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042657083	description	DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows the upper portion of a nuclear reactor fuel assembly 10 engaged with the fuel alignment plate 12 during typical nuclear reactor operating conditions. The fuel assembly 10 includes a plurality of guide tubes 14 to which are attached fuel spacer grids 16 which form a matrix to support a plurality of fuel elements 18. The guide tubes 14 typically extend a distance of approximately 13 feet from the fuel alignment plate 12 to the fuel assembly lower end fitting (not shown). The guide tubes 14 have giude posts 20 welded to their upper ends and are rigidly connected to a perforated flow plate 22. A spider-shaped holddown plate 24 having one lobe associated with each guide post 20 is located below the alignment plate 12 and is vertically movable relative to the guide post in order to tansmit a downward force from the alignment plate 12 through the holddown springs 26 to the guide tubes 14 whereby the assemby is held down against the upward flow of coolant over the fuel elements. During the course of their lifetimes within a reactor, most assemblies 10 will have control rods 28 located within the guide tubes 14. The control rods 28 are typically about 15 feet long and are rigidly held at their upper ends (not shown) and reciprocated vertically within the guide tubes 14. The control rod 28 is protected from the highly turbulent coolant flow that interacts with the fuel elements 18 below the alignment plate 12, and from the strong cross-flows existing in the plenum region 30 above the alignment plate 12. This protection is afforded by the guide tube 14, the post 20, the alignment plate 12, and shrouds 34 in the plenum region 30. Although not shown, the alignment plate 12 has a plurality of flow passages for directing the coolant flow from the fuel assemblies 10 into the plenum region 30. A continuous flow of coolant must be maintained within the guide tube 14 to provide cooling to the control rods 28. Because the control rods 28 are so elongated, each rod is unlikely to be exactly centered within its respective guide tube 14 and therefore, especially when the rod is in the withdrawn position shown in FIG. 1, the rod will be eccentric relative to the guide post exit 36. It is believed that such eccentricity produces a pattern of axial vortices 38, with axes generally vertical, and diffuser vortices 40, with axes generally in a horizontal plane, as schematically represented. The structure associated with the control rod 28 as it exits the guide posts 20 can be generally described as a center rod eccentrically disposed within a rather abrupt diffuser region represented generally at 42. It should be appreciated that depending on the particular nuclear reactor, the exact structure defining the diffuser region 42 and the diffuser cross section can be quite different. During reactor operation, most control rods 28 are maintained in the withdrawn position so that the control rod tip 44 is continuously located, depending on the particular reactor, at a fixed elevation approximately 1 to 2 feet from the guide post exit 36. Inspection of fuel assemblies 10 removed from operating reactors shows severe fretting on the inside of the guide tube 14 at precisely the elevation corresponding to the control rod tip 44 in the withdrawn position. Analyses were made and tests outside the reactor were performed in order to identify the mechanism causing the guide tube wear. Although the source of wear has not been completely explained analytically it was found that the vibrations causing the control rod interaction with the guide tubes 14 are apparently self-excited and predominantly at the natural frequency of the control rod (about 4H for a typical control rod). These vibrations are believed to be the result of guide tube flow effects caused by driving forces related to the periodic interaction near the guide post exit 36 of the axial vortices 38 with the diffuser vortices 40, as described above. A variety of proposed improvements were tested in a flow loop wherein the dimensions and flow rates were similar to typical reactor operating conditions. Most of the tested guide posts had very little effect in reducing the vibration of the control rod in the guide tube 14. The present invention was effective in reducing control rod vibration. An invention described in another patent application field on even date herewith entitled "Parallel Flow Collar for Reducing Vibration of a Rod Within a Diffuser", by F. Bevilacqua, and assigned to the same assignee as the present invention, was, however, most effective. FIGS. 2 and 3 show the preferred embodiment of the improved guide post 20B having a uniform inner diameter that is the same as the inner diameter of the guide tube 14 except that at the upper end of the post 20B the inner diameter is reduced to form a flow restriction 46. In this embodiment of the invention the tube and post inner diameter are 0.900 inches for receiving a control rod 28 having an outer diameter of 0.816 inches. The flow restriction 46 has an inner diameter of 0.860 inches. Generally, the flow restriction is chosen to be as narrow as will permit acceptable control rod scram time. Immediately below the restriction 46 there are provided a plurality of bypass channels 48 which divert most of the coolant away from the rod 28. This reduces the velocity of the coolant exiting the guide post 20B at the diffuser mouth 36 immediately adjacent to the control rod 28. Although the flow exiting the post at 36 may produce the diffuser vortices 40 (since the rod is still eccentric relative to the exit cross section), the bypass flow through the channels 48 enters the diffuser region 42 spaced away from the control rod 28. In addition, the axial vortices 38 are dissipated or at least distributed in a manner that minimizes their periodic interaction with the diffuser vortices 40 Since the exact mechanisms causing the control rod vibration are not thoroughly understood, the foregoing explanation cannot be analytically demonstrated. It is believed, however, that at least four discrete flow channels are preferred. The illustrated embodiment has eight flow channels symmetrically located about the upper portion of the guide post, each channel being upwardly oriented at approximately 45 degrees to the horizontal. This orientation minimizes the pressure drop in the guide tube. Preferably, the flow channels are located such that the channel exits 50 are in the enlarged head 52 of the guide post 20B in order that the diverted flow exits as far as possible from the post exit 36. As an example of the improvement provided by the preferred embodiment of the invention, the results of comparative flow test on a guide tube 14, guide post 14, diffuser region 42 and shroud 34 equivalent to the structure shown in FIG. 1 will be discussed. In the tests the guide tube 14 inside diameter was 0.900 inches and the control rod outside diameter was 0.816 inches. The control rod 28 was 14 feet long and fixedly suspended at its top. The mass of the control rod 28 was equivalent to a stainless steel clad column of B.sub.4 C pellets. The rod tip 44 was located 21 inches below the guide post exit 36. The standard prior art post 20A was similar to that depicted in FIG. 1 and had an inside diameter of 0.900 inches. Accelerometer probes were connected to the midspan of the control rod 28. At the typical operating volumetric flow rate of 9 gallons per minute (4500 lbs. per hour) flow through the guide tube and standard post 20A, the rod response was 0.23 g's. Since the guide tube 14 in the test model was made of plexiglass, the control rod tip 44 could be observed vibrating against the guide tube 14 inner wall. The test was repeated with the same flow conditions using the improved guide post 20B shown in FIGS. 1, 2 and 3. Eight flow channels at angles of 45 degrees were provided. The dimensions indicated by lower case letters in FIGS. 2 and 3 were as follows: a=1.375 inches PA1 b=0.600 inches PA1 c=0.200 inches PA1 d=0.25 inches The variation in the angle of the transition from the restriction 46 to the post exit 36 was six degrees, but this parameter was found to have little effect on the control rod vibration. With the improved guide post 20B, the acceleration response at the rod midspan dropped down to 0.17 g's. There was a visible oscillation of the control rod but the tip 44 did not touch the guide tube 14. Although the present invention was not as effective in reducing control rod vibrations as was the invention claimed in the above-mentioned related application, the present invention is easy to implement in fuel assemblies that have already been built. It is also an inexpensive way to provide a safety margin in new assemblies where the prior art guide posts are barely acceptable.
	claims	1. An x-ray diffraction apparatus for measuring a known characteristic of a sample of a material in an in-situ state, comprising:an x-ray source for emitting substantially divergent x-ray radiation;a collimating optic disposed with respect to the x-ray source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation toward the sample, the collimating optic employing multiple total external reflections as its primary transmission technique; andfirst and second point x-ray detectors for collecting radiation emitted from the sample, wherein the first x-ray detector is fixed in position to measure a diffraction peak determined according to the a-priori knowledge, and wherein the second x-ray detector is fixed in position to measure off the diffraction peak determined according to the a-priori knowledge;wherein the source and detectors are fixed, during operation thereof, in positions relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample; andfurther comprising at least one angular filter, having multiple, parallel capillaries employing total external reflection, the at least one angular filter affixed to the first and/or second x-ray detectors for limiting the angles from which the radiation is collected by the respective detector. 2. The apparatus of claim 1, wherein the second x-ray detector is fixed in position to measure substantially noise off the diffraction peak. 3. The apparatus of claim 1, further comprising the sample, wherein the sample requires phase monitoring and the apparatus is adapted to monitor said phase. 4. The apparatus of claim 3, wherein the sample is in a production line and moving past the source and detectors. 5. The apparatus of claim 1, further comprising a second source fixed relative to the second detector, wherein the first source and detector operate as a pair, and the second source and detector operate as a pair. 6. The apparatus of claim 5, further comprising the sample, wherein the sample requires texture monitoring and the apparatus is adapted to monitor said texture. 7. The apparatus of claim 6, wherein the sample is in a production line and moving past the sources and detectors. 8. An x-ray diffraction apparatus for measuring a known characteristic of a sample of a material in an in-situ state, comprising:an x-ray source for emitting substantially divergent x-ray radiation;a collimating optic disposed with respect to the x-ray source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation toward the sample, the collimating optic employing multiple total external reflections as its primary transmission technique; andfirst and second point x-ray detectors for collecting radiation emitted from the sample, wherein the first x-ray detector is fixed in position to measure a diffraction peak determined according to the a-priori knowledge, and wherein the second x-ray detector is fixed in position to measure off the diffraction peak determined according to the a-priori knowledge;wherein the source and detectors are fixed, during operation thereof, in positions relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample; andwherein the collimating optic has a plurality of capillaries and is shaped such that each capillary of the plurality of capillaries essentially points at the x-ray source, and employs multiple total external reflections within the capillaries to shape the divergent x-ray radiation into the substantially parallel beam by receiving and redirecting the divergent paths of the divergent x-ray radiation; andfurther comprising at least one angular filter, having multiple, parallel capillaries employing total external reflection, the at least one angular filter affixed to the first and/or second x-ray detectors for limiting the angles from which the radiation is collected by the respective detector. 9. The apparatus of claim 8, wherein the second x-ray detector is fixed in position to measure substantially noise off the diffraction peak. 10. An x-ray diffraction method for measuring a known characteristic of a sample of a material in an in-situ state, comprising:emitting substantially divergent x-ray radiation with an x-ray source;producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation toward the sample with a collimating optic which employs multiple total external reflections as its primary transmission technique;collecting radiation emitted from the sample with first and second x-ray detectors, wherein the first x-ray detector is fixed in position to measure a diffraction peak determined according to the a-priori knowledge, and wherein the second x-ray detector is fixed in position to measure off the diffraction peak determined according to the a-priori knowledge;wherein the source and detectors are fixed, during operation thereof, in positions relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample; andfurther comprising using at least one angular filter, having multiple, parallel capillaries employing total external reflection, the at least one angular filter affixed to the first and/or second x-ray detectors for limiting the angles from which the radiation is collected by the respective detector. 11. The method of claim 10, wherein the second x-ray detector is fixed in position to measure substantially noise off the diffraction peak. 12. The method of claim 10, wherein the sample requires phase monitoring, the method further comprising monitoring said phase. 13. The method of claim 12, further comprising moving the sample in a production line past the source and detectors. 14. The method of claim 10, further comprising emitting substantially divergent x-ray radiation with a second source fixed relative to the second detector, wherein the first source and detector operate as a pair, and the second source and detector operate as a pair. 15. The method of claim 14, wherein the sample requires texture monitoring, the method further comprising monitoring said texture. 16. The method of claim 15, further comprising moving the sample in a production line past the source and detectors. 17. An x-ray diffraction method for measuring a known characteristic of a sample of a material in an in-situ state, comprising:emitting substantially divergent x-ray radiation with an x-ray source;producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation toward the sample with a collimating optic which employs multiple total external reflections as its primary transmission technique;collecting radiation emitted from the sample with first and second x-ray detectors, wherein the first x-ray detector is fixed in position to measure a diffraction peak determined according to the a-priori knowledge, and wherein the second x-ray detector is fixed in position to measure off the diffraction peak determined according to the a-priori knowledge;wherein the source and detectors are fixed, during operation thereof, in positions relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample;wherein the collimating optic has a plurality of capillaries and is shaped such that each capillary of the plurality of capillaries essentially points at the x-ray source, and employs multiple total external reflections within the capillaries to shape the divergent x-ray radiation into the substantially parallel beam by receiving and redirecting the divergent paths of the divergent x-ray radiation; andfurther comprising using at least one angular filter, having multiple, parallel capillaries employing total external reflection, the at least one angular filter affixed to the first and/or second x-ray detectors for limiting the angles from which the radiation is collected by the respective detector. 18. The method of claim 17, wherein the second x-ray detector is fixed in position to measure substantially noise off the diffraction peak.
062748769	abstract	The inspection apparatus uses a particle beam and has a high throughput by obtaining a characteristic frequency corresponding to the characteristic quantity of focusing-shift from a Fourier spectrum of a sample image using a focusing-shift evaluator. A beam blur profile is produced corresponding to the characteristic frequency in a beam blur profile generator. A component of the beam-blur profile is removed from the sample image stored in one dimensional image memory using a de-convolution operator. A dimensional measurement is performed in a critical dimension evaluator for an obtained sample image. Since time spent for focus adjustment using particle beam scanning is obviated, it is possible to reduce the inspection time for a dimension and an appearance abnormality of a semiconductor element.
	summary
	claims	1. A water reactor fuel cladding tube for a pressurized water reactor, said cladding tube comprising an outer layer of a first zirconium based alloy and having directly metallurgically bonded thereto an inner layer of a second zirconium based alloy, wherein the cladding tube does not have any further zirconium based alloy layer, wherein the inner layer is adapted to protect the cladding tube against stress corrosion cracking, wherein the second zirconium based alloy comprises tin as an alloying material, and wherein each one of the zirconium based alloys comprises at least 96 percent by weight zirconium, wherein the main alloying materials of the first zirconium based alloy are niobium, iron and tin with the content of any additional substances being below 0.05 percent by weight, wherein the first zirconium based alloy comprises oxygen;the first zirconium based alloy comprising 0.6-1.2 percent by weight niobium, 0.6-1.2 percent by weight tin, and 0.1-0.3 percent by weight iron;wherein the main alloying materials of the second zirconium based alloy are tin and iron and wherein the content of any additional substances is below 0.05 percent by weight, and wherein the second zirconium based alloy comprises 0.1-1 percent by weight tin and 0.02-0.3 percent by weight iron; andwherein the thickness of the inner layer is 5-40% of the thickness of the reactor fuel cladding tube. 2. A water reactor fuel cladding tube according to claim 1, wherein the first zirconium based alloy comprises 500-2000 ppm by weight oxygen. 3. A water reactor fuel cladding tube according to claim 1, wherein the inner layer is partially re-crystallized. 4. A water reactor fuel cladding tube according to claim 1, wherein the inner layer is fully re-crystallized. 5. A water reactor fuel cladding tube according to claim 1, wherein the outer layer is partially re-crystallized. 6. A water reactor fuel cladding tube according to claim 5, wherein the degree of re-crystallization in the outer layer is 45 percent −90 percent. 7. A water reactor fuel cladding tube according to claim 6, wherein the degree of re-crystallisation in the outer layer is 50 percent −70 percent. 8. A water reactor fuel cladding tube according to claim 1, which has been manufactured by co-extrusion of a first tube of the first zirconium based alloy and a second tube of the second zirconium based alloy. 9. A water reactor fuel cladding tube according to claim 1, wherein the thickness of the inner layer is 5-15% of the thickness of the reactor fuel cladding tube. 10. A water reactor fuel rod comprising a water reactor fuel cladding tube according to claim 1 and fuel pellets enclosed by the water reactor fuel cladding tube. 11. A water reactor fuel assembly comprising at least two fuel rods according to claim 10.
053176138	description	DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a reactor vessel V is shown in section for a forced circulation boiling water reactor. The reactor contains a core C with a plenum P therebelow. A plurality of control rods R extending through plenum P penetrate on a selected basis to control reactive output of the core C in its fission reaction. The vessel V includes a circuitous flow path which includes upward flow through core C into steam separators S and steam dryers D. Liquid rejected by the separators S passes downwardly between the core and the outside wall of the vessel in the direction of vector 14 and into the plenum P. At plenum P, the water again circulates up through the core. This reactor is a forced circulation reactor including pumps 16-19, which each include propellers 20 for drawing the water downwardly along the sides of the core, and into plenum P. At plenum P, released water passes upwardly through the core, repeating in a cycle of endless circulation, the flow path here described. Typically, feed water is introduced at an inlet 22 and disbursed through spargers 24. Likewise, steam for energy extraction is discharged from outlets 26 with extraction occurring at conventional turbines and condensers (not shown). Discharge from the condensers occurs to feed water makeup apparatus (also not shown) with return at apertures 22 of the reactor. The bottom of the core includes a boundary known as core plate 29. Core plate 29 provides lateral support for fuel support pieces to form a hydraulic boundary at the bottom or entrance to core C. The fuel support pieces rest upon the control rod guide tubes 27. Fuel assemblies 31 are positioned in turn on the fuel support pieces. Specifically, the fuel assembly lower tie plate 30 rests upon the fuel support pieces embedded within the core plate 29. The lower tie plate is further described by referring to FIG. 2, showing a cut away cross sectional view. Two types of apertures may be seen in the lower tie plate 30. A first set of apertures 32 communicates to the interior of each fuel channel, one of which, as described below, surrounds each individual fuel rod in the fuel assembly. Moderating coolant entering through the aperture 32 cools the fuel rods, and is eventually generated into steam for the extraction of energy. Additionally, a second set of apertures 34 is illustrated. Apertures 34 flood the so-called core bypass region in between the fuel channels. This bypass region provides a surrounding moderator to each of the respective fuel rods. Referring to FIGS. 3A and 3B, the configuration of the core can be better understood. Referring first to FIG. 3B, each fuel rod includes fuel cladding 40, surrounding a column of fuel pellets 42. A gap 41 typically exists between the pellets and the clad for the purpose of collecting and distributing released fission product gases. As is common in the art, the columns are sealed at their respective ends 44 and constitute discrete pressure vessels containing fuel pellets and collected fission product gases interior of the reactor. As a novel feature of this invention, each column is surrounded by its own discrete channel 50. Channels 50 are communicated at their lower end 52 to each of the apertures 32 in the lower tie plate 30. It will be understood that there will be two flow volumes interior of the core. The first flow volume 60 is defined in the upright concentric annulus about the fuel rods 40. It is in this region that the coolant is heated by the fuel rod. Secondly, there is a bypass region 64 between the respective channels. It is into this region that liquid moderator from the lower tie plate extends the entire distance between the respective lower tie plate and the top of the core with proper sizing of holes 34, as illustrated at the top portion of FIG. 3A. The fuel rod 40 is displaced from the fuel channel 50 by a spacer 80. Although various spacer designs are possible, a novel and exemplary design is illustrated in FIG. 4. Rings 80 and 84 form tight ferrule bushings between the channel wall 50 and fuel rod 40, respectively. Angular disposed vanes 86 maintain a fixed distance between the fuel channel 50 and fuel rod 40. Spacers are periodically provided along the axial extent of the fuel channels as shown in FIG. 3A. The new design contains additional structural material in the channels 50 over present conventional BWR fuel designs. This additional material has the advantage of adding considerable rigidity to the contained fuel rod 40. Unfortunately, this channel design absorbs neutrons. Since each fuel rod has its own channel, more neutrons will be lost in channel absorption than in conventional fuel designs. This absorption of neutrons at the channel walls can be partially mitigated. It is to be noted that by optimizing fuel rod cladding and fuel rod channel dimensions, half of the channel material can be compensated for by elimination of the relatively thick fuel bundle channel of current designs. Accordingly, representative dimensions compared to a conventional fuel design which can be utilized are contained in the following table: ______________________________________ This Invention Conventional ______________________________________ Number of fuel rods 91 64 Fuel rod geometry Triangular Pitch Square Pitch Cladding Outer Diameter 8.0 mm 12.3 mm Cladding Thickness 0.64 mm 0.76 mm Number of Channels 91 1 Channel Geometry Cylindrical Tube Square Box Channel Inside Span 15 mm 134 mm Channel Thickness 0.64 mm 2.0 mm ______________________________________ It will be seen that the resulting core and fuel rod configuration includes a more homogenous cross section. Consequently, all of the contained fuel rods 42 will approach their respective thermal limits with uniformity. As a consequence, the power density of the reactor can be increased. A summary of the advantages realized by this design includes advantage realized in maximum linear heat generation rate, minimum critical power ratio, and stability of the reactor at certain less-than-rated coolant flow rates. Maximum Linear Heat Generation Rate More uniformly distributed core bypass flow volume 64 (of the liquid water phase in a BWR application) provides for flatter axial power distributions and lower power mismatch between fuel rods at any given axial level ("local peaking" reduction) due to the relatively more homogeneous mixture of materials throughout the extent of the core. This in turn results in smaller deviations of the maximum linear heat generation rate (MLHGR) from average value during operations, permitting higher power densities while still satisfying the MLHGR criterion. Use of the triangular pitch also yields a higher packing density of fuel rods within the core relative to that attained with a square pitch. Relative to the current square pitch, this means lower power per fuel rod for a given common power level, providing additional MLHGR relief and opportunity for increasing the power density. Minimum Critical Power Ratio Reductions in rod-to-rod power mismatch also has a beneficial effect for the minimum critical power ratio (MCPR). All rods uniformly approach this critical power ratio limitation. Further benefits are provided by the capability to selectively orifice each discrete fuel rod at its discrete channel to match flow rates to power production rates and to promote flow turbulence near the fuel rod clad boundary. As a result, the bundle critical power increases and margin is provided to increase power density. Selective orificing can be provided by adjusting the angular deflection of the fixed vanes 86 shown in FIG. 4. This changes the coolant flow resistance or pressure drop characteristics of the individual fuel channel, forcing a particular distribution of inlet flow. Another means to selectively orifice is show in FIG. 6. Referring to FIG. 6, the bottom section 52 of two channels 50 are illustrated. It can be seen that the bottom sections 52 can be provided with different size apertures 72, 74. These differing size apertures throttle the inflow of the moderator coolant and permit varying flow rates to occur through the bundles of this invention. Stability Stability is not necessarily a limitation for increasing power density for the forced circulation plant illustrated in FIG. 1. In such forced circulation reactors, power-flow map exclusion regions can be defined and appropriate controls and instrumentation installed to avoid operations, even for upset conditions, in an operating region which may potentially result in fuel channel flow instability. Some designs, for example, selectively insert control rods automatically when flow is reduced below a certain setpoint to limit the core power level and avoid unstable power-flow regions. Nonetheless, this invention provides capability to improve stability from the viewpoint of root cause, which is insufficient coolant flow and high pressure drop in the upper two phase region of the fuel bundles. It can be seen that through selective orificing, higher flows can be promoted in fuel rod channels which would otherwise have lower margins for stable operation. Spacer Construction Referring to FIG. 4, the construction of a spacer utilized with this invention can be understood. Spacer 80 consists of two concentric ferrules 82, 84 separated by vanes 86 through which coolant flow passes. The inner ferrule 82 fits over the fuel rod clad 40, while the outer ferrule 82 fits against the fuel rod channel 50 at the inner wall. Spacers 80 are positioned at the entrance, exit and intermediate positions of the fuel rod channel as necessary to satisfy mechanical requirements to limit fuel rod and channel displacements. Spacers can also be positioned as appropriate to promote turbulent flow and improved heat transfer characteristics. Vanes 86 are pitched in a propeller-like array. The pitch of vanes 86 may impart a spiral curvature to upwardly flowing fluid. This spiral curvature imparted to the fluid can promote additional flow turbulence. Additionally, the pitch of the spacer vanes 86 can provide an orificing effect for matching inlet flow to the discrete fuel rod power production. As can be seen, vane 86 in FIG. 4 has imparted to fluid flowing by vane 86 a spiral path. Referring to FIG. 5, it can be seen that individual fuel channels 50 each with contained fuel rods 40 and spacers 80 are bundled together using external bundle wrappers 100 (straps). The bottom and top of the fuel bundle are secured with lower tie plate 30 and upper tie plate 31, respectively. Selected channels extend through the tie plates and are provided with end threads for the purpose of bolting the bundle to form a secured assembly. As seen in FIG. 5, ninety one fuel rods 40 are each fastened in an hexagonal configuration with their respective surrounding channels 50. It is contemplated that this group of ninety one fuel rods 40 and fuel channels 50 would be handle as a unitary group, much in the same manner that many fuel rods contained within more conventional fuel bundles are now handled.
062597590	summary	BACKGROUND OF THE INVENTION The present invention relates to a maintenance technology of an incore piping section of a reactor such as a boiling water reactor or the like, and in particular, to an incore piping section maintenance system of a reactor, which performs preventive repair and preventive maintenance of weld (welded or to be welded) zones or portions in an incore piping section located in a reactor pressure vessel. A boiling water reactor such as a light water reactor is constructed as shown in a longitudinal cross-sectional view of FIG. 7. A reactor core 2 is installed in a reactor pressure vessel 1, and the reactor core 2 is immersed in a coolant 3. Further, the reactor core 2 is constructed in a manner that a plurality of fuel assemblies (not shown) and control rods are arranged in a cylindrical core shroud 4. A reactor water (coolant) 3 in the reactor pressure vessel 1 flows upward through the core 2 from a core lower plenum 9. The coolant 3 receives a nuclear reaction energy when flowing upward through the core 2, and then, its temperature and pressure rise up, and thus, becomes a two-phase flow state of water and steam (vapor). The coolant 3, which is in a gas-liquid two-phase flow state, flows into a steam separator 5 located above the reactor core 2, and then, is separated into water and steam by means of the steam separator 5. A steam thus gas-liquid separated is introduced into a steam desiccator or drier 6 located above the steam separator 5, and then, is dried here so as to become a dry steam. The dry steam is supplied as a main steam to a steam turbine (not shown) via a main steam pipe (tube) 7 connected to the reactor pressure vessel 1, and then, is used for power generation. On the other hand, a water thus gas-liquid separated is guided to a truss or sleeve-like downcomer portion 8 between the reactor core 2 and the reactor pressure vessel 1, and then, flows downward through the downcomer portion 8, and thus, is guided to a core lower plenum 9. Further, in the downcomer portion 8, an outer periphery of the core shroud 4 is provided with a plurality of jet pumps 10 at equal intervals. Meanwhile, the core lower plenum 9 below the reactor core 2 is provided with a control rod guide pipe 11, and a control rod driving mechanism 12 is located below the control rod guide pipe 11. The control rod driving mechanism 12 carries out a control for inserting and pulling a control rod into and out of the reactor core 2 through the control rod guide pipe 11, and thus, performs a power control of reactor. Moreover, two reactor re-circulation systems including a reactor re-circulation pump (not shown) are located outside the reactor pressure vessel 1. When the re-circulation pump of the reactor re-circulation system is operated, a coolant in the reactor pressure vessel 1 passes through a reactor re-circulation system (not shown) from a cooler re-circulation water outlet nozzle 12, and then, is returned into the reactor pressure vessel 1, and thus, is guided to the jet pump 10 via the re-circulation water inlet nozzle 13. The jet pump 10 sucks its surrounding coolant, and then, supplies it into the core lower plenum 9. More specifically, by a driving water supplied from the reactor recycle pump to the jet pump 10, the jet pump 10 forcibly circulates the coolant 3 in the reactor core 2 via the core lower plenum 9. On the other hand, the reactor pressure vessel 1 is provided with a core spray system 15 which constitutes an emergency cooling system of a reactor. The core spray system 15 has a piping arrangement as shown in FIG. 5 and FIG. 6. FIG. 6 is a perspective view showing a state that the core spray system 15 is located in the reactor pressure vessel. As shown in FIG. 5, the core spray system 15 extends into the core shroud 4 from the outside of the reactor pressure vessel 1 penetrating through the reactor pressure vessel (RPV) 1 and the core shroud and includes a core spray system pipe for introducing a spray water into the core shroud 4. The core spray system pipe is a piping part for connecting the RPV 1 and the core shroud 4 in the RPV 1. Moreover, a pipeline of the core spray system 15 is arranged as shown in FIG. 6. In the core spray system 15, an incore branch part 16 is connected to one end of the core spray system pipeline after penetrating through the RPV 1. A semi-circular pipe 17 is formed in a manner of extending from the incore branch part 16 like a semicircular arc and branching right and left. Each end portion of the semi-circular pipe 17 branching right and left is formed at a position separating by an angle of about 180.degree. along an inner wall of the RPV 1. The semi-circular pipe 17 is connected with a vertical pipe 18 which extends downward from each end portion thereof. A lower end of the vertical pipe 18 constitutes the other end of the core spray system pipeline. A lower end of each vertical pipe 18 is connected via a sleeve 20 to a riser pipe 19 which rises up from the core shroud 4, and thus, a core spray system pipeline is constructed. The core spray system pipeline functions as a reactor emergency cooling system into which a cooling water for cooling the core is supplied in a reactor emergency shutdown. When the emergency cooling system is operated, a fluid vibration, thermal deformation and the like are generated in the core spray system pipeline. For this reason, the core spray system pipeline is used under severe circumstances as compared with other equipments, and as a result, a great load is applied to each member of the core spray pipeline, and as the case may be, a great stress is applied to the core spray pipe. Some early nuclear power plants have been operated for more than twenty years, and hence, stable operation for aged plants makes it more vitally important to implement the preventive maintenance of a reactor pressure vessel and internal elements of the early plants which were made of high carbon stainless steel susceptible to Stress Corrosion Cracking (SCC). As mentioned hereinlater, the SCC is caused by the combination of three factors of Material, Stress and Environment, and it is important to get rid of one of three factors for the preventive maintenance. In the event that an excessive load is applied to the core spray pipe of the core spray system 15 due to any factors, or an inner surface of the core spray pipe rusts away, there is the possibility that a crack or the like is generated in the pipe due to the rust. Furthermore, because an austenitic stainless steel pipe is mainly used as a material for the core spray pipe, if the following three factors, that is, Stress, Corrosion Environment and Material (generation of chromium deficiency layer) are realized, the Stress Corrosion Cracking (SCC) is generated, and for this reason, it is anticipated that the core spray pipe is damaged. This stress corrosion cracking phenomenon does not happen if any one of the three factors, mentioned above, lacks. In order to prevent this stress corrosion cracking, there is a need of making various measures so that the aforesaid three factors are not established. Moreover, in the case where a rush and crack is generated in a surface of the core spray pipe due to any factors, when these rush and crack have left, the crack is progressing, and as a result, there may be the case where a crack is generated in the core spray pipe. Thus, when the core spray system 15, which functions as an emergency cooling system of a reactor, becomes a state as described above, it is anticipated that a harmful influence is given to other equipments included in the core, thus being not preferable. Furthermore, recently, a laser de-sensitization treatment (LDT) technology has mainly been developed for the preventive maintenance of the thin pipe and plate. A high power laser beam produces a molten layer and solution heat treated layer and can change the sensitized surface of a stainless steel to be de-sensitized. The LDT is a treatment for suppressing a sensitivity (de-sensitization) of an Intergranular Stress Corrosion Cracking (IGSCC) by the steps of irradiating with laser beams a surface of a stainless steel sensitized by an influence of welding heat or the like and forming a solution heat treatment layer and a molten coagulation layer. That is, FIG. 8 shows relationship among the above mentioned three factors such as Material, Stress and Environment for improving the SCC proof property in view of the de-sensitization treatment, and as shown in FIG. 9, when a YAG laser beam of high energy density passing through an optical fiber, for example, is irradiated on a laser execution portion through optical means such as mirror or lens, the portion subjected to the laser execution is rapidly heated, a Cr carbide is decomposed and, hence, a Cr-lacking layer near a grain boundary is lost. After the laser beam has passed, the laser execution portion is rapidly cooled and the surface thereof is de-sensitized. By continuously performing such de-sensitization treatment to the surface contacting the solution, the solution heat treatment layer and the molten coagulation layer are formed. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances. It is, therefore, an object of the present invention to provide an incore piping section maintenance system of a reactor, which can securely and effectively perform a preventive maintenance treatment such as a surface de-sensitization of the reactor incore piping section by a laser beam irradiation, that is, a laser de-sensitization treatment, and thus, can improve normalization, soundness and reliability of the reactor core piping section. Another object of the present invention is to provide an incore piping section maintenance system of a reactor, which can carry out a laser irradiation through remote control with respect to a maintenance target portion of the reactor core piping section so as to perform a surface de-sensitization of weld zone, that is, a laser de-sensitization treatment for a short time, and can effectively and smoothly perform a preventive maintenance such as a preventive repair or the like. Still another object of the present invention is to provide an incore piping section maintenance system of a reactor, which can effectively perform an inspection, repair or polishing work of the reactor incore piping section through remote control without draining off a reactor water in a reactor pressure vessel. These and other objects can be achieved, according to the present invention, by providing, in one aspect, an incore piping section maintenance system of a reactor, comprising: a maintenance system main body which is fixed to a maintenance target portion in a reactor pressure vessel or in the vicinity thereof to which a preventive-maintenance operation is executed; PA1 support means provided for the maintenance system main body so as to be movable in a reciprocal manner towards the maintenance target portion; PA1 laser generation means for generating a laser beam; PA1 laser de-sensitization treatment means which is rotatably supported around an axis of the support means and which includes a laser irradiation section for irradiating the laser beam to the maintenance target portion; and PA1 optical transmission means which guides the laser beam outputted from the laser generation means to the laser de-sensitization treatment means. PA1 a maintenance system main body to be inserted into a pipe of an incore piping section located in a reactor pressure vessel; PA1 main body supporting means for detachably fixing the maintenance system main body in the pipe; PA1 a turning arm supported to the maintenance system main body; PA1 turning means turning and driving the turning arm; PA1 axial moving means which is supported so as to be slidable in a direction substantially perpendicular to the turning arm, the axial moving means being movable in an axial direction with respect to a header; PA1 laser generation means for generating laser beam; PA1 laser de-sensitization treatment means which is supported on the axial moving means and includes a laser irradiation section for irradiating the laser beam to an outer surface of the pipe; and PA1 optical transmission means which guides a laser beam outputted from the laser generation means to the laser de-sensitization treatment means. In this aspect, the maintenance target portion is an incore piping section located in the reactor pressure vessel, the support means includes seal means including expandable seal members so as to seal both sides of the laser irradiation section, and the seal means forms an atmospheric environment to the laser irradiation section so that the laser irradiation section between the seal members is filled with a purge gas, a laser irradiation being then carried out in the purge gas. The laser de-sensitization treatment means further includes an inspection monitoring means provided for the laser irradiation section or in the vicinity thereof. The laser de-sensitization treatment means further includes a maintenance target portion detector which detects and confirms a laser execution position to which the preventive-maintenance operation is executed. The maintenance target portion detector is an ultrasonic flaw detector which detects and confirms the laser execution position. The maintenance target portion detector may be a ferrite indicator, the ferrite indicator distinguishing a difference in ferrite quantity between a weld zone and a base material of the incore piping section so as to detect and confirm a laser execution position. The laser de-sensitization treatment means further includes a polishing means so that the laser execution portion is subjected to polishing working by means of the polishing means. In another aspect, there is provided an incore piping section maintenance system of a reactor, comprising: In this aspect, the main body supporting means includes at least three main body supporting mechanisms and each of the main body supporting mechanisms is constructed in combination with a link mechanism including a guide member and a cylinder apparatus for driving the guide member of the link mechanism so that the guide member comes in and out from the maintenance system main body. According to the present invention of the characters mentioned above, in the incore piping section maintenance system of a reactor, the laser de-sensitization treatment means is located in the pipe of the incore piping section or on a predetermined position on the pipe outer peripheral surface, and a laser beam is irradiated from the laser de-sensitization treatment means to the entire periphery of the incore piping section thereby to perform a surface de-sensitization of the incore piping section and a laser de-sensitization treatment and to effectively perform preventive repair and preventive maintenance by a laser beam. Therefore, it is possible to greatly enhance normalization, soundness and reliability of the incore piping section such as a core spray pipe or the like. Further, in the incore piping section maintenance system of a reactor according to the present invention, it is possible to carry out a surface de-sensitization, that is, laser de-sensitization treatment through the laser de-sensitization treatment means in the water by remote control. Therefore, a maintenance work can be readily performed, and also, it is possible to greatly reduce a possibility that a worker is exposed to a radiation. Furthermore, in the incore piping section maintenance system of the present invention, it is possible to stably set the maintenance system main body onto the maintenance target portion of the incore piping section or in the vicinity thereof by the remote control. Therefore, a work for the preventive maintenance and the preventive repair of the incore piping section can be stably and effectively carried out. The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.
047567686	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a method for the chemical decontamination of metallic parts of nuclear reactor installations, in which first, an oxidative treatment with a permanganate solution is applied before dicarbonic acids are used for further treatment. 2. Description of the Prior Art In the method known from German Patent No. 26 13 351 and U.S. Pat. No. 4,226,640, which has found acceptance in practice, an alkaline permanganate solution is used for the oxidative treatment of contaminated nuclear reactor components at a temperature of about 100.degree. C. The components are subsequently flushed with demineralized water (deionate) before continuing with a citrate-oxalate solution which is adjusted with ammonia to a pH-value of 3.5. The solution contains an inhibitor as well as ethylenediamine tetraacetic acid. The inhibitor is iron-III formate. The known method with its individual stages and in-between rinsing operations uses high chemical concentrations and the time of treatment is quite long. Also, the known method has not been applied to primary systems of nuclear reactors which would have to be practically emptied for this purpose and would have to be filled again after the treatment. SUMMARY OF THE INVENTION An object of the invention is to lower the radiation exposure of inspection and repair personnel by chemical decontamination of the primary system of nuclear reactors or of parts thereof, which chemical decontamination can be carried out at a lower cost. Only little secondary waste is produced in the chemical decontamination. This waste is eliminated in a radiation-proof manner. With the foregoing and other objects in view, there is provided in accordance with the invention a method for the chemical decontamination of metallic parts of nuclear reactor installations in which an oxidative treatment with a permanganate solution is applied before dicarbonic acids are used for the further treatment, characterized by the feature that permanganic acid is used for the oxidative treatment. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a method for the chemical decontamination of metallic parts of nuclear reactor installations, it is nevertheless not intended to be limited to the details shown, since various modification may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
	summary
056235267	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to nuclear reactors. More specifically, the present invention relates to a technique which enables the repair and/or reinforcement of shrouds which have developed cracks or the like types of faults. 2. Brief Description of the Related Art Nuclear reactors such as a boiling water type (BWR) 10 shown in FIG. 1, enclose a plurality of spaced fuel rods, generally denoted by the numeral 12, within a shroud 14 which is supported within the reactor pressure vessel (RPV) 16. The shroud 12 locates on the core support plate 20 and the top guide 32. It also supports a separator arrangement 22 and maintains a volume of water over the fuel 12. In this arrangement, a plurality of control rods 18 are disposed below the fuel rods 12 and are arranged to move up through the core support plate 20 into position to control the combustion of the nuclear fuel. The separator arrangement 22 is located on top of the shroud 22, while a dryer 24 is arranged at a still higher level and essentially opposite a main steam line 26. A pressure vessel head 28 is secured to the upper flange of the reactor pressure vessel in a manner which hermetically seals off the top of the RPV 16. As shown in FIG. 2, the shroud 14 is constructed of a number of cylindrical and/or annular sections which are welded together. In the shroud shown in FIG. 2, only seven (H1 to H7) of the welds, which form essential parts of the shroud structure, are shown. However, it is possible that, due to intergrannular stress corrosion cracking (IGSCC) and other metallurgical phenomenon, cracks can develop in the shroud, particularly at the sites of the welds, and lead to a situation wherein portions of the shroud can separate in an undesirable manner which may interfere with the proper operation of the reactor. Repair of such types of cracks is of course difficult and usually requires the fuel (fuel rods 12) to be offloaded and the repair carried out with the fuel stored in a separate holding pool. However, as will De appreciated, in order for the fuel rods 12 to be released, lifted out of the reactor vessel and immersed in a holding tank, all of the apparatus which is disposed in the reactor above the fuel rods must first be removed and placed in holding tanks. Accordingly, the number of operations which must be carried out before the actual repair work can actually begin is substantial and the length of the outage of the reactor is prolonged considerably. Even in the case of relatively minor cracks, the above-mentioned troublesome removal of the dryer 24, the shroud head and separator arrangement 22, and the fuel rods 12 must be carried out before repair operations can be initiated, irrespective of the fact that the repair operation itself may be relatively simple and quickly carried out. SUMMARY OF THE INVENTION It is an object of the present invention to provide a technique which enables the repair of the shroud without the need to remove the fuel from the reactor. It is a further object of the invention to provide a simple apparatus which can be used to fortify or repair a nuclear reactor shroud while the fuel is still in the reactor pressure vessel. It is yet another object of the invention to provide a repair technique which involves the use of straps which are fastened to the external surface of the shroud in a manner which supports the shroud against bending forces, shearing forces, and torsion forces. In brief, the above mentioned objects and others are achieved by an arrangement wherein straps, which are formed of the same material as the shroud, are placed in strategic positions with respect to cracks or the like types of weaknesses which have been detected in the shroud, and fastened in place using a suitable fastening technique. In the preferred embodiments of the invention, holes are formed using an EDM technique and bolt units which have an expanding portion are inserted into the holes, torqued and expanded in a manner which fastens the strap to the shroud. Welding and the like type of fastening techniques are not excluded and may be used alternatively or in combination with the bolting technique as required. The length of the straps is variable and can be selectively varied so that a suitable number of welds are spanned and the required amount of support is provided. A plurality of straps can be used. The number of straps varies with the problem that needs solving. The separation or interval between the straps need not be uniform. For example, if four straps are used they need not necessarily be arranged uniformly at 90 degree intervals. In the event that a number of straps are used, the length of each strap can be varied as necessary under the instant set of conditions and the degree of support that is required to ensure that the shroud exhibits the desired degree of structural strength for horizontal, vertical and lateral welds. While it is preferable that the straps be made of the same material as the shroud, a different material can be used as long as the material is such as to not introduce corrosion or undergo thermal or radiation induced changes which endangers the support which is intended to be provided by the straps. Electron discharge machining (EDM) is used in connection with the preferred embodiments for removing metal and cutting holes and the like. This technique is favored in that tooling loads during cutting are negligible and chips and the like type of debris is not formed or, alternatively, is easily collected. The combination of the straps with other support structure is not excluded from the scope of the invention. This support structure can be arranged to be disposed either internally or externally of the shroud. For example, U.S. Pat. No. 5,430,779 to Baversten et al. issued on Jul. 4, 1995, and co-pending U.S. patent application Ser. No. 08/241,441 filed on May 11, 1994 in the name of Baversten, could be referred to for teachings pertaining to support structures which could be used in connection with the present invention. The disclosures of these two documents are hereby incorporated by reference. More specifically, a first aspect of the present invention resides in a nuclear reactor having an essentially cylindrically-shaped shroud formed of a plurality of annular segments which are welded to one another and which features: a strap which extends essentially parallel to an axis of said cylindrically-shaped shroud and which is securely fastened to an external surface of the shroud, said strap being arranged to span at least one of the welds of said shroud, said strap withstanding bending, shearing and tension forces which are applied to said shroud. A second aspect of the present invention resides in a method of repairing an essentially cylindrically-shaped shroud formed of a plurality of annular segments which are welded to one another, comprising the steps of: placing a strap against a predetermined portion of an external surface of the shroud wherein the strap spans at least one of the welds which secure the segments of the shroud together; forming a plurality of holes through the strap and the shroud; disposing fastening means through the plurality of holes to fasten the strap to the shroud and to render the strap integral with the shroud. A third aspect of the invention resides in a method of repairing a nuclear reactor which includes a plurality of fuel rods and a shroud which is disposed about the fuel rods, comprising the steps of: placing a strap against the external surface of a nuclear reactor shroud so as to span at least one weld formed in the shroud; and securing the strap to the shroud using fastening means. Another feature of the strap allows the fabrication of EDM support fasteners. The EDM operation is shortened through the use of the prelocated tooling positions. The strap is a long flat structure which may have a channel, H beam or other cross-sectional shape which develops the required strength.
	abstract	An electron beam irradiation device of the present invention includes: a projector 8 for generating a two-dimensional light pattern 13; a microchannel plate 11 for (i) generating an electron beam array based on the light pattern 13 having entered, (ii) amplifying the electron beam array, and (iii) emitting the electron beam array as an amplified electron beam array 14; and an electron beam lens section 12 for converging the amplified electron beam array 14. This electron beam irradiation device is capable of manufacturing a semiconductor device whose performance is improved through a finer processing by means of irradiation using an electron beam. Further, the electron beam irradiation device allows cost reduction, because the device allows collective irradiation using a two dimensional pattern.
048448400	claims	1. A method for containment of hazardous waste materials, said method comprising: collecting a plurality of primary containers which hold the wastes; sealing one or more of the primary containers within a canister; and stacking a plurality of the canisters in an interlocking manner over a substantially impermeable bed in an excavated disposal site, whereby said canisters form an integrated structure in which the individual canisters are generally held in place by gravity but able to shift relative positions in response to earth movement without fracturing of said canisters, wherein the canisters are arranged in at least two layers with each canister in an overlying layer interlocking with canisters in the underlying layer. a barrier layer over the excavation site, said barrier being substantially impermeable to aqueous penetration; a plurality of canisters stacked over the barrier layer to form an integrated structure, wherein each of said canisters houses one or more primary waste containers and includes means for externally interlocking with surrounding canisters so that individual canisters may be stacked and held in place by gravity while remaining able to shift relative positions in response to earth movement and wherein said canisters are arranged in at least two layers with each canister in an overlying layer interlocking with canisters in the underlying layer; and means for sealing over the top and sides of the integrated structure to inhibit accidental penetration. a barrier layer over the bottom of the excavation site, said barrier layer being substantially impermeable to aqueous penetration; a plurality of canisters stacked over the barrier layer to form an integrated structure, wherein each of said canisters houses one or more primary waste containers sealing the hazardous wastes therein, said primary waste containers being sealed within the canisters by a fluid sealant which hardens after curing, said individual canisters each including means for externally interlocking with surrounding canisters so that said individual canisters may be stacked and held in place by gravity while remaining able to shift relative positions in response to earth movements; means intermediate the stacked containers and the barrier layer for collecting drainage separately from a multiplicity of preselected isolated zones beneath the integrated structure; and means for detecting leakage of the hazardous material into the drainage from each of the preselected zones. 2. A method as in claim 1, further comprising collecting drainage from different areas of the bed beneath the integrated structure, and analyzing the discharge from each of the areas for the leakage of hazardous waste. 3. A method as in claim 1, further comprising covering the integrated structure with a substantially impenetrable barrier to inhibit accidental penetration. 4. A method as in claim 1, wherein the primary containers are sealed in the canisters with a fluid sealant which hardens after curing. 5. A method as in claim 4, wherein the fluid sealant is grout. 6. A method as in claim 2, wherein the canisters in a particular area are unstacked and examined for leakage in response to the detection of hazardous waste in the drainage from that area. 7. A containment structure for hazardous waste materials, said structure being located on an excavated site and comprising: 8. A containment structure as in claim 7, wherein the barrier layer includes compacted clay. 9. A containment structure as in claim 7, wherein the canisters are composed of concrete. 10. A containment structure as in claim 9, wherein the primary containers are sealed within the canisters by a grout sealant which fills substantially all the interstices between the containers. 11. A containment structure as in claim 7, wherein each canister in the immediately overlying layer interlocks with four canisters in the immediately underlying layer. 12. A containment structure as in claim 7, wherein the means for sealing over the top and sides comprises panels which will interlock with the integrated structure of canisters. 13. A containment structure for hazardous waste materials, said structure being located on an excavated site and comprising: 14. A containment structure as in claim 13, wherein the barrier layer includes compacted clay. 15. A containment structure as in claim 13, wherein the canisters are composed of concrete. 16. A containment structure as in claim 13, wherein the means for collecting drainage includes collection conduits placed at the low point of said isolated zones beneath the integrated structure. 17. A containment structure as in claim 17 wherein the means for detecting leakage includes separate collection sumps associated with each collection conduit. 18. A containment structure as in claim 19, wherein the canisters are arranged in layers, with each canister locking into four canisters in both the immediately overlying layer and the immediately underlying layer. 19. A containment structure as in claim 13, further comprising means for sealing over the top and sides of the integrated structure to inhibit accidental penetration. 20. A containment structure as in claim 19, wherein the means for sealing over the top and sides comprises top and side panels which will interlock with the integrated structure of canisters.
	summary
	abstract	An X-ray micoanalysis test system comprising a beam generator which induces X-rays to emanate from a semiconductor device containing film stacks. The charged particle beam will penetrate at least two layers of a film stack on a semiconductor device so that these layers may be tested. The X-rays will be detected using multiple X-ray detectors that detect X-ray photons having a specific energy level. The X-rays will then be used to analyze the characteristics of the semiconductor device. Each of the multiple X-ray detectors may be wavelength dispersive system (WDS) detectors. The present invention also provides a method for measuring film stack characteristics on a semiconductor device. The method for measuring includes directing an electron beam towards the semiconductor device so that the electron beam penetrates at least a conductive film layer and a liner layer, detecting the X-rays which are caused to emanate from the device with multiple X-ray detectors that detect X-ray photons having a specific energy level. The present invention also provides a method and a computer-readable medium which determines a film stack""s properties using the data collected with the test system of the present invention. The method and computer-readable medium includes selecting a set of values which estimate the film stack characteristics, using the estimated values to generate predicted data by solving equations which model the film stack, and selecting a new set of estimated film stack characteristic values when the difference between the predicted data and the raw data is larger than a certain margin of error.
	abstract	The present embodiments relate to a method for operating a particle therapy system. The particle therapy system includes a particle generation device, a beam generating device for generating a particle beam from at least one portion of the generated irradiation particles, a measuring device for automatically measuring a particle beam intensity of the particle beam, and a particle beam influencing device. The particle beam influencing device is configured to adjust the particle beam intensity as a function of the measured particle beam intensity and a predefined setpoint value for the particle beam intensity.
047160071	summary	CROSS-REFERENCES TO RELATED APPLICATIONS This application is related to copending applications Ser. No. 217,060 entitled "Mechanical Spectral Shift Reactor" by W. J. Dollard et al.; Ser. No. 217,056 entitled "Latching Mechanism" by L. Veronesi; Ser. No. 217,054 entitled "Spectral Shift Reactor Control Method" by A. J. Impink, Jr.; Ser. No. 217,052 entitled "Displacer Rod For Use In A Mechanical Spectral Shift Reactor" by R. K. Gjertsen et al.; Ser. No. 217,053 entitled "Mechanical Spectral Shift Reactor" by D. G. Sherwood et al.; Ser. No. 217,275 entitled "Mechanical Spectral Shift Reactor" by J. F. Wilson et al.; Ser. No. 217,055 entitled "Hydraulic Drive Mechanism" by L. Veronesi et al.; Ser. No. 217,059 entitled "Fuel Assembly For A Nuclear Reactor" by R. K. Gjertsen; and Ser. No. 217,051 entitled "Fuel Assembly For A Nuclear Reactor" by R. K. Gjertsen et al. all of which are filed Dec. 16, 1980 and to Ser. No. 228,007 entitled "Self-Rupturing Gas Moderator Rod For A Nuclear Reactor" by G. R. Marlatt, filed Jan. 23, 1981 all of which are assigned to the Westinghouse Electric Corporation. BACKGROUND OF THE INVENTION The invention relates to spectral shift reactor control and more particularly to mechanical means for spectral shift reactor control. In typical nuclear reactors, reactivity control is accomplished by varying the amount of neutron absorbing material (poisons) in the reactor core. Generally, neutron absorbing control rods are utilized to perform this function by varying the number and location of the control rods with respect to the reactor core. In addition to control rods, burnable poisons and poisons dissolved in the reactor coolant can be used to control reactivity. In the conventional designs of pressurized water reactors, an excessive amount of reactivity is designed into the reactor core at start-up so that as the reactivity is depleted over the life of the core the excess reactivity may be employed to lengthen the core life. Since an excessive amount of reactivity is designed into the reactor core at the beginning of core life, neutron absorbing material such as soluble boron must be placed in the core at that time in order to properly control the excess reactivity. Over the core life, as reactivity is consumed, the neutron absorbing material is gradually removed from the reactor core so that the original excess reactivity may be used. While this arrangement provides one means of controlling a nuclear reactor over an extended core life, the neutron absorbing material used during core life absorbs neutrons and removes reactivity from the reactor core that could otherwise be used in a more productive manner such as in plutonium fuel production. The consumption of reactivity in this manner without producing a useful product resultss in a less efficient depletion of uranium and greater fuel costs than could otherwise be achieved. Therefore, it would be advantageous to be able to extend the life of the reactor core without suppressing excess reactivity with neutron absorbing material thereby providing an extended core life with a significantly lower fuel cost. One such method of producing an extended core life while reducing the amount of neutron absorbing material in the reactor core is by the use of "Spectral Shift Control". As is well understood in the art, in one such method the reduction of excess reactivity (and thus neutron absorbing material) is achieved by replacing a large portion of the ordinary reactor coolant water with heavy water. This retards the chain reaction by shifting the neutron spectrum to higher energies and permits the reactor to operate at full power with reduced neutron absorbing material. This shift in the neutron spectrum to a "hardened" spectrum also causes more of the U.sup.238 to be converted to plutonium that is eventually used to produce heat. Thus, the shift from a "soft" to a "hard" spectrum results in more neutrons being consumed by U.sup.238 in a useful manner rather than by poisons. As reactivity is consumed, the heavy water is gradually replaced with ordinary water so that the reactor core reactivity is maintained at a proper level. By the end of core life, essentially all the heavy water has been replaced by ordinary water while the core reactivity has been maintained. Thus, the reactor can be controlled without the use of neutron absorbing material and without the use of excess reactivity at start-up which results in a significant uranium fuel cost savings. The additional plutonium production also reduces the U.sup. 235 enrichment requirements. While the use of heavy water as a substitute for ordinary water can be used to effect the "spectral shift", the use of heavy water can be an expensive and complicated technology. Another well known phenomenon related to reactor control is referred to as xenon transient behavior. Xenon-135 is a fission product of uranium fuel some of which is a direct fission product of uranium-235 but most of which originates from the radioactive decay of tellurium-135 and iodine-135 which are produced from the fissioning of uranium-235. The major portion of the xenon thus produced is produced in a delayed manner due to the intermediate isotope production. This results in a time delay of several hours between the fissioning of fissile or fertile material and the production of large quantities of xenon-135. On the other side of the xenon transient phenomenon is the fact that since xenon-135 has a large neutron absorbing cross-section, xenon-135 tends to absorb neutrons and be destroyed thereby. Thus, xenon acts as a neutron poison in a reactor core robbing the core of neutrons that could be used to sustain the chain reaction. The transient usually associated with the xenon phenomenon arises because as power is reduced due to load follow reasons, neutron population in the core decreases which results in less destruction of xenon and in temporary xenon accumulation. This temporary accumulation of xenon further reduces reactor power by xenon absorption of neutrons. However, the reduction in reactor power lowers the core temperature which increases core reactivity due to the negative moderator temperature coefficient of the reactor. Thus, a minor oscillation in reactor power, xenon population, and core temperature can result from transient xenon production. Likewise, a similar result may occur from an attempt to increase reactor power in response to load follow requirements. This may occur since an increase in reactor power requires an increase in neutron population and fuel depletion which increases xenon production in the fuel. But since the xenon production is delayed in time, the poisonous effect of the xenon is temporarily delayed which again produces the transient oscillations between core temperature, xenon population, and reactor power. As is well understood in the art, the effectsd of these xenon transients can be effectively controlled by the addition or subtraction of boron in the reactor coolant by a feed-and-bleed process. The change in boron concentration in the reactor coolant can be timed to correspond to the changes in core reactivity due to the xenon transient thereby negating such transient. This can be accomplished as long as the boron concentration in the reactor coolant is sufficiently high to make a feed-and-bleed process possible in a timely manner. However, when the boron concentration falls below a given level, for example below 100 ppm. as is necessary near the end of core life, boron cannot be removed from the reactor coolant fast enough to compensate for xenon accumulation. Therefore, as the boron concentration in the reactor coolant nears a low level such as at the end of core life, boron compensation of xenon becomes very difficult which effectively prevents load follow maneuvering of reactor power so as to avoid xenon transients. Therefore, what is needed is apparatus to extend core life and provide for load follow capabilities at low reactor coolant boron concentrations. SUMMARY OF THE INVENTION A mechanical spectral shift reactor comprises apparatus for inserting and withdrawing water displacer elements having differing neutron absorbing capabilities for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The displacer elements may comprise substantially hollow cylindrical low neutron absorbing rods and substantially hollow cylindrical thick walled stainless rods. Since the stainless steel displacer rods have greater neutron absorbing capability; they can effect greater reactivity change per rod. However, by arranging fewer stainless steel displacer rods in a cluster, the reactivity worth of the stainless steel displacer rod cluster can be less than a low neutron absorbing displacer rod cluster.
	summary
	claims	1. A radioprotective screen for protecting at least one operator from ionizing radiation, said screen comprising:a front wall structure made of radioprotective material and a lateral wall structure made of radioprotective material linked to one another at a vertical or essentially vertical corner edge,said front wall structure comprising a lower part and an upper part configured to be moved relative to one another, said upper part of said front wall structure being mounted pivotally around a vertical or essentially vertical pivoting axis at said corner edge, said lower part of the front wall structure extending in a vertical or essentially vertical plane which is offset with respect to the plane of said lateral wall structure by a fixed angle between 70° and 120°, the lower part of the front wall structure being defined bya free lateral edge,a lateral edge defining a part of said corner edge, a lower edge, andan upper edge,the lateral wall structure extending in a vertical or essentially vertical plane, the lateral wall structure comprisinga free lateral edge,a lateral edge defining a part of said corner edge,a lower edge,an upper edge,an upper part, at least a portion of the upper part being made of transparent radioprotective material, anda lower part;a base provided with ground support wheels; anda part made of flexible radioprotective material which is shaped as a panel that extends over a part of the height of said corner edge, from the lower edge of the lower part of the lateral wall structure, and from the lower edge of the lower part of the front wall structure, over a part of said lower part of the lateral wall structure and over a part of the lower part of the front wall structure at both sides of said corner edge. 2. The screen according to claim 1, wherein said panel made of flexible radioprotective material extends from the lower edge of said lower part of the lateral wall structure and from the lower edge of the lower part of the front wall structure, over more than half of the height of said lower parts of the lateral wall structure and the front wall structure, the panel extending from said corner edge, over more than half of the width of said lower parts of the front wall structure and the lateral wall structure. 3. The screen of claim 1, wherein said lower part of the front wall structure extends in the vertical or essentially vertical plane which is offset with respect to the plane of said lateral wall structure by the fixed angle on the order of 90°. 4. The screen according to claim 1, wherein the lateral wall structure further comprisesan inner face turned towards a positioning space of the operator, andan opposite outer face opposite the inner face, andwherein the upper edge of the lateral wall structure comprises an extension forming a roof made of radioprotective material, which extends on the side of said inner face. 5. The screen according to claim 1, wherein the lower part of the front wall structure comprisesan inner face turned towards a positioning space of the operator,an opposite outer face opposite the inner face, andan upper edge comprising a protective extension shaped as a tablet or a semi-rigid bib and made of a radioprotective material which extends on the side of said outer face. 6. A radioprotective screen for protecting at least one operator from ionizing radiation, said screen comprising:a front wall structure made of radioprotective material and a lateral wall structure made of radioprotective material linked to one another at a vertical or essentially vertical corner edge,said front wall structure comprising a lower part and an upper part configured to be moved relative to one another, said upper part of said front wall structure being mounted pivotally around a vertical or essentially vertical pivoting axis at said corner edge,the lower part of the front wall structure comprisingan inner face turned towards a positioning space of the operator,an opposite outer face opposite the inner face, andan upper edge including a protective extension shaped as a tablet or a semi-rigid bib and made of a radioprotective material which extends on the side of said outer face; anda base provided with ground support wheels. 7. The screen according to claim 6, wherein said tablet extends in a horizontal or essentially horizontal position from the upper edge of the lower part of the front wall structure,wherein said tablet is mounted pivotally on said upper edge of the lower part of the front wall structure, in order to allow the tablet to be raised from said horizontal position, andwherein said tablet comprises a retractable end extension configured to make the tablet telescopic. 8. A radioprotective screen for protecting at least one operator from ionizing radiation, said screen comprising:a front wall structure made of radioprotective material and a lateral wall structure made of radioprotective material linked to one another at a vertical or essentially vertical corner edge,said front wall structure comprising a lower part and an upper part configured to be moved relative to one another, said upper part of said front wall structure being mounted pivotally around a vertical or essentially vertical pivoting axis at said corner edge, the upper part of the front wall structure being formed by at least one panel made of radioprotective material, the upper part of the front wall structure comprisinga free lateral edge,a lateral edge forming a part of the corner edge,an upper edge,a lower edge,an inner face turned towards a positioning space of the operator, andan opposite outer face opposite the inner face,the lateral wall structure including a lateral edge forming a part of said corner edge, the lateral edge comprising an extension shaped as a lateral wing configured to cover the lateral edge of the front wall structure that is in front of the upper part of the front wall structure, and the associated pivoting axis, the lateral wing being formed on the side of the outer face of the upper part of the front wall structure; anda base provided with ground support wheels. 9. A radioprotective screen for protecting at least one operator from ionizing radiation, said screen comprising:a front wall structure made of radioprotective material and a lateral wall structure made of radioprotective material linked to one another at a vertical or essentially vertical corner edge,said front wall structure comprising a lower part and an upper part configured to be moved relative to one another, said upper part of said front wall structure being mounted pivotally around a vertical or essentially vertical pivoting axis at said corner edge, the upper part of the front wall structure being formed by at least one panel made of radioprotective material, the upper part of the front wall structure comprisinga free lateral edge,a lateral edge forming a part of the corner edge,an upper edge,a lower edge,an inner face turned towards a positioning space of the operator, andan opposite outer face opposite the inner face,the lateral wall structure comprisingan inner face turned towards the positioning space of the operator, andan opposite outer face opposite the inner face of the lateral wall structure, the upper edge of the lateral wall structure comprising an extension forming a roof made of radioprotective material, which extends on the side of said inner face of the lateral wall structure,the upper edge of the upper part of the front wall structure comprising a roof-forming extension made of radioprotective material which extends on the side of the inner face of said upper part of the front wall structure in a plane that is offset with respect to the plane of the roof-forming extension of the lateral wall structure; anda base provided with ground support wheels. 10. A radioprotective screen for protecting at least one operator from ionizing radiation, said screen comprising:a front wall structure made of radioprotective material and a lateral wall structure made of radioprotective material linked to one another at a vertical or essentially vertical corner edge,said front wall structure comprising a lower part and an upper part configured to be moved relative to one another, said upper part of said front wall structure being mounted pivotally around a vertical or essentially vertical pivoting axis at said corner edge, the upper part of the front wall structure being formed by at least one panel made of radioprotective material, the upper part of the front wall structure comprisinga free lateral edge,a lateral edge forming a part of the corner edge,an upper edge,a lower edge,an inner face turned towards a positioning space of the operator,an opposite outer face opposite the inner face,an upper panel at least a part of which is made of radioprotective material, anda lower panel at least part of which is made of a transparent radioprotective material, said lower panel being vertically translationally movable with respect to said upper panel, in order to form a telescopic upper part of the front wall structure, the height of which is adjustable; anda base provided with ground support wheels. 11. The screen according to claim 10, wherein the lower edge of the upper part of the front wall structure is formed by a flexible curtain composed by a juxtaposition of a plurality of flexible bands made of radioprotective material. 12. The screen according to claim 10, wherein the movable lower panel is attached to said upper panel by an equilibrium system. 13. The screen according to claim 12, wherein the equilibrium system is of a spiral-spring type with constant force. 14. A radioprotective screen for protecting at least one operator from ionizing radiation, said screen comprising:a front wall structure made of radioprotective material and a lateral wall structure made of radioprotective material linked to one another at a vertical or essentially vertical corner edge,said front wall structure comprising a lower part and an upper part configured to be moved relative to one another, said upper part of said front wall structure being mounted pivotally around a vertical or essentially vertical pivoting axis at said corner edge, the upper part of the front wall structure being formed by at least one panel made of radioprotective material, the upper part of the front wall structure comprisinga free lateral edge,a lateral edge forming a part of the corner edge,an upper edge,a lower edge,an inner face turned towards a positioning space of the operator,an opposite outer face opposite the inner face,a supporting arm pivotally mounted on said corner edge around said pivoting axis, andat least one panel is movably mounted on said supporting arm for horizontal translational movement. 15. Cover-shaped equipment configured to cover at least part of the height of the radioprotective screen according to claim 14, the cover-shaped equipment comprising:a flexible pocket provided with an opening, said flexible pocket being configured to at least one partially cover the upper part of the front wall structure by entering the lower edge of the front wall structure into the opening of said flexible pocket, said flexible pocket being provided with at least one transparent part and with a fixing system configured to fix the at least one transparent part to said upper part of the front wall structure; andat least one flexible panel configured to at least partially cover said lateral wall structure and the lower part of said front wall structure, said at least one flexible panel comprisingat least one transparent part configured to be positioned in front of the transparent part of said lateral wall structure, anda fixing system on said lateral wall structure and said front wall structure; anda flexible structure at least partially covering a tablet that extends along the upper edge of the lower part of the front wall structure, the flexible structure being either fixed to said panel to cover said lateral wall structure and the lower part of the front wall structure, or independent from said panel, said flexible structure being provided with a fixing system configured to fix the flexible structure to said tablet.
054913454	summary	BACKGROUND The present invention relates generally to a vacuum canister or container for picking up and containing a fluid or a particulate material. More particularly, this invention relates to a vacuum canister for picking up and containing a hazardous fluid or particulate material or waste. Hazardous material includes chemical, radioactive, corrosive agent, poison, biomedical or any other material which can endanger human health or well-being if handled improperly. Various types of devices have been suggested to reduce the danger to human health from improper handling of hazardous material. One type of device for picking up and containing material is a vacuum cleaner-type device that uses a fan to draw particles into an unsealed container. The unsealed container, however, allows smaller sized particles to escape out an exhaust port. Such devices are disclosed in U.S. Pat. Nos. 4,185,355; 4,325,162; 5,018,238; 5,084,937. Another type of device for containing material, particularly hazardous material, is a storage canister that can be sealed after the material has been placed within the canister. However, such a storage canister does not pick up the hazardous material for deposit into the canister. Such storage canisters are disclosed in U.S. Pat. Nos. 4,328,423; 4,625,122; 4,633,091; 5,111,938. Still another type of device for containing material is a storage container provided with vacuum means to draw a vacuum within the container after it is filled with a hazardous material. Such a storage canister for containment of radioactive material is disclosed in U.S. Pat. No. 5,073,305. There is a need for a vacuum canister for quickly picking up material, particularly hazardous material, and safely containing the material to reduce the risk to human health or well-being from handling the material improperly. SUMMARY Accordingly, it is an object of the present invention to provide a vacuum canister that can be operated for controllably and repetitively picking up fluid and particulate material such as hazardous material for containment within the canister It is also an object of the present invention to provide a vacuum canister for picking up and containing hazardous material in which the vacuum canister is hand held and easily used, thereby reducing the amount of handling and risk of danger to human health from the hazardous material. It is another object of the invention to provide such a vacuum canister that provides a storage container in which fluid and/or particulate hazardous material can be stored and easily identified by labeling the vacuum canister. It is a further object of the invention is to provide such a vacuum canister for picking up and containing radioactive hazardous material and/or corrosive agent material in which the vacuum canister includes a protective layer of lead for shielding against radioactivity and/or a protective layer of glass for shielding against acids and bases. Another object of the invention is to provide such a vacuum canister that is simple in construction and that may be manufactured relatively easily and inexpensively for widespread use for picking up, containing and disposing of hazardous material, thus lowering the costs associated with properly handling hazardous material from cleanup to disposal or remediation. Certain of the foregoing and related objects are readily obtained in a vacuum canister for picking up and containing at least one of a fluid and a particulate material, in which the vacuum canister comprises generally a housing and a valve. The housing has a sealed vacuum chamber having a predetermined vacuum pressure therein. The valve has a first port operable to be placed in fluid communication with the vacuum chamber and a second port for receiving at least one of a fluid and a particulate material. The valve is operable between a first position to seal the vacuum chamber and retain the predetermined vacuum within the vacuum chamber, and a second position to allow fluid flow through the valve from the second port into the vacuum chamber, whereby operation of the valve, in the second position when the second port is located adjacent at least one of a fluid and a particulate material, is effective to displace through the valve the at least one of a fluid and a particulate material into the housing. The vacuum canister is desirably suitable for picking up and containing hazardous material such as corrosive agent material and radioactive material. For picking up and containing corrosive agent material, vacuum canister preferably includes a protective layer of glass having a predetermined thickness that is effective to contain the corrosive material within the vacuum canisters. For picking up and containing radioactive material, vacuum canister preferably includes a protective layer of lead having a predetermined thickness that is effective to shield radiation emitted from the radioactive material contained within the vacuum canister. The protective layer is disposed in substantially covering relationship to the vacuum chamber. Preferably the vacuum canister includes a conduit in fluid communication with the second port of the valve. Advantageously, the housing is sized and configured to fit within a person's hand and the valve is sized and configured to be operable by a finger of a person's hand. In an alternative embodiment of the invention for a vacuum canister for picking up and containing at least one of a fluid and a particulate material, the vacuum canister further includes vacuum means for establishing a predetermined vacuum pressure within the vacuum chamber. The vacuum means for creating a vacuum within the vacuum chamber includes a preselected substance disposed in communication with the vacuum chamber for causing a reaction with a gas within the vacuum chamber. An alternative embodiment of the vacuum means for establishing a predetermined vacuum pressure within the vacuum chamber includes a slidable housing member for expanding the volume of the vacuum chamber. Certain of the foregoing and related objects are also readily obtained in a method for picking up and containing at least one of a fluid and a particulate material, the method includes the steps of: providing a housing having therein a sealed vacuum chamber; providing a valve having a first port in fluid communication with the vacuum chamber and a second port for receiving at least one of a fluid and a particulate material, the valve being operable between a first position to seal the vacuum chamber and retain a vacuum within the vacuum chamber, and a second position to permit fluid flow through the valve from the second port to the first port; establishing a predetermined vacuum pressure within the vacuum chamber; locating at least one of a fluid and a particulate material adjacent the second port; and placing the valve in the second position to displace along with fluid flow through the valve at least one of a fluid and a particulate material into the vacuum chamber.
051494957	claims	1. A water rod, usable for containing water in a substantially interior position in a nuclear fuel rod bundle, the bundle having a plurality of lattice positions spaced at a predetermined lattice pitch, comprising: a hollow longitudinally extending tube having a sidewall which defines a cross-sectional interior region of said tube, configured to substantially occupy a predetermined number of the lattice positions of the bundle; said cross-sectional interior region being configured to define two round-cornered, triangular regions continuously connected by a constricted region, said constricted region being defined by two inwardly extending longitudinal projections; wherein said predetermined number is greater than four lattice positions and less than nine lattice positions; and wherein said area of said cross-sectional region, said predetermined number, and said pitch define a water rod efficiency greater than about 0.7; and, at least one projection on an exterior portion of said sidewall; and wherein said sidewall has sufficient resiliency to permit inward flexing of said sidewall, at least in a portion substantially adjacent to said projection, to permit passage of said projection over an obstruction when said water rod is axially moved proximate to said obstruction. a hollow longitudinally-extending tube having a sidewall which defines a cross-sectional interior region of said tube, configured to substantially occupy a predetermined number of lattice positions of the bundle; said cross-sectional interior region being configured to define four interiorly-extending longitudinal projections defined therebetween four exteriorly-projecting lobes; wherein said predetermined number is greater than four lattice positions and less than nine lattice positions; and wherein said area of said cross-sectional region, said predetermined number, and said pitch define a water rod efficiency greater than about 0.7; and, at least one projection on an exterior portion of said sidewall; and wherein said sidewall has sufficient resiliency to permit inward flexing of said sidewall, at least in a portion substantially adjacent to said projection, to permit passage of said projection over an obstruction when said water rod is axially moved proximate to said obstruction. a hollow longitudinally-extending tube having a sidewall which defines a cross-sectional interior region of said tube, configured to substantially occupy a predetermined number of lattice positions of the bundle; said cross-sectional interior region being configured to define a substantially rectangular shape; wherein said predetermined number is greater than four lattice positions and less than nine lattice positions; and wherein said area of said cross-sectional region, said predetermined number, and said pitch define a water rod efficiency greater than about 0.7. at least one projection attached to an exterior portion of said sidewall; and wherein said sidewall has sufficient resiliency to permit inward flexing of said sidewall, at least in a portion substantially adjacent to said projection, to permit passage of said projection over an obstruction when said water rod is axially moved proximate to said obstruction. a hollow, longitudinally extending tube having a sidewall which defines a cross-sectional interior region of said tube, configured to substantially occupy a predetermined number of lattice positions of the bundles; said cross-sectional interior region being configured to define two substantially circular portions, said circular portions being substantially adjacent; wherein said predetermined number is greater than four lattice positions and less than nine lattice positions; and wherein said area of said cross-sectional region, said predetermined number, and said pitch define a water rod efficiency grater than about 0.6. at least one projection on an exterior portion of said sidewall; and wherein said sidewall has sufficient resiliency to permit inward flexing of said at least in a portion substantially adjacent to said projection, to permit passage of said projection over said first means when said water rod is axially moved proximate to said first means. first means for spatially positioning rods wherein said means defines a lattice having a plurality of lattice positions and a lattice pitch; a plurality of nuclear fuel rods operably connected with said means for positioning, wherein said nuclear fuel rods occupy at least some of said lattice positions; at least one hollow longitudinally extending tube having a sidewall which defines a cross-sectional interior region of said tube, configured to substantially occupy greater than four and fewer than nine lattice positions of said lattice; said cross-sectional interior region being configured to define two round-cornered triangular regions continuously connected by a constricted region, said constricted region being defined by two inwardly extending longitudinal projections; wherein the area of said cross-sectional region for said tubes, said number of occupied positions for said tubes, and said pitch define a water rod efficiency greater than about 0.7; and, at least one projection on an exterior portion of said sidewall; and wherein said sidewall has sufficient resiliency to permit inward flexing of said sidewall, at least in a portion substantially adjacent to said projection, to permit passage of said projection over an obstruction when said water rod is axially moved proximate to said obstruction. first means for spatially positioned rods wherein said means defines a lattice having a plurality of lattice positions and a lattice pitch; a plurality of nuclear fuel rods operably connected with said means for positioning, wherein said nuclear fuel rods occupy at least some of said lattice positions; at least one hollow longitudinally extending tube having a sidewall which defines a cross-sectional interior region of said tube, configured to substantially occupy greater than four and fewer than nine lattice positions of said lattice; and said cross-sectional interior region being configured as a rectangle; and wherein the area of said cross-sectional region of said tubes, said number of occupied positions of said tubes, and said pitch define a water rod efficiency greater than about 0.7. at least one projection attached to an exterior portion of said sidewall; and wherein said sidewall has sufficient resiliency to permit inward flexing of said sidewall, at least in the portion substantially adjacent to said projection, to permit passage of said projection over said first means when said water rod is axially moved proximate to said first means. first means for spatially positioning rods wherein said means defines a lattice having a plurality of lattice positions and a lattice pitch; a plurality of nuclear fuel rods operably connected with said means for positioning, wherein said nuclear fuel rods occupy at least some of said lattice positions; at least one hollow longitudinally extending tube having a sidewall which defines a cross-sectional interior region of said tube, configured to substantially occupy greater than four and fewer than nine lattice positions of said lattice; said cross-sectional interior region being configured to define two substantially circular regions being substantially adjacent; and wherein the area of said cross-sectional region of said tubes, said number of occupied positions of said tubes, and said pitch define a water rod efficiency greater than about 0.6. at least one projection on an exterior portion of said sidewall; and wherein said sidewall has sufficient resiliency to permit inward flexing of said sidewall, at least in a portion substantially adjacent to said projection, to permit passage of said projection over said first means when said water rod is axially moved proximate to said first means. 2. A water rod, as claimed in claim 1, wherein said predetermined number is seven. 3. A water rod, usable for containing water in a substantially interior position in a nuclear fuel rod bundle, the bundle having a plurality of lattice positions spaced at a predetermined lattice pitch, comprising: 4. A water rod, as claimed in claim 2, wherein said predetermined number is five. 5. A water rod, usable for containing water in a substantially interior position in a nuclear fuel rod bundle, the bundle having a plurality of lattice positions spaced at a predetermined lattice pitch, comprising: 6. A water rod, as claimed in claim 5, wherein said predetermined number is seven. 7. A water rod, as claimed in claim 5, further comprising: 8. A water rod, usable for containing water in a substantially interior position in a nuclear fuel rod bundle, the bundle having a plurality of lattice positions spaced at a predetermined lattice pitch, comprising: 9. A water rod, as claimed in claim 8, herein said predetermined number is seven. 10. A water rod, as claimed in claim 8, further comprising: 11. A nuclear fuel rod bundle comprising: 12. A nuclear fuel rod bundle, as claimed in claim 11, wherein the number of said lattice positions occupied by said tubes is seven. 13. A nuclear fuel rod bundle comprising: 14. A nuclear fuel rod bundle, as claimed in claim 13, wherein the number of lattice positions occupied by said tubes is 7. 15. A nuclear fuel rod bundle, as claimed in claim 13, further comprising: 16. A nuclear fuel rod bundle comprising: 17. A nuclear fuel rod bundle, as claimed in claim 16, wherein the number of said lattice positions occupied by said tubes is seven. 18. A nuclear fuel rod bundle, as claimed in claim 16, further comprising:
	description	The present invention relates to new polymers, their preparation methods and their uses, in particular for the capture of metals. Uranium, in its current form (mining) is a non-renewable resource whose resources known today represent about a century of consumption. Two possibilities can be exploited to help overcome the uranium shortage: draw dissolved uranium from the oceans, Recycle used fuel to reduce the loss of fissile material via final waste. The oceans, with an estimated reserve of 4,500 million tons (nearly 1,000 times the terrestrial reserves) represent an interesting source of nuclear fuel with more than a millennium of consumption. In recent years, research has intensified to discover simple means of recovering uranium from seawater present at 3.3 ppb. New materials, generally polymers, have been developed for the capture of marine uranium. After being immersed in seawater, these polymers form a uranium-polymer complex, and allow the extraction of uranium from seawater. The reprocessing of these polymers out of water makes it possible to decomplex the uranium and to recover it. But the presence of poisons for polymers reduces the effectiveness of this method. The vanadium present in seawater competes with uranium and complexes with current polymers instead of uranium, which limits the recovery capacity of these polymers. The recycling of used fuels from nuclear power stations is already integrated into the life cycle of uranium. Currently, the reprocessing of uranium is based on liquid-liquid extraction methods in the presence of complexing compounds such as the DIAMEX or PUREX methods. These techniques use toxic compounds and have a very high cost. One aspect of the invention relates to new polymers which are both soluble and insoluble depending on the conditions of the medium in which they are found and which can easily pass from one state to another. Another aspect of the invention relates to new polymers that are capable of being able to complex with metals, in particular with metals in the form of a trace in the medium in which they are found. Another aspect of the invention relates to methods for capturing metals and in particular uranium, in particular in seawater. Another aspect of the invention relates to a method for the selective capture of uranium in seawater, with high yields. Another aspect of the invention relates to a method for the reprocessing of spent nuclear fuel for the recovery of unreacted fissile materials. Another aspect of the invention relates to the use of new polymers complexed with metals as catalysts in homogeneous or heterogeneous catalysis. Another aspect of the invention relates to the use of new polymers for labeling cells in the biomedical field, or the labeling of luxury products in the field of fighting counterfeiting. The present invention relates to a composition comprising or consisting of a polymer having a degree of polymerization n, ranging from 2 to 10000, and containing 2 to 10000 monomer units, said monomer units being: either monomer units derived from 4-vinylpyridine, in which the carbons in position 2 and 6 can be substituted by one of the substituents of the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, carboxylic acid of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester of 1 to 20 carbons, amine of 1 to 20 carbons, heterocycle of 1 to 5 cycles in which the heteroatom is either nitrogen, oxygen, sulfur or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms, or monomer units derived from a co-monomer, provided that when one of the substituents chosen in position 2 (respectively in position 6) represents either hydrogen, or an alkyl radical of 1 to 4 carbons, or an aryl radical of 1 to 4 carbons, or an alkene radical of 1 to 4 carbons, the other substituent in position 6 (respectively in position 2) is different from hydrogen, from the alkyl radical from 1 to 4 carbons, from the aryl radical from 1 to 4 carbons, and the alkene radical of 1 to 4 carbons, and provided that said monomer units derived from 4-vinylpyridine represent at least 20% of the degree of polymerization n,said polymer optionally being complexed with a metal,said polymer being linear or cross-linked. The polymers according to the present invention have the advantage of having different solubility properties depending on the substituent groups on the monomer units derived from 4-vinylpyridine and on the organization of the constituent monomer units of the polymer. For example, when the substituent groups in position 2 and 6 of all the monomer units are carboxylic acid groups, the solubility of the polymer thus obtained varies according to the pH of the solution. In neutral or basic medium, the polymer is soluble in aqueous medium. In very acidic aqueous medium, the polymer becomes insoluble. This property makes it possible to easily vary the solubility of the polymer obtained and thus to change the behavior of the polymer for the capture of metals. The polymers according to the present invention have the advantage of being unsupported, which makes them usable in homogeneous catalysis. The polymers according to the present invention comprise more than 20% of monomer units derived from 4-vinylpyridine, in particular more than 30%, in particular more than 40%, in particular more than 50%, in particular more than 60%, in particular more than 70%, in particular more than 80%, in particular more than 90% and in particular 100%. The polymers according to the present invention are adaptable and can be optimized according to the difficulties encountered. For example, in the case where the substituent groups in position 2 and 6 are very bulky, a spacer co-monomer can be added at significant rates (>50%) to limit the steric hindrance around the monomer units derived from 4-vinylpyridine. The polymers according to the present invention can comprise: a) either a single type of monomer unit derived from 4-vinylpyridine, without a monomer unit derived from a co-monomer, the polymer is then a homopolymer, b) or a single type of monomer units derived from 4-vinylpyridine, and a single type of monomer units derived from a co-monomer, the polymer is then a copolymer, c) or a single type of monomer unit derived from 4-vinylpyridine, and several types of monomer unit derived from a different co-monomer, the polymer is then a copolymer, d) or several different types of monomer units derived from 4-vinylpyridine, without a monomer unit derived from a co-monomer, e) or several different types of monomer units derived from 4-vinylpyridine, and only one type of monomer units derived from a co-monomer, the polymer is then a copolymer, f) or several different types of monomer units derived from 4-vinylpyridine, and several different types of monomer units derived from a co-monomer, the polymer is then a copolymer. According to the present invention, the term “homopolymer” means a polymer in which all the constituent monomer units of the polymer have the same formula, that is to say that all the monomer units are monomer units derived from 4-vinylpyridine and all the monomer units derived from 4-vinylpyridine have the same substituent groups in position 2, as well as in position 6. The metals optionally complexed on the monomer units can vary within the same homopolymer. The conjugate forms of the same acid/base couple are considered to be identical for the concept of homopolymer. For example, a polymer having a COOH group on a first monomer unit and a COO− group on a second monomer unit will remain to be considered as a homopolymer. According to the present invention, the term “copolymer” means a polymer in which at least one monomer unit is derived from a co-monomer and at least one monomer unit is derived from 4-vinylpyridine. The polymers according to the present invention are complexed or not with a metal, for example a complex each monomer unit may or may not be complexed with a metal independently of each other. The polymers according to the present invention can form particles, in particular of a micrometric size or in particular of a nanometric size. According to the present invention, the term “derivative of 4-vinylpyridine” means a compound of formula in which Ri,1 and Ri,2 may be substituted by one of the substituents of the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, carboxylic acid of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester of 1 to 20 carbons, amino of 1 to 20 carbons, heterocycle of 1 to 5 rings of which the heteroatom is either nitrogen, either oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms. According to the present invention a “monomer derived from 4-vinylpyridine” means a compound of formula in which the definitions of Ri,1 and Ri,2 are as indicated above. According to the present invention, the term “co-monomer” means a compound of formula in which Bi is different from a 4-vinylpyridine derivative. According to the present invention, the term “monomer unit derived from 4-vinylpyridine” means the basic brick which constitutes the polymer and whose definitions of Ri,1 et Ri,2 are as indicated above. Within the meaning of the present invention, the term “monomer unit derived from a co-monomer” means the basic brick of formula constitutes the polymer and in which Bi, is different from a 4-vinylpyridine derivative. According to the present invention, the term “monomer unit” means the basic brick, constituting the polymer, composed either of a monomer unit derived from 4-vinylpyridine, or of a monomer unit derived from a co-monomer. According to the present invention, the term “linear polymer” means a polymer in which all of the monomeric imitates are linked in a single direction forming a chain without branching or cross-linking. According to the present invention, the term “cross-linked polymer” means a polymer in which at least two linear polymers are linked together by at least one cross-linking bridge, said cross-linking bridge being formed by a monomer unit derived from a-co-monomer belonging to at least one of the two linear polymers and said monomer unit derived from a co-monomer being covalently bonded to the carbon chain of the other linear polymer. According to the present invention, the term “carbon chain” means the series of linear carbon formed during the polymerization by the carbon-carbon double bonds of the monomers which constitute the polymer. According to the present invention, the term “alkyl radical of 1 to 20 carbons” means an acyclic carbon chain, saturated, linear or branched, comprising from 1 to 20 carbon atoms. Examples of alkyl radicals of 1 to 20 carbons include methyl-, ethyl-, propyl-, butyl groups, . . . . Within the alkyl radical, one or more hydrogens can be substituted by a group chosen from: halogen, hydroxyl, alkoxyl, amino, nitro, cyano, trilfuoro, carboxylic acid, carboxylic ester, phosphine, thiols . . . . According to the present invention, the term “alkene radical of 2 to 20 carbons” means an acyclic carbon chain, linear or branched, comprising from 2 to 20 carbon atoms and comprising at least one carbon-carbon double bond. Examples of alkene radicals of 2 to 20 carbons include ethenyl-, propenyl-, butenyl groups . . . . Within the alkene radical, one or more hydrogens can be substituted by a group chosen from: halogen, hydroxyl, alkoxyl, amino, nitro, cyano, trilfuoro, carboxylic acid, carboxylic ester, phosphine, thiols . . . . According to the present invention, the term “aryl radical of 2 to 20 carbons” means a carbon chain comprising at least one saturated or partially saturated ring and, comprising from 2 to 20 carbon atoms, without heteroatoms in the rings. Examples of aryl radicals of 2 to 20 carbons include phenyl-, benzyl groups, . . . . Within the aryl radical, one or more hydrogens can be substituted by a group chosen from: halogen, hydroxy, alkoxyl, amino, nitro, cyano, trifluoro, carboxylic acid, carboxylic ester, phosphine, thiols . . . . According to the present invention, the term “heterocycle of 1 to 5 rings” means a carbon chain comprising from 1 to 5 saturated or partially saturated rings, having at least one ring which contains a different carbon atom to form the ring and comprising from 2 to 20 carbon atoms. Examples of heterocycles comprising from 2 to 20 carbons include pyrrolidinyl, piperidinyl, . . . . Within the heterocycle, one or more hydrogens can be substituted by a group chosen from: halogen, hydroxyl, alkoxyl, amino, nitro, cyano, trifluoro, carboxylic acid, carboxylic ester, phosphine, thiol . . . . According to the present invention, the term “thiols of 1 to 20 carbon” means a carbon chain comprising from 1 to 20 carbons of formula SR2. According to the present invention, the term “phosphine from 1 to 20 carbon” means a carbon chain comprising from 1 to 20 carbons of formula PR3. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a linear or cross-linked polymer and having one or more types of monomer units derived from 4-vinylpyridine and one or more types of monomer units derived from a co-monomer, said polymer being complexed or not with one or more different metals. The composition according to the invention comprises or consists of a linear or cross-linked polymer consisting of monomer units, of Formula I in which: R4 is a compound allowing the propagation of the polymerization, whether or not originating from a polymerization initiator, or allowing the termination of the polymerization, or a transfer agent, A is a compound derived from said polymerization initiator or a fragment derived from the polymerization method, a and r are identical or different and are 0 or 1, i is a strictly positive, indexed integer, varying from 1 to n, itself comprised from 2 to 10000,and for each i: Ri,1 and Ri,2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, carboxylic acid of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester of 1 to 20 carbons, amine of 1 to 20 carbons, heterocycle of 1 to 5 rings in which the heteroatom is either nitrogen or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms, Bi is a monomer unit derived from a co-monomer, whether or not forming a cross-linking bridge, Mi is a metal, ni et mi, are integers equal to 0 or 1, ni+mi=1, xi is a number comprised from 0 to 6, pi is the electrical charge of the metal complex ranging from −6 to +6,provided that when Ri,1 (respectively Ri,2) represents either hydrogen, or an alkyl radical of 1 to 4 carbons, or an aryl radical of 1 to 4 carbons, or an alkene radical of 1 to 4 carbons, then Ri,2 (respectively Ri,1) is different from hydrogen, from the alkyl radical of 1 to 4 carbons, from the aryl radical of 1 to 4 carbons, and from the alkene radical of 1 to 4 carbons,said polymer being linear when there is no Bi forming a cross-linking bridge,said polymer being cross-linked when there is at least one Bi, forming a cross-linking bridge between two linear polymers. In this embodiment, the polymer of Formula I can be, for example: a copolymer comprising at least one type of monomer units derived from 4-vinylpyridine and at least one type of monomer units derived from a co-monomer, a polymer comprising at least two types of monomer units derived from 4-vinylpyridine and without monomer unit derived from a co-monomer, a homopolymer comprising a single type of monomer unit derived from 4-vinylpyridine,said polymer being or not being complexed with metals. In this embodiment, the polymer of Formula I can take any form of organization of copolymers, in particular a random copolymer, a block copolymer, a periodic copolymer, or a random copolymer. These polymers can themselves be linear or cross-linked and complexed or not with metals. In this embodiment, each monomer unit which forms the polymer of Formula I can be electrically charged, positively or negatively depending on the monomer unit and the presence or absence of a complexed metal itself charged. In this embodiment, one of the ends of the polymer is: either a compound derived from a polymerization initiator such as, for example, benzene which comes from benzyl chloride, or the last carbon in the polymer chain, which implies a=0,and the other end of the polymer is: either a compound allowing the propagation of the polymerization such as for example a Chlorine atom Cl, or a compound allowing the termination of the polymerization, or a transfer agent such as, for example, benzyl benzene carbodithioate, or the last carbon of the polymeric chain, which implies r=0. According to the present invention, the term “polymerization initiator” means a compound which makes it possible to initiate polymerization. The monomers which constitute react on this compound after its initiation. According to the present invention, the term “compound permitting the propagation of the polymerization” means a compound capable of reacting with a monomer to increase the degree of polymerization of the polymer in formation by one. According to the present invention, the term “compound allowing the termination of the polymerization” means a compound incapable of reacting with a monomer to continue the polymerization. According to the present invention, the term “transfer agent” means a compound incapable of reacting alone with a monomer to continue the polymerization, but which can be activated by a radical compound of the reaction medium and become a compound allowing the propagation of polymerization. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having one or more types of monomer units derived from 4-vinylpyridine and one or more types monomer units derived from a co-monomer, said polymer being complexed or not with one or more different metals, being linear and not cross-linked. The composition according to the invention comprises or consists of a non-cross-linked linear polymer consisting of monomer unit, of Formula II in which: the definitions of Ri,1, Ri,2, A, R4, a, r, Mi, xi, ni, mi, pi and i are as described in Formula I, Bi is a monomer unit derived from a co-monomer which does not form a cross-linking bridge. In this embodiment, no monomer unit forms a cross-linking bridge with another monomer. In this embodiment, the absence of cross-linking makes it possible to increase the solubility of the polymers. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having one or more types of monomer units derived from 4-vinylpyridine and having no monomer units derived from a co-monomer, said polymer is complexed or not with one or more different metals, is linear and is not cross-linked. The composition according to the invention comprises or consists of a polymer of Formula III in which: the definitions of Ri,1, Ri,2, A, R4, a, r, Mi, xi, pi and i are as described in Formula I. In this embodiment, the polymer of Formula III can be: a polymer with at least two types of monomer units derived from 4-vinylpyridine and without monomer unit derived from a co-monomer, or a homopolymer. In this embodiment, the absence of co-monomer makes it possible to increase the capacity for capture of metals by the polymer. If 100% of the monomer units are monomer units derived from 4-vinylpyridine, the two substituent groups of which in positions 2 and 6 are carboxylic acid groups, the capacity for complexing with the metal is doubled, compared with the capacity for complexing d a polymer containing 50% of monomer units derived from co-monomers. In this embodiment, the possibility of having several monomer units derived from 4-vinylpyridine makes it possible to complex different metals according to the monomer units or to complex the same metal differently according to the monomer units. These differences make it possible to obtain different catalytic sites on the same polymer and thus to carry out catalytic reactions requiring several different catalytic sites with a single catalyst. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having a single type of monomer units derived from 4-vinylpyridine and having no units monomers derived from a co-monomer, said polymer being complexed or not with one or more different metals, being linear and not cross-linked. The composition according to the invention comprises or consists of a homopolymer of Formula IV in which: the definitions of A, R4, a, r, Mi, xi, pi and i are as described in Formula I, R1 et R2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, carboxylic acid with 1 to 20 carbons, alcohol of 1 to 20 carbons, ether with 1 to 20 carbons, ester of 1 to 20 carbons, amine with 1 to 20 carbons, heterocycle of 1 to 5 rings in which the heteroatom is either nitrogen, or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms,provided that when R1 represents either hydrogen or an alkyl radical of 1 to 4 carbons, or an aryl radical of 1 to 4 carbons, or an alkene radical of 1 to 4 carbons, then 2 is different from hydrogen, of the alkyl radical of 1 to 4 carbons, of the aryl radical of 1 to 4 carbons, and of the alkene radical of 1 to 4 carbons. In this embodiment, the polymer of Formula IV is a homopolymer. In this embodiment, the polymer can be optimized for a single action. For example, the polymer comprising only monomer units derived from 4-vinylpyridine, the two substituent groups of which in positions 2 and 6 are carboxylic acid groups, exhibit optimal activity for the capture of uranyl ions in aqueous solution. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having a single type of monomer units derived from 4-vinylpyridine, of which the two substituent groups are positions 2 and 6 are carboxylic acid groups, and having no monomer units derived from a co-monomer, said polymer being complexed or not with a single metal, being linear and not cross-linked. The composition according to the invention comprises or consists of a homopolymer of chelidamic acid of Formula V in which: the definitions of R4, A, a, and r are as described in the general formula, M is a metal, x is a number comprised from 0 to 6, p is the electrical charge of the metal complex ranging from −6 to +6. In this embodiment, the polymer of Formula V is a homopolymer with a single type of monomer units derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are carboxylic acid groups. In this embodiment, the constituent monomer units of the polymer of Formula V are either all complexed with the same metal, or all not complexed. In this embodiment, the constituent monomer units of the polymer of Formula V all have the same electrical charge. In this embodiment, the polymers of Formula V have the advantage of being able to dissolve easily in an aqueous medium, with a solubility dependent on the pH conditions of the medium and with an ability to complex with the metals optionally present in the solution. According to another particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having a single type of monomer units derived from 4-vinylpyridine, the two substituent groups of which positions 2 and 6 are carboxylic acid groups and having no monomer units derived from a co-monomer, said polymer not being complexed by a metal, being linear and not cross-linked. The composition according to the invention comprises or consists of a homopolymer of chelidamic acid of Formula VI in which: the definitions of R4, A, a, and r are as described in Formula I,in particular the polymers of Formula VII, Formula VIII, Formula IX, Formula X, and Formula XI in which: the definitions of R4, A, a, and r are as described in Formula I, n1, n2 and n3 are integers, in Formula VIII, n1+n2=n, in Formula IX, n1+n2+n3=n, in Formula X, n1+n3=n. In this embodiment, the polymer of Formula VI is a homopolymer comprising a single type of monomer units derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are carboxylic acid groups, not complexed with a metal. In this embodiment, the polymer of Formula VI varies depending on the pH of the solution in which the polymer is found. The polymer of Formula VI thus has one of the following formulas: in very acidic medium: the polymer of Formula VII, by slightly increasing the pH: the polymer of Formula VIII, by continuing to increase the pH: the polymer of Formula IX, by continuing to increase the pH: the polymer of Formula X, in neutral and basic medium: the polymer of Formula XI. In this embodiment, the ratio n1/n2 ratio of the polymer of Formula VIII; the n1/n2 and n1/n3 ratios of the polymer of Formula IX and the n1/n3 ratio of the polymer of Formula X depend on the pH of the solution. The variation in the ratios between n1, n2 and n3 for the polymers of Formula VIII, Formula IX and Formula X, has an impact on the overall charge of the polymer, the capacity of the polymer to dissolve, as well as the capacity of the polymer for complexing metals. According to another particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having a single type of monomer units derived from 4-vinylpyridine, of which the two substituent groups in positions 2 and 6 are methyl ester groups, and having no monomer units derived from a co-monomer, said polymer not being complexed by a metal, being linear and not cross-linked. The composition according to the invention comprises or consists of a homopolymer of Formula XII in which: the definitions of A, R4, r, and a are as described in Formula I. In this embodiment, the polymer of Formula XII is a homopolymer with a single type of monomer units derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are methyl ester groups. In this embodiment, no monomer unit constituting the polymer of Formula XII is complexed with a metal. In this embodiment, the polymer thus obtained is soluble in organic solution such as DMSO and acetonitrile. This property allows easier polymerization of the monomer derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are methyl ester groups. According to another particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having a single type of monomer units derived from 4-vinylpyridine, of which the two substituent groups in positions 2 and 6 are carboxylic acid groups, and having no monomer units derived from a co-monomer, said polymer being complexed or not with uranium, being linear and not cross-linked. The composition according to the invention comprises or consists of a homopolymer of a chelidamic acid complexed with uranium, represented by Formula XIII in which the definitions of A, R4, r, a are as described in Formula I, xU is a number comprised from 0 to 1,in particular the polymers of Formula VII, Formula XIV, Formula XV, Formula XVI and Formula XVII, in which: the definitions of R4, A, a, and r are as described in Formula I, n1, n2 et n3 are non-zero integers, in Formula XIV, n1+n2=n, in Formula XV, n1+n2+n3=n, in Formula XVI, n2+n3=n. In this embodiment, the polymer of Formula XIII is a homopolymer comprising a single type of monomer units derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are carboxylic acid groups, and in which each unit monomer may or may not form a complex with a uranyl cation. In this embodiment, the polymer of Formula XIII varies depending on the pH of the solution in which the polymer is found. The polymer of Formula XIII thus has one of the following formulas in very acidic medium: the polymer of Formula VII, by slightly increasing the pH: the polymer of Formula XIV, continuing to increase the pH: the polymer of Formula XV, by continuing to increase the pH: the polymer of Formula XVI, in neutral and basic medium: the polymer of Formula XVII. In this embodiment, the n1/n2 ratio of the polymer of Formula XIV; the n1/n2 and n1/n3 ratios of the polymer of Formula XV and the n2/n3 ratio of the polymer of Formula XVI depend on the pH of the solution. The variation in the ratios between n1, n2 and n3 for polymers of Formula XIV, Formula XV and Formula XVI, has an impact on the overall charge of the polymer, the capacity of the polymer to dissolve, as well as the capacity of the polymer for complexing metals. In this embodiment, for example, in a neutral pH solution containing uranyl ions, the polymer of Formula V dissolves and becomes a polymer of Formula XI. This polymer complexes with uranyl ions and becomes a polymer of Formula XVII which precipitates. This polymer of Formula XVII is then placed in an aqueous solution with a very acidic pH. The polymer reacts and releases uranyl ions while the polymer becomes of Formula VII. This polymer of Formula VII is no longer soluble and precipitates. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a copolymer with at least one monomer unit derived from a co-monomer, in particular monomer units derived from styrene, acrylic acid or tert-butyl acrylate. In this embodiment, the polymer contains at least one monomer unit derived from a co-monomer and in particular, this co-monomer is either styrene or acrylic acid. In this embodiment, the co-monomers can act: as a spacer by reducing the steric hindrance around the monomer units derived from 4-vinylpyridine which can allow easier access of metals to the complexing sites, or as an agent for modifying the properties of the polymer, in particular radiation resistance or thermal resistance. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a copolymer in which the level of monomer unit derived from a co-monomer varies from a value strictly greater than 0% to a value less than 80%. In this embodiment, the polymer contains at least one monomer unit derived from a co-monomer, but the proportion of monomer units derived from a co-monomer can take all the values from a value strictly greater than 0 up to 80%, in particular from a value strictly greater than 0 to 10%, from a value strictly greater than 0 to 20%, from a value strictly greater than 0 to 30%, from a value strictly greater than 0 to 40%, from a value strictly greater than 0 to 50%, from a value strictly greater than 0 to 60%, from a value strictly greater than 0 to 70% or from a value strictly greater than 0 to 80%. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer having a single type of monomer units derived from 4-vinylpyridine and a single type of unit monomers derived from a co-monomer, said polymer not being complexed by a metal, being linear, being non-cross-linked, and being polymerized by blocks. The composition according to the invention comprises or consists of a block copolymer of Formula XVIII, in which: the definitions of A, R4, a and r, are as described in Formula I, the definitions of R1 and R2 are as described in Formula IV, B is a monomer unit derived from a co-monomer which does not form a cross-linking bridge, d is the degree of polymerization of the block consisting of the monomer units derived from 4-vinylpyridine and a is an integer, c is the degree of polymerization of the block consisting of the monomer units derived from the co-monomer and b is an integer, c+d=n. According to the present invention, the term “block copolymer” means a polymer in which at least one monomer unit is derived from a co-monomer and in which the monomer units of identical formula are linked to one another. In this embodiment, the polymer is polymerized in the form of blocks, with a first block containing all the monomer units derived from a co-monomer, and a second block containing all the monomer units derived from 4-vinylpyridine. In this embodiment, the polymer has the characteristics and properties of each block. For example if the first block consists of a hydrophobic polymer and the second block of a hydrophilic polymer, the overall polymer forms micelles. According to another particular embodiment, the composition of the invention, as defined above, comprises or consists of: either of a polymer having a single type of monomer units derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are methyl ester groups, and a single type of monomer units derived from a co monomer, styrene, said polymer being not complexed by a metal, being linear, being non-cross-linked, and is block polymerized, or of a polymer having a single type of monomer units derived from 4-vinylpyridine, the two substituent groups of which in positions 2 and 6 are carboxylic acid groups, and a single type of monomer units derived from a co monomer, styrene, said polymer being not complexed by a metal, being linear, being non-cross-linked, and is block polymerized. The composition according to the invention comprises or consists of a two-block copolymer of Formula XIX a and b, in which: The definitions of A, R4, a, c, d and r are as described in Formula XVIII In this embodiment, the polymer is polymerized in the form of blocks, with a first block containing only monomer units derived from styrene, and a second block containing all the monomer units derived from 4-vinylpyridine. In this embodiment, the polymer of Formula XIX b, is insoluble in an aqueous medium. The block consisting of monomer units derived from styrene is hydrophobic. The block consisting of monomer units derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are carboxylic acid groups, is hydrophilic. The polymer of Formula XIX b can form micelles. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a copolymer having one or more types of monomer units derived from 4-vinylpyridine and one or more types monomer units derived from a co-monomer, said polymer being complexed or not with one or more different metals, being non-linear and being cross-linked with at least one other polymer. The composition according to the invention comprises or consists of a cross-linked copolymer, said copolymer being of Formula XX, in which: W is a strictly positive, indexed integer varying from 1 to the number of polymers cross-linked with the polymer of index 0, itself comprised from 1 to 1000, A0 and Aw are compounds derived from polymerization initiators, R4,0 and R4,w are compounds allowing the propagation of the polymerization, whether or not originating from said polymerization initiator, or allowing the termination of the polymerization, or a transfer agent, a0, r0, aw and rw are identical or different and are 0 or 1, i and j, w are integers which are strictly positive, indexed, varying respectively from 1 to ni and 1 to nj,w, ni and nj,w, being comprised from 1 to 9999, ni+nj,w=n, n being comprised from 3 to 10000,and for each i and each j, w: Ri,1, Ri,2, Rj,w,1 and Rj,w,2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, carboxylic acid of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester from 1 to 20 carbons, amino of 1 to 20 carbons, heterocycle of 1 to 5 rings of which the heteroatom is either nitrogen, or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms, provided that when Ri,1 (respectively Ri,2) represents either hydrogen, or an alkyl radical of 1 to 4 carbons, or an aryl radical of 1 to 4 carbons, or an alkene radical of 1 to 4 carbons, then Ri,2 (respectively Ri,1) is different from hydrogen, from the alkyl radical of 1 to 4 carbons, from radical aryl of 1 to 4 carbons, and of the alkene radical of 1 to 4 carbons, provided that when Rj,w,1 (respectively Rj,w,2) represents either hydrogen, or an alkyl radical of 1 to 4 carbons, or an aryl radical of 1 to 4 carbons, or an alkene radical of 1 to 4 carbons, then Rj,w,2 (respectively Rj,w,1) is different from hydrogen, of the alkyl radical of 1 to 4 carbons, of the aryl radical of 1 to 4 carbons, and the alkene radical of 1 to 4 carbons, Bi,j,w is a monomer unit derived from a co-monomer, forming a cross-linking bridge between the polymer 0 in position i and the polymer of index w in position j, Ci and Cj,w are monomer units derived from a co-monomer which does not form a cross-linking bridge, ni, mi, oi, nj,w, mj,w, and oj,w, are integers equal to 0 or 1, ni+mi+oi=1, nj,w+mj,w+oj,w=1, the sum of the oj,w is non-zero and the sum of the oi is non-zero. In this embodiment, the polymer of Formula XX is a cross-linked copolymer in which the crosslink bridges are formed only on monomer units derived from a co-monomer. In this embodiment, the polymer of Formula XX may contain monomer units derived from a co-monomer which does not form a cross-linking bridge. In this embodiment, the cross-linked polymers are capable of reinforcing the structure of the particles formed by weaving a three-dimensional network at the heart of the particle. In this embodiment, the polymer can form a hydrogel. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a copolymer having a single type of monomer units derived from 4-vinylpyridine, of which the two substituent groups are positions 2 and 6 are carboxylic acid groups, and a single type of monomer unit derived from a co-monomer, 1,4-divinylbenzene, said polymer being not complexed by a metal, being nonlinear and being cross-linked with at minus another polymer. The composition according to the invention comprises or consists of a cross-linked copolymer, said copolymer being of Formula XXI, in which: the definitions of w, A0, Aw, a0, aw, i, j, w, ni, nj,w, mi, mj,w, oi, oj,w, R4,0, R4,w, r0 and rw are as defined in Formula XX. In this embodiment, the polymer of Formula XXI is a cross-linked copolymer comprising a single type of monomer units derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are carboxylic acid groups, and comprising only one type of monomer units derived from a co-monomer, 1,4-divinylbenzene. In this embodiment, the monomer units derived from 1,4-divinylbenzene of the polymer of Formula XXI may or may not form a cross-linking bridge. At least one cross-linking bridge is formed in the polymer of Formula XXI. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer in which said polymer is complexed with a metal. In this embodiment, the polymer is complexed with at least one metal atom, in particular for its use as a chelating agent or as a catalyst. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer in which said polymer is complexed with a metal chosen from actinides, lanthanides or transition metals. In this embodiment, the polymer is complexed to a particular family of metals. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer in which said polymer is complexed with uranium. In this embodiment, the polymer is complexed only with uranium. This polymer is useful for recovering uranium from seawater or used nuclear fuel. It also allows the preparation of uranium-based catalysts to catalyze reactions such as the degradation of volatile organic compounds in the gas phase or the oxidation of methane to methanol. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer soluble in aqueous solution and in particular in sea water. In this embodiment, the polymer is soluble in aqueous solutions and more particularly in sea water. This is in particular the case for the homopolymer with a monomer unit derived from 4-vinylpyridine, the two substituent groups in positions 2 and 6 of which are carboxylic acid groups. The carboxylic acid groups facilitate the solubilization of the polymer under neutral or basic pH conditions, as is the case in seawater. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer complexed with a metal which is soluble or insoluble in aqueous solution. In this embodiment, the polymer can be soluble or insoluble depending on the conditions in which the polymer is found, when the polymer is complexed with a metal. This is particularly the case for the polymer of Formula XIII. This polymer, complexed with uranium, is insoluble at neutral pH and again becomes soluble complexed with uranium in aqueous solution at acidic pH. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer soluble in aqueous solution not complexed with a metal and insoluble in solution complexed with a metal, in particular with uranium. In this embodiment, the polymer is soluble in an aqueous solution and the polymer precipitates along with the metal when the polymer and the metal complex. This is particularly the case for the polymer of Formula VI, which is soluble in water at neutral pH and which, once complexed with uranium, gives Formula XIII, and precipitates at neutral pH. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer soluble in organic solvents, in particular acetonitrile, and dimethyl sulfoxide (DMSO). In this embodiment, the polymer is soluble in an organic solution such as acetonitrile, this is in particular the case for the homopolymer comprising a monomer unit derived from 4-vinylpyridine, of which the two substituent groups in position 2 and 6 are methyl ester groups. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer in which A, A0 and Aw are derived from a polymerization initiator chosen from 4-(chloromethyl)-benzoyl chloride, benzyl chloride, AIBN, methyl-2-bromo-2-methylpropanoate. In this embodiment, the first end of the polymer cannot be the last carbon in the polymeric chain. The above list is not exhaustive and includes all of the polymerization initiators which can be used in radical polymerizations. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer in which R4, R4,0 and R4,w are chosen from a chlorine atom, or the compounds of Formula XXII In this embodiment, the second end of the polymer cannot be the last carbon in the polymer chain. The list is not exhaustive and includes all of the transfer agents which can be used in so-called controlled radical polymerizations. According to a particular embodiment, the composition of the invention, as defined above, comprises or consists of a polymer of Formula XXIII. In this embodiment, the polymer of Formula XXHI is a homopolymer consisting of monomer units derived from 4-vinylpyridine and substituted by two carboxylic acid groups. The initiator chosen is benzyl chloride which splits into two parts to give a benzyl end and a chlorine end at the other end of the chain. The present invention further relates to a method for the preparation of a polymer, as defined above, comprising the following preparation steps: A radical polymerization step starting with the initiation of a polymerization initiator to obtain an initiated polymerization initiator followed by the contacting of said initiated polymerization initiator with, at least one monomer derived from 4-vinylpyridine in which the carbons in position 2 and 6 can be substituted by one of the substituents of the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester of 1 to 20 carbons, amine of 1 to 20 carbons, heterocycle of 1 to 5 rings in which the heteroatom is either nitrogen, or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms, and optionally with at least a co-monomer,with or without cross-linking,to obtain a polymer, optionally a modification step by bringing said polymer into contact with a reagent to modify at least one of the above substituents in position 2 and/or 6, in order to obtain a optionally modified polymer, optionally a complexation step by bringing said optionally modified polymer into contact with a metal to obtain an optionally modified and optionally complexed polymer. According to the present invention, the term “radical polymerization” means the polymerization techniques which make it possible to polymerize monomers and the propagation of which is ensured by the presence of a radical. These techniques include so-called classical radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide polymerization (NMP), atomic transfer radical polymerization (ATRP), polymerization radical by atom transfer by additional activator and reducing agent (SARA ATRP). The method of synthesis of polymers according to the present invention has the advantage of being able to carry out the polymerization step in a solution in which the monomers which form the monomer units are insoluble. The presence of the modification step makes it possible to polymerize monomers having groups in positions 2 and 6 different from the final groups. For example, the monomer derived from 4-vinylpyridine, the two substituent groups of which in positions 2 and 6 are carboxylic acid groups, is insoluble in organic solution. It is therefore very difficult to polymerize this monomer in organic solution. On the other hand, the monomer derived from 4-vinylpyridine, the two substituent groups of which in positions 2 and 6 are methyl ester groups, is soluble in organic medium. The polymerization of the monomer derived from 4-vinylpyridine, in which the two substituent groups in position 2 and 6 are methyl ester groups, is then possible and the following modification step makes it possible to hydrolyze the ester function into an acid function. The polymer thus obtained, with the acid functions, is insoluble in organic medium. The polymer synthesis method according to the present invention has the advantage of being able to easily control the polymerization step. The presence of the modification step is a solution to protect the two groups of monomers derived from 4-vinylpyridine. In fact, if the desired groups are very reactive (COOH, NH2, etc.) the risk of these groups reacting during the polymerization stage is significant. This can lead to the formation of uncontrolled ramifications and/or the loss of certain grouping. The post-polymerization modification stage makes it possible to start the polymerization with protective groups which will subsequently be removed during the modification stage. The choice in addition of a controllable radical polymerization method such as RAFT or ATRP polymerization further improves control over the polymerization. The method for the synthesis of the polymers according to the present invention can comprise an additional stage of preparation of the monomers derived from 4-vinylpyridine. According to the present invention, the term “initiation of a polymerization initiator” is understood to mean the step enabling the polymerization to be initialized. For example in the case of radical polymerization, this step makes it possible, by physical or chemical means, to create a radical on the polymerization initiator on which a monomer unit will react. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula I in which: R4 is a compound allowing the propagation of the polymerization, whether or not originating from a polymerization initiator, or allowing the termination of the polymerization, or a transfer agent, A is a compound derived from said polymerization initiator or a fragment derived from the polymerization method, a and r are identical or different and are 0 or 1, i is a strictly positive, indexed integer, varying from 1 to n, itself comprised from 2 to 10000,and for each i: Ri,1 and Ri,2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, carboxylic acid of 1 to 20 carbons, alcohol from 1 to 20 carbons, ether from 1 to 20 carbons, ester from 1 to 20 carbons, amino from 1 to 20 carbons, heterocycle from 1 to 5 rings in which the heteroatom is either nitrogen or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms, Bi is a monomer unit derived from a co-monomer, whether or not forming a cross-linking bridge, Mi is a metal, ni et mi are integers equal to 0 or 1, ni+mi=1, xi is a number comprised from 0 to 6, pi is the electrical charge of the metal complex ranging from −6 to +6,provided that when Ri,1 (respectively Ri,2) represents either hydrogen, or an alkyl radical of 1 to 4 carbons, or an aryl radical of 1 to 4 carbons, or an alkene radical of 1 to 4 carbons, then Ri,2 (respectively Ri,1) is different from hydrogen, from the alkyl radical of 1 to 4 carbons, from the aryl radical of 1 to 4 carbons, and from the alkene radical of 1 to 4 carbons,said polymer being linear when it does not there is no Bi, forming a cross-linking bridge,said polymer being cross-linked when there is at least one Bi, belonging to two different polymers of formula I,includes: a radical polymerization step starting with the initiation of a polymerization initiator then continuing with the contacting of said initiated polymerization initiator with a 4-vinylpyridine derivative of Formula XXIV, in which: Zi,1 and Zi,2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester of 1 to 20 carbons, amine of 1 to 20 carbons, heterocycle of 1 to 5 rings in which the heteroatom is either nitrogen, or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms,with optionally at least one co-monomer,with or without cross-linking bridge,to obtain the polymer of Formula XXV optionally a modification step when at least one of Zi,1 is different from Ri,1 or when at least one of Zi,2 is different from Ri,2 of said polymer of Formula XXV with a reagent containing a hydroxide anion, carbonate or phosphate, to obtain the polymer of Formula XXVI optionally a complexation step of said polymer of Formula XXVI with at least one metallic compound to obtain the polymer of Formula I. In this embodiment, the method for synthesizing the polymer of Formula I begins with the radical polymerization of the monomers forming the polymer of Formula XXV. These monomers consist of co-monomers, as well as monomers derived from 4-vinylpyridine which do not necessarily have the same substituents as the monomer units derived from 4-vinylpyridine present in Formula I, as well as. During polymerization, it is possible that cross-linking bridges are formed via a co-monomer. After polymerization and obtaining a polymer of Formula XXV, if the substituent groups of the monomer units derived from 4-vinylpyridine are different in Formula I and Formula XXV, a modification step is carried out to allow the substituent groups of Formula XXV different from those of Formula I to react and thus obtain the polymer of Formula XXVI. If the polymer of Formula I is complexed with metals, there only remains one step of complexing the polymer of Formula XXVI to obtain the polymer of Formula I. According to a particular embodiment, the preparation method, such as defined above, of a polymer of the invention of Formula II, in which the definitions of Ri,1 and Ri,2 are as described in Formula II, comprises: a radical polymerization step starting with the initiation of a polymerization initiator then continuing with the contacting of said initiated polymerization initiator with a 4-vinylpyridine derivative of Formula XXIV, to obtain the polymer of Formula XXVII in which: the definitions of A, R4, ni, mi, r, a and i, are as described in Formula II, the definitions of Zi,1 and Zi,2 are as described in Formula XXIV, Bi is a monomer unit derived from a co-monomer which does not form a cross-linking bridge, a modification step, when at least one of Zi,1 is different from Ri,1 or when at least one of Zi,2 is different from Ri,2 of said polymer of Formula XXVII with a reagent containing a hydroxide, carbonate or phosphate anion, to obtain the polymer of Formula XXVII, optionally a step of complexing said polymer of Formula XXVIII with at least one metal to obtain the polymer of Formula II. In this embodiment, the method for synthesizing the polymer of Formula II begins with the radical polymerization of the monomers forming the polymer of Formula XXVII. These monomers consist of monomers derived from 4-vinylpyridine which do not necessarily have the same substituents as the monomer units derived from 4-vinylpyridine present in Formula II, as well as optionally co-monomers. The co-monomer is either chosen not to form a cross-linking bridge, or absent. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula III, in which the definitions of Ri,1 and Ri,2 are as described in Formula III, includes: a radical polymerization step starting with the initiation of a polymerization initiator then continuing with the contacting of said initiated polymerization initiator with a 4-vinylpyridine derivative of Formula XXIV, to obtain the polymer of Formula XXIX, in which: the definitions of A, R4, r, a and i are as described in Formula III, the definitions of Zi,1 and Zi,2 are as described in Formula XXIV, a modification step, when at least one of Zi,1 is different from Ri,1 or when at least one of Zi,2 is different from Ri,2 of said polymer of Formula XXIX with a reagent containing a hydroxide, carbonate or phosphate anion, to obtain the polymer of Formula XXX, optionally a complexing step of said polymer of Formula XXX with at least one metal to obtain the polymer of Formula III. In this embodiment, the method for synthesizing the polymer of Formula III begins with the radical polymerization of the monomers forming the polymer of Formula XXIX. These monomers consist of monomers derived from 4-vinylpyridine which do not necessarily have the same substituent groups as the monomer units derived from 4-vinylpyridine present in Formula III. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula IV, in which the definitions of Ri and R2 are as described in Formula IV, comprises: a radical polymerization step starting with the initiation of a polymerization initiator and then continuing with the contacting of said initiated polymerization initiator with a monomer derived from 4-vinylpyridine of Formula XXXI, in which: Z1 and Z2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester of 1 to 20 carbons, amine of 1 to 20 carbons, heterocycle of 1 to 5 rings in which the heteroatom is either nitrogen, or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols from 1 to 20 carbons, phosphine from 1 to 20 carbons, the said substituents which can be cyclized with one another and which can contain sulfur or phosphorus atoms,to obtain a polymer of Formula XXXII in which: the definitions of A, R4, r, and a are as in Formula IV, a step of modification, when Z1 is different from R1 or when Z2 is different from R2, of said polymer of Formula XXXII with a reagent containing a hydroxide, carbonate or phosphate anion, in order to obtain the polymer of Formula XXXIII, optionally a step of complexing said polymer of Formula XXXIII with at least one metal to obtain the polymer of Formula IV. In this embodiment, the method for synthesizing the polymer of Formula IV begins with the radical polymerization of the monomers forming the polymer of Formula XXXII. These monomers are all identical to each other and consist of a monomer derived from 4-vinylpyridine which does not necessarily have the same substituent groups as the monomer units derived from 4-vinylpyridine present in Formula IV. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula XVIII, in which the definitions of R1 and R2 are as described in Formula XVIII, comprises: a radical polymerization step starting with the initiation of a polymerization initiator and then continuing with the contacting of said initiated polymerization initiator with a monomer derived from 4-vinylpyridine of formula XXXI, in which: Z1 and Z2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, alcohol of 1 to 20 carbons, ether of 1 to 20 carbons, ester of 1 to 20 carbons, amine of 1 to 20 carbons, heterocycle of 1 to 5 rings in which the heteroatom is either nitrogen, or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols from 1 to 20 carbons, phosphine from 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms,with a polymer of Formula XXXIV in which: the definitions of A, R4, a, and r are as described in Formula XVIII, B is a monomer unit derived from a co-monomer which does not form a cross-linking bridge, c is the degree of polymerization of the polymer and c is an integer strictly lower than 0.8 n,to obtain the polymer of Formula XXXV in which: d is an integer, c+d=n, A modification step, when Z1 is different from R1 or when Z2 is different from R2, of said polymer of Formula XXXV with a reagent containing a hydroxide, carbonate or phosphate anion, to obtain the polymer of Formula XVIII. In this embodiment, the method for synthesizing the polymer of Formula XVIII begins with the initiation of a polymer of Formula XXXIV. This initiation makes it possible to initiate the step of radical polymerization of the monomers derived from 4-vinylpyridine. This polymerization makes it possible to form a block following the first preexisting block on the polymerization initiator used. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula XVIII, comprises before the step of radical polymerization by bringing into contact a derivative monomer of 4-vinylpyridine of Formula XXXI, with a polymer of Formula XXXIV, a step of radical polymerization of a co-monomer of Formula XXXVI to obtain said polymer of Formula XXXTV, in which the definition of B is as described in Formula XVIII. In this embodiment, the method for synthesizing the polymer of Formula XVIII begins with the polymerization of the co-monomers which allows the synthesis of the polymer of Formula XXXIV This polymer is then used as a polymerization initiator. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula XX, in which the definitions of i, j,w, Rj,w,1, Rj,w,2, Ri,1 and Ri,2 are as described in Formula XX, includes: a radical polymerization step starting with the initiation of a polymerization initiator and then continuing with the contacting of said initiated polymerization initiator with the 4-vinylpyridine derivative of Formula XXIV and of Formula XXXVII, in which: Zj,w,1 and Zj,w,2 are substituents chosen from the following group: hydrogen, alkyl radical of 1 to 20 carbons, alkene radical of 1 to 20 carbons, aryl radical of 1 to 20 carbons, alcohol of 1 with 20 carbons, ether with 1 to 20 carbons, ester with 1 to 20 carbons, amine with 1 to 20 carbons, heterocycle with 1 to 5 rings in which the heteroatom is either nitrogen, or oxygen, or sulfur, or phosphorus, amide of 1 to 20 carbons, thiols of 1 to 20 carbons, phosphine of 1 to 20 carbons, said substituents can be cyclized with each other and can contain sulfur- or phosphorus atoms, with at least one co-monomer,with cross-linking of at least one of the co-monomers,to obtain a polymer of Formula XXXVIII, in which: the definitions of w, A0, Aw, Bi,j,w, Ci, Cj,w, R4,0, R4,w, a0, aw, ni, mi, oi, nj,w, mj,w, oj,w, r0 and rw are as defined in Formula XX, the definitions of Zi,1, Zi,2 are as defined in Formula XXIV, a modification step, when at least one of the Zi,1 is different from Ri,1 or when at least one of the is different from R, 2 or when at least one of the Zi,2 is different from Ri,2 or when at least one of Zj,w,1 is different from Rj,w,2 said polymer of Formula XXXVIII with a reagent to modify at least one of Zi,1, Zi,2, Zj,w,1 or Zj,w,2, said reagent containing a hydroxide, carbonate or phosphate anion, to obtain the polymer of Formula XXXIX, optionally a step of complexing said polymer of Formula XXXIX with at least one metal to obtain the polymer of Formula XX. In this embodiment, the method for synthesizing the polymer of Formula XX begins with the simultaneous polymerization of all of the cross-linked polymers by bringing into contact the initiated polymerization initiators, co-monomers which will form cross-linking bridges, co-monomers which will not form a cross-linking bridge, as well as monomers derived from 4-vinylpyridine. Once the polymers have been formed and if at least one substituent is different between Formula XXXVIII and Formula XX, a modification step with, for example, a base makes it possible to obtain the polymer of Formula XXXIX. This polymer is itself complexed with a metal to obtain a polymer of Formula XX. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula V, comprises: a radical polymerization step starting with the initiation of a polymerization initiator then continuing with the contacting of said initiated polymerization initiator with 4-vinylpyridine derivative of Formula XL, to obtain a polymer of Formula XII, a step of modifying said polymer of Formula XII with a base to obtain a polymer of Formula VI, a step of complexing said polymer of Formula VI with a metal to obtain a polymer of Formula V. In this embodiment, the method for synthesizing the polymer of Formula V begins with the polymerization of the monomer derived from 4-vinylpyridine with two methyl ester substituents to obtain a homopolymer of Formula XII. This polymer is then reacted with sodium hydroxide which allows the methyl hydrolysis of the methyl ester groups to obtain two carboxylic acid groups. This reaction makes it possible to obtain the polymer of Formula VI. This polymer of Formula VI is then complexed with metals to obtain a polymer of Formula V. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula XIX, comprises: a radical polymerization step by bringing a polymer of Formula XLI into contact with 4-vinylpyridine derivative of Formula XL,to obtain the polymer of Formula XIX. In this embodiment, the method for synthesizing the polymer of Formula XIX begins with the initiation of a polymer of Formula XLI. This initiation makes it possible to initiate the step of radical polymerization of the monomers derived from 4-vinylpyridine. This polymerization makes it possible to form a block following the first preexisting block on the polymerization initiator used. According to a particular embodiment, the method for the preparation, as defined above, of a polymer of the invention of Formula XX, comprises before the radical polymerization step by bringing into contact a monomer derived from the 4-vinylpyridine of Formula XL, with a polymer of Formula XLI, a step of radical polymerization of styrene to obtain said polymer of Formula XLI. In this embodiment, the method for synthesizing the polymer of Formula XIX begins with the polymerization of the co-monomers which allows the synthesis of the polymer of Formula XLI which is then used as a polymerization initiator. According to a particular embodiment, said radical polymerization step, as defined above, may be a polymerization of NMP, RAFT, ATRP, SARA ATRP type or a conventional radical polymerization. According to a particular embodiment, the method for preparing a polymer of the invention of Formula XIX, comprises: a first reaction step by bringing a compound of Formula XLII into contact, with PhPOCl2 and methanol to synthesize the compound of Formula XLIII, a second reaction step by bringing a compound of Formula XLIII into contact with NaI, MeCN and MeCOCl to synthesize the compound of Formula XLIV, a third reaction step by bringing the compound of Formula XLIV into contact with CH2═CHBF3K, Cs2CO3, PPh3, and Pd(OAc)2 to synthesize the compound of Formula XL a radical polymerization step by bringing the compound of Formula XL into contact with benzyl chloride, CuCl2 and metallic copper to synthesize the polymer of Formula XLV, a fourth modification step by bringing the polymer of Formula XLV into contact with sodium hydroxide to synthesize the compound of Formula XXIII. In this embodiment, the method for synthesizing the polymer of Formula XXIII begins with the synthesis of the monomer derived from 4-vinylpyridine with two methyl ester groups. This synthesis begins by replacing the alcohol function of carbon 4 of chelidamic acid with a chlorine group. During this step, the two carboxylic acid groups are modified to form methyl ester groups. Then this synthesis is continued by replacing the new chlorine function with an iodine function. This synthesis continues with the replacement of this function I by a function CH2═CH—, which makes it possible to obtain the monomer of Formula XL. This monomer is then polymerized according to the SARA ATRP technique, which makes it possible to obtain a linear polymer with a controlled degree of polymerization of Formula XLV. The polymer thus obtained of Formula XLV is reacted with sodium hydroxide to obtain the polymer of Formula XXIII. The present invention also relates to the use of the composition of the present invention chosen from the group comprising the capture of metals and their restitution, the service as a homogeneous or heterogeneous catalyst, the labeling of organic and/or inorganic surfaces, the labeling by fluorescence of biomolecules, and post-functionalization of the chelidamic ester. According to a particular embodiment, the composition of the present invention can be used as a metal adsorbent in seawater, in particular the adsorption of actinides, more particularly the adsorption of uranium and even more particularly the adsorption selective uranium versus vanadium. According to a particular embodiment, the composition of the present invention can be used as a treatment for effluents contaminated with metals, in particular radioactive effluents and in particular nuclear waste from nuclear power plants. This reaction is known in the prior art, in particular in the reference. RSC Adv., 2014, 4, 25486. This reaction is known in the prior art, in particular in the reference J. Chem. Soc., Dalton Trans., 2000, 2031-2043. This reaction is known in the prior art, in particular in the reference Tetrahedron, 2008, 64, 399-411. 2-Dimethyl 4-iodopyridine-2,6-dicarboxylate (6.2 mmol) is added to a flask with 1 mmol of triphenylphosphine, and 0.33 mmol of Palladium(II) acetate. These compounds are dissolved in 20 mL of a THF/water solution (Ratio 9/1). Cesium(III) carbonate (19 mmol) and potassium vinyl trifluoroborate (7.5 mmol) are added to the mixture. The medium is heated at 85° C. for 8 h with stirring, then cooled and finally filtered. The white residue obtained is washed with ethyl acetate and then concentrated. The concentrate obtained is purified on silica gel. Elution with a mixture of petroleum ether and ethyl acetate (Ratio 3/1) makes it possible to obtain the dimethyl 4-vinylpyridine-2,6-dicarboxylate in the form of one gram of white solid at 78% by mass, recrystallized from a mixture of dichloromethane and petroleum ether (Ratio 1/10). 4-vinylpyridine-2,6-dimethyl ester (0.5 mmol) is dissolved in 1 ml of acetonitrile solvent. Copper(Π) chloride (0.05 μmol) is added to the solution, as well as 0.2 μmol of tri-(2-picolyl) amine and 1 cm of copper wire (D 1 mm). Benzyl chloride (halogenated initiator) is added up to 5 μmol. The reactor is heated at 25° C. for 1 h with stirring. The polymer obtained is then precipitated from a mixture of THF and methanol of molar ratio (1/1). The precipitate obtained is filtered. The radical polymerization is of SARA ATRP type. The reaction was also carried out at a temperature of 30 and 50° C. The precipitate obtained previously and containing the linear poly(4-vinylpyridine-2,6-dimethyl ester) is re-solubilized in 1 ml of acetonitrile then hydrolyzed with 1 ml of a 1 M NaOH solution. 2 M hydrochloric acid is added until a pH of 2 is reached. The poly(4-vinylpyridine-2,6-dicarboxylic acid) precipitates and is recovered (molar yield of 80%). Styrene (1 mL) is dissolved in 1 ml of sulfolane solvent. Copper(II) chloride (0.25 mg) is added to the solution, as well as 5 mg of tri-(2-picolyl) amine and 1 cm of copper wire per milliliter of solution (D 1 mm). Benzyl chloride (halogenated initiator) is added up to 10 μL. The reactor is heated at 60° C. for 10 h with stirring. The polymer obtained is then precipitated in methanol. The precipitate is filtered. The radical polymerization is of SARA ATRP type. 4-vinylpyridine-2,6-dimethyl ester (0.5 mmol) is dissolved in 1 ml of dimethylsulfoxide/sulfolane solvent (Ratio 1/1). Copper(II) chloride (0.05 μmol) is added to the solution, as well as 0.2 μmol of tri-(2-picolyl) amine and 1 cm of copper wire (D 1 mm). The precipitate from step 1 is added. The reactor is heated at 50° C. for 1 h with stirring. The polymer obtained is then precipitated in methanol. The precipitate obtained is filtered. The radical polymerization is of SARA ATRP type. 4-vinylpyridine-2,6-dimethyl ester (0.5 mmol) is dissolved in 1 ml of dimethylsulfoxide solvent with 0.01 mmol of 1,4-divinylbenzene. Copper(II) chloride (0.05 μmol) is added to the solution, as well as 0.2 μmol of tri-(2-picolyl) amine and 1 cm of copper wire (D 1 mm). Benzyl chloride (halogenated initiator) is added up to 5 μmol. The reactor is heated to a temperature between 60 and 80° C. with stirring until the medium gels. The gel obtained is then filtered, washed using dimethylsulfoxide and dried. The radical polymerization is of SARA ATRP type. A solution of linear poly(4-vinylpyridine-2,6-dicarboxylic acid of 80 μl to 5 M is added to a solution of distilled water of 1920 μl containing 200 μmol of uranyl nitrate UO2(NO3)2. The solution has a neutral pH. After 5 minutes at room temperature, the complex of poly(2,6 dicarboxylic acid-4-vinylpyridine) and uranium precipitates. More than 98% (detection limit) of the uranium is precipitated with the polymer. A linear solution of poly(4-vinylpyridine-2,6-dicarboxylic acid) of 80 μl to 5 M is added to a simulated aqueous solution of seawater of 1920 μl containing 200 μmol of uranyl nitrate UO2(NO3)2. The simulated seawater solution at a pH of 8 and an ionic strength of 0.44. After 5 minutes at room temperature, the complex of poly(4-vinylpyridine-2,6-dicarboxylic acid) and uranium precipitates. More than 98% (detection limit) of the uranium is precipitated with the polymer.
	abstract	A plate mounted fuel assembly hold-down system that provides a defined channel for both the insertion and removal of reactor head mounted, fixed in-core detector instrumentation, provides a guided path for the fixed in-core detector during insertion, and shields the instrument shroud against coolant cross flow. The hold-down assembly includes a base plate that seats on the adapter plate of the fuel assembly and has openings that align with the control rod guide thimbles. A hollow sleeve extends through and below a central opening in the base plate to mate with the fuel assembly instrument thimble. The sleeve extends above the base plate and through and above an upper core plate of the reactor. A hold-down bar is slidably mounted on the sleeve and is restrained below the top of the sleeve. A spring is positioned around the sleeve and is captured between the hold-down bar and the base plate.
039878600	claims	1. In a nuclear reactor having a core provided with a baffle plate enclosure, said core consisting of elongated fuel assemblies positioned in adjacent, parallel, laterally spaced apart relation to one another, said fuel assemblies each provided with a mid-point spacer grid having an outside band portion, the improvement of a device for use in stabilizing said core comprising: former plate means mounted on the exterior of said enclosure, a guide sleeve supported by said plate means, said guide sleeve having a longitudinal passageway of open-end construction, a cylindrical sleeve passing through said guide sleeve transverse the axis of said passageway, a cam rod having two end portions, one of said ends of said cam rod having two surfaces, a key piece passing through said cylindrical sleeve and adapted to follow said keyway of said cam rod, a wedge piece passing through said cylindrical sleeve and having an end adapted to follow said inclined surface of said cam rod, spring actuating means provided on the free end of said cam rod whereby downward pressure on said actuating means induces longitudinal movement of said cam rod which is translated into transverse movement of said wedge piece and pressure against said outer band surface of said grid. 2. In a nuclear reactor having a core consisting of elongated fuel assemblies positioned in adjacent, parallel, laterally spaced apart relation to one another, a device for use in stabilizing said core comprising, former plate means mounted on the exterior of the core, a guide sleeve supported by said plate means, said guide sleeve having a longitudinal passageway of open-end construction, another sleeve passing through said guide sleeve transverse to said passageway, a cam rod having two end portions, said cam rod having an inclined surface and a keyed surface formed on the end portion of said cam rod which passes longtiduinally through said passageway of said guide sleeve and transversely through said transverse sleeve, a key piece passing through said transverse sleeve and adapted to said cam rod keyed surface, a wedge piece also passing through said transverse sleeve and having an end adapted to follow said inclined cam rod surface, said wedge piece having a second end provided with a platen for separable engagement with at least one said fuel assemblies, and spring actuating means provided on the other end of said cam rod, whereby force applied to said cam rod in the direction of said keyed surface induces a longitudinal movement of said cam rod which is translated into transverse movement of said wedge piece and pressure against said fuel assembly. 3. The nuclear reactor of claim 1 wherein a plurality of said devices are operatively positioned in spaced relation around the periphery of said baffle plate for engagement with a plurality of said grids, by said platen of each of said individual devices. 4. The nuclear reactor of claim 3 wherein each of said platens of said devices separably engage a grid of said assemblies in a common plane that is tranverse to the longitudinal axis of said assemblies. 5. The nuclear reactor of claim 1 wherein said assemblies are positioned in a more compact group by engagement of said platens with said grid. 6. The nuclear reactor of claim 1 wherein said cam rod keyed surface is provided with mechanical stop means in the form of a curved blind end portion which limits the travel of said key piece thereby limiting the compaction of said plurality of assemblies. 7. In a nuclear reactor having a core consisting of elongated fuel assemblies positioned in adjacent, parallel, laterally spaced apart relation to one another, a device for use in stabilizing the core comprising a cam rod spaced from the reactor core and generally coextensive with at least a portion of and parallel to the elongated fuel assemblies for lengthwise rod movement and transmitting force therealong, said cam rod having a cam surface and a keyed surface formed thereon adjacent to at least one of the fuel assemblies, a plunger having a key adapted to said cam rod keyed surface, and a wedge with an end adapted to follow said cam surface and limit said lengthwise cam rod movement, said wedge having an end provided with a platen for engagment with at least one of the fuel assemblies to apply said transmitted cam rod force inwardly toward the core and against at least one of the fuel assemblies.
	claims	1. An apparatus for inspecting a substrate using an electron beam, the apparatus comprising:an electron source and illumination electron-optics configured to generate an incident electron beam;objective electron-optics configured to receive the incident beam, to focus the incident beam onto the substrate, and to retrieve an emitted beam from the substrate;projection electron-optics configured to receive the emitted beam and to provide a projected beam;a beam separator coupled to and interconnecting the illumination electron-optics, the objective electron-optics, and the projection electron-optics; anda detection system configured to receive the projected beam and which includes a scintillating screen, a detector array, and an optical coupling apparatus positioned therebetween, wherein the optical coupling apparatus includes both refractive and reflective elements. 2. The apparatus of claim 1, wherein the detection system comprises a time-delay integration (TDI) detection system. 3. The apparatus of claim 1, wherein said elements include a plurality of refractive lenses. 4. The apparatus of claim 1, wherein said elements include at least one mirror. 5. The apparatus of claim 1, wherein said elements include a plurality of prisms. 6. The apparatus of claim 1, wherein the resolution of the optical coupling apparatus is eight microns or less. 7. The apparatus of claim 1, wherein the numerical aperture of the optical coupling apparatus is 0.4 or more. 8. The apparatus of claim 1, wherein the distortion of the optical coupling apparatus is 0.1% or less. 9. The apparatus of claim 1, wherein said elements include two prisms, three lenses and one mirror. 10. The apparatus of claim 9, wherein light from a point on the scintillating screen passes through a first prism, passes through each of the three lenses, reflects from the mirror, passes again through each of the three lenses in reverse order, passes through the second prism, and is focused on a corresponding point on the detector array. 11. The apparatus of claim 10, wherein the resolution of the optical coupling apparatus is eight microns or less, the numerical aperture of the optical coupling apparatus is 0.4 or more, and the distortion of the optical coupling apparatus is 0.1% or less. 12. The apparatus of claim 1, further comprising an intensity adjustment aperture within the optical coupling apparatus. 13. A method of inspecting a substrate using electrons, the method comprising:generating an incident electron beam;bending the incident beam through a prism array;focusing and decelerating the incident beam such that the incident beam impinges on a substrate at a second tilt angle;retrieving an emitted electron beam;bending the emitted beam through the prism array;projecting the emitted beam to provide a projected beam;receiving the projected beam on a scintillating screen; andcoupling light from the scintillating screen to a detector array using an optical coupling apparatus having refractive and reflective elements. 14. The method of claim 13, further comprising synchronizing clocking of the detector array and translation of the substrate. 15. The method of claim 13, wherein said elements include two prisms, multiple lenses, and a mirror. 16. The method of claim 13, wherein light from a point on the scintillating screen passes through a first prism, passes through the multiple lenses, reflects from the mirror, passes again through the multiple lenses in reverse order, passes through the second prism, and is focused on a corresponding point on the detector array. 17. An electron beam apparatus comprising a detection system which is configured to receive a projected electron beam and which is further configured to include a scintillating screen, a detector array, and an optical coupling apparatus positioned therebetween, wherein the optical coupling apparatus includes both refractive and reflective elements. 18. The apparatus of claim 17, wherein light from a point on the scintillating screen passes through a first prism, passes through multiple lenses, reflects from a mirror, passes again through the multiple lenses in reverse order, passes through a second prism, and is focused on a corresponding point on the detector array. 19. The apparatus of claim 17, further comprising an intensity adjustment aperture within the optical coupling apparatus. 20. A method performed in a detection system of an electron beam apparatus, the method comprising coupling light from a scintillating screen to a detector array using an optical coupling apparatus having refractive and reflective elements. 21. The method of claim 20, wherein light from a point on the scintillating screen passes through a first prism, passes through multiple lenses, reflects from a mirror, passes again through the multiple lenses in reverse order, passes through a second prism, and is focused on a corresponding point on the detector array.
045253242	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Reference numeral 5 designates a longitudinally-extending storage building of a dry storage facility. The building 5 contains storage modules 7, 9, 11 and 13. Storage modules 7 and 9 are arranged on one longitudinal side of the building and storage modules 11 and 13 are on the other longitudinal side thereof. Storage module 13 is shown without any covering. Each of the storage modules is configured as a separate unit and has a square base area. The modules are arranged in the building 5 so that the diagonal plane defined by one pair of diagonally opposite vertical corners of each module extends in a direction parallel to the longitudinal walls 6 and 8 of the building 5. Supporting and guiding rails 15 and 17 are mounted in the building 5 and extend in a direction parallel to the longitudinal walls 6 and 8. A bridge crane 19 is mounted on the rails 15 and 17 so as to be movable therealong. The supporting rail 15 extends approximately over the diagonal planes of respective storage modules 7 and 9; whereas, rail 17 extends approximately over the diagonal planes of storage modules 11 and 13. The storage building 5 includes a base plate 21 made of concrete in which are formed four square openings 23 for receiving the storage modules 7, 9, 11 and 13, respectively. Each of the storage modules 7, 9, 11 and 13 is bounded by vertical concrete walls 24, 25, 26 and 27 with a concrete top covering 28. The supporting rails 15 and 17 upon which the bridge crane 19 runs are fixedly mounted above the storage modules 7, 9, 11 and 13. The bridge crane 19 is part of a transport vehicle 20 which includes a transport apparatus 29 movable in a direction transverse to the supporting rails 15 and 17 of bridge crane 19. The transport apparatus 29 includes a transport mast 31, a receiving apparatus 32 for receiving the storage containers 33 and a small vehicle 35. The receiving apparatus 32 is rotatably mounted on the mast and is provided with a pushing apparatus 37 which can move the storage containers 33 out of the receiving apparatus 32 in the direction of the longitudinal axis of the containers 33. The containers 33 are used to store irradiated nuclear reactor fuel rods and can be 4 to 5 meters in length and have a diameter of approximately 0.38 meters. A pass-through opening 41 is provided in the concrete wall 43 at the entrance of the storage building 5 through which the individual storage containers 33 can be brought into the storage building 5. The storage modules 7, 9, 11 and 13 are supplied with fresh cooling air via an air inlet conduit 45 of large cross section and branch conduits 47. The storage modules are fed by the branch conduits 47. The cooling air warms as it rises and is directed by exhaust conduit 48 to a main exhaust conduit 49. An exhaust conduit 48 is arranged atop each of the storage modules and extends over the triangular half section of each storage module facing away from the transport passageway 61. The other triangular half section of each module 7, 9, 11 and 13 is provided with a roof-like concrete covering 28 above which the transport vehicle 20 can run. Storage tubes 51 are arranged in the storage modules 7, 9, 11 and 13 so that they are stacked horizontally in sets with one set atop the other as shown in FIG. 4. The back end of each storage tube 51 is held by a suitable mounting arrangement embedded in concrete walls 24, 27; whereas the front ends of the storage tubes are supported in respective bores 53 in the front concrete walls 25 and 26 of each storage module 7, 9, 11 and 13, the walls 25 and 26 facing toward the transport passageway 61 extending through the storage building 5 in the longitudinal direction thereof as indicated by axis 62. The storage tubes 51 are also sealed about their periphery at the bores 53. The storage tubes 51 arranged parallel to one another in one horizontal plane extend in a direction transverse to the storage tubes lying in the next adjacent horizontal plane as shown in FIG. 4. The storage containers 33 holding irradiated nuclear reactor fuel elements are pushed into these storage tubes 51. The openings of the tubes 51 are then tightly sealed with plugs. Referring to FIGS. 3 and 4, the cooling air flowing through the air inlet conduit 45 is caused to flow via branch conduits 47 up through the storage modules 7, 9, 11 and 13 by the chimney effect. This cooling air is continuously directed away from the vertical direction as it passes upwardly through the storage modules 7, 9, 11 and 13 by the layers of storage tubes 51 arranged crosswise as shown. This leads to a swirling effect and to a good heat transfer between the storage tubes 51 and the quantity of cooling air which is available. In this way, the indirect cooling of the storage containers 33 is increased. Referring to FIG. 5 and according to another preferred embodiment of the invention, the storage tubes 51 in horizontal plane c are displaced laterally from the tubes disposed in horizontal plane a so that there is a gap in horizontal plane c directly above each one of the tubes of horizontal plane a. Also, the tubes of plane d are laterally displaced from the tubes of plane b in the same manner as discussed above for planes c and a. This pattern is repetitive and extends up the storage module as shown substantially in FIG. 5. As mentioned above, with the arrangement shown in FIG. 5, the storage tubes of plane a always have an open gap directly above the plane c and so on. The upwardly flowing cooling air is continuously deflected and swirling of the cooling air is increased thereby increasing the contact of flowing air with the outer surfaces of the storage tubes; this improves the transfer of heat to the upwardly flowing cooling air from irradiated fuel elements held within storage containers in the storage tubes 51. An intervention room 63 extends above the rails 15 and 17 of the bridge crane. An auxiliary crane 65 is movably mounted within the room 63. The intervention room 63 is shielded by means of concrete walls. The transport passageway 61 between the mutually adjacent storage modules 7 and 9 on the one side and storage modules 11 and 13 on the other side, can have a narrow width which must only be somewhat larger than the width of the transport mast 31. The storage tubes 51 of the storage modules 7, 9, 11 and 13 are loaded in the direction of their longitudinal axes which is at acute angles .alpha.1 and .alpha.2 to the longitudinal direction 62 of transport passageway 61 (FIG. 1). The storage containers 33 are passed through the concrete walls 25 and 26 of the storage modules 7, 9, 11 and 13 facing the passageway 61. The transport passageway 61 can be configured to have a narrow width because storage tubes 51 in the storage modules are loaded in a direction which forms an acute angle with respect to the longitudinal direction of the passageway 61. By making the passageway 61 narrower, a savings in floor space within the building 5 is realized. It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention, as defined in the appended claims.
	abstract	Disclosed herein is an apparatus comprising: a radiation absorption layer comprising an electrode; a counter configured to register a number of radiation particles absorbed by the radiation absorption layer; a controller configured to start a time delay from a time at which an absolute value of an electrical signal on the electrode equals or exceeds an absolute value of a first threshold; wherein the controller is configured to cause the number registered by the counter to change, in response to the absolute value of the electrical signal equaling or exceeding an absolute value of a second threshold during the time delay.
041994027	summary	BACKGROUND OF THE PRIOR ART The feasability of generating electricity by plasma formation has been demonstrated by two processes, the subject of considerable experimentation. According to one process, it has been found that gasses, particularly monatomic helium agron or neon, can be ionized to produce a plasma which, when confined and passed through a fixed magnetic field, induces a useful voltage. Various gas formulations seeded with additional ions have been used with limited success. In another process under study, Duterium and Tritium are bombarded with laser energy to produce large quantities of useful heat for driving turbines. Tritium by-products are also produced which can be recycled in the process. The disadvantage of this process resides in the need to confine the ions within a limited volume, i.e., a "plasma bottle" for a sufficient time period in order that the ions are compressed or, more specifically, imploded by laser energy to release useful heat. The heat produced is accordingly a function of the ion density and the confinement time of the ions within the plasma bottle. It has been found that electromagnetic radiation at the plasma boundary is a serious drawback to successful fusion over extended periods of time and also to obtaining efficient energy conversion. The leakage phenomenon, known as the Bremsstrahlung effect, reduces the plasma temperature such that the desired temperature of fusion cannot be attained for a time period to satisfy the well known Lawson criterion. The escaped ions and radiation also are lost to the atmosphere together with their potential for energy production. BRIEF DESCRIPTION OF THE INVENTION The present invention relates to plasma generation for either nuclear fusion or magnetohydrodynamic production by eliminating the drawbacks of the prior art plasma systems wherein the Bremsstrahlung effect presents itself to lower the temperature of the plasma or to extinguish a fusion process. The present invention further accommodates the transient kinetic nature of the ions and escaping radiation, recycling the kinetic energy, radiation and mass of the ions to sustain plasma generation rather than permitting escape of the ions. As a further feature, the positive particles may be passed through a fixed magnetic field to produce a magnetohydrodynamic effect as an alternative to fusion. These features are accomplished by confining the particles in a closed loop path of an accelerator using a multiple number of sections or locations about the closed loop path to provide nodes of relative minimum cross-section at which the ion mass is accelerated at high velocity. The presence of a magnetic field concentrates the high velocity particle mass into a small volume or well densifying the mass and slowing the particles. Electrons are injected to neutralize the space charge of the particles at each node section and to create a plasma. A tube of circulating electrons encircling the minimum cross-section purposely causes ion migration back and forth perpendicular to the force field of the magnetic well at the minimum cross-section. When the magnetic field of the well or particle trap is collapsed or released the ions exit the nodes and disperse into a lesser mass density along the accelerator path. The reduction in both kinetic energy and mass density will lower the exit temperature of the ions to insure that the fusion reaction takes place only at the node locations. Electrons and other waste products can be extracted from the accelerator by conventional techniques, retaining only ions, Duterium or Tritium. The accelerator path permits repeated recycling of the ions continuously through the numerous nodes. The magnetic field present at the nodes is used to compress the ions to raise the temperature necessary for fusion. According to another feature of the present invention, the ions exiting each of the nodes are considered as a flow of positive particles for production of direct current by magnetohydrodynamic or other conventional techniques. OBJECTS It is therefore an object of the present invention to provide a process for generating useful energy from a plasma of ionized particles continuously recycling the ions in order to repeatedly produce plasma at a plurality of minimum cross-sections within an accelerator. Another object of the present invention is to provide a process for nuclear fusion wherein a plasma mass is continuously regenerated with ions and with electrons injected into the minimum cross-sections of an accelerator. Another object of the present invention is to provide a process for generating a plasma suitable for nuclear fusion or magnetohydrodynamic production by using an accelerator to recycle and accelerate ions in a return path to the plasma mass to sustain a temperature sufficient to satisfy the Lawson criterion.
039705838	description	The reference numeral 1 in this Figure refers to a reservoir which is provided with an inlet opening 2 at the top and an outlet opening 3 at the bottom. The reservoir is substantially cylindrical and is provided with a flange position 4 at either end. In the lower part of the reservoir has an internal diameter transition 5. At the location of the diameter transition 5 the reservoir 1 is provided with a trapezoidal glass filter 6. The openings 2 and 3 of the reservoir are closed by a rubber stopper 7 which comprises a flange portion 8 and a jacket portion 9. The jacket portion 9 fits the openings of the reservoir 1, whilst the flange portion 8 engages the flange portion 4 of the reservoir 1. The flange portion 8 of the stopper 7 and the flange portion 4 of the reservoir 1 are connected to each other by means of a metal capsule such as an aluminium capsule 10. The capsule 10 has an opening 11. The reservoir 1 contains a carrier material for a parent isotope. Said carrier material consists of an upper layer 12 and a lower layer 13. The upper layer 12 contains Al.sub.2 O.sub.3 particles which are entirely or partially coated with a layer of hydrated or partially hydrated manganese dioxide. The lower layer 13 consists of Al.sub.2 O.sub.3 particles. The total weight of the carrier material is for example 7 grammes, of which 3 grammes are contained in the upper layer. In the reservoir the carrier material is enclosed between the glass filter 6 and a micropore filter 14 which is pressed against the carrier material by means of a washer 15. The upper layer 12 contains the radioactive parent isotope 99m Mo in the form of an alkali metal molybdate such as sodium molybdate. When using the isotope generator according to the invention shown in the Figure a washing liquid such as a physiological salt solution is admitted at the top via a hollow injection needle inserted through the upper rubber stopper 7. The washing liquid passes through the micropore filter 14 and subsequently through the upper layer 12 of the carrier material. In said upper layer the parent isotope 99m Mo in the form of sodium molybdate on the carrier material is absorbed. Owing to radioactive decay of 99m Mo the upper layer will also contain 99m Tc in the form of sodium pertechnate. The washing liquid absorbs the pertechnate containing the 99m Tc and subsequently passes through the lower layer 13 of the carrier material. After having passed the filter 6 the washing liquid with 99m Tc is collected in a receptacle via an injection needle inserted through the lower rubber stopper 7. The radioactive eluate thus obtained is of a high chemical purity, i.e. it contains no contaminations such as Al.sup.+.sup.+.sup.+ ions, it has a pH value of 6.5 - 7.5 and is directly suited for use in medical diagnosis.
	description	The proposed technology generally relates to x-ray detectors and more specifically to a modular x-ray detector and a detector module for such a modular x-ray detector. When constructing x-ray detectors, the main challenges are to achieve high detection efficiency, enable a modular arrangement of detectors and/or make sure packaging and wiring is possible so that the detector can be efficiently produced. It is furthermore beneficial if all requirements can be met at the same time, which is a challenge since in part the requirements contradict each other. For example the wiring and packaging required for a modular arrangement often means you have to sacrifice active detector area such that the geometrical efficiency is reduced. Furthermore the x-ray detector in most cases has to be integrated with an anti-scatter collimator or grid to eliminate scatter from the object and/or between detector modules. It is also desirable that sensitive integrated circuits are protected from direct radiation since a high accumulated dose could negatively impair the functioning of the circuits. At the same time each detector module and anti-scatter grid should preferably be accurately aligned to the incident x-rays from the source. State-of-the art detectors in for example Computed Tomography are based on a scintillator converting the x-rays to visible light that is detected by a dedicated photo diode that integrate the signal for many x-rays. The photo diode is connected to integrated circuits that digitize the produced current and this value is used to calculate grey scale values displayed in the x-ray image. A one-dimensional or two dimensional anti scatter grid is placed on top of the scintillators and diodes. To avoid cross talk a trench separates each scintillator-diode assembly. The anti-scatter collimator is positioned to match the trenches in order to minimize any dead area. There are several ways to solve the packaging and wiring challenges: to connect the diode to the integrated circuit, to provide power and data transmission. There are good examples how these challenges can be addressed. One example is disclosed in reference [1] where a fully modular arrangement is presented that can be tiled in two dimensions. Another example for an interconnect and packaging method is presented in reference [2] where an elastomer conducting contact is configured to provide a high-voltage anode signal. The last years a lot of research focus both in academia and in industry has been focused on how to provide x-ray detectors with higher spatial and contrast resolution. One of the most promising ways to achieve this is through photon counting spectral detectors. So far these imaging detectors are only available for mammography in early breast cancer detection, see reference [3], but the next use may be in Computed Tomography. Two different solutions have emerged, one based on heavy detector elements such as CdTe or CdZnTe presented for example in reference [4] and another based on Silicon as detector material as outlined in reference [5]. In a Silicon detector assembly such as outlined in reference [5] the challenges in detection efficiency and modularity are very different compared to assemblies with heavy elements as detector material since the Silicon detectors need to be much longer (around 30-40 times) in the direction of the incoming x-rays in order to absorb a major fraction of the x-rays. This means the geometry and mechanical constraints are very different. It is an object to provide an improved detector module for a modular x-ray detector. It is also an object to provide an improved modular x-ray detector based on such detector modules. These and other objects are met by embodiments of the proposed technology. In a first aspect of the proposed technology, there is provided a detector module for a modular x-ray detector, wherein the detector module comprises multiple x-ray detector substrates and associated anti-scatter collimators. Each x-ray detector substrate has a number of detector diodes, and each x-ray detector substrate has an associated anti-scatter collimator. Further, each x-ray detector substrate has an integrated circuit for collecting x-ray signals from the diodes attached to the x-ray detector substrate at the bottom of the x-ray detector substrate assuming the top is where the x-rays enter, and the associated anti-scatter collimator is placed above the integrated circuit. This type of detector module enables an efficient way of building a modular x-ray detector. In a second aspect of the proposed technology, there is thus provided a modular x-ray detector comprising a number of detector modules of the first aspect. Other advantages will be appreciated when reading the detailed description. An illustrative, non-limiting example of the present invention is illustrated in FIG. 1 where an x-ray detector module and a corresponding modular detector assembly 100 is displayed where modules can be tiled to achieve any area of the full detector assembly as long as boundary conditions of maximum power and data transfer rates can be handled. FIG. 2 is a schematic diagram illustrating an example of a detector module for a modular x-ray detector. In this example, the detector module 1 comprises multiple x-ray detector substrates 10 and associated anti-scatter collimators 20. Each x-ray detector substrate 10 has a number of detector diodes, and each x-ray detector substrate 10 has an associated anti-scatter collimator 20. Further, each x-ray detector substrate 10 has an integrated circuit 30 for collecting x-ray signals from the diodes attached to the x-ray detector substrate at the bottom of the x-ray detector substrate 10 assuming the top is where the x-rays enter, and the associated anti-scatter collimator 20 is placed above the integrated circuit 30. This type of detector module enables an efficient way of building a modular x-ray detector. Embodiments of the modular x-ray detector have several structural advantages, as will be appreciated from the examples described herein. In a second aspect of the proposed technology, there is thus provided a modular x-ray detector 100 comprising a number of detector modules 1 of the first aspect. The detector module may be embodied in many different variations. By way of example, the integrated circuits may be Application Specific Integrated Circuits, ASICs. For example, the ASIC may be extending over the edge of the x-ray detector substrate so that part of the ASIC is outside of the silicon detector substrate to enable connection of power and data transfer to the ASIC without having to route this on the silicon detector substrate. The signals may for example be routed from the individual diodes to inputs of the ASIC. Optionally, power lines and data transfer lines are wire-bonded to power and data transfer pads at the ASIC outside the substrate, or a redistribution layer on the substrate is used to connect to power, data transfer pads and to input signal pads and redistribute the input signals from the x-ray detector substrate to the ASIC. As a complement, a heat conductor may be attached to the ASIC as a means for cooling. By way of example, the anti-scatter collimators may be anti-scatter foils or plates. For example, anti-scatter foils may positioned between the x-ray detector substrates. The anti-scatter foils may be made of a heavy material such as Tungsten. In a particular example, the integrated circuits are Application Specific Integrated Circuits, ASICs, and the anti-scatter collimators are Tungsten foils and the ASICs are placed on the x-ray detector substrate under the Tungsten foils to minimize so-called dead area in the detector and the ASICs will be protected from direct radiation. Preferably, a tapered geometry in which, for each x-ray detector substrate, the x-ray detector substrate and the associated anti-scatter collimator are pointing back to the source may be provided for by means of a spacer placed at the silicon detector substrate or at the anti-scatter collimator. Normally, a number of x-ray detector substrates are tiled with respect to each other to form a detector module. As an example, each x-ray detector substrate and corresponding integrated circuit may be formed as a sensor multi-chip module, MCM, assembly, and a multitude of sensor MCM assemblies may then be connected into the detector module. For example, the detector module may be sub-divided into a number of detector tiles, where each detector tile includes a number of sensor MCM assemblies, for example as illustrated in FIG. 7. In a particular example, each detector tile includes a circuit for demultiplexing commands from the corresponding detector module to the detector tile to reduce the number of connections between the detector tile and the detector module, for example as illustrated in FIG. 7. Typically, the commands are control commands directed to the sensor MCM assemblies. The detector module may comprise a number of data storage circuits and data processing circuits, wherein each detector tile is managed by a data processing circuit. For example, the detector module may include a control and communication circuit for distributing control commands for the sensor MCM assemblies and controlling the readout of stored scanning data from the data storage circuits. In a particular example, the x-ray detector substrates are Silicon detector substrates. For a better understanding, the proposed technology will now be described with reference to non-limiting illustrative examples. In order to avoid any dead area the integrated circuit (ASICs) collecting the x-ray signals from the diodes has been attached to the x-ray detector diode substrate at the bottom side assuming top side is where the x-rays enter. The anti-scatter collimator is e.g. made up of Tungsten foils in between each Silicon detector substrate. In order to minimize so called dead area in the detector (area which is not functioning as a detector such is the mechanical support, the Tungsten foils, air gaps etc.) the ASICs for collecting the x-ray signals from the diodes are placed under the Tungsten foils. This also means the ASICSs will be protected from direct radiation. In order not to be significantly thicker than the Tungsten foils the ASICs are thinned down to 50-100 um. In a particular example, the ASIC is flip chipped to the Silicon detector substrate and each diode is connected through a trace to a dedicated ASIC input. Moreover the ASIC is sticking out over the edge of the silicon detector substrate. This gives space for larger components like capacitors that has to be situated close to the ASIC to optimize reliability and noise performance. This means that thick traces for power, which would make the silicon substrate more expensive to produce, is not required. The power connections can be provided for by other means to the ASIC. For example power lines could be wire-bonded to supply pads at the ASIC. Another solution would be to use a redistribution layer that would connect to power, data transfer pads and to input signal pads and redistribute the signals from the ASIC to the Silicon detector substrate. Behind the Silicon detector substrate there will be space for electronic components such as capacitances that should be positioned close to the electronic. It is also possible to put an x-ray absorber in a heavy material such as Tungsten or Molybdenum after the Silicon to avoid that any x-rays transmitted through the silicon is penetrating further into the assembly. It is also possible to put radiation-protected material around the integrated circuit to minimize any radiation damage. As a means for cooling a heat conductor, preferably with matching heat expansion co-efficient to Silicon, can be attached to the ASIC and the heat produced by the ASIC power can be transferred to a place where it can easily be taken care of by standard air or liquid cooling means. FIG. 1 is a schematic diagram illustrating an example of an x-ray detector module and a corresponding modular detector assembly. FIG. 1 shows an example of a module and how such modules could build up a corresponding modular detector assembly having a full detector area of desired size. Note that the modules are pointing back to the x-ray source. FIG. 2 is a schematic diagram illustrating an example of a detector module for a modular x-ray detector. FIG. 2 thus displays an example of a module design. Starting from the top, the anti-scatter foils made of a heavy material like W is displayed, the foils are typically significantly thinner than the silicon detector substrate which is the active detector volume consisting of diodes. The x-ray detector substrate is positioned in-between the foils. The x-ray detector substrate may for example be in the order of 0.5 mm thick. Both foils and x-ray detector substrate is pointing back to the x-ray source to avoid parallax errors and shadowing from the anti-scatter foils. At the bottom the ASICs are indicated, they are typically as thin as the W foils and positioned behind those foils (looking from above) FIG. 3 is a close-up of FIG. 2 showing the anti-scatter foils, the silicon detector substrate and the ASICs. FIG. 4 shows an example of how to get a tapered geometry when Tungsten and Silicon detector substrate are pointing back to the source by placing a spacer as for example a stud bond at the silicon detector substrate or at the anti-scatter grid. In order for all Tungsten foils and Silicon detectors to precisely point back to the source a spacer between each element may be used. Due to this spacer the whole detector will be curved. FIG. 4 shows an example of how to achieve a tapered geometry by placing a spacer of for example a stud bump at the silicon detector substrate or at the Tungsten foil FIG. 5 displays an example of how the ASIC can be flip chipped to the silicon detector substrate where input signals are routed from the individual diodes to the ASIC inputs. Part of the ASIC is outside of the silicon detector substrate to enable connection of power and data transfer to the ASIC without having to route this on the silicon detector substrate. FIG. 6 is a view from the side showing that there is space for wire-bonds, passive components and cabling behind the silicon detector substrate. Heat conductor is not indicated in the image but can be attached to ASIC. FIG. 7 is a schematic diagram illustrating an example of the architecture for electronic readout of data. A significant challenge is to read out the data for a multitude of x-ray detector modules. An example of a possible architecture solution is shown in FIG. 7. In this example a multitude of sensor MCM (Multi-Chip Module) assemblies are connected into one detector module. In this context, a sensor MCM assembly means silicon substrate detector and ASIC assembly. For example, each detector module may be managed by a small FPGA (Field Programmable Gate Array) or similar circuit that handles clock distribution, loading of configuration data and distribution of commands to the sensor MCMs. By way of example, a full detector can contain several 10:th of thousands ASICs thus connecting and setting up/programming all ASICs in a detector is a particular challenge. Each detector module may be based on the sensor MCMs in steps, for example by arranging sensor MCMs on detector tiles and then building a detector module based on a number of detector tiles. In other words, each detector module may include a number of detector tiles, where each detector tile includes a number of sensor MCM assemblies. In order to physically fit all connections and meet bandwidth demands a scheme illustrated in FIG. 7 can be used. Each tile includes a small FPGA for demultiplexing of low information content signals such as clock and/or commands from the module to the tile. As indicated in FIG. 7 this can for example reduce the number of connections between tile and module from 42+21 to 3+21. Local memories (3DDR in FIG. 7) distributed in the modules stores/buffers data to relax bandwidth demands on downstream connections. All these memories are read out at a lower rate when acquisition is finished. This arrangement can reduce the number of connections from the module to the motherboard, in the example in FIG. 7 the reduction is from 72 (324) to 8 connections. Local memories and processors/FPGAs are preferably used to handle setup of the circuits, in order to parallelize the task. A single source configuring 10:ths of thousands of ASICs is too slow. A preferred way might be to broadcast common information parts and send specific information separately. Calibration may be handled locally on the module level, including calculation, storage, loading and so forth. By way of example, the detector mother board has the control of the complete system, and can be regarded as an overall control system and link to external systems. In a particular example, three detector tiles are put together into a detector module. Each detector tile is managed by a processing circuit with associated memory/data storage, e.g. a data storage FPGA or similar circuit. This FPGA/circuit stores all scanning data from one sensor MCM assembly locally and sends control commands intended for the sensor MCM assembly. A control and communication FPGA or similar circuit may also be placed in the detector module. At power up, this unit manages configuration of other FPGAs/circuits in the detector module, using configuration data stored in a local FLASH. When the system is up and running, it distributes the control commands for the sensor MCM assemblies and controls the readout of stored scanning data from the three processing circuits with associated memory/data storage, e.g. data storage FPGAs. The data is sent to the detector mother board. By way of example, commands may be broadcast to all detector modules for synchronous execution, or individually addressed for other tasks. It controls the readout of the scanning data from the detector modules, downloading of calibration data to the sensor MCM, etc. From the detector mother board the data can be further transmitted to one or more external computers for post-processing and/or image reconstruction. The embodiments described above are merely given as examples, and it should be understood that the proposed technology is not limited thereto. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the present scope as defined by the appended claims. By way of example, it will be appreciated that the arrangements described herein can be implemented, combined and re-arranged in a variety of ways. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible. [1] U.S. Pat. No. 7,582,879 [2] U.S. Pat. No. 7,560,702 [3] M. Danielsson, H. Bornefalk, B. Cederstrom, V. Chmill, B. Hasegawa, M. Lundqvist, D. Nygren and T. Tabár, “Dose-efficient system for digital mammography”, Proc. SPIE, Physics of Medical Imaging, vol. 3977, pp. 239-249 San Diego, 2000 [4] C. Xu, M. Danielsson and H. Bornefalk, “Evaluation of Energy Loss and Charge Sharing in Cadmium Telluride Detectors for Photon-Counting Computed Tomography”, IEEE Transactions on Nuclear Science, vol. 58, no. 3, pp. 614-625, June 2011 [5] U.S. Pat. No. 8,183,535
	description	For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-described drawings. The properties of several key Auger electron emitters are summarized in Table I. For 195mPt, the principal source of Auger electrons are from the 99.9% conversion of the 135 keV y-rays, which follow the metastable decay of 195mPt, which results in very high radiotoxicity and usefulness for cancer therapy. Moreover, 195mPt is of interest for use a tracer for studies of the biokinetics and mechanism of action of the widely used clinical anti-tumor drug, cis-dicholorodiammineplatinum(II) (also known as Cis-platinum and Cis-DDP), carbo-platinum and other platinum-based anti-tumor agents. The use of 195mPt for both biokinetic studies of platinum-based anti-tumor agents and for possible intracellular therapy, however, requires much higher specific activity than is currently available (about 1 mCi/mg). The availability of high specific activity 195mPt would thus be expected to be of great interest for the preparation of these agents also. Neutron inelastic neutron scattering, 195Pt[n,nxe2x80x2]195mPt, was examined as a route to a possible alternative to provide higher specific activity than from the traditional xe2x80x9cradiative thermal neutron capturexe2x80x9d, 194Pt[n,xcex3]195mPt, route which provides specific activity values of only about 1 mCi/mg platinum, even at the highest thermal neutron flux available at the core of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) (Oak Ridge Tenn.). In some cases, the yield from the [n,nxe2x80x2] neutron scattering reaction is generally higher than that obtained from the [n,xcex3] neutron capture reaction. In the case of 195mPt, however, the relative gain in the specific activity is only about 1.4, as shown in Table II. In accordance with the present invention, high specific activity, no-carrier-added 195mPt can be obtained from reactor-produced 195mIr as shown in FIG. 1. FIG. 2 compares the calculated production yields of 195mPt produced by 194Pt and 195Pt direct routes, and the 193mIr indirect route of the present invention. Irradiation of Enriched 193Ir Metal Target Material A high neutron flux reactor such as the ORNL HFIR is required due to the low yield of multi-neutron capture reaction in 195mPt production: The 193Ir target material is preferably in metal powder form, but other physical and/or chemical forms can be used. The level of enrichment of 193Ir should be at least 80%, preferably at least 90%, more preferably at least 95%, and most preferably at least 98%. The 193Ir used in testing the present invention was highly enriched 99.59%, which is available from the stable isotope department at ORNL and possibly from similar facilities elsewhere. 193Ir can be enriched (separated) from natural Ir by several known methods, especially by electromagnetic separation methods. Irradiation time of 193Ir in HFIR is operable in the range of several hours to several days, and is generally optimized at 7 to 10 days to produce the greatest 195mPt yield. Hydraulic Tube (HT) position at the HFIR is not particularly critical to the present invention. It is contemplated that HT position No. 5 would be most, preferable due to maximized available neutron flux, although all of nine HT positions, preferably Nos. 4-8 can be used in carrying out the present invention. As an example, irradiation operations at HFIR or other neutron source may generally include, but are not limited to the following steps: 1. Load desired amount of enriched 193Ir metal powder into a suitable irradiation vessel, for example, a quartz ampoule. 2. Hermetically seal the vessel under an inert gas blanket, usually He. 3. Load the sealed vessel into a metal (usually aluminum) irradiation vessel, generally known as a xe2x80x9crabbitxe2x80x9d and seal by welding, usually by argon arc welding, then perform a standard leak test. 4. Irradiate the rabbit with a high flux of neutrons for a period of time sufficient to convert at least a portion of the 193Ir to 195mPt. For parameters used in some small batch tests, see Table III. 5 mg of enriched 193Ir metal powder was prepared as described hereinabove and irradiated for 24 hours in the HT 7 position of the HFIR. Subsequent analysis showed that the process provided greater than 273 mCi 195mPt/mg 193Ir target material, with a calculated 195mPt specific activity of greater than 72 mCi/mg Pt. The major radioactive by-product from this irradiation was 192Ir, with a yield of approximately 0.1 mCi/mg 193Ir target material. Dissolution of Irradiated Ir Target Material Following irradiation, it is necessary to dissolve the Ir target material in order to accommodate hot-cell processing and chemical separation of the 195mPt product from the Ir. Hot-cell processing is required because of the high radiation levels of the radioisotopes produced, especially 192Ir, a radioisotopic by-product. Iridium metal is very difficult to dissolve, especially with the constraints of hot-cell processing. In addition to the necessity of working in a hot-cell for large-scale preparation, other challenges for chemical separation of the 195mPt product from the irradiated 193Ir target include the relatively short half-life (4.02 days) of the 195mPt product and the necessity of separating very low (microscopic) levels of 195mPt from the large macroscopic levels of the 193Ir target material. Therefore, dissolution of the metallic iridium target material is an important step in obtaining the desired 195mPt product. It is desirable to produce a dissolution yield of at least 99%, which has heretofore proven elusive. A method of dissolving the iridium target material has been developed in accordance with the present invention. Iridium metal is dissolved with aqua regia or another strong acid or acidic mixture inside a closed, inert, high-pressure vessel (for example, a polytetrafluoroethylene-lined pressure bomb or a sealed high-temperature-glass ampule) at elevated temperature and pressure. Aqua regia is generally known as a mixture of conc. HCl and HNO3 in variable proportions. In carrying out the present invention, the ratio of HCl to HNO3 can affect the solubility of the irradiated target material. A ratio of 10:1 HCl:HNO3 was used in experiments with an observed Ir solubility of about 2 mg/ml. It is contemplated that, since the resultant compounds are believed to be chlorides, HCl would preferably be the major constituent. It is further contemplated that the HCl:HNO3 ratio is not a critical parameter to the present invention, but may adjusted to obtain maximum solubility of the target material. Dissolution can occur at temperature in the range of about 210xc2x0 C. to about 250xc2x0 C., preferably in the range of about 215xc2x0 C. to about 235xc2x0 C., and most preferably in the range of about 215xc2x0 C. to about 235xc2x0 C. Selection of temperature ranges is based on observations wherein 217xc2x0 C. is the lowest temperature at which Ir metal powder was observed to significantly dissolve and 230xc2x0 C. is about the melting point of the polytetrafluoroethylene liner. Effective temperature may vary with conditions and equipment used. Acidic vapors are believed to attain a high pressure inside the pressure bomb or ampule, but the pressure was not measurable during tests of the present invention. The dissolution time under above-described conditions is generally two hours, but dissolution time is not a critical process parameter. As an example, dissolution operations may generally include, but are not limited to: 1. Open the rabbit in a hot-cell, usually by cutting, and remove the hermetically sealed vessel therefrom. 2. Wash the hermetically sealed vessel with conc. HCl (30%), followed by H2O, and finally alcohol in order to decontaminate the exterior thereof. 3. Break the hermetically sealed vessel by conventional means and empty irradiated target material into a high-pressure reaction vessel having an inert inner surface, for example, a polytetrafluoroethylene-lined pressure bomb. 4. Add sufficient aqua regia into the pressure bomb and close the bomb. 5. Heat the bomb to a sufficient temperature and for a sufficient time to dissolve the irradiated target material. Steps 4 and 5 are critical to the dissolution aspect of the present invention. It is believed that the dissolved Iridium is in the form of H2IrCl6 and that the product is in the form of H2PtCl6, but that issue is not believed to be critical. Material irradiated in accordance with Example I was dissolved as follows. The rabbit was cut open in a hot cell and the quartz ampoule was emptied into a beaker. The quartz ampoule was washed with HCl, H2O, and then alcohol. The ampoule was crushed in a break tube and the contents thereof were emptied into a polytetrafluoroethylene-lined pressure bomb having a capacity of 22 ml. 15 ml of 10:1 aqua regia (HCl:HNO3) was added into the pressure bomb and the bomb was assembled. The assembled bomb was heated in an oven at 220xc2x0 C. for two hours. The material dissolved into the solution with very little residue remaining. Chemical Separation of 195mPt Product from Ir The effective separation of the microscopic amount of Pt product from the macroscopic amount of Ir is an important aspect of the present invention. Conventional methods for the separation of platinum from iridium, including solvent extraction and chromatographic methods, have not been developed to a feasible level of effectiveness. Therefore, a new cation exchange method has been developed to separate microscopic amounts of Pt product from the macroscopic amount of Ir. A suitable ion-exchange column is loaded with a cation exchange resin, for example, Dowex-50 or AG-50Wx4, in any particle size, but preferably in the range of 50-600 mesh resin and conditioned with a solution comprising 0.1M-3M HCl and 0.05M-1M thiourea. The volume of the column is preferably minimal. The dissolution product of aqua regia containing Pt and Ir is heated to near dryness, dissolved with minimum amount of the HCl-thiourea solution, and loaded onto the column. The column is first eluted with at least 5 to 10 column volumes of the HCl-thiourea solution to elute the Ir. The column is then eluted with HCl in a concentration from 0.5M to 12 HCl (without thiourea) to elute the Pt. Pt product was separated from Ir as follows. AG-50Wx4 (100-200 mesh) resin was loaded into a column having a volume of 0.2 ml and conditioned with greater than 1 ml of a solution comprising 1M HCl and 0.2M thiourea. An aqua regia solution resulting from the process of Example II was heated to near-dryness, re-dissolved with a minimum of the HCl-thiourea solutionxe2x80x94about 0.5 ml, and loaded onto the column. The column was then eluted with 4.8 ml of the HCl-thiourea solution to elute the Ir. The column was then eluted with 3.3 ml 12M HCl (without thiourea) to elute the Pt. Data from Example III, summarized in FIGS. 5 and 6, demonstrate that 99% of the Iridium was eluted from the column with 4.8 ml of HCl-thiourea solution (about 24 column volumes) with about 20% loss of Pt. It is contemplated that the actual Pt loss under the same conditions may be reduced if a cut is made at less than 24-column volume elution. A larger-scale production of 195mPt is carried out as generally described hereinabove and more particularly as follows. 100 mg of highly enriched 193Ir metal target ( greater than 90% enrichment, produced at ORNL) is subjected to 7-10 day neutron-irradiation in the hydraulic tube facility of the ORNL HFIR in accordance with the above description. Following irradiation, the metal powder is dissolved in 100 ml aqua regia in a pressure bomb having an inert liner. The bomb is heated for at least 1 hour at 220xc2x0 C. in a convection, induction, or microwave oven. After complete dissolution, the dark brown solution containing Ir and Pt is evaporated to near-dryness and the residue is dissolved with in 20 ml of a solution comprising 1M HCl and 0.1 M thiourea. The target solution is loaded on a 4 ml volume cation exchange column (AG 50X4, 200-400 mesh), pre-equilibrated with greater than 8 ml of the HCl-thiourea solution. The Ir is eluted with 20 bed volumes of the HCl-thiourea solution. The 195mPt is then eluted with 5 bed volumes of conc. HCl. The 195mPt product eluted from the cation exchange column can be further processed, if desired, to remove more Ir in order to further purify the 195mPt. The 195mPt fraction from Example IV is evaporated to dryness and re-dissolved with a minimum volume of the HCl-thiourea solution and loaded onto another cation exchange column and eluted as described hereinabove to effect further separation of Pt from Ir. HNO3 is added to the 195mPt fraction, which is then evaporated to dryness and subsequently re-dissolved in 3M HCl. The 195mPt product can be further processed, if desired, to remove a 199Au byproduct in order to obtain a very high-purity 195mPt product. The 195mPt fraction from Example IV or Example V is further processed to remove a 199Au by-product therefrom. A 3M HCl solution thereof is extracted in methyl isobutyl ketone (MIBK). The 199Au by-product is extracted into the MIBK with a little of the Pt, while most of the Pt remains in the aqueous phase. The MIBK is washed with a lower acidity, for example, 1M of HCl to back-extract as much of the Pt as possible from the MIBK. The two aqueous phases are combined and evaporated to dryness and the residue thereof is dissolved in 0.1 M HCl. Gamma-ray spectroscopy can be used throughout the chemical processing to monitor levels of 195mPt, 192Ir and 199Au. Mass analysis by mass spectrometry of the final 195mPt sample will provide an experimental value for the 195mPt specific activity. Specific activity for the 195mPt product is at least 30 mCi/mg Pt, preferably at least 50 mCi/mg Pt, more preferably at least 70 mCi/mg Pt, most preferably at least 90 mCi/mg Pt. Maximum attainable specific activity is largely dependent on the available neutron flux. The skilled artisan will understand that concentrations and amounts of reagents used to elute the Ir and Pt, and to purify the Pt, can vary with conditions and are not critical to the present invention. While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be prepared therein without departing from the scope of the inventions defined by the appended claims.
	abstract	A laser irradiation apparatus is provided in which the occurrence of adverse effects on an object to be irradiated with a laser beam due to the difference in the polarization state between pulsed laser beams can be prevented or significantly reduced when the pulsed laser beams emitted from two laser light sources are guided to pass through the same optical path for irradiation of an object to be irradiated with the pulsed laser beams. The laser irradiation apparatus is provided with a first laser light source 3, a second laser light source 4, an optical path combining optical member 7 which guides the pulsed laser beams emitted from the first laser light source 3 and the second laser light source 4 to pass through the same optical path, and a polarization control member 9 which controls polarization state of the pulsed laser beam from the optical path combining optical member 7. The polarization control member 9 includes a first polarization control portion 13 and a second polarization control portion 15 through which beam components of the pulsed laser beam pass. The polarization states of the beam components that have passed through the first polarization control portion 13 and the beam components that have passed through the second polarization control portion 15 become different from each other. The beam components in different polarization states are superimposed on each other on a surface to be irradiated with the laser beam of the object to be irradiated with the laser beam.
048866350	abstract	A gripping tool for a device for the remote-controlled removal of samples in housings with heads from a container includes a mast having a first coupling part. A second coupling part is opposite and associated with the first coupling part. A guide bar elastically bears on the second coupling part in a telescoping manner with pivots disposed on the guide bar. At least two catches of a two-armed lever are disposed on the pivots and have guide grooves formed therein. A bushing surrounding the guide bar has guide pins each engaging a respective one of the guide grooves. At least one remotely controlled linear drive moves the bushing in the direction of the longitudinal axis of the bushing for surrounding the head of the sample housing with the catches like tongs.
048184713	description	DETAILED DESCRIPTION OF THE INVENTION In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings. Also in the following description, it is to be understood that such terms as "forward", "rearward", "left", "right", "upwardly", "downwardly", and the like are words of convenience and are not to be construed as limiting terms. IN GENERAL Referring now the the drawings, and particularly to FIGS. 1 to 3, there is shown a nuclear fuel assembly, generally designated 10 for a boiling water nuclear power reactor (BWR), in which the improvement of the present invention is incorporated. The fuel assembly 10 includes an elongated outer tubular flow channel 12 that extends along substantially the entire length of the fuel assembly 10 and interconnects an upper support fixture or top nozzle 14 with a lower base or bottom nozzle 16. The bottom nozzle 16 which serves as an inlet for coolant flow into the outer channel 12 of the fuel assembly 10 includes a plurality of legs 18 for guiding the bottom nozzle 16 and the fuel assembly 10 into a reactor core support plate (not shown) or into fuel storage racks, for example in a spent fuel pool. The outer flow channel 12 (also see FIG. 4) generally of rectangular cross-section is made up of four interconnected vertical walls 20 each being displaced about ninety degrees one from the next. Formed in a spaced apart relationship in, and extending in a vertical row at a central location along, the inner surface of each wall 20 of the outer flow channel 12, is a plurality of structural ribs 22. The outer flow channel 12, and thus the ribs 22 formed therein, are preferably formed from a metal material, such as an alloy of zirconium, commonly referred to as Zircaloy. Above the upper ends of the structural ribs 22, a plurality of upwardly-extending attachment studs 24 fixed on the walls 20 of the outer flow channel 12 are used to interconnect the top nozzle 14 to the channel 12. For improving neutron moderation and economy, a hollow water cross, as seen in FIGS. 1, 2 and 4 and generally designated 26, extends axially through the outer channel 12 so as to provide an open inner channel 28 for subcooled moderator flow through the fuel assembly 10. The hollow water cross 26 has a plurality of four radial panels 30 which extend in a cruciform configuration to divide the fuel assembly 10 into four separate elongated compartments 32. The water cross 26 is mounted to the angularly-displaced walls 20 of the outer channel 12. Preferably, outer elongated lateral ends of the water cross panels 30 are connected such as by welding to the structural ribs 22 along the lengths thereof in order to securely retain the water cross 26 in its desired central position within the fuel assembly 10. Further, the inner ends of the panels 30 together with the outer ends thereof define the inner central cruciform channel 28 which extends the axial length of the hollow water cross 26. Also, the water cross 26 has a lower flow inlet end 34 and an opposite upper flow outlet end 36 which each communicate with the inner channel 28 for providing subcoolant flow therethrough. Disposed within the channel 12 is a bundle of fuel rods 38 which, in the illustrated embodiment, number sixty-four and form an 8.times.8 array. The fuel rod bundle is, in turn, separated into four mini-bundles thereof by the water cross 26. The fuel rods 38 of each mini-bundle, such being sixteen in number in a 4.times.4 array, extend in laterally spaced apart relationship between an upper tie plate 40 and a lower tie plate 42. The fuel rods 38 in each mini-bundle are connected to the upper and lower tie plates 40,42 and together therewith comprise a separate fuel rod subassembly 44 within each of the compartments 32 of the channel 12. A plurality of grids 46, such being six in number, are axially spaced along the fuel rods 40 of each fuel rod subassembly 46 and maintain the fuel rods in their laterally spaced relationships. The lower and upper tie plates 42,40 of the respective fuel rod subassemblies 44 have flow openings (not shown) defined therethrough for allowing the flow of coolant/moderator fluid into and from the separate fuel rod subassembly 44. Also, coolant flow paths provide flow communication between the fuel rod subassemblies 44 in the respective separate compartments 32 of the fuel assembly 10 through a plurality of openings 48 formed between each of the structural ribs 22 along the lengths thereof. Coolant flow through the openings 48 serves to equalize the hydraulic pressure between the four separate compartments 32, thereby minimizing the possibility of thermal hydrodynamic instability between the separate fuel rod subassemblies 44. The above-described basic components of the BWR fuel assembly 10 are known in the prior art, being disclosed particularly in the above-cited U. S. patents to Barry et al and Taleyarkhan, and have been discussed in sufficient detail herein to enable one skilled in the art to understand the improvement of the present invention presented hereinafter. The BWR fuel assembly 10 just described is manufactured and sold by Westinghouse Electric Corporation, the assignee of the present invention and of the Barry et al and Taleyarkhan patents. LPRM CALIBRATION STRIPS ON FUEL ASSEMBLY OUTER CHANNEL Referring now to FIG. 5, there is seen a schematic representation of a group of four Westinghouse BWR fuel assemblies 10 and a LPRM string 50 located centrally therebetween and spaced from the adjacent corners 52 of their rectangular channels 12. Also shown in FIG. 5 (and in FIGS. 1-4 as well) is the improvement of the present invention in the form of a plurality of angle-shaped strips 54 composed of neutron absorber material and located about and attached such as by welding to the adjacent corners 52 of the fuel assembly channels 12. The strips 54 are placed on the outer tubular channels 12 of the above-described Westinghouse BWR fuel assemblies 10 at the axially spaced locations shown in FIG. 6 for facilitating calibration of Local Power Range Monitor (LPRM) neutron detectors 56 contained within a hollow tube 58 of the LPRM string 50. More specifically, as is conventionally known, the detectors 56 are adapted to provide local power monitoring information during reactor operation. Also, the hollow tube 58 of the string 50 is adapted to receive a conventional neutron flux sensitive probe 60 at selected times for calibrating the detectors 56. Also in FIG. 6 is a schematic representation of a GE BWR fuel assembly 62 with the axially spaced Inconel sacers 64. The axial positions of the neutron absorber strips 54 on the Westinghouse fuel assembly channel 12 are in alignment with the axial positions of the Inconel spacers 64 in the GE BWR fuel assembly 62. The spacers or grids 46 of the Westinghouse fuel assembly 10 by being composed of a material incapable of producing a localized change in neutron flux and by being located at different axial positions than the Inconel spacers 64 of the GE BWR fuel assembly 62 are thus not capable nor adaptable for serving the purpose of the Inconel spacers 64 with respect to the probe 60 when the GE BWR fuel assembly 62 is replaced in a reactor core by the Westinghouse fuel assembly 10. However, the improvement in the form of the strips 54, being composed of neutron absorber material, such as material containing boron, hafnium and/or silver, does adequately serve such purpose. By each strip 54 being composed of a material capable of producing a localized change in neutron flux, then upon passage of the probe 60 through the hollow tube 58 of the string 50 and past the strips 54, the probe 60 will sense the neutron flux change being produced by each strip and thereby the position of the probe can be tracked as it is moved through the string tube. It is thought that the present invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the forms hereinbefore described being merely a preferred or exemplary embodiment thereof.
	claims	1. A nuclear power plant exhaust system comprising:a chimney comprising at least one chimney wall that defines a chimney channel with a chimney inlet and a chimney outlet, wherein the chimney inlet is connected to an exhaust outlet of a nuclear reactor containment structure and configured to receive, from the exhaust outlet, an exhaust gas comprising a combustible component;a combustion apparatus installed inside the chimney channel and comprising a support frame, a plurality of recombiners, and a quenching mesh;the support frame comprising at least one sidewall that defines a hollow channel extending along and inside the chimney channel and that also separates the hollow channel from a chimney space that is inside chimney channel but outside the hollow channel;a first one of the plurality of recombiners installed inside the hollow channel over the quenching mesh and comprising a recombiner mesh and a combustion catalyst coated on the recombiner mesh, wherein the first recombiner is configured to burn at least part of the combustible component contained in the exhaust gas flowing in the hollow channel as the exhaust gas passes through the recombiner mesh;the quenching mesh installed inside the hollow channel under the first recombiner; andat least one hole formed between the quenching mesh and the first recombiner through the at least one sidewall of the support frame and configured to allow air introduction into the hollow channel therethrough. 2. The system according to claim 1, wherein the first recombiner has a honeycomb structure or a plate structure. 3. The system according to claim 2, wherein the combustion catalyst is a mixture of platinum or palladium and titanium dioxide or alumina. 4. The system according to claim 1, wherein the first recombiner is installed in a multi-stage manner. 5. The system according to claim 1, wherein the chimney inlet is connected to a filtering equipment disposed outside the nuclear reactor containment structure, the filtering equipment connected to the exhaust outlet. 6. The system of claim 1, wherein the hollow channel is referred to as a first hollow channel, wherein the system further comprises a second hollow channel extending along the first hollow channel inside the first hollow channel, wherein the second hollow channel is separated from the first hollow channel by at least one additional side wall, wherein the system further comprises a fan configured to blow air such that the air flows through the second hollow channel in a downward direction, wherein the system further comprises at least one hole formed between the quenching mesh and the first recombiner through the at least one additional sidewall and configured to allow air blown in the downward direction to flow into the first hollow channel therethrough. 7. The system of claim 6, wherein a bottom portion of the second hollow channel is close. 8. The system of claim 6, wherein the fan is installed inside the second hollow channel at higher than the recombiner.
053944518	abstract	An optical arrangement includes an optical system for transforming synchrotron radiation light emitted from an emission point of a synchrotron ring into a substantially parallel beam, with respect to a first direction which is parallel to an orbit plane of the synchrotron ring and with respect to a second direction which is perpendicular to the orbit plane, wherein an absolute value of a focal length of the optical system in the first direction is smaller than that in the second direction.
	description	The present invention relates generally to systems for and methods of attenuating radiation. More particularly, the present invention relates to systems for and methods of shielding a patient from secondary or scatter radiation during a radiological procedure (e.g., fluoroscopy, radiographic procedures, etc.). One embodiment of the present invention further relates to systems for and methods of shielding the head of an infant, toddler, child, and/or adolescent (i.e., pediatric patients) from secondary or scatter radiation. Radiation is used in a variety of medical procedures (generally referred to herein as “radiological procedures”). For example, radiation is used in diagnostic procedures (i.e., procedures allowing non-invasive investigation of a patient), therapeutic procedures (i.e., procedures wherein discrete anatomical regions of a patient are irradiated as a treatment), and various invasive procedures such as fluoroscopic guidance and/or manipulation of instruments during surgical procedures. Radiation is a valuable tool, but one which may require certain safeguards. Living tissue is susceptible to damage through high intensity, prolonged, and/or repeated exposure to radiation. Scatter radiation is a secondary radiation generated when the primary radiation interacts with the object being impinged. Scatter radiation has a frequency range lower than the primary radiation beam and generally moves in a variety of uncontrollable directions. Scatter radiation, like primary radiation, can cause damage to living tissue. It is well documented that radiation exposure is cumulative. Although the amount of scatter radiation exposure that a patient receives during a single radiological procedure may not be harmful, a patient who undergoes a great number of such procedures may suffer damage due to the cumulative effect of scatter radiation. Studies demonstrate that the cumulative effect of scatter radiation may cause greater damage to an infant, toddler, child, and/or adolescent (i.e., pediatric patients) than to an adult patient. Such studies suggest that repeated exposure of scatter radiation to the head of a pediatrics patient may affect their cognitive ability as they develop. Thus, there is a need for a radiation attenuation system for and method of shielding one or more non-target areas of a patient from scatter radiation. There is also a need for a radiation attenuation system that is configured to shield the head of patient from scatter radiation. There is further a need for a radiation attenuation system that is configured to shield the head of a pediatric patient. Yet further, there is a need for a radiation attenuation system that is configured to shield the head of a infant. There is further a need for a radiation attenuation system having a configuration that may reduce the tension or stress experienced by a patient during a radiological procedure. There is also a need for a radiation attenuation system that can be easily shipped and/or stored. There is further a need for radiation attenuation system addressing these, and/or any other need. One embodiment of the present invention relates to a radiation attenuation system for shielding the head of a pediatric patient from scatter radiation during radiological procedure. The system includes a radiation attenuating barrier having a first region and an opposite second region. The second region is configured to conform to the neck of the pediatric patient. The system further includes a support member coupled to the radiation attenuating barrier for supporting the radiation barrier in a generally upright in-use position. The radiation attenuating barrier is configured to be positioned perpendicular to a longitudinal axis of the pediatric patient. Another embodiment of the present invention relates to a radiation attenuation system for shielding a patient from scatter radiation during a radiological procedure. The system includes a radiation barrier having a lower region defining an aperture for conforming to a portion of the patient, means for supporting the radiation barrier in a generally upright position, and means for selectively reconfiguring the position of the lower region to minimize gaps between the patient and the radiation barrier. A further embodiment of the present invention relates to a method of attenuating scatter radiation during a radiological procedure. The method comprises the steps of placing a radiation attenuation system between a target area on a patient and non-target area on the patient, manipulating the radiation attenuation system so that a portion of the radiation attenuation system at least partially conforms to the patient, positioning the radiation attenuation system in a generally upright position, and exposing the target area on the patient to a primary radiation beam. Referring to FIGS. 1 through 9, a radiation attenuation system 20 and components thereof are shown according to exemplary embodiments. Generally, radiation attenuation system 20 includes one or more radiation shields or barriers supported in a manner and at a position that may be useful in attenuating (e.g., blocking, reflecting, absorbing, etc.) secondary or scatter radiation generated during a radiological procedure (i.e., any medical procedure wherein radiation is applied to a patient). Radiation attenuation system 20 is configured to shield one or more portions of the patient that are not of primary interest to the particular radiological procedure (i.e., non-target areas, etc.). According to a preferred embodiment, radiation attenuation system 20 is configured to shield the head of the patient from scatter radiation during a radiological procedure being performed on a lower portion of the patient. It should be noted that while the exemplary embodiments are described and illustrated herein as a radiation attenuation system for shielding the head of a patient, and more particularly, as a radiation attenuation system for shielding the head of a patient who is an infant, toddler, child, and/or adolescent (collectively referred to herein as a “pediatric patient”), the radiation attenuation system may be configured to shield other non-target areas of the patient. For example, radiation attenuation system 20 may be configured to shield the gonadal, abdominal, torso, and/or extremity regions of a patient, and/or any other area of the patient that may benefit from being shielded from scatter radiation. Further, radiation attenuation system 20 may be sized and configured to be used with non-pediatric patients (e.g., adult patients, etc.). Further still, radiation attenuation, system 20 may be used in a variety of radiological procedures including, but not limited to, diagnostic procedures (i.e., procedures allowing non-invasive examination or investigation of a patient such as x-ray examinations, CT scanning procedures, or the like), therapeutic procedures (i.e., procedures wherein anatomical regions of a patient are irradiated as a treatment), and/or various invasive procedures (e.g., procedures wherein a patient is irradiated for guiding the manipulation of instruments, etc.). Also, radiation attenuation system 20 may be used regardless of the position of the patient. For example, the patient may be provided in a supine position wherein the patient is positioned on his or her back with the legs of the patient being straight or bent, a prone position wherein the patient is positioned face down, and/or a lateral position wherein the patient is positioned on one side. FIG. 1 is a front view showing radiation attenuation system 20 according to an exemplary embodiment. Radiation attenuation system 20 is shown in a relatively flattened or extended position (i.e., a non-in-use position or storage position). Radiation attenuation system 20 generally comprises one or more radiation shields or barriers 30 for attenuating scatter radiation and protecting a portion of a patient. Barrier 30 is shown as a substantially rectangular member having a first or upper region (e.g., edge, periphery, portion, etc.), shown as a first margin 32, and a second or lower region, shown as a second margin 34. Second margin 34 is intended to be positioned adjacent to (e.g., proximate, near, at, etc.) a patient and/or a patient support structure (e.g., medical table, diagnostic surface, examination table, patient stretcher, etc.) and includes a configuration suitable for allowing barrier 30 to substantially conform to the contours of the patient. According to an exemplary embodiment, second margin 34 is shown as having a cutout or missing portion, shown as an aperture 36, that is shaped and dimensioned to substantially conform to the contours of the neck of a typical pediatric patient. Aperture 36 is defined by an edge 38 of second margin 34 having a curvilinear shape (e.g., arcuate, semi-circular, etc.). According to various alternative embodiments, aperture 36 may have any of a variety of shapes, including shapes having linear portions, non-linear portions, or combinations thereof. Referring further to FIG. 1, radiation attenuation system 20 is also shown as comprising first and second legs 50, 52 which are used to support radiation attenuation system 20 in an in-use position (shown in FIG. 3). First and second legs 50, 52 are positioned adjacent to second margin 34 of barrier 30, and are shown in a first or storage position in which first and second legs 50, 52 are substantially disposed within the same plane as barrier 30. First and second legs 50, 52 are configured to move between the first position (shown in FIG. 1) and a second or in-use position (shown in FIG. 3). Configuring radiation attenuation system 20 as a member that can be substantially flattened may facilitate in the shipping and/or storing of radiation attenuation system 20. According to an alternative embodiment, first and second legs 50, 52 may be fixed in an in-use position. Preferably, first and second legs 50, 52 are integrally formed with barrier 30, but alternatively may be provided as separate components. FIG. 2 shows an exploded view of radiation attenuation system 20. For the illustrated embodiment, radiation attenuation system 20 is shown as utilizing more than one barrier 30 (e.g., a front barrier and a back barrier, etc.). Each barrier 30 includes a radiation attenuating member or pad 39 (shown in dashed lines) made of a radiation attenuating material. Preferably, the radiation attenuating material is generally light and flexible to maximize workability for bending, folding, reconfiguring, etc., or otherwise manipulating barrier 30. The material may be formable (e.g. deformable) or compliant, and/or relatively “stretchable” (e.g. elastic). According to alternative embodiments, the material used may be generally rigid and inflexible (as in the exemplary embodiment shown in FIG. 9), and/or substantially weighted. Radiation attenuating pad 39 may be fabricated of any radiation attenuation material including, but not limited to, bismuth, barium, lead, tungsten, antimony, copper tin, aluminum, iron, iodine, cadmium, mercury, silver, nickel, zinc, thallium, tantalum, tellurium, and uranium. Anyone of the aforementioned radiation attenuation materials alone or in a combination of two or more of the radiation attenuation materials may provide the desired level of radiation attenuation. Preferably, the radiation attenuating material is comprised of a polymeric matrix charged with an attenuating filler. Examples of suitable radiation attenuation materials for radiation attenuating pad 39 are disclosed in U.S. Pat. No. 4,938,233, entitled “Radiation Shield,” and U.S. Pat. No. 6,674,087, entitled “Radiation Attenuation System,” both of which are hereby incorporated by reference in their entirety. It should be noted that radiation attenuating pad 39 is not limited to such radiation attenuating materials, and according to various alternative embodiments may be formed of any suitable radiation attenuating material including more conventional attenuating materials. The radiation transmission attenuation factor of radiation attenuating pad 39 may vary depending upon the intended application of radiation attenuation system 20 and/or the number of barriers 30 provided. According to one exemplary embodiment, radiation attenuating pad 39 has a radiation transmission attenuation factor of a percent (%) greater than about 50%, suitably greater than about 90%, suitably greater than about 95% (with reference to a 100 kVp x-ray beam). According to various alternative embodiments; radiation attenuating pad 39 may have a radiation transmission attenuation factor of a percent less that 50% such as 10-50% or 10-20%. Radiation attenuating pad 39 may also at least partially attenuate gamma rays, and may have a gamma ray attenuation factor of at least 10% of a 140 keV gamma radiation source. Referring further to FIG. 2, each barrier 30 is shown having a covering 40 disposed about or containing radiation attenuating pad 39. Covering 40 may enhance processability, provide softness or comfort to a patient, and/or may allow radiation attenuation system 20 to be more easily cleaned and/or sanitized. Covering 40 is preferably made of a fabric material such as that of a surgical drape, but can also be made of a non-fabric material such as a plastic sheet, non-woven paper material, or any other material suitable for covering radiation attenuating pad 39. According to an exemplary embodiment, covering 40 is constructed from a front sheet and a back sheet which are coupled together at the periphery to enclose radiation attenuating pad 39. For purposes of this disclosure, the term “coupled” means the joining or combining to two or more members (e.g., portions, layers, materials, components, etc.) directly or indirectly to one another. Such joining or combining may be relatively stationary (e.g., fixed, etc.) in nature or movable (e.g., adjustable, etc.) in nature. Such joining or combining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another (e.g., one-piece, etc.) or with the two members or the two members and any additional intermediate member being attached to one another. Such joining or combining may be intended to be relatively permanent in nature or alternatively may be intended to be relatively detachable or removable in nature. Covering 40 may be configured so that it permanently encloses radiation attenuating pad 39, or alternatively may be configured so that radiation attenuating pad 39 may be selectively removed. According to an alternative embodiment, barrier 30 may include a radiation attenuating pad 39 that is not enclosed by a covering 40. According to another alternative embodiment, barrier 30 may include a covering 40 that is integrally formed with a radiation attenuating pad 39. Radiation attenuation system 20 further comprises one or more support members 60 for supporting radiation attenuation system 20 in an in-use position (shown in FIG. 3). Preferably, support members 60 are malleable (e.g., flexible, impressible, pliable, etc.) members that can be configured and reconfigured with minimal effort by a physician and/or medical assistant so that radiation attenuation system 20 can accommodate patients of varying size and/or to allow radiation attenuation system 20 to be selectively moved to a position that does not substantially interfere with the particular radiological procedure. According to an exemplary embodiment, support members 60 are strips or bands that can be folded or bent into any of a number of positions and can then be returned to a substantially flattened positioned for storage and/or disposal of radiation attenuation system 20. The strips or bands may be formed of metal, plastic, or any other suitable material. According to various alternative embodiments, support members 60 may be provided by a variety of know or otherwise suitable components that can support radiation attenuation system 20 in the in-use position. For example, support members 60 may be generally rigid and inflexible members which have been set in an in-use position. According to a further alternative embodiment, support members may be unnecessary if barrier 30 is formed of a material that can sufficiently support radiation attenuation system 20 in the in-use position without the need of additional support (as in the exemplary embodiment shown in FIG. 9). Referring further still to FIG. 2, radiation attenuation system 20 is shown as having a pair of support members 60 extending in a substantially vertical direction relative to barrier 30 and a third support member 60 extending in a substantially horizontal direction. The vertical support members 60 are shown extending between barrier 30 and first and second legs 50, 52. According to an alternative embodiment, separate support members 60 may be provided for barrier 30 and first and second legs 50, 52. The horizontal support member 60 may extend from one vertical support member 60 to the other vertical support member (as shown) or alternatively may extend only partially therebetween. Support members 60 are shown as being sandwiched between barriers 30. Preferably, support members 60 are coupled to one or more of barriers 30 and/or first and second legs 50, 52. Support members 60 may be coupled to barrier 30 and/or first and second legs 50, 52 using any of a variety of known or otherwise suitable techniques including, but not limited to, mechanical fasteners (e.g., hook and loop, clips, snaps, etc.), adhesives, welding, bonding, fusing, stitching, etc. According to an alternative embodiment, support members may be supported at a desired position as a result of being sandwiched between two or more barriers 30. If more than one barrier 30 is utilized (as shown in FIG. 2), the plurality of barriers 30 may be coupled to each other using any known or otherwise suitable technique. For example, barriers 30 may be coupled using mechanical fasteners, adhesives, welding, bonding, fusing, stitching, etc. Barriers 30 may be intended to be permanently coupled to each other, or alternatively may be intended to be detachably coupled to each other. According to an alternative embodiment, radiation attenuation system 20 may include a single barrier 30. Such a barrier 30 may comprise one or more layers of a radiation attenuation material. If a single barrier 30 is provided, support members 60 may be disposed at a front and/or back side of barrier 30, or alternatively may be integrally formed with barrier 30. According to a preferred embodiment, one or more of the components of radiation attenuation system 20 (e.g., barrier 30, including covering 40 and/or radiation attenuating pad 39, support members 60, an additional covering, etc.) may be generally disposable in whole or in part, thereby minimizing ancillary sources of contamination that may arise from multiple uses. According to another suitable embodiment, one or more of the components of radiation attenuation system 20 are generally non-toxic, recyclable, and/or biodegradable. According to an alternative embodiment, one or more of the components of radiation attenuation system 20 may be reusable. According to a preferred embodiment, one or more of the components of radiation attenuation system 20 may be sterilized between uses to minimize the likelihood of bacteriological or virus contamination. Sterilization may be performed in any convenient manner, including gas sterilization and irradiation sterilization. FIG. 3 is a front perspective view showing radiation attenuation system 20 in an in-use position. In the in-use position, first and second legs 50, 52 have been selectively reconfigured so that they are substantially perpendicular to at least a portion of barrier 30. The in-use position is obtained by manipulating (e.g., bending, shaping, etc.) support members 60 until the desired position is achieved. In the in-use position, first and second legs 50, 52 can be placed upon a surface (e.g., a patient support structure, etc.) and they will support barrier 30 in a generally upright position. For purposes of this disclosure, the phrase “generally upright” is used broadly to define to any position in which barrier 30 may be moved to that is suitable for shielding the head of a patient. Design criteria and application parameters may affect the definition of “generally upright.” For example, “generally upright” may describe barriers that have a linear and/or a non-linear trajectories, that extend upward in a substantially vertical direction, and/or that extend upward at any angle ranging from approximately 0 degrees to approximately 90 degrees. Accordingly, all such definitions of “generally upright” are included in the scope of the appended claims. In FIG. 3 first margin 32 is shown as being folded or bent backwards relative to the remaining portions of barrier 30. Such positioning, as detailed below, may enhance the effectiveness in shielding the head of a patient from scatter radiation. According to various alternative embodiments, first margin 32 and/or other portions of barrier 30 may be selectively moved to a variety of positions. For example, first margin 32 may be substantially aligned with second margin 34 so that barrier 30 is vertically orientated relative to first and second legs 50, 52, and/or may be folded or bent in a forward direction. FIG. 4 is a front perspective view showing radiation attenuation system 20 being used with a patient P who is positioned on a patient support structure, shown as a patient table 100. Radiation attenuation system 20 is disposed about patient P in manner and at a position intended to reduce the amount of scatter radiation received by the head of patient P during a radiological procedure wherein the target area is a lower portion of patient P. Particularly, aperture 36 is shown as receiving the neck of patient P. Preferably, support members 60 which dictate the positioning of first and second legs 50, 52 and/or second margin 34 can be manipulated so that edge 38 substantially conforms to the contours of the neck patient P without providing significant discomfort to patient P and/or without leaving a significant space or gap between the neck of patient P and edge 38. Depending on the neck size of patient P, the point at which first and second legs 50, 52 are bent backwards relative to second margin 34 may vary. For example, if patient P has a relatively small structure, it may be beneficial to bend first and second legs 50, 52 closer to second margin 34 than if patient P has a relatively large structure. Preferably, radiation attenuation system 20 is configured so that the weight of radiation attenuation system 20, or a substantial portion thereof, is not carried by patient P, but is instead carried by another structure such as patient table 100. Such a configuration may be particularly advantageous when radiation attenuation system 20 is used with pediatric patients who may not have the strength to carry the weight of radiation attenuation system 20 even though radiation attenuation system 20 is preferably light in weight. While patient P is not required to carry a substantial portion of the weight of radiation attenuation system 20, it may still be desirable to allow a portion of barrier 30 (e.g., second margin 34, edge 38, and/or an additional drape, etc.) to drape across or otherwise come in contact with patient P in an attempt to limit the number of gaps between patient P and radiation attenuation system 20. FIG. 5 is a side perspective view of radiation attenuation system 20 being used on pediatric patient P. According to an exemplary embodiment, radiation attenuation system 20 is configured to both shield the head of patient P and reduce the amount distress or trauma that will be experienced by patient P during the radiological procedure. Radiation attenuation system 20 may reduce trauma to patient P by having a generally open (e.g., non-enclosing, etc.) disposition when disposed about the neck of patient P. As shown in FIG. 5, radiation attenuation system 20 is generally open to the surrounding environment on the sides, back, and partially on the top. Such openness may allow personnel (e.g., physicians, medical assistants, parents, etc.) to comfort (e.g., distract, entertain, support, etc.) patient P during the radiological procedure by gaining access to patient P and/or by allowing patient P to see and/or hear personnel attempting to comfort patient P. The method of using radiation attenuation system 20 is described herein with reference to FIGS. 4 and 5. Prior to a radiological procedure in which the primary area of interest (i.e., the target area) of the radiological procedure is at a lower portion of patient P, a physician, medical assistant, and/or any other personnel obtains radiation attenuation system 20. When first obtained, radiation attenuation system 20 may be in a relatively flattened or extended position. The physician (or other personnel) then moves first and second legs 50, 52 backwards by manipulating support members 60 and places radiation attenuation system 20 over patient P so that aperture 36 receives the neck of the patient. The positioning of first and second legs 50, 52 may be further adjusted to obtain the desired fit around the neck of patient P. During the radiological procedure, a primary radiation beam is applied to a lower portion of patient P. As the primary radiation beam is applied to patient P, scatter radiation is generated due to the interaction of the primary beam with patient P, patient table 100, and/or any other object in the path of the primary radiation beam. The scatter radiation tends to be directed in all directions. Barrier 30 shields the head of patient P from this scatter radiation. First margin 32 of barrier 30 may be bent backwards in an attempt to further shield the head of patient P from scatter radiation that may come over the top of radiation attenuation system 20. Referring next to FIG. 6, radiation attenuation system 20 is shown according to another exemplary embodiment. Radiation attenuation system 20 of FIG. 6 is similar to radiation attenuation system 20 of FIG. 1, but is further shown as including one or more supplemental (e.g., auxiliary, add-on, etc.) members, shown as a pair of side flaps 54, 56. Side flaps 54, 56 are provided to further shield a patient from scatter radiation. Similar to first and second legs 50, 52, side flaps 54, 56 are intended to be manipulated, and are configured to move between a first or storage position (shown in FIG. 6) and a second or in-use position (shown in FIG. 7). Preferably, side flaps 54, 56 have the same construction as barrier 30. According to one exemplary embodiment, side flaps 54, 56 are integrally formed with barrier 30 and extend outwardly therefrom. Alternatively, side flaps 54, 56 may be provided as separate components that are coupled to barrier 30 and/or first and second legs 50, 52. Side flaps 54, 56 are further shown as including one or more support members 60 for allowing side flaps 54, 56 to be selectively moved to a variety of positions. The additional support members 60 are shown extending substantially perpendicular to the vertical support members 60, but alternatively may be provided in some other position. FIG. 7 is a front perspective view showing radiation attenuation system 20 of FIG. 6 being used with patient P. Side flaps 54, 56 are shown as having been selectively manipulated so that side flaps 54, 56 extend backwards from barrier 30 to further enclose and shield the head of patient P from scatter radiation. In such a position, side flaps 54, 56 are disposed in substantially parallel planes that are substantially perpendicular to a plane in which a portion of barrier 30 is disposed within. In this in-use position, side flaps 54, 56 may further shield the head of patient P by attenuating scatter radiation that may come around the side of radiation attenuation system 20. According to an alternative embodiment (not shown), side flaps 54, 56 may extend to patient table 100 and may be configured to at least partially support radiation attenuation system 20 in the in-use position. In such an embodiment, first and second legs 52, 54 may be eliminated if side flaps 54, 56 can support barrier 30 in a generally upright position. FIG. 8 is a side perspective view of radiation attenuation system 20 of FIG. 6. As shown in FIG. 5, radiation attenuation system 20 remains generally open to the surrounding environment at the back and partially at the top, while is partially enclosed along the sides. While gaps are shown between side flap 54 and first margin 32 and patient table 100, according to various alternative embodiments, side flap 54 may be configured so that one or more of such gaps is eliminated. FIG. 9 shows radiation attenuation system 20 according to another exemplary embodiment. Radiation attenuation system 20 of FIG. 9 is shown as box-like structure wherein barrier 30 provides a front wall, side flaps 54, 56 provide a pair of side walls, and a top wall is provided by a member 58. In such an embodiment, barrier 30 and side flaps 54, 56 are formed of a substantially rigid material so that the need for support members 60 is eliminated. Similar to the above described embodiments, second margin 34 of barrier 30 defines aperture 36 which is configured to receive the neck of a patient. It is important to note that the construction and arrangement of the elements of the radiation attenuation system as shown in the illustrated embodiments is illustrative only. Although only a few embodiments of the present inventions have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, or the length or width of the structures and/or members or connectors or other elements of the system may be varied. It should be noted that the elements and/or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures and combinations. For example, the radiation attenuation material may be a relatively flexible material, or alternatively, may be a relatively rigid material. Further, barrier 30 may not include an aperture 36, but instead may be configured to conform to the contours of a patient by being formed of a material that can be draped across the patient without applying a significant amount of weight to the patient. Accordingly, all such modifications are intended to be included within the scope of the present inventions. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the present inventions. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating configuration and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the inventions as expressed in the appended claims.
	description	This application is a continuation-in-part application of U.S. patent application Ser. No. 11/600,298, filed Nov. 14, 2006 now U.S. Pat. No. 7,680,625 and entitled “Systems and Methods for Monitoring System Performance,” which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 60/736,788, filed Nov. 14, 2005 and entitled “System Integrity Monitoring Device and Process,” and U.S. Provisional Application Ser. No. 60/789,854, filed Apr. 5, 2006 and entitled “System Integrity Monitoring Device and Process.” The complete disclosures of the above applications are herein incorporated by reference for all purposes. Generally, pipe is used in the nuclear, petrochemical, and other industries for transporting fluids. A system or network of pipes and other equipment may be set up around a facility in an intricate, non-linear fashion. The transported fluids in the network may be corrosive, toxic, hazardous, reactive, combustible, and/or flammable. Those fluids also may be under high temperatures and/or pressures. Thus, equipment must be made of materials that are compatible with the transported fluids, operating conditions, and/or other factors. Additionally, when the equipment is replaced, the replacement equipment must be made of compatible materials. This scenario applies to all equipment of a process system, including pipes, tanks, support structures and other components of the system. Even when the proper components are used, the transported fluids and/or other factors may cause the components to degrade over time by corrosion, erosion, depositing, or blockage. That degradation may result in leakages, explosions, or other undesirable results. Leaks or fugitive emissions also may occur along pipe at flanges, joints, valves, vessels, etc. Monitoring the performance and/or integrity of the components, such as wall thickness, may allow operators to replace the components before any significant degradation. Referring to FIG. 1, a system 10 for testing, monitoring, and/or replacing equipment 11, such as a pipe network 12 having plural inspection sites 14, may include a site identifier 20, a target 30, a measuring instrument or device 40, a location device 50, a data collection device or portable reader 60, and a remote processor or database 70. Site identifier 20 may be associated with one or more inspection sites 14 for the equipment, which may be on the field (such as along pipe network 12), being used, being repaired, and/or in inventory. Site identifier 20 may, for example, be associated with, or attached to, the equipment adhesively, mechanically, or by any other suitable method. Site identifier 20 may be associated with inspection site 14 at any suitable spot, location, point, position, etc. Site identifier 20 also may form a part of the equipment. The phrase “associated with” may mean that site identifiers 20 are located, attached, and/or positioned at any point, position, location, spot, place, etc. in any suitable way in, on, near, adjacent to, and/or along the equipment. In some embodiments, a single site identifier 20 may be associated with plural inspection sites 14. Alternatively, or additionally, plural site identifiers 20 may be associated with a single inspection site 14. For example, one site identifier may be used to store a first set of data, such as performance parameters and associated identity/testing information, and another site identifier may be used to store a second set of data, such as characteristics and associated identity/testing information. When more than one site identifier is used for a single inspection site, such as to store different sets of data, those site identifiers (and/or associated targets) may be distinguished by color coding, different labels, and/or other suitable methods. Site identifier 20 may be any device that allows for unique identification of inspection sites 14. For example, site identifier 20 may be a memory module, a radio-frequency identification (RFID) device, a bar-code, and/or any other suitable data-storage device read and/or written by electrical, magnetic, infrared, optical, optical character recognition (OCR), and/or any other suitable technology. In some embodiments, site identifier 20 may be configured to be written to once. Site identifier 20 may alternatively, or additionally, be configured for read only access. As illustrated in FIG. 2, site identifiers 20 may be associated with one or more inspection sites 14 for equipment 11. Although plural inspection sites 14 may be employed, for simplicity of disclosure, only a single inspection site 14 is shown in FIG. 1. Although a particular memory module configuration is shown in FIG. 1, the memory module may take any of a variety of forms, and may include any suitable structure configured to retain or store data. As used herein, the term “data” may refer to singular or plural information, parameters, quantities, characters, files, symbols, etc. in any electronic, written, and/or other suitable format. The memory module may include any number of electronic and/or other devices, including nonvolatile memory, volatile memory, microprocessors, clocks, sensors, etc. The memory module may utilize any of a variety of memory technologies, including semiconductor memory, magnetic storage media, optical storage media, etc. The memory module may be equipped with an interface for accessing data stored in the memory, such as to add data to memory, retrieve data from memory, overwrite data in memory, and/or erase data in memory. In some embodiments, the interface may include one or more electrical contacts through which a signal may pass. Other interfaces may alternatively, or additionally, be used. For example, in some embodiments, the memory module may include a wireless or contactless interface providing access to stored data on the memory module. As used herein, “store,” “stored,” and “storage” mean that data is at least temporarily placed in memory for retrieval later. Stored data may be temporarily stored or permanently stored. Temporarily stored data may be subsequently erased or overwritten with other data, while permanently stored data may not be subsequently erased or overwritten with other data. Data may be stored in any suitable format, which may be with or without compression, encryption, and/or password protection. In some embodiments, the memory module may be a contact memory button (CMB) manufactured by MacSema, Inc. In some embodiments, the memory module may be an iButton® manufactured by Dallas Semiconductor. Other examples of memory modules are described in U.S. Pat. Nos. 5,576,936; 5,506,757; and 5,539,252; and U.S. Patent Application Publication No. 2004/0135668. The complete disclosures of the above patents and patent application are herein incorporated by reference for all purposes. Memory module(s) associated with a respective inspection site 14 may allow for storage and/or retrieval of one or more types of data. For example, the memory module may allow for storage and/or retrieval of one or more identity and/or testing information, such as a unique inspection site identifier (e.g., a serial number), site location data of a corresponding inspection site 14, a last monitoring or testing date corresponding to inspection site 14, the identity of the last user who performed an inspection at inspection site 14, duration of testing performed (e.g., trigger time) at inspection site 14, drawing identification number, identity of person who replaced the equipment, etc. Additionally, or alternatively, the memory module may allow for storage and/or retrieval of one or more performance (or historical or unique performance) parameters, which may be related to monitoring integrity, emissions, temperature, pressure, chemical compositions, flow-rates, and/or for any other conditions and/or issues that may be monitored using system 10. For example, performance parameters may include a nominal wall thickness corresponding to inspection site 14, a minimal wall thickness corresponding to inspection site 14, a current wall thickness measurement corresponding to inspection site 14, a last wall thickness measurement on the last date monitored corresponding to inspection site 14, etc. The memory module may additionally, or alternatively, allow for storage and retrieval of one or more characteristics of the equipment, such as a material type or material classification corresponding to inspection site 14, percentage compositions of one or more elements corresponding to inspection site 14, dimensional information (e.g., diameter, length, width) corresponding to the inspection site, flange type, gasket type, pump type, etc. Examples of material classifications may include 1¼, 2¼, 5, 9, and 12 Cr, Titanium, Monel, Inconel, Hastaloy, A-53 Gr B (carbon steel), A-106 Gr B (carbon steel), etc. Examples of elements may include Sb, Sn, Pd, Ag, Al, Mo, Nb, Zr, Bi, Pb, Se, W, Zn, Cu, Ni, Co, Fe, Mn, Cr, V, Ti, Sb, Sn, Pd, Ag, Al, Nb, Zr, Bi, Pb, Se, W, Zn, Cu Ni, Co, V, Ti, etc. System 10 may include a cover 22 that may be configured to protect site identifier 20. Cover 22 may be temporarily secured over site identifier 20 to shield site identifier 20 from potential damage. Cover 22 may be held in place by frictional, magnetic, and/or mechanical force, and/or by other means. Target 30 may include a target rim 32 and a hole 34. Target 30 may be attached to equipment 11 adhesively, mechanically, or by any other suitable method. Target 30 may take any convenient shape, including circular, oblong, square, or rectilinear. Target 30 may be associated with one or more inspection sites 14 to define a data collection point at such inspection site 14. The data collection point may be a point, position, spot, and/or location on the equipment for collecting data, such as performance and/or characteristic data. Hole 34 may be fittably sized to receive a sensor 46 of measuring device 40. The data collection point may be defined as a point that may be fittably sized to receive sensor 46 for collecting data. Target 30 may be advantageous for generating a consistent (e.g., accurate and/or precise) measurement for collecting data at inspection site 14. Target 30 may indicate the data collection point in any suitable way. In some embodiments, target 30 and site identifier 20 may form a unitary component associated with, or attached at, inspection site 14. The unitary component may be a plate to which site identifier 20 may be attached and comprised of target 30 including 34. The plate may be metal, plastic, and/or any other suitable material. FIG. 2 shows an illustrative facility or factory F including a pipe network 12 and other equipment 35 that may be separate from the pipe network (such as operating separate from the pipe network, in inventory, being repaired, etc.). Pipe network 12 may include a network of pipes, flanges, fasteners, vessels, pressure vessels, equipment supports, pipe racks, etc. located around and throughout facility or factory F. Other equipment 35 may include a container that at least partially contains one or more replacement equipment. For example, other equipment 35 may include a pallet with a plurality of replacement pipes, as shown in FIG. 3. Inspection site 14e may be associated with other equipment 35 and may include one or more site identifiers 20. Those site identifiers may be associated with the equipment in any suitable way. For example, a single site identifier may be attached to a pallet, as shown in FIG. 3. Alternatively, or additionally, site identifier 20 may be attached to a door leading to a room or area with other equipment 35. Additionally, or alternatively, the site identifier may be attached to the other equipment. In some embodiments, the pipe network and/or the other equipment may be located around and throughout a plant, a power plant, a ship, a submarine, and/or in any other location. Pipe network 12 may include multiple pipes with one or more pipes configured to carry different fluids. Pipe network 12 may include any type(s) of material, including metals, plastics, etc. Plural inspection sites 14 may be associated with pipe network 12 and other equipment 35. For illustrative purposes, inspection sites 14a, 14b, 14c, and 14d may be associated with pipe network 12, and inspection site 14e may be associated with equipment 35. In some embodiments, pipe network 12 and/or equipment 35 may have as many inspection sites 14 as suitable, including hundreds or even thousands of inspection sites. A site identifier 20 and a target 30 may be associated with and/or attached at one or more inspection sites 14. Portable reader 60 and/or measuring device 40 may be transported to any of inspection sites 14a-e for reading, collecting, and/or storing data. Now returning to FIG. 1, system 10 may include measuring device 40. Measuring device 40 may include a screen 42, a plurality of keys 44, a sensor 46, a first connector 48, and a second connector 49. Measuring device 40 may be operable to make certain suitable measurements of inspection site 14. Measuring device 40 may be operable to collect data of inspection site 14. The data may be related to integrity, emissions, material type or material classification, percentage composition of one or more elements, dimensional information, temperature, pressure, chemical compositions, flow-rates, and/or for any other conditions and/or issues for which data may be collected using system 10. Screen 42 may be configured to view data stored in measuring device 40. Keys 44 may include an on/off key, a calibration key, a plurality of key pad keys, a set of scroll left/right keys, and/or a set of scroll up/down keys. In some embodiments, measuring device 40 may include a touch-pad, a touch-screen, voice input and/or another suitably configured data entry device and/or tool. Measuring device 40 may be configured to control partially or entirely the operation of location device 50 and/or portable reader 60. Alternatively, measuring device 40 may act as a peripheral to another device, such as location device 50 and/or portable reader 60, where location device 50 and/or portable reader 60 may be configured to control partially or entirely the operation of measuring device 40. Sensor 46 may be configured to make measurements and/or collect identity/testing, performance, and/or characteristic data of inspection site 14. In some embodiments, sensor 46 may be fittably configured to fit into rim 32 on target 30 associated with inspection site 14. Sensor 46 may transmit or send data, including identity/testing, performance, and/or characteristic data, to measuring device 40 of a selected or present inspection site 14 being measured via a first connector 48. First connector 48 may allow data to pass between measuring device 40 and sensor 46. First connector 48 may connect measuring device 40 to sensor 46. First connector 48 may create an electrical connection, an optical connection, a radio frequency (RF) connection, a wireless connection, and/or any other suitable type(s) of connections. For example, first connector 48 may be a cable. In some embodiments, measuring device 40 may measure the performance and/or characteristics of equipment 11 using ultrasonic inspection, mechanical inspection, optical inspection, electromagnetic and electronic inspection, thermal inspection, chemical and analytical inspection, x-ray fluorescence, spark emission spectrography, infrared thermography, magnetic flux leakage (MFL), radioisotope gamma radiometry, radiography, and/or any other suitable methods. Measuring device 40 may collect identity/testing, performance, and/or characteristic data from the measurements. In some embodiments, the data may include a current wall thickness of inspection site 14. Methods used to measure and monitor wall thickness include ultrasonic, visual, mechanical, optical, electromagnetic, electronic, thermal, chemical, and analytical inspection as well as infrared thermography, magnetic flux leakage (MFL), radioisotope gamma radiometry, and radiography. For example, measuring device 40 may be an ultrasound device, such as a Panametrics Corrosion Thickness Gage 37DL Plus. Measuring device 40 may be a modified Panametrics Thickness Gage 37DL Plus. The Panametrics Thickness Gage 37DL Plus may be controlled entirely or in part by portable reader 60. Measuring device 40 may be a Krautkramer DMS2E. Measuring device 40 may be a modified Krautkramer DMS2E. The Krautkramer DMS2E may be controlled entirely or in part by portable reader 60. Additionally, or alternatively, the data may include percentage compositions of one or more elements of the equipment, and material classifications determined based on those percentage compositions. Methods used to measure percentage compositions of one or more elements of the equipment include x-ray fluorescence and spark emission spectrography. For example, measuring device 40 may be an x-ray fluorescence device, such as a Niton XL3t XRF Analyzer. The Niton XL3t may be controlled entirely or in part by portable reader 60. Measuring device 40 may be connected to portable reader 60 via a second connector 49. Second connector 49 may allow measuring device 40 and portable reader 60 to connect and/or interface. Second connector 49 may allow data to pass between measuring device 40 and portable reader 60. Second connector 49 may be in the form of an electrical connection, an optical connection, an RF connection, a wireless connection, and/or any other suitable type of connection. For example, second connector 49 may be a cable. Sensor 46 may communicate with portable reader 60 via first connector 48 and second connector 49. That sensor may be connected via first connector 48 to portable reader 60, and may communicate with measuring device 40 via second connector 49 and/or with location device 50 via a third connector 52. System 10 may include location device 50. Location device 50 may be any device capable of determining site location data. Location device 50 may be a global positioning satellite (GPS) device. The location device may be a Galileo positioning system device. Additionally, or alternatively, location device 50 may use GPS, Galileo, and/or any other suitable technology for gathering site location data. The location device may have an antenna 54 for receiving one or more signals from, for example, GPS satellites 56 and/or Galileo satellites 56. Location device 50 may have its own controls, and/or act as a peripheral to another device, such as portable reader 60 and/or measuring device 40, where portable reader 60 and/or measuring device 40 may be configured to control operation of location device 50. The location device may be configured to control partially or entirely the operation of measuring device 40 and/or portable reader 60. Location device 50 may be permanently or temporarily connected via a third connector 52 with portable reader 60 and/or measuring device 40. Third connector 52 may allow location device 50 and portable reader 60 to connect and/or interface. The third connector may allow data to pass between location device 50 and portable reader 60. Additionally, or alternatively, third connector 52 may be in the form of an electrical connection, an optical connection, an RF connection, a wireless connection, and/or any other suitable type(s) of connection. For example, the third connector may be a cable. Portable reader 60 may store data passed from location device 50. Moreover, third connector 52 may allow location device 50 and measuring device 40 to connect and interface either by directly connecting third connector 52 to measuring device 40 or indirectly via portable reader 60. Various site location data may be associated with a corresponding inspection site 14. Site location data may include a distance value and/or a direction value. The distance value may include a measurable distance between points (e.g., inches, feet, meters, etc.). The direction value may include coordinates or bearings (e.g., North, South, East, West, Up, Down, Left, Right, Starboard, Port, etc.). The distance value and the direction value, or any suitable combination of distance values and direction values, may be used to determine the location of a selected or destination inspection site 14. Site location data may be in any suitable format, such as latitude coordinates and longitude coordinates, GPS coordinates, Galileo coordinates, user-defined values or coordinates (e.g., “5 feet above the third door on the left”), and/or any suitable combination thereof. As described above, site identifier 20 (e.g., the memory module) may store site location data corresponding to such inspection site 14 associated with site identifier 20. Portable reader 60 may store site location data corresponding to one or more inspection sites 14 in pipe network 12 and/or other equipment 35. System 10 also may include portable reader 60. The portable reader may include a screen 62, a plurality of keys 64, a reader/writer 66, a fourth connector 67, an internal on-board memory 68, and a processor 69. Screen 62 may be configured to view data in portable reader 60. The screen also may be configured to view data in measuring device 40 and/or in location device 50. Portable reader 60 may be configured to partially or entirely control measuring device 40 and/or location device 50. Keys 64 may include an on/off key, a calibration key, a plurality of key pad keys, a set of scroll left/right keys, and/or a set of scroll up/down keys. The keys may be configured to control portable reader 60. In some embodiments, portable reader 60 may include a touch-pad, a touch-screen, voice input, and/or another suitably configured data entry device or tool. Portable reader 60 may be configured to control partially or entirely the operation of measuring device 40 and/or location device 50. Keys 64 also may be configured to control measuring device 40 (via second connector 49), and/or location device 50 (via third connector 52). Alternatively, or additionally, portable reader 60 may act as a peripheral to another device, such as measuring device 40 and/or location device 50. Furthermore, measuring device 40 and/or location device 50 may be configured to control partially or entirely the operation of portable reader 60. Portable reader 60 and site identifier 20 may be complementary-configured for allowing data, and/or parameters to pass. In some embodiments, reader/writer 66 may be associated with portable reader 60 and site identifier 20 may be complementary-configured so that portable reader 60 may read data from, erase data of, and/or write data to site identifier 20. An interface on reader/writer 66 may be aligned with an interface on site identifier 20 so that data may be transferred between reader/writer 66 and site identifier 20. Reader/writer 66 may transmit data to and/or from site identifier 20 electrically, optically, with radio waves, and/or with infrared waves, etc. Reader/writer 66 may be a sensor and/or probe. Reader/writer 66 may send and/or retrieve data from portable reader 60 via fourth connector 67. Fourth connector 67 may allow data to pass between portable reader 60 and reader/writer 66. The fourth connector may connect portable reader 60 to reader/writer 66. Fourth connector 67 may be in the form of an electrical connection, an optical connection, an RF connection, a wireless connection, and/or any other suitable types of connections. For example, fourth connector 67 may be a cable. Reader/writer 66 may communicate with measuring device 40 via fourth connector 67 and second connector 49, and/or with location device 50 via fourth connector 67 and third connector 52. The reader/writer may be connected to measuring device 40 via fourth connector 67, and/or may communicate with portable reader 60 via second connector 49 and/or with location device 50 via third connector 52. Portable reader 60 may include internal on-board memory 68. The internal on-board memory may take any of a variety of forms, and may include any suitable structure configured to retain or store data. Internal on-board memory 68 may include any number of electronic and/or other devices, including nonvolatile memory, volatile memory, microprocessors, clocks, sensors, etc. Internal on-board memory 68 may utilize any of a variety of memory technologies, including semiconductor memory, magnetic storage media, optical storage media, etc. Internal on-board memory 68 may retain and/or store data for measuring device 40, location device 50, and/or portable reader 60. Internal on-board memory 68 may store, and/or receive for storage, any suitable type(s) of data, such as one or more identity/testing information, one or more performance parameters, and/or one or more characteristics corresponding to one or more inspection sites 14. Additionally, or alternatively, the memory may store, and/or receive for storage, one or more standard characteristics associated with the equipment. The standard characteristics may include characteristics required or recommended for the equipment and/or the fluids handled by the equipment, such as minimum percentage compositions of certain elements. For example, the standard characteristics may be provided by one or more standards organizations, such as the American Society of Mechanical Engineers and the American Petroleum Institute. Processor 69 may be configured to analyze, compute, and/or compare data retrieved by and/or stored in portable reader 60. The processor may analyze, compute, and/or compare data associated with a selected inspection site 14 in real-time and/or while at, near, around, adjacent to, and/or in proximity to the selected inspection site 14. Although memory 68, processor 69, and other components (such as screen 62 and keys 64) are shown to be internal to portable reader, the memory, the processor and/or the other components may alternatively, or additionally, be internal to measuring device 40 and/or location device 50. In some embodiments, processor 69 may verify the one or more identity/testing information, one or more performance parameters, and/or one or more characteristics corresponding to and/or associated with a respective inspection site 14. Additionally, or alternatively, processor 69 may compare the data corresponding to and/or associated with a first inspection site with data of a second inspection site, and/or make a determination based on that comparison, such as whether a second equipment associated with the second inspection site is a suitable replacement for a first equipment associated with the first inspection site. Alternatively, or additionally, processor 69 may compare data corresponding to and/or associated with an inspection site with one or more standard characteristics for that site, and/or make a determination based on that comparison, such as whether the equipment associated with the inspection site meets the one or more standard characteristics. Processor 69 may validate, e.g., the accuracy and/or precision, of the data in real time or while on-location at the present inspection site 14. Additionally, or alternatively, the processor may interpret the data in real time or while on-location at the present inspection site 14. Moreover, processor 69 may validate the data of the present inspection site 14 (and/or the performance of system 10) in real time or while on-location at the present inspection site 14. In some embodiments, processor 69 may be configured to compare site location data of the present inspection site 14 with reference site location data to determine a location of a destination inspection site 14. The site location data corresponding to the destination inspection site 14, or any other inspection site 14, may be the reference site location data. Processor 69 may determine the location of the destination inspection site 14 without the use of location monitoring device 50. In some embodiments, portable reader 60 may be a suitably configured PDA device, notebook computer, and/or other suitable portable or hand-held computing or processing device. In some embodiments, portable reader 60 may be a BR3065 manufactured by MacSema, Inc., that communicates (e.g., reads/writes) with the contact memory button (CMB). The portable reader may transmit, download and/or upload data to the contact memory button. The portable reader may control entirely, or in part, measuring device 40 and/or location device 50. The portable reader may communicate with measuring device 40 and/or location device 50 for transmitting data. For example, the Panametrics Thickness Gage 37DL Plus may be connected to the portable reader via second connector 49. Alternatively, Krautkramer DMS2E may be connected to the portable reader via second connector 49. As another example, the Niton XL3t XRF Analyzer may be connected to the portable reader via second connector 49. In some embodiments, as illustrated in FIG. 1, portable reader 60 and measuring device 40 may form a unitary portable instrument. The unitary portable instrument may be configured so that one or more measuring devices 40, one or more location devices 50, one or more portable readers 60, and/or any suitable combination thereof may be integrated as one unit, integrated as connected components, or integrated in any suitable way. As shown in dashed lines in FIG. 2, the unitary portable instrument including portable reader 60 may be transported as needed to inspection sites 14 at the facility for monitoring. Measuring device 40 may be located at inspection site 14 for performing constant or real-time monitoring and/or other measurement(s). In some embodiments, one or more components of portable reader 60 may be integrated with and/or contained in measuring device 40 and/or location device 50. For example, memory 68 and/or processor 69 may be integrated with and/or contained in measuring device 40. Alternatively, or additionally, one or more components of measuring device 40 may be integrated with and/or contained in location device 50 and/or portable reader 60. For example, screen 42 and/or keys 44 may be integrated with and/or contained in portable reader 60. Additionally, or alternatively, one or more components of location device 50 may be integrated with and/or contained in measuring device 40 and/or portable reader 60. System 10 may include remote processor or database 70. Remote database 70 may be any device allowing for storage, retrieval, and/or processing of data, such as a computer. Remote database 70 may contain any parts needed for storing, retrieving, and/or processing data, such as a memory module, a microchip, a screen, and a keyboard. For example, the remote database may take the form of a PDA, a laptop computer, and/or some other processing device with suitable firmware and/or software to accomplish the desired tasks. Remote database 70 may use a fifth connector 71 to interface with measuring device 40, location device 50, and/or portable reader 60, allowing data to pass. Fifth connector 71 may be in the form of an electrical connection, an optical connection, an RF connection, a wireless connection, and/or any other suitable type(s) of connection. For example, the fifth connector may be a cable. FIG. 4 is a flow chart depicting an example method 100 for monitoring inspection sites 14. At block 110, plural inspection sites 14 may be selected and associated with pipe network 12 and/or other equipment 35 in facility F. For example, inspection sites 14 may be associated with one or more pipes, fasteners, flanges, valves, vessel, pressure vessels, pumps, compressors, etc. At block 112, one or more targets 30 may be associated with one or more inspection sites 14. At block 114, one or more site identifiers 20 may be associated with one or more inspection sites 14. Site identifier 20 may be configured to store and/or contain data associated with such inspection site 14. In some embodiments, site identifier 20 may be a memory module. Portable reader 60 and/or remote database 70 may be used to write to site identifier 20 the one or more identity/testing information, one or more performance parameters, and/or one or more characteristics associated with such inspection site 14. At block 116, an inspection site 14 for monitoring and/or other measurement(s) may be selected. Portable reader 60 may be transported to the selected inspection site 14. A unitary portable instrument that may include portable reader 60, measuring device 40 and/or location device 50 may be transported to the selected inspection site 14. Using FIG. 2 as an example, inspection site 14a may be selected. The unitary portable instrument including portable reader 60 may be transported to inspection site 14a. At block 120, the one or more identity/testing information, one or more performance parameters, and/or one or more characteristics stored on site identifier 20 associated with the selected inspection site 14 may be acquired by portable reader 60. Reader/writer 66 may read site identifier 20 to acquire that data. In some embodiments, portable reader 60 may acquire one or more identity/testing information, one or more performance parameters, and/or one or more characteristics from the memory module onsite and/or in real time. For example, as illustrated in FIG. 2, portable reader 60 may acquire the data corresponding to inspection site 14a while portable reader 60 may be located at or around inspection site 14a. Screen 62 of portable reader 60 may indicate that data was transmitted from site identifier 20 to portable reader 60. Turning to block 121 of FIG. 4, portable reader 60 may be suitably programmed to compare the one or more identity/testing information, one or more performance parameters, and/or one or more characteristics with data stored on portable reader 60 to verify that the data being compared matches. For example, portable reader 60 may compare the last pipe or wall thickness reading and the last date of the last pipe or wall thickness reading acquired at block 120 with data stored with portable reader 60 including a last pipe or wall thickness reading and a last date of a last pipe or wall thickness to verify that the data matches. Portable reader 60 may provide an alert if the data stored with portable reader 60 does not match the data stored with site identifier 20. At block 122, measuring device 40 may collect identity/testing data, performance data, and/or characteristic data of the selected inspection site 14. Sensor 46 of measuring device 40 may, for example, be placed in hole 34 on target 30 for taking a reading or measurement to collect the data. In some embodiments, the data collected by measuring device 40 may be the current pipe or wall thickness associated with inspection site 14, such as at hole 34 of target 30. Alternatively, or additionally, the data collected by the measuring device may include percentage compositions of one or more elements of the equipment associated with the inspection site. The performance data may be collected after a visual and/or other inspection without using measuring device 40. In some embodiments, measuring device 40 may collect plural performance and/or characteristic data over a predetermined time interval. The time interval may be in seconds, minutes, hours, days, etc. At block 124, the identity/testing, performance, and/or characteristic data of block 122 may be acquired by portable reader 60. Portable reader 60 may acquire the data while onsite and/or in real time. For example, as illustrated in FIG. 2, portable reader 60 may acquire the data of inspection site 14a while portable reader 60 may be located at or around inspection site 14a. Portable reader 60 may be configured to manually receive the data. In some embodiments, keys 64 may be used to manually type into portable reader 60 the identity/testing, performance, and/or characteristic data. In some embodiments, pressing a key 64 may cause portable reader 60 to communicate with measuring device 40 to retrieve the collected identity/testing, performance, and/or characteristic data. Portable reader 60 may be suitably programmed to retrieve or acquire automatically the data from measuring device 40. In some embodiments, portable reader 60 may be programmed to perform a reading process to read measuring device 40. The reading process may determine whether measuring device 40 has collected identity/testing, performance, and/or characteristic data. The reading process may begin when reader/writer 66 receives data from site identifier 20. The reading process may end when measuring device 40 has collected the data. Portable reader 60 may be programmed to retrieve or acquire the data from measuring device 40 after the data reading has substantially stabilized. The reading process may end after a predetermined amount of time if measuring device 40 does not collect the identity/testing, performance, and/or characteristic data, and/or does not collect a substantially stabilized reading. Portable reader 60 may alert the user if the data has not been acquired in the predetermined time. The alert may include resetting portable reader 60 and/or prompting the collection of the data at block 122. Screen 62 of portable reader 60 may indicate that data was transmitted from measuring device 40 to portable reader 60. Portable reader 60 may be suitably programmed to acquire the identity/testing, performance, and/or characteristic data collected over the interval at block 122 from measuring device 40. Now turning to block 130 in FIG. 4, portable reader 60 may compare, compute, and/or analyze the data. Portable reader 60 may perform one or more tests in real time and/or onsite at or around inspection site 14. The tests may include validation and/or interpretation of data. Portable reader 60 may be suitably programmed to compare identity/testing, performance, and/or characteristic data collected at block 122 from measuring device 40. At block 132, portable reader 60 may compare the data acquired at block 122 with one or more identity/testing information, one or more performance parameters, and/or one or more characteristics acquired at block 120 to validate the performance data acquired at block 124. The validation of data may be performed onsite and/or in real time. The validation of data may provide real-time feedback of the reliability and/or accuracy of the data acquired at block 122. Portable reader 60 may alert a user as required if problems exist with the reliability and/or accuracy of the data acquired at block 124. In some embodiments, comparing the data stored with site identifier 20, with data stored with portable reader 60, as described at block 120, may help validate the data collected by confirming onsite that the data was collected at the correct inspection site 14 in the correct order, etc. In some embodiments, validation of identity/testing, performance, and/or characteristic data may include portable reader 60 determining that the data may be out of range. For example, the current pipe or wall thickness acquired at block 124 may be compared to the nominal pipe or wall thickness corresponding to the selected inspection site 14. In some embodiments, if the current pipe or wall thickness is plus or minus about 12.5% of the nominal pipe or wall thickness, then the current pipe or wall thickness data may be out of range. In some embodiments, validation of data may include portable reader 60 determining if measuring device 40 collected imprecise and/or inaccurate data (e.g., it took a “bad” or faulty reading). For example, the current pipe or wall thickness acquired at block 124 may be above the nominal pipe or wall thickness of the corresponding inspection site 14. In some embodiments, when the current pipe or wall thickness is greater than about 0.005 of nominal pipe or wall thickness, measuring device 40 collected bad or faulty data. One or more responses may occur based on the validation of the data acquired at block 124. If the data is determined to be invalid (for example, out of range, inaccurate, and/or imprecise) and/or the data collected is determined to be bad or faulty, then portable reader 60 may prompt measuring device 40 or the user to acquire or collect new data at block 122. In some embodiments, portable reader 60 may automatically prompt measuring device 40 to collect a new current pipe or wall thickness reading. Invalid performance data readings also may mean a problem exists with measuring device 40 or elsewhere in system 10. In response, appropriate changes, tuning, calibrations or adjustments may be made to system 10, such as, moving, adjusting, replacing, repairing, etc. measuring device 40 and/or system 10. At block 134, portable reader 60 may compare the data acquired at block 124 with data acquired at block 120 to interpret the data acquired at block 124. The interpretation of data may be performed onsite and/or in real time. That interpretation may provide real-time feedback of the status of pipe network 12, other equipment 35, and/or of system 10. Portable reader 60 may alert a user as required based on the interpretation. For example, in some embodiments, the interpretation of the data may determine if pipe network 12 is at optimal performance. Portable reader 60 may determine that the current pipe or wall thickness acquired at block 124 is moderately or severely below the nominal pipe or wall thickness corresponding to inspection site 14. The portable reader also may determine the current pipe or wall thickness acquired at block 124 is below the minimal level of thickness for the pipe of the corresponding inspection site 14. Portable reader 60 may be configured to only interpret data determined to be valid at block 132. One or more responses may occur based on the interpretation of data acquired at block 124. The data may signal that pipe network 12 and/or other equipment 35 is not at optimal performance. In response, appropriate changes, tuning, calibrations, or adjustments may be made. In response, a user may adjust, replace and/or repair the pipes, flanges, etc., in pipe network 12 and/or other equipment 35. The performance and/or characteristic data may alert a user that a problem exists with one or more components of system 10. For example, a faulty portable reader 60 or measuring device 40 may exist. In response, appropriate changes, replacements, repairs, tuning, or adjustments may be made to system 10. Alternatively, or additionally, portable reader 60 may compare data acquired in block 120 and/or block 122 with one or more standards, such as one or more standard characteristics. At block 140, data may be transmitted (e.g., written to) to site identifier 20 using reader/writer 66. In some embodiments, updated data may be transmitted to site identifier 20 (e.g., the memory module) associated with the selected inspection site 14 for storage. For example, the performance and/or characteristic data acquired at block 124 and the date on which the performance and/or characteristic data was collected at block 122 and/or acquired at block 124 may be transmitted to the selected site identifier 20 for storage. The identity of the last user who performed an inspection corresponding to inspection site 14 also may be transmitted (e.g., written to) site identifier 20. In this manner, site identifier 20 may maintain a historical record of one or more performance parameters and/or one or more characteristics that are unique to such inspection site 14 associated with site identifier 20. Portable reader 60 may be locked manually and/or automatically to prevent overwriting of data stored in internal on-board memory 68 and/or to prevent measuring device 40 from collecting performance data. Portable reader 60 may lock data associated with a selected site identifier 20 after reader/writer 66 has transmitted data to such site identifier 20. Portable reader 60 may be locked manually, e.g., using keys 64. Alternatively, or additionally, the portable reader may be configured to lock automatically after a predetermined delay. Screen 62 of portable reader 60 may indicate in any suitable way(s) that portable reader 60 is locked. Portable reader 60 may be unlocked to allow for modification of stored data, removal of stored data, and/or to allow measuring device 40 to collect performance data. Portable reader 60 may be unlocked manually. Alternatively, or additionally, the portable reader may be suitably programmed to unlock for a selected inspection site 14 after data may be transmitted from site identifier 20 associated with the selected inspection site 14 to reader/writer 66. In some embodiments, portable reader 60 may be suitably programmed to verify whether data, such as one or more updated performance parameters and/or one or more updated characteristics, have been written to site identifier 20. For example, portable reader 60 may provide an alert if portable reader 60 has not written to site identifier 20 after a predetermined time. The predetermined time may be some time interval after portable reader 60 validated the data at block 132 and/or interpreted the data in 134. The alert may include prompting the collection of new data at block 122 and/or discrediting the data already collected and stored in portable reader 60. This verification may confirm that data was collected at inspection site 14. That verification may confirm that the data was validated by using the identity/testing, performance, and/or characteristic data stored on site identifier 20. At block 142, data may be transmitted, sent, or uploaded to remote database 70 for storage, analysis, etc. Returning to block 116, another inspection site 14 may be selected for monitoring. Referring again to FIG. 2, a user at inspection site 14a may select to monitor inspection site 14b, 14c, 14d, or 14e. The unitary portable instrument including portable reader 60 may be transported to the next-selected inspection site 14. The steps disclosed at blocks 110-140 may be repeated for inspection site 14b, 14c, 14d, and/or 14e as necessary. Additionally, the steps discussed above may be performed in different sequences and in different combinations, not all steps being required for all embodiments of the method. For example, characteristic data acquired from the memory module may be compared with standard characteristic data without performing any measurements using the measuring device. Alternatively, characteristic data acquired from the measuring device may be compared with standard characteristic data without performing any reading of the memory module. FIG. 5 shows an example of a method 200 for determining the location of inspection sites 14 along pipe network 12 and/or other equipment 35. At block 202, site location data may be associated with one or more inspection sites 14 selected at block 110. Location device 50 may be used to determine site location data for one or more inspection sites 14. Blueprints, survey tools (i.e., lasers), and/or any manual or other method to determine site location data also may be used. In some embodiments, site location data may be determined while onsite or while associating site identifier 20 with inspection site 14 at block 114 in FIG. 4. Site location data may be associated with inspection site 14, site identifier 20, and/or target 30 in any suitable way in, on, near, adjacent to, and/or along pipe network 12 and/or other equipment 35 at any suitable point, position, location, spot, place, etc. Any method described, and/or other suitable method, may be employed to determine site location data of one or more inspection sites 14. Any of the various site location data described above may be associated with a corresponding site inspection site 14. At block 204 of FIG. 5, one or more site identifiers 20 (e.g., the memory module) associated with inspection site 14 may store the determined site location data corresponding to such inspection site 14. Site location data may be stored in a machine-readable format, as a barcode, as electronic data, and/or in any other suitable format. Using FIG. 2 as an illustration, inspection sites 14a, 14b, 14c, 14d, and 14e may be selected. Site location data for inspection site 14a may be stored at site identifier 20 associated with inspection site 14a. Likewise, site location data for 14b may be stored at inspection site 14b, etc. At block 206 of FIG. 5, the determined site location data for one or more inspection sites 14 may be sent to a database accessible from any inspection site 14. In the illustrated embodiment, the database may be stored in internal on-board memory 68 in portable reader 60. The database also may be stored on one or more site identifiers 20 and/or on remote database 70. The site location data may include reference site location data. The reference site location data may be one or more fixed locations, including any suitable inspection site 14 and/or any other suitable location. Again using FIG. 2 as an example, site location data corresponding to one or more of inspection sites 14a, 14b, 14c, 14d, and 14e may be stored in portable reader 60. The site location data at blocks 202 and 204 may be used to determine the location of inspection sites 14 along pipe network 12. For example, the site location data may be used to determine the location of the inspection site selected for monitoring at block 116 of FIG. 4. At block 208 of FIG. 5, site location data may be transmitted from site identifier 20 (e.g., the memory module) at a present inspection site 14 to portable reader 60. Reader/writer 66 of portable reader 60 may be used to acquire site location data from site identifier 20. In some embodiments, portable reader 60 may be configured to read a bar-code storing site location data associated with inspection site 14. At block 210, portable reader 60 may compare site location data from the present inspection site 14 to reference site location data to determine the location of a destination inspection site. In one embodiment, keys 64 on portable reader 60 may be used to select any suitable destination inspection site 14 stored in portable reader 60. In this manner, a location, e.g., a relative distance value and a relative direction value, between the present inspection site and the destination inspection site may be determined. Additionally, or alternatively, a user may locate the destination inspection site from the present inspection site in real time. When site location data is stored in portable reader 60 and/or at one or more inspection sites 14 associated with pipe network 12 and/or other equipment 35, location device 50 may not be needed for determining a location of a destination inspection site 14. Additionally, the steps discussed above may be performed in different sequences and in different combinations, not all steps being required for all embodiments of the method. In some embodiments, the relative distance value and the relative direction value determined by portable reader 60 may be adjusted for increased precision and/or accuracy. For example, current GPS, Galileo, or other location technology may be unable to provide exact or pinpoint coordinates corresponding to an actual location. Site location data (e.g., GPS coordinates) determined for one or more inspection sites 14 may therefore be off by a few degrees, feet, etc. relative to the exact or pinpoint coordinates of the actual location of inspection site 14 in pipe network 12. Accordingly, the relative distance value and/or the relative direction value determined by portable reader 60 between the present inspection site 14 and the destination inspection site 14 may be off by a few degrees, feet, etc. Portable reader 60 may be suitably programmed to allow a user to enter data to account for any disparity between the location of the destination inspection site 14 determined by portable reader 60 and the actual location of the destination inspection site 14. The data may be input into portable reader 60 onsite. Portable reader 60 may reconfigure in real-time the relative distance value and the relative direction value to substantially correspond with the exact or pinpoint coordinates of the actual location. In another example, facility F may be generally positioned and/or angled at some degree of deviation relative to a true north reading. A true north reading may be obtained using a magnetic compass or other suitable means. The degree of deviation from true north may be determined by using a compass, blueprints of facility F, etc., or using any other suitable method. The degree of deviation may be recorded as the degree that facility F, etc. is positioned or angled relative to true north. Site location data determined from GPS may be based on a true north reading. The location (e.g., the relative distance value and the relative direction value) determined by portable reader 60 between the present inspection site and the destination inspection site may be based on a true north reading. Accordingly, the location determined by portable reader 60 may be inaccurate by whatever degree of deviation the facility F, etc., is angled or positioned relative to true north. Portable reader 60 may be suitably programmed to allow a user to input data to substantially account for the degree of deviation facility F, etc. is from true north. The inputted data may be the degree that facility F, etc. is positioned or angled relative to true north. The data may be inputted into portable reader 60 onsite. Portable reader 60 may reconfigure in real-time the relative distance value and the relative direction value to substantially account for the degree of deviation of facility F relative to true north. Using FIG. 2 as an example, inspection site 14a may be the present inspection site, inspection site 14b may be the destination inspection site, and inspection site 14b also may be the reference site location data. The location data for the present inspection site 14a may be retrieved from the database in portable reader 60. Keys 64 may be used to select destination inspection site 14b. Portable reader 60 compares site location data for present inspection site 14a to reference site location data of inspection site 14b to determine a location of destination inspection site 14b. Portable reader 60 may calculate a distance value and a direction value between present inspection site 14a and destination inspection site 14b. Portable reader 60 may adjust the calculated distance value and direction value as described above. In some embodiments, inspection site 14c, 14d, and/or another location may serve as the reference site location data. In some embodiments, location device 50 may be associated and/or coupled with the database stored on portable reader 60 to determine the location of a destination inspection site 14. The user may take a location-data reading from any location using location device 50. This reading may serve as the reference point. A user may then use keys 44 on portable reader 60 to select a destination inspection site. As described in the last paragraph, portable reader 60 may then calculate a distance value and a direction value between a present inspection site 14 and the destination inspection site 14. In some embodiments, a location of a destination inspection site 14 may be determined using only the site location data stored on portable reader 60. In some embodiments, a location of a destination inspection site 14 may be determined using a combination of GPS and/or Galileo coordinates with user-defined values. For example, the GPS and/or Galileo coordinates may be used to determine a selected location near one or more inspection sites 14. The user-defined values may then define and/or be used to determine the distance and the direction of the one or more inspection sites 14a relative to the selected location. System 10 is not limited to the systems, apparatus, and methods depicted in FIGS. 1-4. In some embodiments, system 10 may be used for locating and/or monitoring fugitive emissions inspection sites along pipe network 12. Fugitive emissions may generally include leaks from, or in the connections between, flanges, pipes, pumps, compressors, valves, vessels, pressure vessels, etc. System 10 may include any suitable combination of components described above, including a site identifier 20 (such as a memory module) associated with one or more fugitive emissions inspection sites, and a measuring device. In some embodiments, the memory module may allow for storage and retrieval of one or more performance (or historical or unique performance) parameters corresponding to a fugitive emissions inspection site in system 10. For example, the memory module may allow for storage and retrieval of a unique fugitive emissions inspection site identifier corresponding to the fugitive emissions inspection site, location data corresponding to the fugitive emissions inspection site, material types corresponding to the fugitive emissions inspection site, diameters corresponding to the fugitive emissions inspection site, flow rates corresponding to the fugitive emissions inspection site, torque values corresponding to the fugitive emissions inspection site, historical emission readings corresponding to the fugitive emissions inspection site, and/or other suitable data corresponding to the fugitive emissions inspection site. The measuring device may be configured to monitor for fugitive emissions. The measuring device may be configured to collect performance data including a fugitive emissions value. The performance data, including the fugitive emissions value, may be acquired by portable reader 60 in any manner described above, i.e., manually, automatically, etc. In some embodiments, the measuring device may not be connected to and/or in communication with portable reader 60. The performance data may be manually entered into portable reader 60 in those instances. A method for monitoring fugitive emissions may be similar to the method already described above. In some embodiments, reader/writer 66 may acquire the one or more performance parameters from a site identifier 20 associated with a selected fugitive emissions inspection site 14. Portable reader 60 may be configured to prompt the user to collect performance data in response to sensor 46 acquiring the one or more performance parameters. The measuring device may be used to measure and/or collect performance data including one or more fugitive emissions values. The collected performance data may then be manually entered into portable reader 60, e.g., using keys 64. Portable reader 60 may be configured to provide an alert if performance data has not been entered into portable reader 60 after a predetermined time. Portable reader 60 may be configured to prompt a user to communicate (write) one or more updated performance parameters to site identifier 20. Portable reader 60 may be configured to provide an alert if the one or more updated performance parameters have not been written to site identifier 20 after a predetermined time. The alert may include erasing the collected performance data and/or prompting the user to again collect performance data using the measuring device. In some embodiments, system 10 may be used for materials tracking, including for locating pipes, pumps, compressors, valves, flanges, machines, and/or any other equipment. System 10 may include any suitable combination of components described above, including a site identifier 20 (such as a memory module) associated with one or more materials tracking inspection sites 14. In some embodiments, the memory module may allow for storage and retrieval of data corresponding to the materials tracking inspection site 14. For example, the memory module may allow for storage and retrieval of a unique material tracking inspection site identifier, location data for the materials tracking inspection site 14, historical tracking data corresponding to the materials tracking inspection site 14, and/or suitable data. In some embodiments, system 10 may be used to ensure proper replacement of equipment. For example, the system may ensure that a second equipment is a suitable replacement for a first equipment. “Suitable replacement,” as used herein, means that the second equipment is expected to perform at least substantially similar to the first equipment when subjected to the same operating conditions (such as type(s) of fluids transported or contained, operating pressures, operating temperatures, etc.) as the first equipment. System 10 may be able to determine if the second equipment is a suitable replacement for the first equipment by, for example, comparing one or more characteristics of the second equipment with one or more characteristics of the first equipment, and determining if the one or more characteristics of the second equipment match, are equivalent to, and/or are greater than or less than the one or more characteristics of the first equipment. For example, system 10 may be used to determine if second equipment 411 is a suitable replacement for first equipment 311, as shown in FIG. 6. The first and second equipment may be any suitable equipment, such as pipes (or sections of pipe), flanges, fasteners, vessels, pressure vessels, equipment supports, pipe racks, pumps, compressors, etc. First equipment 311 and second equipment 411 may be at two or more inspection sites 14. For example, first equipment 311 may be at a first inspection site 314 and second equipment 411 may be at a second inspection site 414. The first and second equipment may be at any suitable locations. For example, first equipment 311 may be connected to pipe network 12, while second equipment 411 may be in inventory or in a warehouse. Alternatively, first equipment 311 may be connected to pipe network 12 and second equipment 411 may be connected to a separate portion of the pipe network. System 10 may include any suitable combination of components described above. For example, system 10 may include site identifiers 20 and targets 30 that may be associated with inspection sites 14. For example, a first site identifier 320 and a first target 330 may be associated with or attached at first inspection site 314, and a second site identifier 420 and a second target 430 may be associated with or attached at second inspection site 414, as shown in FIG. 6. The first and second site identifiers may be memory modules, as discussed above. When those site identifiers are memory modules, they may be referred to as first and second memory modules that may be associated with the first and second equipment, respectively. As discussed above, the first and second memory modules may be configured to store data, such as one or more identity/testing information, one or more characteristics, and/or one or more performance parameters corresponding to the first and second inspection sites (which may be associated with the first and second equipment). The first and second targets may include target rims 32 and holes 34, as discussed above. For example, the first target may include a first target rim 332 and a first hole 334, and the second target may include a second target rim 432 and a second hole 434. System 10 also may include covers 22 for the site identifiers, such as a first cover 322 and a second cover 422. Portable reader 60 may be configured to read the first and second memory modules and compare the read one or more second characteristics with the read one or more first characteristics to determine if second equipment 411 is a suitable replacement for first equipment 311. For example, the portable reader may determine whether the one or more second characteristics match, are equivalent, or are greater than or less than the one or more first characteristics. Alternatively, or additionally, the portable reader may be configured to read the memory module associated with either the first equipment or the second equipment, and then compare the read characteristics from that module to characteristics measured by measuring device 40 for the other equipment to determine if either the first or second equipment is a suitable replacement for the other equipment. When the one or more first characteristics include a first material classification, and the one or more second characteristics include a second material classification, the portable reader may be configured to determine if the second material classification matches, or is an acceptable equivalent to, the first material classification. Alternatively, or additionally, the portable reader may be configured to determine if the percentage compositions of one or more elements of the second equipment matches or is within an acceptable range of the percentage compositions of one or more elements of the first equipment. Additionally, or alternatively, portable reader 60 may be associated with measuring device 40 and/or may be configured to store one or more first characteristics measured by the measuring device on the first memory module, and/or to store one or more second characteristics measured by the measuring device on the second memory module. The portable reader may erase any existing characteristics stored on the memory modules before storing the measured characteristics, or may add the measured characteristics to the data already stored on the memory modules. Measuring device 40 may be configured to measure one or more first characteristics of the first equipment and/or one or more second characteristics of the second equipment. For example, the measuring device may be configured to perform an x-ray fluorescence to measure percentage compositions of one or more elements of the first equipment and the second equipment. In some embodiments, the measuring device (and/or the portable reader) may be further configured to determine a first material classification of the first equipment and/or a second material classification of the second equipment based, at least in part, on the measured percentage compositions of one or more elements. FIG. 7 shows an example of a method 500 of replacing equipment. The first target and/or the first site identifier may be associated with the first equipment at 502 and 504, respectively. One or more first characteristics of the first equipment may be measured at 506. Those characteristics may be referred to as “measured first characteristics.” The first characteristic(s) may be measured in any suitable way(s). For example, percentage compositions of one or more elements of the first equipment may be measured, such as 0.486% Mo, 97.08% Fe, 0.639% Mn, and 1.23% Cr, and then material of the first equipment may be classified, such as 1¼ Cr. The measured first characteristics may then be stored on the first memory module associated with the first equipment at 508. In some embodiments, existing first characteristics already stored on the first memory module may be erased before storing the measured first characteristics. Alternatively, the measured first characteristics may be added to the existing first characteristics. The first memory module may be read by the portable reader and the first characteristic(s) may be transmitted to the portable reader at 510. The first characteristics read by and/or transmitted to the portable reader may be referred to as “read first characteristics.” Similar steps may be taken for the second equipment. For example, the second target and/or the second site identifier may be associated with the second equipment at 512 and 514, respectively. One or more second characteristics of the second equipment may be measured at 516. Those characteristics may be referred to as “measured second characteristics.” The second characteristic(s) may be measured in any suitable way(s). For example, percentage compositions of one or more elements of the second equipment may be measured, and then material of the second equipment may be classified. The measured second characteristics may then be stored on the second memory module associated with the second equipment at 518. In some embodiments, existing second characteristics already stored on the second memory module may be erased before storing the measured second characteristics. Alternatively, the measured second characteristics may be added to the existing second characteristics. The second memory module may be read by the portable reader and the second characteristic(s) may be transmitted to the portable reader at 520. The second characteristics read by and/or transmitted to the portable reader may be referred to as “read second characteristics.” The first and second characteristic(s) may then be compared at 522 and the suitability of replacing the second equipment for the first equipment, or vice-versa, may be determined at 524. In some embodiments, the first characteristics may include the first material classification, and the second characteristics may include the second material classification. In those embodiments, comparing the first and second characteristics may include comparing those material classifications, and/or determining suitability of replacement may include determining whether the material classifications match or are equivalent. Additionally, the steps discussed above may be performed in different sequences and in different combinations, not all steps being required for all embodiments of the method. For example, where a target and/or site identifier has already been associated with the first and second equipment, and the characteristics already measured and stored for the first and second equipment, then the method may skip those steps and may include reading the memory modules, comparing the characteristics, and determining suitability of replacement. Alternatively, when the characteristics for one of the first and second equipment has already been measured and stored, then the method may involve reading the stored characteristics of one of the first and second equipment, comparing the stored characteristics with measured characteristics of the other equipment, and determining suitability of replacement. While embodiments of a system, apparatus, and methods of use thereof have been particularly shown and described, many variations may be made therein. This disclosure may include one or more independent or interdependent inventions directed to various combinations of features, functions, elements, and/or properties, one or more of which may be defined in the following claims. Other combinations and sub-combinations of features, functions, elements, and/or properties may be claimed later in this or a related application. Such variations, whether they are directed to different combinations or directed to the same combinations, whether different, broader, narrower or equal in scope, are also regarded as included within the subject matter of the present disclosure. An appreciation of the availability or significance of claims not presently claimed may not be presently realized. Accordingly, the foregoing embodiments are illustrative, and no single feature or element, or combination thereof, is essential to all possible combinations that may be claimed in this or a later application. Each claim defines an invention disclosed in the foregoing disclosure, but any one claim does not necessarily encompass all features or combinations that may be claimed. Where the disclosure recites “a” or “a first” element or the equivalent thereof, such recitations include one or more such elements, neither requiring nor excluding two or more such elements. Further, ordinal indicators, such as first, second or third, for identified elements are used to distinguish between the elements, and do not indicate a required or limited number of such elements, and do not indicate a particular position or order of such elements unless otherwise specifically stated. Inventions embodied in various combinations and subcombinations of features, functions, elements, and/or properties may be claimed through presentation of claims in a related application. Such claims, whether they are directed to different inventions or directed to the same invention, whether different, broader, narrower or equal in scope to the other claims, are also regarded as included within the subject matter of the present disclosure.
048775584	summary	BACKGROUND OF THE INVENTION The present invention relates to a method of chemical decomposition by which the volumes of spent radioactive ion-exchange resins (hereinafter sometimes referred to as waste resins) originating from atomic energy facilities can be reduced. Ion-exchange resins are extensively used in many applications such as purification of water, treatment of wastewaters, and separation of various elements. They are also used in large quantities in the field of atomic energy for the purpose of purifying cooling water in nuclear reactors and treating liquid wastes. Therefore, treatment and disposal of spent waste ion-exchange resins containing radioactive substances has been a serious concern in this field. The method in common use in the technology of disposal of radioactive waste ion-exchange resins is to dehydrate the resins, solidify them by incorporation in cements, plastics, etc., place the solidified wastes in containers, and store them for a prescribed number of years, often almost perpetually. However, the waste resins treated by this method are not reduced significantly in volume and have posed substantial problems in the area of waste storage and management. As described above, no really satisfactory method for treating or finally disposing of the variety of solid wastes that result from the operation of nuclear power plants has yet been established. One of the serious problems that remain to be solved is how to reduce the volume of ion-exchange resins that are discarded after they have been used in the purification of liquid media. Several methods, including combustion (incineration), pyrolysis, and acid decomposition have so far been proposed as techniques for reducing the volumes of waste ion-exchange resins, but none of these have proved to be a complete solution to the problem. The combustion method has the advantage of achieving rapid treatment but, at the same time, it requires complicated off-gas lines for handling dust and tars, and/or produces volatile radioactive compounds. The last-mentioned problem is absent from the pyrolysis method, but, on the other hand, it yields high residual contents of carbonaceous materials, and still requires complicated flow systems as in the case of the incineration method. In the acid decomposition method, up to about 90% of the spent ion-exchange resins can be decomposed by successive treatments with concentrated sulfuric acid and nitric acid at a temperature of about 260.degree. C. Although this method is free from any of the problems associated with the first two methods, it has the disadvantage of generating NOx and SOx. Furthermore, the reaction vessel must be made of an expensive material such as tantalum that is capable of withstanding the extremely high temperatures employed. As a further problem, the volume of the waste resins being treated cannot be reduced to the desired extent, since large quantities of salts form during neutralization of the reaction solution. In order to avoid this problem, a method of decomposing waste resins at about 100.degree. C. using hydrogen peroxide and an iron catalyst has been described in Japanese Patent Application (OPI) No. 1446/82 (the term "OPI" as used herein means an "unexamined published Japanese patent application"). This method readily achieves up to 95% decomposition if the waste resin is a cation-exchange resin, but the decomposition of an anion-exchange resin is no higher than 90%. To overcome this disadvantage, it has been proposed that a combination of iron and copper ions be used as a catalyst when the waste resin is decomposed by oxidation with hydrogen peroxide (Japanese Patent Application (OPI) No. 44700/84). This approach achieves at least 95% decomposition of anion-exchange resins, but if the amount of feed (i.e., anion-exchange resin) is increased, organic sludge containing iron and copper ions will form. Furthermore, the decomposition of waste resins by this method has been found to be highly dependent on the pH of the reaction solution, notwithstanding the previously held view that good decomposition is achieved within the pH range of 3 to 11, with particularly good results being attained in the neighborhood of neutrality. If the organic sludge is formed in a large quantity, it will be accumulated in the reaction vessel (reactor) or pipes to form "secondary" wastes which require another treatment, and may even cause a problem with transportation. Other problems exist in the method of decomposing waste resins with hydrogen peroxide using iron and copper ions as catalysts. First of all, the reaction rate is very slow (at least one to two hours is necessary to convert the waste resin to inorganic matter), and a reactor of large capacity is required. Secondly and because of this slow reaction rate, decomposition must be performed under fairly H.sub.2 O.sub.2 -rich conditions. Since the running cost of this method is essentially determined by the amount of hydrogen peroxide used, it is important both technically and economically to achieve decomposition with the least possible amount of hydrogen peroxide used. The prior art technology also has another problem that has to be solved before it can be employed in practical applications, viz., leakage of radioactivity from mechanical seals in the agitating and mixing apparatus used for achieving accelerated decomposition reaction. SUMMARY OF THE INVENTION An object, therefore, of the present invention is to provide a method by which a radioactive ion-exchange resin, and in particular, a radioactive anion-exchange resin, can be decomposed with hydrogen peroxide used as an oxidizing agent in the presence of iron and copper ions used as catalysts with high percent decomposition being achieved in a short period of treatment with low consumption of hydrogen peroxide and the production of organic sludge being held to minimum levels. Another object of the present invention is to provide an apparatus that can be used to implement the aforementioned method of decomposing a radioactive ion-exchange resin. The first object of the present invention can be attained by a method of oxidative decomposition of a radioactive ion-exchange resin, and, in particular, a radioactive anion-exchange resin with hydrogen peroxide used as an oxidizing agent in the presence of iron and copper ions used as catalysts, wherein the weight ratio of hydrogen peroxide to the ion-exchange resin, that is, the ratio of the net weight of hydrogen peroxide to the dry weight of the anion-exchange resin or a mixture thereof with a cation-exchange resin to be decomposed, is held to be no higher than 17 (i.e., 17/1) and (1) the pH of the reaction system is adjusted to be within the range of 0.5 to 6, or (2) citric acid ions are preliminarily adsorbed on the waste ion-exchange resin before it is subjected to decomposition treatment or citric acid coexists with the waste ion-exchange resin in the oxidatively decomposing system. The waste ion-exchange resin may be crushed before the addition of the oxidizing agent and the catalyst. The first object of the present invention is also attained in a manner by crushing the waste ion-exchange resin into fine particles when or before it is mixed with hydrogen peroxide and the decomposition catalysts. The waste ion-exchange resin may be one adsorbing citric acid ions.
	description	The present invention is generally related to apparatuses and methods for a cask that stores and/or transports spent nuclear fuel and, more particularly, is related to a cask that includes a modular fin and a modular neutron shield. The removal of spent nuclear fuel from nuclear power plants and the subsequent transport of the spent fuel to an away-from-reactor (AFR) facility for storage or for disposal is a consideration within the nuclear fuel cycle in the United States. As nuclear power plants reach maximum spent fuel pool capacity, the nuclear power plants are off-loading the longer-cooled fuel into storage. Existing storage campaigns could soon deplete the longer-cooled fuel and result in an ever-increasing supply of short cool-time fuel and high heat loads. Development of large, high-heat capacity storage and transport casks could support this future need of the nuclear industry. Two major issues, among others, drive the desire for a more thermally efficient packaging. First, a more thermally efficient package holds more fuel assemblies, e.g., the package has higher capacity. This feature makes both storage and transport packages very attractive. Reduction of materials, fabrication, operations, project oversight and/or storage area directly reduces the cost per fuel assembly of both fuel storage and transport. Secondly, current spent fuel pool inventories are trending toward short cool-time fuel. As the inventory of cooler fuel is reduced, the per-fuel-assembly thermal load could steadily increase. A high thermal capacity design could address the increasing heat loads for this short cool-time fuel inventory, facilitating dry spent fuel storage. A high thermal capacity cask might also address the needs of nuclear power plants to ship very hot fuel directly to a repository or AFR storage. This high thermal capacity cask could utilize an approach for a more efficient, more economical cooling configuration. Thus, a special need exists in the industry to address the evolving conditions of spent fuel storage and transport. Disclosed are apparatuses and methods for transporting or storing spent nuclear fuel. In one embodiment, among others, a transport or storage cask comprises a cask body, a modular thermal conducting and shielding system, and a mechanical attachment. The modular thermal conducting and shielding system includes a modular fin and a modular neutron shield. The modular fin is disposed between the modular neutron shield and the cask body. The modular fin is capable of dissipating thermal energy from the cask body. The modular neutron shield is capable of shielding radiation generated within the cask. The mechanical attachment retains the modular thermal conducting and shielding system to the cask body. In another embodiment, among others, a method of making a transport or storage cask comprises the steps of providing a cask body and attaching a mechanical attachment to the cask body. The method further comprises retaining a modular thermal conducting and shielding system on the cask body via the mechanical attachment. The modular thermal conducting and shielding system includes a modular fin and a modular neutron shield. The method further comprises disposing the modular fin between the modular neutron shield and the cask body. The modular fin is capable of dissipating thermal energy from the cask body. The modular neutron shield is capable of shielding radiation generated within the cask. In yet another embodiment, among others, a method for operating a transport or storage cask comprises the steps of loading fuel assemblies into a cask body of the cask. The fuel assemblies are capable of generating thermal energy. The method further comprises absorbing thermal energy by the cask body and dissipating thermal energy absorbed by the cask body via a modular fin that is retained on the cask body via a mechanical attachment. The modular fin is disposed on the outer surface of the cask body. The method further comprises shielding radiation generated from the fuel assemblies via a modular neutron shield that is retained on the cask body via the mechanical attachment. The modular neutron shield is disposed on top of the modular fin. One advantage, among others, of utilizing a modular thermal conducting and shielding system is that the modular fin and the modular neutron shield allow for a wider selection of thermally efficient materials, as well as variations in profiles and sizes of either the cooling fins or the modular neutron shield. Another advantage, among others, is the protection of the thermally sensitive modular neutron shield from the potentially damaging heat generated by the casks. Neutron shield materials used for storage and transport casks have temperature limits below which the neutron shield materials must function to reliably provide shielding performance. Temperatures in excess of these limits are one of the factors that restrict cask capacity or the heat content of the fuel to be stored or transported in casks. Disclosed are apparatuses and methods for a cask that stores and/or transports spent nuclear fuel. In one embodiment, the cask includes a modular thermal conducting and shielding system that includes a modular fin and a modular neutron shield. The cask further includes a mechanical attachment that retains the modular thermal conducting and shielding system to a cask body. The modular fin is disposed between the modular neutron shield and the cask body. The modular fin is capable of dissipating thermal energy from the cask body. The modular neutron shield is capable of shielding radiation generated within the cask. The embodiments within this disclosure could protect the modular neutron shield from the heat generated from the cask body by conducting the heat around the modular neutron shield and dissipating the heat to the ambient atmosphere. Exemplary apparatuses are first discussed with reference to the figures. Although the apparatuses are described in detail, the apparatuses are provided for purposes of illustration only and various modifications are feasible. After the exemplary apparatuses have been described, examples of methods of making and operating a cask are provided. Referring now in more detail to the figures in which like reference numerals identify corresponding parts, FIG. 1 is a perspective view of an embodiment of a cask that stores and/or transports nuclear spent fuel. The cask 1 includes a right cylindrical cask body 5. It should be understood that there may be other cross-sectional shapes for the cask body 5, e.g., square, rectangular, octagonal, triangular cask bodies, as well as a variety of lengths. The cask 1 further includes a modular thermal conducting and shielding system 3 that is retained to the cask body 5 by way of mechanical attachments 13. The modular thermal conducting and shielding system 3 may extend between the top and bottom of the cask 1. The modular thermal conducting and shielding system 3 includes a modular fin 15 and a modular neutron shield 17, which are described hereafter and illustrated in FIGS. 2-3. FIG. 2 is a partially cut-away, perspective view of an embodiment of the cask 1 shown in FIG. 1. Each mechanical attachment 13 includes a welded or threaded stud 7, washer 9 and nut 11. In the preferred embodiment, the stud 7 is welded onto the outer surface of the cask body 5. However, the stud 7 may also be threaded like a bolt for attachment to the cask body 5. An outer threaded portion 8 of the stud 7 extends away from the cask body 5 and is capable of engaging with a washer 9 and nut 11 to retain the modular thermal conducting and shielding system 3. The stud 7 should not be substantially thermally conducting because the application of the cask 1 may require that the thermal energy be conducted around the modular neutron shield 17 and not through it. There may be a temperature limitation on the modular neutron shield 17 in order to maintain the modular neutron shield 17 design life. In this particular embodiment, the modular neutron shield 17 has a shape of a trapezoid and the modular fin 15 has a shape of an elongated letter V. A base 27 of the modular fin 15 is capable of coupling to the cask body 5. Each arm 29, 31 of the modular fin 15 has a distal and a proximal end. The distal end of each arm 29, 31 extends away from the cask body 5, and the proximal end of each arm 29, 31 is integrally connected to the base 27 of the modular fin 15. Each distal end of the arms 29, 31 has slots 41 that enable air to flow through the slots 41 of the modular fin 15 to facilitate dissipation of thermal energy conducted from the cask body 5. The slots 41 are distributed along the modular fin 15 that extends between the top and bottom of the cask 1. The modular fin 15 is essentially an elongated V-shaped fin. The base 27 of the modular fin 15 further includes holes 21 that are located along the length of the base 27. The welded studs 7 pass through the holes 21 of the modular fin 15 as the modular fin 15 is placed on the cask body 5. The modular neutron shield 17 is an elongated trapezoid that conforms to the inner section of the modular fin 15. The modular neutron shield 17 extends along the elongated modular fin 15. The modular neutron shield 17 further includes holes 23 that are located along the length of the modular neutron shield 17. The modular neutron shield 17 is placed on the cask body 5 by passing the studs 7 through holes 23 of the modular neutron shield 17. In this particular embodiment, the modular thermal conducting and shielding system 3 can further include a conductive cover 19 in which the modular neutron shield 17 is disposed between the modular fin 15 and the conductive cover 19. The conductive cover 19 engages and conducts thermal energy from the modular fin 17. The conductive cover 19 includes a base 33, a first arm 35, and a second arm 37. The base 33 is capable of covering the modular neutron shield 17. Each of the first and second arms 35, 37 has a distal end and a proximal end. The distal end of each arm 35, 37 extends away from the cask body 5. The proximal end of each arm 35, 37 is integrally connected to the base 33 of the conductive cover 19. The distal end of each arm 35, 37 has slots 43 that are aligned with the slots 41 of the modular fin 15 to enable air to flow through the slots of the modular fin 15 and the conductive cover 19, which facilitates dissipation of thermal energy conducted from the cask body 5. The conductive cover 19 may extend between the top and bottom of the cask 1 and further includes holes 25 along the length of the conductive cover 19. The welded stud 7 passes through the holes 25 of the conductive cover 19 as the conductive cover is placed on the cask body 5. According to one embodiment, in order to retain the conductive cover 19, modular neutron shield 17, and modular fin 15 of the modular thermal conducting and shielding system 3, the washer 9 is placed through the stud 7 and on top of the conductive cover 19. The nut 11 is screwed onto the outer threaded portion 8 of the stud 7 and is disposed on top of the washer 11. FIG. 3 is a partially cut-away, cross-sectional, top view of an embodiment of the shield system for the cask 1 shown in FIG. 1 that includes a modular fin and modular neutron shield. Each modular neutron shield 17 is retained to the modular thermal conducting and shielding system 3 by way of the mechanical attachment 13. Each stud 7 of the mechanical attachment 13 is welded at weld 42 on the cask body 5. The modular thermal conducting and shielding system 3 further includes second modular neutron shields 45 that are retained to the cask body 5 by way of the V-shaped fins 15. Each second modular neutron shield 45 is placed between the V-shaped fins 15. The use of alternating trapezoidal neutron shields 45 provides a nested or keystone method of retaining the intermediate neutron shield 45 that is not retained by mechanical attachment 13. This embodiment utilizes a minimum number of mechanical attachments 13, thereby reducing fabrication and assembly costs. The mechanical attachment 13 may include, for example, but is not limited to, aluminum alloys, copper alloys, silver alloys, and/or any higher thermally conductive metal or alloys. Each of the modular neutron shields 17, 45 may be encapsulated by neutron-shield enclosures 39, 40, that protect the modular neutron shield 17 from exposure to some particular environment. According to one embodiment, it would be appreciated that the enclosures 39, 40 for the modular neutron shields 17, 45 are made of material that is capable of providing the necessary thermal protection in the event of a regulatory hypothetical accident condition. The modular neutron shields 17, 45 would remain intact and capable of performing the intended function. The enclosure 39 provides the necessary stiffness for the modular neutron shield 17 over the length of the cask 5 to insure intimate contact of the modular fin 15 to the cask body 5 when the mechanical attachment 13 is installed. The enclosure 40 provides the necessary stiffness for the second modular neutron shield 45 over the length of the cask 5 to insure intimate contact of the second modular neutron shield 45 to the cask body 5 when the modular fin 15 is installed. FIG. 4 is a partially cut-away, cross-sectional, top view of another embodiment of the modular thermal conducting and shielding system. The cask 46 includes modular thermal conducting and shielding systems 47 that include modular L-shaped fins 49 and modular square-shaped neutron shields 51. The modular thermal conducting and shielding systems 47 are retained to the cask 46 by way of the mechanical attachments 59. The modular thermal conducting and shielding systems 47 are sequentially aligned adjacent to each other along the outer surface of the cask body 48. In this embodiment, the modular neutron shields 51 are identical to each other, thereby simplifying the fabrication process by reducing the number of different parts to assemble the modular thermal conducting and shielding systems 47. Further, each modular fin 49 and each modular shield 51 are independently retained by one mechanical attachment 59. Each mechanical attachment 59 includes stud 62 connected at weld or bolt recess 62, washer 63 and nut 65. Each modular shield 51 is encapsulated by a square enclosure 53. Each modular fin 49 includes a base 57 that is integrally connected to an arm 55. The distal end of each arm 55 extends away from the cask body 48. The proximal end of each arm 55 is integrally connected to the base 57 of the modular fin 49. The distal end of each arm 55 may have slots (not shown) that enable air to flow through the slots of the modular fin to facilitate the dissipation of the thermal energy conducted from the cask body 48. FIG. 5 is a partially cut-away, cross-sectional, top view of an embodiment of yet another modular thermal conducting and shielding system. The cask 66 includes modular thermal conducting and shielding systems 67 that are similar to the modular thermal conducting and shielding systems shown in FIG. 3, which includes V-shaped modular fins 71, mechanical attachments 69, and trapezoidal shaped neutron shields 73, 75. Each mechanical attachment 69 includes a stud 77 that is attached at weld or bolt recess 82, washer 79, and nut 81. In addition, in this embodiment, the cask 66 further includes modular thermal extensions 83 that may extend between the top and bottom of the cask 66. Each thermal extension 83 includes an extended member 85 and an annular air gap 87. The thermal extensions 83 can conduct thermal energy from the cask body 64. Each extended member 85 includes holes (not shown) in which the stud 77 passes through, as the thermal extension 83 is disposed on the cask body 64. The extended members 85 are disposed between the V-shaped modular fin 71 and the cask body 64. The annular air gap 87 of the thermal extension 83 is disposed between the cask body 64 and the modular thermal conducting and shielding system 67 and also between the extended members 85. The annular air gap 87 enables convective heat flow through an annular region 89 of the annular air gap 87 that further facilitates dissipation of thermal energy from the cask body 64. The annular air gap 87 addresses the need for high heat load applications and enables air convection to occur. The air convection of the annular air gap 87, in conjunction with the heat dissipation of the modular fins 71, enables the cask to remove the high heat loads stored and transported using the cask 66. It should be appreciated from the different modular thermal conducting and shielding systems in FIGS. 3, 4, and 5 that the number and geometry of the thermal extensions, modular neutron shields and modular fins are determined based on each separate analysis and application of a cask. In this regard, the geometry of the modular fins and the modular neutron shields may include, but is not limited to, the shapes of the following: trapezoidal, rectangular, circular, square, etc. The geometry of the arms and bases of the modular fins may include, but is not limited to, the shapes of the following: rectangular plates, round tubes or posts, serrated or perforated plates, re-entrant forms, etc. FIG. 6 is a flow diagram that illustrates an embodiment of a method 90 for making a cask 1 using modular fins 15 and modular neutron shields 17. Referring now to block 91, the method 90 for making a transport or storage cask 1 includes providing a cask body 5. In block 93, a mechanical attachment 13 is attached to the cask body 5. The mechanical attachment 13 can include a welded stud or a bolt, or any other similar mechanical attachments. In block 95, the method 90 further includes retaining a modular thermal conducting and shielding system 3 on the cask body 5 via the mechanical attachment 13. The modular thermal conducting and shielding system 3 includes a modular fin 15 and a modular neutron shield 17. In block 97, the modular fin 15 is disposed between the modular neutron shield 17 and the cask body 5. In block 99, the modular neutron shield 17 is encapsulated with a neutron-shield enclosure 39 that protects the modular neutron shield 17 from exposure to any form of liquid or particular environments. In block 101, the modular neutron shield 17 is disposed between the modular fin 15 and a conductive cover 19. In block 103, the method 90 includes disposing a thermal extension 83 between the modular fin 15 and the cask body 5. The thermal extension 83 includes an annular air gap 87 having a convective air flow region 89. The thermal extension 83 is capable of conducting thermal energy from the cask body 5 enabling the dissipation of thermal energy from the cask body 5. FIG. 7 is a flow diagram that illustrates an embodiment of a method 110 for operating a cask 1 using modular fins 15 and modular neutron shields 17. Referring now to block 113, the method 110 for operating a transport or storage cask 1 includes loading fuel assemblies (not shown) into a cask body 5 of the cask 1. The fuel assemblies generate thermal energy, which is absorbed by the cask body 5 shown in block 115. In block 117, the method 110 further includes dissipating thermal energy absorbed by the cask body 5 via a modular fin 15, which is retained on the cask body 5 via a mechanical attachment 13. The modular fin 15 is disposed on the outer surface of the cask body 5. In block 119, the method 110 further includes shielding radiation generated from the fuel cell via a modular neutron shield 17, which is also retained on the cask body 5 via the mechanical attachment 13. The modular neutron shield 17 is disposed on top of modular fin 15. It should be emphasized that the above-described embodiments of the present invention, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.
052166996	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Currently, the method is proposed of securing selectively a microscopic image with high contrast, of the molecule of particular protein in a wavelength band excluding .lambda.=43.7.about.23.6 .ANG.. Referring now to FIGS. 4 to 8, prior to explaining the embodiments of the present invention, the principle of this method and the arrangement and function of the X-ray microscope according to the present invention will be described below. FIGS. 4 and 5 show the configuration and transition states of electrons where a carbon atom absorbs X rays. FIG. 4A shows the electron configuration of the carbon atom in the ground state, in which there are 2 electrons each (represented by reference symbol E in the figure) in the 1s, 2s, and 2p orbits. Assuming now that X rays are radiated thereto, the electron in the 1s orbit is excited by the X rays to ionize and the carbon atom leaves a hole in the 1s orbit (see FIG. 4B; which is hereinafter referred to as "a first transition"). Since this state is very unstable in view of energy (see FIG. 4C), however, the electron in the 2p orbit transfers to the 1s orbit to secure its stability (see FIG. 4D; which is hereinafter referred to as "a second transition"). Further, a hole has been produced in the 2p orbit (see FIG. 4E), so that if carbon is a constituent element of the molecule of, for example, protein, the carbon atom will capture an electron from a surrounding constituent element to resume an initial ground state (see FIG. 4F; which is hereinafter termed "a third transition"). In general, the observation for which the X-ray microscope is used, of the transmitted microscopic image of protein, is made by utilizing energy absorption due to the first transition in the irradiation of X rays. In this case, unless the wavelengths of X rays are shorter than the absorption edge of carbon, the X rays will not be absorbed by protein, with the result that the contrast of the transmitted microscopic image is deteriorated. Considering the preceding electron transitions from their inverse processes, however, it is noted that even though the wavelengths of X rays to be incident are longer than the absorption edge of carbon, the transmitted microscopic image can be observed with good contrast. Specifically, in the electron configuration of the carbon atom in the ground state shown in FIG. 5A, an electron of the 2p orbit in the ground state is first ionized so that a hole is produced in the 2p orbit (see FIG. 5B; which is the inverse process of the third transition). Then, in this state (see FIG. 5C), an electron in the 1s orbit is excited by X rays to the 2p orbit (see FIG. 5D; which is the inverse process of the second transition). This transition can be realized by photon energy lower than the absorption edge of carbon, that is, X rays of wavelengths longer than the absorption edge of carbon. The transition state (see FIG. 5D) is exactly the same as the state where the electron of the 1s orbit is directly ionized from the ground state in the first transition. In this technique, the energy required for ionizing the electron of the 2p orbit is approximately 5 eV (200 nm), and as a measure of ionization, for instance, an ultraviolet laser beam can be utilized. Further, the energy required for exciting the electron of the 1s orbit into the 2p orbit is nearly 10.about.20 eV lower than the case of the excitation by the first transition. FIG. 6 shows this situation, from which it is seen that the inverse process of the second transition requires somewhat low energy compared with ordinary ionization of the electron due to absorption, namely, the first transition. In the case of the carbon atom of protein, the absorption wavelength by the inverse process of the second transition is within the range of nearly 43.about.65 .ANG.. Thus, by a two-stage process that the electron of the 2p orbit of the carbon atom in the ground state is ionized and subsequently the electron of the 1s orbit is excited into the 2p orbit, the transmitted image of protein can be obtained even in the wavelengths longer than the absorption edge of carbon. The technique mentioned above was theoretically verified by J. H. Klems, regarding the following quantitative superiority (J. H. Klems, Phys. Rev., Vol. 43, 1991, pp. 2041.about.2045): (1) The use of X rays of wavelengths longer than the carbon absorption edge makes it possible to choose satisfactory materials, such as W (tungsten)/C (carbon), which are excellent in optical constant and easy of film fabrication, in fabricating the multilayer film mirror. PA0 (2) Since the energy required for ionizing the electron of the 2p orbit depends on the kind of protein, the carbon atom of particular protein can be selectively ionized by adjusting the wavelength of incidence of the ultraviolet laser beam, for instance. Further, the energy required for a successive electron transition from the 1s orbit to the 2p orbit is also determined uniquely. Hence, when X rays having the equivalent photon energy are taken as a probe, the transmitted microscopic image of particular protein can be observed. Additionally, the contrast of the transmitted microscopic image is enhanced more than one figure compared with the conventional method utilizing the wavelength band of .lambda.=43.7.about.23.6 .ANG. (see FIG. 6). The application of the foregoing principle to an X-ray microscope brings about a high-performance X-ray microscope. An ordinary X-ray microscope of prior art, as depicted in FIG. 7, comprises an X-ray radiation source 1, an X-ray condenser lens 2 for collecting radiation, a biological specimen 3 to be observed, an X-ray objective lens 4, a filter 5, and a detector 6. The objective lens 4 falls into two categories: a wave dispersion type such as the zone plate or the Schwarzschild optical system and a grazing incidence mirror type of collecting white light as in the Wolter optical system, but where a source of white light is used for the source 1 to employ the Wolter objective lens, there is a necessity for the disposition of a spectrometer on an optical path in front of the detector 6. An image sensor, such as an MCP (microchannel plate), a CCD, etc., is utilized for the detector 6, and when the source of white light is used for the source 1, a thin film filter made of, for example, Be (beryllium), is disposed for the filter 5 in order to cut stray light of long wavelengths from the ultraviolet region. FIG. 8 shows a basic conceptional view of the X-ray microscope according to the present invention in which the technique proposed by J. H. Klems is applied to the preceding arrangement. In FIG. 8, reference numeral 7 represents an ultraviolet light source outputting ultraviolet laser beams, 8 a condenser lens, and 9 an X-ray filter. Although its fundamental arrangement is the same as in FIG. 7, the X-ray microscope of the present invention is provided with the X-ray filter 9 between the biological specimen 3 and the X-ray objective lens 5. The X-ray filter 9, composed of a thin film made of, for example, Be, uses a thin film material chosen from substances and is formed so as to possess properties of producing high transmittance for the incident radiation in the wavelength band of 65.about.43.7 .ANG. and high reflectance for that in the ultraviolet region. In such an arrangement, if, in imaging the biological specimen 3, it is irradiated at the same time with X-rays having photon energy accommodating the inverse process of the second transition from the radiation source 1 and the ultraviolet laser beam adjusted to photon energy accommodating the inverse process of the third transition from the ultraviolet light source 7, it is possible to ionize only the carbon atom of particular protein, and the resultant is the transmitted microscopic image of the biological specimen 3 secured through the detector 6. Furthermore, since the X-ray filter 9 reflects the stray light of long wavelengths from the ultraviolet region which results in an image noise at the detector 6, the transmitted microscopic image can be observed as the image of high quality in which noise components are cut. In addition to this arrangement, if a measure is disposed for changing the intensity of the ultraviolet light with which the biological specimen is irradiated, thereby adjusting artificially the intensity of the ultraviolet light, it is possible to control easily the contrast of the transmitted microscopic image without any adjustment of the wavelengths of X rays for irradiation and the thickness of the biological specimen. Specifically, in the electron configuration after the irradiation of the ultraviolet light shown in FIG. 5D, the absorptance of X rays of the biological specimen is proportional to the number of carbon having holes in the 2p orbit, which is proportional to the intensity of the ultraviolet light with which the biological specimen has been irradiated. Making use of this property, the intensity of the ultraviolet light is adjusted, thereby enabling the absorptance of X rays of the biological specimen to be easily changed and the transmitted microscopic image having the optimum contrast to be secured. Further, if photographs are taken of the transmitted microscopic images of the biological specimens where the specimen is irradiated with the ultraviolet light from the ultraviolet light source and where it is not irradiated to prepare a differential image in which the difference in brightness between the transmitted microscopic images is extracted, it is possible to remove the background attributable to absorption due to elements other than carbon, with the resultant transmitted X-ray image of excellent contrast, of pure carbon only. Now, in reference to the drawings, the embodiments of the present invention will be described below. First embodiment FIG. 9 shows the first embodiment of the present invention, in which SOR (synchrotron radiation) is used as a radiation source and a Fresnel zone plate is utilized as an X-ray optical system. In the figure, reference numeral 11 denotes an SOR source; 12 a crystal spectrometer; 13 a specimen composed of, for example, protein; 14 a condenser zone plate; 15 an objective zone plate; 16 a detector consisting of an MCP; 17 an ultraviolet light source; 18 a condenser lens; and 19 an X-ray filter. The X-ray filter 19 is composed of a thin Be film of a thickness of approximately 300 .ANG. and disposed, at an angle of 45.degree. with the optical axis of the X-ray microscope, between the specimen 13 and the objective zone plate 15 so that an ultraviolet laser beam emitted from the ultraviolet light source 17 is reflected from the thin Be film to irradiate the back face of the specimen 13. The thin Be film, which has low transmittance for incident light of long wavelengths from the ultraviolet region, provides also blocking action for preventing the stray light causing an image noise from entering the detector 16. The first embodiment is constructed as mentioned above, so that in imaging the specimen 13, if it is irradiated at the same time with the radiation of photon energy accommodating the inverse process of the second transition from the radiation source 11 and the ultraviolet laser beam adjusted to photon energy accommodating the inverse process of the third transition from the ultraviolet light source 17, only the carbon atom of particular protein can be ionized and the stray light of noise components is cut by the X-ray filter 19, with the result that the transmitted microscopic image of the specimen 13 can be observed as the image of high quality through the detector 16. Second embodiment FIG. 10 shows the second embodiment of the present invention, which has the same arrangement as the first embodiment, except that a wedge filter 20 is disposed in the optical path of the ultraviolet light source 17. The wedge filter 20 is made of glass of high absorptance, for example, BK 7, in terms of ultraviolet light, and disposed in the optical path of the ultraviolet light source 17 to be movable perpendicular to the optical axis of the ultraviolet laser beam emitted from the light source 17 (the direction of movement is indicated by an arrow A in the figure). The second embodiment is constructed as mentioned above, so that if the wedge filter 20 is shifted to a proper position, the ultraviolet laser beam emitted from the ultraviolet light source 17, when passing through the wedge filter 20, will be changed in terms of the optical path length, thereby allowing the amount of the ultraviolet laser beam for irradiating the biological specimen 13 to be properly adjusted and the absorptance of X rays of the biological specimen 13 to be changed. Thus, if, in imaging the biological specimen 13, it is irradiated at the same time with the radiation of photon energy accommodating the inverse process of the second transition from the radiation source 11 and the ultraviolet laser beam adjusted to photon energy accommodating the inverse process of third transition from the ultraviolet light source 17 and controlled in amount of light by the wedge filter 20, only the carbon atom of particular protein can be ionized, which is detected by the detector 16, and thereby the transmitted microscopic image of the biological specimen 13 can be derived with good contrast. Moreover, since the stray light of noise components is cut by the X-ray filter 19, the observation of the transmitted microscopic image of high quality, having little noise, can be realized. Third embodiment FIG. 11 shows the third embodiment of the present invention which uses a laser beam source for converging a YAG laser beam to a target to change the irradiated part of the target into a plasma and outputting X rays therefrom, as a radiation source, and utilizes the Wolter mirror as the X-ray condenser lens and the Schwarzschild optical system as the X-ray objective lens. In this figure, reference numeral 21 represents a laser beam source; 22 a laser target on which the YAG laser beam from the laser beam source 21 is incident, for outputting X rays; 23 an X-ray condenser lens for the Wolter mirror; 24 a biological specimen; 25 an X-ray objective lens for the Schwarzschild optical system; 26 a KDP crystal; 27 a detector utilizing the MCP; 28 a half mirror for splitting the YAG laser beam output from the laser beam source 21; 29 a mirror; 30 an x-ray filter; and 31 and 32 condenser lenses. The function of the third embodiment, although fundamentally identical with that of the first embodiment, in such that a part of the laser beam output from the laser beam source 21 is split by the half mirror 28 in order to produce X rays at the target 22, higher harmonics four times those of the ultraviolet region are produced from the other of the split laser beam by the KDP crystal 26, and the biological specimen 24 is irradiated with the higher harmonics as photon energy accommodating the inverse process of the third transition through the X-ray filter 30, thus doing away with the need for the ultraviolet light source for outputting the ultraviolet laser beam. Also, for the multilayer film mirror used in the Schwarzschild optical system of the X-ray objective lens 25, the one composed of W/C is excellent, and in the case of the normal incidence of the laser beam having the wavelength of 45 .ANG., the reflectance of nearly 30% can be derived if the number of layers to be built up is 200. Fourth embodiment FIG. 12 shows the fourth embodiment of the present invention, which in addition to the arrangement of the third embodiment, provides a polarizer 33 rotated, in the direction indicated by an arrow B in the figure, through a polarizer driving circuit 51 which will be described later. By rotating the polarizer 33 about the optical axis of the laser beam incident on the KPD crystal 26, the amount of the ultraviolet light with which the biological specimen 24 is irradiated can be adjusted. FIG. 13 is a circuit block diagram of an image signal processing system in the fourth embodiment. In this figure, reference numeral 41 designates a TV camera for photographing, through a variable magnification lens 43, the transmitted microscopic image visualized through the detector 27 and a phosphor 42; 44 and 45 A/D converting boards for converting analog image signals Vd output from the TV camera 41 into digital signals; 46 and 47 frame memories for storing temporarily the image signals converted into the digital signals in the A/D converting boards 44 and 45, respectively; and 48 a differential circuit for calculating the difference in brightness between the pixel elements of an image signal Fa stored into the frame memory 46 and an image signal Fb into the frame memory 47 to prepare a differential image signal (Fa-Fb). Reference numeral 49 represents a host computer in which the Q-switching control of the laser beam source 21 is made by the output of a control signal Qs to determine the emission timing of the laser beam and in synchronization with this, trigger signals are output to the TV camera and the frame memories 46 and 47 for detection and photography of the transmitted microscopic image and processing the image signal, and 50 demotes a data selector having a counter therein, for counting the control signal Qs output from the host computer 49 so that when the counted value is odd, a trigger signal Ta is output to the frame memory 46, while when it is even, a trigger signal Tb is output to the frame memory 47. The frame memories 46 and 47 are designed so that the output signals from the A/D converting boards 44 and 45 are stored into the memories, respectively, according to the input timing of the trigger signals Ta and Tb. Reference numeral 51 designates a polarizer driving circuit for outputting a polarizer driving signal Sr to the polarizer 33 in virtue of a control signal Pr output from the host computer 49, and 52 represents a CRT for displaying the differential image signal (Fa-Fb) analog-converted in the host computer 49. Next, reference is made to the function of the above system. First of all, adjustment is made of the amount of ultraviolet light with which the biological specimen 24 is irradiated. The control signal Pr is output to the polarizer driving circuit 51 from the host computer 49 and the polarizer driving signal Sr to the polarizer 33 from the polarizer driving circuit 51 to rotate the polarizer 33 to an adequate angle, and the amount of ultraviolet light is adjusted so that the transmitted microscopic image can be photographed with favorable contrast. After that, the control signal Qs is output form the host computer 49, the Q-switching control of the laser beam source 21 is made to output a laser pulse from the laser beam source 21, and X rays are produced from the target 22. At the same time, the trigger signals are delivered to the TV camera 41 and the frame memory 46, the transmitted microscopic image of carbon of the biological specimen 24 is photographed, and the digitized image signal is stored into the frame memory 46. Next, the rotation angle of the polarizer 33 is controlled so that the biological specimen 24 now is not entirely subjected to the irradiation of the ultraviolet light. Similar to the foregoing, the control signal Qs is output from the host computer 49 to produce X rays from the target 22 and in synchronization with this, the trigger signals are supplied to the TV camera 41 and the frame memory 47, followed by photography of the transmitted microscopic image in terms of elements, excluding carbon, of the biological specimen 24 and storing of the digitized image signal into the frame memory 47. Here, the transmitted microscopic image of the elements, excluding carbon, stored as the image signal Fb into the frame memory 47 is a background signal opposite to the transmitted microscopic image of carbon stored as the image signal Fa into the frame memory 46. Hence, if, in the differential circuit 48, calculations are preformed of the difference in brightness between the pixel elements of the image signal Fa stored into the frame memory 46 and the image signal Fb into the frame memory 47 so that the differential image signal (Fa-Fb) is prepared and taken into the host computer 49 for conversion into the analog image signal which is displayed on the next CRT 52, it is possible to observe the transmitted microscopic image of pure carbon only, which is free from the background attributable to absorption due to elements other than carbon, with good contrast. Also, although the fourth embodiment is constructed so that, in view of the speed response of signal processing, the image signals are processed through a hardware differential circuit, it may well be such that the host computer directly reads out the image signals, which are processed by software. Further, although each embodiment is designed so that the X-ray filter is disposed between the specimen and the X-ray objective lens, the disposition of the X-ray filter is not necessarily be limited to this position and it is only necessary to dispose it at the best position suitable for the design of the system, according to materials of optical elements to be used. Finally, a description will be made of a specimen vessel applicable to the microscope system of the present invention. In the X-ray microscope system, it is an important subject that a soft X-ray microscopic image of the biological specimen is formed without exposing directly the specimen in a vacuum. Specifically, since soft X rays undergo considerable attenuation in air and cannot be transmitted over a long distance, there was the necessity of incorporating the entire system of the microscope in a vacuum vessel. As a result, the biological specimen had to be dried and could be observed only in vitro. Recently, an attempt is made to encapsulate the biological specimen in a pellet composed of a thin Si.sub.3 N.sub.4 (silicon nitride) film developing mechanical strength to conserve the biological specimen in vivo even in a vacuum. With the wavelength band of .lambda.=approximately 40 .ANG. which arouses biologically interest, however, the transmittance of soft X rays regarding the thin Si.sub.3 N.sub.4 film is so low that it has no appreciable practical use. The specimen vessel mentioned above, which is suitable for the imaging system of the soft X-ray microscopic image including ultraviolet irradiation, has sufficient mechanical strength, can intercept a normal pressure space from a vacuum space, and provides complete transmittance in the wavelength band of .lambda.=65.about.43.7 .ANG., in which at least an entrance window and an exit window are provided, the biological specimen to be observed is incorporated in the vessel, and the entrance and exit windows are each composed of a thin diamond film. The specimen vessel for X-ray microscopes according to the present invention utilizes the property of the thin diamond film which has recently come to be fabricated, for example, by a CVD technique (chemical vapor deposition technique). Compared with thin films fabricated from silicon-based materials, such as Si, SiC, and Si.sub.3 N.sub.4, the features of the thin diamond film are that it is homogeneous and withstands breaking stress. Further, in comparison with these thin silicon-based films, the thin diamond film has extremely high transmittance in the wavelength band of .lambda.=43.7 .ANG. or more. For the thin diamond film and the thin Si.sub.3 N.sub.4 film, 1.mu. thick each, it is found that the transmittance of the thin diamond film is 56%, while that of the thin Si.sub.3 N.sub.4 film amounts to no more than 0.1%, when the transmittance of soft X rays having .lambda.=44.7 .ANG. is calculated from the equation: EQU T=exp[-4 .pi..kappa./.lambda.] where T is the transmittance, .kappa. is the imaginary part of the complex index of refraction, and .lambda. is the wavelength of a soft X ray. From the fact that a band gap Eg of the diamond is 5.5 eV [about 200 nm (2000 .ANG.) in terms of a wavelength], when protein is irradiated with ultraviolet light of .lambda.=300.about.250 nm (3000.about.2500 .ANG.) to photograph the soft X-ray microscopic image in amino acids, such as phenylalanine, tryptophan, and tyrosine, the excitation of the thin diamond film does not occur because the wavelength of the ultraviolet light is longer than that corresponding to the band gap Eg of the diamond, with the result that the ultraviolet light of .lambda.=300.about.250 nm (3000.about.2500 .ANG.) is favorably transmitted through the thin diamond film. Thus, for the soft X-ray microscope for forming the soft X-ray microscopic image of the biological specimen by means of soft X rays with the wavelength of .lambda.=65.about.43.7 .ANG., including the ultraviolet irradiation, the use of the thin diamond film makes it possible to provide an idealized biological specimen vessel in which its mechanical strength is sufficient and the transmittance of soft X rays is also high. Fifth embodiment FIG. 14 shows a sectional view of a specimen vessel for soft X-ray microscopes which is the fifth embodiment of the present invention. A specimen vessel 60 of this embodiment is constructed from two sets of structures A and B configured symmetrically by providing thin diamond films 62 on supporting substrates 61 whose materials are Si (silicon), in which the portions of the thin diamond films 62 function as an entrance window 63 and an exit window 63 and are shaped into a capsule form as a whole. The method of fabricating the specimen vessel is outlined as follows: The structures A and B are made in such a way that Si wafers are coated with the thin diamond films through the CVD technique and then an anisotropic etching process is applied to remove Si only. The two sets of structures A and B thus constructed, after a biological specimen 73 is contained therein, along with a physiological saline solution 64, are bonded with an Si-based adhesive at a contact surface 65. It is only necessary to dispose the specimen vessel 60 of the capsule form at the position of an object point in the vacuum chamber of the soft X-ray microscope. Next, reference is made of the arrangement of the X-ray microscope using the specimen vessel. The X-ray microscope is designed to have a biological specimen incorporated in a specimen vessel, a light source for emitting ultraviolet light liberating the outermost cell electrons of a carbon atom contained in the specimen from the carbon atom, a radiation source for emitting X rays containing a wavelength of 65.about.43.7 .ANG., an objective lens for converging the X rays transmitted through the specimen, and a detector for sensing the X rays converged by the objective lens, in which the specimen is irradiated with the ultraviolet light and the X rays at once to secure a specimen image, and an entrance window of the specimen vessel on which the ultraviolet light and the X rays are incident and an exit window of the specimen vessel from which the X rays emerge are made of thin diamond films. Sixth embodiment FIG. 15 shows the sixth embodiment of the present invention, with the arrangement of the soft X-ray microscope using the specimen vessel. The soft X-ray microscope is equipped with two chambers of a chamber C1 disposed on the condenser side and a chamber C2 on the objective side, each of which is in a vacuum state, sandwiching the specimen vessel 60 therebetween. The chamber C1 on the condenser side houses an X-ray radiation source 71 and a condenser lens (totally reflecting mirror type) 72, while the chamber C2 on the objective side a Schwarzschild objective lens 74, a detector (CCD) 76, and an X-ray filter 79 also used as a mirror for ultraviolet irradiation (thin Be film). The condenser lens (totally reflecting mirror type) 72 utilizes total reflection like the Wolter type mirror. Further, an ultraviolet optical system 80 is disposed which is provided with a radiation beam perpendicular to that of the chamber C2 on the objective side and includes an ultraviolet light source 77 for outputting an ultraviolet laser beam and a condenser lens 78. On the side face of the chamber C2 is disposed an ultraviolet entrance window 81 opposite to the mirror 79. The specimen vessel 60 is exaggerated in the figure, compared with other components. The specimen vessel 60 situated between the chambers C1 and C2 is constructed as follows: The end portions at which the chambers C1 and C2 are opposite to each other correspond to the optical windows 63 formed of the thin diamond films and the chambers C1 and C2 are each held in a vacuum state. These two optical windows 63 provide an extremely narrow space of a few .mu. between the thin diamond films, and the wet biological specimen 73 is enclosed in the space, with an additional hermetical measure, if necessary. For the purpose of replacing the biological specimen 73 with another, the mechanism, although not shown, is provided such that the relative positions of the chambers C1 and C2 can be adjusted. Hence, the X-ray microscope of the present invention has the advantage that the replacement of the biological specimen 73 is possible in the atmosphere, without opening the chambers C1 and C2 in vacuum states. In the sixth embodiment shown in FIG. 15, the ultraviolet laser beam emitted from the ultraviolet light source 77 traverses the condenser lens 78 and, through the mirror 79, is transmitted by the optical window 63 which is the entrance window of the specimen vessel 60, at the end portion of the chamber C2, to irradiate the biological specimen 73. Consequently, only the carbon atom of particular protein contained in the biological specimen 73 is ionized by the ultraviolet laser beam. On the other hand, X rays emitted as a probe from the X-ray radiation source 71 pass through the condenser lens (totally reflecting mirror type) 72 and are transmitted through the optical window 63 which is the entrance window of the specimen vessel 60, at the end portion of the chamber C1, to irradiate the biological specimen 73. Subsequently, the X rays leave the optical window 63 of the chamber C2 as the exit window of the specimen vessel 60 and, through the X-ray filter 79 and the Schwarzschild objective lens 74, reach the detector (CCD) 76. The transmitted microscopic image of the biological specimen 73 can thus be observed as the image of high quality through the detector (CCD) 76.
	description	This application claims priority of German application No. 10 2005 028 216.4 filed Jun. 17, 2005, which is incorporated by reference herein in its entirety. The invention relates to a device for computer tomography with: a radiation source for x-raying an object to be examined from various projection directions, a detector for detecting the radiation from the radiation source and an evaluation unit downstream of the detector that corrects, with respect to radiation hardening, the projection images, taken by the detector, of an object to be investigated.The invention also relates to a method for computer tomography. A computer tomographic device and a method for correcting the radiation hardening is known from DE 100 51 462 A1. The known device has an x-ray source and an x-ray detector that together rotate around an object to be examined. The projection images taken by the x-ray detector are applied to an evaluation unit that corrects the radiation hardening. To do this the evaluation unit performs a post-reconstructive correction procedure. As part of the post-reconstructive correction procedure, the evaluation unit first reconstructs approximate volumetric images from the object to be examined from the uncorrected projection images. The term volumetric image in this case, and in the following, means both three-dimensional volumetric views and two-dimensional section images. A reprojection is then performed, with only those pixels being used in the volumetric image whose the image value is above a specified threshold value and that are interpreted as materials to be distinguished from soft tissue. These materials can, for example, be bones or a contrast medium. The limitation to specific pixels enables the computing expense for the reprojection to be reduced. With conventional computer tomography, a constant voltage is used for all projection directions, except for small fluctuations due to the generator for the tube voltage. The tube voltage is in this case preferably chosen so that the radiation dose received by the detector is adequate for all projection directions and object thicknesses. If the object to be examined is a patient, the patient under certain circumstances is exposed to a dose of radiation that is greater than would be necessary to take the particular projection image. Devices and methods have therefore been developed to reduce as far as possible the radiation dose to which the patient is exposed. A device and a method of this kind are, for example, known from U.S. Pat. No. 6,222,907 B1. With the known device and known method, the parameters of the x-ray tube are controlled corresponding to the beam path through the object being examined. The application areas for the known device and known method are radiography and fluoroscopy. In recent times, the C-arch device for rotational angiography has been continuously improved. In particular, the mechanical stability of the C-arch has been increased, thus enabling approximate rotation about an isocenter. Together with the use of area detectors with an increased dynamic compared with x-ray image amplifiers, this enables a computer tomography volumetric reconstruction. Starting from this prior art, the object of the invention is to provide a device for computer tomography with an optimized radiation dose and good image quality. The object of the invention is also to provide a method for the reconstruction of volumetric images from projection images. These objects are achieved by a device and a method with the features of the independent claims. Advantageous embodiments and developments are given in associated dependent claims. The device is especially characterized in that the radiation source used transmits radiation with different energy distributions in various projection directions depending on the absorption characteristics of the object to be examined, by adapting at least one operating parameter. The evaluation unit supplied with the value used at a specific projection direction reads, from a data memory, a correction value allocated to the value of the operating parameter and thus corrects the radiation hardening on the relevant projection image. Accordingly, for a method for reconstructing volumetric images, an evaluation unit is supplied with at least one operating parameter together with projection image data, that is characteristic of the energy distribution of the radiation used to take the projection images. Furthermore, correction values for radiation correction relative to the value of the operating parameters, stored in a data memory, are read by the evaluation unit and the projection images are thus corrected with respect to radiation hardening. Because the operating parameters of the radiation source determine the energy of the emitted radiation, the energy distribution of the radiation transmitted by the radiation source at known operating parameters is also known. It is thus possible to determine in advance the correction values for various values of the operating parameter, with which the radiation hardening can be corrected. The radiation hardening can thus be corrected in real time even with large amounts of data. With a preferred form of embodiment, the radiation source is an x-ray source and the operating parameter the tube voltage of the x-ray source. Then, by means of the value of the tube voltage, the energy distribution, for a known material composition of the anode, of the x-ray photons emitted from the anode is known. With a further preferred form of embodiment, the evaluation unit performs what is called a water correction in that the evaluation unit determines, at a specific image value, a correction value stored in a data memory and relative to both the image value and the tube voltage. In this case it assumed for simplification that the attenuation of the radiation is caused by water-equivalent material. Furthermore, the evaluation unit can also perform a post-reconstructive correction for radiation hardening relative to the tube voltage. To do so, the evaluation unit generates a three-dimensional object model, differentiated according to absorption characteristics, and allocates to the image values object data records derived in each case from the object model. Furthermore, the evaluation unit reads out from a data memory the correction values allocated to the object data records and the tube voltage, and thus performs the correction of the radiation hardening. To reduce the computing expense, the evaluation unit preferably performs the correction of the radiation hardening with a spatial resolution that is less that the spatial resolution of the projection images. This is generally sufficient because the artifacts in the reconstructed volumetric images induced by the radiation hardening generally have low spatial frequencies. FIG. 1 shows a perspective view of an x-ray system 1 that can be used for rotational angiograph y. The x-ray system 1 enables the computer-tomographic volumetric reconstruction of the inner structure of a patient 2. The x-ray system 1 includes an x-ray tube 3 and a detector 4, that detects the x-ray radiation transmitted from the x-ray tube 3. On the way to the detector 4 the x-ray radiation passes through the patient 2 so that the detector 4 takes projection images of the patient 2. The detector 4 is preferably a digital area detector. The x-ray tube 3 and detector 4 are mounted on a C-arch 5 that is secured by a mounting 6. The C-arch 5 is supported in the mounting 6 in such a way that it can move in a circumferential direction 7. The mounting 6 is fitted to a stand 8 so that it can rotate about a rotary axis 9. The stand 8 is secured to a floor mounting 10 that enables the stand 8 to move. When the x-ray system 1 is operating, the C-arch 5 rotates about the rotary axis 9 and thus passes around a patient couch 11, on which the patient 2 is supported. The detector 4 is connected to an evaluation unit 12 that calculates a volumetric image of the inner structure of the patient 2 from the projection images taken by the detector. The volumetric image can, for example, be displayed on a monitor 13. Connected to the evaluation unit 12 are mainly input devices 14 by means of which the x-ray system 1 can be controlled. In the case of conventional devices for high-speed computer tomography, the x-ray detector and the x-ray radiation source rotate around the object to be examined at high speed in a fixed frame. Compared with this, the x-ray tube 3 and detector 4 on the x-ray system 1 move relatively slowly. Control of the tube voltage U matched to the dimensions of the object to be examined therefore appears relatively easy to accomplish. FIG. 2 shows a voltage curve 15 of the typical pattern of the tube voltage U for a rotational angiograph image of the heart. In this case, the C-arch 5 is, for example, moving over an angular range of 200 degrees from the left anterior oblique position 100 to the right anterior oblique position 100. During the movement of the C-arch 5, 200 projection images are, for example, taken. To be able to compensate for the different attenuation at different projection angles φ the parameters of the tube voltage, x-ray pulse width and tube current are dynamically matched during the rotation of the C-arch 5. For thorax rotational images, the tube voltage U can vary completely in the range between approximately 70 kV for anterior posterior radiation and 125 kV for lateral imaging through the shoulder area. Voltage-Dependent Radiation Hardening The radiation of x-ray tube 3 is also polychromatic. The energy spectrum of the photons emitted as braking radiation at the anode depends mainly on the applied tube voltage U, with which the electrons can be accelerated from the cathode to the anode. At a tube voltage U, it is usually a high voltage in the kV range. The maximum photon energy is thenEmax(U)=U(keV/kV)=eU,with kilo electron volts (keV) usually being used as the unit of energy. Some typical emission spectra QU(E) for various voltages are shown in FIG. 3, in the emission spectra 16, 17 and 18 the pattern of the emission spectrum QU(E) in each case is shown at a tube voltage of 60 kV, 90 kV and 120 kV. It should be noted that the anode of the x-ray tube 3 is manufactured of tungsten and the radiation emitted from the anode is internally filtered through a 2.5 mm thick wall of aluminum. However, the emission spectrum alone does not determine the imaging, but also the transparency of the spectral filters usedW(E)=exp(−μ(E)T)with energy-dependent attenuation coefficient μ(E) and thickness T The spectral response sensitivity ηD(E) of the detector is also determinant for the imaging. The resulting effective standard spectral distributions SU(E) are therefore defined by:SU(E)=QU(E)W(E)ηD(E)/cU (#1)with the standard factor: c U = ∫ 0 eU ⁢ Q U ⁡ ( E ) ⁢ W ⁡ ( E ) ⁢ η D ⁡ ( E ) ⁢ ⁢ ⅆ E , ⇒ ∫ 0 eU ⁢ S U ⁡ ( E ) ⁢ ⁢ ⅆ E = 1. Examples of effective spectral distributions SU(E) are shown in FIG. 4, where various resulting spectral distributions SU(E) that originate from emission spectra 16 to 18 when considering additional filters and the detector response sensitivity of the detector 4 are recorded. In particular, the emission spectra 16, 17 and 18 each lead to spectral distribution 19, 20 and 21. For the case shown in FIG. 4, a filter of copper 0.3 mm thick was used and the detector was a CsI scintillator detector 0.55 mm thick with a density of 3.6 grams per cubic cm. Furthermore, during the penetration through matter the number of low-energy photons is reduced more severely by absorption or scatter than the number of high-energy photons, which leads to a radiation hardening depending on the material and path length. For example, the dominance of photons of higher energies in the resulting spectral distribution SUR(E) can be seen in FIG. 5. In FIG. 5, the resulting spectral distributions 22, 23 and 24 originating from the resulting spectral distributions 19, 20 and 21 during the passage through 20 cm of water are shown. A comparison with FIG. 4 clearly shows that the resulting spectral distributions 19, 20 and 21 from FIG. 4 have been attenuated at the low-energy end when passing through 20 cm of water. This phenomenon of radiation hardening occurs with objects made of homogenous material. With a cylindrical cross-section of water, for example, with a radiation passage transverse to the longitudinal axis the radiation hardening at the edge is less than in the area of the center of the cylinder where the radiation has to cover a long path through the cylinder. However, the theory of reconstruction of volumetric images presumes monochromatic radiation. Ignoring polychromacity leads, for example, to something called the cupping effect after the reconstruction, i.e. the reconstructed attenuation coefficient (gray value) reduces continuously from the edge inwards. This effect can be relatively easily corrected for materials of a lower atomic number, that are similar to water, such as soft tissue, fat and many plastics. The expression water correction or first order hardening correction is used. Furthermore, the radiation hardening is intensified by the presence of materials with high atomic numbers, particularly by bones, contrast media or metal implants. Local density distortions occur after the reconstruction even after water correction, particularly bar or shadow-type artifacts, for example between heavily absorbent bone structures. Such second order hardening artifacts 2 can reach an intensity of 10 to approx 100 HU (Hounsfield unit, corresponding to 0.1 percent of the attenuation coefficient of water). The cause is ultimately the energy dependency of the attenuation coefficients for materials with a higher atomic number that deviates strongly from water. The correction of this effect is referred to in the following as second order hardening correction. The dependency of the attenuation coefficient on the photon energy is shown in FIGS. 6 and 7 for various materials. FIG. 6 shows the dependence of the linear attenuation coefficient μ on the photon energy, whereas FIG. 7 shows the dependency of the mass attenuation coefficient μ/ρ. An attenuation curve 25 represents the attenuation through bony tissue. The attenuation curve 25 for bony tissue is distinctly above an attenuation curve 26 for soft tissue, above an attenuation curve 27 for fatty tissue, an attenuation curve 28 for Plexiglas and an attenuation curve 29 for water. What is striking in FIG. 6 is that the attenuation curve 26 for soft tissue is almost exactly the same as the attenuation curve 29 for water. The mass attenuation coefficient shown in FIG. 7 shows that the differences between bony tissue on the one hand and soft tissue, fatty tissue and water on the other is even more distinct. In this case, the attenuation curve 25 for bone is clearly raised above the other attenuation curves 26 to 29, that lie comparatively close together. Multispectral Water Correction: Preconstructive First Order Radiation Hardening Correction For simplicity, when considering water correction or first order hardening correction the attenuation of an x-ray photon beam in the object to be examined, that is usually a patient 2, is caused solely by water-equivalent material. In this case water equivalence means that it is assumed that the energy dependency of the mass attenuation coefficient (μ/ρ)(E) is identical to water and differences are due only to local differences in density. Accordingly, muscle tissue, blood or also bony tissue is treated as water with a higher density (ρ>1 g/cm3)) We now consider a measuring beam that penetrates the object to be examined. Let the coordinate along its path be x and the local (linear) energy-dependent attenuation co-efficientμ(x,E)=ρ(x)α)(x,E),with the mass attenuation coefficient being shortened with α:α(x,E)=μ(x,E)/ρ(x). The polychromatic logarithmic CT projection value for the measuring beam under consideration is then p ~ = - log ⁡ ( ∫ 0 eU ⁢ exp ⁡ ( - ∫ μ ⁡ ( x , E ) ⁢ ⅆ x ) ⁢ S U ⁢ ⁢ ⅆ E ) = - log ⁡ ( ∫ 0 eU ⁢ exp ⁡ ( - ∫ ρ ⁡ ( x ) ⁢ α ⁢ ⁢ ( x , E ) ⁢ ⅆ x ) ⁢ S U ⁢ ⁢ ⅆ E ) ( #2 ) with the measuring beam belonging to a projection number j, recorded at a tube voltage U=Uj. For this purpose, an equivalent water density bU=bU({tilde over (p)}) is determined in the following manner: let αW(E) be the energy-dependent mass attenuation coefficient of water, then the polychromatic logarithmic projection value for a measuring beam with a voltage-dependent spectral distribution SU(E), that is attenuated along a path length (coverage density) b in water (ρ=1 g/cm3) is determined as: f U ⁡ ( b ) = - log ⁡ ( ∫ 0 eU ⁢ exp ⁡ ( - b ⁢ ⁢ α W ⁡ ( E ) ) ⁢ S U ⁢ ⁢ ⅆ E ) ( #3 ) This function can be calculated in advance for every voltage U or also experimentally determined. In FIG. 8, the functions fU are shown as projection value curves 30 and 31 for the tube voltage relative to various voltage values. The projection value curve 30 shows the relationship between the polychromatic logarithmic projection value {tilde over (p)} depending on the path length b at a tube voltage of 70 kV, and a projection value curve 31 shows the relationship between the polychromatic logarithmic projection value {tilde over (p)} and the path length b at a tube voltage of 100 kV. The projection value curves 30 and 31 rise monotonously with b and can be inverted. This preferably takes place numerically, for example by means of an inverse interpolation. For each measured value {tilde over (p)} in accordance with equation (#2) an equivalent water density bU=bU({tilde over (p)})=b can be determined so that {tilde over (p)}=fU(b) applies in accordance with equation (#3), i.e. by inversion of equation (#3):bU=fU−1({tilde over (p)}) (#4)with bU it is then possible to convert to the corresponding projection value, that ideally would have been measured at a monochromatic spectrum with photons with only a single reference energy E0. With bU according to equation (#4) the corrected water-equivalent monochromatic logarithmic project value resultspkorr(0)=αW(E0)bU=αW(E0)fU−1({tilde over (p)})=FU({tilde over (p)}) #5) In FIG. 8 a projection value curve 32 represents the pattern of the equivalent monochromatic logarithmic projection value pkorr(0) at a photon energy E0 of 40 kV. The water correction can be illustrated using FIG. 8. With the measured projection value {tilde over (p)}, the associated bU is sought using the projection value curve 30 or 31 matching the tube voltage. With the value for bU, the corrected monochromatic projection pkorr(0) can then be sought by using the projection value curve 32. It should be noted that in fact the conversion {tilde over (p)}→pkorr(0) depends on the voltage U. With the homogenous material, water, and the fixed specified path b, a constant path length bU=b is, however, obtained from the inversion of the equation (#4) and a constant monochromatic projection value pkorr(0) from the equation (#5), that in each case is independent of U. It should also be noted that the right-hand sides of equations (#2) and (#3) are identical if the measuring beam penetrates a thickness b in water. Then in the equation (#2) we get b=∫ρ(x)dx and α(x,E)=αW(E) Multispectral, Material-Selective Post-Reconstructive Hardening Correction: Second Order Hardening Correction Following the illustration of the first order hardening correction, that is used directly on the projection data, a description of a multispectral, material-selective, second order hardening correction is now described using FIG. 9. The second order hardening correction is based on an iterative post-reconstructive correction approach, whereby the physical process of the spectral hardening is remodeled using an already reconstructed, but not yet adequately corrected, volumetric image 33. A material-selective segmentation is applied to the existing volumetric image 33, which is usually a three-dimensional volumetric dimension image 33, by means of threshold criteria. FIG. 9 shows the segmentation of the volumetric image 33. For simplicity, FIG. 4 shows only the cross-section through the three-dimensional volumetric image 33. The volumetric image 33 contains structure data of a patient 2, the outer contours of whom are shown by an ellipse in FIG. 9. Within the patient 2 is, in addition to soft tissue 34, also bony tissue 35. Furthermore, vessels filled with contrast media or metal implants can also be present. The volumetric image 33 is made up of individual volumetric elements 36, known as voxels. The individual voxels are allocated to the categories soft tissue 34 or bony tissue 35 and to other categories as appropriate, depending on the gray values. The volumetric image 33 is then projected on pixel 37 of the detector 4. In doing so, the mass coverage in grams per square centimeter for the soft tissue 34 and bony tissue 35 along a measuring beam 38 allocated to the particular pixel 37 is determined. From the reprojection after the segmentation we then get, for each individual measuring beam 38, a value tuple for the coverage thickness with a densitypath length unit in g/cm2 of the various segmented material along the measuring beam 38 through the object volume. The following explanations are, without restricting the generality, limited for simplicity to two materials with coverage thicknesses bW and bk. By access to tables, generally followed by interpolation, a correction factor is then allocated to the value pair (bW, bK) for conversion of polychromatic projection data, disturbed by the hardening effect, into monochromatic projection data. The multiparameter correction Table C, that is broken down into fine discreet steps relative to bW and bK and still depends on the tube voltage U, can then be calculated in advance as follows before taking an image using the x-ray system 1, or if necessary also determined by measurements or adapted:CU(bW,bK)=g(0)(bW,bK,E0)/gU(bW,bK,) (#6) In this case, g(0) and gU are the logarithmic mono- and polychromatic projection values, defined by g ( 0 ) ⁡ ( b W , b K , E 0 ) = b W ⁢ α W ⁡ ( E 0 ) + b K ⁢ α K ⁡ ( E 0 ) ( #7 ) g U ⁡ ( b W , b K ) = ⁢ - log ⁢ ( ∫ 0 eU ⁢ exp ⁡ ( - b W ⁢ α W ⁡ ( E ) - b K ⁢ α K ⁡ ( E ) ) ⁢ S U ⁢ ⁢ ⅆ E ) ( #8 ) The comparison with equation (#3) shows that the following applies:fU(b)=gU(b,0) (#9) The hardening correction of the polychromatic measured projection data {tilde over (p)} then takes place by multiplication with a correction factor CUpkorr=CU(bW,bK){tilde over (p)} (#10)or by additionpkorr={tilde over (p)}+δp(1) (#11)with the correction projection dataδp(1)=(CU(bW,bK)−1){tilde over (p)} (#12) It is noted that the corrections depend on the voltage U=Uj used in the particular projection No. j. The corrected projection data or the correction projection data is used for a new volumetric image reconstruction. The correction cycle can then be iteratively repeated with a new segmentation, with a new determination of material-specific coverages bW′,bK′ by segmented reprojection, new correction in accordance with equations (#10) and (#11)-(# 12) and with a new reconstruction. Two-Stage Correction: Multispectral First and Second Order Hardening Correction It is pointed out that for the actual implementation in the x-ray system 1 the correction (#11), {tilde over (p)}→pkorr, is not performed in one step, but instead the water correction is carried out first. This operates directly on the projection data and requires no reprojection. Only then is the deviation from the water correction, as a second order correction, corrected. The segmented reprojection is then required for this:First order correction: {tilde over (p)}→pkorr(0) according to (#5)Second order correction: pkorr(0)→pkorr=pkorr(0)+δp(2) (#13) δ ⁢ ⁢ p ( 2 ) = ( C U ( 2 ) ⁡ ( b W , b K ) - 1 ) ⁢ p korr ⁡ ( 0 ) ( #14 ) C U ( 2 ) ⁡ ( b W , b K ) = C U ⁡ ( b W , b K ) ⁢ p ~ p korr ⁡ ( 0 ) ( #15 ) The corrections depend, as mentioned, on the voltage U=Uj used in the particular projection No. j. The correction procedure can be iteratively continued. Reduction of the Computing Expense of the Post-Reconstructive Corrections There are various methods of keeping the computing expense low. In DE 100 51 462 the fact that the non-water-similar hardening materials with a higher atomic number, for example, bones, contrast media or metal usually have only a fraction of pixels 37 or voxels 36 is utilized by clever data organization. Furthermore, it is possible to subject only correction projection data, corresponding to δp(1) or δp(2), to a new volumetric image reconstruction, in order to calculate a correction volumetric image and only then superimpose it by addition to the uncorrected volumetric image. This essentially uses the linearity of the image reconstruction because the linearity enables the sequence of addition and reconstruction to be switched. Both methods of expense reduction can be combined. In the following, a detailed description of the performance of the hardening correction is described with the aid of FIGS. 10 to 12. The hardening correction taking place in the evaluation unit 12 can be implemented both in the software and in the hardware. In the following, block diagrams that reflect the sequence are described and also pseudocode is given. Multispectral Water Correction FIG. 10 shows the sequence of a water correction carried out by the evaluation unit 12. First, a data acquisition 39, that leads to projection image data 40, is performed with the aid of the detector 4. The projection image data 40 also contains the particular tube voltage U used of the x-ray tube 3. Using the correction table 41 applicable for the tube voltage U in which the corrected projection values are entered relative to the measured projection values, a multispectral correction 42 of the beam revaluation is carried out. The correction 42 depends on the actual tube voltage U of the x-ray tube 3. Using the corrected projection image data, an image reconstruction 43 is then carried out, leading to a volumetric image 44 with the radiation hardening due to water or body parts of the patient 2, that have similar absorption properties to water, being corrected. In the following, the process of water correction is described again by pseudocode. When doing so, it is assumed that the (two-parameter) water correction family of tables FU(p) for the voltage range Umin≦U≦Umax, used for system control and calculated in advance with suitable discretization U=Un=Umin+(n−1)ΔU, n=1,2, . . . , is available (for example ΔU=5 kV). The pseudocode is then: for each projection direction j=1,N with a projection angle φj=φ0+(j−1)Δφ and tube voltage Uj: load table FU( ) with U=Uj or interpolated table from FU( ) and FU′( ) with U=Un≦Uj<U′=Un+1; read projection image {tilde over (p)}=({tilde over (p)}kl), whereby k,l are pixels indices of the projection image for projection No. j; for each projection image pixel (k,l): water correction according to equation (#5) using table FU( ): {tilde over (p)}kl→FU({tilde over (p)}kl) for the corrected projection image pkorr(0)=(FU({tilde over (p)}kl)): image reconstruction updating (additive superimposition in the reconstruction volume) It is pointed out that the image reconstruction is not limited to the Feldkamp algorithm, under certain circumstances with Parker weighting, at projection angles of less than 360 degrees. There are generalizations that are still back projections filtered from the type. Furthermore, every suitable reconstruction algorithm can, in principle, be used, for example also a reconstruction method of the algebraic iterative reconstruction type. Iterative, Multispectral, Second Order Hardening Correction FIG. 11 is a flow diagram of an iterative, multispectral second order correction of the beam hardening. As for the water correction described using FIG. 10, the data acquisition 39 leads to projection image data 40. Using the projection image data 40, an image reconstruction 45 was carried out that leads to an uncorrected volumetric image 46. The original projection image data 40 and the uncorrected volumetric image 46 are each subjected to coarsening 47 and 48, with the spatial resolution of the original projection image data 40 and uncorrected volumetric image 46 being reduced. Using the data obtained in this way and the values for the tube voltage U, a multispectral correction 49 of the radiation hardening is then carried out, with the relevant allocated tube voltage U being taken into account for the projection images. By means of a succeeding refinement 50 of the correction volume image supplied from the correction 49, a correction volumetric image 51 is generated that is added to the uncorrected volumetric image 46 and a corrected volumetric image 52 thus results. As part of the refinement 50, the spatial resolution of the correction volumetric image is increased by interpolation corresponding to the spatial resolution of the uncorrected volumetric image 43. In principle, the coarsening 47 and 48 and refining 50 steps can be omitted. This does, however, lead to a higher computing cost. FIG. 12 shows the details of the correction 49 from FIG. 11. The coarsening 47 of the uncorrected projection image data 40 leads to coarsened projection image data 53 and the coarsening 48 to a coarsened uncorrected volumetric image 54. A segmentation 55 in accordance with FIG. 9 is carried out using the coarsened uncorrected volumetric image 54 and this is followed by a reprojection 56 that produces the mass coverage data 57, for example (bK, bW). Depending on the tube voltage U and mass coverage data 57, a correction table 58 is consulted that contains the correction values CU(bK, bW) relative to the tube voltage U for conversion of polychromatic projection values into monochromatic projection values. With this correction data from the correction table 58, a correction algorithm 59 is used that processes the coarsened projection image data 53 and from this generates estimated correction projection image data 60. Using the estimated correction image data 60, a reconstruction 61 is performed that leads to a correction image 62 with less spatial resolution. A subsequent question 63 is then asked to determine whether the correction image 62 has substantially changed in the last iteration step. If a substantial change is present, the correction image 62 is added to the coarsened uncorrected volumetric image 54 and the segmentation 55 is performed again. This is followed by a new reprojection 56 to generate improved mass coverage data 57, followed by consultation of the correction table 58 and performance of the correction algorithm 59 again, that leads to improved, estimated correction projection image data 60. The reconstruction 61 can then be repeated, so that an improved correction image 62 results. If the correction image 62 has not substantially changed, the refining 50 is carried out, leading to the correction volumetric image 51 with the original spatial resolution. The process of a second order hardening correction again using pseudocode is described in the following. It is again assumed that the (three or more parameter) family of hardening correction tables CU( ) according to equation (#6) is available, calculated in advance with suitable discretizing, for the voltage range Umin≦U≦Umax used for the system control. The pseudocode is then: first volumetric image reconstruction with the aid of a standard reconstruction volumetric image segmentation with material-selective threshold values calculate the material-selective, hardening corrective volumetric image as follows: for each projection direction j=1,N with a projection angle φj=φ0+(j−1)Δφ and tube voltage Uj: load multiparameter, hardening correction table CU with U=Uj or interpolated table from CU and CU′ with U=Un≦Uj<U′=Un+1; read projection image {tilde over (p)}=({tilde over (p)}kl) with k,l being pixel indices for the projection image for projection No. j for each projection image pixel (k,l) and the measuring beam striking this pixel: segmented (material selective) reprojection from which coverage thicknesses bW,bK, . . . result hardening correction projection value according to equation (#12) using the look-up table CU: {tilde over (p)}k,l→p(1)kl for the correction projection image δp(1)=(δp(1)kl): filtered reprojection image reconstruction updating (additive superimposition in the reconstruction volume) adding the hardening correction volumetric image as a superimposition to the standard reconstruction volumetric image Iteration (optional): Repeat steps 1 to 3* Simulation Calculations The method described here was tested in the simulation calculations. During the simulation calculations, a heavily simplified femur phantom with low contrast inserts was used. FIG. 13 shows a cross-section through a reconstructed volumetric image that was taken using variable voltage, but with the hardening correction having been performed assuming a constant voltage. FIG. 14 shows the same cross-section that results if the variability of the tube voltage is taken into account when correcting the hardening in accordance with the method described here. FIG. 15 then shows the differential image of the cross-section images from FIGS. 13 and 14. The errors reach approximately +/−20 HU in the soft tissue. The method described here and the x-ray system 1 described here has a number of advantages. With the x-ray system 1, the dose of the x-ray radiation can be minimized. By correcting the voltage dependent multispectral radiation hardening, the image quality is improved at the same time. This substantially increases the quantitative accuracy of the reconstructed volumetric images. Hardening artifacts are largely eliminated. This means that it is then possible to consider the use of the method described here also in conjunction with conventional computer tomography devices that have a fixed frame in which the x-ray source and the x-ray detector rotate. It is pointed out that the method described here can be realized using software or with the aid of hardware. It is also pointed out that the term evaluation unit is to be understood as being functional. The evaluation unit does not necessarily have to be formed by a physical unit but instead the function of an evaluation unit can also be performed by several physical units. It should finally be pointed out that with the exemplary embodiment described here the tube voltage of the x-ray tube has been used to vary the energy distribution of the x-ray radiation. It is also conceivable to vary other operating parameters of the x-ray system 1. For example, the energy distribution of the x-ray radiation can also be varied by using filters. In this case, the multiparameter correction table C must also be calculated relative to the additional operating parameters. Other operating parameters that influence the energy distribution of the x-ray radiation can be taken into account for other x-ray sources that are used instead of the x-ray tube.
	claims	1. A method for dynamically creating a virtual storage device on a physical computer system, the physical computer system comprising software monitoring created devices, the method comprising:loading a system bus driver module, wherein the system bus driver module simulates a system bus adapted to interface with a plurality of virtual storage devices;dynamically creating a virtual storage device on the simulated system bus by creating a physical device object for the created virtual storage device, the created virtual storage device simulating a physical storage device not operatively connected to the physical computer system;returning a hardware ID to the software monitoring created devices, wherein the hardware ID identifies a type of the physical storage device simulated by the created virtual storage device;attaching, to the created virtual storage device, a storage class driver corresponding to the type of the physical storage device based on processing done by the software monitoring created devices;creating at least one partition on a storage medium of the physical computer system, the storage medium being of a first device type;creating a formatted backing store on the at least one partition, the formatted backing store being formatted like a second device type different from the first device type, the second device type being a type of the simulated physical storage device;mapping the virtual storage device to the formatted backing store in the storage medium of the physical computer system such that data written to the virtual storage device is written to the at least one partition on the storage medium of the physical computer system;mounting a file system to each partition on the created virtual storage device; andhandling I/O requests to the created virtual storage device by calculating offsets in the formatted backing store; anddynamically creating at least one second virtual storage device of the plurality of virtual storage devices on the simulated system bus by creating a second physical device object for the at least one second virtual storage device wherein the second virtual storage device is of a different type than the first virtual storage device, the at least one virtual storage device simulating a second physical storage device not operatively connected to the computer system different from the first physical storage device; andautomatically performing a plurality of testing operations to test functions of the software or hardware components involving interactions with the first and second physical storage devices, the automatically testing comprising simulating the first and second physical storage devices with the first virtual storage device and the second virtual storage device, wherein performing a plurality of testing functions comprises performing at least one testing operation for the first virtual storage device and the second virtual storage device. 2. The method of claim 1 wherein the created virtual storage device is a removable disk drive. 3. The method of claim 1 wherein the created virtual storage device is a fixed disk drive. 4. The method of claim 1 wherein the created virtual storage device is an optical disk drive. 5. The method of claim 1 wherein the formatted backing store is formatted in IS09660 format. 6. The method of claim 1 wherein the formatted backing store is formatted in UDF format. 7. The method of claim 1 wherein the formatted backing store contains a partition table and at least one partition. 8. A computer storage medium having computer-executable instructions for performing the steps recited in claim 1. 9. A computer storage medium having computer-executable components and software monitoring created devices, the computer-executable components adapted for execution on a physical computer comprising a memory, the computer-executable components comprising a plurality of modules, the modules comprising:a system bus driver module for simulating a system bus adapted to interface with a plurality of virtual storage devices;a virtual storage device creation module for creating a virtual storage device on the simulated system bus by creating a physical device object, the created virtual storage device simulating a physical storage device not operatively coupled to the physical computer system, and returning a hardware ID to software monitoring created devices identifying a type of the physical storage device simulated by the created virtual storage device;a storage class attachment module for attaching, to the created virtual storage device, a storage class driver corresponding to the type of the physical storage device based on processing done by the software monitoring created devices;a partition manager module for creating a partition on a storage medium of the physical computer system, the storage medium being of a first device type, and mapping the virtual storage device to the partition in the storage medium of the physical computer system such that data written to the virtual storage device is written to the partition on the storage medium of the physical computer system;a file system mounting module for mounting a file system to each partition on the created virtual storage device;an I/O request module for handling I/O requests to the created virtual storage device by calculating offsets in the formatted backing store; anddynamically creating at least one second virtual storage device of the plurality of virtual storage devices on the simulated system bus by creating a second physical device object for the at least one second virtual storage device wherein the second virtual storage device is of a different type than the first virtual storage device, the at least one virtual storage device simulating a second physical storage device not operatively connected to the computer system different from the first physical storage device; andautomatically performing a plurality of testing operations to test functions of the software or hardware components involving interactions with the first and second physical storage devices, the automatically testing comprising simulating the first and second physical storage devices with the first virtual storage device and the second virtual storage device, wherein performing a plurality of testing functions comprises performing at least one testing operation for the first virtual storage device and the second virtual storage device. 10. The computer storage medium of claim 9 wherein the created virtual storage device is a removable disk drive. 11. The computer storage medium of claim 9 wherein the created virtual storage device is a fixed disk drive. 12. The computer storage medium of claim 9 wherein the created virtual storage device is an optical disk drive. 13. A method for automating testing of software or hardware components by creating a plurality of virtual storage devices on a computer system comprising software monitoring created devices, the method comprising:loading a system bus driver module, wherein the system bus driver module simulates a system bus adapted to interface with the plurality of virtual storage devices;dynamically creating a first virtual storage device of the plurality of virtual storage devices on the simulated system bus by creating a physical device object for the first virtual storage device, the first virtual storage device simulating a first physical storage device not operatively connected to the physical computer system;returning a hardware ID to the software monitoring created devices, wherein the hardware ID identifies a type of the physical storage device simulated by the first virtual storage device;attaching, to the first virtual storage device, a storage class driver corresponding to the type of the physical storage device based on processing done by the software monitoring created devices;creating a partition on a storage medium of the physical computer system, the storage medium being of a first device type;mapping the first virtual storage device to the partition on the storage medium of the computer system such that data written to the first virtual storage device is written to the partition on the storage medium of the computer system;mounting a file system to the partition on the storage medium;handling I/O requests to the first virtual storage device by calculating offsets in the formatted backing store; anddynamically creating at least one second virtual storage device of the plurality of virtual storage devices on the simulated system bus by creating a second physical device object for the at least one second virtual storage device wherein the second virtual storage device is of a different type than the first virtual storage device, the at least one virtual storage device simulating a second physical storage device not operatively connected to the computer system different from the first physical storage device; andautomatically performing a plurality of testing operations to test functions of the software or hardware components involving interactions with the first and second physical storage devices, the automatically testing comprising simulating the first and second physical storage devices with the first virtual storage device and the second virtual storage device, wherein performing a plurality of testing functions comprises performing at least one testing operation for the first virtual storage device and the second virtual storage device. 14. The method of claim 13 further comprising an act of creating a formatted backing store on the at least one partition, the formatted backing store being formatted like a second device type different from the first device type. 15. The method of claim 13 wherein the plurality of testing operations comprises simulating, using one of the first and second virtual storage devices, insertion of a compact disc into a CD-ROM drive to test at least one of autoplay functionality, CD burning functionality, or audio playback functionality. 16. The method of claim 13 wherein the plurality of testing operations comprises a first subset of testing operations involving interactions with the first physical storage device and a second subset of testing operations involving interactions with the second physical storage device. 17. The method of claim 13 wherein the partition manager module is further adapted to create a formatted backing store on the partition, the formatted backing store being formatted like a second device type, different from the first device type.
047160144	description	DESCRIPTION OF THE PREFERRED EMBODIMENT The invention will be described as applied to the steam generator of a pressurized water reactor (PWR) nuclear power plant, however, it will be realized by those skilled in the art that it will also have application to systems for measuring fluid level in other types of steam generators. As shown in FIG. 1, a steam generator 1 is provided with a lower tap 3 below the level 5 of the water 7 and an upper tap 9 in the region 11 of the steam phase. The lower tap 3 is located below the lowest water level to be measured and the upper tap is located above the highest level expected. In this manner, the lower tap is always in communication with liquid phase and the upper tap is always exposed to the steam phase within the steam generator 1. A differential pressure measuring device 13 is connected to the lower tap 3 by a lower connecting line 15 which is provided with an isolation valve 17. Typically, this line is tubing having, for example, an inside diameter of about 3/4 of an inch. A reference leg 19 in the form of a tube extends upward from the measuring device 13 to a point above the level of the upper tap 9. A condensation pot 21 is mounted on the top of the reference leg 19. An upper connecting line 23 has a first section 23' extending from the upper tap 9 and a second section 23" connected to the condensation pot 21. The two sections 23' and 23" of the line 23 are connected to a separator pot 25. An isolation valve 17 is provided in the line section 23'. As seen in FIG. 2, the separator pot 25 has a housing 27 which defines an expansion chamber 29. A baffle 31 depending from the top wall 33 of the housing divides the upper portion of the expansion chamber on one side of the baffle into an inlet section 35, and, on the other side, an outlet section 37. Steam from the steam generator 1 passes through the first section 23' of the connecting line, the separator pot 25 and the second section 23" of the connecting line to the condensation pot 21 where it condenses to keep the reference leg filled with water 39. Excess condensation 41 flows back down the connecting line 23" into the separator pot 25 which is below the level of the condensation pot 21. The velocity of steam through the first section 23' of the connecting line, combined with capillary effects due to the small diameter of line 23', tends to carry liquid slugs 43 with it. The volume of the chamber 29 slows the steam and entrained liquid down which aides in separation, with the liquid accumulating at the lower end 45 of the chamber 29. The diameter of the chamber 29 must be much larger than that of the connecting line 23'; the sizing must allow a free downflow of liquid against steam upflow. According to Zukoski (Influence of Viscosity, Surface Tension and Inclination Angle on Motion of Long Bubbles in Closed Tubes--J. Fluid Mechanics (1966) vol 25, part 4 pp 821-837) the governing parameter for this phenomenon is: EQU .SIGMA.=.sigma./.DELTA..rho.ga.sup.2 where .sigma.=superficial tension of water PA1 .DELTA..rho.=density difference between liquid and steam PA1 a=tube (chamber) diameter For .SIGMA.=1.2 the separation rate of liqid and steam is close to zero; below .SIGMA.=0.1, the separation rate no longer increases with a. For PWR applications, a chamber inside diameter of 2 inches is sufficient for an efficient separation. The baffle 31 directs the steam and liquid, which enters the chamber 29 horizontally through line section 23', downward in the inlet section 35. The liquid and steam separate from each other in chamber 29 with the steam flowing through the outlet section 37 toward the line section 23" while liquid is left at the bottom of the chamber. The baffle height is greater than the inside line diameter 23" to prevent liquid slugs delivered by line 23' from penetrating the inlet of line 23". Thus, all of the entrained slugs 43 of liquid have been removed from the steam by the time that it enters line section 23" and flows countercurrent to the excess condensate 41 returning through this same line section to the separator pot 25. Both sections of the connecting line 23 and the separator pot 25 are covered with insulation 47 to prevent condensation of the steam within these components, which would cause an unnecessary increase of the condensate flow. The condensation pot 21 is of course uninsulated. the liquid which accumulates in the lower portion 45 of the expansion chamber 29 in the separator pot 25 is returned to the steam generator through a drain line 49 connected to the lower connecting line 15 between the isolation valve 17 and measuring device 13. As indicated in FIG. 1, the separator pot 25 is above the highest level 5 of water in the steam generator to be measured so that the liquid can drain from the separator pot through this drain line. In the preferred arrangement, the first section 23' of the upper connecting line is horizontal to avoid having to consider a level measurement error caused by the two phase mixture density multiplied by the elevation difference between the steam generator upper tap 9 and the separation pot entrance. Moreover, as no credit is taken for steam liquid separation in this section of the line 23, there is no requirment to have it sloped in one direction or another. Since the drain line 49 forms one leg of a u-tube with the steam generator 1 forming the other leg, consideration must be taken of the effects of level oscillation which are always present in a steam generator. For a given frequency, level oscillation in the drain line 49 can be smaller or larger than those in the steam generator 1, with the ratio of oscillation amplitude between drain line and steam generator being the amplification factor. The resonant frequency, which is the frequency of natural oscillation of the water column in the drain line, is defined by the equation. EQU F=0.1592.sub.Ho (go)0.5 where go equals the acceleration of gravity and Ho equals water column height. FIG. 3, which is a plot of the amplification factor on the ordinate and the steam generator level oscillation frequency/resonance frequency on the abscissa (dimensionless), shows by the curve 51 that with a 1/4 inch inside diameter drain line 49, the level measurement will not be disturbed by excessive oscillation in the drain line. The curve 53 shows that with a 3/4 inch inside diameter drain line, unacceptable effects on level measurement would be encountered. While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.
047769823	abstract	The invention is a method for the storage in a storage room (9) of radioactive material and particularly for the temporary storage of radioactive nuclear fuel from nuclear reactors and of non-reprocessed radioactive material.. A remote-controlled robot arrangement, comprising a transfer robot (4) and a lifting and carrying robot (5), is designed to fit into a lift (8) for moving the material from ground level to the storage room, to transfer the material into double-walled containers (1), and to carry stacks of containers. The material is transferred by the transfer robot (4) to and from the double-walled containers (1). The containers are provided with safety arrangement (2) with three safety locks to prevent the radioactive material from escaping during transfer.. Heat removal from the double-walled containers (1) is effected by means which make the heat available for practical use and maintain the correct temperature in the containers.
	abstract	An ion implantation apparatus is disclosed in this invention. The ion implantation apparatus includes a target chamber for containing a target for implantation and an ion source chamber includes an ion source with a mass filter for generating an ion beam with certain mass and original energy. The ion source chamber further includes beam deceleration optics for decelerating the ion beam from the original energy to the desired final energy. The ion beam apparatus is able to accurately direct low energy ions to a target wafer. The beam deceleration optics further includes a plurality of electrodes for generating an electric field for spreading the charged ion beam over an angular range to accurately control the trajectory paths of ions of different energy levels. The purpose is to eliminate the energy contamination by more accurately controlling the energy range of the charged ions that reach the target for implantation and to block the neutralized particle and ions of higher energy from reaching the target for implantation.
	abstract	Fuel bundles for a nuclear reactor are described and illustrated, and in some cases include fuel elements each having a fissile content of 235U between about 0.9 wt % 235U and 5.0 wt % 235U, and wherein at least one of the fuel elements is a poisoned low-enriched uranium fuel element including a neutron poison in a concentration greater than about 5.0 vol %.
	claims	1. A target device for a neutron generating device, comprising:a plurality of solid particles serving as a target body; anda target body reaction chamber configured for accommodating the plurality of solid particles such that the solid particles are discharged from the target body reaction chamber by gravity,wherein the solid particles accommodated in the target body reaction chamber are configured to generate neutrons when a beam is applied to the solid particles,wherein the target body reaction chamber has an injection conduit defining an injection opening and a discharge conduit defining a discharge opening, and the solid particles are injected into the target body reaction chamber through the injection opening and moved out of the target body reaction chamber through the discharge opening, andwherein a ratio of a diameter of the target body reaction chamber to a particle diameter of the plurality of solid particles is in a range of 5:1-30:1. 2. The target device of claim 1, whereinthe solid particles have at least one of a spherical shape, an ellipsoidal shape, and a polyhedral shape. 3. The target device of claim 1, wherein the solid particle comprises anyone of tungsten, a tungsten alloy, uranium, a uranium alloy, uranium ceramics, thorium, a thorium alloy, and thorium ceramics. 4. An accelerator-excited neutron generating device comprising:the target device according to claim 1; anda solid particle conveying device for injecting the solid particles into the target body reaction chamber. 5. The accelerator-excited neutron generating device of claim 4, further comprising:a cooling device, wherein the solid particles are cooled by the cooling device after the solid particles are moved out of the target body reaction chamber, and then the solid particles are injected into the target body reaction chamber by the solid particle conveying device. 6. The accelerator-excited neutron generating device of claim 4, further comprising:a sorting device configured such that those of the solid particles that conform to a predetermined standard are selected from the solid particles by the sorting device after the solid particles are moved out of the target body reaction chamber, and then injected into the target body reaction chamber. 7. The accelerator-excited neutron generating device of claim 4, whereinthe solid particles have at least one of a spherical shape, an ellipsoidal shape, and a polyhedral shape. 8. The accelerator-excited neutron generating device of claim 4, further comprising: a buffer chamber disposed at a solid particle injection opening for temporarily storing the solid particles. 9. The accelerator-excited neutron generating device of claim 4, whereinthe solid particle conveying device is configured to circulate the solid particles from an inside of the target body reaction chamber through an outside of the target body reaction chamber to the inside of the target body reaction chamber while the beam is applied to the solid particles. 10. The accelerator-excited neutron generating device of claim 9, further comprising: a cooling device and a sorting device, wherein the solid particles which are being circulated and situated outside the target body reaction chamber are cooled by the cooling device, and those of the solid particles that conform to a predetermined standard are selected by the sorting device from the solid particles which are being circulated and situated outside the target body reaction chamber. 11. A beam coupling method for the accelerator-excited neutron generating device according to claim 4, comprising:injecting the solid particles serving as the target body into the target body reaction chamber, andapplying a beam to the solid particles. 12. The beam coupling method of claim 11, wherein the solid particles are circulated from an inside of the target body reaction chamber through an outside of the target body reaction chamber to the inside of the target body reaction chamber while the beam is applied to the solid particles. 13. The beam coupling method of claim 12, wherein the solid particles which are being circulated and situated outside the target body reaction chamber are processed. 14. The beam coupling method of claim 13, wherein the processing comprises cooling the solid particles and selecting those of the solid particles that conform to a predetermined standard from the solid particles. 15. The target device of claim 1, wherein a ratio of a caliber of the injection conduit to the diameter of the target body reaction chamber is in a range of 1:1-1:10. 16. The target device of claim 1, wherein a ratio of a caliber of the discharge conduit to the diameter of the target body reaction chamber is in a range of 1:1-1:10.
048516945	claims	1. A device for driving and positioning at least one radioactive source holder in an applicator tube used in radiotherapy, the applicator tube having a first end and a second end, the second end being open, said device comprising: a guide tube having one end connected to said second end of the applicator tube, a cable longitudinally displaceable along said guide tube and said applicator tube between a first position and a second position, the cable having a first end in the vicinity of which said source holder is mounted, and second end, and means for driving the cable along the guide tube and the applicator tube, the driving means including: means for causing rotation of the motor-driven first roller, and an encoder equipped with a second roller in tangential contact, without sliding, with the cable, the encoder having means for detecting an interruption in the rotation of the second roller. a guide tube having one end connected to the second end of the applicator tube; a cable displaceable longitudinally along the guide tube and the applicator tube between a first position and a second position, the cable having a first end and a second end and the source holder being mounted on the cable in the vicinity of the first end; means for driving the cable along the guide tube and the applicator tube including a first drive roller in tangential and sliding contact with the cable, and means for rotating the first roller to drive the cable; an encoder having a second roller in tangential non-sliding contact with the cable and having means for detecting an interruption in the rotation of the second roller; and an end-of-course detector in front of which the second end of the cable is located when the cable is in the first position. a guide tube having one end connected to the second end of the applicator tube; a cable displaceable longitudinally along the guide tube and the applicator tube between a first position and a second position, the cable having a first end and a second end and the source holder being mounted on the cable in the vicinity of the first end; means for driving the cable along the guide tube and the applicator tube including a first drive roller in tangential and sliding contact with the cable, and means for rotating the first roller to drive the cable; an encoder having a second roller in tangential non-sliding contact with the cable and having means for detecting an interruption in the rotation of the second roller; and an end-of-course detector located to detect passage of the second end of the cable upon the cable moving beyond said second position. 2. A device as defined by claim 1, wherein the encoder is an incremental encoder. 3. A device as defined by claim 1, further including a detector past which the source holder moves when it is mounted on the cable, in the course of displacement of the cable, for counting sources. 4. A device as defined by claim 1, further including a first end-of-course detector in front of which the second end of the cable is located when the cable is in its first position. 5. A device as defined by claim 1, further including a second end-of-course detector located in such a manner as to detect the passage of the second end of the cable if the cable moves beyond said second position. 6. A device as defined by claim 1, further including a second guide tube in which at least a portion of the cable can be displaced, the second guide tube having one end closed by a stop, the second end of the cable coming into contact with the stop upon the cable being displaced to near said first position. 7. A device for driving and positioning a radioactive source holder in an applicator tube used in radiotherapy, the applicator tube having a first end and an open second end, said device comprising: 8. A device for driving and positioning a radioactive source holder in an applicator tube used in radiotherapy, the applicator tube having a first end and an open second end, said device comprising:
	claims	1. A method for recovery of residual actinide elements from a chloride molten salt, comprising:conducting electrolysis using a liquid cadmium cathode (LCC) in a chloride molten salt that is formed after electro-refining and/or electro-winning of a spent nuclear fuel and that contains rare-earth elements as well as actinide elements;electro-depositing the actinide elements contained in the chloride molten salt on the LCC to reduce a concentration of the actinide elements in the chloride molten salt while co-electro-depositing rare-earth elements contained in the chloride molten salt on the LCC;stepwise adding a CdCl2 oxidant to the chloride molten salt containing the LCC with co-deposited actinide and rare-earth elements to oxidize selectively only the rare-earth elements co-deposited with the actinide elements on the LCC, thereby forming rare-earth chlorides in the chloride molten salt; andrecovering actinide elements deposited on the LCC. 2. The method according to claim 1, wherein the chloride molten salt is a LiCl—KCl eutectic salt. 3. The method according to claim 1, further comprising heating the chloride molten salt to 500 to 700° C. to melt the same, before the electrolysis process using the LCC in the chloride molten salt. 4. The method according to claim 1, wherein the electrolysis process using the LCC in the LiCl—KCl eutectic salt is conducted at a current density of 10 to 100 mA/cm2.
	abstract	An operator-free and fully automated semiconductor inspection system with high throughput is realized. All conditions required for capturing and inspection are generated from design information such as CAD data. In order to perform actual inspection under the conditions, a semiconductor inspection system is composed of a navigation system for generating all the conditions required for capturing and inspection from the design information and a scanning electron microscope system for actually performing capturing and inspection. Moreover, in the case of performing a matching process between designed data and a SEM image, deformed parts are corrected by use of edge information in accordance with multiple directions and smoothing thereof. Furthermore, a SEM image corresponding to a detected position is re-registered as a template, and the matching process is thereby performed.
	summary
	summary
	claims	1. A medical particle irradiation apparatus comprising: a rotating gantry including an irradiation unit emitting particle beams; a first frame located within and supported by said rotating gantry such that it can rotate relative to said rotating gantry; a second frame fixedly located opposite said first frame; an anti-corotation unit disposed on said rotating gantry, said anti-corotation unit being in contact with both said first and second frames to prevent said first frame from rotating together with said rotating gantry during rotation of said rotating gantry; and a flexible moving floor located between said first and second frames, said flexible moving floor being engaged with said first and second frames in such a manner as to move freely such that its bottom is substantially level and that it moves as said rotating gantry rotates, wherein said anti-corotation unit comprises a first rotational element having an uneven portion which meshes with a first uneven portion formed on said first frame, a second rotational element having an uneven portion which meshes with a second uneven portion formed on said second frame, and a shaft member which couples said first and second rotational elements together, wherein said shaft member is attached to said rotating gantry such that said shaft member is free to rotate on its axis. 2. The medical particle irradiation apparatus according to claim 1 , wherein said first and second frames are each provided with a moving floor guide unit engaged separately with both ends of said moving floor, said moving floor guide unit having a level portion at the bottom. claim 1 3. The medical particle irradiation apparatus according to claim 1 , wherein said first rotational element is in mesh with said first frame outwardly from the center of rotation of said rotating gantry, and said second rotational element is in mesh with said second frame outwardly from the center of rotation of said rotating gantry. claim 1 4. The medical particle irradiation apparatus according to claim 1 , wherein said first rotational element is in mesh with said first frame toward the center of rotation of said rotating gantry from the outside thereof, and said second rotational element is in mesh with said second frame toward the center of rotation of said rotating gantry from the outside thereof. claim 1 5. A medical particle irradiation apparatus comprising: a rotating gantry including an irradiation unit emitting particle beams; a first frame located within and supported by said rotating gantry such that it can rotate relative to said rotating gantry; a second frame fixedly located opposite said first frame; an anti-corotation unit disposed on said rotating gantry, said anti-corotation unit being in contact with both said first and second frames to keep the positions of said first and second frames, located opposite each other, substantially unchanged regardless of the rotation of said rotating gantry; and a flexible moving floor located between said first and second frames, said flexible moving floor being engaged with said first and second frames in such a manner as to move freely such that its bottom is substantially level, that it forms therein a therapy room into which a therapy bed is slid and that it moves as said rotating gantry rotates, wherein said anti-corotation unit comprises a first rotational element having an uneven portion which meshes with a first uneven portion formed on said first frame, a second rotational element having an uneven portion which meshes with a second uneven portion formed on said second frame, and a shaft member which couples said first and second rotational elements together, wherein said shaft member is attached to said rotating gantry such that said shaft member is free to rotate on its axis. 6. The medical particle irradiation apparatus according to claim 5 , wherein said first and second frames are each provided with a moving floor guide unit engaged separately with both ends of said moving floor, said moving floor guide unit having a level portion at the bottom. claim 5 7. The medical particle irradiation apparatus according to claim 5 , wherein said first rotational element is in mesh with said first frame outwardly from the center of rotation of said rotating gantry, and said second rotational element is in mesh with said second frame outwardly from the center of rotation of said rotating gantry. claim 5 8. The medical particle irradiation apparatus according to claim 5 , wherein said first rotational element is in mesh with said first frame toward the center of rotation of said rotating gantry from the outside thereof, and said second rotational element is in mesh with said second frame toward the center of rotation of said rotating gantry from the outside thereof. claim 5 9. A medical particle irradiation apparatus comprising: a rotating gantry including an irradiation unit emitting particle beams; a first frame located within and supported by said rotating gantry such that it can rotate relative to said rotating gantry; a second frame fixedly located opposite said first frame; a frame position retaining unit disposed on said rotating gantry and being in contact with both said first and second frames, said frame position retaining unit moving in the circumferential direction of said second frame as said rotating gantry rotates; and a flexible moving floor located between said first and second frames, said flexible moving floor being engaged with said first and second frames in such a manner as to move freely such that its bottom is substantially level, that it forms therein a therapy room into which a therapy bed is slid and that it moves as said rotating gantry rotates, wherein said frame position retaining unit comprises a first rotational element having an uneven portion which meshes with a first uneven portion formed on said first frame, a second rotational element having an uneven portion which meshes with a second uneven portion formed on said second frame, and a shaft member which couples said first and second rotational elements together, wherein said shaft member is attached to said rotating gantry such that said shaft member is free to rotate on its axis.
	claims	1. A multi-leaf collimator comprising;an array of laterally spaced elongate leaves each having a longitudinal edge on which is mounted a reflective element;a scanning light source adapted to issue a beam of light in a scanning pattern, so as to illuminate a point that moves over the longitudinal edges of a plurality of leaves of the array; anda detector for light reflected from the reflective elements. 2. The multi-leaf collimator according to claim 1 in which the scanning light source comprises a source of light that illuminates a mirror, the mirror being controllably adjustable so as to direct a reflected beam of light in a scan pattern. 3. The multi-leaf collimator according to claim 2 in which the mirror is part of a micro-electromechanical device. 4. The multi-leaf collimator according to claim 1 further comprising at least one mirror locatable in a radiation beam path to permit location of the scanning light source out of the beam path. 5. The multi-leaf collimator according to claim 1 in which the scanning pattern illuminates a point that moves along the longitudinal edges of a plurality of leaves of the array in succession. 6. The multi-leaf collimator according to claim 1 in which the scanning light source comprises a laser. 7. The multi-leaf collimator according to claim 1 in which the reflective element is retro-reflective. 8. The multi-leaf collimator according to claim 1 in which the leaves are mounted in a frame, on which is mounted at least one reflective object. 9. An apparatus for location-detection of an object according to claim 1, adapted to repeat the scanning pattern once a scan of the region has been completed. 10. A Radiotherapeutic apparatus comprising a multi-leaf collimator according to claim 1.
	description	The subject matter described herein relates generally to analyzing a substance and, more specifically, to performing an analysis of a substance using a portable spectrometer. Portable spectrometers, also referred to as analyzers, are used to examine the composition of a sample material in a number of applications. For example, portable spectrometers are used for metal identification, detection and identification of hazardous materials or explosives, detection and identification of environmental pollutants, and identification of lead in paint. Portable spectrometers may also be referred to as handheld spectrometers if the portable spectrometer is configured for handheld operation. Examples of specific portable analyzers include X-ray fluorescence (XRF) spectrometers and ion mobility spectrometers (IMS). XRF spectrometers detect secondary radiation emitted from a sample of material that has been excited by radiation applied to the sample material by the spectrometer. A wavelength distribution of the emitted radiation is characteristic of the elements present in the sample, while the intensity distribution gives information about the relative abundance of the elements in the sample. By means of a spectrum obtained in this manner, an expert typically is able to determine the components, and quantitative proportions of those components, within the examined test sample. An IMS analyzes ion mobility to determine the composition of a sample material. Ion mobility analysis measures the movement of ionized sample molecules in a uniform electric field through a given atmosphere. Once a spectrum is obtained corresponding to the measured ion mobilities, a composition of the sample material can be determined. A full-sized laboratory diffraction analyzer typically includes a collimator having three sets of slits or apertures. The slits or apertures are typically defined within plates. Radiation striking the plate beyond the margin of the aperture is deflected or absorbed. The beam projected through the aperture has a cross-sectional shape similar to that of the aperture and a size or diameter controlled by the position and size of the aperture, and the position of the source. More specifically, the first slit is located near the radiation source and defines the spot size. The spot size is, for example, a diameter of a spot on a sample illuminated by the radiation. The second slit is positioned so it slightly cuts into the radiation beam and is of a size similar to the first slit. The first and second slits collimate the source beam. The third slit is located between the second slit and the sample and is of a slightly larger size than the first and the second slits. The third slit removes the scattered radiation that is emitted from the second slit. Typically, the size of such a three-slit collimator prohibits use in a portable analyzer, and even more so, in a handheld analyzer. A portable analyzer may use a pipe or a tube that defines an opening to direct generated radiation toward the sample. In the case of an XRF spectrometer, the pipe or tube is typically more for shielding all but the sample from the generated radiation than it is an attempt to collimate the generated radiation. For analyzers that include a laser source, an external collimator may be used to control the spot size, but collimation is unnecessary since the emitted radiation is inherently well collimated. Furthermore, a typical three-slit collimator is not suitable for use in a portable or handheld analyzer because the three-slit collimator increases a distance between the radiation source and the sample. More power is required to maintain a flux at the sample as the distance between the radiation source and the sample increases. Therefore, it is generally beneficial, especially in portable or handheld analyzers where available power may be limited to power provided by a battery, to minimize the distance between the radiation source and the sample. For similar reasons, the detector is also positioned close to the sample. The field of view of a detector with this type of geometry is typically large. Such small distances between the radiation source and the sample may cause problematic XRF scattering, Compton and Rayleigh back scatter that increases background noise, Bragg peaks that are not consistent from sample to sample, as well as sample orientations that result in fictitiously high results. Additionally, scattered radiation from the collimator may excite atoms present in the instrument and the resulting fluorescence may be received at the detector, causing an inaccurate reading. In one aspect, a collimating device is provided. The collimating device includes a housing defining an interior surface and an exterior surface of the collimating device. The housing includes an inlet and an outlet and a cavity extending between the inlet and the outlet. The collimating device also includes a plurality of ridges extending from the interior surface of the housing toward a center of the cavity. The plurality of ridges form a plurality of slits within the cavity configured to collimate radiation entering the inlet and exiting the outlet. In another aspect, a method of collimating radiation output by a radiation source is provided. The method includes providing a radiation source for generating radiation and positioning a collimating device between the radiation source and a sample. The collimating device includes an interior surface that defines a cavity. The cavity includes a plurality of ridges extending from the interior surface toward a center of the cavity. The plurality of ridges define a plurality of slits configured to facilitate reducing scattering of radiation exiting the collimating device. In yet another aspect, a detection system is provided. The system includes a radiation source configured to generate a primary radiation and impinge the primary radiation onto a sample. The primary radiation is configured to excite the sample and cause the sample to reflect a secondary radiation. The system also includes a radiation detector configured to detect the secondary radiation. The system also includes a collimating device positioned between the radiation source and the sample. The collimating device includes a housing that defines a cavity extending between an inlet and an outlet of the collimating device. The collimating device includes a plurality of ridges extending from the housing toward a center of the cavity, the plurality of ridges defining a plurality of slits configured to facilitate reducing scattering of radiation exiting the outlet of the collimating device. In yet another aspect, a collimating device is provided. The collimating device includes a housing defining an interior surface and an exterior surface of the collimating device. The housing includes an inlet and an outlet and a cavity extending between the inlet and the outlet. The collimating device also includes a spiraling ridge extending from the interior surface of the housing toward a center of the cavity. The spiraling ridge begins at the inlet and ends at the outlet. The spiraling ridge includes a first surface configured to collimate radiation entering the inlet and exiting the outlet. The methods, systems, and devices described herein facilitate reducing scatter of radiation applied to a sample during testing of the sample. The methods, systems, and devices described herein reduce scatter without increasing a distance between a radiation source and the sample. A reduction in scattered radiation facilitates reducing unwanted Bragg peaks, reducing X-ray florescence (XRF), Compton and/or Rayleigh back scatter, and reducing excitation of atoms present in the instrument that may result in fluorescence detectable by the detector. Maintaining the distance between the radiation source and the sample prevents having to increase the power provided to the radiation source to counteract the additional distance needed to apply collimation of the radiation applied to the sample. FIG. 1 is a functional illustration of the general components of a detection system 10, for example, but not limited to, an X-ray fluorescence (XRF) spectrometer or an ion mobility spectrometer (IMS). In the illustrated embodiment, detection system 10 includes a primary beam source 12, a detector 14, and an analyzer 16. Primary beam source 12 may include an X-ray tube that projects a primary beam of X-rays 18 towards a sample 20 that is to be tested. In another exemplary embodiment, primary beam source 12 is a radioactive isotope, which projects a primary beam of gamma rays toward the sample 20. In yet another exemplary embodiment, primary beam source 12 is an electron beam source that projects a primary beam of electrons towards the sample 20. Any suitable radiation source, or plurality of sources, that allow detection system 10 to function as described herein may be used as primary beam source 12. Sample 20 becomes excited after being exposed to primary beam 18. This excitation causes sample 20 to emit a secondary (i.e., characteristic or fluorescent) radiation 22. Secondary radiation 22 is collected by detector 14. Detector 14 includes electronic circuitry, which is sometimes referred to as a preamplifier, that converts collected secondary radiation to a detector signal 24 (i.e., a voltage signal or an electronic signal) and provides the detector signal 24 to analyzer 16. In at least one embodiment, analyzer 16 includes a digital pulse processor or multi-channel analyzer. While illustrated as a non-handheld unit, detection system 10 illustrates the major components that are also utilized in a handheld spectrometer. FIG. 2 is perspective view of an exemplary embodiment of a handheld instrument, for example, a handheld XRF spectrometer 40. Handheld XRF spectrometer 40 includes a housing 42. Housing 42 encloses and protects the internal assemblies of handheld XRF spectrometer 40. Housing 42 of handheld XRF spectrometer 40 includes a nosepiece 44 and a body 46. In an exemplary embodiment, housing 42 may have a “handgun-shaped” profile, with a handle 48, extending from body 46. Handle 48 may be positioned such that a user may comfortably hold handle 48 and direct nosepiece 44 to a desired position. Handheld XRF spectrometer 40 includes components similar to those described with respect to FIG. 1, including a detector, a beam source, and an analyzer. In an exemplary embodiment, housing 42 may be composed of one, or a combination of the following: ABS plastics, and alloy materials such as Magnesium, Titanium, and Aluminum. Housing 42 may be composed of any material with the strength to encase and protect the internal components of handheld XRF spectrometer 40. This protection may include, but is not limited to, protection from elements such as wind and rain, protection from dust and other impurities, and protection from damage caused by dropping spectrometer 40 onto a surface or from rough handling of spectrometer 40. This protection may also be bolstered through the use of over molding, rubber bumpers, shock absorbing mounts internal to the instrument assembly, and/or the use of crushable impact guards. In one embodiment, housing 42 is composed of lightweight materials, as when in use, handheld XRF spectrometer 40 is held by one of a user's hands. A light-weight handheld XRF spectrometer 40 increases maneuverability and increases the ease-of-use of handheld XRF spectrometer 40 over a heavier handheld spectrometer. FIG. 3 is a schematic diagram of an exemplary embodiment of a handheld instrument, for example, handheld XRF spectrometer 40 (shown in FIG. 2). A radiation source 58 is positioned adjacent to, or at least partially within, nosepiece 44. Radiation source 58 may include, but is not limited to, an electron beam source, a radioisotope source, a pyroelectric source, and an X-ray tube. In at least some embodiments, radiation source 58 directs a primary X-ray beam 60 toward a sample 62, which is in a position to be tested. Primary X-ray beam 60 may be directed through a slit or opening 64 included within a plate 66. Primary X-ray beam 60 may also be directed through an opening 68 defined by, for example, a tube 70 (also referred to herein as a shielding pipe). Opening 64 and opening 68 at least partially collimate primary X-ray beam 60 and/or reduce scatter of X-ray beam 60. In the exemplary embodiment, spectrometer 40 also includes a primary beam collimating device 72. X-ray beam 60 is directed through primary beam collimating device 72. Collimating device 72 may be positioned within tube 70 and/or coupled to radiation source 58 or plate 66 in any suitable manner that allows spectrometer 40 to function as described herein. In the exemplary embodiment, collimating device 72 at least partially collimates X-ray beam 60. A collimated beam of X-rays is a beam whose X-rays are nearly parallel and therefore, the beam will spread slowly as it propagates. Collimating device 72 allows X-rays, of X-ray beam 60, oriented in a particular manner, to pass through and irradiate sample 62. A detector 74 is also positioned adjacent to, or at least partially within, nosepiece 44. After sample 62 is exposed to primary X-ray beam 60, the material of sample 62 is excited and secondary radiation 76 is emitted from sample 62. Secondary radiation 76 is detected by detector 74. By at least partially collimating X-ray beam 60, unwanted scattered radiation reaching detector 74 is reduced. Detector 74 may include, but is not limited to, one of a silicon pin detector, a cadmium telluride detector, a mercuric iodide detector, and a silicon drift detector (SDD). Spectrometer 40 also includes a preamplifier (not shown in FIG. 3). The preamplifier amplifies voltage signals produced by detector 74 that correspond to the secondary radiation 76 received by detector 74. The preamplifier also provides the voltage signals to an analyzer (not shown in FIG. 3) for processing. FIG. 4 is a cut-away view of collimating device 72 (shown in FIG. 3). Collimating device 72 is primarily intended for use in a portable XRF instrument, but may be included within other instruments which can benefit from collimation and/or reduced scattering. In the exemplary embodiment, collimating device 72 includes a housing 80 having a length 82 and a diameter 84. Housing 80 includes an interior surface 86 and an exterior surface 88. In the exemplary embodiment, housing 80 is generally cylindrical, centered about a longitudinal center axis 90. In alternative embodiments, housing 80 may include any suitable shape that allows spectrometer 40 to function as described herein. In certain embodiments, collimating device 72 is configured to be positioned within tube 70 (shown in FIG. 3), facilitating improved collimation of primary X-ray beam 60 when compared to spectrometer 40 without collimating device 72. In other embodiments, housing 80 is integrated with tube 70 and/or coupled to plate 66 in any suitable manner that allows spectrometer 40 to function as described herein. Housing 80 includes an inlet 92 and an outlet 94, and a cavity 96 extending between inlet 92 and outlet 94. Inlet 92 is configured to receive primary X-ray beam 60 (shown in FIG. 3) and outlet 94 is configured to output a collimated beam toward sample 62 (shown in FIG. 3). In the exemplary embodiment, cavity 96 is an internal volume that is cylindrical-shaped, having a varying internal diameter 98. Cavity 96 is also referred to herein as an opening extending between inlet 92 and outlet 94. In the exemplary embodiment, interior surface 86 of housing 80 includes a plurality of ridges, extending from interior surface 86 radially toward center axis 90. The plurality of ridges, also referred to herein as rings, form alternating parallel grooves and ridges. FIG. 5 is a cross-sectional view of an exemplary radiation source and collimating system 99. In the exemplary embodiment, system 99 includes a collimating device and a radiation source 58, for example, collimating device 72 and radiation source 58. Collimating device 72 is formed from a material that reflects and/or absorbs X-ray radiation. In the exemplary embodiment, collimating device 72 includes a first circumferential ridge 100, a second circumferential ridge 102, a third circumferential ridge 104, a fourth circumferential ridge 106, and a fifth circumferential ridge 108. Ridges 100, 102, 104, 106, and 108 extend from interior surface 86 radially toward longitudinal center axis 90. In the exemplary embodiment, ridges 100, 102, 104, 106, and 108 share a center (i.e., center axis 90). Each successive ridge is a greater distance from inlet 92 than the previous ridge. For example, second ridge 102 is a first distance 110 from inlet 92 and third ridge 104 is a second distance 112 from inlet 92, wherein second distance 112 is larger than first distance 110. Each of ridges 100, 102, 104, 106, and 108 is substantially parallel to all of the other ridges. Furthermore, a plane that includes each individual ridge 100, 102, 104, 106, and 108 is substantially perpendicular to center axis 90. In the exemplary embodiment, each of ridges 100, 102, 104, 106, and 108 includes a triangular cross-section having a first edge 118 substantially perpendicular to center axis 90. Each of ridges 100, 102, 104, 106, and 108 also includes a second edge 120, which forms a substantially saw-tooth cross-sectional profile to ridges 100, 102, 104, 106, and 108. Such a saw-tooth cross-section facilitates ease in manufacturing collimating device 72. Although described as saw-tooth in cross-section, any other shape may be used that allows collimating device 72 to function as described herein. For example, ridges 100, 102, 104, 106, and 108 may include a cross-section having any shape where second edge 120 does not have a direct view of radiation source 58 and first edge 118 does not have a direct view of sample 62. As described above, radiation source 58 generates primary X-ray beam 60. Primary X-ray beam 60 includes individual X-rays, for example, a first X-ray 130, a second X-ray 132, a third X-ray 134, a fourth X-ray 136, a fifth X-ray 138, and a sixth X-ray 140. In the example illustrated, first X-ray 130 and sixth X-ray 140 are collimated. In other words, first X-ray 130 is substantially parallel to sixth X-ray 140, and X-rays 130 and 140 are substantially perpendicular to source 58. Second X-ray 132 and fifth X-ray 138 are not well collimated. Third X-ray 134 and fourth X-ray 136 are stopped by collimating device 72. X-rays 130 and 140 define a beam width 150. X-rays that exit collimating device 72 outside of beam width 150 are referred to herein as scatter or divergent. For example, second X-ray 132 and fifth X-ray 138 are not included within beam width 150, and define a maximum divergent width 152. Beam width 150 is substantially defined by a diameter 154 of ridges 100, 102, 104, 106, and 108. In the exemplary embodiment, each of ridges 100, 102, 104, 106, and 108 has diameter 154. In an alternative embodiment, a diameter of ridges 100, 102, 104, 106, and 108 increases as ridges 100, 102, 104, 106, and 108 increase in distance from source 58. For example, ridge 100 may have a smaller diameter than ridge 108. Each individual ridge 100, 102, 104, 106, and 108 may have any diameter that allows collimating device 72 to function as described herein. Ridges 100, 102, 104, 106, and 108 act as slits or apertures that facilitate reducing scatter while maintaining an acceptable level of collimation which will lessen the occurrence of unwanted Bragg, Rayliegh, and Compton peaks in XRF instruments. Collimating device 72 facilitates increasing collimation of X-ray beam 60 and therefore, reducing scatter width 152. FIG. 6 is a cross-sectional view of an alternative embodiment 160 of collimating system 99 (shown in FIG. 5). Collimating system 160 includes collimating device 72, a radiation source 162, and a first slit 166. In the alternative embodiment, first slit 166 is positioned adjacent to radiation source 162. In comparison to radiation source 58 (shown in FIG. 5), radiation source 162 generates a wider beam of radiation 168. Beam 168 includes a plurality of individual X-rays, for example, a first X-ray 170, a second X-ray 172, a third X-ray 174, a fourth X-ray 176, a fifth X-ray 178, a sixth X-ray 180, a seventh X-ray 182, and an eighth X-ray 184. In the exemplary embodiment, first slit 166 includes a material that reflects and/or absorbs X-ray radiation. For example, first slit 166 absorbs and/or reflects first X-ray 170, second X-ray 172, and seventh X-ray 182, thereby preventing X-rays 170, 172, and 182 from exiting collimating device 72. Collimating device 72 absorbs and/or reflects eighth X-ray 184. The combination of first slit 166 and collimating device 72 enhances collimation of beam 168. The larger a distance 188 between first slit 166 and the slit defined by ridge 108, the greater a provided level of collimation. If slit 166 is not present, but a smallest diameter 190 of the plurality of ridges 100, 102, 104, 106, and 108 is of similar size to radiation source 162, then similar collimation is achieved. FIG. 7 is a cut-away view of an alternative embodiment of a collimating device 192 that may be included within handheld XRF spectrometer 40 (shown in FIG. 2). In the alternative embodiment, collimating device 192 includes a housing 194 having a length 196 and a diameter 198. Housing 194 includes an interior surface 210 and an exterior surface 212. Housing 194 is generally cylindrical, centered about a longitudinal center axis 214. Housing 194 includes an inlet 220 and an outlet 222, and a cavity 224 extending between inlet 220 and outlet 222. Inlet 220 is configured to receive primary X-ray beam 60 (shown in FIG. 3) and outlet 222 is configured to output a collimated beam toward sample 62 (shown in FIG. 3). In the exemplary embodiment, cavity 224 is an internal volume that is cylindrical-shaped, having a varying internal diameter 230. Cavity 224 is also referred to herein as an opening extending between inlet 220 and outlet 222. In the alternative embodiment, collimating device 192 includes a single spiraling ridge 240 continuous from inlet 220 to outlet 222. Spiraling ridge 240 may also be referred to herein as a thread. Spiraling ridge 240 includes at least a first surface 242 and a second surface 244. X-ray radiation incident upon first surface 242 is either reflected or absorbed. First surface 242 may be substantially perpendicular to radiation applied to collimating device 192 at inlet 220. Spiraling ridge 240 is similar to an internal thread of a fastening device, for example, a nut. Spiraling ridge 240 may have a square cross-sectional shape, a triangular cross-sectional shape, a trapezoidal cross-sectional shape, or any other shape that allows collimating device 192 to function as described herein. Unlike ridges 100, 102, 104, 106, and 108 (shown in FIGS. 5 and 6), spiraling ridge 240 does not form a plurality of slits or apertures that are perpendicular to longitudinal center axis 214. However, first surface 242 of spiraling ridge 240 collimates an X-ray beam in substantially the same manner as collimating device 72. Collimating device 192 may be manufactured using a cutting tool, for example, a tap. Collimating device 192 may be any length 196, and may be particularly useful as length 196 increases due to ease in manufacturing. FIG. 8 is a flow chart 260 of an exemplary method for collimating radiation, for example, radiation generated by radiation source 58 (shown in FIG. 3). In the exemplary embodiment, the exemplary method includes providing 270 a radiation source, for example, radiation source 58, for generating radiation, for example, primary X-ray beam 60 (shown in FIG. 3). The method may also include positioning 272 a collimating device, for example, collimating device 72 (shown in FIG. 3), between radiation source 58 and a sample, for example, sample 62 (shown in FIG. 3). In the exemplary embodiment, collimating device 72 includes an interior surface 86 (shown in FIG. 4) that defines cavity 96 (shown in FIG. 4). In the exemplary embodiment, cavity 96 includes a plurality of ridges extending from interior surface 86 radially toward center axis 90 of cavity 96. The plurality of ridges define a plurality of slits configured to facilitate reducing scattering of radiation exiting collimating device 72. In the exemplary embodiment, collimating device 72 is a single part configured to fit substantially within a shielding pipe of a portable instrument, for example, but not limited to, a portable X-ray fluorescence instrument. In an alternative embodiment, the method also includes positioning 274 a first slit, for example, first slit 166 (shown in FIG. 6), between radiation source 58 and collimating device 72. First slit 166 further collimates the generated radiation (i.e., primary X-ray beam 60). The larger a distance between first slit 166 and an opposite end of collimating device 72, relative to the slit width, the greater a level of collimation produced by the first slit/collimating device combination. Described herein are exemplary methods, systems, and devices for performing an analysis of a substance using a portable spectrometer. More specifically, the methods, systems, and devices described herein facilitate reducing scatter of radiation applied to a sample during testing of the sample without increasing a distance between a radiation source and the sample. A reduction in scattered radiation facilitates reducing unwanted Bragg peaks, reducing XRF, Compton and/or Rayleigh back scatter, and reducing excitation of atoms present in the instrument that may result in fluorescence detectable by the detector. Maintaining the distance between the radiation source and the sample prevents having to increase the power provided to the radiation source to counteract the additional distance needed to apply collimation of the radiation applied to the sample. The methods, systems, and devices described herein facilitate efficient and economical examination of a sample material. The methods, systems, and devices described herein allow for a series of slits to be machined as a single part and inserted into a larger tube without using special alignment procedures. Exemplary embodiments of methods, systems, and devices are described and/or illustrated herein in detail. The methods, systems, and devices are not limited to the specific embodiments described herein, but rather, components of each system, as well as steps of each method, may be utilized independently and separately from other components and steps described herein. Each component, and each method step, can also be used in combination with other components and/or method steps. This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
041705122	summary	BACKGROUND OF THE INVENTION This invention relates generally to the fabrication of metal patterns on thin polyimide membranes and more particularly to the production of masks for x-ray lithography. Soft x-ray lithography (see Soft X-Ray Lithographic Apparatus and Process, Smith et al, U.S. Pat. No. 3,743,842, July 3, 1973) has been shown to be an effective and convenient means of replicating high resolution patterns. This capability has been demonstrated by the replication in an x-ray sensitive resist of a repetitive grating with linewidths less than 160 nanometers. In general, the masks used in x-ray lithography consist of a thin transmitter membrane which acts as a mechanical support for the absorber pattern. High attenuation in the mask membrane leads not only to long exposure time, but also to a reduction in the effective contrast of the mask. This is because the softer x-rays which are desirable for lithography are attenuated more than the harder x-rays. It is therefore desirable to minimize the attenuation of the soft x-rays in the mask transmitter membrane by utilizing a material with low absorptivity and by making the thickness of the transmitter membrane as small as possible. Several materials have been used to fabricate x-ray transmitter membranes. These include silicon (See "Soft X-Ray Mask Support Substrate", David L. Spears et al, U.S. Pat. No. 3,742,230, June 26, 1973), Al.sub.2 O.sub.3 (See P. A. Sullivan and J. H. McCoy, IEEE Trans. Electron. Devices, ED-22, 412, (1976)), Si.sub.3 N.sub.4 (See E. Spiller et al, Solid State Technol., 19 62, (1976)) and Mylar .RTM. and polyimide (J. S. Greeneich, IEEE Trans. Electron Devices, ED-22 434, (1975)). Silicon membranes thinner than 3 micrometers have not been fabricated. Silicon membranes are also opaque to visible radiation, a fact which makes the use of optical alignment techniques difficult. Al.sub. O.sub.3 membranes as thin as 0.2 micrometers have been produced. However, they are quite fragile and are limited to small areas. Si.sub.3 N.sub.4 and Si.sub.3 N.sub.4 -SiO.sub.2 membranes of 0.1 and 0.2 micrometer thickness, respectively, have been fabricated, but they also are very fragile and have been limited to areas smaller than 3 mm by 3 mm. Mylar.RTM. membranes have been used extensively for x-ray masks. The minimum thickness of Mylar.RTM. films used for x-ray masks has been limited to the commercially available thickness of 3 micrometers. A major difficulty encountered in the use of Mylar.RTM. mask transmitter membranes has been the extreme roughness of the surface of commercially available Mylar.RTM.. In addition, it is necessary to provide a means of cooling the thin, heat sensitive polymer film when depositing metal on it or during ion beam etching of the x-ray absorber pattern. Commercially available polyimide films as thin as 6 micrometers have been used as x-ray transmitter membranes. The surface of commercial polyimide is considerably smoother than the surface of commercial Mylar.RTM.. However, the difficult problem of heat-sinking the membrane during metal deposition and etching of the absorber pattern remains. It is therefore the object of this invention to provide a novel and useful mask and a process for fabricating an x-ray mask whose transmitter membrane has low x-ray attenuation, has a smooth surface, and is optically transparent. It is a feature of this invention that the thin mask membrane remains attached to a glass substrate during fabrication of the absorber pattern thus eliminating any problems of heating during absorber pattern formation. SUMMARY OF THE INVENTION X-ray masks with optically smooth polyimide transmitter membranes 0.05-50 micrometers thick which are supported on a rigid holder can be fabricated by the following procedure. A glass substrate is coated with a film of polyamic acid (typically Dupont product PI-2530, U.S. Pat. No. 3,179,634). The film is polymerized by heating, to yield polyimide. The desired absorber pattern is fabricated on the polyimide surface by any of the thin film lithographic techniques known to those skilled in the art. A metal tube is sealed to the polyimide surface using an adhesive, typically, an epoxy, and the glass substrate is dissolved by etching in hydrofluoric acid. The mask membrane can be transferred to a rigid holder smaller than the metal tube by glueing the holder to the top or bottom surface of the membrane and cutting away the excess membrane outside the ring. Distortion of the membrane during mounting of the holder can be avoided by glueing the holder to the polyimide prior to the etching of the substrate. An attractive feature of this process is the fact that the membrane remains attached to the glass substrate during fabrication of the absorber pattern. The problem of heat-sinking a thin membrane is eliminated and handling of the membranes is simplified. Other features and advantages will occur from the following description of a preferred embodiment and the accompanying drawings in which:
	summary
	abstract	A radiation therapy apparatus includes a housing, a radiation source carried by the housing, and an aperture assembly carried by the housing. The aperture assembly includes a radiation aperture body, an aperture holder and a cover. The radiation aperture body has a shaped opening therein to control a radiation dosing profile. The aperture holder has an aperture-receiving passageway therein receiving the radiation aperture body, and a recessed end. The cover is received within the recessed end of the aperture holder, and retains the radiation aperture body within the aperture holder. The cover has an opening aligned with the shaped opening in the radiation aperture body. A radiation filter is carried by the housing.
054854970	claims	1. An optical element, comprising: a substrate having a surface; and a reflective member having a predetermined thickness, said reflective member being provided on the substrate surface and including a material for reflecting one of vacuum ultraviolet radiation and X-radiation which is incident to said member, the reflectivity of said reflective member with respect to vacuum ultraviolet radiation and X-radiation being relatively higher than the reflectivity, with respect to vacuum ultraviolet radiation and X-radiation, of said substrate surface; wherein said member includes a first portion having a first reflectivity to incident vacuum ultraviolet radiation and X-radiation introduced to said member at a finite incidence angle, and a second portion having a second reflectivity to incident vacuum ultraviolet radiation and X-radiation that is smaller than the first reflectivity. wherein one pair of opposed parallel sides of the parallelogram extend substantially in parallel to the surface of said substrate while each of the other pair of opposed parallel sides of the parallelogram has a predetermined substantially finite angle .THETA..gtoreq.0 with respect to the normal line; and wherein the second portion has a cross-sectional area, the ratio of the second portion cross-sectional area to the entire cross-sectional area of said reflective member being smaller when .THETA.>0 than when .THETA.=0. a substrate having a surface; and a reflective member having a predetermined thickness, said reflective member being provided on the substrate surface and including a material for reflecting one of vacuum ultraviolet radiation and X-radiation which is incident to said reflective member, the reflectivity of said reflective member with respect to vacuum ultraviolet radiation and X-radiation being relatively higher than the reflectivity, with respect to vacuum ultraviolet radiation and X-radiation, of said substrate surface; wherein said reflective member includes a first portion having a first reflectivity to vacuum ultraviolet radiation and X-radiation introduced to said member at a finite incidence angle, and a second portion having a second reflectivity to incident vacuum ultraviolet radiation and X-radiation that is smaller than the first reflectivity. wherein the cross-section defining the cross-sectional shape is taken in the direction of a normal line to a surface of said reflective member that is generally parallel to the substrate surface; wherein one pair of opposed parallel sides of the parallelogram extend substantially in parallel to the surface of said substrate while each of the other pair of opposed parallel sides of the parallelogram has a predetermined substantially finite angle .THETA.>0 with respect to the normal line, and the optical element further comprises attenuation means provided on one of the other pair of opposed parallel sides of the parallelogram for at least reducing reflected radiation of the incident radiation from being reflected out of the side of the parallelogram on which the attenuation means is provided. a radiation source for irradiating an optical element; and an imaging optical system for directing reflected radiation from said optical element to a subject exposure member; wherein said optical element includes: the radiation from said radiation source being introduced into a first side face of said reflective member and part of the introduced radiation thereafter reflecting to emerge from a second side face of said reflective member; and said reflective member being disposed at a position on said substrate surface at which less than the total reflected radiation emerges from the second side face. a radiation source for irradiating an optical element; and an imaging optical system for directing reflected radiation from said optical element to a subject exposure member; wherein the optical element includes: the radiation from said radiation source being introduced into a first side face of said reflective member and thereafter reflecting to emerge from a second side face of said reflective member; wherein a plurality of said reflective members are provided on said substrate surface such that they are spaced from one another; and wherein the plurality of reflective members are individually disposed at positions on said substrate surface at which less than the total radiation reflected from each member emerges from the second side faces of the members. a radiation source for irradiating an optical element; and an imaging optical system for directing reflected radiation from said optical element to a subject exposure member, wherein said optical element includes: wherein said reflective member includes a first portion through which the incident radiation received from said radiation source is introduced at a finite incidence angle with respect to the direction of a normal line to the surface of said reflective member and is thereafter reflected by said reflective member, the reflectivity of said reflective member with respect to the incident radiation having a first value, and a second portion having reflectivity to the incident radiation of a second value that is smaller than the first value. wherein said reflective member has a cross-sectional shape that is substantially a parallelogram, the cross-section defining the cross-sectional shape being taken in the direction of a normal line to a surface of said reflective member that is generally parallel to the substrate surface; wherein one pair of opposed parallel sides of the parallelogram extend substantially in parallel to the surface of said substrate while each of the other pair of opposed parallel sides of the parallelogram has a predetermined substantially finite angle .THETA..gtoreq.0 with respect to the normal line; and wherein the second portion has a cross-sectional area, the ratio of the second portion cross-sectional area to the entire cross-sectional area of said reflective member being smaller when .THETA.>0 than when .THETA.=0. 2. An optical element according to claim 1, wherein said optical element is a reflection mask, a linear zone plate or a diffraction grating. 3. An optical element according to claim 1, wherein said reflective member has a cross-sectional shape that is substantially a parallelogram, the cross-section defining the cross-sectional shape being taken in the direction of a normal line to a surface of said member that is generally parallel to the substrate surface. 4. An optical element according to claim 3, wherein one pair of opposed parallel sides of the parallelogram extend substantially in parallel to the surface of said substrate while each of the other pair of opposed parallel sides of the parallelogram has a predetermined substantially finite angle .THETA. with respect to the normal line, and the optical element further comprises attenuation means provided on one of the other pair of opposed parallel sides of the parallelogram for at least reducing reflected radiation of the incident radiation from being reflected out of the side of the parallelogram on which the attenuation means is provided. 5. An optical element according to claim 4, wherein the predetermined substantially finite angle .THETA.>0. 6. An optical element according to claim 1, wherein the reflective member reflects incident radiation having a wavelength between 3 nm and 150 nm. 7. An optical element according to claim 1, wherein said reflective member is a multilayer having first and second layers respectively comprising first and second substances having different respective refraction factors for one of the vacuum ultraviolet radiation and the X-radiation, and wherein said first and second layers are cyclically arranged in said multilayer. 8. An optical element according to claim 1, wherein said reflective member includes at least one of Ni, Cr, V, W, Ti, C, Ru, Rh, Mo, Pd, Ag, B, Si, N, Be, Cu, Co, Fe and Mn. 9. An optical element according to claim 1, wherein the first reflectivity is the substantially maximum reflectivity for the material. 10. An optical element according to claim 1, wherein a cross-section of said reflective member has a cross-sectional shape other than rectangular, said cross-section being taken in the direction of a normal line to a surface of said member that is generally parallel to the substrate surface. 11. An optical element according to claim 10, wherein the cross-sectional shape of the reflective member is substantially a parallelogram; 12. An optical element according to claim 11, wherein .THETA.>0. 13. An optical element, comprising: 14. An optical element according to claim 13, wherein the first reflectivity is the substantially maximum reflectivity for the material. 15. An optical element according to claim 13, wherein the reflective member reflects incident radiation having a wavelength between 3 nm and 150 nm. 16. An optical element according to claim 13, wherein a cross-section of said reflective member has a cross-sectional shape other than rectangular, said cross-section being taken in the direction of a normal line to a surface of said member that is generally parallel to the substrate surface. 17. An optical element according to claim 13, wherein said reflective member has a cross-sectional shape that is substantially a parallelogram. 18. An optical element according to claim 17, 19. A projection exposure apparatus, comprising: 20. A projection exposure apparatus, comprising: 21. A projection exposure apparatus, comprising: 22. A projection exposure apparatus according to claim 21, wherein the first value is the substantially maximum reflectivity for the material. 23. A projection exposure apparatus according to claim 21, 24. A projection exposure apparatus according to claim 23, wherein .THETA.>0.
	claims	1. A method comprising:placing a GaAs die having a thickness of less than approximately 50 microns on a lead frame having a die attach surface comprising a soft solder; andheating the soft solder to attach the die to the lead frame. 2. The method as in claim 1, further including encapsulating the GaAs die in a plastic die package. 3. The method as in claim 1, wherein the GaAs die comprises:said GaAs substrate having an active surface and a backside surface;a diffusion barrier layer overlying the backside surface; anda copper back-metal layer overlying the diffusion barrier. 4. The method as in claim 3, wherein the GaAs substrate has a thickness of between approximately 15 microns and 50 microns. 5. The method as in claim 3, wherein the GaAs substrate has a thickness in the range of approximately 15–35 microns. 6. The method as in claim 3, wherein the GaAs substrate has a thickness of less than approximately 25 microns. 7. The method as in claim 3, wherein the copper back-metal layer has a thickness sufficient to provide mechanical support for the GaAs substrate during a soft-solder die attach process. 8. The method as in claim 3, wherein after the soft solder is heated, gold is intermingled with the soft solder. 9. A method comprising:forming a diffusion barrier layer overlying a backside surface of a GaAs substrate;forming a stress relief layer overlying the diffusion barrier layer;forming a copper back-metal layer overlying the stress relief layer; andforming an oxidation resistant layer overlying the copper-back metal layer. 10. The method as in claim 9, wherein the stress relief layer and the oxidation resistant layer comprise gold layers. 11. The method as in claim 9, further comprising coupling the oxidation resistant layer to a die attach surface of a lead frame. 12. The method as in claim 11, further comprising encapsulating the GaAs substrate, the stress relief layer, the copper back-metal layer and the oxidation resistant layer in a plastic die package. 13. The method as in claim 9, wherein coupling the oxidation resistant layer to a die attach surface comprises reflowing a soft solder layer overlying the die attach surface so as to form a solder joint between the die attach surface and at least the oxidation resistant layer. 14. The method as in claim 9, wherein the GaAs substrate has a thickness of between approximately 15 microns and 50 microns and the back-metal layer has thickness of between approximately 11 microns to 15 microns. 15. A method comprising:forming a semiconductor die comprising a GaAs substrate and a copper back-metal layer overlying a backside surface of the GaAs substrate;disposing the semiconductor die at a soft solder layer of a die attach surface of a lead frame;reflowing the soft-solder layer so as to form a solder joint between the die attach surface and the semiconductor die;electrically coupling the semiconductor die to one or more leads of the lead frame; andencapsulating the semiconductor die and the lead frame in a plastic die package. 16. The method as in claim 15, wherein forming the semiconductor die comprises forming a stress-relief layer overlying the backside surface of the GaAs substrate, wherein the stress relief layer is between the backside surface of the GaAs substrate and the back-metal layer. 17. The method as in claim 15, wherein forming the semiconductor die comprises forming an oxidization resistant layer overlying the back-metal layer. 18. The method as in claim 15, wherein forming the semiconductor die comprises forming a stress-relief layer overlying the backside surface of the GaAs substrate, wherein the stress-relief layer is between the backside surface and the back-metal layer. 19. The method as in claim 15, wherein reflowing the soft solder layer comprises providing sufficient heat to at least partially melt the copper back-metal layer. 20. The method as in claim 15, wherein the GaAs substrate has a thickness of between approximately 15 microns and 50 microns and the back-metal layer has thickness of between approximately 11 microns to 15 microns.
	summary
	claims	1. A system, comprising:means for thermoelectrically converting heat generated with a nuclear reactor to electrical energy; andmeans for selectively transferring the electrical energy to at least one first operation system of the nuclear reactor in response to a signal from a second operation system of the nuclear reactor to supply power to the at least one first operation system using the transferred electrical energy, the at least one first operation system affecting the nuclear reactor responsive to the power supplied, wherein the signal from the second operation system is responsive to at least one third operation system. 2. The system of claim 1, wherein the signal is from at least one control system. 3. The system of claim 2, wherein the signal from the at least one control system is responsive to the at least one third operation system, the at least one third operation system responsive to at least one internal condition. 4. The system of claim 2, wherein the signal from the at least one control system is responsive to the at least one third operation system, the at least one third operation system responsive to at least one external condition. 5. The system of claim 1, wherein the signal is in response to at least one shutdown event. 6. The system of claim 1, wherein the means for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor. 7. The system of claim 6, wherein the activation circuitry for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:coupling circuitry for selectively coupling at least one thermoelectric device to the at least one first operation system of the nuclear reactor. 8. The system of claim 1, wherein the means for thermoelectrically converting heat generated with a nuclear reactor to electrical energy comprises:at least one thermoelectric device for thermoelectrically converting heat generated with a nuclear reactor to electrical energy. 9. The system of claim 1, wherein the means for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:means for selectively transferring the electrical energy to at least one control system of the nuclear reactor. 10. The system of claim 1, wherein the means for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:means for selectively transferring the electrical energy to at least one monitoring system of the nuclear reactor. 11. The system of claim 1, wherein the means for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:means for selectively transferring the electrical energy to at least one coolant system of the nuclear reactor. 12. The system of claim 11, wherein the means for selectively transferring the electrical energy to at least one coolant system of the nuclear reactor comprises:means for selectively transferring the electrical energy to at least one coolant pump of the nuclear reactor. 13. The system of claim 1, wherein the means for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:means for selectively transferring the electrical energy to at least one shutdown system of the nuclear reactor. 14. The system of claim 1, wherein the means for selectively transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:means for selectively transferring the electrical energy to at least one warning system of the nuclear reactor. 15. The system of claim 1, further comprising:means for protecting the means for thermoelectrically converting heat generated with a nuclear reactor to electrical energy. 16. The system of claim 1, further comprising:means for selectively augmenting the means for thermoelectrically converting heat generated with a nuclear reactor to electrical energy. 17. The system of claim 16, wherein the means for selectively augmenting the means for thermoelectrically converting heat generated with a nuclear reactor to electrical energy comprises:at least one reserve thermoelectric device and reserve actuation circuitry for selectively augmenting the at least one thermoelectric device, the reserve actuation circuitry configured to selectively couple the at least one reserve thermoelectric device to the at least one thermoelectric device. 18. The system of claim 1, further comprising:means for modifying the electrical energy. 19. An apparatus, comprising:at least one thermoelectric device for thermoelectrically converting heat generated with a nuclear reactor to electrical energy;at least one first operation system, at least one second operation system, and at least one third operation system; andactivation circuitry for, responsive to at least one signal from the at least one second system responsive to the at least one third operation system, selectively transferring the electrical energy from at least one electrical output of the at least one thermoelectric device to the at least one first operation system of the nuclear reactor to supply power to the at least one first operation system, the at least one first operation system affecting the nuclear reactor responsive to the power supplied. 20. The apparatus of claim 19, wherein the activation circuitry for selectively transferring the electrical energy from at least one electrical output of the at least one thermoelectric device to at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one condition, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 21. The apparatus of claim 20, wherein the activation circuitry for, responsive to at least one condition, transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one signal from the at least one second operation system, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 22. The apparatus of claim 21, wherein the at least one second operation system is different than the at least one first operation system of the nuclear reactor. 23. The apparatus of claim 21, wherein the activation circuitry for, responsive to at least one signal from at least one second operation system, transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one signal from at least one monitoring system, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 24. The apparatus of claim 21, wherein the activation circuitry for, responsive to at least one signal from at least one second operation system, transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one signal from at least one safety system, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 25. The apparatus of claim 21, wherein the activation circuitry for, responsive to at least one signal from at least one second operation system, transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one signal from at least one security system, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 26. The apparatus of claim 21, wherein the activation circuitry for, responsive to at least one signal from at least one second operation system, transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one signal from at least one control system, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 27. The apparatus of claim 21, wherein the activation circuitry for, responsive to at least one signal from at least one control system responsive to at least one third operation system, transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one signal from at least one control system responsive to at least one third operation system, the at least one third operation system responsive to at least one internal condition, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 28. The apparatus of claim 21, wherein the activation circuitry for, responsive to at least one signal from at least one control system responsive to at least one third operation system, transferring the electrical energy to the at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one signal from at least one control system responsive to at least one third operation system, the at least one third operation system responsive to at least one external condition, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 29. The apparatus of claim 20, wherein the activation circuitry for, responsive to at least one condition, transferring the electrical energy to at least one first operation system of the nuclear reactor comprises:activation circuitry for, responsive to at least one shutdown event, transferring the electrical energy to the at least one first operation system of the nuclear reactor. 30. The apparatus of claim 19, wherein the at least one thermoelectric device for thermoelectrically converting nuclear reactor generated heat to electrical energy comprises:at least one thermoelectric device optimized for a specified range of operating characteristics for thermoelectrically converting nuclear reactor generated heat to electrical energy. 31. The apparatus of claim 19, wherein the at least one thermoelectric device for thermoelectrically converting nuclear reactor generated heat to electrical energy comprises:a first thermoelectric device optimized for a first range of operating characteristics and at least one additional thermoelectric device optimized for a second range of operating characteristics, the second range of operating characteristics different from the first range of operating characteristics, for thermoelectrically converting nuclear reactor generated heat to electrical energy. 32. The apparatus of claim 19, wherein the at least one thermoelectric device for thermoelectrically converting nuclear reactor generated heat to electrical energy comprises:at least one thermoelectric device sized to meet at least one selected operational requirement of the nuclear reactor for thermoelectrically converting nuclear reactor generated heat to electrical energy. 33. The apparatus of claim 32, wherein the at least one thermoelectric device sized to meet at least one selected operational requirement of the nuclear reactor for thermoelectrically converting nuclear reactor generated heat to electrical energy comprises:at least one thermoelectric device for thermoelectrically converting nuclear reactor generated heat to electrical energy, the at least one thermoelectric device sized to at least partially match the heat rejection of the at least one thermoelectric device with at least a portion of the heat produced by the nuclear reactor. 34. The apparatus of claim 19, wherein the at least one thermoelectric device for thermoelectrically converting nuclear reactor generated heat to electrical energy comprises:at least two series coupled thermoelectric devices for thermoelectrically converting nuclear reactor generated heat to electrical energy. 35. The apparatus of claim 19, wherein the at least one thermoelectric device for thermoelectrically converting nuclear reactor generated heat to electrical energy comprises:at least two parallel coupled thermoelectric devices for thermoelectrically converting nuclear reactor generated heat to electrical energy. 36. The apparatus of claim 19, wherein the at least one operation system of the nuclear reactor comprises:at least one control system of the nuclear reactor. 37. The apparatus of claim 19, wherein the at least one operation system of the nuclear reactor comprises:at least one monitoring system of the nuclear reactor. 38. The apparatus of claim 19, wherein the at least one operation system of the nuclear reactor comprises:at least one coolant system of the nuclear reactor. 39. The apparatus of claim 38, wherein the at least one coolant system of the nuclear reactor comprises:at least one coolant pump of the nuclear reactor. 40. The apparatus of claim 19, wherein the at least one operation system of the nuclear reactor comprises:at least one shutdown system of the nuclear reactor. 41. The apparatus of claim 19, wherein the at least one operation system of the nuclear reactor comprises:at least one warning system of the nuclear reactor. 42. The apparatus of claim 19, further comprising:regulation circuitry for protecting the at least one thermoelectric device. 43. The apparatus of claim 19, further comprising:at least one reserve thermoelectric device and reserve actuation circuitry for selectively augmenting the at least one thermoelectric device, the reserve actuation circuitry configured to selectively couple the at least one reserve thermoelectric device to the at least one thermoelectric device. 44. The apparatus of claim 43, wherein the at least one reserve thermoelectric device and reserve actuation circuitry for selectively augmenting the at least one thermoelectric device, the reserve actuation circuitry configured to selectively couple the at least one reserve thermoelectric device to the at least one thermoelectric device, comprises:at least one relay system, at least one electromagnetic relay system, at least one solid state relay system, at least one transistor, at least one microprocessor controlled relay system, at least one microprocessor controlled relay system programmed to respond to at least one external condition, or at least one microprocessor controlled relay system programmed to respond to at least one internal condition for selectively coupling at least one reserve thermoelectric device to the at least one thermoelectric device.
	summary
	abstract	The present invention relates to a disposal container and a storage system for high-level radioactive waste and, more specifically, to a disposal container for high-level radioactive waste using multiple barriers and a barrier system using thereof, the disposal container having the multiple barriers consisting of an inner wall made of carbon steel for excellent corrosion resistance and ease of manufacture, a middle wall made of Inconel, which is bonded to a lateral surface of the inner wall, and an outer wall made of copper, which is bonded to a lateral surface of the middle wall.
054917310	claims	1. An automated method for maintaining pressure within a nuclear power plant primary loop, the method comprising the steps of: partially filling a portion of a pressurizer vessel, in fluid communication with the primary loop, with a liquid for maintaining pressure in the primary loop; circulating a primary coolant through the primary loop with a reactor coolant pump while controlling the pressure in the pressurizer vessel bye: circulating the primary coolant through the primary loop with a reactor coolant pump after: sensing the pressure of the primary coolant circulating through the primary loop by the first automated device; and initiating or terminating said injection step by the first automated device in response to the sensed pressure of the primary coolant. sensing the pressure of the primary coolant circulating through the primary loop by the second automated device; and initiating or terminating said venting step by the second automated device in response to the sensed pressure of the primary coolant. 2. The method as in claim 1, wherein nitrogen is injected into the pressurizer vessel. 3. The method as in claim 2, wherein said injecting of step (i) includes: 4. The method as in claim 3, wherein said venting of step (ii) includes: 5. The method as in claim 1, wherein the inert gas is injected by the first automated device at a first predetermined pressure of about 380 psig. 6. The method as in claim 5, wherein the inert gas is vented by the second automated device at a second predetermined pressure of about 400 psig. 7. The method as in claim 18 wherein the pressure is automatically controlled within a range of about 20 psi.
	description	This is a continuation, under 35 U.S.C. §120, of copending International Application No. PCT/EP2011/061234, filed Jul. 4, 2011, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2010 031 610.5, filed Jul. 21, 2010; the prior applications are herewith incorporated by reference in their entirety. Field of the Invention The invention relates to a component for conducting or receiving a fluid, in particular a component of a fluid-conducting line system of an industrial plant, especially a line system of a tertiary cooling circuit of a nuclear power station. The invention relates, moreover, to a method for testing such a component. The components of a fluid-conducting line system in industrial plants, for example in plants in the chemical industry or in power plants, for example the cooling lines in the tertiary cooling circuit of a nuclear power station, are often composed of underground, internally and externally rubberized steel lines or concrete pipes. Both types of pipe, however, are subject to wear due to corrosion or erosion and often have to be replaced in older nuclear power plants. Particularly in the case of nuclear power plants cooled by seawater, the corrosion of a steel line presents a serious problem, as soon as the rubberizing layer is attacked or damaged. For that reason, the components of those line systems which are composed of steel or concrete are replaced by components having a load-bearing structural element which is constructed from a glass fiber reinforced plastic, for example a composite material composed of glass fibers and epoxy resin (EP). The respective components are additionally provided both on their inside and their outside with a protective or reinforcing layer. The disadvantage of components of that type, however, is their restricted testability since commonly acceptable methods, such as for example, eddy-current testing, cannot be adopted, since they presuppose an electrically conductive material. Ultrasonic testing methods, although fundamentally possible, are nevertheless unsuitable for practical use because of the complex composite construction. At the present time, therefore, the testing of such components, which are constructed from a composite glass fiber/plastic material and which may not only be components of a line system, but also containers fillable with a fluid, is only carried out by a visual inspection, in such a way that a manipulator is inserted into the component to be tested and the inner surface of the latter is inspected with a video camera. Visual inspection is difficult, however, since the emptied components are usually wet and there are sometimes deposits, sludge and biofilm on the inner walls. Only conspicuous changes on the inner pipe wall can therefore be established by a visual inspection. It is accordingly an object of the invention to provide a component for conducting or receiving a fluid and a method for testing the component, which overcome the hereinafore-mentioned disadvantages of the heretofore-known components and methods of this general type and in which the component is constructed on the basis of a glass fiber reinforced plastic and can be tested in a simple way for the presence of damage. With the foregoing and other objects in view there is provided, in accordance with the invention, a component for conducting or receiving a fluid, in particular a component of a fluid-conducting line system of an industrial plant, especially of a line system of a tertiary cooling circuit of a nuclear power station. The component has a wall comprising a carrying structure composed of a glass fiber reinforced plastic, the carrying structure having inner and outer surfaces, electrically insulating inner and outer protective layers each disposed on a respective one of the inner and outer surfaces of the carrying structure, an electrically conductive inner intermediate layer having an electrical terminal and being disposed between the inner protective layer and the carrying structure, and an electrically conductive outer intermediate layer having an electrical terminal, being insulated electrically from the inner intermediate layer and being disposed between the outer protective layer and the carrying structure. In this context, both pipelines and components of a fluid-conducting line system and stationary and transportable containers fillable with a fluid, that is to say receiving a fluid, are to be understood as being a component in the sense of the present invention. By virtue of these measures, leakages in the carrying structure can be detected in a simple way by measurement of the electrical resistance between the inner and outer intermediate layers if the fluid located in the component is intrinsically electrically conductive or has been made electrically conductive at the measurement time by the addition of suitable chemical substances. In accordance with another feature of the invention, since the production of the carrying structure takes place, as a rule, in a so-called winding method in which resin-impregnated glass fiber rovings are wound crosswise onto a rotating steel core, the production of the component is simplified if the intermediate layer or intermediate layers is or are formed by an electrically conductive fabric, since it can be applied in the same winding or application technique as the carrying structure. With the objects of the invention in view, there is concomitantly provided a method for testing a component. The method comprises providing a component according to the invention and detecting an electrical resistance between the outer and inner intermediate layers. Thus, defects in the carrying structure can be detected by carrying out a simple electrical continuity test, that is to say by measuring the electrical resistance between the outer and inner intermediate layers if the fluid is electrically conductive. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a component for conducting or receiving a fluid and a method for testing the component, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a wall of a component of a fluid-conducting line system which is constructed from a carrying structure 2 serving as a load-bearing wall part. The carrying structure 2 is electrically nonconductive and is composed of a glass fiber reinforced composite material. The wall is provided on its inner surface and outer surface with respective electrically insulating inner and outer protective layers 4 and 6. An electrically conductive inner intermediate layer 10 provided with an electrical terminal 8 is located between the inner protective layer 4 and the carrying structure 2, and a likewise electrically conductive outer intermediate layer 14 provided with an electrical terminal 12 and insulated electrically from the inner intermediate layer 10 by the carrying structure 2 is located between the outer protective layer 6 and the carrying structure 2. In other words: the carrying structure 2 is provided on each of its inner and outer surfaces with a respective electrically conductive inner and outer intermediate layer 10 and 14, to which the inner and outer protective layers 4 and 6 are applied. The inner and outer protective layers 4 and 6 respectively protect the component against damage from the inside and outside. Line components in which abrasive particles, for example sand, are entrained by the coolant, are usually provided with an inner protective layer 4 made from rubber which is about 2 mm thick. The electrical terminals 8 and 12 of the inner and outer electrically conductive intermediate layers 10 and 14 are accessible from outside and, for example, are disposed on the outside of the outer protective layer 6. The electrically conductive intermediate layers 10 and 14 are manufactured from a netting or fabric, for example a fine silver netting, a high-grade steel fabric, a glass fiber netting or a glass fiber fabric with woven-in metal filaments or a carbon fiber composite material. An electrical resistance R between the inner and outer intermediate layers 10 and 14 can be monitored by a measuring device 16. In the event of a leakage in the carrying structure 2 and in the inner protective layer 4, the fluid located inside the component penetrates into the carrying structure 2 and forces its way through it as far as the outer intermediate layer 14. If the fluid, usually water, located inside the component is electrically conductive, the electrical insulation properties of the carrying structure 2 are impaired correspondingly and the ohmic resistance R between the inner and outer intermediate layers 10 and 14 is reduced. Electrically nonconductive fluids may be made conductive for a measurement duration by an admixing of additives. Simple and reliable monitoring of the component for the occurrence of a leak is thereby possible. According to FIG. 2, a line system 20 is constructed from a plurality of components 20a-e and has pipeline parts connected to one another through flanges 22, as illustrated in the figure. Ohmic resistances between conductive intermediate layers of the individual components 20a-e are detected in a central monitoring device 30 which is provided for monitoring the line system 20. Thus, the occurrence of a leakage in the line system can be detected automatically and the component affected can be recognized.
050842366	claims	1. A nuclear reactor coolant pump for pumping reactor coolant fluid in a reactor coolant system, said pump comprising: (a) a casing defining an inlet nozzle for receiving a reactor coolant fluid, a converging spout outlet nozzle for discharging the reactor coolant fluid, and a passage interconnecting said inlet nozzle and said outlet nozzle through which the reactor coolant fluid can flow from said inlet nozzle to said outlet nozzle; (b) a rotor extending axially through said casing and having an end disposed adjacent said passage defined by said casing; and (c) an impeller mounted to said end of said rotor and disposed in communication with said passage, said impeller being rotatable with said rotor about an axis, said impeller being axially offset from said outlet nozzle for drawing fluid into said casing through said inlet nozzle and discharging fluid from said casing tangentially through said converging spout outlet nozzle after flow through said passage; (d) said converging spout outlet nozzle being composed of first and second wall portions defined above and below an imaginary plane extending generally parallel to said rotation axis of said impeller, said first wall portion extending substantially tangentially to said casing and having a substantially semi-cylindrical shape, said second wall portion having a combined substantially semi-elliptical and semi-conical shape. 2. The coolant pump as recited in claim 1, wherein an exit opening of said converging spout outlet nozzle has a substantially circular shape. 3. The coolant pump as recited in claim 1, wherein said semi-conical shape of said second wall portion defines a cone angle of less than approximately thirty degrees. 4. The coolant pump as recited in claim 1, wherein said semi-conical shape of said second wall portion defines a cone angle of approximately twenty-five degrees.
047770082	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, a water chamber isolating device (50) according to one preferred embodiment of the present invention will be described in more detail with reference to FIGS. 1 to 7. In FIG. 1, a water chamber (1) communicated with a nuclear reactor vessel via coolant piping communicates with a nozzle section (2) of the coolant piping, and at a manhole (25) communicating with the water chamber (1) is formed a mount seat (3) for a cover (not shown). A plug (4) disposed within the nozzle section (2) consists of a circular plate shaped seal lid (5), a hold plate (6), a mount plate (7) and the like, and it occupies a principal portion of the water chamber isolating device (50). A rigid support frame comprising a rigid support arm (8) has its one end detachably secured to the mount seat (3) at the manhole (25) by means of bolts (9) and the other end engaged with an inner wall surface of the nozzle section (2). An attitude of the plug (4) is held in a favorable manner by means of an angle adjusting screw (10) comprising a threaded support rod interposed between the support arm (8) and the mount plate (7). The seal lid (5) has a diameter greater than that of the manhole but is formed of a lid member and hinges (11), the lid member being foldable in three rigid plate-shaped pieces at hinges (11) as shown in FIG. 2(a) (by dash lines) and in FIG. 2(b) (by dash-dot lines) in order that it can be brought into the water chamber (1) through the manhole (25), and onto the bottom and top surfaces of the seal lid (5) are attached rubber seal plates (12) and (13), respectively. In addition, four stud bolts (14) for integrally fastening the hold plate (6) and the mount plate (7) are fixedly secured to the seal lid (5). The hold plate (6), also having a diameter greater than that of the manhole, is divided into two pieces as shown in FIGS. 3(a) and 3(b) in order that it can be brought into the water chamber (1) through the manhole (25) which is smaller than (has a diameter smaller than that of) the nozzle section (2), and it is provided with mushroom-shaped bolt-holes (15) through which the stud bolts (14) penetrate, in order to facilitate positioning of the hold plate (6). The mount plate (7) is provided with brackets (16) projecting from its top surface at its one end as shown in FIGS. 4(a) and 4(b), and these brackets (16) are pivotably engaged with a pin (17) which is in turn pivotably engaged with brackets (18) projecting from the bottom surface of the support arm (8) at its one end. In addition, in a seat (19) fixedly secured to a central portion of the top surface of the mount plate (7) is fitted a sphere (20) provided at the bottom end of the angle adjusting screw (10) so as to be able to perform a precession motion. The angle adjusting screw (10) is threadedly mated with a threaded hole (22) in a cylindrical pin (21) that is slidably and rotatably supported by the support arm (8) and extends through the hole (22), and a rectangular surface (23) is formed at the top end of the angle adjusting screw (10). In the mount plate (7) are also formed mushroom-shaped bolt-holes (24) through which the stud bolts (14) penetrate, in order to facilitate positioning of the mount plate (7). Then, under the condition that water has been extracted from the coolant circulating loop including the steam generator and the manhole (25) has been opened, the water chamber isolating device (50) is mounted. More particularly, after the seal lid (5) has been folded in three pieces and thus brought into the water chamber (1) through the manhole (25), it is again extended into a plate shape within the water chamber (1). Subsequently, the hold plate (6) is brought into the water chamber (1) through the manhole (25) as divided into two pieces. Furthermore, the mount plate (7) and the support arm (8) are brought into the water chamber (1) through the manhole (25) in the assembled state as shown in FIGS. 4(a) and 4(b). Then the hold plate (6) is superposed on the seal lid (5), further the mount plate (7) is superposed thereon with the stud bolts (14) penetrated through the mushroom-shaped bolt-holes (15) and (24) to effect positioning, nuts (26a) are threadedly engaged with the top ends of the stud bolts (14) and fastened, and thereby the plug (4) is assembled. Next, if the angle adjusting screw (10) is rotated by engaging a spanner or the like with the rectangular surface (23) formed at the top end of the screw (10), then the plug (4) is rotated about the pin (17) and forms a predetermined angle with respect to the support arm (8). Then, the plug (4) is inserted into the nozzle section (2), and under the condition that the tip end of the support arm (8) is engaged with the inner wall surface of the nozzle section (2), the base end of the support arm (8) is fixedly secured to the mount seat (3) at the manhole (25) by means of the bolts (9). In this way, blocking of the nozzle section (2) by means of the plug (4) is completed. It is to be noted that the seal lid (5) could be modified in such manner that it is divided into two pieces as shown in FIGS. 5(a) and 5(b) and the two pieces are connected by the rubber plate (12) secured to their bottom surfaces so as to be folded in two pieces as shown by dash-dot lines. Moreover, as shown in FIG. 6, the hold plate (6) could be omitted. Thus, when the blocking of the nozzle section (2) by the plug (4) has been completed, water is poured into the nuclear reactor cavity (05). Then, the water reaches the nozzle section (2) through the coolant piping (04), a hydraulic pressure of about 1 kg/cm.sup.2 is exerted upon the bottom surface of the plug (4), hence the rubber plate (12) attached to the bottom surface of the seal lid (5) is brought into press-contact with the inner wall surface of the nozzle section (2) to seal the plug (4), and at the same time, the force applied to the plug (4) by this hydraulic pressure is borne by the inner wall surface of the nozzle section (2) via the tip end of the support arm (8). In this way, the steam generator can be isolated from the other primary cooling systems, so that under this condition, inspection of the thin tubes in the steam generator can be carried out as by means of a robot or the like, and simultaneously with this thin tube inspection, routine inspection tasks relating to the nuclear reactor can be effected. In order to prevent leakage water from flowing out of the water chamber (1) in the event that water should leak through the plug (4) provided in the nozzle section (2), the manhole (25) is closed by a cover (26) as shown in FIGS. 7(a) and 7(b). The cover (26) is connected to a seat plate (28) so as to be swingable about a hinge (27), and the seat plate (28) is fastened to the mount seat (3) at the manhole (25) by means of bolts (29) and nuts (30). By rotating levers (31) in the direction of arrows, which levers are mounted so as to be rotatable about the bolts (29), the tip ends of the levers (31) are brought into contact with the outwardly convexed outer surface of the cover (26), and hence the cover (26) is brought into tight contact with the seat plate (28). Reference numeral (32) designates a handle provided on the outer surface of the cover (26), numeral (33) designates a robot for inspection and repair of the thin tubes in the steam generator, numeral (34) designates a cable for controlling the robot (33), which cable extends externally through a seal (35) provided at the center of the cover (26). Upon inspection and repair of the thin tubes in the steam generator, the manhole (25) is opened while the cover (26) is kept in the state shown by dash-dot lines in FIG. 7(a), but in the event that water should leak through the plug (4), the manhole (25) is closed by rotating the cover (26) about the hinge (27) while gripping the handle (32), then the cover (26) is brought into tight contact with the seat plate (28) by rotating the levers (31) about the bolts (29) in the direction of arrows, and thereby the leakage water through the plug (4) is prevented from flowing out through the manhole (25). According to the present invention, owing to the fact that a plug is disposed in a nozzle section of a coolant piping communicating with a water chamber in a steam generator for a pressurized water type nuclear reactor, the plug is supported by a support arm having an angle adjusting screw and fixedly secured to a mount seat at a manhole communicating with the same water chamber and a cover is provided on the mount seat at the same manhole, the nozzle section of the coolant piping communicating with the water chamber in the steam generator can be blocked by the plug and thereby the steam generator can be isolated from the other primary coolling systems. Accordingly, inspection and repair of thin tubes in the steam generator as well as routine inspection tasks relating to the nuclear reactor can be carried out in parallel and simultaneously, so that the period of routine inspection can be shortened, and therefore, the present invention can contribute to reduction of exposure to radiation and enhancement of an operation rate of an atomic power station. Moreover, since the plug is supported at a predetermined attitude from the support arm fixedly secured to the amount seat at the manhole by means of the angle adjusting screw, and since a hydraulic pressure applied to the plug is borne by the steam generator via the support arm, a special support means is unnecessary. Furthermore, owing to the fact that a cover is provided on the mount seat at the manhole, even if water should leak through the plug, the leakage water can be prevented from flowing out through the manhole. Since many changes and modifications can be made to the above-described construction without departing from the spirit of the present invention, it is intended that all matter contained in the above description and illustrated in the accompanying drawings shall be interpreted to be illustrative and not as a limitation to the scope of the invention.
	claims	1. A tool configured to reposition a spring-biased retainer of a boiling water reactor core shroud head bolt about a head bolt nut, the tool comprising:a frame having a first end and a second end, said frame defining a side opening and including:a plurality of elongate arms each having first and second ends, a length, and a longitudinal axis,a first transverse arm coupled to a first pair of said plurality of elongate arms at their second ends, and a second transverse arm coupled to a second pair of said plurality of elongate arms at their second ends;an engagement member coupled to said frame at said first end such that said frame and said engagement member are relatively movable; anda collar coupled to said frame at said frame second end, said collar defining an opening therein, said collar opening being aligned with said frame side opening, and said collar being configured to engage the retainer;wherein said collar is coupled to said first and second transverse arms and extends inward toward a center of said frame; andwherein the tool is configured to exert a repositioning force to the retainer upon engagement of said engagement member with the core shroud head bolt.
	claims	1. A method of disposing nuclear waste and other hazardous waste, the method comprising the steps of:(i) blending a waste stream, which includes at least one waste selected from the group consisting of a radioactive waste and a hazardous waste, with a liquid to produce a dense fluid denser than a surrounding rock formation;(ii) pumping a portion the dense fluid into a tubing string of an injection boring; and(iii) gravity fracturing the surrounding rock formation using the portion of the dense fluid;the portion of the dense fluid after step (iii) continuing to propagate downward in a gravity fracture as the gravity fracture continues to propagate downward. 2. A method according to claim 1 wherein a second portion of the dense fluid after being pumped into the tubing string of the injection boring enters the gravity fracture and continues a downward travel as the dense fluid drains from the injection boring. 3. A method according to claim 1 wherein the portion of the dense fluid after entering the gravity fracture continues a downward travel after becoming detached from any dense fluid remaining in the injection boring. 4. A method according to claim 1 wherein the portion of the dense fluid after entering the gravity fracture continues a downward travel and remains connected by a thin film to any dense fluid remaining in the injection boring. 5. A method according to claim 1 wherein the portion of the dense fluid, when in a detached state, reaches an immobilization point below the initial entry point of the portion of the dense fluid into the surrounding rock formation. 6. A method according to claim 5 wherein the immobilization point occurs at a depth in a range of about 2,000 to 50,000 feet (about 600 to 15,000 meters). 7. A method according to claim 1 wherein the portion of the dense fluid propagates downward and then curves in a horizontal direction creating a sub-horizontal storage space. 8. A method according to claim 1 further comprising the step of adding at least one other dense fluid to the injection boring. 9. A method according to claim 1 further comprising the step of monitoring a movement of the portion of the dense fluid after it has exited the injection boring. 10. A method according to claim 1 wherein the dense fluid is a slurry. 11. A method according to claim 1 wherein the liquid includes at least a portion thereof selected from the group consisting of a cross-linked polymer gel and a hydrated clay slurry. 12. A method according to claim 10 further comprising the slurry including a solid material which is blended with the waste stream. 13. A method according to claim 12 wherein the solid material is a metal. 14. A method according to claim 13 wherein the metal is selected from the group consisting of bismuth, iron, lead, and copper. 15. A method according to claim 12 wherein a liquid component of the slurry is a metal having a melting temperature less than a temperature at a bottom end of the injection boring. 16. A method according to claim 15 wherein the metal is selected from the group consisting of mercury, woods metal, indalloy 15, and gallium. 17. A method according to claim 12 wherein the solid material contains one or more radionuclides. 18. A method according to claim 5 wherein the immobilization point occurs at a depth greater than 50,000 feet (about 15,000 meters). 19. A method according to claim 1, wherein the portion of the dense fluid, when in a detached state, does not reach an immobilization point below the initial entry point of the portion of the dense fluid into the surrounding rock formation. 20. A method according to claim 10 wherein the slurry contains one or more radionuclides. 21. A method according to claim 1 wherein the gravity fracture continues to propagate downwards after the dense fluid detaches from any dense fluid remaining in the injection boring. 22. A system for abyssal sequestration of nuclear waste and other types of hazardous waste, the system comprising:a gravity fracture filled with a dense fluid having at least one waste selected from the group consisting of a radioactive waste and a hazardous waste, with a liquid and, a solid material added as needed, the dense fluid being denser than a rock formation into which the dense fluid is to be disposed so as to cause the surrounding rock formation to gravity fracture when the dense fluid exits an injection boring drilled into the rock formation, the dense fluid propagating downward in the gravity fracture as the gravity fracture propagates downward. 23. A system according to claim 22 wherein the dense fluid has a density of at least 3.0 g/cm3.
	claims	1. A core spray sparger T-box attachment assembly for a nuclear reactor pressure vessel, the pressure vessel including a shroud, a sparger T-box penetrating the shroud, a plurality of sparger distribution header pipes coupled to the sparger T-box, and a downcomer pipe, the sparger distribution header pipes including at least one sparger nozzle, the sparger T-box attachment assembly comprising:a downcomer pipe coupling; anda sparger T-box clamp;wherein the downcomer pipe coupling includes a draw bolt,wherein the sparger T-box clamp includes:an anchor plate including side ends;a seal plate;a first clamp block substantially aligned at a first of the side ends;a second clamp block substantially aligned at a second of the side ends;a plurality of first bolts;a plurality of second bolts; anda plurality of third bolts;wherein the anchor plate further includes a first draw bolt opening configured to receive the draw bolt,wherein the seal elate includes a second draw bolt opening configured to receive the draw bolt,wherein the seal plate further includes a plurality of bolt openings configured to receive the third bolts,wherein the seal plate is coupled to the anchor plate with the plurality of third bolts,wherein the first clamp block is configured to be fixed to a first sparger distribution header pipe by the plurality of first bolts acting between the first clamp block and the first sparger distribution header pipe, andwherein the second clamp block is configured to be fixed to a second sparger distribution header pipe by the plurality of second bolts acting between the second clamp block and the second sparger distribution header pipe. 2. The attachment assembly of claim 1, wherein the anchor plate further includes:a plurality of openings configured to receive the third bolts and configured to align with the plurality of bolt openings of the seal plate. 3. The attachment assembly of claim 1, wherein the anchor plate and the first clamp block are connected by a first dovetail joint, andwherein the anchor plate and the second clamp block are connected by a second dovetail joint. 4. The attachment assembly of claim 1, wherein the first and second clamp blocks each include a plurality of aligned T-bolt openings configured to receive a T-bolt assembly, andwherein the T-bolt assembly includes a T-bolt, a T-bolt nut, and a pipe seal. 5. The attachment assembly of claim 4, wherein the T-bolt nut engages with a latch spring to permit rotation of the T-bolt nut in only one direction. 6. The attachment assembly of claim 4, wherein the T-bolt is inserted into a slot in a respective sparger distribution header pipe to provide the sparger T-box clamp with a tight seal against the respective sparger distribution header pipe. 7. The attachment assembly of claim 4, wherein the pipe seal is sealed adjacent to a respective sparger distribution header pipe. 8. The attachment assembly of claim 4, wherein bearing surfaces of the T-bolt nut, pipe seal, and first and second clamp blocks allow articulation of the T-bolt to ensure a tight seal with a respective sparger distribution header pipe. 9. The attachment assembly of claim 4, wherein the T-bolt includes a key that interfaces with a slot in a bore of the pipe seal to permit a 90-degree rotation of the T-bolt. 10. The attachment assembly of claim 4, wherein the pipe seal includes an external key to prevent rotation, andwherein the external key interfaces with a slot on the first or second clamp block. 11. The attachment assembly of claim 1, further comprising:a plurality of legs extending from a face of the anchor plate;wherein the plurality of legs is configured to engage an inside surface of the shroud. 12. The attachment assembly of claim 1, wherein the draw bolt engages a latch spring to permit rotation of the draw bolt in only one direction. 13. The attachment assembly of claim 1, wherein the third bolts include a circumferential groove at one end of the third bolts,wherein each of the third bolts is coupled to the seal plate by a respective dowel pin,wherein the respective dowel pin extends at least partially into the seal plate, andwherein the respective dowel pin is positioned to interface with the circumferential groove. 14. The attachment assembly of claim 1, wherein the anchor plate further includes:a plurality of bolt openings configured to accommodate the third bolts; anda plurality of slots configured to accommodate a plurality of latch springs. 15. The attachment assembly of claim 1, wherein the first clamp block includes a plurality of openings configured to accommodate the first bolts,wherein the first clamp block includes a plurality of slots configured to accommodate a plurality of latch springs,wherein the second clamp block includes a plurality of openings configured to accommodate the second bolts, andwherein the second clamp block includes a plurality of slots configured to accommodate a plurality of latch springs. 16. The attachment assembly of claim 1, wherein the first clamp block includes a plurality of openings configured to accommodate the first bolts, andwherein the first clamp block includes a plurality of slots configured to accommodate a plurality of latch springs. 17. The attachment assembly of claim 1, wherein the second clamp block includes a plurality of openings configured to accommodate the second bolts, andwherein the second clamp block includes a plurality of slots configured to accommodate a plurality of latch springs. 18. A core spray sparger T-box attachment assembly for a nuclear reactor pressure vessel, the pressure vessel including a shroud, a sparger T-box penetrating the shroud, a plurality of sparger distribution header pipes coupled to the sparger T-box, and a downcomer pipe, the sparger distribution header pipes including at least one sparger nozzle, the sparger T-box attachment assembly comprising:a downcomer pipe coupling; anda sparger T-box clamp;wherein the downcomer pipe coupling includes a draw bolt,wherein the sparger T-box clamp includes:an anchor plate including side ends;a first clamp block substantially aligned at a first of the side ends;a second clamp block substantially aligned at a second of the side ends;a plurality of first T-bolts; anda plurality of second T-bolts;wherein the anchor plate further includes a first draw bolt opening configured to receive the draw bolt,wherein the first clamp block is configured to be fixed to a first sparger distribution header pipe by the plurality of first T-bolts acting between the first clamp block and the first sparger distribution header pipe, andwherein the second clamp block is configured to be fixed to a second sparger distribution header pipe by the plurality of second T-bolts acting between the second clamp block and the second sparger distribution header pipe. 19. A core spray sparger T-box attachment assembly for a nuclear reactor pressure vessel, the pressure vessel including a shroud, a sparger T-box penetrating the shroud, a plurality of sparger distribution header pipes coupled to the sparger T-box, and a downcomer pipe, the sparger distribution header pipes including at least one sparger nozzle, the sparger T-box attachment assembly comprising:a downcomer pipe coupling; anda sparger T-box clamp;wherein the downcomer pipe coupling includes a draw bolt,wherein the sparger T-box clamp includes:an anchor plate including side ends;a first clamp block substantially aligned at a first of the side ends;a second clamp block substantially aligned at a second of the side ends;two first T-bolts; andtwo second T-bolts;wherein the anchor plate further includes a draw bolt opening configured to receive the draw bolt,wherein the first clamp block is configured to be fixed to a first sparger distribution header pipe by the two first T-bolts acting between the first clamp block and the first sparger distribution header pipe, andwherein the second clamp block is configured to be fixed to a second sparger distribution header pipe by the two second T-bolts acting between the second clamp block and the second sparger distribution header pipe. 20. The attachment assembly of claim 18, further comprising: a seal plate coupled to the anchor plate with a plurality of third bolts; wherein the seal plate includes:a plurality of bolt openings configured to receive the third bolts; anda second draw bolt opening configured to receive the draw bolt.
	description	The present invention relates to a SEM-type defect-reviewing apparatus that uses a detection system of a scanning electron microscope (SEM) to automatically acquire high-resolution images of any semiconductor wafer surface defects detected by an inspection apparatus during manufacturing processes for semiconductor products. The invention also relates to a method for reviewing defects using the SEM-type defect-reviewing apparatus. To achieve early ramp-up of high yield manufacturing of large-scale integrated circuits and stable operation of their manufacturing process equipment, information on the occurrence of the defects detected by visual inspection apparatus, must be analyzed rapidly and utilized for defect route cause analysis. Reviewing apparatuses that automatically acquire high-resolution images of the inspection apparatus-detected defects in order to analyze obtained defect information are broadly divided into a type having an optical detection system, and a type having a detection system based on a scanning electron microscope (SEM). Compared with the optical type of reviewing apparatus, the SEM type of reviewing apparatus can obtain detailed defect images. For this reason, adoption of the SEM type of reviewing apparatus capable of obtaining high-resolution images is increasing with finer wiring patterns on semiconductor wafers. However, since SEM images require a longer acquisition time than optical images, the SEM type of reviewing apparatus has the problem that its throughput (hourly defect detection capability) is low, compared with that of the optical type of reviewing apparatus. Known conventional techniques relating to such a SEM-type reviewing apparatus are disclosed in JP-A Nos. 2002-310962 (Patent Document 1), 2000-67243 (Patent Document 2), 2003-98114 (Patent Document 3), 2000-30652 (Patent Document 4), and 2002-323458 (Patent Document 5). JP-A-2002-310962 describes an image acquisition apparatus that uses a SEM to automatically form and acquire images of any plural surface defect sections of a semiconductor wafer. This image acquisition apparatus has a scheduling unit for determining a defect-imaging sequence and a moving speed of a stage from a positional relationship between the defective sections on the wafer, and a control unit for feeding back to the quantity of beam deflection a moving distance of the stage. The scheduling unit and the control unit make it possible to form and acquire the images of the plural defective sections while moving the stage along an ideal route. Also, JP-A-2000-67243 describes an automatic defect information acquisition method that uses a SEM. In this defect information acquisition method, a user can efficiently detect defects by assigning pattern information on an object to be inspected, since there is no need, for example, to move a field of view of the SEM to a reference point when inspecting a non-patterned or cyclically patterned region. JP-A-2003-98114 describes a method for inspecting and reviewing defects using a SEM. This method includes splitting a defect image into regions of a grid format, then executing pattern matching (or the like) to evaluate whether a split image region to be inspected is similar to other split image regions, and if the evaluated region has no similarity to any other regions, identifying defect positions in that region because of the defects being regarded as included therein. JP-A-2000-30652 describes a method for reviewing a sample using a SEM. In this reviewing method, information on defects which have been detected on the sample by an inspection apparatus is first used to image the sample and obtain a reference image not including the detected defects. Next after the information relating to the detected defects has been used to image the sample and obtain a defect image including the detected defects, the reference image and the defect image are compared and the defects within the defect image are detected. Additionally, an enlarged image of the detected defects is obtained by imaging part of a region in which the detected defects have been imaged above, then a background region is erased from the enlarged image, and the resulting image without the background region is displayed. JP-A-2002-323458 describes a SEM-type apparatus for reviewing defects. In this apparatus, during acquisition of approximate defect position coordinates obtained during inspection with an inspection apparatus, whether the defect occurred in a cell section, a non-cell section, a section with dense patterns, or other sections, is first judged using layout data. Next, an image detection mode (a mode for determining whether a reference image is to be detected) and inspection parameters including an imaging magnification are set up according to particular judgment results, and management standards relating to criticality are established. As outlined above, a cell comparison scheme and a die comparison scheme are used as the methods of acquiring defect images based on SEM images. The cell comparison scheme, compared with the die comparison scheme, is high in throughput, but is limited in the number of applicable semiconductor wafer types, whereas the die comparison scheme, compared with the cell comparison scheme, is low in throughput, but is applicable to almost all types of semiconductor wafers. Regions to which the cell comparison scheme can be applied, and regions to which the cell comparison cannot be applied are usually present in mixed form in a semiconductor wafer region to be reviewed, so it is difficult to improve throughput by adopting only the cell comparison scheme. To perform defect detection operations and detailed analyses while maintaining optimal throughput for semiconductor wafers, therefore, both the cell comparison scheme and die comparison scheme that are review sequences must be selected for each semiconductor wafer inspected or for each defect inspected. However, none of the above five Patent Documents (1 to 5) has paid sufficient consideration to the fact that a review sequence suited to each semiconductor wafer and defect to be analyzed can be automatically selected using defect detection results obtained at least in the cell comparison scheme. The present invention provides a SEM-type defect-reviewing apparatus constructed so that a review sequence suited to each of semiconductor wafers and defects to be analyzed can be automatically selected using defect detection results, and thus so that optimal throughput relating to detailed analysis of the defects reviewed can be maintained for various semiconductor wafers. The invention also provides a method for reviewing defects using the above apparatus. That is to say, an aspect of the present invention relates to a method for reviewing defects using a SEM-type reviewing apparatus, in which, after position coordinate data of review defects on wafer has been obtained from an inspection apparatus, a stage with wafer mounted thereon is moved in accordance with the position coordinate of the review defect and then an electron beam defect image of each review defect is acquired by imaging at a low magnification using an electron beam optical system. The above method includes: a cell comparison step subdivided into four major steps of (a) acquiring an electron beam defect image of a low magnification by moving a stage on which the wafer is mounted in accordance with position coordinate of a review defect on the wafer obtained from an inspection apparatus, and then imaging the review defect at the low magnification by using an electron beam optical system, (b) selecting a review sequence of either a cell comparison scheme or a die comparison scheme on the basis of a defect detection success ratio or defect detection success map due to at least the cell comparison scheme for each wafer or for each chip formed on the wafer, (c) if the cell comparison scheme is selected in the sequence selection step, judging whether detection of the review defect is possible (successful) by executing the selected cell comparison scheme based on the electron beam defect image acquired from the review defect at the low magnification, and (d) a first calculation step of, if judgment result in the detection possibility judgment step indicate that the detection of the review defect is possible (successful), calculating position coordinate of the detected review defect in a coordinate system of a defect-reviewing apparatus; a die comparison step subdivided into two major steps of (a) if the judgment result in the detection possibility judgment step indicates that the detection of the review defect is impossible (unsuccessful), or if the die comparison scheme is selected in the sequence selection step, acquiring an electron beam reference image of a low magnification of a normal part to perform the selected die comparison scheme by using the electron beam optical system with moving the stage, and (b) a second calculation step of detecting the review defect by performing the selected die comparison scheme between the acquired electron beam defect image of the review defect at the low magnification and the acquired electron beam reference image of the low magnification, and calculating the position coordinate of the detected review defect in the coordinate system of the defect-reviewing apparatus; and a defect image acquisition step of acquiring an electron beam defect images of a high magnification by imaging the review defect at the high magnification by using of the electron beam optical system in accordance with the position coordinates of the review defects calculated in the coordinate system of the defect-reviewing apparatus in the first and second calculation steps. Another aspect of the present invention relates to a method for reviewing defects using a SEM-type reviewing apparatus, in which, after position coordinate data of review defects on wafer has been obtained from an inspection apparatus, a stage with wafer mounted thereon is moved in accordance with the position coordinate of the review defect and then an electron beam defect image of each review defect is acquired by imaging at a low magnification using an electron beam optical system. The above method includes: a cell comparison step subdivided into five major steps of (a) acquiring an electron beam defect image of a low magnification by moving a stage on which the wafer is mounted in accordance with position coordinate of a review defect on the wafer obtained from an inspection apparatus, and then imaging the review defect at the low magnification by using an electron beam optical system, (b) previously providing (preparing) a defect detection success ratio or defect detection success map due to at least the cell comparison scheme for each wafer or for each chip formed on the wafer, (c) selecting a review sequence of either a cell comparison scheme or a die comparison scheme on the basis of the provided (prepared) defect detection success ratio or defect detection success map due to at least the cell comparison scheme for each wafer or for each chip formed on the wafer, (d) if the cell comparison scheme is selected in the sequence selection step, judging whether detection of the review defect is possible (successful) by executing the cell comparison scheme based on the electron beam defect image acquired from the review defect at the low magnification, and (e) a first calculation step of, if judgment result in the detection possibility judgment step indicates that the detection of the review defect is possible (successful), calculating position coordinate of the detected review defect in a coordinate system of a defect-reviewing apparatus; a die comparison step subdivided into two major steps of (a) if the judgment result in the detection possibility judgment step indicates that the detection of the review defect is impossible (unsuccessful), or if the die comparison scheme is selected in the sequence selection step, acquiring an electron beam reference image at a low magnification for a normal part to perform the die comparison scheme by using the electron beam optical system with moving the stage, and (b) a second calculation step of detecting the review defect by performing the die comparison scheme between the acquired electron beam defect image of the review defect at the low magnification and the acquired electron beam reference image of the low magnification, and calculating the position coordinate of the detected review defect in the coordinate system of the defect-reviewing apparatus; and a defect image acquisition step of acquiring an electron beam defect images of a high magnification by imaging the review defects at the high magnification by using the electron beam optical system in accordance with the defect position coordinates calculated in the coordinate system of the defect-reviewing apparatus in the first and second calculation steps. According to the present invention, in a SEM-type defect-reviewing apparatus, a review sequence suited to each semiconductor wafer and each defect to be analyzed can be automatically selected on the basis of detection results on defects to be reviewed, and thus, optimal throughput relating to detailed analysis of the defects reviewed can be maintained for various semiconductor wafers. These and other objects, features, and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. Embodiments of the present invention relating to an apparatus and method for reviewing defects using a SEM (Scanning Electron Microscope) will be described hereunder using the accompanying drawings. A first embodiment of a SEM-type defect-reviewing apparatus according to the present invention is described below using FIG. 1. FIG. 1 is a configuration diagram showing the first embodiment of a SEM-type defect-reviewing apparatus for conducting detailed analyses on semiconductor wafer surface defects according to the present invention. The SEM-type defect-reviewing apparatus 10 includes a vacuum chamber 100, a total control unit 90, an image processing unit 91, an electron beam optical system controller 92, and a stage controller 93. The vacuum chamber 100 includes an XY stage 102 for moving a wafer 1, an electron beam optical system 101 for irradiating the wafer 1 with electron beams, and an optical microscope unit 114 with an illumination optical system 1141 for bare wafer defect detection. The electron beam optical system 101 includes an electron gun 103. The electron beam optical system 101 also includes, as its electron beam control elements, electron beam extraction electrodes 104, condenser lenses 105, blanking deflectors 106, scanning deflectors 107, aperture stops 108, objective lenses 109, reflectors 110, and ExB deflectors 111. In addition, the electron beam optical system 101 includes a secondary electron detector 112 and/or backscattered electron detectors 113, the secondary electron detector 112 and/or backscattered electron detectors 113 being constructed to respectively detect secondary electrons and/or backscattered electrons stemming from the wafer 1. The total control unit 90 controls the entire defect-reviewing apparatus by having the image processing unit 91, the electron beam optical system controller 92, and the stage controller 93 each connected to the total control unit 90. A display device 94 with a graphical user interface (GUI) function block having an input/output tool, and a storage device 95 are also connected to the total control unit 90. The total control unit 90 transmits/receives parameters and instructions to the electron beam optical system controller 92, the stage controller 93, and the image processing unit 91. The total control unit 90 is constructed so that various parameters can be set up arbitrarily or selectively according to particular needs. These parameters include: an accelerating voltage, electron beam deflection width (this determines an imaging magnification), and other parameters to specified to the electron beam optical system 101 via the electron beam optical system controller 92 prior to generation of the electron beams; timing and other parameters relating to signal acquisition from the secondary electron detector 112 and/or the backscattered electron detectors 113; and a moving speed of the XY stage 102 and other parameters that can be sent via the stage controller 93. A correction control circuit (not shown) that is provided in the total control unit 90 monitors wafer position and wafer height errors in accordance with signals from a position-monitoring critical-dimension measuring instrument (not shown) and wafer height measuring instrument (not shown) installed at the XY stage 102. The correction control circuit also makes a correction signal from obtained monitoring results and sends the made correction signal to an objective lens power supply (not shown) and scanning deflector signal generator (not shown) provided in the electron beam optical system controller 92 so that the irradiated electron beams always arrive at a correct position. The secondary electrons and/or backscattered electrons that have been detected by the secondary electron detector 112 and/or the backscattered electron detectors 113 are input to a scintillator, in which the electrons are then converted into electrical signals. The electrical signals are further A-D converted to form electron beam images, which are then input to the image processing unit 91. The image processing unit 91 performs a defect detection process based on an electron beam image imaged at a first magnification (for example, 5,000 through 30,000 magnifications) and a defect detail analytical process based on an electron beam image formed at a second magnification (for example, 30,000 through 200,000 magnifications) higher than the first magnification. The image processing unit 91 includes a CPU and an image memory 916. The CPU is functionally divided into a review sequence switching (selecting) unit 911, a cell comparator 912, a determining unit 913 for determining whether the defect can be detected using the cell comparator, a die comparator 914, and a detail analyzer 915. That is to say, the review sequence switching (selecting) unit 911, the cell comparator 912, the determining unit 913 for determining whether the defect can be detected using the cell comparator, the die comparator 914, and the detail analyzer 915 may be constructed so that each is executed by software processing based on a program. The detail analyzer 915 calculates electron beam image feature quantities of the defects to be reviewed, that is, shapes, brightness (grayscale levels), texture, and other factors, from associated defect position information in a coordinate system of the defect-reviewing apparatus, the defect position information being stored within the image memory 916, and from the electron beam defect image formed above at the second magnification. Next, the detail analyzer 915 acquires detailed analytical information (category information and classification information of the defects) from the electron beam image feature quantities (values), and stores the detailed analytical information as electron beam defect review results for each semiconductor wafer into a database 115. The electron beam images that the SEM-type defect-reviewing apparatus 10 has formed using electron beams (i.e., the electron beam defect image in the cell comparison scheme, the electron beam reference image and electron beam reference image in the die comparison scheme, and the electron beam defect image formed at the second magnification for detailed analysis) are sent to the database 115 connected to the defect-reviewing apparatus 10 via a network 119 and saved together with information that specifies defect-reviewing apparatus operating parameters and the like. The results of processing by the image processing unit 91 (i.e., defect detection success ratios or defect detection success maps in the cell comparison scheme for each kind of semiconductor wafer and/or for each region on the semiconductor wafer, the defect position information in the coordinate system of the defect-reviewing apparatus, and electron beam image feature quantities (values) of the defects, such as shapes, brightness or grayscale levels, and texture) are also saved in the database 115 via the route described above. The same further applies to the detailed analytical information based on the electron beam image feature quantities (i.e., category information and classification information of the defects). Of course, defect inspection data (approximate defect position coordinate data) obtained in an inspection apparatus 117 may be appended to semiconductor wafer classification information before being stored into the database 115. A processing terminal 116, the inspection apparatus 117, and a CAD database 118 that contains layout data which is information on wiring patterns formed on the semiconductor wafer are also connected to the network 119, and access can be made to the images, defect information, and semiconductor wafer information existing within the database 115 (the semiconductor wafer information includes the information relating to the kind of semiconductor wafer, and the layout information that is design information of the wafer). The processing terminal 116 includes the CPU that can conduct parallel processing with the image processing unit 91 (the CPU is functionally divided into a cell comparator 1161, a judgment unit 1162 for judging whether the review defect can be detected by using the cell comparator, a defect detection success map update unit 1163, and an image memory 1164 or the like; the cell comparator 1161, the judgment unit 1162 for judging whether the review defect can be detected by using the cell comparator, and the defect detection success map update unit 1163 may be constructed so that each is executed by software processing based on a program). That is to say, the processing terminal 116 is constructed so that concurrently with the defect detection process for defect reviews by the image processing unit 91 of the defect-reviewing apparatus 10, the terminal 116 can conduct a process which, as shown in FIGS. 7 and 11, includes the step (S30) of determining whether the defect to be reviewed can be detected using the cell comparator, and the step (S31) of updating a defect detection success map based on results of the above determination. Next, defect detection and defect detail analysis sequences in the first embodiment of the present invention are described below using FIG. 2. That is to say, the invention improves throughput by, in the defect detection sequence, maximizing the number of defects to be reviewed using the cell comparison scheme according to the invention, and minimizing the number of defects to be reviewed using the die comparison scheme according to the invention. The cell comparison scheme according to the invention uses, for example, a method of creating an electron beam reference image beforehand by means of electron beam imaging of an repeating pattern (cell section), or a method of creating an electron beam reference image by combining an electron beam defect image that has been acquired beforehand by electron beam imaging at a first magnification, and an image obtained from erasing the defect from the electron beam defect image. In the cell comparison scheme of the invention, therefore, throughput can be improved over that achievable in the die comparison scheme of the invention, since the stage movement intended to form an electron beam reference image can be made unnecessary by omitting the electron beam reference imaging operation in the die comparison scheme. For defect reviews, various kinds of semiconductor wafers that were inspected by the inspection apparatus 117 are loaded onto the XY stage 102 of the SEM-type defect-reviewing apparatus 10 according to the present invention. According to the first embodiment of the present invention, therefore, in step S20, among all defects having defect inspection data (approximate position coordinate data of the defect), only several (say, about 10) defects are specified as samples for each semiconductor wafer that was inspected by the inspection apparatus 117, and the defect samples to be reviewed are detected in the cell comparison scheme which makes throughput improvable. Next in step S21, whether the defects are to be further inspected in the cell comparison scheme or the die comparison scheme is selected according to a particular success ratio of the defect detection in the cell comparison scheme (i.e., whether the acquisition of an electron beam reference image at a low magnification, namely, a first magnification, is to be executed for each wafer) [if yes, the die comparison scheme is to be adopted; if no, the cell comparison scheme is to be adopted]. If the success ratio of the defect detection in the cell comparison scheme is higher than a required reference value, the defects to be reviewed are detected in step S22 using the cell comparison scheme that is high in throughput. If the success ratio of the defect detection in the cell comparison scheme is lower than the required reference value, the defects to be reviewed are detected in step S27 using the die comparison scheme. In this manner, throughput in the defect detection of one entire set of defects to be reviewed can be improved. That is to say, in the present first embodiment, for each semiconductor wafer or each set of wafers to be reviewed, several (say, about 10) of all inspected defects are detected as samples in the cell comparison scheme in step S20. Next, it is determined in step S21 whether, based on detection of the sample defect, the review sequence for each semiconductor wafer is to be executed in the die comparison scheme or the cell comparison scheme (i.e., whether the acquisition of an electron beam reference image at the low magnification, namely, the first magnification, is to be executed for each wafer). This method is applied for the following reason. That is, for a memory product, most of the wiring patterns formed on the wafer are repeating patterns, whereas, for a logic product, most of the wiring patterns formed on the semiconductor wafer are non-repeating patterns, so whether the defects on the semiconductor wafer can be detected using the cell comparison scheme is usually determinable just by detecting the several defect samples. For this reason, for a memory product, defects present in the memory cell section occupying a large portion of the semiconductor wafer's effective surface area can be detected using the cell comparison scheme. In this case, since the logic section occupying only a small portion of the effective surface area cannot be subjected to the defect detection in the cell comparison scheme, defects present in this region need to be detected using the die comparison scheme. At this time, switching from the cell comparison scheme to the die comparison scheme makes it necessary to move the stage once too often than in normal die comparison scheme. However, for example, when the defect detection process is conducted for 500 defect samples, if the moving speed of the stage is 500 milliseconds, the electron beam image acquisition time required is 300 milliseconds, and an auto-focusing time is 200 milliseconds, provided that a minimum of about 200 samples can be detected in the cell comparison scheme, throughput in the present first embodiment can be improved over the throughput obtainable by using only the die comparison scheme. Another feature of the first embodiment according to the present invention is described below. Selection of the cell comparison scheme in step S11 for each semiconductor wafer in the review sequence that was determined in step S21 according as the memory cell section occupies a large majority of the effective area does not mean that all of the defects on the semiconductor wafer 1 to be reviewed can be detected in the cell comparison scheme. Therefore, for each subsequent defect or for each subsequent set of defects, it is first determined in step S23 whether the defect can be detected in the cell comparison scheme. If results of the determination indicate that the defect can be detected, a detection signal of the defect is output, or if the determination results indicate that the defect cannot be detected, step S24 is executed to select the die comparison scheme reliable in the defect detection (the use of the die comparison scheme, however, requires the acquisition of an electron beam reference image at the first magnification) and detect the defect. After this, the defect that has thus been detected for a review is imaged at a second magnification by electron beam irradiation in step S25. Next, step 26 is executed to repeat the above procedure for all other defects on the wafer that are to be reviewed. It is thus possible to detect all review target defects on each semiconductor wafer, and to acquire electron beam defect images whose electron beam image feature values (shapes, brightness or grayscale levels, texture, and other factors) can be calculated for detailed analysis. In addition to, in review sequence of the step S21 determined in each semiconductor wafer, when switching to the die comparison scheme of the step S27, the defect is detected with the die comparison scheme for review defect on the semiconductor wafer 1 and the detected review defect is imaged at the second magnification with the electron beam in the step S28. After this, step 29 is executed to repeat the above procedure for all other review defects. It is thus possible to detect all review defects on each semiconductor wafer, and to acquire electron beam defect images whose electron beam image feature quantities can be calculated for detailed analysis. Next, the above is described in further detail below. Suppose that the defects to be reviewed are already inspected in the coordinate system of the inspection apparatus 117 and that the approximate position coordinates of these defects are already stored within the image database 115. In a normal ADR (Automatic Defect Review) sequence, the semiconductor wafer 1 to be reviewed and analyzed is mounted on the XY stage 102 of the defect-reviewing apparatus 10, and inspection data that is the results of the inspection with the inspection apparatus 117 is read in from the image database 115, for example, and stored into the storage device 95, for example. Next, the defect data of the semiconductor wafer 1 that has been stored into the storage device 95, for example, is displayed on the GUI screen of the display device 94, and several (say, about 10) of the defects to be reviewed are specified as samples by use of the input tool 94. The defect-reviewing apparatus 10 then executes step S20 to detect all specified (say, about 10) defect samples by conducting cell comparative inspections with the cell comparator 912 or the like. After the detection of the semiconductor wafer defect samples (say, about 10 pieces) by the cell comparator 912 or the like, the review sequence switching (selecting) unit 911 operates appropriately according to the particular detection results (information on whether the defects have been successfully detected). If the ratio of the successfully detected defect samples to all specified defect samples (i.e., the success ratio of the defect detection) is equal to or greater than the required reference value (say, about 40% to 50%), that is, in this example, if defects have been actually detected on at least about four to five of the defect samples, subsequent defect detection also uses the cell comparison scheme expected to improve throughput. If the above defect detection success ratio is less than about 40% to 50%, the review sequence is switched in step S21 so that the subsequent defect detection uses the die comparison scheme more reliable in terms of defect detection. A reference value (threshold value) for determining whether the use of the review sequence is to be continued is uniquely determined by a processing time required of the die comparison scheme in step S27, and a processing time required of the cell comparison scheme in step S22 (this processing time includes the time required for switching to the die comparison scheme in the event of a defect detection failure). For example, as described above in the first embodiment, if the moving speed of the stage is 500 milliseconds, the electron beam image acquisition time required is 300 milliseconds, and the auto-focusing time is 200 milliseconds, provided that a minimum of about 40% of all defects to be reviewed can be detected in the cell comparison scheme, the cell comparison scheme improves in throughput, compared with the die comparison scheme. Next, if the success ratio of the defect detection by cell comparisons based on the several defect samples to be reviewed is high and the cell comparison scheme expected to improve throughput is selected for each semiconductor wafer (or for each set of wafers) in step S22 by the review sequence switching unit 911, step S23 is executed for the cell comparator 912 or the like to conduct a cell comparative inspection on each subsequent defect to be reviewed, and for the defect detection possibility judgment unit 913 to determine whether the defect can be successfully detected during the cell comparative inspection. If determination results indicate that the detection is impossible, a die comparison inspection high in defect detection reliability, compared with the cell comparative inspection, is conducted in step S24 by the die comparator 914 or the like. Next, the defect-reviewing apparatus 10 executes step S25 to image the defect at the defect position in the coordinate system of the reviewing apparatus 10, at a second magnification higher than the first magnification, and stores the defect image together with the defect position information into the image memory 916, for example. Whether all necessary defects have been analyzed is confirmed in step S26. If there are any defects still remaining unanalyzed for reviews, processing is switched to next defect to be reviewed. If all defects have been analyzed, the analytical process is completed. Next, if the success ratio of the defect detection by the cell comparisons based on the several defect samples to be reviewed is low and the die comparison scheme is selected for each semiconductor wafer (or for each set of wafers) in step S27 by the review sequence switching unit 911, the die comparator 914 or the like detects all defects on the semiconductor wafer by conducting die comparative inspections higher in defect detection reliability. Next, the defect-reviewing apparatus 10 executes step S28 to image the defect at the defect position in the coordinate system of the reviewing apparatus 10, at the second magnification higher than the first magnification, and stores the defect image together with the defect position information into the image memory 916, for example. Whether all necessary defects have been analyzed is confirmed in step S29. If there are any defects still remaining unanalyzed for reviews, processing is switched to next defect to be reviewed. If all defects have been analyzed, the analytical process is completed. As described above, the cell comparison/die comparison review sequence based on the success ratio of the defect detection using the cell comparison scheme suitable for the repeating patterns for the several defect samples that are to be reviewed is selected for each semiconductor wafer (or for each set of wafers) in step S21. When the die comparison scheme is selected, all defects on the semiconductor wafer are detected in steps S27-S29 using the die comparison scheme higher in defect detection reliability. When the cell comparison scheme expected to improve throughput is selected, step S23 is executed to determine whether the defects can each be detected using the cell comparison scheme. If results of the determination indicate that the defect can successfully be detected, the defect detection in the cell comparison scheme is continued for each subsequent defect. If the determination results indicate that the defect cannot successfully be detected, the die comparison scheme is adopted to conduct defect inspections in step S24. The detection of all defects on the semiconductor wafer to be reviewed is thus improved in throughput. Next, the die comparison scheme and cell comparison scheme that are the methods of identifying the positions of defects in the coordinate system of the defect-reviewing apparatus according to the present invention are described below using FIG. 3. In the die comparison scheme executed by the die comparator 914 (or the like) according to the present invention, as flowcharted in FIG. 3A, the total control unit 90 reads out, from the CAD database 118, die layout information that is the design information of the semiconductor wafer mounted on the XY stage 102, then stores the die layout information into the storage device 95, for example, and in accordance with information such as the stored die layout information and the approximate defect position coordinate information obtained as inspection results in the inspection apparatus 117, controls the stage 102 via the stage controller 93 in order to move the stage to a nondefective (normal) section on an adjacent die present on the wafer. These operations including the control of the stage are conducted in step S30. In next step S31, the total control unit 90 controls the electron beam optical system controller 92, acquires an electron beam reference image by imaging the nondefective (normal) section at a first magnification, and stores the image into the image memory 916, for example. In step S32, the total control unit 90 controls the stage 102 via the stage controller 93 in accordance with information such as the approximate defect position coordinate information obtained as inspection results in the inspection apparatus 117, then after moving the stage from the above-mentioned adjacent die to a desired defect position on a defective die, acquires an electron beam defect image by controlling the electron beam optical system controller 92 and imaging the defect at the first magnification by using electron beam imaging, and stores the image into the image memory 916, for example. After this, in step S34, the die comparator 914 (or the like) of the image processing unit 91 detects the associated die by comparing the above-mentioned electron beam reference image obtained from the nondefective adjacent die and stored within the image memory 916, for example, and the above-mentioned electron beam defect image obtained from the defective die, recalculates the position of the detected defect in the coordinate system of the reviewing apparatus, associates the thus-recalculated data with at least the electron beam defect image, stores the data into the image memory 916, for example. As described above, since a plurality of dies each formed with the same wiring pattern thereon are arrayed on the semiconductor wafer, nondefective dies adjacent to defective ones are present. For this reason, an electronic beam reference image associated with an electron beam defect image can always be acquired and the defects to be reviewed can be reliably detected by die comparisons. For the die comparisons, however, the acquisition of an electron beam reference image and an electron beam defect image must be repeated for all intended defects by moving the stage. The die comparison scheme, therefore, decreases in throughput, compared with the cell comparison scheme. The cell comparison scheme in the cell comparator 912 (or the like) according to the present invention features less frequent repetition of stage moving in step S30 for electron beam reference image acquisition as shown in FIG. 3B. Accordingly, two ways are likely to be usable to acquire an electron beam reference image. One is by utilizing the iterative pattern formed in any die on the semiconductor wafer, and imaging beforehand the iterative pattern one time, for example. The other is by utilizing the characteristics of the iterative pattern and combining a previously acquired electron beam defect image of the defect and an image obtained by erasing the defect from this electron beam defect image. It is also possible to utilize the iterative pattern and detect the defect by pattern matching based only on the defect image. In this case, as shown in FIG. 12, electron beam defect image 1 is split into regions of a grid format and then the regions are each matched to other regions independently (if there are wiring patterns 1202, matching is conducted between the wiring patterns). If the region matches any other split regions, the defect is regarded as having unsuccessfully been detected. When the defect image is split, if a plurality of wiring patterns are present, there is a need to split the image so that one wiring pattern exists in one split region. In the cell comparison scheme, step S35 is executed to move the stage to the next defect position in accordance with the defect position coordinates that are output from the inspection apparatus located at a stage immediately previous to the reviewing apparatus, and then step S36 follows to acquire an electron beam defect image by electron beam imaging at that position at a first magnification. After this, step S37 is executed to detect the defect by comparing the electron beam defect image and, for example, one electron beam reference image that has been acquired beforehand. That is to say, the cell comparison scheme is subdivided into a scheme applicable only to, for example, memory cell sections having only repeating patterns, and a scheme applicable to not only memory cell sections, but also logic sections having complex wiring patterns as well as repeating patterns. Although the latter scheme (as shown in FIG. 12, the electron beam defect image 1 is split into regions of a grid format and then the regions are each matched to other regions independently) is applicable to almost all wiring patterns, except in some specific logic sections, since the latter scheme, compared with the former scheme, needs computing a great amount of data to detect the defect, the former cell comparison scheme is used for repeating patterns and the latter cell comparison scheme is used for logic sections not having repeating patterns. Throughput can be improved by so doing. However, neither of the cell comparison schemes may be effective for the defect detection. In that case, the defect detection is to use the die comparison scheme. More specifically, a defect is detected in the cell comparison scheme in step S22, then whether the next defect can be detected in the cell comparison scheme is judged in step S23, and if the next defect is judged not to be detectable in the cell comparison scheme, this comparison scheme is switched to the die comparison scheme higher in defect detection reliability, in step S24. Next, an image display GUI menu of the display device 94 in the present first embodiment employing the defect detection with the above-described cell comparison scheme is described below using FIGS. 4 and 5. The GUI menu 400 includes a display region 401 for displaying an ID of a defect for which a review sequence is to be executed for detailed analysis of the defect, a selecting unit 402 for a user to select the review sequence to be executed, a button 403 that specifies displaying an electron beam reference image, a display region 404 for displaying a position of the defect on the semiconductor wafer, a display region 405 for displaying the ID, position, size, and other information of the defect, and a button 406 for specifying an ending process. A press of the button 403 for specifying the display of an electron beam reference image displays in a display region 501 the ID of the defect for which the electron beam reference image is to be formed. Also, the electron beam reference image is displayed in a reference image display region 500. Although the present first embodiment displays the electron beam reference image on another GUI menu 500, the reference image may be displayed on the GUI menu 400. Next, detailed analysis of the defect by the detail analyzer 915 is described below. The present first embodiment does not use electron beam imaging at a second magnification to form an electron beam reference image. As disclosed in JP-A-2000-30652, therefore, an electron beam image of a magnification equivalent to the second magnification is first made by image processing based on an electron beam reference beam that has been formed by electron beam imaging at a first magnification. The electron beam imaging is followed by, for example, calculation of electron beam image feature values (shape, brightness, i.e., grayscale level, texture, and more) of the defect, and thus the defect is analyzed in detail. In the present first embodiment, since, even in the cell comparison scheme, using the method disclosed in JP-A-2003-98114 does not cause an electron beam reference image to be formed, even by electron beam imaging at a first magnification, the electron beam reference image needs to be made from an electron beam defect beam that has been formed by electron beam imaging at the first magnification. This is why the GUI menu 400 is required that includes the GUI display region 500 for confirming the made electron beam reference image, and the display region 402 for displaying the defect detection scheme. In the first embodiment, the defect detection review sequence is determined from the cell comparative detection results obtained from the first several defect samples on the semiconductor wafer. In the first embodiment, however, even for a wafer with arrayed dies (chips) in which logic sections are mainly disposed, if the first several samples are selected only from memory cell sections, the defect detection in the cell comparison scheme is conducted, so the number of samples for which defect detection requires switching to the die comparison scheme due to a defect detection failure in the cell comparison scheme becomes large, which results in reduced throughput. Hence, the second embodiment of a SEM-type defect-reviewing apparatus according to the present invention differs from the first embodiment in terms of review sequence determination method. Details are described below. As shown in FIG. 6, for each semiconductor wafer (for each kind of semiconductor wafer, each process step for the semiconductor wafer), including defect detection at logic sections and defect detection at memory cell sections, the defect-reviewing apparatus 10 records in, for example, the database 115, defect detection information 600 [e.g., count of defects successfully detected in the cell comparison scheme (success ratio or success map)] that has been obtained during the past defect detection in the cell comparison scheme. For defect detection, the above-recorded information 600 [the count of defects successfully detected in the cell comparison scheme (success ratio or success map)] is retrieved from the database 115, and then in accordance with the information 600, a review sequence suitable for the semiconductor wafer to be reviewed is determined in step S21 to switch between the cell comparison scheme or die comparison scheme in the total control unit 90 or the review sequence switching unit 911 of the image processing unit 91. A reference value (threshold value) for determining the review sequence is uniquely determined by a processing time required for the die comparison scheme in step S27, and a processing time required for the cell comparison scheme in step S22 (this processing time includes the time required for switching to the die comparison scheme in the event of a defect detection failure). In addition, in the second embodiment, even if manufacturing processes differ between semiconductor products of the same kind, since the wiring patterns formed on these semiconductor products are essentially the same, past defect detection histories obtained in the defect-reviewing apparatus 10 can be used and this provides the advantage that the review sequence can be determined from the defect detection results that the defect-reviewing apparatus obtains during defect reviews of the semiconductor wafers requiring other manufacturing processes. A third embodiment of a SEM-type defect-reviewing apparatus according to the present invention differs from the first and second embodiments involving the selection of a review sequence (defect detection scheme) for each semiconductor wafer, in that defects are detected by selecting a defect detection scheme suitable for each defect (or each set of defects) to be reviewed. Such selection allows optimal throughput to be maintained. Next, review sequences for performing defect detection and detailed analytical processes on semiconductor wafer surface defects, in the third embodiment of the defect-reviewing apparatus according to the present invention, are described below using FIG. 7. As with that of the first to third embodiments, a defect detection scheme in the third embodiment includes a die comparison scheme (selected in step S27) and a cell comparison scheme (selected in steps S22, S23), and one of the two schemes is appropriately selected in step S21 by the review sequence switching unit 911. The selection between the two defect detection schemes in step S21 by the review sequence switching unit 911 is performed by referring to defect detection success maps stored into the database 115, for example. In the third embodiment, the appropriate review sequence is selected, basically for each defect (or each set of defects) to be reviewed, with reference being made to the defect detection success maps compiled (summed up) for each chip on the semiconductor wafer. Therefore, if judgment result in step S23 indicates that the defect detection in the cell comparison scheme is impossible, this comparison scheme is switched to the die comparison scheme in step S27. As a result, from the defect detection possibility judgment due to the cell comparison scheme (step S23) onward, the defects to be reviewed are detected on a cell comparison basis in the coordinate system of the reviewing apparatus. Images of the thus-detected defects are acquired by electron beam imaging at a second magnification, and the defect images are stored into the image memory 916 [step 30 (S25, S28)]. From die comparison (step S27) onward, defects are detected on a die comparison basis in the coordinate system of the reviewing apparatus. Images of the thus-detected defects are acquired by electron beam imaging at a second magnification, and the defect images are stored into the image memory 916 [step 30 (S25, S28)]. This sequence is repeated until all defects on the semiconductor wafer have been detected [step 31 (S26, S29)]. The defect detection success maps are obtained through the steps described below. In the defect-reviewing apparatus 10 and the processing terminal (personal computer) 116 that can perform, for example, parallel processing, it is judged in step S33 whether or not the defect detection using the cell comparison scheme is successful, in accordance with the electron beam defect images that were stored into the database 115 after being acquired by imaging at a first magnification at each defect position on the semiconductor wafer by the defect-reviewing apparatus 10. Results of the above judgment are compiled for each chip and updated as defect detection success maps in step S34, and then the success maps are stored into the database 115, for example. Therefore, the review sequence switching unit 911 in the image processing unit 91 of the defect-reviewing apparatus 10 refers to the defect detection success maps and can thus select an appropriate defect detection scheme for the positions of each defect to be reviewed. In order to be able to perform parallel processing with the image processing unit 91, the processing terminal (personal computer) 116 is functionally divided into a cell comparator 1161 that detects defects in the cell comparison scheme in accordance with the defect images at the defect positions on the semiconductor wafer, a judgment unit 1162 that judges whether the defect can successfully be detected by using the cell comparator, a defect detection map update unit 1163 that compiles determination results for each chip and updates compilation results as defect detection success maps, and an image memory 1164 for temporary storage of the defect images, the defect detection success maps, and the like. The processing terminal 116 further has a connected display device 1165. Next, a method for creation of a defect detection success map by the defect detection success map update unit 1163 of the processing terminal 116 is described below using FIGS. 8 and 9A-9C. First, the defect detection success map update unit 1163 judges whether a defect detection success map is present in the database 115. If the map is present, the defect detection success map update unit 1163 reads out the map from the database 115 and creates a new map in the procedure below. The defect detection success map update unit 1163 associates the defect detection schemes that were used to detect each defect, with defect position coordinates (801, 802, 803) obtained by converting on-wafer coordinates (800) into chip coordinates, and then records the two mutually associated kinds of information in the image memory 1164. The defect positions and the above-mentioned defect detection schemes (cell comparison scheme and die comparison scheme) are thus recorded for each chip. This state is shown in FIG. 8. Next as shown in FIG. 8, the defect detection schemes (cell comparison scheme and die comparison scheme) for each chip on the semiconductor wafer are compiled (summed up) into one chip of data (804). After this, the defect detection success map update unit 1163 uses the GUI function of the display device 1165 to select a region (in FIG. 9A, a rectangular region) present within a range specified from one of the above defect positions by a user, and set up this region as a region (900, 901) in which the defect can be detected in the particular defect detection scheme (e.g., the cell comparison scheme). FIG. 9B shows the defect detection executable region (901) set up for both the cell comparison scheme and the die comparison scheme. Next, the defect detection success map update unit 1163, by using as a reference a distance between any two defects which were detected using the same defect detection scheme, combines (integrates) the associated defect detection executable regions into one region (902) if the distance is shorter than that specified by the user. The above combination uses a polygon that surrounds all regions to be combined. At this time, if there is a region corresponding to neither the cell comparison scheme nor the die comparison scheme, this region is regarded as one for which the optimal defect detection scheme for defect detection cannot yet be determined, so this region is set up as a region in which the die comparison scheme is to be used to detect the associated defects. In this way, all regions, except those in which the cell comparison scheme is to be used to detect defects, are basically set up as the regions in which to detect defects using the die comparison scheme. There is a need, therefore, to set up the regions in which the defect detection is possible by using at least the cell comparison scheme. The defect detection success map that has thus been created is stored into the database 115. FIG. 10 shows an example of a created defect detection success map. The defect detection success map stored within the database 115, therefore, is displayed on a GUI menu 1000 of the display device 94 of the defect-reviewing apparatus 10, and the GUI menu 1000 includes a display region 1001 to display the defect detection success map. The user uses a parameter adjusting unit to adjust a defect detection executable region (area). The user can adjust three parameters. One is contents of a wafer list 1002 listing the past defect detection histories to be used to create defect detection success maps. One is a range threshold value 1003 indicating an effective range of the defect detection scheme in which the defect detection is most likely to succeed, one is a range threshold value 1004 for combining defect detection executable regions (areas). These parameters can each be changed each time a defect is detected, and the defect detection success map is updated each time. The GUI menu 1000 may further include a display region 1005 for displaying the defect positions on the semiconductor wafer, a display region 1006 for displaying information such as defect IDs, positions, and sizes, and a button 1007 for specifying an ending process. Next, a description is given below of a case in which neither a defect detection history of the past nor a defect detection success map is present. In this case, a defect detection success map cannot be created using the above method. Therefore, for example, the defect detection success map update unit 1163 of the processing terminal 116 creates a defect detection success map by utilizing CAD data stored within the CAD database 118, and by utilizing inspection recipes of the inspection apparatus 117 that are stored within the database 115. First, the creation of a defect detection success map by utilizing CAD data is described. The CAD data has information of the wiring patterns formed on the semiconductor wafer, and using the CAD data allows shapes of the wafer surface in each manufacturing process to be reproduced using, for example, the processing terminal 116. The user can therefore use the processing terminal 116, for example, to reproduce all wiring patterns present on the wafer, and select either the cell or die comparison scheme as the optimal defect detection scheme, depending on whether repeating pattern exists, or by manual user setup. The defect detection success map update unit 1163 creates a defect detection success map appropriately according to the above. Each time a defect is detected, the created defect detection success map will be updated as appropriate. Next, the creation of a defect detection success map by utilizing an inspection recipe of the inspection apparatus is described below. The inspection apparatus 117 may use CAD data and/or wiring pattern layout data to separate a desired chip region on the semiconductor wafer into cell sections and non-cell sections, and inspect each of the two kinds of sections in accordance with independent inspection parameter settings. Therefore, for example, the defect detection success map update unit 1163 of the processing terminal 116 can automatically set up cell comparative and die comparative defect detection executable regions by referring to the inspection recipe of the inspection apparatus 117. A created defect detection success map, as with that created using CAD data, will be updated each time a defect is detected. In the third embodiment, only an electron beam defect image associated with the position of a defect is acquired when electron beam imaging at a second magnification higher than a first magnification is conducted to obtain the defect image for detailed analysis of the defect. A fourth embodiment of a SEM-type defect-reviewing apparatus according to the present invention, however, differs from the third embodiment in that electron beam imaging of a normal section at a second magnification is also conducted to acquire an electron beam reference image at the second magnification. In the fourth embodiment, although forming an additional electron beam image in this way requires a longer total review processing time than in the third embodiment, there is the advantage that during the detailed defect reviews using the electron beam image of the second magnification, more detailed analyses than in the third embodiment can be conducted. Next, a semiconductor wafer surface defect detection scheme that is the fourth embodiment in the SEM-type defect-reviewing apparatus according to the present invention is described below using FIG. 11. The fourth embodiment, as with the third embodiment shown in FIG. 7, employs a defect detection scheme that includes a die comparison scheme (executed in step S27) and a cell comparison scheme (executed in steps S22, S23). A defect detection success map stored within the database 115 is referred to, whereby either of the two detection schemes is switched to the other in step S21. At this time, in the fourth embodiment, as shown in FIG. 11, an electron beam reference image obtained by imaging a normal section at a second magnification higher than a first magnification is acquired in the cell comparison scheme and die comparison scheme for detailed analyses. Stage moving (step S36) and imaging (step S37) consequently increase. Accordingly, for example, if stage moving requires 500 milliseconds and electron beam imaging requires 200 milliseconds, the total time required for processing of one defect increases to 700 milliseconds. Meanwhile, during the detailed defect reviews using the electron beam image that was acquired at the second magnification in the detail analyzer 915 of the image processing unit 91, as disclosed in, for example, JP-A-2001-331784, a differential image between an electron beam defect image and an electron beam reference image is used to recognize surface roughness of the defect, extract wiring patterns from the electron beam reference image, and/or obtain wiring defect information from the relationship with respect to the defect position. If an electron beam reference image that was acquired at the second magnification is absent, the electron beam reference image that was acquired at the first magnification must necessarily be used to conduct the above process steps. This electron beam reference image is, in terms of resolution, inferior to the electron beam reference image that was acquired at the second magnification, the amount of information obtained will decrease. For this reason, although there are disadvantageous in comparison with the third embodiment, the fourth embodiment can provide more detailed defect information during the detailed defect analysis at a posterior stage. The fourth embodiment can be applied to the first and second embodiments. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
051397099	summary	BACKGROUND OF THE INVENTION Uranium dioxide for the manufacturing of current light water reactor fuel is currently produced from the conversion of UF.sub.6, mainly based either on a dry- or a wet-conversion process. Several routes of the dry-conversion process have been revealed so far, and chemical procedures involved in those routes are similar. UF.sub.6 is usually pyrohydrolyzed with steam to form UO.sub.2 F.sub.2 powder which is reduced to UO.sub.2 directly by a hydrogen-steam mixture, or is calcined in air to U.sub.3 O.sub.8 first and then reduced to UO.sub.2 with a hydrogen-steam gas. In the wet-conversion process, vaporized UF.sub.6 is hydrolyzed with water to form an aqueous UO.sub.2 F.sub.2 -HF solution, from which ammonium diuranate (ADU) or ammonium uranyl carbonate (AUC) is precipitated with ammonia water or ammonium carbonate, respectively. After filtration, ADU or AUC is calcined to UO.sub.3, which is then reduced to UO.sub.2 with a hydrogen-steam gas. According to the chemical compositions of the precipitates, it is called an ADU process or an AUC process. It is recognized that the UO.sub.2 powder produced from the wet-ADU process possesses excellent powder characteristics required for pelletizing and sintering, and gives good microstructure to the sintered pellet. Although the ADU process is widely used currently, it is plagued by some inherent drawbacks. For example, in the conventional ADU process, such as that disclosed in the U.S. Pat. Nos. 3,394,997 and 3,998,925, UF.sub.6 is hydrolyzed with water to form an aqueous solution containing 100 to 200 g/l of uranium and 0.4 to 0.8 mol/l of hydrogen fluoride. As ADU is precipitated from this solution, a pasty slurry is obtained and several tens of liters of the fluoride-containing liquid filtrate is thus generated for the production of 1 kg UO.sub.2. This introduces a serious problem of liquid waste disposal to the conventional ADU process. Moreover, because ADU is a kind of slimy cake, the process also involves a complicated filtration operation. After a series of studies on the formation of ADU, it was found that ADU is formed simultaneously as soon as fine droplets of a concentrated solution of an uranyl compound are introduced into an ammonia gas stream, and the fluorine content of the UO.sub.2 powder consequently produced using uranyl fluoride solution as a feed can be lower than 50 ppm. Therefore, instead of being precipitated from a dilute solution of uranyl compounds with ammonia water, ADU is prepared in particle form directly by introducing atomized droplets of a concentrated solution of uranyl compound into an ammonia gas stream in the novel process disclosed herein. The generation of the fluoride-containing liquid filtrate in converting uranyl fluoride to UO.sub.2 is thus avoided, and filtration operation is no longer necessary. The process is thus greatly simplified. SUMMARY OF THE INVENTION It is the object of the present invention to provide a process generating no liquid filtrate and involving no tedious filtration operation for converting UF.sub.6 or uranyl compounds to UO.sub.2 via ADU. Due to the simple process variables involved in this new process, the UO.sub.2 powder produced inherently possesses much higher consistency in quality than those produced with the conventional wet-ADU process. To achieve its object, this invention provides a process for converting UF.sub.6 to UO.sub.2 powder comprising the steps of (a) pyrohydrolyzing UF.sub.6 with steam to obtain UO.sub.2 F.sub.2 powder; (b) dissolving the said UO.sub.2 F.sub.2 powder in water to form an aqueous uranyl solution; (c) atomizing the said aqueous solution into a gas stream of ammonia gas or ammonium hydroxide to prepare wet ADU particles; (d) drying and calcining the said ADU particles directly to UO.sub.3 or U.sub.3 O.sub.8, or their mixture; (e) reducing the said calcined particles to UO.sub.2 with hydrogen or hydrogen-steam gas. Accordingly, the present invention also provides a process for converting other uranyl compounds which form ADU with ammonium hydroxide, such as uranyl nitrate, uranyl sulfate, uranyl chloride, and etc., to UO.sub.2, comprising dissolving the uranyl compound in water as the first step and the foregoing steps of (c) to (e), whether or not additional metal species is incorporated into the aqueous solution of uranyl compound. Instead of precipitating ADU from diluted uranyl solution with ammonia water in the conventional wet-ADU process, in the present invention, ADU is made by reacting gaseous ammonia or ammonium hydroxide vapor with a rather concentrated solution of uranyl compound. Basically, uranyl solution of any concentration can be used to prepare the ADU powder directly with the present invention, but only from those with high uranium concentration can the ADU be obtained as a divided wet particle rather than a slimy slurry. Nevertheless, dry ADU particles can be obtained directly in all cases by heating the wet ADU particle before settling, just as is usually done in spray drying. The particle thus obtained is of easy-easy-handling and free flowing. No filtration operation is involved and no liquid filtrate is generated in the present invention. The only liquid effluent coming out of the ADU preparation is a limited amount of water condensate recovered in the drying of ADU which it is free from uranium and is re-usable in the dissolution of UO.sub.2 F.sub.2 powder. DESCRIPTION OF THE INVENTION In conducting this invention, UF.sub.6 in a cylinder is vaporized by heating in a water bath. The vapor is then introduced to a tube reactor, where it is pyrohydrolyzed with steam to carry out the reaction: EQU UF.sub.6 +2H.sub.2 O=UO.sub.2 F.sub.2 (HF).sub.n +(4-n)HF (1) With a careful control of the flow rates of UF.sub.6 and steam, finely divided UO.sub.2 F.sub.2 powders are obtained and collected at the bottom of the reactor. HF gas produced in reaction (1) may be neutralized in an alkali scrubber or recovered as a by-product after passing through a sintered-metal filter assembly. The UO.sub.2 F.sub.2 powder obtained is dissolved in de-ionized water to prepared UO.sub.2 F.sub.2 solution. The solution is then atomized to form very small liquid droplets with an atomizer, such as: an impingement type nozzle, or a single-fluid nozzle, or a double-fluid nozzle, or an ultra sonic atomizer, on the top of a spray column. To the bottom of the column, ammonia gas is introduced to react with the liquid droplets of UO.sub.2 F.sub.2 as follows: ##EQU1## As shown, ammonia gas is absorbed by water in the droplets to form NH.sub.4 OH, which then reacts with UO.sub.2 F.sub.2 to form ADU following reaction (3). It is generally recognized that there are four types of ADU, i.e., type I, II, III, and IV, with the value of x expressed in reaction (3) equal to 0, 1/3, 1/2, and 2/3, respectively. Except type I, all other types of ADU may be included in the product of the present invention with their molar ratios depending on the operating conditions, such as UO.sub.2 F.sub.2 concentration in feed solution; the pressure of ammonia gas; the drop size of the aqueous solution of UO.sub.2 F.sub.2 ; and the resident time. Generally, a high pressure of ammonia gas is good for the formation of the high type ADU. However, too high a pressure may cause some operational troubles. A small droplet size of the uranyl compound solution will increase the rate of the formation of ADU, and will be good for the formation of the high type ADU too. However, a droplet too small in size may cause some problems in separating ADU from gas stream. Additional heat may be applied to increase the reaction temperature to facilitate the formation of ADU, and to accomplish a quick removal of the moisture from the ADU product. Ammonium uranyl fluoride (AUF) is a precursory product in the reaction, and it may exist in the ADU product, when a feed solution having a very high concentration of uranium is used, or when the ammoniation is not sufficiently done. Nevertheless, the presence of AUF in the ADU mixture will not give any trouble in converting all the uranium species to UO.sub.2, since AUF, as well as ADU, is also decomposed to form uranium oxide on calcining. The formation reaction of ADU is exothermic, therefore, part of the water in the liquid UO.sub.2 F.sub.2 droplets is vaporized during the formation of ADU. Meanwhile, some of the water becomes a constituent part of ADU. Therefore, a feed solution of UO.sub.2 F.sub.2 having an uranium concentration higher than 500 g/l, or preferably higher than 600 g/l, will give wet finely divided ADU particles in the reaction without applying additional heat. When a less concentrated feed solution is used, the ADU product obtained is no longer divided particles, but is paste-like. Nevertheless, the stream of the wet ADU particles can be heated before settling, so as to remove the moisture to obtain a free flowing dry powder, directly, just as the way usually done in a spray drying. It is preferrable, for simplifing the operation, to carry out the drying and the calcining steps together in a drying-and-calcining step at 300.degree. to 750.degree. C., or preferably at 400.degree. to 600.degree. C. Ammonium fluoride vaporized in the step is separated from water vapor by condensing it at a temperature ca. 105.degree. C. The ammonium fluoride thus recovered is free from uranium, and is readily a valuable resource of fluorine. The water vapor is condensed and recycled for the dissolution of UO.sub.2 F.sub.2 powder. Clearly, no liquid filtrate is generated, and no complicated filtration operation is involved in the preparation of ADU, if the method of the present invention is used. Produced under an atmosphere of nitrogen gas, the calcined product is essentially UO.sub.3, which is then reduced to UO.sub.2 in a reduction furnace with a hydrogen-steam mixture at 500.degree. to 850.degree. C., or preferably at 550.degree. to 650.degree. C. In the reduction furnace, the residual fluoro species interact with steam to form HF and then leave the product. The UO.sub.2 thus obtained is a finely divided powder having low fluorine content, high activity, and good sinterability. Besides uranyl fluoride, other uranyl compounds such as uranyl nitrate, uranyl chloride, uranyl sulfate, and etc., can also be used to prepare ADU with the present method. Furthermore, the present invention is also applicable to the preparation of mixed metal oxides containing uranium, for instance, the mixed oxide of uranium and gadolinium can be made, if a solution containing uranyl nitrate and gadolinium nitrate is used as the feed solution. The following examples illustrate the present invention. It is understood that they are only exemplary and do not limit the scope of the present invention.
047160080	description	DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, there is shown a fuel assembly in the vessel 2 of a pressurized water nuclear reactor. Fuel assembly 1 is associated with two movable clusters 3 and 4, cluster 3 being a control cluster having neutron absorbing rods and cluster 4 being a spectral shift cluster, of fertile material for example. The rods of clusters 3 and 4 are fixed to respective carriers 5 and 6. The carriers 5 and 6 are housed in respective split guide tubes 7 and 7' and are rectilinearly movable along the axes of the guide tubes. Each carrier 5 or 6 is securely connected to the end of a drive shaft 8 or 9, respectively. The drive shaft 8 is provided with conventional driving means having electromagnetic coils 10 and pawls 10' which may be similar to those described in European Patent Application No. 111,435 and will therefore not be described in detail. The drive shaft 9 is movable inside and along a water tight enclosure or envelope 11 communicating with the vessel 2 at its lower end. Upward movement of shaft 9 may be caused by an upward hydraulic force produced by partially depressurizing the upper part of enclosure 11 by opening a solenoid valve 12; downward gravity movement of the shaft occurs when valve 12 is closed again. Means for catching and locking the upper end of the drive shaft 9 are provided at 13 and will be described in greater detail with reference to FIGS. 4 to 12. The guide tubes 7 and 7' are positioned inside a structure 14 located above the fuel assembly 1 and are held in place by guide plates 15 perpendicular to the axis of the guide structure 14 and located at several levels inside the latter. Referring to FIG. 3, the guide plates 15 are held by studs 16 and a peripheral clearance exists between the plates 15 and an outer casing of the guide structure 14. In the central part of the guide structure 14, three reinforcing tie bars 17 maintain the spacing of the guide plates 15. Referring again to FIG. 1, the carriers 5 and 6 are equipped with pairs of slide blocks 18 which take the forces due to overhang and restrict accidental movements and distortions of the rods of clusters 3 and 4, thereby avoiding wear of the latter due to rubbing contact with the guide plates 15. Referring to FIG. 2, the fuel assembly lattice of a reactor core is illustrated having one fuel assembly out of two provided with a pair of clusters. The guide structures 14 associated with the fuel assemblies 1 are hexagonal in shape. The hatched circles indicate the guide tubes 7' of spectral shift clusters 4 and the unhatched circles indicate the guide tubes 7 of control clusters 3. The core assemblies inserted between those assemblies 1 which are associated with the guide structures 14 of hexagonal shape receive neither absorbing rods nor fertile rods but clusters of plugs (not shown) closing the guide tubes in the assembly for avoiding bypass of the core through the fuel assemblies devoid of clusters. Referring to FIG. 3 again, the carriers 5 and 6 of clusters 3 and 4 are shown in guide structure 14. Four of the walls or facets 19 of the casing of the guide structure 14 are thinner due to recesses in their outer surfaces. The spaces available outside the casing for coolant transfer and circulation are consequently increased. Each cluster 3 or 4 has a plane of symmetry containing the axes of the two carriers 5 and 6 but does not have rotational symmetry relative to the axis of an extension of the respective carrier 5 or 6 which is connected to the associated drive shaft. The clusters 3 and 4, together with carriers 5 and 6, are distributed throughout the space inside the guide structure 14. Referring to FIG. 4, a system for catching and locking the spectral shift control shaft 9 in a high position and for unlocking this shaft is located in the upper part of the water tight enclosure 11. The system includes a hollow cylindrical bush 20 rotatably received in a casing 21 through two ball bearings 22 and 23. The casing 21 is securely connected to the enclosure 11. The lower part 24 of the casing 21 is housed inside the bush 20 and carries a pair of pawls 25, pivotably connected on an axis 26 fixed to the lower part 24. An offset lower finger 27 of each pawl 25 is dimensioned for engagement into a circular groove 28 of the drive shaft 9. Two annular cams 29 and 30 carried by the bush are shaped for rocking the pawls 25 around their axes 26 responsive to rotation of the hollow bush 20 around its axis. Means for rotating bush 20 comprises a set of upper inclined surfaces 31 (FIG. 12); the inclined surfaces 31 co-operate with studs 32 secured to a thimble 33, axially slidable along the axis of the water-tight enclosure 11 by the drive shaft 9 when the latter rises upon opening of the solenoid valve 12. The drive shaft 9 is formed with a chamfered shoulder 34 sized to abut thimble 33 and to force the latter upwards when it is subjected to the upward hydraulic force produced by depressurization of the upper portion of enclosure 11. The thimble 33 is biased downwardly by a spring 35 which exerts a shock-absorbing force on the thimble 33, in the direction opposite to that exerted by the drive shaft 9. The inclined surfaces 31 machined in the rotatable bush are such that axial movement of the studs 32 in either direction with respect to the bush causes rotation of the bush 20 and, consequently, of the annular cams 29 and 30. Openings 36 formed in the fixed casing 21 permit longitudinal movement of the studs 32 while preventing their rotation about the shaft axis. Referring to FIG. 4, the drive shaft 9 is illustrated in an intermediate position while it is lifted by the upward force f due to opening of the solenoid valve 12. The groove 28 is still below the level of pawls 25. The latter are open and permit the drive shaft 9 to move freely. The bush 20 remains in its rest position since the studs 32 are stationary. When the chamfered shoulder 34 abuts thimble 33 and starts raising the thimble and the studs 32, the latter move along part 37 (FIG. 12) of the inclined surfaces or ramps 31 and the bush 20 begins to rotate. When the studs 32 have run along the whole length of the part 37, the locking means is as shown in FIG. 5. The pawls 25 have been closed by cam 30 and the finger 27 have lodged in the circular groove 28 formed in the drive shaft 9. Reference can be made to FIGS. 8, 9, 10, and 11 for a more complete understanding of operation of cams 29 and 30 to open or close the pawls 25. FIG. 8 is a section along B--B of FIG. 5 and illustrates the profile of the upper cam 29, while FIG. 9, which is a section along C--C of FIG. 5, shows the profile of the lower cam 30. In FIG. 11, the profiles of both cams are superimposed, making it possible to understand which cam acts on the pawls 25 upon each rotational movement of the rotatable bush 20. FIG. 10 is a section along D--D of FIG. 5 and shows the pawls 25 and their axes 26 in casing 21. When the drive shaft 9 is in the position illustrated in FIG. 5, the solenoid valve 12 is turned off. Then the shaft 9 moves down slowly, since the fall of shaft 9 requires that pressurized water flows along a restricted flow path consisting of the narrow clearance between shaft 9 and enclosure 11. The drive shaft 9 is stopped when its location with respect to the axes 26 of the pawls 25 is as shown in FIG. 6; it is then locked in a "high" position. The movement of the studs 32 between the locations of FIGS. 5 and 6 occurs along ramp 38 and ends when the slides are at the level identified as P6 in FIG. 12. The shaft is then locked (the levels shown respectively as P4, P5 and P7 in FIG. 12 correspond to the positions in FIGS. 4, 5 and 7). When it is desired to move down the cluster 4 for inserting it into fuel assembly 1, in order to shift the neutron spectrum during the first part of the operating cycle, for example, the solenoid valve 12 is temporarily opened again. The drive shaft 9 is forced up by the upward force produced by partial depressurization in the enclosure 11. The chamfered shoulder of drive shaft 9 again abuts thimble 33. The stud 32 again moves along the ramp 39 and rotates the rotatable bush 20. The cam 29 comes to bear on the upper part of the pawls 25 which finally is in an open position as shown in FIG. 7. In FIG. 12, the studs 32 are in the region shown as P7. The solenoid valve 12 is then closed in order to cause fall of the drive shaft 9. The device is once again in the position of FIG. 4, the studs 32 having moved along ramp 40. References P4, P5, P6 and P7, correspnding to those shown in FIG. 12, have been entered in Figure 11. The position of the cams 29 and 30 relative to the pawls 25 in each position to which reference is made in FIG. 12 can thus be seen. The control device of the invention makes it possible to insert completely the spectral shift clusters 4 during part of the core operating cycle, and to keep cluster 4 locked in a "high" position during the balance of the operating cycle, while the control clusters 3 can be inserted at any depth into the core. The motions of clusters 3 and 4 are completely mutually independent of each other. For instance, the cluster 3 may be inserted slightly into the assembly 1 without inserting the rods of cluster 4 at all into the fuel assembly 1. The control device according to the invention is not bulky since it has only two drive shafts 8 and 9 only. All the spectral shift rods forming the cluster 4 are handled by a single drive device (9, 13) and all control rods forming the cluster 3 also are moved by a single control device (8, 10, 10'). The locations of the control devices on the cover of vessel 2 form a uniform polygonal network which is compatible with the ancillary equipment required for installing, constructing and cooling the devices. Moreover, the outer profiles of each of the guide structures 14 are such that they permit horizontal coolant transfer and exchange without excessive head loss towards radial outlets distributed over the vessel. The invention is not restricted to the specific embodiment which has been described by way of example; numerous modifications are possible. For instance the means for catching and locking the drive shaft of the spectral shift clusters could, of course, be modified and incorporate, for example, only an axially slidable bush acting directly on the pawls. Slide blocks 18 could be carried not only by the carrier 5 or 6, but also by other parts. It could also consist of a first slide block placed on the carrier 5 or 6 and a second slide block placed on the drive shaft 8 or 9 which extends the carrier 5 or 6. Finally, the clusters 4 of the second set could be clusters other than spectral shift clusters, for example clusters of "passive" or inert rods.
	abstract	Hydrophobic filter materials, methods of making them, and their use in various industrial applications are presented. In an example, thermally stable, gas permeable hydrophobic filters which maintain their integrity upon exposure to elevated temperature, radiation, acid, or all are described.
	abstract	A thin specimen producing method acquires a work amount in a 1-line scan by an FIB under a predetermined condition, measures a remaining work width of a thin film on an upper surface of a specimen by a microscopic length-measuring function, determines a required number of scan lines of work to reach a predetermined width by calculation, and executes a work to obtain a set thickness. The work amount in a one-line scan by the FIB under the predetermined condition is determined by working the specimen in scans of plural lines, measuring the etched dimension by the microscopic length-measuring function, and calculating an average work amount per one-line scan.
	summary
040574636	abstract	This invention provides a method of operating a nuclear reactor with the object of maintaining a substantially symmetric axial xenon distribution during normal power operation including load follow. Variations in the xenon distribution are controlled by maintaining a substantially symmetric axial power distribution. Procedures are described for maintaining the axial offset value of the core, as an indicia of the axial power distribution, substantially equal to a target value, which is modified periodically to account for core burnup. In one embodiment a neutron absorbing element within the core coolant, or moderator, is employed to assist control of reactivity changes associated with changes in power with the full length control rods mainly employed to adjust variations in the axial power distribution, while the part length rods remain completely withdrawn from the fuel region of the core. In a second embodiment reactivity changes associated with changes in power are controlled by the full length rods, while the part length rods are used to adjust the axial power distribution and the neutron absorbing element within the core coolant or moderator is used to compensate for xenon buildup or depletion.
043081002	claims	1. Apparatus for charging a nuclear reactor disposed at the bottom of a pool and constituted by a plurality of tiers of combustible assemblies having different stages of enrichment, each assembly having combustible rods and an auxiliary cluster associated with the particular tier of the assembly, said apparatus comprising a rolling bridge supported for movement in a plane above the pool, a turnable platform on said bridge having an axis of rotation, three vertical telescopic manipulation arms on said platform arranged in angular spaced relation thereon around the axis of rotation of said platform, each arm carrying a respective grappling means, the grappling means for one arm being constructed to engage a complete combustible assembly, the grappling means of the second arm being constructed to engage a first type of cluster and the grappling means of the third arm being constructed to engage a second type of cluster, said turnable platform having the same number of angular stop positions as there are telescopic arms and further having an active position at which each telescopic arm is selectively fixed in operative position while at the other angular positions the arms are inactive, and means for extending and retracting each of the telescopic arms at said active position comprising a self-contained winch for each arm. 2. Apparatus as claimed in claim 1 wherein said manipulation arms are angularly spaced equally around said axis of rotation of said platform such that with the bridge at rest as said platform is successively rotated through said stop positions said arms successively pass through said operative positions at precisely the same vertical position and the grappling means on the respective arms can operatively coact with the rods and cluster of each assembly. 3. Apparatus as claimed in claim 1 comprising an auxiliary mast secured to said carriage at the axis of rotation of said platform, said mast projecting vertically between said arms, and camera means on said auxiliary mast. 4. Apparatus as claimed in claim 3 wherein said arms and mast extend vertically downwards, said mast extending to a level above the lowermost extended position of each arm.
	claims	1. A method for analyzing at least one fuel rod comprising a stack of nuclear fuel, a rod comprising packed zones completely filled with fuel and intermediate zones partially full of fuel, the method being implemented by an analysis system comprising a gamma ray spectrometry device having a sensor and a spectrometry processing unit, the method comprising the following steps:measuring gamma ray radiation emitted by the nuclear fuel with the sensor of the gamma ray spectrometry device to acquire spectrometry measurements of said at least one fuel rod;acquiring a count profile with the spectrometry processing unit associated with a non-migrating isotope in said at least one fuel rod, a count profile being derived from the spectrometry measurements taken along the at least one rod for said non-migrating isotope with the sensor of the gamma ray spectrometry device;determining with the spectrometry processing unit a set of at least one indicator K_i to quantify a reduction in material at an intermediate zone of index i, the said indicator being deduced from the count profile; anddetecting a change in geometry of said at least one fuel rod with the spectrometry processing unit by comparing the set of at least one indicator K_i against a set of at least one reference value RK indicative of the initial geometry of the nuclear fuel stack. 2. The analysis method according to claim 1, comprising a step of estimating the location of the intermediate zones by analyzing the count profile with the spectrometry processing unit. 3. The analysis method according to claim 1, in which the detecting the change in geometry is detected in at least one intermediate zone and deduced by statistical analysis of the indicators of K_i, a change in geometry being flagged when at least one value K_i is incompatible with a theoretical measurement spread that could be expected with no change in geometry. 4. The analysis method according to claim 1, in which the detecting the change in geometry is detected for at least one intermediate zone by comparing K_i with a predefined reference value RK, a change in geometry being detected when the ratio between K_i and RK exceeds a previously-chosen comparison threshold k1 or lies below another previously chosen comparison threshold k2. 5. The method according to claim 4, in which the reference value RK is determined statistically by the mean of the K_i values observed experimentally over a plurality of rods of the same type. 6. The method according to claim 4, in which the reference value RK is determined by theoretical calculation for a given pellet geometry. 7. The method according to claim 1, in which the rod is a rod or a section of rod of PWR type made up of a plurality of pellets, an intermediate zone corresponding to an inter-pellet zone. 8. The method according to claim 1, in which a non-migrating isotope of Ru-136 type is used to determine the count profile. 9. A system for analyzing at least one nuclear fuel rod comprising the gamma-ray spectrometry device and the spectrometry processing unit implementing the method according to claim 1. 10. A computer program stored on a non-transitory computer readable storage medium containing instructions for executing the method according to claim 1 when the program is executed by a processor of the analysis system.
	abstract	Systems produce desired isotopes through irradiation in nuclear reactor instrumentation tubes and deposit the same in a robust facility for immediate shipping, handling, and/or consumption. Irradiation targets are inserted and removed through inaccessible areas without plant shutdown and placed in the harvesting facility, such as a plurality of sealable and shipping-safe casks and/or canisters. Systems may connect various structures in a sealed manner to avoid release of dangerous or unwanted matter throughout the nuclear plant, and/or systems may also automatically decontaminate materials to be released. Useable casks or canisters can include plural barriers for containment that are temporarily and selectively removable with specially-configured paths inserted therein. Penetrations in the facilities may limit waste or pneumatic gas escape and allow the same to be removed from the systems without over-pressurization or leakage. Methods include processing irradiation targets through such systems and securely delivering them in such harvesting facilities.
039403122	claims	1. A nuclear fuel comprising monocrystalline particles with a maximum size lying between 20 .mu. and 400 .mu., of carbide of uranium or uranium-plutonium with vanadium carbide in supersaturated solution, and coated with a layer of vanadium carbide with a maximum thickness of 10 .mu.. 2. A nuclear fuel as claimed in claim 1, in which the coating is comprised of VC and V.sub.2 C. 3. A nuclear fuel as claimed in claim 1, in which the coating has a density of about 3.67 g/cc.
050948016	claims	1. In a nuclear reactor coolant system pressurizer having a cladding on its interior surface and wherein an original heater and heater sleeve have been removed and the bore for the heater sleeve enlarged, a replacement heater sleeve, said replacement heater sleeve comprising: a. an outer sleeve installed in the enlarged bore of the pressurizer on the same center as the original heater sleeve, said outer sleeve having its upper end seal welded to the cladding on the interior of the pressurizer and said outer sleeve being welded to the exterior surface of the pressurizer; and b. an inner sleeve installed in the inner diameter of said outer sleeve so as to extend beyond said outer sleeve into said pressurizer and to maintain the original heater alignment in the pressurizer, said inner sleeve being welded to the lower end of said outer sleeve. 2. The heater sleeve of claim 1, wherein said inner sleeve is provided with an inner diameter sized to receive a heater of the same size as that originally installed in the pressurizer.
	abstract	Disclosed is a basket 50 that is located within a basket containment vessel, into which a boric acid solution capable of dissolving a pH adjuster flows, and can allow a pH adjuster solution to flow out by the inflowing boric acid solution. The basket 50 includes a plurality of containment units 71 stacked in a vertical direction with a predetermined first space L1 therebetween. The pH adjuster can be stored in each of the containment units 71. Also disclosed is a pH adjusting device including the basket 50, the basket containment vessel in which the basket 50 can be contained and in which cooling water can be stored, and an overflow pipe that, within the basket containment vessel, allows the pH adjuster solution that is obtained from the pH adjuster dissolved in the cooling water to flow out.
	abstract	A system and method for transferring a canister of spent nuclear fuel from a transfer cask to a receiving cask. In one aspect, the system comprises a below grade opening adapted for receiving a cask; a platform positioned within the opening, the platform capable of vertical movement; and at least two jacks for vertically moving the platform; wherein the platform is capable of lowering the cask within the opening. In another aspect, the invention is a method of transferring a canister of spent nuclear fuel to a cask comprising the steps of: lowering a receiving cask having a height into a below grade opening so that a portion of the receiving cask's height is below grade level; and transferring the canister to the receiving cask.
047537736	abstract	A double tube modular coil steam generator is provided in which a multiplicity of inner tubes conducting water are individually surrounded by outer tubes containing liquid metal as a heat transfer agent. The double tubes form into coils, providing a large surface area while conserving space. Immersion of the double tube coil in hot liquid metal, e.g., from the core of a nuclear reactor, causes efficient transfer of heat across the liquid metal in the outer tube to the water in the inner tube, creating superheated steam, which can be cycled to a turbine and converted to electrical power.. The efficiency, reliability and safety of the multiple double tube design of the steam generator obviates the necessity of many secondary heat removal and emergency components in addition to conserving space and material. The modular design allows ease of operation, fabrication and repair.
	description	The present invention relates to a recycled fuel assembly storage basket and a recycled fuel assembly storage container that store therein recycled fuel assemblies, and a method for manufacturing a recycled fuel assembly storage basket. Spent nuclear fuel assemblies that are nuclear fuel assemblies used in nuclear power plants, for example, and extracted from nuclear reactors after being loaded and burned in the nuclear reactors are called recycled fuel assemblies. The recycled fuel assemblies contain highly radioactive substances such as fission products (FP). Accordingly, the recycled fuel assemblies are generally cooled in a cooling pit of a nuclear power plant, for example, for a certain period of time. The recycled fuel assemblies are then stored in a cask that is a recycled fuel assembly storage container having a radiation shielding function and used for transportation and storage, delivered to a reprocessing plant or an interim storage facility by a vehicle or a vessel, and stored therein until being reprocessed. To store the recycled fuel assemblies in the cask, a recycled fuel assembly storage basket formed of a material having neutron absorbing power, and is a collection of storage spaces called cells in which recycled fuel assemblies are stored, is used. The recycled fuel assemblies are inserted into the storage spaces formed in the recycled fuel assembly storage basket, one by one. In this manner, the recycled fuel assemblies maintain appropriate intervals and are prevented from reaching criticality while being transported, and an appropriate holding force relative to vibrations during transportation, events that can be assumed, and the like is secured. Patent Documents 1 to 5 are, examples of such conventional recycled fuel assembly storage baskets. Patent Document 6 discloses a method for forming spaces in which recycled fuel assemblies are stored, by intersecting and combining plate-shaped members made of boron-aluminum (B—Al) material, with one another. [Patent Document 1] Japanese Patent Application Laid-open No. 2004-020568 [Patent Document 2] Japanese Patent Application Laid-open No. 2004-069620 [Patent Document 3] Japanese Patent Application Laid-open No. 2004-163120 [Patent Document 4] Japanese Patent Application Laid-open No. 2005-208062 [Patent Document 5] Japanese Patent Application Laid-open No. H6-94892 [Patent Document 6] Japanese Patent Application Laid-open No. 2001-201595 Because boron is very hard, the B—Al material is difficult to cut. Accordingly, it is difficult to cut the plate-shaped members of a recycled fuel assembly storage basket disclosed in Patent Document 1, thereby requiring extra efforts to manufacture the recycled fuel assembly storage basket. In a recycled fuel assembly storage basket disclosed in Patent Document 1, materials are wasted due to cutting. Accordingly, the present invention has been made in view of the circumstances described above, and an object of the present invention is to provide a recycled fuel assembly storage basket and a recycled fuel assembly storage container that can reduce the number of cutting processes on the members of the recycled fuel assembly storage basket, and a method for manufacturing a recycled fuel assembly storage basket. According to an aspect of the invention, a recycled fuel assembly storage basket includes: a plurality of first plate members being stacked with long side ends thereof abutting to each other; a plurality of connecting members extended in a direction towards which the first plate members are stacked, attached to a side surface of each of the first plate members being stacked, connecting the first plate members, and projecting from the side surface; a plurality of second plate members both of whose long side ends have recesses into which the connecting members are fitted; and a recycled fuel assembly stored in a space surrounded by the first plate members and the second plate members. In this recycled fuel assembly storage basket, a plate member joint body is formed by stacking first plate members and connecting the first plate members with a connecting member, disposing a plurality of plate member joint bodies so that the connecting members are placed opposite from each other, and inserting each of the connecting members into a recess of a second plate member. The first plate member, the second plate member, and the connecting member that are members of the recycled fuel assembly storage basket can be manufactured, for example, by extrusion molding. Accordingly, with the recycled fuel assembly storage basket according to the present invention, the number of cutting processes on the members of the recycled fuel assembly storage basket can be reduced. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that each of the first plate members and the second plate members has a through hole penetrating in a longitudinal direction. In this manner, in particular, in a basket that stores therein recycled fuel assemblies for a pressurized water reactor (PWR), the through hole can be used as a flux trap for moderating fast neutrons from the recycled fuel assemblies. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that a cross-section of each of the connecting members perpendicular to the longitudinal direction is a trapezoid, and an upper base of the cross-section comes into contact with the side surface of the first plate member. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that a cross-section of each of the recesses in the second plate member perpendicular to the longitudinal direction is a trapezoid, and an upper base side of the cross-section comes into contact with the side surface of the first plate member. In this manner, by forming the cross-section of the connecting member in a trapezoid, and forming the recess meshed with the connecting member at the long side end of the second plate member, it is possible to prevent the second plate member from being disengaged from the connecting member. It is also possible to facilitate the assembly and handling of the recycled fuel assembly storage basket, and the deviation between the first plate member and the second plate member can be suppressed. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that the second plate member and the connecting member be made of different materials. If the second plate member and the connecting member are made of materials of the same type, material loss may occur on the second plate member and the connecting member due to galling. However, this can be prevented, by forming the second plate member and the connecting member with different materials. Examples of methods for adopting a different material may include using the same base material and performing oxidation treatment, thermal spraying, plating, or other surface treatment to make only the surface have different characteristics from those of the second plate member to prevent galling; coating the surface of the second plate member or the connecting member with a lubricating layer represented by graphite and the like; using the surface treatment and the lubricating layer coating in combination; and using a material having relatively higher strength and higher hardness (stainless, carbon steel, titanium, or the like) than the strength and hardness of the second plate member for the base material of the connecting member. As a different material, a material softer than the second plate member may be chosen for the connecting member. In this case, to receive the load in a dispersed manner, the number of connecting members must be increased or the size of the connecting member must be enlarged. Accordingly, this is not suitable for the purpose of producing an inexpensive recycled fuel assembly storage basket. However, as a basket exclusively used as a storage container, if the assumed load is lighter than that of the transportation-storage container, a soft material may be possibly chosen for the connecting member. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that the connecting member be divided at different positions in the direction towards which the first plate members are stacked. In this manner, a plate member joint body (barrier) that is a joint body of the first plate members is formed, by dividing the connecting member at different positions in the direction towards which the first plate members are stacked, in other words, in the longitudinal direction of the connecting member, and attaching the connecting member to the side surfaces of the first plate members. Accordingly, the entire length of the connecting member, in other words, the size in the longitudinal direction can be reduced, thereby relieving the effects due to difference in thermal elongation, caused when the material of the connecting member and the material of the first plate member are different. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that the connecting member be attached to the first plate member by a fastening member. In this manner, the connecting member can be fixed to the first plate member without fail, thereby connecting a plurality of plate members without fail. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that a long hole be provided at a side of the connecting member, and the fastening member penetrate through the long hole. By using the long hole, the connecting member is movable relative to the fastening member, thereby allowing a relative movement between the connecting member and the first plate member. As a result, it is possible to relive the thermal stress generated due to difference in thermal elongation, caused when the material of the connecting member and the material of the first plate member are different. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that a load supporting unit that supports a load of the second plate member be interposed between the fastening member and the connecting member, and between the fastening member and the first plate member. In this manner, the load transmitted to the fastening member from the second plate member through the connecting member is received by the load supporting unit. Accordingly, it is possible to suppress the stress applied to the fastening member. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that at least one rotation suppressing member that suppresses rotation of the load supporting unit be provided between the load supporting unit and the first plate member, and between the load supporting unit and the second plate member. For example, if a key having a circular cross-section is used for the load supporting member, the rotation of the load supporting unit is suppressed, by the rotation suppressing member, thereby facilitating the operation of attaching the connecting member and the first plate member with the fastening member. Accordingly, the workability is improved. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that a reinforcement member made of a material having higher stiffness than that of the first plate member be disposed inside the through hole of the first plate member, and the reinforcement member and the fastening member be connected. In such a structure, a part of the load applied to the first plate member can be received by the reinforcement member, thereby forming the recycled fuel assembly storage basket further stronger. For example, if a bolt, a screw, or the like is used as the fastening member, the fastening member is connected with a nut. By using this structure, screw holes need not be formed on the first plate member. As an exemplary aspect of the present invention, in the recycled fuel assembly storage basket, it is preferable that a groove extending in the direction towards which the first plate members are stacked be formed at the side surface of the first plate member, and the connecting member be fitted into the groove. In this manner, the load applied to the first plate member from the connecting member can be received by a portion where the connecting member and the groove are engaged. As a result, the load applied to the fastening member for fixing the connecting member to the first plate member can be drastically reduced, thereby reducing the size of the fastening member and the number of fastening members. According to another aspect of the present invention, a recycled fuel assembly storage container includes: a trunk having an opening portion and a cavity; a lid attached to the opening portion and sealing the cavity; and the recycled fuel assembly storage basket described above which is disposed in the cavity. This recycled fuel assembly storage container includes the recycled fuel assembly storage basket according to the present invention. Accordingly, the number of cutting processes on the members of the recycled fuel assembly storage basket can be reduced. According to still another aspect of the present invention, a method for manufacturing a recycled fuel assembly storage basket includes: stacking a plurality of first plate members with long side ends thereof abutting to each other; forming a plurality of plate member joint bodies by connecting the first plate members with connecting members attached to a side surface of each of the first plate members and projecting from the side surface; disposing side surfaces of the plate member joint bodies so as to face each other, and placing the connecting members opposite from each other; and inserting the connecting members placed opposite from each other into recesses formed at both long side ends of a second plate member. According to the method for manufacturing a recycled fuel assembly storage basket, the number of cutting processes on the members of the recycled fuel assembly storage basket can be reduced. The present invention can reduce the number of cutting processes on the members of a recycled fuel assembly storage basket. 1, 1a, 1b basket (recycled fuel assembly storage basket) 10, 10b, 10c first plate member 10H screw hole 10H1 key receiving recess 10H2 key receiving hole 10H3 fixed key groove 10H4 bolt through hole 10LT1, 10LT2 long side end 10S, 10Sb side surface 10ST short side end 11 protruded portion 12 groove 13 through hole 15 leg 16, 16c connecting member fitting groove 20, 20b, 20c second plate member 20LT long side end 20S side surface 20ST short side end 21, 21c recess 21H groove opening 23 through hole 30, 30b, 30c connecting member 30A first side surface 30B second side surface 31 bolt through hole 32 key receiving recess 33, 35 bolt screw hole 34 bolt through hole 40, 40a bolt 41, 42, 43 load supporting key 41H through hole 42 key hole 42H, 43H through hole 44 fixed key 50 reinforcement member 50H screw hole 100, 100a plate member joint body 200 cask 201 trunk main body 201C cavity The present invention will now be described in detail with reference to the drawings. However, the present invention is not limited to the best modes (hereinafter, “embodiments”) for carrying out the invention. Constituent elements of the following embodiments include elements that can be easily assumed by a person skilled in the art, elements being substantially the same as those elements, and elements that fall within a so-called range of equivalents. A recycled fuel assembly storage basket, which will be described below, is mainly used as a cask for transportation and storage, but not limited thereto. For example, the recycled fuel assembly storage basket may be used as a concrete cask for storing purpose or a rack in a canister or in a recycled fuel assembly storage pool. The present invention is also applicable for recycled fuel assemblies used in either a pressurized water reactor (PWR) or a boiling water reactor (BWR). In a first embodiment, a recycled fuel assembly storage basket is formed by stacking a plurality of first plate members with long side ends thereof abutting to each other, connecting the first plate members by attaching a connecting member to the side surfaces of the first plate members being stacked, and inserting the connecting member projecting from the side surfaces of the first plate members into a recess of a second plate member both of whose long side ends have recesses. Each of the recycled fuel assemblies is stored in a space surrounded by the first plate members and the second plate members. Before explaining a recycled fuel assembly storage basket according to the first embodiment, a recycled fuel assembly storage container will be described. In the following explanation, a recycled fuel assembly storage basket is referred to as “basket” as needed. FIG. 1 is a sectional view of an outline of a cask that is an example of a recycled fuel assembly storage container. FIG. 2 is a sectional view taken along the line A-A of the cask illustrated in FIG. 1. As illustrated in FIG. 1, a cask 200 includes a lid 200T and a trunk 200B, and after storing recycled fuel assemblies in the inside of the trunk 200B, the trunk 200B is sealed by the lid 200T. The trunk 200B of the cask 200, as illustrated in FIG. 2, includes a cylindrical trunk main body 201, heat transfer fins 207 attached to the outer periphery of the trunk main body 201, an outer casing 205 attached to the other long side ends of the heat transfer fins 207, and a neutron shielding material 209 filled into a space formed by the outer periphery of the trunk 200B, the heat transfer fins 207, and the outer casing 205. To exert a gamma-ray shielding function, the trunk main body 201 is manufactured of carbon steel or stainless steel having a sufficient thickness. If the trunk main body 201 is manufactured of carbon steel, to exert a sufficient gamma-ray shielding function, the thickness of the trunk main body 201 is from 20 to 30 centimeters. The trunk main body 201 may be formed, by attaching a bottom plate to the cylindrical trunk main body 201 by welding. The trunk main body 201 and the bottom plate may also be integrally formed, by inserting a metal billet into a container having the inner shape matched with the exterior shape of the trunk main body 201, and hot-forming the metal billet with a piercing punch having the exterior shape matched with the inner shape of the trunk main body 201. The trunk main body 201 may also be manufactured by casting. The inside of the trunk main body 201 is a cavity 201C in which a basket 1 for containing recycled fuel assemblies is stored. The cross-sectional internal shape perpendicular to the axis (cavity axis Z) direction of the cavity 201C is circular. However, depending on the specification of the cask 200, a cavity having a cross-sectional internal shape such as octagon, square, an approximately cross shape, and a step-like shape may also be used. In the present embodiment, the cross-sectional internal shape of the cavity 201C is circular. Accordingly, to store the basket 1 having a polygonal exterior shape therein, a first spacer 202a to a fifth spacer 202e are interposed between the basket 1 and the cavity 201C, thereby positioning the basket 1 in the cavity 201C. A groove in which a plate member of the basket 1 is fitted in may be provided in the first spacer 202a to the fifth spacer 202e, and the first spacer 202a to the fifth spacer 202e, and the plate member may be combined by a shrink fit, a cold shrink fit, or the like. The outer peripheral surface of the basket 1 preferably comes into contact with the inner wall of the cavity 201C. Accordingly, while securing a subcritical function, heat is transferred to the container on a wide surface, thereby transferring heat at a small temperature difference. In this manner, even if a borated stainless steel (B-SUS) having inferior heat transfer characteristics than that of the B—Al material is used, the temperature of the stored article can be kept low. If the B—Al material is used, the temperature of the stored article can be kept lower. Upon storing recycled fuel assemblies in the cavity 201C, to prevent radioactive substances from leaking out the cavity 201C, the cavity 201C is sealed by attaching a primary lid 200T1, a secondary lid 200T2, and a tertiary lid T3 (FIG. 1) at an opening portion of the trunk. To secure sealability, a gasket made of metal or elastomer, or made of metal and elastomer, is provided between the primary lid 200T1 and the secondary lid 200T2, and the trunk main body 201. The tertiary lid T3 is used for the purpose of further backing up the primary lid T1 and the secondary lid T2. However, depending on the required specification, this lid structure may only include the primary lid and the secondary lid. The heat transfer fins 207 formed of plate members are radially attached to the outer periphery of the trunk main body 201. The heat transfer fins 207 are made of a good thermal conductor such as aluminum plate and copper plate, and attached to the outer periphery of the trunk main body 201 by welding or other connecting means, thereby efficiently transmitting the heat. The outer casing 205 made of carbon steel with a thickness of a few centimeters is attached to the outside of the heat transfer fins 207 by welding or other connecting means. The recycled fuel assemblies stored in the cavity 201C generate decay heat. The decay heat is transmitted to the basket 1 and the trunk main body 201, conducted to the outer casing 205 through the heat transfer fins 207, and released to the atmosphere from the surface of the outer casing 205. To shield neutrons, a material having a neutron shielding function (neutron shielding material 209) is filled into a space surrounded by the trunk main body 201, the outer casing 205, and two heat transfer fins 207. As a material having such a function, a neutron shielding material such as resin, polyurethane, or silicon that is a polymer material containing a large amount of hydrogen, can be used. The neutron shielding material shields neutrons emitted from the recycled fuel assemblies, and reduces the number of neutrons leaking out from the cask 200 to less than the regulated limit. The cask 200, upon storing recycled fuel assemblies therein, is used for transportation and storage. To transport the cask, as illustrated in FIG. 1, buffers 204 are attached to both ends of the axis of the cask, in other words, in the direction of the cavity axis Z. Therefore, should an accident such as falling of the cask 200 occurs, a sufficient sealability of the container and safety of the stored articles will be ensured. The basket according to the present embodiment will now be described. FIG. 3 is a perspective view of the basket according to the first embodiment. FIG. 4 is a sectional view of a portion in which the connecting members are attached to the first plate member in the basket according to the first embodiment. FIG. 5 is an enlarged partial view of the basket according to the first embodiment. FIG. 6A is a side elevation view of the first plate member of the basket according to the first embodiment. FIG. 6B is a front view of the first plate member of the basket according to the first embodiment. FIG. 7 is a front view of a modification of the first plate member of the basket according to the first embodiment. FIGS. 6C to 6E are front views of modifications of the first plate member of the basket according to the first embodiment. FIG. 8A is a side elevation view of the second plate member of the basket according to the first embodiment. FIG. 8B is a front view of the second plate member of the basket according to the first embodiment. FIG. 9A is a perspective view of the connecting member of the basket according to the first embodiment. FIG. 9B is a front view of the connecting member of the basket according to the first embodiment. The basket 1 is formed by combining a first plate member 10, a second plate member 20, and a connecting member 30. As illustrated in FIGS. 6A and 6B, the first plate member 10 is a rectangular shaped member when viewed from the side, and has four ends. When viewed from the side, two ends corresponding to the long sides of the first plate member 10 are long side ends 10LT1 and 10LT2, and when viewed from the side, two ends corresponding to the short sides of the first plate member 10 are short side ends 10ST. A protruded portion (ridge) 11 extending in the longitudinal direction of the first plate member 10 is provided on the long side end 10LT1, and a groove 12 fitted with the protruded portion 11 extending in the longitudinal direction of the first plate member 10 is provided at the long side end 10LT2. The long side end 10LT2 has legs 15 that are two protruded portions extending in the longitudinal direction of the first plate member, and a portion surrounded by the legs 15 is the groove 12. As illustrated in FIG. 3, when the first plate members are stacked with the long side ends 10LT1 and 10LT2 thereof abutting to each other, the protruded portion 11 of the long side end 10LT1 is fitted into the groove 12 of the long side end 10LT2. At this time, the legs 15 of the long side end 10LT2 are brought into contact with shoulders 11a of the long side end 10LT1. Screw holes 10H for attaching the connecting member 30 with bolts 40 that are fastening members for attaching the first plate member 10 to the connecting member 30, are provided at a side surface 10S of the first plate member. The first plate member 10 also has a through hole 13 extending in the longitudinal direction. In the present embodiment, two through holes 13 are provided in the first plate member 10. The two through holes 13 are partitioned by a partition portion (rib) 14 included in the first plate member 10. In this manner, the strength of the first plate member 10 is increased in the thickness direction of the first plate member 10, in other words, in the direction perpendicular to the side surface 10S of the first plate member 10. The through hole 13 also acts as a neutron flux trap. As modifications of the first plate member, a first plate member 10A illustrated in FIG. 6C has one through hole 13A, and a first plate member 10B illustrated in FIG. 6D has three through holes 13B. As a first plate member 10C illustrated in FIG. 6E, grooves 12C may be provided at both long side ends, and the first plate members 10C may be stacked by interposing a member 11C that can fill the adjacent grooves 12C therebetween. As illustrated in FIG. 7, a reinforcement member 50 may be disposed in the through hole 13 of the first plate member 10. The reinforcement member 50 is made of a material having higher stiffness than that of the first plate member 10, and the length of the reinforcement member 50 (size in the longitudinal direction of the reinforcement member 50) is substantially the same as the entire length of the through hole 13. In this manner, by disposing the reinforcement member 50 having higher stiffness than that of the first plate member 10 in the through hole 13, the strength against the bending of the first plate member 10 is further enhanced. For example, if an aluminum material containing boron, which will be described later, is used for the first plate member 10, stainless is used for the reinforcement member 50. A hollow reinforcement member 50a having a through hole penetrating in the longitudinal direction may also be used, enabling to act as a flux trap. The mass of the basket 1 can be prevented from being increased, for example, by inserting the reinforcement member 50 or the reinforcement member 50a only at positions where the grids of the recycled fuel assemblies come in contact at a certain interval, and placing only the first plate member 10 at the other portions. As illustrated in FIGS. 8A and 8B, similar to the first plate member 10 described above, the second plate member 20 is a rectangular shaped member when viewed from the side, and has four ends. When viewed from the side, two ends corresponding to the long sides of the second plate member 20 are long side ends 20LT, and when viewed from the side, two ends corresponding to the short sides of the second plate member 20 are short side ends 20ST. Recesses 21 extending in the longitudinal direction of the second plate member 20 are provided at the long side ends 20LT. The recesses 21 are fitted into the connecting members 30 attached to the side surfaces 10S of the first plate members 10. The second plate member 20 has a through hole 23 extending in the longitudinal direction. In the present embodiment, two through holes 23 are provided in the second plate member 20. The two through holes 23 are partitioned by a partition portion (rib) 24 included in the second plate member 20. In this manner, the strength of the second plate member 20 in the thickness direction of the second plate member 20, in other words, in the direction perpendicular to a side surface 20S of the second plate member 20 is increased. The through hole 23 also acts as a neutron flux trap. As illustrated in FIG. 3, in a state in which plate member joint bodies (barriers) 100 formed by stacking the first plate members 10 in a plurality of stages and being connected with the connecting members 30 are disposed so as to face each other, and the connecting members 30 are placed opposite from each other, the corresponding connecting members 30 are inserted into both recesses 21 of the second plate member 20. Each of the recesses 21 is a dovetail groove and has a shape that spreads towards the inside of the recess 21 from a groove opening 21H illustrated in FIG. 8B, in other words, towards the through hole 23 of the second plate member 20. In this manner, the recess 21 is meshed with the connecting member 30 whose cross-section is trapezoid, thereby preventing the second plate member 20 from being disengaged from the connecting member 30. The second plate member 20 also functions to connect the adjacent plate member joint bodies 100. In this dovetail groove coupling structure, the first plate member 10 can be placed at any position. Accordingly, cells can be stacked at different positions, which was not possible in the conventional structure (such as FIGS. 21 to 23 in Japanese Patent Application Laid-open No. 2001-166089). In the conventional structure (such as FIGS. 21 to 23 in Japanese Patent Application Laid-open No. 2001-166089), many joint portions are present from the center to the outer peripheral surface of the basket. Accordingly, the heat transfer from the center region to the outer periphery of the basket may be obstructed. However, in the dovetail groove coupling structure of the basket 1 illustrated in FIG. 3, the first plate member 10 is formed of one plate member from the center to the outer peripheral surface of the basket 1. Accordingly, the heat transfer from the center region to the outer periphery of the basket 1 can be facilitated. In another conventional structure (such as FIG. 22 in Japanese Patent Application Laid-open No. 2004-069620), if cells are stacked at different positions, the connection surfaces of the plate members become small. Accordingly, the heat transfer from the center region to the outer periphery of the basket is not easy. Even if the plate members are aligned and stacked, many joint portions are present from the center to the outer peripheral surface of the basket. Accordingly, the heat transfer from the center region to the outer periphery of the basket may be obstructed. In the dovetail groove coupling structure of the basket 1 illustrated in FIG. 3, a half of the first plate members 10 and the second plate members 20 that form the cells, is formed by one first plate member 10 from the center region to the outer peripheral surface of the basket 1. Accordingly, the heat transfer from the center region, to the outer periphery of the basket 1 can be facilitated. In still another conventional structure (such as FIG. 2 in Japanese Patent Application Laid-open No. 2004-020568), cells can be stacked at different positions. However, because recesses are formed in the elements as engagement portions, the depth of the recesses is removed from the thickness of the plate. As a result, the heat transfer area is reduced, thereby reducing the mechanical stiffness. On contrary, in the dovetail groove coupling structure of the basket 1 illustrated in FIG. 3, a large recess (such as deep notch or large notch) is not provided at the first plate member 10 or the second plate member 20. Consequently, the heat transfer performance and the mechanical stiffness can be improved. The first plate member 10 and the second plate member 20, to secure a subcritical function and to reduce weight, are manufactured of an aluminum (Al) material containing boron (B10) (hereinafter, “boron-aluminum material”) (the same applies hereinafter). Boron may also be a boron compound such as boron carbide (B4C). The first plate member 10 and the second plate member 20, for example, can be manufactured by hot rolling or hot extruding a billet made of boron-aluminum manufactured by powder metallurgy. If materials of the same type are rubbed with each other, material loss may occur due to galling. While a material for the connecting member 30 is not especially specified in the present embodiment, at least the surface of the connecting member 30 that comes into contact with the second plate member 20 is preferably made of a material different from that of the second plate member 20 (different characteristics from those of the second plate member 20 can be achieved to prevent galling by performing oxidation treatment, thermal spraying, plating, or other surface treatment; by coating the surface with a lubricating layer represented by graphite and the like; or by using the surface treatment and the lubricating layer in combination). Both of the surface and the inside of the connecting member 30 are preferably made of a material different from that of the second plate member 20, thereby preventing galling. Examples of methods for adopting a different material may include using the same base material and performing oxidation treatment, thermal spraying, plating, or other surface treatment to make only the surface have different characteristics from those of the second plate member to prevent galling; coating the surface of the second plate member or the connecting member with a lubricating layer represented by graphite and the like; using the surface treatment coating and the lubricating layer coating in combination; and using a material having relatively higher strength and higher hardness (stainless, carbon steel, titanium, or the like) than the strength and hardness of the second plate member for the base material of the connecting member. As a different material, a material softer than the second plate member may be chosen for the connecting member. In this case, to receive the load in a dispersed manner, the number of connecting members must be increased or the size of the connecting member must be enlarged. Accordingly, this is not suitable for the purpose of producing an inexpensive recycled fuel assembly storage basket. However, as a basket exclusively used as a storage container, if the assumed load is lighter than that of the transportation-storage container, a soft material may be possibly chosen for the connecting member. In this manner, the galling that occurs by forming the second plate member 20 and the connecting member 30 with materials of the same type (in other words, materials having similar hardness) can be prevented, thereby preventing material loss on the second plate member 20 and the connecting member 30. In the present embodiment, the connecting member 30 is made of, for example, stainless steel, copper, copper alloy, high strength aluminum alloy whose surface is hardened, or a metal (alloy) obtained by combining the surface treatment and the lubricating layer coat. For example, a dovetail groove may be formed in the side surface 10S of the first plate member 10, so that both ends of the second plate member 20 are fitted into the dovetail groove. However, because materials of the same type are used for the first plate member 10 and the second plate member 20 in the present embodiment, material loss may occur due to galling between the first plate member 10 and the second plate member 20 in such a structure. However, in the structure of the present embodiment, a portion where galling between the materials may occur, in other words, a portion where the connecting member 30 and the second plate member 20 are fitted to each other, can be easily made of different materials. Consequently, it is possible to prevent galling. As illustrated in FIGS. 9A and 9B, the connecting member 30 has first side surfaces 30A and second side surfaces 30B parallel to each other, and the cross-section of the connecting member 30 perpendicular to the longitudinal direction is a trapezoidal shape. The second side surface 30B, in other words, a size L1 of the upper base side is shorter than the first side surface 30A, in other words, a size L2 of the lower base side. The upper base of the cross-section, in other words, the side of the second side surface 30B comes into contact with the side surface 10S of the first plate member 10 illustrated in FIGS. 3 and 6A, for example. In other words, the second side surface 30B of the connecting member 30 comes into contact with the first plate member 10. A bolt through hole 31, through which the bolt 40 is penetrated, is formed in the first side surface 30A. The bolt through hole 31 is a long hole to which spot facing is performed. In this manner, as illustrated in FIG. 4, if the connecting member 30 is fastened and attached to the first plate member 10 by having the bolt 40 penetrated through the bolt through hole 31, the head of the bolt 40 is hidden in the bolt through hole 31, thereby preventing the head of the bolt 40 from being projecting from the first side surface 30A of the connecting member 30. By making the bolt through hole 31 into a long hole, the connecting member 30 is movable relative to the bolt 40. Accordingly, the connecting member 30 and the first plate member 10 are relatively movable. As a result, it is possible to relieve the thermal stress generated due to difference in thermal elongation, caused when the material of the connecting member 30 and the material of the first plate member 10 are different. The positions of the first plate member 10 and the connecting member 30 may be defined, by forming a specific hole to which the bolt 40 is attached into a simple round hole, instead of the long hole. In this case, the thermal stress generated in the connecting member 30 due to thermal elongation of the first plate member 10 can be reduced than when all the holes are made into long holes, by making the position to which the bolt 40 is attached to approximately a half of the entire length of the connecting member 30. FIGS. 10A, 10B, and 10C are schematics for explaining a plate member joint body obtained by stacking the first plate members and connecting them with the connecting members. FIG. 10D is a schematic for explaining another example of the plate member joint body. The plate member joint body 100 is integrally formed by connecting the first plate members 10, by stacking the first plate members 10 with the long side ends thereof abutting to each other, and attaching the connecting members 30 to the side surfaces of the first plate members 10. At this time, as illustrated in FIGS. 1 and 5, the connecting members 30 project out from the side surfaces 10S of the first plate members 10. The connecting members 30 are attached in the longitudinal direction of the first plate member 10 at a predetermined interval. In this manner, the second plate member 20 disposed between the plate member joint bodies 100 is disposed in a predetermined interval. The direction towards which the first plate members 10 are stacked is the direction of the cavity axis Z. In the plate member joint body 100 illustrated in FIG. 10A, the sizes of the connecting members 30 in the longitudinal direction are substantially equal to the entire length in the direction towards which the first plate members 10 are stacked. Accordingly, a prior stage of the plate member joint body 100 formed by stacking the first plate members 10 in a plurality of stages is connected by one connecting member 30. In the plate member joint body 100 illustrated in FIG. 10B, the sizes of the connecting members 30 in the longitudinal direction are shorter than the entire length in the direction towards which the first plate members 10 are stacked. In other words, the connecting members 30 are divided at different positions in the direction towards which the first plate members 10 are stacked. This means that the connecting members 30 are divided at different stages of the first plate members 10 being stacked in a plurality of stages. For example, the connecting member 30 at the position A in FIG. 10B is divided between the stage (2) and the stage (3), the connecting member 30 at the position B is divided between the stage (3) and the stage (4), and the connecting member 30 at the position C is divided between the stage (4) and the stage (5). In this manner, by dividing the connecting members 30 at different positions towards which the first plate members 10 are stacked, in other words, by dividing the connecting members 30 at different positions in the longitudinal direction of the connecting member 30, the entire length of the connecting member 30, in other words, the size in the longitudinal direction can be reduced. Accordingly, the effects due to difference in thermal elongation, caused when the material of the connecting member 30 and the material of the first plate member 10 are different, can be relieved. In consideration of common use of parts, the number of parts can be reduced, if the connecting members 30 are divided into lengths of connecting two stages, three stages, and four stages of the first plate members 10. However, if a difference in thermal elongation between the first plate member 10 and the connecting member 30 is small, the number of stages may be increased (for example, from four stages to six stages). As illustrated in FIG. 10C, it is preferable to divide the connecting members 30 at the center of the first plate members 10 in the direction of the cavity axis Z, because all the connecting members can contribute to connecting the first plate members 10. As illustrated in FIG. 10D, a plate member joint body 100a may be formed by inclining the long side ends of the first plate members 10 relative to a bottom B of the cavity 201C (FIGS. 1 and 2), and connecting them with the connecting members 30. In this case, a spacer S having an inclined surface is disposed between the plate member joint body 100a and the bottom B. This is preferable, because water from the through hole 13 (refer to FIG. 6B) formed in the inside of the first plate member 10 can be easily drained. The basket 1 illustrated in FIG. 3, for example, is assembled and manufactured by the following procedures. First, the first plate members 10 are stacked, by fitting the groove 12 and the protruded portion 11 of the long side ends 10LT1 and 10LT2 to each other. The plate member joint bodies 100 (barriers) are then formed in plurality by attaching the connecting members 30 at the side surfaces 10S of the first plate members 10, and connecting the first plate members 10. At this time, the connecting members 30 are projecting from the side surfaces 10S of the first plate members 10. As illustrated in FIGS. 3 and 4, the connecting members 30 are attached to the first plate members 10 by using the bolts 40. The side surfaces of the plate member joint bodies 100 are disposed so as to face each other, and the connecting members 30 are placed opposite from each other. The connecting members 30 placed opposite from each other are inserted into the recesses 21 formed in both of the long side ends 20LT of the second plate member 20. When the connecting members 30 are inserted into the recesses 21, as illustrated in FIG. 5, the recesses 21 of the second plate member 20 and the connecting members 30 are meshed with each other. Accordingly, the second plate member 20 is prevented from being disengaged from the connecting members 30. Accordingly, the basket 1 can be easily assembled, and it is possible to prevent a deviation from occurring between the plate member joint bodies 100 and the second plate members 20. By using such a procedure, the basket 1 can be assembled. Spaces surrounded by the plate member joint bodies 100 and the second plate members 20 are cells in which the recycled fuel assemblies are stored. In the basket 1 assembled in this manner, only the screw holes 10H are formed in the side surface 10S of the first plate member 10, and the second plate member 20 is not inserted by forming a groove thereto. Consequently, the risk of losing stiffness of the first plate member 10 can be reduced to a minimum. In this manner, the integrity of the basket 1 can be sufficiently secured. In the basket 1 illustrated in FIG. 3, the first plate member 10 and the second plate member 20 are made of a boron-aluminum material having neutron absorbing power. However, the first plate member 10 and the second plate member 20 may be made of normal aluminum alloy or stainless steel that does not have neutron absorbing power. In this case, a material (a boron plate and a plate made of stainless-steel containing boron, for example) having neutron absorbing power is separately disposed at the inner surfaces of the cells and on the side surfaces of the plate members facing each other. FIGS. 11A and 11B are plan views of the basket according to the first embodiment. The basket 1 illustrated in FIG. 11A includes 24 pieces of cells surrounded by the first plate members 10 and the second plate members 20, and stores the recycled fuel assemblies therein. #1 to #24 indicate the cells. In the basket 1, a cell column is formed by aligning a plurality of cells in the longitudinal direction of the first plate member 10. The adjacent cell columns do not deviate from each other. A basket 1′ illustrated in FIG. 11B includes 26 pieces of cells surrounded by the first plate members 10 and the second plate members 20, and stores the recycled fuel assemblies therein. #1 to #26 indicate the cells. In the basket 1′, a cell column is formed by aligning a plurality of cells in the longitudinal direction of the first plate member 10. The cell columns adjacent to each other in the direction from the center region to the outside, are deviated as much as a half of the alignment pitch of the cell. In the basket disclosed in Patent document 1, such cell alignment is not possible. However, in the present embodiment, the basket 1′ is formed by combining the first plate members 10 and the second plate members 20, thereby allowing such cell alignment. If the cells are aligned in this manner, even if an outer diameter Da of the basket 1 and an outer diameter Db of the basket 1′ are the same, the number of cells can be increased. In the basket 1′ illustrated in FIG. 11B, the adjacent cell columns are disposed at positions deviated from each other. Accordingly, compared with a basket in which deviations are not allowed, more number of recycled fuel assemblies can be stored therein. Consequently, it is possible to take advantages of this structure. For example, if the cask 200 illustrated in FIGS. 1 and 2 falls in the Y direction, the load of the recycled fuel assemblies stored in the cells is transmitted to the second plate member 20, and then transmitted to the first plate member 10 from the connecting member 30 through the bolts 40. At this time, a piece of the second plate member 20 and the pair of connecting members 30 only receive the load of one of the recycled fuel assemblies. Accordingly, the integrity of the basket 1 can be readily secured. If the basket 1′ illustrated in FIG. 11B falls in the Y direction, because the first plate member 10 does not have a notch as large as a half of the member (see the plate member in Patent Document 1), the basket 1′ can be assembled without impairing the original strength of the first plate member 10. Even if the size and the thickness of the first plate member 10 according to the present embodiment are the same as those of the plate member in Patent Document 1, because the first plate member 10 does not have a notch as large as a half of the plate member, the strength of the first plate member 10 is approximately twice as much as that of the plate member in Patent Document 1, thereby corresponding to the load. If the basket 1′ illustrated in FIG. 11B falls in the X direction, the load of the second plate member 20 applied to the side surface of the first plate member 10 must be taken into account. However, because the first plate member 10 does not have a notch as large as a half of the member (see the plate member in Patent Document 1), the first plate member 10 can sufficiently endure the load of the second plate member 20 and the recycled fuel assemblies trying to bend the first plate member 10. Accordingly, the load is effectively dispersed. Even if the size and the thickness of the first plate member 10 according to the present embodiment are the same as those of the plate member in Patent Document 1, because the first plate member 10 does not have a notch as large as a half of the member, the strength of the first plate member 10 is approximately twice as much as that of the plate member in Patent Document 1, thereby corresponding to the load in the X direction. As a result, the integrity of the basket 1 can be secured. Depending on the needs, as illustrated in FIG. 7, the entire strength of the first plate member 10 can be improved, by disposing the reinforcement member 50 in the through hole 13 of the first plate member 10. Accordingly, the integrity of the basket 1 can further be secured without fail. The first plate member 10 of the basket 1 is disposed so as to intersect the direction parallel to the radial direction (radial direction of the cavity 200C illustrated in FIG. 2) of the baskets 1 and 1′. Accordingly, the first plate member 10 has very good heat transfer characteristics. As a result, the heat transfer characteristics in the entire baskets 1 and 1′ can be sufficiently secured. A material having a high thermal conductivity, for example, a heat transfer accelerating layer made of a metal paste such as a silver paste or a copper paste, or a carbon paste may be inserted between the recess 21 of the second plate member 20 and the connecting member 30. In this manner, the heat transfer performance between the second plate member 20 and the first plate member 10 is improved, thereby further improving the heat transfer characteristics of the entire baskets 1 and 1′. This heat transfer accelerating layer made of a metal paste such as a silver paste or a copper paste, or a carbon paste, can eliminate the risk of material loss due to galling that occurs when the second plate member 20 is assembled to the basket 1. Accordingly, it is preferable to form such a heat transfer accelerating layer. FIG. 11C is a schematic for explaining a modification of an attachment structure of the connecting member and the first plate member. This attachment structure is an attachment structure between the connecting member 30 and the first plate member 10, when the reinforcement member 50 is disposed in the through hole 13 of the first plate member 10 illustrated in FIG. 7. In the attachment structure, screw holes 50H into which the bolts 40 are screwed, are formed in the reinforcement member 50. The connecting member 30 is attached to the first plate member 10, by screwing the bolt 40 that has passed through the bolt through hole 31 of the connecting member 30 into the screw hole 50H. In this attachment structure, a nut for connecting with the bolt 40 is not required, thereby reducing the number of parts. In FIG. 11C, the screw holes in the reinforcement member 50 are expressed by the bolts 40. However, it is easier to form a screw hole, if the screw hole 50H is penetrated through the reinforcement member 50. Nevertheless, as illustrated in FIG. 11B, if cell columns are provided at positions deviated from the adjacent cell column, the screw hole 50H does not have to penetrate through the reinforcement member 50. In the present embodiment, the first plate members are stacked with the long side ends thereof abutting to each other, and the connecting members are attached to the side surfaces of the stacked first plate members, thereby connecting the first plate members. The basket is formed by inserting the connecting member projecting from the side surfaces of the first plate members into recesses formed at both long side ends of the second plate member. In this manner, for example, upon manufacturing the first plate members, the second plate members, and the connecting members of the basket by extrusion molding, the basket can be assembled by performing a simple process of punching and the sort on the first plate members, the second plate members, and the connecting members. As a result, the number of cutting processes on the members of the basket can be drastically reduced. Accordingly, even if the members of the basket are made of difficult-to-cut materials such as a boron-aluminum material, it is possible to manufacture the basket relatively easily, and save the waste of materials resulting from the cutting process. Consequently, it is possible to reduce processing costs. A structure of a second embodiment is substantially the same as that of the first embodiment. However, the second embodiment is different from the first embodiment in providing a load supporting unit that supports the load of the second plate member, in other words, the load in the direction perpendicular to the longitudinal direction of the connecting member between the fastening member and the connecting member, and between the fastening member and the first plate member. Other structures are the same as those in the first embodiment. FIG. 12 is a perspective view of a basket according to the second embodiment. FIG. 13 is a sectional view of a portion in which a connecting member is attached to the first plate member in the basket according to the second embodiment. FIG. 14 is a perspective view of the connecting member of the basket according to the second embodiment. As illustrated in FIGS. 12 and 13, a load supporting key 41 that is a load supporting unit is provided between the bolt 40 that is a fastening member and the connecting member 30, and between the bolt 40 and the first plate member 10. The load supporting key 41 is a cylindrical member and has a through hole 41H penetrated in the longitudinal direction. Screw holes in which the bolts 40 are screwed are formed at the both ends of the through hole 41H. In this manner, the outer diameter of the load supporting key 41 is larger than the outer diameter of the bolt 40. The material of the load supporting key 41 may be the same as that of the connecting member 30, or may be different from that of the connecting member 30. In the present embodiment, the load supporting key 41 is made of stainless steel that is the same material as that of the connecting member 30. However, the connecting member 30 is not limited to stainless steel, but a material having high strength that can receive a large load by a small area can also be applied, thereby obtaining the effects of the second embodiment. As illustrated in FIG. 14, a key receiving recess 32 into which the load supporting key 41 is fitted is provided at the second side surface 30B of the connecting member 30. A portion of the key receiving recess 32 into which the load supporting key 41 is fitted, is matched with the outer shape of the load supporting key 41. In the present embodiment, the shape of the load supporting key 41 is circular. In other words, because the shape of the outer cross-section perpendicular to the longitudinal direction of the load supporting key 41 is circular, the inner shape of the key receiving recess 32 is also circular. If the shape of the outer cross-section perpendicular to the longitudinal direction of the load supporting key 41 is rectangular, the inner shape of the key receiving recess 32 will be rectangular. In this manner, the rotation of the load supporting key 41 is suppressed when the bolt 40 is screwed in, thereby facilitating the work. The load of the second plate member 20 transmitted through the connecting member 30 is transmitted to the load supporting key 41 without fail. A key through hole 10H2, through which the load supporting key 41 is penetrated, is formed in the first plate member 10. The shape of the key through hole 10H2 is matched with the outer shape of the load supporting key 41. In the present embodiment, the shape of the outer cross-section perpendicular to the longitudinal direction of the load supporting key 41 is circular. Accordingly, the inner shape of the key through hole 10H2 is also circular. If the shape of the outer cross-section perpendicular to the longitudinal direction of the load supporting key 41 is rectangular, the inner shape of the key through hole 10H2 will be rectangular. In this manner, the load of the second plate member 20 transmitted to the load supporting key 41 is transmitted to the first plate member 10 without fail. To fix the connecting member 30 to the side surface 10S of the first plate member 10, the load supporting key 41 is inserted into the key through hole 10H2 formed in the first plate member 10, thereby coupling the load supporting key 41 and the first plate member 10. The end of the load supporting key 41 projecting from the side surface 10S of the first plate member 10 is fitted into the key receiving recess 32 of the connecting member 30, thereby coupling the connecting member 30 and the load supporting key 41. The bolts 40 are then screwed into the screw holes formed at both ends of the load supporting key 41, thereby attaching the connecting member 30 to the side surface 10S of the first plate member 10 with the bolts 40. The screw holes formed at the load supporting key 41 may only be formed at both ends. However, if the screw hole is formed into a through screw hole from one side, the processing may only be performed from one side, thereby improving the workability in assembling the basket. Upon confirming the presence of a foreign matter in the screw hole formed at the load supporting key 41, if the screw hole is formed into the through screw hole, the screw hole can be seen through. Accordingly, it is possible to visually confirm the presence of a foreign manner with ease, thereby improving the workability in assembling the basket. If the connecting member 30 is attached to the first plate member 10 only with the bolts 40, the entire load of the second plate member 20 must be received by the bolts 40. Accordingly, the diameter of the bolts 40 must be increased. However, the width of the connecting member 30, in other words, the size in the direction perpendicular to the longitudinal direction of the connecting member 30 needs to be smaller than the thickness of the second plate member 20. Consequently, there is a limitation in increasing the diameter of the bolts 40. In this case, the load can be received by increasing the number of bolts 40, but if this method is used, an operation of forming screw holes for a large number of bolts 40 and an operation of screwing a large number of bolts 40 into the screw holes are increased. In a basket 1a according to the second embodiment, the load of the second plate member 20 is received by the load supporting key 41 having a larger outer diameter than that of the bolt 40. Accordingly, an area of receiving the load can be increased. In this manner, even if the number of load supporting keys 41 is reduced, the load can be received without fail. Because the number of bolts 40 can be reduced, the operation of forming screw holes for the bolts 40 and the operation of screwing a large number of bolts 40 into the screw holes can be reduced. FIGS. 15 and 16 are sectional views of other structures of the portion in which the connecting members are attached to the first plate member in the basket according to the second embodiment. FIG. 17 is a perspective view of the first plate member used in the structure illustrated in FIG. 16. In the structure illustrated in FIG. 15, a bolt through hole 42H, through which a bolt 40a is penetrated, is provided in a cylindrical load supporting key 42. The bolt through hole 31 is provided at one of the connecting members 30 attached to both side surfaces of a piece of the first plate member 10, and a bolt screw hole 33 is provided at the other connecting member 30. The length of the bolt 40a extends from one of the connecting members 30 to the other connecting member 30 through the first plate member 10. To attach the connecting members 30 to the first plate member 10, the load supporting key 42 is inserted into the key through hole 10H2 formed in the first plate member 10, thereby coupling the load supporting key 42 and the first plate member 10. The key receiving recess 32 of the connecting member 30 is fitted into the end of the load supporting key 42 projecting from the side surface of the first plate member 10, thereby coupling the connecting member 30 and the load supporting key 42. The bolt 40a is passed through the bolt through hole 31 provided at one of the connecting members 30, and inserted into the bolt through hole 42H of the load supporting key 42. The bolt 40a is then screwed into the bolt screw hole 33 provided at the other connecting member 30, thereby attaching the connecting member 30 to the first plate member 10 with the bolt 40a. In this structure, screw holes need not be formed at both ends of the load supporting key 42, thereby reducing the number of processes of forming the screw holes as much. A structure illustrated in FIG. 16 is similar to the structure in FIG. 15. However, the structure in FIG. 16 is different from that in FIG. 15 in using a plate-like load supporting key 43 to which a bolt through hole 43H, though which the bolt 40a is passed, is formed. The load supporting key 43 does not penetrate through the first plate member 10, but coupled with the first plate member 10 by being inserted into a key receiving recess 10H1 (see FIGS. 16 and 17) formed at the side surface 10S of the first plate member 10, in other words, the side of the connecting member 30. In this example, the load supporting key 43 is formed in a disk shape, or more specifically, formed in a donut shape. However, the load supporting key 43 may be formed in a non-circular shape such as an oval. An area required for receiving the load may be secured by forming the load supporting key 43 into a rectangular plate shape. To attach the connecting member 30 to the first plate member 10, the load supporting key 43 is fitted into the key receiving recess 10H1 formed in the first plate member 10, thereby coupling the load supporting key 43 and the first plate member 10. The key receiving recess 32 of the connecting member 30 is then fitted into the end of the load supporting key 43 projecting from the side surface of the first plate member 10, thereby coupling the connecting member 30 and the load supporting key 42. The bolt 40a is passed through the bolt through hole 31 provided at one of the connecting members 30, and inserted into the bolt through hole 43H of one of the load supporting keys 43. The bolt 40a is then passed through a bolt through hole 10H4 provided at the first plate member 10, inserted into the bolt through hole 43H of the other load supporting key 43, and screwed into the bolt screw hole 33 provided at the other connecting member 30. In this manner, the connecting member 30 is attached to the first plate member 10 with the bolt 40a. In this structure, the first plate member 10 docs not require a hole through which a load supporting key having a large diameter is penetrated. Accordingly, it is possible to prevent the heat transfer performance of the first plate member 10 from being deteriorated. FIGS. 18 and 19 are sectional views of other structures of the portion in which the connecting members are attached to the first plate members in the basket according to the second embodiment. FIG. 20 is a front view of another example of the portion in which the connecting member is attached to the first plate member in the basket according to the second embodiment. In these structures, a fixed key 44 that is a rotation suppression member for suppressing the rotations of the keys 41 and 43 is provided at least one between the keys 41 and 43 that are load supporting units, and the first plate member 10, and between the keys 41 and 43, and the second plate member 20. The structure illustrated in FIG. 18 is a structure in which the fixed key 44 is provided in the structure illustrated in FIG. 13. The structure illustrated in FIG. 19 is a structure in which the fixed key 44 is provided in the structure illustrated in FIG. 16. The shape of the fixed key 44 may be rectangular as illustrated in FIG. 20. However, the rotation can also be suppressed by the circular-shaped fixed key 44. As illustrated in FIGS. 18, 19, and 20, in the first plate member 10, a notch provided at a part of the key through hole 10H2 or the key receiving recess 10H1 is a fixed key groove 10H3. The fixed key 44 in a square pillar shape is inserted into a space formed by the fixed key groove 10H3, and the notch provided at the outer periphery of the load supporting key 41 or the load supporting key 43, thereby preventing the rotation of the load supporting key 41 or the load supporting key 43. In the present embodiment, the fixed key 44 is provided between the first plate member 10 and the load supporting key 41 or the load supporting key 43. However, the fixed key 44 may be provided between the connecting member 30 and the load supporting key 41 or the load supporting key 43. The rotation of the load supporting key 41 or the load supporting key 43 can be prevented, by forming the cross-section perpendicular to the longitudinal direction of the load supporting key 41 or the load supporting key 43 in a non-circular shape. However, such a process requires a large amount of efforts. Accordingly, as the structure described above, by using the fixed key 44, an anti-rotation function can be provided on the load supporting key 41 and the like by a simple process. Upon assembling the basket 1a illustrated in FIG. 12, the fixed key 44 is attached to the load supporting key 41 and the like, and fixing them with the first plate member 10. Consequently, the basket 1a can be assembled at ease. The fixed key 44 is not limited to the one described above, but may be any one as long as it can suppress the rotation of the load supporting key 41 and the like. In the present embodiment, in addition to the structure disclosed in the first embodiment, a load supporting unit that supports the load of the second plate member, in other words, the load in the direction perpendicular to the longitudinal direction of the connecting member, is provided between the fastening member and the connecting member, and between the fastening member and the first plate member. In this manner, in addition to the effects similar to those of the first embodiment, because of the load supporting unit, even if the load of the second plate member is applied to the fastening members, the load in the X direction is not as large as the load in the Y direction. Here, relative to the load in the Y direction, when the present embodiment is compared with the first embodiment in which only bolts are used as the fastening members, an area to receive the load in the Y direction can be increased. In this manner, even if the number of load supporting units (such as bolts) is reduced, it is possible to receive the load without fail. As a result, because the number of fastening members can be reduced, an operation of forming screw holes for the bolts, and an operation of screwing a large number of bolts into the screw holes, required when bolts are used as the fastening members can be reduced. In a third embodiment, in addition to the structure in the first embodiment, a groove extending in the direction (direction in parallel with the cavity axis Z in FIG. 1) towards which the first plate members are stacked, is formed at the side surface of the first plate member, and the connecting member is fitted into the groove. Other structures are the same as those in the first embodiment. FIG. 21 is a perspective view of a basket according to the third embodiment. FIG. 22 is a sectional view of a portion in which the connecting members are attached to the first plate member in a basket according to the third embodiment. FIG. 23 is a perspective view of the connecting member of the basket according to the third embodiment. In a first plate member 10b of a basket 1b according to the present embodiment, a groove (hereinafter, referred to as connecting member fitting groove) 16 is formed at a side surface 10Sb. The connecting member fitting groove 16 is formed in the direction towards which the first plate members 10b are stacked. Because the depth of the connecting member fitting groove 16 is such as to engage with a guiding member 30b, the strength deterioration of the first plate member 10b is suppressed to a minimum. The connecting member 30b is attached to the connecting member fitting groove 16, and fastened and attached to the first plate member 10b with the bolts 40. As illustrated in FIGS. 22 and 23, the cross-section of the connecting member 30b perpendicular to the longitudinal direction is rectangular. A bolt through hole 34, through which the bolt 40 is penetrated, is formed in the connecting member 30b, at the side facing the first plate member 10b. The bolt through hole 34 is a long hole to which spot facing is performed. In this manner, as illustrated in FIG. 22, if the connecting member 30b is fastened and attached to the first plate member 10b by having the bolt 40 penetrated through the bolt through hole 34, the head of the bolt 40 is hidden in the bolt through hole 34. Consequently, the head of the bolt 40 can be prevented from being projecting from the side surface 30A of the connecting member 30b. A material having a high thermal conductivity, for example, a heat transfer accelerating layer made of a metal paste such as a silver paste or a copper paste, or a carbon paste may be inserted between the connecting member fitting groove 16 and the connecting member 30b fitted into the connecting member fitting groove 16. In this manner, the heat transfer performance between, a second plate member 20b and the first plate member 10b is improved, thereby further improving the heat transfer characteristics of the entire basket. Accordingly, it is preferable to form such a heat transfer accelerating layer. The screw holes 10H are formed in the connecting member fitting groove 16 provided at the side surface 10Sb of the first plate member 10b. Upon fitting the connecting member 30b into the connecting member fitting groove 16, the bolt 40 is penetrated through the bolt through hole 34 of the connecting member 30b, and screwed into each of the screw holes 10H of the first plate member 10b. Accordingly, the connecting member 30b is fastened and attached to the connecting member fitting groove 16. The connecting members 30b placed opposite from each other are fitted into the recesses of the second plate member 20b, to which recesses for coupling with the connecting members 10b are formed at both long side ends, thereby forming the basket 1b. In the basket 1b, the connecting member 30b is fitted into the connecting member fitting groove 16 formed at the side surface 10Sb of the first plate member 10b, and the load of the second plate member 20b, in other words, the load in the direction perpendicular to the longitudinal direction of the connecting member 30b is received by the connecting member 30b and the connecting member fitting groove 16. In this manner, because an area to receive the load is increased, very little load is applied to the bolts 40. Accordingly, the diameter of the bolt 40 may be small, and the number of bolts 40 may be reduced, thereby reducing the operation of forming screw holes for the bolts 40, and the operation of screwing a large number of bolts 40 into the screw holes. Because the diameter of the bolt 40 may be small, and the number of bolts 40 may be reduced, the manufacturing costs of the basket 1b can be reduced. FIG. 24 is a sectional view of another structure of the portion in which the connecting members are attached to the first plate member in the basket according to the third embodiment. In this structure, the first plate member 20b has the bolt through hole 10H4 through which the bolt 40a is penetrated. The bolt through hole 34 is provided at one of the connecting members 30b attached to the both side surfaces of one piece of the first plate member 10b, and a bolt screw hole 35 is provided at the other connecting member 30b. The length of the bolt 40a extends from one of the connecting members 30b to the other connecting member 30b through the first plate member 10b. To attach each of the connecting members 30b to the first plate member 10b, the connecting member 30b is fitted into the connecting member fitting groove 16, thereby coupling the connecting member 30b and the first plate member 10b. The bolt 40a is passed through the bolt through hole 34 provided at one of the connecting members 30b, inserted into the bolt through hole 10H4 of the first plate member 10b, and screwed into the bolt screw hole 35 provided at the other connecting member 30b. Accordingly, the connecting members 30b are attached to the first plate member 10b with the bolt 40a. In this structure, screw holes need not be formed at both side surfaces of the first plate member 10b. Consequently, it is possible to reduce the number of processes of forming the screw holes as much. FIG. 25 is a sectional view of another structure of the portion in which the connecting member is attached to the first plate member in the basket according to the third embodiment. In this structure, a connecting member fitting groove 16c formed at a first plate member 10c and recesses 21c provided at both ends of a second plate member 20c are all formed into dovetail groove shapes. Accordingly, the first plate member 10c and the second plate member 20c are coupled by a connecting member 30c, fitted into the connecting member fitting groove 16c and the recess 21c. In this structure, the shapes and sizes of the connecting member fitting groove 16c and the recess 21c are preferably the same. If the shapes and sizes thereof are the same, when the connecting member 30c is fitted into the first plate member 10c, they can be assembled without paying attention to the direction, thereby improving workability. A material having a high thermal conductivity, for example, a heat transfer accelerating layer made of a metal paste such as a silver paste or a copper paste, or a carbon paste may be inserted between the connecting member fitting groove 16c and the connecting member 30c, and between the recess 21c and the connecting member 30c fitted into the recess 21c. In this manner, the heat transfer performance between the second plate member 20c and the first plate member 10c is improved, thereby further improving the heat transfer characteristics of the entire basket. The heat transfer accelerating layer made of a metal paste such as a silver paste or a copper paste, or a carbon paste can eliminate the risk of material loss due to galling that occurs when the first plate member 10c and the second plate member 20c are assembled into a basket. Accordingly, it is preferable to form the heat transfer accelerating layer. The width (size in the direction perpendicular to the direction towards which the connecting member fitting groove 16c is formed) of the connecting member fitting groove 16c formed in the first plate member 10c is increased towards the inside from the opening portion. The width (size in the direction perpendicular to the direction towards which the recess 21c is formed) of each of the recesses 21c formed at both ends of the second plate member 20c is increased towards the inside from the opening portion. The shape of the cross-section of the connecting member 30c perpendicular to the longitudinal direction is formed in a shape in which upper bases of the trapezoids are connected. In such a structure, the connecting member 30c is fitted into the connecting member fitting groove 16 of the first plate member 10, and into the recess 21c of the second plate member 20, thereby coupling the first plate member 10c and the second plate member 20c. In such a structure, the connecting member 30c is meshed with the connecting member fitting groove 16 of the first plate member 10, and with the recess 21c of the second plate member 20. Accordingly, the assembly and handling of the basket are facilitated, thereby preventing deviation between the first plate member 10c and the second plate member 20c. In the present embodiment, in addition to the structure disclosed in the first embodiment, a connecting member fitting groove extending in the direction towards which the first plate members are stacked is formed at the side surface of the first plate member, and a connecting member is fitted into the connecting member fitting groove. The connecting members placed opposite from each other are fitted into the recesses of the second plate member to which recesses for coupling with the connecting members are formed at both long side ends. In this manner, in addition to the effects similar to those of the first embodiment, because of the load of the second plate member in the Y direction is received by the connecting member and the connecting member fitting groove, the load in the Y direction is scarcely applied to the fastening members (such as bolts). In this manner, even if the number of load supporting units is reduced, the load in the Y direction can be received without fail. As a result, the number of fastening members can be reduced, and if bolts are used as the fastening members, the bolts with a small diameter can be used. The operation of forming screw holes for the bolts and the operation of screwing a number of bolts into the screw holes can be reduced, thereby reducing manufacturing costs of the basket. In this manner, the recycled fuel assembly storage basket, the recycled fuel assembly storage container, and the method for manufacturing the recycled fuel assembly storage basket according to the present invention can be advantageously used for transporting and storing recycled fuel assemblies. More specifically, the recycled fuel assembly storage basket, the recycled fuel assembly storage container, and the method for manufacturing the recycled fuel assembly storage basket are suitable for reducing the number of cutting processes on the members of the recycled fuel assembly storage basket.
	summary
	description	This invention is related to the field of fuel elements used in nuclear reactors and in particular to fuel plates developed for new designs of reactor termed fourth generation. More particularly, the device according to the invention is designed for installations operating in the high temperature field, i.e. for High Temperature Reactors (HTR) in which the temperature of the coolant at the reactor output is above 800° C.; more preferably, these are gaseous heat exchanger reactors operating with a fast neutron flow cooled by a gas, or GFR (for “Gas Fast Reactor”). The invention proposes an element design suited to the operating conditions imposed and offering improved performance; it proposes more particularly a new design of macro-structured composite fuel “plate element” which meets the GFR specification. Stations for the production of energy from fission reactions use fuel elements in which fissions releasing power in the form of heat occur, which is extracted from them by heat exchange with a heat conducting fluid providing their cooling. To this end, while supporting the stresses which the behaviour of the fuel and its operating conditions impose, the general principles for designing basic fuel elements aim to satisfy the following functionalities: to have a density of fissile atoms compatible with the neutron operating conditions and with the power density per unit volume of the reactive volume, to provide heat transfer between the fuel material and the heat-conducting fluid, to confine the solid and gaseous fission products released by the fuel. Of course, fission reactions within the fuel generate solid and gaseous fission products which cause an expansion of the structure of the material, a phenomenon activated by the heat, which also induces mechanisms for releasing fission gases outside the fuel material. Sheathing the fuel material can accommodate these distortions without loss of the element's integrity. The density of the fissions within the fuel is correlated directly with the power density to be evacuated to the heat exchanger through the sheath. The thermal resistance between the source of heat and the heat exchanger must accordingly be minimal in order to control the maximum temperature of the fuel and the effects induced by this heat flow, in other words the gradient within the materials and the differential expansions between the fuel and the sheath. The density of fissile material in the reactive volume itself depends principally on the form of the fuel elements: the form determines the capacity of the fissile material to be arranged in a given volume while aiming for a maximum filling rate, as well as giving the permeability necessary for the heat exchanger to guarantee evacuation of the power produced by the elements with an acceptable load loss. In nuclear installations, conventionally, three families of basic fuel elements can be used: a plate-type element (any shape), a cylindrical-type element (most often of circular or annular cross-section) extending along its axis, and a spherical-type element, most often in the form of small particles (with a diameter of approximately one millimeter). Spherical particles can also be enclosed in an inert matrix to generate composite fuel elements, which can also occur in the three preceding forms of bullet, plate and compact. Each type of fuel element combines different solutions to the problems posed and represents a compromise according to its field of operation. For example, in plates, the sheaths behave as shells with a high slendering ratio (ratio between the free length of the shell and its thickness). By its malleability, the sheathing material adapts its geometry to that of the central part of the fuel, which allows accommodation of differential distortions (inflation and expansion) relative to the fuel material, transversally and at a very low stress level. However, this plate structure has little capacity to accommodate distortions in the direction of the thickness, owing to the very low rigidity of the sheaths perpendicular to their plane, and this freedom allows the fuel to be distorted anisotropically, more preferably in this direction. This structure is also unstable when buckling if it is put in compression in its plane, overall or locally (on a hot point, for example), particularly if the core of the fuel is not connected, or is weakly connected, to the sheaths. In view of these shortcomings, plate elements are in fact used only for cold fuels, i.e. in the temperature range where the fuel material does not release its gaseous products, and at moderate power density levels. Optimisation parameters apply in general, for an intended power density level, to the thickness of the plate and the quality of the fuel/sheath contact, to control of corrosion of the sheath and to the preservation of its ductility properties in operation. In fact, the principal methods of ruining plates are connected either to an imposed lack of ductility in distortion of the sheathing (damage by corrosion or hardening under irradiation), or to an increase in the thermal resistance between the fuel and the heat exchanger (resistive corroded area on the sheath, separation of the fuel and sheath with opening of a gap by local buckling of the sheath, for example) which causes heating of the fuel with releasing of fission gases and internal pressurising of the sheathing, leading to fracture by instability in distortion of the sheath. Cylindrical elements comprise graphite/gas reactor cartridges, pressurised water reactor (REP) pencils or fast neutron reactor (RNR) needles, for example. In this case, there is a radial gap between the fuel in the form of pellets and the sheath enclosing them, a gap which can accommodate differential distortions between the fuel material and the sheath: this gap is capable, at a minimum, of compensating for differential expansions as the element builds up power and the share of the fuel expansion that it cannot absorb itself by creep and re-densifying over its internal cavities. Actually, the fuel material must operate at a temperature which allows it to activate its own mechanisms for accommodating its distortions; as consideration, it releases a part of its fission gases. A second expansion volume is arranged in the sheath, in the ends of the stacks of fuel pellets, in order to limit the pressure inside the element. Heat transfer between the fuel pellets and the heat exchanger is then effected radially through a thermal resistance consisting of the radial gap between the pellet and the sheath filled with gas and the thickness of the sheath. Control of this thermal resistance throughout the life of the element can guarantee compliance with the temperature limits acceptable in the fuel. In this element design, there is therefore a heat transfer through a calibrated gaseous seal and an expansion chamber arranged in the direction transverse to that of the heat transfer. The principal optimisation parameters for these cylindrical elements are the initial radial gap between the fuel and the sheath, the type of fluid providing the thermal bond between the fuel and the sheath (gaseous seal or molten metal seal), the effective filling density of the fuel in the cross-section of the sheath (radial gap, porosity, presence of discontinuities, such as a central hole and/or lenticular voids at the ends of the pellet), the rigidity of the sheath (thickness), the behavioural laws (inflation and creep) of the materials of the sheath and of the fuel, and their mechanical properties (strength and ductility). The presence of a gap between the fuel and the sheath, however, provides a variable thermal resistance in operation (changes to the gap and a decrease in conductivity owing to the presence of fission gases) which complicates control of the maximum temperature of the fuel with regard to not reaching the melting point of the fuel material in all operating situations. Second, operating as a “pressurised chamber” for this type of element involves the use of materials capable of ensuring the mechanical strength of the element without risk of catastrophic failure (instantaneous and/or delayed) under pressure; to this end, a circular cross-section, which has the best resistance to pressure, is most often adopted: in a situation of mechanical interaction between the fuel and the sheath, the former opposes a significant reinforcing rigidity by its circumferential traction and the circumferential pressure exercised by the sheath on the fuel activates its self-rearrangement mechanisms. The choice of material for the sheath therefore appears critical in that it must have a resistance to breakage compatible with the intended operating temperatures, a ductility in plasticity and in thermal creep, and adequate strength (typically >20 MPa·√m); this choice (yield point instantaneously and in creep) and that for the fuel material (melting point) determine the limit operating conditions (temperatures and power density) for the fuel elements. The principal method of residual ruin associated with this type of element is actually the instantaneous mechanical interaction between the fuel and the sheath exceeding the distortion capability of the latter (case of the power rising to a level greater than the preceding operating mode or into an operating mode where the temperature of the fuel does not activate its mechanisms for auto-accommodating its distortions). As regards spherical elements, different surrounding layers are deposited on a fissile core which must be centred; empty spaces are thus created, in the form of porosities, within the fissile core and in an intermediate buffer layer with very high porosity, which ensures initial continuity between the fissile core and the sheathing layers. The accommodation of the differential distortions between the fuel and the sheath, in other words the cladding layer, is effected by filling the gaps: in operation, the gradual densifying of the buffer releases a radial gap capable of preventing a strong mechanical interaction between the fissile core and the sheathing layers. Moreover, free volumes inside the sheathing retain the fission gases released by the fissile material: the spherical form of the sheath is accordingly well suited to resisting the internal pressure which builds up. The optimisation parameters for the elementary particles are fundamentally the choice of materials (type, structure, properties and laws of behaviour under neutron flow and in temperature) and the thickness of the different layers. These fuel elements are used only for gas-cooled heat flow reactors operating at high temperature. Their principal mode of residual ruin corresponds to the strong interaction between the fissile core and the sheathing layers (put into traction by the distortion imposed by the sheath) which can cause breakage of the confinement sheath: from this point of view, the spherical form of the sheathing, although ideal as regards the mechanical interaction, is the least favourable because it does not leave any direction of distortion for the fuel material (beyond its maximum densification) to relax the interaction forces (put under hydrostatic pressure by the internal volume of the sheath). This spherical type of fuel element is actually used principally as part of composite elements of various shapes diluting the particles in a matrix ensuring heat transfer to the heat exchanger, with a low volumic fraction (a few %) of the fissile material in the reactive volume. Composite elements were developed principally to reduce the risk of pollution of the primary heat exchanger circuit if the fuel elements fracture, so as to reduce as far as possible the amount of fission products capable of being released following an event initiating a break. In particular, elements in the form of macro-structured plates can be considered as one solution, with an ordered arrangement of the fuel particles and/or the quest for a particle density compatible with the volumic fraction of the intended application. In any case, to obtain good and uniform conductivity across the plate, a fuel dilution matrix and sheathing plates in a metallic material are used for the intended applications. It appears that GFRs, including the heat exchanger gas, helium for example, can reach in the output of the reactor a sufficiently high temperature compatible with the intended high yield electricity production applications (for example in direct cycle) or hydrogen production and must operate with a fast flow providing a possibility of achieving a conversion rate greater than 1 (over-generation) and/or an ability to transmute the waste (fission products and minor actinides): an adaptation of the safety and reliability levels in operation to these requirements relative to those already achieved in previous generation systems is accordingly desirable. The problem to be solved in order to have a fuel element compatible with the GFR specification has four components: 1) to provide a high volumic fraction of fuel in the matrix, 2) to guarantee the mechanical strength of each cell against the internal pressure of the fission gases released by the fuel, 3) to avoid strong interactions between the fuel (by its expansion) and the structures of the cell, 4) to evacuate the power produced to the heat exchanger with good conductivity across the plate in order to control temperatures at the core of the plate and the stresses induced in the structures. In particular, to achieve the neutron characteristics for GFR cores, the fuel volumic fractions in the composite core of the plate element should be greater than 50%, the balance consisting of an inert matrix. Because the power density in the composite core can achieve some hundreds of MW/m3, the heat transfer to the heat exchanger induces high temperature differences between the sheath (surfaces for exchange by the plate element with the heat exchanger) and the composite core of the plate; operation at high temperature (temperature of the heat exchanger over 850° C.) also mandates for the sheathing and the plate element materials having compatible properties of thermal conductivity, transparency to neutrons and mechanical strength, in particular metals and refractory alloys or ceramics. Second, the high rates of combustion achieved will cause significant expansion of the fuel (several %) and a significant release of gaseous fission products, exacerbated the more by the temperature of the fuel. Each elementary cell of the fuel plate must, if possible, be capable of accommodating these stresses without fracture and without excessive distortion of the plate, which could influence the cross-section for passing the heat transfer between the plate elements: the expansion volume provided in each cell between the fuel and the matrix should be guaranteed in order to avoid a strong mechanical interaction generating unacceptable stress levels for the matrix/sheath structure and to maintain a level of the internal pressure of the fission gases compatible with the mechanical strength of the sheath in all operating situations for the fuel element (normal, in the event of incidents, or even an accident). This problem is particularly difficult to solve as the operating temperature level implies for structures of the element in plate form the use of materials with low ductility and strength, which makes them particularly sensitive to imposed loads of the distortion type, such as thermal expansion gradients and inflation inside the materials, as well as interactions between fuel and structures (differential inflation and thermal expansion). No existing structure is ideal for meeting these criteria. In particular, the document U.S. Pat. No. 3,097,152 proposes a cell geometry including fuel particles which is incapable of covering the range of operating temperatures intended in the GFR: the structural materials of the plate are not compatible with the intended temperatures, in particular where the matrix and the fuel are in contact, with a high density of fuel in the matrix and a high power density. Moreover, the absence of free space around the fuel particles makes it impossible to accommodate at the same time storage at a pressure acceptable by the structure of the fission gases released by the fuel and the differential fuel/matrix distortions thus combined in the thickness of the plate. The plate design described in the document U.S. Pat. No. 3,070,527 is no longer suited to GFR operating conditions: the plate in this case consists of a compartmented central core, each of the compartments accommodating a metallic or ceramic fuel, the plated sheathings either side providing obturation. As the intended target is water reactors, the fuel is defined to be colder, with thin plates of metallic structures (aluminium, stainless steel, zirconium, zirconium alloys) of the same grade and unconnected to the fuel. The document U.S. Pat. No. 3,855,061 itself describes a plate design based on the principle of an ordered network of spherical fuel particles, where the scope relates to boiling water reactors (BWR) and pressurised water reactors (PWR or REP): control of the dispersion and of the volumic fraction of the fuel in the composite and its capacity to achieve higher combustion rates are sought. The fuel spheres are therefore arranged in metal plates pierced with circular cylindrical holes (the thickness of each of the plates and the diameter of the holes are equal to the diameter of the spheres), which releases around each sphere an expansion volume accommodating the fission gases and allowing a certain geometric expansion of the fuel. Two metal sheathing plates on either side secure the element against leaks. The filling densities in fuel material of the central matrix of plates can approach 20 to 25%; its ability to achieve large volumic fractions with high power densities and operating temperatures is not discussed. The development of a new fourth generation of nuclear reactors must therefore more preferably be accompanied by the design of new fuel elements which offset the disadvantages of existing structures. The invention thus proposes a configuration for the nuclear fuel capable of operating with GFR reactors although not limited to this use. More generally, the invention relates to a fuel element comprising a sheathing plate provided with a network of walls forming cells, more preferably in the form of a honeycomb, advantageously integral with the plate, and at least one localised pellet of nuclear fuel, with a radial gap, in a cell. Each fuel pellet of the element extends along an axis between two opposing sides, for example in the form of a revolving cylinder; advantageously, at least one of the opposing faces is curved, more preferably in its centre, in other words it has an outward-facing projection such that an initial axial space is also left between the pellet and the cell. For its use, the element according to the invention comprises a second sheathing plate, provided with the same network of walls as the first or plane, which can be matched to the first plate such that the cells are closed. Advantageously, brazing, bonding or welding can obtain sealed cells, each of which are more preferably filled with an inert gas, such as helium and a fuel pellet. The plates and walls of the cells according to the invention can be produced in refractory metal or in ceramic, monolithic or reinforced by fibres, such as a silicon carbide with fibres of the same nature or of a different nature. In the case of ceramic plates in particular, a metallic layer can be interposed in the cells, between the pellet and the walls, to perfect confinement of the fission products. The dimensions of the plates and pellets are matched and optimised according to the reactor. More preferably, the fissile phase represented by the pellets makes up more than 20% by volume of the reactive environment (core), i.e. more than 50% of the volume of the composite core of the plate element, and the free volume between pellets and internal wall represents more than 40% of the volume of the pellets. In order to best understand the innovative character of the proposed element, a prior analysis of the phenomena occurring in reactors of the GFR type for which the fuel element according to this invention was primarily designed, even if there are other possible applications, will allow the stresses to be considered to be deduced. Nuclear reactors which work with a fast flow need fuel elements providing a high volumic fraction of fissile materials in the core. Working with the fuel at high temperature also mandates having in the fuel elements an expansion volume capable of collecting the fission gases released. Given the space necessary for passage of the heat exchanger fluid to limit load losses to reasonable values and the volume which other core structures occupy, the part of the volume remaining for the structures and expansion volumes of the fuel elements is small. For the invention, this accordingly involves reducing to the maximum the structural volume (sheath and matrix) in the fuel element to obtain sufficient quantities of fuel together with an expansion volume between the fuel and the confinement cell which contains it. In particular, so that GFRs achieve satisfactory neutronic operating conditions, the volumic fractions of the fuel material in the reactive environment (core) approximate to at least 20-25% according to the density and enrichment in fissile material of the fuel. The volumic power densities in the core are of the order of 100 MW/m3, and the volumic fraction occupied by the heat exchanger gas necessary for cooling with an acceptable load loss and a heat exchanger temperature meeting the target of T>850° C. should approximate to at least 40%. The volumic powers in the fissile material achieve on average values of 400 to 500 MW/m3, i.e. maximum values of 600-750 MW/m3 according to the flow profiles in the core. Because the other materials making up the composition of the structures occupy the remaining volumic fraction of 30 to 35% (excluding any gap) must have a neutronic transparency in order not to degrade the flow (in intensity and in spectrum). Finally, to reduce the risk of pollution of the primary circuit of the heat exchanger in case of fracture, the quantity of fission products likely to be released is reduced by a composite geometry of the fuel elements. Accordingly, the design principles for the new fuel element in the form of plate for GFRs are: dispersion of the fuel in elementary cells, each providing with a good degree of reliability (sealing and safety margin before fracture), confinement of the gaseous fission products released at the working temperature of the fuel, which involves strength under pressure of the cells and accommodation of the differential inflation and thermal expansion between the fuel and the structure of the cell, without excessive distortion of the cell, arrangement of the elementary cells to correspond to the volumic fraction of fissile product in the core, a uniform cooling of the cells by the heat transfer to reduce the range of variation of the operating temperature of the fuel from one cell to another and during irradiation, the use of materials compatible with the working temperature level, transparency and non-slowing down of the neutrons, and with the heat flows to be evacuated, a slendering ratio (ratio of the thickness or diameter to the largest dimension of the element) compatible with an overall good mechanical strength of the element, guaranteeing its maintenance in position as a structure in the architecture of the core (strength in vibration and non-dislocation of the fuel), a form of element accommodating the distortions imposed by the gradients of the operating conditions (temperature, neutronic flow) to which it is subjected, with an induced level of stresses compatible with its mechanical strength. It was found that a suitable structure comprised a composite element in the form of a plate with a macrostructure defining individual cells for each pellet, illustrated in a preferred form in FIG. 1. The macro-structured composite plate element 1 is constructed on the basis of a sandwich panel with two sheathing plates 2, 4 in which the core is a network 6 of cells 8 ordered as a honeycomb, placed approximately orthogonally to the faces of the plates 2, 4. The honeycomb structure 6 is the network which gives both: the greatest compactness of cells 8 in the plane and thus the greatest free volume to place the fuel 10 in the network 6, a good isotropy of the mechanical behaviour of the element 1 in its plane, a good rigidity of the element 1 in bending, and a high resistance to buckling in compression in its plane. However, it is possible to adopt, according to the circumstances, other networks of cells, regular (for example a square ram) or not (for example a mixed structure of octagons and squares). Similarly, it is preferable that the walls which form the network 6 should be of identical thickness for each cell 8, and that they should be perpendicular to the plane of the structure 1; however, variations can be considered, particularly for construction reasons. Each cell 8, delimited by the walls 6 and closed at its ends by the sides 2, 4 of the plate element 1, constitutes an elementary cell built according to the design principles set out earlier to provide heat transfer between the fuel 10 which will be located in it and the sides of the sheathing plates 2, 4 cooled by the heat exchanger, in order to look after the expansion volume for the fission gases, and to foster a mechanical interaction between the fuel 10 and the sheath 2, 4 with low stress levels in the structures of the cell. Each hexagonal section cell 8 can accommodate and advantageously accommodates a fuel pellet 10 of cylindrical and circular form having (see FIG. 2): a calibrated axial gap 12 between pellet 10 and sheath 2, 4 (for example some tens of μm) to regulate the temperature at the core of the fuel throughout the period of use of the element 1, the objective being to ensure the transfer of all the power from the pellet 10 through this gap, a radial gap 14 between pellet 10 and walls 6 of the cell 8, dimensioned to create the expansion volume necessary in the cell and to prevent circumferential mechanical interaction between the pellet 10 and the cell 8. The expansion volume de facto consists of the circumferential gap 14 and the difference in volume released between the internal hexagonal shape of the cell 8 and the circular cylinder 10 inscribed in the hexagon. The radial gap 14 is more preferably large (for example some hundreds of μm) to provide thermal decoupling between the pellet 10 and the wall 6 of the cell 8. Radial heat exchanges via the walls of the cell are in this way avoided, or at least minimised, in order to maintain the network 6 at an average temperature equal to that of the sheaths 2, 4 and thus avoid differential expansions between the sheaths 2, 4 and the central structure 6 of the composite. It is also possible to create a controlled mechanical interaction between the pellet 10 and the sheath 2, 4 in an axial direction, by regulating the initial gap and by using in particular the pellets 10 with a curved end profile which establishes a gradual contact of the centre of the cell 8 towards the periphery (any other protuberance would be feasible, but the curved geometry, besides its simplicity in manufacture, can obtain a symmetry and a gradual contact which distributes the force over a large area). The bending distortion imposed on the sheaths 2, 4 by the pellet is then accommodated, on one hand, by the pellet 10 itself (which is distorted radially: see below), and on the other hand in bending by the sheath, the rigidity of which is matched (thickness of the sheath 2, 4 and dimensions of the cells 8) to minimise the stresses induced in the structures of the cell 8. The accommodation by the fuel 10, itself prevented from some distortions axially owing to the mechanical contact is achieved more preferably by circumferential expansion in the radial gap 14. The distortions of the fuel pellet 10 thus occur in a system where one direction is stressed (direction in the axis AA of the pellet 10), and the other two are free (circumferential expansion). In this system, the fuel pellet 10 has a minimum rigidity in its direction AA of interaction with the sheath 2, 4. Accordingly, as illustrated in FIG. 2, the honeycomb network 6 has in a particularly preferred manner hexagonal cells 8 each with a fuel pellet 10 of circular cross-section. A free volume 14 is arranged between the pellet 10 and the walls 6, which guarantees an absence of radial interaction between pellet 10 and cell 8; the sheaths 2, 4 close the ends of the cell 8, with an axial gap 12 providing heat transfer between the pellet 10 and the sheath 2, 4. Each face opposite the fuel pellet 10 along its axis AA has a convexity 16 to localise the gradual contact between pellet 10 and sheath 2, 4 at the centre of the cell 8. More preferably, the entire structure of the element 1, i.e. the network 6 and each of the sheathing plates 2, 4, is manufactures in the same refractory material, which can be a metal, or a ceramic, the ceramic possibly being monolithic or incorporating fibres that are themselves ceramic. In particular, if the walls are ceramic, as illustrated in FIG. 2C, it is possible to add a metallic layer 18, or “sheet”, plated on the walls of each cell 8. More preferably, the sheet 18 encapsulates the pellet 10 and its expansion volume 12, 14, to increase in this way confinement of the products generated while the reactor is in operation. As regards the assembly, as is clear in FIG. 1, the plate element 1 can consist of two half-elements assembled in the mid-thickness plane, in other words midway up the walls 6. The two half-elements 2, 6′ and 4, 6 can actually be identical and each incorporate on one side of the sheathing plate 2, 4 the network 6, 6′ of hexagonal cells as an “impression”. In another embodiment, this can be the assembly of a plate 4 incorporating in impression on one side of the complete network 6 of cells 8 with a smooth sheathing plate closing the cells 8 on the other plane. It is also possible to produce the central grid 6 as a honeycomb structure independently, then to assemble it with two plane plates 2, 4 manufactured separately. If the structures of the fuel element 1 (sheaths 2, 4 and grid 6) allow the choice of a metallic material, the three preceding embodiments are feasible: the positioning of the linking planes between the structures 2, 4, 6 is determined by ease of production considerations. However, in the case of an embodiment of an “all ceramic” element, it can be preferable to use only one linking plane between two sub-structures, and to site it at the median plane of the element 1 (as illustrated in FIG. 1), i.e. where the stresses in operation are least; this option broadens the choice of the ceramic-ceramic bonding methods to be used (brazing, welding by diffusion, bonding by a ceramic precursor, etc.). According to one particularly advantageous embodiment for satisfying the fast flow operating conditions, high heat exchanger temperature and high power density in a GFR, the fuel pellets 10 are cylindrical and circular of a diameter of 11.18 mm and a height of 4.9 mm, comprising a curved form 16 at the ends (arrow at the centre 30 μm at least); these pellets are manufactured from (U, Pu)C according to a standard method with a porosity rate of 15%. It must be understood that the numerical values given are purely for information and must in any event be interpreted with the usual margins for error. The fuel element 1 is then designed with a sheath 2, 4, 6 made from monolithic ceramic (SiC for example) or a fibrous composite (SiC—SiCf for example), with a total thickness of 7 mm. It is produced by assembling two identical half-elements, each incorporating flat base 2, 4 of a thickness of 1 mm and a network 6, 6′ of a height of 2.5 mm defining a honeycomb grid with cells 8 at intervals of 14 mm, and walls with a uniform thickness of 1.3 mm. The assembly of the two half-elements is effected by brazing (with the method adapted to the ceramic and to the temperature range), by welding by diffusion or by bonding. The cells are filled with helium gas at atmospheric pressure. The axial gap 12 between pellet 10 and sheath 2, 4 is 100 μm, the radial gap 14 (between the flats of the hexagon) is 760 μm: the initial free volume between the pellet 10 and the sheath 2, 4, 6 (not counting the volume of the porosities of the fuel) then accounts for 47% of the volume of the fuel pellet. In the case of installing a metallic sheet 18, its thickness between 25 and 100 μm inclusive, is included in the thickness of the walls 6 of the cells 8 and the sheaths 2, 4: for example, the thickness of the walls is adjusted from 1.3 mm to 1.1 mm for a sheet thickness of 100 μm. The sheet can consist of semi-refractory metal alloys, for example based on tungsten, molybdenum, niobium, etc. Furthermore, titanium or zirconium carbides can replace silicon carbide; ternary carbides can also be considered, or titanium or zirconium nitride, in particular for a nitrided fuel, for example UPuN. In this configuration, the volumic fraction of the fuel in the composite central core of the plate is 56%. The plates 2, 4 are rectangular and with dimensions approximately 120×250 mm. The arrangement of these elements 1 in the core of the reactor provides the volumic fraction of 22.4% for the fissile phase in the reactive environment necessary for operation of the GFR core. The behaviour of this element 1 was analysed in the operating conditions of a 2400 MW GFR with a uniform volumic power density in the core of 100 MW/m3, a temperature in the output of the heat exchanger of 850° C. and a fuel combustion rate of at least 10% atomic. The thermomechanical behaviour of an elementary cell was analysed with the CAST3M finite elements software in all operating situations allowing dimensioning: normal operation and shutdown situation (return to an isothermic cold state without pressure in the heat exchanger), incidents with fast load variation (increase in power of 10%), and accidental situations with slow or fast depressurisation of the heat exchanger gas. This study was conducted: 1) on the cell having the maximum power density value in the core (in the plane of maximum flow at the centre of the core), i.e. a value of 670 MW/m3 and an external temperature of the faces of the plate of 872° C., 2) for cells having different operating conditions along an axial profile at the centre of the core (conditions varying from the input to the output of the core while passing through the plane of maximum flow). The results showed that, for normal operation up to 10% atomic, while assuming a rate of release for the fission gases of 10% of then fuel (U—Pu)C: i. The internal pressure at the end of life in the most loaded cell 8 (6.2 MPa) just approaches the value of the external pressure of the heat exchanger (7 MPa). The unit 1 of cells 8 thus operates throughout its life with an internal pressure less than the external pressure, which favours a quasi-contact between plate and pellet (the beneficial effects of which are discussed below). ii. The axial gap 12 during the life is corrected with an interaction between pellet 10 and sheaths 2, 4 which induces: a regulation of the temperature of the fuel 1 during irradiation (if the volumic power is supposed constant, the maximum temperature of the fuel varies over a range of 50° C. and remains below 1300° C.); the gradual closure of the axial gap 12 compensates for the loss of conductivity of the gas as the fission gases are released, a diametral expansion of the fuel 10 (by anisotropy of the inflation and by creeping) with a level of axial distortion of the cell 8 which remains very low (maximum distortion in the cell environment of the thickness of the plate of 44 μm), a low level of stress induced in the structures, whatever the bending stress in the sheaths 2, 4 or the tensile stress in the bonding plane 6, 6′ which remains below 10 MPa. iii. There is no correction of the radial gap 14, the residual gap at the end of life and the gradual degradation of its conductivity by the fission gases capable of isolating thermally the partitions 6 of the cells 8 of the fuel pellet 10. The average temperature of these walls 6 being the same as that of the sheaths 2, 4, there are accordingly no differential distortions between the honeycomb 6 and the two plates 2, 4 (by expansion and inflation). The simulation of a rapid increase of the volumic power by 10%, although the pellet 10 is interacting with the sheaths 2, 4 shows that the low bending rigidity of the sheaths can accommodate without significant additional stresses the instantaneous distortion imposed on the cell 8 by the pellet 10. Similarly, the loss of external pressure, in the shutdown situation in question and in depressurisation accidents, which puts the cells 8 of the elements 1 into internal overpressure, causes an acceptable stressing of the structures 2, 4, 6 of the cell: moderate bending of the sheaths and putting under tension the bonding plane with a maximum value of 24 MPa in the event of rapid depressurisation. This study reveals that a significant part of the stresses in the structures 2, 4, 6 of the cells 8 in operation is induced by the distortion loads imposed, by thermal expansion and inflation, locally in the thicknesses, longitudinally or between sub-structures. These stresses can be relaxed during irradiation by creeping (irradiation creeping and thermal creeping). Their level depends also directly on the physical and mechanical properties of the materials used. The modulus M = E × α λ × ( 1 - ν ) where E is Young's modulus, α the coefficient of thermal expansion, λ the thermal conductivity and ν Poisson's ratio, is used to choose the material which minimises these loads by a low value of M. For example, the table below gives values of M at 1000° C. for a metallic sheath in Nb-1Zr—C and the composite ceramic SiC—SiCf. Properties at 1000° C.Nb—1Zr—CSiC—SiCfE (GPa)84192α (10−6/K)7.1854λ (W/m · K)61.1610ν0.40.18M16.64593.66 The fuel element according to the invention, while meeting the specification imposed by GFRs, shows in this way its ability to cover a range of operating conditions and performances broader than existing elements, for any network: option to access filling densities of the fuel 10 greater than 50% in the composite 1 (U.S. Pat. No. 3,855,061 allowed only 25%) as a result of the geometry of the composite plate, capacity to provide confinement of the fission gases (as well as the current elements of current RNR and HTR spheres) and to accommodate the interaction between pellet 10 and sheath 2, 4, 6 without breaking owing to blocking, with a low rigidity, to a single direction AA of distortion (better than the RNR elements blocking 2 directions of distortion of the fuel, and than HTR spheres blocking the three), capacity to provide thermal exchange to the heat exchanger by regulating the maximum temperature at the core of the fuel, capacity to operate in a high performance manner (high temperature, rate of combustion and power density) with structural materials ceramic—(monolithic or fibrous composite) or metallic refractory-types while accommodating the distortion loads imposed with a low stress level. This type of plate element can be adapted for applications in other networks (experimental reactors, thermal reactors, fast reactors and high temperature thermal reactors in particular). The sheath/fuel material pairs commonly employed in these applications can actually be transposed directly to the design of macro-structured plate elements according to the invention: as the honeycomb structure functions under the same conditions of thermal, chemical and mechanical stresses as the usual sheaths, the same material is therefore implicitly qualified. The composite plate fuel elements designed according to the invention can therefore: have heavy core density compatible with obtaining fast flows, the hexagonal mesh honeycomb structure allowing volumic fractions in fuel filling of over 50%, be used to refill the cells fuel pellets such as UO2, UO2—PuO2, UC, (U,Pu)C, UN, (U,Pu)N, etc., produced using standard methods, limit the internal pressure of the fission gases released by the fuel in the cells by means of the expansion volume defined by the gaps between the pellet and the matrix, this expansion volume accounting for approximately 0.5 times the volume of the fuel pellet, which allows high-performance nuclear combustions (“burnups”), reduce the inventory of fission products capable of being salted out in the heat exchanger in case of leaks in the cell, each cell closed at its ends by the sheaths constituting a sealed cell; accommodate differential distortions (thermal expansion and inflation) between the fuel and the structures of the cell with very low distortions of the plate element not prejudicing the distribution of the cooling flows between elements, optimise the size of the cells (no hexagonal network) with centimetric size cells and millimetric wall and sheath thicknesses to: provide thermal transfer to the heat exchanger, more preferably via the ends of the pellets, obtain uniformity of the average temperatures in the materials of the structure, adjust the bending rigidity of the sheaths which close the cells, minimise the stresses induced in the cell structures (at this level, the choice of materials in order to minimise loads of the distortion type imposed, by thermal expansion and inflation also plays a part with, as the criterion of choice, the search for the smallest modulus M = E × α λ × ( 1 - ν ) to optimise the behaviour of the cell), regulate the maximum temperature of the fuel throughout its life by managing the gradual contacts between pellet and sheath providing heat transfer, operate in all types of fast or thermal reactors with levels of power density in the fuel which can reach some hundreds of MW/m3 with structural materials (metallic) for the plate matched to the operating temperatures, to the nature of the heat transfer and to the fuel, operate in fast high temperature or thermal reactors with an element produced completely in monolithic or fibre-reinforced ceramic, add a refractory metallic component, in the form of a thin sheet or a deposit to guarantee the sealing in the case of a fuel for high temperature reactors, thus warning of insufficient quality in the confinement of the ceramic.
	description	The invention relates to an analysis device for the detection of fission products by measurement of a radioactivity and an analysis system comprising such an analysis device. Operators of nuclear power plants must provide clear evidence that the fuel rods arranged in fuel assemblies are tight, before a reuse of the fuel assembly occurs in the next reactor cycle or before the fuel assembly is transported away for off-site storage. The detection typically occurs by means of so-called sipping process or sipping tests. These are leakage tests, in which radioactive fission products are expelled from the potentially leaking fuel rods. Subsequently, a gas- or liquid sample is taken from the environment of the fuel rod and examined with respect to its radioactivity. Different analysis systems and methods typically referred to as sipping systems are known, such as, for example, the so-called mast-sipping/telescope-sipping for pressurized water reactors (PWR), water-water energy reactors (WWER) and boiling water reactors (BWR), incore-sipping for BWR, box-sipping/vacuum-sipping for PWR, WWER and BWR and single rod-sipping for PWR and BWR. These analysis systems and methods differ primarily in their integration into different sequences of the process, in order to obtain an analysis result at a specific point in time. If, for example, such an analysis result is needed before the unloading of the reactor core, then the incore-sipping is used, in which the tightness of fuel assemblies or fuel rods in the reactor core is checked. If a reliable analysis result is to be produced with as little time loss as possible, then, for example, a mast-sipping method can be used in the course of the core unloading. In the case of mast sipping, the removal of a sample possibly containing fission products typically occurs via the interior region of the mast of the fuel assembly loading machine. Depending on the type of defect of the fuel rod or depending on the length of the decay time clear evidence with the aid of these known test methods can be difficult. In particular, this problem results in the case of a longer storage time, since it is necessary to assume that a defect could have occurred after a sipping test was performed and under certain circumstances a sipping test which occurred in the past and possibly after several manipulations which occurred in the meantime. A defect detection is therefore difficult in particular in the case of very long storage times, since in this case usually only Cs-137 is still available as a detectable nuclide in the water phase. A very high activity background in the immediate environment, from which the sample is taken, is also problematic, or if due to the size or type of the defect a fission gas can completely escape from the fuel rod, so that said fission gas is no longer available for analysis. The problem addressed by the present disclosure is to provide a novel analysis device for detecting fission products, which is suitable for use in different analysis- or sipping systems and makes possible a reliable detection also under difficult boundary conditions and/or in the case of different types of leakage. An analysis device for the detection of fission products by measurement of a radioactivity, comprises a first line for carrying a liquid sample, a first detector connected to the first line and designed for measuring the radioactivity of fission products contained in the liquid sample, a second line for carrying a gas sample and a second detector connected to the second line and designed for measuring the radioactivity of fission products contained in the gas sample. According to the present disclosure, a separation device is provided for separating gas from the first line carrying the liquid sample, which line has an outlet opening for removed gas opening into the second line in such a manner that the removed gas can be supplied as a gas sample to the first detector for measuring the radioactivity of fission products contained therein. The present disclosure for the first time provides an analysis device, which is suitable for different sipping methods and thus for the detection of a plurality of different types of leakage, such as, for example, small continuous hairline cracks in fuel rods, visible open partial regions on the side of fuel rods, missing or defective end caps and/or broken fuel rods. The analysis device is designed in particular to detect releasible fission products or nuclides in different concentrations. Gaseous fission products can be removed directly or separated by means of the separation device from the liquid sample by degassing. In particular the nuclides krypton and/or xenon are preferably detectable as gaseous fission products. In particular it is possible to continuously supply gas- and/or liquid samples to the first and/or second detector. In this sense, the terms gas sample or liquid sample also refer to continuously extracted and supplied volume flows, therefore, gas flows or liquid flows. Analysis systems based on sipping are used, in particular, depending on the fission products to be detected. Incore sipping, in which a testing of the fuel rods in the reactor core takes place, is used, for example, in the case of a short decay or storage time. For this purpose, it can be provided in particular, to detect xenon (Xe-133), krypton (Kr-85), iodine (I-131) and/or cesium (Cs-134 and/or Cs-137) as fission products. Mast sipping, in which the removal of the liquid- and/or gas sample takes place during the unloading of the reactor core or transfer of the fuel assemblies in the fuel assembly storage basin, is used, for example, in the case of short to longer decay or storage times. For this purpose, depending on the type of leakage, it can be provided in particular to detect Kr-85, Cs-134 and/or Cs 137 as fission products. These fission products can also be detected with the aid of box sipping and/or single-rod sipping, in particular as part of the repair process on the fuel assembly. In the case of yet longer decay times the nuclides Kr-85 and/or Cs-137 can, for example, be detected as fission products. The removal of the gas- and/or liquid samples containing these fission products takes place preferably as part of the mentioned mast-, box- or single-rod sipping processes. In the case of very long decay- or storage times, typically only Cs-137 is available as a fission product for detection. The detection occurs in this case preferably by means of box sipping under additional heating. To remove the gas- and/or liquid sample, a device is used, which is designed to expel fission products from at least one in particular defective fuel rod. The device is furthermore designed for removing liquid- and/or gas samples from the environment of the at least one fuel rod. The fission products possibly expelled via an existing defect site are also contained in part in the removed liquid- and/or gas sample. According to embodiments of the invention an analysis system based in particular on sipping comprises an analysis device, which is fluidically connected to the above-described device in order to supply the liquid- and/or gas sample. The concrete design in question of the device for expelling fission products and for removing gas- and/or liquid samples containing such fission products is different in the case of incore-, mast-, vacuum- or single-rod sipping systems. Regardless of this, the analysis device can be used in all of the mentioned sipping systems, since the analysis device can be supplied with both a removed gas—as well as a removed liquid sample. With the aid of the first and the second detector a broad range of different, in particular gaseous or dissolved fission products can be detected. This makes it possible to use the analysis device almost independently of the decay- or storage time of the fuel rods to be examined. The expulsion of fission products from a defective fuel rod takes place, for example, by heating the fuel rod by suppling heat. For this purpose, for example, a self-heating of the fuel assembly or of the fuel rod by partial withdrawal of the coolant or by interruption of the convection can take place. Alternatively or additionally, an escape of the fission products via a possibly existing defect site can be assisted by pressure reduction, in particular, by lifting the fuel rod. The analysis device provided for the analysis of the in particular dissolved and/or gaseous fission products preferably has an inlet for the separation device, which is arranged downstream of the first detector. The liquid sample removed in particular from the immediate environment of a leaking fuel rod is thus only supplied to the separation device after passing through the first detector. The liquid sample can thus, in particular, be analyzed with regard to dissolved fission products, before possibly existing gaseous fission products are separated from the liquid phase with aid of the separation device. Preferably the first detector is designed for measuring gamma radiation. Particularly preferably the first detector is a gamma spectrometer. Such devices are designed, optionally in conjunction with a corresponding evaluation routine, to develop and to evaluate in particular multiple lines of the detected gamma spectrum. In conjunction with a previously measured background activity statements about the relative concentration of the gamma-emitting fission products in the liquid sample are then possible. The second detector is preferably designed for measuring beta radiation. Particularly preferably the second detector is a scintillation counter. The second detector is thus used for determining gaseous beta-emitting fission products, which were removed directly from the environment of a leaking fuel rod and/or were separated from the liquid sample. Particularly preferably the first and/or the second detector is provided with a radiation absorbing radiation shield for shielding against ambient radiation, so that its influence on the measurement result is minimized. Preferably, a closable outlet, which forms a sampling point for a water sample, branches off from the first line. This water sample serves in limit cases as a further possibility for a more targeted examination in the laboratory, in order to be able to detect other relevant fission products, that allow conclusions to be drawn about a defective fuel rod, in the water- or separated gas phase. In a preferred embodiment a drying device and/or drying means for drying a volume flow containing a gas sample to be analyzed is arranged downstream of the first detector and in particular upstream, that is, before the second detector, which in particular is designed for measuring beta radiation. Moisture, which is contained in the gas sample supplied, can thus be separated by means of the drying device and/or by means of the drying means, in particular, silica gel. The moisture discharge can take place in particular continuously. Thus, it can be prevented that a water film or water drops can be formed on the second detector, which could distort the measurement due to shielding. Preferably, filling materials, in particular, filling materials with a large outer surface, are arranged within the separation device, which serves to separate gas from the liquid sample, for forming the stripping gas into fine beads and thus for increasing the phase boundary interfaces. Thus, the separation of gaseous fission products from the liquid sample can be assisted. Preferably, a membrane contactor (membrane degassing) can also be used, with which a material separation by means of diffusive material transport through a porous membrane is used. An analysis system for the identification of defective fuel rods comprises the above-described analysis device and a device designed for the expulsion of fission products from at least one defective fuel rod and for removal of liquid- and/or gas samples containing fission products from the environment of the at least one fuel rod. Such a device can also be referred to as a sipping device. According to embodiments of the invention the device for supplying the liquid- and/or gas samples containing fission products is connected fluidically to the analysis device. In particular, it is provided to feed a liquid sample removed from the immediate environment of a leaking fuel rod into the first line of the analysis device and a gas sample removed from the immediate environment of a leaking fuel rod into the second line of the analysis device. Preferably, the device of the analysis system designed for removing water- and gas samples forms a lowerable structure, in particular a structure lowerable in a fuel assembly storage basin, transport container basin or reactor basin. The device has an inner duct-shaped intermediate space, in which the at least one fuel rod to be examined or the fuel assembly comprising at least one fuel rod can be introduced. An upper end of the duct-shaped intermediate space can be covered by a hood element in such a manner that above the intermediate space and below the hood element a gas cushion can be formed by blowing in a gas. The duct-shaped intermediate space is in particular not designed fluid-tight, so that the surrounding water can enter at least via openings in a lower region. The device lowerable in the fuel assembly storage basin is thus of the type of a box-sipping device. The introduction of the gas cushion serves, inter alia, to interrupt the heat convection to the basin water. Water, which in particular is heated by self-heating of the fuel assembly in the duct-shaped intermediate space, can no longer escape via the upper end of the duct-shaped intermediate space, since the latter is closed by the gas cushion, which is formed within the hood element. This promotes an accumulation of fission products expelled from the fuel rod or the fuel rods in the upper region of the duct-shaped intermediate space. Preferably the duct-shaped intermediate space is formed by a plurality of structural elements stacked one above another on a lowerable work support and which can be fastened to one another. Such a design is characterized in that it can be built up rapidly and flexibly under water, in particular, in the fuel assembly storage basin or transport container loading basin, with the aid of corresponding gripping tools. Preferably the structural element or the structural elements which form a lower section of the duct-shaped intermediate space have a plurality of openings, in order to permit a water exchange with the basin water of the surrounding fuel assembly storage basin. The hood element and/or the structural elements are preferably designed with a double wall, wherein insulating material is introduced between an outer and an inner wall of the hood element and/or of the respective structural element for thermal insulation or a vacuum was applied for thermal insulation. As a result, a heat transfer to the surrounding basin water is minimized and the fuel assembly introduced into the duct-shaped intermediate space or the fuel rod introduced there can be heated, in order to expel fission products via any existing points of leakage. The hood element is preferably designed remotely controllably adjustable with respect to a vertical axis of the device, in particular height adjustable parallel to the vertical axis and/or rotatable about the vertical axis, by means of a drive unit. In this way, the hood elements can be positioned, in order in particular to free up access to the duct-shaped intermediate space for loading or unloading with a fuel assembly. Alternatively thereto the hood element can be designed to be adjusted manually by means of a rod tool. In a preferred embodiment a heating device is arranged on the lower end of the duct-shaped intermediate space, which is opposite to the hood element. If necessary, this separate hood element serves to support the self-heating of the fuel rods to be examined. This makes it possible also to examine fuel rods or a fuel assembly after a longer decay or storage time. Preferably, a temperature sensor is arranged within the duct-shaped intermediate space for measuring the temperature of the basin water contained therein and/or of the gas cushion contained therein, so that in particular the heating process for the expulsion of fission products from the defective fuel rods can be monitored. The same parts or parts corresponding to one another are provided with the same reference signs in all figures. FIG. 1 shows the schematic structure of an analysis device 10 for the detection of fission products by measurement of a radioactivity. The analysis device is intended to be provided in conjunction with a sipping device, in particular with the device 100 depicted in FIGS. 2 and 3, to form an analysis system, which is designed to identify defective fuel rods or fuel assemblies containing defective fuel rods. The analysis device 10 comprises a gas analysis section and a liquid analysis section. Liquid samples can be supplied via a first inlet 11 to a first line 12. For sucking in the liquid sample a pump 13, for example, a water jet pump, is connected on the inlet side to the first line 12. A further outlet 15, which can be shut off via valve 14, is used for taking a water sample, in particular, a water sample from a fuel assembly storage- or reactor basin, for further targeted examination of said sample in a laboratory. The liquid sample carried in the first line 12 passes through a region shielded by a radiation shield 16, in which a first detector 17 designed for the detection of gamma radiation is arranged. Specifically, in the embodiment shown and not to be interpreted in a limited manner, this is a gamma spectrometer. At the end of the liquid analysis section a separation device 18 is arranged, which is designed to separate in particular any dissolved, gaseous components present in the liquid sample. In the depicted separation device 18 forms a liquid reservoir, into which stripping gas can be blown via a supply line 19, in particular in the counter-flow process. Gas taken from the liquid sample can be supplied to the gas analysis section via a connecting line 21 having a check valve 20. Filling materials, in particular filling materials with a large outer surface, are arranged within the separation device 18, in order to increase the phase boundary interfaces between the gaseous and the liquid phase. The water level within the separation device 18 can be adjusted and in particular regulated via a level regulator 25 with regulator valve 26. Excess water can be discharged via the outlet 27, in particular, to a basin cleaning system of the fuel assembly storage basin. The embodiment of the separation device as a membrane contactor is not explicitly depicted in the figures. Gas samples can be supplied both via a second inlet 22 as well as via the connecting line 21 to a second line 23 of the gas analysis section. In the region of the second inlet 22 a throttle valve 24 is arranged, so that, if necessary, a volume flow containing the gas sample can be adapted and in particular regulated. The gas analysis section furthermore comprises a drying device 28, which is arranged downstream of a second detector 29. The drying device 28 is used in particular for separating any moisture or water contained in the gas volume flow. A further level regulator 30 with further regulator valve 31 ensures a continuous water discharge. Discharged water can be supplied via the outlet 27 in particular to the basin cleaning system of the fuel assembly storage basin. The second line 23 is also shielded in the region of the second detector 29 by a radiation shield 32 against radiation from the environment. The second detector 29 is designed in the depicted example for the measurement of beta radiation as a scintillation counter. At the end of the gas analysis section a gas pump 33, for example, a membrane pump is located. Gas can be supplied to a nuclear ventilation system, in particular, of a nuclear power plant via a further outlet 34. The analysis device is operated for the detection of fission products, in particular according to the method described below: A reference sample, consisting of water from the fuel assembly storage basin is taken to determine a background activity. Subsequently, a liquid sample from the immediate environment of fuel assembly containing the fuel rod to be examined or the fuel rods to be examined is sucked in by means of the pump 13. Optionally, a further sample is taken as an extra sample for more detailed examination in the radiochemistry laboratory. Subsequently, the liquid sample containing the removed and potentially detectable fission products passes through the region of the first detector 17 shielded by the radiation shield 16, so that radiation influences from the environment, in particular, from the basin floor area of the nuclear power plant are largely excluded. The first detector 17 designed for the detection of gamma radiation as a gamma spectrometer preferably possesses an evaluation routine for the evaluation and development of multiple lines of the detected gamma spectrum. The objective of the evaluation of the gamma spectrum is to determine the relative concentration of fission products contained in the liquid sample, therefore, of the nuclide components emitting gamma radiation, in order to determine whether a defect exists in comparison to the previously determined background activity. The liquid sample is subsequently fed into the separation device 18, in which stripping gas is blown in, preferably in the counter-flow process and using filling materials for mixing and increasing the phase boundary interface between the gaseous and the liquid phase. The thus induced desorption process brings it about that a part of the blown in stripping gas passes into the water of the liquid sample fed in. At the same time, bound gaseous, radioactive fission products are released from the liquid sample (stripping-separation process). With the level regulator 25 a separation surface is maintained in the separation device 18, via which the gas, which was taken from the liquid sample, collects. Excess water is drained via the regulator valve 26 and disposed of via the basin cleaning system of the fuel assembly storage basin. The gas extracted from the liquid sample is supplied via a check valve 20 to the second line 23 and thus to the gas analysis section. The taking of a gas sample is activated by activation of the gas pump 33, which is mounted at the end of the gas analysis section. Initially, a gas sample or a gas sample flow is fed via the second inlet 22 and the throttle valve 24 into the second line 23. In this connection, a defined volume flow is set. Before the gas flow containing the gas sample is passed over the second detector 29, the latter is dried in the drying device 28, since the measurement results can be distorted by a water film or by water drops on the detector membrane. An active dryer can be provided as drying device 28. In this case, a reduction of the dew point takes place by cooling and discharging the water. A continuous water discharge is ensured with the level regulator 30, which accordingly regulates the regulator valve 31. Alternatively or additionally the water discharge can take place with the aid of drying means (for example, silica gel). The second detector 29 is designed to detect beta radiation and is designed in the depicted example as a scintillation counter. With the aid of the second detector 29 and a corresponding evaluation routine the relative concentration of the beta-emitting nuclide components relative to the background is determined. During the sipping process, therefore during the removal of the liquid- and/or gas sample from the environment of the fuel rod or fuel assembly to be examined, an inherent safety must be ensured. For this purpose, in particular, supercriticality is to be excluded and adequate cooling is to be ensured. In addition, stringent radiation protection requirements (“As Low As Reasonably Achievable”, ALARA) exist for such analysis systems based on sipping. The removal of the gas- and/or liquid sample is preferably carried out with the device 100 schematically depicted in FIGS. 2 and 3. The device 100 is designed for expelling fission products from defective fuel rods and for the removal of liquid- and/or gas samples from the environment at least of one defective fuel rod. The device 100 can be provided as part of a box sipping system. The device 100 is mobile and has a separate heating device 101. The device 100 is placed under water on a work support 102 in the fuel assembly storage basin and comprises a plurality of structural elements 103, 104, 105, which can be stacked one above another and can be fastened to one another, which in the mounted state define the duct-shaped intermediate space 106, in which a fuel assembly 200 containing fuel rods can be arranged. The depicted example shows a three-part structure. The structural elements 103, 104, 105 define thermally insulated wall sections of the duct-shaped intermediate space 106 and can be connected to one another via separation zones 107, 108. The structural elements 103, 104, 105 are designed with double walls. Insulating material for thermal insulation is introduced between an outer and an inner wall of the respective structural element 103, 104, 105. The mounting of the device 100 in the fuel assembly storage basin comprises in particular the following steps: Initially, a lower structural element 103 is mounted on the work support 102. A further, middle structural element 104 is mounted on the lower structural element 103 via the first separation zone 108. A third, upper structural element 105 is arranged above the second separation zone 107. The longitudinal extension of the structural elements with respect to a vertical axis, therefore with respect to the direction running perpendicular to the work support 102, is adapted to the corresponding length of the fuel assembly 200 to be accommodated. The structural elements 103, 104, 105 are dimensioned with respect to their cross section so that the fuel assemblies 200 with the largest cross section can be accommodated. Through the use of filling materials, which are introduced into the duct-shaped intermediate space 106, it is optionally possible to adapt both the cross section as well as the length of the intermediate space 106 available for accommodation of the fuel assembly 200. In this way, different types of fuel assemblies 200, which differ in particular with regard to their spatial extension, can be handled. The flat heating device 101 installed in the lower region of the duct-shaped intermediate space 106 is designed to rapidly heat the basin water located in the duct-shaped intermediate space 106. Between heating device 101 and fuel assembly 200 a grate-like grid element 109 is arranged, which offers only little resistance to the heating. The duct-shaped intermediate space 106 formed by the structural elements 103, 104, 105 is not designed fluid-tight, rather openings, which permit a free inflow of water, are provided laterally in the walls of the structural elements 103 at the height of the heating device 101. On the upper end of the duct-shaped intermediate space 106 a guide 110 is mounted, which facilitates the insertion of the fuel assembly 200 with the aid of the fuel assembly loading machine or with the aid of a gripping tool. Above the duct-shaped intermediate space 106 a hood element 111 can be positioned, which ends just above the upper end of the fuel rods arranged in the fuel assembly 200. By flooding the hood element 111 with a gas, in particular with air, a water-free region is created in the upper region of the fuel assembly 200. However, the fuel rods themselves are not thereby exposed. The free convection between water entry at the lower end of the duct-shaped intermediate space 106 and the upper section of the fuel assembly 200 towards the fuel assembly storage basin is prevented and thus leads to the heating of the fuel assembly 200 by self-heating. The heating is optionally assisted, in particular in the case of fuel assemblies with a long decay- or storage time, with the aid of the heating device 101. An overheating, which, for example, is visible through water evaporation in the lower region of the fuel rods, can be avoided, since basin water can continue to flow in in the lower region of the duct-shaped intermediate space 106 and thus the fuel rods constantly remain surrounded by water. The hood element 111 is also designed with double walls. Thermally insulating insulation material is located between an inner and an outer wall of the hood element 111 or a vacuum is applied, for the same purpose. The hood element 111 is further provided with a drive unit 112, which is designed as a lift-rotary drive. The hood element 111 is thus remotely controllable or manually adjustable in such a manner that said hood element can be placed over the structural elements 103, 104, 105 by rotation about the vertical axis and by translation parallel to the vertical axis, in such a manner that the duct-shaped intermediate space 106 is covered. FIG. 3 shows the device 100 in the open position, whereas the hood element 111 in FIG. 2 covers the duct-shaped intermediate space 106. By lifting and rotating the hood element 111 a free access to the fuel assembly 200 can thus be provided from above. In the case of an emergency this process can also be carried out manually with rod tools. In an upper region of the duct-shaped intermediate space 106 a line section 113 is arranged, which is provided for the connection of the analysis device 10 to the first line 12, in particular via the first inlet 11. A further line section 114, which is provided for the connection to the second line 22 of the analysis device 10, in particular via the second inlet 22, has an inlet for gas, which is arranged in the region of the hood element 111. This further line section 114 furthermore is used preferably for blowing in gas, in order to form the gas cushion G underneath the hood element (see FIG. 3). For the economical implementation of the sipping processes, it makes sense to work with two devices 100 designed in this way. A first device 100 is thereby used for testing a fuel assembly 200, while a second device 100 is loaded or unloaded with another fuel assembly. The sipping process is as follows: Initially, the device 100 is in the open position (FIG. 3). In this state, the water sample is taken to measure the background activity. After the insertion of the fuel assembly 200 the hood element 111 is closed (FIG. 2) and the gas cushion G is introduced via the further line section 114. After reaching a minimum heating time period, which is checked with the aid of a temperature measurement, the actual sipping test, that is, the removal of the liquid sample and the gas sample, can be carried out. The evaluation is made with the aid of the analysis device 10, which is fluidically connected with the device 100. In this connection, the line section 113 of the device 100 is connected with the first line 12 of the analysis device 10 and the further line section 114 of the device 100 is connected to the second line 114 of the analysis device 10. The liquid sample and the gas sample are fed into the analysis device 10. The totality of analysis device 10 and device 100 forms the analysis system. After discharging the gas underneath the hood element 111 the latter can be opened again and the fuel assembly 200 can be removed. The advantages of the device 100 designed as a box sipping device in connection with the above-described analysis device 10 are in particular the following: No vacuum-tight housing, which could impair the inherent safety, is required. The analysis system exemplarily described is characterized, inter alia, by a passive failure protection with regard to adequate cooling of the fuel rods or the fuel assembly during the sipping process. The device 100 comprises double-walled structural elements 103, 104, 105, the outer and inner surfaces of which are formed in particular from smooth steel sheets. With this arrangement an easy decontamination is possible both of the inside defining the duct-shaped intermediate space 106, as well as of the outside of the device 100. This promotes the radiation exposure due to the reduction of a possible contamination. Through the blown-in gas cushion G an effective thermal insulation is realized, which can be constantly maintained and remain controllable when leaks occur. The gas cushion G offers a thermal insulation for the surrounding water in the fuel assembly storage basin and at the same time an overheating is excluded by the control of the level of the water coverage of the fuel rods. With regard to the thus resulting spatial distance and the absence of the moderator from a fuel assembly 200 handled in the immediate environment the subcriticality is given. The arrangement of the heating device 101 in the lower region of the duct-shaped intermediate space 106 in conjunction with the natural self-heating of the fuel assembly 200 brings about in the sipping process a thermal flow upwards and thus a concentration of the fission products, in particular dissolved fission products, to be analyzed in the upper region of the duct-shaped intermediate space 106. Gaseous fission products accumulate accordingly in the gas cushion G underneath the hood element 111. The removal of the gas- and liquid samples to be analyzed takes place in this region. The separate heating device 101 makes it possible that fission products can also be expelled in sufficient concentration from fuel assemblies 200 or from fuel rods after a long decay- or storage time. The analysis device 10 makes possible an analysis both of liquid—as well as of gas samples. In addition, if desired, gas contained in the liquid sample can be examined. Furthermore there is the possibility of the additional evaluation of the liquid- and/or gas sample in a radiochemistry laboratory. The analysis results are therefore characterized by a high reliability. Due to the simple handling and the technology used a rapid execution of the sipping process is possible. The repair effort is low due to fewer active components, which also promotes the reduction of a possible radiation exposure. A temperature sensor 116, which is shown schematically in FIG. 2, may be arranged within duct-shaped intermediate space 106 for measuring the temperature of the basin water contained therein and/or of the gas cushion contained therein, so that in particular the heating process for the expulsion of fission products from the defective fuel rods can be monitored. 10 analysis device 11 first inlet 12 first line 13 pump 14 valve 15 outlet 16 radiation shield 17 first detector 18 separation device 19 supply line 20 check valve 21 connecting line 22 second inlet 23 second line 24 throttle valve 25 level regulator 26 regulator valve 27 outlet 28 drying device 29 second detector 30 level regulator 31 regulator valve 32 radiation shield 33 gas pump 34 outlet 100 device 101 heating device 102 work support 103 structural element 104 structural element 105 structural element 106 intermediate space 107 separation zones 108 separation zone 109 grid element 110 guide 110 hood element 112 drive unit 113 line section 114 line section 200 fuel assembly G gas cushion
	description	Referring to FIG. 1, polymer dope is fed by positive displacement to an extruder 1 where it is forced through die orifice 2 by piston 11. Said piston is schematic only, and in practice it may consist of two gear pumps operating at differential speeds, or a diaphram which is displaced by pressurized gas. When manufacture is contemplated in space, the lack of gravity must be taken into consideration in designing the metering system. The polymer dope, selected to illustrate this process, consists of tritium substituted polystyrene dissolved in a suitable solvent. Many organic compounds have been reported as solvents for polystyrene and a related resin, poly a-methyl styrene. They include benzene, toluene, xylene, ethylbenzene, chlorobenzene, tertiary butyl benzene, isopropyl benzene, triphenyl methane, heptane, butyl acetate, methyl ethyl ketone, chloroform, carbon tetrachloride, tetrahydrofuran, carbon disulfide, and ethyl chloride. Preferred solvents should possess (1) good solvency, (2) low heat of vaporization, (3) ease of handling and (4) radiation resistance. Besides being readily soluble, tritium substituted polystyrene has a number of other advantages. It is resistant to radiation damage and it possesses a relatively low average atomic number (Z number). Tough, clear, cellophane-like films can be prepared from tritium substituted polystyrene with good chemical and physical properties. A particular form of this resin, isotactic polystyrene in which tritium is substituted for hydrogen, is of interest because of its predictable elevated melting point. Compressed gas 3 is metered at 12 into the center of the extrusion. An inert gas such as hydrogen, deterium, helium, nitrogen, carbon dioxide, air, fluorocarbon or any combination of these gases may be used. Subsequently, in another location, e.g. on earth, and shortly before use, the gas in the pellets can be exchanged for the required D-T fuel. Because of the permeability of plastic materials, the exchange of gases can be achieved by means of diffusion. The inert gas in each pellet will diffuse outward through the pellet wall as D-T diffuses into the pellet from the surrounding medium. A pressurized tank can be used for the above operation. By means of hyperbaric pressures the D-T charge can be increased over the amount in equilibrium at one atmosphere. The gas is introduced into the polymer dope through a hypodermic needle. The size of the bubbles is proportional to the orifice diameter. The needle must be perfectly centered in order to obtain symmetrical pellets. Because of the difficulty in centering the needle, it may be partly withdrawn from the tip of the extruder as shown in FIG. 4. Thus, a slight misalignment of the needle results in a smaller deviation as a percent of the extruder diameter. Since the flow of the dope is lamina;, the bubbles will move in a straight line. Because of the buoyancy of the bubbles, this scheme is best suited for operation in near zero gravity. Transducers 4 driven by driver 13 apply acoustical vibrations which have a frequency close to the natural frequency at which the extruding polymer rod tends to break up. This frequency can be estimated by the well-known Rayleigh equation or determined experimentally. The amplitude or strength of the vibration can be varied as needed. An additional effect helps to form drops from the extruded rod. A disruptive force is provided by the relative motion between the rod and surrounding gas. The relative flow rates can be altered by modifying the cross section of chamber 14 as shown in FIG. 4. As this drag effect becomes more important the contribution from the transducers can be reduced or eliminated. The preferred fuel for laser fusion is a combination of Deuterium and Tritium (D-T). An examination of rates for certain fusion reactions shows that D-T reactions occur with roughly 100 times the probability of its nearer competitor over the range of anticipated ion temperatures (0-10 Kev.). Thus the D-T fuel is the best to employ. The D-T fuel in the pellet is compressed to extremely high densities (103-104 times liquid density) by laser produced converging shock waves which also ignite a small portion of the compressed core. In the D-T thermonuclear reaction, alpha particles and neutrons deposit energy in the core, giving rise to a xe2x80x9cboot strapxe2x80x9d heating effect, and a propagating burn front. This burn front propagates through the core before the pellet has time to disintegrate, so that a significant fraction of the available fuel mass can burn. So-called D-T fuel is actually made up of a mixture of the molecules, D2, DT, and T2. Rather than using such a mixture, this invention envisions the likely use of only DT that has been spin-polarized or as high a proportion of this molecule as is practical. It has been reported that DT better retains nuclear polarization which would provide an assist in igniting the fuel. Unfortunately, DT slowly breaks up into D2 and T2 because of the radiation given off by tritium. Therefore, fuel pellets should be consumed as soon as possible after they are charged with fuel. The pellets are dried by removing the solvent as a portion of the gas surrounding the pellets in drying chamber 14 is recirculated by pump or blower 15 through an adsorbent 5. Activated carbon or silica gel has been found to be an effective adsorbent for many solvents. The rate of vaporization can be increased by applying heat to the pellets 9. The heat of vaporization of the solvent one way or another should be compensated for. While the pellets 7 are still in a fluid or plastic state, the surface tension tends to form spherical inner and outer surfaces. In the environment of near zero gravity this effect is greater because drag effects from the surrounding gas can be reduced. The application of acoustical vibration, in addition to breaking the extruded rods into pellets, helps to achieve concentric inner and outer surfaces. This vibration increases molecular motion within the walls of the pellet. The pressure of the gas external to the pellets 9 in chamber 14 is related to the pressure applied by piston 11 according to the following equation: q = k ⁢ Δ ⁢ xe2x80x83 ⁢ p D μ D where q is the flow rate of the dope, k is a constant established by the geometry of the die, xcex94 PD is the pressure drop through the die, and xcexcD is the viscosity of the dope in the die. The injected gas material at 12 must have a slightly higher pressure than the dope contained in the extruder 1. The gas flow rate may be controlled by a pressure reducer and a needle valve. There are no fundamental restrictions on the absolute pressure in chamber 14 except as imposed by the design of the apparatus. As previously noted, however, because of contemplated operation in space, the apparatus should be kept as light as possible and therefore design pressures must be limited to a few atmospheres at most. The pellets, in a subsequent process, may be pressurized in a tank, whereby not only is DT exchanged for the injected gas, but the gas can be equalized at some elevated pressure. As the polymer rod leaves the die of the extruder it is observed to expand. This expansion will continue until the pressure of injected gas in the pellets equals the ambient pressure. Further expansion of the pellets can be achieved by heating them in a controlled or programmed manner as they are dried. Heat can be applied by means of infrared lamps located on the periphery of the drying chamber 14. As the temperature of the pellets is raised the vapor pressure of the solvent is increased. Using a modified form of Raoult""s Law, Dalton""s Law, and the Perfect Gas Law the equilibrium volume of the pellets can be estimated as follows: V = n ⁢ xe2x80x83 ⁢ RT π - kP where n is the moles of inert gas in each pellet, R is the gas law constant, T is absolute temperature, xcfx80 is the ambient pressure in the drying chamber, k is the relative vapor pressure and P is the vapor pressure of the solvent. As the pellet walls become more viscous due to the loss of solvent, the equilibrium volume will not be attained, but instead some intermediate value will be realized. As the pellets are expanded an important rheological effect is achieved in the plastic walls. This expansion of the wall of a pellet will tend to line up the polymer strands parallel to the wall. A similar effect will be achieved as when synthetic fibers are drawn to increase their strength. In the case of a pellet, the molecules become oriented in two dimensions resulting in what may be called xe2x80x9cbiaxial orientation.xe2x80x9d This change will contribute to significantly improved physical properties such as tensile strength and permeability. The pellets 9 are kept separated from each other and the surface of the container 14 until they have hardened or cured. Gas jets (not shown) may be used to keep the pellets 9 separated until they have hardened. Sonic vibrations are also useful in this application, inasmuch as, these exert small forces. A variation of the invention is that a final portion of the die orifice 2 may be rotated so that a spinning motion of the emerging bubbles will produce oblate spheroidal pellets which may be desirable in certain reactors. In space, the entire apparatus may be rotated to achieve this effect. As a corollary, rotation must be avoided in order to produce spherical pellets. The apparatus can be prevented from rotating about its axes by means of booster rockets or jets. The above described method of manufacturing microballoons by extrusion is not unique and can be replaced by other fabricating techniques. For example, Bayless in U.S. Pat. No. 4,107,071 describes a process for microcapsules whereby a core material is encapsulated with a polymeric resin. The encapsulation is achieved in an agitated system comprising two phases, one of which is the core material and the other is the vehicle for the polymer. Upon induction of phase separation, the polymer forms a sheath about the capsule core material. Only one further step is required to convert the coated capsules produced by the Bayless process to microballoons. Leaching, or vaporization or dissolution of the core material through the semi-permeable coating would result in hollow pellets suitable for charging with thermonuclear fuel. The Bayless process could be carried out in whole or in part in the near-zero gravity environment of space. As in the case of the extrusion process, pellets so produced would have improved symmetry. Already, in a noteworthy experiment, microscopic plastic beads have been produced in space that are not only more spherical than those manufactured on earth but also more uniform in size. (Science News, Aug. 10, 1985, pp. 92-93). Such beads could provide the core material for the Bayless process. It is known that tritium will substitute for hydrogen in organic materials. However, complete substitution by this method is unlikely in polymeric materials. Therefore the preferred method of preparing tritium substituted high polymers is by starting with monomers in which hydrogen has been completely replaced by tritium. Starting with tritium oxide the preparation of tritium substituted polyethylene is shown below: Likewise tritium substituted polystyrene can be produced making use of the classical Reppe chemistry. In this instance tritium substituted acetylene is reacted with a catalyst to produce styrene and benzene both containing only tritium. The benzene compound can be burned in order to recover the tritium values. Tritium substituted polypropylene depends on the oxo reaction for its preparation. In this process an olefin (tritium substituted ethylene) is reacted with carbon monoxide and tritium to produce an aldehyde which is subsequently reduced to an alcohol. Dehydration of the alcohol produces tritium substituted propylene monomer. Monomer preparation by isotope exchange is carried out in the apparatus shown in FIG. 5. Tritium gas and a hydrogen containing monomer, in this case ethylene, are fed into reaction vessel 10. Agitator 11 assures the intimate mixing of the two reactants. In order to increase production, the reaction can be run at pressures above one atmosphere. A product sample is withdrawn from the vessel and passed through gas chromatograph column 13 to separate the sample into its component fractions. Hydrogen gas is introduced into the column via three-way valve 12 in order to elute the sample. Each of the fractions is identified by detector 14. Two three-way valves 15 and 16 divert the fractions to the proper lines. The valves are automatically operated by a controller (not shown) which receives a signal from the detector. Purified product, tritiated ethylene, is collected for subsequent polymerization. Reactants and partially substituted monomers are recycled to the reaction vessel, while tritium values are recovered from the hydrogen before the latter is discarded. Pellets produced by the invention may have varying dimensions. The outside diameter can range from 50 micrometers to 1 cm. and the wall thickness from 0.5 micrometer to 1 mm., however, these values are not meant to be limiting. The strength of the pellet, and thus the maximum pressure of the fuel gas, will depend on the tensile strength of the wall, the diameter of the pellet, and the wall thickness. Pellets produced in near-zero gravity of space can be expected to possess a non-concentricity of less than 5 percent and asphericity of under 3 percent. Those pellets, however, produced on earth cannot be expected to equal the ones produced in space with respect to symmetry or uniformity. Although it is possible to manufacture hollow spheres under normal gravitational conditions on earth, low or zero gravitational conditions help to reduce nonconcentricity and deformation. In the case of large gas-filled spheres, the gas bubble within the sphere has a tendency-to rise toward the top of the sphere in a gravitational environment. A zero-gravity environment helps to avoid deformations that can be produced by rapid gas movements past the sphere as it falls. This resistance tends to distort the shell , especially one which is relatively large, producing significantly reduced concentricity (FIG. 2, Dxe2x80x94D) and non-spericity of the shell (not shown). Low gravity of less than one tenth gravity at the surface of the earth may be considered zero gravity for the purposes of this process. A uniform wall thickness, FIG. 3, Axe2x80x94A, not only creates a higher energy yield, but also withstands higher pressures so that more fuel, usually DT, can be stored inside each sphere. Pellets, which are as described, may be subsequently coated with so-called pusher and/or ablator layers. These coatings are designed to increase the efficiency of the incident beams. Alternatively, the pellets may be used in a reactor that contains a gaseous atmosphere rather than being completely evaluated. For example, helium under low pressure would absorb some of the laser energy, but a controlled amount would reach the target. Being monoatomic, helium would absorb less laser energy than, for example, hydrogen would. Since the intensity of the beams is inversely proportional to the square of the reactor radius, most of the energy absorbed by the helium would be adjacent to the target. The helium in effect would function as an ablator. Fuel pellets made by the present invention possess unique properties which make them suited for use in devices employing thermonuclear fusion by inertial confinement. Such pellets, however, cannot be used for thermonuclear fusion by magnetic confinement because of the carbon impurities which would be introduced into the plasma. In fusion by magnetic confinement, feasibility studies have proposed the use of frozen deuterium/tritium pellets, the size of sand grains, which are injected at very high speed into the plasma. (Power, May 1982, p. 32) Experiments at MIT with the Alcator C Tokamak have confirmed the practicality of this concept. (Space Calendar, Nov. 21-27, 1983, p. 3). It will thus be seen that the objects set forth above among those. made apparent from the preceding description are efficiently attained, and, since certain changes may be made in carrying out the above processes and in the above described articles without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in the limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention hereinafter described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.
060118261	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the figures of the drawings as a whole, there is seen a steam conduit 1 which comes from a non-illustrated steam generator and is led through a wall 2 of a containment of a nuclear power station. In order to form a fixed point in a leadthrough through the wall 2, a conical supporting body 3 is provided for supporting the steam conduit 1 in the leadthrough of the wall 2. Forces and moments acting on the steam conduit 1 are introduced into the wall 2 at the fixed point. A housing of a main valve 4 is connected to the steam conduit 1 at the fixed point, directly at the leadthrough, without a high-pressure pipe being interposed. Housings of satellite valves 5 to 7 are likewise connected to the housing of this main valve 4, without a high-pressure pipe being interposed. Center points of the satellite valves 5 to 7 are located on circles around a center point of the main valve 4. There may no longer be any room on the housing of the main valve 4 for additional valves which are still required. If that is the case, in the steam conduit according to the invention, at least one additional valve 8, 9 is fastened to the housing of a satellite valve 5 to 7, without a high-pressure pipe being interposed and without any support. A plurality of additional valves can also be aligned with one another to form a row and their housings can be connected to one another. In this case, a housing of a first additional valve of this row is fastened to the housing of the satellite valve 5 to 7, without a high-pressure pipe being interposed. One or more of such rows can be fastened to each satellite valve 5, 6. It is even possible for at least one supplementary valve and/or one or more rows of supplementary valves, which can be connected to one another in the same way as additional valves to be fastened to the housing of an additional valve 8, 9. The entire illustrated valve configuration makes it possible for forces and moments acting on it to be introduced into the wall 2 through the fixed point shown.
	description	The present patent document is a §371 continuation of PCT Application Serial Number PCT/EP2005/056466, filed Dec. 12, 2005, designating the United States. This patent document also claims the benefit of DE 10 2004 060 582.3, filed Dec. 16, 2004. The present embodiments relate to an X-ray device with scattered-beam suppression. X-radiation has been used in medical imaging. The X-rays are generated at a virtually punctate source. After passage through the patient, the attenuated radiation is recorded in a detector. Scattered radiation is created in the patient. Scattered radiation generates a background on the images. Scattered radiation makes noise in the X-ray images because of the quantum nature of X-ray photons. This kind of scattered radiation can be suppressed with the aid of scanning methods in which only a small area of the detector is exposed directly to radiation at any time. This area is quickly shifted within one pulse over the entire detector. Adding up the individual pixels produces the total image. The disadvantage of such a scanning method is generally a reduction in the capacity of the X-ray tube, since a large proportion of the radiation generated must be blanked out. The reduction in radiation output of the X-ray tube must be compensated for by reducing the prefiltration, by a higher voltage, or by longer exposure times, which leads to poorer monochromotization of the beam or blurs from motion. The mechanical construction is relatively complex and vulnerable, since two screen systems in front of and behind the patient have to be shifted synchronously. The present embodiments may obviate one or more of the limitations or drawbacks inherent in the related art. For example, in one embodiment, an X-ray apparatus having a simple, operationally reliable construction can achieve an effective reduction in scattered radiation. In one embodiment, an X-ray device includes an X-radiation source and a preferably digital detector disposed in the beam path of the radiation source behind the object, in particular a patient. Using a scanner by which the object and the detector are scanned in only some portions, scattered radiation is suppressed. In the half-scanning method, the X-ray image is composed of half-images, in which one image half at a time is blanked out. The half-scanning method, in contrast to punctate scanning, includes a compromise between suppressing the scattered radiation and reducing the radiation output of the tube. In contrast to the classic scanning method, the nonexposed places in the digital detector are simply ignored. The scattered radiation that occurs need not be absorbed by a second screen system. A rotating small plate is provided adjacent to the radiation source in the beam path. A rotary shaft of the rotating small plate extends perpendicularly through the center axis of the radiation cone. One side of the shaft comprises X-ray-absorbing material or is coated with X-ray-absorbing material. Upon a rotation, two time slots exist chronologically staggered, in which one image half or the other is blanked out in alternation. The X-ray-absorbing material ends a short distance from the rotary shaft, in order to attain overlapping of the partial images. The small plate may be embodied practically on the order of a lug that protrudes past the rotary shaft on only one end. Alternatively, the plate may be essentially rectangularly symmetrical to the rotary shaft, and the second half is a frame acting as a balance, or a plate of X-ray permeable material. This balanced embodiment is expedient with the high rotary speeds in the operation of a small plate of this kind. The two time slots in which one half of the detector and then the other half of the detector is blanked out are separated by variable time intervals, depending on the size of the small plate and on the speed of rotation, in which intervals radiation would reach both image halves. The X-radiation is interrupted between the half-image radiation exposure time slots. The X-radiation can be interrupted either when the X-radiation source is operated in the pulsed mode, or when the time intervals between the half-image radiation exposure time slots, a screen interrupts the beam path of the X-radiation source. The scattered-beam component can be reduced by up to 50% with the half-scanning method. This half-scanning method is suitable whenever large proportions of scattered radiation occur, or with large-area X-ray detectors or with small spacing between the focal point and the detector, as in a C-arch device, for example. Under some circumstances, because of the low proportions of scattered radiation in a half-scanning method, the matrix can be left out entirely, which additionally increases the primary radiation at the detector inlet. In contrast to conventional scanning methods, the half-scanning method does not need a mechanical screen system on the side toward the patient. The half-scanning method is distinguished by a simple mechanism. Suppressing the scattered radiation makes it possible to improve the image quality. If these improvements in image quality are used with a goal of reducing the patient dose, then a considerable increase in the radiation output by a factor of 2 is furthermore unnecessary. FIG. 1 shows the schematic construction of an X-ray device, with an X-radiation source 1. A rectangular rotating small plate 3 is located in a radiation cone 2 of the X-radiation source 1. The small plate 3 is located as close as possible to the radiation source 1 so that it need not be embodied as overly large. One half 4 of the small plate 3 has X-ray-absorbing material, while the other half 5, in the exemplary embodiment shown, has only a frame 6, which does not affect the beam path or has limited affect on the beam path of the radiation cone 2. The frame 6 balances the concentric rotation of the small plate 3. A rotary shaft 7 is located at a short spacing from the X-ray-absorbing material on that half 4 of the small plate 3. In the time within which the plate 3 with its absorbent side covers half of the beam path, that half of the image can be recorded. After a half-rotation, the X-ray absorbent side covers the other half of the image, and the second half of the image can be recorded. At the dividing line between the two images, there is a slight radiation overlap, because of the slight spacing of the X-ray-absorbing material on that half 4 of the small plate 3 relative to the shaft 7, so that the peripheral regions will be illuminated. A digital detector 9 may be disposed behind a patient 8 for recording the image in the half-scanning method. A heavy metal such as tungsten can for instance be used as the absorbent material for the small plate 3. A heavy metal at a thickness of only 0.5 mm already suffices to reduce the radiation output to 1%. The small plate 3 is balanced for concentric running by means of weights on the nonabsorbent side. The small plate 3 is operated via an electric motor with a rotary speed of 900 rpm, for instance, or at an image frequency of 900/60=15 Hz. The pulse length (exposure time) for one half-image is fixed at 7 ms, and the time without radiation exposure between two half-images is set at 26.3 ms. The small plate 3 at the onset and end of the pulse then forms an angle α of 19° with the plane that is perpendicular to the primary beam direction. While the plate 3 traverses the distance from the position 3′ in FIG. 3 to the position 3″, or during a rotation of 38°, the exposure of the left-hand image half takes place, and later, separated by 26.3 seconds from this time slot, the exposure of the right-hand image half takes place. From these figures, the pulse length is calculated as follows: The length of one revolution of the small plate 3 is 1/15 seconds=66.7 ms. The angle α of 18 to 19° is equivalent to a displacement angle of the small plate 3 from the position 3′ to 3″ of approximately 36 to 38°, or 1/10 of 360°, and from this, the pulse length for one half-image is then approximately 7 ms. By suitable intelligent image-reprocessing algorithms, which are known in the prior art, the two partial images can be harmoniously joined to one another, for example, with the aid of a pixel shift correction. The time of 26.3 ms between the recording of the two half-images can be reduced using the following method. The small plate 3 rotates at twice the speed of revolution, that is, 1800 rpm. The exposure time for one half-image should again be 7 ms, which in this case means that the angle α must be 38°. A larger small plate 3 is used, since shielding is required for a longer time. Given this configuration, the second half-image can already be recorded after only 9.67 seconds. In the ensuing full revolution of the small plate 3, no image is recorded. An image frequency of 15 Hz is again attained. A maximum angle α of 60° is conceivable; at that angle, the recordable half-images can succeed one another virtually seamlessly. A period without radiation exposure is located between when the two half-images is made. This can be achieved by a suitable pulsed mode of the X-ray tube 1, but optionally also by the provision of a further screen, not shown, between the small plate 3 and the X-radiation source 1.
	abstract	A method of polymerizing by a free radical polymerization mechanism, product formed thereby, and apparatus for performing this method, are disclosed. The composition to be polymerized by the free radical polymerization mechanism is irradiated by a substantially constant radiation, the radiation being substantially without pulsation. The use of the substantially constant radiation without pulsation reduces premature termination of the polymerization. The substantially constant radiation can be the output of a lamp powered by a constant current, direct current power supply.
062427474	claims	1. A system for in situ controlling the operational parameters of a radio frequency (RF) linear accelerator (linac) (23) in an ion implanter (1), comprising: (i) a user input device (10) for accepting from a user numeric value calculation codes and data representing necessary operational conditions of the linac; (ii) a control calculation device (11) for (a) storing the numeric value calculation codes and the data representing necessary operational conditions, (b) calculating one or more operational parameters for the linac based on said numeric value calculation codes and said data; and (c) outputting one or more control signals; said control calculation device including means for simulating the acceleration or deceleration of an ion beam based on said numeric value calculation codes and said data, and for automatically calculating at least one of said operational parameters and outputting at least one of said control signals; and (iii) control devices (12, 13, 14) for receiving said one or more control signals and, in response thereto, controlling said operational parameters of the linac (23). (i) accepting from a user input device (10) numeric value calculation codes and data representing necessary operational conditions of the linac; (ii) (a) storing the numeric value calculation codes and the data representing necessary operational conditions, (b) automatically calculating one or more operational parameters for the linac by simulating the acceleration or deceleration of an ion beam using said numeric value calculation codes and said data; and (c) outputting one or more control signals; and (iii) receiving said one or more control signals with control devices (12, 13, 14) which respond thereto by controlling said operational parameters of the linac (23). 2. The system of claim 1, wherein said operational parameters of the linac (23) include phase, frequency, and amplitude of an output signal of the linac. 3. The system of claim 2, wherein said control devices include an amplitude control device (12), a phase control device (13), and a frequency control device (14). 4. The system of claim 3, wherein said control calculation device (11) includes a storage device (18) for storing said numeric value calculation codes and the data representing necessary operational conditions. 5. The system of claim 3, wherein further comprising an operator display device (17). 6. The system of claim 3, wherein the linac (23) has one or more RF power supplies (15) and one or more amplitude control devices (12) for controlling the amplitude of the outputs of the RF power supplies, and said control calculation device (11) uses said numeric value calculation codes and said data to calculate a numeric value of the RE amplitude, whereby the calculated value controls said one or more amplitude control devices (12), which control the output voltage amplitudes of said one or more RF power supplies. 7. The system of claim 3, wherein the linac (23) has one or more RF power supplies (15) and one or more phase control devices (13) for controlling the phase of the outputs of the RF power supplies, and said control calculation device uses said numeric value calculation codes and said data to calculate a numeric value of the RF phase, whereby the calculated value controls said one or more phase control devices (13), which control the output voltage phase of said one or more RF power supplies. 8. The system of claim 3, wherein the linac has one or more RF power supplies (15) and one or more frequency control devices (14) for controlling the frequency of the outputs of the RF power supplies, and said control calculation device uses said numeric value calculation codes and said data to calculate a numeric value of the RE frequency, whereby the calculated value controls said one or more frequency control devices (14), which control the output voltage frequency of said one or more RF power supplies. 9. The system of claim 3, wherein the linac has one or more RE resonators (23-1) and one or more frequency control devices (14) for controlling the resonance frequency of the RF resonators, and said control calculation device uses said numeric value calculation codes and said data to calculate a numeric value of the RE frequency, whereby this calculated value controls said one or more frequency control devices (14), which control the resonance frequencies of said one or more RE resonators. 10. The system of claim 3, wherein said numeric value calculation codes can be altered according to the geometrical dimensions of the ion implantation apparatus, the number of RF acceleration stages, a utilized frequency band, and the maximum value of the amplitude. 11. The system of claim 3, wherein said user input device (10) provides means by which an operator or a higher level computer can enter conditions such as a desired type of ions, ionic valence value of ions, and the final implantation energy value, wherein said control calculation device automatically calculates all or part of RF parameters, which are amplitude, frequency and phase, under the entered conditions so that a desired ion beam is thereby automatically created. 12. A method of in situ controlling the operational parameters of a radio frequency (RF) linear accelerator (linac) (23) in an ion implanter (1), comprising: 13. The method of claim 12, wherein said operational parameters of the linac (23) include phase, frequency, and amplitude of an output signal of the linac. 14. The method of claim 13, wherein said control devices include an amplitude control device (12), a phase control device (13), and a frequency control device (l4). 15. The method of claim 14, wherein the linac (23) has one or more RF power supplies (15) and one or more amplitude control devices (12) for controlling the amplitude of the outputs of the RF power supplies, and said numeric value calculation codes and said data are used to calculate a numeric value of the RF amplitude, whereby the calculated value controls said one or more amplitude control devices (12), which control the output voltage amplitudes of said one or more RF power supplies. 16. The method of claim 14, wherein the linac (23) has one or more RF power supplies (15) and one or more phase control devices (13) for controlling the phase of the outputs of the RF power supplies, and said numeric value calculation codes and said data are used to calculate a numeric value of the RF phase, whereby the calculated value controls said one or more phase control devices (13), which control the output voltage phase of said one or more RF power supplies. 17. The method of claim 14, wherein the linac has one or more RF power supplies (15) and one or more frequency control devices (14) for controlling the frequency of the outputs of the RF power supplies, and said numeric value calculation codes and said data are used to calculate a numeric value of the RF frequency, whereby the calculated value controls said one or more frequency control devices (14), which control the output voltage frequency of said one or more RF power supplies. 18. The method of claim 14, wherein the linac has one or more RF resonators (23-1) and one or more frequency control devices (14) for controlling the resonance frequency of the RF resonators, and said numeric value calculation codes and said data are used to calculate a numeric value of the RF frequency, whereby this calculated value controls said one or more frequency control devices (14), which control the resonance frequencies of said one or more RF resonators. 19. The method of claim 14, wherein said numeric value calculation codes can be altered according to the geometrical dimensions of the ion implantation apparatus, the number of RF acceleration stages, a utilized frequency band, and the maximum value of the amplitude. 20. The method of claim 14, wherein said user input device (10) provides means by which an operator or a higher level computer can enter conditions such as a desired type of ions, ionic valence value of ions, and the final implantation energy value, wherein said control calculation device automatically calculates all or part of RF parameters, which are amplitude, frequency and phase, under the entered conditions so that a desired ion beam is thereby automatically created.
	abstract	An X-ray grating configured for use in an X-ray imaging apparatus is provided. The X-ray grating has a silicone-based base layer. A plurality of silicon-based ridges is on a surface of the silicon-based base layer, wherein the plurality of silicon-based ridges from a plurality of trenches, where a trench of the plurality of trenches is between two silicon-based ridges of the plurality of silicon-based ridges. A plurality of silicon-based bridges extends between adjacent silicon-based ridges, wherein each silicon-based ridge of the plurality of silicon-based ridges is connected to at least one adjacent silicon-based ridge of the plurality of silicon-based ridges by at least one of a silicon-based bridge of the plurality of silicon-based bridges and wherein at least one of a plurality of four adjacent trenches does not have any silicon-based bridges.
	summary
041359720	summary	BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates to the supporting of fuel elements within a nuclear reactor and particularly to the attachment of web members comprised of a first metal to guide tubes comprised of a second metal to define a fuel element supporting spacer grid. More specifically, the present invention relates to high strength nuclear reactor fuel assemblies characterized by the use of different metals to define the fuel element receiving grids and the guide tubes on which the grids are supported and in which neutron absorber elements move for control purposes. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character. (2) Description of the Prior Art The functions performed by and the considerations which enter into the design of spacer grids for nuclear reactor fuel assemblies are discussed in detail in U.S. Pat. Nos. 3,607,640 and 3,664,924 issued to Donald M. Krawiec and assigned to the assignee of the present invention. Prior art spacer grids have, in many cases, been fabricated substantially entirely of a zirconium alloy; i.e., zircaloy. The use of annealed zircaloy has been dictated by its desirable combination of mechanical strength, workability and low neutron capture cross-section. Some designers, however, have favored fuel assemblies wherein the guide tubes are comprised of a first metal, for example zircaloy, while the grid defining members are fabricated from a second metal; the second metal typically having a higher neutron capture cross-section when compared to zircaloy but also having a greater stiffness than annealed zircaloy. Typical of the materials employed in spacer grids and having a greater stiffness than zircaloy is the steel alloy known as Inconel. A fuel assembly for a nuclear reactor will, in most instances, comprise a plurality of guide tubes which extend between upper and lower support plates; the support plates maintaining the requisite parallelism of the guide tubes. Intermediate the support plates, and mounted on the guide tubes, will be a plurality of grids each of which define an "egg crate" type structure. The fuel elements, which typically will comprise zircaloy tubes containing pellets of enriched uranium, are frictionally engaged in the spacer grids and are held in position thereby in parallelism to the guide tubes. As noted above, it is often considered desirable to employ a material such as Inconel to define the spacer grids while utilizing zircaloy guide tubes. Inconel, however, cannot reliably be welded to zircaloy and thus the use of dissimilar materials for the spacer grid and guide tubes precipitates a problem in the mounting of the spacer grids on the guide tubes. There have, in the prior art, been a number of techniques proposed for the joining of spacer grids comprised of a first metal to guide tubes comprised of a second dissimilar metal. These prior art techniques generally provide for a friction fit and/or mechanical stops between the grids and tubes and have proved to be a less than satisfactory solution since the inherently present clearances between parts have made possible vibration induced movement of the spacer grids relative to the guide tubes with the inherent possibility of fretting the fuel element cladding incident to any such vibration. Restated, the prior art joining techniques have provided only for mechanical capture of the grids on the tubes and have not guaranteed tightness between the parts as is required to insure against relative axial, radial and azimuthal motion. U.S. Pat. No. 3,920,516 discloses a prior art mechanical capture technique for use in mounting Inconel grids on zircaloy guide tubes. SUMMARY OF THE INVENTION The present invention overcomes the above briefly discussed deficiencies and disadvantages of the prior art by providing a novel and improved technique for the interconnection of components formed of dissimilar metals and particularly for the attachment of web members comprised of a first metal to tubes comprised of a second metal. The present invention also encompasses an improved nuclear reactor fuel assembly utilizing non-zircaloy spacer grids and zircaloy control element receiving guide tubes. In accordance with the invention web-like spacer grid defining members of a first metal are mechanically coupled to a guide tube comprised of a second metal by means of a cylindrical sleeve comprised of the same metal as the spacer grid defining web members. The cylindrical sleeve is continuous at its upper and lower ends and has an axial length greater than the width of the spacer grid. The cylindrical sleeve initially has, along at least a portion of its length extending from a first end along an axial distance greater than the width of the spacer grid, an outer diameter commensurate with the outer diameter of the guide tubes. The sleeve is provided with a plurality of cutouts or windows, typically four, having a length substantially equal to the width of the spacer grid web members; these windows being centered about the midpoint of the length of the sleeve. The width of these windows in the sleeve is selected so as to insure, when the sleeve is installed, contact between the side edges of each window and a grid web member whereby relative radial and azimuthal motion between the grid and tube is precluded. In accordance with a first embodiment of the invention, the sleeve is also provided with a plurality of apertures, spaced about the circumference of the sleeve, adjacent the oppositely disposed ends thereof. In use of the first embodiment of the invention, the sleeve is inserted in the spacer grid with the windows in registration with those portions of the spacer grid web members which would normally contact the guide tube. The sleeve is then expanded radially outwardly, for example by swaging, so as to have along its entire length an inner diameter slightly larger than the outer diameter of the guide tube. The outward expansion of the sleeve results in a guaranteed tight fit between the spacer grid web members and all four edges of each window intercepted thereby. This tight fit, in turn, produces a definite mechanically locking of the sleeves to the grid and, when the sleeves are attached to the guide tubes, prevents any axial, radial or azimuthal motion between the grids and guide tubes. Since the spacer grid web members and the sleeve are of the same material in the first embodiment, the interconnection of the sleeves and web members can be enhanced by welding these components to one another. The retention of the spacer grid at the proper point along the guide tube is accomplished by subsequently inserting the guide tube through the sleeve and thereafter expanding the guide tube radially outwardly in the areas where the apertures have been formed in the sleeve to lock the guide tube to the sleeve both above and below the spacer grid. In accordance with a second embodiment of the invention, the sleeve is comprised of the same material as the guide tubes; i.e., zircaloy; and thus the sleeve may be welded to the guide tube subsequent to the expansion of the sleeve which permits passage of the guide tube therethrough. In view of the attachment of the sleeve to the guide tube by welding, the sleeve need not be provided with the apertures of the first embodiment and no expansion of the guide tube is required. In the second embodiment, as in the first embodiment, the sleeve is provided with windows located intermediate the length of the sleeve; these windows having a length commensurate with the grid width and a width appropriate to achieve anti-rotation. As a result of the expansion of the sleeve, the top and bottom edges of the windows extend outwardly over the grid web members thus locking the spacer grid in place axially and the loading of the side edges of the windows in the expanded sleeve against the grid web members prevents radial and azimuthal relative motion between the guide tubes and grids.
	description	Korean Patent Application No. 10-2018-0056689, filed on May 17, 2018, in the Korean Intellectual Property Office, and entitled: “Light generator including debris shielding assembly, photolithographic apparatus including the light generator, and method of manufacturing integrated circuit device using the photolithographic apparatus,” is incorporated by reference herein in its entirety. The present disclosure relates to a light generator, a photolithographic apparatus including the same, and a method of manufacturing an integrated circuit (IC) device by using the apparatus, and more particularly, to a light generator providing extreme ultraviolet (EUV) light, a photolithographic apparatus including the light generator, and a method of manufacturing an IC device by using the apparatus. Recently, in accordance with high integration of semiconductor devices, various photolithography techniques for forming fine patterns have been developed. In particular, as the degree of integration of semiconductor devices increases, the critical dimension (CD) of a photoresist pattern is further decreasing. To form such a photoresist pattern having a fine CD, EUV light may be adopted as a light source of a photolithographic apparatus. To generate EUV light in the photolithographic apparatus, laser light may be radiated onto a target material in a vacuum chamber to convert the target material into a plasma state. According to an aspect of the present disclosure, there is provided a method of manufacturing an integrated circuit (IC) device, the method including forming a photoresist layer on a substrate, and exposing the photoresist layer to light by using a photolithographic apparatus including a light generator, wherein the light generator includes a chamber having a plasma generation space, an optical element in the chamber, and a debris shielding assembly between the optical element and the plasma generation space in the chamber, wherein the debris shielding assembly includes a protective film facing the optical element and being spaced apart from the optical element with a protective space therebetween, the protective space including an optical path, and a protective frame to support the protective film and to shield the protective space from the plasma generation space. According to another aspect of the present disclosure, there is provided a method of manufacturing an integrated circuit (IC) device, the method including forming a photoresist layer on a substrate, and exposing the photoresist layer to light by using a photolithographic apparatus including a light generator, wherein the light generator includes a chamber having a plasma generation space, an optical collector in the chamber, the optical collector having a reflective surface, and a debris shielding assembly between the optical collector and the plasma generation space in the chamber, wherein the debris shielding assembly includes a protective film being spaced apart from the reflective surface with a protective space therebetween and facing the reflective surface, the protective space including an optical path, and a protective frame that is in contact with an edge portion of the optical collector and supports the protective film. According to yet another aspect of the present disclosure, there is provided a method of manufacturing an integrated circuit (IC) device, the method including forming a photoresist layer on a substrate, and exposing the photoresist layer to light by using a photolithographic apparatus including a light generator, wherein the light generator includes a chamber having a plasma generation space, an optical collector in the chamber, the optical collector having a reflective surface, and a debris shielding assembly between the optical collector and the plasma generation space in the chamber, wherein the debris shielding assembly includes a protective film facing the reflective surface with a protective space therebetween, the protective space including an optical path, the protective film having a through hole formed in a position corresponding to the optical path in the protective film. FIG. 1 is a schematic view illustrating main elements of a light generator 100 according to embodiments of the present disclosure. Referring to FIG. 1, the light generator 100 may be an extreme ultraviolet (EUV) light generator which generates EUV light using a laser produced plasma (LPP) method. The light generator 100 may include a chamber 110 having a plasma generation space (PS), optical elements arranged in the chamber 110, and a laser focusing system 160 which radiates a laser beam into the chamber 110. The optical elements may include an optical collector 120 and a spectral purity filter (SPF) 130. However, the optical elements are not limited thereto. The chamber 110 may be provided with an introduction window 112 through which a laser beam (LB) radiated from the laser focusing system 160 may be introduced into the chamber 110. The chamber 110 may be maintained at a vacuum state by an evacuation apparatus 140, e.g., a vacuum pump, installed in the chamber 110. The light generator 100 may include a droplet generator 152 which provides droplets (DL) of a target material into the chamber 110, and a catcher 154 which collects droplets not involved in a plasma generation reaction among the droplets provided from the droplet generator 152. In the chamber 110, the droplets (DL) may flow in a straight line direction from the droplet generator 152 toward the catcher 154. The target material may include Sn, Li, Ti, Xe, or a combination thereof. In some embodiments, the target material may include pure tin (Sn), a Sn compound, a Sn alloy, or a combination thereof. The Sn compound may be at least one of, e.g., SnBr4, SnBr2, and SnH. The Sn alloy may be at least one of, e.g., Sn—Ga alloy, a Sn—In alloy, and a Sn—In—Ga alloy. However, embodiments are not limited thereto. The laser focusing system 160 may radiate the laser beam (LB) onto the droplets (DL) of the target material to thereby convert the droplets of the target material into a plasma state in the plasma generation space (PS). For example, the laser focusing system 160 may radiate a pre-pulse laser beam onto a primary target, i.e., the droplet (DL) of the target material, to generate a secondary target, and radiate a main pulse laser beam onto the secondary target to thereby generate plasma from the droplets (DL) of the target material. The pre-pulse laser beam may be a beam having a wavelength of about 1064 nm provided from a Nd:YAG (Yttrium Aluminum Garnet) laser device. The main pulse laser beam may be a beam having a wavelength of about 10.6 μm provided from a CO2 laser device. However, types of the pre-pulse laser beam and the main pulse laser beam are not limited to the above examples. The laser beam (LB) generated from the laser focusing system 160 may be focused onto the droplet (DL) in the chamber 110 through the introduction window 112. While plasma is generated from the droplet (DL), the chamber 110 may be maintained in a comparatively high vacuum condition of about 1 Torr or less. The optical collector 120 may have a reflective surface 122 capable of collecting and reflecting EUV light having a wavelength of about 1 nm to about 31 nm, e.g., about 13.5 nm, from light having various wavelengths emitted from the plasma generated from the droplets (DL) of the target material in the chamber 110. For example, as illustrated in FIG. 1, the optical collector 120 may be positioned in the chamber 110, such that the reflective surface 122 of the optical collector 120 may face the plasma generation space (PS). The reflective surface 122 may be a concave surface. The reflective surface 122 may selectively reflect EUV light having a wavelength of about 13.5 nm. The optical collector 120 may include a multilayer mirror providing the reflective surface 122. The multilayer mirror may be configured as a stack structure in which a plurality of layers, e.g., a Mo layer, a Si layer, a SiC layer, a B4C layer, a Mo2C layer, and a Si3N4 layer, are alternately stacked upon one another. The optical collector 120 may have an aperture (AP) in a substantially central portion of the optical collector 120, and the aperture (AP) penetrates through the reflective surface 122. The reflective surface 122 may be a curved surface having a prolate ellipsoidal shape concavely converging to the aperture (AP). The laser beam (LB) provided from the laser focusing system 160 may be irradiated through the introduction window 112 of the chamber 110 and through the aperture (AP) of the optical collector 120 onto the droplets (DL) of the target material to generate plasma in the plasma generation space (PS). The EUV light (LT) collected from the plasma generated in the chamber 110 may be provided to an exposure apparatus, e.g., a scanner or a stepper, through the SPF 130. For example, as illustrated in FIG. 1, light of the EUV light (LT) collected from the plasma generated in the chamber 110 is reflected from the reflective surface 122 of the optical collector 120 toward the SPF 130, e.g., the SPF 130 and the introduction window 112 may be on opposite sidewalls of the chamber 110. The SPF 130 may remove unnecessary light of the EUV light (LT) collected from the plasma generated in the chamber 110, i.e., UV rays, visible rays, and infrared rays, having a longer wavelength than the EUV light (LT) and may transmit only desired EUV light, e.g., light having a wavelength of about 13.5 nm, to the exposure apparatus. The light generator 100 may further include a debris shielding assembly 170 arranged between the optical collector 120 and the plasma generation space (PS) in the chamber 110. The debris shielding assembly 170 may include a protective film 172, a protective frame 174 supporting the protective film 172, and a fixing member 176 for fixing the protective film 172 to the protective frame 174. In detail, referring to FIG. 1, the protective film 172 may cover, e.g., overlap, the reflective surface 122 of the optical collector 120. The protective film 172 may be arranged at a location separated from the optical collector 120 with a protective space 180 between the protective film 172 and the reflective surface 122 of the optical collector 120, so a path of the EUV light (LT) is through the protective space 180. For example, as illustrated in FIG. 1, the protective film 172 may be spaced apart a predetermined distance from the reflective surface 122 of the optical collector 120, so the protective space 180 may separate between the protective film 172 and the reflective surface 122. For example, as illustrated in FIG. 1, since the reflective surface 122 may be a curved surface, and the protective film 172 may have a flat surface facing the reflective surface 122. the distance between the reflective surface 122 and the surface of the protective film 172 facing the reflective surface 122 may be non-constant. The protective film 172 may have a through hole 172LH in a substantially central portion of the protective film 172, e.g., the through hole 172LH may be aligned with the aperture (AP) of the optical collector 120. Therefore, the laser beam (LB) radiated from the laser focusing system 160 may be irradiated onto the droplet (DL) of the target material through the through hole 172LH of the protective film 172 after passing through the introduction window 112 of the chamber 110 and through the aperture (AP) of the optical collector 120. In some embodiments, the protective film 172 may not have the through hole 172LH. The protective frame 174 may be arranged to contact an edge portion of the optical collector 120, e.g., the protective frame 174 may connect between the edge portion of the optical collector 120 and the protective film 172. The protective frame 174 may shield, at the edge portions of the protective film 172 and the optical collector 120, the protective space 180 from the plasma generation space (PS). For example, as illustrated in FIG. 1, the protective frame 174 may be directly between the edge portion of the optical collector 120 and the protective film 172, e.g., along entire perimeters of the optical collector 120 and the protective film 172, so the protective space 180 may be shielded, e.g., completely separated from the plasma generation space (PS), e.g., with the exception of the through hole 172LH. The protective frame 174 may have a planar shape corresponding to a planar shape of the edge portion of the optical collector 120. For example, when the edge portion of the optical collector 120 has a circular ring shape in a front view facing the reflective surface 122 of the optical collector 120, e.g., when looking from the SPF 130 toward the reflective surface 122, the protective frame 174 may have a circular ring shape corresponding to, e.g., overlapping, the edge portion of the optical collector 120. For example, the protective frame 174 may, e.g., continuously, extend along an, e.g., entire. edge perimeter of the optical collector 120. In some embodiments, the protective film 172 may include a material that is transparent to the EUV light (LT). In some other embodiments, the protective film 172 may include a material transparent to the laser beam (LB) radiated from the laser focusing system 160 and the EUV light (LT). For example, the protective film 172 may include a material transparent to a laser beam having a wavelength of about 1064 nm, a laser beam having a wavelength of about 10.6 μm, and EUV light having a wavelength of about 13.5 nm. In this case, even when the protective film 172 does not have the through hole 172LH, the laser beam (LB) radiated from the laser focusing system 160 may transmit through the protective film 172. In some embodiments, the protective film 172 may include at least one of carbon isomers. For example, the protective film 172 may include carbon nanotubes, diamond, graphite, graphene, fullerene, or a combination thereof. In some embodiments, the protective film 172 may include a carbon nanotube film including single-wall carbon nanotubes (SWCNT), multiwall carbon nanotubes (MWCNT), or a combination thereof. In some other embodiments, the protective film 172 may include a diamond layer. In some embodiments, the diamond layer may be a layer formed by using a chemical vapor deposition (CVD) process. For example, the diamond layer may be obtained by depositing diamond on a support substrate with a combination of methane and hydrogen gases at a temperature of about 800° C. to about 1,200° C. under reduced pressure. The inclusion of the hydrogen gas may prevent growth of graphite during nucleation and growth of the diamond. However, according to embodiments of the present disclosure, a process of forming the diamond layer available as the protective film 172 is not limited to the above-described example method. A diamond layer available as the protective film 172 may be obtained through any of a variety of methods known in the art. In some other embodiments, the protective film 172 may include a diamond-like carbon (DLC) film. The DLC film may include amorphous carbon including a sp3 carbon bond and a sp2 carbon bond. The DLC film may include sp3 carbon bonds and sp2 carbon bonds in a ratio of about 1:1. However, embodiments are not limited thereto. In some other embodiments, the protective film 172 may include a graphene-carbon nanotube composite. The graphene-carbon nanotube composite may include graphene and carbon nanotubes in a weight ratio of about 2:1 to about 1:5. In some embodiments, the protective film 172 may have a thickness of about 2 nm to about 500 nm. However, embodiments of the present disclosure are not limited thereto. The protective frame 174 of the debris shielding assembly 170 may support the protective film 172, in contact with the edge portion of the optical collector 120. The protective frame 174 may include a metal. For example, the protective frame 174 may include Al, stainless steel, Mo, or a combination thereof. The debris shielding assembly 170 may include the fixing member 176 for fixing the protective film 172 to the protective frame 174. In some embodiments, the fixing member 176 may include an adhesive layer. In some embodiments, the adhesive layer may include a thermosetting epoxy resin or bovine serum albumin (BSA). However, embodiments of the present disclosure are not limited thereto. In some embodiments, the debris shielding assembly 170 may not include the fixing member 176 between the protective film 172 and the protective frame 174. Instead, the protective film 172 may be fixed directly onto the protective frame 174 by pressing. Although FIG. 1 illustrates an embodiment in which the optical collector 120 as an optical element is protected by the debris shielding assembly 170, embodiments of the present disclosure are not limited to the embodiment illustrated in FIG. 1. For example, the debris shielding assembly 170 may be installed to protect the SPF 130, e.g., between the SPF 130 and the plasma generation space (PS), or other optical elements in the chamber 110. For example, if the debris shielding assembly 170 were not in the chamber 110, during plasma generation in the plasma generation space PS, debris, e.g., particles unable to become plasma, would be deposited on surfaces of optical elements, e.g., on a surface of the optical collector 120 or on a surface of the SPF 130, thereby lowering operation efficiency, e.g., reflectance or transmittance, thereof. While efforts could be made to clean the surfaces of the optical elements in the chamber 110, e.g., via various cleaning gases or radicals obtained from cleaning gases, the cleaning processes, e.g., using cleaning gases or radicals, would raise the processing costs, and optical characteristics, e.g., reflectance, of the optical elements would be deteriorated due to repeated deposition of debris generated from the target material in the chamber 110. Further, the surfaces of the optical elements would also be deteriorated by the cleaning gases or radicals, and accordingly, durability would be lowered. In contrast, according to embodiments of the present disclosure, the light generator 100 may include the debris shielding assembly 170 installed between optical elements which are prone to contamination by debris and the plasma generation space (PS) in the chamber 110. For example. as illustrated in FIG. 1, the debris shielding assembly 170 may be installed between the optical collector 120 and the plasma generation space (PS). Accordingly. when debris generated from the droplet (DL) in the plasma generation space (PS) flows from the plasma generation space (PS) toward the reflective surface 122 of the optical collector 120, various travel paths of the debris to the reflective surface 122 of the optical collector 120 may be blocked by the protective film 172 and the protective frame 174. In particular, even when the debris generated from the droplet (DL) in the plasma generation space (PS) is likely to move from the plasma generation space (PS) towards the reflective surface 122 of the optical collector 120 through the space between the protective film 172 and the optical collector 120 via various travel paths of the debris, there is no concern of flowing of the debris from the plasma generation space (PS) towards the reflective surface 122 of the optical collector 120 through the space between the protective film 172 and the optical collector 120, since the protective space 180 is shielded by the protective frame 174 of the debris shielding assembly 170 at the edge portions of the protective film 172 and the optical collector 120. Thus, it is unlikely that debris generated in the plasma generation space (PS) flows to the reflective surface 122 of the optical collector 120 and into the protective space 180 extending a predetermined distance from the reflective surface 122 of the optical collector 120 to the protective film 172. Accordingly, the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris, and the performance of the optical collector 120 may also be maintained without periodic cleaning. In the light generator 100 according to the one or more embodiments of the present disclosure, the internal environment of the chamber 110 may be maintained under a stable operation condition only by periodic cleaning and/or replacement of the protective film 172 and the protective frame 174, without cleaning the optical elements in the chamber 110. Accordingly, without the need to perform the cleaning process using a gas source, which may increase the process cost and deteriorate the optical elements, the contamination of the optical elements by debris and consequential productivity reduction may be prevented or substantially minimized. FIG. 2A is a plane view illustrating an example configuration of a debris shielding assembly 270A which may be employed in a light generator according to embodiments of the present disclosure. FIG. 2B is a cross-sectional view taken along line B-B′ in FIG. 2A. In FIGS. 2A and 2B, like reference numerals as those in FIG. 1 refer to like elements, and thus redundant descriptions thereof are omitted here. Referring to FIGS. 2A and 2B, similar to the debris shielding assembly 170 illustrated in FIG. 1, the debris shielding assembly 270A may include a protective film 272A and a protective frame 274 supporting the protective film 272A. The protective film 272A may have a substantially same configuration as that of the protective film 172 described above with reference to FIG. 1. The protective film 272A may have a through hole 272LH in a substantially central portion thereof. The protective frame 274 may include a support portion 274A, a shield portion 274B that is integrally connected with the support portion 274A and extends between the support portion 274A and the protective film 272A, and an outer fixing portion 274C that faces the shield portion 274B with the protective film 272A therebetween. The outer fixing portion 274C supports the protective film 272A in cooperation with the shield portion 274B. The support portion 274A, the shield portion 274B, and the outer fixing portion 274C, which constitute the protective frame 274, may have a substantially circular planar shape. Outer diameters of the support portion 274A, the shield portion 274B, and the outer fixing portion 274C may substantially be the same. The support portion 274A. the shield portion 274B. and the outer fixing portion 274C may include a metal. For example, the support portion 274A, the shield portion 274B, and the outer fixing portion 274C may include Al, stainless steel, Mo, or a combination thereof. The support portion 274A may be a ring member having a straight cross-sectional shape extending from the shield portion 274B. A width WA of the support portion 274A may be less than a width WB of the shield portion 274B. In some embodiments, the width WB of the shield portion 274B may substantially be the same as the width WC of the outer fixing portion 274C. In some other embodiments, the width WB of the shield portion 274B may be different from the width WC of the outer fixing portion 274C. The protective frame 274 may further include a first buffer film 278A between the shield portion 274B and the protective film 272A, and a second buffer film 278B between the protective film 272A and the outer fixing portion 274C. In some embodiments, the first buffer film 278A and the second buffer film 278B may include an elastic material. For example, each of the first buffer film 278A and the second buffer film 278B may include a polyimide film and/or an engineering plastic material, e.g., polyetheretherketone (PEEK). The protective frame 274 may further include a fixing member 292 for maintaining the protective film 272A and the protective frame 274 bound to each other. The fixing member 292 may include a screw. In some embodiments, the fixing member 292 may include a metal. However, embodiments of the present disclosure are not limited thereto. FIG. 2C is a plane view of the protective film 272A included in the debris shielding assembly 270A as illustrated in FIGS. 2A and 2B. Referring to FIG. 2C, the protective film 272A may have a circular shape in a plane view, having a substantially same outer diameter as the diameter of the protective frame 274, e.g., the protective film 272A may have a same outer diameter as an outer diameter of the ring-shaped protective frame 274. The protective film 272A may include a through hole 272LH in a substantially central portion thereof and a plurality of holes 272H in, e.g., spaced apart along, an edge portion thereof. The fixing member 292 illustrated in FIGS. 2A and 2B may penetrate through the plurality of holes 272H. A material of the protective film 272A may be the same as that of the protective film 172 described above with reference to FIG. 1. FIG. 2D is a plane view of the outer fixing portion 274C included in the debris shielding assembly 270A as illustrated in FIGS. 2A and 2B. Referring to FIG. 2D, the outer fixing portion 274C may have a circular shape in a plane view. The outer fixing portion 274C may include a plurality of holes 274H which the fixing member 292 illustrated in FIGS. 2A and 2B may penetrate through. A planar structure of the shield portion 274B illustrate in FIGS. 2A and 2B may substantially be the same as the planar structure of the outer fixing portion 274C illustrated in FIG. 2D. FIG. 2E is a plane view of the first buffer film 278A included in the debris shielding assembly 270A as illustrated in FIGS. 2A and 2B. Referring to FIG. 2E, the first buffer film 278A may have a circular planar shape. The first buffer film 278A may include a plurality of holes 278H which the fixing member 292 illustrated in FIGS. 2A and 2B penetrates through. A planar structure of the second buffer film 278B illustrated in FIGS. 2A and 2B may substantially be the same as the planar structure of the first buffer film 278A illustrated in FIG. 2E. FIG. 2F illustrates a state before the debris shielding assembly 270A and the optical collector 120 are coupled together. FIG. 2G illustrates a state where the debris shielding assembly 270A and the optical collector 120 are coupled together. Referring to FIG. 2F, in the debris shielding assembly 270A, an inner diameter AD1 of the support portion 274A may be greater than an inner diameter BD1 of the shield portion 274B. An outer diameter OD of the outermost edge portion of the optical collector 120 farthest away from the aperture AP may be equal to or less than the inner diameter AD1 of the support portion 274A. An inner diameter ID of the edge portion of the optical collector 120 may substantially be the same as an inner diameter BD1 of the shield portion 274B. Therefore, to couple the optical collector 120 to the debris shielding assembly 270A, the edge portion of the optical collector 120 may be inserted into the support portion 274A. That is, the edge portion of the optical collector 120 may be positioned to abut, e.g., directly contact, a surface of the shield portion 274B facing the optical collector 120, so the support portion 274A is flush against and surrounds an outer diameter of the optical collector 120. As a result, as illustrated in FIG. 2G, the edge portion of the optical collector 120 may partially be surrounded by the support portion 274A. In some embodiments, in the light generator 100 (see FIG. 1), the optical collector 120 may be installed such that the reflective surface 122 is inclined in a vertical direction (Z direction) with respect to a horizontal direction (X-Y plane direction) at a certain angle, e.g., by a first acute angle (α). The laser beam (LB) may be radiated from the laser focusing system 160 at a certain tilt angle, e.g., the first acute angle (α), in a vertical direction (Z direction) with respect to the horizontal direction (X-Y plane direction, such as to pass through the aperture (AP) of the optical collector 120 and the through hole 272LH of the protective film 272A. As illustrated in FIG. 2G, with the optical collector 120 coupled to the debris shielding assembly 270A, the protective film 272A facing the reflective surface 122 of the optical collector 120 may extend tilted at a predetermined angle towards the optical collector 120, e.g., at a second acute angle β, with respect to the vertical direction (Z direction). To couple the optical collector 120 to the debris shielding assembly 270A, as the edge portion of the optical collector 120 is inserted into the support portion 274A, an upper portion of the support portion 274A and an upper portion of the shield portion 274B of the debris shielding assembly 270A may contact the upper edge portion of the optical collector 120 due to gravity, so that the upper edge portion of the optical collector 120 may support the debris shielding assembly 270A. Accordingly, no binding tools may be needed for coupling the optical collector 120 to the debris shielding assembly 270A. The shield portion 274B may have an inner surface S1 facing the protective space 180 between the support portion 274A and the protective film 272A. In the state where the optical collector 120 and the debris shielding assembly 270A are coupled together, an edge of the inner surface S1 of the shield portion 274B and an edge portion of the reflective surface 122 of the optical collector 120 may contact each other, and the inner surface S1 and the reflective surface 122 may smoothly extend, e.g., may be level with each other and directly contact each other, forming one, e.g., sealed, plane without a step difference in a contact region between the inner surface S1 and the reflective surface 122. In the light generator 100 illustrated in FIG. 1, the debris shielding assembly 270A illustrated in FIGS. 2A and 2B may be employed instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 270A are coupled together, the protective film 272A and the shield portion 274B may shield the protective space 180 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) may unlikely flow into the protective space 180 between the reflective surface 122 and the protective film 272A from the plasma generation space (PS). In particular, due to the shield portion 274B between the edge portion of the optical collector 120 and the protective film 272A, the debris generated in the plasma generation space (PS) may unlikely flow through a gap between the edge portion of the optical collector 120 and the protective film 272A into the protective space 180 and the reflective surface 122 of the optical collector 120 from the plasma generation space PS. Accordingly, the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 3A is a plane view for explaining an example configuration of a debris shielding assembly 270B according to an embodiment, which may be used in the light generator according to embodiments of the present disclosure. FIG. 3B is a cross-sectional view taken along line B-B′ in FIG. 3A. FIG. 3C is a view illustrating a state in which the debris shielding assembly 270B and the optical collector 120 are coupled. In FIGS. 3A to 3C, like reference numerals as those in FIGS. 1 to 2G refer to like elements, and thus redundant descriptions thereof are omitted. Referring to FIGS. 3A to 3C, the debris shielding assembly 270B may have a substantially same structure as the debris shielding assembly 270A illustrated in FIGS. 2A and 2B. Unlike the debris shielding assembly 270A, the debris shielding assembly 270B may not have the through hole 272LH (see FIGS. 2A to 2C) at a center portion. Accordingly, the laser beam (LB) passing through the aperture (AP) of the optical collector 120 after being radiated from the laser focusing system 160 may be transmitted through a protective film 272B to irradiate the droplet (DL) of the target material (see FIG. 1). Examples of the material of the protective film 272B may be the same as those of the protective film 172 described above with reference to FIG. 1. The debris shielding assembly 270B illustrated in FIGS. 3A and 3B may be employed in the light generator 100 of FIG. 1, instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 270B are coupled together, the protective film 272B and the shield portion 274B may shield the protective space 180 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) is unlikely to flow through a gap between the edge portion of the optical collector 120 and the protective film 272B into the protective space 180 and the reflective surface 122 of the optical collector 120 from the plasma generation space (PS). Accordingly, the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 4A is a plane view for explaining an example configuration of a debris shielding assembly 370 according to an embodiment, which may be used in the light generator according to embodiments of the present disclosure. FIG. 4B is a cross-sectional view taken along line B-B′ in FIG. 4A. In FIGS. 4A and 4B, like reference numerals as those in FIGS. 1 to 3C refer to like elements, and thus redundant descriptions thereof are omitted. Referring to FIGS. 4A and 4B, the debris shielding assembly 370 may have a substantially same configuration as the debris shielding assembly 270A illustrated in FIGS. 2A and 2B. Unlike the debris shielding assembly 270A, the debris shielding assembly 370 may include a protective film 372. and a protective frame 374 supporting the protective film 372. The protective frame 374 of the debris shielding assembly 370 may include a support portion 374A, a shield portion 374B, and an outer fixing portion 374C. The support portion 374A, the shield portion 374B, and the outer fixing portion 374C of the protective frame 374 may have substantially same configurations as those of the support portion 274A, the shield portion 274B, and the outer fixing portion 274C of the debris shielding assembly 270A, respectively. Unlike the debris shielding assembly 270A, the debris shielding assembly 370 may not have a through hole 272LH at a center portion thereof. Accordingly, the laser beam (LB) passing through the aperture (AP) of the optical collector 120 after being radiated from the laser focusing system 160 illustrated in FIG. 1 may be transmitted through the protective film 372 to irradiate the droplet (DL) of the target material (see FIG. 1). Examples of the material of the protective film 372 may be the same as those of protective film 172 described above with reference to FIG. 1. Further, the support portion 374A, the shield portion 374B, and the outer fixing portion 374C of the protective frame 374, and the protective film 372 may not have holes for the fixing member 292 illustrated in FIGS. 2A and 2B. To fix the protective film 372 to the protective frame 374, the debris shielding assembly 370 may have a fixing member 394 of a press type, e.g., a clamp or a binder clip. In some embodiments, the fixing member 392 may include a metal. However, embodiments are not limited thereto. In the light generator 100 illustrated in FIG. 1, the debris shielding assembly 370 illustrated in FIGS. 4A and 4B may be employed instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 370 are coupled together, the protective film 372 and the shield portion 374B may shield the protective space 180 (see FIG. 1) in front of the reflective surface 122 of the optical collector 120 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) is unlikely to flow into the protective space 180 and the reflective surface 122 from the plasma generation space (PS), so that the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 5A is a plane view for explaining an example configuration of a debris shielding assembly 470 according to an embodiment, which may be used in the light generator according to embodiments of the present disclosure. FIG. 5B is a cross-sectional view taken along line B-B′ in FIG. 5A. In FIGS. 5A and 5B, like reference numerals as those in FIGS. 1 to 3C refer to like elements, and thus redundant descriptions thereof are omitted. Referring to FIGS. 5A and 5B, the debris shielding assembly 470 may have a substantially same configuration as the debris shielding assembly 270B illustrated in FIGS. 3A and 3B. Unlike the debris shielding assembly 270B, the debris shielding assembly 470 may include a protective frame 474 supporting the protective film 272B. The protective frame 474 of the debris shielding assembly 470 may include a support portion 474A, a shield portion 474B, and an outer fixing portion 474C. The support portion 474A, the shield portion 474B, and the outer fixing portion 474C of the protective frame 474 may have substantially same configurations as those of the support portion 274A, the shield portion 274B, and the outer fixing portion 274C of the debris shielding assembly 270B, respectively, as described above with reference to FIGS. 3A and 3B. Unlike the debris shielding assembly 270B, a central axis 470C1 of an inner diameter BD2 of the protective frame 474 and a central axis 470C2 of an outer diameter AD2 of the protective frame 474 may not correspond to each other and be misaligned. The central axis 470C2 of the outer diameter AD2 of the protective frame 474 may correspond to a central axis of the debris shielding assembly 470. The support portion 474A, the shield portion 474B, and the outer fixing portion 474C of the protective frame 474 may have widths varying in a circumferential direction with respect to the central axis 470C2 of the outer diameter AD2 of the protective frame 474, i.e., the central axis of the debris shielding assembly 470. The support portion 474A may include a ring member having an L-like cross-sectional shape extending from the shield portion 474B. In detail, in the support portion 474A, the shield portion 474B, and the outer fixing portion 474C of the protective frame 474, a width W41 of each of the support portion 474A, the shield portion 474B, and the outer fixing portion 474C at a first edge of the protective frame 474 may be less than a width W42 of the same elements at a second edge of the protective frame 474. The first and second edges of the protective frame 474 may be opposite edges of the protective frame 474 along a straight line (i.e., diameter) crossing the central axis 470C2 of the outer diameter AD2 of the protective frame 474. In the debris shielding assembly 470, an inner diameter DD2 of the support portion 474A may be greater than an inner diameter BD2 of the shield portion 474B. The inner diameter DD2 of the support portion 474A may be greater than an outer diameter OD of the edge portion of the optical collector 120 (see FIG. 2F). An inner diameter ID of the edge portion of the optical collector 120 may substantially be the same as the inner diameter BD2 of the shield portion 474B. FIG. 5C is a view illustrating a state where the optical collector 120 and the debris shielding assembly 470 are coupled together. Referring to FIGS. 5A to 5C, to couple the optical collector 120 to the debris shielding assembly 470, the edge portion of the optical collector 120 may be inserted into the support portion 474A. Once the optical collector 120 and the debris shielding assembly 470 are coupled together, the edge portion of the optical collector 120 may partially be surrounded by the support portion 474A. In the state where the optical collector 120 and the debris shielding assembly 470 are coupled together, the protective film 272B facing the reflective surface 122 of the optical collector 120 may extend tilted at a predetermined angle towards the optical collector 120, e.g., at the second acute angle β, with respect to the vertical direction (Z direction). The central axis 470C1 of the inner diameter BD2 of the protective frame 474 and the central axis 120C of the optical collector 120 may be collinear. A straight line along the central axis 470C2 of the outer diameter AD2 of the protective frame 474 and a straight line along the central axis 120C of the optical collector 120 may not be collinear (e.g., dashed lines in FIG. 5C). When the inner diameter DD2 of the support portion 474A is greater than the outer diameter OD of the edge portion of the optical collector 120 (see FIG. 2F), it may facilitate insertion of the edge portion of the optical collector 120 into the support portion 474A so as to couple the optical collector 120 to the debris shielding assembly 470. Once the edge portion of the optical collector 120 is inserted within the support portion 474A, an upper portion of the support portion 474A and an upper portion of the shield portion 474B of the debris shielding assembly 470 may partially contact the upper edge portion of the optical collector 120 due to gravity, so that the upper edge portion of the optical collector 120 may support the debris shielding assembly 470. In the debris shielding assembly 470, the support portion 474A of the protective frame 474 may include a ring member extending having an L-like cross-sectional shape. In the coupling state as illustrated in FIG. 5C, as an upper edge portion of the support portion 474A having the L-like cross-sectional shape, the upper edge portion being bent towards the center of the protective frame 474, contacts the upper edge portion of the optical collector 120, the debris shielding assembly 470 may be supported by the optical collector 120. In the coupling position illustrated in FIG. 5C, the edge portion of the support portion 474A, bent toward the center of the protective frame 474, may function as a latch unit that may prevent detachment of the optical collector 120 downwards. That is, due to the edge portion of the protective frame 474 bent towards the center of the protective frame 474, detachment of the optical collector 120 from the protective frame 474 of the debris shielding assembly 470 may be prevented. Accordingly, no binding tools may be needed for coupling the optical collector 120 to the debris shielding assembly 470. The shield portion 474B may have an inner surface S2 facing the protective space 180 between the support portion 474A and the protective film 272B. In the state where the optical collector 120 and the debris shielding assembly 470 are coupled together, an edge portion of the inner surface S2 of the shield portion 474B and an edge portion of the reflective surface 122 of the optical collector 120 may contact each other, and the inner surface S2 and the reflective surface 122 may continuously extend forming one plane without a step difference in a contact region between the inner surface S2 and the reflective surface 122. Although FIGS. 5A to 5C illustrate the embodiments in which the debris shielding assembly 470 includes the protective film 272B, embodiments of the present disclosure are not limited thereto. For example, the debris shielding assembly 470 may include protective film 272A as illustrated in FIGS. 2A and 2B. In the light generator 100 illustrated in FIG. 1, the debris shielding assembly 470 illustrated in FIGS. 5A and 5B may be employed instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 470 are coupled together, the protective film 272B and the shield portion 474B may shield the protective space 180 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) is unlikely to flow into the protective space 180 through a space between protective film 272B and the optical collector 120 from the plasma generation space (PS). Accordingly, the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 6A is a cross-sectional view for explaining an example configuration of a debris shielding assembly 570 according to an embodiment, which may be used in the light generator according to embodiments of the present disclosure. FIG. 6B is a sectional view illustrating a state where the optical collector 120 and the debris shielding assembly 570 are coupled together. FIG. 6C is an enlarged view of a region “CX1” in FIG. 6B. In FIGS. 6A to 6C, like reference numerals as those in FIGS. 1 to 3C refer to like elements, and thus redundant descriptions thereof are omitted. Referring to FIGS. 6A to 6C, the debris shielding assembly 570 may have a substantially same configuration as the debris shielding assembly 270B illustrated in FIGS. 3A and 3B. Unlike the debris shielding assembly 270B, the debris shielding assembly 570 may include the protective film 272B, and a protective frame 574 supporting the protective film 272B. The protective frame 574 of the debris shielding assembly 570 may include a support portion 574A, a shield portion 574B, and an outer fixing portion 574C. The support portion 574A, the shield portion 574B, and the outer fixing portion 574C of the protective frame 574 may have substantially same configurations as the support portion 274A, the shield portion 274B, and the outer fixing portion 274C of the debris shielding assembly 270B, respectively, described above with reference to FIGS. 3A and 3B. Unlike the debris shielding assembly 270B, the shield portion 574B may have an inner surface 574EW facing the protective space 180 between the support portion 574A and the protective film 272B. In detail, the inner surface 574EW may be a curved surface. In the state where the optical collector 120 and the debris shielding assembly 570 are coupled together, an edge portion of the inner surface 574EW of the shield portion 574B and an edge portion of the reflective surface 122 of the optical collector 120 may contact each other, and the inner surface 574EW and the reflective surface 122 may smoothly extend forming one plane without a step difference in a contact region between the inner surface 574EW and the reflective surface 122. In some embodiments, in the state where the optical collector 120 and the debris shielding assembly 570 are coupled to each other as illustrated in FIG. 6B, the inner surface 574EW of the shield portion 574B may form an elliptic surface together with the reflective surface 122 of the optical collector 120. As the inner surface 574EW forms such an elliptic surface, interruption of travel paths of EUV light (LT) reflected from the reflective surface 122 caused by the shield portion 574B may be reduced. Although FIGS. 6A to 6C illustrate embodiments in which the debris shielding assembly 570 may include the protective film 272B, embodiments of the present disclosure are not limited thereto. For example, the debris shielding assembly 570 may include the protective film 272A as illustrated in FIGS. 2A and 2B. Although FIGS. 6A and 6B illustrate the embodiments that the debris shielding assembly 570 includes the fixing member 292, embodiments of the present disclosure are not limited thereto. In some embodiments, the debris shielding assembly 570 may include, instead of the fixing member 292, the fixing member 394 illustrated above with reference to FIGS. 4A and 4B. In some other embodiments, instead of including the first buffer film 278A, the second buffer film 278B, the outer fixing portion 574C, and the fixing member 292, the debris shielding assembly 570 illustrated in FIGS. 6A and 6B may include the protective film 272B, which may be directly adhered onto the shield portion 574B by pressing, or by using the fixing member 176 in a similar manner as described above with reference to FIG. 1. In the light generator 100 illustrated in FIG. 1, the debris shielding assembly 570 illustrated in FIGS. 6A and 6B may be employed instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 570 are coupled together, the protective film 272B and the shield portion 574B may shield the protective space 180 in front of the reflective surface 122 of the optical collector 120 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) is unlikely to flow into the protective space 180 and the reflective surface 122 of the optical collector 120 from the plasma generation space (PS), so that the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 7A is a cross-sectional view for explaining an example configuration of a debris shielding assembly 670 according to an embodiment, which may be used in the light generator according to embodiments of the present disclosure. FIG. 7B is a sectional view illustrating a state where the optical collector 120 and the debris shielding assembly 670 are coupled together. FIG. 7C is an enlarged view of a region “CX2” in FIG. 7B. FIG. 7D is an enlarged partial cross-sectional view for explaining the shield portion 674B in the protective frame 674 of the debris shielding assembly 670. In FIGS. 7A to 7D, like reference numerals as those in FIGS. 1 to 6C refer to like elements, and thus redundant descriptions thereof are omitted. Referring to FIGS. 7A to 7D, the debris shielding assembly 670 may have a substantially same configuration as the debris shielding assembly 570 described above with reference to FIGS. 6A to 6C. Unlike the debris shielding assembly 570, the debris shielding assembly 670 may include a protective frame 674 supporting the protective film 272B. A shield portion 674B of the protective frame 674 may include a shield frame 674F, and a reflective layer 674M on the shield frame 674F, the reflective layer 674M being exposed to the protective space 180. The reflective layer 674M may have a reflective surface 674EW facing the protective space 180 between the support portion 574A and the protective film 272B. The reflective surface 674EW may be a curved surface. In some embodiments, the reflective layer 674M may include a multilayer mirror. The multilayer mirror may include a stack structure in which a plurality of layers selected from among a Mo layer, a Si layer, a SiC layer, a B4C layer, a Mo2C layer, and a Si3N4 layer may be alternately stacked one another. In some embodiments, the reflective layer 674M may have a stack structure as illustrated in FIG. 7D. That is, the reflective layer 674M may include a plurality of first reflective layers M1, a plurality of second reflective layers M2, and a plurality of barrier layers BL stacked on the shield frame 674F. The first reflective layers M1 and the second reflective layers M2 may be alternately stacked one by one in the reflective layer 674M with one barrier layer BL between every adjacent two of the first reflective layer M1 and the second reflective layer M2. In some embodiments, the first reflective layer M1 may include, e.g., consist of, a Mo layer, and the second reflective layer M2 may include a Si layer. The barrier layer BL may include a material that may be maintained in a stable state at a high temperature of several hundreds of degrees Celsius (° C.) or greater. In some embodiments, the barrier layer BL may include, e.g., consist of, carbide or nitride. For example, the barrier layer BL may include a SiC layer, a B4C layer, a Mo2C layer, a Si3N4 layer, or a combination thereof. The barrier layer BL may prevent diffusion of atoms between the first reflective layer M1 and the second reflective layer M2 at a high temperature. Accordingly, even when the reflective layer 674M reaches a high-temperature condition while the light generator including the debris shielding assembly 670 is in operation, performance of the reflective layer 674M may not be deteriorated due to the barrier layer BL, and the reflective ability of the reflective layer 674M may be maintained. The reflective layer 674M may further include a capping layer CP. The capping layer CP may include ruthenium (Ru) or silicon oxide (SiO2). In the state where the optical collector 120 and the debris shielding assembly 670 are coupled together, a top surface of the capping layer CP of the reflective layer 674M may provide the reflective surface 674EW exposed to the protective space 180. The shield frame 674F may include a metal. For example, the shield frame 674F may include Al, stainless steel, Mo, or a combination thereof. As illustrated in FIG. 7C, the optical collector 120 may include a collector substrate 120S, and a collector reflective layer 120M on the collector substrate 120S, the collector reflective layer 120M providing the reflective surface 122. The collector reflective layer 120M may have a similar reflective structure to the reflective layer 674M of the shield portion 674B. The reflective layer 674M of the shield portion 674B may have a thickness smaller than that of the collector reflective layer 120M. However, embodiments of the present disclosure are not limited thereto. For example, the reflective layer 674M of the shield portion 674B and the collector reflective layer 120M may have the same thickness. In the state where the optical collector 120 and the debris shielding assembly 670 are coupled together, an edge portion of the reflective surface 674EW of the shield portion 674B and an edge portion of the reflective surface 122 of the optical collector 120 may contact each other. The reflective surface 674EW and the reflective surface 122 may smoothly extend forming one plane without a step difference in a contact region between the reflective surface 674EW and the reflective surface 122. In some embodiments, as illustrated in FIG. 7B, in the state where the optical collector 120 and the debris shielding assembly 670 are coupled together, the reflective surface 674EW of the shield portion 674B may form an elliptic surface together with the reflective surface 122 of the optical collector 120. The reflective surface 674EW of the shield portion 674B may contribute to, together with the reflective surface 122 of the optical collector 120, collecting and reflecting EUV light having a wavelength of about 1 nm to about 31 nm, e.g., about 13.5 nm, of light having various wavelengths radiated from the plasma. For example, the reflective surface 674EW of the shield portion 674B may selectively reflect EUV light having a wavelength of about 13.5 nm. Accordingly, in addition to the reflection efficiency of the optical collector 120, a reflection efficiency of the reflective surface 674EW of the shield portion 674B may be additionally provided, so that a collecting efficiency for EUV light may be improved in the light generator including the debris shielding assembly 670. Although FIGS. 7A and 7B illustrate embodiments in which the debris shielding assembly 670 includes the protective film 272B, embodiments of the present disclosure are not limited thereto. For example, the debris shielding assembly 670 may include the protective film 272A illustrated in FIGS. 2A and 2B. Although FIGS. 7A and 7B illustrate embodiments in which the debris shielding assembly 670 may include the fixing member 292, embodiments of the present disclosure are not limited thereto. In some embodiments, the debris shielding assembly 670 may include the fixing member 394 described with reference to FIGS. 4A and 4B, instead of the fixing member 292. In some other embodiments, instead of including the first buffer film 278A, the second buffer film 278B, the outer fixing portion 574C and the fixing member 292, the debris shielding assembly 670 illustrated in FIGS. 7A and 7B may include the protective film 272B, which may be directly adhered onto the shield portion 674B by pressing, or by using the fixing member 176 in a similar manner as described above with reference to FIG. 1. In the light generator 100 illustrated in FIG. 1, the debris shielding assembly 670 illustrated in FIGS. 7A and 7B may be employed instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 670 are coupled together, the protective film 272B and the shield portion 674B may shield the protective space 180 in front of the reflective surface 122 of the optical collector 120 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) is unlikely to flow into the protective space 180 and the reflective surface 122 of the optical collector 120 from the plasma generation space (PS), so that the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 8 is a cross-sectional view for explaining an example configuration of a debris shielding assembly 770 according to an embodiment, which may be used in the light generator according to embodiments of the present disclosure. In FIG. 8, like reference numerals as those in FIGS. 1 to 5C refer to like elements, and thus redundant descriptions thereof are omitted. Referring to FIG. 8, the debris shielding assembly 770 may have a substantially same configuration as the debris shielding assembly 470 illustrated in FIGS. 5A to 5C. Unlike the debris shielding assembly 470, the debris shielding assembly 770 may include the protective film 272B and a protective frame 774 supporting the protective film 272B. The protective frame 774 of the debris shielding assembly 770 may include a support portion 774A, a shield portion 774B, and an outer fixing portion 774C. The support portion 774A, the shield portion 774B, and the outer fixing portion 774C of the protective frame 774 may have substantially same configurations as the support portion 474A, the shield portion 474B, and the outer fixing portion 474C of the debris shielding assembly 470, respectively, as described above with reference to FIGS. 5A to 5C. Unlike the debris shielding assembly 470, the shield portion 774B may have an inner surface 774EW between the support portion 774A and the protective film 272B. In detail, the inner surface 774EW may be a curved surface. In the state where the debris shielding assembly 770 is coupled to the optical collector 120 illustrated in FIG. 5C, an edge portion of the inner surface 774EW of the shield portion 774B and an edge portion of the reflective surface 122 of the optical collector 120 may contact each other, and the inner surface 774EW and the reflective surface 122 may smoothly extend forming one plane without a step difference in a contact region between the inner surface 774EW and the reflective surface 122. In some embodiments, in the state where the debris shielding assembly 770 is coupled to the optical collector 120 illustrated in FIG. 5C, the inner surface 774EW of the shield portion 774B may form an elliptic surface together with the reflective surface 122 of the optical collector 120. Although FIG. 8 illustrates an embodiment in which the debris shielding assembly 770 may include the protective film 272B, embodiments of the present disclosure are not limited thereto. For example, the debris shielding assembly 770 may include the protective film 272A illustrated in FIGS. 2A and 2B. Although FIG. 8 illustrates an embodiment in which the debris shielding assembly 770 may include the fixing member 292. embodiments of the present disclosure are not limited thereto. In some embodiments, the debris shielding assembly 770 may include the fixing member 394 described above with reference to FIGS. 4A and 4B, instead of the fixing member 292. In some other embodiments, instead of including the first buffer film 478A, the second buffer film 478B, the outer fixing portion 774C, and the fixing member 292, the debris shielding assembly 770 illustrated in FIG. 8 may include the protective film 272B, which may be directly adhered onto the shield portion 774B by pressing, or by using the fixing member in a similar manner as described above with reference to FIG. 1. In the light generator 100 illustrated in FIG. 1, the debris shielding assembly 770 illustrated in FIG. 8 may be employed instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 770 are coupled together, the protective film 272B and the shield portion 774B may shield the protective space 180 in front of the reflective surface 122 of the optical collector 120 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) is unlikely to flow into the protective space 180 and the reflective surface 122 of the optical collector 120 from the plasma generation space (PS), so that the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 9 is a cross-sectional view for explaining an example configuration of a debris shielding assembly 870 according to an embodiment, which may be used in the light generator according to embodiments of the present disclosure. In FIG. 9, like reference numerals as those in FIGS. 1 to 8 refer to like elements, and thus redundant descriptions thereof are omitted. Referring to FIG. 9, the debris shielding assembly 870 may have a substantially same configuration as the debris shielding assembly 770 described above with reference to FIG. 8. Unlike the debris shielding assembly 770. the debris shielding assembly 870 may include a protective frame 874 supporting the protective film 272B. A shield portion 874B of the protective frame 874 may include a shield frame 874F, and a reflective layer 874M on the shield frame 874F. The reflective layer 874M may have a reflective surface 874EW between the support portion 774A and the protective film 272B. The reflective surface 874EW may be a curved surface. Detailed configurations of the shield frame 874F and the reflective layer 874M may be the same as those of the shield frame 674F and the reflective layer 674M, respectively, described above with reference to FIGS. 7A to 7D. In the state where the debris shielding assembly 870 is coupled to the optical collector 120 illustrated in FIG. 5C, an edge portion of the reflective surface 874EW of the shield portion 874B and an edge portion of the reflective surface 122 of the optical collector 120 may contact each other, and the reflective surface 874EW and the reflective surface 122 may smoothly extend forming one plane without a step difference in a contact region between the reflective surface 874EW and the reflective surface 122. In some embodiments, in the stage where the debris shielding assembly 870 is coupled to the optical collector 120 illustrated in FIG. 5C, the reflective surface 874EW of the shield portion 874B may form an elliptic surface together with the reflective surface 122 of the optical collector 120. The reflective surface 874EW of the shield portion 874B may contribute to, together with the reflective surface 122 of the optical collector 120, collecting and reflecting EUV light having a wavelength of about 1 nm to about 31 nm, for example, about 13.5 nm, of light having various wavelengths radiated from the plasma. For example, the reflective surface 874EW of the shield portion 874B may selectively reflect EUV light having a wavelength of about 13.5 nm. Accordingly, in addition to the reflection efficiency of the optical collector 120, a reflection efficiency by the reflective surface 874EW of the shield portion 874B may be additionally provided, so that a collecting efficiency for EUV light may be improved in the light generator including the debris shielding assembly 870. Although FIG. 9 illustrates an embodiment in which the debris shielding assembly 870 may include the protective film 272B, embodiments of the present disclosure are not limited thereto. For example, the debris shielding assembly 870 may include the protective film 272A illustrated in FIGS. 2A and 2B. Although FIG. 9 illustrates an embodiment in which the debris shielding assembly 870 may include the fixing member 292, embodiments of the present disclosure are not limited thereto. In some embodiments, the debris shielding assembly 870 may include the fixing member 394 described above with reference to FIGS. 4A and 4B, instead of the fixing member 292. In some other embodiments, instead of including the first buffer film 478A, the second buffer film 478B, the outer fixing portion 774C, and the fixing member 292, the debris shielding assembly 870 illustrated in FIG. 9 may include the protective film 272B, which may be directly adhered onto the shield portion 874B by pressing, or by using the fixing member 176 in a similar manner as described above with reference to FIG. 1. In the light generator 100 illustrated in FIG. 1, the debris shielding assembly 870 illustrated in FIG. 9 may be employed instead of the debris shielding assembly 170. In the state where the optical collector 120 and the debris shielding assembly 870 are coupled together, the protective film 272B and the shield portion 874B may shield the protective space 180 in front of the reflective surface 122 of the optical collector 120 from the plasma generation space (PS) (see FIG. 1). Accordingly, the debris generated in the plasma generation space (PS) is unlikely to flow into the protective space 180 and the reflective surface 122 of the optical collector 120 from the plasma generation space (PS), so that the reflective surface 122 of the optical collector 120 may be protected from contamination by the debris. FIG. 10 is a schematic view illustrating main elements of a photolithographic apparatus 1000 according to embodiments of the present disclosure. Referring to FIG. 10, the photolithographic apparatus 1000 may include a light generator 1100 according to embodiments of the present disclosure. In some embodiments, the light generator 1100 may include the light generator 100 according to an embodiment as illustrated in FIG. 1. In some embodiments, the light generator 1100 may include one of the debris shielding assemblies 170, 270A, 270B, 370, 470, 570, 670, 770, and 870 described above with reference to FIGS. 1 to 9. The photolithographic apparatus 1000 may include an illumination optical system 1200, a reticle stage 1300, a blinder 1400, a projection optical system 1500, and a wafer stage 1600. The EUV light (“LT” in FIG. 10) generated from the light generator 1100 may be radiated toward the illumination optical system 1200. The EUV light LT may have a wavelength of about 1 nm to about 31 nm, e.g., about 13.5 nm. The illumination optical system 1200 may include a plurality of mirrors 1210, 1220, 1230, and 1240. The plurality of mirrors 1210, 1220, 1230, and 1240 may focus and transmit the EUV light LT to reduce a loss of the EUV light LT. The plurality of mirrors 1210, 1220, 1230, and 1240 may uniformly control a EUV light LT intensity distribution overall. The plurality of mirrors 1210, 1220, 1230, and 1240 may include a concave mirror, a convex mirror, or a combination thereto to verify paths of the EUV light LT. In FIG. 10, although the illumination optical system 1200 is illustrated as including four mirrors 1210, 1220, 1230, and 1240, the number and locations of the mirrors in the illumination optical system 1200 are not limited to the embodiment illustrated in FIG. 10. and various modifications and changes may made thereto. The illumination optical system 1200 may include a separate vacuum chamber. The illumination optical system 1200 may include various lenses and optical elements not described above. The reticle stage 1300 may move in a horizontal direction as indicated by arrows AR1 and AR2 in FIG. 10, with a reticle R mounted on an electrostatic chuck therein. The reticle R may be mounted on a lower surface of the reticle stage 1300 such that optical patterns on a surface of the reticle R face downwards. The blinder 1400 may be disposed under the reticle stage 1300. The blinder 1400 may include a slit S. The slit S may shape the EUV light LT transmitted from the illumination optical system 1200 to the reticle R mounted on the reticle stage 1300. The EUV light LT transmitted from the illumination optical system 1200 may radiate a surface of the reticle R through the slit S of the blinder 1400. The EUV light (LT) reflected from the reticle R fixed to the reticle stage 1300 may be transmitted to the projection optical system 1500 through the slit S. The projection optical system 1500 may receive the EUV light (LT) passed through the slit S and transmit the EUV light (LT) to a wafer W. The projection optical system 1500 may perform reduction projection of the patterns on the reticle R onto the wafer W. The projection optical system 1500 may include a plurality of mirrors 1510, 1520, 1530, 1540, 1550, and 1560. The plurality of mirrors 1510, 1520, 1530, 1540, 1550, and 1560 may correct various aberrations. In FIG. 10, although the projection optical system 1500 is illustrated as including six mirrors 1510, 1520, 1530, 1540, 1550, and 1560, the number and locations of the mirrors in the projection optical system 1500 are not limited to the embodiment illustrated in FIG. 10, and various modifications and changes may made thereto. The wafer stage 1600 may move in a horizontal direction as indicated by arrows AR3 and AR4. In FIG. 10, the traveling paths of the EUV light (LT) are only for illustrative purposes, and the present disclosure of the present application is not limited to the embodiment illustrated in FIG. 10. Although the photolithographic apparatus 1000 including the light generator 1100 according to embodiments of the present disclosure are described with reference to FIG. 10, embodiments of the present disclosure are not limited thereto. For example, the light generator 1100 according to embodiments of the present disclosure may be applied to a test apparatus using the EUV light generated in the light generator 1100. In some embodiments, the test apparatus may be an apparatus for testing a reticle or a substrate. In some other embodiments, the test apparatus may be metrology equipment for measuring or monitoring process variations such as focus, overlay, critical dimension, and the like. FIG. 11 is a flowchart of a method of manufacturing an integrated circuit (IC) device, according to embodiments of the present disclosure. Referring to FIG. 11, in an operation P2100, a photoresist layer may be formed on a substrate having a feature layer. The substrate may include a semiconductor element such as silicon (Si) or germanium (Ge), or a compound semiconductor such as silicon carbide (SiC), gallium arsenide (GaAS), indium arsenide (InAs), and indium phosphide (InP). In some embodiments, the substrate may have a silicon on insulator (SOI) structure. For example, the substrate may include a buried oxide (BOX) layer. In some embodiments, the substrate may include a conductive region, for example, a well doped with impurities or a structure doped with impurities. The substrate may have various device isolation structures. for example, a shallow trench isolation (STI) structure. The substrate may have a structure including at least one layer of an insulating layer, a conductive layer, a semiconductor layer, a metal layer, a metal oxide layer, a metal nitride layer, a polymer layer, or a combination thereof on a semiconductor wafer. In some embodiments, the substrate may include a semiconductor wafer. The feature layer may be formed on the semiconductor wafer. In this case, the feature layer may be a conductive layer or an insulating layer. For example, the feature layer may include a metal, a semiconductor, or an insulating material. In some embodiments, the feature layer may be a part of the substrate. The photoresist layer may cover the feature layer. The photoresist layer may include a resist material for EUV light (13.5 nm). Referring to FIGS. 10 and 11, in an operation P2200, the substrate having the photoresist layer formed thereon may be loaded on a reticle stage 1300 of the photolithographic apparatus 1000. Referring to FIGS. 10 and 11, in an operation P2300, the photoresist layer may be exposed using the EUV light (LT) generated in the light generator 1100 of the photolithographic apparatus 1000. Referring to FIG. 11, in an operation P2400, the exposed photoresist layer may be developed to thereby form a photoresist pattern. Referring to FIG. 11, in operation P2500, the feature layer may be processed by using the photoresist pattern. In some embodiments, to process the feature layer, the feature layer may be etched using the photoresist pattern as an etch mask to thereby form a feature pattern. In some other embodiments, to process the feature layer, impurity ions may be implanted into the feature layer using the photoresist pattern as an ion implantation mask. In some other embodiments, to process the feature layer, a separate process film may be formed on the feature layer that is exposed through the photoresist pattern formed in operation P2400. The process film may be a conductive layer, an insulating layer, a semiconductor layer, or a combination thereof. FIG. 12 is a block diagram of a memory system 3000 including an integrated circuit (IC) device manufactured by using the method of manufacturing an IC device, according to embodiments of the present disclosure. Referring to FIG. 12, the memory system 3000 may include a memory card 3010. The memory system 3000 may include a modern 3020 that may communicate via a common bus 3060, a processor 3030 such as a central processing unit (CPU), random access memory 3040, and a user interface 3050. These elements may transmit signals to the memory card 3010 through common bus 3060 and may receive signals from the memory card 3010. The memory system 3000 may include an IC device manufactured using the method described above with reference to FIG. 11. The memory system 3000 may be applicable to various electronic systems, for example, solid state disks (SSDs), CMOS image sensors (CISs), computer systems, or the like. The IC devices disclosed herein may be encapsulated using any one of a ball grid array (BGA) technique, a chip scale package (CSP) technique, a plastic leaded chip carrier (PLCC) technique, a plastic dual in-line package (PDIP) technique, a multi-chip package (MCP) technique, a wafer-level fabricated package (WFP) technique, a wafer-level processed stack package (WSP) technique, and the like. However, embodiments of the present disclosure are not limited thereto. By way of summation and review, in order to generate EUV light in the photolithographic apparatus. laser light may be radiated onto a target material in a vacuum chamber to convert the target material into a plasma state. However, debris. e.g., particles from the target material not converted into plasma, may be deposited on surfaces of optical elements in the vacuum chamber, thereby lowering operation efficiency thereof, e.g., reflectance or transmittance of the optical elements. Attempts have been made to periodically clean the optical elements using various cleaning gases or radicals from such gases. However, such cleaning may increase the process unit price. Further, although the optical elements may be partially cleaned by cleaning gases or radicals, repeated deposition of the debris separated from the target material may lower optical characteristics, e.g., reflectance, of the optical elements or may deteriorate surfaces of the optical elements, consequently lowering durability of the optical elements. In contrast, as described above with respect to one or more embodiments, a light generator according to the present disclosure may include a debris shielding assembly installed between optical elements which are prone to contamination by debris, and a plasma generation space (PS) in a chamber. Accordingly, the internal environment of the chamber may be maintained under a stable operation condition only by periodic cleaning and/or replacement of the components of the debris shielding assembly, without cleaning the optical elements in the chamber. As such, without the need to perform the cleaning process using a gas source, which may increase the process cost and deteriorate the optical elements, contamination of the optical elements by debris and consequential productivity reduction may be prevented. By inclusion of the light generator according to embodiments of the present disclosure, a photolithographic apparatus according to the present disclosure may lower the manufacturing cost and improve productivity in the process of manufacturing an IC device using the photolithographic apparatus. That is, the provided light generator may prevent a reduction in operation efficiency of optical elements exposed in an optical path and increase the lifespan of the optical elements and may prolong a preventive maintenance (PM) cycle for cleaning and/or replacing parts of the optical elements. Further, the provided photolithographic apparatus may prevent a reduction in operation efficiency of optical elements exposed in an optical path and increase the lifespan of the optical elements and may prolong a PM cycle for cleaning and/or replacing parts of the optical elements, thereby lowering a manufacturing cost of integrated circuit (IC) devices and improving productivity. Finally, the provided method of manufacturing the IC device reduces the manufacturing costs and improves productivity. Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
	description	This application is a Continuation of PCT/EP2010/065707 filed Oct. 19, 2010, which in turn claims priority to European Patent Application No.: 09173989.6, filed on Oct. 23, 2009. The present invention relates to a charged particle therapy apparatus used for radiation therapy. More particularly, this invention relates to a rotatable gantry designed for receiving a charged particle beam in a direction substantially along a rotation axis of the gantry, for transporting and for delivering said beam to a target to be treated. Radiotherapy using charged particles (e.g. protons, carbon ions, . . . ) has proven to be a precise and conformal radiation therapy technique where a high dose to a target volume can be delivered while minimizing the dose to surrounding healthy tissues. In general, a particle therapy apparatus comprises an accelerator producing energetic charged particles, a beam transport system for guiding the particle beam to one or more treatment rooms and, for each treatment room, a particle beam delivery system. One can distinguish between two types of beam delivery systems, fixed beam delivery systems delivering the beam to the target from a fixed irradiation direction and rotating beam delivery systems capable of delivering beam to the target from multiple irradiation directions. Such a rotating beam delivery system is further named gantry. The target is generally positioned at a fixed position defined by the crossing of the rotation axis of the gantry and the central treatment beam axis. This crossing point is called isocenter and gantries of this type capable of delivering beams from various directions to the isocenter are called isocentric gantries. The gantry beam delivery system comprises devices for shaping the beam to match the target. There are two major techniques used in particle beam therapy to shape the beam: the more common passive scattering techniques and the more advanced dynamic radiation techniques. An example of a dynamic radiation technique is the so-called pencil beam scanning (PBS) technique. In PBS a narrow pencil beam is magnetically scanned across a plane orthogonal to the central beam axis. Lateral conformity in the target volume is obtained by adequate control of the scanning magnets. Depth conformity in the target volume is obtained by adequate control of the beam energy. In this way, a particle radiation dose can be delivered to the entire 3D target volume. The particle beam energies required to have sufficient penetration depth in the patient depend on the type of particles used. For example, for proton therapy, proton beam energies are typically ranging between 70 MeV and 250 MeV. For each required penetration depth the beam energy needs to be varied. The energy spread of the beam should be limited as this directly influences the so-called distal dose fall-off. However, not all accelerator types can vary the energy. For fixed energy accelerators (e.g. a fixed isochronous cyclotron) typically an energy selection system (ESS) is installed between the exit of the accelerator and the treatment room as shown in FIGS. 1, 2 and 3. Such an energy selection system is described by Jongen et al. in “The proton therapy system for the NPTC: equipment description and progress report”, Nuc. Instr. Meth. In Phys. Res. B 113 (1996) 522-525. The function of the Energy Selection System (ESS) is to transform the fixed energy beam extracted from the cyclotron (e.g. 230 MeV or 250 MeV for protons) into a beam having an energy variable between the cyclotron fixed energy down to a required minimum energy (for example 70 MeV for protons). The resulting beam must have a verified and controlled absolute energy, energy spread and emittance. The first element of the ESS is a carbon energy degrader which allows to degrade the energy by putting carbon elements of a given thickness across the beam line. Such an energy degrader is described in patent EP1145605. As a result of this energy degradation, there is an increase in emittance and energy spread of the beam. The degrader is followed by emittance slits to limit the beam emittance and by a momentum or energy analysing and selection device to restore (i.e. to limit) the energy spread in the beam. A layout of such a known energy selection system 10 is shown in FIG. 1 together with a stationary, fixed energy accelerator 40 (in this example a cyclotron). After the degrader and emittance limiting slits, the beam passes through a 120° achromatic bend made up of two groups of two 30° bends. To meet the specification for the distal fall off, the momentum spread or the energy spread in the beam is limited by a slit placed at the center of the bend. The beam is focused by quadrupoles before the bend and between the two groups of two 30° bending magnets so that the emittance width of the beam is small and the dispersion is large at the position of the slit. The entire beam line starting at the energy degrader 41 up to the treatment isocenter 50 forms an optical system that is achromatic, i.e. a beam-optical system which has imaging properties independent from momentum (dispersionless) and independent from its transverse position. The beam line can be divided in multiple sections and each section is forming itself an achromat. As shown in FIG. 2, the first section is the ESS 10 followed by an achromatic beamline section that brings the beam up to the entrance point of a treatment room. In the case of a gantry treatment room, this entrance point is the entrance point or coupling point of the rotating gantry 15. The gantry beam line is then forming a third achromatic beam line section. In the case of a single treatment room particle therapy configuration, as shown in FIG. 3, the beam line comprises two achromatic beam line sections: a first section is the ESS 10 that brings the beam up to the gantry entrance point and the second achromatic section corresponds to the rotating gantry 15 beam line. At the gantry entrance point, the beam must have the same emittance in X and Y in order to have a gantry beam optics solution that is independent from the gantry rotation angle. The X and Y axis are perpendicular to each other and to the central beam trajectory. The X axis is in the bending plane of the dipole magnets. A disadvantage of the use of such a degrader and energy analyzer is that this device requires a relative large space area as shown in FIG. 1 and hence a large building footprint is required. The installation of an ESS results also in an extra equipment cost. The present invention aims to provide a solution to overcome at least partially the problems of the prior art. It is an objective of the present invention to provide a charged particle therapy apparatus that has a reduced size and that can be built at a reduced cost when compared to the prior art particle therapy apparatus. The present invention is set forth and characterized by the appended claims. In the prior art particle therapy configurations as shown for example in FIGS. 1 to 3, the functionalities of limiting the momentum spread (or energy spread, which is equivalent) and the emittance of the beam is performed by a separate device, namely with the energy selection system (ESS) 10, which is installed between the stationary accelerator 40 and the rotating gantry 15,. As shown on FIG. 1, a first element of the ESS is an energy degrader 41 which is used to degrade the energy of the particle beam of the fixed-energy accelerator 40. With the present invention, a rotatable gantry beam delivery system is provided having a gantry beam line configuration which fulfils multiple functions: The known function of transporting, bending and shaping an entering particle beam in such a way that a particle treatment beam can be delivered at a gantry treatment isocenter for use in particle therapy; The additional function of limiting the energy spread of the entering particle beam to a selected maximum value.With the present invention, the ESS functionality of limiting the energy spread or momentum spread of the beam to a selected value is performed by the gantry system itself. Hence the size and cost of a particle therapy facility can be reduced.In the context of the present invention, the momentum spread is defined as the standard deviation of the momentums of the particles at a given location and is expressed as a percentage of the average momentum of all particles at this location. Whatever the location of the means for limiting the momentum spread in the gantry, these means are preferably designed for limiting said momentum spread to 10%, more preferably to 5%, and even more preferably to 1% of the average momentum of all particles. Preferably, the gantry also fulfils a second additional function of limiting the transverse beam emittance of the entering particle beam to a selected maximum value, which further reduces cost and size of the particle therapy facility. More preferably, the gantry according to the invention also comprises a collimator installed in-between the gantry entrance point and a first quadrupole magnet in the gantry. This collimator is used for reducing the emittance of the beam before the beam is arriving at the first magnet in the gantry beam line. In an alternative preferred embodiment, the above mentioned collimator is installed outside of the gantry, i.e. in-between the energy degrader and the entrance point of the gantry. According to the invention, a particle therapy apparatus is also provided comprising a stationary particle accelerator, an energy degrader and a rotatable gantry having means to limit the momentum spread of the beam. Preferably said gantry also comprises means to limit the emittance of the beam. Alternatively, a particle therapy apparatus is provided comprising a stationary particle accelerator, an energy degrader, a rotatable gantry comprising means to limit the momentum spread of the beam and a collimator installed in-between said energy degrader and said gantry for limiting the emittance of the beam. More preferably, said gantry comprises additional means to limit the emittance of the beam. The present invention will now be described in detail in relation to the appended drawings. However, it is evident that a person skilled in the art may conceive several equivalent embodiments or other ways of executing the present invention. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. A exemplary particle therapy configuration according to the invention is shown in FIG. 4. In this example, the rotatable gantry according to the invention is coupled with a stationary-, fixed energy-particle accelerator 40 to form a single room particle therapy apparatus 100. An example of a particle accelerator for protons is a superconducting synchrocyclotron which has a compact geometry (e.g. with an extraction radius of 1.2 m). The gantry according to the invention is installed in the gantry room and a shielding wall (e.g. a 1.7 m thick concrete wall) separates the gantry room from the accelerator room. An energy degrader 41 is installed between the accelerator 40 and a gantry entrance point 45 (coupling point) . This energy degrader 41 is positioned within the accelerator room just in front of the shielding wall 52 separating the accelerator room from the gantry room. The gantry entrance point 45 is located after the degrader 41 and is an entrance window for the beam line of the gantry. This entrance window 45 is the first part of a gantry beam line section where the beam is entering the gantry in a direction substantially along the rotation axis of the gantry. The rotation axis of the gantry is indicated by a horizontal dash-dotted line passing through the isocentrer 50 and the entrance point 45. As shown in FIG. 4, there is no momentum or energy analyser device installed between the degrader and the gantry entrance point as is the case in the prior art systems (FIGS. 1 to 3). Similar as in the prior art configurations shown in FIGS. 1 to 3, there is a short beam line section between the exit of the accelerator and the degrader 41, where for example two quadrupole magnets 44 are installed for transporting and focussing the beam into a small spot (for example between 0.5 mm and 2 mm one sigma) at the energy degrader. The energy degrader 41 is for example a rapidly adjustable, servo controlled, rotating, variable thickness, cylinder of degrading material (as disclosed in EP1145605). The distance between the exit of the accelerator and the degrader can be about 2 m. Other types of energy degrading systems, e.g. lateral moving wedge shaped based degraders can be used as well. The energy degrader currently used by the applicant has at its entrance an integrated horizontal-vertical beam profile monitor which allows measurement of the size and position of the beam spot and, through a control system algorithm, means for automatic tuning of the up-stream beam optics. Hence, the beam at the degrader 41 can be well defined, for example, the beam is focused into a small waist with a half width not exceeding 2 mm in both planes. With these input beam conditions, the output emittance of the beam degraded in energy is dominated by multiple scattering in the degrader and is relatively independent from the input conditions. The resulting beam after energy degradation can be considered as a diverging beam from a virtual waist in X and Y at the degrader with a given size and divergence. The two orthogonal coordinate axis X and Y are perpendicular (transverse) to the central beam trajectory. The emittances in X and Y (also called “transverse emittances”) can be considered to be substantially identical at this point. The larger the energy reduction introduced by the degrader, the larger will be the transversal emittance in X and Y and the larger will be the momentum spread of the degraded beam. The embodiment of the invention is a gantry configuration comprising means 43 to limit the momentum spread of the incoming beam. A beam entering the gantry comprising particles having an average momentum value and a momentum spread. To limit the momentum spread of the incoming beam, a pair of momentum analyzing slits 43 are installed in the gantry. These momentum analyzing slits 43 are preferably located at a position along the beam path where the particles of the beam are dispersed according to their momentum. More preferably, these slits are installed at a position where the nominal dispersion is larger than the nominal beam size. The nominal dispersion is defined as a transversal displacement of a particle whose momentum differs by 1% (one percent) of an average momentum P of all particles of the beam. The nominal beam size is defined as the one sigma beam size value in X of a mono-energetic particle beam having the average momentum P. Suppose that the nominal dispersion is 2.5 cm: this means that a particle having a momentum P′=1.01.P will be displaced by 2.5 cm in X from a particle having momentum P. In this example, a particle having a momentum P′=0.99.P will also be displaced in X by 2.5 cm but having an X coordinate with an opposite sign. The momentum limiting slits can for example be installed at a position where the nominal beam size in X is between 0.2 cm and 1 cm and the nominal dispersion in X is between 1 cm and 3 cm. By opening or closing the slits, the maximum momentum spread that is required (selected) can be obtained. One can for example select to limit the maximum momentum spread to 0.5% of the average momentum by adjusting the slits correspondingly. If one wants to limit the maximum momentum spread to 0.4% of the average momentum, then one has to close the pair of momentum slits more. For this purpose a calibration curve can be established, defining the slit opening as function of the required momentum spread. In the configuration of FIG. 4, the nominal dispersion is large in comparison with the beam size at a position in-between gantry quadrupole magnet number seven and the second dipole magnet 48 and hence this is a preferred position to install the momentum spread limiting slits. These slits can for example be installed just before the second dipole magnet 48. The exact position can vary depending on the detailed gantry configuration. Instead of using a pair of slits as means for reducing the momentum spread of the beam, other means can be used as well. For example one can use apertures or collimators with various diameters which can be put in the beam line, preferably at the above discussed positions. In the example shown in FIG. 4, a gantry for delivering scanning beams at the treatment isocenter 50 is presented and the beam line of this gantry comprises three dipole magnets 47,48,49 and seven quadrupole magnets 44. In this gantry configuration, scanning magnets 46 are installed upstream of the last dipole magnet 49. Between the gantry entrance point 45 and the first dipole magnet and in between the first and second dipole magnet there are respectively, two and five quadrupole magnets. Preferably, in addition to the means 43 to limit the momentum spread of the beam, also means 42 to limit the transverse beam emittance can be installed in the gantry 15. For this purpose, two pairs of slits (in X and Y) limiting the beam divergence can for example be installed in-between the second quadrupole magnet and the first dipole magnet 47. Hence, by limiting the divergence of the beam, the transverse beam emittance, which is proportional to the beam divergence, is limited. The first two quadrupoles installed in the gantry in-between the entrance point 45 and the first dipole magnet 47 serve to focus the divergent beam, originating from the degrader, before the beam reaches the divergence limiting slits. To what extent the beam emittance needs to be reduced will depend on what the maximum emittance the gantry can accept to efficiently transport the beam and it will also depend on what the beam requirements are at the treatment isocenter (such as for example the beam size required at the treatment isocenter). Acceptable beam emittances and beam sizes may depend on the technique used for shaping the beam (e.g. pencil beam scanning or passive scattering). The example given in FIG. 4 is for a scanning beam delivery system. For a pencil beam proton scanning system the beam emittance can for example be limited to 7.5 Pi mm mrad in both X and Y. For practical beam tuning purposes, just in front, downstream, of the divergence limiting or emittance limiting slits, a beam profile monitor can be installed (not shown on FIG. 4). Instead of using a pair of slits in X and Y as means for reducing the divergence of the beam, other means can be used as well. For example one can use apertures or collimators with various diameters which can be put in the beam line. If the energy reduction of the beam is very large (e.g. reduction of 250 MeV protons down to 70 MeV), the emittance and divergence of the beam becomes very large and the diameter of the beam, just before the first quadrupole magnet in the gantry, can become larger than the diameter of the beam line pipe. For this purpose a collimator (not shown in FIG. 4) can furthermore be installed upstream of the first quadrupole magnet in the gantry 15 to cut off already a part of the beam. This collimator can be installed in the gantry 15 in-between the entrance point 45 and the first quadrupole magnet of the gantry. Alternatively, such a collimator can be installed outside the gantry, i.e. in-between the degrader and the entrance point 45 of the gantry 15. When such a collimator for limiting the emittance of the beam is installed in either of the two positions mentioned above, in an alternative gantry embodiment the means 42 for limiting the emittance can be omitted. When a particle beam hits divergence and/or momentum limiting slits, neutrons are produced. To limit the neutron radiation at the level of the treatment isocenter 50 where the patient is positioned, adequate shielding need to be provided. As neutrons are mainly emitted in the direction of the beam, one can install just after the first dipole magnet, across the axis of rotation of the gantry, a neutron shielding plug 51 to shield the neutrons produced on means to limit the emittance of the beam installed upstream of the first dipole magnet 47. As the neutrons are mainly emitted in the direction of the beam, neutrons produced at the momentum limiting slits 43 are not directing to the patient. Nevertheless, a local neutron shielding (not shown on FIG. 4) can be installed around the momentum limiting slits 43 in order to reduce overall neutron background radiation. In order not to overload FIG. 4, details of the mechanical construction of the gantry have been omitted on purpose. Examples of such mechanical elements not shown on FIG. 4 are: two spherical roller bearings for rotating the gantry by at least 180° around the patient, a gantry drive and braking system, a drum structure for supporting a cable spool, a counterweight needed to get the gantry balanced in rotation, . . . When designing a gantry for particle therapy, several beam optical conditions need to be fulfilled. At the gantry entrance point 45 the beam must have identical emittance parameters in X and Y in order to have a gantry beam optics solution that is independent from the gantry rotation angle. As discussed above, these conditions are naturally fulfilled when placing the energy degrader just in front of the gantry entrance point. In addition, the following beam optical conditions need to be met: 1. The gantry beam-optical system must be double achromatic, i.e. the beam imaging properties must be independent from momentum (dispersionless) and independent from position. 2. The maximum size of the beam (one sigma) inside the quadrupoles should preferably not exceed 2 cm in order to keep a reasonable transmission efficiency in the gantry.There is also a third condition that however can vary depending on the technique used for shaping the beam as discussed above. For a scanning system this third condition can be described as follows: 3. At the isocenter 50 the beam must have a small waist, of substantially identical size in X and Y.For a scattering system, required beam sizes can be specified more upstream of the isocenter (for example at the exit of the last bending magnet) and the acceptable beam sizes for scattering are in general larger than for scanning (for example 1 cm at the exit of the last bending magnet)In addition to these three conditions (1 to 3), new requirements are introduced resulting from the current invention: 4. At the position of the energy spread limiting slits 43, the nominal dispersion in X should preferably be large in comparison with the nominal beam size in X (for examples of values see discussion above).Preferably, a gantry according to the invention also comprises means to limit the emittance of the beam. This results in an additional requirement: 5. At the position of the emittance limiting slits 42, the beam must have beam optical parameters (size and divergence) in X and Y that allow to cut the divergence. This means for example that the beam must have a reasonable size (e.g. 0.5 cm to 2 cm, one sigma). The gantry configuration shown in FIG. 4 is based on a beam optical study performed with the beam optics “TRANSPORT” code (PSI Graphic Transport Framework by U. Rohrer based on a CERN-SLAC-FERMILAB version by K. L. Brown et al.). The beam envelopes in X and Y in the gantry beam line for an entering proton beam of 170 MeV are shown in FIG. 5 as an example. The beam envelopes are plotted for the X direction and Y direction in the lower panel and upper panel, respectively. In this example the emittance of the final beam is 12.5 Pi mm mrad. This corresponds to a situation where the divergence of the incoming beam has been limited to 6 mrad in X and Y. The beam transported through the system can then be considered as a beam starting at the degrader with a small beam spot of 1.25 mm and a divergence of 6 mrad. With this beam optics a beam size at the treatment isocenter of 3.2 mm (one sigma value) is obtained which is an adequate value for performing pencil beam scanning. The positions of the quadrupole magnets and dipole magnets are shown on FIG. 5. The transversal positions of the dipole magnets (the vertical gaps) are not shown on scale in this figure and the purpose is only to indicate their position along the central trajectory. Especially the gap in X an Y of the last bending magnet 49 are much larger than on the scale of FIG. 5 as a large opening is needed because the scanning magnets are positioned upstream of this dipole magnet and a large scanning area need to be covered at isocenter. The position of the scanning magnets along the beam path is indicated by a vertical line. The dotted line represents the nominal dispersion in X of the beam. As shown, just before the second dipole magnet 48 a large nominal dispersion value is obtained and this is the position where the momentum limiting slits 43 are preferably installed. The position along the central beam trajectory of the momentum limiting slits 43 is indicated by a vertical line on FIG. 5. The nominal beam size in X at the momentum limiting slits is about 0.23 cm while the nominal dispersion in X at this position is about 2.56 cm, hence obtaining a good momentum separation of the incoming beam. Preferably, also divergence limiting slits 42 are used. A good position for these slits 42 is indicated on FIG. 5 by a vertical line. At this position, the beam size in X and Y is about 1.8 cm and 0.6 cm, respectively. This beam optical solution presented fulfils the conditions of a double achromat. In the example shown in FIG. 4 and FIG. 5, a three dipole gantry configuration was used with dipole bending angles of respectively 36°, 66° and 60°. However, the invention is not limited to a specific gantry configuration for what concerns number of dipoles or bending angles of the dipoles. The invention is neither limited to the number of quadrupole magnets and the relative positions of the quadrupoles with respect to the dipole magnets. As a second example, the invention has been applied to a conical two dipole large throw gantry. This corresponds to the gantry configuration shown on FIG. 2 and FIG. 3. These large throw gantries have been built by the applicant and are discussed by Pavlovic in “Beam-optics study of the gantry beam delivery system for light-ion cancer therapy”, Nucl. Instr. Meth. In Phys. Res. A 399(1997) on page 440. In these gantries a first 45° dipole magnet bends the beam away from the axis of rotation of the gantry and the beam then further follows a second straight beam line section before entering the second 135° dipole magnet which is bending and directing the beam essentially perpendicular to the axis of rotation. The straight beam line section between the gantry entrance point and the first 45° dipole magnet comprises, in the original gantry design, four quadrupole magnets (FIG. 2 is a configuration having only two quadrupole magnets installed in this beam line section), and the second straight section between the first and second dipole magnet comprises five quadrupole magnets. With this gantry the distance between the exit of the last bending magnet and the treatment isocenter is 3 m and the beam shaping elements configured in a so-called nozzle are installed upstream of the last bending magnet. This nozzle uses either the passive scattering technique or the scanning technique for shaping the beam conform the treatment target. The scanning magnets are part of the nozzle and are hence installed downstream of the last gantry dipole magnet. A beam optical analysis has been performed for this two dipole gantry configuration. The same conditions and requirements as discussed above have been respected. The resulting beam envelopes in this gantry are shown in FIG. 6 for a proton beam of 160 MeV. The beam envelopes are plotted for the X direction and Y direction in the lower panel and upper panel, respectively. The positions along the central beam path of the 45° dipole magnet 67, the 135° dipole magnet 68 and the various quadrupole magnets 44 are indicated in FIG. 6. Also here the energy degrader is installed just before the entrance window of the gantry and, as an example, in this calculation the divergence was cut at 8 mrad and the emittance of the final beam is 10 Pi mm mrad both in X and Y. The beam envelope as shown in FIG. 6 starts at the gantry entrance window and the beam has a size of 1.25 mm (one sigma value). In this gantry configuration the first straight section between the entrance window and the first 45° gantry bending magnet 67, comprises four quadrupole magnets 44. Divergence limiting devices 42 are installed in between the second and third quadruople magnet and are indicated by a vertical line on FIG. 6. The momentum spread limiting slits 43 are installed at a position where the nominal dispersion in X is large compared to the nominal beam size. The dotted line on FIG. 6 represents the nominal dispersion in X of the beam. The position of the momentum spread limiting slits 43 are indicated by a vertical line on FIG. 6. At this position the nominal dispersion is about 2.6 cm in X and the nominal beam size in X (one sigma value) is about 0.6 cm which is adequate for analysing the incoming beam according to momentum and limiting the momentum spread to a given value by setting the slits at the corresponding position. The beam envelope shown in FIG. 6 is a tuning solution for a nozzle using the scanning technique (the scanning magnets are installed downstream of the 135° dipole magnet but are not shown on FIG. 6). This gantry configuration used in this beam optics study also comprises two quadrupole magnets installed upstream of the 135° last dipole magnet 68 as indicated on FIG. 6. With this tuning solution, a double waist in X and Y is obtained at isocenter having a beam size of 4 mm (one sigma value), which is suitable for performing pencil beam scanning. This beam optical solution fulfils the conditions of a double achromat. A particle therapy apparatus 100 can be formed by combining a stationary, fixed energy particle accelerator, an energy degrader and a rotatable gantry according to the invention, i.e. a rotatable gantry comprising means for limiting the energy spread or momentum spread of the beam and preferably also comprising means for limiting the emittance of the beam. As shown on FIG. 4, which is an example of a proton therapy apparatus, a compact geometry can be obtained and the building footprint that is needed to install this apparatus is smaller than with a separate energy selection system. Although the embodiments described are focussing on proton gantries, the invention is not limited to proton gantries. The person skilled in the art can easily apply the elements of the invention, i.e. means for analyzing the beam (limiting the emittance and limiting the energy spread), to gantries for use with any type of charged particles such as e.g. a gantry for carbon ions or other light ions. Gantries for particle therapy have been designed since many years and, in combination with stationary, fixed energy particle accelerators, a separate energy selection system was always installed in the beam line between the accelerator and the gantry. According to the present invention a new gantry configuration is provided comprising means for limiting the energy spread or momentum spread of the beam and preferably also comprising means for limiting the emittance of the beam. Hence the gantry itself comprises functionalities of the standard prior art energy selection system. By designing a gantry with these means to analyse the beam as described, a more compact particle therapy apparatus can be built.

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