprising a second valve disposed between the discharge exhaust of the cyclone combustor and the second stage recuperator. 7. The method as recited in claim 1, further comprising a pinon gear attached to the shaft between the turbine and the compressor. 8. The method as recited in claim 7, further comprising a bull gear and a drive shaft connected to the pinion gear. 9. The method as recited in claim 8, further comprising a motor generator connected to the drive shaft. 10. The method as recited in claim 8, further comprising a high bypass fan connected to the drive shaft. 11. The method as recited in claim 8, further comprising a propeller connected to the drive shaft. 12. The method as recited in claim 1, wherein the first electrode is hollow and further comprising the step of introducing a fuel into the hollow first electrode. 13. The method as recited in claim 1, further comprising the step of introducing a fuel into the tangential inlet of the plasma arc torch. 14. The method as recited in claim 1, further comprising the step of introducing the fuel into the plasma that discharges through the hollow electrode nozzle.
	claims	1. A grating interferometer system for obtaining absorption, differential phase contrast (DPC) and dark-field data from quantitative X-ray images from a sample, the grating interferometer system comprising:an X-ray source;gratings including one of:a phase grating and an analyzer grating; ora source grating, said phase grating and said analyzer grating;a position-sensitive detector;means for recording images of said position-sensitive detector;means for evaluating intensities for each pixel in a series of the quantitative X-ray images, in order to identify characteristics of an object for each individual pixel as at least one of an absorption-dominated pixel, a DPC-dominated pixel, and an X-ray dark-field dominated pixel;means to tilt either said phase grating or said analyzer grating by a predetermined angle; andmeans to move the sample, said x-ray source, or said gratings and said position-sensitive detector to perform a scanning of a probe; andwherein for near-field-regime operation, a distance between said gratings is chosen freely within the near-field-regime, and a Talbot-regime is chosen according to: D n , sph = L · D n L - D n = L · n · p 1 2 / 2 ⁢ ⁢ η 2 ⁢ λ L - n · p 1 2 / 2 ⁢ ⁢ η 2 ⁢ λ where ⁢ n = 1 , 3 , 5 ⁢ ⁢ … ⁢ , and ⁢ η = { 1 ⁢ if ⁢ ⁢ the ⁢ ⁢ phase ⁢ ⁢ shift ⁢ ⁢ of ⁢ ⁢ G 1 ⁢ ⁢ is ⁢ ⁢ ( 2 ⁢ l - 1 ) ⁢ π 2 , p 2 = L + D n , sph L ⁢ p 1 2 if ⁢ ⁢ the ⁢ ⁢ phase ⁢ ⁢ shift ⁢ ⁢ of ⁢ ⁢ G 1 ⁢ ⁢ is ⁢ ⁢ ( 2 ⁢ l - 1 ) ⁢ π 2 , p 2 = L + D n , sph L where l=1, 2, 3 . . . , Dn is an odd fractional Talbot distance when a parallel X-ray beam is used, G1 is said phase grating, Dn,sph is when a fan or cone X-ray beam is used and L is a distance between said source grating and said phase grating. 2. The system according to claim 1, wherein said phase grating is a line grating, an absorption grating or a phase grating that is a low-absorption grating but generating a considerable X-ray phase shift and of Π or odd multiples thereof. 3. The system according to claim 1, wherein said analyzer grating is a line grating having a high X-ray absorption contrast with its period being a same as that of a self-image of said phase grating, wherein said analyzer grating is placed closely in front of said position-sensitive detector with its lines parallel to those of said phase grating, before tilting said phase grating or said analyzer grating. 4. The system according to claim 1, wherein said position-sensitive detector is a line sensitive detector. 5. A method to retrieve absorption, differential phase contrast (DPC) and dark field signals from a Moire fringe pattern obtained by detuning a grating interferometer system having an X-ray source, a phase grating, an analyzer grating and a line sensitive detector, which comprises the steps of:producing the Moire fringe pattern of a desired period by tilting one of the phase grating or the analyzer grating by a predetermined angle; andcalculating a tilting angle using:a period P2 of the analyzer grating;a number n of detector lines;a number m of the periods P2 that are to be covered;a separation D between the detector lines of the line sensitive detector;and employing formulas: δ x = m ⁢ p 2 n θ = arc ⁢ ⁢ tan ⁡ ( δ x D ) where θ is the tilting angle; andscanning either a sample or the grating interferometer system along the Moire fringe pattern. 6. The method according to claim 5, which further comprises using reference and sample data acquired with the grating interferometer system to retrieve the absorption, the DPC and the dark-field signals by Fourier Component analysis. 7. The method according to claim 5, wherein:the grating interferometer system has the phase grating and the analyzer grating, and one of the phase grating and the analyzer grating is tilted; orthe grating interferometer system has a source grating, the phase grating and the analyzer grating, and wherein:only the phase grating is tilted; oronly the analyzer grating is tilted; ora pair of the source grating and the phase grating is tilted; ora pair of the phase grating and the analyzer grating is tilted. 8. The method according to claim 5, wherein compatible with radiography, tomosynthesis and computed tomography, either the sample or the grating interferometer system is rotated to acquire multiples views.
	abstract	A system for monitoring a condition of a nuclear reactor pressure vessel disposed in a radioactive environment includes an instrument structured to monitor a condition of the nuclear reactor pressure vessel; a powered wireless transmitting modem disposed in the radioactive environment, the wireless transmitting modem being electrically coupled to the instrument; a receiving modem disposed in the line of sight of the transmitting modem, the receiving modem being in wireless communication with the transmitting modem; and a signal processing unit electrically coupled to the receiving modem, the signal processing unit being structured to determine the condition of the nuclear reactor pressure vessel from the instrument. The transmitting modem is powered by a thermocouple disposed in or on the reactor pressure vessel.
	summary
047560673	summary	BACKGROUND OF THE INVENTION This invention relates to nuclear reactors and it has particular relationship to the replacement of damaged old split-pin assemblies (OSPA's) by new split-pin assemblies (NSPA's). Split-pin assemblies are secured to the lower guide tubes (LGT's) of a nuclear reactor. The bifurcated ends, i.e., the tines, of each split pin engage in holes in the upper core support plate supporting the associated guide tube. The guide tubes to which the OSPA's are secured typically include a lower section or lower guide tube (LGT) and an upper section or upper guide tube. The LGT and the upper guide tube are secured together coaxially by abutting flanges which are bolted together. In some guide tubes the LGT includes a lower flanged section and an upper flanged section joined axially by bolts through the flanges. The LGT has a lowermost flange having counterbores spaced circumferentially by 180.degree. in which OSPA's are secured. Application Ser. No. 617,857 filed June 6, 1984 to Calfo et al. for Replacement of Split Pins in Guide Tubes assigned to Westinghouse Electric Corporation and the related applications referred to in Calfo et al. disclose an automatic system including robotic tooling for replacing OSPA's by NSPA's. This process has proven highly useful in situations where the split pins on all guide tubes (typically 37 to 61) of a reactor are to be replaced. Typically, the automatic system is conveyed to the site of the replacement by seven trailers and several weeks are consumed in a replacement. The damage to an OSPA is typically a crack in the old pin. Sonic apparatus is available to determine if there is a crack in an OSPA so that replacement by an NSPA is required. Typically the use of this apparatus uncovered cracks in the OSPA's of some of the guide tubes; the OSPA's in the other guide tubes were crack free. In such cases, it is only necessary to replace the defective OSPA's and the complexity, time consumed and cost involved in the use of the automatic system outweighs its benefits. It is an object of this invention to provide a method and apparatus (tooling) less complicated and costly than the above-described automatic system for replacing OSPA's by NSPA's, particularly when a limited number of guide tubes are to be processed but also having more general use in situations where all split-pin assemblies are to be replaced. SUMMARY OF THE INVENTION In accordance with this invention, there are provided, for complete replacement of an OSPA by and NSPA, a saw-and-drill stand, an installation stand, unique runner-and-torque tools and a unique crimping tool. The saw-and-drill and the installation stand are suspended from the wall of the refueling pool of the nuclear reactor plant at a depth of about 20 feet of water. The runner and torque tools and the crimping tool are long-handled tools which are manipulated from a platform above the pool to perform their functions on OSPA's and NSPA's on the respective stands. There are also long-handled auxiliary tools such as clamps or grippers for removing the fragments of an OSPA from the saw-and-drill stand, a tool for releasing the flange fragment of the OSPA from the guide tube flange, and a tool for positioning the NSPA in the installation stand. The saw-and-drill stand includes a rotary saw of abrasive material such as tungsten carbide and a drill. The guide tube with the OSPA's secured to it is mounted in the saw-and-drill stand so that it can be rotated. Each OSPA is severed by the saw into a pin fragment and a second fragment. The pin fragment is the part of the pin which extends below the under surface of the guide tube flange. This fragment is severed without damage to the guide tube and is separated from the guide tube. The second fragment includes the flange of the OSPA and the remainder of the pin and the nut secured to it. The second fragment remains secured to the flange of the guide tube. The drill is spaced by a predetermined angle, circumferentially from the saw. Where there are two diametrically positioned OSPA's in the guide tube, this angle is 180.degree.. The drill is oriented so that its bit may be advanced generally vertically into the second fragment. The bit has a diameter slightly greater than, or approximately equal to, the diameter of the shank of the old split pin. To remove the second fragment, the guide tube is rotated through the circumferential angle so that the drill bit is generally coaxial with the remainder of the old pin of the second fragment. The drill bit is advanced into the second fragment separating the second fragment into a third fragment including predominantly the flange of the pin and a fourth fragment including the remainder of the pin with the nut secured to it. Where the guide tube has two pins, the above-described process is then carried out on the second pin. The guide tube sans the OSPA's is then moved to the installation stand. This stand has facilities for mounting a new split pin. Such facilities are shown in FIG. 25 of application Ser. No. 617,854 filed June 6, 1984 to Nee et al. for Replacement of Split-Pin Assemblies in Nuclear Reactor and assigned to Westinghouse Electric Corporation. The guide tube sans the OSPA's is mounted on the installation stand with the lower counterbores in its flanges coaxial with the new split pin and with the flanges of the new split pins to be engaged with the bases of the lower counterbores. The new nut is then threaded onto each pin by the long-handled runner and is secured with a predetermined measured limited torque by the long-handled extension torque tool. The cup extending from each new nut is then crimped to the new pin to complete the installation of the NSPA's. A significant feature of the runner is that its socket is connected through a gear train to the long rod handle which is turned to thread a new nut onto a new split pin. The necessary offset between the handle and the socket is thus provided. A measured torque is impressed near the upper end of the long-rod handle of the torque wrench to torque the new nut onto the new pin. The socket of the torque wrench is connected to the rod by an offset arm, but the arm is so short compared to the rod that the measured torque is substantially equal to the torque applied to the new nut. The crimper tool is characterized by fixed jaws with tapered cam surfaces. The crimping is produced by moving the jaws downwardly generally parallel to flutes in the new split pin.
	abstract	The disclosure relates to a method for commissioning pneumatically operated actuators that are controlled by a positioner. To determine the drive type, a constant flow of pneumatic fluid is applied to the actuator during commissioning while a drive-specific characteristic curve of the fed back position is recorded over time. Then the measured characteristic curve is compared with a given specimen characteristic curve. The drive type is inferred from the level of difference or agreement between the drive-specific characteristic curve and the specimen characteristic curve.
056129831	abstract	A device for filtering water to at least one emergency cooling system in a nuclear power plant of the type comprising a reactor arranged in a containment which substantially consists of an upright, suitably cylindrical container whose bottom part forms a pool for collecting water formed by condensation of steam present in the containment, the condensation pool including a number of back-flushable containers filter water which is taken from the pool and, if required, is supplied to nozzles in the emergency cooling system in order to cool the reactor core in the event of an inadmissible temperature rise therein, each strainer having a shape of a housing with at least one, suitably cylindrical, apertured strainer wall through which the water can flow from the outside and into the housing, and being connected, by a first conduit passing through the container wall, to a suction pump disposed outside the container wall, as well as connected to a secondary conduit for supplying wash water to the interior of the housing in order, if required, to flush the strainer wall by flowing the wash water through it from the inside and out, thereby removing filtrate deposited on the outside of the strainer wall, characterized in that a number of secondary strainers each consisting of an elongate, apertured tube having a diameter or maximum cross-sectional dimension from about 200 mm to about 400 mm and a length dimension at least five times greater than the diameter dimension, are connected either directly or indirectly by a third conduit to the first conduit connected to the suction pump.
	abstract	A navigation system includes: a map information acquiring unit for acquiring map information; an HOV lane decision unit for deciding whether an HOV lane is included in a road represented by the map information acquired by the map information acquiring unit or not; a road number processing unit for performing, when the HOV lane decision unit decides that the HOV lane is included, processing of adding information representing the HOV lane to a road number of the road including the HOV lane; and a display processing unit or a voice information unit for causing the road number passing through the processing by the road number processing unit to be displayed on the guide map or output in voice.
	description	The present specification relies on U.S. Patent Provisional Application No. 61/266,217, filed on Dec. 3, 2009, for priority. The present invention generally relates to the field of radiant energy imaging systems for detecting concealed objects, and more specifically to an X-ray backscatter system capable of measuring the surface profile of an object under inspection which can be used to produce dimensionally accurate images with an improved level of material characterization. Given the presently increasing threats of violence, the inspection of vehicles, including, but not limited to, luggage and cargo at transit points, has become almost universally mandatory. The screening of small and large objects is required to detect the presence of contraband such as explosives, weapons, narcotics and dangerous chemicals. Non-invasive inspection is typically achieved using X-ray scanning systems. Transmission based X-ray systems are traditionally used to inspect trucks and cargo containers, in particular when these may contain high-density materials and/or nuclear materials. In backscatter-based systems, X-rays are used for irradiating a vehicle or object being inspected, and X-rays that are scattered back by the object are processed to provide images which help identify the presence of contraband. Typically, a backscatter imaging system utilizes a flying spot which is derived from a rotating collimator located close to a wide angle source of X-rays, such as a constant potential X-ray tube. As the collimator rotates, the resulting pencil beam of X-rays sweeps over the surface of the object to be inspected and interacts with the surface. Some of the X-rays backscatter away from the surface of the object and in the direction from which the X-rays originated. Some of the X-rays will penetrate, and pass through, the object. Those X-rays that backscatter away from the object may be captured by X-ray detectors which are located at some distance from the surface of the object. Using trigonometry, it is possible to form a one-dimensional image of the backscattered signal intensity, assuming that the surface of the object is flat. If motion is introduced between the X-ray system and the object under inspection, a two-dimensional image may then be generated In an alternative configuration, a fan beam of X-rays may be used to irradiate a whole line across the object, and a combination of collimators and detectors can be used to capture the backscatter image. In another alternative configuration, a multi-focus X-ray source whose individual source points are arranged in a linear array may be placed behind a parallel collimator array such that each source point is constrained to irradiate only a small portion of the object under inspection. By sequencing the emission from each X-ray source point in turn, the effect of sweeping the X-ray beam across the object is generated and the resulting X-ray backscatter signal may be recorded in X-ray detectors which are located at some distance from the surface of the object. In each configuration, a constant potential X-ray source is utilized with the imaging signal being purely the magnitude of the backscattered X-ray signal at the X-ray detector. All the above mentioned configurations of known X-ray backscatter imaging systems are based on the assumption that the objects being screened are planar or straight sided. Also, the backscatter signal has a dependence on the distance, r, which scales approximately as 1/r4. Therefore, in order for an X-ray backscatter system to produce a distortion-free image, the photon detector must be equidistant from all portions of the object being scanned. Thus, such systems are well-adapted for producing images of trucks or railcars, which generally have vertical sidewalls. They are not, however, as well suited for scanning aircrafts or even cars which have oval or elliptical cross-sections because, as a collimated beam scans an oval or cylindrical surface, some portions of the scanned surface are located closer to the photon detector(s) than other portions. The variations in distance from the detector(s) produce distortions in the backscattered image. For the same reason, producing accurate and distortion-free images when screening luggage (such as on a conveyer system) and even when screening people, remains a challenge for backscatter X-ray imaging systems. Therefore, what is needed is an inspection system that produces distortion free images for accurately determining the presence of concealed illegal materials in different types of objects, such as luggage, cargo and vehicles. Such a system should also be capable of providing both depth and material type information for an object being scanned. There is also a need for the inspection system to be mobile and non-intrusive, with an ability to work in various orientations, scanning ranges, and fields of view to suit different kinds of inspection applications. The present invention is directed toward an X-ray imaging apparatus for determining a surface profile of an object under inspection and positioned at a distance from said apparatus, comprising an X-ray source for producing a scanning beam of X-rays directed toward said object; a detector assembly for providing a signal representative of an intensity of X-rays backscattered from said object; and processing circuitry to determine a time difference between when the X-ray source is switched on and when the backscattered X-rays arrive at the detector assembly and to output data representative of the surface profile of the object under inspection. Optionally, the minimum distance between the apparatus and the object under inspection is 100 mm. The maximum distance between the apparatus and the object under inspection is 5 m. The X-ray source is pulsed such that the duration of the X-ray beam being on is in the range of 1 μs to 100 μs and a duration of the X-ray being off is in the range of 1 μs to 100 μs. The duration of the X-ray beam on time and off time is each less than 1 ns. The X-ray imaging apparatus is mounted on a vehicle which is adapted to be driven past the object under inspection. The X-ray imaging apparatus is mounted on a vehicle that is adapted to be driven to an inspection site and kept stationary while the object under inspection passes the vehicle. In another embodiment, the present invention is directed toward an X-ray imaging apparatus for determining the presence and location of a threat beneath the exterior surface of an object under inspection, comprising: an X-ray source for producing a scanning pencil beam of X-rays directed toward said object; a detector assembly for providing a first signal representative of the intensity of the X-rays backscattered from said exterior surface of the object under inspection and a second signal representative of the intensity of the X-rays backscattered from said threat beneath the exterior surface of the object under inspection; and processing circuitry to determine a first time difference between when the X-ray source is switched on and when the X-rays backscattered from the exterior surface of the object under inspection arrive at the detector assembly and a second time difference between when the X-ray source is switched on and when the X-rays backscattered from the threat beneath the exterior surface of the object under inspection arrive at the detector assembly and to output data representative of the surface profile of the object under inspection based upon at least one of said first time difference or second time difference. Optionally, the minimum distance between the apparatus and the object under inspection is 100 mm. The maximum distance between the apparatus and the object under inspection is 5 m. The X-ray source is pulsed such that a duration of the X-ray beam being on is in the range of 1 μs to 100 μs and a duration of the X-ray being off is in the range of 1 μs as to 100 μs. The duration of the X-ray beam on time and off time is each less than 1 ns. The X-ray imaging apparatus is mounted on a vehicle which is adapted to be driven past the object under inspection. The X-ray imaging apparatus is mounted on a vehicle that is adapted to be driven to an inspection site and kept stationary while the object under inspection passes the vehicle. In another embodiment, the present invention is directed toward determining a surface profile of an object under inspection, said method comprising the steps of positioning an object under inspection at a distance from an X-ray imaging apparatus, wherein said X-ray imaging apparatus comprises an X-ray source and a detector array; operating said X-ray source to produce a scanning pencil beam of X-rays directed toward said object; detecting a signal representative of the intensity of the X-rays backscattered from said object, using said detector array; determining the time difference between when the X-ray source is switched on and when the backscattered signal is detected; and outputting data representative of the surface profile of the object under inspection. Optionally, the object under inspection is positioned no closer than 100 mm and no farther than 5 m from the X-ray imaging apparatus. The X-ray source is kept on for no less than 1 μs and no more than 100 μs and is kept off for no less than 1 μs and no more than 100 μs. The X-ray source is kept on for less than 1 ns and kept off for less than 1 ns. In another embodiment, the present invention is directed toward a portal gantry having a top side, left side, and right side, comprising the X-ray imaging apparatus of claim 1. The portal X-ray imaging apparatus is integrated into at least two of the top side, left side, or right side. These and other embodiments shall be described in greater detail in the Detailed Description when read in light of the Figures. The present invention is a time of flight backscatter system which uses the finite velocity of the X-ray signal to determine the distance from the X-ray source to the surface of the object such that the surface profile of the object may be determined. The system of present invention provides an accurate spatial representation of backscattering from the object to be scanned and eliminates the assumption of straight sided objects on which conventional X-ray backscatter imaging systems are based. Knowledge of the surface profile provides a further inspection result which may be used to verify the integrity of the object under inspection. Although one embodiment of the present invention is described with reference to X-ray scanning, one of ordinary skill in the art would appreciate that object screening may be performed using any available radiation imaging technique such as, but not limited to X-ray scattering, infrared imaging, millimeterwave imaging, RF imaging, radar imaging, holographic imaging, CT imaging, and MRI. Any imaging system that has the potential for displaying object detail may be employed. The present invention is directed towards multiple embodiments. The following disclosure is provided in order to enable a person having ordinary skill in the art to practice the invention. Language used in this specification should not be interpreted as a general disavowal of any one specific embodiment or used to limit the claims beyond the meaning of the terms used therein. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention. FIG. 1 illustrates a conventional backscatter X-ray imaging system 100. Referring to FIG. 1, the system 100 comprises an X-ray tube 101 with a rotating collimator assembly 110 and two large area backscatter imaging sensors 102 and 103. A scanning pencil beam of X-rays 104 is emitted towards an object 105. The pencil beam 104 is obtained by rotating the collimating disk 110 around a constant potential X-ray source (X-ray tube 101). As the beam 104 scans across the object 105 to be inspected, a fraction of the X-rays backscatter away from the surface of the object and towards one or more X-ray detectors. In this manner, a backscatter signal 106 is generated, which is sensed by the detectors 102 and 103. Knowing the angle of the X-ray pencil beam with respect to a fixed plane and the distance to the surface of the object under inspection from the X-ray source point and detectors, it is possible to reconstruct a backscatter X-ray image. An exemplary X-ray backscatter image 107 for the object 105 is shown in FIG. 1. One of ordinary skill in the art would note that the distances between the surface of the object and the planar detector arrays are variable, since the object is not straight sided. Further, since the distance from the X-ray source to the object under inspection is not known in general, an assumption is generally made that the object is planar and at a fixed distance from the source. Thus, if the object is closer than assumed, then the object will appear smaller in the image and conversely, if the object is further away then it will appear to be larger. The result is an image which is representative of the object under inspection but not with correct geometry. This makes it difficult to identify the precise location of a threat or illicit object within the object under inspection. The present invention addresses the above problem by integrating time of flight processing into conventional backscatter imaging. X-rays travel at a constant speed which is equal to the speed of light (3×108 m/s). An X-ray will therefore travel a distance of 1 m in 3.3 ns or equivalently, in 1 ns (10−9 s) an X-ray will travel 0.3 m. Thus, if the distance between a backscatter source and the object under inspection is on the order of 1 m, it corresponds to around 3 ns of transit time. Similarly, if the backscatter X-ray detector is also located around 1 m from the surface of the object, it corresponds to an additional 3 ns of transit time. Thus, the signal received at the detector should be received, in this example, 6 ns after the X-ray beam started its transit from the X-ray tube. In sum, the X-ray's transit time is directly related to the detectors' distance to or from the object. Such times, although quite short, can be measured using detection circuits known to those of ordinary skill in the art. The minimum distance is practically associated with the time resolution of the system. Objects can be proximate to the source, but one will not see much scattered signal since the scatter will generally be directed back to the X-ray source rather than to a detector. A practical lower limit, or the minimum distance between the plane of the system and the nearest part of the object to be inspected, is 100 mm. The further away the object is from the detector, the smaller the signal size and thus a practical upper limit for distance is of the order of 5 m. In the system of present invention, as shown diagrammatically in FIGS. 2a and 2b, the distance between the X-ray source and the object under inspection is determined precisely by recording the time taken for an X-ray to leave the source and reach the detector. FIG. 2a depicts a representation, as a step function, of an X-ray source being switched rapidly from its beam-off condition to its beam-on condition. While 201 represents the step function at the source, 202 represents the detector's response. Thus, as can be seen from 201 and 202, after the beam is switched on from its off state at the source, the detector responds with a step-function like response after a time delay Δt 203. Referring to FIG. 2b, as the source 210 emits a pencil beam 211 of X-rays towards the object 212, some of the X-rays 213 transmit into the object 212, while some X-rays 214 backscatter towards the detectors 215. It may be noted that there are different path lengths from the X-ray interaction point (with the object) to the X-ray detector array. Therefore if a large detector is used, there will be a blurring to the start of the step pulse at the detector, where the leading edge of the start of the pulse will be due to signal from the part of the detector which is nearest to the interaction spot, and the trailing edge of the start of the pulse will be due to signal from parts of the detector which are further away from the interaction spot. A practical system can mitigate such temporal blurring effects by segmenting the detector such that each detector sees only a small blurring and the changes in response time each provide further enhancement in localisation of the precise interaction position, hence improving the determination of the surface profile of the object under inspection. The detector size (minimum and/or maximum) that would avoid such blurring effects described above is commensurate with the time resolution of the system. Thus, a system with 0.1 ns time resolution has detectors of the order of 50 mm in size. A system with 1 ns time resolution has detectors of the order of 500 mm in size. Of course, smaller detectors can be used to improve statistical accuracy in the time measurement, but at the expense of reduced numbers of X-ray photons in the intensity signal, so there is a trade-off in a practical system design which is generally constrained by the product of source brightness and scanning collimator diameter. Ideally, for best time of flight data, the spatial resolution should be reduced (i.e. large area of irradiation) and combined with a bright X-ray source to give best measurement accuracy. In one embodiment, a reasonable trade-off is an irradiation diameter in the range of 5 mm and 10 mm at the surface of the object with an X-ray beam current in the range of 5 mA to 20 mA with 0.5 ns time resolution and detector size of around 200 mm square per sub-panel. In general, spatial resolution depends on the sweep speed of the flying spot and on the design of the collimator used—the better the spatial resolution, the worse the statistical noise in the image data for constant X-ray source brightness. Generally, it is practical to design a system with spatial resolution in the range of 1 mm to 20 mm full-width-at-half-maximum of the irradiating spot, but this size is dependent on the distance from the source to the surface of the object, so a slightly complicated relationship. In principle, depth resolution and spatial resolution are independent but in practice they are associated through practical constraints in X-ray source brightness. The time of flight backscatter system of the present invention is also used to determine the depth profile component of the signal, which, in turn, is used to establish the presence and location of any threat objects beneath the exterior surface of an object being scanned. This is shown in FIGS. 3a and 3b. Referring to FIG. 3a, object A 301 is the primary object being scanned, and another object B 302 is located under the surface of the object A 301. This is representative, for example, of a package of goods (object B) placed within a cargo container (object A) with a metal skin. For the purpose of clarity, the second object B 302 is shown beside the object A 301. A pencil beam 303 of X-rays is emitted from the source 304 and illuminates object A 301. Some of the X-rays 305 are backscattered from object A 301, while some radiation is transmitted through object A 301 to illuminate object B 302. Rays 306 are also backscattered from object B 302. In this case, the detectors 307 will sense two distinct signals, one at a first time due to the metal skin on the surface of the object A 301, and a further signal at a second time due to the package of goods (object B 302) located beneath the surface. FIG. 3b illustrates the step function 310 at the source and the detector response 320 when the detectors sense two signals corresponding to one object being beneath another object. The two signals at the detector are represented by A 321 and B 322. While pulse A 321 starts after a time delay of ΔtA 323 after the source is turned on, pulse B 322 starts after a time delay of ΔtB 324. These two different signals may then be interpreted in order to determine the exact location of an object within the object under inspection. For example, such additional information may be used to determine if the object B 302 in FIG. 3a is situated within a hidden compartment in the wall of the container (object A 301) or whether it is located within the normal storage area of the container. Depth resolution is dependent on the speed of the electronics and the switch-on time of the source. A 1 ns time resolution will give depth resolution of the order of 100 mm, while a 0.5 ns time resolution will give depth resolution of the order of 50 mm. It is known in the art that the backscatter signal intensity falls off rapidly with distance into the object and with the presence of overlying structures. However, the time of flight backscatter signal as used in the present invention enables a system to determine the presence of weakly scattering signals in the presence of highly scattering signals through analysis of the leading edge of the time of flight signal. Thus, the present method provides an opportunity for deeper inspection into the object as compared to existing backscatter systems, where only the total backscatter signal is measured and hence small signals from deeper objects are obscured by the larger signal from nearer objects. One of ordinary skill in the art would appreciate that the time of flight backscatter signal also exists at the time when the X-ray beam is switched off. This is shown diagrammatically in FIG. 4. FIG. 4 illustrates the step function at the source 401 and the step function corresponding to the backscatter signal collected at the detector 402 when the X-ray beam is switched off. For the purpose of step function response, the objects shown in FIG. 3 (A 310 and B 302) are considered. Thus the detector signal again comprises two step pulses 411 and 412 corresponding to two objects. While the end of pulse 411 starts after a time delay of ΔtA 413 after the source is turned off, the end of pulse 412 starts after a time delay of ΔtB 414. It is therefore possible to improve the accuracy of the time of flight backscatter signal by recording the profile of the detected signal at beam switch on and again at beam switch off. According to an aspect of the present invention, the signal-to-noise ratio in the time of flight measurement is further improved by using X-ray pulse sequences. This is shown in FIG. 5. Referring to FIG. 5, a rapid sequence of pulses 501 is provided by the source (X-ray tube). The duration of the beam on phase (P1) 511 and beam off phase (P2) 512 for each pulse is selected to accommodate electronics data acquisition system bandwidth and according to X-ray tube target loading capacity. In one embodiment for example, the duration of beam on and off phases, P1 511 and P2 512 respectively, are optimized to be in the range 1 μs as to 100 μs. Also in one embodiment, the pulsed X-ray source is capable of rapid turn on and turn off times. As an example, the X-ray source delivers pulses with a beam turn on and beam turn off time of less than 1 ns each. The detector response is illustrated by 502 in FIG. 5, and it represents for the backscatter signal sensed in response to the sequences of pulses 501 generated by the source. FIG. 6 illustrates an example of a suitable X-ray tube configuration for delivering pulsed X-rays. In one embodiment, a pulsed X-ray tube design that uses an electrostatic grid to control the pulsing of the X-ray output is employed. Referring to FIG. 6, a thermionic electron gun 601 is fitted with a grid 602 in close proximity to the electron emitting surface 603. In this configuration, the electron gun 601 can be operated in a space charge limited mode such that the actual grid voltage is only weakly related to the delivered tube current. By keeping the grid 602 in close proximity to the gun 601, the switching voltage that is required to turn the beam on and off may be kept at quite a low value, and generally below 100V. By making the grid elements very thin, for example by using a crucifix grid with 100-300 um wide elements, the capacitance of the grid is kept to a low value, thereby improving the grid drive circuit performance. A high speed switching circuit can then be used to switch the grid with nanosecond turn on and turn off times. The grid 602 is thus used to provide a pulsed electron beam 607 which modulates the X-ray output 608. The anode 604 is held at a positive high voltage with respect to the cathode 605 at ground potential. In one embodiment, the high voltage 606 is in the range of 120 kV to 320 kV. An alternative X-ray tube configuration is shown in FIG. 7. This configuration uses a photocathode to provide a pulsed electron beam which modulates the X-ray output. Referring to FIG. 7, photocathode 701 is deposited onto an optically transparent window 702, which may be comprised of, for example, a quartz or sapphire element. A pulsed optical system, comprising a light emitting diode 703 and a lens 704, is focused onto the photocathode 701 through the window 702. As the optical system pulses, the photocathode emits electrons 705. By placing an anode 706 at high potential (HV 708) with respect to the photocathode 701, electrons 705 from the photocathode will be accelerated to the anode 706, thereby forming an X-ray signal. A suitable electrostatic focusing system 707 is also provided to control the electron trajectories within the tube 700. In this case, the output pulse from the tube 700 is determined almost completely by the pulse characteristics of the optical system. Those skilled in the art would recognise that contemporary optical systems are capable of sub-nanosecond pulsing in compact configurations with reliable components. One of ordinary skill in the art would also appreciate that alternate X-ray tube configurations can be designed and the configurations described above with reference to FIGS. 6 and 7 are representative examples of suitable X-ray tube designs. It should also be recognized by persons of ordinary skill in the art that alternate X-ray sources such a pulsed electron accelerators or high power laser sources may be used in place of high voltage X-ray tubes. In order to record the time of flight backscatter signal, a high speed X-ray detector is required. FIG. 8 shows one example of a high speed backscatter detector module for measurement of the time of flight backscatter signal. Referring to FIG. 8, in this configuration a sheet of scintillation material 801, such as a plastic scintillator with fast rise time, is optically coupled to a high speed photodetector 802 such as a photomultiplier tube. As X-rays interact in the detector 802, light photons are generated and a fraction of these light photons transport to the detector through reflection and are scattered from the surfaces of the sheet of scintillator material 801. Since an optical photon needs to travel a finite distance through the scintillator material and there is also a finite transit time for a pulse through the photodetector, it results in the detector having a characteristic response time. One of ordinary skill in the art would appreciate that these are constant effects and may be calibrated out from the measured data in a straightforward fashion. In one embodiment, an exemplary detector is designed with an area ranging from 100×100 mm to 300×500 mm, depending on the performance requirement of the system and the overall cost of the system. To mitigate against the effect of finite transit time of the optical photons through the scintillation material, it is advantageous to fabricate a large area detector from a series of smaller area detectors. One example of how this can be achieved is shown in FIG. 9a. Referring to FIG. 9a, smaller detector elements 901, 902 similar to the detector 802 shown in FIG. 8 are stacked together to form a larger detector assembly. All the detector elements 901, 902 are optically coupled to a common sheet 905 of scintillator material. Alternatively, the detector elements may be individually coupled to sheets of scintillator material. Another alternative configuration for employing an array of detectors is shown FIG. 9b. Referring to FIG. 9b, two sets of rectangular detectors 910, 920 are situated in orthogonal directions. By analysing the signals from the detector set in coincidence, further information about the interaction point of the X-ray beam with the object can be inferred. Thus, using an array of high speed backscatter imaging modules improves the overall detection efficiency and area coverage of the time of flight backscatter imaging system. One of ordinary skill in the art would appreciate that alternate detector materials and detector configurations could be selected for use in a time of flight backscatter imaging system and the examples shown in FIGS. 8, 9a and 9b should be considered as being representative only. FIG. 10 shows an exemplary electronic circuit that is used in the X-ray backscatter system of the present invention to read out the signal from the photomultiplier tube detector. The circuit shown in FIG. 10 is a low cost, primarily analog circuit that reads out the detected signal. Referring to FIG. 10, the photomultplier tube 1001 is operated with a negative cathode 1002. The anode 1003 is connected directly to a capacitor 1004. Current passing through this capacitor 1004 as a result of optical photon arrival at the photocathode 1002 will integrate resulting in the formation of a voltage across the capacitor 1004. An ADC (analog to digital converter) 1005 is provided to read this voltage in order to determine the total signal recorded during a pulse and this is the equivalent to the standard X-ray backscatter imaging signal. This photodetector circuit provides both the magnitude of the conventional backscatter signal and the additional time of flight backscatter signal 1006. FIG. 11 illustrates another exemplary circuit that can be used for recording the time difference between when the X-ray tube was switched on and when the backscattered signal arrives at the detector. Referring to FIG. 11, the time-to-digital circuit 1100 compares the voltage on the capacitor 1101 against a threshold reference voltage Vref 1102. When the voltage across the capacitor and the reference voltage become equal, a digital value is produced that is proportional to the time delay between the X-ray source turning on and the detector signal being received. This is the time of flight backscatter imaging signal described above with reference to FIGS. 2a and 2b. As shown schematically in FIG. 11, the comparator circuit comprises two parts: (1) a comparator 1103 which compares the photomultiplier charging capacitor voltage, VPMT 1104, and a known reference voltage Vref 1102 and (2) a constant current source 1105, a three-position switch 1106, capacitor 1101 and an analog to digital converter 1108. The output of the comparator 1103 is fed to an XOR gate 1109, whose other input is the X-ray on signal 1110. As soon as the X-ray beam is turned on (X-Rays-On 1110 is activated), the three position switch 1106 is moved from its ground connected position to connect to the output of the constant current source 1105. This begins charging up the comparator capacitor 1101. The comparator capacitor 1101 continues to charge up as long as VPMT 1104 is lower than the reference voltage Vref 1102. As soon as VPMT 1104 equals or exceeds the reference voltage Vref 1102, the three position switch 1106 is rotated to the disconnected position and the voltage is maintained on the comparator capacitor 1101. At this point the voltage is sampled by the analog to digital converter 1108 and the resulting digital value is thus directly proportional to the time difference between the X-ray beam turning on and the backscattered X-ray signal being received at the detector. Once the analog to digital conversion is completed, the three position switch 1106 is connected to the ground position in order to discharge the capacitor 1101 and prepare for the next pulse. As an extension of the above circuit, it is possible to time digitize the rising edge of the pulse by using multiple copies of the comparator circuit of FIG. 11. This technique is shown in schematically in FIG. 12, and may be used for recording depth profile information, as described earlier with reference to FIGS. 3a and 3b. Referring to FIG. 12, a plurality of comparator circuits 1201, 1202 and 1203 are connected to the X-ray on signal 1204. As the second input, reference voltages Ref1 1211, Ref2 1212 and Ref3 1213 are fed to comparator circuits 1201, 1202 and 1203 respectively. The voltage across the capacitor 1205 is sampled by the analog to digital converter 1215, and the resulting digital value is directly proportional to the time difference between the X-ray beam turning on and the backscattered X-ray signal being received at the detector. In cases where there are multiple objects hidden beneath a given object, the plurality of comparator circuits 1201, 1202 and 1203 produce signals at different time intervals represented by Δt1 1221, Δt2 1222, and Δt3 1223 respectively. This provides a means to collect the depth profile information. That is, the different signals produced by the comparator circuits may be interpreted in order to determine the exact location of an object within the object under inspection. One of ordinary skill in the art would appreciate that there are many ways in which the data required for time of flight backscatter imaging may be collected, and that the circuits described in FIGS. 11 and 12 represent exemplary approaches. Many other approaches are possible, including high speed digitization at the anode output of the photomultiplier tube and the use of multiple ADCs, each triggered at a time offset to the others. In one embodiment of the time of flight backscatter imaging system of the present invention, the detection system may be mounted on a mobile platform. Such an exemplary imaging system is shown in FIGS. 13a and 13b. Referring to FIG. 13a, an X-ray apparatus 1301 is installed in a vehicle 1302 that can be driven past stationary targets at a known velocity. As the vehicle drives by, time of flight backscatter data is collected in order to form a two-dimensional image. In another embodiment, shown in FIG. 13b, the X-ray vehicle 1310 is driven to a location, such as a roadside, and the time of flight backscatter 1320 system is activated. The backscatter imaging system 1320 further comprises the X-ray source 1321 and two large area detectors 1322 an 1323. In one embodiment, one or more sensors (not shown) that are located on the X-ray vehicle determine the presence of a passing object to be scanned, such as a passing vehicle, and the time of flight backscatter system 1320 is turned on automatically. In one embodiment, speed sensors (not shown), such as a scanning laser beam or a radar sensor, determine the speed of the passing vehicle and the two dimensional image is formed. Once the vehicle has been scanned, the X-ray apparatus 1320 is turned off automatically. Once scanning at a given location is completed, the vehicle 1310 can simply be driven to a new location and scanning can recommence as required. This feature provides the capability for random location scanning in a reasonably covert manner. In a further embodiment of the present invention, a time of flight backscatter system is combined with a high energy transmission X-ray imaging system to improve clarity and accuracy in imaging. Advantageously, the high energy transmission imaging system will be operated using a pulsed linear accelerator source in which case the high energy transmission imaging pulse is active typically for only a few microseconds at a time. In one embodiment, the rotation of the flying spot collimator for the time of flight backscatter system is controlled such that the flying spot is not interacting with the object during the high energy pulse to ensure that there is no cross talk between the high energy and time of flight backscatter imaging systems. FIG. 14 illustrates a schematic diagram of a time of flight backscatter imaging system 1410 in partnership with a high energy transmission X-ray inspection system 1420. Referring to FIG. 14, the time of flight backscatter imaging system 1410 comprises a plurality of time of flight imaging sensors 1411, 1412 and 1413, which can be located on multiple sides of the object 1430 under inspection. This improves coverage of the time of flight backscatter inspection. A person skilled in the art would understand that the time of flight backscatter system 1410 should be offset in the scan direction from the high energy transmission imaging beam 1420 to simplify system assembly. The combined high energy transmission and time of flight backscatter system may be configured in any of a plurality of arrangements based on the requirement of application, such as but not limited to, on a mobile platform, on a stationary drive through portal gantry or rail scanner, on a scanning gantry system mounted on rails or with any other cargo motion system such as a platen system or roller bed conveyor. In a further embodiment of the present invention, as shown in FIG. 15, the time of flight backscatter system 1510 is combined with a transmission X-ray screening system 1520. This arrangement can be advantageously used to inspect the underside of vehicles as they are driven past as well as objects on a conveyor system. FIG. 16 illustrates diagrammatically exemplary electronics and control systems employed by the system of present invention in order to process data from the detectors and to synchronize the acquisition of data with the operation of the source. Referring to FIG. 16, in order to maximize accuracy in the location of the origin of each scatter signal, two groups of segmented detectors 1610 and 1620 are shown. One of ordinary skill in the art would appreciate that any number of groups of detectors may be used, depending upon the requirements of clarity and accuracy of imaging in a given application. Each group of detectors 1610, 1620 are connected to signal processor units 1611 and 1621, respectively. The signal processor units 1611 and 1621 combine the information from the respective detector to determine the most likely interaction spot, from where the X-rays are backscattered from the object under inspection. This is done by analyzing the time domain data from each detector for each X-ray pulse and then “centroiding” this to determine the exact location of the interaction site. “Centroiding” refers to taking a geometric mean of a set of measurements. In this case, the measurements are of position, and the idea is to combine the multiple measurements together to get an average distance based on the set of independent measurements. The signals 1612, 1622 corresponding to corrected time profile and exact interaction site are then passed by the processors 1611 and 1621 respectively on to a system control and image processing block 1615. The image processing block 1615 then generates and renders the final output image on a display 1630. The system control block 1615 also controls the X-ray source 1640, via the source control signals 1641. It will be obvious to one skilled in the art that alternative data acquisition systems, other than the one described above, may be designed. In one embodiment for example all the detectors may communicate with a single signal processor block. The time profile data generated by the detectors and signal processor units as shown in FIG. 16 contains both depth and material type information. This data may be rendered to a display as a three dimensional image where the shape of the rendered image is derived from the position of the time step pulses in the corrected time profile while grey-scale value is derived from the height of each step pulse in the corrected time profile. In one method used by the system of present invention, the heights of step pulses are corrected for distance from the source by application of the inverse square law. The heights of time steps are also corrected for self-attenuation of the backscattered beam by overlapping objects. An example of a three-dimensional time of flight backscatter image rendered as described above is shown in FIG. 17. Referring to FIG. 17, in the image 1700 on display, a rectangular object 1701 and a cylindrical object 1702 can be seen behind a planar skin 1703. It may be noted that both grey-scale and pseudo-colour tables can be used to represent image data on the screen. To display the time of flight backscatter data, each measurement is associated with a position in a 3D volume. The position of a signal is first mapped into a 2D radial grid whose origin is at the X-ray tube focus and whose plane is described by the rotation of the collimator. This radial grid may then be interpolated into an equivalent 2D Cartesian grid. As the object is scanned past the X-ray beam, a series of 2D images are obtained which together form a 3D image of the object under inspection. The 3D Cartesian grid may then be rendered to a computer screen using standard ray-tracing methods with suitable transparency and coloring as required by the operator. While it is known that time of flight calculations are used across many different industries, for example, IR systems use time of flight to calculate object distances, there are complications to such uses. For example in using time of flight in ultrasound B-scan, the velocity of sound is much lower than velocity of light, so electronics can be much slower. Here one can get attenuation and reflection by overlapping objects whereas in X-ray systems there is attenuation only. In laser range finder applications, one looks for the leading edge of the pulse only without unscrambling the leading edge profile, since the attenuation of the length of light in reflective materials is relatively small. In the X-ray case, however, there is a substantial amount of information in the shape profile, and this is what makes the X-ray system very different (more complex but powerful) than the optical case. In radar applications, one only looks for the time of arrival of the leading edge of the pulse only with some information contained in the intensity (corrected of course for distance from the source). Note that the leading edge profile is not used since the wavelength of radio waves is generally large compared to the size of the object of interest and therefore there is little depth information to be obtained. This time of flight backscatter system provides the ability to take into account and measure the surface and sub-surface profile of an object under inspection. This capability is advantageous as it allows the production of dimensionally accurate images, such that, for example, an object or a person does not appear larger or smaller than its actual size. The screening and imaging method of the present invention further provides for much deeper inspection than is provided by currently available backscatter systems. The time of flight backscatter system of the present invention also offers the capability of three-dimensional display of backscatter data with a much improved level of material characterization, compared to existing systems. The above examples are merely illustrative of the many applications of the system of present invention. Although only a few embodiments of the present invention have been described herein, it should be understood that the present invention might be embodied in many other specific forms without departing from the spirit or scope of the invention. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive, and the invention may be modified within the scope of the appended claims.
	abstract	This invention relates to an illumination system for scanning lithography with wavelengths xe2x89xa6193 nm, particularly EUV lithography, for the illumination of a slit. The illumination system includes a light source, and a field lens group. The field lens group is shaped so that an illuminated field is distorted in a plane of a reticle perpendicular to a scanning direction.
	summary
052079805	abstract	A replacement guide pin assembly is provided for aligning a nuclear fuel assembly with an upper core plate of a nuclear reactor core. One embodiment of the guide pin assembly includes an elongated guide pin body, a ferrule, and a lock screw. The guide pin body has a lower expandable base insertable within a hole in the top nozzle, and capable of expanding radially outwardly relative to a longitudinal axis of the guide pin body to provide an interference fit with the top nozzle. The ferrule is insertable within the top nozzle hole, interfitted with the guide pin body, and capable of imparting a radially and outwardly directed force on its lower expandable base to expand it within the hole of the top nozzle and thereby secure the guide pin body to the top nozzle in response to a predetermined displacement of the ferrule relative to the guide pin body along its longitudinal axis. The lock screw is insertable within the top nozzle hole, interfitted with the ferrule and threaded into the guide pin body so as to produce the predetermined displacement of the ferrule. Another embodiment of the guide pin assembly includes a guide pin body, an expandable insert body, and a ferrule. The guide pin body has a lower attachment base insertable within the top nozzle hole. The expandable body is insertable within the top nozzle hole, interfitted about the lower attachment base of the guide pin body, and capable of expanding radially outwardly relative to a longitudinal axis of the guide pin body to provide an interference fit with the top nozzle. The ferrule is insertable within the hole in the top nozzle, interfitted with the expandable body, and threaded with the lower attachment base of the guide pin body to produce a predetermined displacement of the ferrule relative to the guide pin body along its longitudinal axis sufficient to impart a radially and outwardly directed force on the expandable body to produce expanding thereof within the hole of the top nozzle into the interference fit with the top nozzle and thereby secure the guide pin body to the top nozzle.
	claims	1. A substrate cover comprising:a frame-like member configured to be placed on a substrate which is to be written using a charged particle beam, and to have an outer perimeter dimension larger than a perimeter end of the substrate and an inner perimeter dimension, being a border between the frame-like member and an inner opening portion, smaller than the perimeter end of the substrate; anda contact point part configured to be provided on an undersurface of the frame-like member, in order to be electrically connected to the substrate. 2. The substrate cover according to claim 1, wherein the substrate cover includes a predetermined mark formed on the frame-like member. 3. The substrate cover according to claim 1, wherein the substrate cover is formed of conductive material. 4. The substrate cover according to claim 3, wherein the conductive material is metal material. 5. The substrate cover according to claim 1, wherein the substrate cover is formed of insulating material and a surface thereof is coated with conductive material. 6. The substrate cover according to claim 5, wherein the insulating material is ceramic material. 7. A charged particle beam writing apparatus comprising:a stage configured to hold thereon a substrate attached with a substrate cover covering a whole perimeter part of the substrate and including a contact point electrically connected to the substrate;an electric conductive member configured to be electrically connected to the contact point and couple the substrate charged to ground potential, in a state that the substrate is arranged on the stage; anda writing unit configured to write a predetermined pattern onto the substrate by using a charged particle beam, in a state that the substrate is coupled to ground potential by using the electric conductive member. 8. The writing apparatus according to claim 7, wherein the substrate cover includes a frame-like member configured to have an outer perimeter dimension larger than a perimeter end of the substrate and an inner perimeter dimension, being a border between the frame-like member and an inner opening portion, smaller than the perimeter end of the substrate, wherein a predetermined mark is formed on an uppersurface of the frame-like part member. 9. A charged particle beam writing method comprising:carrying a substrate attached with a substrate cover with a predetermined mark formed thereon into a pattern writing apparatus;checking a position of the substrate by using the predetermined mark formed on the substrate cover; andwriting a predetermined pattern on the substrate whose position has been checked, by using a charged particle beam. 10. A charged particle beam writing method comprising:carrying a substrate attached with a substrate cover that covers a whole perimeter part of the substrate into a pattern writing apparatus; andwriting a predetermined pattern on the substrate attached with the substrate cover, by using a charged particle beam.
	summary
	summary
047956542	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the figures identical elements as well as elements of identical function are marked with identical reference numbers. In FIG. 1 a structure shielding the X-ray or gamma radiation arriving from the direction of arrow 7 comprises a protective layer 8 and a number of layers 11, 12, . . . 1n made of materials differing from each other, where n designates the number of the layers. The material of the first layer 11 from the direction of the arrow 7 shall be chosen according to the maximum energy of the incoming radiation in such a manner that the K-edge of the element of the layer 11 shall be lower than said maximum energy. Table I contains elements from which this element may be chosen in most practical cases. In the following, before the symbol of an element also the atomic number of the element will be given. In Table I there are the K-edge and L.sub.I -edge in the radiation absorption of each listed element, as well as the most probable .alpha.1 and .alpha.2 energy levels of a secondary radiation corresponding to the K-L electron shell transition of the excited element, all these in keV units. From the point of view of the practical application, the most important elements are 92U, 82Pb and 74W. When applying 92U, the radioactive radiation of 92U itself shall also be taken into consideration. The element of the second layer 12 shall be chosen so that its K-edge shall be in the energy range between the K-edge and L.sub.I -edge of the element of the first layer 11, as near as possible to the L.sub.I -edge. Table II contains elements being suitable for the layer 12 if the element of the layer 11 was chosen according to Table I. It can be seen that for the element 92U of the layer 11, in principle, any of the elements 50Sn, . . . 44Ru may be chosen because the K-edge of these latters is higher than the L.sub.I -edge of 92U. For any other elements 82Pb, . . . 73Ta of the layer 11, in principle, any of the elements 50Sn, . . . 41Nb may be chosen since even the K-edge of 41Nb is higher than the L.sub.I -edge of 82Pb. TABLE I ______________________________________ Element K-edge .alpha.1 .alpha.2 L.sub.I -edge ______________________________________ 92 U 115.6 98.4 94.6 21.7 82 Pb 88.0 75.0 72.8 15.9 79 Au 80.7 68.8 67.0 14.3 78 Pt 78.4 66.8 65.1 13.9 77 Ir 76.1 64.9 63.3 13.4 76 Os 73.9 63.0 61.5 13.0 75 Re 71.7 61.1 59.7 12.5 74 W 69.5 59.3 58.0 12.1 73 Ta 67.4 57.5 56.3 11.6 ______________________________________ TABLE II ______________________________________ Element K-edge .alpha.1 .alpha.2 L.sub.I -edge ______________________________________ 50 Sn 29.2 25.3 25.0 4.4 49 In 27.9 24.2 24.0 4.2 48 Cd 26.7 23.2 23.0 4.0 47 Ag 25.5 22.2 22.0 3.8 46 Pd 24.3 21.2 21.0 3.6 45 Rh 23.2 20.2 20.0 3.4 44 Ru 22.1 19.3 19.1 3.2 42 Mo 20.0 17.5 17.4 2.8 41 Nb 19.0 16.6 16.5 2.7 ______________________________________ The element of the third layer 13 shall be chosen so that its K-edge should be in the energy range between the K-edge and L.sub.I -edge of the element of the second layer 12, as near as possible to the L.sub.I -edge. Table III indicates elements and their K-edges which are suitable for the purpose of layer 13, if the element of the layer 12 was chosen according to Table II. TABLE III ______________________________________ Element K-edge ______________________________________ 30 Zn 9.7 29 Cu 9.0 28 Ni 8.3 27 Co 7.7 26 Fe 7.1 25 Mn 6.5 24 Cr 6.0 23 V 5.4 22 Ti 5.0 ______________________________________ It can be seen that for any one of the elements 50Sn, . . . 41Nb of the layer 12, in principle, any of the elements 30Zn, . . . 22Ti of Table III may be chosen, since even the K-edge of 22Ti is higher than the L.sub.I -edge of 50Sn. In respect of a practical application, the triple layer combination 82Pb - 50Sn or 48Cd - 29Cu or 28Ni and the combination 74W - 50Sn or 42Mo - 30Zn or 24Cr are advantageous. In several cases, the triple layer combination 82Pb - 50Sn - 29Cu is suitable and favourable as for its price. The structure according to the invention shall not necessarily be provided with a third layer 13 or further layers 13, . . . 1n. A double layer combination 82Pb - 50Sn or 48Cd or 42Mo may also be applied. For soft radiations /30-88 keV/, a double layer combination shall be applied expediently, where the element of the first layer 11 is 50Sn, that of the second layer 12 is 29Cu. FIG. 2 illustrates a structure where all layers 11, 12, . . . 1n are built up of thin layers. Accordingly, the layer 11 consists of thin layers 21, 22, . . . 2k of identical material, the layer 12 of thin layers 31, 32, . . . 3j of identical material, and the layer 1n of thin layers 41, 42, . . . 4i of identical material, all arranged on carrier 5. The carrier 5 is on the side of the thin layer package which is towards the radiation and it performs simultaneously the function of a protective layer. Between the thin layers of identical material thin separating layers not shown in FIG. 2 are foreseen, made e.g. of the oxide of the adjacent thin layer or of aluminium. The thin aluminium separating layers disperse the X-ray or gamma radiation and simultaneously increase thereby the shielding effect of the structure. For the sake of demonstration, none of FIGS. 2-4 is proportionate. In FIG. 3 the materials of the first thin layer 111, the second thin layer 121 and the third thin layer 131 are chosen according to the structure shown in FIG. 1. Thin layers 111, 121 and 131 form a layer group. In the structure m pieces of such layer groups are arranged one behind the other. The thin layers 111, 121, 131; 112, 122, 132; . . . 11m, 12m, 13m are arranged between two carriers 5 and 6. With this arrangement no separating layer must be placed between the thin layers since the adjacent thin layers are made everywhere of materials different from each other. In FIG. 4 such a structure is shown in which only the first layer 11 is built up of thin layers 21, 22, . . . 2k, the structure of the other layers 12, 13, . . . 1n is the same as in FIG. 1. The structure according to the invention may be shaped otherwise than a wall structure shown in the drawings. It may be manufactured e. g. as a flexible plate from which radiation protective clothing may be made or which may be used as a radiation protective casing having no flat surface.
	description	In industry today, there is a continuing need to develop increasingly small sensors that can run with very low power consumption. Cold atom sensors represent one developing technology that have the potential to satisfy both the size and power needs for such small sensors such as highly stable miniature atomic clocks and high performance inertial measurement systems. Cold atom sensors operate by laser cooling and trapping of atoms. An anti-Helmholtz magnetic field can then be applied in order create a trapping potential, the minimum of which defines the center of the trap. The anti-Helmholtz field profile is usually produced by electro-magnetic coils where electric current to the coils can be switched on and off during the measurement cycle. However, these electro-magnetic coils can consume large amounts of power in a cold atom sensor. This configuration requires the coils to remain energized to maintain the atom trap, and then momentarily turned off so that the trapped atoms can be probed to obtain measurements. For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for alternate systems and methods for providing low power magnetic field generation for atomic sensors. The Embodiments of the present invention provide methods and systems for providing low power magnetic field generation for atomic sensors and will be understood by reading and studying the following specification. Systems and methods for switchable low power magnetic field generation for atomic sensors using electro-permanent magnets are provided. In one embodiment, a method for magnetic field generation for an atomic sensor comprises: laser cooling a sample of atoms in a chamber; and trapping the sample of atoms in a magneto-optical trap within the chamber by applying an atom trapping field across the sample of atoms using at least one pair of electro-permanent magnet units. In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize features relevant to the present invention. Reference characters denote like elements throughout figures and text. In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of specific illustrative embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. Embodiments of the present disclosure provide system and methods for producing a switchable anti-Helmholtz-like field for cold atomic sensors that exhibit relatively low power consumption by utilizing electro-permanent magnets. As the term is used herein, an electro-permanent magnet unit refers to an assembly of magnetic materials that each possess a permanent inherit magnetism and produce magnetic fields without external stimulus (i.e., as opposed to an electromagnet which requires application of an electric current into a coil to produce a magnetic field). However, the polarity of the magnetic fields produced by at least one of the magnetic materials in an electro-permanent magnet unit may be altered by exposing that magnetic material to an external magnetic field of sufficient strength. As explained below, electro-permanent magnet units are arranged in pairs to create a magnetic gradient in the center of a vacuum chamber or other vessel in conjunction with a pair of laser beams to create a potential well where atoms may be cooled and trapped. Once the atoms are cooled and localized in space, the trapping potential can be shut off and the atoms can be interrogated and probed (using lasers, for example) to implement devices such as atomic clocks, magnetometers, and inertial sensors. In one embodiment, an electro-permanent magnet unit may comprise what is referred to herein as a “hard” magnet in magnetic alignment with what is referred to herein as a “semi-hard” magnet. The terms “hard” and “semi-hard” with respect to magnets are well known to those of skill in the art of magnetics and generally refers to the coercivity (Hc) of the magnetic materials. High-coercivity magnetic materials are magnetized to saturation and experience a reversal in polarity in comparatively strong magnetic fields. Thus the magnetic hardness of the material at least in part represents how amenable the magnetic material is to having its polarity flipped by exposure to an externally applied magnetic field. This will be further explained below. A semi-hard magnet is one that has relatively less coercivity than a hard magnet, but greater than what would generally be considered a soft magnet. An example of a “hard” magnet material is NdFeB, and an example of a “semi-hard” magnet material is AlNiCo, but other magnetic materials can be used. FIGS. 1 and 1A are a diagram illustrating generally at an electro-permanent (EP) magnet unit 101 of one embodiment of the present disclosure. FIG. 1 provides an exploded view of EP magnet unit 101 illustrating that comprises a first magnetic ring 110 and a second magnetic ring 120 that are positioned next to each other so that their center axes align to define a center axis 115 of EP magnet unit 101, and a coil of magnet wire 130 that is wrapped around the magnetic rings 110 and 120. As shown in FIG. 1A, when the elements of FIG. 1 are assembled, the first magnetic ring 110 and second magnetic ring 120 produce a net magnetic field aligned with the center axis 115 having a first pole (P1) extending from a first side of (EP) magnet unit 101 and a second pole (P2) extending from the opposite second side of (EP) magnet unit 101. As would be appreciated, P1 and P2 represent the opposing magnetic polarities associated with either side of the magnetic field produced by EP magnet unit 101. That is, when P1 is a north magnetic pole, then P2 is a south magnetic pole. Likewise, when P1 is a south magnetic pole, then P2 is a north magnetic pole. In this embodiment, the first magnetic ring 110 defines the “hard” magnet of the EP magnet unit 101 while the second magnetic ring 120 defines the “semi-hard” magnet In their initial states, each of the magnetic rings 110 and 120 comprise materials that exhibit a magnetic moment and each produce their own magnetic fields even when no current is applied to magnet wire 130. In one embodiment, when EP magnet unit 101 is in its initial state (also referred to herein as its “off” state), the magnetic rings 110 and 120 are arranged so that the same magnetic polarity from each of the magnetic rings 110 and 120 face each other. That is, in the off state, either the north pole of ring 110 faces the north pole of ring 120, or the south pole of ring 110 faces the south pole of ring 120. In this configuration, their respective magnetic fields produced by each magnetic ring offset so that the net magnetic field from unit 100 will have a magnitude that is a function of the difference between the magnitudes of their individual fields. In some embodiments, the dimensions, geometry and material used to fabricate the magnetic rings 110 and 120 are selected so that the magnetic fields completely, or almost completely offset each other when in the off state and EP magnet unit 101 produces a net magnetic field of essentially zero. The off state, where the respective fields of rings 110, 120 offset, is also referred to herein as the deactivated state of EP magnet unit 100. In contrast to the off state, EP magnet unit 101 may also be set to a second state referred to herein as the “on” or “activated” state. To switch the EP magnet unit 101 from the off state to the on state, a pulse of electric current is passed through magnetic wire 130 so that the magnetic polarization vector of the second magnetic ring 120 (i.e., the semi-hard magnet) is flipped parallel to the polarization of magnetic ring 110. That is, the polarity of magnetic ring 120 is flipped so that dissimilar magnetic poles of ring 120 and ring 110 face each other. In this configuration, rather than offsetting each other, the two magnetic fields produced by the magnetic rings 110 and 120 are additive so that the net magnetic field from unit 100 will have a magnitude that is cumulative (i.e. a function of the sum of the magnitudes of their individual fields). To once again deactivate EP magnet unit 101 from the on state back to the off state, another short pulse of current may be passed in through magnetic wire 130 in the opposite direction as the current applied to activate EP magnet unit 101. When such current is applied, the magnetic polarization vector of magnetic ring 120 is flipped anti-parallel to that of magnetic 110 so that their individual magnetic fields once again offset. The pulse of current applied to flip the state of unit 100 may be on the order of a micro seconds to hundreds of microseconds and of sufficient magnitude to produce a magnetic field sufficient to flip the polarity of magnetic ring 120, but not sufficient to flip the polarity of magnetic ring 110. At the same time, the material selected for ring 120 is also selected to have sufficient magnetic coercivity that it will not flip polarity or become demagnetized in response to the magnetic field produced by magnetic ring 110. That is, magnetic ring 120 has sufficient magnetic hardness to resist flipping poles in response to the magnetic field from magnetic ring 110, but will flip in response to the magnetic field produced by magnetic wire 130 when a current is applied. Magnetic ring 110 has sufficient magnetic hardness to resist flipping poles in response to the magnetic field from magnetic ring 120 and resist flipping poles in response to the magnetic field from magnetic wire 130. FIG. 1B provides example magnetization (M) verses applied magnetic field (H) hysteresis curves 190 and 192 that illustrate the characteristics of “hard” verses “semi-hard” magnetic materials. Generally speaking, the “hardness” of a magnetic material (i.e., its coercivity or the magnitude of an applied magnetic field necessary to cause the material to flip in polarity) is at least in part a function of the width of the material's hysteresis curve along the horizontal “applied magnetic field” (H) axis so that the relative hardness or semi-hardness of any two magnetic materials (as those term is used herein) can be evaluated by comparing the relative widths of their hysteresis curves at this axis. When a driving field (i.e., an applied magnetic field) sufficient to cause saturation magnetization is applied to a hard magnetic material (illustrated at 190), it will retain a fraction of the saturation field even when the driving field is removed. In comparison, when the same driving field sufficient to cause saturation magnetization is applied to a semi-hard magnetic material (illustrated at 192) it will retain a smaller fraction of the saturation field when the driving field is removed. As such, the semi-hard magnetic material is more amenable to reversing polarity in response to an externally applied magnetic field than a hard magnetic material because, at least in part, of the differences in the saturation fields present in the material after the externally applied magnetic field is removed. With cold atom sensors such a clocks or inertial sensors, an atom trapping field such as an anti-Helmholtz field is applied to trap atoms (such as, but not limited to atomic Rubidium (Rb), Cesium (Cs), calcium (Ca) or Ytterbium (Yb)) within a high vacuum chamber. FIG. 2 is a diagram illustrating such a cold atom sensor 200 comprising a set of paired EP magnet units 201-1 and 201-2, each of which having the structure and configuration as described above for EP magnet unit 101. As such, details from the above discussion regarding EP magnet unit 101 applies to each of the EP magnet units 201-1 and 201-2 and vice versa. The EP magnet units 201-1 and 201-2 are positioned on opposite sides of an ultra-high vacuum cell or chamber 220 to introduce an atom trapping magnetic field (such as an anti-Helmholtz magnetic field or a quadrupole magnetic field) within the vacuum changer 220. That is, as further illustrated in FIG. 2A, the center axis of each of the two EP magnet units 201-1 (shown at 215-1) and 201-2 (shown at 215-2) are aligned to be co-linear with each other and with the center of a magneto-optical trap 222 defined within the vacuum chamber 220. Each of the two EP magnet units 201-1 and 201-2 are oriented with respect to magneto-optical trap 222 so that when they are both switched to the on state, the polarities of their respective magnetic fields are anti-parallel and offset each other at the very center of the magneto-optical trap 222 (i.e., their respective poles oriented in opposite directions) resulting in an atom trapping magnetic gradient 225 such as an anti-Helmholtz magnetic field configuration. For trapping to occur, the atoms are laser cooled by appropriately detuned laser beams 230, 232. The atom trapping magnetic field can be applied by switching EP magnet units 201-1 and 201-2 to the on state in order create the trapping potential 225, the minimum of which defines the center of the magneto-optical trap 222. As the term is used herein, a detuned laser beam refers to a laser tuned to a frequency slightly off from the natural atomic resonant frequency. Red-detuned light can provide a friction force to the atom whenever it moves towards a laser source, thereby slowing, or “cooling” the atom. In the embodiment shown in FIG. 2, each of the detuned laser beams 230, 232 are generated by respective laser sources 231 and 233. Laser sources 231 and 233 are aligned with the center axis 115 of each of the respective EP magnet units 201-1 and 201-2 so that the laser beams 230, 232 pass through the center ring hole 112 of each and meet at the center of the trap 222. In this way, the laser beams 230, 232 are each aligned with the magnetic gradient produced in chamber 220 by the EP magnet units 201-1 and 201-2. It should also be appreciate that the laser sources 231 and 233, although shown as separate, will typically (but not always) be implemented using one single laser generating device such that laser beams 230, 232 are both derived from a single common laser beam. To load cooled atoms into the spatially dependent trap 222, a pulse of current is applied to activate the EP magnet units 201-1 and 201-2 generating the atom trapping magnetic field gradient 225 that results in a net magnetic field of the anti-Helmholtz like configuration (i.e. at trap 222). More specifically, the atom trapping magnetic field 225 comprises a linear gradient that is zero at the very center of the trap 222 and increases in magnitude moving towards the EP magnet units 201-1 and 201-2. Because the atoms seek to rest at the point of lowest potential, they become trapped in the magneto-optical trap 222. Although the atom trapping magnetic field in sensor 200 is applied to trap atoms, in order to characterize the atoms (for example, by interrogating and probing the internal states of the atoms), the magnetic field is momentarily de-energized. To de-energize the magnetic field providing the magnetic gradient, a current pulse is applied to each of the EP magnet units to turn their respective EP magnet units to the off state. The atoms can then be characterized by means known to those in the art. Once the characterization is completed, another current pulse is applied in the opposite direction to each of the EP magnet units to turn their respective EP magnet units to their on state and re-establish trap 222. The EP magnet units described herein, unlike traditional electromagnetic coils, have the ability to remain magnetized once activated without using any power to maintain the magnetic field. By utilizing the EP magnet unit 101 shown in FIGS. 1 and 1A, embodiments of the present disclosure provide a low power and fast way to perform switching because each EP magnet unit only needs to be momentarily energized to switch the EP magnet units between on and off states, but the EP magnet units do not need to remain energized to maintain the anti-Helmholtz magnetic field. One problem with the magnetic materials used to fabricate permanent magnets is that the magnetic field they generate may drift over time. For example, some magnetic materials are sensitive to temperature and will produce a magnetic field that changes as a function of changes in temperature. Therefore, for some embodiment, magnetic field biases may optionally be calibrated out of an EP magnet unit by measuring the internal state of the laser cooled atoms and translating those states into a feedback signal applied to the EP magnet unit. One such embodiment for mitigating drift is shown in FIG. 2B. FIG. 2B is a diagram illustrating cold atom sensor 200 where each of the paired EP magnet units 201-1 and 201-2 further comprise shim coils 280. It should be appreciated that although shim coils 280 are discussed with respect to EP magnet units 201-1 and 201-2, they may also be utilized for other geometries as well. In one embodiment, shim coils 280 are low current carrying coils that can be utilized to compensate for any drift in the permanent magnet fields of EP magnet units 201-1 and 201-2 caused by temperature or other environmental effects. Shim coils 280 could also be used to further null any remnant magnetic field that may exist within trap 222 when the EP magnet units are in the off state. That is, even in the off state, the magnetic fields of the first magnetic ring 110 and second magnetic ring 120 may drift so that they do not perfectly offset which in the off state which means a low remnant magnetic field may remain present. By passing a current through shim coils 280, that low remnant magnetic field may be mitigated. In one embodiment, cold atom sensor 200 further comprises an atom characterization function 285. The internal states of the laser cooled atoms are sensitive to the remnant magnetic field and may be probed, in the same manner as for a magnetometer, to determine the magnitude of any magnetic field acting on them. In one embodiment, active magnetic field nulling, using Zeeman state calibration or other methods, can be used in order to compensate for the field variations in time. For example, Zeeman spectroscopy can be used by atom characterization function 285 to probe the atomic state of the atoms in trap 222 to measure the remnant magnetic field. From that measurement, atom characterization function 285 generates a proportional current into one or both of shim coils 280 to produce a calibrating magnetic field that acts to null the remaining magnetic field. In one embodiment, periodic recalibration is performed using shim coils 280 to correct for magnetic drift that may occur over time. The current applied to shim coils 180 is essentially an error, or feedback, signal used to drive the magnetic field as measured in the atom trap 222 to zero when the magnetic field should be zero (i.e., when the EP magnet units 201-1 and 201-2 are in the off state). It should be noted that in some alternate embodiments, the dimensions, geometry and material used for the magnetic rings 110 and 120 are selected to only partially offset in the off state so that there remains an intentional bias in the magnetic field around unit 101 even when unit 101 is deactivated. Such embodiments may be used in some clock applications. In such alternate embodiments, shim coils 280 may be utilized with atom characterization function 285 to calibrate an EP magnet unit to have the desired intentional offset in the off state, rather than a net magnetic field of zero. It should be appreciated that although FIGS. 2, 2A and 2B illustrate utilization of one pair of laser beams which are aligned with the EP magnet units 201-1 and 201-2, magneto-optical trap 222 may in fact be implemented in all three Cartesian directions through additional laser beam pairs. For example, FIG. 2C illustrates the pair of laser beams 230 and 232 (shown at 260 produced by respective laser sources 231 and 233) used in conjunction with a second pair of laser beams 270 and 272 (shown at 262 produced by respective laser sources 271 and 273) and a third pair of laser beams 275 and 277 (shown at 264 produced by respective laser sources 276 and 278) each orthogonally oriented with respect to each other and having axes mutually intersecting at the center of magneto-optical trap 222. FIG. 3 is a flow chart illustrating a method 300 of one embodiment of the present disclosure for low power magnetic field generation for atomic sensors. In some embodiments, the elements of method 300 may be used to implement one or more elements of any of the embodiments described above with respect to the above Figures. As such, elements of method 300 may be used in conjunction with, or in combination with the embodiments described above and details from the above discussions apply to method apply to method 300 and vice versa. The method begins at 310 with laser cooling a sample of atoms in a chamber. For trapping to occur, the atoms are laser cooled by appropriately detuned laser beams. The atom trapping magnetic field (such as an anti-Helmholtz magnetic field or a quadrupole magnetic field) is applied by switching the EP magnet units to the on state in order create a trapping potential gradient, the minimum of which defines the center of the magneto-optical trap. Accordingly, the method proceeds to 320 with trapping the sample of atoms in a magneto-optical trap within the chamber by applying an atom trapping magnetic field across the sample of atoms using at least one pair of electro-permanent magnet units. As described above, each of the electro-permanent magnet units of the at least one pair of electro-permanent magnet units may comprise: a first magnetic ring of a first magnetic material, a second magnetic ring of a second magnetic material, and a coil of magnet wire that is wrapped around one or both of the first magnetic ring and the second magnetic ring. In that case, applying an anti-Helmholtz magnetic field, or other atom trapping magnetic field, across the sample of atoms further comprises applying a first pulse of current having a first duration and amplitude to the coil, wherein there first pulse of current switches each electro-permanent magnet unit from an off state to an on state by switching a magnetic polarity of the second magnetic ring without switching a polarity of the first magnetic ring. In other words, the first magnetic ring defines the “hard” magnet of the EP magnet unit while the second magnetic ring defines the “semi-hard” magnet. In the off state, a first magnetic field of the first magnetic ring and a second magnetic field of the second magnetic ring are oppositely polarized to offset each other in the same manner as describe above with respect to FIG. 1. Similarly, in the on state, the first magnetic field of the first magnetic ring and the second magnetic field of the second magnetic ring are similarly polarized to add to each other. The atom trapping magnetic field is applied to trap atoms. But, in order to characterize the atoms (that is, probe the internal states of the atoms), the magnetic field is momentarily de-energized. As such in some embodiments, method 300 may proceed to 330 by performing a desired atomic interrogation scheme on the sample of atom while momentarily de-energizing the atom trapping magnetic field across the sample of atoms. This interrogation scheme may comprise probing an internal state of the atom sample, probing an external motional state of the atom sample, or some other atomic interrogation. In the manner described above, to de-energize the magnetic field providing the magnetic gradient, a second current pulse is applied (in the opposite direction of the first pulse) to each of the EP magnet units to turn their respective EP magnet units to their off state. The atoms can then be characterized by means known to those in the art. Once the characterization is completed, another current pulse is applied in the opposite direction to each of the EP magnet units to turn their respective EP magnet units to their on state and re-establish the magneto-optical trap. Example 1 includes a method for magnetic field generation for an atomic sensor, the method comprising: laser cooling a sample of atoms in a chamber; and trapping the sample of atoms in a magneto-optical trap within the chamber by applying an atom trapping field across the sample of atoms using at least one pair of electro-permanent magnet units. Example 2 includes the method of example 1, further comprising: performing an interrogation scheme on the sample of atoms while momentarily de-energizing the atom trapping magnetic field across the sample of atoms. Example 3 includes the method of any of examples 1-2, wherein each electro-permanent magnet unit of the at least one pair of electro-permanent magnet units comprises: a first magnetic ring of a first magnetic material; a second magnetic ring of a second magnetic material; and a coil of magnet wire that is wrapped around one or both of the first magnetic ring and the second magnetic ring; wherein applying an atom trapping magnetic field across the sample of atoms further comprises applying a first pulse of current having a first duration and amplitude to the coil, wherein there first pulse of current switches each electro-permanent magnet unit from an off state to an on state by switching a magnetic polarity of the second magnetic ring without switching a polarity of the first magnetic ring. Example 4 includes the method of example 3, wherein in the off state, a first magnetic field of the first magnetic ring and a second magnetic field of the second magnetic ring are oppositely polarized to offset each other, and wherein, in the on state, the first magnetic field of the first magnetic ring and the second magnetic field of the second magnetic ring are similarly polarized to add to each other. Example 5 includes the method of any of examples 3-4, the first magnetic material having first magnetic hardness sufficient to not change polarity in response to the first pulse of current; and the second magnetic material having a second magnetic hardness less than the first magnetic material such that the second magnetic material will change polarity in response to the first pulse of current, but wherein the second magnetic hardness is sufficient to not change polarity in response to the first magnetic field of the first magnetic ring Example 6 includes the method of any of examples 1-5, wherein the least one pair of electro-permanent magnet units comprises a first electro-permanent magnet unit having a first center ring hole and a second electro-permanent magnet unit having a second center ring hole; wherein laser cooling further comprises: launching a first laser beam through the first center ring hole towards the second center ring hole, and launching a second laser beam through the second center ring hole towards the first center ring hold, wherein the first laser beam and the second laser beam are collinear and intersect at the magneto-optical trap. Example 7 includes the method of any of examples 1-6, wherein laser cooling further comprises applying a first laser beam and a second laser beam into the magneto-optical trap each aligned to an axis of the anti-Helmholtz magnetic field. Example 8 includes the method of any of examples 1-7, wherein the sample of atoms comprise one of atomic Rubidium (Rb), Cesium (Cs), atomic Calcium (Ca) or atomic Ytterbium (Yb). Example 9 includes the method of any of examples 1-8, further comprising: probing the sample of atoms to measure a net magnetic field; and calibrating at least a first electro-permanent magnet unit of the at least one pair of electro-permanent magnet units based on the net magnetic field measured by the probing. Example 10 includes the method of example 9, wherein the first electro-permanent magnet unit further comprising at least one shim coil; and wherein calibrating at least the first electro-permanent magnet unit comprises controlling a feedback current to the at least one shim coil based on the net magnetic field measured by the probing. Example 11 includes a cold atom sensor, the sensor comprising: a vacuum chamber having a sample of atoms sealed within the vacuum chamber; at least one pair of electro-permanent magnet units arranged across the vacuum chamber, the least one pair of electro-permanent magnet units comprising a first electro-permanent magnet unit having a first center ring hole and a second electro-permanent magnet unit having a second center ring hole; a first laser source configured to launch a first laser beam through the first center ring hole and towards the second center ring hole, and a second laser source configured to launch a second laser beam through the second center ring hole and towards the first center ring hold, wherein the first laser beam and the second laser beam are collinear; wherein the first laser source and the second laser source are configured to laser cool the sample of atoms when the first laser beam and the second laser beam are energized and the first electro-permanent magnet unit and the second electro-permanent magnet unit are configured to produce an atom trapping magnetic field that holds the sample of atoms in an magneto-optical trap. Example 12 includes the sensor of example 11, wherein each electro-permanent magnet unit of the at least one pair of electro-permanent magnet units comprises: a first magnetic ring of a first magnetic material; a second magnetic ring of a second magnetic material; and a coil of magnet wire that is wrapped around one or both of the first magnetic ring and the second magnetic ring; wherein the at least one pair of electro-permanent magnet units are configured to produce the atom trapping magnetic field across the sample of atoms by applying a first pulse of current having a first duration and amplitude to the coil, wherein there first pulse of current switches each electro-permanent magnet unit from an off state to an on state by switching a magnetic polarity of the second magnetic ring without switching a polarity of the first magnetic ring. Example 13 includes the sensor of example 12, wherein the cold atom sensor is configured to perform interrogation on the sample of atoms while momentarily de-energizing the atom trapping magnetic field across the sample of atoms by switching a polarity of the second magnetic ring. Example 14 includes the sensor of any of examples 12-13, wherein when switched to an off state, a first magnetic field of the first magnetic ring and a second magnetic field of the second magnetic ring are oppositely polarized to offset each other, and wherein when switched to an on state, the first magnetic field of the first magnetic ring and the second magnetic field of the second magnetic ring are similarly polarized to add to each other. Example 15 includes the sensor of any of examples 12-14, the first magnetic material having first magnetic hardness sufficient to not change polarity in response to the first pulse of current; and the second magnetic material having a second magnetic hardness less than the first magnetic material such that the second magnetic material will change polarity in response to the first pulse of current, but wherein the second magnetic hardness is sufficient to not change polarity in response to the first magnetic field of the first magnetic ring Example 16 includes the sensor of any of examples 11-15, wherein first laser beam and the second laser beam are each aligned to an axis of the atom trapping magnetic field. Example 17 includes the sensor of any of examples 11-16, wherein the sample of atoms comprise one of atomic Rubidium (Rb), Cesium (Cs), atomic Calcium (Ca) or atomic Ytterbium (Yb). Example 18 includes the sensor of any of examples 11-17, further comprising: an atom characterization function configured to probe the sample of atoms to measure a net magnetic field; and wherein the atom characterization function is configured to calibrate at least a first electro-permanent magnet unit of the at least one pair of electro-permanent magnet units based on the net magnetic field measured by the probing. Example 19 includes the sensor of any of examples 11-18, wherein the at least one of the pair of electro-permanent magnet units comprises a shim coil; and wherein the atom characterization function is configured to control a feedback current to the at least one shim coil based on the net magnetic field measured by the probing. Example 20 includes the sensor of any of examples 11-19, wherein the at least one pair of electro-permanent magnet units comprise: a first pair of electro-permanent magnet units producing a first anti-Helmholtz magnetic field gradient across the magneto-optical trap. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
040240177	description	The computation may be made not only on the basis of the epithermal/thermal flux ratio but may be based on any other ratio of the flux densities of two selected neutron groups or energies. The local burn-up changes the local epithermal/thermal flux ratio in a predetermined manner. The epithermal/thermal flux ratio .GAMMA.(x) is defined as the ratio of the flows of the fast and the thermal neutron groups or energies: ##EQU1## wherein .GAMMA.(x) = local epithermal/thermal flux ratio .phi. (E, x) = local neutron flux dependent on neutron energy PA1 E.sub.et = epithermal cut off energy PA1 .phi..sub.s (x) = local epithermal neutron flux PA1 .phi..sub.th (x) = local thermal neutron flux PA1 .rho..sub.SK = local influences of structural materials, control rods, temperature, etc. PA1 .sigma. = thermal activation cross section However, the interrelationship between the epithermal/thermal flux ratio .GAMMA. and burn-up A is not monotone for the entire burn-up range because the boron content .rho..sub.B of the cooling medium is changed as the burn-up increases for reasons of reactivity. Further influences disturbing the spectrum-burn-up relationship include the structural materials of the reactor, the control rods, and the cooling medium temperature dependent on the locale. These disturbing influences can be eliminated by correlation or importance functions in a diffusion program. The change of the epithermal/thermal flux ratio .DELTA. .GAMMA. (x) in the xenon equilibrium condition may be approximated by the following equation if terms of higher order are neglected: ##EQU2## wherein A = burn-up .rho..sub.B = concentration of boron If .GAMMA.(x, t.sub.o) is the calibrating measurement of the ratio at a time t.sub.o, the following equation is derived from equation (1), above, for burn-up A(x,t) at time t.sub.o ##EQU3## In practical terms, the change in the epithermal/thermal flux ratio may be derived from computations with a burn-up program including the disturbance variables ##EQU4## so as to obtain a ratio .GAMMA.(x,t) corrected for boron content and structural material influences, which is a definite and monotone function of the burn-up (see FIG. 1): ##EQU5## wherein ##EQU6## is a total correction factor derived from the following equation if terms of higher order are neglected (see FIG. 2): ##EQU7## Using (4), the following simplified equation is derived from equation (2): ##EQU8## Thus, the locale burn-up A(x,t) may be determined by measuring the epithermal/thermal flux ratio while taking into account the influence of the boron content and the structure. The method of the present invention has been tested in the nuclear power station Obrighein, German Federal Republic (hereinafter called KWO), by using the ball measuring system which is known e.g. from DAS (German Published Patent Application) No. 1,930,439 for measuring the neutron flux distribution in pressurized water reactors (PWR). The flux ratio .GAMMA..sup.x (x,t) was computed from a single measurement by activating the column of balls of the generally conventional ball measuring system installed at KWO schematically shown in FIG. 3. This system includes indicator nuclides Ni.sup.58 and Mn.sup.55. The two activities Co.sup.58 (fast activation of Ni.sup.58) and Mn.sup.56 (thermal activation) were separated in time by their different half-lifes of 72 and 2.57 h, respectively. The balls of this ball measuring system were made of the alloy "Incoweld" which has the following composition: 70% Ni, 15-17% Cr, 8% Fe, 2.75-3.35% Ti, 2-2.75% Mn and traces of Cu, C, Al, Si and S. FIG. 4 shows a decay curve of activated "Incoweld" balls. This type of probe material is advantageous because of its high nickel content which delivers a sufficient threshold detector activity and because the decay gammalines of Co.sup.58 and Mn.sup.56 are almost the same (0.81 and 0.85 Mev), which permits the adjustment of the discriminator threshold of the electronic measuring instrument to be maintained unchanged. The two activities Co.sup.58, Mn.sup.56 (see output 20, 20a in FIG. 3) for the evaluation of the burn-up can be obtained by measuring the ball column by device 8 (FIG. 3) at two different time intervall t.sub.1, t.sub.2 (FIG. 4). The E.sub.1 activation, decay and measuring times are so chosen and correlated that, under the chosen measuring conditions, the pulse rates are high enough to provide a good statistical survey while the disturbing influence of complementary activity is less than 1%. In the ball system used at KWO, as illustrated in FIG. 3, measurements were taken in 5.5 cm sections of the column of balls so that the height of the reactor (2.7 m) was divided into 50 axial compartments. As schematically shown in FIG. 3, nuclear reactor 1 contains shielded nuclear fuel core 2 into which extends guide tube 3 for a test column of balls, the end of the guide tube in the core being closed off at 3'. Solenoid valve 4 permits controlled introduction of compressed air to convey the balls into the portion of the guide tube extending axially into core 2. The opposite end of U-shaped guide tube 3 extends into rotatable storage drum 5 which also receives one end of second guide tube 7. Solenoid valve 6 permits controlled introduction of compressed air into the drum to convey the balls between the two guide tubes. Thus, after the balls have been exposed to radiation in the nuclear reactor core to activate the different components of the alloy, they are conveyed through guide tube 7 to measuring device 8 surrounded by radiation shield 9, the measuring device producing measuring signals which are at the chosen time intervals a function of the flux of the neutron energy and of each component of the alloy of which the balls are made. During the measurement, the column of balls is moved past the measuring device by a wire reeled in a wire pulling machine 10. Another solenoid valve 11 permits compressed air to be delivered into the end of the guide tube 7 to convey the balls back into the storage drum after measurement. Instead of a column of balls, a helical spring can be used. Since the measured epithermal/thermal flux ratio change between the new and burnt up nuclear fuel core amounts only to about 20% to 30% (a little more if plutonium is used as fuel), the pulse rates of the indicator nuclides used to indicate the flux ratio must have a sufficiently good statistic. The flux ratios .GAMMA.(x,t) are computed from the ratio of the pulse rates of the activation of nickel by fast neutrons (A.sub.Ni.sup.s) at time t by the reaction EQU Ni.sup.58 (n,p)Co.sup.58 and of the activation of manganese by thermal neutrons (A.sub.Mn.sup.th) by the reaction EQU Mn.sup.55 (n,.gamma.)Mn.sup.56 according to the following equation (with Mn and Ni being paired as indicator nuclides): ##EQU9## If thermal neutron absorbers are combined with epithermal activation components of different magnitudes, for instance manganese and vanadium, the following equation prevails: ##EQU10## wherein I.sup.res = resonance integral I.sup.s = mean cross section of the threshold reaction of fast flux .phi..sub.s In FIG. 5, the pulse rates A'.sub.s, A'.sub.th are converted with known magnitudes to specific saturation activities (block 21). Thereupon the epithermal/thermal flux ratio is determined according to equation (6) at block 22 and then the quotient is formed at block 24 by using the locally dependent value .GAMMA..sub.o (x) from the library (block 23). The boron concentration .rho..sub..beta. is used as an additional input at 25 for measurement. With the aid of the boron concentration and taking into account the locale (x), correction factor B is received from the library (block 26) to correct for boron content (block 27). In block 29, the computer executed equation (5) by obtaining from the library (block 28) those values A(x) and ##EQU11## which meet the requirements of equation (5). The burn-up condition A.sub.o of the reference measurement, received from the library (block 30), permits the determination of the actual local burn-up A. A further program (block 31) extrapolates to the entire reactor core and thus to the local burn-up condition of each fuel element. FIG. 6 is a graph of the axial curve of the burn-up in the nuclear fuel core of the KWO reactor, comparing the results of several known burn-up measurements and measurements according to the present invention. The results of the measurement according to the invention are indicated with +. Even a one-dimensional diffusion burn-up program for computing A() shows that the results conform closely to the classical measuring methods (gamma-scan, power density integration). The deviations are less than 3%. The required measuring time for determining the burn-up with the illustrated ball measuring system is about 60 hours and is essentially determined by the required decay time (see graph of FIG. 4). In the ball measuring system of the nuclear power plant at Stade, Federal German Republic (hereinafter called KKS), manganese and vanadium are used as indicator nuclides. This permits a reduction of the total measuring time to about 2 hours, about a quarter of an hour being required for the decay of the vanadium activity. A combination of the indicator nuclides vanadium and nickel is particularly useful, measuring times of about two hours being required for the entire core with these activity components. Furthermore, tests have shown that the measuring time may be reduced with the use of non-linear filters. It is also possible by means of the burn-up measuring system of the present invention to measure the burn-up of operating boiling water nuclear reactors which have fixedly arranged fission chambers and calibrating chambers associated therewith and arranged to be moved during the operation through guide tubes distributed through the nuclear fuel core. Measurements are effected in such reactors by introducing additional fission chambers charged with a different fissile material into a respective one of the guide tubes to produce the measuring signals for comparison. The measuring signals are computed when the movable additional fission chamber is at the level of the associated fixed fission chamber. Two or more additional fission chambers may be formed into a structural unit and moved simultaneously into the nuclear fuel core. In any event, according to this invention, the measurement of the burn-up is effected by comparing at least two measuring signals derived from activity detectors, such as fission chambers, which are moved into the core and/or at fixedly mounted therein. The detectors have a different sensibility for different neutron groups or energies so that the comparison of at least two detector signals produces the coarse spectrum or a like parameter correlated to the burn-up.
	description	This application is a Divisional of U.S. application Ser. No. 10/157,089, filed May 29, 2002 which is incorporated herein by reference in its entirety. A number of techniques exist for the elemental analysis of objects using X-rays. Some of these techniques rely on the different X-ray attenuation characteristics of elements, whereas others rely on X-ray fluorescence. An example of an attenuation-based analysis technique utilizes characteristic elemental resonance energies. The attenuation of an X-ray beam of a sufficiently narrow spectral bandwidth increases substantially, when the central energy increases over the resonance energy of a constituent element of a test object. X-ray microscopes taking advantage of this characteristic have been developed for element-specific imaging. The microscopes typically combine a source, such as a synchrotron, a monochromator, a lens, such as a zone plate lens, a detector array, and possibly a scintillator to generate an image of a given test object. Typically, the microscopes are used in transmission. Two images at X-ray energies below and above the resonance energy of the element of interest are often required to obtain the necessary contrast between the element of interest and other constituent elements of the test object to thereby yield an image of the element's distribution within the test object. X-ray fluorescence analysis or spectrometry (XRF) is a nondestructive analysis technique, which uses primary radiation, such as X-rays or energetic electrons, to eject inner-shell electrons from the atoms of the test object, yielding electron vacancies in the inner shells. When outer-shell electrons in the atoms fill the vacancies, secondary radiation is emitted with energies equal to the energy difference between the inner- and outer-shell electron states. The fluorescence emissions are characteristic of different elements. Thus, measurement of the spectrum of the secondary X-rays yields a quantitative measure of the relative abundance of each element that is present in the test sample. Element-specific imaging of a test object with a spatial resolution better than about 1 micrometer is obtained currently by analyzing the X-ray fluorescence spectrum at each point by raster scanning a small probe of ionizing radiation, such as X-rays or energetic electrons, across the test object. Element specific imaging with a spatial resolution approaching 100 nanometers (nm) has been demonstrated with high elemental sensitivity using a high brightness synchrotron radiation source, but the serial nature of the raster scanning significantly limits the throughput and the high source brightness requirement makes it unpractical for producing an element-specific imaging system using a laboratory x-ray source. The present invention is directed to an X-ray analysis technique that relies on the generation of secondary radiation from the test object. The invention enables high resolution, high contrast imaging of structures within a test object based on their elemental composition or absorption. It also enables the elemental analysis of the test object. In more detail, an element-specific imaging technique is disclosed that utilizes the element-specific fluorescence X-rays that are induced by primary ionizing radiation. The fluorescence X-rays from an element of interest are then preferentially imaged onto a detector using an optical train. In one embodiment, the preferential imaging of the optical train is achieved using a chromatic lens in a suitably configured imaging system. A zone plate is an example of such a chromatic lens; its focal length is inversely proportional to the X-ray wavelength. This embodiment of the present invention relies on both the imaging and chromatic properties of the chromatic lens to image an element of interest in a test object by appropriately configuring the imaging system to form images on the detector array of the characteristic fluorescence X-rays from the test object. A given element in the test sample can be imaged using its fluorescence X-rays. If a zone plate is used as the chromatic lens, the preferential imaging of the element can be enhanced if the plate itself is made of a compound including the same element. For example, when imaging copper using the Cu Lα spectral line, a copper zone plate lens is used. This enhances the preferential imaging of the zone plate lens because its diffraction efficiency (percent of incident energy diffracted into the focus) changes rapidly near an absorption line and can be made to peak at the X-ray fluorescence line of the element from which it is fabricated. In another embodiment, a spectral filter, such as a thin film filter or crystal, is used in the optical train. Wavelength dispersive elements can be used in the optical train between the object of interest and the detector to improve preferential imaging. According to the invention, primary ionizing radiation emitted by a radiation source impinges on a test object and excites elements within the test object to emit secondary X-ray fluorescence radiation. The secondary X-ray fluorescence radiation that is emitted by the test object from an element of interest is then preferentially imaged on a detector system, using a lens with an appropriate imaging configuration. In some examples, the distribution of the secondary radiation is of interest, whereas in other implementations, the secondary radiation is used as backlighting. The preferential imaging is achieved, in one embodiment, by using a zone plate lens that will focus only a narrow band of energies around the fluorescence line of the element of interest onto the detector system in a suitably configured imaging system. This property results from the dependence of the focal length of a zone plate on the wavelength of radiation and thus only one wavelength satisfies the imaging condition for a given microscope configuration (object-to-lens and lens-to-detector distances). It is recognized that element-specific imaging using a zone plate's high order diffraction, such as the 3rd order diffraction, offers significantly better elemental specificity than using the primary 1st order diffraction. Generally, a zone plate's focusing efficiency for higher order diffraction is smaller than the primary 1st order diffraction. A central stop on the zone plate may be required or desirable to obtain high signal to noise in the image formed on the detector by the fluorescence x-rays of interest by reducing or eliminating the x-rays photons that are not focused by the zone plate. According to another embodiment, the preferential imaging is also achieved by a combination of an imaging system employing a chromatic or nonchromatic imaging optic, such as a zone plate or a suitably configured mirror (e.g., Wolter optic), and a wavelength dispersive device such as a suitably designed multilayer optic. This optic is configured to reflect efficiently the fluorescence x-rays from the element of interest while maintaining the necessary imaging properties of the imaging system. More specifically, the x-ray fluorescence microscope includes a condenser relaying the primary ionizing radiation to the test object, a mechanical stage for manipulating the test object, a zone plate, a wavelength dispersive optic such as a multilayer coating or crystal, and a detector such as detector array. Alternatively, the x-ray fluorescence microscope includes a condenser for relaying the primary ionizing radiation to the test object, a mechanical stage for manipulating the test object, a suitably figured reflective imaging optic such as a Wolter optic, a wavelength dispersive optic such as a multilayer filter, and a detector such as detector array. It is recognized that the preferential imaging can be further improved by using a filter of high transmission of the fluorescence x-rays of interest but low transmission for some x-rays of energies substantially different from that of the fluorescence x-rays. In one implementation of the present invention, an X-ray fluorescence microscope includes a primary ionizing radiation source, a condenser relaying the primary ionizing radiation to the test object, a mechanical stage for manipulating the test object, a zone plate lens, and a detector such as detector array. In the preferred implementation of the X-ray fluorescence microscope, a given element is imaged by using a zone plate made of a compound comprising the same element, or a compound consisting essentially of the same element. The object-to-lens and lens-to-detector distances of the X-ray fluorescence microscope are typically configured to image a characteristic X-ray fluorescence line of an element in a test object, and the recorded image thus represents the distribution of the element. Images of other elements in the object are obtained using configurations appropriate for their respective X-ray fluorescence lines. This imaging mode is referred to as X-ray fluorescence imaging mode. In another embodiment, the X-ray fluorescence microscope is configured for a specific characteristic fluorescence X-ray line of an element in the object with a known structure to image structures within a volume defined by the field of view and the depth of focus of the microscope using the illumination provided by the fluorescence from the element. This imaging mode is referred to as X-ray fluorescence backlighting imaging mode. In yet another embodiment, the X-ray fluorescence microscope is configured for a specific characteristic fluorescence line of an element but all of the X-ray fluorescence signals are integrated to measure the total amount of an element within a specific volume. Amount of other elements are measured using microscope configurations appropriate for their respective X-ray fluorescence lines. This X-ray fluorescence microscope mode is referred to as fluorescence spectrometer mode. It is recognized that the test object can be illuminated with an illumination beam with a large solid angle for increasing the rate of the secondary x-ray fluorescence generation. It is further recognized that the throughput of the x-ray fluorescence microscope can be improved by optimization of the illumination system, which typically comprises the source and the condenser, to increase the production rate of the secondary fluorescence x-rays within the volume of interest in the test object. An example of such a design includes a fine focus x-ray source specifically designed for high brightness applications and an x-ray condenser specifically designed for collecting primary ionizing x-rays from the source over a large solid angle and directing them onto the test object. In other embodiments, multiple imaging systems are used to increase throughput and/or perform stereoscopic or tomographic imaging. The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. FIG. 1 shows an X-ray fluorescence microscope 100, which has been constructed according to the principles of the present invention. Specifically, a test object, such as the integrated circuit (IC) 10 of a semiconductor wafer 12, is irradiated by primary ionizing radiation 110 such as electrons or X-rays from a radiation generator 102. In the preferred embodiment, the wafer/test object is held on precision x-y stage 130 to position the test sample in the x-ray fluorescence microscope 100. In one example, the primary X-ray radiation 110 is generated by source 112, by bombarding a solid target with energetic electrons, or by focusing a sufficiently intense laser beam on a solid or liquid target. In the illustrated example, a condenser 114, such as a suitably shaped capillary tube, with or without multilayer coatings, is used to concentrate and relay the primary radiation 110 to a small area on the test object 10, which is placed correctly by control of the x-y stage 130 holding the test object 10. Other types of x-ray condensers, such as polycapillary and bent crystal, are used in alternative implementations. The condenser 114 increases the flux density at the test object 10 and thus maximizes the induced secondary fluorescence X-rays. The test object is preferably illuminated with an illumination beam with a large solid angle. This increases the rate of the secondary x-ray fluorescence generation. This property is important for effective utilization of laboratory x-ray sources because they typically emit x-rays over a large solid angle. In principle, the acceptable solid angle can be as high as 2 pi steradians. A lower solid angle of about 1 steradian is desirable. The energy of the primary radiation 110 is selected in order to induce fluorescence in an element of interest. For example, with X-rays as the primary radiation, the following elements exhibit sharply increased absorption of radiation at or above the respective absorption edges: Oxygen at 543 electron-Volts (eV); silicon at 99.8 and 1839 eV; aluminum at 1560 eV; copper at 933 and 8979 eV; tantalum at 2389 eV; phosphorus at 2145 eV; and boron at 188 eV. In some implementations when using x-rays as the primary radiation, it is recognized that selection of the x-ray energy is important to the performance of the x-ray fluorescence microscope. Sometimes, it may be beneficial to select an energy of the primary X-ray radiation to reduce or eliminate excitation of certain other elements in the test object to thereby increase the signal-to-noise ratio of the fluorescence X-rays from the element(s) of interest. Sometimes, it may be beneficial to select an energy of the primary x-ray radiation to be sufficiently higher than the absorption edge of the element of interest. This provides for a large energy separation between the secondary fluorescence x-rays and other x-rays arriving at the detector by means of elastic and Compton scattering of the primary x-rays. The energy of the primary X-ray radiation may also be selected to achieve a desired probing depth because the depth of excitation changes with the incident X-ray energy. In some other implementations, the primary radiation is a finely focused electron beam, such as from a scanning electron microscope (SEM) or from an electron gun operating with electron energy greater than the absorption-edge energy of the element of interest. Typically, an electron energy that is three-to-four times the absorption-edge energy is selected to obtain a high ratio of the X-ray fluorescence signal to “bremstrahlung” continuum radiation background. The electron energy is also selected to obtain a desired probing depth. Sometimes, the electron energy is selected to be below absorption edges of some elements in the test object to improve signal to noise ratio in the fluorescence x-ray image. As illustrated in FIG. 2, the primary radiation 110 causes an inner-shell electron (1) in the element of interest to be ejected (ionization). The vacancy (2) so created in the inner-shell is filled by an electron (3) in an outer electron shell (4). This transition generates either photons of a corresponding energy, or Auger electrons. The photons emitted constitute the secondary or fluorescence radiation 116 from the element of interest, such as the copper that forms the traces in an IC 10 of wafer 12, as illustrated in FIG. 3. Returning to FIG. 1, other radiation may be coming from the test object 10, such as secondary radiation from other elements, reflected or scattered primary radiation, and the bremstrahlung radiation generated by photoelectrons that have been ejected by the primary radiation. An imaging system 105 minimally includes a lens 118 and a detector system 122. The lens 118 is used to create a focused beam 120 of the secondary radiation 116 from the element of interest onto the detector system 122. In one implementation, the detector system 122 is a two dimensional array of elements, such as a charge coupled device (CCD) detector array. Depending on the energies involved, a scintillator may also be required to convert X-rays into light, which is then imaged by a suitable detector array with appropriate imaging optics. In another implementation, the detector system 122 is a detector with no spatial resolution, such as a single element solid state detector. In some implementations, the detector system further has energy resolution. According to the present embodiment of the invention, the lens 118 is selected to preferentially image the secondary X-ray radiation 116 from only (typically) the element of interest onto the detector system 122. Specifically, the lens 118 is a chromatic lens that effectively focuses only a narrow band of energies, i.e., the energies around the fluorescence line of the element of interest, onto the detector system 122. This is achieved by using a lens in which the focal length depends on energy and by suitably arranging the distances between the object 10 and the lens 118 (distance L1), and the lens 118 and the detector system 122 (distance L2) so that the normal imaging condition is only satisfied for that narrow band of energies. In the present implementation, the lens 118 is a zone plate lens. Generally, the focal length of a zone plate lens is linearly dependent on energy. The energy bandwidth (ΔE/E) is approximately given by the equation ΔE/E=2V/D, where D is the zone plate lens diameter, and V the effective field of view of the X-ray fluorescence microscope. The effective field of view can be designed to a desired value by controlling the size of the primary ionizing radiation or using a pupil aperture in the optical train, e.g., the aperture 126 in FIG. 1. The zone plate diameter is preferably designed to achieve a required energy resolution for a given field of view. Radiation with energies outside the energy bandwidth will be out of focus at the detector plane. The pupil aperture 126 is typically located between the lens 118 and the detector, and preferably in near proximity to the detector. However, in other applications, the pupil aperture is located between the lens 118 and the object of interest 10. The energy bandwidth ΔE/E can be improved by using a zone plate that has a diffraction efficiency that peaks in a narrow energy band at the x-ray fluorescence energy. In the present implementation, the lens 118 is preferably a zone plate lens that includes the element of interest. Preferably, the zone plate lens 118 is made of a compound, e.g., alloy, consisting substantially of the element of interest. In other cases, the zone plate lens is made solely of the element of interest. In still other cases, the zone plate lens 118 is made from a compound comprising the element of interest. For example, if the element of interest is copper, i.e., the operator is seeking to image the copper structures of an IC such as in FIG. 3, for example, a copper or copper-containing zone plate lens 118 is used. Generally, the absorption of its own fluorescence X-rays by an element is near a local minimum over a finite energy range near the fluorescence X-ray energy, and this property can generally be used to construct a zone plate lens using a compound including the element of interest to obtain a high diffraction (focusing) efficiency. For a large number of elements, such as the elements with atomic numbers between 4–30, the diffraction (focusing) efficiency of a zone plate lens can be made to peak at the fluorescence X-ray energy of the element of which the zone plate is made. This is achieved for fluorescence X-ray energies less than about 1 keV in the present implementation by making use of the change in the real part of the atomic scattering factor of an element, which decreases from a positive value to a negative value near the fluorescence X-ray energy. This is typically several electron-Volts less than that of an absorption edge of the element. FIG. 4 shows an example implementation where a Cu zone plate is designed to have its diffraction efficiency to peak at 932 eV, which is approximately the energy of a Cu Lα fluorescence line. In comparison, a gold zone plate would have an efficiency at the copper fluorescence line (930 eV) of about 10%, and would vary very little from this value from 850 to 1000 eV (see FIG. 6). With reference to FIGS. 4 and 1, the preferential imaging is enhanced when the zone plate is produced using a compound comprising, and preferably comprising substantially, the same element, because of the combined effect of the loss of diffraction efficiency and out of focusing for x-ray energies away from the x-ray fluorescence line of interest. Consider a 500-nm thick copper zone plate designed for the 930 eV copper fluorescence line with a focal length of 1 centimeter and an outermost zone width of 50 nm. The wavelength is about 1.3 nm. At 905 eV, the copper zone plate lens will have a focal length of 9.73 millimeters. The depth of focus is a few micrometers, so the image plane for fluorescence occurring at 905 eV is substantially out of focus and well away from the image at 932 eV. The focusing efficiency of the zone plate at 905 eV is about half of that for 930 eV, further reducing its contribution to the background intensity on the image formed by the 930 Cu La fluorescence x-rays. Generally, the spatial resolution of a zone plate-based X-ray fluorescence imaging microscope is k1 λ/(NA); depth of focus=k2 λ/(NA)2; k1=k2=½, corresponding to the usual definition of diffraction-limited imaging. To further cut-off higher energy radiation from the test object, a plate 124 containing suitable elemental composition, such as the element of interest for an x-ray energy less than 2 keV, is added in series with the zone plate lens 118 in some embodiments. Fluorescing materials are relatively transparent for their own fluorescence energies, but absorption is quite high above the absorption edge (see FIG. 5), resulting in a low-pass transmission characteristic, which reduces the amount of X-rays with energies higher than the X-ray fluorescence energy that are transmitted to the detector 122. Of course, the zone plate lens 118 itself becomes absorbing above the absorption edge, but the zones cover only about 50% of its area. Zone plate lenses comprising other constituent elements for imaging of these elements are possible. The following sets forth the parameters for zone plates with 1 cm focal length, 50 nm finest zone: energywavelengthdiameterElement(eV)(nanometers)(millimeters)number of zonesB 1836.781.366820Cu 9301.330.2661330As12820.9670.193967(1317)Al14860.8330.166833Ta17100.7240.145724Si17400.7120.143712P20130.6150.123615Cu80480.1540.031156 It is recognized that it is important to use low attenuation materials for the membrane, on which the zone plate is fabricated, especially for low energy fluorescence imaging applications, such as boron. A large diameter is needed to compensate for a low fluorescence rate. The zone plate substrate should, therefore, not be silicon nitride, since for such a large window it would have to be thick, which would render it highly absorbing. An appropriate substrate would be boron nitride, which is a material that provides substantially more attenuation than B, i.e., greater than 90%, but is more radiation sensitive than silicon nitride. Also, there is a concern about choosing the energy of the exciting radiation to be too close to the fluorescence energy, for example As with W L beta for Cu K. In this case, it is more difficult to discriminate against scattering and Compton radiation, than if the excitation were at higher energy. Of course, the absorber helps, but it can also be a secondary source of fluorescence. Finally, it should be noted that there is a need for a central stop to block zeroth order radiation. FIG. 7 shows another embodiment of an X-ray fluorescence microscope 100 according to the present invention. Here, the preferential imaging is achieved by inserting a suitable spectral filter 150 in the imaging system 105. The filter is selected to pass, i.e., reflect, a narrow spectral band centered on the fluorescence line of the element of interest. In one implementation, the spectral filter 150 is a multilayer optic or a crystal. In this embodiment, the imaging optic 118 is either a chromatic lens, such as a zone plate, or an achromatic optic, such as a Wolter optic. The spectral filter 150 is configured so that the imaging condition between the object 10, and the lens 118, and the detector 122 is maintained. Generally, the combination of a chromatic lens 118 and the spectral filter 150 leads to better performance as to the preferential imaging property of the x-ray fluorescence microscope. FIG. 8 shows the x-ray reflectivity of an exemplary multilayer filter or optic 150 that is designed and arranged to reflect efficiently a narrow energy band of x-rays near the Cu Ka (8046 eV) fluorescence x-rays. For a given multilayer or crystal, it reflects the fluorescence x-rays of interest efficiently only within a finite angle of incidence (angular acceptance). To avoid the reduction of throughput and maintain the resolution of the x-ray fluorescence microscope due to the finite angular acceptance, it is important to place the multilayer optic or crystal away from the lens 118 and close to the detector 122, because the angular divergence of the imaging forming fluorescence x-ray beam decreases as the distance from the lens 118 increases and thus reduces the required angular acceptance of the multilayer or crystal optic for high throughput. The depth of the object to be explored depends on the energy of the primary and fluorescence radiation, and on the geometry. Generally, lower energy radiation is less penetrating, and leads to a shallower object volume. By adjusting the angle of incidence and the angle of collection of fluorescence relative to the surface normal, the depth probed is adjustable. The type of the primary ionizing radiation 110 can be optimized based on specific applications. In general, X-rays offer a significantly higher ratio of fluorescence X-rays to background signal than electrons. X-rays also offer other advantages such as applicability to all materials, because there is no charging effect and they are usable in an ambient environment, i.e., no vacuum requirement. FIG. 9 shows another embodiment that is capable of imaging multiple elements of interest at the same time. Specifically, multiple imaging systems 105-1, 105-2, 105-3 are directed to image approximately the same or the same volume in the test object 10. Each imaging system 105-1, 105-2, 105-3 is configured to image fluorescence X-ray lines of different elements. Therefore, in one specific example, the zone plate lenses of each imaging system 105-1, 105-2, 105-3 comprise different constituent materials. According to still another embodiment, the system of FIG. 9 is configured for increased throughput. Each imaging system 105-1, 105-2, 105-3 is configured to image the same fluorescence line and is aimed to image adjoining or adjacent volumes of the test object. According to another embodiment, a set of element-specific two dimensional (2D) images is collected over a large range of angles and reconstructed using tomographic reconstruction. This yields an element-specific three-dimensional (3D) image. A simple implementation of this method collects two 2D stereo image pairs with an angular separation of about 10 degrees and the stereo information of the object can be viewed using stereo viewing technology. The collection of the 2D images can be obtained using several identical imaging systems 105, which image approximately the same volume in the test object. The X-ray fluorescence from important materials of an IC are induced with radiation energy in the approximately 100 to 8000 eV range. The materials that produce the x-ray fluorescence are copper at 930 eV (La) and 8046 eV (Ka), silicon at 99 eV (La) and 1740 eV (Ka), germanium at 1186 eV (La), tantalum at 1710 eV (Ma), titanium at 452 eV (La) and 4510 eV (Ka), cobalt at 776 eV (La) and 6929 eV (Ka), phosphorus at 2013 eV (Ka), arsenic at 1282 eV (La), and aluminum at 1486 eV (Ka), for example. Boron at 183 eV (Ka) is another alterative. Considering copper as an example, FIG. 4 shows the efficiency of a 500 nanometer (nm) copper zone plate in the 900 to 950 eV range, where copper has a fluorescence line. Note that the efficiency peaks to about 30% around 932 eV, which is close to the energy of a Cu La fluorescence line at 930 eV. FIG. 5 shows the transmission of copper over this 900 to 950 eV range. For example, 200 nm of copper has a transmission above 933 eV of only 8%, but a transmission of 75% where the grating efficiency is high. The abrupt change in transmission is due to the absorption edge of copper and fluorescence is emitted at an energy slightly below this edge, i.e, at about 930 eV. As a result, a solid plate 124 of copper, which is 200 nanometer (nm) thick, combined with a 500 nm thick zone plate lens 118 will have a focusing efficiency of about 20% at 930 eV and less than 1% above about 933 eV. Below 930 eV, the efficiency falls to less than 1% at 925 eV. It remains below 10% until the energy has fallen to about 905 eV. While the diffraction efficiency recovers at lower energies, the focal length of the zone plate is now significantly changed from that at the fluorescing energy—any radiation such as fluorescence radiation at this energy (from other materials) is not imaged on the detector array 122. It should be noted that the number of elements used in IC fabrication is typically limited and thus the characteristic fluorescence lines are widely spaced, so the element specific character of the zone plate lens made of the fluorescing material will not be compromised in most situations. An example application is to image Cu structures in an IC, such as interconnects, and vias, and defects associated with them. It is beneficial to use the Cu La X-ray fluorescence line for this application. The primary ionizing radiation is either an electron beam of energy greater than 1000 eV or an X-ray beam generated for example by electron bombardment of a solid target producing x-rays of energy greater than 940 eV. Specific applications include failure analysis of IC components, IC metrology and inspection in a production line. In a different example, copper K alpha fluorescence at 8046 eV is used to image copper interconnect lines in IC packaging. The primary radiation is provided by electron bombardment of a solid anode capable of producing the required primary radiation, such as tungsten and gold anodes. The tungsten L beta lines around 9670 eV are efficient in inducing fluorescence in copper. This higher energy radiation can be used to explore packages up to several hundred micrometers thick. Zone plates fabricated using lithographic techniques may be limited in throughput for higher resolution applications because of limited solid angle acceptance. The low solid angle acceptance can be addressed, however, by the following design. The focusing lens is made up of two linear zone plates oriented at right angles to each other. These linear zone plates are fabricated by sputtering alternating layers of appropriate materials (such as W and C) on a substrate, and slicing this multilayer structure to the thickness that gives maximum efficiency. This way, finest zones as small as 3 nanometers can be fabricated, and the resulting solid angle acceptance improved by a factor of 278 compared to zone plates with 50 nm finest zones. These optical elements are not likely to obtain 3 nanometer resolution, but they offer significantly larger solid angles of acceptance for high throughput at resolutions substantially larger than 3 nm. For example, a zone plate with a 3 nm finest zone width has a solid angle acceptance 100 times larger than a zone plate with a 30 nm finest zone width, and increases throughput by approximately 100 times for 30 nm resolution x-ray fluorescence imaging. Yet another example would involve the study of buried structures such as steel and other structural materials underneath coatings (applied by thermal spraying or otherwise). In this application a copper or tungsten anode is to be used to generate the primary radiation to excite fluorescence in iron, nickel, chromium, or cobalt. Again, the crossed linear zone plates would be preferred as the lens to study microcracking and corrosion, for example. Yet another application is the imaging of biological specimens, such as bones and single biological cells. Spatial distribution of elements, such calcium and phosphorus in a bone or a cell, can be imaged in 2D or 3D using present invention. It is recognized that such imaging may be performed without significantly affecting the livelihood of the biological specimen under investigation and thus time lapse imaging may be taken to study development. X-ray Fluorescence Backlighting Imaging Mode FIG. 10 shows an X-ray fluorescence microscope 100 that is configured in an X-ray fluorescence backlighting imaging mode, according to the present invention. Specifically, the fluorescence that is imaged originates from the known structure 12 (such as the substrate, rather than from the object of interest 10. The object of interest 10 is positioned between the known structure 12 and the lens 118. The object of interest absorbs or scatters part of the characteristic X-ray radiation, and thus casts a shadow at the image plane. In this mode of operation the elements present in the object are not directly identified, but if their composition is known, then the geometry of the object, such as the thickness and shape, can be determined from the image that contains the attenuation information of the backlighting. Other image contrast enhancement methods, such as the Schilieren method, can be employed to increase image contrast of materials of low absorption contrast. For example, silicon L alpha or K alpha fluorescence x-rays are used in one application as backlighting to image IC structures above a silicon substrate, such as Cu interconnect lines and vias, Ta-containing diffusion barriers, interlayer dielectrics, and polysilicon gate contacts. It is recognized that silicon is a preferred material for making zone plates of high focusing efficiency. Other preferred materials include molybdenum and rhodium for Si L alpha line and Au, W, and Ta for Si K alpha line. For yet another example, the profile of etched structures produced in an IC production process can be studied using the x-ray fluorescence backlighting imaging mode. Backlighting by the x-ray fluorescence produced in the wafer 12 arrives at the lens 118 after being absorbed or scattered by the test object 10, which includes etched structures. The geometry of the etched structure 10, including its profile, together with the material composition of the etched structure, determines the effect on the backlighting fluorescence x-rays, and leads to measurable effects in the x-ray fluorescence image. It is recognized that for etched structures of a linear dimension not significantly larger than approximately 30 times of the wavelength of the fluorescence x-rays, and of an aspect ratio greater than approximately 3, the profile of the etched structure produces a significant effect on the angular distribution of the backlighting fluorescence x-rays due to the scattering effect. This effect increases with decreases in linear dimensions of the etched structure and increases in the aspect ratio. It is further recognized that the effect of the profile of the etched structure can be enhanced when the etched structure is suitably arranged, such as a periodic structure. It is beneficial in some implementations to use x-ray fluorescence line(s) of longer wavelength(s) and from element(s) contained in major IC fabrication materials, such as silicon, copper, oxygen, tantalum, and carbon. For yet another example, Cu L alpha fluorescence line from Cu interconnect lines or vias is used to detect and image residuals and particles on top of them in an IC production process. In a preferred implementation, the zone plate is constructed using Cu. For example, defects, such as contamination by resist residues or other contamination, on a mask used in IC fabrication can be seen by imaging the silicon fluorescence from the substrate 12, which may be silicon wafer material or a silicon compound, such as glass, quartz, or silicon nitride. The defect will show up as a deviation from the desired image of the clean and intact mask. In this imaging mode, the mask may be designed to be used either in transmission or in reflection. Using a zone plate with 1 cm focal length, an area 0.1 mm on the side could be imaged in one exposure with 50 nm resolution onto a CCD detector. A full wafer would be explored in a step-and-repeat operation. Defect identification would be performed automatically by comparing the digital images with the standard stored in the control computer. Another application is the inspection of coatings, such as thermal coating for improving surface operating temperature, hardness coating for improving surface hardness, and painting for improving surface chemistry resistance to erosion. Using fluorescence radiation from the bulk material underneath the coating, the image will clearly show non-uniformities, pinholes, cracks and other defects. Fluorescence Spectrometer Mode With reference to FIG. 1, in the fluorescence spectrometer mode, the object-to-lens distance L1 and the lens-to-detector distance L2 are adjusted so that all the characteristic fluorescence of a given element falls upon a single-element detector or is integrated over all the pixels in a two-dimension imaging detector 122. X-ray spectrum can be measured by scanning the chromatic lens such as zone plate along the axis connecting the center of the object 10 and the center of the detector 122 or the pupil aperture 126. Several of these spectrometers can be configured so as to monitor multiple elements simultaneously as described in connection with FIG. 9. Because the numerical aperture of the lens used is inversely proportional to the energy, both the solid angle acceptance and the energy resolution of the instrument improve for lower energies. This is an important advantage over both energy dispersive and wavelength dispersive spectrometers, since the fluorescence yield drops with energy and the energy resolution of typical solid state energy dispersive detectors are often too limited for low energy x-ray analysis applications. This arrangement is applicable to the monitoring of the dose of the shallow doping of semiconductor material with boron, phosphorus, and/or arsenic. High spatial resolution is generally not desired in this case, so the zone plate is used in a geometry yielding a convenient working distance and throughput. The area to be investigated can be defined using an aperture in front of the single-element detector. The observed count-rate, after matrix and element dependent calibration factors and correction for background will be directly proportional to the amount of the dopant within the probed volume. Another example that takes advantage of the imaging property of the lens for film thickness measurement is based on the recognition that the imaging property allows both the probed area and the solid angle of fluorescence collection to be well defined, thus permitting accurate determination of the number of fluorescing atoms in the probed volume. If the probed volume is a known, uniform thickness (film), then its film thickness can be determined. Example applications include measuring the film thickness of various materials in an IC production line, such as Cu, diffusion barrier, and interlayer dielectric layers. While this invention has been particularly shown and described with references to preferred embodiments 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 scope of the invention encompassed by the appended claims. For example, typical scanning electron microscopes (SEM) have X-ray detectors (EDAX), which are used to identify materials being imaged. In the fluorescence spectrometer mode, the present invention is used as an element specific imaging attachment to a SEM.
061577014	description	OBJECTS AND SUMMARY OF THE INVENTION It is a first object of the present invention to provide an x-ray generating apparatus using laser plasma capable of preventing scattering particulates from being released or preventing scattering particulates from reaching and sticking to peripheral optical elements and the like. It is a second object of the present invention to provide an x-ray generating apparatus using laser plasma which is improved in x-ray generating efficiency. It is a third object of the present invention to provide an x-ray microscope using, as the x-ray source, an x-ray generating apparatus using laser plasma, in which an influence of scattering particulates from the laser plasma is eliminated, in which a sample to be observed can be disposed as close to the x-ray source as possible, thereby to eliminate the disposition of an optical system such as a condensing mirror or the like, and in which the amount of x-rays irradiated to the sample to be observed can be increased, thereby to obtain a bright x-ray image. To achieve the first and second objects above-mentioned, the first invention provides an x-ray generating apparatus for generating x-rays by laser plasma formed by condensing and irradiating a laser beam on and to a target in a vacuum, and this x-ray generating apparatus is characterized by comprising a strong magnetic field generating means arranged such that a strong magnetic field formed by the strong magnetic field generating means, acts on the laser plasma to bend the tracks of charged particles therein, causing the charged particles to be confined in the magnetic field. A more specific arrangement of the first invention provides an x-ray generating apparatus in which x-rays emitted from laser plasma generated by condensing and irradiating a laser beam on and to a target in a vacuum, are taken out from at least one side out of the laser beam irradiation side of the target and the side thereof opposite to the laser beam irradiation side, and this x-ray generating apparatus is characterized in that there is disposed, in the vicinity of the laser plasma, a magnetic field generating means for generating a magnetic field component substantially parallel or vertical with respect to the target surface in the vicinity of the laser plasma, this magnetic field component being arranged to generate a magnetic force which acts directly on charged particles in the laser plasma to bend the tracks of the charged particles, causing the same to be confined in a magnetic field formed by the magnetic field component. Further, the magnetic field component formed by the strong magnetic field generating means may contain a magnetic field component inclined at a predetermined angle with respect to the target surface. According to the first invention, a strong magnetic field formed by the strong magnetic field generating means is arranged to apply a magnetic force to charged particles to change the tracks thereof, causing the charged particles to be confined in the magnetic field. As the means for generating the strong magnetic field, a permanent magnet or an electromagnet may be used. In the strong magnetic field generating means, the direction of the magnetic flux can be adjusted according to the manner in which the strong magnetic field generating means is disposed with respect to the laser plasma or target. According to the first invention, the laser plasma is generated in a direction at right angles to the target surface and in a predetermined generation pattern with the direction above-mentioned serving as an axis. In the x-ray generating apparatus of the first invention, when the magnetic flux direction of the strong magnetic field generating means is different from the plasma generating direction, it is possible to enhance the effect of confining, in the magnetic field, charged particles having a speed component deviated from the magnetic flux direction. This improves the x-ray generating efficiency. In the x-ray generating apparatus of the first invention, when the magnetic flux direction of the strong magnetic field generating means is the same as the plasma generating direction, it is possible to enhance the effect of confining, in the magnetic field, charged particles having a speed component deviated from the plasma generating direction. This improves the x-ray generating efficiency. In the x-ray generating apparatus of the first invention, the strong magnetic field generating means is disposed in the vicinity of the laser plasma such that a magnetic force acts on charged particles in the strong magnetic field generated by the strong magnetic field generating means, thereby to change the direction in which the charged particles are emitted from the magnetic field. This reduces the amount of charged particles which scatter in a direction toward an x-ray supply object. According to a specific arrangement for reducing the amount of charged particles scattering in a direction toward the x-ray supply object, the magnetic flux direction of the strong magnetic field generating means is different from the plasma generating direction, and the x-ray supply object is disposed in the plasma generating direction. According to this arrangement, charged particles emitted in the plasma generating direction are taken in the strong magnetic field to reduce the amount of charged particles scattering toward the x-ray supply object. According to another specific arrangement for reducing the amount of charged particles scattering toward the x-ray supply object, the plasma is generated in the magnetic flux direction of the strong magnetic field generating means and the x-ray supply object is disposed in a direction shifted from the plasma generating direction. According to this arrangement, charged particles emitted in other directions than the plasma generating direction, are taken in the strong magnetic field to reduce the amount of charged particles scattering toward the x-ray supply object. In the x-ray generating apparatus of the first invention, the target may be disposed at the center of the magnetic field formed by the strong magnetic field generating means. In this case, a uniform and strong magnetic field can be applied to the laser plasma. Such a placement of the target at the center of the magnetic field, may be achieved by disposing the target at the center of the gap between oppositely disposed magnets. According to the arrangement of the first invention, the strong magnetic field formed by the strong magnetic field generating means bends the tracks of the charged particles emitted from the laser plasma. Bending the tracks causes the charged particles to stay in the laser plasma in a longer period of time, thereby to improve the x-ray generating efficiency. Further, the direction of the tracks of the charged particles which have got out of the strong magnetic field, is shifted from the direction toward the x-ray supply object. This prevents the charged particles from being directed toward the x-ray supply object, thereby to prevent a reduction in x-ray supply amount due to the sticking of charged particles to the optical element or the like. FIG. 1 is a conceptual view illustrating an example of the arrangement of main portions of the first invention. The following description will discuss the operation of the first invention with reference to FIG. 1. In FIG. 1, when a laser light 7 is condensed on and irradiated to the surface of a target 1 of Al, Mo, Au or the like, plasma 6 is generated by laser excitation. The plasma 6 emits not only scattering particulates including neutral particles and charged particles 8 such as ions, electrons and the like, but also x-rays 9. The x-rays 9 from the plasma 6 are directed toward an x-ray supply object 11 through an optical element 10 such as a mirror or the like. The tracks of the charged particles 8 in the plasma are bent by a strong magnetic field 5 formed by a strong magnetic field generating means 2 as shown in FIGS. 2 and 3. The strong magnetic field generating means 2 may be formed, for example, by disposing magnets 3 in the vicinity of or in close contact with the target 1 such that the plasma 6 is formed between the opposite magnetic poles of the respective magnets 3 disposed as facing each other. By disposing pole pieces 4 at the magnets 3, the magnetic field can be increased in intensity. FIG. 2 is a view illustrating the track of a charged particle in a strong magnetic field. In FIG. 2(a), a solid line B shows, in a strong magnetic field C having a directional property shown by arrows in a broken line, the track of a charged particle having an initial speed in a direction shown by an arrow A. FIG. 2(b) shows the track of the charged particle when viewed in a direction shown by an arrow D in FIG. 2(a). When a charged particle does not come into collision with another charged particle in the strong magnetic field C, the charged particle behaves as follows. That is, while maintaining a speed component in the direction of the strong magnetic field C, the charged particle receives a magnetic force in a direction at right angles to the strong magnetic field C and is moved in the direction of the strong magnetic field C while presenting a spiral motion as shown by the arrow B. FIG. 3 is an enlarged view illustrating the tracks of charged particles in a strong magnetic field. In FIG. 3, solid lines E and F show the tracks of charged particles as accelerated in the strong magnetic field C. It is now supposed that the charged particles do not come into collision with each other. When the speed of a charged particle is fast as compared with the influence exerted to the track of the charged particle by the strong magnetic field C, the charged particle is moved in a straight line after passed through the strong magnetic field C while presenting a spiral motion, as shown by the solid line E. When the speed of the charged particle is slow, the charged particle is taken in the strong magnetic field C while presenting a spiral motion, as shown by its track shown by the solid line F. When a strong magnetic field is applied to a zone such as plasma or the like where charged particles are present, each charged particle describes a track along the strong magnetic field while presenting a circular or spiral motion due to the strong magnetic field. The length of the track of a charged particle bent by the strong magnetic field, is longer than that of the track in the same zone when the strong magnetic field is not present. More specifically, when a charged particle is placed in a strong magnetic field, this can make longer the time during which the charged particle stays in the same zone. Accordingly, when a strong magnetic field is formed in a zone where plasma is generated as done in the first invention, the time during which charged particles stay in the plasma, is made longer to increase the chances of x-ray generation by the charged particles. This improves the x-ray generating efficiency. FIG. 4 is a view schematically illustrating a charged particle in spiral motion which comes into collision with another charged particle in a strong magnetic field. As compared with a charged particle which is not present in a strong magnetic field, a charged particle present in a strong magnetic field is increased in chance of collision with another charged particle, thus increasing chances of x-ray generation. Charged particles are emitted from plasma in a variety of directions. As apparent from FIG. 3, however, the tracks of the charged particles generally undergo a change while the charged particles are moved in the direction of the strong magnetic field C while presenting a spiral motion in the strong magnetic field C. Also, the distribution in scattering direction of the charged particles after having passed through the strong magnetic field, undergoes a change according to the direction of the strong magnetic field. Accordingly, in a distribution in scattering direction of the charged particles after having got out of the strong magnetic field, the direction in which scattering frequency is great, can be shifted from the direction toward the x-ray supply object. Such an arrangement can prevent the charged particles from reaching and sticking to the x-ray supply object or the optical system. It is noted that the x-rays are not influenced by the strong magnetic field but advance toward the x-ray supply object or the optical system while maintaining their tracks. Thus, according to the first invention, it is possible not only to improve the x-ray generation efficiency because of a longer period of time during which the charged particles stay in the plasma, but also to increase the amount of x-rays supplied to the x-ray supply object because of the effect of restraining the scattering particulates from scattering toward the x-ray supply object by controlling the distribution in scattering direction of the charged particles. To achieve the objects above-mentioned, the second invention provides an x-ray generating apparatus for generating x-rays by irradiating a laser beam to a target, and this x-ray generating apparatus is characterized by comprising an x-ray transmitting film disposed at at least one side of the target with a predetermined gap provided therebetween, the x-ray transmitting film having a thickness such that the film is not broken due to an action in the x-ray generating process, x-rays being taken out through the x-ray transmitting film. The third invention provides an x-ray microscope using the x-ray generating apparatus of the second invention, and this x-ray microscope is characterized by comprising: an x-ray generating apparatus which has an x-ray transmitting film disposed at at least one side of the x-ray generating target with a predetermined distance provided therebetween, this x-ray transmitting film being arranged not to be broken due to an action in the x-ray generating process, and in which x-rays generated by irradiating a laser beam to the target, are taken out through the x-ray transmitting film, a sample to be observed being disposed in the vicinity of the x-ray transmitting film; and a detecting means for detecting an x-ray image formed by the x-rays passed through the sample to be observed. In each of the second and third inventions, factors acting on the x-ray transmitting film in the x-ray generating process, include the plasma pressure generated in the x-ray generating process, the transmission of a laser beam to be irradiated for x-ray generation, scattering light which scatters in the plasma, and the like. The x-ray transmitting film used in each of the x-ray generating apparatus and x-ray microscope of the second and third inventions, is a member which is good in x-ray transmittance and which has a function of preventing the passage of scattering particulates. The thickness of the x-ray transmitting film is set such that the film is not broken due to the plasma pressure and the energy of scattering particulates resulting from the generation of high-density plasma by the irradiation of a laser beam. In a preferred embodiment of each of the second and third inventions, the thickness of the x-ray transmitting film exceeds at least 1 .mu.m, and is in the range of 2 to 3 .mu.m for example. Thus, the x-ray transmitting film can not only transmit x-rays generated by the high-density plasma, but also intercept scattering particulates generated at the same time. Examples of the material of the x-ray transmitting film to be used in each of the second and third inventions, include Al, Be, C, Sn, Ti, V, Mo, polyimide, vinyl and the like. When the x-ray transmitting film used in each of the second and third inventions is made of Al, Be or polyimide, there can be obtained an x-ray generating apparatus or an x-ray microscope having an x-ray transmitting film excellent in transmittance of x-rays having a wavelength not greater than 20 .ANG.. When the x-ray transmitting film is made of Sn, Ti or V, there can be obtained an x-ray microscope or an x-ray generating apparatus having an x-ray transmitting film excellent in transmittance of x-rays having a wavelength of 20 .ANG. to 50 .ANG. When the x-ray transmitting film is made of C, Sn or Mo, there can be obtained an x-ray microscope or an x-ray generating apparatus having an x-ray transmitting film excellent in transmittance of x-rays having a wavelength of 45 .ANG. to 100 .ANG. In a preferred embodiment of each of the second and third inventions, each of the target and the x-ray transmitting film is made in the form of a tape and provision is made such that the target and the x-ray transmitting film are movable with respect to the laser beam irradiation position and the sample to be observed. This enables the target and the x-ray transmitting film to be substantially replaced for each irradiation of a laser beam. According to the third invention, as the detector for detecting an x-ray image, there may be used a two-dimensional detector such as CCD, MCP, an x-ray film or the like. According to the third invention, the x-ray transmitting film, the sample to be observed and the resist may be disposed in the vicinity of one another. Thus, there may be provided a contact-type x-ray microscope in which the resist and the sample to be observed come in close contact with each other. In the arrangement of each of the second and third inventions, plasma is generated by irradiating a laser beam to the target. From the high-density plasma thus generated, x-rays and scattering particulates are emitted. Of these, the x-rays are taken through the x-ray transmitting film and released toward the x-ray supply object (sample to be observed). On the other hand, the scattering particulates are intercepted by the x-ray transmitting film and cannot scatter toward the sample to be observed. Accordingly, there is no need for interposing a scattering particulate preventing means between the x-ray supply object (sample to be observed) and the x-ray source. This enables the x-ray supply object and the x-ray source to be disposed as close to each other as possible. Further, without an optical system such as a condensing mirror or the like interposed between the x-ray supply object and the x-ray source, the amount of x-rays supplied to the x-ray supply object can be increased such that a bright x-ray image can be obtained in the x-ray microscope. When plasma is generated by the irradiation of a laser beam to the target, a pressure generated by the free-swelling of the plasma is applied to the x-ray transmitting film and scattering particulates come into collision therewith. However, when the thickness of the x-ray transmitting film exceeds at least 1 .mu.m, and is in the range from 2 to 3 .mu.m for example, such a thickness is sufficient to resist the plasma pressure and the collision energy of scattering particulates such that the x-ray transmitting film is not broken. Further, by the irradiation of a laser beam, the target is bored and scattering particulates stick to the x-ray transmitting film. As the target and the x-ray transmitting film, a tape-like target and a tape-like film may be used as mentioned earlier and moved by a suitable distance for each irradiation of a laser beam. Accordingly, a nonbored portion of the target may be supplied to the laser beam irradiation position, and that portion of the x-ray transmitting film to which no scattering particulates are sticking, may be positioned at the laser beam irradiation position. It is therefore possible to always supply a large quantity of x-rays to the x-ray supply object. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 5 is a view illustrating the arrangement of an embodiment of the first invention. In this arrangement, the x-ray taking direction is opposite to the side at which a laser beam is irradiated to a target. In FIG. 5, the target is formed by a tape target 1 of a tape-like thin film, and a laser beam 7 is irradiated, as condensed in a point or line shape, to the tape target 1 at one side thereof. The irradiation of the laser beam 7 produces high-density plasma 6 at both sides of the tape target 1. Charged particles 8 and x-rays 9 are released from the plasma 6 to both sides of the tape target 1. In this embodiment, however, the x-rays emitted to the side opposite to the laser beam 7 are utilized. In this embodiment, a pair of magnets 3 are disposed as sandwiching the plasma 6 generated at the side opposite to the laser beam irradiation side, thereby to form a strong magnetic field generating means 2. A strong magnetic field 5 formed by the strong magnetic field generating means 2, gets across the plasma 6. The x-rays 9 emitted from the plasma 6 are guided to an optical element 10 through slits 12 and a scattering particulate preventing means 13. Then, the x-rays 9 are irradiated to an x-ray supply object 11 such as a sample or the like through the optical element 10. As the scattering particulate preventing means 13, there may be used a high-speed mechanical shutter arranged such that, after the x-rays 9 have passed through the shutter, the shutter is operated to intercept the course of low-speed scattering particulates. Also, there may be used a gas flowing device for causing gas to flow from the outside into the course of the scattering particulates such that gas molecules come into collision with scattering particulates, thereby to change the tracks of the scattering particulates. The strong magnetic field 5 formed by the strong magnetic field generating means 2 is arranged (i) to lengthen the time during which the charged particles 8 remain in the plasma 6, (ii) to increase the opportunity of the charged particles 8 coming in contact with one another, thereby to increase the x-ray generating efficiency, and (iii) to reduce a distribution, in the direction toward the optical element 10, of the charged particles 8 after having got out from the strong magnetic field 5. Since the x-rays 9 are not influenced by the strong magnetic field 5, the x-rays 9 advance toward the optical element 10 and are then irradiated to the sample 11. Even though the strong magnetic field generating means 2 restrains the charged particles 8 from scattering toward the optical element 10, there is still present a small amount of charged particles 8 which scatter toward the optical element 10. The slits 12 and the scattering particulate preventing means 13 prevent such charged particles 8 from scattering toward the optical element 10. This improves the charged particles preventing effect. Further, the slits 12 and the scattering particulate preventing means 13 also prevent the neutral particles scattering with no influence exerted thereto by the strong magnetic field, from sticking to the optical element 10. The following description will discuss specific examples of the strong magnetic field generating means 2 in the embodiment above-mentioned with reference to the schematic views in FIGS. 7 to 11. FIG. 7 shows an example in which the strong magnetic field 5 is formed only in the vicinity of the plasma generating zone. There are disposed a pair of magnets 3 each having a height substantially equal to the size of the plasma 6 generated by the irradiation of the laser beam 7, such that the plasma 6 is held by and between the magnets 3. As each of the magnets 3, there may be for example used a magnet of which magnetic pole distance is several mm and of which intensity is about 10000 G(1T). In FIG. 7, the direction of the strong magnetic field 5 formed by the magnets 3 is substantially parallel with the target 1. The charged particles 8 in the plasma 6 receive a force at right angles to the magnetic field direction by the magnetic force of the strong magnetic field 5 and present a spiral motion (shown by an arrow in a solid line in FIG. 7). This not only lengthens the time during which the charged particles 8 stay in the plasma, but also changes the distribution in scattering direction of the charged particles 8 emitted from the strong magnetic field 5. Here, it is noted that the plasma is generated in a direction at right angles to the target surface and that the plasma is generated in a predetermined generating pattern with the direction above-mentioned serving as an axis. The time during which the charged particles 8 stay in the plasma 6, and the distribution in scattering direction of the charged particles 8 emitted from the strong magnetic field 5, depend on the conditions such as the energy of a laser beam to be irradiated, the size and distribution of the strong magnetic field 5 and the like. It is therefore desired that these relationships are previously obtained by experiments or the like and that the conditions above-mentioned are suitably set according to the disposition direction of the optical element 10 or the required amount of x-rays. FIG. 8 is an example in which the strong magnetic field 5 is formed not only in the plasma 6 generating zone but also in a zone which extends by a certain distance in the x-ray taking direction from the plasma generating zone. There are disposed magnets 3 each having a height exceeding the size of the plasma 6 generated by the laser beam 7, such that the plasma 6 is held by and between the magnets 3. In FIG. 8, the strong magnetic field 5 formed by the magnets 3 is substantially parallel with the target 1. Initially, the charged particles 8 in the plasma 6 receive a force at right angles to the magnetic field direction by the magnetic force of the strong magnetic field 5 and present a spiral motion. Then, when the charged particles 8 are emitted from the plasma 6 and reach the zone in which only the strong magnetic field 5 exists, there is no acceleration for the charged particles 8 due to free expanding of the plasma 6. Accordingly, the speed held by the charged particles 8 is only the initial speed. Accordingly, in this zone, the charged particles 8 present a spiral motion along the direction of the strong magnetic field 5 and is confined therein as far as the charged particles come into collision with one another (shown by an arrow in a solid line in FIG. 8).The size of the zone where only the magnetic field exists, can be set according to the volume of the plasma to be generated and the intensity of the strong magnetic field. Accordingly, the arrangement in FIG. 8 produces the effect that the rate of charged particles confined in the strong magnetic field 5 is increased while the rate of charged particles to be emitted toward the optical element 10, is decreased. FIG. 9 shows an example in which the direction of the magnetic flux of the strong magnetic field is inclined with respect to the surface of the target 1. To form such a strong magnetic field 5, one of a pair of magnets 3 is disposed at one side of the target 1 such that the magnetic poles are directed in a direction at right angles to the surface of the target 1, and the other magnet is disposed at the other side of the target 1 such that the magnetic poles are directed in a direction parallel with the surface of the target 1. In FIG. 9, the direction of the strong magnetic field 5 formed by the magnets 3 is inclined at a predetermined angle with respect to the surface of the target 1 or the plasma 6 generating direction. Because of the inclination of the magnetic field, the charged particles 8 emitted from the plasma 6 generally advance as presenting a spiral motion in the direction connecting the magnetic poles of the respective magnets 3 (shown by an arrow in a solid line in FIG. 9). According to the arrangement in FIG. 9, the charged particles emitted from the strong magnetic field 5 can be distributed as biased in the direction above-mentioned. FIG. 10 shows an example in which the direction of the strong magnetic field is at right angles to the surface of the target 1 or the same as the plasma generating direction. To form such a strong magnetic field 5, a pair of magnets 3 are disposed such that the plasma 6 generated by the irradiation of a laser beam is held by and between the magnets 3 and that the magnetic poles are directed in a direction parallel with the surface of the target 1. In FIG. 10, the direction of the strong magnetic field 5 formed by the magnets 3 is substantially vertical with respect to the surface of the target 1. Out of the charged particles 8 in the plasma 6, those having a speed component in a direction identical with the direction of the strong magnetic field 5, advance as they are with no influence exerted thereto by the strong magnetic field 5. Charged particles having a speed component in a direction deviated from the direction of the strong magnetic field 5, are influenced by the strong magnetic field 5. These charged particles receive a force in a direction at right angles to the magnetic field direction by the magnetic force of the strong magnetic field 5, and present a spiral motion while advancing along the magnetic flux direction of the strong magnetic field 5. Then, these charged particles are confined in the strong magnetic field 5 as far as they do not come into collision with one another (shown by an arrow in a solid line in FIG. 10). In this example, charged particles having a speed component in a direction identical with the direction of the strong magnetic field 5, advance with no influence exerted thereto by the strong magnetic field 5. To prevent such charged particles from being emitted to the outside, a screening member 14 is disposed on an extension line in the magnetic flux direction passing through the plasma 6. FIG. 11 shows an example in which the target 1 is disposed at the center of the strong magnetic field generated by the strong magnetic field generating means. In this arrangement, a uniform and strong magnetic field can be applied to laser plasma. In the example in FIG. 11, a pair of magnets 3 are disposed with a distance provided therebetween such that the magnetic poles respectively having opposite polarities face each other, and the target 1 is disposed at the center of the strong magnetic field 5 formed between the magnets 3. The intensity of the magnetic field in this arrangement is the greatest at the center where the target 1 is disposed. That is, the magnetic field having the greatest intensity is applied to laser plasma generated in the vicinity of the target 1. It is therefore possible to apply a uniform and strong magnetic field to the laser plasma. Thus, the confinement of laser plasma and the correction of the tracks of charged particles can more effectively be conducted. In each of the examples in FIGS. 8 to 11, there may be used, as each magnet 3, a magnet of which magnetic pole distance is several mm and of which intensity is 10000 G(1T), likewise in the example in FIG. 7. It is desired to previously obtain, by experiments or the like, the relationships between (i) each of the time during which charged particles stay in the plasma and the directional distribution of the charged particles scattering from the strong magnetic field, and (ii) the conditions such as the energy of the laser beam to be irradiated, the size and distribution of the strong magnetic field 5 or the like, such that the desired x-ray irradiation amount is obtained based on the relationships thus obtained. It is also desired to set such conditions as to minimize the amount of charged particles scattering toward the optical element. The following description will discuss another embodiment of the first invention. FIG. 6 shows the arrangement thereof. In this embodiment, the x-ray taking direction is identical with the direction in which a laser beam 7 is irradiated to a target 1. This embodiment is the same in arrangement as the embodiment in FIG. 5, except that x-rays are to be taken out from a plasma portion at the laser beam irradiation side of the target 1, out of plasma generated by irradiating the laser beam 7. As a strong magnetic field generating means 2 in this embodiment, there may be used any of the means shown in FIGS. 7 to 11. Thus, there may be produced effects equivalent to those produced by the embodiment mentioned earlier. As the magnets 3 used in the strong magnetic field generating means 2 in each of the embodiments above-mentioned, electromagnets may also be used instead of permanent magnets. When electromagnets are used, the intensity of the strong magnetic field 5 or the distribution in magnetic flux of the strong magnetic field 5 can be changed to control the time during which charged particles stay in the plasma, or to change the distribution in scattering direction of the charged particles. In each of the embodiments above-mentioned, a tape target is used as the target. It is a matter of course, however, that a plane target or a cylindrical target can also be used. The following description will discuss embodiments of the second and third inventions. FIG. 12 is a view illustrating the arrangement of an embodiment of an x-ray microscope according to the third invention using an x-ray generating apparatus of an embodiment of the second invention. That is, FIG. 12 shows an embodiment common in the second and third inventions. FIG. 13 is an enlarged section view of a target 31 and an x-ray transmitting film 32 in the vicinity of a zone where a laser beam 39 is irradiated in FIG. 12. As shown in FIG. 13, each of the target 31 and the x-ray transmitting film 32 is made in the form of a tape, and the target 31 and the film 32 are placed one upon another. At the position where the laser beam 39 is irradiated, a gap of about 1 mm for example is formed between the target 31 and the x-ray transmitting film 32 by holding members 33, thus forming a space 34. Examples of the material of the target 31 include Al, Au, Mo, Ta, Ti and Kapton(trademark). The tape-like target 31 may have a width of about 5 mm and a thickness t2 of about 1 to about 10 .mu.m. The x-ray transmitting film 32 may be made of Al, Be, C, Sn, Ti, V, Mo, polyimide or vinyl. The material is selected dependent on the wavelength of x-rays to be transmitted. For example, the x-ray transmitting film 32 is made of Al, Be or polyimide when there are transmitted x-rays having a wavelength of about 20 .ANG. or less; C, Sn, Ti, V or polyimide when there are transmitted x-rays having a wavelength of about 20 .ANG. to 50 .ANG.; and Sn or Mo when there are transmitted x-rays having a wavelength of 45 .ANG. to 100 .ANG.. The x-ray transmitting film 32 has a width of about 5 mm for example and a sufficient thickness ti such that the x-ray transmitting film 32 is not broken as resisting the plasma pressure and the energy of scattering particulates. Thus, the film thickness t1 exceeds at least 1 .mu.m and is suitably in the range of about 2 to about 3 .mu.m for example. To prevent the film 32 from being broken, the film thickness t1 is suitably changed according to the plasma and scattering particulate forming conditions such as the intensity of the laser beam irradiated to the target 31, the irradiation time, the volume of the space where plasma is to be generated, and the like. The tape-like target 31 and the tape-like x-ray transmitting film 32 are wound at both ends thereof on common winding members 35a, 35b and intermittently moved by a drive device 36 as shown in FIG. 12. The drive device 36 may mainly be formed by an intermittently operable actuator such as a step motor or the like. In association with the irradiation of the laser beam 39, the drive device 36 is controlled by a control signal from a control device 40 to move a predetermined amount of each of the target 31 and the x-ray transmitting film 32 for each irradiation of the laser beam 39. The laser beam 39 to be irradiated to the target 1 is generated by a laser light source 37 to be driven and controlled by the control device 40 and an optical system 38 for condensing the output light of the laser light source 37. The laser beam 39 is irradiated to the target 31 at the side opposite to the side where the x-ray transmitting film 32 is disposed. The control device 40 controls the irradiation timing of the laser beam 39 and the moving timing of the target 31 and the x-ray transmitting film 32 as follows. After completion of the emission of x-rays by the irradiation of the laser beam 39, the control device 40 causes the target 31 and the x-ray transmitting film 32 to be moved, and then causes the laser beam 39 to be irradiated after completion of the movement of the target 31 and the x-ray transmitting film 32. The laser light source 37 is driven by a drive pulse of about 3 to about 7 nsec for example. A sample cell 41 is disposed in the vicinity of the side of the x-ray transmitting film 32 opposite to the side where the target 31 is disposed. The sample cell 41 includes a sample 42, and is provided in the side thereof facing the x-ray transmitting film 32 with an x-ray window 41a. The sample cell 41 also has a resist 43 at the side opposite to the x-ray window 41a. The resist 43 is placed in contact with the sample cell 41. The x-ray window 41a and the x-ray transmitting film 32 can be disposed in close proximity to each other with a distance of 0.1 mm for example provided therebetween. As above, by making the resist 43 and the sample cell 41 come closely into contact, a contact x-ray microscope may be formed. The following description will discuss the x-ray generating process in the embodiment above-mentioned with reference to FIG. 14. As shown in FIG. 14(a), the space 34 is formed between the target 31 and the x-ray transmitting film 32 by the holding members 33, and the laser beam 39 is irradiated to the target 31. As shown in FIG. 14(b), the target 31 is then evaporated to generate high-temperature and high-density plasma 44, from which high-luminance x-rays 45 are radially generated. The plasma 44 generated by the irradiation of the laser beam 39 is confined in a period of time in the order of nsec in the space 34 defined by the target 31 and the x-ray transmitting film 32. This lengthens the time during which the interaction between the laser beam 39 and the plasma is conducted, thus efficiently generating x-rays. At this time, a bore 31a having a diameter of about 10 .mu.m.about.100 .mu.m is formed in the target 31 by the laser beam 39 as shown in FIG. 14(b). The x-rays 45 thus generated pass through the x-ray transmitting film 32 and are emitted not only toward the sample side, but also toward the laser light source side through the bore 31a. On the other hand, particulates generated from the plasma 44 come into collision with the x-ray transmitting film 32 such that their kinetic energies are absorbed and reduced in speed. Thus, the particulates do not pass through the x-ray transmitting film 32 but are caught thereby. As a result, the scattering particulates stick to the x-ray transmitting film 32. At the step where one irradiation of the laser beam 39 is finished and x-ray generation is also finished, the bore 31a is formed in the target 31 and the scattering particulates stick to the x-ray transmitting film 32. This is not an environment suitable for the next irradiation of laser beam for x-ray generation. At this point of time, the target 31 and the x-ray transmitting film 32 are moved. More specifically, the target 31 is moved such that its portion having no bore 31a reaches the laser beam irradiation position, and the x-ray transmitting film 32 is moved such that its portion having no scattering particulates stuck thereto reaches the x-ray transmitting position. At such a state, the laser beam 39 is irradiated as shown in FIG. 14(c). Again, the target 31 is bored at 31a and scattering particulates stick to the x-ray transmitting film 32. Thereafter, the target 31 and the x-ray transmitting film 32 are similarly moved and the laser beam 39 is then irradiated as shown in FIG. 4(d). By repeating the operations above-mentioned, x-ray generation is intermittently repeated. The amount of movement of the target 31 for each irradiation of the laser beam 39 may be set such that at least the irradiation position of the laser beam 39 does not overlap the bore 31a. The amount of movement of the x-ray transmitting film 32 for each irradiation of the laser beam 39, may be set such that at least the x-ray transmitting position does not overlap the scattering particulate sticking zone. For example, each of the amounts of movement may be for example about 1 mm. Such an amount of movement may be smaller than the amount of movement of each of the target and the x-ray transmitting film in the x-ray generating apparatus of prior art shown in FIG. 23. More specifically, in the x-ray generating apparatus of prior art in FIG. 23, the x-ray transmitting film is bored as shown in FIG. 24 and such bore must be kept sufficiently away from the plasma. For example, the x-ray transmitting film is required to be moved by 2 to 3 mm for example. In the embodiment above-mentioned, however, the x-ray transmitting film 32 is not bored. Thus, the amount of movement of the x-ray transmitting film 32 can accordingly be reduced. The x-rays thus generated are irradiated, through the x-ray window 41a, to the sample 42 in the sample cell 41 disposed in the vicinity of the x-ray transmitting film 32. The x-rays having passed through the sample 42 reaches the resist 43 at the back side of the sample cell 41 such that an x-ray image of the sample is formed. In this embodiment, the scattering particulates emitted from the plasma are intercepted by the x-ray transmitting film 32. This involves no likelihood that the scattering particulates exert adverse effects to the sample or the like. It is therefore not required to dispose a scattering particulate preventing means, a condensing optical system or the like between the x-ray source and the sample as done in apparatus of prior art. Thus, the x-ray transmitting film 32 and the sample cell 41 can be disposed in close proximity to each other. This enables the x-rays emitted through the x-ray transmitting film 32 to reach the sample 42 before diffused and damped. Thus, the amount of x-rays irradiated to the sample 42 is remarkably increased as compared with a prior art apparatus. Further, the arrangement requiring no optical system such as a condensing mirror or the like between the x-ray source and the sample or the like, is advantageous also in view of elimination of adjustment or the like of the wavelength characteristics of the optical system. The following description will discuss another embodiment of the third invention. FIG. 15 shows in section the arrangement of main portions of this embodiment. In this embodiment, a sample cell 41 having two parallel x-ray windows 41a and a sample 42 housed therebetween, is disponed in the vicinity of an x-ray transmitting film 32. Thus, an x-ray image of the sample 42 in the sample cell 41 is enlarged through an x-ray enlarging optical system 46 and formed on the sensitive surface of an x-ray detector 47. As the x-ray detector 47, CCD, MCP or the like may be used. In this embodiment, a Schwarzschild optical system comprising two concavo-convex mirrors is used as the x-ray enlarging optical system 46. FIGS. 16 and 17 are section views respectively illustrating the arrangements of main portions of a further embodiment and still another embodiment of the third invention. The embodiment in FIG. 16 employs a zone plate 46a as the enlarging optical system interposed between the sample cell 41 and the x-ray detector 47, while the embodiment in FIG. 17 employs a Wolter-type mirror 46b as the enlarging optical system interposed between the sample cell 41 and the x-ray detector 47. FIG. 18 shows the arrangement of main portions of a still further embodiment of the third invention. This embodiment employs the arrangement in which the x-ray image of a sample 42 disposed in the vicinity of a target 31 is enlarged as directly projected on a two dimensional detector 47a separated, for example, by dozens of cm or more from the sample 42. This arrangement is made based on the fact that the x-rays can be regarded as generated from a point light source since the x-rays are generated from a fine zone in the form of a spot in the order of 10 .mu.m. In each of the embodiments of the second and third inventions, the incident angle of the laser beam 39 upon the target 31 is perpendicular to the surface of the target 31. However, such an incident angle may be optionally set. More specifically, the x-rays generated from plasma formed by the irradiation of the laser beam 39 are radial. Accordingly, even though the laser beam 39 is irradiated to the target 31 at any incident angle, the x-rays can readily be taken out in the desired direction. To obtain a more practical x-ray generating apparatus or x-ray microscope, it is desired to make provision as shown in a schematic layout in FIG. 19 such that the laser beam 39 is irradiated to one side of the target 31 in an oblique direction and that x-rays emitted in an oblique direction from the other side of the target 31 are irradiated to the sample 42. The arrangement in FIG. 19 is advantageous in that the sample 42 is not influenced by the laser beam 39 having passed through the target 31. FIG. 20 shows the arrangement of main portions of yet another embodiment of each of the second and third inventions. In this embodiment, a target 31 and a x-ray transmitting film 32 are individually wound on winding members 48a, 48b and winding members 49a, 49b. According to this arrangement, it is not required to previously prepare the target 31 and the x-ray transmitting film 32 in a double-layer structure. Further, this arrangement is advantageous in that the amounts of movement of the target 31 and the film 32 can individually be set.
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047675926	summary
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	description	The present application claims priority as a national stage application, under 35 U.S.C. §371, to international application No. PCT/US2013/053644, filed Aug. 5, 2013, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/680,133, filed Aug. 6, 2012. The disclosures of the aforementioned priority applications are incorporated herein by reference in their entirety. The present invention relates to control rod drive systems for nuclear reactors, and more particularly to a fail-safe control rod drive system. A rod cluster control assembly (RCCA) comprises an array of tubular elements (“control rods”) containing neutron absorber “poison” connected to a common support header for raising and lowering the control rod array as a unit. The control rods in an RCCA are arrayed at a precise spacing, which ensures each rod is perfectly aligned with respective circular cavities in the fuel assemblies of the fuel core. The extent of insertion of the rod assembly into the fuel core is controlled by the device referred to as a control rod drive mechanism (CRDM), which is a subcomponent of the control rod drive system (CRDS). In typical pressurized light water reactors (PLWRs), the CRDM is operated from the top of the reactor head which is approximately 15 to 20 feet above the top of the nuclear fuel core. However, in certain new reactor systems, the height of the reactor head may be many times greater above the top of the fuel core. For example, in the HI-SMUR™ SMR-160 from Holtec International, the RCCAs may require operation from a distance of over 60 feet, which using the present existing technology, would require the drive rod (DR) which is normally supplied with existing CRDM to be in excess of 60 feet long. DRs with such a long length, however, would be impractical for the following reasons: Removing drive rods from the reactor vessel would require an inordinate amount of crane head room; Performing routine maintenance would require a large laydown area; The weight of the drive rod becomes so large due to the increased length, that during a SCRAM (emergency shutdown procedure of the reactor in which control rod are quickly inserted into the fuel core to suppress the nuclear reaction), the top nozzle of the fuel assembly risks becoming damaged from the weight of the falling RCCA as well as the ESA; During a SCRAM, the drive rod is at risk of being damaged because of the inertia load, which is magnified in the CRDM which utilizes a lead screw for the drive rod; and Manufacture of drive rod becomes difficult thereby increasing the cost to fabricate the CRDS. Another problem is presented by the location of the CRDM. Contemporary commercial technology requires the CRDM to be installed External to the Reactor Vessel. This presents major concerns with regards to the operational safety of the CRDS. With presently available technology should a failure of the pressure retaining portion of the CRDM occur the pressure differential between the inside of the reactor vessel and the atmosphere external to the reactor vessel would subsequently cause the CRDM drive rod to be ejected from the reactor. This in turn could cause a spike in the reactivity of the reactor core, since the drive rod is mechanically connected to the RCCA in the current state-of-the-art technology. One solution would be to locate CRDM within the reactor vessel. However, this would pose several technical challenges. First, control rod drive mechanisms are complex electromechanical devices. Exposing these to the high pressure and temperature environment inside the reactor vessel can cause the mechanism to fail prematurely. Second, placing the control rod drive mechanism inside the reactor vessel presents possibly structural problems since the mechanism is also subject to flow induced vibration. Accordingly, although this approach would solve the long drive rod problem, it is undesirable for the foregoing reasons. An improved control rod drive system is desired. The present invention provides a control rod drive system (CRDS) that overcomes the foregoing problems and yields a number of additional benefits, which will be readily discerned from the description which follows. The present invention may be beneficially used for nuclear reactor vessel designs of a high head design described above (e.g. top of the reactor head located at a vertical distance greater than approximately 15 to 20 feet above the top of the nuclear fuel core), but has broader application as well to virtually any reactor vessel design. In one configuration, a control rod drive system (CRDS) generally includes a drive rod mechanically coupled to a control rod drive mechanism operable to linearly raise and lower the drive rod along a vertical axis, a rod cluster control assembly (RCCA) comprising a plurality of control rods positioned proximate to and insertable into a nuclear fuel core, and a drive rod extension (DRE) releasably engaged between the drive rod and RCCA. The CRDS is remotely operable to selectively couple and uncouple the DRE from the RCCA and drive rod. The CRDM includes an electromagnet which releasably couples the CRDM to DRE. This arrangement contrasts to known CRDSs in which the drive rod is directly coupled to the RCCA, which is unsuitable in situations requiring drive rods with excessively long lengths (e.g. greater than 15-20 feet). In the event of a power loss or SCRAM, the CRDM may be configured to remotely uncouple the RCCA from the DRE without releasing or dropping the drive rod which remains engaged with the CRDM and in axial position. Advantageously, this protects the integrity of the CRDM and eliminates potential problems with known designs caused by dropping the drive rod which may damage equipment, as described above. The present DRE includes unique features providing the remote coupling and uncoupling functionality, and failsafe operation in the event of a power loss or SCRAM, as further described herein. According to one exemplary embodiment of the present invention, a control rod drive system for a nuclear reactor vessel includes: a vertically oriented drive rod mechanically coupled to a control rod drive mechanism operable to raise and lower the drive rod through a plurality of axial positions; a rod cluster control assembly comprising a plurality of control rods configured for removable insertion into a nuclear fuel core; a drive rod extension extending axially between the rod cluster control assembly and the drive rod, the drive rod extension having a bottom end releasably coupled to the rod cluster control assembly; and a drive rod extension grapple assembly connected to the drive rod, the grapple assembly releasably coupled to a top end of the drive rod extension. Raising and lowering the drive rod raises and lowers the rod cluster control assembly. In one embodiment, the grapple assembly includes an electromagnet which magnetically couples the drive rod extension to the grapple assembly when the electromagnet is energized and uncouples the drive rod extension from the grapple assembly when the electromagnet is de-energized. According to another exemplary embodiment, a control rod drive system for a nuclear reactor vessel includes: a control rod drive mechanism mounted externally to the reactor vessel; a drive rod mechanically coupled to the control rod drive mechanism and extending through the reactor vessel into an interior cavity of the reactor vessel holding a nuclear fuel core, the control rod drive mechanism operable to raise and lower the drive rod through a plurality of vertical axial positions; a grapple assembly connected to the drive rod in the interior cavity of the reactor vessel and movable with the drive rod; an electromagnet mounted in the grapple assembly; a rod cluster control assembly comprising a plurality of control rods configured for removable insertion into the nuclear fuel core; and a drive rod extension extending axially between the rod cluster control assembly and the grapple assembly. The drive rod extension includes: an axially extending actuator shaft having a top end including a magnetic block configured to releasably engage the electromagnet of the grapple assembly and a bottom end configured to releasably engage the rod cluster control assembly; and a lifting head sleeve including a diametrically enlarged lifting head, the lifting head sleeve slidably receiving the actuating rod therethrough for axial upward and downward movement. The electromagnet is operable to magnetically couple the actuating shaft to the grapple assembly at the top of the drive rod extension when the electromagnet is energized and uncouple the actuating shaft from the rod cluster control assembly at the bottom of the drive rod extension when the electromagnet is de-energized. Raising the actuator shaft when the electromagnet is energized couples the actuator shaft to the rod cluster control assembly and de-energizing the electromagnet lowers and uncouples the actuating shaft from the rod cluster control assembly. According to another exemplary embodiment, a control rod drive system for a nuclear reactor vessel includes: a reactor vessel having a top head and an interior cavity; a nuclear fuel core supported in the interior cavity of the reactor vessel; a rod cluster control assembly comprising a plurality of control rods configured for removable insertion into the nuclear fuel core; a control rod drive mechanism mounted externally to the reactor vessel above the top head; a drive rod mechanically coupled to the control rod drive mechanism and extending through the top head of reactor vessel into the interior cavity, the control rod drive mechanism operable to raise and lower the drive rod through a plurality of vertical axial positions; a grapple assembly connected to the drive rod inside the interior cavity of the reactor vessel and movable with the drive rod, the grapple assembly including an electromagnet; a drive rod extension extending axially between the rod cluster control assembly and the grapple assembly, the drive rod extension including a bottom end releasably coupled to the rod cluster control assembly and a top end releasably coupled to the grapple assembly via the electromagnet; and a longitudinally-extending drive rod extension support structure mounted in the reactor vessel above the nuclear fuel core, the support structure including a plurality of vertically-oriented guide tubes at least one of which is configured to slidably receive the drive rod extension therein for axial upward and downward movement. The electromagnet is operable to magnetically couple the drive rod extension to the grapple assembly when the electromagnet is energized and uncouple the drive rod extension from the grapple assembly when the electromagnet is de-energized. De-energizing the electromagnet drops and uncouples the drive rod extension from the rod cluster control assembly remotely at the bottom of the drive rod extension. An exemplary method for coupling a control rod drive mechanism to a rod cluster control assembly in a nuclear reactor vessel is provided. The method includes the steps of: providing: a reactor vessel having a top head and an interior cavity; a nuclear fuel core supported in the interior cavity; a rod cluster control assembly positioned at a top of the fuel core and comprising a plurality of control rods configured for removable insertion the fuel core; a control rod drive mechanism mounted externally above the reactor vessel; a drive rod assembly including a drive rod mechanically coupled to the control rod drive mechanism and extending into the interior cavity of the reactor vessel, and a grapple assembly disposed on an end of the drive rod and including an electromagnet. The method further includes lowering the drive rod assembly; contacting the drive rod assembly with a top end of a drive rod extension extending vertically between the rod cluster control assembly and the top head of the reactor vessel, a bottom end of the drive rod extension contacting the rod cluster control assembly in a non-locking manner; energizing the electromagnet to magnetically couple the drive rod assembly with the drive rod extension; raising the drive rod assembly by a first vertical distance; locking the bottom end of the drive rod extension with the rod cluster control assembly, wherein raising and lowering the drive rod assembly with the control rod drive mechanism raises and lowers the rod cluster control assembly for controlling the reactivity within the fuel core. All drawings are schematic and not necessarily to scale. Parts given a reference numerical designation in one figure may be considered to be the same parts where they appear in other figures without a numerical designation for brevity unless specifically labeled with a different part number and described herein. In addition, a reference to a single figure number prefix (e.g. FIG. 10) which comprises multiple figures of the same prefix number distinguished by different alphabetical suffixes (e.g. FIGS. 10A and 10B) shall be construed as a general reference to all figures sharing that same prefix number. The features and benefits of the invention are illustrated and described herein by reference to exemplary embodiments. This description of exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Accordingly, the disclosure expressly should not be limited to such exemplary embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features. System Component Definitions In one non-limiting example to provide an overview, a control rod drive system according to the present disclosure may generally include the following major assemblies defined below in summary fashion and further described herein in greater detail: Rod ejection protection device (REPD)—a hydraulically-actuated mechanically-returned collet which engages the drive rod of the CRDM and prevents the drive rod from moving in position in the event of a failure of the CRDS. Control rod drive mechanism (CRDM)—An electro mechanical device used to control the position of the Control Rods located in the reactor core Drive rod (DR)—A shaft that passes through the CRDM into the reactor vessel through the reactor vessel nozzle and is attached to the DREGA. Drive rod extension grapple assembly (DREGA)—An assembly that is used to connect the DR to the DRE. This assembly also contains an electromagnet which, when energized and de-energized, engages and disengages the DRE with the RCCA respectively. Drive rod extension support structure (DRESS)—a support structure designed to hold and guide the DREs. In one illustrative embodiment, for example without limitation, the DRESS may include thirty seven guide tubes. The guide tubes may be perforated to allow for water circulation (e.g. primary coolant) therethrough. Retaining collars (located at the top of the DRESS) may hold spring loaded retention devices. These devices attach to the DRE lifting head sleeve. Their purpose is to prevent the guide DRE from being removed from the DRESS inadvertently during reactor vessel head removal. The DRESS provides lateral and seismic restraint of the DREs. Drive rod extension (DRE)—A device that is connected to the DR by means of the DREGA which extends the reach of the DR to engage the RCCA located below. FIGS. 1 and 2 depict an exemplary embodiment of a control rod drive system 100. The control rod drive system 100 is shown installed on a reactor vessel 110 which includes a longitudinally-extending and elongated cylindrical shell 111 defining a vertical axis, bottom head 112, and top head 113. In one embodiment, the top head 113 may be removable form the shell 111 such as via a bolted flange joint or other form of detachable mounting. The reactor vessel defines an interior cavity 114 which holds a core support structure 115 configured to support a nuclear fuel core 116. In one embodiment, the core support structure 115 may be in the form of a tubular riser pipe 119 which conveys primary coolant flowing in an annular space 118 between the riser pipe 119 and shell 111 upwards through the fuel core 116 and outwards through a flow nozzle 117 fluidly coupled to a steam generator for generating steam. The primary coolant is heated by flow upwards through the fuel core 116. In one embodiment, the fuel core 116 may in the form of a self-supporting fuel cartridge such as the SMR-160 unitary fuel cartridge available from Holtec International which is insertable into the core support structure 115. As will be well known to those skilled in the art without undue elaboration, a typical nuclear reactor core in a light water reactor comprises tightly packed fuel assemblies 700 (also referred to as fuel bundles) as further shown in FIG. 8B. Each fuel assembly 700 is an assemblage of bundled fuel rods 702 which are sealed hollow cylindrical metal tubes (e.g. stainless steel or zirconium alloy) packed with enriched uranium fuel pellets and integral burnable poisons arranged in an engineered pattern to facilitate as uniform a burning profile of the fuel as possible (in both axial and cross sectional/transverse directions). Multiple longitudinally-extending cavities are formed within each fuel assembly 700 for insertion of the control rods 504 into the fuel core in the usual manner, such as through the top nozzles boxes 704 mounted atop each fuel assembly 700 which are disposed proximate to the bottom of the drive rod extension support structure (DRESS) 160 and accessible to the RCCAs 500. Numerous variations in the arrangement are possible. It will be appreciated that numerous variations are possible in the arrangement of components within the reactor vessel 110; the foregoing arrangement described representing only one possible exemplary embodiment. Accordingly, the invention is not limited in this regard to the embodiment described herein. As shown in FIG. 2, reactor vessel 110 may be considered a high head reactor vessel design in which the fuel core 116 is disposed near the bottom head 112 of the vessel within the core support structure 115 riser pipe. The distance between the top of the fuel core and top head 113 of the reactor vessel may exceed the usual 15-20 feet distance in typical pressurized light water reactors (PLWRs). The reactor vessel 110 may be made of any suitable metal, such as for example without limitation steels such as stainless steel for corrosion resistance. With continuing reference to FIGS. 1 and 2, control rod drive system 100 includes drive rod (DR) 130, drive rod extension (DRE) 400, drive rod extension support structure (DRESS) 160, drive rod extension grapple assembly (DREGA) 200, control rod drive mechanism (CRDM) 300, and rod ejection protection device (REPD) 140. Other than the DRESS 160 and fuel core 116 for which a single assembly of each may be provided for a reactor vessel 110, the control rod drive system (CRDS) 100 may actually include a plurality of the foregoing remaining components each associated with providing a lifting mechanism for raising/lowering one of the plurality of rod cluster control assemblies (RCCA) 500 (see, e.g. FIG. 11B) provided with the reactor vessel 110. Accordingly, there may in fact be a plurality of the component assemblies shown in FIGS. 1 and 2 although only a single CRDM 300 rod drive mechanism 300 and associated lifting components are shown for clarity of description. In one exemplary embodiment, for illustration, a reactor vessel 110 installation of a small modular reactor design may include approximately 37 CRDMs 300 and associated DREs 400. The invention is not limited to any particular number of CRDMs or other components. Control rod drive mechanisms 300 may each be housed in a structural enclosure 302 mounted to top head 113 of reactor vessel 110 for protection of the drive mechanism. The function of this enclosure structure includes to provide lateral and seismic support of the CRDMs 300, protect the CRDMs from projectile or missile generated within the primary containment structure (not shown) which encloses the reactor vessel 110, protect the CRDMs from potential drops of equipment from the overhead crane, provide a means of lifting the reactor vessel head, and provide a mounting location for the REPD 140 which may be mounted on top of enclosure 302 in one embodiment. The CRDM enclosures 302 may be attached to the reactor vessel top head 113 by any suitable means, such as without limitation welding. In one embodiment, the top head 113 of reactor vessel 110 may include a flanged nozzle 304 configured to receive a bottom mounting flange 306 on control rod drive mechanism 300 for coupling and supporting the drive mechanism from the reactor vessel head. The bottom mounting flange 306 may be detachably coupled to the flanged nozzle 304 with fasteners (e.g. bolts and nuts) to allow the control rod drive mechanism 300 to be removed for maintenance or replacement. The drive rod 130 extends vertically downwards through the rod ejection protection device 140, top of the enclosure 302, control rod drive mechanism 300, and further through the flanged nozzle 304 into the top portion of reactor vessel beneath top head 113 as shown in FIGS. 1 and 2. A set of seals may be provided with the drive rod 130 at the flanged nozzle 304 to prevent leakage of reactor coolant from the reactor vessel along the drive rod during operation. The bottom end of the drive rod 130 is coupled to the drive rod extension grapple assembly (DREGA) 200, as further described herein. Control rod drive mechanism (CRDM) 300 may be any type of commercially available electro-mechanical drive operable to lower/raise the drive rod 130 (and in turn DREGA 200 attached to the drive rod). As one non-limiting example diagrammatically illustrated in FIG. 18, a CRDM 300 of one type may have a drive assembly 600 generally utilizing a motor drive to rotate a lead screw 604 formed on the drive rod 130. Such drive mechanisms for drive rods are well known to those skilled in the art. In one arrangement, as shown, the electric drive motor 610 may be axially offset from the drive rod 130 and rotates a worm 608 (i.e. worm gear) arranged transversely to the drive rod. The worm 608 in turn rotates a ring gear 606 rigidly affixed to a ball collar or nut or collar 602 having ball bearings 612 engaged with the lead screw 604 on the drive rod 130. Rotating the ring gear 606 in opposing directions using the motor drive 610 which operates to rotate the worm 608 in opposing rotational directions alternatingly axially raises or lowers the drive rod 130 in a controlled manner. In other possible arrangements, the ball nut or collar may be directly coupled to the drive motor which may be arranged axially in line with the drive rod. In either of the foregoing arrangements, the CRDM rotates the ball nut or collar which axially advances or retracts the drive rod via the lead screw. Numerous variations of CRDMs using drive rod lead screws are possible. CRDMs are commercially available from a number of manufacturers, including for example General Atomics of San Diego, Calif. CRDMs are further described in U.S. Pat. No. 5,999,583 and U.S. Patent Application Publication 2010/0316177, which are incorporated herein by reference in their entireties. FIGS. 3 and 4 show drive rod extension grapple assembly (DREGA) 200 in greater detail. DREGA 200 includes a cylindrical grapple body 202 having sidewalls 232 defining an interior chamber 212, an open top 224, and a downwardly open bottom 226. Top 224 may be closed by a removable top plate 204 in one embodiment which is attached to the top annular face of grapple body 202 via a plurality of circumferentially spaced fasteners 206. The open bottom 226 allows an upper portion of drive rod extension 400 to be inserted therein, as further described herein. An electromagnet 228 is disposed in chamber 212 which is engageable with a magnetic block 402 of drive rod extension 400 (see, e.g. FIG. 9). In one embodiment, electromagnet 228 may be mounted at the top end of chamber 212 and affixed to the underside of top plate 204 by one or more fasteners 208. Other variations for mounting electromagnet 228 are possible. With continuing reference to FIGS. 3 and 4, drive rod extension grapple assembly (DREGA) 200 further includes plurality of circumferentially spaced and radially movable lifting pins 216. Lifting pins 216 may be oriented horizontally in one embodiment and are operable to project radially inwards into chamber 212 towards the vertical centerline of grapple body 202 through corresponding circumferentially spaced openings 214 formed through the body. The lifting pins 216 are radially movable between a projected position (shown in FIG. 4) extending partially into the chamber 212 and a retracted position withdrawn from the chamber. Lifting pins 216 may each be biased inwards towards the projected position via a suitably configured lift spring 218 having an end which engages an outward facing open socket formed in each pin as shown. In one embodiment, lifting pins 216 may be movably disposed in an annular shaped housing 222 which extends radially outwards from grapple body 202. Housing 222 includes a plurality of circumferentially spaced bores 230 having a circular cross section configured to slidably receive lifting pins 216 therein. Bores 230 may extend radially completely through the housing 222 and sidewalls 232 of grapple body 202 communicating with openings 214. Each bore 230 includes a lifting pin 216 and associated spring 218. The lifting pins 216 may include a stepped shoulder 234 which engages a complementary configured stepped portion of the bore 230 to prevent the lifting pins from being ejected by the spring 218 completely through holes 214 into the chamber 212 of the grapple body 202. In one embodiment, the exterior opening in each bore 230 may be closed off by a removable cap 220 which threadably engages the annular housing 222. The caps 220 each have an interior surface which may engage one end of spring 218. In one embodiment, the annular housing 222 may be threaded along an exterior portion surrounding each bore 230 and the caps 220 may threadably engage these threaded bore surfaces. Other suitable arrangements of mounting caps 220 to close bores 230 may be used. The drive rod extension grapple assembly (DREGA) 200 may be mounted to the bottom end of the drive rod 130 by any suitable means. For example, without limitation, drive rod 130 may be threadably coupled directly to DREGA 200 via a threaded socket formed in the top plate 204 and threading the bottom end of the drive rod, via mounting brackets and fasteners, welding, or other suitable mechanical mounting techniques used in the art. Preferably, in certain embodiments, DREGA 200 is rigidly mounted to the drive rod 130. In one embodiment, cylindrical grapple body 202 may have a maximum outside diameter larger than the interior diameter of the flanged nozzle 304 so that the DREGA A cannot be inserted or retracted through the nozzle. In such an arrangement, the DREGA 200 is connected to the end of the drive rod 130 beneath the top head 113 of the reactor vessel 110. Other suitable arrangements are possible. FIGS. 5-8 (including all alphabetical subparts) depict the drive rod extension support structure (DRESS) 160. DRESS 160 is a vertically elongated structure which includes a plurality of upper guide tubes 161 and lower guide tubes 162 circumscribed by an open lattice outer support frame 163 having a cylindrical shape to complement the shape of the riser pipe 119 in which the DRESS may be inserted from the top. The open structure reduces the weight of the support frame 163 while providing structural strength. In one exemplary embodiment, without limitation, the outer support frame 163 may have an X-shaped lattice formed by diagonal supports 164 arranged in an X-pattern and enlarged junction plates 165 formed at the intersection of the diagonal supports. Other suitable open or closed structures are possible for support frame 163. The upper and lower guide tubes 161, 162 may be intermittently supported along their lengths by axially spaced apart horizontal supports 166. A horizontal support 166 is provided at the top 166a and bottom 166b of DRESS 160. In one exemplary embodiment, the supports 166 may be spaced axially apart at approximately 5-6 feet intervals along the longitudinal length of the guide tubes 161, 162. Other appropriate axial spacing may be used. In one embodiment, the horizontal supports 166 may be comprised of interconnected lateral grid plates 171 extending between adjacent guide tubes 161, 162. The outermost supports 166 may be attached at their ends to an annular shaped peripheral rim 169 which may be attached to the interior surface of the cylindrical outer support frame 163, such as at the junction plates 165 and/or along horizontal arcuately shaped strap members 167 connected between junction plates. In one embodiment, the horizontal supports 166 may be welded to the outer support frame; however, other suitable attachment methods may be used instead of or in addition to welding such as fasteners. In one embodiment, the uppermost horizontal support 166 may include an array of laterally spaced circular retaining collars 170 mounted onto the top ends of each upper guide tube 161. This forms a grid array of retaining collars 170 having a pattern or layout in top plan view which matches the horizontal pattern or layout of the upper guide tubes 161. The retaining collars 170 each have a central opening configured to receive a respective upper guide tube therein. The retaining collars 170, located at the top of the drive rod extension support structure (DRESS) 160, may include spring loaded retention devices in the form of radially movable retaining pins 172 spaced circumferentially around the retaining collars (see, e.g. FIGS. 5A and 11A). The retaining pins 172 may be horizontally oriented and movable to be retracted from or projected into the central hole of the retaining collar 170. As noted above the retaining pins 172 engage the DRE lifting head sleeve 408 (see also FIGS. 10 and 11). One of their purposes is to prevent the guide DRE 400 from being removed from the DRESS 160 inadvertently during reactor vessel head removal. The upper guide tubes 161 have a diameter selected to allow the drive rod extension (DRE) 400 to be axially inserted completely through the guide tube in one embodiment. This allows raising and lowering of the DREs 400 by the control rod drive mechanism (CRDM) 300. Each of the lower guide tubes 162 may have a larger diameter than the upper guide tubes 161. The lower guide tubes 162 have a diameter selected to allow the entire control rod support plate 502 of the rod cluster control assembly (RCCA) 500 (shown in FIG. 11B) to be raised and lowered within the lower guide tubes for inserting and retracting the control rods 504 into and from the fuel core 116. The control rod support plate 502 has a larger diameter than the widest component of the DRE 400 in the present exemplary embodiment, thereby necessitating a larger diameter for the lower guide tubes 162 than the upper guide tubes 161. In one embodiment, guide tube transition fittings 168 may be used to couple the lower ends of each upper smaller diameter upper guide tube 161 to a corresponding concentrically aligned lower guide tube 162. In one embodiment, the transition fittings 168 may be frusto-conical shaped as best shown in FIGS. 5B and 6A and have an open structure comprised of axially spaced apart upper and lower rings 168a, 168b each attached respectively to an upper and lower guide tube 161, 162. Accordingly, the lower rings 168b have a larger diameter than the upper rings 168a in this embodiment. The rings 168a, 168b may be joined to form a structural unit by angled and vertically extending struts 168c extending between the rings. In other embodiments, the guide tube transition fittings 168 may be closed. Other suitable configurations of guide tube transition fittings 168 are possible including non-frusto-conical shapes. The guide tube transition fittings 168 help maintain axial alignment between the upper and lower guide tubes 161, 162. The guide tubes 161, 162 in turn help maintain axial alignment of the control rods with respective corresponding cavities in the fuel core 118 for insertion or retraction of the rods to control the nuclear reaction rate in various portions of the core. Other suitable configurations of transition fitting, however, may be used and numerous variations are possible. In some embodiments, the upper and lower guide tubes 161, 162 may each include a plurality of holes or perforations along their respective lengths as shown in FIGS. 5-8 which allow the primary coolant to flow inside the guide tubes within the riser pipe 119. The holes or perforations may be distributed both circumferentially and longitudinally around each guide tube 161, 162 in a suitable pattern. Referring to FIGS. 2 and 8, the drive rod extension support structure (DRESS) 160 may be mounted inside the upper portion of riser pipe 119 proximate to the top of the fuel core 116. This allows the lower operating ends of each drive rod extensions (DREs) 400 which may be coupled and uncoupled from the rod cluster control assembly (RCCA) 500 to be in proper position for inserting or retracting the control rods 504 into/from the fuel core 116 for controlling the nuclear reaction rates in parts or all of the fuel core, as further described herein. FIGS. 9 and 10 show the drive rod extension (DRE) 400 in greater detail. Each DRE 400 is intermediate link which operably couples a drive rod 130 at top end 401 of the DRE to a corresponding rod cluster control assembly (RCCA) 500 at bottom end 403 of the DRE. DRE 400 includes an inner actuator shaft 404 which is disposed inside an outer actuator tube 406 and a lifting head sleeve 408. Actuator shaft 404 extends longitudinally for substantially the entire length of the DRE 400 and may be a single unitary structure in some embodiments. In one embodiment, lifting head sleeve 408 is positioned at an upper portion of the DRE above the top of the drive rod extension support structure (DRESS) 160. Lifting head sleeve 408 has a bottom end 421 and a top end 412 that abuts a lower surface 414 of a diametrically enlarged lifting head 410. Axially spaced between ends 412 and 421 is an annular stop flange 416 extending radially outwards from lifting head sleeve 408. The stop flange 416 is configured to engage an axially movable bobbin 430 which is slidable on lifting head sleeve 408 and defines a lower travel stop for the bobbin. Stop flange 416 may be further arranged to engage the top of retaining collar 170 to limit the insertion depth of the lifting head sleeve into the upper guide tube 161 (see also FIG. 11A). Lifting head sleeve 408 may further include a stepped portion 420 which defines a downward facing surface which abuts a top end 422 of actuator tube 406. In one embodiment, the bottom end 421 of lifting head sleeve 408 may be sized to be inserted into the open top end 422 of actuator tube 406. An axial portion of lifting head sleeve 408 disposed between stop flange 416 and stepped portion 420 defines a recessed annular seating surface 423 configured to removably receive and engage spring biased retaining pins 172 of retaining collar 170 which is initially positioned around the lifting head sleeve at this location (see also FIGS. 5A and 11A). With continuing reference to FIGS. 9 and 10, bobbin 430 includes an outward-upward facing angled upper bearing surface 432 and an opposing outward-downward facing angled lower bearing surface 434 which meet at a circumferentially extending apex A. Lower bearing surface 434 is selectively engageable with 216 of drive rod extension grapple assembly (DREGA) 200. Upper bearing surface 432 is selectively engageable with lifting head 410. The functionality of these bearing surfaces will be further described herein. Lifting head 410 may be an annular generally inverted cup-shaped member in some embodiments. Lifting head includes an annular outward-upward facing angled upper bearing surface 424 and opposing annular inward-downward facing angled lower bearing surface 414. Bearing surface 414 defines a downwardly open cavity 426 which is configured to receive and complement the configuration of bobbin upper bearing surface 432. A portion of lower bearing surface 414 is engaged by top end 412 of lifting head sleeve 408 to maintain the axial position of the lifting head 410. Lifting head 410 has a larger diameter than the top end 412 of lifting head sleeve 408. DRE 400 may further include a drive extension spring 462 having a bottom end engaging a top surface 427 of lifting head 410. Spring 462 is arranged concentrically around actuator shaft 404 and may be a helical coil spring in some embodiments. In one embodiment, a hollow and cylindrically-shaped spring retainer 460 may be provided which holds spring 462 therein. Spring retainer 460 may have an open bottom and a partially open top defining a central opening 466. A top end of spring 462 may engage the underside of a spring spacer 464 disposed inside the spring retainer beneath central top opening 466 configured to receive magnetic block 402 at least partially therethrough (see, e.g. FIGS. 15 and 16). The spring spacer 464 may be generally shaped as a washer having a diameter larger than the diameter of central opening 466 to prevent the drive extension spring 462 from being ejected out the top of the spring retainer 460. The bottom of magnetic block 402 may bear against the top side of spring spacer 464 in some positions. Lifting head 410 may further include a stepped portion 425 formed in the top surface 427 and/or upper bearing surface 424 which engages a bottom annular edge 429 of spring retainer 460 for locating the spring retainer on the lifting head. In one embodiment, as shown in FIGS. 9 and 10, lifting head 410 and spring retainer 460 may be disposed in the general proximity of top end 401 of actuator shaft 404 spaced axially downwards from the top end. With continuing reference to FIGS. 9 and 10, the lower portion of the drive rod extension (DRE) 400 includes an adapter sleeve 440 having a bottom end 444 and a top end 442 attached to the bottom end 428 of the actuator tube 406. Adapter sleeve 440 has a hollow cylindrical body which slidably receives actuator shaft 404 therein. In one embodiment, the bottom end 428 of the adapter sleeve 440 may be open. Actuator cap 454 may be inserted through the open bottom end 428 of adapter sleeve 440 to threadably engage bottom end 403 of actuator shaft 404 via a fastener. Adapter sleeve 440 includes an RCCA locking mechanism configured for releasably coupling the sleeve to the rod cluster control assembly (RCCA) 500. In one embodiment, the locking mechanism may be a locking element assembly 450 comprised of a plurality of circumferentially spaced apart and radially moveable locking elements. The locking elements in one exemplary configuration may be locking balls 452 which may be retained on an outer surface of the adapter sleeve 440 by ball retaining plates 451 spaced circumferentially about the sleeve. The locking balls 452 are engageable with an annular machined groove 510 formed on an inside surface of a tubular mounting extension 506 rising upwards from a hub 508 of the RCCA 500 (see, e.g. FIG. 11B). The locking balls 452 are actuated by the actuator cap 454, as further described herein. When the drive rod extension (DRE) 400 is mounted in the reactor vessel 110, the adapter sleeves 440 of each DRE are located proximate to the bottom ends of lower guide tubes 162 in the drive rod extension support structure (DRESS) 160. This positions the adapter sleeve 440 to releasably engage the rod cluster control assembly (RCCA) 500 via the locking ball assembly 450. The locking ball assembly 450 is operable to couple and uncouple the RCCA 500 from the DRE 400, as further described herein. The fuel core 116 is located at the bottom of the reactor vessel 110 supported inside the core support structure 115, such as riser pipe 119. On top of the fuel core 116 is the drive rod extension support structure (DRESS) 160. The DRESS 160 is oriented such that each guide tube is axially and vertically centered above a RCCA 500 installed in the fuel core 116. The drive rod extensions (DRE) 130 are each positioned in the DRESS 160 and the lower portion of each DRE is seated in and loosely engaged with an RCCA 500, although not yet locked in place during initial assembly as evidenced in FIG. 11B showing the actuator cap 454 positioned below the locking ball assembly 450 near the bottom of the adapter sleeve 440. Control Rod Drive System Operation An exemplary method for coupling a control rod drive mechanism (CRDM) 300 to a rod cluster control assembly (RCCA) 500 will now be described with various reference to FIGS. 11-17 showing sequential steps in the method or process. The drive rod extension support structure (DRESS) 160 is not shown in these figures for clarity. In one embodiment, as described in greater detail below, the method may be generally accomplished by first coupling the drive rod 130 to the top of the drive rod extension (DRE) 400 which will enable the DRE to then be finally coupled to the RCCA 500. It should be noted that the following process addresses the coupling of a single CRDM 300 to a RCCA 500. This same process, however, may be repeated for making the other CRDM-RCCA couplings for embodiments of control rod drive system (CRDS) 100 in which multiple RCCAs are each individually controlled by a separate dedicated CRDM. The reactor vessel 110 is initially provided with the drive rod extension support structure (DRESS) 160 installed above the fuel core 116 in the core support structure 115, in this embodiment tubular riser pipe 119. DRE 400 is preliminarily installed and inserted in the drive rod extension support structure (DRESS) 160. The DRE 400 is positioned within the upper and lower guide tubes 161, 162. At this juncture, however, the DRE 400 is initially not operably coupled to either the RCCA 500 or the drive rod assembly (i.e. drive rod extension grapple assembly (DREGA) 200 attached to drive rod 130). As shown in FIG. 11A, the drive rod extension (DRE) 400 is in an initial or starting vertical axial position with the top end of the actuator shaft 404, lifting head 410, and bobbin 430 exposed and extending above retaining collar 170 of the drive rod extension support structure (DRESS) 160. The makes the upper portion of DRE 400 accessible to the drive rod extension grapple assembly 200 below the top head 113 of the reactor vessel 110. In this initial position of DRE400, the flange 416 of lifting head sleeve 408 may be engaged with the retaining collar 170 and the lifting head sleeve is engaged with the radially biased retaining pins 172 of the collar. At the bottom end of the DRE 400, the adapter sleeve 440 is positioned and inserted into, but not lockingly engaged with the tubular mounting extension of the rod cluster control assembly (RCCA) 500. Accordingly, at this initial starting position, the RCCA 500 cannot be operably raised or lowered by CRDM 300 because the RCCA has not yet been operably coupled and locked to the DRE 400. To engage the DRE 400 with the RCCA 500 at the fuel core 116, the DREGA 200 is first connected to the DRE in the overall coupling process. The DREGA 200 and drive rod 130 are axially (vertically) aligned with but spaced apart from top end 401 of DRE 400 (see FIG. 11A). The CRDM 300 is operated to lower the drive rod 130 with DREGA 200 attached thereto towards the top end 401 of DRE 400. As the DREGA 200 is lowered onto the DRE 400, the lifting pins 216 initially in a fully extended position engage angled upper bearing surface 424 of lifting head 410 (see FIGS. 4, 10, and 12A). The lifting pins 216 and lift springs 218 gradually retract farther and farther into the DREGA housing 222 on the grapple body 202 as DREGA 200 continues to be lowered and pushed over the lifting head 410 of DRE 400. The lifting pins 216 slidingly engage the upper bearing surface 424 moving from top to bottom of the lifting head 410 (see FIG. 12B). The lift springs 218 become compressed by the retracting motion of the lifting pins 216. When the lifting pins 216 clear and reach a position just beneath the lifting head 410, the pins return to their original fully extended positions inside DREGA interior chamber 212 under the inwards biasing force of the lift springs 218 (i.e. lifting pins are in a position slightly above that shown in FIG. 13). The DREGA 200 is now attached to the DRE 400 and lifting pins 216 are positioned above the bobbin 430 as shown. It should be noted that DREGA 200 cannot be disengaged from DRE 400 at this point with the lifting pins 216 in this axial position by merely raising the drive rod and DREGA with the CRDM 300. Accordingly, the method carries on by continuing to lower the DREGA 200 until the electromagnet 228 in the DREGA comes into complete physical contact with the magnetic block 402 fastened to the top end 401 of the DRE actuator shaft 404, as shown in FIG. 13. The electromagnet 228 is then activated (energized) from a power source. Activation of the electromagnet 228 causes the magnetic block 402 to be releasably coupled to the electromagnet. After this magnetic coupling is completed, the DREGA 200 and drive rod 130 assembly is now fully connected to the DRE 400 such that raising and lowering the drive rod using CRDM 300 concomitantly raises and lowers the actuator shaft 404 of the DRE as long as the electromagnet 228 remains energized. In the foregoing position shown in FIG. 13, it should be noted that drive extension spring 462 is uncompressed. The bottom of the magnetic block 402 is positioned proximate to and may be in contact with the top of the spring retainer 460. In order to attach the RCCA 500 remotely situated at the top of the fuel core 116 from the CRDM 300 to the DRE 400, the actuator shaft 404 in one embodiment needs to be pulled up to force the locking balls 452 radially outwards through the adapter sleeve 440 and into the machined groove 510 located in the RCCA which engages the actuator shaft with the RCCA to complete the coupling at the bottom of the DRE. At this point in the installation process, the lifting head sleeve 408 of DRE 400 is still in its initial axial starting position shown similarly in FIGS. 11A and 13, but with the DREGA 200 magnetically coupled to the DRE as shown in FIG. 13. The uncoupled DRE 400 and RCCA 500 are in their respective lowermost initial positions and at the bottom of their vertical range of travel in the reactor vessel 110 and DRESS 160. The control rods 504 are fully inserted in the fuel core 116. The lifting head sleeve 408 remains as yet engaged with the retaining pins 172 in retaining collar 170. With additional reference to FIG. 10A, the recessed annular seating surface 423 of lifting head sleeve 408 is engaged with the spring biased retaining pins 172 of retaining collar 170 which serve to releasably hold the sleeve 408 in position during coupling of the DREGA 200 to the DRE 400. As a point of reference, it may be noted that the lifting head sleeve stop flange 416 may still rest on the top of retaining collar 170 at present (see, e.g. FIG. 13) which prevents the lifting head sleeve 408 from dropping any lower into the upper guide tube 161 of the DRESS 160. With the DRE 400 in the position of FIG. 13 and the foregoing magnetic coupling completed of the DREGA 200 with the DRE, the DREGA is then next raised upwards by a first vertical distance (via the drive rod 130 using CRDM 300) which pulls and slides the actuator shaft 404 upwards inside the adapter sleeve 440 which remains stationary. The actuator cap 454 mounted to the bottom of the actuator shaft 404 moves axially upwards with the shaft from an unlocked position (shown, e.g. in FIG. 11B) to a locked position (shown, e.g. in FIG. 14B) forcing the locking balls 452 radially outwards from the adapter sleeve 440 to engage the machined groove 510 inside RCCA 500. As shown in FIG. 14B, the DRE 400 is now fully but releasably coupled at the bottom to RCCA 500 which can be raised or lowered by the CRDM 300 via the DRE 400. Accordingly, the CRDM 300 has now been linked to the RCCA 500 for controlling the insertion depth of the control rods 504 into the fuel core 116 for controlling the reactivity. It should be noted that in the unlocked position of actuator cap 454 (see, e.g. FIG. 11B, 15B, or 16B), the larger diameter lower actuating portion 470 of the cap with annular bearing surface 472 does not contact the locking balls 452 which remain seated but relatively loose in the ball retaining plate 451. This does not create positive locking engagement of the locking balls 452 with the machined groove 510 on the inside of the tubular mounting extension 506 of RCCA 500 sufficient to couple the DRE 400 to the RCCA. The reduced diameter upper portion 471 of actuator cap 454 even when positioned adjacent to the locking balls 452 (see, e.g. FIG. 10B) leaves an annular gap G between the cap and adapter sleeve 440 so the locking balls 452 remain loose and not positively engaged with the machined groove 510 of the RCCA 500. In the locked position of the actuator cap 454 (see, e.g. FIG. 14B), the annular bearing surface 472 of the larger diameter lower actuating portion 470 of the cap is adjacent to and contacts locking balls 452. Since there is no appreciable annular gap or space between the lower portion 470 of actuator cap 454 and adapter sleeve 440, the annular bearing surface 472 drives the locking balls 452 outwards to engage machined groove 510 of the RCCA tubular mounting extension 506 which positively couples the DRE 400 to the RCCA 500. In one embodiment, a sloping transition 475 (see, e.g. FIG. 16B) may be formed between the larger diameter lower portion 470 and reduced diameter upper portion 471 of the actuator cap 454 to provide smooth sliding operation and engagement of the lower portion 470 with the locking balls 452. After the RCCA 500 has been coupled to the CRDM 300 in the foregoing manner, the RCCA remains in its bottom and lowermost position within the lower guide tubes 162 proximate to the top of the fuel core 116. To provide the ability to operationally retract the control rods 504 from the fuel core 116, the DREGA 200 is slightly raised further upwards if necessary via the CRDM 300 until the lifting pins 216 engage the bottom of lifting head 410 (as shown in FIG. 14A) if not already engaged by the DREGA-RCCA coupling process). Until the lifting pins 216 engage the underside of lifting head 410, this initial limited upward range of travel raises the actuator shaft 404 and DREGA 200, but not the lifting head sleeve 408 which remains engaged with retaining collar 170 and retaining pins 172. DREGA 200 is then further raised through a second upward vertical distance and range of travel which pulls both the actuator shaft 404 (via the magnetic coupling with the DREGA) and lifting head 410 with lifting head sleeve 408 fixed thereto upwards together simultaneously. This action disengages the lifting head sleeve 408 from the retaining pins 172 in retaining collar 170 as also shown in FIG. 14A. The DRE 400 (including actuator shaft 404, lifting head sleeve, actuator tube 406, and adapter sleeve 440 shown in FIGS. 10A and 10B) and the RCCA 500 coupled thereto may now be freely raised as a unit to a maximum height within the reactor vessel 110 representing the fullest retracted position of the control rods 504 from the fuel core 116 during normal operation of the reactor vessel 110. The actuator shaft 404 and lifting head sleeve 408 may further be alternatingly lowered and then raised again through a plurality of possible axial positions via operation of the CRDM 300 and drive rod 130. It may be noted that the RCCA 500 fits inside and slides axially upward and downward within the confines of the lower guide tubes 162 of the DRESS 160 which have a diameter selected to fully receive the RCCA therein in one embodiment. The length of the lower guide tubes 162 establishes the maximum vertical range of travel of the RCCA 500 and correspondingly the control rods 504 mounted thereto. A method to detach the rod cluster control assembly (RCCA) 500 from the drive rod extension (DRE) 400 and CRDM 300 for SCRAM events or other purposes such as opening the reactor vessel head will now be described. In one embodiment, the electromagnet 228 is first de-activated. This allows the actuator shaft 404 to fall or drop by a preset distance determined by the drive extension spring 462 and the spring spacer 464. Doing so permits the locking balls 452 to fall into the gap G created by the reduced diameter upper portion 471 of the actuator cap 454. The RCCA 500 is now disengaged from the actuator shaft 404 of drive rod extension (DRE) 400 and the CRDM 300. The foregoing falling action of the actuator shaft 404 also re-engages the lifting head sleeve 408 with the retaining pins 172 in retaining collar 170 of the DRESS 160 (see FIG. 15A). It should be noted that this uncoupling action ensures that the control rods attached to the RCCA 500 remain fully inserted into the fuel core 116 which shuts down the nuclear reaction. FIGS. 14 and 15 illustrate this foregoing uncoupling sequence. When in the foregoing position, it should be noted that the DRE 400 can also be completely removed from the drive rod extension support structure (DRESS) 160 if desired by simply lifting the drive rod extension grapple assembly (DREGA) 200 via the control rod drive mechanism (CRDM) 300. Because the electromagnet 228 has been de-energized, this lifting action will disengage the lifting head sleeve 408 from the retaining pins 172 in retaining collar 170 of the DRESS 160 (see also FIGS. 5A and 11A). A method for uncoupling and removing the DREGA 200 from the DRE 400 (remaining in place in DRESS 160) will now be described. First, the electromagnet 228 is deactivated (and the RCCA 500 is unlocked) in the manner already described above and shown in FIGS. 15A and 15B. Next, the DREGA 200 is pushed downwards via the CRDM 300 (and drive rod 130) to engage the bobbin 430. The lifting pins 216 initially engage angled upper bearing surface 432 which increasingly drives the pins radially outwards (i.e. retracted from chamber 212) back into the DREGA 200 as the pins advance downwards along the upper bearing surface. The lifting pins 216 reach a maximum retracted position at the apex A of the bobbin 430, and then increasingly begin projecting back inwards into chamber 212 of DREGA 200 again as the pins travel downwards along the angled lower bearing surface 434 (see FIG. 16A). Eventually, the lifting pins 216 become fully extended beneath the bobbin 430 immediately above stop flange 416 on lifting head sleeve 408. The downward movement of DREGA 200 simultaneously compresses drive extension spring 462 as shown in FIG. 16A which allows the positioning of lifting pins 216 below bobbin 430 to occur. Note that a portion of magnetic block 402 has passed through the central opening 466 and entered spring retainer 460 to compress the spring 462. To complete the uncoupling of DREGA 200 from the DRE 400, the DREGA is then raised concomitantly lifting the bobbin 430 with it via the lifting pins 216 into the lifting head 410 until the bobbin cannot move any higher, as shown in FIG. 17A. This occurs when the angled upper bearing surface 432 of bobbin 430 enters cavity 426 and engages complementary configured lower bearing surface 414 of lifting head 410. The bobbin 430 is now nested in lifting head 410. As the DREGA 200 then continues to be raised, the lifting pins 216 will again retract outward back into DREGA housing 222 and ride along the outside of the bobbin (angled lower bearing surface 434) as shown in FIG. 17B. The lifting pins 216 then engage and slide along angled upper bearing surface 424 of lifting head 410 whereon the pins again increasingly begin projecting back inwards into chamber 212 of DREGA 200. Eventually, the lifting pins 216 become fully extended and are free of the lifting head 410 as shown in FIG. 17C. The DREGA 200 is now fully disengaged from the drive rod extension (DRE) 400 which in turn has disengaged the CRDM 300 from the DRE. A control rod drive system according to the present disclosure provides numerous advantages, including the following. The length of the CRDM drive rod 130 may be limited to a relatively short length that is easily manufacturable. The shorter length drive rod has the added benefits of ease of maintenance. There is no risk of the drive rod being damaged during a SCRAM because the drive rod does not fall in a SCRAM event for full insertion of control rods into the fuel core to suppress the nuclear reaction as in prior known designs. In embodiments of the present invention, the control rod assembly (RCCA) 500 holding the control rods is released by uncoupling the RCCA from the drive rod extension (DRE) 400 during a SCRAM. Furthermore, because the drive rod does not fall during a SCRAM, the top nozzle of the fuel assembly is not at risk for being damaged during a SCRAM. The complex electromechanical components in the CRDM system 100 are not subject to the harsh environment inside of the reactor vessel because the CRDM 300 is mounted external to the reactor vessel. The redundant rod ejection protection device (REPD) 140 eliminates the potential for the drive rod 130 to be ejected from the reactor vessel due to a CRDM housing failure. A final advantage is that the CRDS 100 may be designed so that so that the CRDS will always SCRAM under gravity if the power to the CRDM 300 is cut via magnetically uncoupling the DREGA 200 from the DRE 400, as described above. Unless otherwise specified, the components described herein may generally be formed of a suitable material appropriate for the intended application and service conditions. A suitable metal is generally preferred for the components described herein with exception of the magnetic components. Components exposed to a corrosive or wetted environment may be made of a corrosion resistant metal (e.g. stainless steel, galvanized steel, aluminum, etc.) or coated for corrosion protection. While the foregoing description and drawings represent exemplary embodiments of the present disclosure, it will be understood that various additions, modifications and substitutions may be made therein without departing from the spirit and scope and range of equivalents of the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, sizes, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. In addition, numerous variations in the methods/processes described herein may be made within the scope of the present disclosure. One skilled in the art will further appreciate that the embodiments may be used with many modifications of structure, arrangement, proportions, sizes, materials, and components and otherwise, used in the practice of the disclosure, which are particularly adapted to specific environments and operative requirements without departing from the principles described herein. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive. The appended claims should be construed broadly, to include other variants and embodiments of the disclosure, which may be made by those skilled in the art without departing from the scope and range of equivalents.
048067695	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the preferred embodiments of the present invention, an example of a prior art system is described with reference to the drawings, for comparison. FIG. 1 is a block diagram of an ion implantation system to which the present invention can be applied. In FIG. 1, the ion implantation system includes an outer cabinet 4, an inner cabinet 41, and a first power supply 48 connected between the outer cabinet 4 and the inner cabinet 41. The first power supply 48 provides typically a maximum voltage of 160 KV to 175 KV. In the inner cabinet 41 are provided an ion source 43, and an ion extraction electrode 44. A second power supply 45 is provided between the ion source 43 and the ion extraction electrode 44 and provides typically a voltage of approximately 25 KV to 40 KV, to cause the emission of ion beams from the ion source 43. The emitted ion beams are introduced into an analysis magnet tube 46 installed in the inner cabinet 41. When a magnetic flux B is directed thereto as shown in the drawing, light mass ions i.sub.l and heavy mass ions i.sub.h, both contained in the ion beams, are impinged on an inner wall of the analysis magnet wall 46, as shown in the drawing, and are absorbed thereat. As a result, ions i having a predetermined mass are emitted from the analysis magnet tube 46, and a speed thereof is accelerated at an accelerator 42. A low potential side of the power supply 45, the analysis magnet tube 46, and an entrance side of the accelerator 42 are commonly connected to the inner cabinet 41. The voltage of the accelerator 42 is provided by the voltage of the power supply 48, the accelerator 42 accelerating the input ions i by the electric field provided by the above voltage. The accelerated ions are introduced into an exposure chamber 5. In the implantation process, atmosphere in an inner space of the exposure chamber 5 is pumped out to produce a vacuum therein. A target mechanism is placed in the inner space prior to this pumping. The operation for ion implantation of semiconductor wafers is described below. FIG. 2 is a sectional view of the target mechanism 3 of the prior art. The target mechanism 3 includes a support shaft 32 of aluminum (Al) or stainless steel and a target disk 31 of Al mounted thereon. A plurality of semiconductor wafers 2 to be implanted are mounted on a surface of the circumference of the target disk 31. The target mechanism 3 is placed in the exposure chamber 5, which is brought to a vacuum condition, in the direction as shown by the broken line arrow in FIG. 1, and is rotated around a rotation center line 0--0'. Ion implantation of the semiconductor wafers 2 mounted on the target disk 31 is achieved sequential exposure to the ion beams ION. The target mechanism 3 can be moved in a vertical direction V--V' in the exposure chamber 5, ensuring an ion implantation of the whole surface of the semiconductor wafers 2. After completion of the ion implantation, the target mechanism 3 is extracted from the exposure chamber 5. At this time the target mechanism 3 is rotated by 9020 , as shown by a broken line in FIG. 1, to bring the wafer mounting surface of the target disk 31 to the horizontal plane. The target disk 31 is then removed from the support shaft 32 by releasing holding claws 33. A new target disk 31 on which untreated semiconductor wafers 2 are already mounted is then mounted on the support shaft 32. The target mechanism 3 with the new target disk 31 is inserted into the exposure chamber 5, and the ion implantation is carried out for the untreated semiconductor wafers 2. The ion implanted semiconductor wafers are detached from the target disk 31 removed from the support shaft 32 outside the exposure chamber 5, and thereafter, untreated semiconductor wafers are mounted on the removed target disk 31. The above disk exchange operation can be applied in the present invention. The problems of the prior art are now discussed in detail. Assuming an implantation energy of 80 KeV and a high ion implantation dosage of approximately 1.times.10.sup.16 cm.sup.-2, the beam current should be 10 mA, and the beam power should be 800 W. Also, assuming a permanent implantation as for a theoretical analysis is carried out under the above condition, the temperature of the semiconductor wafer may rise to approximately 180.degree. C., giving a temperature difference of approximately 17.degree. C. between the wafer and the target disk, and a temperature difference of approximately 160.degree. C. between the target disk and the support shaft, etc. The above temperature rise depends on the beam power. In practice, the implantation time is approximately 1 to 30 minutes and given a diameter of the target disk of 70 cm, the actual temperature of the wafer may rise by approximately 120.degree. C. to 130.degree. C. during an usual implantation time. This temperature rise will damage resists on the semiconductor wafers, because the temperature tolerance of the resists is approximately 100.degree. C. In addition, ion implantation at such high temperatures has an adverse affect on the quality of the wafers, because of the difficulty of lattice recovery of the wafer after implantation. An embodiment of a target mechanism 1 of the present invention will be described with reference to FIGS. 3a to 3d. The ion implantation system of this embodiment is similar to that in FIG. 1, except for the target mechanism 1. The target mechanism 1 includes a target disk 11 of Al, a support 12 of Al or stainless steel, and a thermal contact means such as a silicon (Si) rubber sheet 13 inserted between the target disk 11 and the support 12. Semiconductor wafers 2 to be implanted are mounted on a surface of the target disk 11 opposite to the surface of the target disk 11 in contact with the Si rubber sheet 13. In FIG. 3a, the structure of the support 12 includes a first shaft 12-1, a base 12-2, and a second shaft 12-4. A cavity 12-3 is provided in the base 12-2, and a hole 12-5 communicating with the cavity 12-3 is formed in the second shaft 12-4. The support 12 can be rotated in a direction A with respect to a center axis 0--0'. The structure of the target disk 11 comprises a disk 11-1 having a center hole through which the first shaft 12-1 is fitted, and claws 11-3 detachably holding the target disk 11 to the base 12-2 of the support 12. A thermal transportation means 11-2 is provided in the disk 11-1. The lower surface of the disk 11-1 and the top surface of the base 12-2 facing the lower surface of the disk 11-1 are precision-machined. However, from a microscopic view point, these surfaces are uneven, and thus, if brought into face-to-face contact, the contact therebetween may be considered to be a point contact. This point contact would limit the thermal transfer from the target disk 11 to the support 12, causing a temperature rise of the target disk 11, and accordingly, a temperature rise of the semiconductor wafers 2 during the ion implantation. The Si rubber sheet 13, as shown in FIG. 3b, is inserted between the lower surface of the disk 11-1 and the top surface of the base 12-2, and functions as a contact means to cause a perfect face-to-face contact between those surfaces. As a result, the above prior art temperature difference between the target disk and the support of a theoretical value of approximately 160.degree. C. can be reduced to a theoretical value of approximately 40.degree. C. The Si rubber sheet 13 has a thermal transportation coefficient greater than 20 mW/cm.sup.2..degree. C. FIG. 3c is a plan view of the disk 11-1 having the wafers 2 mounted thereon, taken along a line H.sub.1 --H.sub.1 ' in FIG. 3a. Eight wafers 2 mounted around the circumference of the disk 11-1 are rotated together with the support 12 in the direction A during the implantation. FIG. 3d is a plan view of the disk 11-1 and the thermal transportation means 11-2 provided therein, taken along a line H.sub.2 --H.sub.2 ' in FIG. 3a. The thermal transportation means 11-2 includes eight heat pipes 11-2-1 to 11-2-8 provided radially with respect to the rotation center. The heat pipes 11-2-1 to 11-2-8 are installed independently from each other, and each heat pipe is provided with a cavity extending along the longitudinal direction and webs or slots on an inner wall thereof. A cooling medium, such as water, a hydrocarbon fluoride gas e.g., "Freon" (trade name) or ethanol, is inserted in the cavity. The principle of the heat pipe is widely known. When the ion beam exposure causes a rise in the temperature of the wafers 2, the cooling medium at the circumferential edges of the heat pipes beneath the wafers 2 is also heated. Accordingly, a thermal convection is produced between the high temperature portions, i.e., the circumferential edge of the heat pipes, and low temperature portions, i.e., a portion adjacent to the rotation center, resulting in a high speed flow of the cooling medium between the high temperature portions and the low temperature portion through the webs or the slots in accordance with a capillary action, and accordingly, a high speed transporting of thermal energy from the high temperature portions to the low temperature portion. Thus, the thermal transportation means 11-2 contributes to a lowering of the temperature of the wafers 2. Further, a cooling medium, for example, water, is circulated through the cavity 12-3 of the base 12-2, which accelerates the cooling of the wafers 2. Namely, the thermal energy at the wafer 2 is distributed by the thermal transportation means 11-2, and the distributed thermal energy is forcibly transferred to the base 12-2 force-cooled from the inner wall of the cavity 12-3 in the base 12-2. In addition, during the ion implantation, the target disk 11-1 is rotated at a high speed, for example, 1000 rpm, and therefore the cooling medium at the center of the target disk 11-1 is forcibly moved to the circumference thereof, where the temperature is high, accelerating the thermal transportation. According to the embodiment, the ion implantation process is carried out under the following conditions: Beam power: 800 W PA1 Implantation time: approximately 15 minutes PA1 Size of Si rubber sheet: 1000 cm.sup.2 PA1 Cooling medium: Freon gas This results in the temperature at the wafers being approximately 80.degree. C. This temperature satisfies the requirements necessary for the protection of the resist on the wafer and of the wafer quality. The thermal contact means 13 should have the characteristics of good contactability with metal, high thermal conductivity, and stability in vacuum conditions. Accordingly, the thermal contact means 13 can be a polyfloraethylene film, e.g., "Teflon" (trade name), an RTV (Room Temperature Vulcanization) Si rubber, an Indium (In) film, etc., instead of the Si rubber sheet mentioned above. Freon gas is vaporized at a temperature higher than approximately 50.degree. C., and this vaporization will accelerate the thermal convection in the heat pipe. Preferably, Freon gas is used as the cooling medium in the heat pipe, rather than water having a boiling point of 100.degree. C.. Ethanol, which vaporizes at approximately 80.degree. C., is also preferable to water as the cooling medium. As shown by a broken-line circle in FIG. 3d, the heat pipes can be commonly connected at the center portion of the mechanism, where the temperature is low. After ion implantation, the heated (to approximately 80.degree. C.) target mechanism 1 is taken out of the exposure chamber 5, and the target disk 11 having the ion implanted wafers 2 mounted thereon is removed from the support 12. During the target disk exchange operation, preferably, the target mechanism 1 is forcibly water-cooled while outside exposure chamber 5 by supplying water to the hole 12-5 of the support 12. Another embodiment of the thermal transportation means will be described with reference to FIG. 4. FIG. 4 is a plan view of a second variety of heat pipes 11-2-1`to 11-2-8', taken along the line H.sub.2 -H.sub.2 ' in FIG. 1 and corresponding to FIG. 3d. In FIG. 4, a circumferential end of each heat pipe, above which the wafer to be ion-implanted is mounted, is bent to form an L-shape, to increase an inner space to which the cooling medium is inserted and from which the heat is removed. The heat pipes 11-2-1' to 11-2-8' can be replaced by boxes drilled in the mechanism per se. Still another embodiment of a target mechanism of the present invention will be described with reference to FIG. 5. FIG. 5 is a sectional view of the target mechanism and corresponds to FIG. 3a. In FIG. 5, an Si rubber sheet 13' as the thermal contact means is inserted not only between the lower surface of the target disk 11-1 and the upper surface of the base 12-3 but also between the first shaft 12-1 and an inner wall of the target disk 11-1, thereby increasing the thermal contact area. Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in this specification, except as defined in the appended claims.
	summary
	abstract	A method of fabricating a fuel assembly grid that includes providing a plurality of interconnected straps that form a lattice pattern, wherein the lattice pattern of the straps defines a plurality of cells, providing a sleeve that has a cylindrical portion and a flared portion, and inserting the sleeve into at least one of the cells. When inserted, at least a portion of the cylindrical portion of the sleeve will reside inside the cell and the flared portion will extend above the top end of the cell and overhang the perimeter of the cell. The flared portion is melted and flows over and fuses to the straps that define the cell. The straps may include weld tabs over which the melted material flows and to which it fuses. The melting and fusing steps also preferably cause any loose straps surrounding the cell to become attached to the sleeve.
	summary
	description	This application is a continuation of U.S. application Ser. No. 15/313,101 filed 21 Nov. 2016, which is a 35 U.S.C. § 371 National Phase Application of Int'l App No. PCT/AU2015/000302 filed May 22, 2015, which claims the benefit of the filing date and priority of Australian patent application no. 2014901905 filed 22 May 2014, the content of which as filed is incorporated herein by reference in its entirety. The invention pertains to radiation detection and imaging, and in particular to a compressed sensing gamma-ray or neutron imaging device with a detector and one or more coded masks. Gamma-ray imaging is an important radiation detection capability that can provide the location and identity of gamma-ray emitting radionuclides. Gamma-ray imaging can be utilised in many applications, including but not limited to: decommissioning, decontamination, environmental monitoring (i.e. site surveys, mining surveys), medical imaging (SPECT), astronomy and national security applications (i.e. search for illicit radiological & nuclear material). Traditional gamma-ray imaging techniques rely on either focusing an image onto very expensive arrays of detectors or slowly raster scanning a single detector across the image plane. The expense of pixelated detector arrays or slow speeds of raster scanning systems are often prohibitive. Unlike optical photons, which are easily focused, the highly penetrating nature of gamma-ray photons make them very difficult to focus. Gamma-ray imaging systems that use pixelated detector arrays typically use a single pinhole, multiple pinhole or planar coded aperture optics. These systems are used to form an image or an encoded image on the detector array. The use of pinhole and coded aperture optics has been around for decades in astronomy and medical applications. The fields of view of these types of imaging systems are approximately 30°-40° in the horizontal or vertical direction. Rotating Modulation Collimators (RMCs), first introduced by Mertz in 1967, typically use two masks with parallel slits that run the entire length of the mask. When the masks are rotated, the projection of the front mask appears to orbit the rear mask with respect to the source. The rotation of the masks creates a modulated count pattern at the detector that depends on the number of sources, source intensity, location and size. The RMC has a number of drawbacks, including: a single RMC has difficulty imaging extended sources, it has a small field of view, when using a single RMC it is impossible to distinguish a source on the central axis of rotation (see B. R. Kowash, A Rotating Modulation Imager for the Orphan Source Search Problem, PhD Thesis, 2008). The scenes to be imaged in many gamma-ray imaging applications are sparse in nature and typically require the detection of one or more point sources. For the simple case of a single point source that will be sampled into a 16×16 image and, assuming background is zero, this will provide 1 non-zero pixel and 255 zero pixels. Rather than taking N (in this case 256) measurements, most of which will be zero, intuition says that smarter strategies should be able to determine the location of the non-zero pixel in far fewer than N measurements. This intuition has recently been proven through the development of a new signal processing theory, known as Compressed Sensing. Compressed sensing is enabling new approaches to image formation. The Compressed Sensing approach can produce images with a fraction of the measurements (when compared to traditional imaging techniques) and enables low cost (single detector) system options to be realised. Single pixel imaging systems, based on compressed sensing, have been recently developed for optical, infrared and THz wavelengths (see R. G. Baraniuk et al., Method and Apparatus for Compressive Imaging Device, U.S. Pat. No. 8,199,244 B2, 2012). For example, a terahertz imaging system is known that uses a single pixel detector in combination with a series of random masks to enable high-speed image acquisition (see W. L. Chan et al., A Single-Pixel Terahertz Imaging System Based on Compressed Sensing, Applied Physics Letters, Vol. 93, 2008). These single pixel imaging systems all use some sort of lens to focus an image and then use random compressive measurements to sample the image plane. However, it should be possible to perform compressive measurements when sampling the scene plane rather than forming an image and then sampling. Huang et al. have taken this approach and describe a single pixel optical imaging system that requires no lens; they use an aperture assembly to randomly sample the scene and at no stage form a ‘traditional’ image (see G. Huang et al., Lensless Imaging by Compressive Sensing, 2013). It is an object of the invention to provide a gamma-ray imaging device that takes fewer measurements than prior gamma-ray imaging techniques. Images of a scene can be produced with fewer measurements than the number of pixels in the image. It is another object of the invention to provide a gamma-ray imaging device having a larger field of view than prior aperture based gamma-ray imaging techniques. It is an object of the invention to provide a mask apparatus that can randomly sample a scene for gamma-rays. These random projections of the scene can be used to reconstruct images. Accordingly, there is provided an imaging apparatus comprising a single detector surrounded by one or more rotating masks. In preferred embodiments, the masks are cylindrical, hemispherical, or segments of spheres, or spheres. Imager Layout and Sensing As shown in FIGS. 1 and 2, a single gamma-ray detector 10 is located at the centre of a mask 11 that encircles or encloses the detector 10. The detector is located centrally of the mask or masks preferably the detector occupies a centre or axis of rotation of the mask 11. A cylindrical or spherical mask 11 may be used. Although a non-central detector position can be used, it will have a slightly different field of view. More than one detector 12, 13 can be used and these additional detectors can be in different positions. Using multiple detectors can reduce the imaging time. An optional cylindrical or other radiation shield 14 may have an arcuate opening 15 for limiting the field of view to an arc defined by the opening 15. The mask 11 may be indexed or rotated by a stepper motor driven turntable 19 or directly geared stepper motor 20 or otherwise to suit the coded mask or optic methodology being employed. Through the use of stepper motors 20, gearing 21 and a control computer 22 having for example display and print capabilities for generating an image from the collected and processed data, the data collection and coordinated motion/rotation of the mask can be automated. The motion of the mask may be in discrete steps or in a continuous movement. As shown in FIG. 2, when a cylindrical mask 11 is used, the top and bottom usually need to be covered by a shield 16, 17, so that the only radiation reaching the detector is through the open apertures 18 of the mask 11 that are not otherwise shielded. The compressed sensing gamma-ray imager may be used in conjunction with any gamma-ray sensitive sensor 10, 12, 13. The typical gamma-ray detector systems based on materials such as Sodium Iodide (NaI), Caesium Iodide (CsI), Bismuth Germanate (BGO), Cadmium Telluride (CdTe), Cadmium Zinc Telluride (CZT), High Purity Germanium (HPGe), Strontium Iodide (SrI2) and CLYC may be used. Spectroscopic detectors that determine the energy of each measured photon can be used to identify the radionuclide being imaged. Non-spectroscopic detectors that just record gross counts will provide general information on radiation hotspots. Other radiation detection equipment, such as dose rate meters, could be used as the sensor and in this case would map the dose in the field of view. The preferred embodiment uses a spectroscopic detector that measures the energy of each gamma-ray photon detected. The photon count values from any particular energy bin or energy bin range can be used as the observed data from a set of measurements. The reconstruction of observed photon count data for a given peak region of interest (e.g. the 60 keV 241Am line) will provide the location of the 241Am, provided the radionuclide is present. The reconstruction of observed photon data for additional regions of interest can give the location of additional radionuclides. A compressed sensing neutron imager may be used in conjunction with any neutron sensitive sensor or sensors 10, 12, 13. Dual modality sensors 10, 12, 13, including but not limited to CLYC, may be used to measure the modulation of both the gamma-rays and neutrons. It will be appreciated that the teachings of this invention may be applied to radiation of any wavelength (or of any particle) by using the appropriate mask and detector. Mask and Mask Apertures Mask pattern openings or apertures are preferably arranged in rows and columns. The location of mask pattern openings 18 may, for example, be produced randomly. For example, in a 16×16 possible aperture mask there are a total of 256 numbered apertures. A random number generator is used to randomly select 128 of the aperture numbers between 1 and 256. These 128 numbers are then set to be the open apertures. The remaining 128 locations (from the original 256 numbers) are set as zero (closed). This provides a mask pattern that is 50% open. For rotational masks, where the mask columns are indexed or rotated, the random selection of open/closed apertures may be made for each row rather than the whole mask. This would ensure that each mask row is 50% (for example) open and would prevent situations where a row has too many or too few open apertures, which may impact on the image reconstruction. The geometry of the system will define the spatial resolution. The aperture size should preferably be equal to or greater than the detector dimensions. For example, a system may have apertures 18 with dimensions of 0.5 cm×0.5 cm and the cross-sectional area of the detector should also be 0.5 cm×0.5 cm or less. The further away the detector is from the mask, then the better the spatial resolution. Detectors with dimensions larger than those of the aperture may be used, however, for this case there will be an increased overlap between the fields of view of adjacent apertures. This overlap (which is a degradation/blurriness in the spatial resolution) can be removed by deconvolving the response function of the mask. The preferred aperture cross-sectional shape is square. The preferred number of apertures is a power of 2 (i.e. 64, 128, 256, 512, 1024), although it is not essential. It is preferred that there be minimal or no separation between the mask apertures. The thickness of the mask will depend on the application. For the imaging of high energy photons (for example the 1.3 MeV photons from 60Co) a total mask thickness of 2 cm of lead would attenuate approximately 72% of the 1.3 MeV photons. The mask materials are made from a body material that can sufficiently modulate the intensity of the incoming radiation. For high energy gamma-rays the materials will typically be high in atomic number (Z) and high in density, which would absorb (attenuate) the gamma-ray radiation. Typical materials could include but not be limited to tungsten, lead, gold, tantalum, hafnium and their alloys or composites (e.g. 3D printing—mixing tungsten powder with epoxy). For low energy gamma-ray photons, low to medium Z materials, such as steel, are sufficient to modulate the photon intensity. In a preferred embodiment the mask material will attenuate the photons in order to modulate the photon intensity. Other embodiments may use other interaction mechanisms, such as Compton scattering, if they show an appreciable modulation in photon intensity. For imaging of neutron radiation, the mask body will need to modulate the neutron intensity and therefore mask materials will require a high neutron interaction cross-section. Neutron mask body materials may include but not be limited to: Hafnium, Gadolinium, Cadmium, Boron doped materials, Hydrogen rich materials and their combinations. Masks may be designed from materials that would enable the modulation of both gamma-rays and neutrons. A single material such as Hafnium may be suitable to modulate the intensity of both gamma-rays and neutrons. Use of multiple materials, for example, a combination of Tungsten and Cadmium, may be suitable to modulate the intensities of both gamma-rays and neutrons. The open apertures, for the gamma-ray mask, may consist of some hydrogen rich material which does not influence the modulation of the gamma-ray intensity. These hydrogen rich apertures would then represent the closed apertures or modulating regions for the neutron mask. By extension, these mask materials could be used to modulate the intensity of any EM wavelength (i.e. optical, infrared, THz, etc.) or any particle (i.e. electrons, protons, etc.). As shown in FIG. 11, a coded mask is capable of modulating both gamma-rays and neutrons separately, that is, some mask regions being used to block gamma-rays only and some mask regions being used to block neutrons only. In the example of FIG. 11, one sub-set of mask regions 91 (represented in solid shading) are fabricated from a material that modulates gamma-rays only. Another sub-set of mask regions 92 (represented without shading) modulates only neutron and not gamma-rays. Masks of this type may be fabricated in accordance with any of the techniques and materials, shapes or configurations disclosed by or suggested by this specification. Masks may be singular or multiple and nested, rectangular, circular, arcuate, hemispherical or spherical. Consecutive measurements required for coded mask sensing will require a new mask pattern obtained by replacing a current mask with a new one or using some form of rotation of the mask or masks. Flat mask shapes will have a limited field of view as they are only looking in the forward direction, with the field of view angle determined by the detector and mask geometry. The advantage of arcuate, cylindrical or spherical masks is that large fields of view (FOV) are possible. Current commercially available pinhole/coded aperture gamma-ray cameras have horizontal and vertical FOV between approximately 30° and 40°. An upright cylindrical mask embodiment would have a horizontal FOV of 360°, a hemispherical mask embodiment would have a 2π FOV and a spherical mask embodiment would have a nearly 4π FOV. Other embodiments may include but not be limited to: ellipsoid, cone, cuboid or hexagonal shaped masks. In the case of a single cylindrical mask embodiment, the rotation of the mask by one column would constitute a new mask pattern viewing the desired FOV for a new measurement. For a single cylindrical mask embodiment, a radiation shield can be used to restrict the FOV and therefore have a large number of columns to enable more measurements (see FIG. 2). The down side to the single cylindrical mask approach is that more columns are required to perform more measurements, which increases the diameter of the cylinder and the physical size of the whole system. As shown in FIG. 3, an approach utilising a nested or mask within a mask (or dual or multiple mask approach), where each mask body 35, 36 can move or be indexed by the computer 22 independently, enables far more measurements from the number of possible combinations of the two mask patterns. In a preferred embodiment the dual mask approach would consist of a cylinder within a cylinder (see FIG. 3). Each mask is rotated independently in the manner suggested for a single mask in FIG. 2 about a sensing axis or imaging axis along which a detector may be located. The large number of mask patterns (and therefore measurements) would allow for a more compact system (less total columns in one cylinder) that could image a 360° FOV. A similar argument for dual hemispherical and spherical mask designs can also be made. For the dual mask approach, the combined open fraction of the mask may approximate 50%, but there will be a variation in this as the masks are rotated. One mask may be indexed in rotation angle for a full revolution before the other mask is indexed by a single column, thus generating a number of virtual masks, being the number of columns squared. In other embodiments the masks are counter-rotated by one column in an alternating or non-alternating arrangement. Each virtual mask is used for a radiation measurement before the next mask is generated. Each mask need only rotate in one direction. The cross-sectional or projected shape of the mask apertures may include but not be limited to: square, rectangular, circular, triangular and hexagonal. There may or may not be separation between the mask apertures. In a preferred embodiment of a single mask system, the mask aperture shape is square. As shown in FIG. 4, for a dual mask embodiment the dimensions and orientation of the inner 30 and outer mask 31 may be different, such that they are tapered 32 (but aligned as to their edges) to produce the same FOV for both the inner and outer masks relative to the detector 33. The 3 dimensional shapes of these apertures 34 may include but not be limited to a trapezoidal prism and a cone. As shown in FIG. 5, the open apertures may be formed through the overlapping of continuous open structures, in the form of spiral lines 41 or some other structure on one mask and another shape such as a vertical slit 43 on the other mask. Rotation of the masks 42, 44 relative to one another produces a coded aperture. The mask pattern may be random, pseudo-random, non-random or deterministic in design. The mask pattern will typically be required to meet the defined conditions for compressed sensing to work. A representation of the mask pattern, in matrix form, will be used in the reconstruction process. The sensing matrix used in the reconstruction may be a Circulant or Toeplitz matrix, which may provide a faster computational time. In a preferred embodiment a pseudo-random mask pattern is generated where each mask element has an equal probability to be either 1 (open—100% transmission) or 0 (closed—0% transmission). The percentage transmission for a closed mask element should be some value less than 100%, for example, preferably 0% but a transmission of 50% will still be enough to effectively modulate the intensity to reconstruct an image. The percentage transmission relates to the increased penetrating nature of higher energy gamma-rays. For example, a closed mask element consisting of 10 mm lead may have 0% transmission for 60 keV gamma-ray photons, but its percentage transmission may be approximately 53% for 1332 keV gamma-ray photons. There will be a point where the transmission percentages for the open and closed apertures are too close together to modulate the photon intensity enough to reconstruct an image. As an example, transmission percentages of 100% and 90%, for open and closed apertures respectively, may be too close together for sufficient modulation in the photon intensity. There may be more than two levels of transmission within the mask for a given energy, for example, three levels of transmission may be 33%, 66% and 100%. Other levels of transmission may be 25%, 50%, 75% and 100% or 0.16%, 4% and 100%. In the latter example, the proximity of the two lower transmissions states will effectively cause the three levels of transmission to resemble two levels, potentially providing quicker reconstruction times, higher quality reconstruction and few measurements. The levels of transmission may cover two or more levels between 0% and 100%. The sensing matrix values may be the attenuation values for particular gamma-ray energies. Different attenuation values and therefore different sensing matrices may be used for reconstructions at different gamma-ray energies. As shown in FIG. 6, the mask pattern for any shape mask may be generated such that mask structure is self-supporting. For example, mask patterns with an array of floating or unattached “closed” elements 50 are fixed, adhered or attached to a non-masking substrate 51. Thus the radiation opaque mask elements 50 need not be attached to one another other than by the substrate 51. Alternatively, mask patterns with no floating or unattached “closed” elements 50 may be selected, which would not require a substrate 51, but would require the outer closed elements 50 to be attached to a common structure. As shown in FIGS. 7 to 9, the mask or masks may be hemispherical, spherical or a part of a sphere such as a cap above any given secant plane or optionally a segment between two planes. FIG. 7 shows two nested and concentric masks in the shape of spherical caps, an inner cap 61 and an outer cap 62, both being hemispheres with the rims (or lowest rows) of both in a common plane. One or both masks 61, 62 are rotated into data sampling positions wherein the columns 63, 64 and the rows of both are aligned or in registry when data is sampled or acquired. Both have the same number of columns and rows. Each row occupies a zone of a sphere between two parallel planes. In one example, the inner hemispherical mask 61 is indexed by one column in one direction and the outer mask 62 is indexed or rotated by an angle defined by a single column in the opposite direction, consistent with FIG. 3. Having both masks move simultaneously offers greater variability in which mask elements are open or closed when compared to having one mask stationary and the other mask moving. This arrangement allows for single detector coded mask imaging of the entire space above the plane that includes the rims 65, 66. FIGS. 8 and 9 illustrate the use of two masks or optionally two pairs of nested masks 71, 72 that are spherical and concentric. In this way, all of the space around the central detector or detectors can be imaged. Each spherical mask or mask pairing 71, 72 may be formed from 2 hemispherical masks or mask pairings as shown in FIG. 7. Each mask in the arrangement will have its own drive system comprising a turntable or stepper motor arrangement, driven by the system's computer 22 (see FIG. 2). Mask Geometrical Design The mask design will be dictated by the requirements of the radiological imaging application in question. The geometry of the system will influence the system performance such as spatial resolution, FOV and sensitivity. The geometrical parameters of importance include: the detector dimensions, the detector to mask distance, the aperture dimensions (i.e. thickness, length and width), the mask to source distance, the septal thickness, the number of mask apertures and the angle subtended from the centre of the detector and two neighboring mask apertures. For example, a smaller mask aperture will provide a higher spatial resolution. Reconstruction Algorithm There are a large number of reconstruction algorithms that have been used for compressed sensing. For example, there are gradient projection methods, iterative shrinkage/thresholding methods and matching pursuit methods (see R. M. Willett, R. F. Marcia and J. M. Nichols, Compressed Sensing for Practical Optical Imaging Systems: a Tutorial, Optical Engineering Vol. 50(7), July 2011). Any of these methods or some other appropriate method can be used for reconstructing the compressed sensing measurements. The ANSTO compressed sensing implementation used the Gradient Projection for Sparse Reconstruction (GPSR) algorithm (see M. A. Figueiredo, R. D. Nowak, S. J. Wright, Gradient Projection for Sparse Reconstruction: Application to Compressed Sensing and Other Inverse Problems, Journal of Selected Topics in Signal Processing, December 2007). Image Fusion The gamma-ray image that is generated after the compressed sensing measurements may be overlayed with an optical image that is registered to the same field of view. The neutron image may be overlayed with an optical image. The overlayed radiation images with an optical image will help the user to visualise the location of the radiation sources. The radiation images may be overlayed with images at any other wavelengths (e.g. infrared). Method As shown in FIG. 10, a source emits radiation 80. That radiation 80 passes through a mask or masks 81 as previously disclosed. The system's computer 22 causes the detector 10 to operate or takes a reading from an operating detector 82. The detector then transmits a measured value 83 to the computer 22. The computer saves and uses the value and the positioning of the mask or masks to compile data that will be reconstructed into an image. The computer then causes the motor or motors controlling the mask or masks to rotate or index to the next measurement position. Radiation then passes through, in effect, a new mask or mask orientation 81 as the process is repeated. Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. Reference throughout this specification to “one embodiment” or “an embodiment” or “example” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an example” in various places throughout this specification are not necessarily all referring to the same embodiment or example, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. Similarly it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Any claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining” or the like, refer to the action and/or processes of a microprocessor, controller or computing system, or similar electronic computing or signal processing devices, that manipulates and/or transforms data. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. While the present invention has been disclosed with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope or spirit of the invention.
	abstract	A repair device for underwater repair of a hole in a nuclear reactor part includes a holder (32), a cutting tool (22) held by the holder (32) and having at least one cutting tooth (70) for remachining an inner surface of the hole. The cutting tool (22) has a suction channel (44) extending into the cutting tool (22) between at least one inlet opening (46) and at least one outlet opening (48), a drive shaft (34) for rotating the cutting tool (22), the drive shaft (34) being held by the holder (32), and a suction tube (36) connected to the holder (32) and fluidly connected to the outlet opening (48) of the suction channel (44).
	summary
	summary
	description	The present invention concerns a nuclear reactor, in particular a nuclear reactor consisting of several fuel elements characterized by an expansion system which, as the temperature increases, spaces the top of relative active parts characterized by a system of constraints and rigidities of relative component parts, such as to make said spacing mechanically possible. In the particular case of fast reactors cooled by using liquid metals as a primary coolant, the reactivity of the core is closely linked to the geometry: the reactivity increases if the core is compacted and decreases if the core expands. Also in the choice of materials, their capacity to expand with temperature is normally taken into account to enhance the effects of neutron counter-reactions. The use of bimetallic elements arranged parallel to the axis of the fuel element to amplify arching of the same in a predetermined direction as the temperature increases is known in particular from GB1176646A. However, a device of this type has the drawback that also during assembly the direction of the fuel element in the core established at the design stage must be observed (so that, in use, the arching does not occur in the opposite direction to the one desired: an assembly error therefore produces the opposite result to the one desired); furthermore, rotations of the fuel element are not permitted, whereas rotations are often performed during fuel replacement operations (refueling) to minimize arching of the fuel element due to the different neutron damage of two opposite parts of the element. It is also important for the fuel elements to be loaded in the core without leaving space between them in order to prevent them moving closer together, resulting in uncontrolled increase in reactivity during operation. On the other hand it is known that, during operation of the reactor, the fuel is subject to deformations and swelling which can make refueling problematic if the fuel elements are not assembled with a minimum distance from one another. In the design of the core it is therefore necessary to seek the best compromise between two opposite needs. One object of the present invention is to provide a nuclear reactor that overcomes the drawbacks highlighted of the known solutions and has further construction and safety advantages. The present invention therefore concerns a nuclear reactor, as defined in the attached claim 1, with its ancillary characteristics and plant configurations defined in the dependent claims. With reference to FIG. 1, which shows in particular a nuclear reactor 1 of the pool type cooled by liquid metal or molten salts, the nuclear reactor 1 comprises a vessel 2 which is substantially cup- or pool-shaped and a closing structure 3 positioned above the vessel 2; the vessel 2 contains a core 4 and a hydraulic separation structure 5 delimiting a hot manifold 6 and a cold manifold 7 in which a primary cooling fluid F circulates for cooling the core 4. The primary fluid F has a free surface which in normal operation of the reactor 1 is at different levels H1, H2 in the manifolds 6,7. Inside the vessel 2, circulation pumps 8 are housed for circulating the primary fluid F, heat exchangers 9, through which the primary fluid F flows to transfer the power generated in the core 4 to a secondary fluid, and other components which are known and not illustrated. The hydraulic separation structure 5 preferably has an amphoralike shape, according to the solution known from patent application GE2015A000036, and is suspended from the closure structure 3 of the vessel 2. With reference also to FIGS. 2 and 3, inside the upper part of the hydraulic separation structure 5 an anchoring structure 11 is inserted for anchoring the fuel elements 12. The fuel elements 12 extend along respective parallel longitudinal axes A and have respective active parts 13 and respective service parts 14 which comprise a foot 15 and a head 16 at the bottom and top respectively of the fuel element (i.e. located at a lower axial end and at an upper axial end of the fuel element 12 respectively) and a connection shaft 17 between the active part 13 and the head 16. The shaft 17 is provided with a certain mechanical flexibility and an upper portion 18 thereof is inserted in an empty cylindrical volume inside the head 16 of the fuel element 4. Said upper portion 18 is mechanically coupled with the head 16 by means of a spherical coupling 19 not described in detail, since it is known in the art, positioned at its upper end. The feet 15 of the fuel elements 12 are in contact with one another and, as a whole, constitute a pack radially constrained by means of the inner rim 20 of the opening 21 on the bottom of the hydraulic separation structure 5. On the head 16 of the fuel element 12, near two opposite edges of the hexagonal section of the head 16, support devices 22 are housed, in particular two vertical support devices 23 and two horizontal support devices 24 near further two opposite edges of the head 16. The vertical support devices 23 consist of a substantially cylindrical main body 25 with the bottom end connected by means of a pin 26 to a vertically locking hollow cylindrical element 27. The main body 25 of the support element terminates at the top in a hexagonal head 28 and comprises a latch 29. The vertical support devices 23 can rotate by approximately 90° around their own axis B, to switch from a closed position 30 in which their projection on a horizontal plane is contained entirely within the projection 31 of the head 16 of respective fuel elements 12, to an open position 32, represented by all the other vertical support devices 23 of FIG. 3, in which the latch 29 protrudes from the projection 31 of the head 16 of respective fuel elements 12 to bring the terminal part 33 above the adjacent fuel element 12 or, limited only to the peripheral devices of the peripheral fuel elements 12 of the core, to engage in a slot 34 obtained on the anchoring structure 11 of the fuel elements 12. The vertical support devices 23 belonging to the fuel element 12 in the opening position 32 prevent downward movement of said fuel element 12 which, with said latches 29 open, rests on the adjacent fuel elements 12. The vertical support devices 23 which from adjacent fuel elements 12 project above a certain fuel element 12 prevent the upward movement of said fuel element 12. With all the support devices 23 in the open position, the core 4 becomes one single block where no fuel element 12 can move up or down with respect to the others. The vertical support devices 23, which are in a peripheral position of the core and in an open position and which engage the slots 34 of the anchoring structure 11 of the fuel elements 12, furthermore prevent vertical movements of the entire core 4. The horizontal support devices 24 are also substantially cylindrical in shape and characterized by at least two cams 35 and can rotate more than 90° around their own axis C, from a closed position 36 in which their projection on a horizontal plane is contained entirely within the projection 31 of the head 16 of the respective fuel element 12, to an open position 37, represented by all the other horizontal support devices 24 of FIG. 3, in which the cam 35 protrudes from said projection 31 to bring a terminal part thereof 38 beyond the gap 39 between the heads 16 of the fuel elements 12, until contact is established with two heads 16, in particular with one of their respective faces 40 or, limited only to the peripheral fuel elements 12, contact with the anchoring structure 11 of the fuel elements 12. The vertical support devices 23 perform the function already described of vertical constraint of the fuel elements, while the horizontal support devices 24 perform, as a whole, the function of radial constraint of the heads 16 of the fuel elements when a gap 39 is provided between them. With all the support devices 22 in the open position, the core becomes one single block vertically and radially anchored to the anchoring structure 11. With reference to FIG. 4, extraction of a generic internal fuel element 41 of the core can be performed: (i) after closing the two vertical support devices 42a and 42b belonging to adjacent fuel elements, (ii) after closing the two horizontal support devices 43a and 43b belonging to the same fuel element 41 and (iii) after closing the four horizontal support devices 44a, 44b, 44c, 44d belonging to four adjacent elements. Extraction of a generic external fuel element 45 of the core can be performed (i) after closing a vertical support device 46 belonging to an adjacent element, (ii) closing its vertical support device 47 which engages in the groove 34 obtained on the anchoring structure 11 of the fuel elements 12, (iii) after closing the two horizontal support devices 48a and 48b belonging to the same fuel element 45 and (iv) after closing the two horizontal support devices 49a, 49b belonging to two adjacent elements. The rotation limits for closing and opening the horizontal support devices 24 can be determined by the shape of the slots 34 occupied by the latches on the head 16 of the elements 12. Opening and closing of the support devices 22 can be performed by acting on the hexagonal head 28 via the gripper of the fuel transfer machine or by means of an appropriate device or remote manipulator not illustrated being known in the art. By an analogous extraction and insertion procedure it is also possible to rotate the fuel element by 180°. What is described for the fuel element support can be applied to other components inserted in the core such as the control rods. With reference to FIGS. 1, 5a, 5b, 6a and 6b on the shaft 17 of the fuel elements 12, expanders 50 are applied characterized by an increased radial expansion capacity with the temperature, an embodiment example of which is given in FIGS. 5a, 5b. Each shaft 17, i.e. each fuel element 12, is provided with a plurality of expanders 50 (in the example shown, six expanders 50) positioned radially around the shaft 17 and angularly (circumferentially) spaced around the shaft 17, i.e. around the axis A of the corresponding fuel element 12, with axial-symmetric arrangement with respect to the axis A. Each expander 50 projects radially from the shaft 17; in the example shown, each expander 50 has a development perpendicular to a respective face 40 of the fuel element 12. Each expander 50, which for improved structural performance is symmetrical with respect to a middle plane a perpendicular to the shaft 17 and to the axis A, comprises a plurality of low thermal expansion elements 51, made of zircaloy for example, substantially Z-shaped, and a plurality of high thermal expansion elements 52, made of Mn72Cu18Ni10 alloy for example, substantially in the shape of a parallelepiped. The low thermal expansion elements 51 and the high thermal expansion elements 52 are alternated axially along the shaft 17 (i.e. parallel to the axis A): each element 52 is axially interposed between two axially adjacent elements 51. The elements 51 have a thermal expansion coefficient lower than the elements 52. In other words, the elements 51 are made of a first material having a first thermal expansion coefficient and the elements 52 are made of a second material having a second thermal expansion coefficient, greater than the first thermal expansion coefficient. Each expander 50 also comprises a terminal closing element 53, also made of material with a high thermal expansion coefficient; the element 53, having a U shape for example, covers the elements 51, 52 and has two (or more) bolts 54 (or other fastening members) which axially secure the various elements 51, 52 of the expander 50 and prevent disassembly thereof due to radial displacements away from the shaft 17. The terminal element 53 projects radially outside the elements 51, 52. The shaft 17 is provided, for each expander 50, with a radial extension 55 which projects radially from the shaft 17 and has a radially external end (opposite a radially internal end, joined to the shaft 17) which engages a radially external terminal part 56, axially bent, of the low thermal expansion element 51, the latter being axially more internal (i.e. nearer to the middle plane a and to the radial extension 55); on a radially internal end of said element, a first high thermal expansion element 52 engages, having a radially external end which in turn engages the radially external terminal part 56 of a second element 51, and so on. Following an increase in temperature, the high thermal expansion elements 52 elongate more than the low thermal expansion element 51 nearer the plane of symmetry α giving rise to a differential radial displacement of the radial end of the high thermal expansion elements 52; said displacement accumulates for each pair of elements 51, 52 until resulting in a radial displacement ε. The bolts 54 engage with precision in the closing elements 53, whereas to allow radial expansion of the expander 50, they engage with the other elements 51, 52 and with the radial extension 55 with gradually increasing play as they approach the plane of symmetry α. The elastic element 57, inserted in a groove of the radial extension 55 and acting on a bolt 54, allows radial compacting of the expander 50 as the temperature decreases also in the absence of forcing on the part of adjacent elements. When cold, the expanders are mounted so as to maintain their projection within the horizontal projection of the outline of the fuel elements 12 and protrude from said projection only when, at high temperature, they are required to function. In operating conditions of the reactor, the heads 16 of the fuel elements are practically isothermal with the support structure 11 because they are immersed in the reactor covering gas 58 above the free levels H1, H2 of the primary coolant of the reactor inside the vessel 2 and therefore always maintained rigidly in position. The feet 15 of the fuel elements are at the temperature of the cold manifold 7 and at the same temperature as the inner rim 20 of the opening 21 of the hydraulic separation structure 5 and therefore they can be mounted with narrow tolerances, eliminating the play due also to the structural elasticity of the feet 15. The assembly play is minimized also at the upper grid 59 supporting the fuel rods 60. The fuel element is therefore always radially secured on the head at the top and on the foot at the bottom and is free to thermally expand downwards. As the power increases, the fuel element expands radially more at the grid 59 than at the foot 15. Said differential expansion accumulates from the centre towards the outside of the core and is made possible (i) by the rotation of the foot 15 around its radial constraints consisting of the point of contact 61 with the feet 15 of the adjacent elements and/or with the inner rim 20 of the opening 21, (ii) by the rotation of the shaft 17 of the fuel element 12 with respect to the head 16 by means of the spherical coupling 19, (iii) by the inflexion of the shaft 17. The fuel elements 12 are mounted alongside the grid 59 (FIG. 6a) and remain positioned alongside said grid 59 also during normal operation of the reactor, with expanders 50 spaced, whereas in an accident situation, when a predetermined temperature is exceeded, the greater radial expansion of the expanders 50 interlocks them (FIG. 6b) and amplifies the radial expansion of the core by a predetermined value δ according to the temperature. In short, the core 4 expands by means of rotation of the feet 15 of the fuel elements 12, positioned at respective lower axial ends of the fuel elements 12, while the heads 16 of the fuel elements 12, positioned at respective upper axial ends of the fuel elements 12, remain substantially stationary. Since the core must never be radially slack, the intervention on the expanders 50 must always be countered by elastic elements that re-set the core to a compact configuration when cooling terminates the intervention of the expanders 50; in the example indicated, the elastic element consists of the shaft 17 of the fuel element 12. With reference in particular to FIGS. 7 and 8, an example is shown of application of extenders 50 to rigid fuel elements anchored at the bottom on a grid not shown since it is a known solution. The heads 16 of the fuel elements are radially constrained by flexible containing elements 62 containing the core connected to the closing structure 3. When the heads 16 of the fuel elements 12 are spaced from one another by thermal expansion of the expanders 50, the flexible elements 62 continue to radially clamp the core 4, preventing vibration. With a rigid fuel element 12, the radial elastic element can be obtained also according to other construction solutions, for example flexible containing elements containing the core 4 connected to the bottom part of the hydraulic separation structure 5 or elastic return elements interposed between said heads 16 of the fuel elements 12, not described in detail in view of the plurality of possible embodiments. From the above, the advantages of the present invention are evident. The expanders 50 which, in normal reactor operating conditions do not engage with each other and do not alter the normal temperature counter reactions of the core, but which when the core output temperature exceeds a predetermined reference value amplify the radial expansion of the core and the associated negative counter-reaction of the reactivity, introduce an important safety factor into the design of the core. Given their geometry and axial-symmetric operation, the expanders do not have a predetermined direction to be observed in the assembly phase, nor do they preclude the possibility of rotation of the fuel element during the refueling phases. The flexible elements 17, 62 provided to permit expansion of the core also allow elimination of the play between fuel elements 12 to maintain the core 4 compact and eliminate the risks of vibration with associated variations in reactivity. Refueling is facilitated by the presence of flexible elements 17, 62. The presence of releasable horizontal support devices 24 allows advantageous use of the play between the heads of the fuel elements during refueling operations.
	abstract	An automatic reloading and transport system for solid targets for a particle accelerator using a pneumatic tube transport system from the point of target activation by a particle accelerator to a target processing point and back, comprising a pneumatic tube transport system with end stations for receipt and dispatch of a capsule accommodating the target, a handling mechanism for both manipulating the solid target and handling the capsule and a target positioning system.
	description	This application: 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; U.S. provisional patent application No. 61/137,574 filed Aug. 1, 2008; U.S. provisional patent application No. 61/192,245 filed Sep. 17, 2008; U.S. provisional patent application No. 61/055,409 filed May 22, 2008; U.S. provisional patent application No. 61/203,308 filed Dec. 22, 2008; U.S. provisional patent application No. 61/188,407 filed Aug. 11, 2008; U.S. provisional patent application No. 61/188,406 filed Aug. 11, 2008; U.S. provisional patent application No. 61/189,815 filed Aug. 25, 2008; U.S. provisional patent application No. 61/201,731 filed Dec. 15, 2008; U.S. provisional patent application No. 61/205,362 filed Jan. 12, 2009; U.S. provisional patent application No. 61/134,717 filed Jul. 14, 2008; U.S. provisional patent application No. 61/134,707 filed Jul. 14, 2008, now U.S. Pat. No. 7,940,894 B2; U.S. provisional patent application No. 61/201,732 filed Dec. 15, 2008, now U.S. Pat. No. 7,953,205 B2; U.S. provisional patent application No. 61/198,509 filed Nov. 7, 2008; U.S. provisional patent application No. 61/134,718 filed Jul. 14, 2008; U.S. provisional patent application No. 61/190,613 filed Sep. 2, 2008; U.S. provisional patent application No. 61/191,043 filed Sep. 8, 2008; U.S. provisional patent application No. 61/192,237 filed Sep. 17, 2008; U.S. provisional patent application No. 61/201,728 filed Dec. 15, 2008; U.S. provisional patent application No. 61/190,546 filed Sep. 2, 2008; U.S. provisional patent application No. 61/189,017 filed Aug. 15, 2008; U.S. provisional patent application No. 61/198,248 filed Nov. 5, 2008, now U.S. Pat. No. 7,943,913 B2; U.S. provisional patent application No. 61/198,508 filed Nov. 7, 2008; U.S. provisional patent application No. 61/197,971 filed Nov. 3, 2008; U.S. provisional patent application No. 61/199,405 filed Nov. 17, 2008; U.S. provisional patent application No. 61/199,403 filed Nov. 17, 2008; and U.S. provisional patent application No. 61/199,404 filed Nov. 17, 2008; is a continuation-in-part of U.S. patent application Ser. No. 12/687,387 filed Jan. 14, 2010, which is a continuation-in-part of U.S. patent application Ser. No. 12/425,683 filed Apr. 17, 2009; claims the benefit of U.S. provisional patent application no. 61/209,529 filed Mar. 9, 2009; claims the benefit of U.S. provisional patent application No. 61/208,182 filed Feb. 23, 2009; claims the benefit of U.S. provisional patent application No. 61/208,971 filed Mar. 3, 2009; and claims the benefit of U.S. provisional patent application No. 61/270,298, filed Jul. 7, 2009; 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. 61/308,621, filed Feb. 26, 2010; claims the benefit of U.S. provisional patent application No. 61/309,651, filed Mar. 2, 2010; and claims the benefit of U.S. provisional patent application No. 61/324,776, filed Apr. 16, 2010; claims the benefit of U.S. provisional patent application No. 61/936,100 filed Feb. 5, 2014; claims the benefit of U.S. provisional patent application No. 61/937,312 filed Feb. 7, 2014; claims the benefit of U.S. provisional patent application No. 61/937,325 filed Feb. 7, 2014; claims the benefit of U.S. provisional patent application No. 61/941,968 filed Feb. 19, 2014; claims the benefit of U.S. provisional patent application No. 61/947,072 filed Mar. 3, 2014; claims the benefit of U.S. provisional patent application No. 61/948,301 filed Mar. 5, 2014; and claims the benefit of U.S. provisional patent application No. 61/948,335 filed Mar. 5, 2014, 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 a cancer therapy method and apparatus for reducing toxins created in ablation of a tumor with charged particles by sealing a surface of the tumor without direct ablation of the bulk of the tumor. 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. Synchrotron 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. Problem There exists in the art a need to reduce the amount of toxins produced in the charged particle irradiation therapy/ablation of tumors. The invention comprises a cancer therapy method and apparatus for reducing toxins created in ablation of a tumor with charged particles by sealing a surface of the tumor without direct ablation of the bulk of the tumor. 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 comprises a method and apparatus used to seal the periphery of a tumor. In one embodiment, a charged particle cancer therapy system is used to seal the periphery of a tumor, which restricts and/or eliminates the ability for the body to deliver sufficient nutrients to the tumor, which restricts further tumor growth and ultimately leads to death of the tumor. The tumor is sealed using a scanning charged particle beam, such as a proton or carbon ion beam. Preferably, the charged particle beam delivers searing energy to adjacent, overlapping, pencil-beam scanned, overlaid, and/or interwoven treatment volumes along the tumor/healthy tissue interface. Used in combination with the invention, novel design features of a charged particle beam cancer therapy system are described. Particularly, a negative ion beam source with novel features in the negative ion source, ion source vacuum system, ion beam focusing lens, and tandem accelerator is described. Additionally, the synchrotron includes: turning magnets, edge focusing magnets, magnetic field concentration magnets, winding and correction coils, flat magnetic field incident surfaces, and extraction elements, which minimize the overall size of the synchrotron, provide a tightly controlled proton beam, directly reduce the size of required magnetic fields, directly reduce required operating power, and allow continual acceleration of protons in a synchrotron even during a process of extracting protons from the synchrotron. The ion beam source system and synchrotron are preferably computer integrated with a patient imaging system and a patient interface including respiration monitoring sensors and patient positioning elements. Further, the system is integrated with intensity control of a charged particle beam, acceleration, extraction, and/or targeting method and apparatus. More particularly, intensity, energy, and timing control of a charged particle stream of a synchrotron is coordinated with patient positioning and tumor treatment. The synchrotron control elements allow tight control of the charged particle beam, which compliments the tight control of patient positioning to yield efficient treatment of a solid tumor with reduced tissue damage to surrounding healthy tissue. In addition, the system reduces the overall size of the synchrotron, provides a tightly controlled proton beam, directly reduces the size of required magnetic fields, directly reduces required operating power, and allows continual acceleration of protons in a synchrotron even during a process of extracting protons from the synchrotron. All of these systems are preferably used in conjunction with an X-ray system capable of collecting X-rays of a patient: (1) in a positioning, immobilization, and automated repositioning system for proton treatment; (2) at a specified moment of the patient's respiration cycle; and (3) using coordinated translation and rotation of the patient. Combined, the systems provide for efficient, accurate, and precise noninvasive tumor treatment with minimal damage to surrounding healthy tissue. In various embodiments, the charged particle cancer therapy system incorporates any of: an injection system having a central magnetic member and a magnetic field separating high and low temperature plasma regions; a dual vacuum system creating a first partial pressure region on a plasma generation system side of a foil in a tandem accelerator and a second lower partial pressure region on the synchrotron side of the foil; a negative ion beam focusing system having a conductive mesh axially crossing the negative ion beam; a synchrotron having four straight sections and four turning sections; a synchrotron having no hexapole magnets; four bending magnets in each turning section of the synchrotron; a winding coil wrapping multiple bending magnets; a plurality of bending magnets that are beveled and charged particle focusing in each turning section; a magnetic field concentrating geometry approaching the gap through which the charged particles travel; correction coils for rapid magnetic field changes; magnetic field feedback sensors providing signal to the correction coils; integrated RF-amplifier microcircuits providing currents through loops about accelerating coils; a low density foil for charged particle extraction; a feedback sensor for measuring particle extraction allowing intensity control; a synchrotron independently controlling charged particle energy and intensity; a layer, after synchrotron extraction and before the tumor, for imaging the particle beam x-, y-axis position; a rotatable platform for turning the subject allowing multi-field imaging and/or multi-field proton therapy; a radiation plan dispersing ingress Bragg profile energy 360 degrees about the tumor; a long lifetime X-ray source; an X-ray source proximate the charged particle beam path; a multi-field X-ray system; positioning, immobilizing, and repositioning systems; respiratory sensors; simultaneous and independent control of: x-axis beam control; y-axis beam control; irradiation beam energy; irradiation beam intensity; patient translation; and/or patient rotation; and a system timing charged particle therapy to one or more of: patient translation; patient rotation; and patient respiration. In another embodiment, safety systems for a charged particle system are implemented. For example, the safety system includes any of: multiple X-ray images from multiple directions, a three-dimensional X-ray image, a proton beam approximating a path of an X-ray beam, tight control of a proton beam cross-sectional area with magnets, ability to control proton beam energy, ability to control proton beam energy, a set of patient movement constrains, a patient controlled charged particle interrupt system, distribution of radiation around a tumor, and timed irradiation in terms of respiration. In yet another embodiment, the tumor is imaged from multiple directions in phase with patient respiration. For example, a plurality of two-dimensional pictures are collected that are all in the about the same phase of respiration. The two-dimensional pictures are combined to produce a three-dimensional picture of the tumor relative to the patient. One or more safety features are optionally used in the charged particle cancer therapy system independently and/or in combination with the three-dimensional imaging system, as described infra. In still yet another embodiment, the system independently controls patient translation position, patient rotation position, two-dimensional beam trajectory, delivered radiation beam energy, delivered radiation beam intensity, timing of charged particle delivery, beam velocity, 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. 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. Any of the techniques described herein are equally applicable to any charged particle beam system. Referring now to FIG. 1, 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 extraction system 134; 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 then 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. 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 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 the plane of the synchrotron 130. The focused protons having an initial energy are introduced into an injector magnet 240, which is preferably an injection Lambertson 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 the inflector/deflector system 290 is used in combination with a Lambertson extraction magnet 292 to remove protons from their circulating beam path 264 within the synchrotron 130. One example of a deflector component is a Lambertson 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 transport path 268 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 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. Each of the above listed elements are further described, infra. Ion Beam Generation System An ion beam generation system generates a negative ion beam, such as a hydrogen anion or H− beam; preferably focuses the negative ion beam; converts the negative ion beam to a positively charged ion beam, such as a proton, H+, carbon ion, and/or C6+ cation beam; and injects the positive ion beam 262 into the synchrotron 130. Portions of the ion beam path are preferably under partial vacuum. Each of these systems are further described, infra. Referring now to FIG. 3, an exemplary ion beam generation system 300 is illustrated. As illustrated, the ion beam generation system 300 has four major subsections: a negative ion source 310, a first partial vacuum system 330, an optional ion beam focusing system 350, and a tandem accelerator 390. Still referring to FIG. 3, the negative ion source 310 preferably includes an inlet port 312 for injection of hydrogen gas into a high temperature plasma chamber 314. In one embodiment, the plasma chamber includes a magnetic material 316, which provides a magnetic field 317 between the high temperature plasma chamber 314 and a low temperature plasma region on the opposite side of the magnetic field barrier. An extraction pulse is applied to a negative ion extraction electrode 318 to pull the negative ion beam into a negative ion beam path 319, which proceeds through the first partial vacuum system 330, through the ion beam focusing system 350, and into the tandem accelerator 390. Still referring to FIG. 3, the first partial vacuum system 330 is an enclosed system running from the hydrogen gas inlet port 312 to a foil 395 in the tandem accelerator 390. The foil 395 is preferably sealed directly or indirectly to the edges of the vacuum tube 320 providing for a higher pressure, such as about 10−5 torr, to be maintained on the first partial vacuum system side of the foil 395 and a lower pressure, such as about 10−7 torr, to be maintained on the synchrotron side of the foil. By only pumping first partial vacuum system 330 and by only semi-continuously operating the ion beam source vacuum based on sensor readings, the lifetime of the semi-continuously operating pump is extended. The sensor readings are further described, infra. Still referring to FIG. 3, the first partial vacuum system 330 preferably includes: a first pump 332, such as a continuously operating pump and/or a turbo molecular pump; a large holding volume 334; and a semi-continuously operating pump 336. Preferably, a pump controller 340 receives a signal from a pressure sensor 342 monitoring pressure in the large holding volume 334. Upon a signal representative of a sufficient pressure in the large holding volume 334, the pump controller 340 instructs an actuator 345 to open a valve 346 between the large holding volume and the semi-continuously operating pump 336 and instructs the semi-continuously operating pump to turn on and pump to atmosphere residual gases out of the vacuum line 320 about the charged particle stream. In this fashion, the lifetime of the semi-continuously operating pump is extended by only operating semi-continuously and as needed. In one example, the semi-continuously operating pump 336 operates for a few minutes every few hours, such as 5 minutes every 4 hours, thereby extending a pump with a lifetime of about 2,000 hours to about 96,000 hours. Further, by isolating the inlet gas from the synchrotron vacuum system, the synchrotron vacuum pumps, such as turbo molecular pumps can operate over a longer lifetime as the synchrotron vacuum pumps have fewer gas molecules to deal with. For example, the inlet gas is primarily hydrogen gas but may contain impurities, such as nitrogen and carbon dioxide. By isolating the inlet gases in the negative ion source system 310, first partial vacuum system 330, ion beam focusing system 350, and negative ion beam side of the tandem accelerator 390, the synchrotron vacuum pumps can operate at lower pressures with longer lifetimes, which increases operating efficiency of the synchrotron 130. Still referring to FIG. 3, the optimal ion beam focusing system 350 preferably includes two or more electrodes where one electrode of each electrode pair partially obstructs the ion beam path with conductive paths 372, such as a conductive mesh. In the illustrated example, two ion beam focusing system sections are illustrated, a two electrode ion beam focusing section 360 and a three electrode ion beam focusing section 370. For a given electrode pair, electric field lines, running between the conductive mesh of a first electrode and a second electrode, provide inward forces focusing the negative ion beam. Multiple such electrode pairs provide multiple negative ion beam focusing regions. Preferably the two electrode ion focusing section 360 and the three electrode ion focusing section 370 are placed after the negative ion source and before the tandem accelerator and/or cover a space of about 0.5, 1, or 2 meters along the ion beam path 319. Ion beam focusing systems are further described, infra. Still referring to FIG. 3, the tandem accelerator 390 preferably includes a foil 395, such as a carbon foil. The negative ions in the negative ion beam path 319 are converted to positive ions, such as protons, and the initial ion beam path 262 results. The foil 395 is preferably sealed directly or indirectly to the edges of the vacuum tube 320 providing for a higher pressure, such as about 10−5 torr, to be maintained on the side of the foil 395 having the negative ion beam path 319 and a lower pressure, such as about 10−7 torr, to be maintained on the side of the foil 390 having the proton ion beam path 262. Having the foil 395 physically separating the vacuum chamber 320 into two pressure regions allows for a system having fewer and/or smaller pumps to maintain the lower pressure system in the synchrotron 130 as the inlet hydrogen and its residuals are extracted in a separate contained and isolated space by the first partial vacuum system 330. Negative Ion Source An example of the negative ion source 310 is further described herein. Referring now to FIG. 4, a cross-section of an exemplary negative ion source system 400 is provided. The negative ion beam 319 is created in multiple stages. During a first stage, hydrogen gas is injected into a chamber. During a second stage, a negative ion is created by application of a first high voltage pulse, which creates a plasma about the hydrogen gas to create negative ions. During a third stage, a magnetic field filter is applied to components of the plasma. During a fourth stage, the negative ions are extracted from a low temperature plasma region, on the opposite side of the magnetic field barrier, by application of a second high voltage pulse. Each of the four stages are further described, infra. While the chamber is illustrated as a cross-section of a cylinder, the cylinder is exemplary only and any geometry applies to the magnetic loop containment walls, described infra. In the first stage, hydrogen gas 440 is injected through the inlet port 312 into a high temperature plasma region 490. The injection port 312 is open for a short period of time, such as less than about 1, 5, or 10 microseconds to minimize vacuum pump requirements to maintain vacuum chamber 320 requirements. The high temperature plasma region is maintained at reduced pressure by the partial vacuum system 330. The injection of the hydrogen gas is optionally controlled by the main controller 110, which is responsive to imaging system 170 information and patient interface module 150 information, such as patient positioning and period in a respiration cycle. In the second stage, a high temperature plasma region is created by applying a first high voltage pulse across a first electrode 422 and a second electrode 424. For example a 5 kV pulse is applied for about 20 microseconds with 5 kV at the second electrode 424 and about 0 kV applied at the first electrode 422. Hydrogen in the chamber is broken, in the high temperature plasma region 490, into component parts, such as any of: atomic hydrogen, H0, a proton, H+, an electron, e−, and a hydrogen anion, H−. In the third stage, the high temperature plasma region 490 is at least partially separated from a low temperature plasma region 492 by the magnetic field 317 or in this specific example a magnetic field barrier 430. High energy electrons are restricted from passing through the magnetic field barrier 430. In this manner, the magnetic field barrier 430 acts as a filter between, zone A and zone B, in the negative ion source. Preferably, a central magnetic material 410, which is an example of the magnetic material 316, is placed within the high temperature plasma region 490, such as along a central axis of the high temperature plasma region 490. Preferably, the first electrode 422 and second electrode 424 are composed of magnetic materials, such as iron. Preferably, the outer walls 450 of the high temperature plasma region, such as cylinder walls, are composed of a magnetic material, such as a permanent magnet, ferric or iron based material, or a ferrite dielectric ring magnet. In this manner a magnetic field loop is created by: the central magnetic material 410, first electrode 422, the outer walls 450, the second electrode 424, and the magnetic field barrier 430. Again, the magnetic field barrier 430 restricts high energy electrons from passing through the magnetic field barrier 430. Low energy electrons interact with atomic hydrogen, H0, to create a hydrogen anion, H−, in the low temperature plasma region 492. In the fourth stage, a second high voltage pulse or extraction pulse is applied at a third electrode 426. The second high voltage pulse is preferentially applied during the later period of application of the first high voltage pulse. For example, an extraction pulse of about 25 kV is applied for about the last 5 microseconds of the first creation pulse of about 20 microseconds. The potential difference, of about 20 kV, between the third electrode 426 and second electrode 424 extracts the negative ion, H−, from the low temperature plasma region 492 and initiates the negative ion beam 319, from zone B to zone C. The magnetic field barrier 430 is optionally created in number of ways. An example of creation of the magnetic field barrier 430 using coils is provided. In this example, the elements described, supra, in relation to FIG. 4 are maintained with several differences. First, the magnetic field is created using coils. An isolating material is preferably provided between the first electrode 422 and the cylinder walls 450 as well as between the second electrode 424 and the cylinder walls 450. The central material 410 and/or cylinder walls 450 are optionally metallic. In this manner, the coils create a magnetic field loop through the first electrode 422, isolating material, outer walls 450, second electrode 424, magnetic field barrier 430, and the central material 410. Essentially, the coils generate a magnetic field in place of production of the magnetic field by the magnetic material 410. The magnetic field barrier 430 operates as described, supra. Generally, any manner that creates the magnetic field barrier 430 between the high temperature plasma region 490 and low temperature plasma region 492 is functionally applicable to the ion beam extraction system 400, described herein. Ion Beam Focusing System Referring now to FIG. 5, the ion beam focusing system 350 is further described. In this example, three electrodes are used. In this example, a first electrode 510 and third electrode 530 are both negatively charged and each is a ring electrode circumferentially enclosing or at least partially enclosing the negative ion beam path 319. A second electrode 520 is positively charged and is also a ring electrode at least partially and preferably substantially circumferentially enclosing the negative ion beam path. In addition, the second electrode includes one or more conducting paths 372 running through the negative ion beam path 319. For example, the conducting paths are a wire mesh, a conducting grid, or a series of substantially parallel conducting lines running across the second electrode. In use, electric field lines run from the conducting paths of the positively charged electrode to the negatively charged electrodes. For example, in use the electric field lines 540 run from the conducting paths 372 in the negative ion beam path 319 to the negatively charged electrodes 510, 530. Two ray trace lines 550, 560 of the negative ion beam path are used to illustrate focusing forces. In the first ray trace line 550, the negative ion beam encounters a first electric field line at point M. Negatively charged ions in the negative ion beam 550 encounter forces running up the electric field line 572, illustrated with an x-axis component vector 571. The x-axis component force vectors 571 alters the trajectory of the first ray trace line to a inward focused vector 552, which encounters a second electric field line at point N. Again, the negative ion beam 552 encounters forces running up the electric field line 574, illustrated as having an inward force vector with an x-axis component 573, which alters the inward focused vector 552 to a more inward focused vector 554. Similarly, in the second ray trace line 560, the negative ion beam encounters a first electric field line at point O. Negatively charged ions in the negative ion beam encounter forces running up the electric field line 576, illustrated as having a force vector with an x-axis force 575. The inward force vector 575 alters the trajectory of the second ray trace line 560 to an inward focused vector 562, which encounters a second electric field line at point P. Again, the negative ion beam encounters forces running up the electric field line 578, illustrated as having force vector with an x-axis component 577, which alters the inward focused vector 562 to a more inward focused vector 564. The net result is a focusing effect on the negative ion beam. Each of the force vectors 572, 574, 576, 578 optionally has x and/or y force vector components resulting in a 3-dimensional focusing of the negative ion beam path. Naturally, the force vectors are illustrative in nature, many electric field lines are encountered, and the focusing effect is observed at each encounter resulting in integral focusing. The example is used to illustrate the focusing effect. Still referring to FIG. 5, optionally any number of electrodes are used, such as 2, 3, 4, 5, 6, 7, 8, or 9 electrodes, to focus the negative ion beam path where every other electrode, in a given focusing section, is either positively or negatively charged. For example, three focusing sections are optionally used. In the first ion focusing section 360, a pair of electrodes is used where the first electrode encountered along the negative ion beam path is negatively charged and the second electrode is positively charged, resulting in focusing of the negative ion beam path. In the second ion focusing section 370, two pairs of electrodes are used, where a common positively charged electrode with a conductive mesh running through the negatively ion beam path 319 is used. Thus, in the second ion focusing section 370, the first electrode encountered along the negative ion beam path is negatively charged and the second electrode is positively charged, resulting in focusing of the negative ion beam path. Further, in the second ion focusing section, moving along the negative ion beam path, a second focusing effect is observed between the second positively charged electrode and a third negatively charged electrode. In this example, a third ion focusing section is used that again has three electrodes, which acts in the fashion of the second ion focusing section, described supra. Referring now to FIG. 6, the central region of the electrodes in the ion beam focusing system 350 is further described. Referring now to FIG. 6A, the central region of the negatively charged ring electrode 510 is preferably void of conductive material. Referring now to FIGS. 6B-D, the central region of positively charged electrode ring 520 preferably contains conductive paths 372. Preferably, the conductive paths 372 or conductive material within the positively charged electrode ring 520 blocks about 1, 2, 5, or 10 percent of the area and more preferably blocks about five percent of the cross-sectional area of the negative ion beam path 319. Referring now to FIG. 6B, one option is a conductive mesh 610. Referring now to FIG. 6C, a second option is a series of conductive lines 620 running substantially in parallel across the positively charged electrode ring 520 that surrounds a portion of the negative ion beam path 319. Referring now to FIG. 6D, a third option is to have a foil 630 or metallic layer cover all of the cross-sectional area of the negative ion beam path with holes punched through the material, where the holes take up about 90-99 percent and more preferably about 95 percent of the area of the foil. More generally, the pair of electrodes 510, 520 are configured to provide electric field lines that provide focusing force vectors to the negative ion beam 319 when the ions in the negative ion beam 319 translate through the electric field lines, as described supra. In an example of a two electrode negative beam ion focusing system having a first cross-sectional diameter, d1, the negative ions are focused to a second cross-sectional diameter, d2, where d1>d2. Similarly, in an example of a three electrode negative beam ion focusing system having a first ion beam cross-sectional diameter, d1, the negative ions are focused using the three electrode system to a third negative ion beam cross-sectional diameter, d3, where d1>d3. For like potentials on the electrodes, the three electrode system provides tighter or stronger focusing compared to the two-electrode system, d3<d2. In the examples provided, supra, of a multi-electrode ion beam focusing system, the electrodes are rings. More generally, the electrodes are of any geometry sufficient to provide electric field lines that provide focusing force vectors to the negative ion beam when the ions in the negative ion beam 319 translate through the electric field lines, as described supra. For example, one negative ring electrode is optionally replaced by a number of negatively charged electrodes, such as about 2, 3, 4, 6, 8, 10, or more electrodes placed about the outer region of a cross-sectional area of the negative ion beam probe. Generally, more electrodes are required to converge or diverge a faster or higher energy beam. In another embodiment, by reversing the polarity of electrodes in the above example, the negative ion beam is made to diverge. Thus, the negative ion beam path 319 is optionally focused and/or expanded using combinations of electrode pairs. For example, if the electrode having the mesh across the negative ion beam path is made negative, then the negative ion beam path is made to defocus. Hence, combinations of electrode pairs are used for focusing and defocusing a negative ion beam path, such as where a first pair includes a positively charged mesh for focusing and a where a second pair includes a negatively charged mesh for defocusing. Tandem Accelerator Referring now to FIG. 7A, the tandem accelerator 390 is further described. The tandem accelerator accelerates ions using a series of electrodes 710, 711, 712, 713, 714, 715. For example, negative ions, such as H−, in the negative ion beam path are accelerated using a series of electrodes having progressively higher voltages relative to the voltage of the extraction electrode 426, or third electrode 426, of the negative ion beam source 310. For instance, the tandem accelerator 390 optionally has electrodes ranging from the 25 kV of the extraction electrode 426 to about 525 kV near the foil 395 in the tandem accelerator 390. Upon passing through the foil 395, the negative ion, H−, loses two electrons to yield a proton, H+, according to equation 1.H−→H++2e− (eq. 1) The proton is further accelerated in the tandem accelerator using appropriate voltages at a multitude of further electrodes 713, 714, 715. The protons are then injected into the synchrotron 130 as described, supra. Still referring to FIG. 7, the foil 395 in the tandem accelerator 390 is further described. The foil 395 is preferably a very thin carbon film of about thirty to two hundred angstroms in thickness. The foil thickness is designed to both: (1) not block the ion beam and (2) allow the transfer of electrons yielding protons to form the proton beam path 262. The foil 395 is preferably substantially in contact with a support layer 720, such as a support grid. The support layer 720 provides mechanical strength to the foil 395 to combine to form a vacuum blocking element 725. The foil 395 blocks nitrogen, carbon dioxide, hydrogen, and other gases from passing and thus acts as a vacuum barrier. In one embodiment, the foil 395 is preferably sealed directly or indirectly to the edges of the vacuum tube 320 providing for a higher pressure, such as about 10−5 torr, to be maintained on the side of the foil 395 having the negative ion beam path 319 and a lower pressure, such as about 10−7 torr, to be maintained on the side of the foil 395 having the proton ion beam path 262. Having the foil 395 physically separating the vacuum chamber 320 into two pressure regions allows for a vacuum system having fewer and/or smaller pumps to maintain the lower pressure system in the synchrotron 130 as the inlet hydrogen and its residuals are extracted in a separate contained and isolated space by the first partial vacuum system 330. The foil 395 and support layer 720 are preferably attached to the structure 750 of the tandem accelerator 390 or vacuum tube 320 to form a pressure barrier using any mechanical means, such as a metal, plastic, or ceramic ring 730 compressed to the walls with an attachment screw 740. Any mechanical means for separating and sealing the two vacuum chamber sides with the foil 395 are equally applicable to this system. Referring now to FIG. 7B, the support structure 720 and foil 395 are individually viewed in the x-, y-plane. Referring now to FIG. 8, another exemplary method of use of the charged particle beam system 100 is provided. The main controller 110, or one or more sub-controllers, controls one or more of the subsystems to accurately and precisely deliver protons to a tumor of a patient. For example, the main controller sends a message to the patient indicating when or how to breathe. The main controller 110 obtains a sensor reading from the patient interface module, such as a temperature breath sensor or a force reading indicative of where in a respiration cycle the subject is. Coordinated at a specific and reproducible point in the respiration cycle, the main controller collects 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 then optionally controls the injection system 120 to inject hydrogen gas into a negative ion beam source 310 and controls timing of extraction of the negative ion from the negative ion beam source 310. Optionally, the main controller controls ion beam focusing using the ion beam focusing lens system 350; acceleration of the proton beam with the tandem accelerator 390; and/or injection of the proton into the synchrotron 130. The synchrotron typically contains at least an accelerator system 132 and an extraction system 134. The synchrotron preferably contains one or more of: turning magnets, edge focusing magnets, magnetic field concentration magnets, winding and correction coils, and flat magnetic field incident surfaces, some of which contain elements under control by the main controller 110. The main controller preferably controls the proton beam within the accelerator system, such as by controlling speed, trajectory, and/or 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 main controller 110 also preferably controls targeting of the proton beam through the targeting/delivery system 140 to the patient interface module 150. One or more components of the patient interface module 150 are preferably controlled by the main controller 110, such as vertical position of the patient, rotational position of the patient, and patient chair positioning/stabilization/immobilization/control elements. 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. Synchrotron Herein, the term synchrotron is used to refer to a system maintaining the charged particle beam in a circulating path. Further, the charged particle beam is referred to herein as circulating along a circulating path about a central point of the synchrotron. The circulating path is alternatively referred to as an orbiting path; however, the orbiting path does not refer to a perfect circle or ellipse, rather it refers to cycling of the protons around a central point or region 280. Circulating System Referring now to FIG. 9, the synchrotron 130 preferably comprises a combination of straight sections 910 and ion beam turning sections 920. Hence, the circulating path of the protons is not circular in a synchrotron, but is rather a polygon with rounded corners. In one illustrative embodiment, the synchrotron 130, which is also referred to as an accelerator system, has four straight sections or elements and four turning sections. Examples of straight sections 910 include the: inflector 240, accelerator 270, extraction system 290, and deflector 292. Along with the four straight sections are four ion beam turning sections 920, which are also referred to as magnet sections or turning sections. Turning sections are further described, infra. Referring still to FIG. 9, an exemplary synchrotron is illustrated. In this example, protons delivered along the initial proton beam path 262 are inflected into the circulating beam path with the inflector 240 and after acceleration are extracted via a deflector 292 to the beam transport path 268. In this example, the synchrotron 130 comprises four straight sections 910 and four bending or turning sections 920 where each of the four turning sections use one or more magnets to turn the proton beam about ninety degrees. As is further described, infra, the ability to closely space the turning sections and efficiently turn the proton beam results in shorter straight sections. Shorter straight sections allow for a synchrotron design without the use of focusing quadrupoles in the circulating beam path of the synchrotron. The removal of the focusing quadrupoles from the circulating proton beam path results in a more compact design. In this example, the illustrated synchrotron has about a five meter diameter versus eight meter and larger cross-sectional diameters for systems using a quadrupole focusing magnet in the circulating proton beam path. Referring now to FIG. 10, additional description of the first bending or turning section 920 is provided. Each of the turning sections preferably comprise multiple magnets, such as about 2, 4, 6, 8, 10, or 12 magnets. In this example, four turning magnets 1010, 1020, 1030, 1040 in the first turning section 920 are used to illustrate key principles, which are the same regardless of the number of magnets in a turning section 920. The turning magnets 1010, 1020, 1030, 1040 are particular types of main bending or circulating magnets 250. In physics, the Lorentz force is the force on a point charge due to electromagnetic fields. The Lorentz force is given by equation 2 in terms of magnetic fields with the electron field terms not included.F=q(v×B) (eq. 2) In equation 2, F is the force in Newtons; q is the electric charge in coulombs; B is the magnetic field in Teslas; and v is the instantaneous velocity of the particles in meters per second. Referring now to FIG. 11, an example of a single magnet bending or turning section 1010 is expanded. The turning section includes a gap 1110 through which protons circulate. The gap 1110 is preferably a flat gap, allowing for a magnetic field across the gap 1110 that is more uniform, even, and intense. A magnetic field enters the gap 1110 through a magnetic field incident surface and exits the gap 1110 through a magnetic field exiting surface. The gap 1110 runs in a vacuum tube between two magnet halves. The gap 1110 is controlled by at least two parameters: (1) the gap 1110 is kept as large as possible to minimize loss of protons and (2) the gap 1110 is kept as small as possible to minimize magnet sizes and the associated size and power requirements of the magnet power supplies. The flat nature of the gap 1110 allows for a compressed and more uniform magnetic field across the gap 1110. One example of a gap dimension is to accommodate a vertical proton beam size of about two centimeters with a horizontal beam size of about five to six centimeters. As described, supra, a larger gap size requires a larger power supply. For instance, if the gap 1110 size doubles in vertical size, then the power supply requirements increase by about a factor of four. The flatness of the gap 1110 is also important. For example, the flat nature of the gap 1110 allows for an increase in energy of the extracted protons from about 250 to about 330 MeV. More particularly, if the gap 1110 has an extremely flat surface, then the limits of a magnetic field of an iron magnet are reachable. An exemplary precision of the flat surface of the gap 1110 is a polish of less than about five microns and preferably with a polish of about one to three microns. Unevenness in the surface results in imperfections in the applied magnetic field. The polished flat surface spreads unevenness of the applied magnetic field. Still referring to FIG. 11, the charged particle beam moves through the gap 1110 with an instantaneous velocity, v. A first magnetic coil 1120 and a second magnetic coil 1130 run above and below the gap 1110, respectively. Current running through the coils 1120, 1130 results in a magnetic field, B, running through the single magnet turning section 1010. In this example, the magnetic field, B, runs upward, which results in a force, F, pushing the charged particle beam inward toward a central point of the synchrotron, which turns the charged particle beam in an arc. Still referring to FIG. 11, a portion of an optional second magnet bending or turning section 1020 is illustrated. The coils 1120, 1130 typically have return elements 1140, 1150 or turns at the end of one magnet, such as at the end of the first magnet turning section 1010. The turns 1140, 1150 take space. The space reduces the percentage of the path about one orbit of the synchrotron that is covered by the turning magnets. This leads to portions of the circulating path where the protons are not turned and/or focused and allows for portions of the circulating path where the proton path defocuses. Thus, the space results in a larger synchrotron. Therefore, the space between magnet turning sections 1160 is preferably minimized. The second turning magnet is used to illustrate that the coils 1120, 1130 optionally run along a plurality of magnets, such as 2, 3, 4, 5, 6, or more magnets. Coils 1120, 1130 running across multiple turning section magnets allows for two turning section magnets to be spatially positioned closer to each other due to the removal of the steric constraint of the turns, which reduces and/or minimizes the space 1160 between two turning section magnets. Still referring to FIG. 12, an optional embodiment of the second magnetic coil 1130 is further described. Generally, a single main bending magnet 250 has a top half and a bottom half. In FIG. 12, only the bottom halves of two sequential main bending magnets 250 are illustrated. The top halves, not illustrated for clarity of presentation, are essentially a repeat of the bottom halves rotated one hundred eighty degrees about the x-axis. The gap 1110 runs between the two halves. Referring now to only the left side of FIG. 12, a bottom half of a first main bending magnet using an optional flattened magnetic coil system 1200 is illustrated. A shaped coil 1132, which is an example of the first winding coil 1250 and is further an example of the second magnetic coil 1130, is wrapped about a central metal member 1211, such as the first magnet 1210, and between yoke members 1212, which are also referred to as return yoke members of a first magnet 1210. The gap 1110 runs directly above the central metal member 1211. The shaped coil 1132 has a first width, w1, and a first thickness, t1, along the x-axis along the length of the magnet. Herein, the length of the magnet is along the axis of the circulating charged particle. The shaped coil 1132 has a second width, w2, and a second thickness, t2, along the y-axis at the end of the central metal member 1211. The first width, w1, is larger than the second width, w2. The smaller second width, w2, allows a smaller distance, d1, between the first magnet turning section 1010 and the second magnet turning section 1020. For example, the first width, w1, is more than about 1.1, 1.2, 1.3, 1.5, 1.75, 2.0, 2.25, or 2.5 times the second width, w2. Similarly, the second thickness, t2, is more than about 1.1, 1.2, 1.3, 1.5, 1.75, 2.0, 2.25, or 2.5 times the first thickness, t1. The second thickness, t2, of the coil 1130 along the y-axis at the end of the first magnet turning section 1010 or similarly at the end of central metal member 1211 is larger than the first thickness, t1, of the shaped coil 1132 along the x-axis between the yoke members 1212, which allows a current along the x-axis length of the coil 1130 to be maintained when running along the y-axis as the end of the coil 1130 as a first cross-sectional area (w1×t1) and a second cross-sectional area (w2×t2) are preferably about equal, such as within less than a 2, 5, 10, or 15 percent different. In practice, the dimension of the first width, w1, optionally tapers into the dimension of the second width, w2, and the dimension of the first thickness, t1, optionally tapers into the second thickness, t2. Optionally, sections of the coil 1130 are welded together, such as where the length of the coil meets the end of the coil. As illustrated, the gap 1110 runs above the central metal member 1211. A top half of a first main bending magnet using an optional flattened magnetic coil system is substantially the same as the herein described bottom half, is rotated one hundred eighty degrees about the x-axis and is positioned above the gap 1110. Still referring to FIG. 12 and referring now to only the right side of FIG. 12, a second coil 1134 is illustrated wrapped between two second yoke members 1292 and around a second metal member 1291 in the second magnet turning section 1020. The second coil 1131 and its matching top half preferably has the design characteristics of the first coil 1132, described herein. Referring now to FIGS. 13 and 14, two illustrative 90 degree rotated cross-sections of single magnet bending or turning sections 1010 are presented. The magnet assembly has a first magnet 1210 and a second magnet 1220. A magnetic field induced by coils, described infra, runs between the first magnet 1210 to the second magnet 1220 across the gap 1110. Return magnetic fields run through a first yoke 1212 and second yoke 1222. The combined cross-section area of the return yokes roughly approximates the cross-sectional area of the first magnet 1210 or second magnet 1220. The charged particles run through the vacuum tube in the gap 1110. As illustrated, protons run into FIG. 14 through the gap 1110 and the magnetic field, illustrated as vector B, applies a force F to the protons pushing the protons towards the center of the synchrotron, which is off page to the right in FIG. 14. The magnetic field is created using windings. A first coil is used to form a first winding coil 1250 and a second coil of wire is used to form a second winding coil 1260. Isolating or concentrating gaps 1230, 1240, such as air gaps, isolate the iron based yokes from the gap 1110. The gap 1110 is approximately flat to yield a uniform magnetic field across the gap 1110, as described supra. Still referring to FIG. 13, the ends of a single bending or turning magnet are preferably beveled. Nearly perpendicular or right angle edges of a turning magnet 1010 are represented by dashed lines 1374, 1384. The dashed lines 1374, 1384 intersect at a point 1390 beyond the center of the synchrotron 280. Preferably, the edge of the turning magnet is beveled at angles alpha, a, and beta, β, which are angles formed by a first line 1372, 1382 going from an edge of the turning magnet 1010 and the center 280 and a second line 1374, 1384 going from the same edge of the turning magnet and the intersecting point 1390. The angle alpha is used to describe the effect and the description of angle alpha applies to angle beta, but angle alpha is optionally different from angle beta. The angle alpha provides an edge focusing effect. Beveling the edge of the turning magnet 1010 at angle alpha focuses the proton beam. Multiple turning magnets provide multiple magnet edges that each have edge focusing effects in the synchrotron 130. If only one turning magnet is used, then the beam is only focused once for angle alpha or twice for angle alpha and angle beta. However, by using smaller turning magnets, more turning magnets fit into the turning sections 920 of the synchrotron 130. For example, if four magnets are used in a turning section 920 of the synchrotron, then for a single turning section there are eight possible edge focusing effect surfaces, two edges per magnet. The eight focusing surfaces yield a smaller cross-sectional beam size, which allows the use of a smaller gap. The use of multiple edge focusing effects in the turning magnets results in not only a smaller gap 1110, but also the use of smaller magnets and smaller power supplies. For a synchrotron 130 having four turning sections 920 where each turning sections has four turning magnets and each turning magnet has two focusing edges, a total of thirty-two focusing edges exist for each orbit of the protons in the circulating path of the synchrotron 130. Similarly, if 2, 6, or 8 magnets are used in a given turning section, or if 2, 3, 5, or 6 turning sections are used, then the number of edge focusing surfaces expands or contracts according to equation 3. T ⁢ ⁢ F ⁢ ⁢ E = N ⁢ ⁢ T ⁢ ⁢ S * M N ⁢ ⁢ T ⁢ ⁢ S * F ⁢ ⁢ E M ( eq . ⁢ 3 ) where TFE is the number of total focusing edges, NTS is the number of turning sections, M is the number of magnets, and FE is the number of focusing edges. Naturally, not all magnets are necessarily beveled and some magnets are optionally beveled on only one edge. The inventors have determined that multiple smaller magnets have benefits over fewer larger magnets. For example, the use of 16 small magnets yields 32 focusing edges whereas the use of 4 larger magnets yields only 8 focusing edges. The use of a synchrotron having more focusing edges results in a circulating path of the synchrotron built without the use of focusing quadrupole magnets. All prior art synchrotrons use quadrupoles in the circulating path of the synchrotron. Further, the use of quadrupoles in the circulating path necessitates additional straight sections in the circulating path of the synchrotron. Thus, the use of quadrupoles in the circulating path of a synchrotron results in synchrotrons having larger diameters, larger circulating beam pathlengths, and/or larger circumferences. In various embodiments of the system described herein, the synchrotron has any combination of: at least four and preferably six, eight, ten, or more edge focusing edges per 90 degrees of turn of the charged particle beam in a synchrotron having four turning sections; at least about sixteen and preferably about twenty-four, thirty-two, or more edge focusing edges per orbit of the charged particle beam in the synchrotron; only four turning sections where each of the turning sections includes at least four and preferably eight edge focusing edges; an equal number of straight sections and turning sections; exactly four turning sections; at least four focusing edges per turning section; no quadrupoles in the circulating path of the synchrotron; a rounded corner rectangular polygon configuration; a circumference of less than sixty meters; a circumference of less than sixty meters and thirty-two edge focusing surfaces; and/or any of about eight, sixteen, twenty-four, or thirty-two non-quadrupole magnets per circulating path of the synchrotron, where the non-quadrupole magnets include edge focusing edges.Flat Gap Surface While the gap surface is described in terms of the first turning magnet 1010, the discussion applies to each of the turning magnets in the synchrotron. Similarly, while the gap 1110 surface is described in terms of the magnetic field incident surface 1270, the discussion additionally optionally applies to the magnetic field exiting surface 1280. Referring again to FIG. 12, the incident magnetic field surface 1270 of the first magnet 1210 is further described. FIG. 12 is not to scale and is illustrative in nature. Local imperfections or unevenness in quality of the finish of the incident surface 1270 results in inhomogeneities or imperfections in the magnetic field applied to the gap 1110. The magnetic field incident surface 1270 and/or exiting surface 1280 of the first magnet 1210 is preferably about flat, such as to within about a zero to three micron finish polish or less preferably to about a ten micron finish polish. By being very flat, the polished surface spreads the unevenness of the applied magnetic field across the gap 1110. The very flat surface, such as about 0, 1, 2, 4, 6, 8, 10, 15, or 20 micron finish, allows for a smaller gap size, a smaller applied magnetic field, smaller power supplies, and tighter control of the proton beam cross-sectional area. Referring now to FIG. 14, additional optional magnet elements, of the magnet cross-section illustratively represented in FIG. 12, are described. The first magnet 1210 preferably contains an initial cross-sectional distance 1410 of the iron based core. The contours of the magnetic field are shaped by the magnets 1210, 1220 and the yokes 1212, 1222. The iron based core tapers to a second cross-sectional distance 1420. The shape of the magnetic field vector 1440 is illustrative only. The magnetic field in the magnet preferentially stays in the iron based core as opposed to the gaps 1230, 1240. As the cross-sectional distance decreases from the initial cross-sectional distance 1410 to the final cross-sectional distance 1420, the magnetic field concentrates. The change in shape of the magnet from the longer distance 1410 to the smaller distance 1420 acts as an amplifier. The concentration of the magnetic field is illustrated by representing an initial density of magnetic field vectors 1430 in the initial cross-section 1410 to a concentrated density of magnetic field vectors 1440 in the final cross-section 1420. The concentration of the magnetic field due to the geometry of the turning magnets results in fewer winding coils 1250, 1260 being required and also a smaller power supply to the coils being required. In one example, the initial cross-section distance 1410 is about fifteen centimeters and the final cross-section distance 1420 is about ten centimeters. Using the provided numbers, the concentration of the magnetic field is about 15/10 or 1.5 times at the incident surface 1270 of the gap 1110, though the relationship is not linear. The taper 1460 has a slope, such as about twenty, forty, or sixty degrees. The concentration of the magnetic field, such as by 1.5 times, leads to a corresponding decrease in power consumption requirements to the magnets. Referring now to FIG. 15, an additional example of geometry of the magnet used to concentrate the magnetic field is illustrated. As illustrated in FIG. 14, the first magnet 1210 preferably contains an initial cross-sectional distance 1410 of the iron based core. The contours of the magnetic field are shaped by the magnets 1210, 1220 and the yokes 1212, 1222. In this example, the core tapers to a second cross-sectional distance 1420 with a smaller angle theta, θ. As described, supra, the magnetic field in the magnet preferentially stays in the iron based core as opposed to the gaps 1230, 1240. As the cross-sectional distance decreases from the initial cross-sectional distance 1410 to the final cross-sectional distance 1420, the magnetic field concentrates. The smaller angle, theta, results in a greater amplification of the magnetic field in going from the longer distance 1410 to the smaller distance 1420. The concentration of the magnetic field is illustrated by representing an initial density of magnetic field vectors 1430 in the initial cross-section 1410 to a concentrated density of magnetic field vectors 1440 in the final cross-section 1420. The concentration of the magnetic field due to the geometry of the turning magnets results in fewer winding coils 1250, 1260 being required and also a smaller power supply to the winding coils 1250, 1260 being required. Still referring to FIG. 15, optional correction coils 1510, 1520 are illustrated that are used to correct the strength of one or more turning magnets. The correction coils 1520, 1530 supplement the winding coils 1250, 1260. The correction coils 1510, 1520 have correction coil power supplies that are separate from winding coil power supplies used with the winding coils 1250, 1260. The correction coil power supplies typically operate at a fraction of the power required compared to the winding coil power supplies, such as about 1, 2, 3, 5, 7, or 10 percent of the power and more preferably about 1 or 2 percent of the power used with the winding coils 1250, 1260. The smaller operating power applied to the correction coils 1510, 1520 allows for more accurate and/or precise control of the correction coils. The correction coils are used to adjust for imperfection in the turning magnets. Optionally, separate correction coils are used for each turning magnet allowing individual tuning of the magnetic field for each turning magnet, which eases quality requirements in the manufacture of each turning magnet. Referring now to FIG. 16, an example of winding coils 1630 and correction coils 1620 about a plurality of turning magnets 1010, 1020 in an ion beam turning section 920 is illustrated. The winding coils preferably cover 1, 2, or 4 turning magnets. One or more high precision magnetic field sensors 1650 are placed into the synchrotron and are used to measure the magnetic field at or near the proton beam path. For example, the magnetic sensors are optionally placed between turning magnets and/or within a turning magnet, such as at or near the gap 1110 or at or near the magnet core or yoke. The sensors are part of a feedback system to the correction coils, which is optionally run by the main controller. Thus, the system preferably stabilizes the magnetic field in the synchrotron rather than stabilizing the current applied to the magnets. Stabilization of the magnetic field allows the synchrotron to come to a new energy level quickly. This allows the system to be controlled to an operator or algorithm selected energy level with each pulse of the synchrotron and/or with each breath of the patient. The winding and/or correction coils correct one, two, three, or four turning magnets, and preferably correct a magnetic field generated by two turning magnets. Optionally, a correction coil 1640 winds a single magnet section 1010 or a correction coil 1620 winds two or more magnet turning sections 1010, 1020. A winding or correction coil covering multiple magnets reduces space between magnets as fewer winding or correction coil ends are required, which occupy space. Reduction of space between turning magnets allows operation of the turning magnets with smaller power supplies and optionally without quadrupole magnet focusing sections. Space 1160 at the end of a turning magnets 1010, 1040 is optionally further reduced by changing the cross-sectional shape of the winding coils. For example, when the winding coils are running longitudinally along the length of the circulating path or along the length of the turning magnet, the cross-sectional dimension is thick and when the winding coils turn at the end of a turning magnet to run axially across the winding coil, then the cross-sectional area of the winding coils is preferably thin. For example, the cross-sectional area of winding coils as measured by an m×n matrix is 3×2 running longitudinally along the turning magnet and 6×1 running axially at the end of the turning magnet, thereby reducing the width of the coils, n, while keeping the number of coils constant. Preferably, the turn from the longitudinal to axial direction of the winding coil approximates ninety degrees by cutting each winding and welding each longitudinal section to the connecting axial section at about a ninety degree angle. The nearly perpendicular weld further reduces space requirements of the turn in the winding coil, which reduces space in circulating orbit not experiencing focusing and turning forces, which reduces the size of the synchrotron. Referring now to FIG. 17A and FIG. 17B, the accelerator system 270, such as a radio-frequency (RF) accelerator system, is further described. The accelerator includes a series of coils 1710-1719, such as iron or ferrite coils, each circumferentially enclosing the vacuum system 320 through which the proton beam 264 passes in the synchrotron 130. Referring now to FIG. 17B, the first coil 1710 is further described. A loop of standard wire 1730 completes at least one turn about the first coil 1710. The loop attaches to a microcircuit 1720. Referring again to FIG. 17A, an RF synthesizer 1740, which is preferably connected to the main controller 110, provides a low voltage RF signal that is synchronized to the period of circulation of protons in the proton beam path 264. The RF synthesizer 1740, microcircuit 1720, loop 1730, and coil 1710 combine to provide an accelerating voltage to the protons in the proton beam path 264. For example, the RF synthesizer 1740 sends a signal to the microcircuit 1720, which amplifies the low voltage RF signal and yields an acceleration voltage, such as about 10 volts. The actual acceleration voltage for a single microcircuit/loop/coil combination is about five, ten, fifteen, or twenty volts, but is preferably about ten volts. Preferably, the RF-amplifier microcircuit and accelerating coil are integrated. Still referring to FIG. 17A, the integrated RF-amplifier microcircuit and accelerating coil presented in FIG. 17B is repeated, as illustrated as the set of coils 1711-1719 surrounding the vacuum tube 320. For example, the RF-synthesizer 1740, under main controller 130 direction, sends an RF-signal to the microcircuits 1720-1729 connected to coils 1710-1719, respectively. Each of the microcircuit/loop/coil combinations generates a proton accelerating voltage, such as about ten volts each. Hence, a set of five coil combinations generates about fifty volts for proton acceleration. Preferably about five to twenty microcircuit/loop/coil combinations are used and more preferably about nine or ten microcircuit/loop/coil combinations are used in the accelerator system 270. As a further clarifying example, the RF synthesizer 1740 sends an RF-signal, with a period equal to a period of circulation of a proton about the synchrotron 130, to a set of ten microcircuit/loop/coil combinations, which results in about 100 volts for acceleration of the protons in the proton beam path 264. The 100 volts is generated at a range of frequencies, such as at about one MHz for a low energy proton beam to about fifteen MHz for a high energy proton beam. The RF-signal is optionally set at an integer multiple of a period of circulation of the proton about the synchrotron circulating path. Each of the microcircuit/loop/coil combinations are optionally independently controlled in terms of acceleration voltage and frequency. Integration of the RF-amplifier microcircuit and accelerating coil, in each microcircuit/loop/coil combination, results in three considerable advantages. First, for synchrotrons, the prior art does not use microcircuits integrated with the accelerating coils but rather uses a set of long cables to provide power to a corresponding set of coils. The long cables have an impedance/resistance, which is problematic for high frequency RF control. As a result, the prior art system is not operable at high frequencies, such as above about ten MHz. The integrated RF-amplifier microcircuit/accelerating coil system is operable at above about ten MHz and even fifteen MHz where the impedance and/or resistance of the long cables in the prior art systems results in poor control or failure in proton acceleration. Second, the long cable system, operating at lower frequencies, costs about $50,000 and the integrated microcircuit system costs about $1000, which is fifty times less expensive. Third, the microcircuit/loop/coil combinations in conjunction with the RF-amplifier system results in a compact low power consumption design allowing production and use of a proton cancer therapy system in a small space, as described supra, and in a cost effective manner. Referring again to FIG. 16, an example of a winding coil 1630 that covers two turning magnets 1010, 1020 is provided. Optionally, a first winding coil 1640 covers two magnets 1010, 1020 and a second winding coil, not illustrated, covers another two magnets 1030, 1040. As described, supra, this system reduces space between turning section allowing more magnetic field to be applied per radian of turn. A first correction coil 1640 is illustrated that is used to correct the magnetic field for the first turning magnet 1010. A second correction coil 1620 is illustrated that is used to correct the magnetic field for a winding coil 1630 about two turning magnets. Individual correction coils for each turning magnet are preferred and individual correction coils yield the most precise and/or accurate magnetic field in each turning section. Particularly, an individual correction coil is preferably used to compensate for imperfections in the individual magnet of a given turning section. Hence, with a series of magnetic field sensors, corresponding magnetic fields are individually adjustable in a series of feedback loops, via a magnetic field monitoring system, as an independent coil is used for each turning section. Alternatively, a multiple magnet correction coil is used to correct the magnetic field for a plurality of turning section magnets. Proton Beam Extraction Referring now to FIG. 18A, an exemplary proton beam extraction process 1800 from the synchrotron 130 is illustrated. For clarity, FIG. 18 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 264, 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 1910. To initiate extraction, an RF field is applied across a first blade 1912 and a second blade 1914, in the RF cavity system 1910. The first blade 1912 and second blade 1914 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 1912 of the first pair of blades is on one side of the circulating proton beam path 264 and the second blade 1914 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 applied RF field is timed to apply outward or inward movement to a given band of protons circulating in the synchrotron accelerator. Each orbit of the protons is 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. 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. With a sufficient sine wave betatron amplitude, the altered circulating beam path 265 touches and/or traverses a material 1930, 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 a 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 1930 is optionally adjusted to created 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. 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 1914 and a third blade 1916 in the RF cavity system 1910. 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 Lambertson extraction magnet, into a transport path 268. Still referring to FIG. 18A, in one example, the material 1930 is a set of foils with different foils having different thicknesses. For example, a first foil 1932 has a thickness less than a thickness of a second foil 1934 and the second foil 1934 has a thickness less than a thickness of a third foil 1936. Each of the foils 1932, 1934, 1936 optionally has any of the properties of the material 1930, described supra. The energy of the charged particles in the altered circulating beam path 265 is preferably in the range of about 70 to 250 MeV. Optionally, a thinner extraction foil is used in the extraction system with lower energy charged particles and a thicker foil is used in the extraction system 1800 with higher energy charged particles. For example, the first foil 1932 having a thickness of about 30 to 70 micrometers and preferably about 50 micrometers is used in the extraction of charged particles having energy of about 70 to 150 MeV, the second foil 1934 having a thickness of about 60 to 140 micrometers and preferably about 100 micrometers is used in the extraction of charged particles having energy of about 150 to 200 MeV, and the third foil having a thickness of about 150 to 250 micrometers and preferably about 200 micrometers is used in the extraction of charged particles having energy of about 70 to 150 MeV. Any number of foils are optionally used. Similarly, various members of the set of foils have varying densities. For example, a second foil has a density about 110, 120, 130, 150, 200, or 300 percent of a density of a first foil. For a given thickness, the denser foil is used in extraction of higher energy charged particles. Similarly, the foils vary in both density and thickness. Still referring to FIG. 18A, each of the foils 1932, 1934, 1936 is optionally moved toward or away from the circulating charged particle beam path 264 prior to and/or in the process of charged particle extraction, such as with one or more actuators. Preferably, the foil actuated toward the circulating beam path 264 is selected to have a larger thickness as a function of higher energy of the charged particles in the beam path, as described infra. Referring now to FIG. 18B and FIG. 18C, in use a thinner foil, such as the first foil 1932, is used for lower energy levels, such as depicted by E1 to traverse a short distance through a patient 2130 or a short distance through tissue to a tumor 2120. Similarly, in use a medium thickness foil, such as the second foil 1934, is used for medium levels of energy of the charged particles, such as depicted by E2 to traverse a medium distance through a patient 2130 or a medium distance through tissue to the tumor 2120. Further, in use a thicker foil, such as the third foil 1936, is used for higher energy levels charged particles, such as depicted by E3 to traverse a larger distance through a patient 2130 or a larger distance through tissue to the tumor 2120. 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 1930, the material 1930 is mechanically moved to the circulating charged particles. Particularly, the material 1930 is mechanically or electromechanically translated into the path of the circulating charged particles to induce the extraction process, described supra. 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 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 1910 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. Referring now to FIG. 19, an intensity control system 1900 is illustrated. 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 1930 electrons are given off resulting in a current. The resulting current is converted to a voltage and is used as part of a 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 1940, 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 1930, 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 1930 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 material 1930. 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 1930 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 1930 is used as a control in the RF generator to increase or decrease the number of protons undergoing betatron oscillation and striking the material 1930. Hence, the voltage determined off of the material 1930 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 1940 preferably additionally receives input from: (1) a detector 1950, which provides a reading of the actual intensity of the proton beam and (2) an irradiation plan 1960. 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 1940 receives the desired intensity from the irradiation plan 1950, the actual intensity from the detector 1950 and/or a measure of intensity from the material 1930, and adjusts the radio-frequency field in the RF cavity system 1910 to yield an intensity of the proton beam that matches the desired intensity from the irradiation plan 1960. As described, supra, the photons striking the material 1930 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. For example, protons initially move at an equilibrium trajectory in the synchrotron 130. An RF field is used to excite 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, RF frequency, or RF field. 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 1910 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 1950 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 or RF modulation in the RF cavity system 1910. 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 1960 is used as an input to the intensity controller 1940, which controls the RF field modulation by directing the RF signal in the betatron oscillation generation in the RF cavity system 1910. The irradiation plan 1960 preferably includes the desired intensity of the charged particle beam as a function of time, 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 130 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. 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. Referring now to FIGS. 20 A and B, a proton beam position verification system 2000 is described. A nozzle 2010 provides an outlet for the second reduced pressure vacuum system initiating at the foil 395 of the tandem accelerator 390 and running through the synchrotron 130 to a nozzle foil 2020 covering the end of the nozzle 2010. The nozzle 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- and y-axes by the vertical control element 142 and horizontal control element 144, respectively. The nozzle foil 2020 is preferably mechanically supported by the outer edges of an exit port of the nozzle 2010. An example of a nozzle foil 2020 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 2020 from the low pressure region, such as about 10−5 to 10−7 torr region, on the synchrotron 130 side of the nozzle foil 2020. The low pressure region is maintained to reduce scattering of the proton beam 264, 268. Still referring to FIG. 20, the proton beam verification system 2000 is a system that allows for monitoring of the actual proton beam position 268, 269 in real-time without destruction of the proton beam. The proton beam verification system 2000 preferably includes a proton beam position verification layer 2030, which is also referred to herein as a coating, luminescent, fluorescent, phosphorescent, radiance, or viewing layer. The verification layer or coating layer 2030 is preferably a coating or thin layer substantially in contact with an inside surface of the nozzle foil 2020, where the inside surface is on the synchrotron side of the nozzle foil 2020. Less preferably, the verification layer or coating layer 2030 is substantially in contact with an outer surface of the nozzle foil 2020, where the outer surface is on the patient treatment side of the nozzle foil 2020. Preferably, the nozzle foil 2020 provides a substrate surface for coating by the coating layer. Optionally, a binding layer is located between the coating layer 2030 and the nozzle foil 2020. Optionally a separate coating layer support element, on which the coating 2030 is mounted, is placed anywhere in the proton beam path 268. Referring now to FIG. 20B, the coating 2030 yields a measurable spectroscopic response, spatially viewable by the detector 2040, as a result of transmission by the proton beam 268. The coating 2030 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 proton beam path 268 hitting or transmitting through the coating 2030. A detector or camera 2040 views the coating layer 2030 and determines the current position of the proton beam 269 by the spectroscopic differences resulting from protons passing through the coating layer. For example, the camera 2040 views the coating surface 2030 as the proton beam 268 is being scanned by the horizontal 144 and vertical 142 beam position control elements during treatment of the tumor 2120. The camera 2040 views the current position of the proton beam 269 as measured by spectroscopic response. The coating layer 2030 is preferably a phosphor or luminescent material that glows 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 proton beam 268. Optionally, a plurality of cameras or detectors 2040 are used, where each detector views all or a portion of the coating layer 2030. For example, two detectors 2040 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 2040 is mounted into the nozzle 2010 to view the proton beam position after passing through the first axis and second axis controllers 142, 144. Preferably, the coating layer 2030 is positioned in the proton beam path 268 in a position prior to the protons striking the patient 2130. Still referring to FIG. 20, the main controller 130, connected to the camera or detector 2040 output, compares the actual 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 proton beam verification system 2000 preferably is used in at least two phases, a calibration phase and a proton beam treatment 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 proton beam treatment phase, the proton beam position is monitored and compared to the calibration and/or treatment plan to verify accurate proton delivery to the tumor 2120 and/or as a proton beam shutoff safety indicator. Patient Positioning Referring now to FIG. 21, the patient is preferably positioned on or within a patient translation and rotation positioning system 2110 of the patient interface module 150. The patient translation and rotation positioning system 2110 is used to translate the patient and/or rotate the patient into a zone where the proton beam can scan the tumor using a scanning system 140 or proton targeting system, described infra. Essentially, the patient positioning system 2110 performs large movements of the patient to place the tumor near the center of a proton beam path 268 and the proton scanning or targeting system 140 performs fine movements of the momentary beam position 269 in targeting the tumor 2120. To illustrate, FIG. 21A shows the momentary proton beam position 269 and a range of scannable positions 2140 using the proton scanning or targeting system 140, where the scannable positions 2140 are about the tumor 2120 of the patient 2130. In this example, the scannable positions are scanned along the x- and y-axes; however, scanning is optionally simultaneously performed along the z-axis as described infra. This illustratively shows that the y-axis movement of the patient occurs on a scale of the body, such as adjustment of about 1, 2, 3, or 4 feet, while the scannable region of the proton beam 268 covers a portion of the body, such as a region of about 1, 2, 4, 6, 8, 10, or 12 inches. The patient positioning system and its rotation and/or translation of the patient combines with the proton targeting system to yield precise and/or accurate delivery of the protons to the tumor. Referring still to FIG. 21, the patient positioning system 2110 optionally includes a bottom unit 2112 and a top unit 2114, such as discs or a platform. Referring now to FIG. 21A, the patient positioning unit 2110 is preferably y-axis adjustable 2116 to allow vertical shifting of the patient relative to the proton therapy beam 268. Preferably, the vertical motion of the patient positioning unit 2110 is about 10, 20, 30, or 50 centimeters per minute. Referring now to FIG. 21B, the patient positioning unit 2110 is also preferably rotatable 2117 about a rotation axis, such as about the y-axis running through the center of the bottom unit 2112 or about a y-axis running through the tumor 2120, to allow rotational control and positioning of the patient relative to the proton beam path 268. Preferably the rotational motion of the patient positioning unit 2110 is about 360 degrees per minute. Optionally, the patient positioning unit rotates about 45, 90, or 180 degrees. Optionally, the patient positioning unit 2110 rotates at a rate of about 45, 90, 180, 360, 720, or 1080 degrees per minute. The rotation of the positioning unit 2117 is illustrated about the rotation axis at two distinct times, t1 and t2. Protons are optionally delivered to the tumor 2120 at n times where each of the n times represent a different relative direction of the incident proton beam 269 hitting the patient 2130 due to rotation of the patient 2117 about the rotation axis. Any of the semi-vertical, sitting, or laying patient positioning embodiments described, infra, are optionally vertically translatable along the y-axis or rotatable about the rotation or y-axis. Preferably, the top and bottom units 2112, 2114 move together, such that they rotate at the same rates and translate in position at the same rates. Optionally, the top and bottom units 2112, 2114 are independently adjustable along the y-axis to allow a difference in distance between the top and bottom units 2112, 2114. Motors, power supplies, and mechanical assemblies for moving the top and bottom units 2112, 2114 are preferably located out of the proton beam path 269, such as below the bottom unit 2112 and/or above the top unit 2114. This is preferable as the patient positioning unit 2110 is preferably rotatable about 360 degrees and the motors, power supplies, and mechanical assemblies interfere with the protons if positioned in the proton beam path 269 Proton Delivery Efficiency Referring now to FIG. 22, a common X-ray distribution profile 2210, a proton ion distribution profile 2220, and a carbon ion distribution profile 2310 is presented. As shown, X-rays deposit their highest dose near the surface of the targeted tissue and then deposited doses exponentially decrease as a function of tissue depth. The deposition of X-ray energy near the surface is non-ideal for tumors located deep within the body, which is usually the case, as excessive damage is done to the soft tissue layers surrounding the tumor 2120. The advantage of protons is that they deposit most of their energy near the end of the flight trajectory as the energy loss per unit path of the absorber traversed by a proton increases with decreasing particle velocity, giving rise to a sharp maximum in ionization near the end of the range, referred to herein as the Bragg peak. Furthermore, since the flight trajectory of the protons is variable by increasing or decreasing the initial kinetic energy or initial velocity of the proton, then the peak corresponding to maximum energy is movable within the tissue. Thus z-axis control of the proton depth of penetration is allowed by the acceleration/extraction process, described supra. As a result of proton dose-distribution characteristics, using the algorithm described, infra, a radiation oncologist can optimize dosage to the tumor 2120 while minimizing dosage to surrounding normal tissues. The use of heavier ions, such as carbon ions and/or C6+, yields: (1) a smaller dose delivery percentage in lead-in healthy tissue, (2) a sharper in tumor dose delivery profile, and/or (3) a more rapid fall off in dose delivery at the Bragg limit due to atomic cross-sectional area. Herein, the term ingress refers to a place charged particles enter into the patient 2130 or a place of charged particles entering the tumor 2120. The ingress region of the Bragg energy profile refers to the relatively flat dose delivery portion at shallow depths of the Bragg energy profile. Similarly, herein the terms proximal or the clause proximal region refer to the shallow depth region of the tissue that receives the relatively flat radiation dose delivery portion of the delivered Bragg profile energy. Herein, the term distal refers to the back portion of the tumor located furthest away from the point of origin where the charged particles enter the tumor. In terms of the Bragg energy profile, the Bragg peak is at the distal point of the profile. Herein, the term ventral refers to the front of the patient and the term dorsal refers to the back of the patient. As an example of use, when delivering protons to a tumor in the body, the protons ingress through the healthy tissue and if delivered to the far side of the tumor, the Bragg peak occurs at the distal side of the tumor. For a case where the proton energy is not sufficient to reach the far side of the tumor, the distal point of the Bragg energy profile is the region of furthest penetration into the tumor. The Bragg peak energy profile shows that protons deliver their energy across the entire length of the body penetrated by the proton up to a maximum penetration depth. As a result, energy is being delivered, in the proximal portion of the Bragg peak energy profile, to healthy tissue, bone, and other body constituents before the proton beam hits the tumor. It follows that the shorter the pathlength in the body prior to the tumor, the higher the efficiency of proton delivery efficiency, where proton delivery efficiency is a measure of how much energy is delivered to the tumor relative to healthy portions of the patient. Examples of proton delivery efficiency include: (1) a ratio of proton energy delivered to the tumor over proton energy delivered to non-tumor tissue; (2) pathlength of protons in the tumor versus pathlength in the non-tumor tissue; and/or (3) damage to a tumor compared to damage to healthy body parts. Any of these measures are optionally weighted by damage to sensitive tissue, such as a nervous system element, heart, brain, or other organ. To illustrate, for a patient in a laying position where the patient is rotated about the y-axis during treatment, a tumor near the heart would at times be treated with protons running through the head-to-heart path, leg-to-heart path, or hip-to-heart path, which are all inefficient compared to a patient in a sitting or semi-vertical position where the protons are all delivered through a shorter chest-to-heart; side-of-body-to-heart, or back-to-heart path. Particularly, compared to a laying position, using a sitting or semi-vertical position of the patient, a shorter pathlength through the body to a tumor is provided to a tumor located in the torso or head, which results in a higher or better proton delivery efficiency. Herein proton delivery efficiency is separately described from time efficiency or synchrotron use efficiency, which is a fraction of time that the charged particle beam apparatus is in a tumor treating operation mode. Depth Targeting Referring now to FIGS. 23 A-E, x-axis scanning of the proton beam is illustrated while z-axis energy of the proton beam undergoes controlled variation 2300 to allow irradiation of slices of the tumor 2120. For clarity of presentation, the simultaneous y-axis scanning that is performed is not illustrated. In FIG. 23A, irradiation is commencing with the momentary proton beam position 269 at the start of a first slice. Referring now to FIG. 23B, the momentary proton beam position is at the end of the first slice. Importantly, during a given slice of irradiation, the proton beam energy is preferably continuously controlled and changed according to the tissue mass and density in front of the tumor 2120. The variation of the proton beam energy to account for tissue density thus allows the beam stopping point, or Bragg peak, to remain inside the tissue slice. The variation of the proton beam energy during scanning or during x-, y-axes scanning is possible due to the acceleration/extraction techniques, described supra, which allow for acceleration of the proton beam during extraction. FIGS. 23C, 23D, and 23E show the momentary proton beam position in the middle of the second slice, two-thirds of the way through a third slice, and after finalizing irradiation from a given direction, respectively. Using this approach, controlled, accurate, and precise delivery of proton irradiation energy to the tumor 2120, to a designated tumor subsection, or to a tumor layer is achieved. Efficiency of deposition of proton energy to tumor, as defined as the ratio of the proton irradiation energy delivered to the tumor relative to the proton irradiation energy delivered to the healthy tissue is further described infra. Multi-Field Irradiation It is desirable to maximize efficiency of deposition of protons to the tumor 2120, as defined by maximizing the ratio of the proton irradiation energy delivered to the tumor 2120 relative to the proton irradiation energy delivered to the healthy tissue. Irradiation from one, two, or three directions into the body, such as by rotating the body about 90 degrees between irradiation sub-sessions results in proton irradiation from the proximal portion of the Bragg peak concentrating into one, two, or three healthy tissue volumes, respectively. It is desirable to further distribute the proximal portion of the Bragg peak energy evenly through the healthy volume tissue surrounding the tumor 2120. Multi-field irradiation is proton beam irradiation from a plurality of entry points into the body. For example, the patient 2130 is rotated and the radiation source point is held constant. For example, the patient 2130 is rotated through 360 degrees and proton therapy is applied from a multitude of angles resulting in the ingress or proximal radiation being circumferentially spread about the tumor yielding enhanced proton irradiation efficiency. In one case, the body is rotated into greater than 3, 5, 10, 15, 20, 25, 30, or 35 positions and proton irradiation occurs with each rotation position. Rotation of the patient is preferably performed using the patient positioning system 2110 and/or the bottom unit 2112 or disc, described supra. Rotation of the patient 2130 while keeping the delivery proton beam 268 in a relatively fixed orientation allows irradiation of the tumor 2120 from multiple directions without use of a new collimator for each direction. Further, as no new setup is required for each rotation position of the patient 2130, the system allows the tumor 2120 to be treated from multiple directions without reseating or positioning the patient, thereby minimizing tumor 2120 regeneration time, increasing the synchrotrons efficiency, and increasing patient throughput. The patient is optionally centered on the bottom unit 2112 or the tumor 2120 is optionally centered on the bottom unit 2112. If the patient is centered on the bottom unit 2112, then the first axis control element 142 and second axis control element 144 are programmed to compensate for the off central axis of rotation position variation of the tumor 2120. Referring now to FIGS. 24 A-E, an example of multi-field irradiation 2400 is presented. In this example, five patient rotation positions are illustrated; however, the five rotation positions are discrete rotation positions of about thirty-six rotation positions, where the body is rotated about ten degrees with each position. Referring now to FIG. 24A, a range of irradiation beam positions 269 is illustrated from a first body rotation position, illustrated as the patient 2130 facing the proton irradiation beam where the tumor receives the bulk of the Bragg profile energy while a first healthy volume 2411 is irradiated by the less intense ingress portion of the Bragg profile energy. Referring now to FIG. 24B, the patient 2130 is rotated about forty degrees and the irradiation is repeated. In the second position, the tumor 2120 again receives the bulk of the irradiation energy and a second healthy tissue volume 2412 receives the smaller ingress portion of the Bragg profile energy. Referring now to FIGS. 24 C-E, the patient 2130 is rotated a total of about 90, 130, and 180 degrees, respectively. For each of the third, fourth, and fifth rotation positions, the tumor 2120 receives the bulk of the irradiation energy and the third, fourth, and fifth healthy tissue volumes 2413, 2414, 1415 receive the smaller ingress portion of the Bragg peak energy, respectively. Thus, the rotation of the patient during proton therapy results in the proximal or ingress energy of the delivered proton energy to be distributed about the tumor 2120, such as to regions one to five 2411-2415, while along a given axis, at least about 75, 80, 85, 90, or 95 percent of the energy is delivered to the tumor 2120. For a given rotation position, all or part of the tumor is irradiated. For example, in one embodiment only a distal section or distal slice of the tumor 2120 is irradiated with each rotation position, where the distal section is a section furthest from the entry point of the proton beam into the patient 2130. For example, the distal section is the dorsal side of the tumor when the patient 2130 is facing the proton beam and the distal section is the ventral side of the tumor when the patient 2130 is facing away from the proton beam. Referring now to FIG. 25, a second example of multi-field irradiation 2500 is presented where the proton source is stationary and the patient 2130 is rotated. For ease of presentation, the stationary but scanning proton beam path 269 is illustrated as entering the patient 2130 from varying sides at times t1, t2, t3, . . . , tn, tn+1 as the patient is rotated. At a first time, t1, the ingress side or proximal region of the Bragg peak profile hits a first area, A1. Again, the proximal end of the Bragg peak profile refers to the relatively shallow depths of tissue where Bragg energy profile energy delivery is relatively flat. The patient is rotated and the proton beam path is illustrated at a second time, t2, where the ingress energy of the Bragg energy profile hits a second area, A2. Thus, the low radiation dosage of the ingress region of the Bragg profile energy is delivered to the second area. At a third time, the ingress end of the Bragg energy profile hits a third area, A3. This rotation and irradiation process is repeated n times, where n is a positive number greater than five and preferably greater than about 10, 20, 30, 100, or 300. As illustrated, at an nth time, tn, if the patient 2130 is rotated further, the scanning proton beam 269 would hit a sensitive body constituent 2150, such as the spinal cord or eyes. Irradiation is preferably suspended until the sensitive body constituent is rotated out of the scanning proton beam 269 path. Irradiation is resumed at a time, tn+1, after the sensitive body constituent 2150 is rotated out of the proton beam path. In this manner: the distal Bragg peak energy is always within the tumor; the radiation dose delivery of the distal region of the Bragg energy profile is spread over the tumor; the ingress or proximal region of the Bragg energy profile is distributed in healthy tissue about the tumor 2120; and sensitive body constituents 2150 receive minimal or no proton beam irradiation.Proton Delivery Efficiency Herein, charged particle or proton delivery efficiency is radiation dose delivered to the tumor compared to radiation dose delivered to the healthy regions of the patient. A proton delivery enhancement method is described where proton delivery efficiency is enhanced, optimized, or maximized. In general, multi-field irradiation is used to deliver protons to the tumor from a multitude of rotational directions. From each direction, the energy of the protons is adjusted to target the distal portion of the tumor, where the distal portion of the tumor is the volume of the tumor furthest from the entry point of the proton beam into the body. For clarity, the process is described using an example where the outer edges of the tumor are initially irradiated using distally applied radiation through a multitude of rotational positions, such as through 360 degrees. This results in a symbolic or calculated remaining smaller tumor for irradiation. The process is then repeated as many times as necessary on the smaller tumor. However, the presentation is for clarity. In actuality, irradiation from a given rotational angle is performed once with z-axis proton beam energy and intensity being adjusted for the calculated smaller inner tumors during x- and y-axis scanning. Referring now to FIG. 26, the proton delivery enhancement method is further described. Referring now to FIG. 26A, at a first point in time protons are delivered to the tumor 2120 of the patient 2130 from a first direction. From the first rotational direction, the proton beam is scanned 269 across the tumor. As the proton beam is scanned across the tumor the energy of the proton beam is adjusted to allow the Bragg peak energy to target the distal portion of the tumor. Again, distal refers to the back portion of the tumor located furthest away from where the charged particles enter the tumor. As illustrated, the proton beam is scanned along an x-axis across the patient. This process allows the Bragg peak energy to fall within the tumor, for the middle area of the Bragg peak profile to fall in the middle and proximal portion of the tumor, and for the small intensity ingress portion of the Bragg peak to hit healthy tissue. In this manner, the maximum radiation dose is delivered to the tumor or the proton dose efficiency is maximized for the first rotational direction. After irradiation from the first rotational position, the patient is rotated to a new rotational position. Referring now to FIG. 26B, the scanning of the proton beam is repeated. Again, the distal portion of the tumor is targeted with adjustment of the proton beam energy to target the Bragg peak energy to the distal portion of the tumor. Naturally, the distal portion of the tumor for the second rotational position is different from the distal portion of the tumor for the first rotational position. Referring now to FIG. 26C, the process of rotating the patient and then irradiating the new distal portion of the tumor is further illustrated at an nth rotational position. Preferably, the process of rotating the patient and scanning along the x- and y-axes with the Z-axes energy targeting the new distal portion of the tumor is repeated, such as with more than 5, 10, 20, or 30 rotational positions or with about 36 rotational positions. For clarity, FIGS. 26A-C and FIG. 26 E show the proton beam as having moved, but in actuality, the proton beam is stationary and the patient is rotated, such as via use of rotating the bottom unit 2112 of the patient positioning system 2110. Also, FIGS. 26A-C and FIG. 26E show the proton beam being scanned across the tumor along the x-axis. Though not illustrated for clarity, the proton beam is additionally scanned up and down the tumor along the y-axis of the patient. Combined, the distal portion or volume of the tumor is irradiated along the x- and y-axes with adjustment of the z-axis energy level of the proton beam. In one case, the tumor is scanned along the x-axis and the scanning is repeated along the x-axis for multiple y-axis positions. In another case, the tumor is scanned along the y-axis and the scanning is repeated along the y-axis for multiple x-axis positions. In yet another case, the tumor is scanned by simultaneously adjusting the x- and y-axes so that the distal portion of the tumor is targeted. In all of these cases, the z-axis or energy of the proton beam is adjusted along the contour of the distal portion of the tumor to target the Bragg peak energy to the distal portion of the tumor. Referring now to FIG. 26D, after targeting the distal portion of the tumor from multiple directions, such as through 360 degrees, the outer tumor perimeter 2122 tumor has been strongly irradiated with peak Bragg profile energy, the middle of the Bragg peak energy profile energy has been delivered along an inner edge of the heavily irradiated tumor perimeter 2122, and smaller dosages from the ingress portion of the Bragg energy profile are distributed throughout the tumor and into some healthy tissue. The delivered dosages or accumulated radiation flux levels are illustrated in a cross-sectional area of the tumor 2120 using an iso-line plot. After a first full rotation of the patient, symbolically, the darkest regions of the tumor are nearly fully irradiated and the regions of the tissue having received less radiation are illustrated with a gray scale with the whitest portions having the lowest radiation dose. Referring now to FIG. 26E, after completing the distal targeting multi-field irradiation, a smaller inner tumor is defined, where the inner tumor is already partially irradiated. The smaller inner tumor is indicated by the dashed line 2630. The above process of irradiating the tumor is repeated for the newly defined smaller tumor. The proton dosages to the outer or distal portions of the smaller tumor are adjusted to account for the dosages delivered from other rotational positions. After the second tumor is irradiated, a yet smaller third tumor is defined. The process is repeated until the entire tumor is irradiated at the prescribed or defined dosage. As described at the onset of this example, the patient is preferably only rotated to each rotational position once. In the above described example, after irradiation of the outer tumor perimeter 2122, the patient is rotationally positioned, such as through 360 degrees, and the distal portion of the newest smaller tumor is targeted as described, supra. However, the irradiation dosage to be delivered to the second smaller tumor and each subsequently smaller tumor is known a-priori. Hence, when at a given angle of rotation, the smaller tumor or multiple progressively smaller tumors, are optionally targeted so that the patient is only rotated to the multiple rotational irradiation positions once. The goal is to deliver a treatment dosage to each position of the tumor, to preferably not exceed the treatment dosage to any position of the tumor, to minimize ingress radiation dosage to healthy tissue, to circumferentially distribute ingress radiation hitting the healthy tissue, and to further minimize ingress radiation dosage to sensitive areas. Since the Bragg energy profile is known, it is possible to calculated the optimal intensity and energy of the proton beam for each rotational position and for each x- and y-axis scanning position. These calculation result in slightly less than threshold radiation dosage to be delivered to the distal portion of the tumor for each rotational position as the ingress dose energy from other positions bring the total dose energy for the targeted position up to the threshold delivery dose. Referring again to FIG. 26A and FIG. 26C, the intensity of the proton beam is preferably adjusted to account for the cross-sectional distance or density of the healthy tissue. An example is used for clarity. Referring now to FIG. 26A, when irradiating from the first position where the healthy tissue has a small area 2610, the intensity of the proton beam is preferably increased as relatively less energy is delivered by the ingress portion of the Bragg profile to the healthy tissue. Referring now to FIG. 26C, in contrast when irradiating from the nth rotational position where the healthy tissue has a large cross-sectional area 2620, the intensity of the proton beam is preferably decreased as a greater fraction the proton dose is delivered to the healthy tissue from this orientation. In one example, for each rotational position and/or for each z-axis distance into the tumor, the efficiency of proton dose delivery to the tumor is calculated. The intensity of the proton beam is made proportional to the calculated efficiency. Essentially, when the scanning direction has really good efficiency, the intensity is increased and vise-versa. For example, if the tumor is elongated, generally the efficiency of irradiating the distal portion by going through the length of the tumor is higher than irradiating a distal region of the tumor by going across the tumor with the Bragg energy distribution. Generally, in the optimization algorithm: distal portions of the tumor are targeted for each rotational position; the intensity of the proton beam is largest with the largest cross-sectional area of the tumor; intensity is larger when the intervening healthy tissue volume is smallest; and intensity is minimized or cut to zero when the intervening healthy tissue volume includes sensitive tissue, such as the spinal cord or eyes. Using an algorithm so defined, the efficiency of radiation dose delivery to the tumor is maximized. More particularly, the ratio of radiation dose delivered to the tumor versus the radiation dose delivered to surrounding healthy tissue approaches a maximum. Further, integrated radiation dose delivery to each x, y, and z-axis volume of the tumor as a result of irradiation from multiple rotation directions is at or near the preferred dose level. Still further, ingress radiation dose delivery to healthy tissue is circumferentially distributed about the tumor via use of multi-field irradiation where radiation is delivered from a plurality of directions into the body, such as more than 5, 10, 20, or 30 directions. Multi-Field Irradiation In one multi-field irradiation example, the particle therapy system with a synchrotron ring diameter of less than six meters includes ability to: rotate the patient through about 360 degrees; extract radiation in about 0.1 to 10 seconds; scan vertically about 100 millimeters; scan horizontally about 700 millimeters; vary beam energy from about 30 to 330 MeV/second during irradiation; vary the proton beam intensity independently of varying the proton beam energy; focus the proton beam with a cross-sectional distance from about 2 to 20 millimeters at the tumor; and/or complete multi-field irradiation of a tumor in less than about 1, 2, 4, or 6 minutes as measured from the time of initiating proton delivery to the patient 2130. Two multi-field irradiation methods are described. In the first method, the main controller 110 rotationally positions the patient 2130 and subsequently irradiates the tumor 2120. The process is repeated until a multi-field irradiation plan is complete. In the second method, the main controller 110 simultaneously rotates and irradiates the tumor 2120 within the patient 2130 until the multi-field irradiation plan is complete. More particularly, the proton beam irradiation occurs while the patient 2130 is being rotated. The 3-dimensional scanning system of the proton spot focal point, described herein, is preferably combined with a rotation/raster method. The method includes layer wise tumor irradiation from many directions. During a given irradiation slice, the proton beam energy is continuously changed according to the tissue's density in front of the tumor to result in the beam stopping point, defined by the Bragg peak, always being inside the tumor and inside the irradiated slice. The novel method allows for irradiation from many directions, referred to herein as multi-field irradiation, to achieve the maximal effective dose at the tumor level while simultaneously significantly reducing possible side-effects on the surrounding healthy tissues in comparison to existing methods. Essentially, the multi-field irradiation system distributes dose-distribution at tissue depths not yet reaching the tumor. Proton Beam Position Control Referring now to FIG. 27A, a beam delivery and tissue volume scanning system is illustrated. Presently, the worldwide radiotherapy community uses a method of dose field forming using a pencil beam scanning system. In stark contrast, FIG. 27 illustrates a spot scanning system or tissue volume scanning system. In the tissue volume scanning system, the proton beam is controlled, in terms of transportation and distribution, using an inexpensive and precise scanning system. The scanning system is an active system, where the beam is focused into a spot focal point of about one-half, one, two, or three millimeters in diameter. The focal point is translated along two axes while simultaneously altering the applied energy of the proton beam, which effectively changes the third dimension of the focal point. The system is applicable in combination with the above described rotation of the body, which preferably occurs in-between individual moments or cycles of proton delivery to the tumor. Optionally, the rotation of the body by the above described system occurs continuously and simultaneously with proton delivery to the tumor. For example, in the illustrated system in FIG. 27A, the spot is translated horizontally, is moved down a vertical y-axis, and is then back along the horizontal axis. In this example, current is used to control a vertical scanning system having at least one magnet. The applied current alters the magnetic field of the vertical scanning system to control the vertical deflection of the proton beam. Similarly, a horizontal scanning magnet system controls the horizontal deflection of the proton beam. The degree of transport along each axes is controlled to conform to the tumor cross-section at the given depth. The depth is controlled by changing the energy of the proton beam. For example, the proton beam energy is decreased, so as to define a new penetration depth, and the scanning process is repeated along the horizontal and vertical axes covering a new cross-sectional area of the tumor. Combined, the three axes of control allow scanning or movement of the proton beam focal point over the entire volume of the cancerous tumor. The time at each spot and the direction into the body for each spot is controlled to yield the desired radiation does at each sub-volume of the cancerous volume while distributing energy hitting outside of the tumor. The focused beam spot volume dimension is preferably tightly controlled to a diameter of about 0.5, 1, or 2 millimeters, but is alternatively several centimeters in diameter. Preferred design controls allow scanning in two directions with: (1) a vertical amplitude of about 100 mm amplitude and frequency up to about 200 Hz; and (2) a horizontal amplitude of about 700 mm amplitude and frequency up to about 1 Hz. Proton Beam Energy Control In FIG. 27A, the proton beam is illustrated along a z-axis controlled by the beam energy, the horizontal movement is along an x-axis, and the vertical direction is along a y-axis. The distance the protons move along the z-axis into the tissue, in this example, is controlled by the kinetic energy of the proton. This coordinate system is arbitrary and exemplary. Referring now to FIG. 27B, preferably control of the proton beam is controlled in 3-dimensional space using two scanning magnet systems and by simultaneously varying and controlling the kinetic energy of the proton beam. The use of the extraction system, described supra, allows for different scanning patterns. Particularly, the system allows simultaneous adjustment of the x-, y-, and z-axes in the irradiation of the solid tumor. Stated again, instead of scanning along an x,y-plane and then adjusting energy of the protons, such as with a range modulation wheel, the system allows for moving along the z-axes while simultaneously adjusting the x- and or y-axes. Hence, rather than irradiating slices of the tumor, the tumor is optionally irradiated in three simultaneous dimensions. For example, the tumor is irradiated around an outer edge of the tumor in three dimensions. Then the tumor is irradiated around an outer edge of an internal section of the tumor. This process is repeated until the entire tumor is irradiated. The outer edge irradiation is preferably coupled with simultaneous rotation of the subject, such as about a vertical y-axis. This system allows for maximum efficiency of deposition of protons to the tumor, as defined as the ratio of the proton irradiation energy delivered to the tumor relative to the proton irradiation energy delivered to the healthy tissue. Combined, the system allows for multi-axes control of the charged particle beam system in a small space with a low or small power supply. For example, the system uses multiple magnets where each magnet has at least one edge focusing effect in each turning section of the synchrotron and/or multiple magnets having concentrating magnetic field geometry, as described supra. The multiple edge focusing effects in the circulating beam path of the synchrotron combined with the concentration geometry of the magnets and described extraction system yields a synchrotron having: a small circumference system, such as less than about 50 meters; a vertical proton beam size gap of about 2 cm; corresponding reduced power supply requirements associated with the reduced gap size; an extraction system not requiring a newly introduced magnetic field; acceleration or deceleration of the protons during extraction; and control of z-axis energy during extraction. The result is a 3-dimensional scanning system, x-, y-, and z-axes control, where the z-axes control resides in the synchrotron and where the z-axes energy is variably controlled during the extraction process inside the synchrotron. Proton Beam Intensity Control Referring now to FIG. 28, an intensity modulated 3-dimensional scanning system 2800 is described. Referring now to FIG. 28A, a proton beam is being scanned across and x- and/or y-axis as a function of time. With each time, the z-axis energy is optionally adjusted. In this case, from the first time, t1, to the third time, t3, the energy is increased, and from the third time, t3, to the fifth time, t5, the energy is decreased. Thus, the system is scanning in 3-dimensions along the x-, y-, and/or z-axes. Notably, the radiation energy delivery efficiency is increasing from t1 to t3 and decreasing from t3 to t5, where efficiency refers to the percentage of radiation delivered to the tumor. For example, at the third time, t3, the Bragg peak energy is located at the distal, or back, portion of the tumor located furthest away from the point of origin where the charged particles enter the tumor 2120. Delivered Bragg peak energy increases exponentially up to the maximum distance of proton energy penetration into the body. Hence, as illustrated the percentage of the delivered Bragg peak energy in the tumor is greatest at the third time period t3, which has the largest tumor cross-section pathlength, less at the second and fourth time periods, t2 and t4, and still less at the first and fifth time periods, t1 and t5, which have the smallest tumor cross-section pathlength Referring now to FIG. 28B, the intensity of the proton beam is also changing with time in a manner correlated with the radiation energy delivery efficiency. In this case, the intensity of the proton beam is greatest at the third time period t3, less at the second and fourth time periods, t2 and t4, and still less at the first and fifth time periods, t1 and t5. The intensity of the proton beam is adjusted to be more intense when radiation delivery efficiency increases using the proton beam extraction process 1800 and intensity control system 1900, described supra. Intensity is generally positively correlated with tumor cross-sectional pathlength, proton beam energy, and/or radiation delivery efficiency. Preferably, the distal portion of the tumor is targeted with each rotational position of the patient 2130 using the multi-field irradiation 2500, described supra, allowing repeated use of increased intensity at changing distal portions of the tumor 2120 as the patient 2130 is rotated in the multi-field irradiation system 2500. As an example, the intensity controller subsystem 1940 adjusts the radio-frequency field in the RF cavity system 1910 to yield an intensity to correlate with radiation delivery efficiency and/or with the irradiation plan 1960. Preferably, the intensity controller subsystem adjusts the intensity of the radiation beam using a reading of the actual intensity of the proton beam 1950 or from the feedback current from the extraction material 1930, which is proportional to the extracted beam intensity, as described supra. Thus, independent of the x- and y-axes targeting system and independent of the z-axis energy of the proton beam, the intensity of the proton beam is controlled, preferably in coordination with the multi-field irradiation system 2500, to yield peak intensities with greatest radiation delivery efficiency. The independent control of beam parameters allows use of a raster beam scanning system. Often, the greatest radiation delivery efficiency occurs, for a given rotational position of the patient, when the energy of the proton beam is largest. Hence, the intensity of the proton beam optionally correlates with the energy of the proton beam. The system is optionally timed with the patient's respiration cycle, as described infra. The system optionally operates in a raster beam scanning mode, as described infra. Proton Beam Position, Energy, and Intensity Control An example of a proton scanning or targeting system 140 used to direct the protons to the tumor with 4-dimensional scanning control is provided, where the 4-dimensional scanning control is along the x-, y-, and z-axes along with intensity control, as described supra. A fifth controllable axis is time. A sixth controllable axis is patient rotation. Typically, charged particles traveling along the transport path 268 are directed through a first axis control element 142, such as a vertical control, and a second axis control element 144, such as a horizontal control and into a tumor 2120. As described, supra, the extraction system also allows for simultaneous variation in the z-axis. Further, as described, supra, the intensity or dose of the extracted beam is optionally simultaneously and independently controlled and varied. Thus instead of irradiating a slice of the tumor, as in FIG. 27A, all four dimensions defining the targeting spot of the proton delivery in the tumor are simultaneously variable. The simultaneous variation of the proton delivery spot is illustrated in FIG. 27B by the spot delivery path 269 and in FIG. 28, where the intensity is controlled as a function of efficiency of radiation delivery. In one example, the protons are initially directed around an outer edge of the tumor and are then directed around an inner radius of the tumor. Combined with rotation of the subject about a vertical axis, a multi-field irradiation process is used where a not yet irradiated portion of the tumor is preferably irradiated at the further distance of the tumor from the proton entry point into the body. This yields the greatest percentage of the proton delivery, as defined by the Bragg peak, into the tumor and minimizes damage to peripheral healthy tissue. Raster Scanning Raster beam scanning is optionally used. In traditional spot targeting systems, a spot of the tumor is targeted, then the radiation beam is turned off, a new spot is targeted, and the radiation beam is turned on. The cycle is repeated with changes in the x- and/or y-axis position. In stark contrast, in the raster beam scanning system, the proton beam is scanned from position to position in the tumor without turning off the radiation beam. In the raster scanning system, the irradiation is not necessarily turned off between spots, rather the irradiation of the tumor is optionally continuous as the beam scans between 3-dimensional locations in the tumor. The velocity of the scanning raster beam is optionally independently controlled. Velocity is change in the x, y, z position of the spot of the scanning beam with time. Hence, in a velocity control system, the rate of movement of the proton beam from coordinate to coordinate optionally varies with time or has a mathematical change in velocity with time. Stated again, the movement of the spot of the scanning beam with time is optionally not constant as a function of time. Further, the raster beam scanning system optionally uses the simultaneous and/or independent control of the x- and/or y-axes position, energy of the proton beam, intensity of the proton beam, and rotational position of the patient using the acceleration, extraction systems, and rotation systems, described supra. In one example, a charged particle beam system for irradiation of a tumor of a patient, includes: a synchrotron configured with an extraction foil, where a timing controller times the charged particle beam striking the extraction foil in an acceleration period in the synchrotron resulting in extraction of the charged particle beam at a selected energy and a raster beam scanning system configured to scan the charged particle beam across delivery positions while both (1) constantly delivering the charged particle beam at and between the delivery positions and (2) simultaneously varying the selected energy level of the charged particle beam across the delivery positions. Preferably, an intensity controller is used that is configured to measure a current resulting from the charged particle beam striking the extraction foil, the current used as a feedback control to a radio-frequency cavity system, wherein an applied radio frequency, using the feedback control, in the radio-frequency cavity system controls the number of particles in the charged particle beam striking the extraction foil resulting in intensity control of the charged particle beam. Preferably, a velocity controller is configured to change a rate of movement of the charged particle beam between the delivery position along x- and/or y-axes in the tumor as a function of time. Imaging/X-Ray System Herein, an X-ray system is used to illustrate an imaging system. Timing An X-ray is preferably collected either (1) just before or (2) concurrently with treating a subject with proton therapy for a couple of reasons. First, movement of the body, described supra, changes the local position of the tumor in the body relative to other body constituents. If the patient or subject 2130 has an X-ray taken and is then bodily moved to a proton treatment room, accurate alignment of the proton beam to the tumor is problematic. Alignment of the proton beam to the tumor 2120 using one or more X-rays is best performed at the time of proton delivery or in the seconds or minutes immediately prior to proton delivery and after the patient is placed into a therapeutic body position, which is typically a fixed position or partially immobilized position. Second, the X-ray taken after positioning the patient is used for verification of proton beam alignment to a targeted position, such as a tumor and/or internal organ position. Positioning An X-ray is preferably taken just before treating the subject to aid in patient positioning. For positioning purposes, an X-ray of a large body area is not needed. In one embodiment, an X-ray of only a local area is collected. When collecting an X-ray, the X-ray has an X-ray path. The proton beam has a proton beam path. Overlaying the X-ray path with the proton beam path is one method of aligning the proton beam to the tumor. However, this method involves putting the X-ray equipment into the proton beam path, taking the X-ray, and then moving the X-ray equipment out of the beam path. This process takes time. The elapsed time while the X-ray equipment moves has a couple of detrimental effects. First, during the time required to move the X-ray equipment, the body moves. The resulting movement decreases precision and/or accuracy of subsequent proton beam alignment to the tumor. Second, the time required to move the X-ray equipment is time that the proton beam therapy system is not in use, which decreases the total efficiency of the proton beam therapy system. X-Ray Source Lifetime Preferably, components in the particle beam therapy system require minimal or no maintenance over the lifetime of the particle beam therapy system. For example, it is desirable to equip the proton beam therapy system with an X-ray system having a long lifetime source, such as a lifetime of about 20 years. In one system, described infra, electrons are used to create X-rays. The electrons are generated at a cathode where the lifetime of the cathode is temperature dependent. Analogous to a light bulb, where the filament is kept in equilibrium, the cathode temperature is held in equilibrium at temperatures at about 200, 500, or 1000 degrees Celsius. Reduction of the cathode temperature results in increased lifetime of the cathode. Hence, the cathode used in generating the electrons is preferably held at as low of a temperature as possible. However, if the temperature of the cathode is reduced, then electron emissions also decrease. To overcome the need for more electrons at lower temperatures, a large cathode is used and the generated electrons are concentrated. The process is analogous to compressing electrons in an electron gun; however, here the compression techniques are adapted to apply to enhancing an X-ray tube lifetime. Referring now to FIG. 29, an example of an X-ray generation device 2900 having an enhanced lifetime is provided. Electrons 2920 are generated at a cathode 2910, focused with a control electrode 2912, and accelerated with a series of accelerating electrodes 2940. The accelerated electrons 2950 impact an X-ray generation source 2948 resulting in generated X-rays that are then directed along an X-ray path 3070 to the subject 2130. The concentrating of the electrons from a first diameter 2915 to a second diameter 2916 allows the cathode to operate at a reduced temperature and still yield the necessary amplified level of electrons at the X-ray generation source 2948. In one example, the X-ray generation source 2948 is the anode coupled with the cathode 2910 and/or the X-ray generation source is substantially composed of tungsten. Still referring to FIG. 29, a more detailed description of an exemplary X-ray generation device 2900 is described. An anode 2914/cathode 2910 pair is used to generated electrons. The electrons 2920 are generated at the cathode 2910 having a first diameter 2915, which is denoted d1. The control electrodes 2912 attract the generated electrons 2920. For example, if the cathode is held at about −150 kV and the control electrode is held at about −149 kV, then the generated electrons 2920 are attracted toward the control electrodes 2912 and focused. A series of accelerating electrodes 2940 are then used to accelerate the electrons into a substantially parallel path 2950 with a smaller diameter 2916, which is denoted d2. For example, with the cathode held at −150 kV, a first, second, third, and fourth accelerating electrodes 2942, 2944, 2946, 2948 are held at about −120, −90, −60, and −30 kV, respectively. If a thinner body part is to be analyzed, then the cathode 2910 is held at a smaller level, such as about −90 kV and the control electrode, first, second, third, and fourth electrode are each adjusted to lower levels. Generally, the voltage difference from the cathode to fourth electrode is less for a smaller negative voltage at the cathode and vise-versa. The accelerated electrons 2950 are optionally passed through a magnetic lens 2960 for adjustment of beam size, such as a cylindrical magnetic lens. The electrons are also optionally focused using quadrupole magnets 2970, which focus in one direction and defocus in another direction. The accelerated electrons 2950, which are now adjusted in beam size and focused strike the X-ray generation source 2948, such as tungsten, resulting in generated X-rays that pass through an optional blocker 3062 and proceed along an X-ray path 3070 to the subject. The X-ray generation source 2948 is optionally cooled with a cooling element 2949, such as water touching or thermally connected to a backside of the X-ray generation source 2948. The concentrating of the electrons from a first diameter 2915 to a second diameter 2916 allows the cathode to operate at a reduced temperature and still yield the necessary amplified level of electrons at the X-ray generation source 2948. More generally, the X-ray generation device 2900 produces electrons having initial vectors. One or more of the control electrode 2912, accelerating electrodes 2940, magnetic lens 2960, and quadrupole magnets 2970 combine to alter the initial electron vectors into parallel vectors with a decreased cross-sectional area having a substantially parallel path, referred to as the accelerated electrons 2950. The process allows the X-ray generation device 2900 to operate at a lower temperature. Particularly, instead of using a cathode that is the size of the electron beam needed, a larger electrode is used and the resulting electrons 2920 are focused and/or concentrated into the required electron beam needed. As lifetime is roughly an inverse of current density, the concentration of the current density results in a larger lifetime of the X-ray generation device. A specific example is provided for clarity. If the cathode has a fifteen mm radius or d1 is about 30 mm, then the area (πr2) is about 225 mm2 times pi. If the concentration of the electrons achieves a radius of five mm or d2 is about 10 mm, then the area (πr2) is about 25 mm2 times pi. The ratio of the two areas is about nine (225π/25π). Thus, there is about nine times less density of current at the larger cathode compared to the traditional cathode having an area of the desired electron beam. Hence, the lifetime of the larger cathode approximates nine times the lifetime of the traditional cathode, though the actual current through the larger cathode and traditional cathode is about the same. Preferably, the area of the cathode 2910 is about 2, 4, 6, 8, 10, 15, 20, or 25 times that of the cross-sectional area of the substantially parallel electron beam 2950. In another embodiment of the invention, the quadrupole magnets 2970 result in an oblong cross-sectional shape of the electron beam 2950. A projection of the oblong cross-sectional shape of the electron beam 2950 onto the X-ray generation source 2948 results in an X-ray beam 3070 that has a small spot in cross-sectional view, which is preferably substantially circular in cross-sectional shape, that is then passed through the patient 2930. The small spot is used to yield an X-ray having enhanced resolution at the patient. Referring now to FIG. 30, in one embodiment, an X-ray is generated close to, but not in, the proton beam path. A proton beam therapy system and an X-ray system combination 3000 is illustrated in FIG. 30. The proton beam therapy system has a proton beam 268 in a transport system after the Lambertson extraction magnet 292 of the synchrotron 130. The proton beam is directed by the scanning/targeting/delivery system 140 to a tumor 2120 of a patient 2130. The X-ray system 3005 includes an electron beam source 2905 generating an electron beam 2950. The electron beam is directed to an X-ray generation source 2948, such as a piece of tungsten. Preferably, the tungsten X-ray source is located about 1, 2, 3, 5, 10, 15, or 20 millimeters from the proton beam path 268. When the electron beam 2950 hits the tungsten, X-rays are generated in all directions. X-rays are blocked with a port 3062 and are selected for an X-ray beam path 3070. The X-ray beam path 3070 and proton beam path 268 run substantially in parallel as they progress to the tumor 2120. The distance between the X-ray beam path 3070 and proton beam path 269 preferably diminishes to near zero and/or the X-ray beam path 3070 and proton beam path 269 overlap by the time they reach the tumor 2120. Simple geometry shows this to be the case given the long distance, of at least a meter, between the tungsten and the tumor 2120. The distance is illustrated as a gap 3080 in FIG. 30. The X-rays are detected at an X-ray detector 3090, which is used to form an image of the tumor 2120 and/or position of the patient 2130. As a whole, the system generates an X-ray beam that lies in substantially the same path as the proton therapy beam. The X-ray beam is generated by striking a tungsten or equivalent material with an electron beam. The X-ray generation source is located proximate to the proton beam path. Geometry of the incident electrons, geometry of the X-ray generation material, and/or geometry of the X-ray beam blocker 262 yield an X-ray beam that runs either substantially in parallel with the proton beam or results in an X-ray beam path that starts proximate the proton beam path an expands to cover and transmit through a tumor cross-sectional area to strike an X-ray detector array or film allowing imaging of the tumor from a direction and alignment of the proton therapy beam. The X-ray image is then used to control the charged particle beam path to accurately and precisely target the tumor, and/or is used in system verification and validation. Referring now to FIG. 31, additional geometry of the electron beam path 2950 and X-ray beam path 3070 is illustrated. Particularly, the electron beam 2950 is shown as an expanded electron beam path 2952, 2954. Also, the X-ray beam path 3070 is shown as an expanded X-ray beam path 3072, 3074. Referring now to FIG. 32, a 3-dimensional (3-D) X-ray tomography system 3200 is presented. In a typical X-ray tomography system, the X-ray source and detector rotationally translate about a stationary subject. In the X-ray tomography system described herein, the X-ray source and detector are stationary and the patient 2130 rotates. The stationary X-ray source allows a system where the X-ray source 2948 is proximate the proton therapy beam path 268, as described supra. In addition, the rotation of the patient 2130 allows the proton dosage to be distributed around the body, rather than being concentrated on one static entrance side of the body. Further, the 3-D X-ray tomography system allows for simultaneous updates of the tumor position relative to body constituents in real-time during proton therapy treatment of the tumor 2120 in the patient 2130. The X-ray tomography system is further described, infra. Patient Imaging with Rotation In a first step of the X-ray tomography system 3200, the patient 2130 is positioned relative to the X-ray beam path 3070 and proton beam path 268 using a patient semi-immobilization/placement system, described infra. After patient 2130 positioning, a series of reference 2-D X-ray images are collected, on a detector array 3090 or film, of the patient 2130 and tumor 2120 as the subject is rotated about a y-axis 2117. For example, a series of about 50, 100, 200, or 400 X-ray images of the patient are collected as the patient is rotated. In a second example, an X-ray image is collected with each n degrees of rotation of the patient 2130, where n is about ½, 1, 2, 3, 5, 10, or 20 degrees of rotation. Preferably, about 200 images are collected during one full rotation of the patient through 360 degrees. Subsequently, using the reference 2-D X-ray images, an algorithm produces a reference 3-D picture of the tumor 2120 relative to the patient's constituent body parts. A tumor 2120 irradiation plan is made using the 3-D picture of the tumor 2120 and the patient's constituent body parts. Creation of the proton irradiation plan is optionally performed after the patient has moved from the X-ray imaging area. In a second step, the patient 2130 is repositioned relative to the X-ray beam path 3070 and proton beam path 268 using the patient semi-immobilization/placement system. Just prior to implementation of the proton irradiation plan, a few comparative X-ray images of the patient 2130 and tumor 2120 are collected at a limited number of positions using the X-ray tomography system 2600 setup. For example, a single X-ray image is collected with the patient positioned straight on, at angles of plus/minus forty-five degrees, and/or at angles of plus/minus ninety degrees relative to the proton beam path 268. The actual orientation of the patient 2130 relative to the proton beam path 268 is optionally any orientation. The actual number of comparative X-ray images is also optionally any number of images, though the preferable number of comparative X-ray images is about 2 to 5 comparative images. The comparative X-ray images are compared to the reference X-ray images and differences are detected. A medical expert or an algorithm determines if the difference between the reference images and the comparative images is significant. Based upon the differences, the medical expert or algorithm determines if: proton treatment should commence, be halted, or adapted in real-time. For example, if significant differences in the X-ray images are observed, then the treatment is preferably halted and the process of collecting a reference 3-D picture of the patient's tumor is reinitiated. In a second example, if the differences in the X-ray images are observed to be small, then the proton irradiation plan commences. In a third example, the algorithm or medical expert can adapt the proton irradiation plan in real-time to adjust for differences in tumor location resulting from changes in position of the tumor 2120 in the patient 2130 or from differences in the patient 2130 placement. In the third example, the adaptive proton therapy increases patient throughput and enhances precision and accuracy of proton irradiation of the tumor 2120 relative to the healthy tissue of the patient 2130. Patient Immobilization Accurate and precise delivery of a proton beam to a tumor of a patient requires: (1) positioning control of the proton beam and (2) positioning control of the patient. As described, supra, the proton beam is controlled using algorithms and magnetic fields to a diameter of about 0.5, 1, or 2 millimeters. This section addresses partial immobilization, restraint, and/or alignment of the patient to insure the tightly controlled proton beam efficiently hits a target tumor and not surrounding healthy tissue as a result of patient movement. Herein, an x-, y-, and z-axes coordinate system and rotation axis is used to describe the orientation of the patient relative to the proton beam. The z-axis represent travel of the proton beam, such as the depth of the proton beam into the patient. When looking at the patient down the z-axis of travel of the proton beam, the x-axis refers to moving left or right across the patient and the y-axis refers to movement up or down the patient. A first rotation axis is rotation of the patient about the y-axis and is referred to herein as a rotation axis, bottom unit 2112 rotation axis, or y-axis of rotation 2117. In addition, tilt is rotation about the x-axis, yaw is rotation about the y-axis, and roll is rotation about the z-axis. In this coordinate system, the proton beam path 269 optionally runs in any direction. As an illustrative matter, the proton beam path running through a treatment room is described as running horizontally through the treatment room. In this section, three examples of positioning systems are provided: (1) a semi-vertical partial immobilization system 3300; (2) a sitting partial immobilization system 3400; and (3) a laying position 3500. Elements described for one immobilization system apply to other immobilization systems with small changes. For example, a headrest, a head support, or head restraint will adjust along one axis for a reclined position, along a second axis for a seated position, and along a third axis for a laying position. However, the headrest itself is similar for each immobilization position. Vertical Patient Positioning/Immobilization Referring now to FIG. 33, the semi-vertical patient positioning system 3300 is preferably used in conjunction with proton therapy of tumors in the torso. The patient positioning and/or immobilization system controls and/or restricts movement of the patient during proton beam therapy. In a first partial immobilization embodiment, the patient is positioned in a semi-vertical position in a proton beam therapy system. As illustrated, the patient is reclining at an angle alpha, α, about 45 degrees off of the y-axis as defined by an axis running from head to foot of the patient. More generally, the patient is optionally completely standing in a vertical position of zero degrees off the of y-axis or is in a semi-vertical position alpha that is reclined about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, or 65 degrees off of the y-axis toward the z-axis. Patient positioning constraints 3315 that are used to maintain the patient in a treatment position, include one or more of: a seat support 3320, a back support 3330, a head support 3340, an arm support 3350, a knee support 3360, and a foot support 3370. The constraints are optionally and independently rigid or semi-rigid. Examples of a semi-rigid material include a high or low density foam or a visco-elastic foam. For example the foot support is preferably rigid and the back support is preferably semi-rigid, such as a high density foam material. One or more of the positioning constraints 3315 are movable and/or under computer control for rapid positioning and/or immobilization of the patient. For example, the seat support 3320 is adjustable along a seat adjustment axis 3322, which is preferably the y-axis; the back support 3330 is adjustable along a back support axis 3332, which is preferably dominated by z-axis movement with a y-axis element; the head support 3340 is adjustable along a head support axis 3342, which is preferably dominated by z-axis movement with a y-axis element; the arm support 3350 is adjustable along an arm support axis 3352, which is preferably dominated by z-axis movement with a y-axis element; the knee support 3360 is adjustable along a knee support axis 3362, which is preferably dominated by z-axis movement with a y-axis element; and the foot support 3370 is adjustable along a foot support axis 3372, which is preferably dominated by y-axis movement with a z-axis element. If the patient is not facing the incoming proton beam, then the description of movements of support elements along the axes change, but the immobilization elements are the same. An optional camera 3380 is used with the patient immobilization system. The camera views the patient/subject 2130 creating a video image. The image is provided to one or more operators of the charged particle beam system and allows the operators a safety mechanism for determining if the subject has moved or desires to terminate the proton therapy treatment procedure. Based on the video image, the operators optionally suspend or terminate the proton therapy procedure. For example, if the operator observes via the video image that the subject is moving, then the operator has the option to terminate or suspend the proton therapy procedure. An optional video display or display monitor 3390 is provided to the patient. The video display optionally presents to the patient any of: operator instructions, system instructions, status of treatment, or entertainment. Motors for positioning the patient positioning constraints 3315, the camera 3380, and/or video display 3390 are preferably mounted above or below the proton transport path 268 or momentary proton scanning path 269. Respiration control is optionally performed by using the video display. As the patient breathes, internal and external structures of the body move in both absolute terms and in relative terms. For example, the outside of the chest cavity and internal organs both have absolute moves with a breath. In addition, the relative position of an internal organ relative to another body component, such as an outer region of the body, a bone, support structure, or another organ, moves with each breath. Hence, for more accurate and precise tumor targeting, the proton beam is preferably delivered at a point in time where the position of the internal structure or tumor is well defined, such as at the bottom or top of each breath. The video display is used to help coordinate the proton beam delivery with the patient's respiration cycle. For example, the video display optionally displays to the patient a command, such as a hold breath statement, a breathe statement, a countdown indicating when a breath will next need to be held, or a countdown until breathing may resume. Sitting Patient Positioning/Immobilization In a second partial immobilization embodiment, the patient is partially restrained in a seated position 3400. The sitting restraint system uses support structures similar to the support structures in the semi-vertical positioning system, described supra, with an exception that the seat support is replaced by a chair and the knee support is not required. The seated restraint system generally retains the adjustable support, rotation about the y-axis, camera, video, and breath control parameters described in the semi-vertical embodiment, described supra. Referring now to FIG. 34, a particular example of a sitting patient semi-immobilization system 3400 is provided. The sitting system is preferably used for treatment of head and/or neck tumors. As illustrated, the patient is positioned in a seated position on a chair 3410 for particle therapy. The patient is further immobilized using any of the: the head support 3340, the back support 3330, the hand support 3350, the knee support 3360, and the foot support 3370. The supports 3320, 3330, 3340, 3350, 3360, 3370 preferably have respective axes of adjustment 3322, 3332, 3342, 3352, 3362, 3372 as illustrated. The chair 3410 is either readily removed to allow for use of a different patient constraint system or adapts under computer control to a new patient position, such as the semi-vertical system. Laying Patient Positioning/Immobilization In a third partial immobilization embodiment, the patient is partially restrained in a laying position. Referring now to FIG. 34, the laying restraint system 3500 has support structures that are similar to the support structures used in the sitting positioning system 3400 and semi-vertical positioning system 3300, described supra. In the laying position, optional restraint, support, or partial immobilization elements include one or more of: the head support 3340 and the back support, hip, and shoulder 3330 support. The supports preferably have respective axes of adjustment that are rotated as appropriate for a laying position of the patient. The laying position restraint system generally retains the adjustable supports, rotation about the y-axis, camera, video, and breath control parameters described in the semi-vertical embodiment, described supra. If the patient is very sick, such as the patient has trouble standing for a period of about one to three minutes required for treatment, then being in a partially supported system can result in some movement of the patient due to muscle strain. In this and similar situations, treatment of a patient in a laying position on a support table 3520 is preferentially used. The support table has a horizontal platform to support the bulk of the weight of the patient. Preferably, the horizontal platform is detachable from a treatment platform. In a laying positioning system 3500, the patient is positioned on a platform 3510, which has a substantially horizontal portion for supporting the weight of the body in a horizontal position. Optional hand grips are used, described infra. In one embodiment, the platform 3510 affixes relative to the table 3520 using a mechanical stop or lock element 3530 and matching key element 3535 and/or the patient 2130 is aligned or positioned relative to a placement element 3560. Additionally, upper leg support 3544, lower leg support 3540, and/or arm support 3550 elements are optionally added to raise, respectively, an arm or leg out of the proton beam path 269 for treatment of a tumor in the torso or to move an arm or leg into the proton beam path 269 for treatment of a tumor in the arm or leg. This increases proton delivery efficiency, as described supra. The leg supports 3540, 3544 and arm support 3550 are each optionally adjustable along support axes or arcs 3542, 3546, 3552. One or more leg support elements are optionally adjustable along an arc to position the leg into the proton beam path 269 or to remove the leg from the proton beam path 269, as described infra. An arm support element is preferably adjustable along at least one arm adjustment axis or along an arc to position the arm into the proton beam path 269 or to remove the arm from the proton beam path 269, as described infra. Preferably, the patient is positioned on the platform 3510 in an area or room outside of the proton beam path 268 and is wheeled or slid into the treatment room or proton beam path area. For example, the patient is wheeled into the treatment room on a gurney where the top of the gurney, which is the platform, detaches and is positioned onto a table. The platform is preferably lifted onto the table or slid onto the table so that the gurney or bed need not be lifted onto the table. The semi-vertical patient positioning system 3300 and sitting patient positioning system 3400 are preferentially used to treatment of tumors in the head or torso due to efficiency. The semi-vertical patient positioning system 3300, sitting patient positioning system 3400, and laying patient positioning system 3500 are all usable for treatment of tumors in the patient's limbs. Support System Elements Positioning constraints 3315 include all elements used to position the patient, such as those described in the semi-vertical positioning system 3300, sitting positioning system 3400, and laying positioning system 3500. Preferably, positioning constraints or support system elements are aligned in positions that do not impede or overlap the proton beam path 269. However, in some instances the positioning constraints are in the proton beam path 269 during at least part of the time of treatment of the patient. For instance, a positioning constraint element may reside in the proton beam path 269 during part of a time period where the patient is rotated about the y-axis during treatment. In cases or time periods that the positioning constraints or support system elements are in the proton beam path, then an upward adjustment of proton beam energy is preferably applied that increases the proton beam energy to offset the positioning constraint element impedance of the proton beam. This time period and energy is a function of rotational orientation of the patient. In one case, the proton beam energy is increased by a separate measure of the positioning constraint element impedance determined during a reference scan of the positioning constraint system element or set of reference scans of the positioning constraint element as a function of rotation about the y-axis. For clarity, the positioning constraints 3315 or support system elements are herein described relative to the semi-vertical positioning system 3300; however, the positioning elements and descriptive x-, y-, and z-axes are adjustable to fit any coordinate system, to the sitting positioning system 3400, or the laying positioning system 3500. An example of a head support system is described to support, align, and/or restrict movement of a human head. The head support system preferably has several head support elements including any of: a back of head support, a right of head alignment element, and a left of head alignment element. The back of head support element is preferably curved to fit the head and is optionally adjustable along a head support axis, such as along the z-axis. Further, the head supports, like the other patient positioning constraints, is preferably made of a semi-rigid material, such as a low or high density foam, and has an optional covering, such as a plastic or leather. The right of head alignment element and left of head alignment elements or head alignment elements, are primarily used to semi-constrain movement of the head or to fully immobilize the head. The head alignment elements are preferably padded and flat, but optionally have a radius of curvature to fit the side of the head. The right and left head alignment elements are preferably respectively movable along translation axes to make contact with the sides of the head. Restricted movement of the head during proton therapy is important when targeting and treating tumors in the head or neck. The head alignment elements and the back of head support element combine to restrict tilt, rotation or yaw, roll and/or position of the head in the x-, y-, z-axes coordinate system. Referring now to FIG. 36 another example of a head support system 3600 is described for positioning and/or restricting movement of a human head 2102 during proton therapy of a solid tumor in the head or neck. In this system, the head is restrained using 1, 2, 3, 4, or more straps or belts, which are preferably connected or replaceably connected to a back of head support element 3610. In the example illustrated, a first strap 3620 pulls or positions the forehead to the head support element 3610, such as by running predominantly along the z-axis. Preferably a second strap 3630 works in conjunction with the first strap 3620 to prevent the head from undergoing tilt, yaw, roll or moving in terms of translational movement on the x-, y-, and z-axes coordinate system. The second strap 3630 is preferably attached or replaceable attached to the first strap 3620 at or about: (1) a forehead position 3632; (2) at a position on one or both sides of the head 3634; and/or (3) at or about a position on the support element 3636. A third strap 3640 preferably orientates the chin of the subject relative to the support element 3610 by running dominantly along the z-axis. A fourth strap 3650 preferably runs along a predominantly y- and z-axes to hold the chin relative to the head support element 3610 and/or proton beam path. The third 3640 strap preferably is attached to or is replaceably attached to the fourth strap 3650 during use at or about the patient's chin position 3642. The second strap 3630 optionally connects 3636 to the fourth strap 3650 at or about the support element 3610. The four straps 3620, 3630, 3640, 3650 are illustrative in pathway and interconnection. Any of the straps optionally hold the head along different paths around the head and connect to each other in separate fashion. Naturally, a given strap preferably runs around the head and not just on one side of the head. Any of the straps 3620, 3630, 3640, and 3650 are optionally used independently or in combinations and permutations with the other straps. The straps are optionally indirectly connected to each other via a support element, such as the head support element 3610. The straps are optionally attached to the head support element 3610 using hook and loop technology, a buckle, or fastener. Generally, the straps combine to control position, front-to-back movement of the head, side-to-side movement of the head, tilt, yaw, roll, and/or translational position of the head. The straps are preferably of known impedance to proton transmission allowing a calculation of peak energy release along the z-axis to be calculated. For example, adjustment to the Bragg peak energy is made based on the slowing tendency of the straps to proton transport. Referring now to FIG. 37, still another example of a head support system 3340 is described. The head support 3340 is preferably curved to fit a standard or child sized head. The head support 3340 is optionally adjustable along a head support axis 3342. Further, the head supports, like the other patient positioning constraints, is preferably made of a semi-rigid material, such as a low or high density foam, and has an optional covering, such as a plastic or leather. Elements of the above described head support, head positioning, and head immobilization systems are optionally used separately or in combination. Still referring to FIG. 37, an example of the arm support 3350 is further described. The arm support preferably has a left hand grip 3710 and a right hand grip 3720 used for aligning the upper body of the patient 2130 through the action of the patient 2130 gripping the left and right hand grips 3710, 3720 with the patient's hands 2134. The left and right hand grips 3710, 3720 are preferably connected to the arm support 3350 that supports the mass of the patient's arms. The left and right hand grips 3710, 3720 are preferably constructed using a semi-rigid material. The left and right hand grips 3710, 3720 are optionally molded to the patient's hands to aid in alignment. The left and right hand grips optionally have electrodes, as described supra. Rapid Patient Positioning System In yet another embodiment, a rapid patient positioning system 3800 is provided, which facilitates positioning of the patient. In the above section, systems for the partial immobilization, restraint, and/or alignment of the patient were described to ensure the tightly controlled proton beam efficiently hits a target tumor and not surrounding healthy tissue as a result of patient movement. For example, the positioning system placing the patient into a laying position 3500 was described. In the current art, the patient lays in any position on a flat table. The resulting variation in patient placement on the table is necessarily compensated for using methods that require fifteen to twenty minutes. Further, many patients have physical and/or health constraints that make it difficult for the patient to climb onto the table. Herein, an alternative rapid patient positioning system 3800 is provided. Generally, the rapid patient positioning system 3800 contains several steps including: positioning the patient 2130 relative to a table 3510 in a substantially vertical orientation; optionally constraining motion of the patient 2130; transitioning the table 3510 through a semi-vertical orientation, such as with a robot arm; and orientating the patient 2130 and table 3510 in a substantially horizontal orientation, such as in a position for tumor 2120 therapy. Optionally, the robot arm is an arm in common with an arm used to move the patient 2130 in traditional proton therapy. Optionally, the robot arm is used to re-orientate the patient 2130 into a substantially vertical orientation at the conclusion of a charged particle therapy session. Referring now to FIG. 38, an example of the rapid patient positioning system 3800 is provided. In this example, the patient 2130 is positioned relative to a table 3510 in a substantially vertical orientation at a first point in time, t1. For example, the patient 2130 leans against the table 3510 held in a substantially vertical orientation, such as at an angle α that is vertical or about 5, 10, 15, 20, 25, or 30 degrees off of vertical. Any of the above described positioning constraints 3315, such as the seat support 3320, the back support 3330, the head support 3340, the arm support 3350, the knee support 3360, and/or the foot support 3370 are optionally used to position the patient 2130 relative to the substantially vertical table 3510. Alternative embodiments of the foot support 3370, the back support 3330, and the head support 3340 are illustrated in FIG. 38. Additionally, FIG. 38 illustrates a knee back support 3364, which is an example of a positioning constraint 3315. The knee back support 3364 supports the back of the knee of the patient 2130 off of the table 3510. At the first point in time, t1, one or more of the positioning constraints 3315 substantially align the patient relative to the table 3510 in an orientation that the patient can readily access. Preferably, the foot of the table 3510 is resting on the floor or is within 10, 20, or 30 centimeters of the floor to facilitate the patient stepping onto the foot support 3370 attached to the table 3510. Subsequently, at a second point in time, t2, the table 3510 is re-orientated through a semi-vertical orientation by one or more robot arms 3850, such as a first robot arm positioned near the head of a table 3510 or a second robot arm positioned at a foot of the table 3510. At a third point in time, t3, the preferably single robot arm 3850 finalizes orientation of the table 3510 into a substantially horizontal position. In this manner, the patient 2130 us rapidly positioned onto the table 3510 in a fixed position in a time period of less than 1, 2, or 3 minutes. As described, infra, the positions of one or more elements of one or more of the positioning constraints 3315 are recorded digitally and are later used in a step of computer controlled repositioning of the patient in the minutes or seconds prior to implementation of the irradiation element of the tumor treatment plan. In yet another embodiment, a patient support system 3900 is used to facilitate positioning of the patient 2130. Referring now to FIG. 39, a patient 2130 is illustrated relative to a support 3301, such as the table 3510 or an element attached to the table 3510. In this example, two positioning constraints 3315 are illustrated, an embodiment of the head constraint 3340 and an embodiment of the back constraint 3330. In this example, the back constraint 3330 has at least degrees of freedom along the x- and/or z-axes for an arbitrary axis system with the z-axis running through the patient 2130 from front to back and the z-axis running from the patient's left shoulder to right shoulder. Preferably, one or both of the x- and z-axes degrees of freedom are under computer and motor control, as described infra for the positioning constraints 3315. Still referring now to FIG. 39, to illustrate the degrees of freedom of the back constraint 3330, the patient is illustrated at three points of time, t1, t2, t3, with the back constraint 3330 in varying configurations. Referring now to FIG. 39A, at the first time, t1, the shoulders of the patient 2130 are observed to not fit into the back constraint 3330. Referring now to FIG. 39B, at the second point in time, t2, a left and a right side of the back constraints have been adjusted along the x-axis in opposite directions a first distance, d1, to a point where the shoulders fit comfortably but are constrained between the left side and the right side of the back constraint 3330. Referring now to FIG. 39A and FIG. 39B, at the first and second time, t1 and t2, the back of the patient 2130 is observed to not be relaxed relative to the head of the patient 2130. Referring now to FIG. 39C, at the third time, t3, the back constraint 3330 has been adjusted along the z-axis a second distance, d2, to allow the back of the shoulders to relax to a natural position along the z-axis relative to the head of the patient 2130. In practice, each of the back constraint 3330 degrees of freedom along the x- and z-axes are independently adjustable. Similarly, the head constraint 3340 is optionally adjustable along the z-axis relative to the back constraint 3330, which have a common fixed element of the support 3301 or table 3510, to achieve relaxation and constraint of the head relative to the shoulders of the patient 2130. The back constraint 3330 and head constraint 3340 of the patient support system 3900 allows for a comfortable, computer recorded, and computer adjustable patient support configuration. The patient support system 3900 is preferably integrated with the rapid patient positioning system 3800, described supra, to facilitate rapid, accurate, and/or precise alignment of the patient 2130 relative to the table 3510 in the charged particle therapy system described herein. Patient Respiration Monitoring Preferably, the patient's respiration pattern is monitored. When a subject or patient 2130 is breathing many portions of the body move with each breath. For example, when a subject breathes the lungs move as do relative positions of organs within the body, such as the stomach, kidneys, liver, chest muscles, skin, heart, and lungs. Generally, most or all parts of the torso move with each breath. Indeed, the inventors have recognized that in addition to motion of the torso with each breath, various motion also exists in the head and limbs with each breath. Motion is to be considered in delivery of a proton dose to the body as the protons are preferentially delivered to the tumor and not to surrounding tissue. Motion thus results in an ambiguity in where the tumor resides relative to the beam path. To partially overcome this concern, protons are preferentially delivered at the same point in each of a series of respiration cycles. Initially a rhythmic pattern of breathing of a subject is determined. The cycle is observed or measured. For example, an X-ray beam operator or proton beam operator can observe when a subject is breathing or is between breaths and can time the delivery of the protons to a given period of each breath. Alternatively, the subject is told to inhale, exhale, and/or hold their breath and the protons are delivered during the commanded time period. Preferably, one or more sensors are used to determine the respiration cycle of the individual. Two examples of a respiration monitoring system 4010 are provided: (1) a thermal monitoring system and (2) a force monitoring system. Referring again to FIG. 35, a first example of the thermal respiration monitoring system is provided. In the thermal respiration monitoring system, a sensor is placed by the nose and/or mouth of the patient. As the jaw of the patient is optionally constrained, as described supra, the thermal respiration monitoring system is preferably placed by the patient's nose exhalation path. To avoid steric interference of the thermal sensor system components with proton therapy, the thermal respiration monitoring system is preferably used when treating a tumor not located in the head or neck, such as a when treating a tumor in the torso or limbs. In the thermal monitoring system, a first thermal resistor 3670 is used to monitor the patient's respiration cycle and/or location in the patient's respiration cycle. Preferably, the first thermal resistor 3670 is placed by the patient's nose, such that the patient exhaling through their nose onto the first thermal resistor 3670 warms the first thermal resistor 3670 indicating an exhale. Preferably, a second thermal resistor 3660 operates as an environmental temperature sensor. The second thermal resistor 3660 is preferably placed out of the exhalation path of the patient but in the same local room environment as the first thermal resistor 3670. Generated signal, such as current from the thermal resistors 3670, 3660, is preferably converted to voltage and communicated with the main controller 110 or a sub-controller of the main controller. Preferably, the second thermal resistor 3660 is used to adjust for the environmental temperature fluctuation that is part of a signal of the first thermal resistor 3670, such as by calculating a difference between the values of the thermal resistors 3670, 3660 to yield a more accurate reading of the patient's respiration cycle. Referring again to FIG. 34, a second example of a monitoring system is provided. In an example of a force respiration monitoring system, a sensor is placed by the torso. To avoid steric interference of the force sensor system components with proton therapy, the force respiration monitoring system is preferably used when treating a tumor located in the head, neck, or limbs. In the force monitoring system, a belt or strap 3450 is placed around an area of the patient's torso that expands and contracts with each respiration cycle of the patient. The belt 3450 is preferably tight about the patient's chest and is flexible. A force meter 3452 is attached to the belt and senses the patients respiration pattern. The forces applied to the force meter 3452 correlate with periods of the respiration cycle. The signals from the force meter 3452 are preferably communicated with the main controller 110 or a sub-controller of the main controller. Coordinated Charged Particle Beam Control In this section, charged particle beam control systems, described supra, are coordinated for cancer therapy. Positioning, Imaging, and Irradiation Referring now to FIG. 40, a method of cancer therapy is provided. In this method, the patient is first positioned 4010, then the tumor is imaged 4020, subsequently a charged particle irradiation plan is developed 4030, and then the charged particle irradiation plan is implemented 4040. Further examples of the steps provided in FIG. 40 are described, infra, along with additional optional steps. For example, the positioning, imaging, and irradiation steps are optionally integrated with patient translation control, patient rotation control, and/or patient respiration control. Additionally, any of the steps described herein are optionally coordinated with charged particle beam generation, acceleration, extraction, and/or delivery. Additionally, any of the steps are optionally coordinated with x-, y-axis beam trajectory control, delivered energy control, delivered intensity control, timing of charged particle delivery, and/or distribution of radiation striking healthy tissue. Tumor Imaging Referring now to FIG. 41, a method of tumor imaging is provided. In a first step, the patient is positioned 4010, such as with the patient immobilization and/or positioning systems described supra. Subsequently, the tumor is imaged 4020, such as with the imaging/X-ray system described supra. Preferably, each image is a 2-dimensional image. If the image is not complete 4010, then the patient is rotated 4020, such as with the multi-field irradiation rotatable platform described supra. For instance, the image is collected with rotation of the patient about the y-axis 2117. After rotation of n degrees of rotation of the patient 2130, where n is about ½, 1, 2, 3, 5, 10, or 20 degrees, another image is collected 4020. The imaging 4020 and rotation 4120 processes are repeated until the tumor 2120 is suitably imaged. A 3-dimensional image is created 4130 using the two-dimensional images collected as a function of patient rotation. The image is sent, optionally dynamically during tumor treatment, to the controller and/or hardware configured to at least temporarily store the digital image. Respiration Control Referring now to FIG. 42, a patient is positioned 4010 and once the rhythmic pattern of the subject's breathing or respiration cycle is determined 4210, a signal is optionally delivered to the patient, such as via the display monitor 3390, to more precisely control the breathing frequency 4220. For example, the display screen 3390 is placed in front of the patient and a message or signal is transmitted to the display screen 3390 directing the subject when to hold their breath and when to breathe. Typically, a respiration control module uses input from one or more of the respiration sensors. For example, the input is used to determine when the next breath exhale is to complete. At the bottom of the breath, the control module displays a hold breath signal to the subject, such as on a monitor, via an oral signal, digitized and automatically generated voice command, or via a visual control signal. Preferably, a display monitor 3390 is positioned in front of the subject and the display monitor displays breathing commands to the subject. Typically, the subject is directed to hold their breath for a short period of time, such as about ½, 1, 2, 3, 5, or 10 seconds. The period of time the breath is held is preferably synchronized to the delivery time of the proton beam to the tumor, which is about ½, 1, 2, or 3 seconds. While delivery of the protons at the bottom of the breath is preferred, protons are optionally delivered at any point in the respiration cycle, such as upon full inhalation. Delivery at the top of the breath or when the patient is directed to inhale deeply and hold their breath by the respiration control module is optionally performed as at the top of the breath the chest cavity is largest and for some tumors the distance between the tumor and surrounding tissue is maximized or the surrounding tissue is rarefied as a result of the increased volume. Hence, protons hitting surrounding tissue is minimized. Optionally, the display screen tells the subject when they are about to be asked to hold their breath, such as with a 3, 2, 1, second countdown so that the subject is aware of the task they are about to be asked to perform. X-Ray Synchronization with Patient Respiration In one embodiment, X-ray images are collected in synchronization with patient respiration. The synchronization enhances X-ray image clarity by removing position ambiguity due to the relative movement of body constituents during a patient respiration cycle. In a second embodiment, an X-ray system is orientated to provide X-ray images of a patient in the same orientation as viewed by a proton therapy beam, is synchronized with patient respiration, is operable on a patient positioned for proton therapy, and does not interfere with a proton beam treatment path. Preferably, the synchronized system is used in conjunction with a negative ion beam source, synchrotron, and/or targeting method and apparatus to provide an X-ray timed with patient respiration. Preferably, X-ray images are collected immediately prior to and/or concurrently with particle beam therapy irradiation to ensure targeted and controlled delivery of energy relative to a patient position resulting in efficient, precise, and/or accurate in-vivo treatment of a solid cancerous tumor with minimization of damage to surrounding healthy tissue. An X-ray delivery control algorithm is used to synchronize delivery of the X-rays to the patient 2130 within a given period of each breath, such as at the top or bottom of a breath, and/or when the subject is holding their breath. For clarity of combined X-ray images, the patient is preferably both accurately positioned and precisely aligned relative to the X-ray beam path 3070. The X-ray delivery control algorithm is preferably integrated with the respiration control module. Thus, the X-ray delivery control algorithm knows when the subject is breathing, where in the respiration cycle the subject is, and/or when the subject is holding their breath. In this manner, the X-ray delivery control algorithm delivers X-rays at a selected period of the respiration cycle. Accuracy and precision of patient alignment allow for (1) more accurate and precise location of the tumor 2120 relative to other body constituents and (2) more accurate and precise combination of X-rays in generation of a 3-dimensional X-ray image of the patient 2130 and tumor 2120. Referring again to FIG. 42, an example of generating an X-ray image of the patient 2130 and tumor 2120 using the X-ray generation device 3000 or 3-dimensional X-ray generation device 3000 as a known function of time of the patient's respiration cycle is provided. In one embodiment, as a first step the main controller 110 instructs, monitors, and/or is informed of patient positioning 4010. In a first example of patient positioning 4010, the automated patient positioning system, described supra, under main controller 110 control, is used to align the patient 2130 relative to the X-ray beam path 3070. In a second example of patient positioning, the main controller 110 is told via sensors or human input that the patient 2130 is aligned. In a second step, patient respiration is then monitored 4210, as described infra. As a first example of respiration monitoring, an X-ray is collected 4230 at a known point in the patient respiration cycle. In a second example of respiration monitoring, the patient's respiration cycle is first controlled in a third step of controlling patient respiration 4220 and then as a fourth step an X-ray is collected 4230 at a controlled point in the patient respiration cycle. Preferably, the cycle of patient positioning 4010, patient respiration monitoring 4210, patient respiration control 4220, and collecting an X-ray 4230 is repeated with different patient positions. For example, the patient 2130 is rotated about an axis 2117 and X-rays are collected as a function of the rotation. In a fifth step, a 3-dimensional X-ray image 4240 is generated of the patient 2130, tumor 2120, and body constituents about the tumor using the collected X-ray images, such as with the 3-dimensional X-ray generation device 3000, described supra. The patient respiration monitoring and control steps are further described, infra. An X-ray timed with patient respiration where the X-ray is preferably collected immediately prior to and/or concurrently with particle beam therapy irradiation to ensure targeted and controlled delivery of energy relative to a patient position resulting in efficient, precise, and/or accurate treatment of a solid cancerous tumor with minimization of damage to surrounding healthy tissue in a patient using the proton beam position verification system. Proton Beam Therapy Synchronization with Respiration In one embodiment, charged particle therapy and preferably multi-field proton therapy is coordinated and synchronized with patient respiration via use of the respiration feedback sensors, described supra, used to monitor and/or control patient respiration. Preferably, the charged particle therapy is performed on a patient in a partially immobilized and repositionable position and the proton delivery to the tumor 2120 is timed to patient respiration via control of charged particle beam injection, acceleration, extraction, and/or targeting methods and apparatus. The synchronization enhances proton delivery accuracy by removing position ambiguity due to the relative movement of body constituents during a patient respiration cycle. Synchrotron control to deliver protons at a desired point in the respiration cycle is described infra. In a second embodiment, the X-ray system, described supra, is used to provide X-ray images of a patient in the same orientation as viewed by a proton therapy beam and both the X-ray system and the proton therapy beam are synchronized with patient respiration. Again, synchrotron control to deliver protons at a desired point in the respiration cycle is described infra. A proton delivery control algorithm is used to synchronize delivery of the protons to the tumor within a given period of each breath, such as at the top of a breath, at the bottom of a breath, and/or when the subject is holding their breath. The proton delivery control algorithm is preferably integrated with the respiration control module. Thus, the proton delivery control algorithm knows when the subject is breathing, where in the respiration cycle the subject is, and/or when the subject is holding their breath. The proton delivery control algorithm controls when protons are injected and/or inflected into the synchrotron, when an RF signal is applied to induce an oscillation, as described supra, and when a DC voltage is applied to extract protons from the synchrotron, as described supra. Typically, the proton delivery control algorithm initiates proton inflection and subsequent RF induced oscillation before the subject is directed to hold their breath or before the identified period of the respiration cycle selected for a proton delivery time. In this manner, the proton delivery control algorithm delivers protons at a selected period of the respiration cycle by simultaneously or nearly simultaneously delivering the high DC voltage to the second pair of plates, described supra, which results in extraction of the protons from the synchrotron and subsequent delivery to the subject at the selected time point. Since the period of acceleration of protons in the synchrotron is constant or known for a desired energy level of the proton beam, the proton delivery control algorithm is used to set an AC RF signal that matches the respiration cycle or directed respiration cycle of the subject. The above described charged particle therapy elements are combined in combinations and/or permutations in developing and implementing a tumor treatment plan, described infra. Proton Beam Generation, Injection, Acceleration, Extraction, and Delivery Referring now to FIG. 43, an example of implementation of the irradiation plan 4040 is provided. The multi-axis and/or multi-field charged particle cancer therapy system elements described herein are preferably coordinated with charged particle delivery 4300. After patient positioning 4010 and reading the irradiation plan instructions 4310, hydrogen is injected 4315 into the negative ion source 310, plasma is generated 4320, a negative ion is extracted 4325, and the negative ion is accelerated 4330, converted into a positive ion 4340, and injected into the synchrotron 4345. Subsequently, the positive ion is accelerated 4350, extraction is initiated 4355, intensity of the irradiation beam is controlled 4360, extraction of the charged particle beam is performed 4365, and the tumor is irradiated 4370. Preferably, one or more elements of the charged particle delivery 4300 system are timed with patient respiration. After tumor irradiation 4370, the patient is preferably rotated 4120 and the irradiation sequence is repeated yielding multi-field irradiation of the tumor 2120. The entire sequence is optionally performed using the intensity modulated 3-dimensional scanning system 2800, described supra. Multi-axis Charged Particle Irradiation Referring now to FIG. 44, another example of implementation of the irradiation plan 4040 is provided. In this example, a multi-axis charged particle beam therapy system is provided, where multi-axis refers to independent control of: x-axis beam control, y-axis beam control, delivered beam energy, and/or delivered beam intensity. The multi-axis control is preferably implemented with multi-field charge particle irradiation, such as via use of independent control of rotation and/or translation of the patient. In this example, the main controller 110 independently adjusts x-axis targeting of the proton beam 4410, y-axis targeting of the proton beam 4420, rotational position of the patient 4430, delivered energy of the proton beam 4440, and/or delivered intensity of the proton beam in the step of irradiating the tumor 4040. The process is optionally repeated or iterated using a continuously irradiating and scanning charged particle irradiation system as described using the 3-dimensional scanning system 2800. Developing and Implementing a Tumor Irradiation Plan A series of steps are performed to design and execute a radiation treatment plan for treating a tumor 2120 in a patient 2130. The steps include one or more of: positioning and immobilizing the patient; recording the patient position; monitoring patient respiration; controlling patient respiration; collecting multi-field images of the patient to determine tumor location relative to body constituents; developing a radiation treatment plan; repositioning the patient; verifying tumor location; and irradiating the tumor. In this section, an overview of developing the irradiation plan and subsequent implementation of the irradiation plan is initially presented, the individual steps are further described, and a more detailed example of the process is then described. Referring now to FIG. 45, an overview of a system for development of an irradiation plan and subsequent implementation of the irradiation plan 4500 is provided. Preferably, all elements of the positioning, respiration monitoring, imaging, and tumor irradiation system 4500 are under main controller 110 control. Initially, the tumor containing volume of the patient 2130 is positioned and immobilized 4010 in a controlled and reproducible position. The process of positioning and immobilizing 4010 the patient 2310 is preferably iterated 4512 until the position is accepted. The position is preferably digitally recorded 4515 and is later used in a step of computer controlled repositioning of the patient 4517 in the minutes or seconds prior to implementation of the irradiation element 4040 of the tumor treatment plan. The process of positioning the patient in a reproducible fashion and reproducibly aligning the patient 2310 to the controlled position is further described, infra. Subsequent to patient positioning 4010, the steps of monitoring 4210 and preferably controlling 4220 the respiration cycle of the patient 2130 are preferably performed to yield more precise positioning of the tumor 2120 relative to other body constituents, as described supra. Multi-field images of the tumor are then collected 4540 in the controlled, immobilized, and reproducible position. For example, multi-field X-ray images of the tumor 2120 are collected using the X-ray source proximate the proton beam path, as described supra. The multi-field images are optionally from three or more positions and/or are collected while the patient is rotated, as described supra. At this point the patient 2130 is either maintained in the treatment position or is allowed to move from the controlled treatment position while an oncologist processes the multi-field images 4545 and generates a tumor treatment plan 4550 using the multi-field images. Optionally, the tumor irradiation plan is implemented 4040 at this point in time. Typically, in a subsequent treatment center visit, the patient 2130 is repositioned 4517. Preferably, the patient's respiration cycle is again monitored 4212 and/or controlled 4022, such as via use of the thermal monitoring respiration sensors, force monitoring respiration sensor, and/or via commands sent to the display monitor 3390, described supra. Once repositioned, verification images are collected 4560, such as X-ray location verification images from 1, 2, or 3 directions. For example, verification images are collected with the patient facing the proton beam and at rotation angles of 90, 180, and 270 degrees from this position. At this point, comparing the verification images to the original multi-field images used in generating the treatment plan, the algorithm or preferably the oncologist determines if the tumor 2120 is sufficiently repositioned 4565 relative to other body parts to allow for initiation of tumor irradiation using the charged particle beam. Essentially, the step of accepting the final position of the patient 4565 is a safety feature used to verify that that the tumor 2120 in the patient 2130 has not shifted or grown beyond set specifications. At this point the charged particle beam therapy commences 4040. Preferably the patient's respiration is monitored 4214 and/or controlled 4224, as described supra, prior to commencement of the charged particle beam treatment 4040. Optionally, simultaneous X-ray imaging 4590 of the tumor 2120 is performed during the multi-field proton beam irradiation procedure and the main controller 110 uses the X-ray images to adapt the radiation treatment plan in real-time to account for small variations in movement of the tumor 2120 within the patient 2130. Herein the steps of monitoring 4210, 4212, 4214 and controlling 4220, 4222, 4224 the patient's respiration are optional, but preferred. The steps of monitoring and controlling the patient's respiration are performed before and/or during the multi-filed imaging 4540, position verification 4560, and/or tumor irradiation 4040 steps. The patient positioning 4010 and patient repositioning 4517 steps are further described, infra. Coordinated Charged Particle Acceleration and Respiration Rate In yet another embodiment, the charged particle accelerator is synchronized to the patient's respiration cycle. More particularly, synchrotron acceleration cycle usage efficiency is enhanced by adjusting the synchrotron's acceleration cycle to correlate with a patient's respiration rate. Herein, efficiency refers to the duty cycle, the percentage of acceleration cycles used to deliver charged particles to the tumor, and/or the fraction of time that charged particles are delivered to the tumor from the synchrotron. The system senses patient respiration and controls timing of negative ion beam formation, injection of charged particles into a synchrotron, acceleration of the charged particles, and/or extraction to yield delivery of the particles to the tumor at a predetermine period of the patient's respiration cycle. Preferably, one or more magnetic fields in the synchrotron 130 are stabilized through use of a feedback loop, which allows rapid changing of energy levels and/or timing of extraction from pulse to pulse. Further, the feedback loop allows control of the acceleration/extraction to correlate with a changing patient respiration rate. Independent control of charged particle energy and intensity is maintained during the timed irradiation therapy. Multi-field irradiation ensures efficient delivery of Bragg peak energy to the tumor while spreading ingress energy about the tumor. In one example, a sensor, such as the first thermal sensor 3670 or the second thermal sensor 3660, is used to monitor a patient's respiration. A controller, such as the main controller 110, then controls charged particle formation and delivery to yield a charged particle beam delivered at a determined point or duration period of the respiration cycle, which ensures precise and accurate delivery of radiation to a tumor that moves during the respiration process. Optional charged particle therapy elements controlled by the controller include the injector 120, accelerator 132, and/or extraction 134 system. Elements optionally controlled in the injector system 120 include: injection of hydrogen gas into a negative ion source 310, generation of a high energy plasma within the negative ion source, filtering of the high energy plasma with a magnetic field, extracting a negative ion from the negative ion source, focusing the negative ion beam 319, and/or injecting a resulting positive ion beam 262 into the synchrotron 130. Elements optionally controlled in the accelerator 132 include: accelerator coils, applied magnetic fields in turning magnets, and/or applied current to correction coils in the synchrotron. Elements optionally controlled in the extraction system 134 include: radio-frequency fields in an extraction element and/or applied fields in an extraction process. By using the respiration sensor to control delivery of the charged particle beam to the tumor during a set period of the respiration cycle, the period of delivery of the charged particle to the tumor is adjustable to a varying respiration rate. Thus, if the patient breathes faster, the charged particle beam is delivered to the tumor more frequently and if the patient breathes slower, then the charged particle beam is delivered to the tumor less frequently. Optionally, the charged particle beam is delivered to the tumor with each breath of the patient regardless of the patient's changing respiration rate. This lies in stark contrast with a system where the charged particle beam delivers energy at a fixed time interval and the patient must adjust their respiration rate to match the period of the accelerator delivering energy and if the patient's respiration rate does not match the fixed period of the accelerator, then that accelerator cycle is not delivered to the tumor and the acceleration usage efficiency is reduced. Typically, in an accelerator the current is stabilized. A problem with current stabilized accelerators is that the magnets used have memories in terms of both magnitude and amplitude of a sine wave. Hence, in a traditional system, in order to change the circulation frequency of the charged particle beam in a synchrotron, slow changes in current must be used. However, in a second example, the magnetic field controlling the circulation of the charged particles about the synchrotron is stabilized. The magnetic field is stabilized through use of: (1) magnetic field sensors 1650 sensing the magnetic field about the circulating charged particles and (2) a feedback loop through a controller or main controller 110 controlling the magnetic field about the circulating charged particles. The feedback loop is optionally used as a feedback control to the first winding coil 1250 and the second winding coil 1260. However, preferably the feedback loop is used to control the correction coils 1510, 1520, described supra. With the use of the feedback loop described herein using the magnetic field sensors, the frequency and energy level of the synchrotron are rapidly adjustable and the problem is overcome. Further, the use of the smaller correction coils 1510, 1520 allows for rapid adjustment of the accelerator compared to the use of the larger winding coils 1250, 1260, described supra. More particularly, the feedback control allows an adjustment of the accelerator energy from pulse to pulse in the synchrotron 130. In this section, the first example yielded delivery of the charged particle beam during a particular period of the patient's respiration cycle even if the patient's respiration period is varying. In this section, the second example used a magnetic field sensor 1650 and a feedback loop to the correction coils 1510, 1520 to rapidly adjust the energy of the accelerator from pulse to pulse. In a third example, the respiration sensor of the first example is combined with the magnetic field sensor of the second example to control both the timing of the delivery of the charged particle beam from the accelerator and the energy of the charged particle beam from the accelerator. More particularly, the timing of the charged particle delivery is controlled using the respiration sensor, as described supra, and the energy of the charged particle beam is controlled using the magnetic filed sensors and feedback loop, as described supra. Still more particularly, a magnetic field controller, such as the main controller 110, takes the input from the respiration sensor and uses the input as: (1) a feedback control to the magnetic fields controlling the circulating charged particles energy and (2) as a feedback control to time the pulse of the charged particle accelerator to the respiration cycle of the patient. This combination allows delivery of the charged particle beam to the tumor with each breath of the patient even if the breathing rate of the patient varies. In this manner, the accelerator efficiency is increased as the cancer therapy system does not need to lose cycles when the patient's breathing is not in phase with the synchrotron charged particle generation rate. Referring now to FIG. 46, the combined use of the respiration sensor and magnetic field sensor 4600 to deliver charged particles at varying energy and at varying time intervals is further described. The main controller 110 controls the injection system 120, charged particle acceleration system 132, extraction system 134, and targeting/delivery system 140. In this embodiment, the previously described respiration monitoring system 4610 of the patient interface module 150 is used as an input to a magnetic field controller 4620. A second input to the magnetic field controller 4620 is a magnetic field sensor 1650. In one case, the respiration rates from the respiration monitoring system 4610 are fed to the main controller 130, which controls the injection system 120 and/or components of the acceleration system 132 to yield a charged particle beam at a chosen period of the respiration cycle, as described supra. In a second case, the respiration data from the respiration monitoring system is used as an input to the magnetic field controller 4620. The magnetic field controller also receives feedback input from the magnetic field sensor 1650. The magnetic field controller thus times charged particle energy delivery to correlate with sensed respiration rates and delivers energy levels of the charged particle beam that are rapidly adjustable with each pulse of the accelerator using the feedback loop through the magnetic field sensor 1650. Referring still to FIG. 46 and now additionally referring to FIG. 47, a further example is used to clarify the magnetic field control using a feedback loop 4600 to change delivery times and/or periods of proton pulse delivery. In one case, a respiratory sensor 4610 senses the respiration cycle of the patient. The respiratory sensor sends the patient's respiration pattern or information to an algorithm in the magnetic field controller 4620, typically via the patient interface module 150 and/or via the main controller 110 or a subcomponent thereof. The algorithm predicts and/or measures when the patient is at a particular point in the respiration cycle, such as at the top or bottom of a breath. One or more magnetic field sensors 1650 are used as inputs to the magnetic field controller 4620, which controls a magnet power supply for a given magnetic, such as within a first turning magnet 1010 of a synchrotron 130. The control feedback loop is thus used to dial the synchrotron to a selected energy level and to deliver protons with the desired energy at a selected point in time, such as at a particular point in the respiration cycle. The selected point in the respiration cycle is optionally anywhere in the respiration cycle and/or for any duration during the respiration cycle. As illustrated in FIG. 47, the selected time period is at the top of a breath for a period of about 0.1, 0.5, 1 seconds. More particularly, the main controller 110 controls injection of hydrogen into the injection system, formation of the negative ion 310, controls extraction of negative ions from negative ion source 310, controls injection 120 of protons into the synchrotron 130, and/or controls acceleration of the protons in a manner that combined with extraction 134 delivers the protons 140 to the tumor at a selected point in the respiration cycle. Intensity of the proton beam is also selectable and controllable by the main controller 130 at this stage, as described supra. The feedback control from the magnetic field controller 4620 is optionally to a power or power supplies for one or both of the main bending magnet 250, described supra, or to the correction coils 1520 within the main bending magnet 250. Having smaller applied currents, the correction coils 1510, 1520 are rapidly adjustable to a newly selected acceleration frequency or corresponding charged particle energy level. Particularly, the magnetic field controller 4620 alters the applied fields to the main bending magnets or correction coils that are tied to the patient's respiration cycle. This system is in stark contrast to a system where the current is stabilized and the synchrotron delivers pulses with a fixed period. Preferably, the feedback of the magnetic field design coupled with the correction coils allows for the extraction cycle to match the varying respiratory rate of the patient, such as where a first respiration period 4710, P1, does not equal a second respiration period 4720, P2. Referring now to FIG. 48, 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 4810, a beam controller 4815, a rotation controller 4850, and/or a timing to a time period in a respiration cycle controller 4860. The beam controller 4815 preferably includes one or more or a beam energy controller 4820, the beam intensity controller 1940, a beam velocity controller 4830, and/or a horizontal/vertical beam positioning controller 4840. 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 4810 controls any element or method associated with the respiration of the patient; the beam controller 4815 controls any of the elements controlling acceleration and/or extraction of the charged particle beam; the rotation controller 4850 controls any element associated with rotation of the patient 2130 or gantry; and the timing to a period in respiration cycle controller 4860 controls any aspects affecting delivery time of the charged particle beam to the patient. As a further example, the beam controller 4815 optionally controls any magnetic and/or electric field about any magnet in the charged particle cancer therapy system 100. Computer Controlled Patient Repositioning One or more of the patient positioning unit components and/or one of more of the patient positioning constraints are preferably under computer control. For example, the computer records or controls the position of the patient positioning elements 3315, such as via recording a series of motor positions connected to drives that move the patient positioning elements 3315. For example, the patient is initially positioned 4010 and constrained by the patient positioning constraints 3315. The position of each of the patient positioning constraints is recorded and saved by the main controller 110, by a sub-controller of the main controller 110, or by a separate computer controller. Then, imaging systems are used to locate the tumor 2120 in the patient 2130 while the patient is in the controlled position of final treatment. Preferably, when the patient is in the controlled position, multi-field imaging is performed, as described herein. The imaging system 170 includes one or more of: MRI's, X-rays, CT's, proton beam tomography, and the like. Time optionally passes at this point while images from the imaging system 170 are analyzed and a proton therapy treatment plan is devised. The patient optionally exits the constraint system during this time period, which may be minutes, hours, or days. Upon, and preferably after, return of the patient and initial patient placement into the patient positioning unit, the computer returns the patient positioning constraints to the recorded positions. This system allows for rapid repositioning of the patient to the position used during imaging and development of the multi-field charged particle irradiation treatment plan, which minimizes setup time of patient positioning and maximizes time that the charged particle beam system 100 is used for cancer treatment. Reproducing Patient Positioning and Immobilization In one embodiment, using a patient positioning and immobilization system 4200, a region of the patient 2130 about the tumor 2120 is reproducibly positioned and immobilized, such as with the motorized patient translation and rotation positioning system 2110 and/or with the patient positioning constraints 3315. For example, one of the above described positioning systems, such as (1) the semi-vertical partial immobilization system 3300; (2) the sitting partial immobilization system 3400; or (3) the laying position system 3500 is used in combination with the patient translation and rotation system 2110 to position the tumor 2120 of the patient 2130 relative to the proton beam path 268. Preferably, the position and immobilization system controls position of the tumor 2120 relative to the proton beam path 268, immobilizes position of the tumor 2120, and facilitates repositioning the tumor 2120 relative to the proton beam path 268 after the patient 2130 has moved away from the proton beam path 268, such as during development of the irradiation treatment plan 4545. Preferably, the tumor 2120 of the patient 2130 is positioned in terms of 3-D location and in terms of orientation attitude. Herein, 3-D location is defined in terms of the x-, y-, and z-axes and orientation attitude is the state of pitch, yaw, and roll. Roll is rotation of a plane about the z-axis, pitch is rotation of a plane about the x-axis, and yaw is the rotation of a plane about the y-axis. Tilt is used to describe both roll and pitch. Preferably, the positioning and immobilization system controls the tumor 2120 location relative to the proton beam path 268 in terms of at least three of and preferably in terms of four, five, or six of: pitch, yaw, roll, x-axis location, y-axis location, and z-axis location. Chair The patient positioning and immobilization system 4200 is further described using a chair positioning example. For clarity, a case of positioning and immobilizing a tumor in a shoulder is described using chair positioning. Using the semi-vertical immobilization system 3300, the patient is generally positioned using the seat support 3320, knee support 3360, and/or foot support 3370. To further position the shoulder, a motor in the back support 3330 pushes against the torso of the patient. Additional arm support 3350 motors align the arm, such as by pushing with a first force in one direction against the elbow of the patient and the wrist of the patient is positioned using a second force in a counter direction. This restricts movement of the arm, which helps to position the shoulder. Optionally, the head support is positioned to further restrict movement of the shoulder by applying tension to the neck. Combined, the patient positioning constraints 3315 control position of the tumor 2120 of the patient 2130 in at least three dimensions and preferably control position of the tumor 2120 in terms of all of yaw, roll, and pitch movement as well as in terms of x-, y-, and z-axis position. For instance, the patient positioning constraints position the tumor 2120 and restricts movement of the tumor, such as by preventing patient slumping. Optionally, sensors in one or more of the patient positioning constraints 3315 record an applied force. In one case, the seat support senses weight and applies a force to support a fraction of the patient's weight, such as about 50, 60, 70, or 80 percent of the patient's weight. In a second case, a force applied to the neck, arm, and/or leg is recorded. Generally, the patient positioning and immobilization system 4200 removes movement degrees of freedom from the patient 2130 to accurately and precisely position and control the position of the tumor 2120 relative to the X-ray beam path 3070, proton beam path 268, and/or an imaging beam path. Further, once the degrees of freedom are removed, the motor positions for each of the patient positioning constraints are recorded and communicated digitally to the main controller 110. Once the patient moves from the immobilization system 4200, such as when the irradiation treatment plan is generated 4550, the patient 2130 must be accurately repositioned in a patient repositioning system 4500 before the irradiation plan is implemented. To accomplish this, the patient 2130 sits generally in the positioning device, such as the chair, and the main controller sends the motor position signals and optionally the applied forces back to motors controlling each of the patient positioning constraints 3315 and each of the patient positioning constraints 3315 are automatically moved back to their respective recorded positions. Hence, re-positioning and re-immobilizing the patient 2130 is accomplished from a time of sitting to fully controlled position in less than about 10, 30, 60, 120, or 600 seconds. Using the computer controlled and automated patient positioning system, the patient is re-positioned in the positioning and immobilization system 4500 using the recalled patient positioning constraint 3315 motor positions; the patient 2130 is translated and rotated using the patient translation and rotation system 2120 relative to the proton beam 268; and the proton beam 268 is scanned to its momentary beam position 269 by the main controller 110, which follows the generated irradiation treatment plan 4550. Cancer Treatment Cancer is typically treated using charged particles to directly ablate the whole tumor. Alternatively, as taught herein, cancer is indirectly treated by ablating the periphery of the tumor and/or the healthy tissue proximately contacting the tumor without therapeutic treatment levels of the entire central volume of the tumor, which reduces/prevents nutrient delivery to the tumor. The second case of peripheral tumor treatment is further described, infra. Referring now to FIG. 49 (A-D), a tumor sealing system 4900 for treating a tumor 2120 is illustrated using the charged particle beam system 100. Referring now to FIG. 49A, the tumor 2120 is illustrated at a first pint in time, t1, with an outer periphery 2122. For clarity of presentation, the tumor periphery 2122 is illustrated in two-dimensions as a perimeter of the tumor. However, the periphery includes all of the outer edge/outer surface area of the tumor 2120 and/or the healthy tissue proximately contacting the outer surface of the tumor 2120. As such, herein the tumor periphery 2122 of the tumor 2120 refers to the outer portions of the tumor proximate healthy tissue and/or portions of the healthy tissue proximately surrounding/contacting the tumor 2120. Referring now to FIGS. 49B and 49C, the tumor treatment is illustrated at a second point in time, t2, and third point in time, t3, where the charged particle beam system 100 has treated a portion of the tumor periphery 2122 to form a sealing layer 2126. Treatment voxels are preferably: (1) adjacent and/or (2) overlapped, such as to yield an approximately uniform dose as a function of 3-dimensional position about an edge of the tumor 2120. The sealing layer 2126 is a physical barrier to nutrient flow, such as caused by localized heating, scarring, and/or ablation, where the sealing layer is a direct result of charged particle therapy and/or a result of body chemistry reacting to the treatment induced trauma, such as by forming a protein barrier or scar tissue. Referring now to FIG. 49D, the tumor treatment is illustrated at a fourth point in time, t4, after forming the sealing layer 2126. The sealing layer 2126 functions to hinder and/or prevent delivery of nutrients to the tumor 2120 by the body. For example, tumor growth is hindered, retarded, stopped, and/or reversed through lack of nutrients, such as glucose, oxygen, proteins, fats, minerals, and/or vitamins. Similarly, the sealing layer 2126 functions to hinder removal of metabolic waste product(s) from the tumor, such as carbon dioxide and urea. Still referring to FIG. 49D, the lack of nutrient delivery to the tumor and/or the lack of metabolic waste removal from the tumor causes natural death/necrosis of the tumor and the natural decay and/or release of natural products back into the body that, if passed by the sealing layer 2126, are recognized and dealt with by the body, such as through the circulatory, lymphatic, digestive, kidney, and/or liver systems. Further, the total treated volume of the tumor 2120 treated directly by the charged particle beam system 100 is reduced relative to the total volume of the tumor as preferably only the surface of the tumor 2120 is treated and the internal sections of the tumor 2120 are relatively untreated and/or treated with a sub-therapeutic and non-cancer lethal dose. In practice, at least 50, 60, 70, 80, 90, 95, 98, 99 percent of the surface area of the tumor is treated with the charged particle beam of the charged particle therapy system 100. By not treating the entire tumor volume, the amount of negative side products resultant from tumor treatment with charged particles is reduced as is treatment time. Preferably, the tail of the Bragg peak is delivered into the tumor, as described supra, and illustrated in FIG. 49B and FIG. 49C. Tracking the perimeter of the tumor is optionally performed using a combination of one or more of the imaging, energy control, intensity control, x- and y-axes control, and/or rotation controls, described supra. Referring now to FIG. 50, a three-dimensional tumor perimeter treatment system 5000 is illustrated, which is an example of the tumor sealing system 4900. In this example, the tumor periphery 2122 of the tumor 2120 is illustrated in a partially completed three-dimensional tumor sealing layer 2126. Optionally, the three-dimensional surface of the tumor 2120 is treated in any order. In this particular case, the treatment forms a series of perimeters along an offset-axis to form a series of concentric and/or eccentric treatment perimeters, such as formed through one or more revolutions of the patient support system relative to the beam delivery angle from the gantry or nozzle of the charged particle therapy system 100. Referring now to FIG. 51A and FIG. 51B, a layered treatment system 5100 of the tumor is illustrated using the charged particle treatment system 100. Referring now to FIG. 51A, treatment of the tumor periphery 2122 of the tumor 2120 is illustrated at a first time, t1, and at a second time, t2. As illustrated, in this example voxels of the tumor 2120 are treated: (1) along a first axis at a first time with movement of the current position of the proton beam 269 relative to the patient 2130 and (2) optionally along a second axis at a second time to form a multiply treated voxel zone 2128 or volume. Preferably, the first and second axis are about perpendicular and/or form an acute angle relative to each other of greater than about 20, 40, 60, 70, 80, or 85 degrees and less than about 95, 100, 110, 120, 130, or 140 degrees. By changing treatment axes, channels and/or leaks resultant from one treatment pass are blocked or woven into channels from a subsequent treatment pass, thereby enhancing the imperviousness of the sealing layer 2126. Referring now to FIG. 51B, the multiply treated voxel zone 2128 is optionally reinforced with a reinforcement sealing layer, such as illustrated at the third time, t3. Preferably, the treatment at the third time treats an inner layer of the tumor 2120 proximate the multiply treated voxel zone 2128; however, the reinforcement layer is optionally overlapped with the multiply treated voxel zone 2128 and/or is on any side of the multiple treated voxel zone 2128, which again if leaks or channels are present, the channels are blocked by the roughly orthogonal treatment layers. Still referring to FIG. 51A and FIG. 51B, treatment of a first portion of the surface area of the tumor along a first charged particle vector, such as illustrated at the first time, t1, and treatment of the same portion of the surface area of the tumor along a second charged particle vector, such as illustrated at the second time, t2, treats a portion of the surface area of the tumor 2120, such as less than about 10, 5, 2, 1, ½, ¼, or ⅛th of the surface area of the tumor 2120. The process is repeated on different surface areas of the tumor until the entire surface area of the tumor is treated. Over a time interval, the first charged particle vector and second charged particle vector form a treatment plane, such as an x/y-treatment plane. At a subsequent time, the third charged particle vector, such as illustrated at the third time, t3, forms a treatment vector forming and angle about normal to the x/y-treatment plane, such as greater than 20, 40, 60, 70, 80, or 85 degrees and less than about 95, 100, 110, 120, 130, or 140 degrees off of the x/y-treatment plane. Optionally, the portion of the tumor surface area treated is a function of angle of recline of the patient using a support structure configured to dynamically orient the patient in a range from 0 to 45 degrees off of horizontal and preferably in a range of 5 to 15 degrees off of horizontal. The varying reclined angle allows addition incident charged particle beam angles relative to the surface of the tumor. Referring still to FIG. 51A and FIG. 51B, the periphery of the tumor 2120 is optionally treated by sweeping the current position of the proton beam 269, or carbon ion beam, across the tumor/healthy tissue boundary, as illustrated at the fifth point in time, t5, across the x- and y-axes and at the sixth point in time, t6, across the z-axis. Generally, the tumor/healthy tissue boundary or tumor penumbra is sealed using the charged particle beam system 100 by treating the periphery of the tumor 2120 of the patient 2130 with one or more overlapped, inter-stitched, interwoven, and/or adjacent sets of tissue volume or tissue voxels to hinder nutrient delivery to the tumor 2120 and/or waste product removal from the tumor 2120. Preferably, inner volumes of the tumor 2120 are not treated with the charged particle therapy system 100 and/or at least 10, 20, 30, 40, 50 percent of the tumor is treated with a sub-therapeutic dosage less than 100 percent of full treatment dosage, such as less than 80, 60, 40, or 20 percent of full dosage. At a subsequent point in time, the tumor 2120 is optionally retreated, as needed, to treat tumor growths through the tumor sealing layer 2126 and/or new tumor growth. Tomography In one embodiment, the charged particle tomography apparatus is used to image a tumor in a patient. In another embodiment, 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 embodiments, 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. 52, an example of a tomography apparatus is described. In one example, the tomography system 5200 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. Preferably, a scintillation plate 5210, such as a scintillating plastic is positioned behind the patient 2130 relative to the targeting/delivery system 140 elements. 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. The intensity or count of protons hitting the plate as a function of position is used to create an image. The patient 2130 is rotated 2117 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. For example, an tomogram is collected and cancer therapy is subsequently performed: without the patient moving from the positioning systems, such as the above described semi-vertical partial immobilization system 3300, the sitting partial immobilization system 3400, or the a laying position 3500. 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 2120 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 2130 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 is optionally in the same position for each image. In still another embodiment, the tomogram is collected with the patient 2130 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 2120 to be separated from surrounding organs or tissue of the patient 2130 better than in a laying position. Positioning of the scintillation plate 5210 behind the patient 2130 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. 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 2120 and patient 2130. 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 Still yet another embodiment includes any combination and/or permutation of any of the elements described herein. 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.
051456370	summary	BACKGROUND OF THE INVENTION This invention relates to the non-destructive examination of welds and tubes inside a nuclear reactor pressure vessel. In particular, this invention relates to the examination of the welds attaching the incore housing to the reactor pressure vessel using ultrasonic transducers. This invention also relates to the eddy current surface examination of the incore housing tubes. In a conventional boiling water reactor, the reactor core comprises a plurality of fuel assemblies arranged in a spaced array and oriented vertically. Each fuel assembly consists of a fuel bundle and its carrying case, called a fuel channel. Fuel assemblies are grouped in sets of four with a control rod interposed between the four assemblies in each set. The control rods contain a neutron absorbing material, and are inserted between the fuel assemblies in varying degrees to control the reactivity of the core. The entire core is immersed in water which serves as a coolant, as well as a neutron moderator. All these are contained in the reactor pressure vessel. Interdispersed throughout the core between the fuel assemblies are removable dry-tubes, which house incore flux monitors and other instrumentation. Dry-tubes rest on the lower core support plate, and extend to the top guide, at the top of the core. Below the dry-tubes, and extending through the bottom head of the pressure vessel the guide and incore housing tube configurations are welded in place. The guide tubes extend downward from the lower core support plate to the tops of the incore housing tubes, which then extend through the pressure vessel. The bottoms of the guide tubes are welded to the tops of the incore housing tubes, forming a single unit. A reactor will have anywhere from twenty to sixty such tube configurations, depending on its size. Nuclear reactors constitute extremely hostile environments for manual examination of any kind. First, nuclear reactors have inherently high levels of radioactivity and radioactive contamination. Secondly, most of the reactor pressure vessel internals are inaccessible for almost any kind of manual examination. A classic example of such inaccessibility is the weld attaching the incore housing to the bottom head of a reactor pressure vessel. The incore housing consists of stainless steel tubes which penetrate the bottom head of the pressure vessel. Attachment welds seal the boundary between the inner surface of the pressure vessel and the incore housing, as well as provide structural support for the incore housing. Any defects in the attachment welds, e.g. cracks, jeopardize the integrity of the pressure system. Non-destructive examination of the attachment welds is used to verify their integrity or to discover any incipient defects, so necessary repairs can be made before failure occurs. An ultrasonic probe for "seeing" into the weld and surrounding metal is suitable for such an examination. Ultrasonic probes send a beam of sound waves through a region, and flaws (called indications) cause reflections which are detected and analyzed. Ultrasonic probes have been used in the past to examine welds inside the reactor pressure vessel. Such a probe is described in "Stub Tube Inspection Device", U.S. Pat. No. 4,548,785, issued Oct. 22, 1985. In this patent a scanning tool, i.e. a device for moving the probe around the region of interest, is placed on top of a stub tube, and the probe is moved vertically along the outside of the stub tube during the scan, then rotated and moved vertically again for another scan. This is done with two tranducers, one which "looks" up, and one which "looks" down. On a given vertical sweep the upwards-looking transducer is on during the upsweep, and the downwards-looking transducer is on during the downsweep. Mechanical switches, at the top and bottom of the sweep, switch the transducers' activation states. No attention is paid to the rotational orientation of the transducers with respect to the reactor. This limits information as to the nature of any flaws since the inspected region is not rotationally symmetric. The nature of weld inspection inside a pressure vessel is such that every situation requires an inspection device specially suited to the particular circumstances involved. For instance, the probe apparatus described in U.S. Pat. No. 4,548,785 can not be used to inspect incore housing welds because the incore housings are not "stubs", but rather part of a continuous tube structure that extends from below the pressure vessel through the bottom, and up to the bottom of the reactor core support plate. This makes it impractical to use any sort of probe external to the tube. The prior method of inspecting these welds involved removing a flange at the bottom of each incore housing tube outside the pressure vessel, and manually inserting a probe up to the weld area. This necessitates violating the pressure boundary of the pressure vessel, and is extremely unsatisfactory because of the the high levels of radiation to which workers are exposed. Workers must wear a "bubble suit" with an external air supply for radiation protection when performing this type of examination. Also, this process is awkward, expensive, and time consuming. Thus it became necessary to develop a new technique for incore housing inspection. SUMMARY OF THE INVENTION In accordance with the present invention, the ultrasonic examination of the incore housing welds is performed with access from above the welds, when the incore instrumentation is being checked and replaced. Examination from above results in a 100:1 reduction in the radiation per person exposure level when compared with the prior method of examining the welds from below. In further accordance with the present invention it is also desirable to perform non-destructive examination of the interior surface and near surface of the incore housing tubes for dents, cracks, corrosion, and the like. Eddy current coils are suitable for this type of examination. Before anything inside the pressure vessel can be accessed from above its top head is removed. The removal of associated fuel assemblies, incore instrumentation (flux monitors), and dry tubes is also required in the areas where incore access is desired. Advantageously, the welds are checked when the incore instrumentation is replaced since this must be done periodically, using established procedures. Handling of equipment is accomplished using a hoist on a refueling bridge. The basic mechanical unit used to examine the welds consists of a probe and a scanning tool, for controlling probe movement. The probe is attached to the scanning tool via a hollow probe tube, which is assembled from shorter sections to facilitate handling. The probe has six ultrasonic transducers, with a "straight-on" transducer above the other five. "Straight-on" refers to the direction of the beam towards the incore housing, i.e. it is perpendicular to the surface of the housing. All of the transducers are focused at the border between the incore housing and the weld, and the five that are grouped together are focused at the same point. The transducers pulse in sequential order, at a high enough frequency relative to the probe speed to enable the five transducers with the same focal point to examine the same region simultaneously. Prior to immersion the angular orientation of the probe tube with respect to the scanning tool is set so the "straight-on" transducer will initially face the same direction in each housing tube, which is defined to be a reference direction (0.degree.) of the pressure vessel. Also, since the weld is at the same level as the inside surface of the bottom head of the pressure vessel, and the distance from the top guide to the bottom head of the pressure vessel is known, the probe tube is adjusted with respect to the scanning tool so that when the scanning tool is level with the top guide the probe is at weld level. When in place the probe and probe tube fit into the incore housing to be inspected, and the scanning tool is clamped to the top guide. After incore access is obtained, the probe, probe tube, and scanning tool unit is positioned above the weld to be inspected. They are lowered into the water, and the probe and probe tube are lowered through the incore guide tube into the incore housing tube until the probe is at the level of the weld inspection region. The scanning tool is then clamped to the top guide in a pre-determined angular position with respect to the pressure vessel. The straight-on transducer now points in the pressure vessel reference direction. The probe is then rotated so the transducers face the high side of the weld. The degree of rotation varies depending on the particular incore housing being inspected. This is the basic starting position for the examination of the specified weld and housing. Once the probe is in its initial position inside the housing its movement is controlled automatically for the respective ultrasonic and eddy current examinations. The initial position for the ultrasonic scan is when the ultrasonic centerline (the focal point of the lower five transducers) is at least 40 millimeters (mm) above the high side of the weld. Similarly, the initial position for the eddy current examination is when the eddy current centerline is 40 mm or more above the high side of the weld. The region from at least 40 mm above the high side of the weld to 40 mm or more below the low side of the weld is inspected in both the ultrasonic and eddy current examinations. The probe travels vertically in one direction, and then rotates by a small amount, e.g. 5.degree., and then travels vertically in the other direction. This is repeated until the probe has rotated the full 360.degree.. All data is processed electronically, and the status of the examined region is determined.
060375973	description	DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. As indicated above, the present invention provides non-destructive detection systems and methods, and devices useful in the same. Referring now to FIG. 1, shown is a preferred device 11 of the invention for delivering epithermal neutrons. Device 11 includes a first polymer layer 12 having embedded therein a self-contained, chemical source of alpha-radiation, for example an amount of .sup.208 Po. Illustrative dimensions for layer 12 include 10 mm.times.10 mm.times.3 mm. The alpha source 13 can be, for example, located within a 3 mm diameter bore centrally located in the layer 12. Device 11 further includes a second polymer layer 14, defining a diffraction opening 15 for passing and diffracting alpha-radiation emanating from alpha source 13. Layer 14 can be sized similarly to layer 12. Diffraction opening 15, which is axially aligned with alpha source 13, can be for example 1 mm in diameter. With continued reference to FIG. 1, device 11 also includes polymer layer 16 having embedded therein Boron-10 (an isotope of boron having mass number 10) which generates epithermal neutrons upon bombardment by alpha-radiation. Again, layer 16 can be sized similarly to layers 12 and 14, and neutron source 17 is in registry with opening 15 to receive alpha-radiation passing through opening 15. Polymer layer 18 is also provided, which can be similar in size to the above-described layers. Layer 18 includes a diffraction opening 19 aligned with thermal neutron source 17, which serves to pass and diffract epithermal neutrons generated by neutron source 17. Device 11 may also optionally include a further layer 20, which can be dimensioned similarly to the above-described layers. Layer 20 can include an embedded article 21 containing an amount of liquid nitrogen, to provide cooling to the device 11. In construction of device 11, the various layers 12, 14, 16, 18 and 20 can be bonded to one another to form an overall laminate which may be used to deliver epithermal neutrons for a variety of applications. FIG. 2 depicts a radiation source/detector array device 31 of the invention, which can incorporate a plurality of devices 11. Array device 31 may include a plurality of other radiation sources and detectors, including for example x-ray, infrared, neutron, and gamma radiation sources and detectors. Suitable X-ray detectors, neutron detectors and gamma radiation detectors include semiconductive wafers available, for example, from Motorola, Inc. In accordance with the invention, the detectors in the array device 31 are selected to detect predetermined characteristic signal(s) from an object to be interrogated, for example signal(s) characteristic of plastique or other explosive types, of particular elements or molecules in a sample to be assayed, or other like characteristic signals. The specific illustrated device 11 includes a plurality of X-ray sources 32, a plurality of neutron detectors 33, and a plurality of x-ray detectors 34, and can be advantageously used in the interrogation of objects such as luggage, as discussed more fully in passages which follow. A preferred array device 31 can constructed by positioning a sheet of mylar 35 on a flat piece of steel, the steel having no more than about 0.01 (0.025 cm) inch of deviation per ft.sup.2 (0.09 m.sup.2). A prefabricated mask of Mylar polyester film with precut 0.1 mm wide grooves is placed on the first sheet of Mylar polyester film. The mask defines the pattern of conductive material desired for electrical connection to detectors 33 and 34 in the array (See. e.g. FIG. 3). Aluminum or another suitable conductive material is then imprinted onto the mask over the Mylar polyester film. The neutron and X-ray semiconductor detectors 33 and 34 are then positioned where desired in the array, and electrically connected to the imprinted leads by heating. A plurality of radiation source devices, e.g. thermal neutron-delivery devices 11 and X-ray sources 32, are then affixed, e.g. bonded, to the Mylar polyester film sheet in the desired locations in the grid. A layer of heat stable adhesive can then be applied overtop the first Mylar polyester film sheet and sources/detectors. At this point, particularly if devices 11 lack layer 20 and its embedded liquid nitrogen 21, a hollow metal wire, such as a hollow aluminum wire, can be run circuitously across the array within the adhesive, filled with liquid nitrogen and capped, to provide cooling to the overall array. Prior to cure of the adhesive, another clean sheet of Mylar polyester film 37 is then placed over the underlying electronics, and the overall device can be topped off with one or more additional layers of Mylar polyester film on the sides. In this regard, the sheets of Mylar polyester film employed can be about 0.1 mm thick. Referring now to FIG. 3, shown is an illustration of a conductive pattern imprint which can be used in devices 31 of the invention. Additionally shown schematically are a plurality of memory storage devices 41 electrically connected to the output from detectors in the device 31. Referring now to FIG. 4, shown is an illustrative non-destructive detection system 51 which includes one or more array devices such as device 31 illustrated herein. The devices 31 are situated on one side of an object path 52 along which objects to be interrogated are passed. On the other side of object path 52 is an array of film 53, for example X-ray film 54, to receive and process signals from objects passed along path 52. In addition, array 53 could also include infrared film 55 to detect infrared radiation emitted by the sample upon impingment by radiation (e.g. epithermal neutrons or other radiation) from the sources in array 31. In use, an object to be interrogated is passed along path 52, and is impinged upon by radiation from the array or arrays 31, thus emitting characteristic signals which are detected by detectors within array device 31 and/or by film within array 53. Those characteristic signals are then compared to characteristic signals for known plastique explosives or other materials of interest, to make a determination whether such substances are present in the object under interrogation. It is preferable in accordance with the invention to utilize low energy epithermal neutrons to interrogate objects or substances under study. Epithermal neutrons, due to their lack of charge, are not significantly susceptible to interference by cations or anions in the object or sample. The epithermal neutrons used will desirably be of a predetermined energy level, typically in the range of about 0.5 eV to about 1.25 eV, which is selected to elicit a specific interaction with the sample and output a predetermined characteristic signal, e.g. a characteristic elastic scattering of neutrons, and/or the generation of a characteristic gamma and/or infrared radiation signal. It will be understood that thermal neutron delivering devices 11 and array devices 31 of the invention can be used in a variety of applications. For example, the devices can be used in the interrogation of luggage or packages in airline and other industries, and in the interrogation for specific metals, plastics, ceramics or textiles. In addition, array devices 31 can be formed as two- or three-dimensional arrays, and used in other areas such as in monitoring the flow of gases or liquids, or components of the same, inside barriers, and/or to monitor environmental hazards such as radioactive materials, high explosives, VOC's and metals, in situ, for environmental bioremediation. The devices of the invention require minimal or no input power, and thus are suited for use in portable devices, e.g. which monitor water, oxygen or other atomic or molecular content in remote areas, e.g. in the field of planetary exploration. In such remote monitoring, devices can be equipped with miniature radio or microwave antenna for transmission of signals. While the invention has been described in detail in the foregoing passages in relation to specific, preferred embodiments, it will be understood by the skilled artisan that modifications and additions can be made to the illustrated devices without departing from the spirit and scope of the present invention.
	description	This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/682,627, filed May 19, 2005, which is herein incorporated by reference in its entirety. The subject invention was made with government support from the Office of Naval Research, Grant Number N00014-99-1-0154. The U.S. Government may have certain rights. This invention relates to methods and systems for asset health management. Existing processes for asset management are mostly ad-hoc, and only take into account short term operations planning based on recent maintenance history. Operations and maintenance planning are often performed in isolation and do not balance current costs and operational benefits against the long term issues of total operating costs and asset life-cycle management. A method for optimizing utilization of one or more assets in accordance with embodiments of the present invention includes obtaining at least one of operational data and condition data for one or more elements of at least one of the assets. At least one of historical maintenance data and life-cycle data for the one or more elements of the at least one of the assets is retrieved. One or more diagnostics on the one or more elements of the at least one of the assets is conducted based on the obtained at least one of the operational data and the condition data. One or more prognostics on the one or more elements of the at least one of the assets is conducted based on the at least one of the obtained operational data and condition data and on the retrieved at least one of the historical maintenance data and the life-cycle data. One or more optimization instructions for the at least one asset are determined based on the conducted diagnostics and prognostics and the determined one or more optimization instructions are displayed. A computer readable medium having stored thereon instructions for optimizing utilization of one or more assets in accordance with other embodiments of the present invention includes obtaining at least one of operational data and condition data for one or more elements of at least one of the assets. At least one of historical maintenance data and life-cycle data for the one or more elements of the at least one of the assets is retrieved. One or more diagnostics on the one or more elements of the at least one of the assets is conducted based on the obtained at least one of the operational data and the condition data. One or more prognostics on the one or more elements of the at least one of the assets is conducted based on the at least one of the obtained operational data and condition data and on the retrieved at least one of the historical maintenance data and the life-cycle data. One or more optimization instructions for the at least one asset are determined based on the conducted diagnostics and prognostics and the determined one or more optimization instructions are displayed. A system for optimizing utilization of one or more assets in accordance with embodiments of the present invention includes one or more sensor systems, one or more databases, at least one diagnostic processing system, at least one prognostic processing system, an optimization processing system, and a display system. The one or more sensor systems obtain at least one of operational data and condition data for one or more elements of at least one of the assets. The one or more databases store at least one of historical maintenance data and life-cycle data for the one or more elements of the at least one of the assets. The diagnostic processing system conducts one or more diagnostics on the one or more elements of the at least one of the assets based on the obtained at least one of the operational data and the condition data. The prognostic processing system conducts one or more prognostics on the one or more elements of the at least one of the assets based on the at least one of the obtained operational data and condition data and on the retrieved at least one of the historical maintenance data and the life-cycle data. The optimization processing system determines one or more optimization instructions for the at least one asset based on the conducted diagnostics and prognostics from the at least one diagnostic processing system and the at least one prognostic system. The display system displays the determined one or more optimization plan or instruction(s). The present invention provides a method and system for optimizing the utilization of an asset or collection of assets over the entire life-cycle of the asset or collection of assets. Diagnostic methodologies are utilized by the present invention to identify factors, such as degradation and failures of elements of the asset, status of consumables, and operational readiness, and these factors are utilized in the determination of an optimization plan or instruction(s). Additionally, predictive or prognostic methodologies are used by the present invention to forecast failures. The prognostic methodologies consider the operation and maintenance of the asset and elements of the asset in the context of the entire life cycle. The present invention balances near term and predicted long term maintenance needs against operational requirements and these additional factors are also utilized in the determination of an optimization plan or instruction(s). Further, the present invention takes into account other factors, such as operational costs, allocation data, and/or availability of upgrades. One or more of these additional factors can also be utilized in the balancing to determine the optimization plan or instruction(s). With the present invention, the consideration of different combinations of these factors allows for an optimal operational and maintenance plan or instruction(s) to be developed. An asset health management system 10 for one or more assets 17(1)-17(n) in accordance with embodiments of the present invention is illustrated in FIG. 1. The asset health management system 10 includes an optimization processing system 12, databases 14(1)-14(n), sensors 15(1)-15(8), and a communication system 16, although the asset health management system 10 can include other types and numbers of systems and components arranged in other manners. The present invention provides a number of advantages including providing a method and system for optimizing the utilization of one of an asset or a collection of assets over the entire life-cycle of the asset. The optimization processing system 12 is used to determine an optimization plan or instruction(s) for one or more of the assets 17(1)-17(n) based on information, such as diagnostic testing, prognostic testing, cost data, and/or allocation data, although other types and numbers of optimization processing system 12 could be used. For example, the optimization processing system 12 could be coupled to a higher level system which managed the optimization processing system 12 along with other optimization processing systems for other assets. The optimization system 12 includes at least one processor 18, at least one memory storage device 20 which stores programmed instructions for one or more aspects of the present invention, at least one interface system or device 24, at least one user input device 26, and at least one display device 28 which are coupled together by a bus system 30 or other link, although the remanufacturing processing system 12 may comprise other components, other numbers of the components, and other combinations of the components. In this particular embodiment, the processor 18 executes a program 22 of stored instructions in memory storage device 20 for at least a portion of the method for optimizing utilization of one or more assets 17(1)-17(n) in accordance with one embodiment of the present invention as described herein and set forth in FIG. 2, although the method in accordance with the present invention can be carried out by other systems and also in a variety of other manners. The memory storage device 20 stores these programmed instructions, including program 22 in a memory device, such as a random access memory (RAM) or a read only memory (ROM) in the system or a floppy disk, hard disk, CD ROM, or other computer readable medium which is read from and/or written to by a magnetic, optical, or other reading and/or writing system that is coupled to the processor 18. Although in this particular embodiment, the method in accordance with one embodiment of the invention is stored as programmed instructions in the optimization processing system 12 for execution by the processor 18, some or all of the programmed instructions could be stored and executed elsewhere. The input/output interface 20 is used to operatively couple and communicate between the remanufacturing processing system 12 and the component information system 14. The user input device 23 enables an operator to generate and transmit signals or commands to the processor 18, such as inputting data or requests for data about components, although the user input device is optional. A variety of different types of user input devices can be used, such as a keyboard or computer mouse. The display device 28 enables the operator to observe displayed data information, such as the optimization plan or instruction(s). A variety of different types of display devices can be used, such as a CRT or a printer. The databases 14(1)-14(n) store data, such as historical maintenance data, life cycle data, specifications, performance, and status, for each of the elements of each of the assets 17(1)-17(n). These databases 14(1)-14(n) can be supplemented on an ongoing basis with additional data, such as historical maintenance data, life cycle data, obtained from the management and optimization of the assets 17(1)-17(n). By way of example only, one of the databases 14(1)-14(n) will store tables or graphs, such as the graph shown in FIG. 3 which shows the expected time to failure versus the usage of an element in one of the assets, which can be utilized in determining an optimization plan or instructions(s). The sensors 15(1)-15(8) are coupled to the optimization processing system 12 via communication system 16, although data from the sensors 15(1)-15(8) can be provided to the optimization processing system 12 in other manners, such as by being input into optimization processing system 12 using user input device 26. The sensors 15(1)-15(8) monitor and provide data about the operation and condition of elements in each of the assets 17(1)-17(n), such as performance data, temperature readings, detected failures, images. In this particular embodiment, sensors 15(1)-15(4) are each coupled to different elements in asset 17(1) and sensors 15(5)-15(8) are each coupled to different elements in asset 17(n), although other numbers and types of sensors for each of the assets 17(1)-17(n) can be used. A variety of different types and numbers of assets 17(1)-17(n) can be managed, such as automobiles, tanks, planes, machines, etc. and a variety of different elements in each asset can be monitored. Communication system 16 is used to control and manage communication between optimization processing system 12, databases 14(1)-14(n), and sensors 15(1)-15(8) and in this embodiment comprises a wireless network, although other types and numbers of communication systems and/or methods can be used, such as a direct connection, Ethernet, a local area network, a wide area network, or modems and phone lines, each having communications protocols. The operation of the asset health management system 10 will now be described with reference to FIGS. 1-3. In step 40, the optimization processing system 12 is engaged to manage the optimization of one or more of the assets 17(1)-17(n). The optimization processing system 12 retrieves from one or more of the databases 14(1)-14(n) data, such as the specification data, the historical maintenance data, and life-cycle data for each of the elements of the asset or assets 17(1)-17(n), although the data could be stored and retrieved from other locations. For example, the optimization processing system 12 could search for and retrieve this data from one or more third party sources, such as in the manufacturing specifications provided by the manufacturer of the element or asset. Data generated during the original manufacture of a component, subsystem, and/or system in an element of the asset might be located and stored at another server and the optimization processing system 12 can access and retrieve this data from that server. The specification data may also be obtained from on site evaluations of the components subsystems, and/or systems in the elements of the assets 17(1)-17(n). Typically, this data is input into the optimization processing system 12 using user input device 26, although other manners of inputting the data could be used. In this example: the specification data comprises operational requirements for the assets and an identification of the types of components in the element, operational ranges for the components, functional characteristics of the components, etc.; the historical maintenance data comprises a history of the type, number, and timing for each repair of an element in the asset; and the life cycle data comprises a history of the recorded length of time before each element in the asset failed, although other types of specification, historical maintenance, and/or life cycle data could be used. By way of example only, assume the assets 17(1)-17(n) comprise a fleet of motor vehicles and the monitored elements in these assets 17(1)-17(n) comprise an electrical system, a fuel system, a braking system, and a steering system. In this example, in step 40 the optimization processing system 12 would retrieve specification data, historical maintenance data, and life-cycle data for the electrical system, the fuel system, the braking system, and the steering system for each of the assets 17(1)-17(n), i.e. the motor vehicles. Additionally, in this example the specification data would include an identification of the components, the performance specifications and operational ranges for each of the components, and the functional characteristics for each of the components in the electrical system, the fuel system, the braking system, the steering system and also the operational requirements for the electrical system, the fuel system, the braking system, the steering system in a motor vehicle, e.g. what the electrical system needs to do for the motor vehicle, what the fuel system needs to do for the motor vehicle, what the braking system needs to do for the motor vehicle, and what the fuel system needs to do for the motor vehicle. Further in this example, the historical maintenance data and life-cycle data for the electrical system, the fuel system, the braking system, and the steering system would comprise stored data on the history of repairs of components or elements in each of the electrical system, the fuel system, the braking system, the steering system and also stored data on the expected life span or cycle for each of the electrical system, the fuel system, the braking system, and the steering system. The data could be in graph or tabular form and also could provide percentages during the life cycle of reaching certain milestones, e.g. after two years a component may have a 95% chance of still being operational after another two years. In step 42, one or more of the elements of assets which are substantially the same as the elements of the assets 17(1)-17(n) may be tested to obtain historical maintenance data and life cycle data over the life cycle of the asset, although other manners for acquiring this data could be used. For example, the optimization processing system 12 might search for and retrieve this historical maintenance data and life cycle data from one or more third party sources or the optimization processing system 12 could theoretically calculate the historical maintenance data and life cycle data. Next, in step 44 the data obtained by testing or in other manners is stored in one or more of the databases 14(1)-14(n), although the data could be stored at other locations, such as in memory storage device 20 in optimization processing system 12. In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, in step 42 an electrical system, a fuel system, a braking system, and a steering system which are substantially the same as those in the assets 17(1)-17(n) would be tested to obtain the historical maintenance data and the life cycle data for each of the electrical, fuel, braking, and steering systems and the data would be stored in one or more of the databases 14(1)-14(n) in step 44. By way of example only, the type of life cycle data obtained from the testing and stored could be a graph of time to failure versus usage for the electrical system as shown in FIG. 3, although other types of data in other formats could be stored, such as in a table format. Referring back to FIG. 2, in step 46 the sensors 15(1)-15(4) monitor and obtain operational and condition data about different elements in asset 17(1) and the sensors 15(5)-15(8) monitor and obtain operational and condition data about different elements in asset 17(n), although other numbers and types of sensors could be used to obtain the operational and condition data and other types of data can be monitored and retrieved. By way of example only, operational data can include actual performance information, temperatures, failure rates, status of consumables, etc. and condition data can include physical conditions, such as the level of corrosion, existence of fractures or cracks, level of wear, etc. The sensors 15(1)-15(8) provide the operational and condition data to the optimization processing system 12, although the data can be provided to other management systems. In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, the sensors 15(1) and 15(5) would monitor and obtain operational and condition data about the electrical system, the sensors 15(2) and 15(6) would monitor and obtain operational and condition data about the fuel system, the sensors 15(3) and 15(7) would monitor and obtain operational and condition data about the braking system, and the sensors 15(4) and 15(8) would monitor and obtain operational and condition data about the steering system in the assets 17(1) and 17(n). In step 48, the optimization processing system 12 conducts one or more diagnostics on the elements of the assets 17(1)-17(n). The diagnostics provide an assessment of the current health state of assets 17(1)-17(n) and may include isolation of a current defect or current set of possible defects in the assets 17(1)-17(n). In these embodiments, the diagnostics on the elements of the assets 17(1)-17(n) are based on the obtained operational and condition data and the retrieved specification data, although diagnostics could be based on information. The obtained operational and condition data for each of the elements provides the optimization processing system 12 with information about the current operating performance and condition or status of degradation for the elements of the assets 17(1)-17(n), although other types of operational and condition data can be obtained. The retrieved specification data for each of the elements provides the optimization processing system 12 with information about the operational characteristics and ranges for the elements of the assets 17(1)-17(n), although other types of specification data can be retrieved. The optimization processing system 12 compares the obtained operational and condition data against this retrieved specification data to provide a diagnosis of each of the monitored elements in the assets 17(1)-17(n), although other types and numbers of diagnostic tests which are based on other information could be conducted. For example, the optimization processing system 12 could run one or more diagnostic tests retrieved from memory storage device 20 or from other sources based on the specification and the obtained operational and condition data for each of the elements. A variety of different types of diagnostics can be used by the optimization processing system 12 based on the particular application. In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, the optimization processing system 12 would conduct one or more diagnostics on the electrical, fuel, braking, and steering systems based on the specification data and the obtained operational and condition data for the electrical, fuel, braking, and steering systems. By way of example, diagnostics might be conducted on the electrical system to test if the alternator, starter, and battery are operating in accordance with the retrieved specification data based on the obtained operational and condition data, e.g. for the battery the operational and condition data might be data on the DC voltage being output and on the ability of the battery to hold a charge. In step 50, the optimization processing system 12 conducts one or more prognostics on the elements of the assets 17(1)-17(n). The prognostics calculate the remaining useful life (or time to failure) of the assets 17(1)-17(n) and/or the prediction or projection of the future health state or condition of the assets 17(1)-17(n) based on the current and past health state and/or condition. This may also include isolation of a particular likely future defect (or set of possible defects), or evaluation of the progression of a current pre-failure defect in the assets 17(1)-17(n). In these embodiments, the prognostics are based on the obtained operational and condition data, the retrieved specification data, and the retrieved historical maintenance and the life-cycle data, although the prognostics could be based on information. Again, in these embodiments the obtained operational and condition data for each of the elements provides the optimization processing system 12 with information about the current operating performance and condition or status of degradation for the elements of the assets 17(1)-17(n), although other types of operational and condition data can be obtained. Also as discussed earlier, the retrieved specification data for each of the elements provides the optimization processing system 12 with information about the operational characteristics and ranges for the elements of the assets 17(1)-17(n), although other types of specification data can be retrieved. The retrieved historical maintenance and the life-cycle data for each of the elements provides the optimization processing system 12 with information about when near term and long term maintenance typically can be expected and what is the life span for elements of the assets 17(1)-17(n). By way of example only, the life cycle data for an element might comprise a graph of time to failure versus usage for the one of the elements in the assets 17(1)-17(n) as illustrated in FIG. 3. Referring back to FIG. 2, the optimization processing system 12 uses the obtained operational and condition data, the retrieved specification data, and the historical maintenance and life cycle data to determine estimates or predictions for when one or more of the monitored elements in the assets 17(1)-17(n) will require maintenance which includes replacement, although other types and numbers of prognostic tests could be conducted. For example, the optimization processing system 12 could run one or more prognostic tests retrieved from memory storage device 20 or from other sources based on the retrieved specification data and the obtained operational and condition data for each of the elements. A variety of different types of prognostics can be used by the optimization processing system 12 based on the particular application. In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, the optimization processing system 12 would conduct one or more prognostics on the electrical, fuel, braking, and steering systems based on the specification data and the obtained operational and condition data for the electrical, fuel, braking, and steering systems. By way of example, prognostics might be conducted on the electrical system to predict when the alternator, starter, and battery will require maintenance or will exceed its life expectancy, e.g. the prognostics conduced by the optimization processing system 12 might predict that there is an X % the battery will need to be recharged and have fluid levels filled in two days and that there is a Y % chance the battery will no longer be able to sufficiently hold a charge in two months. Although in these embodiments, both diagnostics and prognostics are utilized by the system 10 in determining the optimization plan or instruction(s), other combinations could be utilized as well, such as only using diagnostics or only using prognostics. By using both diagnostics and prognostics in these particular embodiments an enhanced optimization plan or instruction(s) is developed for the assets 17(1)-17(n). In step 52, the optimization processing system 12 may optionally retrieve cost data from one or more of the databases 14(1)-14(n). By way of example only, the cost data retrieved by the optimization processing system 12 can comprise costs for replacing elements in the assets 17(1)-17(n) or operational costs for the current configuration of the assets 17(1)-17(n). This obtained cost data can be incorporated in to factors consider by the optimization processing system 12 for determining the optimization plan or instruction(s). By way of example only, based on an established budget for maintenance costs for the assets 17(1)-17(n) retrieved from memory storage device 20 or obtained from other sources, the optimization plan or instruction(s) might delay maintenance or replacement of an element in each of the assets 17(1)-17(n) if the percentage risk for a failure of one of the elements is below a set percentage and the maintenance cost would currently exceed the established budget for maintenance. In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, the optimization processing system 12 could obtain cost for operating and replacement costs for each of the electrical, fuel, braking, and steering systems, e.g. costs for a battery fluid, fuel, brake pads, steering fluid. Based on this cost data, the optimization processing system 12 can change an optimization plan or instruction(s) to conduct maintenance to hold off on the maintenance for another set period of time during which the predicted risk of problems or failure of elements in the assets is acceptable. In step 54, the optimization processing system 12 could optionally obtain allocation data about each of the assets, such as the particular location of each of the assets 17(1)-17(n), the destination for each of the assets 17(1)-17(n), and the proximity of one or more service centers for each of the assets 17(1)-17(n). In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, the allocation data could be used by the optimization processing system 12 to change the optimization plan or instruction(s) which might currently might not recommend maintenance to schedule an earlier maintenance appointment if the travel time for an one of the vehicles to the next scheduled destination retrieved from memory storage device 20 or other source is greater than the time predicted when the electrical, fuel, braking, and/or steering systems might require maintenance. In step 56, the optimization processing system 12 can also optionally obtain upgrade data about options for replacing one or more of the elements in the assets 17(1)-17(n). This upgrade data can take a variety of formats, such as the new specification data which needs to be loaded into the databases 14(1)-14(n) for use in future optimization determinations by the optimization processing system 12 if an element is replaced with an upgraded element. By way of another example, the upgrade data could recommend replacing two existing elements with a single upgrade element and again when this replacement takes place the specification data needs to be loaded into the databases 14(1)-14(n) for use in future optimization determinations by the optimization processing system 12. In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, upgrade data might comprises data that two current batteries can be replaced by a single smaller and lighter battery with a longer life cycle. Accordingly, with this upgrade data the optimization processing system 12 might determine the optimization instruction is to replace the two batteries with the new single battery when the life cycle of the two batteries expires or is within a certain predicted time period of expiring. Alternatively, if the upgrade data comprises data that the two current batteries can be replaced by a single smaller and lighter battery with a longer life cycle, but the cost data indicates the single smaller battery is three times more expensive, then the determined optimization instruction may be to replace the two batteries with two of the same batteries, instead of the single battery because of the cost data. In step 58, the optimization processing system 12 uses the conducted diagnostics and prognostics to determines near term and long term maintenance needs for the elements of the assets 17(1)-17(n) which are then used to determine an optimization plan or instruction(s). Additionally, the optimization processing system 12 can factor in other obtained and retrieved data, such as cost, allocation data, and/or upgrade data to further refine the determined optimization plan or instruction(s). In the example where the assets 17(1)-17(n) comprise a fleet of motor vehicles, the diagnostics might not indicate any current failures with the electrical, fuel, braking, or steering systems, but might indicate degradation of the charge holding capacity of the two batteries in the electrical system and the prognostics might indicate the life cycle for the two batteries is nearing the end and has a high percentage chance of near term failure. As a result, the optimization plan or instruction(s) determined by the optimization processing system 12 would be to replace the two batteries with two new batteries. As discussed in the examples above, this optimization instruction may be further refined by one or more of the cost data, allocation data, and upgrade data. In step 60, the optimization processing system 12 displays the optimization plan or instruction(s) on the display device 28, although the optimization plan or instruction(s) could be displayed or output in other manners. For example, the optimization plan or instruction(s) could be put into an email and sent to one or more designated parties assigned to oversee the management of the asset or assets or the optimization plan or instruction(s) could be sent to and printed at a remote printer. In step 62, the optimization processing system 12 optionally may implement the optimization plan or instruction(s) for one or more of the assets 17(1)-17(n). By way of example only, this implementation of the optimization instruction might be downloading a new software routine to the assets 17(1)-17(n) to improve their operating efficiencies, ordering replacement elements for the assets 17(1)-17(n), or emailing instructions to one or more other systems or parties to provide notification that a particular optimization in an element in one or more of the assets 17(1)-17(n) needs to take place. In step 64, the optimization processing system 12 determines whether to store the recently gathered data, such as the historical maintenance data and the life cycle data, in one or more of the databases 14(1)-14(n). As a result, one of the advantages of the present invention is that the historical maintenance and life cycle data for assets being optimized is being refined to reflect the most recent data. Additionally, when multiple assets of the same type are being managed, the optimization processing system 12 is able to more quickly obtain and store this recent data The present invention provides a method and system for optimizing the utilization of an asset or collection of assets over the entire life-cycle of the asset or collection of assets. Diagnostic methodologies are utilized by the present invention to identify factors, such as degradation and failures of elements of the asset, status of consumables, and operational readiness, and these factors are utilized in the determination of an optimization plan or instruction(s). Additionally, predictive or prognostic methodologies are used by the present invention to forecast failures. The prognostic methodologies consider the operation and maintenance of the asset and elements of the asset in the context of the entire life cycle. The present invention balances near term and predicted long term maintenance needs against operational requirements are also utilized in the determination of an optimization plan or instruction(s). Further, the present invention also balances the implications of operational requirements versus near and long term maintenance needs against total asset life cycle operational costs. With the present invention, the consideration of these factors allows for an optimal operational and maintenance plan or instruction(s) to be developed. Having thus described the basic concept of the invention, it will be rather apparent to those skilled in the art that the foregoing detailed disclosure is intended to be presented by way of example only, and is not limiting. Various alterations, improvements, and modifications will occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested hereby, and are within the spirit and scope of the invention. Further, the recited order of elements, steps or sequences, or the use of numbers, letters, or other designations therefore, is not intended to limit the claimed processes to any order except as may be explicitly specified in the claims. Accordingly, the invention is limited only by the following claims and equivalents thereto.
	claims	1. A robot for machining a part of structure under water, comprising:a machine tool having a submersible motor, a machining element coupled to the motor, a chamber receiving a driven portion of the machining element, and at least one gas inlet communicating with the chamber;a support and guiding structure for the machine tool, fixable with respect to the part to be machined and having submersible mobile elements and corresponding submersible guiding elements defining axes along which the mobile elements are movable for positioning the machine tool with respect to the part to be machined, the machine tool being attached to one of the mobile elements within reach of the part to be machined when the support and guiding structure is fixed with respect to the part to be machined, the mobile elements and the guiding elements having a rigidity resisting to stresses produced by the machine tool when the machine tool is in operation;displacement units for displacement of the mobile elements along the axes;a gas supply connectable to the at least one gas inlet of the machine tool for injecting gas in the chamber; anda control unit connecting to the machine tool and to the displacement units, the control unit being programmable for operating the displacement units and the machine tool based on a closed-loop control mode in order to perform the machining of the part. 2. The robot according to claim 1, wherein:the structure has structural elements between which the part to be machined extends; andthe support and guiding structure has a longitudinal axis in which one of the guiding elements called longitudinal guiding element extends, the robot further comprising attachments projecting at opposite ends of the longitudinal guiding element and operable to lock the support and guiding structure between the structural elements so that the longitudinal guiding element substantially extends in parallel to the part to be machined. 3. The robot according to claim 2, wherein the longitudinal guiding element comprises at least one longitudinal module having opposite ends configured to assemble with opposite ends of like modules used depending on whether a spacing between the structural elements requires more than one longitudinal module. 4. The robot according to claim 2, wherein each attachment comprises:an arrangement of shoes, two of which project in opposite directions and are mobile between extended and retracted positions in which, respectively, the shoes engage against and disengage from the corresponding structural element;articulated rods connected to the mobile shoes; anda jack coupled to the articulated rods and operable so that the articulated rods move the mobile shoes between the extended and retracted positions. 5. The robot according to claim 1, wherein the guiding elements called longitudinal, transverse and vertical guiding elements and the corresponding axes respectively extend in longitudinal, transverse and vertical directions of the support and guiding structure, one of the vertical and transverse guiding elements being attached to the mobile element corresponding to the longitudinal guiding element, and the other one of the vertical and transverse guiding elements being attached to the mobile element corresponding to said one of the vertical and transverse guiding element. 6. The robot according to claim 5, wherein:the longitudinal guiding element comprises an elongated lattice having a triangulation contributing to its rigidity, and a pair of parallel tracks projecting along the elongated lattice, the corresponding mobile element comprising a platform slideably mounted on the tracks; andthe displacement unit of the mobile element corresponding to the longitudinal guiding element comprises a submersible rotary motor having a pinion coupled to a rack extending in parallel to the longitudinal axis, the rack and the rotary motor being respectively mounted on one and the other one of the longitudinal guiding element and the corresponding mobile element. 7. The robot according to claim 5, wherein:the transverse and vertical guiding elements comprise respective housings and respective pairs of parallel tracks projecting along the corresponding housings, the corresponding mobile elements comprising respective platforms slideably mounted on the corresponding pairs of tracks; andthe displacement units for displacement of the mobile elements corresponding to the transverse and vertical guiding elements comprise submersible linear motors having respective magnetic shafts with permanent magnets extending in longitudinal directions of the respective housings, the motors and their magnetic shafts being respectively mounted on one and the other one of the mobile elements and the corresponding guiding elements. 8. The robot according to claim 5, wherein the displacement units comprise respective motors operationally coupled to the mobile elements and to the corresponding guiding elements to move the mobile elements along the axes in response to control signals generated by the control unit, and respective position encoders connecting to the control unit to produce position information of the mobile elements along the axes at the control unit, the closed-loop control mode comprising a control in position of the motors with respect to the position information produced by the position encoders. 9. The robot according to claim 8, wherein:the machine tool is attached to the mobile element corresponding to the vertical guiding element; andthe support and guiding structure further comprises an electrical box mounted on the vertical guiding element on a side opposite to the machine tool, the electrical box having watertight openings for receiving cables connecting the motors and the position encoders to the control unit. 10. The robot according to claim 1, wherein:the machining element comprises a grinding wheel;the machine tool comprises a guard defining the chamber, the guard having a lower opening through which a portion of the perimeter of the grinding wheel extends, and an inner surface extending close to the grinding wheel and having a shape adapted to the grinding wheel; andthe machine tool comprises a transmission coupling the grinding wheel to the motor, and an arrangement slideably supporting the guard with respect to the grinding wheel so that the guard draws back as the grinding wheel wears off. 11. The robot according to claim 10, wherein:the transmission comprises an adjustable transmission unit disposed in a housing defining an inner space;the machine tool comprises at least one extra gas inlet communicating with the inner space of the housing; andthe gas supply also connects to the at least one extra gas inlet to inject gas in the housing. 12. The robot according to claim 10, wherein the at least one gas inlet comprises a gas diffusing channel extending along the inner surface of the guard. 13. The robot according to claim 1, wherein:the control unit comprises:a computer;interface cards connecting to the computer;controllers having communication ports connecting to the interface cards, power supply inputs, controllable power outputs connecting to the displacement units and to the machine tool, electronic supply inputs, and feedback signal inputs connecting to the displacement units and to the machine tool;power converters having electric supply inputs, and power supply outputs connecting to the power supply inputs of the controllers; anda power supply unit having an electric supply input, and electronic supply outputs connecting to the electronic supply inputs of the controllers; andthe gas supply comprises a solenoid valve having a gas supply inlet, a communication port connecting to one of the interface cards, and a controllable gas outlet connecting to the machine tool. 14. The robot according to claim 13, wherein the computer is configured to store a map of the surface of the part to be machined, receive and process the feedback signals, and control the solenoid valve and the controllers based on the closed-loop control mode using the feedback signals, the map of the surface of the part to be machined, and programmable reconditioning parameters of the surface of the part to be machined. 15. The robot according to claim 13, wherein the feedback signals comprise position signals of the mobile elements with respect to the corresponding guiding elements, current signals of the displacement units, and speed and current signals of the machine tool. 16. The robot according to claim 1, wherein the part of structure to be machined comprises a runway, a sill or a lintel of a sluice. 17. A method for machining a part of structure under water with a machine tool having a submersible motor and a machining element coupled to the motor, comprising the steps of:fixing a support and guiding structure for the machine tool with respect to the part to be machined, the support and guiding structure having submersible mobile elements and corresponding submersible guiding elements defining axes along which the mobile elements are movable, and displacement units for displacement of the mobile elements along the axes for positioning the machine tool with respect to the part to be machined, the machine tool being attached to one of the mobile elements within reach of the part to be machined when the support and guiding structure is fixed with respect to the part to be machined, the mobile elements and the guiding elements having a rigidity resisting to stresses produced by the machine tool when the machine tool is in operation;providing the machine tool with a chamber receiving a driven portion of the machining element, and at least one gas inlet communicating with the chamber;supplying the at least one gas inlet of the machine tool with gas for injecting gas in the chamber; andoperating the displacement units and the machine tool based on a closed-loop control mode in order to perform the machining of the part.
	abstract	Described herein are multi-leaf collimators that comprise leaf drive mechanisms. The leaf drive mechanisms can be used in binary multi-leaf collimators used in emission-guided radiation therapy. One variation of a multi-leaf collimator comprises a pneumatics-based leaf drive mechanism. Another variation of a multi-leaf collimator comprises a spring-based leaf drive mechanism having a spring resonator.
	abstract	A moving photoconverter device that converts an incident light image into an equivalent electron or other charged particle beam image. The moving photoconverter is ring shaped and is rotated by using a motor such that the incident light image exposes a moving photoconverter surface. The photoconverter may additionally or alternatively move in an X-Y motion or radially. Continuous regeneration is provided at a site remote from the region of moving photoconverter device that converts an incident light image into an equivalent electron or other charged particle beam image.
	description	This application claims the benefit of U.S. Provisional Application Ser. No. 60/492,138 filed Aug. 1, 2003. The present invention relates to charged particle beam devices and, more particularly, to charged particle beam devices used to generate images of specimens under examination. Although the present invention relates generally to the use of charged particles in generating an image that represents one or more characteristics of a specimen under examination, the present invention will be described in the context of transmission electron microscopes. Transmission electron microscopes use a beam of accelerated electrons that pass through a specimen to provide an image representing the specimen. The image may be a single or multi-dimensional image, a diffraction pattern, a spectrum, or any other suitable representation of the specimen. To provide a record of these images, electrons are converted into light images using a scintillator and a camera then captures the light images. While photographic film has long been used to capture such images, charge coupled devices (CCDs) have found increasing use in this field. Such CCD cameras offer excellent resolution, sensitivity, and linearity, are reusable, and make the image available for viewing within seconds of recording. With the advent of digital image processing in transmission electron microscopy, such CCD cameras have been used to transfer images directly from the microscope to a computer. Typically, the electron image is converted to a light image by means of a scintillator such as a phosphor screen mounted inside the transmission microscope. The light image is then transferred to a CCD pixel array, also located inside of the microscope, using a lens or fiber optic coupling. The image collected by the camera is then digitized electronically and stored in a computer where it can be manipulated and viewed with the aid of appropriate software. CCD cameras and other imaging devices according to the present invention may operate in either a full frame mode or frame transfer mode. In the full frame mode, the image is exposed onto a relatively large active area of the detector, and the electron beam is then blanked (such as by using a shutter to remove the illumination). The pixels on the detector are then read out and stored. In full frame mode, substantially all of the available detector pixels are used for imaging, which allows for a high quality image. When this cycle of exposure and blanking is repeated in a continuous mode at low exposure times, i.e. high frame rates, the active duty cycle for the camera becomes relatively low. That is, the duty cycle of the camera is the fraction of time that imaging can take place with respect to the total time required for the imaging and read out cycle to take place. In the frame transfer mode, a mask is placed on the CCD such that the imaging detector of the camera has a portion (e.g., approximately 50%) of the area masked from electron or photon illumination. The camera is operated in a continuous mode where the image is always being exposed in the unmasked imaging area. After exposure, the image is shifted by rapidly moving it to the area on the CCD behind the mask and is read out and stored. Typically, shifting the image is many times faster than reading it out. In frame transfer mode, the image detector has only half the pixels available for imaging but has a higher duty cycle. The only non-imaging time in the cycle is the transfer of electrical charges to and from the imaging area to the memory area of the detector. Shuttering the beam during image shifting under the mask may not be needed if the shifting process is rapid enough. The present invention addresses the trade-off with respect to the high quality images and low duty cycles of the full frame mode and the high duty cycles and lower resolutions of the frame transfer mode. Charged particle imaging devices according to the present invention are not limited to a single mode of operation and there is no need to change cameras to account for the needs of the particular project because imaging devices according to the present invention are capable of operation in a plurality of modes and can be converted from operation in one mode to another quickly. The present invention meets those needs by providing a camera that can be operated in at least two different modes and that can be quickly converted from operation in one mode to another. In accordance with one aspect of the present invention, a camera is provided having an imaging detector with an imaging area. In a preferred mode, the imaging detector comprises a charge-coupled device (CCD) having a pixel-receiving array. In other embodiments of the invention, the imaging detector may comprise a photodiode array, a CMOS detector, or other imaging device that can convert photons into electrical charges. The camera includes a mask that is capable of being manipulated to permit an image to be received by the full surface area of the imaging detector and then further manipulated to cover or block at least a portion of the area of the image receiving detector from receiving an image. The mask may be either a mechanical mask, a virtual mask implemented using suitable software to manipulate the optics of the system to prevent the image from reaching a portion of the imaging detector, or any other suitable means for restricting an area of the imaging detector from receiving an image. Where the mask is a mechanical mask, it is preferably constructed of a low Z (i.e., low atomic number) material such as, for example, aluminum. The use of low Z materials for the mechanical mask provides the additional benefit of reducing the amount of hard X-rays emitted from the mask, making X-ray shielding of the imaging detector simpler. This in turn reduces any problems associated with X-ray emissions causing false signals to register on the imaging detector. In one embodiment, the mechanical mask comprises a pair of shutters located on either side of the imaging detector. The halves of the mask are driven using suitable mechanical, electrical, or hydraulic motive power. The mask is movable from at least a first position where the mask does not interfere with the imaging detector (e.g., the entire surface of the imaging detector is uncovered) to at least a second position where at least a portion of the imaging detector is covered such that at least a portion of the image does not reach the masked off portion of the detector. In the full frame mode, the image is exposed onto the full area of the detector, and the electron beam is then blanked (such as by using a shutter to remove the illumination). The pixels on the detector are then read out and stored. In full frame mode, all of the available pixels on the device are used for imaging, which allows for a high quality image. In the frame transfer mode, the imaging detector of the camera has a portion (e.g., approximately 50%) of the area masked from electron or photon illumination. In the embodiment of the invention using a mechanical mask, this is accomplished by moving the mask to cover a predetermined percentage of the surface area of the imaging detector. In the embodiment of the invention using a virtual mask, the optics of the system are manipulated to mask of a predetermined percentage of the surface area of the imaging detector. The camera is operated in a continuous mode where the image is always being exposed in the unmasked imaging area. After exposure, the image is rapidly moved to a memory area on the camera behind the mask and is read out and stored. In a pipelined frame transfer mode mode, the image may be an asymmetric spectrum that is exposed on a narrow area of the imaging detector. This mode is typically used in conjunction with a spectrometer. In one embodiment, using a 2048×2048 pixel CCD device, only the middle 200×2048 pixels of the detector are illuminated. The remainder of the surface area of the detector is masked. After the spectrum exposure is complete, the image of the spectrum is transferred along the detector to an area just outside the portion on which the spectrum has been exposed. In this way many spectra, typically 1 to 10, can be exposed on the detector in a “pipeline” before the first spectrum is read out. As moving charge across the full surface area of the detector can take a considerable amount of time, this pipelining allows for much faster frame rates for spectroscopy uses. Imaging devices according to the present invention are versatile in operation and can be used in conjunction with a number of electron microscope configurations. For example, the camera may be positioned at the bottom of a transmission electron microscope (TEM) column or in the 35 mm camera port on the side of the microscope column. The camera may also be used in conjunction with an imaging filter or an electron energy loss spectrometer (EELS) to capture images. Accordingly, it is a feature of the present invention to provide a camera that can be operated in at least two different modes and that can be quickly converted from operation in one mode to another. This and other features and advantages of the invention will become apparent from the following detailed description, and the accompanying drawings. In accordance with one embodiment of the present invention, a charged particle device is provided comprising a charged particle source configured to direct charged particles in the direction of a specimen under examination and an imaging device configured to convert charged particles to an image representing the specimen. The imaging device comprises a detector defining a pixel array. The detector is configured to generate electric charges for individual pixels of the pixel array such that the electric charges collectively define the image. The imaging device is configured such that a portion of the pixel array can be transitioned between a partially masked state and a substantially unmasked state. The partially masked state defines a set of masked readout pixels and a set of unmasked imaging pixels. The set of masked readout pixels occupies a portion of the pixel array that is large enough to accommodate image data held in the unmasked imaging pixels. The imaging device is programmed to operate in a full frame imaging mode when the pixel array is in the substantially unmasked state and in a frame transfer imaging mode when the pixel array is in the partially masked state. The device may also operate in a pipelined frame transfer mode when the pixel array is in the partially masked state. In accordance with another embodiment of the present invention, a charged particle device is provided comprising a specimen holder, a charged particle source, an imaging device, and a user interface. The specimen holder defines a specimen position and the charged particle source is configured to direct charged particles in the direction of the specimen position. The imaging device is configured to convert charged particles to an image representing a specimen held in the specimen position. The detector is configured to generate electric charges for individual pixels of the detector pixel array such that the electric charges collectively define the image. The user interface is configured to enable selection from at least two operating modes comprising a frame transfer mode and a full frame mode. The imaging device is configured to transition the pixel array between a partially masked state in the frame transfer mode and a substantially unmasked state in the full frame mode. In accordance with yet another embodiment of the present invention, a method of operating a charged particle device is provided. The device is configured to direct charged particles in the direction of a specimen under examination and convert the charged particles to an image representing the specimen. The charged particle device comprises a user interface and a controller programmed to prompt a user to select one of a plurality of imaging modes via the user interface. A portion of the pixel array is transitioned between a partially masked state and a substantially unmasked state as a function of the imaging mode selected via the user interface. Accordingly, it is an object of the present invention to provide an improved charged particle device. Other objects of the present invention will be apparent in light of the description of the invention embodied herein. FIGS. 1 and 2 illustrate one embodiment of the invention in which the imaging device 10, typically including a CCD imaging detector 15, is cooled by water from cooling lines 11. Imaging device 10 includes a mechanical mask 12 selectively movable across the pixel array of the CCD detector 15. In FIG. 1, the mechanical mask 12 is illustrated in an open position Such as would be used when the imaging device 10 is operated in the full frame mode. In FIG. 2, the mechanical mask 12 is illustrated in a partially closed position such as would be used when the imaging device 10 is operated in the frame transfer mode. As can be seen, the mask includes a movable piston 14 driven by pneumatic pressure supplied from line 16. Application of pneumatic pressure causes piston 14 to move. A pair of wedge-shaped cams 18 located on either side of piston 14 ride against pins 20, located on opposing halves 22 and 24 of mask 12. As piston 14 moves, the cams, in conjunction with the pins overcome the bias of springs 26 and cause the respective mask halves to retract, exposing additional surface area of the detector 15. The mechanical mask 12 may be constructed of a low Z material, i.e., a low atomic weight material. The use of low Z materials for the mechanical mask provides the additional benefit of reducing the amount of hard X-rays emitted from the mask, making X-ray shielding of the imaging detector simpler. This in turn reduces any problems associated with X-ray emissions causing false signals to register on the imaging detector. Aluminum is a suitable material to construct mask 12. Heavier atomic weight metals such as tungsten do not provide the low X-ray properties of aluminum. Refeffing to FIG. 3, in typical full frame operation, the full surface area of the detector 15 is available for sensing during exposure. During readout of the image 25, charge is shifted sequentially across the pixel array of the detector 15 to designated readout cells coupled to one or more signal output amplifiers 30. In the embodiment of FIG. 3, the pixel array of the detector 15 is divided into quadrants, each coupled to an independent signal output amplifier 30. During readout, a mechanical shutter or other suitable means in the system blocks any incoming charged particles from reaching the detector. The full frame mode uses substantially all of the pixels in the array of the detector 15. The pixels are typically square so that there is no image distortion. In general, and by way of example, not limitation, the array undergoes readout by shifting individual rows of images in sequence in parallel fashion to a serial shift register coupled to an output amplifier 30. The serial shift register then sequentially shifts each row of image information to the amplifier as a serial data stream. The process is repeated until all rows of image data are transferred to the output amplifier 30 and then to an analog to digital converter circuit. Reconstruction of the image 25 in a digital format yields the final image. Referring to FIGS. 4 and 5, in the frame transfer mode, a portion of the pixel array is masked to define a set of masked readout pixels 40 and a set of unmasked imaging pixels 50. The image 25 is captured on the unmasked area of the array while the masked portion serves as a storage array for a transferred image 35. Once captured, the charges representing the image 25 are transferred from the unmasked imaging pixels 50 to the storage area defined by the masked readout pixels 40. Once in the storage area, the charges are transferred off of the pixel array in much the same way as the full frame mode operation described above. Specifically, the detector array undergoes readout by shifting rows of image information in a parallel fashion, one row at a time, to a serial shift register. The serial register then sequentially shifts each row of information to an output amplifier as a serial data stream. During the period in which the readout pixels 40 are being read, the imaging pixels 50 (i.e., the unmasked portion of the detector) is exposed to another image frame. This mode of operation permits faster frame rates and increased duty cycles. It is noted that the multiple modes of operation of the imaging device of the present invention may be controlled by running parallel and serial clock lines in different sequences for the different modes. Such operation can be facilitated by controlling voltages using a digital signal processor (DSP). It is also noted that, the embodiment of FIGS. 4 and 5 illustrates a pixel array that is defined in four quadrants, with each quadrant of the array including masked readout pixels 40 and unmasked imaging pixels 50. It is contemplated, however, that imaging devices according to the present invention may incorporate pixel arrays configured for readout in a variety of ways. For example, FIGS. 6 and 7 illustrate the full frame mode and the frame transfer mode of the present invention in the context of a pixel array 15 that merely includes a single area of masked readout pixels 40 and a single area of unmasked imaging pixels 50, as opposed to respective quadrants of readout and imaging pixels. Referring to FIG. 8, to operate an imaging device according to the present invention in a pipelined frame transfer mode, the mask 24 is positioned so that the image, which in the illustrated embodiment comprises a spectrum, is exposed onto only a relatively narrow area of unmasked imaging pixels 50 of the imaging detector 15. This mode is typically used in conjunction with a spectrometer. In one embodiment using a 2048×2048 pixel CCD device, only the middle 200×2048 pixels of the detector are illuminated. The remainder of the surface area of the detector is mechanically masked or virtually masked using software to modify the spectrometer electron optics. After the spectrum exposure is complete, the image of the spectrum is transferred along the detector to an adjacent equivalent area of masked imaging pixels 40 just outside the portion on which the spectrum has been exposed. Subsequent image transfer occurs in a progressive manner until image data is read out by the signal output amplifier 30 coupled to the final area of masked pixels 40 in the pipeline. In this way many spectra, typically 1 to 10, can be exposed on the detector in a “pipeline” before the first spectrum is read out by the signal output amplifier 30. As moving charge across the full surface area of the detector can take a considerable amount of time, this pipelining allows for much faster frame rates for spectroscopy uses. Imaging devices according to the present invention may be used in conjunction with a variety of charged particle beam systems. For example and by way of illustration, not limitation, as shown schematically in FIG. 9, an imaging device 10 according to the present invention may be mounted in the bottom of a TEM column 60, such as, for example, the TEM described in Krivanek, U.S. Pat. No. 5,065,029, the entire disclosure of which is hereby incorporated by reference. FIG. 9 also illustrates the use of a user interface 62 and a controller 64 programmed to prompt a user to select one of a plurality of imaging modes via the user interface 62. It is noted that the user interface 62 and the controller 64 may take a variety of suitable forms and may be utilized in a variety of embodiments of the present invention. As a further example, referring to the schematic illustration of FIG. 10, an imaging device 10 according to the present invention may be mounted to the end of an imaging filter 70, such as, for example, the energy-selected electron imaging filter described in Krivanek, U.S. Pat. No. 4,851,670, the entire disclosure of which is hereby incorporated by reference. In yet another embodiment of the invention schematically illustrated in FIG. 11, an imaging device 10 of the present invention may be mounted on the end of an electron energy loss spectrometer (EELS) 80, such as, for example, the EELS device described in Krivanek, U.S. Pat. No. 5,097,126, the entire disclosure of which is hereby incorporated by reference. Embodiments of the imaging device of the present invention are capable of multiple modes of operation. This allows high quality images to be captured and fast viewing of captured images with high duty cycles, thereby providing high sensitivity and fast spectra readout using the same device. To achieve these features, a real or virtual removable mask to adjustably shield a portion of the imaging detector is used. Additionally, multiple methods of moving the charge on the imaging detector are used. In many cases the detector will be a CCD, although other suitable detectors can be used, for example a photodiode array or a CMOS detector. It is noted that terms like “preferably,” “commonly,” and “typically” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention. For the purposes of describing and defining the present invention it is noted that the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention.
	claims	1. A shipping container for radioactive materials comprising: an outer, generally cylindrically-shaped container body having a closed lower end and an open, upper end; a top for releasable securement to the container body and closing said open upper end thereof; a generally cylindrical inner containment vessel generally concentrically disposed in said outer container body for receiving at least one radioactive material containing pail, said vessel having a lid for closing an open upper end thereof; a foam material between said outer container body and said inner vessel; said inner vessel having an outwardly directed flange about said open end thereof; a plurality of circumferentially spaced reinforcing gussets between an outer surface of said vessel and an underside of said flange for reinforcing said flange; said lid and said flange having cooperating fastening elements for fastening said lid and said flange to one another. 2. A shipping container according to claim 1 including a gasket formed of heat- and fire-resistant material disposed between said lid and said flange, said foam material comprising a self-extinguishing fire-retardant material. claim 1 3. A shipping container according to claim 1 wherein said inner containment vessel includes a plurality of rods projecting outwardly of said vessel toward said outer container body and extending into the foam material for maintaining said inner vessel substantially concentric within said outer container body. claim 1 4. A shipping container according to claim 3 wherein said rods project generally radially from said vessel adjacent upper and lower ends of said vessel and at circumferentially spaced locations about said vessel. claim 3 5. A shipping container according to claim 1 including an interior dunnage for said outer container body and overlying the inner containment vessel between said lid thereof and said top for said outer container body, said interior dunnage including a foam material disposed between ceramic fiberboard panels and upper and lower metal sheets. claim 1 6. A shipping container according to claim 1 wherein said outer container body has a plurality of circumferentially spaced bolt brackets adjacent said top for receiving bolts passed through the top and into the brackets. claim 1 7. A shipping container according to claim 6 wherein said outer container body has a seam, a plurality of said bolts being uniformly spaced about said lid and a pair of said bolts straddling said seam and being spaced from one another a distance less than the uniform spacing between said plurality of bolts. claim 6 8. A shipping container according to claim 6 including an interior dunnage for said outer container body and overlying the inner containment vessel between said lid of said vessel and said top for said outer container body, said interior dunnage including a foam material disposed between ceramic fiberboard panels and upper and lower metal sheets and having a plurality of circumferentially spaced slots opening through a periphery thereof. claim 6 9. A shipping container according to claim 1 including a retaining ring clamping said top to a radially outwardly extending edge of said container body, said ring having end lugs bolted to one another. claim 1 10. A shipping container according to claim 1 including a plurality of vent holes in said outer container body and plugs sealing said vent holes responsive to a predetermined temperature for opening said vent holes. claim 1 11. A shipping container according to claim 1 including a plurality of reinforcing ribs spaced axially from one another along the outer container body, and a pair of said ribs lying closely adjacent one another and to the open end of the container body for reinforcing the upper end of the container body. claim 1 12. A shipping container according to claim 1 including neutron absorbing material disposed about said inner vessel and within the outer container body. claim 1 13. A shipping container according to claim 1 including a retaining ring clamping said top to a radially outwardly extending edge of said container body, said ring having end lugs bolted to one another, and a set of bolts and lugs on the top and outer container body for securing the top and the container body to one another. claim 1 14. A shipping container according to claim 1 wherein said outer container body has a seam along a side thereof, a metal reinforcement plate overlying said seam to preclude rupture of said seam upon impact. claim 1 15. A shipping container for radioactive materials comprising: an outer, generally cylindrically-shaped container body having a closed lower end and an open, upper end; a top for releasable securement to the container body and closing said upper end thereof; a generally cylindrical inner containment vessel, generally concentrically disposed in said outer container for receiving at least one radioactive material containing pail, said vessel having a lid for closing an open upper end thereof; a foam material between said outer container and said inner vessel; said inner containment vessel including a plurality of rods projecting outwardly of said vessel toward said outer container body and extending into the foam material for maintaining said inner vessel substantially concentric within said outer container body; and a retaining ring for clamping said top to a radially outwardly extending flange of said container body, said ring having end lugs bolted to one another. 16. A shipping container according to claim 15 wherein said rods project generally radially from said vessel adjacent upper and lower ends thereof and are circumferentially spaced from one another. claim 15 17. A shipping container according to claim 15 including interior dunnage for said outer container body and overlying the inner containment vessel between said lid and said top for said outer container body, said interior dunnage including a foam material disposed between upper and lower metal sheets and ceramic fiberboard panels. claim 15 18. A shipping container according to claim 15 wherein said outer container body has a plurality of circumferentially spaced bolt brackets adjacent said top for receiving bolts passed through the top and into the brackets. claim 15 19. A shipping container according to claim 15 including a plurality of vent holes in said outer container body and plugs sealing said vent holes responsive to a predetermined temperature for opening said vent holes. claim 15 20. A shipping container according to claim 15 including neutron absorbing material disposed about said inner vessel and within the outer container body. claim 15 21. A shipping container for radioactive materials comprising: an outer, generally cylindrically-shaped container body having a closed lower end and an open, upper end; a top for releasable securement to the container body and closing said open upper end thereof; a generally cylindrical inner containment vessel, generally concentrically disposed in said outer container body for receiving at least one radioactive material containing pail, said vessel having a lid for closing an open upper end thereof and a closed lower end; a foam material between said outer container body and said inner vessel; an interior dunnage for said outer container body and overlying the inner containment vessel between said lid thereof and said top for said outer container body, said interior dunnage including a foam material disposed between upper and lower metal sheets and ceramic fiberboard panels; an interior dunnage underlying said inner vessel within said container body, said lower dunnage including foam material disposed between said closed lower end of said vessel and said closed lower end of said container body; and a retaining ring clamping said top to a radially outwardly extending edge of said container body, said ring having end lugs bolted to one another. 22. A shipping container according to claim 21 wherein said outer container body has a plurality of circumferentially shaped bolt brackets adjacent said top for receiving bolts passed through the top and into the brackets. claim 21 23. A shipping container according to claim 21 including a plurality of vent holes in said outer container body and plugs sealing said vent holes and responsive to a predetermined temperature for opening said vent holes. claim 21 24. A shipping container according to claim 21 including a plurality of reinforcing ribs spaced axially from one another along the outer container body, and a pair of said ribs lying closely adjacent one another and to the open end of the container body for reinforcing the upper end of the container body. claim 21 25. A shipping container according to claim 21 including neutron absorbing material disposed about said inner vessel and within the outer container body. claim 21 26. A shipping container for radioactive materials comprising: an outer, generally cylindrically-shaped container body having a closed lower end and an open, upper end; a top for releasable securement to the container body and closing said upper end thereof; a generally cylindrical inner containment vessel, generally concentrically disposed in said outer container for receiving at least one radioactive material container pail and having a lid; neutron absorbing material disposed about said inner vessel and within the outer container body; and a retaining ring clamping said top to a radially outwardly extending edge of said container body, said ring having end lugs bolted to one another. 27. A shipping container according to claim 26 including a foam material between said outer container and said inner vessel, said inner containment vessel including a plurality of rods projecting outwardly of said vessel toward said outer container body and extending into the foam material for maintaining said inner vessel substantially concentric within said outer container body. claim 26 28. A shipping container according to claim 26 including a plurality of vent holes in said outer container body and plugs sealing said vent holes responsive to a predetermined temperature for opening said vent holes. claim 26 29. A shipping container according to claim 26 including a plurality of reinforcing ribs spaced axially from one another along the outer container body, and a pair of said ribs lying closely adjacent one another and to the open end of the container body for reinforcing the upper end of the container body. claim 26
055816053	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element for uniformly irradiating X-rays in a broad area, a method for producing the optical element, an optical system using the optical element, and an optical apparatus provided with the illumination optical system. 2. Related Background Art As a semiconductor integrated circuit element becomes finer and finer these days, there has been developed a reduction projection lithography technology using X-rays of shorter wavelength than conventionally used ultraviolet rays in place thereof in order to improve the resolving power of optical system which is limited by the diffraction limit. An X-ray exposure apparatus used in this technology is composed mainly of an X-ray source, an illumination optical system, a mask, an imaging optical system (reduction projection optical system) and a wafer stage. A photon radiation or laser plasm X-ray source is used as the X-ray source. The illumination optical system is constituted mainly by an oblique incidence mirror for reflecting X-rays incident obliquely into a reflecting surface, a multi-layer film mirror having a reflecting surface formed of multi-layered films, and a filter reflecting or transmitting only X-rays of a predetermined wavelength, so that the system may illuminate a mask with X-rays of the desired wavelength. The mask may be a transmitting mask or a reflecting mask. The transmitting mask is constructed such that an X-ray-absorbing material is formed in a desired pattern on a thin membrane of a material which well transmits X-rays. The reflecting mask is constructed such that low-reflectivity portions are formed in a desired pattern on multi-layered films which reflect the X-rays for example. The thus formed pattern on the mask is focused on a wafer coated with a photoresist through the reduction projection optical system comprising a plurality of multi-layer film mirrors. Since the X-rays are attenuated by atmospheric absorption, all optical paths thereof are maintained at a predetermined degree of vacuum. Such an X-ray exposure apparatus must be so arranged that the illumination optical system irradiates (or illuminates) a broad area on the mask. For example, in case of an X-ray reduction projection exposure apparatus provided with a reduction projection optical system of 5:1 reduction ratio, the reduction projection optical system must illuminate a region of square with a side of 100 mm on the mask in order to effect exposure on a region of square with a side of 20 mm on the wafer. To obtain a desired resolving power of the diffraction limit in this case, it is desired to use the entire numerical aperture of reduction projection optical system. That is, it is desired for the rays transmitted or reflected by the mask to have an angular range which covers the angular range of entrance numerical aperture of imaging optical system (reduction projection optical system). To realize it, not only each point in the pattern surface on the mask is simply irradiated by the exposure light (X-rays), but the each point in the pattern surface on the mask must be irradiated with light having an angle of divergence corresponding to the entrance numerical aperture of exposure light of reduction projection optical system as well. Incidentally, in case the synchrotron radiation or laser plasma X-ray source is used as the X-ray source in the X-ray exposure apparatus, the size of portion as the source radiating the X-rays (the size of X-ray source) is very small. The size of X-ray source is determined by the diameter of electron beam in case of the photon radiation, while it is determined by the spot size of laser beam irradiated onto a target in case of the laser plasma X-ray source. The obtainable size of X-ray source is about 0.1 to 1 mm in diameter in either case, which is extremely small as compared with the region to be illuminated on the mask. Therefore, the above requirement cannot be satisfied by the conventional illumination optical system constructed of a curved-surface mirror such as the oblique incidence mirror or the multi-layer film mirror, or of a combination of such mirrors, as long as such a small X-ray source as described above is used. For example, as shown in FIG. 1, if a mask 4 is located near an image P of a light source 2 focused by an illumination optical system 3 (this arrangement is called as critical illumination), the illumination light B is irradiated with a sufficient angle of divergence on and in the vicinity of the optical axis A of exposure light B. However, the region irradiated by the exposure light B has only the size of the image of light source 2 in a very narrow region near the optical axis A. Although the image of light source 2 can be magnified to some extent by increasing the magnification of illumination optical system 3, the angle of divergence of exposure light is inevitably reduced in that case. On the other hand, as shown in FIG. 2, in case an image P of light source 2 is arranged to be focused by the illumination optical system 3 on the entrance pupil 50 of imaging optical system (this arrangement is called as Kohler illumination), the exposure light B can be irradiated in a considerably wide region on the mask 4. However, the divergence angle of light irradiating each point in the pattern surface on mask 4 becomes extremely small, which makes it difficult to obtain a resolving power of the diffraction limit of imaging optical system. Also, in case the mask 4 is located between the positions shown in FIG. 1 and in FIG. 2, that is, at a position between the image P of light source 2 and the entrance pupil of imaging optical system, there cannot exist together the sufficient region on the mask 4 irradiated by the exposure light B and the satisfactory angle of divergence of light irradiating each point in the pattern on mask 4. If the size of light source 2 is nearly equal to that of mask 4 as shown in FIG. 3, rays (exposure light B) are incident in various directions even at a point distant from the optical axis A on the mask 4 and therefore a resolving power of the diffraction limit can be obtained in the region covering the entire pattern surface on the mask 4. FIG. 3 shows the case of Kohler illumination, but the illumination region is also enlarged even in the case of critical illumination, because the image of large light source is formed on the mask. It has been, however, difficult to obtain an X-ray source of such large size in actual. SUMMARY OF THE INVENTION It is an object of the present invention to achieve uniform irradiation of electromagnetic waves in a wide area. The above and other objects will be apparent from the following description. The present invention provides an optical element comprising: a substrate having a plurality of concave surfaces or convex surfaces with a substantially same curvature; and multilayer films for reflecting X-rays, formed on the concave surfaces or convex surfaces of said substrate and composed of thin films; wherein when X-rays are incident into the multilayer films on said concave surfaces or convex surfaces, the X-rays are reflected with a predetermined diverging angle on the multilayer films and as a result a plurality of secondary X-ray sources having the diverging angle are formed on a same plane located a predetermined distance apart from said concave surfaces or convex surfaces. It is preferred that the shape of concave surfaces or convex surfaces is a part of spherical surface or a toroidal surface for example. Also, the present invention provides a method for producing an optical element, comprising: a first step of forming a substrate having convex surfaces or concave surfaces on a surface thereof and being a ground for multilayer films for reflecting X-rays; and a second step of forming the multilayer films for reflecting said X-rays on said substrate. The first step is preferably either one of a method (first method) of applying a photosensitive material onto a substrate and processing the photosensitive material layer by the photolithography process to form fine convex portions, a method (second method) of screen-printing a heat-resistant material on a substrate to form fine convex portions, and a method (third method) of etching a substrate to form fine concave portions. The photosensitive material used in the first method may be a photoresist employed in lithography or a photoreactive polyimide. Since polyimide is superior in heat resistance, it is advantageous in case of strong X-rays being irradiated. Ordinary photoresists or photoreactive polyimides will form columns in a rectangular cross section after development. To smooth the rectangular section, it is preferable to utilize unsharpness of image due to diffraction in the arrangement with a gap between the substrate and the mask. Also, an alternative method may be a method of overlaying a coating on the pattern of rectangular section or a method of post-bake at high temperature (baking the resist after development). The heat-resistant material used in the second method is preferably a heat-resistant resin such as polyimide for example. In this case, concave portions of spherical surface are naturally formed by the surface tension of resin. The etching step in the third method may be either dry etching or wet etching, but it is preferable to properly select a method to maintain smoothness sufficient on the etched surface. The second step for forming the multilayer films on the fine convex portions or concave portions formed in the above step may be one of the ordinary methods for forming multilayer films. For example, a preferable method is the method for producing a thin film, such as the sputtering, the vacuum vapor deposition and the CVD (Chemical Vapor Deposition). The materials for the multilayer films may be a combination of Mo (molybdenum) and Si (silicon), but are not limited to the combination. Also, the present invention provides an optical system for illuminating an illuminated surface in an arc shape. The optical system comprises: an optical reflector having an X-ray reflecting surface forming a part of a parabola of revolution obtained by revolving an arbitrary parabola about a base axis passing through a vertex and a focus of the parabola and inclined at a predetermined angle relative to a normal line to said illuminated surface, said optical reflector reflecting X-rays by said X-ray reflecting surface to irradiate said illuminated surface; and an optical element for reflecting X-rays incident thereinto substantially in parallel with said base axis to irradiate said X-rays onto the X-ray reflecting surface of said optical reflector; wherein said optical reflector and said optical element are rotated in a united manner about a rotation axis passing through said optical element and being parallel to the normal line to said illuminated surface; wherein said optical element comprises: a substrate having a plurality of concave surfaces or convex surfaces with a substantially same curvature; and multilayer films for reflecting X-rays, formed on the concave surfaces or convex surfaces of said substrate and composed of thin films; wherein when X-rays are incident into the multilayer films on said concave surfaces or convex surfaces, the X-rays are reflected with a predetermined diverging angle on the multilayer films and as a result a plurality of secondary X-ray sources having the diverging angle are formed on a same plane located a predetermined distance apart from said concave surfaces or convex surfaces. Also, the present invention provides an optical apparatus for illuminating a predetermined area. The optical apparatus comprises: an optical reflector having an X-ray reflecting surface forming a part of a parabola of revolution obtained by revolving an arbitrary parabola about a base axis passing through a vertex and a focus of the parabola and inclined at a predetermined angle relative to a normal line to said illuminated surface, said optical reflector reflecting X-rays by said X-ray reflecting surface to irradiate said illuminated surface; an optical element for reflecting X-rays incident thereinto substantially in parallel with said base axis to irradiate said X-rays onto the X-ray reflecting surface of said optical reflector; an X-ray source for emitting X-rays toward said optical element; and rotation driving means for rotating said optical reflector and said optical element in a united manner about a rotation axis passing through said optical element and being parallel to the normal line to said illuminated surface; wherein said optical reflector and said optical element are rotated in a united manner by said rotation driving means to irradiate the X-rays emitted from said X-ray source onto said illuminated surface in an arc shape; wherein said optical element comprises: a substrate having a plurality of concave surfaces or convex surfaces with a substantially same curvature; and multilayer films for reflecting X-rays, formed on the concave surfaces or convex surfaces of said substrate and composed of thin films; wherein when X-rays are incident into the multilayer films on said concave surfaces or convex surfaces, the X-rays are reflected with a predetermined diverging angle on the multilayer films and as a result a plurality of secondary X-ray sources having the diverging angle are formed on a same plane located a predetermined distance apart from said concave surfaces or convex surfaces. Also, the present invention provides another optical system for illuminating an illuminated surface in an arc shape. The optical system comprises: an optical reflector having a reflecting surface forming a part of a parabola of revolution obtained by revolving an arbitrary parabola about a base axis passing through a focus of the parabola and inclined at a predetermined angle relative to a normal line to said illuminated surface, said optical reflector reflecting light by said reflecting surface to irradiate said illuminated surface; a fly's eye lens comprising a plurality of lens elements and forming a plurality of secondary light source images on an exit side thereof when light is incident thereinto; and a first light deflecting element for reflecting light emergent from said fly eye lens substantially in parallel with said base axis to irradiate said light onto the reflecting surface of said optical reflector; wherein said optical reflector and said first light deflecting element are rotated in a united manner about a rotation axis passing through said first light deflecting element and being parallel to the normal line to said illuminated surface. Also, the present invention provides another optical apparatus for illuminating a predetermined area. The optical apparatus comprises: an optical reflector having a reflecting surface forming a part of a parabola of revolution obtained by revolving an arbitrary parabola about a base axis passing through a focus of the parabola and inclined at a predetermined angle relative to a normal line to an illuminated surface, said optical reflector reflecting light by said reflecting surface to irradiate said illuminated surface; a fly's eye lens comprising a plurality of lens elements and forming a plurality of secondary light source images on an exit side thereof when light is incident thereinto; a first light deflecting element for reflecting light emergent from said fly eye lens substantially in parallel with said base axis to irradiate said light onto the reflecting surface of said optical reflector; light source means for emitting light toward said fly's eye lens; and rotation driving means for rotating said optical reflector and said first light deflecting element in a united manner about a rotation axis passing through said first light deflecting means and being parallel to the normal line to said illuminated surface; wherein said optical reflector and said first light deflecting element are rotated in a united manner by said rotation driving means to irradiate the light emitted from said light source means onto said illuminated surface in an arc shape. Also, the present invention provides an optical apparatus for illuminating an illuminated surface in an arcuate shape with electromagnetic waves emitted from a light source. The optical apparatus comprises: a first reflective element having a reflective surface with a plurality of concave surfaces or convex surfaces having a substantially same curvature, said reflective surface reflecting the electromagnetic waves incident from said light source to form a plurality of secondary light source images; and an optical reflector for reflecting the electromagnetic waves from said secondary light source images to illuminate said illuminated surface, said optical reflector having a reflective surface forming a part of a parabolic toric surface obtained by revolving an arbitrary parabola about a second axis passing a point located on a first axis passing a vertex of the parabola and a focus of the parabola, said point being opposite to a directrix of the parabola with respect to said focus, said second axis being parallel to the directrix; wherein said first reflective element reflects the electromagnetic waves at a predetermined angle of divergence by the reflective surface thereof when the electromagnetic waves are incident onto the reflective surface of said first reflective element, so that said plurality of secondary light source images with the angle of divergence are formed on a same plane located at a place apart from the reflective surface of said first reflective element. The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
046630864	abstract	The invention relates to a process for bituminizing radioactive waste constituted by cation and/or anion exchange resins.. This process comprises a resin pretreatment stage performed so as to replace the H.sup.+ ions of the cation exchange resins by ions chosen from the group including Ca.sup.++, Sr.sup.++ and Ba.sup.++ and/or for replacing the OH.sup.- and/or Cl.sup.- ions of the anion exchange resins by an anion chosen from the group including NO.sub.3.sup.-, HCO.sub.2.sup.- and CH.sub.3 CO.sub.2.sup.-.. This pretreatment makes it possible to increase the capacity of the coating installation and limit the swelling in water of the bituminized coatings obtained.
	description	This application is a US 371 Application from PCT/RU2017/000915 filed Dec. 8, 2017, which claims priority to Russia Application 2017116513 filed May 12, 2017, the technical disclosures of which are hereby incorporated herein by reference. The invention relates to nuclear engineering, in particular, to the technology of manufacturing pelletized oxide nuclear fuel for fuel elements of NPP. As a result of conducted (but not completed yet) long-term studies of the complex U (Uranium)-O (Oxygen) system, the existence of more than 20 uranium oxides and their modifications has been established [Maiorov A. A., Braverman I. B., Powders of ceramic uranium dioxide production technology, M., Energoatomizdat, 1985, p. 10, Table. 2.1,], 4 of which are of interest for the use in the manufacturing of pelletized ceramic fuel by powder metallurgy method: theoreticalProportioncrystallographicdensity,O/Usystemg/cm3uranium dioxide2.00 . . . 2.19cubic10.96UO2 (α-phase)uranium dioxide2.20 . . . 2.25cubic11.30U4O9 (β-phase)uranium dioxide2.34 . . . 2.41tetragonal11.30-11.50U3O7 (γ-phase)concentrated uranium2.66orthorhombic 8.39oxide U3O8 It is known, for example, the method of fuel pellets' manufacturing [Patent of England No. 1371595, MKI G 21 C 3/62 dated Mar. 16, 1971], including preparation of uranium dioxide (UO2) moulding powder, mixing with a binder, pressing into pellets, sintering of compressed pellets in a reducing media. It is also known the method [Patent No. 0249549 dated Dec. 16, 1987, MKI G 21 C 3/62)], according to which they use a mixture of U3O8 triuranium octoxide powder (concentrated uranium oxide) with UO2 uranium dioxide powder to manufacture sintered pellets, wherein with the predominance of concentrated uranium oxide in this mixture. Obtained by this method, sintered pellets are characterized by low density and high porosity, which is caused by the structural transformations of concentrated oxide in the reduction process according to the reactionU3O8+2H2=3UO2+2H2O (1)long before the start of the sintering process with obtaining the final product (uranium dioxide), having a higher theoretical density (TD). The consequence of these structural transformations is the formation of uranium dioxide particles, the size of which is smaller than the size of the concentrated uranium oxide initial particles. In the volume of a compressed pellet, this leads to a breakdown in the existing contact with a particle of uranium dioxide, the formation of a “gap” between the particles, wherein the larger the particle of the concentrated uranium oxide—the greater this gap. This is why leading foreign and domestic manufacturers limit the amount of concentrated oxide, being added to the ceramic powder of uranium dioxide to 10-15 wt. % when manufacturing the pelletized fuel. Sintered pellets are subject to rather stringent requirements in terms of density, geometric dimensions, mechanical strength, microstructure, thermal stability, and other parameters. It is also known the method [Patent of the Russian Federation No. 2148279 IPC7 G21C 3/62, published in Apr. 27, 2000)], according to which, during the preparation of the moulding powder, they add homogenized agglomerates U3O8 of the required size, made of homogeneous in chemical composition powder, to the UO2 powder. It is also known the method of manufacturing pelletized nuclear fuel [Patent of the Russian Federation No. 2170957 IPC7 G 21 C 3/62, 21/04, published in Jul. 20, 2001)], including three-stage mixing of powders of uranium dioxide UO2, and concentrated uranium oxide U3O8 with a binder. It is also proposed the method [Patent of the Russian Federation No. 2338274 IPC G 21 C 3/62, published in Nov. 10, 2008)], envisaging pretreatment of uranium dioxide UO2 powder or a mixture of uranium dioxide UO2 powder with concentrated uranium oxide U3O8 in grinding devices before the operation of mixing with a solid plasticizer. The closest to the proposed invention is the method, chosen as a prototype [Patent of France No. 2599883, IPC G 21 C 3/62, published in Dec. 11, 1987)], according to which they cold-press pellets from the mixture of UO2 powder with an addition of 5-40% U3O8 powder with particles sixes <350 microns, which pellets next are being sintered at a temperature of 1500-1800° C. in a reducing atmosphere or at 1200-1300° C. in an oxidizing environment. The drawback of all these methods, including the one chosen as a prototype, is the decrease in a mechanical strength of the sintered pellets. The reason for this is considered to be the formation of porous areas with acute-angled pores at the location of the concentrated uranium oxide particles. The transformation of the concentrated uranium oxide with a density of 8.39 g/cm3 into uranium dioxide with a density of 10.96 g/cm3 is accompanied by a decrease in the volume of particles and, accordingly, by a decrease in their linear size. In the system, which is a compressed pellet with contacting particles of uranium concentrated dioxide and dioxide, a new particle of uranium dioxide, formed during the reduction of the concentrated oxide particle, becomes distanced from the matrix's particle of uranium dioxide, which remains motionless. Thus, additional porosity is being created between the matrix's particles of uranium dioxide and the newly formed particles of uranium dioxide, the size of which will depend on the grain size of the concentrated uranium oxide. It is known, that the porosity in a compressed pellet can be reduced by increasing the pressing pressure, however, in this case the wear of the pressing tool increases, the probability of over-pressing cracks increases, the direct output into a useful product reduces. An object of the present invention is the development and creation of the method for manufacturing nuclear fuel pellets, that meets the exclusive standards for mechanical strength, the microstructure of sintered pellets. As a result of solving this object, it is possible to obtain new technical results, providing the expanding range of used raw powders and ensuring the possibility of obtaining nuclear fuel with the density, strength and microstructure of sintered pellets, necessary according to the operating regime. The solution of this object is achieved by that in the method of obtaining fuel pellets, which includes the preparation of moulding powder with or without an addition of concentrated uranium oxide powder: preliminary they oxidize ceramic grade uranium dioxide powder by heating in air in a known manner to the composition of uranium dioxide γ-phase with a proportion of O/U=2.37±0.04. Obtaining the powder of the U3O7 uranium dioxide γ-phase composition is not difficult and it was tested in the workshop conditions with the use of a rotary kiln, a fluidized bed (vibratory fluidized bed), as well as in stationary conditions (muffle). The same as a concentrated uranium oxide, this oxide, when heated in a reducing atmosphere (in a stream of hydrogen), is being reduced long before the start of sintering process to uranium dioxide according to the reactionU3O7+H2=3UO2+H2O (2)However, when this molecular entity is being reduced, in contrast to the reduction of concentrated oxide, the linear size of the uranium dioxide forming particle does not decrease, but increases, i.e. convergence occurs in the mixture for the matrix's particles of uranium dioxide powder and the particles of uranium dioxide, which are newly formed at the reduction of uranium dioxide γ-phase. This circumstance not only contributes to a decrease in the initial porosity of the compressed pellet and to decrease in the size of most “gaps” between particles of uranium dioxide less then a diffusion length of ions at sintering, but also provides an increase in the grain size of the sintered pellet. A conducted comparative analysis between proposed invention and the prototype revealed the following significant distinguishing feature: the use of uranium dioxide with a proportion of O/U=2.37±0.04 (γ-phase of uranium dioxide), specially made from a standard ceramic grade uranium dioxide powder with the proportion O/U=2.01-2.15 in the moulding powder preparation process. Thus, the invention meets the “novelty” patentability criterion. Compared with existing analogues, including the prototype, the specified distinguishing feature ensures the achievement of a new technical result: obtaining sintered pellets with controllable total porosity; obtaining sintered pellets with increased grain size; obtaining sintered pellets with increased mechanical strength. Thus, the invention meets the “inventive step” patentability criterion. The method is implemented as follows. They pour 300 g of a ceramic grade uranium dioxide powder, obtained by the method of uranium hexafluoride dry conversion (the total specific surface area of the powder is 2.8 m2/g), as a layer of 10-15 mm in a stainless steel baking tray, place it in a muffle, preheated to a temperature of 160±10° C., and keep in it for 3-5 minutes when the muffle door is open. Then they remove a baking tray with the powder out of the muffle and cool it down to the room temperature. Thus way obtained the powder with a proportion of O/U=2.37±0.04 is used for manufacturing of sintered pellets according to standard technology: they add a 6% solution of polyvinyl alcohol (PVA) with glycerin to the powder as a binder and mix it thoroughly in a porcelain cup; they press the prepared batch at a specific pressure of 1100-1200 kg/cm2 in a matrix with a diameter of 20 mm; they grind up the obtained “tiles” in a mortar and rubbed through a strainer with a mesh size of 0.63 mm; prepared thus way moulding powder is pressed at specific pressure of 2100-2200 kg/cm2 in a matrix of 9.3 mm diameter; they sinter pressed pellets at a temperature of 1700° C. in an argon-hydrogen mixture; holding at this temperature is equal to 2 hours.The results of the powder processing are shown in the Table 1 in comparison with the results of regular powder sintering; FIG. 1 shows sintered pellets distribution on the grain size, which was determined using optical microscopy. They mix the powder with a proportion of O/U=2.37±0.04, prepared the same as in example 1, with 0.3% 1.2-DISED (distearyl ethylenediamine) with the formula C38H76O2N2 as a dry lubricant. They manufacture pellets from the prepared mixture, as in the example 1. The results of the powder processing are shown in the Table 1 in comparison with the results of regular powder sintering; FIG. 1 shows sintered pellets distribution on the grain size, which was determined using optical microscopy. They mix the powder with a proportion of O/U=2.37±0.04, prepared as in example 1, with 10% of concentrated uranium oxide (specific surface area 8.2 m2/g), obtained from ammonium polyuranate. Prepared homogeneous mixture is processed as in the example 1. The results of powder processing are shown in the Table 1; FIG. 2 shows sintered pellets distribution on the grain size, which was determined using optical microscopy. TABLE 1Powder ofPellets density, g/cm3uranium dioxideBinderpressedsinteredRegular factory-madePVA6.15-6.2010.62-10.66According to the invention6.15-6.2010.68Regular factory-madeDISED5.34-5.3610.58-10.66According to the invention5.57-5.5910.57According to the inventionPVA5.81-5.8310.45with an addition ofconcentrated oxide
	summary
	description	1. Field of the Invention The present invention relates to a probe for a near-field microscope in which a probe is caused to come close to or contact with an evanescent field generated on a sample surface, an evanescent light is scattered by a probe and, by detecting the scattered light by a photodetector, a local optical characteristic of the sample is measured with a resolution beyond diffraction limit of the incident light. 2. Description of the Related Art In a conventional optical microscope, a spatial resolution has been limited to a length of about half of a used wavelength by the diffraction limit. However, in recent years, it becomes that a development in a technique called nano-technology is eagerly performed, and there is an increased demand for measuring the optical characteristic of a substance with the resolution exceeding the diffraction limit. In order to realize the demand, a development in the near-field probe microscope is eagerly performed. The conventional near-field probe microscope is classified into a fiber type and a scattering type. In the fiber type near-field microscope, a tip of an optical fiber is sharpened, the size of an aperture is 100 nm or less, and portions other than the opening part is shielded from the light by a metal. When a laser is entered from an optical fiber aperture, the evanescent light is produced in the vicinity of the aperture. A probe approaches a sample by utilizing a shear force or an atomic force, which acts between a probe tip and the sample surface, the evanescent light irradiate the sample by measuring a near-field light intensity or a spectrum by the photodetector, the optical characteristic of the sample surface is measured with the resolving power exceeding the diffraction limit. On the other hand, in the scattering type near-field microscope, the evanescent field is generated on the sample surface, the scattered light is generated by inserting the probe of a metal or a dielectric. The probe is inserted into the evanescent field and, by measuring the near-field light intensity or the spectra by the photodetector, the optical characteristic of the sample surface is measured with the resolving power beyond the diffraction limit. The fiber type near-field microscope is the present measurement tool, the device is comparatively stable “it evaluates if the level of the background light is low”However, it is used in a fluorescence spectral analysis in which an excited light intensity is weak and a signal light intensity is comparatively easily obtained, an absorption measurement and the like, because a loss of the light in a taper portion inside the optical fiber cause the probe aperture to enlarge. On the other hand, the scattering type near-field microscope can be used also in a Raman spectral analysis in which the scattering cross-sectional area is small and the signal light is difficult to detect and a nonlinear spectroscopy analysis, because it is possible to increase a incident light intensity imposed on the probe made from the metal or the dielectric and an electric field was enhanced by the interaction of the evanescent field both with incident light and the scattered light. The scattering type near-field microscope of the prior art is explained on the basis of a schematic view of FIG. 9 (for example: Norihiko Hayazawa, Yasushi Inouye, Zouheir Sekkat, Satoshi Kawata, Near-field Raman scattering enhanced by a metallized tip, Chemical Physics Letters, 335, 369-374, 2001 (FIG. 1)). A cantilever 101 is used for an interatomic force microscope, which has in its tip a probe 102 of a size of 40 nm in diameter and has been coated by silver 40 nm in thickness. Further, by setting an objective lens 105 whose numerical aperture is 1.4 in a back side with respect to a measured face of a sample 103 through an oil-immersion oil 104 and entering an annular laser light 106 into a region in which the numerical aperture component of the objective lens 105 exceeds 1, the evanescent field is formed in a surface of the sample 103. Next, the probe 102 is contacted with the evanescent field generation region of the sample 103 surface while performing a distance control by the interatomic force acting between the probe 102 and the sample 103 surface. At this time, the evanescent field is scattered by the probe 102. By condensing this scattered light 107 by the same objective lens 105 (not shown in the drawing), an analysis of the local optical characteristic by the probe tip becomes possible. In this prior art, rhotamine 6G that is one kind of dye is measured as the sample. In the scattered light from the sample Raman scattered light is generated also besides a Rayleigh scattered light whose wavelength is the same as the excited light. Further, by the facts that a surface plasmon is excited in a surface of the silver coated probe 102 and that the sample 103 and the silver probe 102 tip are contacted, a so-called surface enhanced Raman scattering (SERS: Surface Enhanced Raman Scattering) occurs, so that it becomes possible to enhance the Raman scattered light. By condensing these scattered lights by the objective lens 105, removing the Rayleigh scattered light by a notch filter or the like and, after spectrally dispersing them by a spectroscope, detecting it by a liquid nitrogen cooled CCD, it is possible to obtain a local Raman spectra (the notch filter, the spectroscope and the CCD are not shown in the drawing). An electron microscope photograph of the probe 102 provided in the cantilever 101 used in FIG. 9 is shown in FIG. 10. The fact is seen that a silver particle of the probe 102 surface adheres to a probe surface like an island and has a longitudinally long shape. Further, in a tip portion 102a of the probe, the whole tip portion of the probe is covered by a uniform silver particle. Next, FIG. 11-FIG. 13 and Table 1 are explained about the Raman spectral analysis. Since a vibration spectroscopy mainly such as Raman spectroscopy can obtain a structural information in comparison with the fluorescence spectral analysis and the absorption measurement, it is possible to obtain detailed information concerning molecule vibration, orientation, intermolecular interaction, and excited state. However, since the Raman scattered light is generally very weak, its measurement is difficult. Especially, in a case where the excitation is performed by the evanescent light, the light quantity becomes weaker. Therefore, in a case where the Raman spectroscopy is performed by scattering the evanescent field by the probe, a Raman signal is intended by utilizing the surface enhanced Raman scattering like the prior art mentioned above. The surface enhanced Raman scattering is a phenomenon in which, by an electron excitation (surface plasmon) of a metal surface, a Raman scattering cross-section area concerning of the signal light from the metal surface is enhanced to about 105 to 1010 times. Accordingly, in order to efficiently induce the surface enhanced Raman scattering, a condition for efficiently exciting the surface plasmon is necessary. And, an efficiency of the surface plasmon excitation largely depends on a kind of the metal and a size and a shape of the particle. As to the metal, it is known that, in a visible light region silver is efficient. Table 1 shows a value of an imaginary number part of a permittivity at a plasmon absorption maximum wavelength and an absorption maximum of a representative metal (refer to C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles, Wiley 1983 (Table 12-1)). TABLE 1BulkSurfaceplasmonplasmonPermittivity: ε = ε′ + i ε″energyenergy(real part ε′ = value of imaginaryMetal kind(eV)(eV)number part ε″ at −2)Lithium6.63.41.0Sodium5.43.30.12Potassium3.82.40.13Magnesium10.76.30.5Aluminum15.18.80.2Iron10.35.05.1Copper—3.54.9Silver3.83.50.28Gold—2.55.0Graphite—5.52.7 From Table 1, among the metals having the absorption maximum in the visible light region, silver has the imaginary number part of the permittivity which is peculiarly small. This shows the fact that an attenuation of the plasmon is small and accordingly the silver is most excellent for the surface enhanced Raman scattering in the visible light region. Further, an influence of a radius of curvature exerting on the absorption cross-sectional area of the silver is shown in FIG. 11, and an influence of the radius of curvature exerting on a near-field scattering efficiency in FIG. 12 (refer to S. Kawata ed, Near-Field Optics and Surface Plasmon Polaritons, Topics Appl. Phys. 81, 97-122 (2001) (FIG. 7, FIG. 8)). From FIG. 11, it is apparent that the absorption cross-sectional area of the silver has a peak when a particle size is between 10 nm and 50 nm in radius, and becomes a maximum value when the radius is 10 to 20 nm. Since a light energy absorbed contributes to a plasmon excitation, the fact that the absorption cross-sectional area is large becomes the fact that an energy inducing the surface enhanced Raman scattering is large. Further, from FIG. 12, also a near-field scattering efficiency has a peak in a vicinity where the particle size is 10 nm to 50 nm in radius and becomes maximum when the radius is 20 nm, and in this region it is possible to efficiently scatter a near-filed light. Additionally, in FIG. 13, there is shown a plasmon absorption efficiency depending on a shape of the silver particle (refer to Stockle R M, Deckert V, Fokas C, Zenobi R, Controlled formation of isolated silver islands for surface-enhanced Raman scattering, APPLIED SPECTROSCOPY 54 (11): 1577-1583 November 2000 (FIG. 2)). Under a state that the silver particle has flatly adhered to a substrate, although the plasmon absorption is scarcely seen, if an island shape of the silver approaches a spherical shape by annealing the surface, a strong plasmon absorption appears. From this fact, for a plasmon induction it is desirable that the shape of the silver particle approximates to the spherical shape, not only its size. Accordingly, in a case where the Raman spectral analysis is performed by using the near-field, by controlling the shape of the metal particle coated to the probe to a shape approximating to the spherical shape whose radius is 10 nm to 50 nm, it becomes possible to efficiently generate the surface plasmon and, as a result, the Raman scattered light is enhanced and it becomes possible to improve the sensitivity of a Raman spectroscopy. Additionally, by controlling the shape and the size of the metal particle, a quantitative experiment of a surface enhanced Raman scattering effect becomes possible. As a result, it becomes possible to quantitatively estimate the near-field Raman scattered light. However, in the prior art, since there has not existed a method capable of controlling the shape and the size of the metal particle to optimum ones only by controlling a film thickness of the metal, which is represented by the silver, the gold and the like, coated to the probe, there was no reproducibility with respect to the shape or the size of the metal particle. Further, since an affinity between a substrate and a vapor-deposited metal is good, the vapor-deposited metal forms an island-like film in the vapor deposition object, so that it has been difficult to form a particle-like film. For this reason, the surface enhanced Raman scattering effect in every probe largely differs, so that it has been impossible to perform from a Raman spectroscopy a quantitative analysis of a intensity. Whereupon, an object of the invention is to improve, in the scattering type near-field microscope, the Raman spectral sensitivity by forming in the probe surface, with a high reproducibility, with metal particles which don't mutually adhere and whose radius of curvature is 10 nm or larger and 50 nm or smaller, desirably the particles of silver, silver alloy, gold or gold alloy, whose radius of curvature is 20 nm, and efficiently generating the surface plasmon to thereby intend enhanse the Raman scattered light. In order to solve the above problems, in a probe for a near-field microscope of the invention, it has been made such a structure that one part or all of the probe due to an interaction of at least the evanescent field has been coated by metal particles which don't mutually adhere and have a particle diameter of 10 nm or larger and 50 nm or smaller in radius of curvature. It has been adapted such that this probe is inserted into the evanescent field generated in the sample surface, the surface plasmon is excited by an interaction between the evanescent field and the metal particles by scattering the evanescent field by a probe tip, and enhancing a scattered light intensity by the surface enhanced Raman to thereby detect that scattered light. Further, in the invention, there is manufactured a probe for a near-field microscope by vapor-depositing, as a first vapor deposition process, gold-palladium as a substrate metal to the probe, next vapor-depositing, as a second vapor deposition process, any metal of silver, silver alloy, gold and gold alloy onto a film of the gold-palladium, thereby forming, in one part or all of a probe surface, particles of the metal having been used in the second vapor deposition process, which don't mutually adhere and have a particle diameter of 10 nm or larger and 50 nm or smaller in radius of curvature, and adjusting a size of the radius of curvature of the metal particles by adjusting a vapor deposition time and a vapor deposition speed in the 2nd vapor deposition process. Additionally, in the invention, there is contained at least a process for reducing silver nitrate to silver by adding an aqueous solution containing an aldehyde compound, such as glucose and folmaldehyde, as a reducing agent to an aqueous solution containing silver nitrate, and there is manufactured a probe for a near-field microscope by growing silver particles in a probe surface by immersing the probe into the mixed solution reducing silver nitrate to silver, forming, in one part or all of the probe surface, the silver particles which don't mutually adhere and have the particle diameter of 10 nm or larger and 50 nm or smaller in radius of curvature, and adjusting a size of the radius of curvature of the silver particles by adjusting a silver nitrate concentration and a time for immersing the probe into the mixed solution. In the probe for the near-field microscope of the invention, one part or all of the probe due to the interaction of at least the evanescent field has been coated by the metal particles which don't mutually adhere and have the particle diameter corresponding to 10 nm to 50 nm in radius of curvature. By this, in a case where the evanescent field is scattered by the probe apex, the surface plasmon is efficiently induced in the probe apex, and the Raman scattered light can be largely enhanced, so the it has become possible to improve the Raman spectral sensitivity. Additionally, even in a case where the probe is different, it becomes possible to obtain a stable surface enhanced Raman scattering effect by controlling the metal particle size, so that a quantitative measurement has become possible. Further, by enhancing the Raman scattered light at the probe tip by the surface enhanced Raman scattering effect, a measurement in a region more minute than the prior art has become possible. Further, in the method of manufacturing the probe of the invention, it has been adapted such that, as the first vapor deposition process, gold-palladium as the substrate metal is vapor-deposited to the probe and, next as the second vapor deposition process, any metal of silver, silver alloy, gold and gold alloy is vapor-deposited onto the film of the gold-palladium. Like this, by using the gold-palladium in the substrate metal, it has become such that the substrate metal has an affinity optimum for forming the vapor-deposited metal in a particle-like form and, additionally by adjusting the time in the second vapor deposition process, it has become possible to form in one part or all of the probe surface, with the high reproducibility, the particles which don't mutually adhere and have the particle diameter of 10 nm or larger and 50 nm or smaller in radius of curvature. Additionally, in the method of manufacturing the probe, there is contained at least the process for reducing silver nitrate to silver by adding the aqueous solution containing the aldehyde compound, such as glucose and folmaldehyde, as the reducing agent to the aqueous solution containing silver nitrate, and it has been adapted such that the silver particles are grown on the probe surface by immersing the probe into the mixed solution reducing silver nitrate to solution. In the case of this method, by adjusting the silver nitrate concentration and the time for immersing the probe into the mixed solution, it has become possible to form in one part or all of the probe surface, with the high reproducibility, the silver particles which don't mutually adhere and have the particle diameter of 10 nm or larger and 50 nm or smaller in radius of curvature. This method is simpler in its equipment than means such as conventional vapor deposition or sputter, and it is also possible to decrease a probe manufacturing cost. Hereunder, it is detailedly explained about best modes for carrying out the invention by referring to the drawings. In FIG. 1, there is shown a schematic view of a probe 1 for a near-field microscope, which is a 1st embodiment of the invention. This is a sectional view cut along a center axis in a longitudinal direction of a cantilever part 3 of a cantilever 2 with a probe, which is made of silicon and generally marketed for a scanning probe microscope. This cantilever 2 with the probe has a probe body with a structure in which a probe 4 whose shape is a quadrangular pyramid and which is about 10 nm in tip radius and 20 μm in height is provided in a tip of the thin rectangle shape cantilever part 3 which is about 350 μm in length, 35 μm in width and 1 μm in thickness, and a support part 5 for fixing to a holder is provided in a tail end of the cantilever 3. A block diagram of an apparatus for coating metal particles to a surface of the cantilever 2 with the probe is shown in FIG. 2. The apparatus is constituted by a bell-jar type vacuum chamber 8, vapor deposition source fixation parts 9(a) and 9(b), evaporation sources 10(a) and 10(b) becoming heaters by the fact that a current flows therein, two kinds of evaporation materials 11(a) and 11(b) for coating to the probe on the evaporation sources 10(a) and 10(b), the cantilever 2 with the probe whose probe 4 side has been disposed in such a direction as to be opposite to the evaporation materials 11(a) and 11(b), a cantilever fixation jig 12 fixing the cantilever 2 with the probe like the above, an electric source 13 capable of flowing the current by selecting either of the evaporation sources 10(a) and 10(b), and a vacuum pump 14 for evacuating the bell-jar type vacuum chamber. In FIG. 3, there is shown a flowchart of a method of manufacturing the probe for the near-field microscope according to the first embodiment of the invention in a case where the apparatus of FIG. 2 has been used. In the bell-jar type vacuum vapor deposition apparatus 8, the vapor deposition sources 10(a) and 10(b) comprising tungsten heaters fixed to the vapor deposition source fixation parts 9(a) and 9(b) are provided in two places. The evaporation materials 11(a) and 11(b) are disposed respectively on the evaporation sources 10(a) and 10(b) in two places. Here, gold-palladium has been used as the first evaporation material 11(a) becoming the substrate metal and, as to a component ratio, components of gold and palladium have been made respectively gold 80% and palladium 20%. Further, wire-like silver of 0.5 mm in diameter φ and 40 mm in length has been used as the second evaporation material 11(b). Next, the cantilever 2 with the probe is fixed to the cantilever fixation jig 12 in a position about 30 cm just above the evaporation sources 10(a) and 10(b) in such a direction that the probe 4 side is opposite to the evaporation sources 10(a) and 10(b). Next, the bell-jar type vacuum chamber 8 is evacuated to a vacuum of 10−5 Torr or lower by using the vacuum pump 14. The vacuum pump is used by connecting a rotary pump or the like to a turbo-molecular pump or a diffusion pump. Under a state that a degree of vacuum is 10−5 Torr or lower, the current is flowed to the evaporation source 10(a) by using the electric source 13. First, a current value is gradually increased from 0 A to 170 A by spending 2 minutes. Next, the current value of 170 A is kept, and the evaporation material 11(a) is vapor-deposited for 3 minutes to the cantilever 2 with the probe. By this first vapor deposition process becoming a formation of the substrate metal, a gold-palladium film 6 is coated to the probe 4 and the cantilever part 3 in a film thickness of about 5 nm. After cooling for about 10 minutes, the current is flowed to the evaporation source 10(b) by using the electric source 13 with the degree of vacuum being kept to the state of 10−5 Torr or lower intact. First, the current value is gradually increased from 0 A to 70 A by spending 1 minute. Next, under a state that 70 A has been maintained, all of the silver wire 11(b) on the evaporation source 10(b) is vapor-deposited to the cantilever 2 with the probe, on which the gold-palladium film has been formed in the 1st vapor deposition process, by spending 2 minutes. Thereafter, after cooling for 10 minutes with the vacuum being kept intact for preventing an oxidation, the vacuum is released to the atmosphere and the probe 1 for the near-field microscope is taken out. In the present embodiment, by the fact that the gold-palladium is used in the substrate metal and the silver is vapor-deposited thereon, it follows that the substrate metal has the affinity optimum for forming the vapor-deposited metal like the particle and, as shown in FIG. 1, it has become such that silver particles 7 are formed without mutually adhering on a surface of the gold-palladium film 6 formed in the probe 4 and the cantilever part 3. Further, by adjusting a vapor deposition time in a second vapor deposition process to 2 minutes, adjusting the heating current flowed to the tungsten heater 10(b) and performing the vapor deposition at a vapor deposition speed of 3 angstroms per second, it is possible to control the radius of curvature of the particle to 7 to 20 nm. An scanning electron microscope photograph of the probe 1 for the near-field microscope, which has been made like the above, is shown in FIG. 4. Here, as to a size of the silver particle 7, although about 20 nm in radius of curvature is optimum, if it is the particle whose radius of curvature is 10 nm or larger and 50 nm or smaller, it is possible to efficiently generate the surface enhanced Raman scattering, and the particle having a particle diameter of this range is included in the invention. As to an ideal shape in the present manufacturing method, although the silver particles having a uniform particle diameter are formed in the probe part and the cantilever part in a shape approximating to spherical shape without mutually adhering, such a matter is considered as well that unavoidably one part of the particles don't become the prescribed shape or are adhered due to the shape of the probe or the cantilever, or an error in a disposed position. Also in this case, if one portion of the metal particles having been coated in the probe surface due to the interaction with a sample are formed in the prescribed shape without adhering, since it is possible to achieve the object of the invention, a probe in which one portion of the coated particles in the probe surface due to the interaction with the sample are 10 nm or larger and 50 nm or smaller in radius of curvature and have no adhesion is included in the invention. Further, also as to the shape of the particle, ideally, although rather a shape approximating to the spherical shape is good, if it is constituted by the particles of 10 nm or larger and 50 nm or smaller in radius of curvature, it is possible to efficiently induce the surface enhanced Raman scattering, and it is included in the invention. Further, the invention is not limited to the above parameters at a manufacturing time, and a probe in which any metal of silver, silver alloy, gold and gold alloy is vapor-deposited with the gold-palladium being used in the substrate, one part or all of the particles are 10 nm or larger and 50 nm or smaller in radius of curvature and no adhesion exists is included in the invention. In FIG. 5, there is shown a schematic view of a probe 15 for a near-field microscope, which is a second embodiment of the invention. FIG. 5 is a sectional view cut along the center axis in the longitudinal direction of the cantilever part 3 of the cantilever 2 with the probe, which is made of silicon. The material and the dimensions of the cantilever 2 with the probe are similar to the 1st embodiment. By a method mentioned later, approximately spherical silver particles 16 having been controlled to 20 nm in radius of curvature are coated to the surface of the cantilever 2 with the probe without mutually adhering. In FIG. 6, there is shown a flowchart of a method of manufacturing the probe for the near-field microscope according to the second embodiment of the invention. A method of coating the silver particles is explained in compliance with this flowchart. First, if a mixed solution is made by adding 3 ml of water to 90 μl of 6 percent weight of silver nitrate aqueous solution and 120 μl of 0.3 percent weight of potassium hydroxide in order to adjust pH, a minute brown precipitate of silver oxide occurs in the mixed solution. Next, 5 wt % ammonia solution is added by 10 μl at a time as a complex formation agent to this mixed solution till the brown precipitate forms ammonia complex to thereby completely dissolve. Additionally, 6 percent weight of silver nitrate aqueous solution is added by 10 μl at a time till an aqueous solution becomes thin yellow again. Next, a reducing agent is made by mixing 0.5 ml of methanol and 1 ml of 35 percent weight of glucose aqueous solution, and it is kept in temperature at 35° C. before performing a reaction. And, a mixed solution is made by adding the above reducing solution to the above silver nitrate aqueous solution followed by mixing. In FIG. 7, there is shown a schematic view of a method of coating the probe. The cantilever 2 with the probe is fixed to a fixing jig 17, and immersed for about 120 second in a container 19 containing the above mixed solution 18. It has been adapted such that the container 19 is inserted into a container 21 containing a water 20, a temperature of the water 20 is kept at 35° C. by a thermometer 22, and the reaction is performed under this temperature environment. Finally, the coated probe 15 for the near-field microscope is taken out of the mixed solution 18, washed by a mixed aqueous solution of acetone and water, and dried in a desiccator while being evacuated. In the present embodiment, silver crystal nuclei in the mixed solution adhere to surfaces of the probe 4 and the cantilever 3 during the cantilever 2 with the probe is immersed in the mixed solution 18, and a crystal growth happens. At this time, by adjusting a concentration of silver nitrate and a time for immersing the cantilever 2 with the probe in the mixed solution, as shown in FIG. 5 it becomes possible to form the approximately spherical silver particles 16 having been controlled to 20 nm in radius of curvature onto the probe surface without mutually adhering. An scanning electron microscope photograph of the probe for the near-field microscope, which has been made by the second embodiment, is shown in FIG. 8. Also in the present embodiment, although it is ideal that the size of the silver particle is about 20 nm in radius of curvature, if the radius of curvature is 10 nm or larger and 50 nm or smaller, it is possible to efficiently generate the surface enhanced Raman scattering, and the particle having the particle diameter of this range is included in the invention. Further, as to an ideal film shape in the present manufacturing method, although the silver particles having the uniform particle diameter are formed in the probe part and the cantilever part without mutually adhering, such a matter is considered as well that unavoidably one part of the particles don't become the prescribed shape or are adhered due to such a fact that a concentration gradient occurs in silver nitrate by shapes of the probe. Also in this case, if one portion of the particles in the probe due to the interaction with the sample are formed in the prescribed shape without adhering, it is possible to achieve the object of the invention, the probe in which one portion of the coated particles in the probe surface due to the interaction with the sample are 10 nm or larger and 50 nm or smaller in radius of curvature and have no adhesion is included in the invention. Additionally, the invention is not limited to the metals mentioned in the first embodiment and the second embodiment, and if it is a probe for a near-field microscope, in which one part or all of the probe at least due to the interaction of the evanescent field is coated by the metal consisting of the particles which are 10 nm or larger and 50 nm or smaller in radius of curvature and have no mutual adhesion, it is included in the invention. Further, also the materials and the shapes of the cantilever and the probe are not limited to the above embodiments, and it is possible to use an arbitrary probe such as silicon, silicon nitride, sharpened optical fiber and metal explorer.
	abstract	A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.
050698613	description	FIG. 1 shows a fuel assembly of a pressurized-water nuclear reactor, designated as whole by the reference 1. This fuel assembly comprises fuel rods 2 forming a bundle, in which the rods are placed in a parallel arrangement and are held by a framework consisting of spacer plates 3 distributed over the length of the rods, guide tubes 4, an upper connector 5 and a lower connector 6. The spacer plates hold the rods according to a network with meshes which are square in the transverse planes of the bundle. Some positions of the network of spacer plates 3 are reserved for the guide tubes 4 which are fastened at their ends to the connectors 5 and 6 and, in zones distributed over their length, to the spacer plates 3. The upper connector 5 has spring leaves 7 fastened to the connector 5 by means of flanges 8. The spring leaves 7 ensure that the fuel assembly 1 is detained in the reactor core, the fuel assembly resting on the lower core plate by means of its lower connector 6, and an upper core plate coming to bear on the springs 7 in order to retain the assembly against the forces exerted by the cooling fluid of the reactor circulating vertically in contact with the rods 2. FIGS. 2 and 3 show the upper connector 5 of the assembly 1, comprising an adaptor plate 9 and a frame 10 which are connected by means of a skirt 12 of square cross-section fastened by welding to the periphery of the adaptor plate 9 and to the periphery of the frame 10. The adaptor plate 9 has passing through it the fastening holes 14 of the guide tubes 4 and holes 13 allowing the passage of the cooling water of the reactor which has flowed through the assembly. The fastening hole 15 of the instrumentation tube of the assembly, located in the central part of the adaptor plate 9, has a different form from the fastening holes 14 of the guide tubes 4. The springs 7 consist of leaves retained on the connector by the flanges 8 and by fastening screws 16. Each of the flanges 8 ensures the retention of two sets of spring leaves 7 arranged at 90.degree. relative to one another along two sides of the frame 10 of the connector. The leaves of the springs 7 are engaged under the flanges 8 by means of an end part, the various leaves stacked under the flange possessing mutually coinciding orifices allowing the passage of the fastening screw 16. Each of the flanges 8 is likewise retained on the frame 10 of the upper connector 5 of the assembly by means of a fastening screw 17. The leaves of the springs 7 are thus retained both by the flanges 8 and by the fastening screws 16. The fastening screws 16 are each engaged in a countersink 18 passing through the upper bearing part of the flange 8. The screws 16 comprise a threaded part 16a engaged in an internally threaded hole 20 passing through the adaptor plate 10, and a head 16b engaged in the countersink 18 of the flange 8 and coming to bear on the leaves of the springs 7 engaged under the flange 8. The head 16b of the hexagon-socket type has an inner bore of hexagonal cross-section for the engagement of a screwing and unscrewing tool. Each of the screws 16 is locked in terms of rotation in the corresponding countersink 18 by means of a key 22 force-fitted into a slot 23 machined in the screwhead 16b. The keys 22, which experience bending when they are being force-fitted into the slot 23 of the screwhead and into the countersink 18, ensure a retention of the screw 16 which is no longer liable to come loose and separate from the connector 5, even in the event of a breakage of the screwhead 16b causing it to be separated from its threaded part 16a. The upper connector of the assembly also possesses welded bosses 24, through which pass bores 25 intended for receiving the fingers of a grab for handling the fuel assembly. FIG. 4 shows part of the upper connector 5 of a fuel assembly during an operation to unscrew and extract a screw 16 for fastening spring leaves 27 engaged, at one of their ends, under a flange 8 fastened to the frame 10 of the connector 5. This operation is carried out by means of an apparatus according to the invention designated as a whole by the reference 30. This operation is conducted under a depth of water sufficient to ensure the biological protection of the operators, inside a fuelassembly deactivation pool. To carry out the replacement of a spring leaf 27 of the fuel assembly, there has previously been an attempt to unscrew the screw 16 by means of the abovedescribed process according to the prior art. During this unscrewing, the screw 16, the threaded part 16a of which was jammed inside the internally threaded hole of the frame 10, experienced a break along a surface of inclined cross-section 31, so that the head of the screw was separated from the threaded part 16a which remained engaged in the frame 10. The unscrewing and extraction of the screw 16 can therefore no longer be carried out by means of the process according to the prior art. The apparatus 30 according to the invention, illustrated in FIG. 4, makes it possible to carry out the unscrewing and extraction of the screw 16 which has undergone a break of its head part 16b. The apparatus 30 has a pole 32 of great length, for example four meters, the lower part of which is shown in FIG. 4. Such a pole, allowing a repair tool to be supported and suspended in the deactivation pool of a nuclear reactor, can be manipulated by operators from the upper platform of the pool. The pole 32, in its lower part, has an orifice 33 of square cross-section, into which engages a part of corresponding form of the frame 34 of the unscrewing and extraction apparatus 30. The fastening and locking of the frame 34 on the end of the pole 32 are obtained by means of a pin 35 engaged in mutually coinciding holes of the pole and of the fastening part of the frame 34. The C-shaped frame 34 comprises two parallel branches 35 and 36 and adjoining part 37 between these two branches. The joining part 37 is fastened in the extension of the pole 32 and is in a substantially vertical position when the tool is in operation, as shown in FIG. 4, on the upper connector 5 of the fuel assembly. The branches 35 and 36 are then substantially horizontal. The upper branch 35 of the frame has passing through it an internally threaded hole 39, the direction of which corresponds to the direction of the axis of the joining part 37 and of the pole 32. An extraction screw 40 is engaged in the internally threaded hole 39 by means of its threaded middle part. The extraction screw 40 has a slot 41 in its upper part, which is extended by a widened insertion part 42 for the end part 43 of a screw driver, the blade 44 of which is intended for engaging in the slot 41 in order to carry out the screwing or unscrewing of the extraction screw 40. The end part 43 of the screw driver is fastened to the end of an actuating rod which can be manoeuvred from the upper platform of the pool. The screw 40 has an end part which is located underneath its threaded middle part and opposite the slot 41 and which consists of a calibrated cylindrical endpiece pierced with radially directed orifices 46. A ring 47 is engaged on the endpiece 45 and is retained in a specific axial position by a pin engaged in a hole 46 and in a corresponding orifice of the ring 47. The outside diameter of the ring 47 corresponds to the inside diameter of the countersink 18, the ring 47 ensuring the centring and positioning of the actuating screw 40 in the countersink 18 of the collar 8 for the purposes of extracting the screw 16. The endpiece 45 of the screw 40 carries, at its end, a punch 50 of great hardness and of conical form, capable of penetrating into the metal of the screw 16 in the region of the breaking surface 31. The lower branch 36 of the frame 34 carries a bearing and centring piece 51 directed towards the inside of the frame in the axial extension of the internally threaded hole 39 and of the screw 40 and having a concave bearing surface 52 at its end. As can be seen in FIG. 4, the frame 34 has dimensions allowing it to be engaged inside the frame 10 of the upper connector 5 of a fuel assembly, in such a way that the parallel branches 35 and 36 are located on either side of a flange 8 and the frame 10 of the connector 5. FIGS. 5 and 6 illustrate two alternative embodiments of an apparatus according to the invention, the corresponding elements in FIG. 4 on the one hand and in FIGS. 5 and 6 on the other hand bearing the same references. The apparatuses illustrated in FIGS. 5 and 6 are intended for extracting fastening screws of springs of upper fuel-assembly connectors, such as the screw 16, the head of which has experienced a break. These apparatuses can be used after the removal of the flange 8 and of the springs, the upper part of the screw having the breaking surface 53 projecting relative to the upper surface of the frame 10 of the upper connector 5. The extraction screw 40' has an end part 45' located below its threaded part and terminating in a punch 50' capable of penetrating into the head of the screw 16. A tubular piece 55 is arranged round the part 45' of the screw and is fastened to this part of the screw by means of a key 56 engaged in mutually coinciding radially directed holes of the tubular piece 55 and of the screw 40'. A helical spring 58 is arranged round the threaded part of the screw 40' above the tubular piece 55. The screw 40', in its threaded part, has a set of holes 57 capable of receiving a pin bearing on a washer ensuring the adjustment of the compression of the spring 58. The spring 58 ensures that the tubular piece 55 is brought to bear on and retained against the upper face of the frame 10 of the connector 5 round the projecting part of the screw 16. The tubular piece 55 forming a ring for centring the extraction screw 40' accompanies this screw in its rotational movement during the screwing or unscrewing. However, the limited force exerted by the spring 58 makes it possible to avoid impeding the functioning of the apparatus. FIG. 6 shows an alternative embodiment of the apparatus according to the invention, of which the extraction screw 40" has a diametrically widened end part 60 possessing an upper shoulder 61 below its threaded part. The tubular piece 62 forming a centring ring is slipped onto the end part of the screw 40" and comes to rest on the shoulder 61 by means of a shoulder 63 provided on its inner bore. A spring 64 arranged round the threaded part of the shank 40" bears on the upper face of the centring ring 62 and is put under compression by means of a washer 66 and a pin engaged in a radially machined hole 65 of the screw 40". The compression of the spring exerting a push on the centring ring 62 can thereby be adjusted. During the putting in position of the apparatus, as shown in FIG. 6, the centring ring 62 takes its place round the projecting part of the screw 16 above the frame 10 of the connector and is retained by the spring 64. On the other hand, the diametrically widened part 60 of the screw 40", engaged virtually without play in the bore of the centring ring 62, ensures a centring and positioning of the extraction screw 40" relative to the screw 16 to be extracted. Reference will now be made to the figures taken as a whole in order to describe the functioning of the apparatus according to the invention. The fuel assembly 1, in the storage position at the bottom of the deactivation pool of a nuclear reactor, is placed in a handling device, called a downward conveyor, fastened to one wall of the pool. The fuel assembly 1 has a fastening screw for a set of spring leaves 7, the head 16b of which has been separated from the threaded body 16a in the region of a breaking surface, such as the surface 31 shown in FIG. 4. The body 16a of the screw projects over an approximate length of 9 mm relative to the lower surface of the frame 10 of the connector. The breaking surface 31 of the screw head is at a depth of approximately 21 mm within the countersink 18 of the flange 8. A receptacle for waste and foreign bodies is arranged underwater in the connector below the screw 16 to be extracted. In a first stage, a recentring of the spring leaves 27 is carried out (FIG. 4) by using a tool mounted on the end of a pole actuable from the platform of the pool. This tool is engaged over a height of 3 mm inside the countersink 18 and has a conical stud ensuring the recentring of the three spring leaves 27. As shown in FIG. 4, the tool according to the invention is then lowered by means of the pole 32 into the region of the upper connector 5 of the assembly 1. The frame 34 of the tool is placed relative to the frame 10 of the connector and relative to the flange 8 in its position shown in FIG. 4. The tool 30 does not have the bearing piece 51 which can be mounted removably on the lower branch 36 of the frame 34. The end of the extraction screw 40 having the centring ring 47 is introduced into the countersink 18 of the flange 8 over a height of approximately 6 mm. During this operation, the pole 32 is maintained in a perfectly vertical position. The screwing of the extraction screw 40 is carried out by means of the screwdriver 43, until the punch 50 of the screw 40 penetrates into the metal of the screw 16 in the region of the breaking surface 31. For this purpose, a tightening torque of approximately 1 m--10 N is exerted. The centring of the extraction screw 40 is obtained by means of the ring 47 engaged in the countersink 18 of the flange 8. The projecting lower part of the screw 16 bears on the lower branch 36 of the frame 34. The apparatus according to the invention acts in the manner of a clamp and ensures the axial clamping of the part 16a of the screw 16. The tool is arranged so as to be capable of exerting a torque on the entire frame 34 about the axis of the extraction screw 40. The arrangement of the frame 34 allows a movement permitting a rotation of approximately 60.degree. of the unit consisting of the frame 34, of the extraction screw 40 and of the part 16a of the screw to be extracted, before the tool comes up against the frame 10 of the upper connector of the assembly. The release and the commencement of loosening of the screw 16a are obtained in this way. The torque exerted from the operating handle of the pole 32 located in the region of the platform for the pool can be considerable, the branches 35 and 36 of the frame 34 having some length. The unscrewing of the extraction screw 40 is then obtained by means of the screwdriver 43, and the frame 34 is then returned to its initial position. As before, the extraction screw 40 is tightened until the punch 50 penetrates into the metal of the screw 16. An additional unscrewing is then carried out, until the tool comes against the frame of the connector of the assembly. Several successive operations, such as that described above, are conducted, up to the moment when the centring ring 47 is completely free of the countersink 18 of the flange 8, this corresponding to an unscrewing of the screw 16 of 6 mm. The lower arm 36 of the frame 34 is then virtually in contact with the lower surface of the frame 10 of the connector 5 of the assembly. The retraction of the tool illustrated in FIG. 4 is then carried out. After the raising of the tool, the lower branch 36 of the frame 34 is equipped with a bearing piece 51 of particular length, projecting towards the inside of the frame 34. The centring ring 47 is placed in a position ensuring centring during the rest of the unscrewing operation. As a precaution, the recentring of the leaf springs 27 is carried out. The tool is lowered into the region of the upper connector of the assembly and is placed in its position shown in FIG. 4. The piece 51 is brought to bear on the end of the screw 16 by means of its concave surface 52, and the extraction screw 40 is clamped against the breaking surface of the screw 16. The unscrewing of the part 16a of the screw 16 is then carried out, as before, the bearing piece 51 ensuring the centring of the apparatus within that part of the internally threaded hole passing through the frame 10 of the connector released by the threaded part 16a of the screw 16. The operation is interrupted when the lower branch 36 of the frame 34 comes in contact with the lower surface of the frame 10 of the connector. The entire tool is then raised to the platform of the pool in order to carry out a new adjustment. The centring ring 47 is removed and a new bearing piece 51 is fastened to the lower branch 36 of the frame 34. This new bearing piece has a length greater than the length of the bearing piece used during the preceding phase. This length is substantially less than the thickness of the frame 10, so that, at the end of the unscrewing operation, the threaded body 16a of the screw 16 remains in engagement with the internally threaded hole of the frame 10. In an embodiment put into practice by the applicant company, this bearing piece had a length of 18 mm. The tool is lowered into the pool and put in place, as shown in FIG. 4, the centring of the tool being obtained by means of the bearing piece 51 introduced into that part of the internally threaded hole released by the threaded part 16a of the screw 16. Unscrewing is carried out in the way described above. At the end of this last unscrewing phase using the apparatus according to the invention, the threaded part 16a of the screw 16 is unscrewed so that its upper end projects relative to the upper surface of the flange 8. A conventional tool consisting of tongs mounted on the end of the pole 32 is then used to carry out the unscrewing of the last threads of that part 16a of the screw still in engagement with the threads of the internally threaded hole of the frame 10 and to deposit the part 16a of the screw in a recovery and discharge container arranged near the assembly. The internally threaded hole of the frame 10 of the upper connector of the assembly has not undergone any damage, and it is thus possible, by means of a known process, to carry out the installation and screwing of a new retaining screw for the springs 27. It should be noted that the form of the punch 50 of the extraction screw 40 makes it possible to exert the tightening force in the axis of the part 16a of the screw to be extracted. During the tightening of the extraction screw, a low torque is thus generated and causes no rotational movement of the threaded part 16a of the screw 16 to be extracted, in the screwing direction. In contrast, the bearing piece 51 has a concave end making it possible to obtain contact with the part 16a of the screw in a zone distant from the axis of the threaded part 16a. A high torque is thus produced on the bearing surface, making it possible to brake the part 16a of the screw during unscrewing. Thus, in all cases, the apparatus according to the invention makes it possible to carry out simply, without damaging the internally threaded hole of the upper connector of the assembly, the removal of a fastening screw of which the head has been separated from the threaded body by breakage. It is clear that the invention is not limited to the embodiment described. Thus, the removal of the screw to be extracted can be carried out more quickly in a procedure involving only two phases, according to the length of the threaded part of the screw. The apparatus according to the invention can be equipped with centring rings having any number of adjustment positions and with bearing pieces of different lengths. It is likewise possible, where a prior removal of the flange of the assembly is carried out or in the removal of screws remaining projecting relative to the upper surface of the flange or of the connector, to employ apparatuses, such as those illustrated in FIGS. 5 and 6. The apparatus according to the invention can also be adapted for the unscrewing and extraction of screws in the horizontal or inclined position. In this case, the method of fastening or connecting the frame to the elongate support must make it possible to obtain the desired inclination. Likewise, the means for the remote actuation of the screw possesses means for desired adaptation and inclination in order to reach the engagement profile of the head of the extraction screw. The apparatus according to the invention for the unscrewing and extraction of screws having experienced a break can be used not only for screws retaining the springs of the upper connectors of the fuel assemblies of water-cooled reactors, but also for fastening screws of other elements of a fuel assembly of a nuclear reactor.
	abstract	Described are optical apparatuses and methods for forming optical apparatuses. The optical apparatus includes a plurality of individually fabricated segments and a holder. Each of the plurality of individually fabricated segments include an inner annular surface and an outer contact surface opposite to the inner annular surface. Each of the inner annular reflecting surfaces define a longitudinal segment axis. The holder contacts each of the outer contact surfaces of the plurality of individually fabricated segments. Each of the longitudinal segment axes of the plurality of individually fabricated segments are linearly aligned.
	summary
	claims	1. A shipping container system for a first nuclear fuel product comprising:an elongated tubular container having an axis extending along an elongated dimension of the container, the container being designed to receive and support the first nuclear fuel product therein, an exterior of the tubular container having at least two substantially flat, movable walls and at least two substantially flat, stationary walls with a circumferential end of the at least two stationary walls connected together along the elongated dimension and another circumferential end of at least one of the stationary walls having a hinged interface with one circumferential end of at least one of the at least two movable walls, another circumferential end of the at least one of the at least two movable walls being connected to one circumferential end of another of the at least two movable walls with the another circumferential end of the another of the at least two movable walls connectable to another circumferential end of another of the at least two stationary walls, with each of the stationary walls and the movable walls having an upper and lower end and the stationary walls having at least one of either a bar or groove on an interior side of at least two of the stationary walls, proximate the upper end, that extend along at least a portion of the corresponding stationary walls substantially in a direction orthogonal to the axis, the elongated tubular container having a top plate that closes off a top of the elongated tubular container, with the top plate having at least two peripheral sides having the other of the one of a bar or groove extending substantially along at least a portion of an outer edge with the other of the one of the bar or groove sized and oriented to mate with the one of the bar or groove and an anchoring mechanism for supporting a side of the top plate against an abutting side of the one or the another of the at least two stationary walls, the top plate having at least one wall that extends parallel to the one or the another of the at least two stationary walls with the anchoring mechanism having an elongated dimension with one end extending through the wall in the top plate and into the at least one or the another of the two stationary walls that the wall in the top plate is parallel to, the anchoring mechanism being anchored within the at least one or the another of the two stationary walls that the wall in the top plate is parallel to and restrained within the at least one or the another of the two stationary walls that the wall in the top plate is parallel to, in a direction along the elongated dimension of the anchoring mechanism;an elongated, tubular overpack having an axial dimension at least as long as the tubular container, an internal cross-section larger than the tubular container and an interior tubular channel having an axially extending lower support section supporting a plurality of shock mounts, with at least one of said plurality of shock mounts positioned on either radial side of the lower support section, the shock mounts support at least one of the flat walls of the tubular container in spaced relationship with the lower support section when the overpack is supported in a horizontal position, with at least one circumferential end of the lower support section having a clamped interface substantially along the axial dimension thereof to provide access to the interior of the overpack; anda stand configured to support the overpack in a horizontal position. 2. The shipping container system of claim 1 wherein the anchoring mechanism is a placement rod having one end with a male locking contour which extends through the wall in the top plate and into an abutting opening in the one or the another of the at least two stationary walls, that has a complimentary female locking mechanism. 3. The shipping container system of claim 2 wherein the male locking contour is a male threaded end of the placement rod and the complimentary female locking mechanism is a female thread on an interior surface of the abutting opening. 4. The shipping container system of claim 3 wherein a hole in the wall in the top plate through which the placement rod extends includes a female thread that mates with the male thread on the placement rod. 5. The shipping container system of claim 3 wherein the male threaded end of the placement rod is tapered. 6. The shipping container system of claim 1 wherein the one of the bars or grooves extend substantially across a full width of each of the walls and the another of the bars or grooves on the edge of the top plate extends substantially around the entire edge. 7. The shipping container system of claim 1 wherein the top plate includes at least two spaced openings extending through the top plate and through which push rods extend from above the top plate to an upper surface of the first nuclear fuel product, wherein an axial length of the push rods within an interior of the elongated tubular container is adjustable from above the top plate on an exterior of the elongated tubular container. 8. The shipping container of claim 7 wherein the adjustment includes a nut supported above the top plate on each push rod and retained on the push rods by locking pins. 9. The shipping container system of claim 7 wherein the spaced openings have female threads that mate with male threads on the push rods. 10. The shipping container system of claim 7 including a third spaced opening in the top plate. 11. The shipping container system of claim 10 wherein the top plate has diametrically opposed corners and the two spaced openings are located proximate the diametrically opposed corners and the third spaced opening is located substantially in the center of the top plate. 12. The shipping container system of claim 7 wherein the top plate has diametrically opposed corners and the two spaced openings are located proximate the diametrically opposed corners. 13. The shipping container system of claim 1 including motion detectors for recording the extent of excessive motion of the elongated tubular container, wherein the extent of excessive motion can be read from an outside of the elongated tubular container without opening any of the walls. 14. The shipping container system of claim 13 wherein the motion detectors are secured to an upper side of the top plate. 15. The shipping container system of claim 1 wherein the first nuclear fuel product includes a nuclear fuel assembly and a control rod spider assembly. 16. The shipping container system of claim 1 wherein the one of either the bar or groove is a bar and the another of the bar or groove is a groove. 17. An elongated tubular shipping container having an axis extending along an elongated dimension of the container, the container being designed to receive and support a first nuclear fuel product therein, comprising:an exterior of the tubular container having at least two substantially flat, movable walls and at least two substantially flat, stationary walls with a circumferential end of the at least two stationary walls connected together along the elongated dimension and another circumferential end of at least one of the stationary walls having a hinged interface with one circumferential end of at least one of the at least two movable walls, another circumferential end of the at least one of the at least two movable walls being connected to one circumferential end of another of the at least two movable walls with the another circumferential end of the another of the at least two movable walls connectable to another circumferential end of another of the at least two stationary walls, with each of the stationary walls and the movable walls having an upper and lower end and the stationary walls having at least one of either a bar or groove on an interior side of at least two of the stationary walls, proximate the upper end, that extend along at least a portion of the corresponding stationary walls substantially in a direction orthogonal to the axis; andthe elongated tubular container having a top plate that closes off a top of the elongated tubular container, with the top plate having at least two peripheral sides having the other of the one of a bar or groove extending substantially along at least at least a portion of an outer edge with the other of the one of the bar or groove sized and oriented to mate with the one of the bar or grooves and an anchoring mechanism for supporting a side of the top plate against an abutting side of the one or the another of the at least two stationary walls, the top plate having at least one wall that extends parallel to the one or the another of the at least two stationary walls with the anchoring mechanism having an elongated dimension with one end extending through the wall in the top plate and into the at least one or the another of the two stationary walls that the wall in the top plate is parallel to, the anchoring mechanism being anchored within the at least one or the another of the two stationary walls that the wall in the top plate is parallel to and restrained within the at least one or the another of the two stationary walls that the wall in the top plate is parallel to, in a direction along the elongated dimension of the anchoring mechanism.
041994027	claims	1. A process for generating nuclear fusion, comprising the steps of: creating non-neutralized Tritium and Duterium ions within an accelerator by impinging laser energy on a Duterium-Tritium pellet, propelling said ions within the accelerator from first positions to each relative minimum cross-section positions of the accelerator, injecting electrons at each relative minimum cross-section of the accelerator to neutralize the space charge of said ions and to create a plasma, compressing and confining said plasma at a maximum density by electromagnetic fields, creating an electron cloud at each relative minimum cross-section encircling said plasma, whereby said ions of said plasma oscillate toward and away from electrons in said electron cloud and whereby the confinement time and density of ions at each relative minimum cross-section is sufficient to generate nuclear fusion, extracting the heat of fusion as useful energy, releasing the magnetic fields subsequent to fusion and allowing the escape of the products of fusion from each relative minimum cross-section, extracting electrons and waste products of fusion from the accelerator leaving solely ions for circulation within the accelerator, and passing said ions through magnetohydrodynamic coils to generate electrical current. 2. The method as recited in claim 1, and further including the step of: evacuating said accelerator to create a vacuum therein 10.sup.-13 Torr.
060944714	summary	BACKGROUND OF THE INVENTION This invention relates to x-ray diagnostic systems and more particularly to a system which concentrates x-rays from a source and delivers them to an x-ray spectrometer. Most focusing x-ray optics take advantage of total reflection at glancing angles of incidence. Total reflection occurs only when the angle of incidence is less than a critical angle that depends upon the properties of the reflecting material and the x-ray energy. Although prior art designs may vary according to application, most such designs have used metal or glass substrates with coatings of nickel, gold or iridium at glancing angles ranging from 10 to 150 arc minutes. Double-reflection geometries of the Wolter-I or Kirkpatrick-Baez types have been developed to focus a parallel beam of x-rays. The Wolter-I configuration consists of confocal parabaloid-hyperboloid shells and has been used most often for x-ray telescopes designed for high angular resolution. This optic is axially compact, has a moderate field of view and, in some cases, a large number of telescopes can be nested to fill a substantial fraction of the available entrance aperture. An approximation to the Wolter-I design replaces the precisely figured optics with simple cones. Telescopes based upon this approximation have been developed for various astrophysical payloads. The Kirkpatrick-Baez geometry uses two parabolic surfaces for parallel-to-point focusing, and it has been adapted to point-to-point geometries for x-ray microscopes. Recently, optics based upon bundles of glass capillary tubes have emerged as a method for focusing x-rays. The x-rays undergo numerous reflections as they travel through the glass channels causing these optics to have lower efficiency than the double reflection systems referred to above. Electron microscopes are widely used in many applications including in the semiconductor fabrication industry. When targets are irradiated with electrons, x-rays are generated as a side effect. The x-ray spectrum provides information about elements contained in the target so that x-rays are often detected for analysis. In the prior art, it is known to place a detector such as a lithium-drifted silicon or germanium detector very close to the target in a scanning electron microscope. Such detectors are typically mounted on the end of a cold finger cooled by thermal conduction by means of a quantity of liquid nitrogen which boils at 77 kelvin. Higher resolution can be achieved utilizing detectors cooled to approximately 0.1 kelvin and in this context it may be desirable to locate the detector outside of the SEM enclosure. However, because of the well known square law dependence of intensity on distance from a source of x-rays, as a detector is moved farther from the source, the intensity drops which degrades the performance of a spectrometer receiving the x-rays. It is also known to use monolithic polycapillary glass optics within an SEM enclosure to concentrate x-rays for subsequent analysis but not to use any such concentrator beyond the confines of the SEM enclosure. SUMMARY OF THE INVENTION In one aspect, the x-ray diagnostic system of the invention includes a source of x-rays and an x-ray beam concentrator spaced apart from the x-ray source and disposed for receiving x-rays from the x-ray source. An x-ray spectrometer is disposed for receiving x-rays from the concentrator. The source of x-rays may be a point source such as a sample volume excited by an electron beam in a scanning electron microscope or excited by a focused synchrotron beam, an ion beam or a laser. The point source of x-rays may also be a commercial x-ray tube or may be produced by a small volume of hot gas produced in a laboratory plasma machine which may be of the magnetically and/or electrostatically confined type. The plasma can also be inertially confined. The x-ray source may also be a commercial electron impact device or even be a distant x-ray emitting object in space. In preferred embodiments, the point-to-point x-ray concentrator is a single reflection concentrator made from either a nest of cylindrical surfaces or a surface wound into the form of a cylindrical spiral. The point-to-point concentrator may be a multiple reflection concentrator made either from opposed sets of nested conical surfaces or surfaces wound into the form of conical spirals. In another embodiment, the point-to-point concentrator is a single glass capillary bundle. The single glass capillary bundle may be monolithic. In another embodiment, the point-to-point concentrator includes a point-to-parallel glass capillary bundle coupled to a parallel-to-point glass capillary bundle and coupling occurs through vacuum or in gas over a variable distance. It is preferred that the spectrometer be an energy dispersive x-ray detector such as a microcalorimeter, lithium-drifted silicon detector, germanium detector, cadmium zinc telluride (CZT) detector, gas scintillation proportional counter or gas proportional counter. The spectrometer may also be a wavelength dispersive x-ray spectrometer which may use at least one flat Bragg crystal or may utilize at least one Bragg crystal in the Johann configuration or von Hamos configuration. In yet another aspect, the invention is an x-ray concentrator comprising a ribbon of material having a reflecting surface and formed into a spiral having a plurality of windings. This concentrator may be either a single or a multiple reflection concentrator. It is preferred that the ribbon material be plastic foil, aluminum foil or quartz ribbon. A suitable plastic foil is polyester, kapton, melinex, hostaphan, apilcal or mylar. A particularly preferred plastic is available from the Eastman Kodak Company under the designation ESTAR.TM.. Suitable foil thicknesses range from 0.004 to 0.015 inches as required. It is preferred that the ribbon material be coated with a thin layer of metal, preferably a high Z metal such as nickel, gold or iridium. The metal coating may be multilayer. In a preferred embodiment, the spiral configuration is maintained by a support structure made of metal, plastic or a composite material. Suitable metals are aluminum, beryllium, stainless steel, titanium or tungsten. In yet another aspect, the invention is an x-ray concentrator comprising a plurality of nested, concentric cylinders or cones made of a ribbon material having a reflecting surface. The nested cylinders or cones may be made of glass, aluminum foil, plastic foil, silicon or germanium. Suitable plastic material is the same as described above in conjunction with the spiral aspect of the invention. The plastic material would also be coated as described above in conjunction with the spiral configuration. The concentrators of the invention may be located, for example, outside the enclosure of an SEM and receive x-rays through an x-ray permeable window or through an evacuated pipe with no window between the SEM and concentrator. The x-rays are concentrated or focused onto a spectrometer which may be located several meters from the target within the SEM. Because of the separation, spectrometers such as microcalorimeters cooled to on the order of 0.1 kelvin can be more conveniently utilized thereby giving much greater spectral resolution.
041636899	claims	1. A vented nuclear fuel element for use in a nuclear reactor, comprising a fissile fuel body, means defining a cladding surrounding and containing said fissile fuel body, a conduit penetrating said fissile fuel body and affixed and sealed to said cladding and having one end opening proximate the center of gravity of said fissile fuel body with distal end of said conduit opening outside said cladding for conduction of volatile and gaseous fission products away from said fissile fuel body. 2. The vented fuel element as defined in claim 1 wherein said fissile fuel body comprises a cylinder of compressed wafers of fissile fuel having a central hole and disks of thermally conductive refractory material having a central hole sandwiched between said wafers. 3. The vented fuel element as defined in claim 2 wherein said thermally conductive refractory material is selected from the group consisting of tungsten, molybdenum and rhenium and alloys thereof. 4. A thermionic nuclear fuel cell for use in a nuclear reactor comprising a fissile fuel body, an emitter cladding surrounding and containing said fissile fuel mass, a conduit penetrating said fissile fuel mass and affixed and sealed to said cladding and having an intake end comprising an end cap having a central hole of diameter smaller than the inside diameter of said conduit sealed and affixed to the end of said conduit proximate the center of gravity of said fissile fuel body with the end of said conduit distal said end cap opening to the exterior of said cladding for conduction of volatile and gaseous fission products away from said fissile fuel body. 5. A thermionic nuclear fuel element for use in a nuclear reactor, comprising a cylindriform fissile fuel body, a gas impervious cladding surrounding and containing said fissile fuel body, a conduit penetrating said fuel mass coincident with the longitudinal axis of said cylindriform fissile fuel mass and sealed and affixed to said cladding, an intake end of said conduit at the geometric center of said fuel body comprising an end cap having a central hole of diameter smaller than the inside diameter of said conduit, and an exit end of said conduit distal said intake end opening to the exterior of said cladding for conduction of volatile and gaseous fission products away from said fuel element.
	abstract	A fuel assembly for a nuclear reactor, a fuel rod of the fuel assembly, and a ceramic nuclear fuel pellet of the fuel rod are disclosed. The fuel pellet includes a first fissile material of UB2, The boron of the UB2 is enriched to have a concentration of the isotope 11B that is higher than for natural B.
	summary
048636789	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The composite of FIGS. IA and IB (referred to hereinafter as FIG. 1) is an elevational view, partly in cross-section, of a pressurized water reactor 10 comprising a vessel 12 including an upper dome, or head assembly, 12a, cylindrical sidewalls 12b, and a bottom closure 12c comprising the base of the reactor 10. Plural radially oriented inlet nozzles 11 and outlet nozzles 13 (only one (1) of each appearing in FIG. 1) are formed in the sidewall 12b, adjacent the upper, annular end surface 12d of the sidewall 12b. Whereas the cylindrical sidewall 12b may be integrally joined, as by welding, to the bottom closure 12c, the head assembly 12a is removably received on the upper, annular end surface 12d of the sidewall 12b and secured thereto. The sidewall 12b further defines an inner, generally annular mounting ledge 12e for supporting various internals structures, as later described. Within the bottom closure 12c, as schematically indicated, is so-called bottom-mounted instrumentation 13. The lower barrel assembly 16 comprises a generally cylindrical sidewall 17 affixed at its lower end to a lower core plate 18, which is received on mounting support 18b, as generally schematically illustrated. The cylindrical sidewall 17 extends substantially throughout the axial height of the vessel 12 and includes an annular mounting ring 17a at the upper end thereof which is received on the annular mounting ledge 12e thereby to support the assembly 16 within the vessel 12. As will be rendered more apparent hereafter, the sidewall 17 is solid in the vicinity of the inlet nozzles 11, but includes an aperture 17b having a nozzle ring 17c mounted therein which is aligned with and removably secured to the outlet nozzle 13. An upper core plate 19 is supported on a mounting support 17d affixed to the interior surface of the cylindrical sidewall 17 at a position approximately one-half the axial height thereof. Fuel rod assemblies 20 are positioned in generally vertically oriented, parallel axial relationship within the lower barrel assembly 16 by bottom mounts 22 carried by the lower core plate 18 and by pin-like mounts 23 carried by, and extending through, the upper core plate 19. Flow holes 18a and 19a (only two of which are shown in each instance) are provided in predetermined patterns, extending substantially throughout the areas of the lower and upper core plates 18 and 19, the flow holes 18a permitting passage of a reactor coolant fluid into the lower barrel assembly 16 in heat exchange relationship with the fuel rod assemblies 20 defining the reactor core, and the flow holes 19a permitting passage of the core output flow into the inner barrel assembly 24. A neutron reflector and shield 21 is mounted interiorly of the cylindrical sidewalls 17, in conventional fashion. The inner barrel assembly 24 includes a cylindrical sidewall 26 which is integrally joined at its lower edge to the upper core plate 19. The sidewall 26 has secured to its upper, open end, an annular mounting ring 26a which is received on an annular hold-down spring 27 and supported along with the mounting ring 17a on the mounting ledge 12e. The sidewall 26 further includes an aperture 26b aligned with the aperture 17b and the output nozzle 13. Within the inner barrel assembly 24, and densely packed within the cylindrical sidewall 26, are positioned a plurality of rod guides in closely spaced, parallel axial relationship; for simplicity of illustration, only two such rod guides are shown in FIG. 1, namely rod guide 28 housing a cluster of radiation control rods 30 (RCC) and a rod guide 32 housing a cluster of water displacement rods 34 (WDRC). The rods of each RCC cluster 30 and of each WDRC cluster 34 are mounted individually to the respectively corresponding spiders 100 and 120. Mounting means 36 and 37 are provided at the respective upper and lower ends of the rod guide 28 and, correspondingly, mounting means 38 and 39 are provided at the respective upper and lower ends of the rod guide 32, the lower end mounting means 37 and 39 mounting the respective rod guides 28 and 32 to the upper core plate 19, and the upper mounting means 36 and 38 mounting the respective rod guides 28 and 32 to a calandria assembly 50, and particularly to a lower calandria plate 52. The calandria assembly 50 includes, in addition to the lower calandria plate 52, an upper calandria plate 54 and a plurality of parallel axial calandria tubes 56 and 57 which are positioned in alignment with corresponding apertures in the lower and upper calandria plates 52 and 54 and to which the calandria tubes 56 and 57 are mounted at their respective, opposite ends. More specifically, calandria extensions 58 and 59 extend through corresponding apertures in and are secured to the lower calandria plate 52, and the corresponding calandria tubes 56 and 57 are respectively secured to the extensions 58 and 59. Similar structures connect the upper ends of the calandria tubes 56 and 57 to the upper calandria plate 54. For the specific configurations of the respective calandria extensions 58 and 59 as illustrated, only the calandria extensions 58 project downwardly from the lower calandria plate 52 and connect to corresponding mounting means 36 for the upper ends, or tops, of the RCC rod guides 28. The upper end mounting means 38, associated with the WDRC rod guides 32, may be interconnected by flexible linkages to the mounting means 36 of the RCC rod guides 28, in accordance with the invention of the pending application, entitled: "FLEXIBLE ROD GUIDE SUPPORT STRUCTURE FOR INNER BARREL ASSEMBLY OF PRESSURIZED WATER REACTOR"-Gillett et al., Ser. No. 798,220 filed Nov. 14, 1985 and assigned to the common assignee hereof. Alternatively, the WDRC rod guides 32 may be connected independently to the lower calandria plate 52 by the top end support structure of the invention disclosed in the copending application, entitled: "TOP END SUPPORT FOR WATER DISPLACEMENT ROD GUIDES OF PRESSURIZED WATER REACTOR"-Sherwood et al., Ser. No. 798,194 filed Nov. 14, 1985 and assigned to the common assignee hereof now U.S. Pat. No. 4,707,331, issued Nov. 17, 1987. In the latter instance, the calandria extensions 59 likewise project downwardly from the plate 52, similarly to the extensions 58, to engage and laterally support the WDRC mounting means 38. Extending upwardly beyond the upper calandria plate 54 and, more particularly, within the head assembly 12a of the vessel 12, there are provided plural flow shrouds 60 and 61 respectively aligned with and connected to the plural calandria tubes 56 and 57. A corresponding plurality of head extensions 62 and 63 is aligned with the plurality of flow shrouds 60, 61, the respective lower ends 62a and 63a being flared, or bell-shaped, so as to facilitate assembly procedures and, particularly, to guide the drive rods (not shown in FIG. 1) into the head extensions 62, 63 as the head assembly 12a is lowered onto the mating annular end surface 12d of the vessel sidewall 12b, as later explained in reference to FIGS. 9A and 9B. The flared ends 62a, 63a also receive therein the corresponding upper ends 60a, 61a of the flow shrouds 60, 61 in the completed assembly, as seen in FIG. 1. The head extensions 62, 63 pass through the upper wall portion of the head assembly 12a and are sealed thereto. Control rod cluster (RCC) displacement mechanisms 64 and water displacement rod cluster (WDRC) displacement mechanisms 66 are associated with the respective head extensions 62, 63, flow shrouds 60, 61 and calandria tubes 56, 57 which, in turn, are associated with respective clusters of radiation control rods 30 and water displacement rods 34. The RCC displacement mechanisms (CRDM's) 64 may be of well known type, as are and have been employed with conventional reactor vessels. The displacer rod drive mechanisms (DRDM's) 66 for the water displacer rod clusters (WDRC's) 34 may be in accordance with the disclosure of U.S. Letters Pat. No. 4,439,054--Veronesi, assigned to the common assignee hereof. The respective drive rods associated with the CRDM's 64 and the DRDM's 66 are structurally and functionally the equivalent of an elongated, rigid rod extending from and in association with the respective CRDM's 64 and DRDM's 66 to the respective clusters of radiation control rods (RCC's) and water displacements rods (WDRC's) 30 and 34 and particularly, are connected at their lower ends to the spiders 100 and 120. The CRDM's and DRDM's 64 and 66 thus function through the corresponding drive rods to control the respective vertical positions of, and particularly, selectively to lower and/or raise, the RCC's 30 and the WDRC's 34 through corresponding openings (not shown) provided therefore in the upper core plate 19, telescopingly into or out of surrounding relationship with the respectively associated fuel rod assemblies 20. In this regard, the interior height D.sub.1 of the lower barrel assembly 16 is approximately 178 inches, and the active length D.sub.2 of the fuel rod assemblies 20 is approximately 153 inches. The interior, axial height D.sub.3 is approximately 176 inches, and the extent of travel, D.sub.4, of the rod clusters 30 and 34 is approximately 149 inches. It follows that the extent of travel of the corresponding CRDM and DRDM drive rods is likewise approximately 149 inches. While the particular control function is not relevant to the present invention, insofar as the specific control over the reaction within the core is effected by the selective positioning of the respective rod clusters 30 and 34, it is believed that those skilled in the art will appreciate that moderation or control of the reaction is accomplished in accordance with the extent to which the control rod clusters 30 are inserted into or withdrawn from the core and with the effective water displacement which is achieved by selective positioning of the water displacement rod clusters 34. It is significant, however, that the RCC's 30 are adjusted in position relatively frequently, compared to the WDRC's 34, to achieve the desired power output level from the reactor. Conversely, the WDRC's 34, initially, are lowered, or inserted, fully into the lower barrel assembly 16 at the initiation of each fuel cycle. The WDRC's 32, through their respective drive rods (not shown in FIG. 1) and DRDM's 66, then are selectively removed as the excess reactivity is depleted, over the fuel cycle. Typically, this is performed by simultaneously removing a group of four such WDRC's 34 from their fully inserted positions in association with the fuel rod assemblies 20, to a fully raised position within the corresponding WDRC guides 32 and thus within the inner barrel assembly 24, in a continuous and controlled withdrawal operation. More specifically, the four WDRC's 34 of a given group are selected so as to maintain a symmetrical power balance within the reactor core, when the group is withdrawn. Typically, all of the WDRC's 34 remain fully inserted in the fuel rod assemblies 20 for approximately 60% to 70% of the approximately 18 month fuel cycle. Groups thereof then are selectively and successively moved to the fully withdrawn position as the excess reactivity is depleted, so as to maintain a nominal, required level of reactivity which can sustain the desired output power level, under control of the variably adjustable RCC's 30. The reactor coolant fluid, or water, flow through the vessel 10 proceeds generally from a plurality of inlet nozzles 11, one of which is seen in FIG. 1, downwardly through the annular chamber between an outer generally cylindrical surface defined by the interior surface of the cylindrical sidewall 12b of the vessel 12 and an inner generally cylindrical surface defined by the cylindrical sidewall 17 of the lower barrel assembly 16. The flow then reverses direction and thereafter passes axially upwardly through flow holes 18a in the lower core plate 18 and into the lower barrel assembly 16, from which it exits through a plurality of flow holes 19a in the upper core plate 19 to pass into the inner barrel assembly 24, continuing in parallel axial flow therethrough and finally exiting upwardly through flow holes 52a in the lower calandria plate 52. Thus, parallel axial flow conditions are maintained through both the lower and inner barrel assemblies 16 and 24. Within the calandria 50, the flow in general turns through 90.degree.. to exit radially from a plurality of outlet nozzles 13 (one of which is shown in FIG. 1). The reactor coolant flow proceeds as well into the chamber defined by the head assembly 12a through certain bypass passageways (not shown in FIG. 1), associated with the mounting of the calandria tubes 56 and 57 to the upper calandria plate 54 and also in accordance with the connections of the head extensions 62, 63 and the flow shrouds 60, 61. The flared ends 62a and 63a of the corresponding head extensions 62, 63 which function to guide the corresponding flow shrouds 60, 61 into alignment during assembly of the head assembly 12a with the sidewall 12b to achieve the assembled relationship illustrated in FIG. 1. The pressure of the cycle water, or reactor coolant, within the vessel 10 typically is in the range of about 2,250 psi, and provides the energy source, or fluid pressure, to the DRDM's 66 for raising the DRDM drive rods from a fully inserted to a fully withdrawn, or up position, as described more fully in the related, above-identified patent. As is apparent from FIG. 1, therefore, the spiders 100 and 120 are continuously subjected to the cycle water, or reactor coolant of the core outlet flow as it passes in substantially a parallel axial flow condition through the inner barrel assembly 24. FIG. 2 is a cross-sectional, schematic view, taken along the line 2-2 in FIG. 1, of the inner barrel assembly 24, and serves to illustrate diagrammatically the dense packing of the arrays of plural control rod clusters (RCC's) 30 and water displacer rod clusters (WDRC's) within the inner barrel assembly 24. For ease of illustration, only the immediately surrounding, cylindrical sidewall 26 of the inner barrel assembly 24 is shown, the sidewalls 16 and 12b being omitted; as well, FIG. 2 illustrates only a general outline of the periphery of the RCC and WDRC rod guides 28 and 32 within which the corresponding RCC and WDRC rods are housed, as seen in FIG. 1. As is readily visualized from FIGS. 1 and 2, the RCC clusters 30 and WDRC clusters 34 are disposed in interleaved arrays, substantially across the entire cross-sectional area of the inner barrel assembly 24. This dense packing of the respective rod clusters and associated spiders thus requires careful design to assure not only that parallel flow is maintained throughout, but also that flow induced vibrations and concomitant deleterious force effects are mitigated, to the extent possible. In accordance with the above-noted invention relating to modular formers, the elevational view of FIG. IA shows three vertical banks 40, 42 and 44 of modular formers of which the middle bank 42 is seen in FIG. 2; since the banks 40, 42 and 44 are identical in construction, with the exception of their respective vertical height dimensions, the view of FIG. 2 is illustrative as well of the banks 40 and 44 and additionally, of both top and bottom plan views of each thereof. Particularly, the modular formers are of two different configurations shown at 70 and 80, respectively disposed symmetrically about quadrature-related diameters D1 and D3, and D2 and D4 and thus in an alternating succession at 45. angular segments. Attachment elements 90 secure the formers 70 and 80 to the sidewall 26, the outer edges 70' and 80' thereof comprising arcuate segments mating the interior circumference of the sidewall 26 so as to be received thereagainst in mating relationship, and the inner edges 70" and 80" having configurations mating the periphery of the interleaved arrays of the RCC and WDRC rod guides 28 and 32. FIGS. 3 and 4 are plan and elevational views of an RCC spider 100, FIG. 3 being schematic in form and FIG. 4 being a partly broken-away, cross-sectional view taken along the line 4-4 in FIG. 3. The RCC spider 100 comprises a central hub 102 of generally cylindrical configuration having an upper, interiorly threaded end 103 for connection to a drive rod (not shown) which extends, as before described, upwardly to an RCC adjustment mechanism 64 by which the spider 100 and its associated control rods (not shown) may be vertically adjusted in position within and relative to the RCC rod guide 28. Recesses 102a provide for locking a metal protective sleeve (not shown in FIG. 3) which surrounds and overlaps the joint between the drive rod (not shown) and the hub 102, by indenting same into recesses 102a. This construction is shown in further detail in the concurrently filed application entitled "PRESSURIZED WATER REACTOR HAVING DISCONNECTABLE TWO-PIECE DRIVE ROD ASSEMBLIES, AND RELATED METHODS OF ASSEMBLY AND MAINTENANCE OPERATIONS"-Altman et al., Ser. No. 806,711 filed Dec. 9, 1985 and assigned to the common assignee hereof now U.S. Pat. No. 4,778,645, issued Oct. 18, 1988. Vane assemblies 106 are secured at the respective inner edges thereof to the hub 102 and extend radially therefrom in quadrature, relative relationship. Each vane assembly 106 includes a pair of cylindrical support mounts 108, each thereof having an interior bore 109 including an interiorly threaded portion 110 into which the upper, correspondingly threaded end of a control rod (not shown) is threadingly engaged so as to be supported by the vane assembly 106 and corresponding hub 102. FIGS. 5 and 6 illustrate a WDRC spider 120, FIG. 5 being a planar, generally schematic view, and FIG. 6 being an elevational view, partially in cross-section and taken along the line 6--6 in FIG. 5. Similarly to the RCC spider 100, the WDRC spider 120 includes a central hub 122 of generally cylindrical configuration, the upper end 123 being interiorly threaded to receive a drive rod which, as discussed in connection with FIG. 1, connects to a corresponding WDRC control mechanism 66. Recesses 122a are provided for the same purpose as recesses 102a in the hub 102 of FIGS. 3 and 4, as above noted. First and second types of vane assemblies 126, 127 are connected to the hub 122 in alternating, equiangularly displaced relationship so as to extend radially therefrom. The vane assemblies 126 are substantially similar to the RCC vane assemblies 106, as seen in FIGS. 3 and 4, and thus include a pair of radially displaced WDRC rod support mounts 128. As best seen from FIG. 5, the vane assemblies 126 are disposed to extend radially from the hub 122 in quadrature relationship. The vane assemblies 127 include integral, transverse vanes 125 extending as first and second oppositely oriented pairs 125A and 125B from the radially extending, planar vane portions 123' and 124' of the assembly 127 and each thereof carrying a WDRC rod support mount 128 at its extremity. As best seen in FIG. 5, four vane assemblies 127 of the second type are disposed to extend radially from the hub 122 in mutual, quadrature relationship, each intermediate an adjacent quadrature-related pair of vane assemblies 106 in the alternating sequence as above described. Each of the WDRC rod support mounts 128 includes a threaded bore 129 at its lower extremity for receiving, in threaded engagement therein, the top end of a corresponding WDRC rod. The configuration of the vane assemblies 106 and 126 is described more specifically in relation to an illustrative, or exemplary, vane assembly 130 shown in FIGS. 7a, 7b and 7c in top plan, side elevation, and cross-sectional views, respectively, the latter taken along the lines 7c-7c in FIG. 7b. The vane assembly 130 is directly representative of either of the vane assemblies 106 and 126 in FIGS. 3 through 6. The vane assembly 130 includes first and second planar vane elements 132 and 134, the latter interconnecting the radially inner and outer rod support mounts 138, and the former connecting the inner rod support mount 138 to the hub of the associated spider, for example, the hub 102 of FIGS. 3 and 4 and the hub 122 of FIGS. 5 and 6. The first planar vane element 132 furthermore is machined to include on its radially inward and radially outward longitudinal edges, respectively, flanges 133 and 133' of reduced thickness and upper and lower stepped portions 135 and 135'. It is to be understood that the designation of a "planar vane element" or "planar vane element portion" as used herein is intended to describe a sheetlike structure, typically of metal, and having parallel, planar major surfaces, substantially as shown. With concurrent reference to FIGS. 7a, 7b, and FIG. 8, the illustrative rod support mount 138 includes a receiving slot 140 for receiving the flange 133 and upper and lower recessed portions 142 for receiving the corresponding upper and lower stepped portions 135 (135') of the flange 132. It is to be understood that the illustrative, second planar vane element 134 includes corresponding flanges on its longitudinal edges for interconnection of the inner and outer rod elements 138. The vane assembly 130 of FIGS. 7a and 7b will be seen to correspond substantially identically to the RCC vane assembly 106 of FIGS. 3 and 4 and the WDRC vane assembly 126 of FIGS. 5 and 6. Accordingly, the vane assemblies 106 and 126 include corresponding first and second planar vane elements 112 and 114 and 123 and 124, respectively, each thereof having longitudinal flanges corresponding to the flange 133 in FIG. 7b for connecting the associated vane assembly 106 and 126 to the respective, RCC spider hub 102 and WDRC spider hub 122. This structure is illustrated for the RCC spider 100 in FIG. 4 by the receiving slot 111 in the hub 102 and the flange 115 received therein, and is illustrated for the WDRC spider 120 in FIG. 6 by the receiving slot 121 in the hub 122 and the flange 131 associated with the first planar vane element 123, received therein. The second type of vane assembly 127 of the WDRC spider 120, as seen in FIG. 6, corresponds substantially to the first vane assembly 126 in that it includes first and second planar vane element portions 123' and 124' which are integrally formed and extend radially from the hub 122, the first portion 123' having a longitudinal flange 131' received in a corresponding receiving slot 121' in the hub 122. The assembly 127 furthermore includes first and second pairs 125A and 125B of third planar vane elements 125 integrally formed with and extending transversely from the first and second vane element portions 123' and 124', the first pair 125A being formed intermediate the portions 123' and 124' and the second pair 125B being formed on the outer longitudinal edge of the second vane element portion 124'. Each of the elements 125 carries a rod support mount 128 on its outer longitudinal edge. It will be understood that the third, or transverse, planar vane elements 125 may include similar flange structures on their outer longitudinal edges for mounting the corresponding rod support mounts 128. In assembling the respective RCC and WDRC spiders 102 and 120, the innermost planar vane elements 112, and 123, 123' preferably are positioned with the respective flanges 115, 131 and 131' inserted into the corresponding receiving slots 111, 121 and 121' of the associated hubs 102 and 120, and then spot welded in place at the upper and lower extremities thereof as indicated by weld beads 116 in FIG. 3 and 119 in FIG. 6. Thereafter, the joints are brazed along the entirety of the lengths thereof. Considering again the densely packed arrays of RCC and WDRC rod clusters as indicated by FIG. 2, it will be appreciated that the planar vane elements 112 and 113 of the RCC spider 100 and the planar vane elements, or integral portions thereof, 123, 124, 123', 124' and 125 of the WDRC spider 120 present, in the composite, a substantial linear length of planar, or sheetlike elements subjected to parallel flow conditions. The core outlet flow can produce a so-called "vortex street" behind the trailing edge of each such vane element. The resulting vortex-induced vibration may be of sufficient magnitude as to produce substantial wear and shortened life. The phenomenon of immersed two-dimensional vibration due to such a vortex street being formed behind the trailing edge of a planar element when subjected to parallel flow conditions has been investigated both experimentally and theoretically. (See: Blevins, R. D., FLOW-INDUCED VIBRATION, Van Nostrand Reinhold Co., 1977, page 18; R. Brepson et al., "Vibrations Induced by Von Karman Vortex Trail in Guide Vane Bends," FLOW-INDUCED STRUCTURAL VIBRATIONS, published by Symposium Karlsruhe (Germany), Aug. 14-16, 1972 and edited by Eduard Naudascher, published by Springer-Verlag, 1974. See also, Tebes, G. H., et al. "Hydroelastic Vibrations of Flat Plates Related to Trailing Edge Geometry," Transactions of the ASME, JOURNAL OF BASIC ENGINEERING, Dec., 1961. For a vane element (e.g., any of the vane elements 112, 114 or 123-125) of approximately 5" in height and 0.32" in thickness, under the flow conditions developed in normal operation of a reactor of the type herein described, the shedding frequency of a vane may be computed as follows: ##EQU1## where f.sub.s =Vortex shedding frequency [Hz.] S=Strouhal number PA1 U=Flow velocity past the vane [inch/sec.] PA1 D=Characteristic length, vane thickness [inch] PA1 U=Flow velocity past the vane [inch/sec.] PA1 .rho.=Fluid density, 6.11E-5 [lbf-sec.sup.2 /inch.sup.4 ] PA1 .mu.=Fluid viscosity, 1.14E-8 [lbf-sec/inch.sup.2 ] PA1 D=Characteristic length, vane thickness [inch] The Strouhal number may be dependent upon the volume of the Reynolds number (Re). The Re may be calculated as follows. ##EQU2## where Re=Reynolds number Thus the Reynolds number is: EQU Re=6.38 E 5 A reasonably applicable Strouhal number may be extracted from Blevins, as: EQU S.apprxeq.0.20 From this, the calculated expected shedding frequency at operating conditions is: ##EQU3## The shedding frequency as thus computed (i.e., f.sub.s =240 Hz) is quite high, compared to the lowest natural frequencies of the surrounding structural components--typically f.sub.n <100 Hz. It thus has been recognized that the primary vortex shedding function passes through the structural frequency domain of these structural components during the transition in operation of the reactor from a down condition, in which zero or low flow exists, to a full flow condition as exists in normal operation. This is contrary to the normal, desired state, which is to have the vortex shedding frequency lower than 0.8 times the lowest natural resonant frequency of the structure. Due to the variations in operating conditions, and the associated different levels of flow velocity, the potential exists that the shedding frequency (f.sub.s) may coincide with one of the structural natural frequencies (f.sub.n). It therefore is desirable to decrease the magnitude of the shedding forcing functions on the spider by an appropriate trailing edge configuration, to mitigate any such forced response. Whereas the foregoing references indicate that a number of different trailing edge configurations of planar sheets disposed in parallel flow conditions are available for decreasing the magnitude of the shedding forcing functions on such structures, the theoretical analyses do not take into account the stress conditions to which the spiders are subjected in the environment of a pressure vessel of a reactor system. Particularly, as before noted, the spiders must not only sustain substantial static weight, but must be capable of withstanding additional kinetic forces both in relation to the height adjustment operations, particularly in view of the need for assured, rapid translational movement of the RCC rod clusters when rapid shutdown of a reactor is required, and due to flow induced forces. These design conditions must also be achieved in a limited axial space envelope. Conventional vane element designs, taking into account general hydrostatic flow conditions, have been based on the belief that a trailing edge configuration affording a gradual transition from the parallel planar surfaces serves to improve flow characteristics (e.g., trailing edge cross-sectional configurations ranging from semicircular to more gradually tapered forms). In fact, it has been determined that the tapered or curved surfaces extend the area of flow separation and expand the surface area subjected to the turbulent vortex which forms in the flow as it passes beyond the vane element. Moreover, tapered or entrant trailing edge configurations which reduce the flow separation problem have a reduced amount of structural material in the cross-section of the trailing edge--weakening the vane for a given height and thickness or, conversely, requiring that the longitudinal dimension of the vane element (i.e., the axial height) being increased to afford sufficient structural strength. Weakening of the vane elements is not acceptable, and the alternative of increasing height is not practical in view of the corresponding increase in height of the inner barrel assembly which would be required to accommodate the increased vane height in view of the significant concomitant increase in the cost of the vessel which would result. Contrary to the standard semicircular cross-section trailing edge designs of prior art vane elements, and in accordance with the present invention, it has been determined that a square cross-sectional trailing edge configuration of the vane elements of the rod supporting spiders is near optimum, taking into account vortex in the flow and shedding frequency considerations, along with the required structural strength of the vane elements and the associate spiders and the restrictive allowable space envelope. The significant and determinative factors are to mitigate the shedding function so as to reduce the vibratory response of the structure, while maintaining maximum strength of the vane elements of a given size--and to achieve these results in a structure which is easy to manufacture, in the interests of mitigating costs. The square, or substantially square, cross-sectional configuration of the trailing edge has been determined to meet these design and operational criteria, and is deemed surprising and unexpected, as a departure from conventional designs. Moreover, the square cross-sectional trailing edge configuration furthermore contributes to ease, and thus lower costs, of manufacture of the vane elements--as contrasted even to the conventional semicircular and/or other tapered cross-sectional trailing edge configurations heretofore employed. Accordingly, the vane elements 132 and 134 of the representative assembly 130 of FIGS. 7A to 7C have square cross-sectional trailing edges 132b and 134b, respectively, while, for purposes of convenience in the foregoing discussion and illustrations of the figures, retaining conventional semicircular leading edges 132a and 134a, respectively. Correspondingly, the vane elements 112, 112', and 114, 114', 123, 123', 124, 124', and 125 of FIGS. 5 and 6 have respective, square cross-sectional trailing edges 112b, 112b', 114b, 114b', 123b, 123b', 124b and 124b', and 125b, and semicircular leading edges 112a, 112a', 114a, 114a', 123a, 123a', 124a, 124a', and 125a. It is to be understood, however, that in accordance with a further feature of the present invention, the semicircular leading edges instead should be modified in accordance with the teachings hereinafter and particularly to have non-symmetrical cross-sectional configurations, such as those of FIGS. 13a through 13d or variations thereof, as now more fully explained, for avoiding the switching or oscillatory loadings to which prior art spider vanes are subjected as a result of flow-induced effects. Particularly, FIG. 9 illustrates in partial cross-section, a segment of a vane 134 as in FIG. 7c having a leading edge 134a of semicircular cross-section. The semi-circular configuration suggests itself as being nearly the obvious choice in the environment of the parallel axial flow F to which the vane 134 is subjected, the flow dividing equally about the vane 134 with respect to the plane of symmetry PL/SYM which intersects the semicircular leading edge 134a at a flow stagnation line ST/LN. The configuration thus, at least under ideal conditions, results in no net lateral loading on the vane 134--a seemingly obvious, desirable feature. It will be understood, of course, that the flow stagnation line ST/LN appears as only a single point and the plane of symmetry PL/SYM appears as a line, in the two dimensional illustration of FIG. 9. In accordance with the present invention, the apparent desirability of providing a symmetrical cross-sectional configuration for the leading edge of a spider vane, be it of semicircular cross-section as in FIG. 9 or another, is in fact undesirable. This result is explained with reference to FIGS. 10, 11 and 12. In FIG. 10, there is shown in a broken-away and partially hidden illustration, a perspective view of a section of the RCC rod guide 28 (see FIG. 1) which accommodates an RCC rod cluster and its associated spider 100 (see FIGS. 3 and 4), taken in the section intermediate the upper and lower mounting means 36 and 37 thereof. Within the sidewall of the RCC rod guide 28, at spaced elevations, there are disposed horizontally oriented support plates 150 having an outer peripheral configuration corresponding to the interior surface of the side wall of the RCC rod guide 28. The support plate 150 includes an interior opening 152 for accommodating axial movement therethrough of a cylindrical rod support mount 108 and its associated rod, and a slotted opening, or channel, 154 for accommodating a corresponding vane section, e.g., vane 134 (FIGS. 7a, 7b and 7c) of the associated RCC spider 100. As will be appreciated, the RCC spider 100 temporarily resides within each of the support plates 150 during the required vertical movement thereof for the normal operational control of the reactor power output. The broken-away vertical cross-sectional views of FIGS. 11 and 12 illustrate the condition of the vane 134 at successive stages of its vertical movement as it passes through the slot 154 of an associated support plate 150. As shown in FIG. 11, the normal parallel axial flow which is symmetrically distributed when the vane 134 is in free space (i.e., not within a support plate 150) and as shown in FIG. 9, is altered significantly when the vane 134 is within the slot 154 in a support plate 150. Specifically, the presence of the vane 134 within the slot 154 creates a significant flow restriction within the normally open, or free area of the slot 154 in the support plate 150. The impinging flow F.sub.I nevertheless must be maintained, with the result that a much higher velocity flow occurs through the now constricted slot 154 before emerging as the outlet flow F.sub.O. At a small range of the elevational locations of the vane 134, the flow restriction produces vibration of the vane 134 and of its associated spider. The effect is believed to be most pronounced when the leading edge 134a of the vane 134 is within the slot 154 of the support plate 150, as illustrated in FIG. 12. As shown therein, as the flow F.sub.I enters the entrance of slot 154, it is confronted by the leading edge 134a of the vane 134. Due to the symmetrical configuration of the leading edge 14a (i.e., semicircular or other), the flow pattern around the leading edge and emerging as the outlet flow F.sub.O may switch from one side of the vane to the other, and thus relatively to the plane of symmetry PL/SYM. It is believed that the flow switching mechanism occurs in the following manner. Due to the turbulent condition of the flow, as illustrated in F.sub.t in FIG. 12, a greater proportion of the inlet flow F.sub.I will be directed to one side of the vane 134, the flow rate gradually building, or increasing, on that side and thereby initially increasing the lateral loading (i.e., in a direction perpendicular to the plane of symmetry PL/SYM) and thereby urging the vane away from the corresponding side wall of the slot 154 and increasing the clearance therethrough, concomitantly increasing the total flow through that side. The increased velocity of the flow through that more opened side, however, produces a decrease in the corresponding pressure on that side of the vane; at the same time, the opposite side of the vane, i.e., that side in which the flow in more significantly constricted or blocked, starts to develop a higher static pressure. The result is that the vane then is pushed laterally towards the opposite side of the slot where the flow rate is higher. Thereafter, the action repeats. Accordingly, there is produced a switching or oscillatory lateral loading on the vane 134 which correspondingly is transmitted to the spider and its associated hub as well as to the control rods supported by the spider and the drive system for the spiders. The resulting structural vibration clearly is potentially detrimental to the structural integrity of both the directly affected components and the associated components. In accordance with the present invention, it has been recognized that a major factor in the initialization of the switching, or oscillatory loading phenomenon is the symmetrical cross-section of the vane leading edge. As before noted, this symmetry enables the static forces to build up on the side of the vane for which the corresponding flow has been reduced, because the most leading line, or edge, ST/LN (i.e., the flow stagnation line) is at the geometric plane of symmetry PL/SYM of the vane 134, and the flow F.sub.I encounters a significant frontal area on that side of the vane. The present invention thus provides for off-setting the flow stagnation line of the vane leading edge away from the plane of symmetry PL/SYM. FIGS. 13A through 13d illustrate exemplary such cross-sectional configurations, in each of which the static flow line ST/LN is shifted away from the plane of symmetry PL/SYM of the vane, as a geometric whole (i.e., relative to its major planar surfaces). More particularly, vane 134A of FIG. 13A has a leading edge cross-section of a non-symmetrical, convex configuration. The leading edge cross-sectional configuration of vane 134B of FIG. 13B defines a single acute angle with respect to one of the major planar surfaces thereof, i.e., the left major planar surface as illustrated in FIG. 13B, in which the flow stagnation line ST/LN is displaced a maximum distance from the plane of symmetry PL/SYM. The leading edge cross-sectional configuration of the vane element 134C of FIG. 13C is convex, as in FIG. 13A, but is defined by a double acute angle relative to the respective major planar surfaces thereby to offset the flow stagnation line ST/LN from the plane of symmetry PL/SYM. Finally, the leading edge cross-sectional configuration of the vane element 134D of FIG. 13D defines a truncated acute angle with respect to one of the major planar surfaces, i.e., the right surface as shown in FIG. 13D; the flow stagnation line ST/LN again is offset from the plane of symmetry PL/SYM, but to a lesser degree than in FIG. 13B. As is apparent from FIGS. 13A through 13D, the extent of offset of the flow stagnation line ST/LN from the plane of symmetry PL/SYM may be adjusted by the configuration of the leading edge cross-section, to the extent desired. Any of the configurations of FIGS. 13A through 13D or variations thereof, which meet the aforestated criterion, when adapted as the leading edge geometry of a spider vane, will serve to mitigate the lateral vibratory loading on the vane and the resultant switching, or oscillatory, loadings applied thereto and the resulting vibration. With reference to the planar views of the RCC spider 100 in FIG. 3 and the WDRC spider 120 in FIG. 5, it will be appreciated that the vanes are symmetrically disposed in generally diametric relationship about the respective central hubs 102 and 122. For ease of reference, the following discussion is directed to the RCC configuration of FIG. 3, but it will be understood to be equally applicable to the WDRC spider configuration of FIG. 5. A non-symmetrical vane configuration, illustratively any of FIGS. 13A through 13D, may be afforded on each of the four vanes of the RCC spider 106 to produce a net torque in a given direction, e.g., counter-clockwise, on the drive rod connected to the spider; as a result, all similarly situated planar surfaces of the spider vanes would be urged against the corresponding, contiguous side wall of the slot 154 in the support plate 150 as those elements are illustrated in FIGS. 10 to 12. Alternatively, the offsets of the non-symmetrical leading edge configurations of successive pairs of angularly displaced vane elements, relative to the respective planes of symmetry, may be oppositely directed, progressing about the central hub 102, so as to produce laterally diagonal loading on the central hub of the spider. The non-symmetrical configuration of the spider vane leading edges, in any such arrangement, serves to eliminate the switching or oscillatory movement of the vanes and thus overcomes the resulting vibratory loading and the related, detrimental effects which are produced by the conventional, symmetrical leading edge configuration of spider vanes. The particular configuration selected is best determined from consideration of environmental factors within a given pressure vessel. For example, the configuration of FIG. 13B is optimum with regard to producing non-symmetrical lateral loading but is less desirable from the standpoint of the bending strength of the vane leading edge. The configurations of FIGS. 13A and 13D afford greater strength than that of FIG. 13B, but, due to the reduced off-set, correspondingly have a reduced capability of eliminating the flow switching problem. The configuration of FIG. 13C has flow-switching and strength characteristics intermediate those of FIGS. 13A and 13B. The configuration of FIG. 13D is easiest to manufacture whereas those of FIGS. 13B and 13C and somewhat more difficult, but easier than that of FIG. 13A. All thereof share the common characteristic that they comprise improvements over the standard, semicircular cross-sectional configuration of conventional spider vanes. While modifications and adaptations of the present invention will be apparent to those of skill in the art, including slight variances from the generally square cross-sectional configuration of the trailing edge of the vane elements employed in spiders as herein disclosed, it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of the present invention.
	description	The present invention relates to an electron beam sterilizer for sterilizing a vessel, which is being conveyed, by being irradiated with an electron beam and, more particularly, to an electron beam sterilizer capable of sterilizing an entire peripheral surface of a vessel during the passing of the vessel in front of an irradiation window formed into an electron beam irradiation device. There have been known electron beam sterilizers, having various structures, for sterilizing vessels by irradiating the vessels with an electron beam generated from an electron beam irradiation device during the conveyance of the vessels being held by vessel holding means (for example, refer to Patent Document 1 to Patent Document 4). A sterilizer for sterilizing a vessel with an electron beam disclosed in the above Patent Document 1 is provided with an electron beam generation section, a sterilization processing chamber including an electron beam irradiation window of the electron beam generation section, vessel conveying means for conveying the vessel to be processed in a vertical orientation from an inlet portion of the sterilization processing chamber to an outlet portion thereof, and rotation imparting means for imparting rotation to the vessel during a time at which the vessel has a position just before reaching the electron beam irradiation window of the electron beam generation section to a time at which the vessel has completely passed in front of the irradiation window. The rotation imparting means is composed of a lateral pair of endless belts disposed to press side surfaces of a neck portion of the vessel from both sides. One of the endless belts has a rotating speed higher than that of the other one of the endless belt, and based on such a difference in the rotating speeds of both the endless belts, the rotation is imparted to the vessel during the conveyance thereof. An electron beam sterilizer disclosed in the Patent Document 2 includes conveying means having tow wires, by which a mouth portion of the vessel is clamped and the vessel is conveyed in a vertically suspended state, and when the vessel passes an irradiation space of an irradiation chamber, an electron beam irradiating means irradiates the vessel with the electron beam from side surfaces of the vessel. In the electron beam irradiating time, rotating means operates two wires so as to rotate the vessel around a central axis thereof by at least 25 degrees. An electron beam sterilizer for sterilizing a plastic hollow vessel disclosed in the Patent Document 3 is provided with an orbit (circulation) mechanism for vacuum-sucking and then fixing a bottom portion of a plastic hollow vessel supplied from a supply mechanism and circulating the fixed plastic hollow vessel, and an electron beam irradiation mechanism for irradiating the circulating plastic hollow vessel with the electron beam, and an interval maintaining mechanism capable of maintaining constant an interval between the electron beam irradiation mechanism and the plastic hollow vessel. A vessel sterilizer disclosed in the Patent Document 4 is provided with a plurality of vessel holding means arranged around a rotary body in a circumferential direction thereof at an equal interval, and each of the vessel holding means has two holding portions so as to hold two vessels side by side in the vertical direction. The rotary body is formed with a conveying path in which an inverting area and a standing conveying area are formed. Inverting means for rotating the vessel holding means around a tangential axial direction as a center of rotation is disposed in the position inverting area, and an electron beam irradiation device is disposed in the standing conveying area. The vessel held by the vessel holding portion of the vessel holding means is irradiated with the electron beam at the electron beam irradiating position in the standing conveying area, and thereafter, the vessel is inverted in the inverting area in the vertical orientation thereof, at which one surface of the vessel opposite to the surface which has been irradiated with the electron beam is directed to the electron beam irradiation device side. In this orientation, the vessel again receives the electron beam irradiation, thereby completely sterilizing the entire surface of the vessel. Patent Document 1: Japanese Patent Laid-open Publication No. HEI 11-1212 Patent Document 2: Japanese Patent Laid-open Publication No. HEI 11-19190 Patent Document 3: Japanese Patent Laid-open Publication No. HEI 11-137645 Patent Document 4: Japanese Patent Laid-open Publication No. 2007-29709 With the structure of the Patent Document 1, there is a fear that an interval between adjacent vessels in conveyance thereof may become unstable and a travelling speed of the vessel may also be unstable, resulting in scattering of the irradiation conditions, and moreover, the structure of the Patent Document 1 is unsuitable for speed-up requirement. Furthermore, with the structure of the Patent Document 2, there also is a fear that an interval between adjacent vessels in the conveyance thereof may become unstable and a travelling speed of the vessel may also be unstable, resulting in the scattering of the irradiation conditions, and moreover, the structure of the Patent Document 2 is unsuitable when requiring an operation speed-up. With the structure of the Patent Document 3, since the bottom surface of the vessel is vacuum-sucked, this bottom portion is not sterilized and thus is inconvenient. With the structure of the Patent Document 4, it is required to provide a number of grippers (vessel holding means), which requires a great number of parts or members to be disposed, thus providing a problem and, moreover, since two vessels are conveyed side by side in a vertical orientation, it is required for the device to have an increased height, resulting in an increase in its entire size. The invention is an electron beam sterilizer for sterilizing a bottle made of a resin by being irradiated with an electron beam generated from an electron beam irradiation means during the conveyance of the bottle while being held by a bottle holding means, wherein the bottle holding means is provided with a rotation shaft having an axis extending in the same direction as a central axis of the held resin bottle and a gripper mounted to one end of the rotation shaft and adapted to hold the resin bottle by clamping a neck portion of the resin bottle from both sides thereof, moving means that circularly moves the rotation shaft of the bottle holding means, and rotating means that rotates the rotation shaft around the axis thereof are provided, and the resin bottle held by the gripper is rotated by a predetermined angle by rotating the rotation shaft in front of the electron beam irradiation means that irradiates the resin bottle with the electron beam and, thereafter, the resin bottle is inverted in position by the predetermined angle to thereby release the resin bottle from the gripper. The invention is also characterized in that there are arranged bottle supply means that pushes the resin bottle to the moving gripper from a direction substantially perpendicular to the rotation shaft and bottle discharge means that pulls out the resin bottle from the moving gripper in a direction substantially perpendicular to the rotation shaft, and the electron beam irradiation means is arranged along a bottle conveying path extending from a supply position at which the resin bottle is pushed into the gripper by the bottle supply means to a discharge position at which the resin bottle is pulled out by the bottle discharge means. Furthermore, the invention is characterized in that the resin bottle is rotated by an angle more than 90 degrees by the rotation of the rotation shaft. Further, the invention is characterized in that the moving means is provided with a rotating body supporting the rotation shafts at an equal interval in a circumferential direction of the rotating body, the rotation shafts being circularly moved by rotating the rotating body, and the electron beam irradiation means is provided with a plurality of irradiation windows through which the electron beam is emitted, the irradiation windows being arranged at different angles respectively along the conveying path of the rotating body. In the electron beam sterilizer of the present invention, the rotation shafts to which grippers holding the bottles are circularly moved, rotated by a predetermined angle in front of the irradiation window of the electron beam irradiation means, and thereafter, reversely rotated (inverted in position) to thereby discharge the bottles, so that the bottles can be stably conveyed, and during the conveyance, the entire outer surface of the vessel can be completely sterilized. Moreover, the structure of the sterilizer can be simplified and made compact. 2 resin bottle 18 electron beam irradiating means (electron beam irradiation device) 19 irradiation window 28 bottle holding means 30 moving means (rotating body) 38 rotation shaft 46 rotating means (pinion gear) 54 rotating means (segment gear) 66 rotating means (disc-shaped cam) 70 gripper (neck gripper) Bottle holding means is provided with a rotation shaft and a gripper mounted to one end of the rotation shaft. There are also provided moving means for circularly moving the rotation shaft of the bottle holding means and rotating means for rotating the rotation shaft around a central axis thereof. The structure is made such that the axis of the rotation shaft is positioned on a central axis of a resin-made bottle held by a gripper in a state that a neck portion of the resin bottle is clamped from both sides thereof, the resin bottle held by the gripper is then moved by the moving means, the rotation shaft is rotated by the rotating means to thereby rotate the resin bottle by a predetermined angle and, after the rotation of the predetermined angle, the resin bottle is released from the gripper. According to such a structure, the device can be simplified in structure and, in addition, the entire surface of the resin bottle can be completely sterilized, thus achieving the object of the present invention. Hereunder, the present invention will be explained with reference to an embodiment shown in the accompanying drawings. A vessel 2 sterilized by an electron beam sterilizer according to this embodiment and, thereafter, filled with an inner content such as a liquid in a subsequent processing is a bottle made of a resin such as a PET bottle (see FIG. 2). The resin bottles 2 are each supported at a lower surface side of a flange portion 2a formed at a neck portion by a support rail of an air conveyer 4 and continuously conveyed from a rear side by blowing air by a propelling blower. The conveyed resin bottles 2 enter an introduction chamber 6 and, thereafter, are separated by an infeed screw 8 at a predetermined interval and then transferred to a rotary wheel 10 in the introduction chamber 6. A plurality of vessel holding means (not shown) are provided for the rotary wheel 10 in the introduction chamber 6 at predetermined intervals in the circumferential direction thereof, and the resin bottles 2 transferred through the infeed screw 8 are received and then rotated and conveyed. An opening (not shown) through which the resin bottle 2 can pass is formed in a wall surface 6a of the chamber 6 into which the resin bottle 2 is conveyed. Subsequent to the introduction chamber 6, there is located a sterilization box (sterilization chamber) 12, composed of a lead wall section, for shielding the electron beam or X-ray (braking X-ray) from leaking outside when sterilizing the resin bottle 2 by the electron beam irradiation. An interior of the sterilization box 12 is sectioned into: a supply chamber 16 on the inlet side at which the supply wheel 14 is arranged; a main chamber 22 provided with a rotary-type vessel conveying device 20 in which the resin bottle 2 received from the supply wheel 14 is conveyed and is moved in front of an electron beam irradiation window 19 of the electron beam irradiation device (irradiator) mentioned hereinafter; and a discharge chamber 26 in which a discharge wheel 24 receiving the resin bottle 2 sterilized by the irradiation with the electron beam from the electron beam irradiation device and then discharging the resin bottle 2 is disposed. An opening, not shown, enabling the resin bottle 2 to pass therethrough is formed at a portion at which the resin bottle 2 is transferred to the supply wheel 14 in the supply chamber 16 from the rotary wheel 10 of the introduction chamber 6. The supply wheel 14 receiving the resin bottle 2 from the rotary wheel 10 in the introduction chamber 6 transfers the resin bottle 2 to the vessel conveying device 20 in the main chamber 22. An opening, not shown, is also formed at a partition wall section 16a sectioning the supply chamber 16 and the main chamber 22 for enabling the resin bottle 2 to pass therethrough. The vessel conveying device 20 disposed in the main chamber 22 is provided with a plurality of bottle holding means 28 (refer to FIGS. 2 to 5 explained hereinafter) disposed in the circumferential direction of an outer peripheral portion of the rotating body 30 at equal intervals, respectively. Further, a plurality of vessel holding means 32 are provided, at equal intervals in the circumferential direction, for the supply wheel 14 for receiving the resin bottle 2 from the vessel holding means of the rotary wheel 10 disposed in the introduction chamber 6 and transferring the resin bottle 2 to the bottle holding means 32 of the vessel conveying device 20. This vessel holding means 32 constitutes bottle supply means. Electron beam irradiation means (electron beam irradiation device) 18 is disposed adjacent to the sterilization box 12 made of lead. This electron beam irradiation device 18 is provided with a vacuum chamber (acceleration chamber) 18a that irradiates the resin bottle 2 with the electron beam and rests on a mount table 21 to be movable on rails 21a. The electron beam irradiation device 18 serves, as is well known, to heat filaments in a vacuum condition in the vacuum chamber 18a to thereby generate thermal electrons, which are then accelerated by a high voltage into a high speed electron beam. The high speed electron beam is taken out into the atmosphere through a metallic window foil, such as Ti, attached to the irradiation window formed to the irradiation section, and an object (article) to be irradiated (resin bottle 2 in this embodiment) positioned within the irradiation area C in front of the irradiation widow is irradiated with the electron beam to be thereby subjected to the sterilization processing. The electron beam irradiation device 18 of this embodiment has four irradiation windows 19 (19A, 19B, 19C, 19D) continuously formed in the irradiation section. These four irradiation windows 19A, 19B, 19C 19D are arranged on an outer peripheral side of the conveying path of the vessel conveying device 20. In this embodiment, since the conveying path of the vessel conveying device 20 has a circular shape, these four irradiation windows 19A, 19B, 19C 19D are arranged two by two (19A, 19B, and 19C, 19D) with different angles so as to provide an equal distance to the circular conveying path. Further, a beam collector 23 is disposed on a side opposite to the irradiation windows 19 of the electron beam irradiation device 18 with the vessel conveying path being interposed. Since the electron beam irradiation range can be increased along the vessel conveying path by increasing the number of the irradiation windows, the number of the irradiation widows may be increased as occasion demands without limiting to four as in this embodiment. The arrangement thereof may be also changed without necessarily differing the angles, and they may be arranged linearly. The electron beam irradiation area C is, as mentioned above, on the front side of the irradiation windows 19 (19A, 19B, 19C, 19D) of the electron beam irradiation device 18. A discharge chamber 26 is formed, by being defined by the wall surface 26a and the ceiling surface 26b, from a position near a position through which the resin bottle 2 conveyed by the vessel conveying device 20 passes the electron beam irradiation area C. The resin bottle 2 subjected to the electron beam irradiation in the electron beam irradiation area C is transferred to the discharge wheel 24 disposed in the discharge chamber 26 from the bottle holding means 28 of the vessel conveying device 20. The discharge wheel 24 is provided with a plurality of vessel holding means 25 arranged at an equal interval along the circumferential direction, and the resin bottle 2 held by the bottle holding means 28 of the vessel conveying device 20 is taken out and then discharged by the vessel holding means 25. This vessel holding means 25 constitutes the bottle discharge means. The structure of the bottle holding means 28 provided for the rotary-type vessel conveying device 20 in the main chamber 22 will be explained hereunder with reference to FIGS. 2 to 5. The plural bottle holding means 28 are arranged at an equal interval along the circumferential direction of the outer peripheral portion of the circular rotary plate 34 constituting the rotating body 30. A mount plate 36 is fixed to the outer peripheral portion of the circular rotary plate 34, a plurality of rotation shafts 38 are supported at the outer peripheral end of this mount plate 36 to be rotatable through ball bearings 40 at an equal interval along the circumferential direction. The rotary plate 34 and the mount plate 36 are formed to be rotatable in a horizontal plane, and the rotation shafts 38 penetrating the mount plate 36 in the supported manner are directed to the perpendicular direction. The resin bottles 2 are held with their central axes Ol being directed perpendicularly, and the rotation shafts 38 have axes 02 of the same direction as the central axes 01 of the resin bottles 2. An annular intermediate plate 42 is disposed above the mount plate 36, and each of the rotation shafts 38 extends upward such that the upper portion thereof penetrates the intermediate plate 42. The rotation shaft 38 is supported to be rotatable via a ball bearing 44 with respect to the intermediate plate 42. A pinion gear 46 is mounted to an upper end portion of the rotation shaft 38 extending upward over the intermediate plate 42. On the inner side in the radial direction of the rotation shaft 38, segment gear support shafts 52 are supported to the mount plate 36 fixed to the outer peripheral portion of the rotary plate 36 and to the intermediate plate 42 disposed above the mount plate 36 to be rotatable through bearings 48 and 50, respectively. Segment gears 54 are fixed to the upper ends of the segment gear support shafts 52. The upper end portion of each of the segment gear support shafts 52 is coupled to substantially the central portion of the segment gear 54, and an engaging tooth 54a (refer to FIG. 3) is meshed with a pinion gear 46 mounted on the rotation shaft 38. Further, a pin 56 directed vertically is attached to an end portion side, of the segment gear 54, directed radially inward of the rotating body 30. A spring 60 is coupled between the lower end of this vertical pin 56 and the upper end of a stand pin 58 disposed most inward side of the intermediate plate 42 so as to always pull the radially inward end of the segment gear 54. A cam follower 62 is mounted to the upper end portion of the vertical pin 56 of the segment gear 54. Incidentally, above the rotary plate 34, a stationary disc 64 is disposed, and a disc-shaped cam 66 is mounted to an outer peripheral portion of this stationary disc 64. The cam follower 62 pulled by the spring 60 abuts against an outer peripheral cam surface of the disc-shaped cam 66. Although a portion of the disc-shaped cam 66 is shown in FIG. 3, the disc-shaped cam 66 is formed so as to move, in the irradiation area C positioned in front of the irradiation window 19 of the electron beam irradiation device 18, to a large diameter portion 66c from a small diameter portion 66a through a transfer portion 66b. According to this transferring, the segment gear 54 is rotated in angles from the state that one end (an end positioned on a lower side in FIG. 3) of the engaging tooth 54a is meshed with the pinion gear 54 to the state that the other end (an end positioned on an upper side in FIG. 3) is meshed therewith (refer to the segment gears 54A, 54B, 54C in FIG. 3). According to the rotation of the segment gear 54, the pinion gear 46 is rotated by substantially 180 degrees. Further, this rotation of the pinion gear 46 (rotation of the rotation supporting shaft 38) is not necessarily 180 degrees, and the rotation by at least more than 90 degrees may be accepted. Furthermore, after the rotation of the segment gear 54 and the pinion gear 46 in front of the irradiation window 19 of the electron beam irradiation device 18, and during a time when the resin bottle 2 reaches the discharge position at which the resin bottle 2 is transferred from the vessel conveying device 20 to the discharge wheel 24, a cam curve described by the disc-shaped cam 66 varies to the small diameter portion 66a from the large diameter portion 66c in a state reverse to the state in the electron beam irradiation area C. According to the shape of this portion of the cam 66, the segment gear 54 rotates reversely by the same angles as the rotating angle at the electron beam irradiation time. Thereafter, the cam curve of the disc-shaped cam 66 accords with the small diameter portion 66a during the movement from the vessel discharge position A to the front portion of the irradiation window 19 via the vessel supply position B. The rotary plate 34, the mount plate 36 disposed on the outer peripheral portion thereof, the intermediate plate 42 disposed above the mount plate 36, the segment gear 54, the pinion gear 46 on the rotation shaft 38, the stationary plate 64 on the stationary side, and the disc-shaped cam 66, which constitute the rotating body 30, are covered by the cover 68 including the peripheral wall 68a and the ceiling wall 68b. Further, the rotating body 30 constitutes moving means for circularly moving the rotation shaft 38, and the pinion gear 46, the segment gear 54, the cam follower 62 and the disc-shaped cam 66 constitute the rotating means of the rotation shaft 38. Next, a neck gripper 70 mounted at the lower end of each of the rotation shafts 38 supported in the vertical orientation will be explained with reference to FIG. 2 and FIGS. 4 and 5. Each of the neck grippers 70 includes two plate springs 74 fixed, perpendicularly in parallel with each other, to both side surfaces of a mount member 72 fixed to the lower end face of each of the rotation shafts 38. Support members 76 are fixed to the mount member 72 outside the plate springs 74 to be parallel therewith. Coil springs 78 are interposed between the plate springs 74 and the front end portions of the support members 76 so as to always urge both the front end portions of the plate springs 74 in a direction approaching each other, and in a usual state, both the front end portions stop in abutment against stoppers (head portions 80a of bolt 80 inserted between the plate springs 74 and the support members 76, respectively,) so as to keep substantially the parallel state. Furthermore, when the front end portions of the plate springs 74 are pushed from their inner surface sides, they are moved in the direction widening from each other against the urging force of the coil springs 78. Both the plate springs 74 and the support members 76 are disposed to be shifted in positions radially inward of the rotating body 30 with respect to the axial line 02 of the rotation shaft 38. Gripping portions 82 are provided at the lower end portions of the plate springs 74, respectively, in a projecting manner so as to hold the resin bottles 2 on extension lines of the rotation shafts 38, the gripping portions 82 are opposed to each other, and the opposing portions thereof are formed into vertically two plate shapes having front ends each having a recessed surface 82a having a circular shape substantially corresponding to the outer diameter of the neck portion 2b of the resin bottle 2. These gripping portions 82 are circularly moved by the rotating body 30, and the front end portions 82b are directed radially outward at the vessel supply position B to the vessel conveying device 20 and the vessel discharge portion A. At the vessel supply position B, the neck portion 2b of the resin bottle 2 is pushed into the direction perpendicular to the rotation shaft 38 and then held thereby. On the other hand, at the vessel discharge portion A, the resin bottle 2 held by both the gripping portions 82 is pulled out toward the direction of the front end portions 82b of the gripping portions 82 approximately perpendicular to the rotation shaft 38 (radially outward direction of the rotating body 30). An intermediate chamber 84 is disposed in adjacent to the discharge chamber 26 positioned on the most downstream side within the sterilization box 12. A chamber (not shown) in which a rinser, a filler, etc., are arranged is disposed on the downstream side of the intermediate chamber 84. Within the intermediate chamber 84, a rotary wheel (neck wheel) 86 provided with vessel holding means (not shown) is disposed, and this neck wheel 86 receives the resin bottle 2 from the discharge wheel 24 in the discharge chamber 26, and rotates and conveys the bottle 2, which is thereafter transferred to the supply wheel in the chamber in which the rinser and the filler are disposed. Further, a position denoted by the letter D in FIG. 1 is a transfer position at which the resin bottle 2 is transferred from the discharge wheel 24 in the discharge chamber 26 to the neck wheel 86 of the intermediate chamber 84. The discharge wheel in the discharge chamber 26 also serves as an intermediate reject wheel, and in a case where it is judged by information from a sensor or like that the resin bottle 2 is normally sterilized, the resin bottle 2 received from the vessel conveying device 20 is transferred to the neck wheel 86 of the next intermediate chamber 84 to be subjected to the next processing. However, in a case where it is judged that the resin bottle 2 has not been irradiated with the electron beam or that the sterilization has not been completely performed, the resin bottle 2 is not transferred to the neck wheel 86 of the intermediate chamber 84 and discharged into a reject chamber 88 disposed adjacent to the sterilization box 12. A position denoted by the letter E in FIG. 1 is a reject position. An operation of the electron beam sterilizer of the structures mentioned above will be explained hereunder. Vessels sterilized by this sterilizer and filled with an inner liquid are resin bottles 2, and are conveyed by blowing air by a propelling blower from the rear side of the bottle in a state of being held on the lower surface side of the flange portion 2a formed at the neck portion by support rails (not shown) of the air conveyer 4. The resin bottles 2 conveyed by the air conveyer 4 enter the introduction chamber 6, are separated at a constant interval by the infeed screw 8, and transferred to the vessel holding means of the rotary wheel 10. After the rotation and conveyance by the rotary wheel 10, the resin bottle 2 is transferred to the supply wheel 14 disposed in the supply chamber 16 of the sterilization box 12 made of lead. The resin bottle 2 held by the vessel holding means 32 of the supply wheel 14 is rotated and conveyed, and then transferred to the bottle holding means of the rotary type vessel conveying device disposed within the main chamber 22. The bottle holding means 28 includes the neck gripper 70 mounted to the lower end of each of the rotation shafts 38 arranged perpendicularly, and this neck gripper 70 holds the neck portion 2b formed below the flange portion 2a of the resin bottle 2. The neck gripper 70 has a pair of gripping portions attached to the two plate springs 74, respectively, and the neck portion 2b of the resin bottle 2 is pushed in a space between both the gripping portions 82 from the radially outer side of the rotating body 30. The resin bottle 2 pushed from the front end sides 82b of both the gripping portions 82 is clamped between the recessed portions 82a of both the gripping portions 82 by the spring force of the plate springs 74. The rotating position of the rotation shaft 38 to which the neck gripper 70 is mounted is determined by engaging the pinion gear 46, which is mounted to the upper end of the rotation shaft 38, with the segment gear 54 which is rotatable in accordance with the cam curve of the disc-shaped cam 66. The cam shape of the disc-shaped cam 66 provides the small diameter portion at the supply position B of the vessel conveying device 20, at which the segment gear 54 has the state denoted by reference numeral 54A shown in FIG. 3. The vessel holding means 28 holding the resin bottle 2 is rotated and moved by the rotation of the rotating body 30, and when the vessel holding means 28 enters the electron beam irradiation area C, the electron beam is emitted through the irradiation windows 19 (19A, 19B, 19C, 19D) of the electron beam irradiation device 18, and the resin bottle 2 is irradiated with the electron beam from the radially outward side of the rotating body 30, i.e., the surface side directed to the irradiation window side. Thereafter, the cam shape of the disc-shaped cam 66 is changed from the small diameter portion 66a to the large diameter portion 66c through the moving portion 66b, and by the rotation of the segment gear 54, the pinion gear 46 meshed with this segment gear 54 is rotated to thereby rotate, approximately by 180 degrees, the rotation shaft 38 and the neck gripper 70 provided at the lower end portion thereof. Then, the resin bottle 2 held by the neck gripper 70 is rotated by 180 degrees during the state 2A in FIG. 3 to the state 2C via the state 2B. As mentioned above, during the passing through the electron beam irradiation area C, the resin bottle 2 is rotated approximately by 180 degrees, and the surface of the bottle 2 facing the radially outer side and the surface thereof facing the radially inner side are changed from each other in their positions, so that the entire outer surface of the resin bottle 2 can be completely sterilized. Since the front end portions 82b of the gripping portions 82 holding the resin bottle 2 rotated by 180 degrees during the passing through the electron beam irradiation area C are directed radially inward of the rotating body 30, the front end portions 82b are rotated reversely (inverted in position) by the same angles as that at the electron beam irradiation time before reaching the discharge position A. In this reversely rotating area, the cam curve of the disc-shaped cam 66 varies from the large diameter portion 66c to the small diameter portion 66a through the moving portion 66b in the manner reverse to the electron beam irradiation time, and the segment gear 54 is rotated reversely to thereby rotate the rotation shaft 38 and both the gripping portions 82 and the front end portions 82b of the gripping portions 82 are directed radially outward of the rotating body 30. After the orientation of the neck gripper 70 returns to the state of the vessel supply position Bf the resin bottle 2 is held by the vessel holding means 25 of the discharge wheel 24 disposed in the discharge chamber at the discharging position A and pulled out from the neck gripper 70. Thereafter, the resin bottle 2 is transferred to the vessel holding means of the intermediate wheel 86 at the receiving position D and then conveyed to the rinser or filler for subjecting to the next processing. Further, in this embodiment, although the vessel conveying device 20 is provided with the bottle holding means 28 at the peripheral portion of the rotating body 30, the vessel conveying device 20 is not limited to such a rotary type one and, for example, there is adopted a structure in which the conveying means may be mounted to a chain, for example, stretched around a plurality of sprockets. Further, although there was adopted the structure in which the gripper 70 is mounted to the lower end of the rotation shaft 38 to hold the resin bottle 2 in the vertically normally standing orientation with its mouth portion being directed upward, the gripper 70 may be mounted to the upper end of the rotation shaft 38 to hold the resin bottle 2 in the vertically inverted orientation.
	summary
	description	To be able to design the fuel assembly such that water and steam are separated in an efficient way, it is desirable for the fuel assembly to be so flexible that it may be given different shapes in the axial direction in a simple manner. Such a fuel assembly is shown in international patent document PCT/SE95/01478 publication number WO 96/20483. This fuel assembly comprises a plurality of fuel units stacked one above the other, each one comprising a plurality of fuel rods extending between a top tie plate and a bottom tie plate. The fuel units are surrounded by a common fuel channel with a substantially square cross section. A fuel assembly of this type may given different shapes in the axial direction in a simple manner. FIGS. 2 and 3a-3f show a fuel assembly according to the invention. During operation, the fuel assembly is arranged vertically in the reactor core. FIG. 2 is a vertical section Fxe2x80x94F through the fuel assembly. FIGS. 3a-3f show a number of horizontal sections Axe2x80x94A, Bxe2x80x94B, Cxe2x80x94C, D1xe2x80x94D1, D2xe2x80x94D2, D3xe2x80x94D3 through the fuel assembly. The fuel assembly comprises an upper handle 1, a lower end portion 2 and a plurality of fuel units 3a, 3b, 3c and 3d stacked one above the other. Each fuel unit comprises a plurality of fuel rods 4 arranged between a top tie plate 5 and a bottom tie plate 6. The fuel units are stacked on top of each other in the longitudinal direction of the fuel assembly and they are stacked in such a way that the top tie plate 5 in one fuel unit is facing the bottom tie plate 6 in the next fuel unit in the stack. A fuel rod 4 comprises fuel in the form of a column of uranium pellets 8 arranged in a cladding tube 7. The fuel assembly is enclosed in a fuel channel 9 with a substantially square cross section. In this embodiment, the fuel assembly contains eight fuel units which are each about 0.5 meters high. A fuel unit has 100 fuel rod positions in an orthogonal 10xc3x9710 lattice. A fuel rod position is a position in the lattice and in these it is possible to arrange a fuel assembly, but all the positions in the lattice need not be occupied by fuel rods. The fuel unit is divided into four sub-bundles with 25 fuel rod positions in an orthogonal 5xc3x975 lattice. The lattice in one sub-bundle comprises a fuel rod position in the center of the sub-bundle, and around this an inner square ring is arranged consisting of 8 fuel rod positions. Outside the inner ring there is an outer square ring consisting of 16 fuel rod positions. The fuel rods in the fuel unit have an upper end arranged at the top tie plate and a lower end arranged at the bottom tie plate. A fuel rod belonging to the inner or the outer ring has its lower end arranged in a first fuel rod position and its upper end arranged in a second fuel rod position. The upper and lower ends of the fuel rod are thus arranged in separate fuel rod positions. The first and second fuel rod positions are positioned side-by-side and, in addition, belong to the same ring. There are two positions in the lattice which fulfil both of these conditions. The fuel rods are thus inclined between the bottom tie plate and the top tie plate, and a fuel rod may be inclined in two different directions within the same ring. In a sub-bundle all the fuel rods in the two rings are inclined in the same direction, that is, either clockwise or counterclockwise around the center of the sub-bundle. The purpose of inclining the fuel rods around the center of the sub-bundle is to set the water and the steam, flowing upwards through the fuel assembly, in rotation, thus achieving an eddy with a center in the center of the sub-bundle. The eddy may be directed in the clockwise or counterclockwise direction depending on in which direction the fuel rods in the two rings are inclined. The angle between the longitudinal axis of the fuel assembly and the longitudinal axis of the inclined fuel rods is determined by the distance between the bottom tie plate and the top tie plate and the distance between two fuel rod positions close to each other in the lattice. The fuel assembly comprises four different types of fuel units 3a, 3b, 3c, 3d. The two lowermost fuel units 3a are identical and a horizontal section Axe2x80x94A through these is shown in FIG. 3a. The fuel unit 3a has 100 fuel rods arranged in a 10xc3x9710 lattice, and is divided into four sub-bundles 15a, 15b, 15c, 15d with 25 fuel rods in each sub-bundle. All the fuel rod positions in the lattice are occupied by fuel rods. In the fuel rod position in the center of each sub-bundle, a straight center rod 4a is arranged. The center rod is parallel to the longitudinal axis of the fuel assembly and has the same fuel rod position in both its upper and lower ends. The figure shows by means of arrows in which direction the fuel rods in the inner ring 20a and the outer ring 20b are inclined. In two of the sub-bundles 15a, 15c the fuel rods in the rings are inclined clockwise around the center rod and in the other two sub-bundles 15, 15d the fuel rods in the rings are inclined counterclockwise around the center rod. FIG. 4 shows the fuel unit 3a in a view from the side in a section Exe2x80x94E through the fuel assembly. The figure shows that the fuel rods in the sub-bundle 15a are inclined to the right and that the fuel rods in the sub-bundle 15b are inclined to the left. By inclining the fuel rods in different directions in the different sub-bundles, four eddies are achieved in the fuel assembly during operation of the reactor, two being directed counterclockwise and two being directed clockwise. The sub-bundles which are arranged along the same diagonal have fuel rods which are inclined in the same direction. It is an advantage if some of the eddies are directed counterclockwise and some are directed clockwise, because in that case the rotational effects which arisexe2x80x94both mechanical and thermohydraulicxe2x80x94may counterbalance each other. The following two fuel units 3b in the stack are of the same type and a horizontal section Bxe2x80x94B through these is shown in FIG. 3b. The fuel unit 3b has 96 fuel rods divided into four sub-bundles. Each one of the sub-bundles contains 24 fuel rods arranged in an inner ring 20a and an outer ring 20b. The fuel rod position in the center of the sub-bundle is unoccupied. In this way, an empty volume is formed in the center of the fuel bundle. Otherwise, the fuel unit 3b is arranged in the same way as the fuel unit 3a. The empty volume constitutes the lower part of a vertical steam channel which extends through the six uppermost fuel units in the fuel assembly. In the two lowermost fuel units 3a, no steam channels are needed since there is no steam there, but on the other hand it is an advantage to initiate the eddy formation at this early stage. There are four steam channels 16a, 16b, 16c, 16d in the fuel assembly, one in each sub-bundle. The inclined fuel rods in the sub-bundle achieve an eddy of water and steam around the steam channel. The directions of the eddies are marked with arrows in the steam channel. In these eddies, the water and the steam are separated from each other by throwing the water outwards and, hence, away from the steam channel whereas the steam is pressed against the center of the eddy. Because of the low density of the steam and the low flow resistance in the steam channel, the steam will flow upwards at great speed through the steam channel and disappear out through the top of the fuel assembly. In this way, the percentage by volume of steam in the coolant is reduced. On top of the fuel units 3b in the stack, two fuel units 3c are stacked. A horizontal section Cxe2x80x94C through these is shown in FIG. 3c. The fuel unit 3c has 88 fuel rods and each sub-bundle contains 22 fuel rods. In one sub-bundle, the fuel rod position in the center is unoccupied and, in addition, two positions in the inner ring are unoccupied. Otherwise, the fuel unit 3c is arranged in the same way as the fuel unit 3a. By increasing the number of unoccupied fuel rod positions, the steam channels 16a, 16b, 16c, 16d will have a larger cross-section area in these fuel units compared with the fuel units 3b further down in the fuel assembly. In this way, the steam channel will have an increasing cross-section area towards the top of the fuel assembly and hence an increasing volume, which is necessary since the percentage of steam which is to be transported away increases towards the top of the fuel assembly. At the top of the fuel assembly, two fuel units 3d are stacked on top of each other. A horizontal section D1xe2x80x94D1 through the fuel unit 3d immediately above the bottom tie plate is shown in FIG. 3d. The fuel unit 3d has 80 fuel rods and each sub-bundle contains 20 fuel rods. In one sub-bundle the fuel rod position in the center and four positions in the inner ring are unoccupied. The unoccupied fuel rod positions are those which are closest to the center of the fuel unit. Otherwise, the fuel unit 3d is arranged in the same way as the fuel unit 3a. The steam channels 16a, 16b, 16c, 16d have their largest cross-section area in these two uppermost fuel units. The steam channels have their outlets 21 through holes in the top tie plate in the uppermost fuel unit in the stack. To illustrate how the lattice positions of the fuel rods are displaced between the top tie plate and the bottom tie plate, FIG. 3e shows a horizontal section D2xe2x80x94D2 through the fuel unit 3d on half its height. In FIG. 3f a horizontal section D3xe2x80x94D3 through the fuel unit immediately below the top tie plate is shown. A fuel rod displaces its lattice position one step in the clockwise or the counterclockwise direction within the ring to which it is associated. It is especially shown how the fuel rods 4b, 4c, 4d, 4e in the inner ring are displaced to the next lattice position one step in the counterclockwise direction in the inner ring. The embodiment described so far is based on an orthogonal lattice with top tie plates and bottom tie plates identical as regards lattice positions. However, the invention may very well be applied also if the lattice is irregular and nor do the lattice positions need to be identical in the top tie plates and the bottom tie plates. The fuel rods may also be inclined to differing degrees in the same fuel unit. Such embodiments may be preferable, for example for increasing the distance between fuel rods which change their direction of inclination in the corners. The bottom tie plate and the top tie plate may be provided with enlarged holes 16 to allow the passage of the steam in the steam channel. To intensify the eddies around the steam channel, both the bottom tie plate and the top tie plate may be provided with fins around these enlarged holes which are oriented such that the eddy is intensified. FIG. 5 shows part of the bottom tie plate for the fuel unit 3b in a section Gxe2x80x94G through FIG. 2. Around the hole 16, fins 17 are arranged to control the water and the steam in the direction of the macroscopic eddy. It is important to note the difference between these fins 17 and know fins which are often arranged on spacers in both boiling water and pressurized-water reactors to mix the coolant in a sub-channel between four adjoining rods and hence improve the dryout margin. In these cases the known fins are to be arranged so as to intensify the microscopic eddy. There are further possibilities of achieving the above-mentioned intensification of the eddy, for example by turning around ligaments in the top tie and bottom tie plates into an inclination of 45xc2x0 with the horizontal plane. The top tie plate and/or the bottom tie plate may be provided with a frame which, in turn, may carry obliquely positioned fins or folds. In another embodiment of the invention, all the fuel rods may be straight and the eddies may be achieved by other means, for example fins on the bottom tie plate and the top tie plate. To seal the fuel rods, they are provided at their upper end with a top plug and at their lower end with a bottom plug. These bottom plugs and top plugs may also be provided with fins or other devices to bring about an eddy in the sub-bundle.
051046105	claims	1. A high flux neutron tube comprising (a) ion source means for producing a high energy ion beam, said ion source means including (b) magnetic means disposed in an axial direction before said ion source means for producing an axial magnetic field within said cavity and within said cylindrical anode means, (c) extraction and acceleration electrode means for extracting and accelerating said ion beam from said ion emission channel, (d) target electrode means receiving said ion beam from said extraction and acceleration electrode means for causing emission of neutrons by fusion reaction, and (e) means associated with said cylindrical anode means for increasing homogeneity of said ion beam across said ion emission channel upon increasing divergence of said magnetic field at said ion emission channel. 2. A high flux neutron tube according to claim 1, wherein said means for increasing homogeneity includes a truncated internal shape of said cylindrical anode means, said truncated internal shape having a first smaller internal diameter near said magnetic means and a second larger internal diameter near said ion emission channel such that lines of force of said magnetic field are spread outwardly before reaching said ion emission channel. 3. A high flux neutron tube according to claim 1, wherein said means for increasing homogeneity includes a circular cylindrical shape of said cylindrical anode means, said circular cylindrical shape having a reduced height and being situated closer to said magnetic means than to said ion emission channel such that lines of force of said magnetic field can spread outwardly before reaching said ion emission channel.
06041099&	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a diagrammatic view of a traditional sequentially ordered Kirkpatrick-Baez mirror system. This sequentially ordered mirror system may focus or collimate an x-ray beam in two dimensions by reflecting a divergent x-ray beam along two directions independently. The mirrors 12a and 12b are arranged in consecutive order and may be configured with a parabolic or elliptical surface. With a point source 10, this sequential order system equipped with two parabolic mirrors will provide a parallel beam. With a finite source, this parabolic mirror system will provide a beam with different divergences in two directions. When elliptical mirrors are substituted for parabolic mirrors the sequentially ordered system will provide a focused beam and give a perfect real point image with a point source at its focal point. For a field object, the image will be magnified or demagnified by the system. The magnification will vary with the distances separating the mirrors and the object. There are several limitations which greatly affect the performance of the sequential order Kirkpatrick-Baez system. There is no way to install both mirrors at the most optimized positions, which results in less flux and a larger aberration. Consider a figure deviation from the ideal curvature .DELTA..alpha. of the reflective surface, the deviation of the ray from the theoretical position at the image plan will be equal to 2.DELTA..vertline., where .vertline. is the distance between incident point and image plane. For a sequential system, the figure error on the mirror nearer to the object results in a larger deviation. When the mirrors are located at different distances from the detector, if both mirrors have the same angular deviation, the aberration from the mirror closest to the source will be larger. A sequential order Kirkpatrick-Baez system will have varied amplification because the mirrors are placed at different positions with relation to field object distance. Lastly, the alignment hardware for a sequential order Kirkpatrick-Baez mirror is bulky and complicated and the alignment procedures are difficult and time consuming since the adjustments include alignments relative to the beam and the alignments relative to both mirrors. A side-by-side Kirkpatrick-Baez system provides a solution to the problems associated with a sequential system as well as providing other advantages. In FIG. 2 a side-by-side system is shown generally as 16. The reflecting surfaces 18a and 18b are mounted adjacent at a 90 degree angle. The side-by-side system has no distance offset between reflecting surfaces as does the sequential order system, reducing potential aberration problems. FIGS. 3a-3b are diagrammatic views of a side-by-side Kirkpatrick-Baez mirror system illustrating a first working zone 20a and second working zone 20b upon the mirror surfaces. The working zones 20a and 20b are located upon and adjacent to the corner formed by the coupling of the reflective surfaces 18a and 18b. FIG. 4 is a more detailed diagrammatic view of a side-by-side Kirkpatrick-Baez system illustrating incident and reflected x-ray beam paths. Individual x-ray beams 26a and 26b are radiated from x-ray source 10 and may first be examined at the cross section 22 of the x-ray beam. The cross section 22 of the beam illustrates the many divergent directions of the x-ray beams exiting the x-ray source 10. Individual x-ray beam 26a is incident upon working zone 20a which lies generally upon the junction of reflective surfaces 18a and 18b. Individual x-ray beam 26b is also incident upon working zone 20a. The beams 26a and 26b are reflected by working zone 20a and redirected to working zone 20b which also lies generally upon the junction of reflective surfaces 18a and 18b opposite and partially overlapping working zone 20a as shown in FIG. 3a and 3b. The beams 26a and 26b then exit the system 16 and may be in divergent, collimated or focused form depending upon the shapes of the reflective surfaces 18a and 18b and the form of the x-ray source. This configuration is generally known as an single corner configuration. Any combination of parabolic or elliptical mirror surfaces for the present invention may be used. For example, one reflecting surface may have an elliptical surface and a second reflecting surface may have a parabolic reflecting surface. The reflective surfaces in the present invention are configured as multi-layer or graded-d multi-layer Bragg x-ray reflective surfaces. Bragg structures only reflect x-ray radiation when Bragg's equation is satisfied: EQU n.lambda.=2d sin (.theta.) where n=the order of reflection .lambda.=wavelength of the incident radiation d=layer-set spacing of a Bragg structure or the lattice spacing of a crystal .theta.=angle of incidence Multi-layer or graded-d multi-layered Bragg mirrors are optics with a fixed focal point which utilize their inherent Bragg structure to reflect narrow band or monochromatic x-ray radiation. The bandwidth of the reflected x-ray radiation can be customized by manipulating the optical and multi-layer parameters. The d-spacing of the multi-layer mirror can be tailored in such a way that the Bragg condition is satisfied at every point on the multi-layer mirror. The d spacing may be changed laterally or depthwise to control the bandpass of the multi-layer mirror. The multi-layer mirror has a large reflection angle resulting in higher collection efficiencies for incident x-rays. These multi-layered mirrors could increase the flux by more than an order with a fine focus x-ray tube, as compared with total reflection mirrors. Multi-layered mirrors, because of their monochromatic output, could also reduce the unwanted characteristic radiation during diffraction analysis by thousands of times. Therefor as seen in FIG. 5 when employing the single corner optic an x-ray aperture assembly 56, an aperture 58 may be placed at the entrance area, exit area or both to eliminate coaxial direct x-rays, single bounce x-rays, or scattered x-rays. The combination of side-by-side Kirkpatrick-Baez scheme and multi-layer or graded-d multi-layer Bragg x-ray reflective surfaces can provide superior optics for many applications requiring directed, focused, or collimated x-rays. FIG. 6 is a diagrammatic drawing showing the alignment method of the present invention. A Kirkpatrick-Baez mirror to work correctly must have a very specific orientation. The present invention utilizes microadjustment hardware to correctly orient a Kirkpatrick-Baez mirror. The alignment of the optic can be achieved with five freedoms of adjustments: two rotations and three translations. The rotating axes for two mirrors should go through the centers of the intersection of the two mirrors, and parallel to the mirrors respectively, as shown in the schematic picture. The two translations, which are perpendicular to the optic, should be parallel to the mirror surfaces respectively, (see the bottom of FIG. 6). These freedoms allow the adjustments of the incident angles and beam positions. It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
	summary
	abstract	In orer to supply a scanning charged-particle microscope that can achieve both the improvement of resolution and that of focal depth at the same time, a scanning charged-particle microscope is supplied which is characterized in that a passage aperture for limiting the passage of the charged-particle optical beam is located between the charged-particle source and the scanning deflector, and in that a member for limiting the passage of the charged-particle optical beam is provided at least in the center of the passage aperture.
	abstract	A particle beam apparatus has an optical axis (OA), an illuminating system (1, 2, 3, 4) for illuminating an object, which is positioned in an object plane (7), with a beam of charged particles and an objective (6) for imaging the illuminated object. The beam of charged particles is split at the object into a null beam and higher diffraction orders. The illuminating system is so configured that it generates an annularly-shaped illuminating aperture in a plane Fourier transformed to the object plane (7). A phase-shifting element (9) is mounted in a focal plane (15) of the objective (6) or in a plane conjugated thereto. The focal plane (15) faces away from the object plane (7). The phase-shifting element can be an einzel lens having two outer electrodes and one or several inner electrodes disposed therebetween when seen in the direction of the optical axis. The phase-shifting element can have an additional electrode at or near the optical axis.
	description	This application is a U.S. national stage application of International Application No. PCT/JP2008/051784 filed Feb. 4, 2008, claiming a priority date of Feb. 19, 2007, and published in a non-English language. The present invention relates to a charged particle beam apparatus configured to irradiate a sample with a charged particle beam for processing and observation of the sample, and a method of adjusting charged particle optics in the charged particle beam apparatus. In the related art, a charged particle beam apparatus configured to irradiate a predetermined position with a charged particle beam such as an ion beam or an electron beam for processing and observation is used in various fields. As the charged particle beam apparatus, there are, for example, a scanning electron microscope (SEM) which is able to irradiate with an electron beam as the charged particle beam or a focused ion beam apparatus (FIB) which is able to irradiate with a focused ion beam or the like as the charged particle beam. The scanning electron microscope allows observation of the state of a surface of a sample by detecting a secondary electron generated from the surface of the sample while scanning with the electron beam on the surface of the sample. Also, the focused ion beam apparatus allows observation of the surface of the sample by detecting the secondary electron in the same manner as the scanning electron microscope and also is able to perform etching or deposition of the sample by increasing the acceleration voltage, so that it is used for preparing samples for TEM (transmission electron microscope) or correcting photomasks. Also, in recent years, in the focused ion beam apparatus, a method of realizing a low-damage processing by using the acceleration voltage of the focused ion beam in a low-acceleration area from 100 V to 5000 V in acceleration voltage receives attention. A method for realizing a large surface processing such as wire bonding or solder bump by using the same in a heavy-current area of at least 1 nA in amount of irradiation of the focused ion beam within a range on the order of 3000 V in acceleration voltage or the like also starts to receive attention. Incidentally, the charged particle beam apparatuses as described above include charged particle optics configured to adjust beam characteristic values, such as the focal length or the astigmatism, of the charged particle beam by electromagnetically acting on the irradiated charged particle beam in order to achieve an adequate observation or processing. In other words, the focused ion beam apparatus, for example, includes an electrostatic lens as an objective lens which causes the focused ion beam to be focused by forming an electric field by an applied voltage as the charged particle optics. Then, by setting a voltage value to be applied to the electrostatic lens as an input value, the focal length is adjusted and the focused ion beam is focused on the surface of the sample. Also, although the electrostatic lens as described above is formed to have rotational symmetry for causing the focused ion beam to be focused uniformly in the circumferential direction, the astigmatism might occur due to the fabrication in accuracy of a lens electrode and axis displacement at the time of assembly, so that the shape of the cross-section of the focused ion beam might not assume a circle. Therefore, an astigmatic correction mechanism (stigmator) configured to correct the astigmatism of the focused ion beam is used as the charged particle optics. The astigmatism correction mechanism corrects the astigmatism of the focused ion beam by forming an electric field by, for example, using two pairs of quadrupoles and setting voltage values to be applied to the respective quadrupoles as input values. The scanning electron microscope or the like is also the same in this respect and includes a magnetic field lens as the objective lens and the astigmatic correction mechanism, each forming a magnetic field which acts on the electron beam to adjust the focal length and correct the astigmatism. In the related art, the displacement of the position of the focal point or the astigmatism as described above are adjusted and corrected specifically in the following method using the above-described charged particle optics. In other words, an image of the sample is obtained by detecting the secondary electron by irradiating the sample with the charged particle beam. Then, the direction of the astigmatism is determined from the state of the obtained image, and an input value to be inputted to an astigmatic corrector is adjusted according to the direction of the astigmatism. Furthermore, the image of the sample is obtained, and whether or not the image is in focus is determined from the state of the image, and the input value to be inputted to the objective lens is adjusted according to the state. Then, if there is further a sign of astigmatism in the obtained image, the correction of the astigmatism and the adjustment of the position of the focal point are performed again. Then, when the obtained image becomes clear without any distortion, the adjustment is completed (for example, see Non-Patent Document 1). Also, as regards an electron beam exposure apparatus as the charged particle beam apparatus, a technology to prevent generation of variations due to an abrupt change of the input value for correcting the astigmatism when performing a linear supplement by determining optimal input values at the respective lattice points on a field according to the method as described above is disclosed (for Example, see Patent Document 1). [Non-Patent Document 1] Fundamentals and Application of Scanning Electron Microscope, from Kyoritsu Publ. Co., Ltd., Oct. 25, 1991, pp. 80-82 [Patent Document 1] JP-A-8-83585 However, with the methods disclosed in Non-Patent Document 1 and Patent Document 1, an operator determines the state of the obtained image qualitatively and determines optimal values as input values of the respective charged particle optics. Therefore, there is a problem that a high level of performance of the operator and a great deal of time are necessary for adjusting the respective charged particle optics. Also, there arise variations in accuracy of adjustment from operator to operator, and even though the adjustment is made by the same operator, it is difficult to unify the accuracy of adjustment in different apparatuses, so that variations in performance from apparatus to apparatus may be disadvantageously resulted. In the focused ion beam apparatus as described above, since the speed of processing is fast when used in a heavy-current area, the sample might be damaged while acquiring and adjusting the image of the sample. Furthermore, since the ion beam cannot be focused effectively when being used in the heavy-current area or a low-acceleration area in comparison with the use in a low-current area and a high-acceleration area, a clear image cannot be obtained as the image of the sample for adjustment, so that the accurate adjustment cannot be achieved. In view of such circumstances as described above, it is an object of the present invention to provide a charged particle beam apparatus which is able to adjust charged particle optics easily in a short time with a high degree of accuracy and a method of adjusting charged particle optics. In order to solve the above-described problems, the present invention proposes the following means. A charged particle beam apparatus according to the present invention includes a charged particle source configured to discharge a charged particle beam; charged particle optics configured to act electromagnetically on the basis of an input value, and set the charged particle beam to a beam characteristic value corresponding to the input value and cause a sample to be irradiated therewith; scanning means configured to be able to move an irradiation point of the charged particle beam with respect to the sample; observing means configured to be able to obtain an image of a surface of the sample, and a control unit configured to be able to adjust the input value of the charged particle optics so that the beam characteristic value of the charged particle beam becomes a desired value, characterized in that the control unit includes spot pattern forming means configured to set the input value of the charged particle optics to different values and cause the sample to be irradiated with the charged particle beam by a plurality of times at positions differentiated by the scanning means to form a plurality of spot patterns on the surface of the sample and spot pattern analyzing means configured to select the spot pattern having the smallest spot characteristic value which indicates the shape of the respective spot patterns formed on the sample from the image obtained by the observing means, and sets the input value of the charged particle optics to a value equal to the input value corresponding to the charged particle beam applied when the spot pattern selected by the spot pattern analyzing means is formed. Also, the present invention is a method of adjusting charged particle optics with a charged particle beam apparatus including the charged particle optics configured to act electromagnetically on the basis of an input value and set a charged particle beam to a beam characteristic value corresponding to the input value, and being configured to cause a sample to be irradiated with the charged particle beam for adjusting the input value of the charged particle beam so that the beam characteristic value of the charged particle beam becomes a desired value including; a spot pattern forming step for forming a plurality of spot patterns on a surface of a sample by setting the input values of the charged particle optics to different values and irradiating the sample prepared in advance with the charged particle beams by a plurality of times at differentiated positions, a spot pattern analyzing step for selecting the spot pattern having the smallest value from spot characteristic values which indicate the shapes of the respective spot patterns, and an input value setting step for setting the input value of the charged particle optics to a value equal to the input value corresponding to the charged particle beam applied when the spot pattern selected in the spot pattern analyzing step is formed. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, the plurality of spot patterns are formed on the surface of the sample as the spot pattern forming step. In other words, the spot pattern forming means of the control unit ejects the charged particle beam from the charged particle source. Then, by causing the charged particle beams to electromagnetically act on the basis of the input value by the charged particle optics, the surface of the sample is irradiated with the charged particle beam in a state of having a certain beam characteristic value. Accordingly, a spot pattern of shape having a certain spot characteristic value is formed on the surface of the sample according to the beam characteristic value of the applied charged particle beam. Subsequently, the spot pattern forming means of the control unit sets the input value of the charged particle optics to a different value and causes the charged particle beam to be applied again at a position differentiated from the previous irradiation point by the scanning means. In this manner, a plurality of spot patterns having different spot characteristic values are formed on the different positions on the surface of the sample respectively. Subsequently, as the spot pattern analyzing step, the formed plurality of spot patterns are analyzed. In other words, the spot pattern analyzing means of the control unit measures the spot characteristic values of the respective spot patterns from an image obtained by the observing means, and selects the spot pattern having the smallest spot characteristic value. Then, the control unit extracts the input value corresponding to the charged particle beam applied when the selected spot pattern is formed and sets the input value of the charged particle optics to a value which is equal thereto as the input value setting step. Accordingly, the charged particle beam which is electromagnetically acted upon by the charged particle optics can be applied on the sample in such a manner that the spot characteristic value of the spot pattern formed on the sample become the smallest, that is, the beam characteristic value is set to a desired value. Also, in the charged particle beam apparatus described above, it is considered to be preferable that the spot pattern forming means of the control unit moves the irradiation point of the charged particle beam with respect to the sample by the scanning means by an amount obtained by multiplying the amount of change of the input value by a predetermined coefficient every time when the charged particle beam is applied on the sample after setting the input value to the different value. Also, in the method of adjusting charged particle optics described above, the spot pattern forming step preferably moves an irradiation point of the charged particle beam with respect to the sample by an amount obtained by multiplying an amount of change of the input value by a predetermined coefficient every time when the charged particle beam is applied on the sample after setting the input value to the different value. According to the charged particle beam apparatus and the method of adjusting the charged particle optics of the present invention, the spot pattern forming means of the control unit relatively moves the irradiation point of the charged particle beam by an amount obtained by multiplying the amount of change of the input value by a predetermined coefficient every time when the charged particle beam is applied in the spot pattern forming step. Accordingly, the plurality of spot patterns are formed on the surface of the sample at distances corresponding to the amount of the change of the input value. Therefore, from the state of the shapes and arrangement of the spot patterns, the spot pattern having the smallest spot characteristic value can be selected more easily and, on the basis of this, the input value of the charged particle optics can be set so that the beam characteristic value of the charged particle beam becomes a desired value. Also, in the charged particle beam apparatus described above, it is considered to be preferable that the spot pattern analyzing means of the control unit determines whether the smallest spot characteristic value is larger than a preset spot reference value or not and, if the smallest spot characteristic value is larger than the spot reference value, and the spot pattern forming means of the control unit changes the input value by an amount of change smaller than the amount of change of the input value when the charged particle beam is applied after changing the input value of the charged particle optics in the previous time to form the spot pattern again. Also, in the method of adjusting charged particle optics described above, it is considered to be preferable that the spot pattern analyzing step compares the smallest spot characteristic value and a preset spot reference value and, if the spot characteristic value is larger than the spot reference value, the procedure goes again to the spot pattern forming step, and the spot pattern forming step changes the input value by an amount of change smaller than the amount of change when the input value of the charged particle optics is changed in the previous spot pattern forming step to form the spot pattern. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, in the spot pattern analyzing step, the spot pattern analyzing means of the control unit compares the smallest spot characteristic value and the preset spot reference value. Then, if the spot characteristic value is larger than the spot reference value, that is, if the spot characteristic value is the smallest, but an amount of change between the plurality of input values set by the spot pattern forming means is large and there exists an input value at which the spot characteristic value becomes smaller as an intermediate value, the spot pattern forming step is performed again. Then, in the spot pattern forming step, by changing the input value by the amount of change smaller than that in the previous spot pattern forming step by the spot pattern forming means, search and adjustment of the input value which achieves a desired beam characteristic value with a higher degree of accuracy on the basis of the spot characteristic value of the formed spot pattern. Also, in the charged particle beam apparatus described above, it is considered to be preferable that the spot pattern analyzing means of the control unit determines whether the input value corresponding to the spot pattern having the smallest spot characteristic value is the smallest or the largest in comparison with the input values corresponding to the other spot patterns and, if the input value corresponding to the spot pattern having the smallest spot characteristic value is the smallest, the spot pattern forming means of the control unit changes the input value within a range including values smaller than the input value and within a range including values larger than the input value if the input value is the largest to form the spot pattern again. Also, in the method of adjusting charged particle optics described above, it is considered to be preferable that in the spot pattern analyzing step, the input value corresponding to the spot pattern having the smallest spot characteristic value is compared with the input values corresponding to the other spot patterns and, if the input value corresponding to the spot pattern having the smallest spot characteristic value is the smallest or the largest, the procedure goes to the spot pattern forming step again, and in the spot pattern forming step the input value is changed within a range including values smaller than the input value if the input value corresponding to the spot pattern having the smallest spot characteristic value is the smallest, and within a range including values larger than the input value if the input value is the largest to form the spot pattern again. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, in the spot pattern analyzing step, the spot pattern analyzing means of the control unit compares the input value of the charged particle optics set when the spot pattern having the smallest spot characteristic value is formed and the input value of the charged particle optics set when other spot patterns are formed. Then, if the input value corresponding to the spot pattern having the smallest spot characteristic value is the smallest or the largest in comparison with the input values corresponding to the other spot patterns, that is, if the spot characteristic value is the smallest but there exists an input value at which the spot characteristic value becomes smaller out of the range of the input values changed by the stop pattern forming means, the spot pattern forming step is performed again. Then, in the spot pattern forming step, by changing the input value within a range including smaller values if the input value corresponding to the spot pattern having the smallest spot characteristic value is the smallest and in a range including larger values if the input value is the largest by the spot pattern forming means, search and adjustment of the input value which achieves a desired beam characteristic value with a higher degree of accuracy on the basis of the spot characteristic value of the formed spot pattern. Also, in the charged particle beam apparatus described above, it is considered to be preferable that the spot pattern analyzing means converts the image obtained from the observing means into binarized binary data and selects the spot pattern having the smallest spot characteristic value from the binary data. Also, in the method of adjusting charged particle optics described above, it is considered to be preferable that the spot pattern analyzing step creates binary data obtained by binarizing an image of the sample on which the spot pattern is formed, and selects the spot pattern having the smallest spot characteristic value from the binary data. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, in the spot pattern analyzing step, by converting the image into the binarized binary data by the spot pattern analyzing means of the control unit, the spot pattern displayed in the image is identified more clearly, and hence adjustment of the input value with a higher degree of accuracy is achieved on the basis of the spot characteristic value of the spot pattern. Also, in the charged particle beam apparatus described above, it is considered to be preferable that the charged particle optics includes an electrostatic lens configured to focus the charged particle beam to cause the sample to be irradiated therewith by applying a voltage to an electrode, the control unit causes the spot pattern forming means to form the spot patterns by setting the voltage values to be applied to the electrode of the electrostatic lens to different values as the input values and causes the spot pattern analyzing means to select the spot pattern having the smallest spot characteristic value as the outer diameter of the spot pattern, and set the voltage value to the voltage value corresponding to the spot pattern having the smallest value, so that the focal length of the electrostatic lens as the beam characteristic value is adjusted. Also, in the method of adjusting charged particle optics described above, it is considered to be preferable that the charged particle beam apparatus includes an electrostatic lens configured to focus the charged particle beam to cause the sample to be irradiated therewith by applying a voltage to an electrode as the charged particle optics, the spot pattern forming step forms the spot patterns by setting voltage values to be applied to the electrode of the electrostatic lens to different values as the input values, and the spot pattern analyzing step selects the spot pattern having the smallest spot characteristic value as the outer diameter of the spot pattern, and sets the voltage value by the input value setting step, so that the focal length of the electrostatic lens as the beam characteristic value is adjusted. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, as the spot pattern forming step, the spot pattern forming means of the control unit changes the voltage value to be applied to the electrode of the electrostatic lens to various values, whereby the charged particle beam is applied with various focal length to form the plurality of spot patterns. Then, the spot pattern analyzing means of the control unit selects a spot pattern having the smallest outer diameter, that is, a spot pattern on the surface of the sample by being irradiated with the charged particle beam in a most focalized state. Therefore, by setting the input value to the input value corresponding to this spot pattern by the control unit as the input value setting step, the focal length as the beam characteristic value of the charged particle beam can be adjusted to be substantially equal to the separation distance between the electrostatic lens and the surface of the sample, so that the smallest beam diameter is obtained. Also, in the charged particle beam apparatus described above, it is also possible to configure in such a manner that a stigmator which includes at least a set of multi-poles having a pair of opposed positive poles and a pair of negative poles opposed in substantially orthogonally to the direction of arrangement of the positive poles and corrects the cross-sectional shape of the charged particle beam into a substantially circular shape by applying a voltage between the positive pole and the negative pole of the multi-pole and applies the same to the sample is provided as the charged particle optics, the control unit causes the spot pattern forming means to set the voltage value to be applied between the positive poles and the negative poles of the stigmator to different values as the input values to form the spot patterns and causes the spot pattern analyzing means to select the spot pattern having the smallest spot characteristic value as the ratio of the short diameter with respect to the long diameter of the outer diameters of the spot pattern in the orthogonal two directions, and set the voltage value to the voltage value corresponding to the spot pattern having the smallest value, so that the beam diameter ratio in the orthogonal two directions of the charged particle beam as the beam characteristic value is adjusted. Also, in the method of adjusting charged particle optics described above, it is also possible to configure in such a manner that the charged particle beam apparatus includes, as the charged particle optics, a stigmator which includes at least a set of multi-poles having a pair of opposed positive poles and a pair of negative poles opposed in substantially orthogonally to the direction of arrangement of the positive poles as the charged particle optics and corrects the cross-sectional shape of the charged particle beam into a substantially circular shape by applying a voltage between the positive pole and the negative pole of the multi-pole and applies the same to the sample, the voltage value to be applied between the positive poles and the negative poles of the stigmator is set to different values as the input values to form the spot patterns in the spot pattern forming step, the spot pattern having the smallest spot characteristic value is selected as the ratio of the short diameter with respect to the long diameter of the outer diameters of the spot pattern in the orthogonal two directions in the spot pattern analyzing step, and the voltage value is set in the input value setting step, so that the beam diameter ratio in the orthogonal two directions of the charged particle beam as the beam characteristic value is adjusted. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, as the spot pattern forming step, the spot pattern forming means of the control unit changes the voltage value to be applied between the positive poles and the negative poles of the multi-pole of the stigmator to various values, whereby the charged particle beam is applied with various cross-sectional shapes of the charged particle beam to form the plurality of spot patterns. Then, as the spot pattern analyzing step, the spot pattern analyzing means of the control unit selects a spot pattern having the smallest ratio of the long diameter with respect to the short diameter in the outer diameters in the two orthogonal direction, that is, being formed by being irradiated with the charged particle beam in a cross-sectional shape closest to a circle. Therefore, by setting the input value to the input value corresponding to this spot pattern by the control unit as the input value setting step, the beam diameter ratio in orthogonal two directions as the beam characteristic value of the charged particle beam can be adjusted to be substantially equal to 1 which assumes a circle. Also, in the charged particle beam apparatus described above, it is considered to be preferable that the spot pattern forming means of the control unit brings the charged particle beam into an over focus state with respect to the sample and forms the plurality of the spot patterns on the surface of the sample with different voltage values, then, brings the charged particle beam into an under focus state with respect to the sample and forms the plurality of the spot patterns of the surface of the sample with the same voltage values as in the case of the over focus state respectively, and the spot pattern analyzing means of the control unit performs pattern matching between the spot patterns formed in the over focus state and in the under focus state with the same voltage values and selects the set of the spot patterns whose ratio of matching of the pattern matching elements becomes highest. Also, in the method of adjusting charged particle optics described above, it is considered to be preferable that the spot pattern forming step includes a first step of bringing the charged particle beam into an over focus state with respect to the sample and forming the plurality of the spot patterns on a surface of the sample with different voltage values, and a second step of bringing the charged particle beam into an under focus state with respect to the sample and forming the plurality of the spot patterns of the surface of the sample with the same voltage values as in the first step respectively, and the spot pattern analyzing step performs pattern matching between the spot patterns formed in the first step and in the second step with the same voltage values and selects the set of the spot patterns whose ratio of matching of the pattern matching elements becomes highest. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, in the spot pattern forming step, the spot pattern forming means of the control unit brings the charged particle beam into the over focus state with respect to the sample to form the plurality of the spot patterns with the different voltage values applied to the multi-pole of the stigmator as the first step. Then, as the second step, the charged particle beam is brought into the under focus state with respect to the sample to form the spot patterns with the same voltage values as in the first step respectively. Here, if the voltage value is the same and the state of the focal point is different such as the over focus and the under focus, the directions of the charged particle beams are different by approximately 90 degrees, that is, the directions of the formed spot patterns are different also by approximately 90 degrees. Therefore, by performing the pattern matching between the spot patterns formed with the same voltage values by the spot pattern analyzing means as the spot pattern analyzing step, the both do not match if the cross-sectional shape of the charged particle beam is an oval shape. In contrast, the both match if it is a circular shape. In other words, in the spot pattern analyzing step, by selecting the set of the spot patterns whose rate of matching of the pattern matching element is the highest, the spot pattern having the smallest ratio of the long diameter with respect to the short diameter in the outer diameters in the two orthogonal directions can be selected more easily. In addition, in the charged particle beam apparatus described above, it is considered to be preferable that the spot pattern forming means of the control unit matches the arrangement of the plurality of the spot patterns to the corresponding voltage values between the state of the over focus and in the state of under focus to form the spot patterns. In addition, in the method of adjusting charged particle optics described above, it is considered to be preferable that the first step and the second step of the spot pattern forming step match the arrangement of the plurality of the spot patterns to the corresponding voltage values to form the spot patterns. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, in the spot forming step, the spot pattern forming means of the control unit matches the arrangement of the plurality of spot patterns to the corresponding voltage values to form the spot pattern in the state of the over focus in the first step and in the state of under focus in the second step. Then, in the spot pattern analyzing step, pattern matching of the spot patterns formed with the same voltage values is performed. Here, the arrangements and the corresponding voltages of the spot patterns formed respectively in the state of over focus in the first step and in the state of under focus in the second step match with each other. Therefore, by obtaining the image including the plurality of spot patterns by the observing means in the state of the over focus and in the state of the under focus respectively, pattern matching for all the sets of the spot patterns can be performed in a collective manner, so that the spot pattern having the smallest spot characteristic value can be selected further easily. Also, in the charged particle beam apparatus described above, it is also possible to configure in such a manner that the stigma includes two sets of the multi-pole including a first multi-pole and a second multi-pole, the voltage value includes a set of a first voltage value to be applied between the positive pole and the negative pole of the first multi-pole and a second voltage value to be applied between the positive pole and the negative pole of the second multi-pole, the spot pattern forming means of the control unit combines the first voltage value and the second voltage value in different manners, moves the charged particle beam in a first direction by an amount obtained by multiplying an amount of change of the first voltage value by a predetermined coefficient and in a second direction intersecting the first direction by an amount obtained by multiplying an amount of change of the second voltage value by the coefficient relatively with respect to the sample by the scanning means, and causes the same to be applied by a plurality of times. Also, in the method of adjusting charged particle optics described above, it is also possible to configure in such a manner that the stigma of the charged particle beam apparatus includes two sets of the multi-pole including a first multi-pole and a second multi-pole, the voltage value includes a first voltage value to be applied between the positive pole and the negative pole of the first multi-pole and a second voltage value to be applied between the positive pole and the negative pole of the second multi-pole and, in the spot pattern forming step, the first voltage value and the second voltage value are combined in different manners, and the charged particle beam is moved in a first direction by an amount obtained by multiplying an amount of change of the first voltage value by a predetermined coefficient and in a second direction intersecting the first direction by an amount obtained by multiplying an amount of change of the second voltage value by the coefficient relatively with respect to the sample, and applied by a plurality of times. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, as the spot pattern forming step, the spot pattern forming means of the control unit applies the charged particle beam by differentiating the combination of the first voltage value of the first multi-pole and the second voltage value of the second multi-pole of the stigmator to form the plurality of spot patterns. Here, when forming the spot patterns by changing the first voltage value and the second voltage value, the irradiation point is moved in the first direction by an amount obtained by multiplying the amount of change of the first voltage value by a predetermined coefficient and is moved in the second direction by an amount obtained by multiplying the amount of change of the second voltage value by the same coefficient by the scanning means. Therefore, the spot pattern having the smallest ratio of the long diameter with respect to the short diameter in the outer diameters in the orthogonal two directions can be selected easily from the shapes and the arrangement of the spot patterns and, on the basis of this, the first voltage value of the first multi-pole and the second voltage value of the second multi-pole can be set so that the beam diameter ratio in the two orthogonal directions is substantially equal to 1, which is a circular shape. Also, in the charged particle beam apparatus described above, it is considered to be preferable to provide a sample base on which at least the two samples can be arranged, and which is capable of moving the samples at least within a plane substantially orthogonal to the direction of application of the charged particle beam. Also, in the method of adjusting charged particle optics described above, it is considered to be preferable to include an adjustment preparation step for arranging a standard sample and a target sample as the sample, a processing and observation preparation step for adjusting the position of the target sample with respect to the irradiation point of the charged particle beam, and after the adjustment preparation step, the spot pattern forming step, the spot pattern analyzing step, and the input value setting step for the standard sample, and after the input value setting step, the procedure is migrated to the processing and observation preparation step. According to the charged particle beam apparatus and the method of adjusting charged particle optics of the present invention, the adjustment of the charged particle optics can be performed by using the standard sample by arranging the standard sample and the target sample on the sample base as the adjustment preparation step and performing the spot pattern forming step, the spot pattern analyzing step, and the input value setting step and, after the adjustment, the processing and observation of the target sample is achieved by moving the target sample to the irradiation point of the charged particle beam quickly without necessity of replacement of the sample as the observation and processing preparation step. [Advantages] According to the charged particle beam apparatus of the present invention, the control unit includes the spot pattern forming means and the spot pattern analyzing means, and the input value of the charged particle optics can be adjusted so that the beam characteristic value of the charged particle beam becomes a desired value automatically and easily in a short time with a high degree of accuracy only by forming the plurality of spot patterns. Also, according to the method of adjusting charged particle optics of the present invention, the spot pattern forming step, the spot pattern analyzing step, and an input value determining step are provided, and the input value of the charged particle optics can be adjusted so that the beam characteristic value of the charged particle beam becomes a desired value easily in a short time with a high degree of accuracy only by forming the plurality of spot patterns so that application of automation is also possible. 1, 40, 50, 60 focused ion beam apparatus (charged particle beam apparatus) 2 sample base 9 ion source (charged particle source) 12 objective lens (charged particle optics) 17 scanning electrode (scanning means) 21 first multi-pole (multi-pole) 22 second multi-pole (multi-pole) 21a, 22a positive pole 21b, 22b negative pole 30 control unit 32 observing means 33 spot pattern forming means 34 spot pattern analyzing means I ion beam (charged particle beam) M target sample (sample) N standard sample (sample) N1 surface A1-Al2 voltage value (input value) Cl-C12 voltage value (input value) D1-D16 first voltage value E1-E16 second voltage value Fl-F16 irradiating position P1-P6, Pa1-Pa8, Pb9-Pb12, Q1-Q16, Q′1-Q′16, R spot pattern V1-V6, Vb4 outer diameter Wl-W16 outer diameter ratio (long diameter with respect to short diameter) S1 adjustment preparation step S11 spot pattern forming step S12 spot pattern analyzing step S13 input value setting step S21 spot pattern forming step S22, S32 spot pattern analyzing step S23 input value setting step (First Embodiment) FIG. 1 shows a first embodiment of the present invention. As shown in FIG. 1, a focused ion beam apparatus (FIB) 1 as a charged particle beam apparatus is configured to perform processing of a surface of a sample by irradiating the sample with an ion beam I as a charged particle beam. For example, it is possible to arrange a wafer as a sample and fabricate a sample for observation by a TEM (transmission electron microscope) or to correct a photomask using a photomask in the photolithography technology as a sample. Detailed description of the focused ion beam apparatus 1 in this embodiment will be given below. As shown in FIG. 1, the focused ion beam apparatus 1 includes a sample base 2 on which at least two samples of a target sample M and a standard sample N can be arranged, and an ion beam column 3 which is able to irradiate the target sample M and the standard sample N arranged on the sample base 2 with the ion beam I. Here, the target sample M means a sample to be processed or observed by the focused ion beam apparatus 1, and the standard sample N means a sample used for adjustment of charged particle optics, described later. The sample base 2 is arranged in an interior 4a of a vacuum chamber 4. The vacuum chamber 4 includes a vacuum pump 5, which is able to exhaust air to bring the interior 4a into a high-vacuum atmosphere. The sample base 2 is provided with a five-axis stage 6, and is able to move the target sample M and the standard sample N in a Z-direction, which is the direction of irradiation of the ion beam I and in a X-direction and a Y-direction which are two axes substantially orthogonal to the Z-direction, and is able to incline the same about the axis substantially parallel to the X-direction and the Z-direction. The ion beam column 3 includes a cylindrical member 8 formed with an irradiation port 7 which communicates with the vacuum chamber 4 at a distal center thereof and an ion source 9 as a charged particle source stored on the proximal end side in an interior 8a of the cylindrical member 8. As ion which constitutes the ion source 9, for example, gallium ion (Ga+) or the like is exemplified. The ion source 9 is connected to an ion source control power source 10. Then, by applying an acceleration voltage and a drawing voltage by the ion source control power source 10, the ion drawn from the ion source 9 is accelerated and may be ejected as the ion beam I. Also, in the interior 8a of the cylindrical member 8, a condenser lens 11 and an objective lens 12 configured to focus the ion beam I ejected from the ion source 9 are provided on the distal side from the ion source as the charged lens optics which electromagnetically acts on the ion beam I. The condenser lens 11 and the objective lens 12 are adjusted so that center axes thereof match with respect to each other in a state of being substantially parallel to the Z-direction. The condenser lens 11 and the objective lens 12 are electrostatic lenses including three electrodes respectively formed with through holes 11a, 12a, and are connected to a condenser lens control power source 13 and an objective lens control power source 14, respectively. By applying a voltage to the condenser lens 11 by the condenser lens control power source 13, the ion beam I in a dispersed state. passing through the through hole 11a is focused. Furthermore, by applying a voltage at a certain voltage value as an input value to the objective lens 12 by the objective lens control power source 14, the ion beam I passing through the through hole 12a can further be focused and be applied on the target sample M and the standard sample N while setting the focal length as beam characteristic values. Also, provided between the condenser lens 11 and the objective lens 12 are a movable aperture 15, a stigmator 16, and a scanning electrode 17 as scanning means in sequence from the proximal side. The movable aperture 15 includes an aperture 18 as a through hole having a predetermined diameter, and an aperture drive unit 19 configured to cause the aperture 18 to move in the X-direction and the Y-direction. The aperture 18 is configured to squeeze the ion beam I applied from the condenser lens 11 according to the diameter thereof. In this embodiment, although only one aperture 18 is provided, it is also possible to provide a plurality of apertures 18 having different diameters, and configure the apertures to be able to select the one having a preferable diameter by moving the same by the aperture drive unit 19. Also, the stigmator 16 is configured to perform astigmatic correction of the ion beam I passing therethrough as the charged particle optics which electromagnetically acts on the ion beam I, which is achieved by applying a voltage from a stigmator control power source 20. More specifically, the stigmator 16 includes a first multi-pole 21 and a second multi-pole 22. As shown in FIG. 2, the first multi-pole 21 of the stigmator 16 is a multi-pole having four poles including a pair of positive poles 21a, 21a opposed to each other, and a pair of negative poles 21b, 21b opposed to each other substantially orthogonally to the direction of arrangement of the pair of positive poles 21a, 21a. In the same manner, the second multi-pole 22 is a multi-pole having four poles including a pair of positive poles 22a, 22a opposed to each other and a pair of negative poles 22b, 22b opposed to each other substantially orthogonal to the direction of arrangement of the pair of positive poles 22a, 22a. Then, the directions of arrangement of the positive pole 22a and the negative pole 22b of the second multi-pole 22 are shifted by approximately 45 degrees with respect to the directions of arrangement of the corresponding positive pole 21a and the negative pole 21b of the first multi-pole 21, so that an eight-pole is configured by arranging the positive poles 21a, 22a and the negative poles 21b, 22b of them are arranged alternately on a XY plane in a substantially circular shape. More specifically, in this embodiment, the positive pole 21a and the negative pole 21b of the first multi-pole 21 are arranged in the X-direction and the Y-direction, respectively, and the positive pole 22a and the negative pole 22b of the second multi-pole 22 are arranged in an X′-direction and a Y′-direction shifted from the X-direction and Y-direction by approximately 45 degrees respectively. Then, in the stigmator 16 by applying a voltage of a first voltage value between the positive pole 21a and the negative pole 21b of the first multi-pole 21 to form an electric field, so that correction of the cross-sectional shape of the ion beam I passing between the positive pole 21a and the negative pole 21b in the X-direction and the Y-direction of arrangement is achieved. Also, by applying a voltage of a second voltage value between the positive pole 22a and the negative pole 22b of the second multi-pole 22 to form an electric field, so that correction of the cross-sectional shape of the ion beam I passing between the positive pole 22a and the negative pole 22b in the X′-direction and the Y′-direction of arrangement is achieved. Then, the voltage value as an input value to be inputted to the charged particle optics is composed of the first voltage value to be applied to the first multi-pole 21 and the second voltage value to be applied to the second multi-pole 22. Also, the scanning electrode 17 is able to deflect the ion beam I passed therethrough by a predetermined amount in the X-direction and the Y-direction by applying a voltage by a scanning electrode control power source 23, whereby the target sample M and the standard sample N are scanned with the ion beam I, or the irradiation point can be shifted so that the predetermined position is irradiated therewith. Also, the five-axis stage 6, the ion source control power source 10, the condenser lens control power source 13, the objective lens control power source 14, the aperture drive unit 19, the stigmator control power source 20, and the scanning electrode control power source 23 described above are connected to a control unit 30. In addition, the focused ion beam apparatus 1 includes a secondary electronic detector 24 which is able to detect a secondary electron generated from the target sample M and the standard sample N when the target sample M and the standard sample N are irradiated with the ion beam I, so that the result of detection may be outputted to an image processing means 31 of the control unit 30. In the image processing means 31, the states of the surfaces of the target sample M and the standard sample N can be obtained as images from the result of detection, that is, the secondary electronic detector 24 and the image processing means 31 constitute observing means 32. The image data obtained by the observing means 32 may be monitored with a terminal 25. The control unit 30 includes spot pattern forming means 33 and spot pattern analyzing means 34 for performing the correction of the astigmatism of the ion beam I ejected from the ion source 9 and adjustment of the focal length automatically and irradiates the target sample M therewith, and also includes a storage unit 35 for storing various preset input values. Then, the control unit 30 controls the respective configurations to cause the ion beam I to be ejected at the predetermined acceleration voltage and current, and to irradiate the target sample M therewith while correcting the astigmatism and adjusting the focal length, so that processing and observation of the target sample M are achieved. It is also possible to irradiate the target sample M with the ion beam I by setting various conditions manually with the terminal 25 connected to the control unit 30. Referring now to flowcharts in FIG. 3 and FIG. 4, a procedure to correct the astigmatism by the stigmator 16 and adjust the focal length of the objective lens 12 and detailed actions of the respective configurations of the control unit 30 will be described. First of all, as an adjustment preparation step S1, the target sample M and the standard sample N prepared in advance are placed on the sample base 2. The standard sample N must simply be a material on which irradiation marks referred to as spot patterns can be formed on the surface thereof by irradiating with the ion beam I. However, since it is intended to adjust the objective lens 12 and the stigmator 16, it preferably has a flat surface. If observation and the processing are not impaired even though the spot pattern is formed on the surface of the sample, the target sample M which is actually observed and processed may be used as the standard sample N. Then, adjustment of the focal length of the objective lens 12 is performed as an objective lens adjusting step S10. In other words, first, a surface N1 of the standard sample N is irradiated with the ion beam I at a plurality of points to form the plurality of spot patterns as a spot pattern forming step S11. First, the spot pattern forming means 33 of the control unit 30 sets a voltage value A1 of the objective lens 12 as an initial value (Step S11a) and sets an irradiation point B1 of the ion beam I to the standard sample N by the scanning electrode 17 (Step S11b). The voltage value A1 of the objective lens 12 and the coordinate information of the irradiation point B1 of the ion beam I set here are stored in the storage unit 35 in one to one correspondence. The voltage value to be applied to the stigmator 16 is also set to an initial value. Then, the surface N1 of the standard sample N is irradiated with the ion beam I for a certain period of time to form a spot pattern P1 as shown in FIG. 5 (Step S11c). Although the respective spot patterns are formed in substantially circular shapes for the clarity of description in FIG. 5, they may assume oval shapes in this stage where the adjustment of the stigmator 16 is not done yet. What should be done at least is to adjust the objective lens 12 while maintaining the voltage value of the stigmator 16 constant in the following steps. If the spot patterns P1 are formed at a preset number of positions by the spot pattern forming means 33 of the control unit 30, the procedure goes to the next step and, if not, the procedure goes back to Step S11a again. In this embodiment, the spot pattern forming means 33 of the control unit 30 is assumed to be set to form the spot pattern at six positions in total. Therefore, the procedure goes back to Step S11a determining that all the spot patterns are not yet formed. In other words, the spot pattern forming means 33 of the control unit 30 resets the voltage value of the objective lens 12 to a voltage value A2 (Step S11a). Here, the voltage value A2 of the objective lens 12 is set to a value changed from the previous voltage value A1 by a preset amount of change +ΔA1. Then, the irradiation point of the ion beam I is reset to an irradiation point B2 (Step S11b). Here, the irradiation point B2 of the ion beam I is determined as follows. That is, a value of +ΔB1(=α×(+αA1)), which is the amount of change obtained by multiplying the amount of change +ΔA1 of the voltage value by a preset coefficient α, is obtained. Then, the position displaced by the amount of displacement +ΔB1 in the X-direction with respect to the previous irradiation point B1 is set to the irradiation point B2 of this time. Then, the surface N1 of the standard sample N is irradiated with the ion beam I for a certain period of time to form a spot pattern P2 as shown in FIG. 5 (Step S11c). By repeating this procedure, the positions of application B1 to B6 are irradiated with the ion beam I at the voltage values A1 to A6 of the objective lens 12 to form spot patterns P1 to P6 at six positions in total. In this embodiment, the amount of change of the voltage value is determined to be constant at the amount of change +ΔA1 and hence the amount of displacement of the irradiation point is also constant at the amount of displacement +ΔB1. However, the amount of change of the voltage value may be varied. Here, when the voltage value of the objective lens 12 is gradually increased, the action of the electric field formed therein is increased, so that the focal length of the objective lens 12 is reduced. That is, the state of the focal point of the objective lens 12 is migrated from the state of over focus to the state of under focus due to the positional relation with respect to the surface N1 of the standard sample N. As shown in FIG. 6, in the state of the over focus, a focal length L51 of an ion beam I51 is larger than a separation distance H from a center O12 of the objective lens 12 to the surface N1 of the standard sample N. Therefore, the range of irradiation of the ion beam I51 is increased, so that the outer diameter of a spot pattern P51 formed thereby is also increased. In contrast, in the state of being in focus, a focal length L52 of an ion beam 152 is substantially equal to the separation distance H. Therefore, the range of irradiation of the ion beam I52 is decreased, so that the outer diameter of a spot pattern P52 formed thereby is also decreased. Also, in the state of being in under focus, a focal length L53 of an ion beam I52 is shorter than the separation distance H. Therefore, the range of irradiation of the ion beam I53 is increased again, to that the outer diameter of a spot pattern P53 formed thereby is also increased. In other words, as shown in FIG. 5, by changing the voltage value from the spot pattern P1 formed by the irradiation of the ion beam I at the voltage value A1, the outer diameter of the spot pattern is gradually decreased according to the voltage value, and then is increased again from a certain position. Substantially, the plurality of spot patterns P1 to P6 formed in the spot pattern forming step S11 are analyzed as a spot pattern analyzing step S12. First of all, the image of the surface N1 of the standard sample N is obtained by the observing means 32 (Step S12a). In other words, the control unit 30 sets the acceleration voltage to a low value by the ion source control power source 10 to cause the ion source 9 to irradiate the ion beam I, and causes the scanning electrode 17 to scan the surface N1 of the standard sample N entirely. Then, secondary electrons ejected from the surface N1 of the standard sample N according to the irradiation are detected by the secondary electronic detector 24 of the observing means 32 in sequence, and the result is imaged by the image processing means 31, so that the image of the surface N1 of the standard sample N is obtained. Then, the spot pattern analyzing means 34 of the control unit 30 binarizes the obtained image to create binary data (Step S12b), whereby the image as shown in FIG. 5 is obtained. Then, the spot pattern analyzing means 34 of the control unit 30 measures outer diameters V1 to V6 of the respective spot patterns P1 to P6 as the spot characteristic values which represent the shapes of the spot patterns from the obtained image (Step S12c). In this embodiment, the measurement of the outer diameter is commonly performed in the X-direction. In this case, since the image is binarized, outer edges of the spot patterns P1 to P6 are clearly recognized, so that further accurate measurement is achieved. Then, the spot pattern analyzing means 34 of the control unit 30 selects a spot pattern having the smallest value from among the measured outer diameters V1 to V6 (Step S12d). In the case of this embodiment, it is assumed that the outer diameter V4 of the spot pattern P4 has the smallest value, and the spot pattern analyzing means 34 of the control unit 30 selects the spot pattern P4. In the spot pattern forming step S11, the amount of displacement +ΔB1 which represents the distance between the positions of application is coordinated with the voltage value by the coefficient a in the Step S11b, whereby the spot patterns are formed. Therefore, the spot pattern having the smallest outer diameter is easily selected from the shapes and the state of arrangement of the spot patterns P1 to P6 without depending on detailed measurement. Subsequently, the spot pattern analyzing means 34 of the control unit 30 reads out the voltage values A1 to A6 of the objective lens 12 set when the respective spot patterns P1 to P6 are formed from the storage unit 35. Then, whether the voltage value A4 corresponding to the selected spot pattern P4 is smallest or largest is determined in comparison with the voltage values A1 to A3, A5, A6 corresponding to the other spot patterns P1 to P3, P5, P6 (Step S12e). In this embodiment, since the voltage value A4 corresponding to the selected spot pattern P4 is larger than the voltage values A1 to A3 and smaller than the voltage values A5, A6, the procedure goes to the next step. Subsequently, whether the outer diameter V4 of the selected spot pattern P4 is not larger than an outer diameter reference value V0 which is a preset spot reference value or not is determined (Step S12f). Here, the outer diameter V4 of the selected spot pattern P4 is assumed to be smaller than the outer diameter reference value V0, and the procedure goes to the next step, that is, an input value setting step S13. In the input value setting step S13, the control unit 30 extracts the voltage value A4 of the objective lens 12 corresponding to the spot pattern P4 selected in the spot pattern analyzing step S12 again from the storage unit 35. Then, the control unit 30 sets the voltage value of the objective lens 12 to the extracted voltage value A4. Here, when the focal length of the objective lens 12 and the separation distance H between the objective lens 12 and the surface N1 of the standard sample N are substantially the same as described above, and hence being in focus, the outer diameter of the spot pattern is small. Therefore, by selecting the spot pattern P4 having the smallest outer diameter and setting the same to the corresponding voltage value A4, the focal length of the objective lens 12 as the beam characteristic value is adjusted to the separation distance H between the objective lens 12 and the surface N1 of the standard sample N, whereby focusing is obtained. Incidentally, in the Step S12e of the spot pattern analyzing step S12, the voltage value corresponding to the selected spot pattern might be the smallest or the largest in comparison with the voltage values corresponding to the other spot patterns. In other words, for example, it is assumed that the voltage value is changed from the voltage values A1 to A6 to form spot patterns Pa1 to Pa6 as shown in FIG. 7, and the spot pattern Pa6 is selected as the one having the smallest outer diameter. The voltage value A6 of the objective lens 12 corresponding to the spot pattern Pa6 is the largest in comparison with the other voltage values A1 to A5. Therefore, a spot pattern having a smaller outer diameter might be formed at a voltage value larger than the voltage value A6. Therefore, the spot pattern analyzing means 34 of the control unit 30 causes the spot pattern forming step S11 to be performed again. Then, in this case, the spot pattern forming means 33 of the control unit 30 changes the voltage value within a range including voltage values larger than the voltage value A6 corresponding to the spot pattern Pa6 selected in the spot pattern analyzing step S12 to form spot patterns. For example, it is assumed that spot patterns Pa7, Pa8 are formed at a voltage value A7 which is larger than the voltage value A6 by the amount of change +ΔA1 and a voltage value A8 which is further larger than that by the amount of change +ΔA1 respectively in the range larger than the voltage value A6. Since the positions of application are the same as described above, the description will be omitted. In this configuration, the spot pattern Pa7 having an outer diameter smaller than the spot pattern Pa6 which is selected first can be selected in the spot pattern analyzing step S12 again, and by setting the voltage value of the objective lens 12 to the voltage value A7 corresponding to the spot pattern Pa7, the focal length is adjusted to a length substantially the same as the separation distance H with a higher degree of accuracy. If the voltage value corresponding to the selected spot pattern is the smallest in comparison with the voltage values corresponding to the other spot patterns in the Step S12e of the spot pattern analyzing step S12, the voltage value may be changed within the range smaller than the voltage value corresponding to the selected spot pattern. Also, in the Step S12f of the spot pattern analyzing step S12, there may be a case where the outer diameter of the selected spot pattern is larger than the preset outer diameter reference value V0. In other words, as shown in FIG. 8(a) for example, it is assumed that the voltage value is changed from the voltage values A1 to A6 and spot patterns Pb1 to Pb6 are formed. Then, it is assumed that the spot pattern Pb4 formed with the voltage value A4 as the voltage value of the objective lens 12 is selected as the one having the smallest outer diameter and a corresponding outer diameter Vb4 is larger than the outer diameter reference value V0. In this case, there might exist a voltage value whose amount of change +ΔA1 of the voltage value set by the spot pattern forming means 33 is large and which achieves the smaller outer diameters as an intermediate value. Therefore, the spot pattern analyzing means 34 of the control unit 30 causes the spot pattern forming step S11 to be performed again. Then, in this case, the spot pattern forming means 33 of the control unit 30 resets the currently set amount of change +ΔA1 to an amount of change +ΔA2 which is smaller than that. Then, the voltage value is changed by the amount of change +ΔA2 within a range including the range before and after the voltage value A4 corresponding to the spot pattern Pb4 selected in the spot pattern analyzing step S12, that is, within the range from the voltage values A3 to A5, and the spot patterns Pb3, Pb9 to P11, and P5 are formed at the voltage values A3, A9 to A12, A5. Accordingly, a spot pattern Pb10 whose outer diameter is not larger than the outer diameter reference value V0 may be selected, so that the voltage value of the objective lens 12 can be adjusted to a voltage value A10 so that the focal length becomes substantially the same as the separation distance with a higher degree of accuracy. By changing the setting of the coefficient α in the Step S11c, even when the amount of change of the voltage value is reduced from the amount of change +ΔA1 to the amount of change +ΔA2, the spot patterns can be formed clearly without being overlapped with each other. Accordingly, when the adjustment of the focal length of the ion beam I by the objective lens 12 is ended, then the correction of the astigmatism of the ion beam I by the stigmator 16 is performed as a stigmator adjusting step S20. In other words, first, the surface N1 of the standard sample N is irradiated with the ion beam I at a plurality of points within a range different from that in the objective lens adjusting step S10 to form the plurality of spot patterns as a spot pattern forming step S21. It is further preferable to perform the following steps with the voltage value of the objective lens 12 constant at a value larger or smaller than the voltage value set in the objective lens adjusting step S10. Accordingly, the ion beam I is brought into a state of over focus or under focus, and hence a large spot pattern is formed, so that the identification of the spot patterns in a spot pattern analyzing step S22 descried later is achieved easily. The spot pattern forming means 33 of the control unit 30 sets a voltage value C1 of the stigmator 16 as an initial value (Step S21a). Here, the voltage value C1 includes a first voltage value D1 to be applied between a positive pole 219a and a negative pole 21b of the first multi-pole 21 and a second voltage value E1 to be applied between a positive pole 22a and a negative pole 22b of the second multi-pole 22, and is expressed as the voltage value C1 (D1, E1) hereinafter. Subsequently, an irradiation point F1 of the ion beam I on the standard sample N is set by the scanning electrode 17 (Step S21b). The irradiation point F1 here includes an X coordinate X1 which represents the position in the X-direction and a Y coordinate Y1 representing the position in the Y-direction, and is expressed by the irradiation point F1 (X1, Y1) hereinafter. Then, the surface N1 of the standard sample N is irradiated with the ion beam I for a certain period of time to form a spot pattern Q1 as shown in FIG. 9 (Step S21c). Here, the shape of the spot pattern Q1 is deformed in the X-direction and the Y-direction according to the first voltage value D1, and assumes an oval shape deformed in the X′-direction and the Y′-direction shifted from the X-direction and Y-direction by 45 degrees according to the second voltage value E1. If the spot patterns are formed at a preset number of positions by the spot pattern forming means 33 of the control unit 30, the procedure goes to the next step and, if not, the procedure goes back to Step S2la again (Step S21d). In this embodiment, the spot pattern forming means 33 of the control unit 30 is assumed to be set to form the spot pattern at sixteen positions in total. Therefore, the procedure goes back to Step S21a determining that all the spot patterns are not yet formed. In other words, the spot pattern forming means 33 of the control unit 30 resets the voltage value of the stigmator 16 to a voltage value C2 (D1, E2) (Step S21a). Here, assuming that the amount of change of the voltage value of the stigmator 16 is +ΔC1, a first amount of change +ΔD1 for the first voltage value and a second amount of change +ΔE1 for the second voltage value are set in advance. Although the first voltage value and the second voltage value may be changed simultaneously as the voltage value of the stigmator 16 on the basis of the preset amount of change, sixteen different sets of voltage values C1 to C16 are composed by combining four each of values of first voltage values D1 to D4 at the first amount of change +ΔD1 and second voltage values E1 to E4 at the second amount of change +ΔE1, respectively, in this embodiment for the sake of clarity. Then, the irradiation point of the ion beam I is reset to an irradiation point F2 (X2, Y1) (Step S21b). The irradiation point of the ion beam I here is set to a position displaced by an amount of displacement obtained by multiplying the amount of change of the voltage value by a predetermined coefficient β. In other words, a first amount of displacement +ΔX1 (=β×(+ΔD1)) corresponding to the first amount of change +ΔD1 is obtained. Also, a second amount of displacement +ΔY1 (=β×(+ΔE1)) corresponding to the second amount of change +ΔE1 is obtained. Then, sixteen different sets of irradiating points F1 to F16 are composed by combining four each of values of X coordinates X1 to X4, and Y coordinates Y1 to Y4 corresponding to the first voltage value and the second voltage value. An operation to irradiate the surface N1 of the standard sample N with the ion beam I for a certain period of time is repeated at the positions of application F1 to F16 corresponding to the voltage values C1 to C16, so that the sixteen corresponding spot patterns Q1 to Q16 are formed in total (Step S21c) as shown in FIG. 9. Then, these spot patterns Q1 to Q6 assume a substantially circular shape or a oval shape elongated in either direction according to the corresponding voltage values C1 to C16 (D1 to D4, E1 to E4). Substantially, the plurality of spot patterns Q1 to Q16 formed in the spot pattern forming step S21 are analyzed as the spot pattern analyzing step S22. First of all, an image of the surface N1 of the standard sample N is obtained by the observing means 32 (step S22a), and the image is binarized by the spot pattern analyzing means 34 of the control unit 30 (Step S22b), so that the image as shown in FIG. 9 is obtained. Then, the spot pattern analyzing means 34 of the control unit 30 measures the smallest outer diameter (short diameter) and the largest outer diameter (long diameter) of the respective spot patterns Q1 to Q16 from the obtained image as the spot characteristic values representing the shapes of the spot patterns, and calculates ratios of the long diameter with respect to the short diameter (hereinafter referred to as outer diameter ratios) W1 to W16 (Step S22c). Then, the spot pattern analyzing means 34 of the control unit 30 selects a spot pattern which has the smallest outer diameter ratio, that is, which assumes the most circular shape (Step S22d). In the case of this embodiment, it is assumed that the outer diameter ratio W7 of the spot pattern Q7 has the smallest value, and the spot pattern analyzing means 34 of the control unit 30 selects the spot pattern Q7. In the spot pattern forming step S21, an amount of change +ΔF1 which represents the distance between the positions of application is coordinated with the voltage value by the coefficient β in the Step S21b, whereby the spot patterns are formed. Therefore, the spot pattern having the smallest outer diameter ratio and assuming the substantially oval shape is easily selected from the shapes and the state of arrangement of the spot patterns Q1 to Q6 without depending on detailed measurement. Subsequently, the spot pattern analyzing means 34 of the control unit 30 extracts the voltage values C1 to C16 of the stigmator 16 set when the respective spot patterns Q1 to Q16 are formed from the storage unit 35. Then, whether the first voltage value D3 and the second voltage value E2 which constitute the voltage value C7 corresponding to the selected spot pattern Q7 are respectively the smallest or the largest is determined in comparison with the first voltage values D1 to D4 and the second voltage values E1 to E4 corresponding to the other spot patterns Q1 to Q6, Q8 to Q16 (Step S22e) respectively. In this embodiment, at the voltage value C7 corresponding to the selected spot pattern Q7, the first voltage value D3 is larger than other first voltage values D1, D2 and smaller than the first voltage value D4, and the second voltage value E2 is larger than another second voltage value E1 and smaller than the second voltage values E3, E4. Therefore, the procedure goes to the next step. Subsequently, whether the outer diameter ratio W7 of the selected spot pattern Q7 is not larger than an outer diameter ratio reference value W0 which is a preset spot reference value or not is determined (Step S22f). Here, the outer diameter ratio W7 of the selected spot pattern Q7 is assumed to be smaller than the outer diameter ratio reference value W0, and the procedure goes to the next step, that is, an input value setting step S23. In the input value setting step S23, the control unit 30 extracts the voltage value C7 (D3, E2) of the stigmator 16 corresponding to the spot pattern Q7 selected in the spot pattern analyzing step S22 again from the storage unit 35 (Step S23a). Then, the control unit 30 sets the first voltage value of the first multi-pole 21 and the second voltage value of the second multi-pole of the stigmator 16 as the extracted voltage value C7 (Step S23b). Here, when the beam diameter ratio of the ion beam I in two orthogonal directions is substantially equal to 1 and the cross-sectional shape assumes a substantially circular shape, the outer diameter ratio of the spot pattern is also reduced. Therefore, by selecting the spot pattern Q7 having the smallest outer diameter ratio and setting the same to the corresponding voltage value C7, the beam diameter of the ion beam I as the beam characteristic value is adjusted to be substantially equal to 1, that is, so as to be the substantially circular shape, whereby the astigmatism is corrected. Incidentally, in the Step S22e of the spot pattern analyzing step S22, the first voltage value or the second voltage value which constitutes a voltage value corresponding to the selected spot pattern might be the smallest or the largest in comparison with the first voltage value or the second voltage value which constitutes a voltage value corresponding to the other spot patterns. In this case as well, the same procedure as the Step S11a of the spot pattern forming step S11 in the objective lens adjusting step S10 may be performed. In other words, if the one or both of the first voltage value or the second voltage value is the smallest, the first voltage value or the second voltage value may be changed within a range including a value smaller than the corresponding first voltage value or the second voltage value. Also, also, if it is the largest, the first voltage value or the second voltage value may be changed within a range including a value larger than the corresponding first voltage value or the second voltage value. Accordingly, the ion beam I having the beam diameter ratio substantially equal to 1 and having a substantially circular cross-sectional shape may be adjusted so as to be irradiated with a higher degree of accuracy on the basis of the outer diameter ratio of the formed spot pattern. Also, in the Step S22f of the spot pattern analyzing step S22, there may be a case where the outer diameter ratio of the selected spot pattern is larger than the preset outer diameter ratio reference value W0. In this case as well, the same procedure as the Step S11a of the spot pattern forming step S11 in the objective lens adjusting step S10 may be performed. In other words, the currently set amount of change +ΔC1 (+ΔD1, +ΔE1) is reset to an amount of change +ΔC2 (+ΔD2, +ΔE2) which is smaller than that. Then, the voltage value may be changed on the basis of the above-described amount of change within a range including respective values before and after the first voltage value and the second voltage value corresponding to the spot patterns selected in the spot pattern analyzing step S22. Accordingly, the ion beam I having the beam diameter ratio substantially equal to 1 and having a substantially circular cross-sectional shape may be adjusted so as to be irradiated with a higher degree of accuracy on the basis of the outer diameter ratio of the formed spot pattern. Finally, as a processing and observation preparing step, the control unit 30 drives the five-axis stage 6 provided on the sample base 2 to adjust the position of the target sample M on the XY plane, so that the target sample M is moved to the irradiation point of the ion beam I, whereby the processing or the observation of the same by the ion beam I is enabled. As described above, in the focused ion beam apparatus 1 in this embodiment, since the control unit 30 includes the spot pattern forming means 33 and the spot pattern analyzing means 34, the respective voltage values of the objective lens 12 and the stigmator 16 may be adjusted so that the focusing length of the ion beam I and the beam diameter ratio become desired values automatically, and easily in a short time with a high degree of accuracy only by forming the plurality of spot patterns on the sample both for the objective lens 12 and the stigmator 16 respectively. Although the control unit 30 is described to perform automatically in this embodiment, the adjustments of the objective lens 12 and the stigmator 16 are achieved with a high degree of accuracy easily in a short time according to the procedure described above even it is performed manually. Also, as regards the adjustment of the objective lens 12 and the stigmator 16 in this embodiment, the adjustment of the objective lens 12 is performed at the beginning. However, the present invention is not limited thereto. In addition, a configuration in which the adjustment is repeated after having completed a series of steps relating to the adjustment of the objective lens 12 and the stigmator 16 is also applicable. In this configuration, the formed spot pattern assumes a substantially circular shape by adjusting the stigmator 16 after having adjusted the objective lens 12 for example, and by adjusting the objective lens 12 again in this state, the focusing with a higher degree of accuracy is achieved. In this embodiment, since at least two samples, that is, the target sample M and the standard sample N can be arranged on the sample base 2, it is not necessary to release the vacuum chamber 4 and replace the sample after having adjusted the charged particle optic, so that the target sample M can be moved quickly to the irradiation point of the ion beam I for the processing and the observation of the target sample M. Also, in this embodiment, although the stigmator 16 includes the first multi-pole and the second multi-pole each having four poles as the positive pole and the negative pole, the present invention is not limited thereto. For example, a configuration having only the first multi-pole is also applicable. Alternatively, even in a configuration having more than four poles such as six poles, eight pole, ten poles and so forth as the configuration of the electrodes of the first multi-pole and the second multi-pole, the adjustment is achieved in the same method. In addition, in a configuration in which the plurality of sets of the multi-poles are arranged in the Z-direction, the same method can be applied. FIG. 9 to FIG. 11 show modifications of the stigmator adjusting step in this embodiment. As shown in FIG. 10, in the stigmator adjusting step S30 in this modification, the focal point of the objective lens 12 is brought to a state of over focus as a preparation step S31. Then, the spot pattern forming step S21 (first step) is performed. Details of the spot pattern forming step S21 are the same as described above, that is, as shown in FIG. 9, the plurality of spot patterns Q1 to Q16 are formed on the surface N1 of the standard sample N. Then, whether this step is performed both in the state of over focus and in the state of under focus or not is determined (Step S21e). Since the step is not performed in the state of under focus, the procedure goes to the preparation step S31 again, where the state of the focal point of the objective lens 12 is changed from the state of the over focus to the state of the under focus. Then, the spot pattern forming step S21 (second step) is performed again. In this case, as shown in FIG. 11, the conditions of the voltage values C1 to C16 of the stigmator 16 are matched and spot patterns Q′1 to Q′16 are formed in the same arrangement. Then, since the spot patterns are formed both in the state of the over focus and in the state of the under focus, the procedure goes to the next step (Step S21e) . Substantially, the plurality of spot patterns Q1 to Q16 and the spot patterns Q′1 to Q′16 formed in the first step and the second step of the spot pattern forming step S21 are analyzed as a spot pattern analyzing step S32. First of all, an image including the spot patterns Q1 to Q16 in the first step as a group and an image including the spot patterns Q′1 to Q′16 in the second step as a group are obtained respectively on the surface N1 of the standard sample N by the observing means 32 (Step S32a), and the images are binarized by the spot pattern analyzing means 34 of the control unit 30 (Step S32b), so that the images shown in FIG. 9 and FIG. 11 are obtained. Then, pattern matching of the spot patterns Q1 to Q16 in the first step and the spot patterns Q′1 to Q16 in the second step having the same voltage value is performed (Step S32c). Then, the set of the spot patterns which achieves the highest ratio of matching of the pattern matching elements is selected (Step S32d). Here, when the spot patterns Q′1 to Q′16 in the second step are compared with the corresponding spot patterns Q1 to Q16 in the first step respectively, they assume the substantially same shapes since the respective voltage values are the same C1 to C16. In contrast, since the state of the focal point is different between the over focus and the under focus, the directions of the charged particle beams are different by approximately 90 degrees, that is, the directions of the respective spot patterns are different by approximately 90 degrees. Therefore, the ratio of matching of the pattern matching elements is low among the spot patterns assuming the oval shape, the ratio of matching of the pattern matching elements is high among the substantially circular spot patterns. Therefore, by selecting the set of the spot pattern having the highest ratio of matching of the pattern matching elements, the set of the spot patterns Q7, Q′7 being almost a circle, that is, having the outer diameter ratio W as the spot characteristic value is substantially equal to 1, and having the smallest value may be selected. Here, the spot patterns Q1 to Q16 and the spot patterns Q′1 to Q16 have the same conditions of the voltage values C1 to C16, and are arranged in the same arrangement, the pattern matching of the images relating to the spot patterns Q1 to Q16 and of the images relating to the spot patterns Q′1 to Q′16 are achieved at once. Therefore, selection of the set of the spot patterns Q7, Q′7 having the smallest outer diameter ratio is achieved more effectively and easily. Then, by setting the voltage value of the stigmator 16 to the voltage value C7 corresponding to the spot patterns Q7, Q′7 selected in the input value setting step S23, the ion beam I having the beam diameter ratio substantially equal to 1 and having a substantially circular cross-sectional shape can be adjusted so as to allow irradiation. (Second Embodiment) FIG. 12 shows a second embodiment of the present invention. In this embodiment, common members as the members used in the embodiment described above are designated by the same reference numerals, and description will be omitted. As shown in FIG. 12, a focused ion beam apparatus 40 in this embodiment includes a SEM column 42 as an observing means 41. Then, by using the SEM column 42 and the secondary electronic detector 24 as means for obtaining the image used in the spot pattern analyzing steps S12, S22, adjustment of the objective lens 12 and the stigmator 16 as the charged particle optics is achieved on the basis of the image with a higher degree of accuracy. In this case, the five-axis stage 6 is tilted and the target sample M or the standard sample N is arranged so that the surface of the target sample M or the standard sample N becomes substantially vertical to the center axis of the SEM column 42. It is also possible to perform the adjustment of the objective lens and the stigmator, not shown, as the charged particle optics by the SEM column 42 as well instead of the ion beam column 3. Here, in the SEM column 42, the objective lens includes a coil, and the electron beam is focused by the action of the magnetic field formed by the coil. Therefore, the current value of the coil of the objective lens is set as an input value to adjust the focal length. In the same manner, in the stigmator as well, by setting the current value of the coil included therein, the strength of the magnetic field which acts thereon is changed, and the beam diameter ratio is adjusted. (Third Embodiment) FIG. 13 shows a third embodiment of the present invention. In this embodiment, common members as the members described above are designated by the same reference numerals, and description will be omitted. As shown in FIG. 13, a focused ion beam apparatus 50 in this embodiment further includes a rare gas ion beam column 51. The rare gas ion beam column 51 is able to irradiate with rare gas ion such as argon ion as an ion beam at a low speed, and is able to process the sample without giving damage thereto, which is used preferably for the finish machining using in the normal processing with the ion beam. With such the focused ion beam apparatus 50, the adjustment of the objective lens or the stigmator, not shown, is achieved as the charged particle optics not only as the ion beam ion beam column 3, but also as the SEM column 42 or the rare gas ion beam column 51 in the same manner. (Fourth Embodiment) FIG. 14 and FIG. 15 show a fourth embodiment of the present invention. In this embodiment, common members as the members used in the embodiment described above are designated by the same reference numerals, and description will be omitted. As shown in FIG. 14, a focused ion beam apparatus 60 in this embodiment further includes a gas introduction mechanism 61. In the focused ion beam apparatus 60, deposition is achieved by irradiating with the ion beam I and introducing organic gas onto the surface of the sample by the gas introduction mechanism 61. Therefore, in the focused ion beam apparatus 60 in this embodiment, the spot patterns are not formed by the etching of the sample, but the spot patterns may be formed by deposition in the spot pattern forming step. In other words, protruding spot patterns R as shown in FIG. 15 are formed at the positions of application by introducing organic gas G thereto by the gas introduction mechanism 61 and irradiating the same with the ion beam I. With the protruding spot pattern R, they can be identified from the image obtained by the observing means, and hence the adjustment of the objective lens or the stigmator as the charged particle optics is achieved on the basis of the similar spot patterns R. Although the embodiments of the present invention have been described in detail referring to the drawings, detailed configurations are not limited to these embodiments, and modifications in design without departing the scope of the present invention are also included. Incidentally, although the focused ion beam apparatus has been exemplified in the respective embodiments as the charged particle beam apparatus, the present invention is not limited thereto. For example, an ion beam exposure apparatus or the like is exemplified as the apparatus in which the ion beam is used as the charged particle beam in the same manner. Also, as the apparatus using the electron beam as the charged particle beam, a scanning electron microscope, an electron beam exposure apparatus, and so on are exemplified. In these apparatuses as well, by providing the same configuration as the control unit, the objective lens or the stigmator as the integrated charged particle optics are automatically and easily adjusted in a short time with a high degree of accuracy. As the standard sample, although those on which the spot patterns can be formed by the etching or the deposition is selected, in addition to it, a resist film is also selected. In this case, by irradiating the resist film as the standard sample with the charged particle beam for exposure, the same adjustment is achieved by the exposure pattern.
	description	1. Field of the Invention The present invention relates to a charged particle beam apparatus that uses a charged particle beam such as an electron beam and an ion beam to observe and process a sample. 2. Description of the Related Art In objects observed by a charged particle beam apparatus, a semiconductor device has a circuit pattern which has been miniaturized. Therefore, in addition to increase the sensitivity of an optical system, methods for inspecting and processing a semiconductor wafer by using a charged particle beam have attracted attention. An inspection device using a scanning electron microscope (SEM) has been developed. In order to inspect a semiconductor wafer on which a semiconductor device is formed, a defect review SEM and a critical dimension SEM are used. The defect review SEM is designed to use an optical image or an image obtained by scanning using a charged particle beam, detect a defect based on the image, and observe and categorize the defect. The critical dimension SEM is designed to measure the size of a pattern. In addition, the following techniques have been development: a technique for processing a defect using a focused ion beam (FIB) system; a technique for observing inclination of a sample using a SEM; a technique for analyzing a defect using an X ray; and the like. The structure and material of the semiconductor device have become increasingly complex. It has therefore been general that multiple inspection methods are used to organize inspected data. A device having multiple inspection functions has been proposed (refer to, for example, JP-A-2006-294481A1). On the other hand, there is a tendency that the diameter of a semiconductor device increases. Especially, since a charged particle beam scheme requires a vacuum chamber, a charged particle beam apparatus needs to have a large size. These affairs result in an increase in cost of an inspection system, reduction in the throughput of the device due to the increase in the size, and increase in risk of attachment of a foreign material to a wafer during transfer of the wafer in the complex inspection processes. This causes reduction in reliability for the inspection which is the most important matter primarily. The sizes of positioning stages provided in an electron beam device and an ion beam device have increased. This result in an increase in resistance required for driving each stage and an increase in residual vibration. Therefore, as well as decreasing of accuracy of the inspection and increasing of the time period to move the stage, increase in the time period for evacuation leads to a reduction in the throughput of the device. Installment of an inspection device having a large vacuum chamber in an expensive clean room may burden a user of the device with a large cost. An object of the present invention is to provide a charged particle beam apparatus, which can be constructed with a smaller size (resulting in a small installation space) and a lower cost, suppress vibration, operate at higher speed, and be reliable in inspection. The charged particle beam apparatus is largely effective when a wafer having a large diameter is used. To accomplish the above object, the charged particle beam apparatus according to the present invention comprises: a plurality of inspection mechanisms, each of which is mounted on a vacuum chamber and has a charged particle beam mechanism for performing at least one inspection on the sample; a single-shaft transfer mechanism that moves the sample between the inspection mechanisms in the direction of an axis of the single-shaft transfer mechanism; and a rotary stage that mounts the sample thereon and has a rotational axis on the single-shaft transfer mechanism, wherein the single-shaft transfer mechanism moves the sample between the inspection mechanisms in order that the sample is placed under any of the inspection mechanisms. The rotary stage positions the sample such that a target portion of the sample can be inspected by the inspection mechanism under which the sample is placed, and the inspection mechanisms inspect the sample. As described above, the charged particle beam apparatus according to the present invention can be constructed with a smaller size (resulting in a small installation space) and a lower cost, suppress vibration, operate at higher speed, and be reliable in inspection. The charged particle beam apparatus is largely effective when a wafer having a large diameter is used. An embodiment of the present invention is described below. In order to accommodate to the increase in the diameter of a wafer and complex inspection processes, a plurality of inspection mechanisms are mounted on a single vacuum chamber, and a rotary stage and a single-shaft transfer mechanism are used to move a sample. That is, the single-shaft transfer mechanism is used to transfer the sample between the inspection mechanisms, and the rotary stage and a single-shaft transfer stage are used to position a target portion of the sample wafer. This configuration makes it possible to use the vacuum chamber having a size equal to or smaller than the half the size of a conventional XY transfer stage, suppress an increase in the weight of a movable part, and reduce the size of a charged particle beam apparatus according to the present embodiment compared with conventional techniques. This reduces a space to install the charged particle beam apparatus and a cost of the device, compared with the conventional techniques. Further, since two inspection devices are mounted on the single vacuum chamber, this configuration can prevent a foreign material from being attached to the wafer during transfer of the wafer between the inspection devices. In addition, since the rotary stage can suppress unnecessary vibration, positioning of the sample can be performed at high speed. In addition, reliability in detection of a defect and in measurement of the size of the defect, and operability of the device, are improved by sharing image information obtained from each of the inspection mechanisms, with its supplementary information such as coordinates of the defect, the height and size of the defect, and contrast of the image. These effects are remarkable when a wafer having a large outer diameter of 450 millimeters or more is used. FIG. 1 is a vertical cross sectional view of the outline configuration of the charged particle beam apparatus. In FIG. 1, a wafer 8 is placed in a vacuum chamber 12. Two respective charged particle beam columns are mounted on the vacuum chamber 12. One of the charged particle beam columns is an SEM that irradiates the wafer 8 with an electron beam, detects a secondary signal generated from the wafer 8 and detects a defect based on the secondary signal. This SEM is hereinafter called a defect inspection SEM. The other one of the charged particle beam columns is an SEM that magnifies and images the defect detected by the defect inspection SEM, and categorizes the defect based on a characteristic amount of the defect. This SEM is hereinafter called a defect review SEM. A rotary stage 10 and a single-shaft transfer stage 11 are provided in the vacuum chamber 12. The wafer 8 is first positioned under the defect inspection SEM by the rotary stage 10 and the single-shaft transfer stage 11. The defect inspection SEM inspects the entire surface of the wafer 8 although a spot size of the electron beam on the surface of the wafer is small. In order to reduce the number of times of scanning operations using the electron beam and create a single image at high speed, the defect inspection SEM uses a large current to irradiate the wafer 8 with the electron beam. The defect inspection SEM has an electron source 1b, a first irradiation lens 2b, a limiting diaphragm 3b, a second irradiation lens 4b, a detector 5b, a deflector 6b, and an objective lens 7b. A large current is supplied to the electron source 1b. Then, the electron source 1b emits an electron beam. The electron beam emitted by the electron source 1b is converged by the first irradiation lens 2b and the limiting diaphragm 3b. The convergence angle of the electron beam is controlled by the second irradiation lens 4b. Then, the objective lens 7b passes the electron beam and focuses the electron beam on the wafer 8. The deflector 6b deflects the electron beam to scan the wafer 8. After the objective lens 7b focuses the electron beam on the wafer 8, an image signal (secondary signal) is generated from the wafer 8. The detector 5b receives the image signal to obtain information (hereinafter referred to as defect information) on a defect present on the wafer 8 (sample). The defect inspection SEM has a control electrode 13. The control electrode 13 controls an electrostatic charge on the surface of the wafer 8 and the trajectory of the electron beam. The control electrode 13 allows for detection of a difference in potential due to the electrostatic charge, an insulated state, a foreign material, an irregularity of a pattern, and the like, with predetermined sensitivity. Then, the single-shaft transfer stage 11 is driven by a drive system 9 to transfer the wafer 8 inspected and placed on the rotary stage 10 in the vacuum chamber 12 and place the inspected wafer 8 under the defect review SEM. The defect information includes coordinates of the defect, the size of the defect, contrast of the image, and the like. The defect information obtained by the defect inspection SEM is stored in a storage device (not shown) and used to search the defect by means of the defect review SEM. The defect review SEM has an electron source 1a, a first irradiation lens 2a, a limiting diaphragm 3a, a second irradiation lens 4a, a detector 5a, a deflector 6a, and an objective lens 7a. The electron source 1a emits an electron beam. The electron beam emitted by the electron source 1a is converged by the first irradiation lens 2a and the limiting diaphragm 3a. A convergence angle of the electron beam is controlled by the second irradiation lens 4a. Then, the objective lens 7a passes the electron beam and focuses the electron beam on the wafer 8. The deflector 6a deflects the electron beam to scan the wafer 8. After the objective lens 7a focuses the electron beam on the wafer 8, an image signal (secondary signal) is generated from the wafer 8. The detector 5a receives the image signal and thereby obtains an image of the scanned wafer. The defect review SEM searches the defect based on the coordinates included in the defect information obtained by the defect inspection SEM. When the defect review SEM finds the defect, the defect review SEM magnifies and images the defect. A calculator (not shown) categorizes the type of the defect based on the image indicative of the defect. Therefore, a user can specify a process during which the defect is generated and identify the cause of the generation of the defect, based on the information related to the defect. The charged particle beam apparatus having the configuration shown in FIG. 1 can efficiently perform the operations from the detection of the defect of the wafer 8 to the categorization of the defect at high speed and low risk. Since the defect inspection SEM performs comparison processing to obtain a difference between a reference image (not including a defect) and the image obtained by the inspection and thereby to extract the defect, the defect inspection SEM may erroneously detect a non-defective pixel (such as noise of an image) as a defect. The defect inspection SEM can easily inspect an area corresponding to coordinates of a defect that cannot be extracted by the defect review SEM. FIG. 2 is a vertical cross sectional view of another example of the outline configuration of the charged particle beam apparatus. The charged particle beam apparatus shown in FIG. 2 includes a defect review SEM and an SEM (hereinafter referred to as an oblique observation SEM) adapted to observe a sample from a direction oblique to a normal to the surface of the sample (wafer 8). The defect review SEM and the oblique observation SEM are mounted on the vacuum chamber 12. The defect review SEM shown on the left side of FIG. 2 has the same configuration and functions as those of the defect review SEM shown in FIG. 1. The oblique observation SEM shown on the right side of FIG. 2 has an electron source 1c, a first irradiation lens 2c, a limiting diaphragm 3c, a second irradiation lens 4c, a detector 5c, a deflector 6c, and an objective lens 7c. The electron source 1c emits an electron beam. The electron beam emitted by the electron source 1c is converged by the first irradiation lens 2c and the limiting diaphragm 3c. A spreading angle of the electron beam is then controlled by the second irradiation lens 4c. The objective lens 7c then passes the electron beam and focuses the electron beam on the wafer 8. The deflector 6c deflects the electron beam to scan the wafer 8. The detector 5c receives an image signal from the scanned wafer 8. An X ray detector may be added to the oblique observation SEM in order to analyze a material of a defect present on the surface of the sample (wafer). In an inspection process, the deflector 6a provided in the defect review SEM deflects the electron beam to scan the wafer 8 at high speed. The defect review SEM obtains information (defect information) on the defect present on the wafer 8, such as the size of the defect, coordinates of the defect, and image contrast. That is, the defect review SEM obtains an image indicative of the defect. The defect review SEM categorizes the type of the defect based on the image indicative of the defect, and displays the defect. The rotary stage 10 provided on the single-shaft transfer stage 11 moves to place the wafer 8 (inspected by the defect review SEM) under the oblique observation SEM. The defect review SEM transmits the defect information to a controller (not shown) provided in the oblique observation SEM. The oblique observation SEM emits an electron beam and irradiates the wafer 8 with the electron beam from a direction oblique to a normal to the surface of the wafer 8. Then, the oblique observation SEM analyzes an irregularity of the defect and a component of the defect to obtain detail information on the defect. That is, the oblique observation SEM can observe the defect. It should be noted that the oblique observation SEM can observe an edge portion of the wafer 8 as well as from the oblique direction, since a defect such as abrasion may easily occur at the edge portion of the wafer 8. FIG. 3 is a vertical cross sectional view of another example of the outline configuration of the charged particle beam apparatus. The charged particle beam apparatus shown in FIG. 3 includes a defect review SEM and a focus ion beam (FIB) device. The defect review SEM and the FIB device are mounted on the single vacuum chamber 12. The defect review SEM shown on the left side of FIG. 3 has the same configuration and functions as those of the defect review SEM shown in FIG. 1. The FIB device has an ion source 1d, a static irradiation lens 2d, an ion current limiting diaphragm 3d, a detector 5d, a deflector 6d, and a static objective lens 7d. The ion source 1d emits an ion beam. The ion beam emitted by the ion source 1d is converged by the static irradiation lens 2d and the ion current limiting diaphragm 3d. The static objective lens 7d then passes the ion beam and focuses the ion beam on the wafer 8. The deflector 6d deflects the ion beam to scan the wafer 8. The detector 5d receives an image signal from the scanned wafer 8. In an inspection process, the defect review SEM obtains information (defect information) on a defect present on the wafer 8, such as the size of the defect, coordinates of the defect, and image contrast. That is, the defect review SEM obtains an image indicative of the defect. The defect review SEM categorizes the type of the defect based on the image indicative of the defect, and displays the defect. The rotary stage 10 provided on the single-shaft transfer stage 11 moves to place the wafer 8 (inspected by the defect review SEM) under the FIB device. The defect review SEM transmits the defect information to a controller (not shown) provided in the FIB device. The FIB device cuts an image indicative of a wafer portion including the defect from the obtained image, and observes a three dimensional structure of the wafer portion including the defect through an X ray analysis. FIG. 4 is a vertical cross sectional view of another example of the outline configuration of the charged particle beam apparatus. The charged particle beam apparatus shown in FIG. 4 includes a defect review SEM and an optical inspection device. The defect review SEM and the optical inspection device are mounted on the single vacuum chamber 12. The defect review SEM shown on the left side of FIG. 4 has the same configuration and functions as those of the defect review SEM shown in FIG. 1. The optical inspection device has an optical source 1e, a limiting diaphragm 3e, an optical detector 5d and an optical microscope 14. The optical source 1e emits a light beam. The light beam emitted by the optical source 1e is focused on the wafer 8 by the limiting diaphragm 3e and the optical microscope 14. The optical detector 5e receives an image signal from the wafer 8. The optical inspection device has a magnification lower than that of the defect review SEM. Therefore, the optical inspection device inspects the entire surface of the wafer 8 to detect a defect present on the wafer 8, and then, the defect review SEM magnifies and images the defect present on the wafer 8 based on coordinates of the detected defect to observe the defect in detail. The optical inspection device may have a bright field system and a dark field system. When the optical inspection device has the dark field system, an optical source that emits a laser beam is used. In the case where the optical inspection device and the defect review SEM are separately provided, when the wafer 8 is inspected before a pattern is formed, accuracy of a coordinate correction performed by the optical inspection device and the defect review SEM is low. It is therefore difficult that the defect review SEM detects a defect detected by the optical inspection device. However, the charged particle beam apparatus shown in FIG. 4 has the optical inspection device and the defect review SEM, which are mounted on the vacuum chamber 12. In addition, the charged particle beam apparatus has the common stages shared by the optical inspection device and the defect review SEM. Therefore, an error in the coordinates does not occur. The defect review SEM can easily detect a defect detected by the optical inspection device. FIG. 5 is a plan cross sectional view of the outline configuration of the charged particle beam apparatus and shows the charged particle beam apparatus shown in FIG. 1 as an example. FIG. 5 illustrates the detector 5a and deflector 6a of the defect review SEM, and the detector 5b and deflector 6b of the defect inspection SEM. The vacuum chamber 12 has a small length and a large length. The small length of the vacuum chamber 12 is a distance between opposed inner walls of the vacuum chamber 12, and is obtained by adding a margin to the outer diameter of the wafer 8. The large length of the vacuum chamber 12 is a distance between opposed inner walls of the vacuum chamber 12, and is obtained by adding a margin to the double of the outer diameter of the wafer 8. The wafer 8 is moved by the single-shaft transfer stage 11 (not shown in FIG. 5) in a longitudinal direction of the single-shaft transfer stage 11 and rotated by the rotary stage 10 (not shown in FIG. 5) in the vacuum chamber 12. A calculator 19 performs both control of electron beam and processing of the image obtained. The calculator 19 transmits digital data indicative of the deflection of the electron beam to a deflection control circuit 17. The deflection control circuit 17 generates digital data (deflection control data) used to control the deflection of the electron beam, and transmits the generated deflection control data to a deflection drive circuit 18. The deflection drive circuit 18 receives the deflection control data from the deflection control circuit 17 and converts the deflection control data into an analog deflection control signal. The deflection drive circuit 18 transmits the analog deflection control signal to the deflector 6a or the deflector 6b. In addition, the calculator 19 transmits stage control data to a stage control circuit 20. The stage control circuit 20 transmits a stage drive signal to a stage drive circuit 21. The stage drive circuit 21 drives the rotary stage 10 and the single-shaft transfer stage 11 based on the stage drive signal. The defect inspection SEM inspects the wafer 8, and the detector 5b detects an analog signal from the wafer 8. The detector 5b transmits the analog signal to a signal processing circuit 16. The signal processing circuit 16 converts the analog signal into a digital signal and transmits the converted digital signal to an image processing circuit 15. The image processing circuit 15 converts the digital signal into an image. The image processing circuit 15 compares the converted image with the reference image (not including a defect) to detect a defect and generate data (result data) on the result of the detection. The image processing circuit 15 transmits the result data to the calculator 19. The result data is stored in the storage device (not shown) provided in the calculator 19. Then, the wafer 8 is moved and placed under the defect review SEM. In this case, the wafer 8 is positioned in order that the defect review SEM detects the defect at a coordinate position of the defect included in the stored result data. The detector 5a detects a signal and transmits the detected signal through the signal processing circuit 16 to the image processing circuit 15 in the same manner as the detector 5b provided in the defect inspection SEM. The image processing circuit 15 converts the signal detected by the detector 5a into an image. The image processing circuit 15 compares the converted image with a reference image (not including a defect) to detect a defect. Alternatively, the image processing circuit 15 compares the converted image with the image stored and obtained by the defect inspection SEM to defect a detect. When the stage moves, a mechanical error may occur, and the position of the detected defect may be shifted due to the mechanical error. When the image processing circuit 15 cannot correct the shifted position of the defect, the deflection control circuit 17 controls the deflection of the electron beam to correct the shifted position of the defect. Alternatively, the stage control circuit 20 adjusts the position of the wafer 8 to correct the shifted position of the defect. After the defect is detected, the defect review SEM changes the magnification and images the defect at high magnification. The image obtained by the defect review SEM is stored in the storage device (not shown) provided in the calculator 19. The calculator 19 calculates a characteristic amount of the defect, such as the size and shape of the defect, based on the highly magnified image, and categorizes the defect. This calculation processing is repeated for the number of defects or the number of specified requirements. A plurality of pieces of information on the shifted position of the defect is stored in the storage device (not shown) provided in the calculator 19 as wafer position shift information. A technique such as a polynomial approximation method and an interpolation calculation of a memory map value can correct the shifted position of the defect with high accuracy. The calculator 19 adjusts a focal point of the electron beam emitted by the defect review SEM based on information on adjustment of the focal point of the electron beam. The information on the focal point of the electron beam is obtained by the defect inspection SEM when the defect inspection SEM obtains the image. The movement of the single-shaft transfer stage 11 shown in FIG. 1 is detected by an existing laser interferometer (not shown). The rotation of the rotary stage 10 is detected by an existing angle reader (not shown). The stage control circuit 20 corrects the shifted position of the single-shaft transfer stage 11 due to vibration and corrects the angle of the rotation of the rotary stage 10. As described above, the charged particle beam apparatus has a single set of the circuits (that are the image processing circuit 15, the signal processing circuit 16, the deflection control circuit 17 and the deflection drive circuit 18). The image processing circuit 15, the signal processing circuit 16, the deflection control circuit 17 and the deflection drive circuit 18 are shared by the defect inspection SEM and the defect review SEM as shown in FIG. 5. However, the charged particle beam apparatus may have two sets of the circuits (that are the image processing circuit 15, the signal processing circuit 16, the deflection control circuit 17 and the deflection drive circuit 18). That is, the one of the two sets of the circuits is provided for the defect inspection SEM, while the other of the two sets is provided for the defect review SEM. This configuration makes it possible to simplify a control algorithm and increase the speed of the algorithm. Furthermore, when a failure occurs in one of the two sets of the circuit, the other of the two sets can be used. FIG. 6 is a plan view of the wafer 8 placed on the stage and shows the movement of the wafer. A symbol L shown in FIG. 6 denotes a distance between the centers of the two columns (SEMs). Circles represented by broken lines shown in FIG. 6 denote the wafer 8 moved in the vacuum chamber 12 in the longitudinal direction of the single-shaft transfer stage 11 and positioned at ends (rightmost and leftmost ends in FIG. 6) of the vacuum chamber 12. An advantage of the rotary stage 10 according to the present invention is that the size and weight of the rotary stage 10 are small. Also, another advantage of the rotary stage 10 according to the present invention is that when the rotary stage is rotationally symmetrical, vibration due to a moment generated during the movement does not occur in principle. However, as shown in FIG. 6, a rotation of a coordinate system occurs at a location (also called an observation location) at which the wafer is observed. It is therefore necessary to perform processing to erect (rotate) an obtained image. The wafer 8 is represented by Cartesian coordinates defined by X and Y axes and by polar coordinates defined by r and θ axes. In FIG. 6, it is assumed that the wafer 8 is positioned at the observation location. The relationship between the Cartesian coordinates (X, Y) and the polar coordinates (r, θ) is represented by the following expressions.X=r·cos θY=r·sin θ The amount of a movement of a rotary stage with reference to the reference Cartesian coordinates (X′, Y′) on a stage is represented by the following expression.X′=r θ′=π−θ The above expressions are used to correct the coordinates of the defect. FIG. 7 is a plan view of the wafer 8 and shows an example of processing for acquiring an image in consideration of the rotation of the wafer 8. A pattern 22 present on the wafer 8 is imaged under the condition that the electron beam is deflected in a deflection area 23 represented in the polar coordinates (r, θ). When the defect inspection SEM images the pattern 22, the defect inspection SEM represents the imaged pattern 22 in the Cartesian coordinates (X, Y) in a direction shown in FIG. 7C. When the defect review SEM images the pattern 22, it is necessary to rotate the image at an angle θ″ shown in the following expression in order to erect an image area 24 shown in FIG. 7B.θ″=π+θ Therefore, after the deflection area 23 is set to include the image area 24, the defect review SEM images the pattern 22 and rotates the imaged pattern 22 to direct the image pattern 22 as shown in FIG. 7C. The rotation of the image can be performed by controlling a scanning direction of the electron beam or by performing image processing to rotate the image. FIG. 8A is an enlarged plan view of a target object present on the wafer. FIG. 8B is an enlarged side view of the target object present on the wafer. The image detected by each of the SEMs includes a target object 25 having a shade as shown in FIG. 8A. When the defect inspection SEM and the defect review SEM use an XY stage that does not rotate, it is necessary that a normal to the flat surface (on which the electron beam is detected) of the detector 5b of the defect inspection SEM be parallel to a normal to the flat surface (on which the electron beam is detected) of the detector 5a of the defect review SEM in order that the position (relative to the target object) of the shade obtained by the defect inspection SEM is the same as the position (relative to the target object) of the shade obtained by the defect review SEM. If electrons emanated from a three dimensional target object is detected at a high angle, the positions (relative to the imaged target object 25) of a bright portion and shade of an image obtained by the capture are shifted due to the angle (as if the bright portion and the shade were rotated in the image of the target object 25). In this case, the target object may be erroneously categorized, and it is required to carefully perform the categorization. An irregularity of the target object is important as information used to categorize the target object in some cases. However, when the convex target object 25 present in the image area 24 on the wafer 8 is detected by the detector 5b as shown in the side view of FIG. 8B and imaged by the defect review SEM, the image (of the target object 25) having the shade is obtained. In the charged particle beam apparatus according to the present invention, the normal to the surface (on which the electron beam is detected) of the detector 5a is directed toward the center of the column (defect review SEM) indicated by the broken line shown in FIG. 5, and the normal to the surface (on which the electron beam is detected) of the detector 5b is directed toward the center of the column (defect inspection SEM) indicated by the broken line shown in FIG. 5. Therefore, the position (relative to the imaged target object 25) of the shade generated in the image indicating the target object inspected by the defect inspection SEM is not shifted to the position (relative to the imaged target object 25) of the shade generated in the image indicating the target object inspected by the defect review SEM. As described above, the present invention provides a charged particle beam apparatus capable of downsizing (resulting in a small installation space), reducing in cost, and having high reliability with suppressed vibration and reduced possibility of attachment of a foreign material. The charged particle beam apparatus is largely effective when a wafer having a large diameter is used. While the invention has been described in its preferred embodiments, it is to be understood that the words which have been used are words of description rather than limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of the invention in its broader aspects.
	description	This application claims priority of German Application No. 10 2005 025 624.4, filed Jun. 1, 2005, the complete disclosure of which is hereby incorporated by reference. a) Field of the Invention The invention is directed to an arrangement for the generation of intensive short-wavelength radiation based on a gas discharge plasma, preferably as a source of EUV radiation. The invention is applied in particular in high-power radiation sources for ELV lithography which requires radiation sources with electrodes having a long life in the process of industrial fabrication of semiconductor chips. b) Description of the Related Art In semiconductor technology, there is a continuing trend toward increasingly smaller structures, and radiation with increasingly shorter wavelengths is required for lithographic generation of these structures. At present, EUV radiation sources, viewed as the most promising lithographic tool, are being developed. Basically, there are two different ways of generating the radiating plasma: by laser (LPP) and by gas discharge (GDPP). Various arrangements are known from the prior art relating to gas discharge-based EUV radiation sources, namely, Z-pinch, plasma focus, star pinch, hollow-cathode discharge arrangements, and capillary discharge arrangements. Further, there are variations in the above-named discharge types (e.g., hypocycloidal pinch discharge) and arrangements that combine elements of different discharge types. In all of these arrangements, a pulsed high-power discharge of >10 kA is ignited in a gas of determined density, and a very hot (kT>30 eV), dense plasma is formed locally as a result of the magnetic forces and dissipated power in the ionized gas. However, the radiation sources must satisfy precisely defined requirements for use in EUV lithography under production conditions: 1. wavelength13.5 nm ± 1%2. radiation output in the intermediate focus115 W3. repetition frequency7-10 kHz4. Dose stability (averaged over 50 pulses)0.3%5. life of the collector optics6 months6. life of the electrode system6 months. It is standard for high-power EUV gas discharge sources of the type mentioned above to have a special ceramic disk or cylinder as an insulator between the electrodes. For example, U.S. Pat. No. 6,414,438 B1 discloses a method and arrangement by which short-wavelength radiation is generated from a gas-discharge plasma in that a pre-ionization of the work gas takes place between coaxial electrodes as a sliding discharge on ceramic surfaces which emits UV radiation and fast electrons, and the ionized gas is conducted through an axial aperture of one of the electrodes in the gas discharge area, where it ignites the main discharge. WO 03/087867 A1 discloses another high-energy photon source that generates EUV radiation in the range of 12-14 nm. In order to limit erosion of the electrodes, particularly of the center electrode and, therefore, to increase the lifetime of the electrodes, cylindrical insulators are arranged at the side walls of the center electrode so that the discharge current after pinch ignition is shifted over a larger area to another portion of the electrode. It is described as particularly advantageous that the center electrode is covered on the inner side and outer side with insulating tubing. DE 101 51 080 C1 describes similar tubular insulator configurations that are also added to the inner wall of the outer electrode. Further, different materials are also indicated for this purpose. It is evident that while all of these insulator tubes limit the erosion of the electrodes to determined surface zones, the lifetime of the insulator/electrode configurations is appreciably shortened through cracking and metallization, particularly with high pulse repetition frequencies of the EUV gas discharge source. For various reasons, the arrangements mentioned above always only meet the above-mentioned requirements (1-7) in a few respects. This can be explained using the example of star pinch discharge which, in itself, is advantageous. Because of the comparatively large distances between plasma and wall (which represents a severe problem in all of the other arrangements due to the otherwise small dimensions), the star pinch arrangement is characterized by a long electrode lifetime. However, the large dimensions of the star pinch discharges cause a luminous plasma with a length of more than 5 mm. This considerably reduces the efficiency of the collector optics and, therefore, the overall efficiency as a quotient of the output in the intermediate focus and the electric power introduced for the discharge. Electrode configurations which employ additional insulator tubes because of their short distances in order to improve the constant, stable generation of the plasma suffer in principle from premature failure of the insulator. It is the primary object of the invention to find a novel possibility for generating intensive short-wavelength radiation, particularly EUV radiation, based on a gas discharge plasma which achieves a long life of the electrodes along with a high total efficiency of the radiation source without substantially increasing the dimensions of the discharge unit. In an arrangement for the generation of EUV radiation based on a gas discharge plasma in which a cathode and an anode are arranged in a cylindrically symmetric manner and a pre-ionized work gas is supplied to the cathode end, this object is met, according to the invention, in that exclusively suitably shaped vacuum insulation areas which have the shape of an annular gap and which are formed depending on the product of the gas pressure and the interelectrode distance of the cathode and anode for reliable suppression of electron arcing are provided for insulating the cathode and anode from one another. A device for pre-ionization of the work gas is advantageously provided within the centrally arranged cathode. The anode is preferably an annular electrode which encloses at least the cathode end with a small interelectrode distance and the discharge chamber. For pre-ionization of the work gas, a pre-ionization electrode with a projecting tubular insulator is advisably arranged in a centrally symmetric manner inside the cathode and opens into a cavity of the cathode. A surface sliding discharge can be generated at the insulator by a pre-ionization pulse between the pre-ionization electrode and the cathode so that the work gas which is ionized in this way flows out of the cavity via at least one through-channel at the cathode end into the discharge chamber, where it is converted into dense, hot plasma by a main discharge pulse. In this connection it should be noted that the ceramic insulator of the pre-ionization electrode needed for the surface sliding discharge is subject to comparatively very little electrical stress because the electrical energy that is dissipated per discharge (about 10 mJ) during pre-Ionization is only about one thousandth of the dissipated pulse energy of the main discharge (>10 J). In a basic variant, only one through-channel is provided coaxial to the axis of symmetry of the discharge space. However, a plurality of uniformly distributed through-channels are directed along an outer conical surface through a common point on the axis of symmetry on an inner surface of the anode. The through-channels can also be combined to form an annular gap. The cathode end is advisably provided with a rounded electrode collar which projects into the interior of the anode that circles the discharge chamber. The vacuum insulation area located between the anode and cathode is protected against debris particles from the plasma and against electrode consumption by the electrode collar. Further, it is advantageous that the cathode end inside the electrode collar has a concave shape and is the location where the dense, hot plasma is formed. A pocket hole or a through-hole is advisably incorporated at the center of the concave curvature of the cathode to distribute the ion beam exiting from the plasma to a larger surface. The cathode advantageously has a small cavity as pre-ionization chamber and long through-channels which are arranged coaxially and shaped in such a way that, at the cathode end in the discharge chamber, primary electrically conducting ionization channels are directed through a common point on the axis of symmetry of the discharge chamber to a surface of the anode. The intersection point determines the preferred location of the luminous plasma. In another advantageous construction, the cathode has a large cavity and short through-channels. The cavity extends to the vicinity of a concave cathode end, and the through-channels are arranged in such a way that primary electrically conducting ionization channels are directed through a common point on the axis of symmetry of the discharge chamber to a surface of the anode from the ionized work gas flowing into the discharge chamber. In a first variant, a surface discharge used for the pre-ionization of the work gas is advisably provided at the inner side of the insulator, and the pre-ionization electrode is constructed so as to be shorter than the tubular insulator and with a central gas inlet inside the tubular insulator. In a second variant, the surface discharge used for the pre-ionization of the work gas is advantageously provided on the outer side of the insulator, and the pre-ionization electrode projecting into the cavity of the cathode is constructed with a central gas inlet and a tubular insulator located on the outer side. In another variant, the cavity of the cathode is expanded in width and, in the shape of a spherical hood, is provided with short through-channels over the concave cathode end which are directed to a common point of the axis of symmetry. In another advantageous construction, the cavity of the cathode is shaped so as to taper conically toward the cathode end and is provided directly with the gas inlet and has a circular opening at the concave cathode end. The pre-ionization electrode is inserted coaxially into this opening and leaves open an annular gap to the discharge chamber through which the work gas is directed in the shape of an outer cone surface to a point on the axis of symmetry in primary electrically conducting ionization channels. In this case, the pre-ionization electrode has a pocket hole at its surface facing the discharge chamber in the axis of symmetry and also advantageously has its own cooling channels. In another construction having a cavity that tapers conically toward the cathode end and a circular opening of the cathode, the pre-ionization electrode is advantageously snugly inserted into the opening with inner and outer insulators. The pre-ionization electrode has a plurality of gas inlets which are directed to the surface of the anode as through-channels between inner and outer insulators through a common point on the axis of symmetry of the discharge chamber. In another construction, an auxiliary electrode which is insulated from the cathode is advantageously inserted into the cavity of the cathode. The auxiliary electrode has the cavity provided for the pre-ionization of the work gas, and the pre-ionization electrode with outer insulator is arranged so as to project into the cavity of the auxiliary electrode, and at least one corresponding through-channel is provided in the cathode and auxiliary electrode for the exit of the pre-ionized work gas. For this purpose, a plurality of corresponding through-channels are advantageously arranged along an outer conical surface, whose tip lies on the axis of symmetry of the discharge chamber, from the cavity to the discharge chamber in the auxiliary electrode and the cathode to form primary ionization channels in the discharge chamber. In addition, the auxiliary electrode is insulated from the cathode end by another cavity. In order to increase the dielectric strength of the vacuum insulation, particularly with larger interelectrode distances, the vacuum insulation space (which has larger dimensions) has additional means for generating a magnetic field, and the flux lines of the magnetic field are oriented orthogonal to those of the electric field between the anode and cathode. For this purpose, concentric magnet rings are advantageously arranged inside and outside the vacuum insulation space between which the magnetic field is formed in radial direction. A body is formed at one of the electrodes (e.g., the anode) toward the transition area in order to prevent inhomogeneities in the electric field between the anode and cathode. In a second embodiment form, concentric magnet rings are arranged inside and outside the vacuum insulation space, around which are formed two opposed, circularly extending magnetic fields, and a body is likewise formed at the inner magnet ring to prevent inhomogeneities in the electric field in the transition area. In order to generate magnetic fields of suitable strength, the concentric magnet rings are advantageously constructed in the form of a plurality of individual, annularly arranged permanent magnets, preferably NdFeB magnets. However, the concentric magnet rings can also be constructed as a plurality of annularly arranged electromagnets. In another embodiment form, a pre-ionization unit has through-channels to a transition area between the vacuum insulation space and discharge chamber, and the work gas that is pre-ionized in this way is introduced into the discharge chamber through the narrow transition area of the vacuum insulation between the cathode and anode and is contracted by the main current pulse to form hot, dense plasma. In another advantageous construction of the invention, gas inlets are arranged at the outer vacuum insulation space which has a large interelectrode distance between the cathode and anode, and the gas pressure and interelectrode distance are adjusted in such a way that a spontaneous ignition can be carried out exclusively on the left-hand branch of the so-called Paschen curve, and the product of gas pressure and interelectrode distance is selected in such a way that the breakdown voltage exceeds a minimum value which depends upon the work gas that is used. In an advantageous manner, grooves or similar structures are additionally incorporated in the outer vacuum insulation space in at least one of the oppositely located electrode surfaces of the cathode and anode for locally increasing the interelectrode distance for the purpose of a local increase in the product of gas pressure and interelectrode distance and to initiate the spontaneous ignition in a plurality of primary ionization channels. In all of the preceding constructions of the invention, it is advantageous when at least the cathode and anode are outfitted with cooling channels for cooling. In arrangements in which additional auxiliary electrodes are provided for pre-ionization of the work gas, these auxiliary electrodes are also provided with cooling channels in an advantageous manner, at least when they extend directly up to the discharge chamber. Deionized water is preferably used as coolant. The arrangements for gas discharge-pumped generation of radiation in the range of 13.5 nm advantageously use xenon, lithium vapor or tin vapor, or gaseous tin compounds as work gas. The basic idea of the invention stems from the consideration that the lifetime of the electrode system of a radiation source based on gas discharge cannot be significantly increased by ceramic insulators which, while limiting the electrode consumption to certain areas, form cracks within a relatively short time due to the high thermal loading or acquire conductive surfaces because they are spattered by eroded electrode material so that the electrode system must be exchanged. Based on this fact, the invention provides a vacuum insulation of the electrodes; however, due to the gas supply lines, suitable pressures and interelectrode distances must be used because the breakdown voltage depends upon the product of the interelectrode distance and pressure level. A number of suitable forms of excitation for generating a pre-ionization in the form of primary (electrically conductive) ionization channels of ionized work gas which are directed into the discharge chamber are described in the following. The invention makes it possible to provide arrangements for generating intensive short-wavelength radiation, particularly EUV radiation, based on a gas discharge plasma which allow the lifetime of the electrode system to be increased appreciably with a high total efficiency of the radiation source and with comparable dimensions of the discharge unit. In the following, the invention will be described in more detail. As is shown in FIG. 1, the basic arrangement according to the invention contains a discharge chamber 1 which is formed by the main electrodes 2 (cathode 21 and anode 22) and a cooling jacket 15 through which a suitable coolant flows, a main pulse generator 3 for the high-voltage gas discharge, which main pulse generator 3 is connected to the main electrodes 2, a pre-ionization pulse generator 4 for pre-ionization (for initiating the main discharge) which is connected between a pre-ionization electrode 51 and one of the main electrodes 2 (cathode 21 or anode 22 depending on the polarity of the main pulse generator 3), and a gas supply unit 6 for supplying work gas to the vacuum chamber 1. The main pulse generator 3 has a low-inductance discharge circuit (not shown) which is constructed in such a way that the polarity at the cathode 21 and anode 22 can easily be changed. According to the invention, the insulation between the cathode 21 and anode 22 is achieved exclusively by an evacuated transition 14 which is arranged between the discharge space 12 and the vacuum insulation space 13 and is shaped as an outer surface of a cone. An interelectrode distance of <1 mm is adjusted in the transition area 14. Particles resulting from electrode consumption are prevented as far as possible from entering the evacuated zone leading up to the vacuum insulation space 13 by means of at least one rounded electrode collar 23 of the center electrode (cathode 21 or anode 22) which is rounded with a large radius in the discharge chamber 12 before the conical transition area 14. This prevents excessive field strengths at the edges. The outer electrode (anode 22 or cathode 21, depending on polarity) preferably also has rounded edges. The cathode 21 and anode 22 each contain at least one opening. The opening in the cathode 21 makes it possible for UV radiation, high-energy ions and electrons formed by the sliding discharge 53 (pre-ionization process), as well as other work gases, to enter the discharge space 12, and the opening in the anode 22 forms a free solid angle for the outlet of the desired EUV radiation. The entire vacuum chamber 1 with the electrode configuration is constructed in a cylindrically symmetric manner with reference to an axis of symmetry 11 (of an axis arranged within the drawing plane). The current fed through the main pulse generator 2 generates a very hot (kT>30 eV) and dense plasma 7 through resistance heating and through magnetic forces. This plasma 7 emits radiation in the desired spectral region (e.g., EUV region between 12.5 nm and 14 nm). The pre-ionization pulse generator 4 and the pre-ionization electrode 51 and a main electrode 2 (preferably cathode 21) can be used with any desired shapes of electrode analogous to the following examples. Xenon, tin vapor or lithium vapor, or gaseous tin compounds and lithium compounds can be used as work gas in all cases. Further, buffer gases are advisably mixed in to increase the efficiency of EUV radiation production on one hand and to achieve an advantageous deceleration of the fast particles from the plasma 7 on the other hand so as to improve the protection of the first collecting optics (not shown). After applying a pre-ionization voltage supplied by the pre-ionization pulse generator 4 to the pre-ionization electrode 51 and the cathode 21 for pre-ionization (for initiating the main discharge), a surface sliding discharge 53 takes place via a tubular ceramic insulator 52. The surface discharge 53 is located on the inner side of the cylindrical insulator 52. It generates high-intensity electron radiation, UV radiation, and x-ray radiation which pre-ionizes the gas in a through-channel 24 of the cathode 21 and transforms it into a conductive pre-plasma in the discharge chamber 12. The conductive pre-plasma formed in the discharge chamber 12 is heated to the required temperature kT>30 eV during the main discharge by magnetic compression and forms luminous plasma 7. Total electrode insulation is ensured by the evacuated conical transition area 14 (pressure p<15 Pa, interelectrode distance d>0.5 mm) between the discharge chamber 12 and vacuum insulation space 13. The rounded electrode collar 23 of the cathode 21 prevents excessive field strength at sharp edges due to its shape and prevents sputter particles of the cathode 21 from entering the evacuated conical transition 14 and the vacuum insulation space 13 of the vacuum insulation from the discharge chamber 12. In both of the constructions shown in FIG. 2 to FIG. 5, the cathode 21 has a cavity 25. This cavity 25 serves to shape the electric flux lines in a suitable manner particularly in the through-channels 24 to the discharge chamber 12. The through-channels 24 cause primary electrically conducting ionization channels 16 (shown in dashed lines), along which the main discharge current flows, to be formed in the discharge chamber 12. In contrast to conventional hollow-cathode arrangements (e.g., according to WO 02/082871 A1 or WO 2004/019662), the connection between the cavity 25 and discharge space 12 is implemented in the present arrangements by means of through-channels 24 (e.g., FIG. 3) or by means of an annular gap 26 (see FIG. 6, for example) which create defined ionization channels 16 for the ignition of the main discharge pulse. These through-channels 24 are arranged on a sufficiently large circular circumference for reducing the thermal load per area unit. The same condition also applies to the shape of an annular gap 26 from the cavity 25 to the discharge chamber 12. As was described with reference to FIG. 1, the cathode 21 and anode 22 are separated by a vacuum insulation comprising the vacuum insulation space 13 and evacuated transition area 14 leading up to the discharge chamber 12, and the cathode 21 is provided with a rounded electrode collar 23 to prevent eroded electrode material from entering the transition area 14 and vacuum insulation space 13. FIG. 3 shows a cathode 21 with long through-channels 24 from a relatively small cavity 25 to the discharge chamber 12. After applying the pre-ionization voltage to the pre-ionization electrode 51, a surface discharge 53 (sliding discharge) takes place between the pre-ionization electrode 51 and the cathode 21 on the outer surface of the cylindrical insulator 52. It generates high-intensity electron radiation, UV radiation, and x-ray radiation which pre-ionizes the work gas in the through-channels 24 and the cavity 25. An almost completely ionized pre-plasma is formed in the through-channels 24 during the main discharge. The electron beams which are generated in this way generate primary electrically conducting ionization channels 16 which intersect in the discharge chamber 12 at a point P on the axis of symmetry 11 and are directed to the opposite surface of the anode 22. During the high-current phase of the main discharge, the current flows through these ionization channels 16 and generates the plasma 7 through heating of the pre-ionized work gas that flows in. The drawing in FIG. 4 shows a cathode 21 in the discharge chamber 12 which is outfitted with a small cavity 25 and geometrically short through-channels 24. In contrast to the second embodiment example described above, the surface discharge 53 takes place on the inner side of the cylindrical insulator 52, since the pre-ionization electrode 51 is arranged inside the tubular insulator 52. In other respects, its operation corresponds to that of the second embodiment example. In the embodiment form according to FIG. 5, the cathode 21 has a larger cavity 25 and a geometrically short annular gap 26 (as a special construction of a plurality of through-channels 24). In this case, webs S are arranged for holding the middle area of the cathode 21 and, at the same time, assist in improving the cooling of the highly thermally loaded central area of the cathode 21. In other respects, the construction and operation correspond to the example according to FIG. 3. The embodiment example according to FIG. 6 differs from the preceding embodiment examples (FIGS. 3 to 5) in that the connection of the cavity 25 of the cathode 21 to the discharge chamber 12 is formed as an annular gap 26 in such a way that the pre-ionization electrode 51 (with insulator 52) is inserted into a centrally symmetric conical bore hole of the cathode 21 to supplement the curved surface of the cathode 21. Accordingly, due to the rotationally symmetric orientation of the pre-ionization electrode 51 in the bore hole of the cathode 21, the uniform annular gap 26 can be accurately adjusted in any desired manner with respect to its gap width. The discharge sequence is carried out in exactly the same way as described with reference to FIG. 3 and FIG. 5. FIG. 7 and FIG. 8 refer to arrangements in which the surface discharge 53 (and the resulting electron beams) is made use of directly for generating primary ionization channels 16 in the discharge chamber 12 between the pre-ionization electrode 51 and the cathode 21 via the insulator 52. For this purpose, it is necessary for the discharge chamber 12 to have “visual contact” with the surface discharge 53 at the insulator 52. This means that the surface tangent of the insulator 52 must face the common point P. FIG. 8 has the distinction that the through-channels 24 are formed by inner and outer insulators 56 and 55, respectively, while the gas inlets 61 which are arranged individually in the pre-ionization electrode 51 are introduced directly in the ceramic through-channels 24 in order to generate the surface discharge 53 toward the cathode 21. In FIG. 9, in contrast to FIG. 5, an additional auxiliary electrode 54 is arranged inside the cathode 21 in an enlarged cavity 25. Another cavity 27 which works in exactly the same way as in the cathode 21 in FIG. 4 is provided inside the auxiliary electrode 54. This arrangement has three different high-voltage potentials: 1. Pulse voltage between the pre-ionization electrode 51 and the auxiliary electrode 54 for generating the surface discharge 53 via the ceramic insulator 52. 2. Pulse voltage between the auxiliary electrode 54 and the cathode 21. This pulse voltage accelerates the electrons starting in the through-channels 24 of the auxiliary electrode 54 toward the through-channels 24 in the cathode 21. 3. Pulse high-voltage for the main discharge between the cathode 21 and anode 22. The accelerated electrons generate primary ionization channels 16 for the main discharge which face in direction of the surface of the anode 22 and intersect at a point P on the axis of symmetry 11 of the discharge chamber 12. The through-channels 24 in the auxiliary electrode 54 and cathode 21 can also be slit-shaped. FIGS. 10 and 11 show modifications of the arrangement shown in FIG. 3. At least one magnetic field having an orientation of the flux lines perpendicular to the direction of the electric field between the anode 21 and cathode 22 is additionally arranged in the vacuum insulation space 13. The function of the magnetic field is explained in the following. If an ideal vacuum existed between the anode 22 and the cathode 21, there would be no problems with electric arcing in the vacuum insulation. The breakdown voltage between the cathode 21 and anode 22 is dependent on a product p·d (gas pressure p times interelectrode distance d), and the breakdown voltage drops as the p·d values increase in all of the examples discussed herein (left-hand branch of the Paschen curve). Since a gas discharge source is additionally filled with gas (as work gas and/or as additional gas influx for debris mitigation), an effective p·d value is one in which the breakdown voltage decreases when gas pressure increases. However, for design-related reasons (e.g., because of the recipient connections for connecting to the vacuum pump 17), the increase in the p·d value cannot be compensated to an unlimited extent in the vacuum insulation space 13 (the area of the greatest interelectrode distance d) by reducing the interelectrode distance d. Initial experiments have shown that the limit of the dielectric strength is reached especially in the vacuum insulation space 13 under these conditions. However, by installing magnetic fields {right arrow over (B)} (electromagnets, permanent magnets of suitable material) in which the B-flux lines are perpendicular to the E-flux lines, the breakdown voltage for the present geometry (e.g., 5 mm interelectrode distance) and the existing work pressure of the gas (e.g., 15 Pa) can be increased by a factor of >5. This is because electrons exiting from the cathode 21 which accelerate the electric field between the anode 22 and cathode 21 are decreased due to the magnetic field {right arrow over (B)} in such way that the acceleration path length of the electrons leading up to an interaction with a gas atom is sharply reduced in direction of the electric field. Therefore, the average kinetic energy of the electrons is comparatively low. Studies has shown that B-fields with field strengths on the order of 1 T (Tesla) are sufficient. These field strengths can also be achieved by permanent magnets (e.g., NdFeB magnets). Magnetic fields should advantageously be arranged at the locations with the greatest p·d values, e.g., in the vacuum insulation space 13, that is, in areas with a large interelectrode distance or in the vicinity of gas inlet openings 61. FIG. 10 shows a variant with two magnet rings 8, between which a magnetic field {right arrow over (B)} is formed in radial direction to the axis of symmetry 11 of the discharge chamber 12 and of the entire electrode configuration. The magnetic field {right arrow over (B)} extends substantially over the entire vacuum insulation space 13 in this example. The areas around the inner and outer magnet rings 81 and 82 are not critical because the breakdown voltage in these locations is automatically increased due to the reduced distance d. However, it is useful to arrange a body 83 at the electrode (in this case, the anode 22) on the inner magnet ring 81 in order to prevent inhomogeneities in the electric field between the anode 22 and cathode 21 by adapting the interelectrode distance d from the transition area 14 to the magnet ring 81. Alternatively, the magnet rings 81 and 82 can also be arranged at the cathode 21. Electromagnets can also be used instead of permanent magnets. In the construction according to FIG. 11, two magnet rings 81 and 82 are arranged at the anode 22 so as to have an identical effect with respect to increasing the dielectric strength, but with circular orientation of the magnetic flux lines. In this variant, two circular magnetic fields {right arrow over (B)}1 and {right arrow over (B)}2 which are oriented opposite to one another are formed inside the magnet ring 81 and 82, respectively. Magnetic field {right arrow over (B)}2 is strengthened between the magnet rings 81 and 82 and, overall, is more homogeneous than in the radial shape shown in FIG. 10. The circular shape of field {right arrow over (B)}2 also removes the charge carriers from the vacuum insulation space 13 more efficiently than with a radial magnetic field. The constructional variants according to FIGS. 12 and 13 are characterized in that the ignition of the pre-plasma (generation of ionization channels 16) is carried out in the vacuum insulation space 13 and in the evacuated transition area 14 after applying the high-voltage main pulse to the cathode 21 and anode 22. As in all of the preceding examples, the vacuum insulation space 13 has a larger interelectrode distance d compared to the transition area 14 of the vacuum insulation between the discharge chamber 12 and vacuum insulation space 13. In the construction shown in FIG. 12, the annular pre-discharge (as was described with reference to FIG. 3 to FIG. 6) is initiated by pre-ionization, and the pre-ionized gas is introduced into the transition area 14 between the vacuum insulation space 13 and the discharge chamber 12 by means of the through-channels 24. The vacuum-insulated transition area 14 which, in this example, takes over the function of shaping the primary insulation channels 16 for the main discharge is used for igniting the main discharge. In this case also, the conducting annular zone that is formed in this way contracts due to magnetic forces during the main current pulse in direction of the axis of symmetry 11 of the discharge space 12 to form the dense, hot plasma 7. According to FIG. 13, the gas inlet 61 for the work gas is connected directly from the outside to the wide vacuum insulation space 13. Since the vacuum chamber 1 is gas-tight and is evacuated in such a way that the gas discharge is carried out on the left-hand side of the Paschen curve, the discharge starts in the areas with the greater product of gas pressure p and interelectrode distance d when—as is the case in FIG. 13—there is no additional discharge initiation (e.g., through pre-ionization). The gas pressure is adjusted in such a way that a spontaneous ignition can be carried out only in the annular vacuum insulation space 13 for voltages above a defined value. In order to achieve a multiple-channel ignition by generating local, radially directed primary ionization channels 16, additional, oppositely located grooves 29 are provided in the cathode 21 and anode 22. These grooves 29 cause a further increase locally in the product of gas pressure p and interelectrode distance d at suitable positions in the vacuum insulation space 13 so as to enable a spontaneous ignition of the plasma especially in these grooves 29 at voltages above a defined value. The current ring or local ionization channels 16 in the grooves 29 formed in the vacuum insulation space 13 in this way are contracted due to the magnetic forces of the main discharge current radially in direction of the axis of symmetry 11 of the discharge chamber 12 through the conical transition 14 to the discharge space 12. A conductive zone which is formed in this way and which occurs along the axis of symmetry 11 below the pocket hole 28 at the cathode end is then heated by the main current pulse to form the plasma 7 emitting EUV radiation. While the foregoing description and drawings represent the present invention, it will be obvious to those skilled in the art that various changes may be made therein without departing from the true spirit and scope of the present invention. Reference Numbers 1vacuum chamber11axis of symmetry12discharge chamber13vacuum insulation space14(evacuated) transition area15cooling channels16primary (electrically conducting) ionization channels17vacuum pump 2electrodes21cathode22anode23rounded electrode collar24through-channel25cavity26annular gap27additional cavity28pocket hole29grooves 3main pulse generator 4pre-ionization pulse generator 5pre-ionization unit51pre-ionization electrode52(tubular) insulator53surface discharge54auxiliary electrode55, 56inner, outer insulator 6gas supply unit61gas inlet 7plasma 8magnet rings81inner magnet ring82outer magnet ring83body{right arrow over (B)}magnetic field{right arrow over (B)}1, {right arrow over (B)}2(oppositely oriented) magnetic fieldsdinterelectrode distancepgas pressurePcommon point (intersection of the ionization channels)Sweb
	claims	1. An imprint lithography system, comprising:an imaging unit having a viewing range configured to monitor a template and a substrate, the imaging unit positioned in superimposition with the template and the substrate, the substrate having a surface having multiple regions with polymerizable material deposited thereon; and,multiple energy sources, each having at least one energy element, positioned outside of the viewing range of the imaging unit, each energy source configured to provide energy along an energy path and wherein the elements of each energy source are inclined at angles so as to provide substantially uniform energy within a region of the substrate for solidifying the polymerizable material at each such region. 2. The system of claim 1, wherein each energy source has a single energy element. 3. The system of claim 1, wherein each energy source has multiple energy elements. 4. The system of claim 1, wherein at least one energy source has a single energy element and at least one energy source has multiple energy elements. 5. The system of claim 1, wherein at least one energy element is a UV LED. 6. The system of claim 1, wherein the energy sources are in a ring formation. 7. The system of claim 1, wherein the energy sources are in a cone formation. 8. The system of claim 1, wherein the energy sources are in a pyramid formation. 9. The system of claim 1, further comprising a supplementary energy source positioned outside of the viewing range of the imaging unit. 10. The system of claim 9, wherein the supplementary energy source is an arc lamp. 11. The system of claim 1, wherein the elements of each energy source are inclined at an angle and inclination of each angle provides substantially uniform energy to the polymerizable material on the substrate. 12. The system of claim 1, wherein each element of each energy source is positioned at a distance from a region of the substrate, and the position of each energy element provides substantially uniform energy to the polymerizable material on the substrate. 13. The system of claim 1, wherein each element is in optical communication with an optical line to provide energy to the polymerizable material. 14. The system of claim 13, wherein at least one energy element is positioned at a distance greater than 2 m from the polymerizable material on the substrate. 15. The system of claim 13, further comprising at least one reflective element positioned in optical communication with at two energy elements of at least one energy source, the reflective element focusing energy from the at least two energy elements to the polymerizable material on the substrate. 16. The system of claim 1, wherein at least one energy element of the energy source is a LED having a low unit power of approximately 3-20 mW/cm2. 17. The system of claim 1, further comprising at least one optical element positioned adjacent to the energy source to direct the energy of at least one energy element to the substrate. 18. A method of imprinting, comprising,positioning an imaging unit such that a viewing path of the imaging unit is in superimposition with a nano-imprint lithography template;positioning a plurality of energy sources between the imaging unit and the nano-imprint lithography template, the positioning of the energy sources being outside of the viewing path of the imaging unit, wherein each energy source is configured to provide energy along an energy path and wherein the elements of each energy source are inclined at angles so as to provide substantially uniform energy within a region of a substrate;positioning a substrate below the template, the substrate having a surface having a plurality of regions;depositing polymerizable material on the regions of the substrate;aligning the template and the substrate;contacting the polymerizable material on the substrate with the template;providing, by the energy sources, energy along the energy paths solidifying polymerizable material on each of the regions of the substrate; and,separating the template from the solidified polymerizable material providing a patterned layer on the substrate.
	claims	1. A process for treating a material that contains leachable radioactive substances, said process comprising the steps of: contacting said material with a suspension comprising a first component and a second component to form a mixture, wherein said first component supplies at least one member selected from the group consisting of sulphates, hydroxides, chlorides, fluorides, magnesium, halides, halites, magnesium aluminum silicates and calcium oxide, and wherein said second component supplies at least one phosphate anion; and curing said mixture for a period of time to form a cured material; wherein the concentration of leachable radioactive substances in said material so treated is decreased and non-leachable solid materials are formed. 2. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said first component or said second component is a liquid. claim 1 3. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said first component is a magnesium aluminum silicate. claim 1 4. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said second component is an aqueous phosphate reagent. claim 1 5. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said second component is phosphoric acid. claim 1 6. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said second component is monocalcium phosphate. claim 1 7. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said second component is tetrasodium pyrophosphate. claim 1 8. The process of treating a material that contains leachable radioactive substances according to claim 1 , further comprising a third component, wherein said suspension further comprises a third component which supplies at least one phosphate anion. claim 1 9. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said suspension further comprises a third component selected from the group consisting of phosphoric acid, pyrophosphates, triple super phosphate, trisodium phosphate, potassium phosphates, ammonium phosphates, monocalcium phosphate and tetrasodium pyrophosphate. claim 1 10. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said suspension comprises monocalcium phosphate, tetrasodium pyrophosphate and a magnesium aluminum silicate. claim 1 11. The process of treating a material that contains leachable radioactive substances according to claim 1 , wherein said metal-bearing material is a sludge. claim 1 12. A process for treating soil that contains leachable radioactive substances, said process comprising the steps of: contacting a soil containing radioactive substances with a suspension comprising a first component and a second component to form a mixture, wherein said metal-bearing soil contains at least one leachable metal selected from the group consisting of lead, aluminum, arsenic (III), barium, bismuth, cadmium, chromium (III), copper, iron, nickel, selenium, silver and zinc, wherein said first component supplies at least one member selected from the group consisting of sulphates, hydroxides, chlorides, fluorides, magnesium, halites, halides, silicates and calcium oxide, and wherein said second component supplies at least one phosphate anion; and curing said mixture for a period of time to form a cured material; wherein the concentration of leachable radioactive substances in said soil so treated is decreased and non-leachable solid materials are formed. 13. The process of treating soil according to claim 12 , wherein said first component or said second component is a liquid. claim 12 14. The process of treating soil according to claim 12 , wherein said first component is a magnesium aluminum silicate. claim 12 15. The process of treating soil according to claim 12 , wherein said second component is an aqueous phosphate reagent. claim 12 16. The process of treating soil according to claim 12 , wherein said second component is phosphoric acid. claim 12 17. The process of treating said metal-bearing soil of claim 12 , wherein said second component is monocalcium phosphate. claim 12 18. The process of treating soil according to claim 12 , wherein said second component is tetrasodium pyrophosphate. claim 12 19. The process of treating soil according to claim 12 , wherein said suspension further comprises a third component which supplies at least one phosphate anion. claim 12 20. The process of treating soil according to claim 12 , wherein said suspension further comprises a third component selected from the group consisting of phosphoric acid, pyrophosphates, triple super phosphate, trisodium phosphate, potassium phosphates, ammonium phosphates, monocalcium phosphate and tetrasodium pyrophosphate. claim 12 21. The process of treating soil according to claim 12 , wherein said suspension comprises monocalcium phosphate, tetrasodium pyrophosphate and a magnesium aluminum silicate. claim 12 22. A process for treating a waste matrix of metal-bearing material and soil that contains leachable radioactive substances, said process comprising the steps of: contacting said waste matrix with a suspension comprising a first component and a second component to form a mixture, wherein said metal-bearing material contains at least one leachable metal selected from the group consisting of lead, aluminum, arsenic (III), barium, bismuth, cadmium, chromium (III), copper, iron, nickel, selenium, silver and zinc, wherein said first component supplies at least one member selected from the group consisting of sulphates, hydroxides, chlorides, fluorides, magnesium, halites, halides, silicates and calcium oxide, and wherein said second component supplies at least one phosphate anion; and curing said mixture for a period of time to form a cured material; wherein the concentration of leachable radioactive substances in said material so treated is decreased and non-leachable solid materials are formed. 23. The process of treating a waste matrix according to claim 22 , wherein said first component or said second component is a liquid. claim 22 24. The process of treating a waste matrix according to claim 22 , wherein said first component is a magnesium aluminum silicate. claim 22 25. The process of treating a waste matrix according to claim 22 , wherein said second component is an aqueous phosphate reagent. claim 22 26. The process of treating a waste matrix according to claim 22 , wherein said second component is phosphoric acid. claim 22 27. The process of treating a waste matrix according to claim 22 , wherein said second component is monocalcium phosphate. claim 22 28. The process of treating a waste matrix according to claim 22 , wherein said second component is tetrasodium pyrophosphate. claim 22 29. The process of treating a waste matrix according to claim 22 , wherein said suspension further comprises a third component which supplies at least one phosphate anion. claim 22 30. The process of treating a waste matrix according to claim 22 , wherein said suspension further comprises a third component selected from the group consisting of phosphoric acid, pyrophosphates, triple super phosphate, trisodium phosphate, potassium phosphates, ammonium phosphates, monocalcium phosphate and tetrasodium pyrophosphate. claim 22 31. The process of treating a waste matrix according to claim 22 , wherein said suspension comprises monocalcium phosphate, tetrasodium pyrophosphate and a magnesium aluminum silicate. claim 22
056132425	claims	1. A solid-waste disposal system for disposing solid waste containing radioactive material, the solid-waste disposal system comprising: a. a producing means for producing water from a first subterranean geological formation; b. a source of radioactive material; c. a grinder for receiving radioactive material from the source and reducing the radioactive material to a slurry of microemulsion particle size, a portion of the slurry being soluble in acid; d. an acidification unit for receiving the slurry from the grinder and treating the slurry with an acid to dissolve the acid soluble portions of the slurry and to produce and disposal brine; and e. an injecting means for injecting said dilute solution into a second subterranean geological formation. (a) said second formation being communicated with surfaces through a well penetrating said strata; (b) said well comprising a bore hole, a casing string within said bore hole, and optionally a tubing string contained within said casing string to prevent flow of said dilute solution into any of said geological strata; and (c) said well further comprising a cementing means between said bore hole and said casing string to further prevent any leakage of said dilute solution into any of said geological strata. a. drawing water from a first subterranean formation; b. grinding solid radioactive waste in a grinding unit to form a slurry of microemulsion particle size, the slurry having a soluble portion and an insoluble portion; c. treating the slurry with an acid to dissolve the soluble portion of the slurry, producing an effluent having a liquid portion and a solid portion; d. emulsifying the solid portion of the effluent to a smaller size to develop a solid disposable sludge; e. mixing together the solid disposable sludge, the liquid effluent, and the water drawn from the first subterranean formation to produce a disposal mixture; and f. disposing of the disposal mixture in a second subterranean formation. 2. The solid-waste disposal system of claim 1 wherein said radioactive material comprises naturally occurring radioactive materials selected from the group consisting of barium, uranium, radium, and thorium. 3. The solid-waste disposal system of claim 1 wherein said solid waste comprises in major portion alkaline earth sulfates. 4. The solid-waste disposal system of claim 1 wherein said solid waste comprises in major portion barium sulfate. 5. The solid-waste disposal system of claim 1 wherein said solid waste comprises in major portion barium sulfate and said radioactive material comprising in major portion radium. 6. The solid-waste disposal system of claim 1 further comprising a filter device in fluid communication with the acidification unit to prevent the injection of undissolved solid waste into said second subterranean geological formation thereby causing injectivity problems. 7. The solid-waste disposal system of claim 1 wherein said first subterranean formation is a geothermal source having an average formation temperature above 200.degree. F. to facilitate the dissolution of said solid waste and said radioactive material contained therein. 8. The solid-waste disposal system of claim 7 wherein said average formation temperature is above 300.degree. F. 9. The solid-waste disposal system of claim 1 wherein said first subterranean geological formation has an average formation pressure substantially greater than said second subterranean geological formation. 10. The solid-waste disposal system of claim 9 wherein said injecting means involves a naturally available mechanism by which water is driven through the entire system via a pressure difference between said first subterranean formation and said second subterranean formation without any externally applied pumping means. 11. The solid-waste disposal system of claim 1 further comprising outlet means from the acidification unit and valve means or other flow constricting means in fluid communication with the outlet means to maintain a high pressure environment inside said acidification unit to facilitate the dissolution of said solid waste and said radioactive material. 12. The solid-waste disposal system of claim 11 wherein said washing chamber being maintained at a fluid pressure above 1,000 psi. 13. The solid-waste disposal system of claim 11 wherein said washing chamber being maintained at a fluid pressure above 2,000 psi. 14. The solid-waste disposal system of claim 1 wherein said water produced from said first formation containing at least 3% of total dissolved solids to facilitate the dissolution of the solid waste. 15. The solid-waste disposal system of claim 14 wherein said water produced from said first formation containing at least 10% of total dissolved solids to facilitate the dissolution of the solid waste. 16. The solid-waste disposal system of claim 1 wherein said first formation is an aquifer. 17. The solid-waste disposal system of claim 1 wherein said first formation is a partially or wholly depleted hydrocarbon-bearing reservoir. 18. The solid-waste disposal system of claim 1 wherein said second formation is a partially or wholly depleted hydrocarbon-bearing reservoir. 19. The solid-waste disposal system of claim 18 wherein at least a portion of said second formation is partially or completely filled with gaseous components. 20. The solid-waste disposal system of claim 1 wherein said second geological formation is overlaid by a plurality of geological strata wherein: 21. A method of disposing of solid radioactive waste comprising the steps of: 22. The method of claim 21 wherein the first subterranean formation having a formation pressure substantially greater than the second subterranean formation to allow the circulation of the water from said produced water from said first subterranean formation to said second subterranean formation without any externally applied pumping means.
	abstract	A spring apparatus in accordance with the disclosed and claimed concept is usable in a nuclear installation. In one embodiment, the spring apparatus includes a plurality of springs that are in a compressed state and that are compressively engaged with an upper core plate of a nuclear reactor when the reactor is in a cold condition. However, when the reactor is in a hot condition, a spring of the plurality of springs is in a free state wherein a free end of the spring is in an uncompressed state and is disengaged from the upper core plate. In another embodiment, the spring apparatus employs a support apparatus that is also in accordance with the disclosed and claimed concept and that includes one or more bumpers that engage the springs of a spring pack from the underside.
047584033	abstract	A spacing grid is provided for a nuclear fuel assembly comprising two sets of intersecting metal plates having fins and defining fuel element receiving pockets. The plates comprise solely half-fins each associated with a single pocket of the grid, disposed in opposed pairs at the angles of the pockets, the half-fins of one pocket being placed at 90.degree. from the half-fins of adjacent pockets.
	abstract	An image processing method includes: obtaining an image that includes a ball image and a cone image; obtaining an estimate of a center of the ball image; converting the image to a converted image using a processor based at least in part on the estimate of the center of the ball image, wherein the converted image comprises a converted ball image that looks different from the ball image in the image, and a converted cone image that looks different from the cone image in the image; identifying the converted ball image in the converted image; and analyzing the converted ball image to determine a score that represents an accuracy of the estimate of the center of the ball image.

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