Split (2)

train · 33.5k rows

patent_number stringlengths 0 9	section stringclasses 4 values	raw_text stringlengths 0 954k
048715107	abstract	A fuel assembly of the present invention comprises fuel rods which are arranged in 9 rows and 9 columns (9.times.9) in a channel box. The channel box has a width L between outer walls thereof and a width D between inner walls thereof, both of which satisfy the following equation: EQU 0.12.ltoreq.(P-L)/D. wherein P denotes the fuel assembly pitch in a reactor core. A sufficient cold shutdown margin for a reactor core can be secured by determining the widths L and D so as to satisfy the above-described equation, even if the average enrichment of the fuel assembly is increased to 4 wt % or more.
	description	Branching Division Several embodiments of methods, according to the invention, for calculating cumulative exposure dose are set forth below. As a preface, the xe2x80x9cbranching divisionxe2x80x9d of regions, used in calculating cumulative exposure dose, is described first, referring first to FIG. 1. Branching division of a region according to the invention yields a xe2x80x9cbranching structurexe2x80x9d of the region as used in various embodiments described below. FIG. 1 schematically depicts a region of a reticle pattern. The region includes multiple pattern elements (not shown) and is the subject of a calculation performed to determine the cumulative dose of exposure energy to be received by the region. The results of such a calculation will be used in configuring the pattern elements, as defined in the region on the reticle, in a manner that decreases the proximity effect experienced when the region is exposed onto the substrate. The region shown in FIG. 1 is divided into eight columns and eight rows, yielding a total of 64 subregions. Each subregion has a unique identifying number 1-64, respectively. In each subregion 1-64, the number in parentheses denotes the respective number of pattern elements contained in the subregion. As a first example, when performing a branching division, the region is divided equally, horizontally and vertically, into four equally sized portions (i.e., divided into two columns and two rows). Each portion is divided further, horizontally and vertically, (according to certain rules as discussed below) into four smaller equally sized portions, and so on. As a second example, a region is divided into nine equally sized portions (i.e., divided equally horizontally and vertically to form three columns and three rows), and each portion is divided further (according to certain design rules) into nine smaller equally sized portions, and so on. As a third example, a region can be divided initially into sixteen equally sized portions (i.e., divided equally horizontally and vertical to produce four columns and four rows) or twenty-five equally sized portions (i.e., divided equally horizontally and vertically to produce five columns and five rows), and so on; however, these larger numbers of divisions quickly result in a large number of subregions that usually are too small and impractical. Also, when making a division, the number of vertical divisions and the number of horizontal divisions need not be always identical. For example, if it is known in advance that the region includes many vertically long pattern elements or many horizontally long pattern elements, a good result may result from changing the number of vertical or horizontal divisions accordingly. In FIG. 1, division of a region or portion thereof is performed until the number of pattern elements included in the resulting subregions is one or less (i.e., 1 or 0). Initially, the number of pattern elements in the entire region (the entire region is referred to as xe2x80x9clevel 1xe2x80x9d) is greater than one. Hence, the entire level-1 region is divided into four xe2x80x9clevel-2xe2x80x9d subregions consisting of, respectively, subregions 1-16, 17-32, 33-48, 49-64. Since the number of pattern elements in each of the level-2 subregions is greater than one, each level-2 subregion is further divided into four xe2x80x9clevel-3xe2x80x9d subregions. The number of pattern elements in the level-3 subregion consisting of subregions 9-12 and in the level-3 subregion consisting of subregions 37-40 is 0. As a result, further division of these level-3 subregions is not performed. Also, for example, the number of pattern elements in the level-3 subregion consisting of subregions 25-28 and in the level-3 subregion consisting of subregions 41-44 is 1. Consequently, these level-3 subregions are not further divided. Level-3 subregions having more than one element are divided further to produce respective sets of four xe2x80x9clevel-4xe2x80x9d subregions. At level 4, the number of pattern elements in each of the subregions is 1 or 0 in this example, so no further subdivision is performed. The scheme of branching division described above is diagrammed in the branching structure shown in FIG. 2. At each level shown in FIG. 2, the subregions included in each group are denoted by number. The numbers in parentheses denote the number of pattern elements included in each region or subregion at each level. In FIG. 2, subregions containing zero pattern elements do not affect the calculation, so further denotation and description of these xe2x80x9czero-elementxe2x80x9d subregions are not provided. In FIG. 1, branching division of a region alternatively can be performed until the number of pattern elements included in a resulting subregion is, for example, less than or equal to 2. First, the number of pattern elements included in the entire region (at level 1) is greater than 2, so the entire region is divided (equally horizontally and vertically) into four equally sized level-2 subregions consisting of subregions 1-16, 17-32, 33-48, and 49-64, respectively. The number of pattern elements included in each of the level-2 subregions is greater than 2 in each case, so each level-2 subregion is further divided into four equally sized level-3 subregions. The number of pattern elements in each of certain level-3 subregions (i.e., the subregion consisting of subregions 9-12 and the subregion consisting of subregions 37-40) is zero; and the number of pattern elements in each of certain other level-3 subregions (i.e., the subregion consisting of subregions 25-28 and the subregion consisting of subregions 41-44) is 1. Since the number of pattern elements in each of these level-3 subregions is two or less, further division of these level-3 subregions is not performed. Similarly, the number of pattern elements in each of certain other level-3 subregions (e.g., the subregion consisting of subregions 5-8, the subregion consisting of subregions 17-20, and the subregion consisting of subregions 53-56) is 2. Hence, these level-3 subregions also are not further subdivided. But, other level-3 subregions (e.g., the subregion consisting of subregions 13-16) have more than two elements each. Hence, each of these level-3 subregions is divided further into four equally sized subregions (level 4). At level 4 the number of pattern elements included in each subregion thus produced is either 1 or 0, so further subdivision is not performed. The results of this branching division are shown in FIG. 3. At each level shown in FIG. 3, the level-4 subregions included in each lower-order subregion are denoted by number. The numbers in parentheses denote the number of pattern elements included in the respective subregion at each level. In FIG. 3, subregions including no pattern elements do not affect the calculation, so further denotation and description of these xe2x80x9czero-elementxe2x80x9d portions are not provided. In view of the branching-division schemes shown in FIGS. 1-3, the first representative embodiment is described with reference to FIGS. 4 and 5. FIG. 4 depicts an exemplary level-1 region of a pattern defining pattern elements that can be used to calculate a cumulative dose of exposure energy for the region. The point denoted xe2x80x9c10xe2x80x9d is a location (xe2x80x9cevaluation pointxe2x80x9d) at which a cumulative exposure dose is calculated. (The point 10 corresponds, for example, to any of the points A1-AN in FIG. 20(c).) The reference numeral xe2x80x9c11xe2x80x9d denotes a side dimension of the level-1 region (and also is used herein to denote the level-1 region itself). Items 12-15 are respective level-2 subregions produced by dividing the region 11 (equally both horizontally and vertically) into four equally sized portions. The reference numerals 16-19 denote four level-3 subregions, respectively, produced by dividing the level-2 subregion 15 equally horizontally and vertically into four equally sized portions. Items F1-F4 are respective pattern elements in the region. FIG. 5 is a flowchart of a process for calculating (determining) a branching structure according to this representative embodiment. In the description, the exemplary pattern region is assumed to contain more than one pattern element. In this example, the region is divided evenly both vertically and horizontally to produce four equally sized lower-level subregions. If the number of pattern elements within a subregion is xe2x89xa61, then further subdivision of the respective subregion is not performed. In the figure, D is the distance between the center of a subject subregion (the center serving in this example as a xe2x80x9creference pointxe2x80x9d for the subregion) and the evaluation point 10, and L is the length of a side of the subregion. For the subregion, if the ratio D/L exceeds a threshold value xcfx86, then further subdivision of the respective subregion is not performed regardless of the number of pattern elements included in the subject subregion, and the pattern element(s) present in the subject subregion are converted into a respective representative figure. The threshold value xcfx86 normally is determined experimentally, taking into account the required accuracy with which cumulative exposure dose is to be calculated and the desired calculation time. The xe2x80x9crepresentative figurexe2x80x9d for a given subregion is located at the centroid of pattern element(s) in the subject subregion. The representative figure includes a weighted factor of the total area of the pattern element(s) present in the subregion. The weighted factor is a compensation factor that takes into account the fact that the representative figure is an approximation of reality, even if the representative figure is situated at the centroid. The weighted factor is applied to the contribution by the element(s) to cumulative exposure dose in the subregion. The representative figure can have any of various profiles. Also, there need not be only one representative figure for a given subregion. Furthermore, a subject subregion can be subdivided into sub-subregions, with a respective representative figure created for each sub-subregion. Referring further to FIG. 5, in step S01 the cumulative dose of exposure energy in the subject region is initialized to 0. Further aspects of FIG. 5 are described in the context of FIG. 4. In step S02, the length L of a side of the region 11 is determined (wherein L is a representative size parameter of the region). In step S03 the distance D is determined between the center of the region 11 (the center serving as a xe2x80x9creference pointxe2x80x9d) and the selected evaluation point 10 (at which cumulative exposure dose is calculated). In step S04 a decision is made on whether D/L exceeds a threshold value xcfx86. If D/L does not exceed xcfx86, then the process proceeds to step S07 at which a decision is made on whether the number of pattern elements in the region 11 is 0. If the number of pattern elements in the region 11 is greater than 0, then the process proceeds to step S08 at which a decision is made on whether the number of pattern elements in the region 11 is equal to 1. If the number of pattern elements in the region 11 is greater than 1, then the process proceeds to step S10 at which the region 11 is divided equally into four subregions 12-15. In step S11, a number k indicating the subregion number is initialized to 1, and the process proceeds to step S12. In step S12 a calculation starting with step S01 is performed for the subregions obtained. In step S13 k is incremented by 1. In step S14, if k is less than or equal to 4, then the process returns to step S12 and a branching structure is determined for the next subregion. If k is greater than 4, then calculation ends for all the subregions, thereby completing processing for the region. In the example shown in FIG. 4, for k=1 (level-2 subregion 12), D/L exceeds the threshold value xcfx86. As a result, for this subregion, the process proceeds to steps S05 and S06, in which a representative figure is created from the pattern elements F1, F2. The contribution of the representative figure to cumulative exposure dose is calculated, and the sum is added to the cumulative exposure dose for the region. In step S15 the value E is entered and the process xe2x80x9creturnsxe2x80x9d to the last division in the branching structure. This means that, for k=1, no further subdivisions or energy calculations are performed. Consequently, the process proceeds to step S 13 during which the value of k becomes 2, and the level-2 subregion 13 now is considered. Step S12 is performed for the subregion 13. That is, with k=2, the process starting at step S01 is performed for the subregion 13. For k=2, D/L exceeds the threshold value xcfx86 in the subregion 13. As a result, the process proceeds to steps S05 and S06. However, because no pattern elements are present in the subregion 13, a calculation and adding of the respective exposure-dose for this subregion to the overall exposure dose for the region 11 do not occur. Hence, k is incremented to k=3. For k=3 (level-2 subregion 14), D/L does not exceed the threshold value xcfx86, and the process proceeds to step S07. However, because no pattern elements are present in the subregion 14, the process proceeds to step S15. For k=4 (level-2 subregion 15), D/L is less than the threshold value xcfx86, and the process proceeds to step S07. But, because the number of pattern elements in the subregion 15 is greater than 0, the process proceeds to step S08. Since the number of pattern elements in the subregion 15 is greater than 1, in step S10 the subregion is divided into four level-3 sub-subregions 16-19. The process starting with step S01 is performed for each of the four sub-subregions 16-19 from k=1 to k=4, respectively. For each of the four level-3 subregions, since D/Lxe2x89xa6xcfx86 for k=1 to k=4, the process proceeds to step S07. For k=1 (sub-subregion 16) and k=4 (sub-subregion 19), the number of pattern elements in each respective sub-subregion is 1. As a result, the process proceeds in each instance to step S09, in which the contribution of the pattern elements F3, F4, respectively, to cumulative exposure dose is added to the cumulative exposure dose for the region 11. These contributions to cumulative exposure dose can be calculated from the shape of the respective pattern elements using well-known methods. Alternatively, as described previously, the process can proceed to step S05, as indicated by the broken-line arrow in FIG. 5, in which, for each sub-subregion, the respective pattern element is converted into a representative figure, and the contribution of the representative figure to cumulative exposure dose is calculated. For each of k=2 (sub-subregion 17) and k=3 (sub-subregion 18), the number of pattern elements is 0, so the process proceeds from step S07 to step S15. To summarize the process, first the region 11 is divided into four level-2 subregions 12-15. The contribution of subregion 12 to cumulative exposure dose is calculated in steps S05 and S06 and added to the cumulative exposure dose for the region 11. Each of the subregions 13 and 14 has no pattern elements, so no exposure dose from these two subregions can be added to the cumulative exposure dose. The subregion 15 is divided into four sub-subregions (level-3 subregions) 16-19. The respective contributions to cumulative exposure dose from the sub-subregion 16 and the sub-subregion 19 are calculated in step S09 and added to the cumulative exposure dose for the region 11. Each of sub-subregions 17 and 18 has no pattern elements, so no exposure dose is contributed by these two sub-subregions to the cumulative exposure dose for the region 11. A calculation of exposure dose in the region 11 is made for each evaluation point 10 in the region 11. A flowchart of a process according to this embodiment is shown in FIG. 6. The basic concept of the FIG.-6 process is as in the FIG.-5 process, and has a similar end effect. The main difference between the two processes is that, in the FIG.-5 process, the decision as to whether D/Lxe2x89xa6xcfx86 is made before a decision on whether the number of pattern elements in a region or subregion is less than or equal to 1. In contrast, in the FIG.-6 process, this sequence of steps is reversed. Hence, both processes have similar end effects. Referring more specifically to FIG. 6 (and referring also to FIG. 4), in step S21 the cumulative exposure dose affecting the region is initialized to 0. In step S22, the length L of one side of the region (wherein L is a representative size parameter) is determined. In step S23 the distance D between the center of the region and the evaluation point 10 is determined. This portion of the process also can occur between step S25 and step S27, described later. In step S24, a decision is made on whether the number of pattern elements in the region is 0. If the number is 0, then the process proceeds to step S35, and no further processing occurs for the region. If the number is greater than 0, then the process proceeds to step S25, and a decision is made on whether the number of pattern elements in the region is 1. If the number is 1, then the process proceeds to step S26, and the exposure-dose contribution of the subject region is added to the cumulative exposure dose for the region 11. During this step, the exposure-dose contribution to the cumulative exposure dose can be calculated from the shape of the respective pattern element using well-known methods. Alternatively, as indicated by the broken-line arrow in FIG. 6, the process can proceed to step S28, described below, during which the respective pattern element is converted to a representative figure, and the contribution to cumulative exposure dose is calculated from the representative figure. If the number of pattern elements in the subject region is 2 or more, then the process proceeds to step S27, and a decision is made on whether D/Lxe2x89xa6xcfx86. If D/Lxe2x89xa6xcfx86, then the process proceeds to steps S28 and S29, and a representative figure is created from the pattern elements. The contribution of the representative figure to cumulative exposure dose is calculated and added to the cumulative dose of exposure energy for the region 11. In step S35 the value of E is entered, meaning that the process is complete with respect to the subject region or subregion. The process then xe2x80x9creturnsxe2x80x9d to the last division in the branching structure and proceeds again. If D/Lxe2x89xa6xcfx86, then the process proceeds to step S30, and the region is divided into four equally sized subregions. Thereafter, steps S31 through S34 are the same as steps S11 through S14, respectively, in FIG. 5. In the embodiment of FIG. 6, branching division of a region and calculation of cumulative exposure dose are performed simultaneously. However, in this third representative embodiment, entry of the subject region (or subregion) into a branching structure for the region occurs first, followed by calculation of the cumulative exposure dose in the region (or subregion). The third representative embodiment is shown in FIG. 7. In step S41, a decision is made on whether the number of pattern elements in the subject region (or subregion) is 0. If the number is 0, then the process proceeds to step S49. Alternatively, the process can proceed to step S42, wherein the region (or subregion) is listed (xe2x80x9cregisteredxe2x80x9d) on a branching structure being created for the region, with the number of pattern elements set at 0 on the list. (Branching structures are created in a memory of a computer used to perform the steps of the process in a controllable manner.) However, in light of subsequent processing, it is more efficient not to register the region on a branching structure. I.e., not registering a region or subregion results in less calculation time. If the number is not zero, then in step S42 the region (or subregion) is registered on the branching structure, and the number of pattern elements included in the region is recorded. That is, as shown in FIG. 2, the subregions for each level and the number of pattern elements included in the respective subregions are registered on the branching structure. Then, in step S43, a decision is made on whether the number of pattern elements in the region (or subregion) is less than or equal to 1. If yes, then the process proceeds to step S49. If no, then the process proceeds to step S44, at which the subject region (or subregion) is divided (equally horizontally and vertically) into four equally sized subregions. Branching division according to step S46 is performed for each respective subregion produced in step S44. That is, the process starting with step S41 is performed for each of the respective subregions formed in step S44. By continuing this process for the entire region shown in FIG. 1, a branching structure such as that shown in FIG. 2 is created. (FIG. 2 shows a case in which regions with zero pattern elements are not registered on the branching structure. But, if regions with zero pattern elements were registered on the branching structure, then those elements would be included in the regions listed in FIG. 2.) As branching division of a region ends, calculation of a cumulative dose of exposure energy in the region begins. The calculations are performed by a process shown in FIG. 8, in which only regions (and subregions) containing pattern elements are regarded as registered in the branching structure. Calculations are performed only for those regions and subregions that are registered in the branching structure, thereby providing greater efficiency than conventional methods. In step S51 of FIG. 8, the cumulative dose of exposure energy affecting a region is initialized at 0. In step S52 the length L of one side of the region is determined (wherein L is a representative size parameter). In step S53 the distance D between the center of the region (as a respective reference point for the region) and the evaluation point in the region is selected. In step S54 a decision is made on whether D/L exceeds the threshold value xcfx86. If yes, then the process proceeds to steps S55 and S56, and a representative figure is created from the pattern element(s) in the region. The contribution of the representative figure to the cumulative exposure dose (energy) is calculated and added to the cumulative dose of exposure energy for the region. In step S60 the value of exposure dose (energy E) determined in a previous step is entered, indicating that processing in the respective region or subregion is complete. The process then returns to the last division in the branching structure and proceeds again, and so on until the entire region is completed. If D/Lxe2x89xa6xcfx86, then the process proceeds to step S57 in which a decision is made on whether the number of pattern elements in the subject region or subregion is 1. If the number is 1, then the process proceeds to step S59 in which the contribution to cumulative exposure dose from the subject pattern element is added to the cumulative dose of exposure energy for the region. (The contribution of a pattern element to cumulative exposure dose can be calculated from the shape of the subject pattern element using well-known methods.) As indicated by the broken-line arrow in FIG. 8, it alternatively is possible to proceed to step S55 and convert the subject pattern element to a representative figure, from which the respective contribution to cumulative exposure dose is calculated. If the number of pattern elements in the region is greater than 1, then the process proceeds to step S58 in which a branching structure is determined (xe2x80x9ccalculatedxe2x80x9d) for the next lower level from the subject region or subregion. That is, calculation (starting from step S51) is performed for all subregions registered at the next lower level. By continuing the process in this manner to the end, the cumulative dose of exposure energy is determined for the entire region with respect to a particular evaluation point. The process is repeated for each of the other evaluation points in the region. In the process shown in FIG. 8, the determination of whether D/Lxe2x89xa6xcfx86 is made before the decision on whether the subject region or subregion contains a single pattern element. Alternatively, the decision on whether the subject region or subregion contains a single pattern element can be made before a determination of whether D/Lxe2x89xa6xcfx86. In the latter instance, the sequence of process steps readily can be determined by applying the difference between FIGS. 6 and 7 to FIG. 8. This embodiment is directed to a method in which, for a given region, the determination of the branching structure and creation of representative figures are performed first, followed by a determination and summation of the respective contributions of the respective pattern elements and representative figures to cumulative exposure dose. FIG. 9 provides a process flowchart of this embodiment. In the first step, step S61, the length L of one side of the subject region (as a representative size parameter) is determined. In step S62 the distance D is determined between the center of the region (as a representative xe2x80x9creference pointxe2x80x9d for the region) and the selected evaluation point. In step S63 a decision is made on whether D/L exceeds the threshold value xcfx86. If D/L greater than xcfx86, then the process proceeds to step S64, in which a representative figure is created from the pattern elements in the region. Then, in step S73, the representative figure is returned (entered), thereby completing the process. If D/Lxe2x89xa6xcfx86, then the process proceeds to step S65, in which a decision is made on whether the number of pattern elements in the subject region (or subregion) is zero. If the number is zero, then the process proceeds to step S73 and processing for the particular region (or subregion) ends. If the subject region (or subregion) contains at least one element, then the process proceeds to step S66, in which a decision is made on whether the number of pattern elements in the region (or subregion) is 1. If the number is 1, then the process proceeds to step S67, in which the pattern element itself becomes the representative figure. Alternatively, as indicated by the broken-line arrow in FIG. 9, the process can proceed from step S66 to step S64, in which the pattern element is converted into a representative figure. If the number of pattern elements in the subject region (or subregion) is greater than 1, then the process proceeds to step S68, in which the subject region (or subregion) is divided (equally horizontally and vertically) into four equally sized subregions. The steps (S69 through S72) of determining a branching structure and creating a representative figure are performed for each of the four subregions. That is, the routine starting at step S61 is performed for each subregion. By continuing this process to its end, all representative figures are found for the subject region. Furthermore, in the process of FIG. 9, the decision on whether D/Lxe2x89xa6xcfx86 is made before making a decision on whether the number of pattern elements in the subject region is 1. Alternatively, it is possible to make the decision on whether there is one pattern element in the region before making the decision on whether D/Lxe2x89xa6xcfx86. In the latter instance, the sequence of process steps readily can be determined by applying the difference between FIGS. 6 and 7 to FIG. 9. After all representative figures are found in this manner, the contributions of the respective representative figures to the cumulative dose of exposure energy at the evaluation point are determined. The process is repeated for all other evaluation points in the region. In all of the foregoing embodiments, representative figures were created with reference to respective relationships of the various subregions of a region with the selected evaluation point in the region. It also is possible to divide the region in a branching manner and create representative figures without consideration of these relationships. In the latter instance, the respective relationships are referred to only when calculating the cumulative dose of exposure energy for the region. This embodiment is exemplary of such a scheme. A process according to this embodiment for dividing a region in a branching manner and creating representative figures in the subregions thus formed is shown in FIG. 10. In step S81, a decision is made on whether the number of pattern elements in the subject region (or subregion) is zero. If the number is zero, then the process proceeds to step S91 and further processing of the region (or subregion) ends. If the number is not zero, then in step 81 the subject region (or subregion) is registered on the branching structure being created for the region. Then, in step S83, a decision is made on whether the number of pattern elements in the subject region (or subregion) is one. If yes, then the process proceeds to step S84, in which the subject pattern element becomes the representative figure, or a specified representative figure is created from the subject pattern element. The process then proceeds to step S91 and further processing of the region (or subregion) ends. In step S83, if the number of pattern elements in the region (or subregion) is two or more, then the process proceeds to step S85, in which a representative figure is created for the subject region (or subregion). In step S86 the subject region (or subregion) is divided equally horizontally and vertically into four subregions at the next lower level (the subregions are equally sized). Branching division in this manner creates a respective portion of the branching structure for the region, and representative figures are created for each of the respective subregions in step S87 through step S90. That is, the process starting from step S81 is performed for each of the respective subregions. Performing this process to completion for all subregions of the region yields a branching structure as shown in FIG. 2, including representative figures corresponding to the respective subregions. This embodiment is directed to calculating cumulative dose of exposure energy using a branching structure and representative figures. The process flow is shown in FIG. 11. In the first step S101 the cumulative dose of exposure energy to the respective region is initialized at zero. In step S102 the length L of one side of the subject region (or subregion) is found, wherein L is a representative size parameter. In step S103 the distance D is found between the center of the region (or subregion) and the selected evaluation point for the region, wherein the center is a representative xe2x80x9creference pointxe2x80x9d for the region or subregion. In step S104 a decision is made on whether D/L exceeds the threshold value xcfx86. If D/L greater than xcfx86, then the process proceeds to step S105, in which the contribution of the representative figure(s) in the region or subregion to the cumulative dose of exposure energy (E) for the region is calculated. In step S108 the value of E is returned (entered), meaning that processing in the subject region (or subregion) is complete. If D/Lxe2x89xa6xcfx86, then the process proceeds to step S106, in which a decision is made on whether the number of pattern elements in the subject region (or subregion) is 1. If the number of pattern elements is 1, then the process proceeds to step S105, in which the contribution to cumulative exposure dose from the representative figure in the subject region (or subregion) is added to the cumulative exposure dose. In this step, the subject representative figure can be the corresponding pattern element itself. Alternatively, the pattern element can be converted into a representative figure having a specified shape according to step S84 in FIG. 10. If the number of pattern elements in the subject region (or subregion) is greater than 1, then the process proceeds to step S107, in which a branching structure is created for subregions at the next lower level from the subject region (or subregion). That is, the calculation is performed, starting with step S101, for all subregions one level down. By continuing this process to the end for all constituent subregions, the cumulative exposure dose at the selected evaluation point is determined for the subject region. (The process is repeated for all other evaluation points in the region.) Furthermore, in the process shown in FIG. 11, the decision on whether D/Lxe2x89xa6xcfx86 is made before the decision on whether there is one pattern element in the region (or subregion). Alternatively, the decision on whether there is one pattern element in the region (or subregion) can be made before the decision on whether D/Lxe2x89xa6xcfx86. In the latter instance, the sequence of process steps readily can be determined by applying the difference between FIGS. 6 and 7 to FIG. 11. In all of the embodiments discussed above, the decision to subdivide a region (or subregion) is made whenever D/L greater than xcfx86 or whenever the number of pattern elements included in the subject region (or subregion) is less than or equal to one. Alternatively, division of a region (or subregion) into subregions at the next lower level may end whenever D/L greater than xcfx86 or whenever the number of pattern elements included in the subject region (or subregion) is less than or equal to a specified number. The latter can be implemented readily by denoting step S08 (FIG. 5) as xe2x80x9cnumber of elements in the regionxe2x89xa6a specified numberxe2x80x9d, for example. In the latter instance, regions or subregions having a plurality of pattern elements remain, but the contribution to the cumulative exposure dose of the respective pattern elements can be calculated. For example, the representative figure in the region or subregion can be found via the broken-line route in FIG. 5. This embodiment is directed to an exemplary method for creating a representative figure. Referring to FIG. 12(a), a situation is considered in which a region 21 contains two pattern elements F5 and F6. The region 21 is square-shaped with side length 2. The element F5 is rectangularly shaped with a length of 2 units in the x-axis direction (horizontal direction in the plane of the page) and a width of 1 unit in the y-axis direction (vertical direction in the plane of the page). If the center of the region 21 is the selected evaluation point in the region 21, then the center of the element F5 is located at (xe2x88x921,1). The element F6 is square-shaped, with each side having a length of 1 unit. The center of the element F5 is located at (1,0). FIGS. 12(b)-12(f) show various respective ways in which the elements F5, F6 in the region 21 can be combined into a single representative figure in the region 21. Turning first to FIG. 12(b), the representative figure is a point located at the center of the region 21. Such a representative figure is applicable, for example, if the respective element is located remotely from the evaluation point. For evaluation purposes, the point has a xe2x80x9cweightxe2x80x9d of 3, which is the total of the areas of F5 and F6. I.e., even though the representative figure is a point, it still takes into consideration the area of the element(s) it represents. In this context, xe2x80x9cweightxe2x80x9d is essentially a factor used when calculating a respective contribution to cumulative exposure dose. Whether or not a point representative figure is or can be used also takes into account the required accuracy of the calculations and/or the calculation time. FIG. 12(c) is an exemplary square representative figure having a center located at the center of the region 21 and having an area of 3 (which is the total of the areas of the elements F5 and F6). FIG. 12(d) is an exemplary round representative figure having a center located at the center of the region 21 and having an area of 3 units (which is the total of the areas of the elements F5 and F6). FIGS. 12(b)-12(d) do not consider the net relative extensions in the x- and y-directions of the elements F5 and F6. Such a consideration is provided in FIG. 12(e), in which the representative figure is elliptical and horizontally extended. In the ellipse, the ratio of x-axis length to y-axis length is 3.5:2. The ellipse has an area of 3 units, which is the total of the areas of the elements F5 and F6. The axial ratio of the ellipse is derived from corresponding x- and y-dimensions of a rectangular figure, surrounding elements F5 and F6, having a length of 3.5 in the x-axis direction and a length 2 in the y-axis direction. FIG. 12(f) shows an exemplary rectangular representative figure of which the ratio of x-axis length to y-axis length is 3.5:2. The area of the rectangle is 3 units, which is the total of the areas of the elements F5 and F6. In FIGS. 12(a)-12(f), the locations of the respective centers of the representative figures are at the center of the region 21. Alternatively, the centers can be located at the center of the respective centroid of the pattern elements F5 and F6 in the region 21, thereby providing a more accurate representative figure. This is shown in FIGS. 13(a)-13(f). FIG. 13(a) shows the dispersion of pattern elements F5, F6 in the region 21. As can be seen, the pattern elements F5, F6 are distributed and sized exactly as in FIG. 12(a). The location of the centroid of elements F5 and F6 is located at (xe2x88x921/3,2/3), at which the center of the representative figure is located. FIGS. 13(b)-13(f) show exemplary representative figures corresponding to FIGS. 12(b)-12(f), respectively, but with respective centers situated at (xe2x88x921/3,2/3). In FIGS. 12(a)-12(f) and 13(a)-13(f), one representative figure was created in the region 21, incorporating multiple pattern elements F5, F6. It also is possible to create multiple representative figures in the region 21. In the latter case, for example, the region 21 is divided equally horizontally and vertically into four equally sized subregions, and a respective representative figure is created for each subregion. As discussed above, the number of divisions does not have to be equal horizontally and vertically. If many pattern elements have respective shapes that are long horizontally or long vertically, then the number of horizontal and vertical divisions can be modified accordingly. In the methods for dividing a region in a branching manner explained above, subregions distant from the selected evaluation point can be configured as large subregions, and subregions nearer to the evaluation point can be configured as small subregions. This is because the cumulative-dose effect of subregions more distant from the evaluation point is less than the effect of closer subregions. This allows the number of calculations to be minimized without significantly degrading the accuracy of the calculations. If a single large pattern element, having a complicated edge profile, is present in the subject region, then subdivision of the region ordinarily would not occur. In such a case, accuracy would not be affected adversely if exposure dose were calculated strictly according to the complex profile of the element, but the calculation time would be excessive. Alternatively, the complex pattern element can be replaced with a representative figure from which the exposure-dose calculation is performed. However, in a representative figure, the complex profile of the element essentially is ignored, and calculation accuracy is reduced undesirably. In such a situation, it is desirable to divide the single complex element into a core portion having a simple profile and multiple xe2x80x9csecondaryxe2x80x9d portions (including portions having a negative profile). With respect to the core portion, cumulative exposure dose can be calculated using conventional methods. I.e., because the profile of the core portion is simple, known rapid calculation methods can be used. With respect to the secondary portions, determination of a branching structure as described above can be performed. The cumulative exposure dose from the element is obtained by combining the results of the two calculations. FIGS. 14(a)-14(c) depict this situation. FIG. 14(a) depicts an actual exemplary pattern element F7 situated inside a region 22. Item 23 is the corresponding element actually to be transferred to the substrate. The pattern element F7 is divided into a relatively large core portion as shown in FIG. 14(b) and secondary portions as shown in FIG. 14(c). In FIG. 14(b) the core portion consists of five parts 24-28, wherein part 24 has a profile substantially the same as the element 23 to be transferred to the substrate, and parts 25-28 are corners. In FIG. 14(c) secondary portions with diagonal crosshatching are situated inside the pattern element F7 but outside the core portion. The secondary portions with horizontal-line shading are not situated inside the pattern element F7 but are situated inside the core portion. As used herein, secondary portions located within the core portion but outside the actual element 23 are referred to as having a xe2x80x9cnegativexe2x80x9d shape, i.e., having a negative area and thus making a negative contribution to cumulative exposure dose for the region 22. After dividing the pattern element in this manner, the contribution to cumulative exposure dose is calculated individually for each of the core parts 24-28 shown in FIG. 14(b). In practice, the profile of the core portion usually is simple, and the core portion usually consists of relatively few parts. As a result, calculating the contribution of the core parts to cumulative exposure dose of the selected evaluation point is relatively simple and can be performed using known methods. On the other hand, the contributions to cumulative exposure dose for the secondary portions shown in FIG. 14(c) are calculated using a branching-structure determination according to the invention. When performing the calculation, secondary portions having a negative shape make negative contributions to centroid, area, and cumulative exposure dose. In any event, the individual contributions of the core portion and secondary portions to cumulative exposure dose are summed to yield the cumulative dose of exposure energy for the region. The pattern-element profile of FIG. 14(a) is simplified for explanation purposes. Typically, in actual practice, the number of core portions is relatively small, and the number of secondary portions is very large. Hence, the advantages of employing a method, according to the invention, for making a branching division of a region are substantial. The methods described above for calculating the cumulative dose of exposure energy for a region can be incorporated into a program executed by a computer, stored on a recording medium such as a CD, optical disk, ROM, etc., and suitably used when configuring the pattern on a reticle, mask, or the like. Whereas, in the foregoing, embodiments are explained in the context of calculating a cumulative dose of exposure energy, it will be understood that calculating a proximity effect obtained using a CPB microlithography apparatus also is a type of cumulative-exposure-dose calculation that can benefit using methods according to the invention. I.e., in the respective flowcharts of the various embodiments described herein, the term xe2x80x9ccumulative exposure dosexe2x80x9d (cumulative dose of exposure energy) can be replaced with xe2x80x9ccumulative exposure dose due to proximity effects.xe2x80x9d If a proximity effect at a point on a sensitive substrate, such as a wafer, is determined, then it is possible to determine a required altered shape of a reticle or mask, and to alter the shape of the reticle or mask, respectively, according to the determination. FIG. 15 is a flowchart of an exemplary microelectronic-device fabrication method to which methods according to the invention readily can be applied. The fabrication method comprises the main steps of wafer production (wafer preparation); reticle production (reticle preparation); wafer processing; device assembly, dicing, and making the devices operational; and device inspection. Each step usually comprises several sub-steps. Among these main steps, wafer processing is key to achieving the smallest feature sizes (critical dimensions), best inter-layer registration, and performance of the microelectronic devices. In the wafer-processing step, multiple circuit patterns are layered successively atop one another on the wafer, wherein the formation of each layer typically involves multiple sub-steps. Usually, many operative microelectronic devices (e.g., microprocessor chips or memory chips) are produced on each wafer. Typical wafer-processing steps include: (1) thin-film formation (by, e.g., CVD or sputtering) involving formation of a dielectric layer for electrical insulation or a metal layer for interconnections; (2) oxidation to oxidize the thin film or the surface of the wafer itself; (3) microlithography to form a resist pattern (as defined by a reticle) on the wafer for selective processing of the thin film or the substrate itself; (4) etching (e.g., dry etching) or analogous step to etch the thin film or wafer according to the resist pattern; (5) doping or impurity implantation to implant ions or impurities into the thin film or wafer; (6) resist stripping to remove the resist from the wafer; and (7) chip inspection. Wafer processing is repeated as required (typically many times) to fabricate the desired microelectronic devices on the wafer. FIG. 5 provides a flowchart of typical steps involved in microlithography, which is a principal step in wafer processing. The microlithography step typically includes: (1) a resist-coating step, wherein a suitable resist is coated on the wafer surface (which can include as circuit pattern formed in a previous wafer-processing step); (2) an exposure step, to expose the resist with the desired pattern and form a latent image of the pattern in the resist; (3) a development step, to develop the latent image in the exposed resist; and (4) an optional annealing step, to enhance the durability of the developed resist pattern. These wafer-production steps, reticle-production steps, wafer-processing steps, and microlithography steps are well known. Hence, additional description of these steps is unnecessary. In any event, the microlithography step employs a reticle or mask that is configured accurately and quickly using a method according to the invention. An important result is the manufacture of microelectronic devices having fine patterns that can be fabricated quickly and with high yield. Referring to FIG. 17, a cumulative dose of exposure energy was calculated for pattern elements in a region measuring 120 xcexcmxc3x97100 xcexcm, using the method described in the first representative embodiment (FIG. 5). Specifically, cumulative-exposure-dose calculations were performed for each of multiple evaluation points in pattern elements to be transferred to the sensitive substrate. Cumulative-exposure-dose calculations for corner portions of the elements (e.g., portions corresponding to parts 25-28 in FIG. 14) were calculated separately from respective core portions of the elements. The method of the first representative embodiment was applied to the remaining parts of the pattern elements. In performing the calculations, the value of xcfx86 was 1. For each pattern element, the respective representative figure was a single point situated at the centroid of the respective pattern element. Whenever a region of the reticle contained only a single pattern element, the contribution to cumulative exposure dose from that region was calculated directly without converting the element to a representative figure. As a comparative example, the conventional method of calculating the effect of moving segments in the region, as shown in FIG. 20, was applied. FIG. 18 is a plot comparing respective calculation times for the example and comparative example, as a function of the number of segments referred to in the comparative example. In the comparative example, although high calculation accuracy is obtained, calculation time increases steeply with increased number of segments. In the example, in contrast, the calculation time is comparatively shorter (i.e., the xe2x80x9cexamplexe2x80x9d curve exhibits substantially less slope than corresponding regions of the xe2x80x9ccomparative examplexe2x80x9d curve) without degrading accuracy more than a significant extent. FIG. 19 depicts exemplary distributions of values of cumulative exposure dose accompanying various differences in cumulative exposure dose calculated according to the embodiment versus cumulative exposure dose calculated according to the comparative example. The area shown in FIG. 19 includes the center element shown in FIG. 17 as well as the respective adjacent longitudinal edges of the elements located above and below the center element (note similarity of coordinates between FIG. 19 and the corresponding region of FIG. 17). At each coordinate shown in FIG. 19, exposure dose is calculated by conventional method (Dc) and the method according to this example (De). The difference (Dcxe2x88x92De) is divided by a value of exposure dose (Dm, calculated according to the conventional method) that defines the pattern-element boundary on the sensitive substrate (i.e., the energy value serving as a threshold above which the resist can be developed and below which the resist cannot be developed). The result of this calculation, obtained at each coordinate shown in FIG. 19, is a xe2x80x9ccalculation errorxe2x80x9d which is a percentage difference in dose of the example method compared to the conventional method. In FIG. 19, the non-shaded regions are where the calculation error is 0.0000 to 0.0005 percent. The various shaded regions depict different percentage differences as indicated, and represent areas where proximity effects most likely would occur. As can be discerned from the figure, the difference between these two calculation methods is less than 1% of the energy value sufficient to create a pattern-element boundary in all regions of the substrate. (A difference of 0.002 to 0.0025 currently is deemed acceptable.) Hence, this embodiment provides a calculation accuracy, for practical purposes, that is essentially the same as realized using conventional methods, but the calculations performed according to the example were performed in substantially less time. Whereas the invention has been described in connection with multiple representative embodiments, it will be understood that the invention is not limited to those embodiments. On the contrary, the invention is intended to encompass all modifications, alternatives, and equivalents as may be included within the spirit and scope of the invention, as defined by the appended claims.
	claims	1. An X-ray apparatus as part of a particle beam cancer therapy system, said particle beam cancer therapy system configured to irradiate a tumor of a patient with a charged particle beam, said apparatus comprising:a respiration sensor configured to generate a respiration signal, said respiration signal corresponding to a respiration cycle of the patient;an X-ray generation source located within about forty millimeters of the charged particle beam, wherein said X-ray source maintains a single static position: (1) during use of said X-ray source and (2) during tumor treatment with the charged particle beam, said apparatus controlled to yield X-ray images at a set point of the respiration cycle by said respiration signal,a rotatable platform holding the patient,wherein said rotatable platform rotates through at least one hundred eighty degrees during an irradiation period of the patient, andwherein said X-ray generation source is timed using said respiration signal to produce X-ray images at a set point in the respiration cycle,wherein X-rays emitted from said X-ray source run substantially in parallel with the charged particle beam,wherein said X-ray images represent greater than ten rotation positions of said rotatable platform,wherein the X-ray images combine to form a 3-dimensional image of the tumor, andwherein said delivery of the charged particle beam at said set point of said respiration cycle occurs in greater than twenty rotation positions of said rotatable platform, wherein ingress energy of said charged particle beam is circumferentially distributed about the tumor. 2. The apparatus of claim 1, wherein said respiration sensor further comprises:a force meter strapped to the patient's chest. 3. The apparatus of claim 1, wherein said respiration sensor further comprises:a first thermal resistor configurably positioned proximate the patient's nose; anda second thermal resistor positioned both out of an exhalation path of the patient and in the same local room environment as the patient,wherein said respiration signal is generated using differences between readings from said first thermal resistor and said second thermal resistor. 4. The apparatus of claim 1, further comprising:a display screen displaying breath control commands to the patient,wherein said respiration signal is used in generating the breath control command and wherein said breath control command comprises a countdown to when the patient's breath is to be held. 5. The apparatus of claim 1, wherein said X-ray generation source comprises a tungsten anode,wherein said X-ray apparatus further comprises:an electron generating cathode having a first cross-sectional distance, wherein X-rays are generated by electrons from said cathode striking said tungsten anode;a focusing control electrode;accelerating electrodes, said control electrode and said accelerating electrodes located between said cathode and said anode, said focusing control electrode focusing electrons from said first cross-sectional distance to a second cross-sectional distance, wherein said second cross-sectional distance is less than one-half of said first cross-sectional distance;a magnetic lens; anda quadrupole magnet, all of said control electrode, said accelerating electrodes, said magnetic lens, and said quadrupole magnet located between said cathode and said anode, said control electrode, said accelerating electrodes, said magnetic lens, and said quadrupole magnet combining to form a substantially parallel electron beam with an electron beam cross-sectional area, wherein a cross-sectional area of said cathode is greater than about eight times that of the electron beam cross-sectional area. 6. The apparatus of claim 5, wherein said substantially parallel electron beam comprises an oblong cross-sectional shape, wherein geometry of said X-ray generation source yields an X-ray beam comprising a nearly circular cross sectional shape when struck by the electron beam having said oblong cross-sectional shape, the X-ray beam running substantially in parallel with the charged particle beam,wherein said tungsten anode further comprises a liquid cooling element connected to a backside of said tungsten anode,wherein said X-ray generation source is configured as usable within thirty seconds of subsequent use of the charged particle beam for tumor therapy. 7. The apparatus of claim 1, further comprising a synchrotron, wherein said synchrotron comprises:a radio-frequency cavity system comprising a first pair of blades for inducing betatron oscillation;a foil yielding slowed charged particles from particles in the charged particle beam having sufficient betatron oscillation to traverse said foil, wherein the slowed charged particles pass through a second pair of blades having an extraction voltage directing the charged particles out of said synchrotron through a Lamberson extraction magnet,wherein said radio-frequency cavity system for inducing betatron oscillation is timed using said respiration signal. 8. A method coordinating an X-ray system and a particle beam cancer therapy system, said particle beam cancer therapy system irradiating a tumor of a patient with a charged particle beam during use, said method comprising the steps of:generating X-rays with an X-ray generation source located within forty millimeters of the charged particle beam, wherein said X-ray source maintains a single static position: (1) during use of said X-ray source and (2) during tumor treatment with the charged particle beam;accelerating the charged particle beam with a synchrotron;generating a respiration signal using a respiration sensor, said respiration signal corresponding to a respiration cycle of the patient;rotating the patient with a rotatable platform, wherein said rotatable platform rotates through at least one hundred eighty degrees during an irradiation period of the patient; andcontrolling delivery the charged particle beam from said synchrotron to the tumor at a set point in the respiration cycle using the respiration signal,wherein said delivery of said charged particle beam at said set point of the respiration cycle occurs in greater than four rotation positions of said rotatable platform,wherein the tumor is targeted using X-ray images collected using X-rays from said X-ray generation source, andwherein the X-rays emitted from said X-ray source run substantially in parallel with the charged particle beam. 9. The method of claim 8, further comprising the steps of:generating electrons with a cathode, said cathode having a first cross-sectional distance, wherein the X-rays are generated by the electrons from said cathode striking a tungsten anode;focusing the electrons from said first cross-sectional distance to a second cross-sectional distance with a focusing control electrode; andaccelerating the electrons with accelerating electrodes, said focusing control electrode and said accelerating electrodes located between said cathode and said anode. 10. The method of claim 9, further comprising the steps of:forming a substantially parallel electron beam from the electrons with said control electrode, said accelerating electrodes, a magnetic lens, and a quadrupole magnet, all of said control electrode, said accelerating electrodes, said magnetic lens, and said quadrupole magnet located between said cathode and said anode, wherein the electron beam comprises a cross-sectional area, wherein a cross-sectional area of said cathode is greater than about eight times that of the electron beam cross-sectional area; andforming a substantially circular cross-section X-ray beam, wherein said substantially parallel electron beam comprises an oblong cross-sectional shape, wherein geometry of said X-ray generation source yields the substantially circular cross section X-ray when struck by the electron beam having said oblong cross-sectional shape, the X-ray beam running substantially in parallel with the charged particle beam. 11. The method of claim 10, further comprising the steps of:cooling said tungsten anode with a cooling element connected to a backside of said tungsten anode;using said X-ray generation source within thirty seconds of subsequent use of the charged particle beam for tumor therapy;rotating said rotatable platform through about three hundred sixty degrees during an irradiation period of the patient; andcombining said images to form a three-dimensional image of the tumor. 12. The method of claim 8, further comprising the step of:producing multi-field images of the tumor, wherein the multi-field images are collected by rotating a patient holding platform between collection of X-ray images,wherein the X-ray images occur in at least ten rotation positions of said platform,wherein the X-ray images are created using X-rays from said X-ray generation source. 13. The method of claim 12, wherein said respiration sensor further comprises:a force meter strapped to the patient's chest. 14. The method of claim 12, further comprising the steps of:positioning a first thermal resistor proximate the patient's nose;positioning a second thermal resistor both out of an exhalation path of the patient and in the same local room environment as said rotatable platform and the patient;generating said respiration signal using differences between readings from said first thermal resistor and said second thermal resistor; anddisplaying breath control commands to the patient on a display screen. 15. The method of claim 14, further comprising the steps of:generating said breath control command using said respiration signal, wherein said breath control command comprises a visually displayed countdown to when the patient's breath is to be held; andcircumferentially distributing ingress energy of said charged particle beam about the tumor by delivering the charged particle beam at said set point of said respiration in greater than twenty rotation positions of said rotatable platform. 16. The method of claim 8, wherein said synchrotron further comprises:a radio-frequency cavity system comprising a first pair of blades for inducing betatron oscillation; anda foil yielding slowed charged particles from particles in the charged particle beam having sufficient betatron oscillation to traverse said foil; andwherein said method further comprises the steps of:directing the charged particles out of said synchrotron through a Lamberson extraction magnet after the slowed charged particles pass through a second pair of blades having an extraction voltage; andtiming said radio-frequency cavity system for inducing betatron oscillation to said respiration signal. 17. The method of claim 16, wherein said synchrotron further comprises:exactly four, ninety degree, turning sections; andno quadrupole magnets about the circulating path of the synchrotron, wherein each of said four, ninety degree, turning sections comprises four magnets, wherein each of said four turning magnets comprise two beveled focusing edges. 18. The method of claim 8, further comprising the step of:converting a negative ion beam at a converting foil into the charged particle beam, wherein an injection system comprising a magnetic material at least partially contained in a plasma chamber yields the negative ion beam.
	claims	1. A spacer grid used in a nuclear fuel assembly such that a plurality of spacer grids are regularly and transversely arranged along the fuel assembly to support a plurality of fuel rods within the fuel assembly while maintaining a desired pitch of the fuel rods and promoting the mixing of a coolant flowing longitudinally upwardly along nuclear fuel rods, comprising: a plurality of first inner straps each having a rectangular-shaped first strap body, with a plurality of main supports and a plurality of upper sub-supports alternately formed along a top edge of the first strap body while being spaced apart from each other at regular intervals, a plurality of lower sub-supports formed along a bottom edge of the first strap body while being spaced apart from each other at regular interval, a pair of flow mixing vanes symmetrically formed along a top edge of each of said main supports, and a plurality of upper vertical slits extending from center of top edge of each said main supports and each upper sub-supports of the first strap body toward a middle of said first strap body; and a plurality of second inner straps each having a rectangular-shaped second strap body, with a plurality of main supports and a plurality of upper sub-supports alternately formed along a top edge of the second strap body while being spaced apart from each other at regular intervals, a plurality of lower sub-supports formed along a bottom edge of the second strap body while being spaced apart from each other at regular interval, a pair of flow mixing vanes symmetrically formed along a top edge of each of said main supports of the second strap body, and a plurality of lower vertical slits extending from center of bottom edge of each said lower sub-supports of the second strap body toward a middle of said second strap body; whereby said first and second inner straps are interlaced at right angles at the vertical slits such that the interlaced inner straps form a plurality of square cells for receiving the fuel rods, with the main supports of the first and second inner strap crossing the upper sub-supports of the second and first inner straps while forming a plurality of upper axial junction lines, and the lower sub-supports of the first and second inner straps crossing each other while forming a plurality of lower axial junction lines, said inner straps being seam-welded to each other along the upper and lower junction lines to form a plurality of side weld lines, and said flow mixing vanes of the interlaced inner straps guiding axial flows of coolant to gaps between the fuel rods, thus forming cross flows of coolant. 2. The spacer grid according to claim 1 , wherein said upper and lower vertical slits of the first and second inner straps, and a plurality of vane gaps each formed between the two flow mixing vanes of each of the main supports of said second inner straps are spaced apart from each other at the same interval as a pitch of the fuel rods. claim 1 3. The spacer grid according to claim 1 , wherein the two flow mixing vanes, formed on each of the main supports of the first and second inner straps and disposed in a central region of a flow channel, are rotationally symmetrical about crossing line of the first and second inner straps. claim 1 4. The spacer grid according to claim 1 , wherein the two flow mixing vanes, formed on each of the main supports of the first and second inner straps, are deflected in opposite directions, with peaks of said flow mixing vanes directed toward the gaps between the fuel rods set in the square cells. claim 1 5. The spacer grid according to claim 1 , wherein each of said main supports of the first and second inner straps has an equilateral trapezoidal shape, with a top edge of said main support being integrated with the two flow mixing vanes and being parallel to a bottom edge integrated with the top edge of an associated strap body. claim 1 6. The spacer grid according to claim 1 , wherein each of said upper and lower sub-supports of the first and second inner straps is integrated with the bottom edge of an associated strap body and has an isosceles triangular shape. claim 1 7. The spacer grid according to claim 1 , wherein said interlaced first and second inner straps are seam-welded together along at least one of each of four upper and four lower axial junction lines formed at each intersection. claim 1 8. The spacer grid according to claim 1 , wherein the two flow mixing vanes, formed on each of the main supports of the first and second inner straps, each have a first edge perpendicular to the top edge of the main support, a second edge extending upward from a top end of said first edge while forming an obtuse angle between the first and second edges, a third edge extending downward from a top end of said second edge while being curved with a predetermined curvature, a fourth edge extending between the top edge of the main support and the third edge while being parallel to the first edge, and a base portion of the vane bending along bottom points of the first and fourth edges while being integrated with the top edge of the main support. claim 1
	abstract	Test molding and mass-production molding are performed by an injection molding machine that includes a control apparatus in which neural networks are used. A quality prediction function determined based on the test molding is revised as necessary during mass-production molding.
047120150	description	A shield 10 for a nuclear reactor core includes a conical side 11 supported on a concrete vault 11a, a normally fixed radially outer annular roof shield 12 (only part shown) and a central radially inner above-core shield 13 (only part shown). The shields 12, 13 are normally fitted with concrete in spaces 9. The shield may have penetrations, one of which is shown at 8. The inner shield 13 can rotate about a vertical axis and may itself have a further inner part also rotatable about a vertical axis. The shield 12 has upper wall 7 and bottom wall 6. The shield 12 includes radially inner wall 14 connected by uninterrupted annular interlocking keys and keyways shown schematically at 15, 15a to the annular wall 16 of the shield 13. The keys connecting are present as a full circle in this plane. In the present case an upper portion 17 of the wall 14 is free standing or cantilevered ie is not connected to the upper wall 7 and the lower portion 18 is fully built into the roof 12. Thus in the normal condition the portion 17 is vertically above the encastre (fixed end) cylinder 18. The concrete engages the wall 14 and 17 in FIG. 1. The wall 17 is annular and continuous around the shield 12. If the roof rotates under pressure about an axis transverse to the vertical (arrow A) and the inner portion moves upward most of the upper cylinder portion 17 undergoes only vertical movement and there is substantially no radial expansion at the position of keys 15 which therefore remain locked and there is no loss of containment. Under these conditions the effect of roof rotation is accommodated in the free standing portion 17 by a region 20 of axial bending near to the connection 21 between the portions 17 and 18. A similar effect occurs at all points around the circumference. The distortion shown in FIG. 2 is exaggerated for clarity.
	summary
059050144	summary	DESCRIPTION 1. Field of the Invention. The present invention relates to a radiation image storage panel having a fluorescent layer comprising a binder and a stimulable phosphor dispersed therein. 2. Background of the Invention In radiography the interior of objects is reproduced by means of penetrating radiation which is high energy radiation belonging to the class of X-rays, .gamma.-rays and high energy elementary particle radiation, e.g. .beta.-rays, electron beam or neutron radiation. For the conversion of penetrating radiation into visible light and/or ultraviolet radiation luminescent substances are used called phosphors. In a conventional radiographic system an X-ray radiograph is obtained by X-rays transmitted imagewise through an object and converted into light of corresponding intensity in a so-called intensifying screen (X-ray conversion screen) wherein phosphor particles absorb the transmitted X-rays and convert them into visible light and/or ultraviolet radiation whereto a photographic film is more sensitive than to the direct impact of the X-rays. In practice the light emitted imagewise by said screen irradiates a contacting photographic silver halide emulsion layer film which after exposure is developed to form therein a silver image in conformity with the X-ray image. As a further development described e.g. in U.S. Pat. No. 3,859,527 an X-ray recording system is disclosed wherein photostimulable storage phosphors are used that in addition to their immediate light emission (prompt emission) on X-ray irradiation, have the property to store temporarily a large part of the energy of the X-ray image which energy is set free by photostimulation in the form of light different in wavelength characteristic from the light used in the photostimulation. In said X-ray recording system the light emitted on photostimulation is detected photo-electronically and transformed in sequential electrical signals. The basic constituents of such X-ray imaging system operating with storage phosphors are an imaging sensor containing said phosphor, normally a plate or panel, which temporarily stores the X-ray energy pattern, a scanning laser beam for photostimulation, a photo-electronic light detector providing analog signals that are converted subsequently into digital time-series signals, normally a digital image processor which manipulates the image digitally, a signal recorder, e.g. magnetic disk or tape, and an image recorder for modulated light-exposure of a photographic film or an electronic signal display unit, e.g. cathode ray tube. A survey of lasers useful in the read-out of photostimulable latent fluorescent images is given in the periodical Research Disclosure Volume 308 No. 117 p.991, 1989. From the preceding description of said two X-ray recording systems operating with X-ray conversion phosphor screens in the form of a plate or panel it is clear that said plates or panels serve only as intermediate imaging elements and do not form the final record. The final image is made or reproduced on a separate recording medium or display. The phosphor plates or sheets can be repeatedly re-used. Before re-use of the photostimulable phosphor panels or sheets a residual energy pattern is erased by flooding with light. From the point of view of image quality of the image storage panels, especially with respect to sharpness, the said sharpness does not depend upon the degree of spread of the light emitted by the stimulable phosphor in the panel, but depends on the degree of spread of the stimulable rays in the panel: in order to reduce this spread of light a mixture can be made of coarser and finer batches to fill the gaps between the coated coarser phosphor particles. A better bulk factor may be attained by making a mixture of coarser and finer phosphor grains resulting in a loss in sensitivity unless the said phosphor grains are only slightly different in sensitivity. For intensifying screens this topic has already be treated much earlier by Kali-Chemie and has been patented in U.S. Pat. Nos. 2,129,295; 2,129,296 and 2,144,040. Radiographs showing improved visualisation, comprising therefore a blue-light absorbing (yellow) dye have been described in EP-A 0 028 521. Especially the phosphor layer thickness can give rise to increased unsharpness of the emitted light, this being the more unfavourable if the weight ratio between the amount of phosphor particles and the amount of binder decreases for the same coating amount of said phosphor particles. Enhancing the weight ratio amount of phosphor to binder to provide sharper images, by decreasing the amount of binder leads to unacceptable manipulation characteristics of the screen due to e.g. insufficient elasticity and brittleness of the coated phosphor layer in the screen. One way to get thinner coated phosphor layers without changing the coated amounts of pigment and of binder makes use of a method of compressing the coated layer containing both ingredients at a temperature not lower than the softening point or melting point of the thermoplastic elastomer as has been described in EP-A 0 393 662. Another way free from compression manufacturing techniques has been proposed in WO 94/0531, wherein the binding medium comprises one or more rubbery and/or elastomeric polymers providing improved elasticity of the screen, high protection against mechanical damage, high ease of manipulation, high pigment to binder ratio and an improved image quality, especially sharpness. Early references referring to the improvement of sharpness of radiation image storage panels are related with the addition of a colorant to the panels. So in U.S. Pat. No. 4,394,581 a dye or colorant is added to the panel so that the mean reflectance of said panel in the wavelength region of the stimulating rays for said stimulating phosphor is lower than the mean reflectance of said panel in the wavelength region of the light emitted by said stimulable phosphor upon stimulation thereof. In U.S. Pat. No. 4,491,736 more specifically an organic colorant is disclosed which does not exhibit light emission of longer wavelength than that of the stimulating rays when exposed thereto. EP-A 0 165 340 and the corresponding U.S. Pat. No. 4,675,271 disclose a storage phosphor screen showing a better image definition by incorporation of a dye. An analogous effect brought about in phosphor layers of image storage panels by incorporation of dyes or colourants has further been described in EP-A 0 253 348 and the corresponding U.S. Pat. No. 4,879,202 and in EP-A 0 288 038. It is however an ever lasting demand to further direct investigations to improve sharpness. OBJECTS OF THE INVENTION Therefore it is an object of the present invention to provide a radiation image storage panel coloured with a dye which gives an excellent image resolution. Other objects and advantages will become clear from the following description and examples. SUMMARY OF THE INVENTION In accordance with the present invention a radiation image storage panel is provided having a support, an intermediate layer and a fluorescent layer comprising a binder and a stimulable phosphor dispersed therein, said panel being colored with a colorant so that the mean reflectance of said panel in the wavelength region of the stimulating rays for said stimulating phosphor is lower than the mean reflectance of said panel in the wavelength region of the light emitted by said stimulable phosphor upon stimulation thereof, characterized in that said colorant is a triarylmethane dye having at least one aqueous alkaline soluble group and is present in at least one of said support, said phosphor layer or an intermediate layer between said support and said phosphor layer.
	claims	1. A focused ion beam apparatus using a liquid metal ion source wherein:a liquid metal being used for said liquid metal ion source is concentrated in the vicinity of an aperture hole and forms a cover which does not expose an edge portion of the hole, said aperture hole is tapered on the side opposite to said liquid metal ion source so that an aperture hole diameter increases as it departs from said liquid metal ion source on the side opposite therein, and said aperture is a current limiting aperture disposed immediately beneath said liquid metal ion source. 2. A focused ion beam apparatus according to claim 1, wherein irregularities of a maximum roughness of 1 to 10 μm are formed at a portion which said liquid metal contacts with said aperture. 3. A focused ion beam apparatus according to claim 1, wherein the liquid metal on said aperture has a volume ranging from 5 mm3 to 17 mm3. 4. A focused ion beam apparatus according to claim 1, wherein said liquid metal is gallium and said aperture is tungsten. 5. A liquid metal ion source attachable to a focused ion beam apparatus, wherein:a liquid metal being used for said liquid metal ion source is concentrated in the vicinity of an aperture hole and forms a cover which does not expose an edge portion of the hole, said aperture hole is tapered on the side opposite to said liquid metal ion source so that an aperture hole diameter increases as it departs from said liquid metal ion source on the side opposite therein, and said aperture is a current limiting aperture disposed immediately beneath said liquid metal ion source. 6. A liquid metal ion source according to claim 5, wherein irregularities of a maximum roughness of 1 to 10 μm are formed at a portion which said liquid metal contacts with said aperture. 7. A liquid metal ion source according to claim 5, attachable to said focused ion beam apparatus, wherein the liquid metal on said aperture has a volume ranging from 5 mm3 to 17 mm3. 8. A liquid metal ion source according to claim 5, attachable to said focused ion beam apparatus, wherein said liquid metal is gallium and said aperture is tungsten.
	summary
	claims	1. A process for the detritiation of radioactive waste containing tritium, comprising:carrying out a thermal desorption by subjecting said waste, placed in a detritiation reactor (RT), to a flow of moist gas and subsequently recovering tritium in the form of gas by means of a membrane reactor (RM) in order to valorize the tritium for re-use, the thermal desorption comprising the following sub-steps:A) shredding and uniformly mixing the waste to be detritiated;B) placing said waste in a detritiation reactor (RT);C) sending inert gas and demineralized water to an evaporation/mixing device;D) feeding a moist gaseous mixture, constituted by said inert gas and vapour formed from said demineralized water, to said detritiation reactor (RT) so that said moist gaseous mixture traverses all the waste, giving rise to a formation of a moist gaseous current containing tritium;E) sending said gaseous current containing tritium to a membrane reactor (RM); andF) feeding said membrane reactor (RM) with a swamping gas, thus obtaining exit from the membrane reactor (RM) itself, as end products, of a gaseous current of isotopes containing tritium extracted from the waste and of a gaseous current of detritiated gases. 2. The process according to claim 1, wherein, in order to facilitate thermal desorption, the detritiation reactor (RT) is introduced into an oven that controls and regulates a temperature of the detritiation reactor (RT) around a pre-defined set-point value. 3. The process according to claim 2, wherein the pre-defined set-point value is 120° C. 4. The process according to claim 1, wherein the swamping gas of step F) is pure hydrogen. 5. The process according to claim 1,wherein the detritiation reactor (RT) is operated at a pressure equal to or higher than atmospheric pressure, andwherein the membrane reactor (RM) is operated at a pressure lower than atmospheric pressure. 6. The process according to claim 1, wherein, in order to keep the concentration of tritium within the detritiation reactor (RT) very low, the moist gaseous mixture flows at a flow rate equal to approximately 30 or 50 times the internal volume of the detritiation reactor (RT) per hour. 7. The process according to claim 1,wherein the moist inert gas is kept within the detritiation reactor (RT) at a pressure slightly higher than atmospheric pressure, andwherein the membrane reactor (RM) operates at a pressure of 100 mbar on a swamping-gas side and at a pressure of 900 mbar on a side of feed of gases coming from the detritiation reactor (RT). 8. The process according to claim 1, wherein a time of stay of the moist gaseous mixture in the detritiation reactor (RT) is long enough to guarantee transfer of tritium and of hydrogen isotopes, without high values of tritium concentration being reached in the moist gaseous current leaving the detritiation reactor (RT). 9. The process according to claim 1, wherein a time of stay of the waste in the detritiation reactor (RT) is long enough to guarantee that required values of decontamination are reached. 10. The process according to claim 4, wherein, in order to keep the concentration of tritium within the detritiation reactor (RT) very low, the moist gaseous mixture flows at a flow rate equal to approximately 30 or 50 times the internal volume of the detritiation reactor (RT) per hour.
	summary
	abstract	A proximity X-ray exposure apparatus for irradiating a reticle with X-rays generated from an X-ray source and irradiating a substrate with X-rays that have passed through the reticle. The apparatus includes a plasma X-ray source for generating X-rays by producing plasma, and a control device for controlling X-ray intensity distribution by controlling production of the plasma so that the plasma is produced at a plurality of positions in one irradiating operation of the substrate with the X-rays. The control device controls the X-ray intensity distribution in order to control the plurality of positions so that a required amount of defocusing, which is a size of a projection image corresponding to one point on the reticle formed by irradiating the reticle with X-rays generated at the plurality of positions, can be obtained.
	abstract	A method of correcting a mask pattern is described. A testing mask including a plurality of original patterns configured according to an original drawing data is provided. The original patterns in the testing mask are transferred to a photo-resistant layer to form a plurality of first post-development patterns and measure first dimensions of the first post-development patterns. A pattern shrink process is performed on the first post-development patterns to form a plurality of first post-shrink patterns and measure second dimensions of the first post-shrink patterns. The bias of each the first dimensions and the second dimensions are calculated. The original drawing data, the first sizes, the second sizes and the bias are collected to set a database. The data of the database is used to establish an optical proximity correction (OPC) model. According to the OPC model, an original drawing data is corrected to obtain a corrected drawing data.
052934101	description	DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a neutron generator 10 which may be used in a logging tool such as described e.g. in U.S. Pat. Nos. 4,794,792, 4,721,853 or 4,600,838, which are herein incorporated by reference. The major components of the neutron generator 10 are a hollow cylindrical tube 11 made of an insulating material such as alumina ceramic and having its respective longitudinal extremities fixed to a ceramic ring 12 and a conductive ring 13, an ion source 45, a gas supply means 25, an extracting electrode 50, and a massive copper target electrode 15. A transverse header 14 and the target electrode 15 close the rings 12 and 13, respectively, to provide a gas-tight cylindrical envelope. Ring 12 comprises parallel transversely disposed flanges 6, 7, 8, and 9, providing electrically conductive paths and sturdy support for the generator components as described subsequently in more complete detail. Flanges 6-9 are substantially equally spaced along ring 12, between header 14 and the corresponding extremity of tube 11. The gas supply means 25 is disposed transversely to the longitudinal axis I--I of the generator 10, between first flange 6 and second flange 7, closest to header 14. The gas supply means 25 comprises a helically wound filament 26 of tungsten, which may be heated to a predetermined temperature by an electric current from a gas supply power means 105 to which both ends 26a and 26b of filament 26 are connected. A film 44 of zirconium or the like, for absorbing and emitting deuterium and tritium, is coated on the intermediate turns of the filament 26 in order to provide a supply of these gases and to control gas pressure during generator operation. Due to physical isolation, a substantially uniform temperature can be maintained along the coated intermediate turns of the filament helix 26. As the gases released from the film 44 are withdrawn from the atmosphere within the envelope for ion generation, more gases are emitted to restore the envelope gas pressure to a level commensurate with the temperature of the intermediate portion of the filament helix 26. The gases emitted by the film 44 diffuse through holes provided in flanges 7-9, i.e. a hole 31 in second flange 7, a hole 33 in third flange 8 and holes 34, 35 in fourth flange 9. The gases emitted finally enter an ion source 45 interposed between the gas supply means 25 and the extremity of tube 11 facing ring 12. An annular shaped electrical insulator 90 is interposed between tube 11 and ring 12. More details on the structure of the neutron generator can be found e.g. in U.S. Pat. Nos. 3,756,682; or 3,775,216; or 3,546,512, which are herein incorporated by reference. The ion source 45 comprises a cylindrical hollow anode 57 aligned with the longitudinal axis I--I of the generator 10 and made out of either a mesh or a coil. Typically, a positive ionizing potential (either direct or pulsed current) comprised in the range of 100-300 volts relative to the cathode, is applied to the anode 57. In one exemplary embodiment of the invention, the anode 57 is about 0.75 inch (1.9 cm) long and has a diameter of approximately 0.45 inch (1.14 cm). The anode 57 is secured rigidly to flange 9, e.g. by conductive pads 60. The ion source 45 also includes a cathode 80 disposed close to the outside wall of the anode 57, in a substantially median position with respect to the anode. The cathode 80 comprises an electron emitter 81 consisting of a block of material susceptible, when heated, to emit electrons. Emitter 81 is fixed (e.g. by brazing) to the U-shaped end 82 of an arm 84 being itself secured to flange 8. The arm 84 provides also an electrical connection between the emitter 81 and a hot cathode heater current means 100 able to generate e.g. a few watts for heating the emitter. Heater current 100 is known per se (see U.S. Pat. Nos. 3,756,682, 3,775,216 or 3,546,512) and thus does not need to be further described. According to an alternate embodiment shown on FIG. 2A, the cathode 80 could also comprise two arms (similar to arm 84), each provided at one of its ends with a block of dispenser material, both arms being disposed outside the hollow anode 57. This embodiment (cathode disposed outside the anode) prevents the material evaporated from the cathode from coating the surface of suppressor 75 causing enhanced field emission. In a further alternate embodiment shown on FIG. 2B, the cathode 80 may also comprise a single arm provided at one end with an emitter, the arm being disposed inside the hollow anode 57, substantially in the center thereof. According to this embodiment, the cathode emitting surfaces are so arranged that electron emission is perpendicular to the axis of the ion source. This embodiment reduces the amount of cathode material being deposited on the suppressor surface. Now described in more detail is the structure of the cathode 80. The thermionic cathode 80 comprises an emitter block including a material forming a substratum and a material susceptible to emit electrons. Thermionic cathodes here mean heated cathodes, as opposed to cold cathodes which emit electrons when not heated. The thermionic cathodes can be broken down into: (i) those with inherent electron emission capability if they can be heated high enough in temperature without melting (e.g. pure tungsten or tantalum or lanthanum hexa boride), and (ii) those to which use a low work function material is applied, either to the surface of a heated substratum (such as thoria coated tungsten, oxide coated) [called "oxide cathode"], or impregnated by bulk into a porous substrate [called "dispenser" cathode]. General information on thermionic cathodes can be found in the book "Materials and Techniques for Electron Tubes" by W. Kohl, Reinhold Publishing, 1960, pages 519-566, which is herein incorporated by reference. In other words, "oxide" cathode involve what could be called a "surface" reaction, whereas in a "dispenser" cathode there occurs what could be called a "volume" reaction. General information on "dispenser" or "volume" type cathodes can be found e.g. in the article "Surface Studies of Barium and Barium Oxide on Tungsten and its Application to Understanding the Mechanism of Operation of an Impregnated Tungsten Cathode" by R. Forman, in Journal of Applied Physics, vol. 47, No 12, December 1976, pages 5272-5279; or in the article "A Cavity Reservoir Dispenser Cathode for CRT's and Low-cost Traveling-wave Tube Applications" by L. R. Falce, in IEEE transactions on electron devices, vol 36, No 1, January 1989. Cathodes of the "oxide" or "surface" type are described in the article "Compact Pulsed Generator of Fast Neutrons" by P. O. Hawkins and R. W. Sutton, The Review of Scientific Instruments, March 1960, Vol. 31, Number 3, Pages 241-248; in "Focused Beam Source of Hydrogen and Helium Ions" by G. W. Scott, Jr., in Physical Review, May 15, 1939, vol 55, pages 954-959; in U.S. Pat. No. 3,490,944 or U.S. Pat. No. 3,276,974; or in the article "Operation of Coated Tungsten Based Dispenser Cathodes in Nonideal Vacuum" by C. R. K. Marrian and A. Shih, in IEEE Transactions on Electron Devices, vol. 36, No 1, January 1989. All of the above mentioned documents are incorporated herein by reference. The thermionic cathode 80 of the ion source of the present invention is preferably of the "dispenser" or "volume" type. A dispenser cathode used in a hydrogen environment maximizes electron emissions per heater power unit compared to other thermionic type cathodes (such as LaB.sub.6 or W), while operating at a moderate temperature. The emitter block 81 comprises a substrate made of porous tungsten, impregnated with a material susceptible to emit electrons, such as compounds made with combinations of e.g. barium oxide and strontium oxide. Each cathode has different susceptibility to their operating environment (gas pressure and gas species). Dispenser cathodes are known to be the most demanding in terms of the vacuum requirements and care that is needed to avoid contamination. One, among others, of the (novel and non-obvious) features of the invention includes using, in a neutron generator, a dispenser cathode which works as long as several hundred hours in a hydrogen gas environment of pressure on the order of several mTorr, providing an average electron emission current of from 50 to 80 mA yet requiring only a few watts of heater power. The cathode 80 according to the invention is provided with hot cathode heater current 100 which is distinct from the ion source voltage supply 102. Such implementation permits a better control of both heater current means 100 and voltage supply 102. The extracting electrode 50 is disposed at the end of the ion source 45 facing target electrode 15, at the level of the junction between tube 11 and ring 12. The extracting electrode 50 is supported in fixed relation to the ring 12 by a fifth flange 32. The extracting electrode 50 comprises a massive annular body 46, e.g. made of nickel or an alloyed metal such as KOVAR (trademark), and which is in alignment with the longitudinal axis I--I of the tube 11. A central aperture 47 in the body 46 diverges outwardly in a direction away from the ion source 45 to produce at the end of body 46 facing target electrode 15 a torus-shaped contour 51. The smooth shape contour 51 reduces a tendency to voltage breakdown that is caused by high electrical field gradients. Moreover, the extracting electrode 50 provides one of the electrodes for an accelerating gap 72 that impels ionized deuterium and tritium particles from the source 45 toward a deuterium- and tritium-filled target 73. The target 73 comprises a thin film of titanium or scandium deposited on the surface of the transverse side, facing ion source 45, of the target electrode 15. The potential that accelerates the ions to the target 73 is established, to a large extent, between the extracting electrode 50 and a suppressor electrode 75 hereafter described. The suppressor electrode 75 is a concave member that is oriented toward the target electrode 15 and has a centrally disposed aperture 78 which enables the accelerated ions to from the gap 72 to the target 73. The aperture 78 is disposed between the target 73 and the extracting electrode 50. The suppressor electrode 75 is connected to a high voltage supply means 103 which is also connected, through a resistor "R" to the ground. In order to prevent electrons from being extracted from the target 73 upon ion bombardment (these extracted electrons being called "secondary electrons"), the suppressor electrode 75 is at a negative voltage with respect to the voltage of the target electrode 15. The velocity of the ions leaving the ion source 45 is, on an average, relatively lower than ion velocity in a known Penning source. Consequently, these slow moving ions tend to generate a tail in the neutron pulse, at the moment the voltage pulse is turned off. The presence of an end tail is detrimental to the pulse shape which, as already stated, is of importance. The present invention remedies this situation by adding to the extractor a cut-off electrode, in the form of a mesh screen 95, which is fixed, e.g. by welding, to the aperture 47 of the extracting electrode 50, facing the ion source 45. The mesh screen 95 (cut-off electrode) is e.g. made of high transparency molybdenum. The cut-off electrode 95 is submitted to voltage pulses synchronized with and complementary to the voltage pulses applied to the anode 57. The pulses applied to cut-off electrode 95 are positive and e.g. of 100 to 300 volts. In an alternate embodiment, the cut-off electrode 95, instead of being submitted to voltage pulses, is maintained at a positive voltage, of e.g. a few volts. This low positive voltage prevents the slow ions produced at the end of the pulse in the ion beam from leaving the ion source, and thus allows one to truncate the terminal part of the ion beam, which in turn provides a sharp cut-off at the end of the neutron pulse (i.e. a short fall time). The cut-off electrode 95 is preferably made of a metallic grid in the form of a truncated sphere, and its concavity turned towards the target 73. Part of the mesh screen 95 might protrude inside cylindrical hollow cathode 57. FIG. 3 shows two examples of neutron pulses obtained respectively with cut-off electrode (solid line) and without cut-off voltage (dotted line), everything else being equal. The benefit to the neutron pulse shape (especially the fall time) derived from the cut-off electrode is easily appreciated from FIG. 3. In an alternate embodiment, (wherein the extractor 50 is not provided with the cut-off screen 95), the end tail of the ion beam is truncated by applying a positive voltage pulse to the extracting electrode 50. In order to generate a controlled output of neutrons, continuously or in recurrent bursts, an ion source voltage supply means 102 provides power for the bombarding ion beam. For pulse operation, an ion source pulser 101 is provided at the output of ion source voltage supply 102 to regulate the operation of voltage supply to the ion source. The ion source pulser 101 has a direct output connected to the anode 57 (via flange 9) and a complementary output connected to extracting electrode 50. The high voltage supply 103, the ion source voltage supply 102, and the ion source pulser 101 may be of any suitable type such as e.g. described in U.S. Pat. Nos. 3,756,682 or 3,546,512, already referred to. A gas supply means regulator 104 (connected to the high voltage supply means 103) regulates, through a gas supply power means 105, the intensity of the ion beam by controlling the gas pressure in the envelope. The current flowing through resistor r provides a measure of ion beam current which enables the gas supply regulator 104 to adjust the generator gas pressure accordingly. The voltage developed by the high voltage supply 103, moreover, is applied directly to the suppressor electrode 75 and through a resistor R to the target electrode 15. The voltages thus developed provide the accelerating and suppressor voltages, respectively. During operation, current is passed through the filament 26 of the gas supply 25 in an amount regulated by the gas supply regulator means 104 to achieve a deuterium-tritium pressure within the generator envelope that is adequate to obtain a desired ion beam current and ad hoc conditions for the generator to operate. The high voltage established between the extracting electrode 50 and the suppressor electrode 75 produces a steep voltage gradient that accelerates deuterium and tritium ions from the electrode aperture 47 in extracting electrode 50 toward the target 73. The energy imparted to the ions is sufficient to initiate neutron generating reactions between the bombarding ions and the target nuclei and to replenish the target 73 with fresh target material. Initial bombardment of a fresh target 73 by, for example, a half-and-half mixture of deuterium and tritium ions, produces relatively few neutrons. As increasing quantities of impinging ions penetrate and are held in the lattice of the target, however, the probability for nuclear reactions increases. Thus, after a short period of ion bombardment, a continuous or pulsed output ranging from 10.sup.7 to 10.sup.9 neutrons per second is reached. As previously described, the regulator 104 regulates the power supplied to the filament 26 and thereby manipulates the tube gas pressure and the ion beam intensity to produce the desired neutron output. If the neutron output should increase as a result of an increase in the current, a corresponding increase in current through the resistor causes the regulator 104 to decrease the filament power supply and thereby reduce the gas pressure within the generator. The lower gas pressure in effect decreases the number of ions available for acceleration, and thus restores the neutron output to a stable, predetermined value. Similarly, a decrease in the current through the resistance causes the regulator 104 to increase the generator gas pressure. If desired, the neutron output can be monitored directly, and either the ion source voltage supply or the high voltage power supply can be controlled automatically or manually to achieve stable generator operation. In the event the generator is supplied only with deuterium gas, neutrons are produced as a result of deuterium-deuterium interactions, rather than the deuterium-tritium reactions considered in the foregoing illustrative description. The present invention provides the following advantages, as compared to the prior art neutron generators. Since no magnet is necessary, the neutron generator is lighter and of smaller dimensions than the prior art generators. This is a substantial improvement for logging applications due to the limited space available in the logging tools. The use of a dispenser cathode virtually cancels, or at least substantially reduces, the delay between the time the generator is turned on and the production of neutrons, and thus provides a sharp rise of neutron burst. This also results in an improved burst timing control. Also, the thermionic cathode operates without troublesome plasma mode transitions responsible for disturbing jumps in the neutron output, and for difficulties in using the beam control feedback loop with the reservoir heater. The erosion of the extractor and consequent coating of insulator surfaces, by sputtered metal due to ion bombardment, is substantially reduced because of the relatively low anode voltage. The reduced anode voltage allows one to use simplified pulsing circuitry. The voltage applied to the cut-off screen-electrode 95 allows the tail of the ion beam to be cut-off, made mainly of slow ions, and thus allows the generation of a neutron pulse showing a sharp end edge. Finally, the lifetime of the cathode is in the range of several hundred hours in a hydrogen gas environment of pressure on the order of several mTorr providing an average electron emission current of from 50 to 80 mA, yet requiring only a few watts of heater power. Above all, the invention is beneficial in term of pulse shape. In particular, the neutron pulse shows the following characteristics, as can be seen from FIG. 3: the time required for the instantaneous neutron output to reach its maximum, called plateau, measured from the instant when the voltage is applied to said cathode, is less than 1.5 microsecond; PA1 the fall time, i.e. the period of time between the instant when the voltage applied to said cathode is turned off and the instant when the instantaneous neutron output falls to 10% of the plateau, is less than 0.5 microsecond; PA1 the neutron output reaches a plateau which remains constant within a 10% range thereof, over a pulse time width comprised between 5 and 500 microseconds; PA1 the time lag between the instant when the voltage is applied to said cathode and the instant when the instantaneous neutron output reaches 10% of the plateau, is less than 0.5 microsecond; another benefit is that the time lag is independent of operational parameters of the ion source, such as gas pressure; and PA1 the rise time for the neutron output to reach 90% of the plateau, measured from the time when the neutron output is 10% of said plateau, is less than 1 microsecond.
	description	The invention relates to a method and a device for testing a weld seam, located on the inner surface of a reactor pressure vessel of a nuclear reactor, by which the outer circumference of an instrumentation nozzle leading into the interior of the reactor pressure vessel is welded onto the reactor pressure vessel. The reactor pressure vessels of pressurized water reactors are frequently provided with bushings on their lower head (bottom head), by means of which bushings the core instrumentation probes are inserted from the outside into the reactor pressure vessel. These bushings or instrumentation nozzles (LCIP=Lower Core Instrumentation Penetration) are produced from a forged rod with a hole through it, and are welded in by means of a weld seam which is located inside the reactor pressure vessel and runs around their outer circumference in an annular fashion. Particularly in older systems, the bushings, the weld filler and the buffer weld, which is applied on the inner surface of the reactor pressure vessel, use materials which have been found to be particularly susceptible to stress corrosion cracking. In this case, stress corrosion cracking is a corrosion process which occurs in the vicinity of water on components which have internal stresses. The weld seam is usually designed as a “J-groove weld” and ends, toward the instrumentation nozzle, in a fillet. The geometry of the weld seam is in this case dependent on the position of the instrumentation nozzle on the bottom head. By way of example, the weld seam, by which an instrumentation nozzle is welded on in the center of the bottom head, has a contour which is rotationally symmetrical about the central axis of the instrumentation nozzle, whereas the contour of the weld seam of an instrumentation nozzle which is welded on at the edge of the bottom head is asymmetric. Since the weld seams are susceptible to stress corrosion cracking, they need to be inspected at regular intervals. Owing to the complexity of the test problem, which is caused in particular by the asymmetric contour of the weld seam, this inspection is generally carried out only visually using a video camera, which is introduced into the reactor pressure vessel. To this end, the fuel assemblies need to be unloaded prior to this. In the course of such a visual inspection, however, it is possible to identify only cracks which have already reached a considerable size. As an alternative to such a visual inspection, an attempt has been made to inspect the weld seams using an eddy current testing probe (http://www.nrc.gov.edgesuite.net/reactors/operating/op s-experience/pressure-boundary-integrity/bottom-head-issues/bottom-head-files/july-17-nrc.pdf). This is made more difficult, however, by the irregular surface geometry of the weld seam. Additionally, in the case of an eddy current test, the determination of the crack depth is restricted by the skin effect. Further, it is also necessary in this case for the core to be completely unloaded. It is known from U.S. Pat. No. 5,460,045 to test the weld seam of an instrumentation nozzle of a boiling water reactor, which nozzle is newly inserted in the course of repair measures, using an ultrasound test probe which can be moved into the interior of the instrumentation nozzle. Depending on the objective of the test, the ultrasound test probe contains five or nine ultrasound transducers which are aligned such that both crack faults which run in the circumferential direction and those which are aligned in the radial direction can be identified. In order to identify crack faults which are aligned in the circumferential direction, at least two ultrasound transducers are provided which are axially spaced apart from one another and produce ultrasound signals which each propagate at an angle to the longitudinal axis of the probe. One ultrasound transducer produces a radially propagating ultrasound signal and two further ultrasound transducers produce an ultrasound signal which propagates at a right angle to the axial direction in the clockwise or counterclockwise direction. In order to inspect the annularly peripheral weld seam, an ultrasound test probe with five ultrasound transducers is used. An ultrasound test probe with five differently aligned ultrasound transducers, which can be inserted into a pipe nozzle, is also known from EP 0 539 049 A1. In this known embodiment, all the ultrasound transducers are arranged on a single plane which is aligned at a right angle to the longitudinal axis of the ultrasound test probe. The invention is now based on the object of providing a method which can be used to test, with great reliability and detection sensitivity, a weld seam which is located on the inner surface of a reactor pressure vessel and can be used to weld the outer circumference of an instrumentation nozzle leading into the interior of said reactor pressure vessel onto the reactor pressure vessel. The invention is further based on the object of providing a device which is suitable for carrying out this method. As regards the method, the stated object is achieved according to the invention by virtue of a method with the features of patent claim 1. In this method, an ultrasound test probe is inserted into the instrumentation nozzle and is used to couple an ultrasound signal into the instrumentation nozzle in the region of the weld seam and to receive a reflected ultrasound signal. The invention is based here on the consideration that the sensitivity with which a crack fault can be detected is improved considerably with respect to the methods known in the prior art by coupling an ultrasound signal into the weld seam starting from the inner face of the instrumentation nozzle on account of the simple geometric conditions prevailing on the inner surface of the instrumentation nozzle. Moreover, the complexity for guiding the ultrasound test probe is simplified since the latter can be moved without problems inside the instrumentation nozzle on the inner surface in its circumferential direction and in its axial direction by means of a rotational movement or an axial translatory movement and does not have to be guided on a complex weld seam surface. Since the weld seam is tested starting from the inner surface of the instrumentation nozzle, it is also possible in principle to carry out the test without unloading the fuel assemblies from the reactor pressure vessel for this purpose. Since the transmitted ultrasound signal propagates inside the instrumentation nozzle at an oblique angle, i.e. at an angle to the central axis, even crack faults which extend at an angle to this central axis and are located in the region of the weld seam surface can be detected with high detection sensitivity. Since, for the purposes of producing the ultrasound signal, an ultrasound transducer array is additionally used which is constructed from a plurality of transducer elements arranged one next to one another in a longitudinal direction and is arranged parallel to the central axis in terms of its longitudinal direction and whose transducer elements are actuated with a time delay with respect to one another for adjusting the angle at which the ultrasound signal propagates inside the instrumentation nozzle in relation to the central axis, a particularly good detectability of crack faults which extend with different inclinations at an angle to the central axis is achieved. Moreover, the ultrasound signal can be focussed additionally at different depths of focus by means of corresponding actuation of the transducer elements with a time delay. This achieves particularly high test sensitivity for crack faults located at this depth of focus. In an advantageous refinement of the method, the transmitted ultrasound signal propagates inside the instrumentation nozzle on a plane which is parallel to and spaced apart from the central axis of the instrumentation nozzle. In other words, the ultrasound signal is transmitted inside the instrumentation nozzle in such a direction that the projection of its propagation direction onto a plane, which extends at a right angle to the central axis of the instrumentation nozzle and through the point of incidence of the ultrasound signal on the inner surface, assumes an angle, which is different from zero, to the normal which is at a right angle to the inner surface at the point of ensonification or of incidence. These measures can be used to detect cracks which extend both axially and radially in the weld seam particularly well. The method is carried out in particular with at least one ultrasound transducer array operated according to a pulse-echo technique. An additionally improved assessment of the received reflected ultrasound signals is possible if an ultrasound transducer arrangement, which has at least two ultrasound transducer arrays and can be operated according to a transmitting/receiving technique, is used, with the ultrasound transducer arrays being arranged in a fashion spaced apart from one another and mirror-symmetric to a plane containing the central axis. Such an arrangement can be used in particular to detect crack faults which extend in the circumferential direction with particular reliability. In a further preferred refinement of the invention, transverse waves are used for the transmitted ultrasound signal. As a result, in particular the traceability of cracks which extend radially and in the axial direction is improved. As regards the device, the object is achieved by virtue of a device having the features of patent claim 6 whose advantages, and also the advantages of its subordinate subclaims, correspond analogously to the advantages stated for the associated method claims. For the purposes of explaining the invention in further detail, reference is made to the exemplary embodiments of the drawing, in which: In accordance with FIGS. 1 and 2, a hollow cylindrical instrumentation nozzle 4 leading into the interior of a reactor pressure vessel 2 is arranged in the bottom head of the reactor pressure vessel 2. On its inner surface, the reactor pressure vessel 2 is provided with a buffer weld 6 or weld plating made of Inconel or stainless steel. The instrumentation nozzle 4 is welded in on this inner surface with a weld seam 8, which annularly surrounds the nozzle, using a weld filler made of Inconel. In the illustrated example this weld seam 8 now has crack faults 10 which start from the free surface of the weld seam 8, which surface has the shape of a hollow fillet, and extend into the interior of the weld seam 8 at an angle to the central axis 12 of the instrumentation nozzle 4. These crack faults extend on the surface approximately in the circumferential direction and have the shape of a half ellipse, as can be seen from the dashed illustration of FIG. 2. The example of FIGS. 3 and 4 illustrates plane crack faults 14 which likewise start from the free surface of the weld seam and, unlike the crack faults 10 illustrated in FIGS. 1 and 2, are aligned substantially radially to the central axis 12. In accordance with FIG. 5, a device in accordance with the invention comprises an ultrasound test probe 20 which can be inserted into the interior of an instrumentation nozzle 4, whose inner wall is illustrated only with dashed lines in the figure, and whose outside diameter is only slightly smaller than the internal diameter of the instrumentation nozzle 4. The ultrasound test probe 20 comprises a cylindrical probe head 22, which is attached via a bellows 24 to an advancing rod or a flexible advancing tube 26, by means of which it can be inserted into the instrumentation nozzle 4 and be advanced therein up to the height of the weld seam. It is also possible to provide a universally jointed hinge rather than a bellows 24 for the purposes of a flexible coupling between the advancing rod 26 and probe head 22. A linear ultrasound transducer array 30 is arranged in the probe head 22 on a damping body (backing) 28 such that its transmission face is situated approximately in a plane containing the longitudinal axis 32 of the probe head 22. The linear ultrasound transducer array 30 is constructed from a plurality of transducer elements arranged next to one another in a longitudinal direction and is arranged parallel to the longitudinal axis 32 of the probe head 22 in terms of its longitudinal direction. The ultrasound transducer array 30 is embedded in a half-cylindrical lead body 34 made of PMMA, whose surface, which faces away from the ultrasound transducer 30, is simultaneously used as a cylindrical coupling face 36 which is brought to bear on the inner surface of the instrumentation nozzle 4. In order to achieve coupling which is as gap-free as possible, a plurality of, in the exemplary embodiment four, knob-like supporting elements 38, which are resiliently supported on the inner surface of the instrumentation nozzle 4 and press the coupling face 36 onto the inner surface of the instrumentation nozzle 4, which faces away from the supporting elements 38, are arranged on the face of the probe head 22, which faces away from the coupling face 36. The ultrasound test probe 20 is connected to a control and evaluation device 40, which is only schematically indicated in the figure and can be used to actuate the individual transducer elements with a time delay such that the ultrasound signal S which is transmitted by the ultrasound transducer 30 and is preferably a transverse wave propagates inside the ultrasound test probe 20 at an angle to its longitudinal axis 32 and thus also at an angle to the central axis 12 of the instrumentation nozzle 4, which virtually coincides with the longitudinal axis 32. The transmitted ultrasound signal S then strikes the inner surface of the instrumentation nozzle 4 at an oblique angle α and is additionally refracted during the transition into the instrumentation nozzle 4 toward the longitudinal axis 32, with the result that it propagates at an oblique angle α′, which is smaller than the oblique angle α, in the instrumentation nozzle 4 toward the weld seam. In this manner, crack faults 10 which are aligned at an angle to the longitudinal axis 32 or to the central axis 12 can be reliably detected using an ultrasound transducer 30, which is operated according to the pulse-echo method. In the illustrated example, the angle α′ is adjusted such that the transmitted ultrasound signal S strikes an interface formed by the crack fault 10 at a right angle and is reflected back on itself, with the result that it is received in the receiving operation by the transducer elements which are actuated with a time delay according to the transmission operation. FIG. 6 shows that the linear ultrasound transducer array 30, which is aligned at a right angle to the plane of the drawing in terms of its longitudinal axis, is also arranged with a lateral offset to the longitudinal axis 32 of the ultrasound test probe 20 such that its transmission axis, which is at a right angle to the transmission face in the centroid of this transmission face in the case of actuation of all the transducer elements without time delay, is arranged spaced apart from the central axis 12 (not drawn in the figure for reasons of clarity) of the instrumentation nozzle 4, which central axis is arranged offset only slightly with respect to the longitudinal axis 32 in the case that the ultrasound test probe 20 is inserted into the instrumentation nozzle 4. The transmitted ultrasound signal S then propagates inside the ultrasound test probe 20 in a plane 42 which is parallel to and spaced apart from the longitudinal axis 32 of the ultrasound test probe 20 and thus also from the central axis 12 of the instrumentation nozzle 4. An ultrasound signal S (all the transducer elements are actuated simultaneously), which propagates at a right angle to this longitudinal axis 32 in the direction of this transmission axis, then assumes, at the point of incidence A, an angle β, which is different from zero, to the normal 44 which is at a right angle in this point of incidence A to the inner surface, with the result that, as it enters the instrumentation nozzle 4, it is refracted away from this normal 44 and propagates there at an angle β′>β with respect to said normal 44. In other words, the ultrasound signal S produced in the instrumentation nozzle 4 has a component T which is tangential to its circumference and is aligned, in the illustrated exemplary embodiment, counterclockwise. In the case of an ultrasound signal S propagating in the plane 42 at an angle to the longitudinal axis 32, i.e. with a direction component at a right angle to the plane of the drawing, the non-central arrangement of the ultrasound transducer array 30 accordingly has the effect that the projection of the propagation direction of the transmitted ultrasound signal S onto a plane, which extends at a right angle to the central axis 12 of the instrumentation nozzle 4 and through the point of incidence A of the ultrasound signal on the inner surface, assumes an angle β, which is different from zero, to the normal 44 which is at a right angle at the point of incidence A on the inner surface. In the exemplary embodiment of FIG. 7, two ultrasound transducer arrays 30 are provided, which are arranged next to one another and can be operated both by themselves in the pulse-echo operation and in the transmitting/receiving operation, in the case of which one of the ultrasound transducer arrays 30 transmits an ultrasound signal S and the other one of the ultrasound transducer arrays 30 receives a reflected ultrasound signal R. The ultrasound transducer arrays 30 are mirror-symmetric to a plane 50, which contains the longitudinal axis 32 and extends at a right angle to the plane of the drawing, in a shared plane 52, which likewise contains the longitudinal axis 32, i.e. with transmission faces which extend parallel to one another in this plane 52, with the result that they produce ultrasound signals S in the instrumentation nozzle 4, whose propagation directions in the instrumentation nozzle have components T, which are tangential to its circumference and are aligned in the opposite direction with respect to each other, i.e. clockwise and counterclockwise. These measures can be used to ensonify cracks from opposite directions in the pulse-echo operation. This increases the likelihood of finding the cracks. If the ultrasound transducer arrays 30 are operated in the transmitting/receiving operation, cracks which are aligned in the circumferential direction about the instrumentation nozzle can be found here particularly well. In the exemplary embodiment according to FIG. 8, the ultrasound transducer arrays 30 are likewise arranged in a fashion mirror-symmetric to a plane 50 containing the longitudinal axis 32, but at an inclination with respect to one another, in order to thus enable in the transmitting/receiving operation an additional adjustment of the propagation conditions to the distance between a crack fault extending in the circumferential direction and the inner surface of the instrumentation nozzle. In the case of the inclination which is illustrated in an exaggerated manner in the example of the figure, in which the transmission faces face each other, crack faults can be detected which are situated closer to the inner surface. 2 reactor pressure vessel 4 instrumentation nozzle 6 buffer weld 8 weld seam 10, 14 crack fault 12 central axis 20 ultrasound test probe 22 probe head 24 bellows 26 advancing rod 28 backing 30 ultrasound transducer array 32 longitudinal axis 34 lead body 36 coupling face 38 supporting element 40 control and evaluation device 42 plane 44 normal 50, 52 plane A point of incidence S, R transmitted, reflected ultrasound signal T tangential component α, β angles
046684646	summary	BACKGROUND OF THE INVENTION In the design of stellarators as plasma confinement devices and candidates for fusion reactors, simplifying assumptions concerning basic MHD equilibrium have been made. In previous analyses of helical axis stellarators, the assumption has been made that for large aspect ratio, the stellarator could be approximated by an infinite cylinder. This assumption reduced the MHD equilibrium equations to two-dimensions, thus affording simplified solutions. However, during experiments on such stellarators, plasma confinement was lost at high plasma pressure, contrary to theoretical predictions based on two-dimensional equilibrium solutions. The inventors have recently determined that in a three-dimensional MHD equilibrium, the diamagnetic and Pfirsch-Schl/u/ ter currents driven by the pressure on any given flux surface may resonate with the rotational transform of a flux surface elsewhere in the plasma. This results in the appearance of magnetic islands and the destruction of flux surfaces in the equilibrium. These resonant equilibrium currents are unique to three-dimensional equilibria and are precluded by symmetry in one or two dimensions. In one- or two-dimensional equilibria islands may be generated by the appearance of a (symmetry breaking) tearing instability. However, the islands driven by resonant diamagnetic and Pfirsch-Schl/u/ ter currents are intrinsic to the equilibrium. When these islands are sufficiently large that they overlap, the flux surfaces are destroyed, and there is no equilibrium. Therefore, it is an object of the present invention to provide a method and apparatus for maintaining three-dimensional MHD equilibrium in helical axis stellarators. Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. SUMMARY OF THE INVENTION To achieve the foregoing and other objects and in accordance with the purposes of the present invention, a method of maintaining three-dimensional MHD equilibrium in a plasma contained in a helical axis stellarator may comprise the steps of: providing a current through a resonant coil system about said stellarator, said coil having a configuration such that said current therethrough generates a magnetic field cancelling the resonant magnetic field, B.sub.1, produced by currents driven by the plasma pressure at any given flux surface resonating with the rotational transform, .chi., of another flux surface in the plasma; and varying said current as a function of .beta., where .beta.=2p.sub.o /B.sub.o.sup.2, p.sub.o is the average plasma pressure, and B.sub.o is the average stellarator magnetic field. Apparatus for maintaining three-dimensional MHD equilibrium in a plasma contained in a helical axis stellarator may comprise: a resonant coil system about said stellarator, said coil having a configuration such that current therethrough generates a magnetic field cancelling the resonant magnetic field, B.sub.1, produced by currents driven by the plasma pressure on any given flux surface resonating with the rotational transform, .chi., of another flux surface in the plasma. Suitable resonant coil systems may include helical coils wound about the stellarator and modular coils. For the case of resonant helical coils .chi.=n/m, where m is the number of periods of the coil, and n is the number of turns of the coil carrying the current in the same direction. Expressions for the resonant magnetic field are developed in the following section. DETAILED DESCRIPTION OF THE INVENTION The MHD equilibrium equation, EQU .gradient.p=j.times.B, also describes steady flow in an incompressible, inviscid, neutral fluid if B.fwdarw.v and p+B.sup.2 2.fwdarw.-p, where p is the pressure of the neutral fluid. This equivalence is clear if the MHD equilibrium equation is rewritten in the form EQU .gradient.(p+B.sup.2 /2)=B.multidot..gradient.B. The MHD equilibrium .beta. limit corresponds to a condition for the onset of stochastic, steady flow. The resonant pressure driven currents in an MHD equilibrium are associated with the variation of .intg.dl/B on the corresponding rational surface, where the integral is taken around a closed field line. There is a distinction between direct resonances, due to the variation of .intg.dl/B in the vacuum field, and nonlinear resonances, due to a variation of .intg.dl/B that arises in the presence of finite .beta.. The amplitude of the direct resonances can be minimized by proper design of the stellarator. The nonlinear resonances, on the other hand, are intrinsic to the three-dimensional nature of the equilibrium, and give a fundamental .beta. limit for each type of stellarator. Even if .intg.dl/B is constant on every rational surface in the vacuum field, it is generally not constant on any rational surface in the presence of finite .beta.. Adding a pressure p(.psi.) to a given vacuum field B, where .psi. is constant on the vacuum flux surfaces, the diamagnetic current at low .beta. is approximately given by EQU j.sub..perp. =(1/B.sup.2)B.times..gradient.p. (1) The corresponding Pfirsch-Schl/u/ ter current is determined by .gradient..multidot.j=0, or EQU B.multidot..gradient.(j.sub..parallel. /B)=-.gradient..multidot.j.sub..perp.. (2) The total field is approximately given by the vacuum field, B plus the field driven by these plasma currents, which we call B.sub.1. If .beta. is sufficiently small, the finite .beta. shifts of the flux surfaces are determined by B.sub.1. We can iterate the above procedure, calculating the diamagnetic and Pfirsch-Schl/u/ ter currents from B+B.sub.1. At low .beta. the corrections to the currents are small. The pressure driven currents are conveniently determined in a set of vacuum flux coordinates (.psi.,.theta.,.phi.) such that EQU B=g.gradient..phi., (3) where cg/2 is the total poloidal current in the coils. The Jacobian is then EQU J=g/B.sup.2. (4) The currents are obtained in terms of the Fourier decomposition of the Jacobian, ##EQU1## where the prime indicates that the term n=0, m=0 is omitted from the sum. In neglecting the sin (n.phi.-m.theta.) terms in Eq (5) we have assumed for convenience a symmetry with respect to double reflection in an appropriately chosen poloidal and equatorial plane. Most stellarator designs have this symmetry. Because all of results are expressed in terms of the .delta..sub.nm, it is important to note that for any given vacuum field the .delta..sub.nm can be determined numerically in a straightforward manner by an integration along the field lines. In solving Eqs. (1) and (2) for the lowest order currents, we take the equilibrium to have zero net current within each flux surface, as is appropriate for stellarators. For p(.psi.) given, the solution of these equations is then ##EQU2## The resonant currents give rise to a resonant part of B.multidot..gradient..psi., which opens up an island at such a rational surface, so that the resonant current vanishes as we approach the rational surface itself. The island width increased as .sqroot..beta.. The importance of such islands can be minimized by properly designing the vacuum field to minimize .delta..sub.nm for those n,m corresponding to a rational surface, .chi.=n/m. The resonant terms in Eq. (6) give rise to resonant components of B.sub.1 .multidot..gradient..sub..psi., which produce magnetic islands. In calculating the island width, we take the net toroidal current to be zero also inside the flux surfaces defined by the islands. During the initial formation of the islands, currents are induced in the islands which retard their growth. These localized currents are rapidly damped. Since we are interested in Ohmic stellarator equilibria, for which the net toroidal current inside each flux surface is zero, we clearly must take the island currents to be zero. For a stellarator with nearly circular flux surfaces, the island half-width, w, at .chi.=n/m is ##EQU3## where L is the length of the magnetic axis, B.sub.o is the field on the axis, .rho. is the distance from the magnetic axis. We find that the resonant radial component of B.sub.1 at the rational surface with .chi.=n/m is ##EQU4## where EQU .beta..sub.o .ident.2p.sub.o /B.sub.o.sup.2. Note that although the ln (a-.rho..sub.o) term blows up if we evaluate Eq. (8) for rational surfaces closer and closer to the plasma edge, the singularity is cancelled by the ln (m) dependence of the following term. The field itself is well-behaved. Equations (7) and (8) together determine the island widths due to the direct resonances. All of the results obtained have been expressed in terms of the Fourier amplitudes of the Jacobian, the .delta..sub.nm. To understand these results, it is necessary to understand the physical significance of the .delta..sub.nm. The toroidal curvature of the stellarator gives the Jacobian a cos .theta. dependence, and thus contributes to the nonresonant .delta..sub.01 term in Eq. (5). The resulting plasma field gives a toroidal shift of the flux surfaces. This is the well-known toroidal Shafranov shifts, which exists even in an axisymmetric device such as the tokamak. In a helical axis stellarator, the helical curvature gives J a cos (.theta.-N.phi.) dependence, contributing to the (the non-resonant) .delta..sub.N1. The resulting field gives a helical flux surface shift. The shape of the flux surfaces is determined by the m.gtoreq.2 contributions to .delta..sub.nm. In stellarator vacuum field designs, the resonant harmonic content of the flux surface shapes is kept small by the requirement that no large islands be present in the vacuum field. This condition is not sufficient to preclude the presence of sizable resonant .delta..sub.nm 's. However, these resonant terms are not intrinsic to the stellarator design, so we expect that they can be suppressed. The amplitudes of the .delta..sub.nm for the vacuum field decay exponentially with increasing m and n, so that at most a few such resonant terms need to be suppressed.
	description	The present patent application incorporates by reference from all patent applications listed below. The present patent application claims benefit of Ser. No. 60/735,108, filed Nov. 9, 2005, and is a continuation-in-part of Ser. No. 11/590,036, filed on Oct. 30, 2006, which in turn claims benefit from Ser. No. 60/731,971, filed Oct. 31, 2005.The present patent application is a continuation-in-part of Ser. No. 11/593,245, filed Nov. 6, 2006, which in turn claims benefit from Ser. No. 60/734,126, filed Nov. 07, 2005. Incorporated by reference are: “Particle Beam Processing System,” U.S. Pat. No. 6,838,676, issued on Jan. 4, 2005; and “Deceleration of Hadron Beams in Synchrotrons Designed for Acceleration,” U.S. Pat. No. 6,822,405 issued on Nov. 23, 2004. A. Field of the Invention The technical field is antiprotons. B. Summary of the Invention Depending on the implementation, there is apparatus, a method for use and method for making, and corresponding products produced thereby, as well as manufactures, and necessary intermediates of the foregoing, each pertaining to embodiments herein. Embodiments herein include testing and designing, regarding a fuel element such as a nuclear fuel. Antiprotons are annihilated upon contacting matter. If the matter is composed of elements with atomic numbers greater than or equal to 92 (transuranic), there is a 98% or greater probability of inducing nuclear fission in those elements. This fission probability does not depend on the isotope of those elements exposed to the antiprotons. Alternatively, when antiprotons irradiate materials with atomic number less than 92, less than two percent of the reactions produce fissions. FIG. 1 provides an illustration of an embodiment in which a process can include, at block 10, inducing, with antiprotons, nuclear fission in a test sample or other mass containing transuranic material. At block 20 there can be measuring leakage of radioactive byproduct produced by the fission referenced at block 10. Block 30 represents producing, responsive to the measuring at block 20, a design for the nuclear fuel element. The design parameters can include test sample composition and density and the compositions, number, and thicknesses of coatings over the test samples. This design can be validated by using the design in block 30 to generate an updated test sample and repeating the process starting at block 10. Representing an embodiment wherein operational fuel elements are produced, block 40 presents the production of those full nuclear fuel elements. FIG. 2 provides a representative illustration of an embodiment wherein there is one manner of inducing, with antiprotons, nuclear fission in a transuranic material, with means therefore. See, e.g., FIG. 1, block 10. FIG. 2 illustrates a particle accelerator 100 which can be used to accelerate or decelerate antiprotons. In one embodiment the particle accelerator 100 is stationary, located where the nuclear testing is taking place, see, e.g., FIG. 1, block 20. In another embodiment, the particle accelerator 100 is portable, and is used to store and then transport the antiprotons to the location where nuclear testing is taking place again, see, e.g., FIG. 1, block 20. When it is time to extract antiprotons from the particle accelerator 100, one embodiment calls for an extraction kicker magnet 102 to fire and deflect the antiprotons into the extraction channel at a septum magnet 104. In one embodiment, the septum magnet is a Lambertson magnet. Once the antiprotons are in a transfer line between the particle accelerator 100 and the samples 114 composed of transuranic materials, there exist embodiments wherein steering 106 and/or focusing 108 magnets are employed. Consider an embodiment wherein the mean kinetic energy of the antiprotons incident on the samples 114 is reduced below the minimum energy of the accelerator 100 through the use of a degrader 110. A degrader 110 is material through which the antiprotons traverse in orderto give up their kinetic energy. Consider the teachings in: “Particle Beam Processing System,” U.S. Pat. No. 6,838,676, naming as inventor Gerald P. Jackson, issued on Jan. 4, 2005; which has been incorporated by reference. FIG. 3 contains one embodiment of the antiproton kinetic energy distribution 150 after a degrader 110. As a lower mean kinetic energy is desired, the survival efficiency of the antiprotons in the degrader 110 decreases rapidly. Between the degrader 110 and the samples 114, either an evacuated vacuum chamber or an air gap 112 can be used during nuclear testing. In an embodiment wherein an already existing proton accelerator used to manipulate antiprotons, the extraction of antiprotons from the particle accelerator can utilize accelerator hardware for proton injection. Antiproton extraction can performed using a proton injection kicker 102 and Lambertson magnets 104. Modifications to the kicker trigger and timing systems can account for a timing difference between the protons and antiprotons, which travel in the same accelerator vacuum chamber but in opposite directions. In an alternative embodiment, the antiprotons can be extracted from a portable antiproton bottle 116 and targeted directly onto the samples 114, bypassing the particle accelerator 100. In another embodiment, antiprotons can be generated and used in experimental studies typically performed by using large particle accelerators, such as the Tevatron at the Fermi National Accelerator Laboratory (Fermilab). The Fermilab accelerator complex includes various linear accelerators and synchrotrons to generate antiprotons, to accelerate these antiprotons to very high energies and momenta (typically to 1 TeV), and to collide these antiprotons together with protons. The results of the collisions can be analyzed to provide information regarding the structure and physical laws of the universe, and more particularly, embodiments herein. If the existing sources of antiprotons at such accelerators are to be used as sources of antiprotons for these other fields, the antiprotons can be decelerated (i.e., energy and momentum of the antiprotons will have to be reduced). Consider the use of the Main Injector at the Fermi National Accelerator Laboratory (FNAL) in Batavia, Ill. as a particle decelerator (instead of its nominal role as an accelerator), and incorporated by reference are U.S. Pat. Nos. 6,838,676 and 6,822,045. In addition, to provide antiprotons to locations that are off-site from the particle accelerators, the antiprotons have to be decelerated sufficiently to enable them to be stored in a portable synchrotron or cyclotron, or trapped in a bottle and transported to other locations. Accordingly, testing can be carried out by transporting a sample of transuranic material to a particle decelerator that lowers the kinetic energy of a beam of antiprotons before irradiation of the material. Yet another embodiment can utilize a portable particle decelerator can be brought to the material testing site. In another embodiment, a bottle of antiprotons can be brought to the material testing site. The antiprotons can be stored directly as a distribution of atomic ions of antihydrogen, or can be stored and transported as either atomic or molecular antihydrogen. In a more general embodiment, the antiprotons can be stored and transported as a constituent of any isotope or molecule of antimatter. The bottle in the above embodiments can be based on electrostatic confinement, as in: “Electrostatic Bottle for Charged Particle Storage,” Ser. No. 60/731,971, naming as inventor Gerald P. Jackson, filed Oct. 31, 2005; and that U.S. Patent Application titled “Containing/Transporting Charged Particles”, naming as inventor Gerald P. Jackson, filed on Oct. 30, 2006, and having express mail label EQ139851562US. Compare this view with “Container for Transporting Antiprotons,” U.S. Pat. No. 5,977,554 issued to Gerald A. Smith, et al. on Nov. 2, 1999 and “Container for Transporting Antiprotons,” U.S. Pat. No. 6,160,263 issued to Gerald A. Smith, et al. on Dec. 12, 2000. FIG. 4 is a representative illustration of an embodiment wherein there is measuring leakage of radioactive byproduct produced by the fission, e.g., the aforementioned testing. In this embodiment, the test and/or measurement procedure performed on the test sample(s) can include inserting each test sample 114 into a sealed vacuum chamber 200. As a function of test sample temperature, the release of radioactive isotopes 202 into the vacuum chamber 200 is measured by capturing these isotopes 202. In an embodiment, this capture process occurs within the titanium plates of an ion-sputter pump 204. Near the ion-sputter pump can be a radiation detector 206. In another specific embodiment, this capture process can occur in getter materials which are incorporated into one or more types of vacuum pump, including titanium sublimation 208, sorption 210, or cryo pumps 212. Another embodiment calls for circulating helium gas through the vacuum chamber 200 and a cryogenic sorption pump 212 using a helium circulation pump 214. In yet another embodiment, this capture occurs in a residual gas analyzer detector 216, wherein ionized atoms of materials migrating out of the test sample 114 are separated and recorded as a function of atomic mass. The temperature of the test sample 114 is increased through the use of a heater 218. During the above measurement, one or more parameters can be recorded, including: test sample 114 temperature; air/gas pressure in the vacuum chamber 200; ion-sputter pump 204 current; cryo pump 212 cryostat surface temperature; ion current in the residual gas analyzer detector 216; and gamma-ray spectrum measured by the radiation detector 206. The data can be recorded, either electronically or through manual input, on a device 220, which can represent a means for producing a measurement of leakage of the byproduct to produce a graphic representation of the measured leakage. Device 220 can comprise a computer, preferably with a USB port, connected to a data acquisition system comprising analog-to-digital converters linked to thermocouples. The “means for” can be engaged in measuring test sample temperature 802, and scalar modules can be utilized in counting and recording integrated count rates each minute 806 from the radiation detector next to the ion pump. Device 220 can really be any device capable of producing a measurement of leakage of the byproduct to produce a graphic representation of the measured leakage, or in another manner of thinking, performing data analysis and summarizing the results. This summarization is incorporated into the written design for the nuclear fuel element. In one exemplary embodiment, intended to illustrate data recording and analysis, FIG. 7 teaches that output 800 from the data recording and analysis device 220 which is a part of an embodied measurement apparatus as illustrated in FIG. 4. While other parameters can be used, in this particular embodiment, the parameters that are displayed in the output 800 are the temperature 802 of the test sample 114 and the integrated gamma-ray counts each minute 806 recorded by the radiation detector 206 placed near a ion-sputter pump 204 used to capture particles that diffused out of the heated test sample 114 previously exposed to antiprotons. Accordingly, curve 806 is a graphic representation of the leakage in this particular example. Note that as the test sample temperature 802 increases, the diffusion of fission byproduct increases exponentially. But because a given number of antiprotons will only produce a fixed number of byproduct, eventually the byproduct population is depleted and the count rate 806 falls off with time. An example of analysis is the summation of the total number of counts 806 during the 2-hour measurement interval in the FIG. 7 embodiment. Another analysis can involve subtraction of the above count rate from the count rate 804 from a test sample that was never exposed to antiprotons. Note that the background count rate 804 can also be a goal of the nuclear fuel element design process, where the ideal cermet composition and coating prescription produces a test sample 114 that does not leak unacceptable fission byproduct. This subtracted, or net, emission rate can be a figure of merit in the nuclear fuel element design process. Representatively, another way of conducting the measuring is (e.g., after storing and transporting antiprotons to a site of the testing) accelerating the antiprotons to high energy to penetrate test samples and expose the transuranic materials in one or more samples, and then measuring the samples to detect the effects of the fission reactions induced by the antiprotons. One way to view the teachings herein is in using antiprotons to test fission processes using readily available depleted uranium in contrast to using rare, dangerous, and protected fissionable materials such as enriched uranium and plutonium. Typically, fission processes are tested using such rare, dangerous, and protected fissionable materials by placing them in a field of neutrons. Especially in the case of testing enriched uranium based fission processes, the ability to substitute the safer, plentiful, and easily available depleted uranium reduces cost and security concerns. This ability to use depleted uranium, without affecting the chemistry of the underlying material being tested, enables nuclear research to be performed at smaller companies at less cost and with less security and safety concerns. Accordingly, one embodiment comprises testing fission product retention with safe isotopes uranium (such as depleted uranium) and/or other such fissionable elements by using antiprotons to induce the fissions. Thus, illumination of coated samples of depleted uranium oxide produces fissions in the central uranium region but can produce little else in the coatings. In addition, the number of fissions is controlled by precisely controlling the number of antiprotons illuminating the target. This enables a sufficiently high amount of fission to occur for detection but does not produce a sample so radioactive that it requires handling at special institutions. In another embodiment, samples of depleted uranium oxide, e.g., particles, wires, foils, or the like, are coated with candidate layers of material. One approach is a combination including tungsten, rhenium, and/or molybdenum. Fission is induced in the depleted uranium in order to produce the entire range of fission products. The result then placed into a furnace and heated to temperatures reminiscent of operation of the NTR, e.g., greater than 2,000° K. Presence of elements above mass four can be detected in the spectrometer if they are able to diffuse out of the cermet. FIG. 5 is a representative illustration of an embodiment wherein there is producing, responsive to the measuring, a design for the nuclear fuel element. Design details can a be matter of preference or choice, or a reflection of the particulars of the application or environment in which the design is to be implemented. However, as to the embodiments herein, design parameters can include test sample 114 composition and density and the composition(s), number, and thickness(es) of coating(s) over the test sample(s) 114 or mass. In one embodiment, the core 300 of a test sample can be comprised of a mixture of transuranic material and high temperature refractory metal(s) that is pressed and sintered into a solid, e.g., a solid block. The transuranic material can be depleted uranium oxide. The refractory materials can include at least one of tungsten and rhenium. Similarly, in another embodiment, the core 300 can comprise a mixture of transuranic material and high temperature graphite. In yet another embodiment, the cermet core 300 can be coated by one 302, two 304, or more 306 layers of materials that can in concert inhibit the high temperature diffusion of radioactive fission byproducts out of the test sample 114 or other mass. The composition and thickness of each coating, and the total number of coatings, can be ingredients of a nuclear fuel element design. FIG. 6 is a representative illustration of an embodiment wherein there is producing the nuclear fuel element. The cermet 402 can be extruded, leaving channels 404 for the flow of hydrogen gas necessary for cooling in a power reactor or generating thrust in a propulsion system. In this embodiment, design parameters are evolved according to the process in FIG. 1, e.g., to determine the composition of the cermet 402, and the composition(s), thickness(es), and number of layers of the diffusion-inhibiting coating(s) 406 inside the hydrogen channels 404 and on the outside of the cermet 402, etc. The fuel element can be utilized in a nuclear propulsion system based on antiproton-induced fissions of depleted uranium in the form of a sail. In such a propulsion system there can be a thin foil of depleted uranium is irradiated with antiprotons. Some embodiments herein are directed, generally, to nuclear fuel element for a thermal rocket (NTR) system (or other vehicle) and reducing emission of radioactivity via the engine exhaust. For general perspective, if fission products leak into the exhaust, the NTR may only be allowed to operate from High Earth Orbit (HEO), which for certain applications may involve the addition of a “shuttle” to go from Low Earth Orbit (LEO) to HEO and negates much of the advantage of the high specific impulse NTR. In contrast, embodiments described herein pertain to a fuel that inhibits the emission of radioactive atoms into the exhaust stream, enabling an NTR to be considered for an increased range of operations, e.g., in space. Embodiments herein therefore can extend to improved coated cermet fuel elements to retain fission products and prevent diffusion into the exhaust. Note that the foregoing is a prophetic teaching and although only a few exemplary embodiments have been described in detail herein, those skilled in the art will readily appreciate from this teaching that many modifications are possible, based on the exemplary embodiments and without materially departing from the novel teachings and advantages herein. Accordingly, all such modifications are intended to be included within the scope of the defined by claims. In the claims, means-plus-function claims are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment fastening wooden parts, a nail and a screw may be equivalent structures.
	summary
	summary
044951469	summary	BACKGROUND OF THE INVENTION The present invention relates to the loading of fuel rods with spherical nuclear fuel. In recent years it has been discovered that conventional nuclear reaction fuel composed of fuel pellets encased in cladding tubes may lead to the splitting of the cladding tubes thereby releasing radioactive material to the adjacent cooling water. This splitting is due to an interaction between the pellet and cladding. One way of avoiding this problem is to limit the surface interaction between the fuel and cladding. This may be achieved by loading the fuel cladding tubes with nuclear fuel in the shape of spheres. If three different sizes of spheres are used, then appropriate packing of the spheres into the rods will result in a sufficient density of nuclear fuel to be properly used in a nuclear reactor. One method for loading a fuel rod is to simply drop the spheres into a vertical cladding tube while vibrating the rod to assist in packing. However, this method is not satisfactory for several reasons. The distribution of the particles sizes freely falling from a height of 6 to 12 feet into a cladding tube does not lead to uniform distribution. This method also leads to the trapping of air which requires a longer time to evacuate at the sealing of the tube. In addition, the vibrating packing is extended because of the random loading of the spheres. SUMMARY OF THE INVENTION The invention is a system and method for the loading of spherical nuclear fuel into a fuel rod. The system includes a main housing having an inert atmosphere and having an opening to receive fuel spheres having three different diameters for loading into fuel rods; a weighing station system for receiving the spheres and separating the spheres into three predetermined quantities, the weighing system including a balance means for weighing the nuclear fuel spheres; a means for transferring the fuel spheres after entering the housing to the weighing station within the housing; a fuel rod support system for supporting the fuel rod in an upright position; a feeding probe for loading the predetermined quantities of the fuel spheres in a controlled manner into the fuel rod; and a means for transferring each of the predetermined quantity of the fuel spheres to a corresponding hopper of the feeding probe for subsequent loading into the fuel rod. In addition, a method if disclosed for loading a nuclear fuel rod with spherical nuclear fuel. The method includes the steps of transferring nuclear fuel spheres having three different diameters into a glove box having an inert atmosphere; transferring the fuel spheres to weighing stations, a different weighing station corresponding to each diameter of the nuclear fuel spheres; weighing out a predetermined quantity of fuel spheres for each diameter; transferring the fuel spheres to hoppers on a fuel probe, one hopper corresponding to each of the diameters of the nuclear fuel sphere; lowering the fuel probe into the fuel rod so that the lower end of the probe is just above the bottom of the fuel rod; discharging the nuclear fuel spheres from the fuel probe discharge tube opening at a controlled rate into the fuel rod; and removing the fuel probe from the fuel rod at a rate such that the lower end of the fuel probe remains just above the top of the ascending fuel column.
	summary
	claims	1. A Tilted Channel Implant (TCI) system for performing TCI operations on supplied production samples having a gate structure of directly or indirectly measured length and one or more sidewalls of directly or indirectly measured thickness, said TCI system comprising: (a) first error determining means for determining an amount of error in each production sample between the measured sidewall thickness and a pre-defined, target sidewall thickness; and (b) energy adjustment means for adjusting TCI energy in response to the amount of error determined by said first error determining means, where said adjusting of TCI energy at least partially counters deviation in depth of TCI dopants due to said sidewall thickness error. 2. The Tilted Channel Implant (TCI) system of claim 1 and further comprising: claim 1 (c) second error determining means for determining an amount of error in each production sample between the measured gate length and a pre-defined, target gate length; and (d) dosage adjustment means for adjusting TCI dosage in response to the amount of error determined by said second error determining means, where said adjusting of TCI dosage at least partially counters deviation in lateral distribution of TCI dopants due to said gate length error. 3. The Tilted Channel Implant (TCI) system of claim 2 wherein: claim 2 (a.1) said measured sidewall thickness is defined at least in part by measuring a pre-trim film thickness of a material that is deposited to define said one or more sidewalls. 4. The Tilted Channel Implant (TCI) system of claim 2 wherein: claim 2 (a.1) said measured sidewall thickness is defined at least in part by measuring a post-trim film thickness of a material that is deposited and thereafter trimmed to define said one or more sidewalls. 5. The Tilted Channel Implant (TCI) system of claim 2 wherein said energy adjustment means includes: claim 2 (b.1) energy adjustment interpolating means for interpolating approximate energy adjustments based on two or more empirically established energy adjustments. 6. The Tilted Channel Implant (TCI) system of claim 5 wherein said energy adjustment interpolating means includes: claim 5 Energy a =E 0 (1 +xcex2e Sw /S wT ) wherein E 0 is a prespecified amount of implant energy used when sidewall thickness error e Sw is zero, wherein said multiplying factor, xcex2 may either be a constant or a function of a specified windowing range of the normalized error, e Sw /S wT , and where S wT is said target sidewall thickness. (b.1a) linear or quasi-linear energy adjustment interpolating means for interpolating approximate energy adjustments in accordance with a formula of the form: 7. The Tilted Channel Implant (TCI) system of claim 6 wherein said multiplying factor, xcex2 is defined as one or more values selected from the range, 0.05 xe2x89xa6xcex2xe2x89xa60.15 where the selected value depends on the sign of e Sw /S wT . claim 6 8. The Tilted Channel Implant (TCI) system of claim 5 wherein said dosage adjustment means includes: claim 5 (d.1) dosage adjustment interpolating means for interpolating approximate dosage adjustments based on two or more empirically-established implant dosage adjustments. 9. The Tilted Channel Implant (TCI) system of claim 8 wherein said dosage adjustment interpolating means includes: claim 8 Dose a =Dose 0 (1+xcex1( L 2T xe2x88x92L 2M )/ L 2T ) wherein Dose 0 is a prespecified amount of implant dosage used when gate length error L 2T xe2x88x92L 2M is zero, wherein said second multiplying factor, xcex1 may either be a constant or a function of a specified windowing range of the normalized error, (L 2T xe2x88x92L 2M )/L 2T , where L 2T is said target gate length and where L 2M is said measured gate length. (b.1a) linear or quasi-linear energy adjustment interpolating means for interpolating approximate energy adjustments in accordance with a formula of the form: 10. The Tilted Channel Implant (TCI) system of claim 9 wherein said second multiplying factor, xcex1 is defined as one or more values selected from the range, 0.05xe2x89xa6xcex1xe2x89xa60.15 where the selected value or values for may depend on the sign and/or windowed magnitude of (L 2T xe2x88x92L 2M )/L 2T . claim 9 11. The Tilted Channel Implant (TCI) system of claim 1 wherein said energy adjustment means includes: claim 1 (b.1) energy adjustment interpolating means for interpolating approximate energy adjustments based on two or more empirically established energy adjustments. 12. The Tilted Channel Implant (TCI) system of claim 11 wherein said energy adjustment interpolating means includes: claim 11 Energy a =E 0 (1 +xcex2e Sw /S wT ) wherein E 0 is a prespecified amount of implant energy used when sidewall thickness error e Sw is zero, wherein said multiplying factor, xcex2 may either be a constant or a function of a specified windowing range of the normalized error, e Sw /S wT , and where S wT is said target sidewall thickness. (b.1a) linear or quasi-linear energy adjustment interpolating means for interpolating approximate energy adjustments in accordance with a formula of the form: 13. A machine-implemented method for performing Tilted Channel Implant (TCI) operations on supplied production samples having a gate structure of directly or indirectly measured length and one or more sidewalls of directly or indirectly measured thickness, said method comprising the steps of: (a) first determining an amount of first error in one or more production samples between the measured sidewall thickness and a pre-defined, target sidewall thickness; and (b) adjusting TCI energy in response to the amount of first error determined by said first determining step, where said adjusting of TCI energy at least partially counters deviation in depth of TCI dopants due to said sidewall thickness error. 14. The machine-implemented TCI method of claim 13 and further comprising: claim 13 (c) second determining an amount of respective second error in said one or more production samples between the measured gate length and a pre-defined, target gate length; and (d) adjusting TCI dosage in response to the amount of second error determined by said second error determining step, where said adjusting of TCI dosage at least partially counters deviation in lateral distribution of TCI dopants due to said gate length error. 15. The machine-implemented TCI method of claim 14 wherein: claim 14 (a.1) said measured sidewall thickness is defined at least in part by measuring a pre-trim film thickness of a material that is deposited to define said one or more sidewalls. 16. The machine-implemented TCI method of claim 14 wherein: claim 14 (a.1) said measured sidewall thickness is defined at least in part by measuring a post-trim film thickness of a material that is deposited and thereafter trimmed to define said one or more sidewalls. 17. The machine-implemented TCI method of claim 14 wherein said energy adjusting step includes: claim 14 (b.1) interpolating approximate energy adjustments based on two or more empirically established energy adjustments. 18. The machine-implemented TCI method of claim 17 wherein said energy adjustment interpolating step includes: claim 17 Energy a =E 0 (1 +xcex2e Sw /S wT ) wherein E 0 is a prespecified amount of implant energy used when sidewall thickness error e Sw is zero, wherein said multiplying factor, xcex2 may either be a constant or a function of a specified windowing range of the normalized error, e Sw /S wT , and where S wT is said target sidewall thickness. (b.1a) using linear or quasi-linear energy adjustment interpolation for interpolating approximate energy adjustments in accordance with a formula of the form: 19. The machine-implemented TCI method of claim 18 wherein said multiplying factor, xcex2 is defined as one or more values selected from the range, 0.05xe2x89xa6xcex2xe2x89xa60.15 where the selected value depends on the sign of e Sw /S wT . claim 18 20. The machine-implemented TCI method of claim 14 wherein said dosage adjusting step includes: claim 14 (d.1) using dosage adjustment interpolation for interpolating approximate dosage adjustments based on two or more empirically established implant dosage adjustments. 21. The machine-implemented TCI method of claim 20 wherein said dosage adjustment interpolating step includes: claim 20 Dose a =Dose 0 (1+xcex1( L 2T xe2x88x92L 2M )/ L 2T ) wherein Dose 0 is a prespecified amount of implant dosage used when gate length error L 2T xe2x88x92L 2M is zero, wherein said second multiplying factor, xcex1 may either be a constant or a function of a specified windowing range of the normalized error, (L 2T xe2x88x92L 2M )/L 2T , where L 2T is said target gate length and where L 2M is said measured gate length. (b.1a) using linear or quasi-linear energy adjustment interpolation for interpolating approximate energy adjustments in accordance with a formula of the form: 22. The machine-implemented TCI method of claim 21 wherein said second multiplying factor, xcex1 is defined as one or more values selected from the range, 0.05xe2x89xa6xcex1xe2x89xa60.15 where the selected value or values for may depend on the sign and/or windowed magnitude of (L 2T xe2x88x92L 2M )/L 2T . claim 21
047724307	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a process for compacting and solidifying various solid waste materials to effect the volume reduction thereof simultaneously with the solidification thereof with thermoplastic resins contained in the waste materials and, if necessary, supplementary thermoplastic resins externally supplied thereto, thus facilitating the waste materials for temporary storage or final disposal thereof, to an apparatus for carrying out said process and to an overall system for disposal of the waste materials. The various solid materials include combustibles such as paper towels, rags, working gloves, veneer boards and hampen ropes; incombustibles such as electric cords, aluminum foils and concrete blocks; and others such as plastic-made sheets and ropes, and rubber-made hoses, gloves and boots, the plastics usually comprising at least thermoplastic resins such as PE (polyethylene) and PVC (polyvinyl chloride), and the above waste materials being discharged from homes and factories. The solid waste materials referred to herein also include those, such as ion exchange resins, concrete fragments and insulating materials, which are likely to have been radioactively contaminated due to the use thereof in atomic power plants, and further include harmful heavy metals-containing ion exchange resins discharged from general industrial factories as waste materials. 2. Prior Art Urban waste materials including various plastics, metals, glass and rubbers discharged from homes and factories, are so-called "combustion-unsuitable waste materials" and they have been disposed of by incineration, landfill or resource recovery. These disposals, however, cause their respective problems or troubles. The various plastics in the waste materials will, in many cases, mainly cause troubles such as clogging of incinerators by molten plastics, damage of the incinerators by local overheating and evolution of harmful gases such as chlorine and dioxin. In case of the landfill disposal, there is much of bulky waste materials such as foamed polystyrene and polyethylene sheets or bags. These bulky waste materials will need high transportation cost and will sometimes come out from underground after once buried in the ground thereby to be blown in pieces by the wind, thus polluting the environments. There have recently been proposed various methods for recovering and exploiting various waste plastics from the viewpoint of effective reuse of resources. In spite of these proposals, however, there is still not overcome the disadvantage that it costs too much to sort urban waste materials since they are composed of various and miscellaneous materials. There has thus been proposed a method for producing coarse pelletized compacted mixtures by adding particulate inorganic materials (such as sand, rubble, and ashes obtained by incineration) to urban waste materials with aid of thermoplastic resins contained therein (Japanese Patent Gazette No. 57-11273). The method so proposed is still unsatisfactory in that metal pieces, cloths and the like are not pelletized and they are required to be treated after sorting of the urban waste materials. On the other hand, it has been customary that thermoplastic resin sheets (such as PE and PVC sheets, paper rags, rags, concrete pieces, steel materials, high performance filters, insulating materials, ion exchange resins and the like, which are contaminated with radioactive materials while they are handled in nuclear power plants, are packed in thermoplastic resin bags or else packed therein after the contaminated waste materials have been sorted into combustibles, incombustibles and combustion-unsuitable materials if necessary, after which the bags so packed are encapsulated in drum cans for custody or storage. As one example, in a case where a comparatively large-sized contaminated waste material such as a high performance filter, composed integrally of wood, filter medium (inorganic material), metal plates and the like, is disposed of, it is necessary to disjoint the waste material and sort the disjointed members thereby disadvantageously making the disposal steps complicated and increasing the possibility of exposing the workers to radioactivity; thus, there has been proposed a specific device for disjointing such a large-sized waste material to prevent the workers from being exposed to radioactivity and facilitate the disposal of the waste material (Japanese Utility Model Gazette No. 59-42720). However, the incombustibles (other than wood) of the disjointed members are destined to be encapsulated in drum cans for storage. As another example, ion exchange resins are now used for, for instance, purifying condensed water or disposing of waste water in nuclear facilities such as nuclear power plants. The thus used ion exchange resins will raise a problem as to the disposal thereof as waste materials since they are contaminated with radioactivity. Since, for example, some of the thus used ion exchange resins has radioactivity of as high as 10.sup.1 -10.sup.-2 .mu.Ci/cc and contain Cs and Sr having a long half-life, they must be stored in the safer form for a long time; to this end, there have been researched and developed a method for volume reduction by incineration or wet-type decomposition, and a method for direct solidification with cement, asphalt or plastics, and these methods have already partly been put to practical use. This volume reduction method using incineration, however, will raise a problem that the exchange groups of cation resins of the ion exchange resins decompose to evolve SO.sub.x gas since the ion exchange resins are treated at high temperatures, whereby is raised a problem as to the material of a facility for treating the thus evolved SO.sub.x gas, the recovery thereof and the like. Further, this volume reduction method using wet-type decomposition is disadvantageous in that it not only needs an after-treatment comprising neutralizing SO.sub.4.sup.2- remaining in the decomposed solution with caustic soda or the like and then evaporating the thus neutralized solution for concentration but also needs an expensive decomposing agent for the wet-type decomposition, thus raising a problem as to economy. This direct solidification methods are disadvantageous in that, for example, the volume reducibility is low and the treating facilities are expensive. On the other hand, such ion exchange resins must be housed or encapsulated as radioactive materials in high integrity containers (HIC) for disposal in U.S.A. for example, even if they are hardly harmful because of their extremely low strength of radioactivity. The HIC, however, is too expensive to be used for encapsulation of ion exchange resins having medium strength radioactivity from the economical viewpoint and, therefore, they are usually stored in tanks and are in few cases subjected to final disposal. Used ion exchange resins discharged from the general industrial fields (not from nuclear facilities) may easily be dealt with and they are thus recovered and heaped or subjected to landfill. Ion exchange resins containing harmful heavy metals will still raise a problem as to their soil contamination and effluence to rivers and streams when treated for disposal. The drum cans encapsulating the solid waste materials therein have been stored in storage houses. However, since the unoccupied storage spaces have more decreased than expected, the solid waste materials capable of being burnt are subjected to incineration treatment and then ashes produced by the incineration are stored in drums or solidified with cement to form more stable solids thereof. The said incineration treatment applies to bulky materials such as thermoplastic resin sheets and bags as well as waste paper and it has been widely used for the treatment of solid waste materials discharged from nuclear power plants, radioisotope institutes (RI) and the like. The incineration treatment is disadvantageous in that when solid waste materials containing plastics in a large proportion are incinerated, a furnace used would be damaged and it is therefore necessary to install a waste gas treating device as an accessory to an incinerator for the incineration treatment, thus producing secondary waste materials from the accessory device and incurring an extra expense for installation of the accessory device. Further, conventional volume reduction treatments by heating or incineration not only need a specific heat source but also leave a problem to insufficient volume reduction for pressure packing of the volume-reduced waste materials in containers. Miscellaneous solid waste materials may also be treated for volume reduction by compressing them by a press, and there is being developed a volume reduction device using a high pressure, particularly a surface pressure of about 1000 to 3000 Kg/cm.sup.2. This device will enable thermoplastic resin sheets and bags, paper rags and the like to be compressed almost without gaps left between the materials and, therefore, it provides an effective method for volume reduction. The compressed body obtained by this method is, per se, a non-homogeneous aggregate of miscellaneous waste materials and it is therefore not preferable for a long-term storage. SUMMARY OF THE INVENTION An object of this invention is to provide a process for compacting, without producing secondary waste materials, solid waste materials containing various plastics discharged from homes and factories or radioactive solid waste materials, such as used ion exchange resins, discharged from nuclear power plants, radioisotope institutes (RI) and the like, to solidify the waste materials with a thermoplastic resin to obtain rod-like masses which are convenient for final disposal. Another object is to provide an apparatus for carrying out the above-mentioned process. Still another object is to provide an overall system for the disposal of solid waste materials, which comprises a shredder for cutting and crushing miscellaneous solid waste materials containing thermoplastic resins such as polyethylene and polyvinyl chloride, a mixer for substantially uniformly mixing the thus cut and crushed waste materials as required, a screw extrusion molder for compression molding the resultant mixture to obtain rod-like bodies thereof, a cutter for cutting the thus obtained rod-like bodies to obtain pellets thereof and a packing means for packing the thus obtained pellets in containers such as drum cans. According to this invention, it is preferable that solid waste materials be finely cut or crushed. Since the compacting and solidifying treatment is effected preferably by extrusion molding, it is necessary to finely divide the solid waste materials so that the finely divided waste materials correspond in size to the die diameter of an extruder used, and it is desirable to further pulverize the waste materials after they have been finely divided or crushed. In this invention, thermoplastic resins are used as a solidifying agent and they are not limited in kind and property and are only capable of solidifying solid waste materials at the time of solidification thereof. These thermoplastic resins may usually be polyethylene (PE) or polyvinyl chloride (PVC) originally contained in the solid waste materials, and a part thereof may be those externally supplied to the solid waste material if necessary. The thermoplastic resins so externally supplied may be new ones, regenerated ones or ones generally discharged as waste plastics since they are used only as a solidifying agent. Any thermoplastic resins may be used as a solidifying agent as mentioned above, and those which are softened or melted at temperatures of about 120.degree.-260.degree. C. can generally be most conveniently used and are also preferable from the viewpoint of the amounts of electric power and heat consumed in extrusion molders at the time of solidifying treatment. However, thermoplastic resins used as a solidifying agent in treating used ion exchange resins should be those which are melted at 100.degree.-190.degree. C. as PE, PVC and the like. When a mixture of used ion exchange resins and solid waste materials is compression molded under agitation at said temperature, SO.sub.x gases will not be evolved (since the temperature at which SO.sub.x gases will be evolved is in the range of 200.degree.-350.degree. C.) and the water contained in the waste materials will evaporate thereby to obtain moldings substantially without free water, thus eliminating the need of expensive HIC. It is preferred that the used ion exchange resins be drained for some dehydration. It is of course possible to compact and solidify solid waste materials even if they originally contain such used ion exchange resins. It is necessary for the solidification that solid waste materials contain thermoplastic resins in an amount of 10 wt.% or more, and it is possible to solidify the solid waste materials as far as they contain moisture in an amount of up to 30 wt.% although it is preferable that they contain moisture in as less an amount as possible (Refer to the following Examples). The above amount of at least 10 wt.% of thermoplastic resins includes the amount of externally supplied ones. In this invention, the solidification is effected by an extrusion molder and it does not need external heating or needs external heating only as supplementary heating since friction heat is produced by solid waste materials moving through between the inner wall of the extrusion molder and the compression screw therein in sliding relation to these wall and screw. The apparatus for compacting solid waste materials, comprises a shredder for cutting and crushing miscellaneous solid waste materials which contain combustibles such as PE, PVC and other thermoplastic resins, incombustibles etc., a mixer for substantially uniformly mixing the thus cut and crushed waste materials together as required, a screw extrusion molder for compression molding the thus crushed and mixed waste materials to obtain rod-like masses, a cutter for cutting the thus obtained rod-like masses to obtain pellets and a packing means for packing the thus obtained pellets in containers such as drum cans.
	abstract	In a debris trap that may be used in an Emergency Core Cooling System of a nuclear power plant, the filter media is arranged to define both filtration and bypass flowpaths that are in fluid communication with one another. At least initially, each of the filtration and bypass flowpaths are open, and the filtration and bypass flowpaths have relatively low and relatively high head loss, respectively. The debris trap is operative so that flow through the debris trap may passively, and typically gradually, transition from the filtration flowpaths to the bypass flowpath in response to the filter media collecting increasing amounts of debris. More specifically, initially substantially all of the flow may be through the filtration flowpaths, and thereafter the filtration flowpaths may become substantially obstructed so that substantially all of the flow is through the bypass flowpath.
046363521	claims	1. In a nuclear fuel rod comprising a metallic tubular cladding containing a plurality of nuclear fuel pellets, said pellets containing enriched uranium-235, the improvement comprising: a plurality of ceramic wafers, each wafer comprising 2. In a nuclear fuel rod as defined in claim 1, the improvement wherein said uranium dioxide comprises a naturally occurring uranium dioxide. 3. In a nuclear fuel rod as defined in claim 1, the improvement wherein said uranium dioxide comprises depleted uranium dioxide containing less uranium-235 than naturally occurring uranium dioxide. 4. In a nuclear fuel rod as defined in claim 3, the improvement wherein said depleted uranium dioxide is substantially devoid of the uranium-235 isotope. 5. In a nuclear fuel rod as defined in claim 1, the improvement wherein said wafer comprises between about 1-8 percent by weight gadolinium oxide. 6. In a nuclear fuel rod as defined in claim 1, the improvement wherein said wafer has a diameter substantially the same as said nuclear fuel pellets and a thickness of between about 10-100 mils. 7. In a nuclear fuel rod as defined in claim 1, the improvement wherein said nuclear fuel pellets are comprised of uranium dioxide, plutonium dioxide, and mixtures thereof. 8. In a nuclear fuel rod as defined in claim 1, the improvement wherein said adjacent nuclear fuel pellets have confronting concave faces. 9. In a nuclear fuel rod as defined in claim 1, the improvement wherein adjacent fuel pellets in the region of high power generation have a wafer therebetween, while no wafer is disposed between adjacent fuel pellets in areas of low power generation. 10. In a nuclear fuel rod as defined in claim 1 wherein a portion of said wafers contain a varying amount of gadolinium oxide relative to the amount of gadolinium oxide in other wafers of said plurality of wafers. 11. A wafer for use in a nuclear fuel rod, to freeze out volatile fission products produced by nuclear fuel pellets within said rod, comprising a sintered mixture for gadolinium oxide and uranium dioxide, said uranium dioxide having no more of the uranium-235 isotope than is present in natural uranium dioxide. 12. A wafer as defined in claim 11 wherein said uranium dioxide comprises a naturally occurring uranium dioxide. 13. A wafer as defined in claim 11, wherein said uranium dioxide comprises depleted uranium dioxide containing less uranium-235 isotope than naturally occurring uranium dioxide. 14. A wafer as defined in claim 13, wherein said depleted uranium dioxide is substantially devoid of the uranium-235 isotope. 15. A wafer as defined in claim 11, wherein said wafer comprises between about 1-8 percent by weight gadolinium oxide. 16. A wafer as defined in claim 11, wherein said wafer has a diameter substantially the same as the nuclear fuel pellets with which it is used, and a thickness of between about 10-100 mils.
	description	1. Technical Field The present invention relates to semiconductor chip design, and more particularly to a design tool for optimizing and providing ground rules waivers for chip designs and fabrication procedures. 2. Description of the Related Art Calculating 2-dimensional and intra-level intersect areas for structures in a semiconductor design remains a challenge within the semiconductor industry. Intersect areas refer to areas common to a pair of layers in layouts of devices or components on a semiconductor chip. These areas are constrained by ground rules which provide requirements for spacings between the components, the component sizes, etc. Ground rules are restrictions with regard to the geometry of the layout that must be adhered to by the designer of a Very Large Scale Circuit (VLSI) chip. Examples of ground rules are minimum width of a channel, minimum distance between two corners, minimum distance between two features and the like, as is known in the art. Such considerations include component placement on multiple levels of the chip design and therefore in turn the ground rules determine intra-level intersect areas which are then subject to their own rules. In earlier technology generations, it was acceptable to use simple Monte Carlo software on strictly rectangular geometries to generate ground rules. However, as the industry advances, designs have become more complex and design density has become a greater issue. As such, it is imperative that intersect area software tools progress to a higher level to address the complexities of advanced technologies. A system and method of employing patterning process statistics to evaluate ground rules layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped into an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization. A system employing patterning process statistics for ground rules waivers and optimization includes a processing device configured to apply Optical Proximity Correction (OPC) to alter a ground rules layout to create a mask pattern to which patterning process variation distributions are applied to create, waive and optimize ground rules for semiconductor chip layouts. An analysis module is configured to map the patterning process variation distributions into an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area and to analyze the intersect area using the histogram to provide ground rule waivers and layout optimization. These and other objects, features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in conjunction with the accompanying drawings. Embodiments in accordance with present principles provide a design or analytical tool that addresses layout considerations and intersection area computations for advanced technologies in semiconductor processes. In one embodiment, Optical Proximity Correction (OPC), lithography and non-lithography biases and non-linear critical dimension (CD) tolerances are combined in the same tool. This tool successfully meets the needs of the semiconductor industry by permitting accurate analysis of complicated, intra-level design layout intersect areas, using production-level OPC which is targeted for the levels being analyzed. OPC includes modifying layout geometries for systematic distortions introduced during fabrication. The OPC tools employ non-printable modifications to a mask or other components to provide desired images for lithography. The intersect area computations from imaged features on the mask, for example, facilitate design rules or ground rules waivers and optimization. A layout checking step may be employed for ground rules layout verification. This provides simulation based software that predicts what manufacturing distortions with what probability will occur during lithographic patterning. If the magnitude of these errors is determined to be significant, corrections are made by re-examining the ground rules for waivers and optimization followed by the use of some form of OPC such as attenuated or alternating phase shifting or sub-resolution assists. OPC can correct for image distortions, optical proximity effects, photoresist kinetic effects, etch loading distortions, and other various process effects. Embodiments of the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment including both hardware and software elements. In a preferred embodiment, the present invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc. Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in conjunction with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that may include, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include but are not limited to a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. A data processing system suitable for storing and/or executing program code may include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code to reduce the number of times code is retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) may be coupled to the system either directly or through intervening I/O controllers. Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modems and Ethernet cards are just a few of the currently available types of network adapters. The design for an integrated circuit chip may be created in a graphical computer programming language, and stored in a computer storage medium (such as a disk, tape, physical hard drive, or virtual hard drive such as in a storage access network). If the designer does not fabricate chips or the photolithographic masks used to fabricate chips, the designer transmits the resulting design by physical means (e.g., by providing a copy of the storage medium storing the design) or electronically (e.g., through the Internet) to such entities, directly or indirectly. The stored design is then converted into the appropriate format (e.g., Graphic Data System II (“GDSII”)) for the fabrication of photolithographic masks, which typically include multiple copies of the chip design in question that are to be formed on a wafer. The photolithographic masks are utilized to define areas of the wafer (and/or the layers thereon) to be etched or otherwise processed. The resulting integrated circuit chips can be distributed by the fabricator in raw wafer form (that is, as a single wafer that has multiple unpackaged chips), as a bare die, or in a packaged form. In the latter case the chip is mounted in a single chip package (such as a plastic carrier, with leads that are affixed to a motherboard or other higher level carrier) or in a multichip package (such as a ceramic carrier that has either or both surface interconnections or buried interconnections). In any case the chip is then integrated with other chips, discrete circuit elements, and/or other signal processing devices as part of either (a) an intermediate product, such as a motherboard, or (b) an end product. The end product can be any product that includes integrated circuit chips, ranging from toys and other low-end applications to advanced computer products having a display, a keyboard or other input device, and a central processor. The methods as described herein are preferably used in the fabrication of integrated circuit chips. However, the present principles may have application in other technologies as well. Referring now to the drawings in which like numerals represent the same or similar elements and initially to FIGS. 1 and 2, probability distributions for exposure focus (FIG. 1) and exposure dose (FIG. 2) for a lithography process are shown illustratively as examples. During manufacturing of semiconductors, resist coated wafers are exposed with an image of a mask formed by a stepper, as is known in the art. Focus and dose for the process are maintained at certain nominal levels (e.g., a mean value) which are established to correspond to high fidelity printing of the critical features on a mask. These levels depend, among other things, on the process, the masks and the application in which the lithography is being used. In practice, the exposure is held at these levels with a certain probability distribution which has a 3 sigma value (sigma representing a standard deviation from the nominal values) and which describe the magnitude and the form of the deviation from the nominal values. The probability distributions depicted in FIGS. 1 and 2 represent a distribution of acceptable process parameters. The example distributions are probability distributions for focus (FIG. 1) measured in linear units (e.g., nm) and for dose (FIG. 2) measured in exposed optical energy per unit area on the wafer, although other parameter distributions may also be employed, e.g. etch bias, level height and etch profile angle, etc. FIG. 1 is an example of a probability distribution for exposure focus for a lithography process where the x-axis is the value of focus (e.g., in nm) and the y-axis includes counts for each bin of the distribution. FIG. 2 is an example of a probability distribution for the exposure dose of radiation on the wafer for a lithography process with the x-axis being the exposure dose in arbitrary units of energy per unit area and the y-axis being counts for each bin of the distribution. For a given feature, e.g., critical dimension or intersect area, the probability distribution is obtained by employing a history of dose or focus settings employed to achieve that feature. This accounts for variations in the manufacturing process up to three sigma from a nominal value. Additionally, as is generally the case, if multiple masks are involved, there will be similar patterning process parameter variation distributions for each of the parameters such as exposure focus and dose for each of the overlay mask combinations. Other effects such as mask error may be incorporated in a similar manner. These patterning process parameter distributions will be employed as examples in the presentation of systems and methods in accordance with the present principles. Referring to FIG. 3, a block/flow diagram describes an illustrative tool in accordance with the present principles. In block 102, the tool applies plan of record Optical Proximity Correction (POR OPC) recipes to alter the ground rules layout to produce a mask pattern. Turning to the example of FIG. 4, a ground rules layout includes five scenarios or contexts 122, 124, 126, 128 and 130, which are illustratively shown, respectively, for cases 1-5 depicted in FIGS. 6 and 7. These scenarios are merely illustrative of contexts likely to be found in a layout, for CA/M1 (first contact layer/first metal layer) intersect areas to be analyzed. The design layout ground rule scenarios 122, 124, 126, 128 and 130 depict mask pattern features in an intersect area of a chip design. These features may repeat throughout a chip layout and may be analyzed individually. In each case, features 123 show locations for M1 structures in accordance with ground rules, and features 125 show locations for CA structures in accordance with ground rules. In block 104 of FIG. 3, images produced by lithographic masks are simulated using lithography models developed for various lithography stages. This simulation includes through-process wafer images which are analyzed for intersect area distributions and ground rules waivers and optimization. This process may be iterative where a corrective action performed by the tool is checked to see if the desired effect is achieved in accordance with the ground rules. As stated, this “test” may be simulated using computer software or actually tested in-situ on wafers. In one embodiment, this analysis may be based on Monte Carlo analysis methods. In the prior art, it was acceptable to use Monte Carlo analysis simply on strictly rectangular geometries to generate ground rules. In accordance with present principles, process (e.g., lithographic) probability distributions, such as the distributions illustratively shown in FIGS. 1 and 2, are used to generate random process points of focus and dose. A process point may include a set of values for the patterning process parameters, such as, a value of exposure dose and a value of exposure focus. Turning to the example in FIG. 5, the layout cases 122, 124, 126, 128 and 130 shown in FIG. 4 are simulated for M1 structures 143 and CA structures 145 over a range of process parameters. The simulated masks (block 104) define regions of process variations. Process variation regions 147 for M1 structures and process variation regions 149 for CA structures are depicted with cross-hatched regions. For each process point, block 106 employs the simulated images of ground rules layouts (FIG. 5) to compute the corresponding intersect area. By accumulating the intersect area data for all random process points and then sorting the data into different bins, the probability distribution for the intersect area is derived. (See, for example, FIGS. 6 and 7). This mapping process may be implemented as follows. Given g and h as the probability distribution functions (e.g., the distribution functions provided in FIGS. 1 and 2) of two of the patterning process parameters x and y (where, for example, x and y may be the exposure dose and focus parameters), the ratio of Monte Carlo sample count over the total sample size for one of the parameters, which is taken to be from x to x+dx, and for the other is taken to be from y to y+dy, will be given by g(x)h(y)dxdy. If the intersect area function is a(x,y), then the distribution function f(z) for the intersect area will be obtained as:f(z)dz=∫g(x)h(y)dxdy, for z≦a(x,y)≦z+dwhere, as is generally understood, g, h and f are the normalized probability distribution functions such that ∫g(x)dx=1 for all x, and ∫h(y)dy=1 for all y, and ∫f(z)dz=1 for all z. In block 106, a histogram of the intersect area under consideration is preferably produced by plotting f(z). For example, for CA (first contact layer in a chip design) and M1 (first metal layer in the chip design) levels, a histogram is provided over the domain of processes specified by probability distributions for cases of interest such as those illustratively shown in FIG. 6 and FIG. 7 where counts versus CA critical dimensions (FIG. 6) and counts versus CA/M1 area (FIG. 7) are shown. In FIG. 6, f(z) is shown for dose and focus in achieving a critical dimension in the CA layer for five different contexts (cases 122, 124, 126, 128 and 130). In FIG. 7, f(z) is shown for dose and focus for an intersect area between CA and M1 for different cases 122, 124, 126, 128 and 130. The probability distributions shown in FIGS. 6 and 7 are used to compute the mean, median and standard deviations of the intersect area. This type of through-process analysis facilitates waivers and optimization of ground rules that are specific to a given technology level with the use of intersect area probability distributions derived from the patterning process parameter's probability distributions by imposing appropriate values on the 3 sigma bounds of the histogram. Thus, a layout describing a ground rule in terms of intersect area may be varied, for example, by moving a contact away or closer to the edge of the metal line, and the resulting histograms may be studied as feedback to optimize the ground rule. In addition, if a layout violates a ground rule because of design considerations, the region where the violation occurs may be studied by the present method to determine the seriousness of the violation from the specified bounds on the intersect area and to decide if a waiver of the rule should be granted. Criteria for determining whether a ground rule can be waived or optimized depends on many factors including but not limited to the types of devices, the application, the materials being employed, the electrical characteristics, the workload, the application, etc. A VLSI circuit layout needs to obey ground rules to be manufactured within the limitations of the patterning process, but occasionally in a custom layout, a context may arise which is not easily covered by geometry based ground rules. Then, that context becomes a new or waived ground rules layout which needs to be studied in accordance with present principles to obtain a waiver. By providing a region within acceptable process variations, the waivers of ground rules can be granted and still be within acceptable technical specifications. In addition, ground rules may be waived to optimize layout area, improve performance or adjust any other requirement or parameter. In contrast to the standard Design Rule Checking (DRC), Optical Rule Checking (ORC), and ground rules engineering, the analysis in accordance with present principles takes a holistic approach to design and manufacturing by integrating the plan of record Optical Proximity Correction (POR OPC) as part of the tool and mapping the process variation statistics (FIGS. 1 and 2) back into intersect area statistics (e.g., the histograms in FIGS. 6 and 7) in block 106. In accordance with present principles, process (e.g., lithographic) probability distributions, such as the distributions illustratively shown in FIGS. 1 and 2, are used to generate random process points of focus and dose. For each process point, block 106 employs simulated images of ground rules layouts to compute the corresponding intersect area. By accumulating the intersect area data for all random process points and then sorting into different bins, the necessary intersect area (such as between the first contact and the first metal layer) probability distribution is derived from the designer's perspective, the tool can be integrated with the computation of contact resistance and other relevant electrical performance metrics. In block 110, the mapped distributions (histograms) are employed to alter the ground rules for waivers or optimization. As illustrated by the five cases in FIGS. 6 and 7, the analysis such as that illustrated in the results presented in FIG. 7 by the five intersect area histograms, may include, e.g., varying space and width tolerances, etc. to create rules specifications and their layouts which more accurately reflect desired pattern geometry and provide ground rule waivers and optimize the rules, particularly with respect to the intersect areas. Devices are preferably manufactured in accordance with these changes. In accordance with experiments by the present inventors, several CA to M1 test cases were run. These tests have shown that the tool can handle complicated geometries, generate through process wafer image contours, use dose and focus lithography data, and map the patterning process variations into Monte Carlo intersect area distributions. The results produced correlate well. Referring to FIG. 8, a system 200 for employing statistical patterning process parameters for ground rules waivers and optimization is illustratively shown in accordance with present principles. System 200 advantageously provides the process and functions for granting waivers and optimization of layout ground rules, and handles OPC, polygonal geometries, non-lithography biases and non-linear critical dimension (CD) tolerances in a same tool. System 200 includes a processing device 202, which preferably includes a computer. Processing device 202 includes an analysis/design module 204 employed in creating, waiving and optimizing layout ground rules for chip or board designs. Module 204 includes a POR program in accordance with the present principles. Module 204 incorporates statistics 206 for patterning processes to be mapped into the intersect area statistics by Monte Carlo simulation for creating, waiving and optimizing layout ground rules resulting in a circuit layout with features having high printability probability on the masks 212. Statistics 206 preferably include probability distributions for exposure focus and dose, although other parametric distributions may be employed. These distributions are employed to generate distributions of intersect areas from a Monte Carlo analysis. Using these statistical distributions, waivers of ground rules can be determined by relaxing the bounds on the standard deviations of the distributions and working with a process team to decide whether the waivers provide satisfactory results. Masks 212 are aligned to a wafer 214 using a stepper 210 to incrementally move and position the mask 212 relative to the wafer 214. A radiation source 208 illuminates the mask 212 to cause an image to form on the wafer 214 to provide a lithographic image of a mask that has resulted from a layout completed with optimal ground rules with respect to patterning process parameters 211 which include the exposure focus and dose. In addition to OPC techniques, the present principles employ statistical patterning process parameters such as dose, focus, etc. variation data to optimize ground rules by examining the resulting variation of the size and shape of the intersect areas of the ground rules layouts that enable a best rendition of the mask into a wafer image by enforcing optimized ground rules with the approach illustrated here. Having described preferred embodiments of a system and method system for employing patterning process statistics for ground rules waivers and optimization (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments disclosed which are within the scope and spirit of the invention as outlined by the appended claims. Having thus described aspects of the invention, with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.
	claims	1. An optical system, comprising:a plurality of elements arranged to image radiation at a wavelength λ along a radiation path from an object field in an object surface to an image field in an image surface,wherein:the plurality of optical elements comprises mirror elements including first and second mirror elements;the first mirror element has a rotationally asymmetric reflective surface which deviates from a best-fit rotationally symmetric reflective surface by about λ or more at one or more locations;the second mirror element has a reflective surface comprising a reflective coating that is a non-rotationally symmetric, graded coating comprising a multilayer stack of different materials;a layer in the multilayer stack has a geometrical layer thickness which varies according to a first grading function in a first direction and which varies according to a second grading function in a second direction perpendicular to the first direction, the second grading function being different from the first grading function. 2. The optical system according to claim 1, wherein:the multilayer stack comprises a cap layer on a radiation entry side facing away from a substrate of the second mirror element; andthe cap layer has a geometrical layer thickness which varies according to a third grading function in a third direction and which varies according to a fourth grading function in a fourth direction perpendicular to the third direction, the fourth grading function being different from the third grading function. 3. The optical system according to claim 2, wherein the geometrical layer thickness of the cap layer increases from an origin towards an edge of the second mirror element with a first amount of increase in the third direction, and a second amount of increase between the origin and an edge region is significantly larger in the fourth direction. 4. The optical system according to claim 2, wherein the geometrical layer thickness of the cap layer is essentially uniform in a central zone around an origin at least up to radial coordinates corresponding to an outer edge of a region corresponding to a first sub-aperture corresponding to a central field point, and the geometrical layer thickness of the cap layer increases outside the central region slightly in the third direction and stronger in the fourth direction. 5. The optical system according to claim 2, wherein the cap layer comprises a material selected from a group consisting of ruthenium, aluminium oxide, silicon carbide, molybdenum carbide, carbon, titanium nitride, titanium dioxide, and a mixture, an alloy or a compound of ruthenium, aluminium oxide, titanium nitride and titanium dioxide. 6. The optical system according to claim 2, wherein the multilayer stack comprises a plurality of intermediate layers between the cap layer and the substrate, and each of the plurality of intermediate layers has a uniform layer thickness. 7. The optical system according to claim 2, wherein the multilayer stack comprises a plurality of intermediate layers arranged between the cap layer and the substrate, and the material of the cap layer has a specific absorbance for the radiation at wavelength λ which is greater than a specific absorbance of each of the materials of the intermediate layers. 8. The optical system according to claim 2, wherein the material of the cap layer has a specific absorbance for the radiation at wavelength λ which is greater than a specific absorbance of silicon and/or molybdenum. 9. The optical system according to claim 2, wherein the material of the cap layer has a specific absorbance characterized by an extinction coefficient k greater than 0.013 in a wavelength range between about 13 nm and 14 nm. 10. The optical system according to claim 2, further comprising a filter layer disposed on the cap layer on the radiation entry side, wherein the filter layer comprises a material configured to absorb radiation at the wavelength λ, and the filter layer has a geometrical thickness which varies spatially. 11. The optical system according to claim 10, wherein the filter layer comprises a material having a greater specific absorbance at wavelength λ than the material of the cap layer. 12. The optical system according to claim 10, wherein the filter layer comprises a material having a smaller specific absorbance at wavelength λ than the material of the cap layer. 13. The optical system according to claim 10, wherein the filter layer comprises a material selected from a group consisting of ruthenium, aluminium oxide, silicon carbide, molybdenum carbide, carbon, titanium nitride, titanium dioxide, and a mixture, an alloy or a compound of ruthenium, aluminium oxide, titanium nitride and titanium dioxide. 14. The optical system according to claim 1, wherein:the multilayer stack comprises a stack of bilayers;each bilayer comprises a layer of a first material having a first refractive index and a layer of a second material having a second refractive index which is lower than the first refractive index,for each bilayer, the layer of the first material is thicker than the layer of the second material;for each bilayer, a ratio between a geometrical thickness of the first layer and a geometrical thickness of the second layer varies according to third grading function in a third direction; andfor each bilayer, the ratio varies according to a fourth grading function, different from the third grading function, in a fourth direction perpendicular to the third direction. 15. The optical system according to claim 1, wherein the second mirror element is positioned optically remote from a pupil surface of the optical system at a position where condition P(M)<1 is satisfied, andP(M)=D(SA)/(D(SA)+D(CR)),where D(SA) is a diameter of a sub-aperture of a ray bundle originating from a field point in the object surface on a respective surface M, and D(CR) is a maximum distance of chief rays of an effective object field imaged by the optical system measured in a reference plane of the optical system on the surface M. 16. The optical system according to claim 15, wherein:the reference plane is a symmetry plane of the optical system;the condition P(M)<0.99 holds for a position of the second mirror element;the second mirror element is positioned in an intermediate region optically between a pupil surface and a field surface of the optical system at a position where condition 0.99>P(M)>0.95 is satisfied; and/orthe second mirror element is positioned optically near to a field surface where the condition 0<P(M)<0.93 is satisfied. 17. The optical system according to claim 1, wherein the second mirror element is positioned at or optically close to a pupil surface of the optical system where the condition 0.98<P(M)<1 is satisfied. 18. The optical system according to claim 1, wherein a third mirror element comprises a non-rotational symmetric coating which is a one-dimensionally graded coating comprising a multilayer stack of layers of different materials, the layers having a geometrical layer thickness which varies according to a third grading function in the first direction of the coating, and the layers having a geometrical layer thickness which is substantially constant in the second direction perpendicular to the first direction. 19. The optical system according to claim 18, wherein the third mirror is configured so that an average angle of incidence varies strongly according to a substantially linear function in the first direction, n and the average angle of incidence is substantially constant in the second direction perpendicular thereto. 20. The optical system according to claim 1, further comprising a third mirror having a reflective coating that is a non-rotationally symmetric, graded coating comprising a multilayer stack of different materials, whereina layer in the multilayer stack of the third mirror has a geometrical layer thickness which varies according to a third grading function in a third direction and which varies according to a fourth grading function in a fourth direction perpendicular to the third direction, the fourth grading function being different from the third grading function. 21. The optical system according to claim 1, wherein the second mirror element is configured to increase symmetry of a spatial intensity distribution present in an exit pupil of the optical system relative to symmetry of spatial intensity distribution that would be present in the exit pupil of the optical system in the absence of the second mirror element. 22. The optical system according to claim 1, wherein the second mirror element is effective to increase rotational symmetry of an intensity distribution present in an exit pupil of the optical system relative to rotational symmetry of spatial intensity distribution that would be present in the exit pupil of the optical system in the absence of the second mirror element. 23. The optical system according to claim 22, wherein the spatial intensity distribution present in the exit pupil of the optical system is characterized by an apodization parameter APO representing a normalized azimuthal variation of the intensity in an edge region of the exit pupil according to:APO=(IMAX−IMIN)/(IMAX+IMIN),where IMAX is the maximum value of the intensity in an edge region of the exit pupil, and IMIN is the minimum value of the intensity in the edge region of the exit pupil, andwherein the apodization parameter APO is decreased by at least 1% relative to the apodization parameter APO that would for the optical system in the absence of the second mirror element. 24. The optical system according to claim 1, wherein the second mirror element has a rotationally asymmetric reflective surface which deviates from a best-fit rotationally symmetric reflective surface by about λ or more at one or more locations. 25. A projection-exposure system, comprising:an illumination system; anda projection objective,wherein:the illumination system is configured to receive radiation from a primary light source and to illuminate a pattern in an object surface of the projection objective;the projection objective comprises the optical system according to claim 1; andthe projection-exposure system is a microlithography projection-exposure system. 26. A projection-exposure system according to claim 25, wherein the radiation is EUV radiation at a wavelength 13 nm<λ<14 nm. 27. A method, comprising:using a projection-exposure system to fabricate semiconductor devices or other types of micro devices, wherein the projection-exposure system comprises:an illumination system; anda projection objective, andwherein:the illumination system is configured to receive radiation from a primary light source and to illuminate a pattern in an object surface of the projection objective; andthe projection objective comprises the optical system according to claim 1.
	abstract	A circulation system for a high refractive index liquid includes a first collecting section configured to collect a high refractive index liquid used in an immersion light exposure section; a first supply section configured to supply the high refractive index liquid collected in the first collecting section to a cleaning section as a cleaning liquid; a second collecting section configured to collect the high refractive index liquid used in the cleaning section; and a second supply section configured to supply the high refractive index liquid collected in the second collecting section to the immersion light exposure section, wherein the high refractive index liquid is circulated between the immersion light exposure section and the cleaning section.
	abstract	A method, system, and apparatus for the thermal storage of energy generated by multiple nuclear reactor systems including diverting a first selected portion of energy from a portion of a first nuclear reactor system of a plurality of nuclear reactor systems to at least one auxiliary thermal reservoir, diverting at least one additional selected portion of energy from a portion of at least one additional nuclear reactor system of the plurality of nuclear reactor systems to the at least one auxiliary thermal reservoir, and supplying at least a portion of thermal energy from the auxiliary thermal reservoir to an energy conversion system of a nuclear reactor of the plurality of nuclear reactors.
	claims	1. A blanker aperture array (BAA) for an e-beam tool, the BAA comprising:a first column of openings along a first direction and having a pitch; anda second column of openings along the first direction and staggered from the first column of openings, the second column of openings having the pitch, wherein a scan direction of the BAA is along a second direction, orthogonal to the first direction. 2. The BAA of claim 1, wherein the first column of openings is a first single column of openings aligned in the first direction, and the second column of openings is a second single column of openings aligned in the first direction. 3. The BAA of claim 1, wherein the pitch of the first column of openings corresponds to twice the pitch of a target pattern of lines for orientation parallel with the second direction. 4. The BAA of claim 3, wherein the pitch of the target pattern of lines is twice the line width of the target pattern of lines. 5. The BAA of claim 1, wherein, when scanned along the second direction, the openings of the first column of openings do not overlap with the openings of the second column of openings. 6. The BAA of claim 1, wherein, when scanned along the second direction, the openings of the first column of openings slightly overlap with the openings of the second column of openings. 7. The BAA of claim 1, wherein the first and second columns of openings are first and second columns of apertures formed in a thin slice of silicon. 8. The BAA of claim 7, wherein one or more of the apertures of the first and second columns of apertures has metal there around. 9. The BAA of claim 1, wherein the first and second columns of openings amount to a total of 4096 apertures formed in a thin slice of silicon. 10. A method of forming a pattern for a semiconductor structure, the method comprising:forming a pattern of parallel lines above a substrate, the pattern of parallel lines having a pitch;aligning the substrate in an e-beam tool to provide the pattern of parallel lines parallel with a scan direction of the e-beam tool, wherein the e-beam tool comprises a blanker aperture array (BAA) comprising a first column of openings along an array direction and a second column of openings along the array direction and staggered from the first column of openings, the first column of openings having a pitch and the second column of openings having the pitch, and the array direction orthogonal to the scan direction, and wherein the pitch of the first column of openings corresponds to twice the pitch of the pattern of parallel lines; andforming a pattern of cuts or vias in or above the pattern of parallel lines to provide line breaks for the pattern of parallel lines by scanning the substrate along the scan direction. 11. The method of claim 10, wherein forming the pattern of parallel lines comprises using a pitch halving or pitch quartering technique. 12. The method of claim 10, wherein forming the pattern of cuts or vias comprises exposing regions of a layer of photo-resist material. 13. The method of claim 10, wherein the pitch of the pattern of parallel lines is twice the line width of each line. 14. A column for e-beam tool, the column comprising:an electron source for providing a beam of electrons;a limiting aperture coupled with the electron source along a pathway of the beam of the beam of electrons;high aspect ratio illumination optics coupled with the limiting aperture along the pathway of the beam of the beam of electrons;a shaping aperture coupled with the high aspect ratio illumination optics along the pathway of the beam of the beam of electrons;a blanker aperture array (BAA) coupled with the shaping aperture along the pathway of the beam of the beam of electrons, the BAA comprising:a first column of openings along a first direction and having a pitch; anda second column of openings along the first direction and staggered from the first column of openings, the second column of openings having the pitch;a final aperture coupled with the BAA along the pathway of the beam of the beam of electrons; anda sample stage for receiving the beam of electrons, wherein a scan direction of the sample stage is along a second direction, orthogonal to the first direction of the BAA. 15. The column of claim 14, wherein the pitch of the first column of openings of the BAA corresponds to twice the pitch of a target pattern of lines for orientation parallel with the second direction. 16. The column of claim 15, wherein the pitch of the target pattern of lines is twice the line width of the target pattern of lines. 17. The column of claim 14, wherein, when the sample stage is scanned along the second direction, the openings of the first column of openings of the BAA do not overlap with the openings of the second column of openings of the BAA. 18. The column of claim 14, wherein, when the sample stage is scanned along the second direction, the openings of the first column of openings of the BAA slightly overlap with the openings of the second column of openings of the BAA. 19. The column of claim 14, wherein the BAA is an array of physical apertures disposed in a thin slice of silicon. 20. The column of claim 19, wherein one or more of the apertures of the first and second columns of apertures of the BAA has metal there around. 21. The column of claim 20, wherein the metal comprises one or more electrodes for passing or steering a portion of the beam of electrons to a Faraday cup or blanking aperture housed in the column. 22. The column of claim 19, wherein the BAA has 4096 apertures. 23. The column of claim 14, wherein the shaping aperture is a one-dimensional shaping aperture. 24. The column of claim 14, wherein the sample stage is rotatable by 90 degrees to accommodate alternating orthogonal layer patterning.
	abstract	An arrangement device including: a photography section, which photographs a first mark and a second mark in a state in which a semiconductor integrated circuit to which the first mark is applied and a member to which the second mark is applied, which member is to be used in combination with the semiconductor integrated circuit, overlap; and a movement section, which relatively moves at least one of the semiconductor integrated circuit and the member with respect to the other thereof on the basis of positions of the first mark and the second mark which have been photographed by the photography section.
044951434	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a containment 10 enclosing a nuclear reactor 11 and a heat exchanger 12. A core 13 made up of a honeycomb array of open-ended passageways 14 (see FIG. 4) is in the reactor. Nuclear fuel "F" is designed to be located in certain of the core passageways according to some predetermined pattern or matrix, as is approximated in FIG. 4. Control rods or other conventional neutron absorbing control devices "C" are also designed to be fitted into other specific core passageways, again according to a specific matrix or pattern. The control devices "C" most typically are raised or lowered relative to the core 13 to establish a certain presence relative to the nuclear fuel "F", which allows fission reaction to proceed and generate heat in the core due to the bombardment of neutrons. To cool the reactor core as well as obtain heat useful for generating electrical power, molten sodium as a reactor coolant is circulated by pump 15 into the reactor 11 where it passes first downwardly in an annular space between the core 13 and the wall of reactor 11 and then upwardly through the passageways 14 of the reactor core 13, and via line 16 to the heat exchanger 12. The reactor sodium gives up heat to a second stream of molten sodium isolated in heat exchanger coil 17 and is circulated then back to reactor 11 through pump 15. The surface level of the molten sodium in the reactor 11 is indicated by dashed line 18, and a cover gas fills the space 19 over the sodium in the reactor. The heater second stream of sodium in heat exchanger coil 17 is circulated by pump 21 through steam generator 22 where in coil 23 it gives off its heat to water to produce steam. The water level in the steam generator 22 is indicated by the dashed line at 24, and the steam in the space 25 above the water surface passes through line 26 to turbine 27 which drives electrical generator 28. Steam leaving turbine 27 is condensed in condenser 29 and pumped by pump 30 through line 31 back to the steam generator 22. The reactor 11 and heat exchanger 12 have been greatly simplified in FIG. 1 for clarity, where in practice they are mechanically complex. From time to time it is necessary to open the reactor for refueling. In the liquid metal cooled reactor, these operations are difficult because the sodium must be maintained above its melting temperature and is a hazardous material to handle. Radioactive material leaking from the nuclear fuel in core 13 will contaminate the sodium coolant, heat exchanger 12 and associated pumps and piping; the radioactive contamination making these maintenance operations even more difficult. As noted, FIG. 4 shows a schematic representation of a horizontal section through the reactor core 13 of FIG. 1 including typical matrix arrangements of the nuclear fuel "F" and the control means "C" therein. The nuclear fuel "F" is generally housed in a fuel assembly 35 (see FIG. 2) shown here having an exterior hexagonal can 37, although any other suitable cross section, such as square rectangular, etc., might be used to fit within the correspondingly shaped core passageways 14. The fuel assembly 35 illustrated is comprised of seven generally parallel separate fuel rods or elements 39 supported in spaced parallel relation within the hexagonal can 37, one element being adjacent each corner of the hexagonal can and one element being at the center. At least two grid supports 40 (only one being shown) are used for holding the separate fuel elements 39 within the can 37, the grid support illustrated including a band 42 secured to the periphery of the can 37 and cross webs 43 which connect between the band 42 and separate collars 45 located on the individual fuel elements. The can 37 is open at its opposite ends (not shown) so that coolant can be readily passed axially through the can from one open end to the other within the core passageway, and the open spacing between the webs allow the coolant to pass axially along and over the fuel elements 39. FIG. 3 illustrates a typical fuel element 39, which in a commercial reactor would consist of cylindrical can or cladding 52 extended between two and six feet in length and having maybe only 0.25" to 0.5" inside diameter. A plurality fuel pellets 54, each likewise of generally cylindrical shape, are fitted within the can or cladding 52 stacked solid one against the other endwise for almost the entire length of the cladding. The cladding is closed by end caps 56 and 57 welded to the opposite ends thereof, where further there is provided a perforated intermediate wall 59 which is located adjacent the end cap 57. Spring devices 60a, 60b are interposed between the end cap 56 and the perforated intermediate wall 59, and the endmost fuel element pellets 54a, 54b operable to bias the fuel pellets snuggly against one another. The fuel pellets 54 themselves are of a smaller overall outer diameter than the inner diameter of the cladding 52 so that some radial clearance is provided and gas migration can occur axially along and within the fuel element 39 from one end to the other. The space 62 between the end cap 57 and intermediate wall 59 is known as the gas plenum and initially during fabrication this plenum 62 is pressurized with tag gases in a preprogrammed proportion. As noted, the fuel element 39 is sealed so that the tagging gas and all fusion gases generated by later reaction of the fuel pellets 54 are confined within the fuel element, but can migrate freely along the entire length of the fuel element. In accordance with the disclosed invention, a cover gas clean up system 64 is connected by lines 65 and 67 and pump 68 from cover gas space 19 and returned by line 69 back to the reactor space 19. A tag recovery and analysis system 72 is located downstream of the cleanup system 64, off tee 75 in line 69, and thus sees only the cover gas cleaned of the fission gases. A fission gas detector or alarm system 78 is included with pump 79, typically in a parallel hookup with the cover gas cleanup system 64, and is used continuously to detect for the presence of fission gases in the cover gas. Thus, operation of the pump 79 provides a small continuous sample of the cover gas for analysis by the detector system 78. The cover gas cleanup system 64 may operate continuously upon operation of pump 68, but otherwise it will be operated upon detection of fission gases in the cover gas. The tag recovery and analysis system 72 includes a means for recovering the tags and a means for analyzing the recovered tags. The recovery system is separated from the gas return line 69 by a valve 80, and is connected also then through valve 82 and line 83 back to the reactor via line 69. The analysis apparatus 84 is connected through valve 86 off of the recovery system. The tag recovery system is operated with the valves 80 and 82 open and valve 86 closed, and only when fission gases are detected in the cover gas and only when the cover gas cleanup system is operated. Thus all of the fission gases are removed in the cover gas clean up system 64, and a portion of the cleaned cover gas is continuously or intermittently passed through the tag recovery system 72. The tag analysis system 84 is operated generally with the valves 80 and 82 closed and valve 86 opened, and typically includes a mass spectrometer (not shown) to appraise of the specific tags present. The output of the mass spectrometer frequently is printed in graphic form. Only a small fraction of the cover gas passed through the tag recovery and analysis system 72 is consumed in the analysis, the remainder is returned to cover gas space 19 via lines 83 and 69. Both the cover gas cleanup system 64 and the tag recovery system 72 would include a bed of charcoal through which the gas including the impurities to be removed or recovery are passed. The specific construction of the charcoal bed is immaterial to this invention (being shown as 64a and 72a in the schematic), but each is operated at a specific cryogenic temperature. Thus the fission gases will be absorbed out of the cover gas in cryogenic bed 64a and the tag gases of neon and argon will be adsorbed out of the cover gas in the cryogenic bed 72a. In this invention, it is contemplated to use helium as the cover gas, and neon and argon as the tag gases. Specifically, the three stable isotopes of neon, namely, Ne.sup.20, Ne.sup.21, and Ne.sup.22, and the three stable isotopes of argon namely, Ar.sup.36, Ar.sup.38 and Ar.sup.40 are to be used where by concentrating the percentage of any one or more of such tag isotopes, it would be possible to define many separate, unique and distinct proportions of tagging combinations. The tag combinations can be comprised solely of the neon isotopes, solely of the argon isotopes, or blends of each. The separate combinations of tags will be injected into the fuel elements where all fuel elements of a specific fuel assembly would have the same tag, and the differently-tagged fuel assemblies would be at the different locations within the reactor matrix. Thus, the later specific identification of such a tag gas combination in the mass spectrometer would provide the unique identity and thus the location of the "leaker" fuel element. The separation by abundance of the varying isotopes in a mass spectrometer is all conventional. In the normal operation, the cover gas cleanup system cryogenic bed 64a would be operated between approximately 0.degree. and -25.degree. C., for example, while the tag gas recovery bed 72a would be operating in the range of -170.degree. to -185.degree. C. The cover gas along with any tag gases and fission gases would be directed through the cyrogenic charcoal bed 64a and via line 69 back to the reactor. Impurities including the fission gases would be adsorbed from the cover gas in the cover gas cleanup system bed 64a. Part of the purified cover gas (still including the tags) would then be passed through the tag recovery charcoal bed 72a, which is effective to adsorb from the cover gas the neon and argon tag gas isotopes used, while the cover gas of helium passes back to the reactor. In a preferred embodiment, the tag recovery and analysis system 72 is made up of three separate similarly arranged series of beds 72a and analysis apparatus 84 (only the one being shown) so that each series can be operated by itself and can be alternately in a batch format, while yet providing for continuous collection. Thus, while one series of apparatus is operating at cryogenic temperatures collecting the gases, the second is being heated to perhaps between 150.degree. and 200.degree. C. to drive off the collected gases for transfer to the analysis apparatus, and the third is being cooled down to the cryogenic temperatures for collecting again. In like manner multiple cover gas cleanup beds 64a can be used (only one bed being shown) to allow regeneration and/or even replacement of an individual bed while the others of the overall system are yet operating. Flow through each tag recovery and analysis system bed or series of beds, and/or through the cover gas clean up system beds will normally be controlled automatically by a timed/temperature sequence of valve operation. Also, a preferred tag recovery bed 72a might actually include a primary tag bed and a secondary tag bed (neither being shown specifically) located in a series flow connection, whereby the collected tag isotopes in the primary bed would be driven off by heat and recollected in a higher concentration in the secondary bed held again at approximately -170.degree. to -185.degree. C. Transfer from the primary tag bed to the secondary tag bed would begin when the valving had been shifted to redirect the cover gas to the next sequential primary bed and the cover gas flow into the original primary bed had been stopped. Clean helium gas could be admitted to backflush the charcoal in the primary tag bed while it is being cooled down. The effluent from the tag bed can be directed to a precooled evacuated sample vial or the like (not shown) in the analysis apparatus 84. The sample vial could either be removed from the system and transported in a shielded container to a laboratory for analysis, or the sample could be directed to an on-line mass spectrometer (not shown). Liquid nitrogen normally surrounding the sample vial would be boiled off to increase the vial temperature to about 50.degree. C. to drive the tag gases through the mass spectrometer. The identity of adsorbed tag gases can be used then with the matrix mapping of the specifically tagged fuel assemblies within the reactor to locate the leaking fuel element. Of particular interest to this invention is the fact that the cover gas cleanup system 64 and the tag recovery and analysis system 72 are operating independently of one another and do not compete with one another. This is of particular importance as the fission gases that escape into the cover gas are different from any of the tag gases. Moreover, the cover gas cleanup system bed 64a is in a series connection with and is operated upstream of the tag recovery system bed 72a and can be operated most efficiently toward removing the greatest percentage of such fission gases. The tag gases of neon and argon are not significantly adsorbed by the cleanup system bed 64a but pass with the cleaned cover gas of helium on through to the tag recovery bed 72a. On the other hand, the downstream tag recovery bed 72a, being operated at much cooler cryogenic temperatures (-170.degree. to -185.degree. C. versus 0.degree. to -25.degree. C.) collect the lighter tag gases of neon and argon but allow the cleaned cover gas of helium to pass through and back to the reactor. One major advantage of the disclosed reactor system having the helium cover gas and the unique blends of neon and argon tag isotopes is the overall lower cost of the system. In fact, it may be only 20-30% of the cost of an overall system having argon cover gas and the xenon and krypton tags, as is more conventionally used. Another advantage of this disclosed system is that the isotopes of neon and argon are very stable and thus are not significantly changed by neutron bombardment, so that tag ratio consistency and vertification can be more easily and reliably maintained. Another major advantage of this cover gas-tag combination is the ability to more accurately resolve the neon and argon isotopes, as compared to the resolution of the heavier xenon and krypton isotope tags. Also, the recovery and analysis efforts are performed on gases that have been cleaned of radioactive fission gases to reduce personnel exposure to the radioactive isotopes of xenon and krypton. Of perhaps greatest importance, however is the fact that the cover cleanup system and the tagging gas recovery system do not compete for the same gases and/or isotopes, but operate independently of one another, so that the sensitivity and accuracy of the tagging system and the effectiveness of the cover gas cleanup system each can be greatly enhanced.
	summary
	description	This application is a Continuation of U.S. application Ser. No. 14/962,029 filed Dec. 8, 2015, which claims benefit from Korean Patent Application No. 10-2014-0175382, filed on Dec. 8, 2014, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety. The present disclosure relates to an X-ray apparatus and system, and more particularly, to an X-ray apparatus and system that may determine a thickness of an object. X-rays are electromagnetic waves which may generally have a wavelength of 0.01 to 100 angstrom (Å). Because X-rays may be transmitted through an object, X-rays are widely used in medical apparatuses capturing images of the insides of bodies, non-invasive examination devices in various general fields, and the like. An X-ray apparatus may acquire an X-ray image by transmitting X-rays emitted from an X-ray source through a target, and detecting an intensity difference of the transmitted X-rays by using an X-ray detector. An inner structure of the target may be identified and diagnosis of the object may be performed by using the X-ray image. The X-ray apparatus may be advantageous for conveniently understanding the inner structure of the object by utilizing the fact that a transmission rate of X-rays varies according to a density of the object and an atomic number of atoms that form the object. When X-rays have short wavelengths, the transmission rate increases and images have improved brightness. Provided are an X-ray apparatus and system that may determine a thickness of an object. Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented exemplary embodiments. According to an aspect of an exemplary embodiment, and X-ray apparatus includes a collimator comprising a lamp, the collimator being configured to adjust an irradiation region of X-rays radiated from an X-ray source; an image acquirer configured to acquire an object image by imaging an object while the lamp illuminates the object; and a controller configured to determine an object distance based on the object image and determine a thickness of the object based on a detector distance and the object distance, wherein the object distance is a distance between the X-ray source and the object, and the detector distance is a distance between the X-ray source and an X-ray detector. The controller may be further configured to determine, based on the thickness of the object, an irradiation condition, the irradiation condition being information related to an X-ray radiation amount of the X-ray source, and the X-ray apparatus may further include an output interface configured to output the irradiation condition. The X-ray apparatus may further include an input interface configured to receive X-ray setting information corresponding to the X-ray radiation amount of the X-ray source from a user. The X-ray source may be configured to radiate X-rays according to the X-ray radiation amount based on the X-ray setting information. The controller may be further configured to detect in the object image a collimation region illuminated by the lamp, and to acquire the object distance based on a size of the collimation region. The X-ray apparatus may further include a memory configured to store at least one of first relationship information about a relationship between the object distance and the size of the collimation region, and second relationship information about a relationship between the thickness of the object and the X-ray radiation amount. The collimator may further include an irradiation window through which X-rays radiated from the X-ray source pass, and the controller may be further configured to adjust a size of the irradiation window to a first size when the object is imaged, and to adjust the size of the irradiation window to a second size when the X-ray source radiates X-rays. The controller may be further configured to detect a center of the collimation region in the object image, and to acquire the object distance based on a location of the center. The image acquirer may be further configured to acquire a detector image by imaging the X-ray detector while the object is not between the X-ray source and the X-ray detector and the X-ray detector is illuminated by the lamp, and the controller may be further configured to determine the detector distance based on the detector image. The X-ray apparatus may further include an input interface configured to receive distance setting information related to the detector distance, and the controller may be further configured to change a location of the X-ray source based on the distance setting information and the detector distance. The image acquirer may be further configured to acquire a non-illuminated object image by imaging the object while the object is not illuminated by the lamp, and the controller may be further configured to acquire a difference image by comparing the object image and the non-illuminated object image, to detect a collimation region illuminated by light radiated from the lamp from the difference image, and to acquire the object distance based on a size of the collimation region. According to another aspect of an exemplary embodiment, a workstation configured to control an X-ray apparatus comprising an X-ray source and a collimator includes a communicator configured to receive an object image acquired by imaging an object while a lamp of the collimator illuminates the object, the collimator being configured to adjust an X-ray irradiation region of X-rays radiated from the X-ray source; and a controller configured to determine an object distance based on the object image, and to determine a thickness of the object based on the object distance and a detector distance, wherein the object distance is a distance between the X-ray source and the object, and the detector distance is a distance between the X-ray source and an X-ray detector. The controller may be further configured to determine, based on the thickness of the object, an irradiation condition, the irradiation condition being information related to an X-ray radiation amount of the X-ray source, and the workstation may further include an output interface configured to output the irradiation condition. The workstation may further include an input interface configured to receive X-ray setting information corresponding to the X-ray radiation amount of the X-ray source from a user. The controller may be further configured to control the X-ray source to radiate X-rays according to the X-ray radiation amount based on the X-ray setting information. The controller may be further configured to detect in the object image a collimation region illuminated by light from the lamp, and to determine the object distance based on a size of the collimation region. The workstation may further include a memory configured to store at least one from among first relationship information about a relationship between the object distance and the size of the collimation region, and second relationship information about a relationship between the thickness of the object and the X-ray radiation amount. The collimator may further include an irradiation window through which X-rays radiated from the X-ray source pass, and the controller may be further configured to adjust a size of the irradiation window to a first size when the object is imaged, and to adjust the size of the irradiation window to a second size when the X-ray source radiates X-rays. According to yet another aspect of an exemplary embodiment, a method of operating an X-ray system includes determining an object distance based on an object image acquired by imaging an object while a lamp of a collimator illuminates the object, wherein the collimator is configured to adjust an X-ray irradiation region of X-rays radiated from an X-ray source; and determining a thickness of the object based on the object distance and a detector distance, wherein the object distance is a distance between the X-ray source and the object, and the detector distance is a distance between the X-ray source and an X-ray detector. The method may further include: determining, based on the thickness of the object, an irradiation condition, the irradiation condition being information related to an X-ray radiation amount of the X-ray source; and outputting the irradiation condition. According to a further aspect of an exemplary embodiment, a non-transitory computer-readable recording medium has recorded thereon a program, which, when executed by a computer, performs the method. The attached drawings for illustrating exemplary embodiments of the present disclosure are referred to in order to gain a sufficient understanding of the present disclosure, the merits thereof, and the objectives accomplished by the implementation of the present disclosure. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein; rather, these exemplary embodiments are provided such that this disclosure will be thorough and complete, and will fully convey concepts to one of ordinary skill in the art. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Hereinafter, the terms used in the specification will be briefly described, and then the present disclosure will be described in detail. The terms used in this specification are those general terms currently widely used in the art in consideration of functions regarding the present disclosure, but the terms may vary according to the intention of those of ordinary skill in the art, precedents, or new technology in the art. Also, specified terms may be selected by the applicant, and in this case, the detailed meaning thereof will be described in the detailed description. Thus, the terms used in the specification should be understood not as simple names but based on the meaning of the terms and the overall description. Throughout the specification, an “image” may denote multi-dimensional data composed of discrete image elements (for example, pixels in a two-dimensional image and voxels in a three-dimensional image). For example, an image may be a medical image of an object acquired by an X-ray apparatus, a computed tomography (CT) apparatus, a magnetic resonance imaging (MRI) apparatus, an ultrasound diagnosis apparatus, or another medical imaging apparatus. In addition, an “object” may be a human, an animal, or a part of a human or animal. For example, the object may include an organ (for example, the liver, the heart, the womb, the brain, breasts, or the abdomen), blood vessels, or a combination thereof. The object may be a phantom. The term “phantom” may denote a material having a volume, a density, and an effective atomic number that are approximately the same as those of a living organism. For example, the phantom may be a spherical phantom having similar properties to those of the human body. Throughout the specification, a “user” may be, but is not limited to, a medical expert, for example, a medical doctor, a nurse, a medical laboratory technologist, or a medical imaging expert, or a technician who repairs medical apparatuses. An X-ray apparatus may be a medical imaging apparatus that acquires images of internal structures of an object by transmitting an X-ray through the human body. The X-ray apparatus may acquire medical images of an object more simply within a shorter time than other medical imaging apparatuses including an MRI apparatus and a CT apparatus. Therefore, the X-ray apparatus is widely used in simple chest imaging, simple abdomen imaging, simple skeleton imaging, simple nasal sinuses imaging, simple neck soft tissue imaging, and breast imaging, among other imaging situations. FIG. 1 is a block diagram of an exemplary embodiment of an X-ray system 1000. Referring to FIG. 1, the example X-ray system 1000 includes an X-ray apparatus 100 and a workstation 110. The X-ray apparatus 100 shown in FIG. 1 may be a fixed-type X-ray apparatus or a mobile X-ray apparatus. The X-ray apparatus 100 may include an X-ray radiator 120, a high voltage generator 121, a detector 130, a manipulator 140, and a controller 150. The controller 150 may control overall operations of the X-ray apparatus 100. The high voltage generator 121 may generate a high voltage for generating X-rays, and apply the high voltage to an X-ray source 122. The X-ray radiator 120 includes the X-ray source 122 receiving the high voltage from the high voltage generator 121 to generate and radiate X-rays, and a collimator 123 for guiding a path of the X-ray radiated from the X-ray source 122 and adjusting an X-ray irradiation region. The X-ray source 122 includes an X-ray tube that may be a vacuum tube diode including a cathode and an anode. An inside of the X-ray tube is set as a high vacuum state of about 10 mmHg, and a filament of the anode is heated to a high temperature to generate thermal electrons. The filament may be a tungsten filament, and a voltage of about 10V and a current of about 3 to 5 A may be applied to an electric wire connected to the filament to heat the filament. In addition, when a high voltage of, for example, about 10 to about 300 kVp is applied between the cathode and the anode, the thermal electrons are accelerated to collide with a target material of the cathode, and then, an X-ray is generated. The X-ray is radiated outside via a window, and the window may be formed of a beryllium thin film. In this case, most of the energy of the electrons colliding with the target material may be consumed as heat, and remaining energy converted into the X-ray. The cathode may be mainly formed of copper, and the target material may be disposed opposite to the anode. The target material may be a high resistive material such as chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), tungsten (W), or molybdenum (Mo). The target material may be rotated by a rotating field. When the target material is rotated, an electron impact area is increased, and a heat accumulation rate per unit area may be increased to be at least ten times greater than that of a case where the target material is fixed. The voltage applied between the cathode and the anode of the X-ray tube may be referred to as a tube voltage, and the tube voltage is applied from the high voltage generator 121 and a magnitude of the tube voltage may be expressed by a crest value (kVp). When the tube voltage increases, a velocity of the thermal electrons increases, and accordingly, an energy of the X-ray (energy of photon) that is generated when the thermal electrons collide with the target material is increased. The current flowing in the X-ray tube may be referred to as a tube current that may be expressed as an average value (mA). When the tube current increases, the number of thermal electrons emitted from the filament is increased, and accordingly, the X-ray dose (the number of X-ray photons) generated when the thermal electrons collide with the target material is increased. Therefore, the energy of the X-ray may be adjusted according to the tube voltage, and the intensity of the X-ray or the X-ray dose may be adjusted according to the tube current and the X-ray exposure time. The detector 130 detects an X-ray that is radiated from the X-ray radiator 120 and has been transmitted through an object. The detector 130 may be a digital detector. The detector 130 may be implemented by using a thin film transistor (TFT) or a charge coupled device (CCD). Although the detector 130 is included in the X-ray apparatus 100 in FIG. 1, the detector 130 may be an X-ray detector that is a separate device capable of being connected to or separated from the X-ray apparatus 100. The X-ray apparatus 100 may further include a manipulator 140 for providing a user with an interface for manipulating the X-ray apparatus 100. The manipulator 140 may include an output interface 141 and an input interface 142. The input interface 142 may receive from a user a command for manipulating the X-ray apparatus 100 and various types of information related to X-ray imaging. The controller 150 may control or manipulate the X-ray apparatus 100 according to the information received by the input interface 142. The output interface 141 may, for example, output sound representing information related to an imaging operation such as the X-ray radiation under the control of the controller 150. The workstation 110 and the X-ray apparatus 100 may be connected to each other by wire or wirelessly. When they are connected to each other wirelessly, a device for synchronizing clock signals with each other may be further included. The workstation 110 and the X-ray apparatus 100 may exist within physically separate spaces. The workstation 110 may include an output interface 111, an input interface 112, and a controller 113. The output interface 111 and the input interface 112 provide a user with an interface for manipulating the workstation 110 and the X-ray apparatus 200. The controller 113 may control the workstation 110 and the X-ray apparatus 200. The X-ray apparatus 100 may be controlled via the workstation 110 or may be controlled by the controller 150 included in the X-ray apparatus 100. Accordingly, a user may control the X-ray apparatus 100 via the workstation 110 or may control the X-ray apparatus 100 via the manipulator 140 and the controller 150 included in the X-ray apparatus 100. In other words, a user may remotely control the X-ray apparatus 100 via the workstation 110 or may directly control the X-ray apparatus 100. Although the controller 113 of the workstation 110 is separate from the controller 150 of the X-ray apparatus 100 in FIG. 1, FIG. 1 is only an example. As another example, the controllers 113 and 150 may be integrated into a single controller, and the single controller may be included in only one of the workstation 110 and the X-ray apparatus 100. Hereinafter, the controllers 113 and 150 may denote at least one from among the controller 113 of the workstation 110 and the controller 150 of the X-ray apparatus 100. The output interface 111 and the input interface 112 of the workstation 110 may provide a user with an interface for manipulating the X-ray apparatus 100, and the output interface 141 and the input interface 142 of the X-ray apparatus 100 may also provide a user with an interface for manipulating the X-ray apparatus 100. Although the workstation 110 and the X-ray radiation apparatus 100 include the output interfaces 111 and 141, respectively, and the input interfaces 112 and 142, respectively, in FIG. 1, exemplary embodiments are not limited thereto. Only one of the workstation 110 and the X-ray apparatus 100 may include an output interface or an input interface. Hereinafter, the input interfaces 112 and 142 may denote at least one from among the input interface 112 of the workstation 110 and the input interface 142 of the X-ray apparatus 100, and the output interfaces 111 and 141 may denote at least one from among the output interface 111 of the workstation 110 and the output interface 141 of the X-ray apparatus 100. Examples of the input interfaces 112 and 142 may include a keyboard, a mouse, a touch screen, a voice recognizer, a fingerprint recognizer, an iris recognizer, and other input devices which are well known to one of ordinary skill in the art. The user may input a command for radiating the X-ray via the input interfaces 112 and 142, and the input interfaces 112 and 142 may include a switch for inputting the command. In some exemplary embodiments, the switch may be configured so that a radiation command for radiating the X-ray may be input only when the switch is pushed twice. In other words, when the user pushes the switch, a prepare command for performing a pre-heating operation for X-ray radiation may be input through the switch, and then, when the user pushes the switch once more, the radiation command for performing substantial X-ray radiation may be input through the switch. When the user manipulates the switch as described above, the controllers 113 and 150 generate signals corresponding to the commands input through the switch manipulation, that is, for example, a prepare signal, and transmit the generated signals to the high voltage generator 121 generating a high voltage for generating the X-ray. When the high voltage generator 121 receives the prepare signal from the controllers 113 and 150, the high voltage generator 121 starts a pre-heating operation, and when the pre-heating is finished, the high voltage generator 121 outputs a ready signal to the controllers 113 and 150. In addition, the detector 130 also needs to prepare to detect the X-ray, and thus the high voltage generator 121 performs the pre-heating operation and the controllers 113 and 150 transmit a prepare signal to the detector 130 so that the detector 130 may prepare to detect the X-ray transmitted through the object. The detector 130 prepares to detect the X-ray in response to the prepare signal, and when the preparing for the detection is finished, the detector 130 outputs a ready signal to the controllers 113 and 150. When the pre-heating operation of the high voltage generator 121 is finished and the detector 130 is ready to detect the X-ray, the controllers 113 and 150 transmit a radiation signal to the high voltage generator 121, the high voltage generator 121 generates and applies the high voltage to the X-ray source 122, and the X-ray source 122 radiates the X-ray. When the controllers 113 and 150 transmit the radiation signal to the high voltage generator 121, the controllers 113 and 150 may transmit a sound output signal to the output interfaces 111 and 141 so that the output interfaces 111 and 141 output a predetermined sound and the object may recognize the radiation of the X-ray. The output interfaces 111 and 141 may also output a sound representing information related to imaging in addition to the X-ray radiation. In FIG. 1, the output interface 141 is included in the manipulator 140; however, the exemplary embodiments are not limited thereto, and the output interface 141 or a portion of the output interface 141 may be located elsewhere. For example, the output interface 141 may be located on a wall of an examination room in which the X-ray imaging of the object is performed. The controllers 113 and 150 control locations of the X-ray radiator 120 and the detector 130, imaging timing, and imaging conditions, according to imaging conditions set by the user. In more detail, the controllers 113 and 150 control the high voltage generator 121 and the detector 130 according to the command input via the input interfaces 112 and 142 in order to control radiation timing of the X-ray, an intensity of the X-ray, and a region radiated by the X-ray. In addition, the control units 113 and 150 adjust the location of the detector 130 according to a predetermined imaging condition, and controls operation timing of the detector 130. Furthermore, the controllers 113 and 150 generate a medical image of the object by using image data received via the detector 130. In detail, the controllers 113 and 150 may receive the image data from the detector 130, and then, generate the medical image of the object by removing noise from the image data and adjusting a dynamic range and interleaving of the image data. The output interfaces 111 and 141 may output the medical image generated by the controllers 113 and 150. The output interfaces 111 and 141 may output information that is necessary for the user to manipulate the X-ray apparatus 100, for example, a user interface (UI), user information, or object information. Examples of the output interfaces 111 and 141 may include a speaker, a printer, a cathode ray tube (CRT) display, a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED) display, a field emission display (FED), a light emitting diode (LED) display, a vacuum fluorescent display (VFD), a digital light processing (DLP) display, a flat panel display (FPD), a three-dimensional (3D) display, a transparent display, and other various output devices well known to one of ordinary skill in the art. The workstation 110 shown in FIG. 1 may further include a communicator that may be connected to a server 162, a medical apparatus 164, and a portable terminal 166 via a network 15. The communicator may be connected to the network 15 by wire or wirelessly to communicate with the server 162, the medical apparatus 164, or the portable terminal 166. The communicator may transmit or receive data related to diagnosis of the object via the network 15, and may also transmit or receive medical images captured by the medical apparatus 164, for example, a CT apparatus, an MRI apparatus, or an X-ray apparatus. Moreover, the communicator may receive a medical history or treatment schedule of an object (e.g., a patient) from the server 162 to diagnose a disease of the object. Also, the communicator may perform data communication with the portable terminal 166 such as a mobile phone, a personal digital assistant (PDA), or a laptop computer of a medical doctor or a client, as well as the server 162 or the medical apparatus 164 in a hospital. The communicator may include one or more elements enabling communication with external apparatuses. For example, the communicator may include a local area communication module, a wired communication module, and a wireless communication module. The local area communication module may refer to a module for performing local area communication with an apparatus located within a predetermined distance. Examples of local area communication technology may include, but are not limited to, a wireless local area network (LAN), Wi-Fi, Bluetooth, ZigBee, Wi-Fi Direct (WFD), ultra wideband (UWD), infrared data association (IrDA), Bluetooth low energy (BLE), and near field communication (NFC). The wired communication module may refer to a module for communicating by using an electric signal or an optical signal. Examples of wired communication technology may include wired communication techniques using a pair cable, a coaxial cable, and an optical fiber cable, and other wired communication techniques that are well known to one of ordinary skill in the art. The wireless communication module transmits and receives a wireless signal to and from at least one selected from a base station, an external apparatus, and a server in a mobile communication network. Here, examples of the wireless signal may include a voice call signal, a video call signal, and various types of data according to text/multimedia messages transmission. The X-ray apparatus 100 shown in FIG. 1 may include a plurality of digital signal processors (DSPs), an ultra-small calculator, and a processing circuit for special purposes (for example, high speed analog/digital (A/D) conversion, high speed Fourier transformation, and an array process). In addition, communication between the workstation 110 and the X-ray apparatus 100 may be performed using a high speed digital interface, such as low voltage differential signaling (LVDS), asynchronous serial communication, such as a universal asynchronous receiver transmitter (UART), a low latency network protocol, such as error synchronous serial communication or a controller area network (CAN), or any of other various communication methods that are well known to one of ordinary skill in the art. FIG. 2 is a perspective view of an example of a fixed type X-ray apparatus 200 according to an exemplary embodiment. The fixed type X-ray apparatus 200 may be another exemplary embodiment of the X-ray apparatus 100 of FIG. 1. Components included in the fixed type X-ray apparatus 200 that are the same as those of the X-ray apparatus 100 of FIG. 1 use the same reference numerals, and repeated descriptions thereof will be omitted. Referring to FIG. 2, the example fixed type X-ray apparatus 200 includes a manipulator 140 providing a user with an interface for manipulating the X-ray apparatus 200, an X-ray radiator 120 radiating an X-ray to an object, a detector 130 detecting an X-ray that has passed through the object, first, second, and third motors 211, 212, and 213 providing a driving power to transport the X-ray radiator 120, a guide rail 220, a moving carriage 230, and a post frame 240. The guide rail 220, the moving carriage 230, and the post frame 240 are formed to transport the X-ray radiator 120 by using the driving power of the first, second, and third motors 211, 212, and 213. The guide rail 220 includes a first guide rail 221 and a second guide rail 222 that are provided to form a predetermined angle with respect to each other. The first guide rail 221 and the second guide rail 222 may respectively extend in directions crossing each other at 90°. The first guide rail 221 is provided on the ceiling of an examination room in which the X-ray apparatus 200 is disposed. The second guide rail 222 is located under the first guide rail 221, and is mounted so as to slide along the first guide rail 221. A roller that may move along the first guide rail 221 may be provided on the first guide rail 221. The second guide rail 222 is connected to the roller to move along the first guide rail 221. A first direction D1 is defined as a direction in which the first guide rail 221 extends, and a second direction D2 is defined as a direction in which the second guide rail 222 extends. Therefore, the first direction D1 and the second direction D2 cross each other at 90°, and may be parallel to the ceiling of the examination room. The moving carriage 230 is disposed under the second guide rail 222 so as to move along the second guide rail 222. A roller moving along the second guide rail 222 may be provided on the moving carriage 230. Therefore, the moving carriage 230 may move in the first direction D1 together with the second guide rail 222, and may move in the second direction D2 along the second guide rail 222. The post frame 240 is fixed on the moving carriage 230 and located under the moving carriage 230. The post frame 240 may include a plurality of posts 241, 242, 243, 244, and 245. In some exemplary embodiments, the plurality of posts 241, 242, 243, 244, and 245 are connected to each other to be foldable, nestable, or retractable within each other, and thus, the post frame 240 may have a length that is adjustable in a vertical direction of the examination room while in a state of being fixed to the moving carriage 230. A third direction D3 is defined as a direction in which the length of the post frame 240 increases or decreases. Therefore, the third direction D3 may be perpendicular to the first direction D1 and the second direction D2. The detector 130 detects the X-ray that has passed through the object, and may be combined with a table type receptor 290 or a stand type receptor 280. A rotating joint 250 is disposed between the X-ray radiator 120 and the post frame 240. The rotating joint 250 allows the X-ray radiator 120 to be coupled to the post frame 240, and supports a load applied to the X-ray radiator 120. The X-ray radiator 120 connected to the rotating joint 250 may rotate on a plane that is perpendicular to the third direction D3. In this case, a rotating direction of the X-ray radiator 120 may be defined as a fourth direction D4. Also, the X-ray radiator 120 may be configured to be rotatable on a plane perpendicular to the ceiling of the examination room. Therefore, the X-ray radiator 120 may rotate in a fifth direction D5 that is a rotating direction about an axis that is parallel with the first direction D1 or the second direction D2, with respect to the rotating joint 250. The first, second, and third motors 211, 212, and 213 may be provided to move the X-ray radiator 120 in the first, second, and third directions D1, D2, and D3. The first, second, and third motors 211, 212, and 213 may be electrically driven, and the first, second, and third motors 211, 212, and 213 may respectively include an encoder. The first, second, and third motors 211, 212, and 213 may be disposed at various locations in consideration of design convenience. For example, the first motor 211, moving the second guide rail 222 in the first direction D1, may be disposed around the first guide rail 221, the second motor 212, moving the moving carriage 230 in the second direction D2, may be disposed around the second guide rail 222, and the third motor 213, increasing or reducing the length of the post frame 240 in the third direction D3, may be disposed in the moving carriage 230. In another example, the first, second, and third motors 211, 212, and 213 may be connected to a power transfer unit in order to linearly move the X-ray radiator 120 in the first, second, and third directions D1, D2, and D3. The driving power transfer unit may be a combination of a belt and a pulley, a combination of a chain and a sprocket, or a shaft, which are generally used. In another example, motors may be disposed between the rotating joint 250 and the post frame 240 and between the rotating joint 250 and the X-ray radiator 120 in order to rotate the X-ray radiator 120 in the fourth and fifth directions D4 and D5. The manipulator 140 may be disposed on a side surface of the X-ray radiator 120. Although FIG. 2 shows the fixed type X-ray apparatus 200 connected to the ceiling of the examination room, the fixed type X-ray apparatus 200 is merely an example for convenience of comprehension. That is, X-ray apparatuses according to exemplary embodiments of the present disclosure may include X-ray apparatuses having various structures that are well known to one of ordinary skill in the art, for example, a C-arm-type X-ray apparatus and an angiography X-ray apparatus, in addition to the fixed type X-ray apparatus 200 of FIG. 2. FIG. 3 is a diagram showing an example configuration of a mobile X-ray apparatus 300 capable of performing an X-ray imaging operation regardless of a place where the imaging operation is performed, according to an exemplary embodiment. The mobile X-ray apparatus 300 may be another exemplary embodiment of the X-ray apparatus 100 of FIG. 1. Components included in the mobile X-ray apparatus 300 that are the same as those of the X-ray apparatus 100 of FIG. 1 use the same reference numerals as those used in FIG. 1, and a repeated description thereof will be omitted. Referring to FIG. 3, the example mobile X-ray apparatus 300 includes a transport unit 370 including a wheel for transporting the mobile X-ray apparatus 300, a main unit 305, an X-ray radiator 120, and a detector 130 detecting an X-ray that is radiated from the X-ray radiator 120 toward an object and transmitted through the object. The main unit 305 includes a manipulator 140 providing a user with an interface for manipulating the mobile X-ray apparatus 300, a high voltage generator 121 generating a high voltage applied to an X-ray source 122, and a controller 150 controlling overall operations of the mobile X-ray apparatus 300. The X-ray radiator 120 includes the X-ray source 122 generating the X-ray, and a collimator 123 guiding a path along which the generated X-ray is emitted from the X-ray source 122 and adjusting an irradiation region radiated by the X-ray. The detector 130 in FIG. 3 may be not combined with any receptor, and the detector 130 may be a portable detector which can exist anywhere. In FIG. 3, the manipulator 140 is included in the main unit 305; however, exemplary embodiments are not limited thereto. For example, as illustrated in FIG. 2, the manipulator 140 of the mobile X-ray apparatus 300 may be disposed on a side surface of the X-ray radiator 120. The controller 150 controls locations of the X-ray radiator 120 and the detector 130, imaging timing, and imaging conditions according to imaging conditions set by the user. In addition, the controller 150 generates a medical image of the object by using image data received from the detector 130. In detail, the controller 150 may generate the medical image of the object by removing noise from the image data received from the detector 130 and adjusting a dynamic range and interleaving of the image data. The main unit 305 of the mobile X-ray apparatus 300 shown in FIG. 3 may further include an output interface outputting the medical image generated by the controller 150. The output interface may output information that is necessary for the user to manipulate the mobile X-ray apparatus 300, for example, a UI, user information, or object information. FIG. 4 is a schematic diagram showing an example of a detailed configuration of a detector 400, according to an exemplary embodiment. The detector 400 may be an exemplary embodiment of the detector 130 of FIGS. 1-3. The detector 400 may be an indirect type detector. Referring to FIG. 4, the detector 400 may include a scintillator, a photodetecting substrate 410, a bias driver 430, a gate driver 450, and a signal processor 470. The scintillator receives the X-ray radiated from the X-ray source 122 and converts the X-ray into light. The photodetecting substrate 410 receives the light from the scintillator and converts the light into an electrical signal. The photodetecting substrate 410 may include gate lines GL, data lines DL, TFTs 412, photodiodes 414, and bias lines BL. The gate lines GL may be formed in a first direction DR1, and the data lines DL may be formed in a second direction DR2 that crosses the first direction DR1. The first direction DR1 and the second direction DR2 may intersect perpendicularly to each other. FIG. 4 shows four gate lines GL and four data lines DL as an example. The TFTs 412 may be arranged as a matrix in the first and second directions DR1 and DR2. Each of the TFTs 412 may be electrically connected to one of the gate lines GL and one of the data lines DL. A gate of the TFT 412 may be electrically connected to the gate line GL, and a source of the TFT 412 may be electrically connected to the data line DL. In FIG. 4, sixteen TFTs 412 (in a 4×4 arrangement) are shown as an example. The photodiodes 414 may be arranged as a matrix in the first and second directions DR1 and DR2 so as to respectively correspond to the TFTs 412. Each of the photodiodes 414 may be electrically connected to one of the TFTs 412. An N-side electrode of each of the photodiodes 414 may be electrically connected to a drain of the TFT 412. FIG. 4 shows sixteen photodiodes 414 (in a 4×4 arrangement) as an example. The bias lines BL are electrically connected to the photodiodes 414. Each of the bias lines BL may be electrically connected to P-side electrodes of an array of photodiodes 414. For example, the bias lines BL may be formed to be substantially parallel with the second direction DR2 so as to be electrically connected to the photodiodes 414. On the other hand, the bias lines BL may be formed to be substantially parallel with the first direction DR1 in order to be electrically connected to the photodiodes 414. FIG. 4 shows four bias lines BL formed along the second direction DR2 as an example. The bias driver 430 is electrically connected to the bias lines BL in order to apply a driving voltage to the bias lines BL. The bias driver 430 may selectively apply a reverse bias voltage or a forward bias voltage to the photodiodes 414. A reference voltage may be applied to the N-side electrodes of the photodiodes 414. The reference voltage may be applied via the signal processor 470. The bias driver 430 may apply a voltage that is less than the reference voltage to the P-side electrodes of the photodiodes 414 in order to apply a reverse bias voltage to the photodiodes 414. On the other hand, the bias driver 430 may apply a voltage that is greater than the reference voltage to the P-side electrodes of the photodiodes 414 so as to apply a forward bias voltage to the photodiodes 414. The gate driver 450 is electrically connected to the gate lines GL and thus may apply gate signals to the gate lines GL. For example, when the gate signals are applied to the gate lines GL, the TFTs 412 may be turned on by the gate signals. On the other hand, when the gate signals are not applied to the gate lines GL, the TFTs 412 may be turned off. The signal processor 470 is electrically connected to the data lines DL. When the light received by the photodetecting substrate 410 is converted into the electrical signal, the electrical signal may be read out by the signal processor 470 via the data lines DL. An operation of the detector 400 will now be described. During the operation of the detector 400, the bias driver 430 may apply the reverse bias voltage to the photodiodes 414. While the TFTs 412 are turned off, each of the photodiodes 414 may receive the light from the scintillator and generate electron-hole pairs to accumulate electric charges. The amount of electric charge accumulated in each of the photodiodes 414 may correspond to the intensity of the received X-ray. Then, the gate driver 450 may sequentially apply the gate signals to the gate lines GL along the second direction DR2. When a gate signal is applied to a gate line GL and thus TFTs 412 connected to the gate line GL are turned on, photocurrents may flow into the signal processor 470 via the data lines DL due to the electric charges accumulated in the photodiodes 414 connected to the turned-on TFTs 412. The signal processor 470 may convert the received photocurrents into image data and output the image data to the outside. The image data may be in the form of an analog signal or a digital signal corresponding to the photocurrents. Although not shown in FIG. 4, if the detector 400 shown in FIG. 4 is a wireless detector, the detector 400 may further include a battery unit and a wireless communication interface unit. FIG. 5 is a block diagram of an example of an X-ray apparatus 500 according to an exemplary embodiment. The X-ray apparatus 500 of FIG. 5 may be another exemplary embodiment of the above-described X-ray apparatuses 100, 200, and 300. Therefore, whether or not described below, the above-described features may be applied to the X-ray apparatus 500 of FIG. 5. Also, the X-ray apparatus 500 may be controlled by the workstation 110 of FIG. 1. Referring to FIG. 5, the X-ray apparatus 500 may include an image acquirer 510, an X-ray radiator 520, a detector 530, and a controller 550. The X-ray radiator 520 includes an X-ray source 522 and a collimator 523. The X-ray source 522 may radiate X-rays. The collimator 523 may adjust an irradiation region of X-rays radiated by the X-ray source 522. The detector 530 detects X-rays. Hereinafter in the present specification, a detector may also be referred to as an “X-ray detector.” Also, because an X-ray image is acquired based on X-rays detected by the detector 530, the detector 530 may also be referred to as an image receptor. Although FIG. 5 illustrates that the detector 530 is included in the X-ray apparatus 500, the detector 530 may be an X-ray detector that may be connected to or separated from the X-ray apparatus 500. The collimator 523 includes a lamp 524. The lamp 524 may be turned on and off. The lamp 524 may include various types of light emission sources. When the lamp 524 is turned on, light is emitted from the lamp 524. The image acquirer 510 may acquire an image of an object by imaging an object while the lamp 524 is turned on. Hereinafter, the image acquired by imaging the object is referred to as “object image.” The object image is captured via imaging, and is different from an X-ray image that is acquired by capturing an object using X-rays. The image acquirer 510 may include various types of imaging devices, such as a camera or a camcorder. The controller 550 may include a central processing unit (CPU), a microprocessor, a graphic processing unit (GPU), and the like. The controller 550 may acquire a distance between the X-ray source 522 and the object based on the object image acquired by the image acquirer 510. Hereinafter, a distance between an X-ray source and an object is referred to as “object distance” or “source to object distance (SOD).” The controller 550 may detect a certain area or a certain point in an object image. According to a relationship between a region and the SOD or a relationship between a point and the SOD, the controller 550 may acquire the SOD based on a detected region or a detected point. A method of acquiring an object distance based on an object image will be described below with reference to the following drawings. The controller 550 may acquire a thickness of the object based on the object distance, and a detector distance that is a distance between the X-ray source 522 and the detector 530. Hereinafter, a distance between an X-ray source and a detector is also referred to as “detector distance” or “source to image receptor distance SID.” FIG. 6 is a perspective view of an example of the collimator 523 included in the X-ray apparatus 500 of FIG. 5, according to an exemplary embodiment. Referring to FIGS. 5 and 6, the collimator 523 may further include an irradiation window 525 and a shutter 526. Although not illustrated in FIG. 6, the collimator 523 may include the lamp 524 of FIG. 5. X-rays may be radiated from the X-ray source 522 through the irradiation window 525 of the collimator 523. Also, when the lamp 524 of the collimator 523 is turned on, light is emitted through the irradiation window 525 of the collimator 523. That is, light from the lamp 524 or X-rays from the X-ray source 522 may pass through the irradiation window 525. Referring to FIG. 6, the irradiation window 525 is a quadrilateral with crossing lines. However, FIG. 6 is only an exemplary diagram of the irradiation window 525, and a shape of the irradiation window 525 is not limited to that shown in FIG. 6. The shutter 526 may adjust a size of the irradiation window 525. The collimator 523 may adjust the size of the irradiation window 525 by using the shutter 526 to thus adjust an X-ray irradiation region. Because light from the lamp 524 and X-rays from the X-ray source 522 are emitted through the irradiation window 525, an irradiation region of light from the lamp 524 may correspond to the X-ray irradiation region. Therefore, before the X-ray source 522 radiates X-rays, a user may recognize or adjust the X-ray irradiation region via the irradiation region of light from the lamp 524. As shown in FIG. 6, the image acquirer 510 may be coupled to the collimator 523. However, FIG. 6 is only an exemplary diagram, and a location of the image acquirer 510 in the X-ray apparatus 500 is not limited to that shown in FIG. 6. FIG. 7 is a diagram showing an example of the X-ray apparatus 500 of FIG. 5 according to an exemplary embodiment. Whether or not described below, the X-ray apparatus 500 of FIG. 7 may also include the above-described features. Also, features of FIGS. 5 and 6 that are not shown in FIG. 7 may also be included in the X-ray apparatus 500 of FIG. 7. The X-ray apparatus 500 of FIG. 7 may include the controller 550 of FIG. 5, and the X-ray radiator 520 of FIG. 7 may include the collimator 523 including the lamp 524 and the X-ray source 522 of FIG. 5. Referring to FIGS. 5 and 7, when the lamp 524 is turned on, light from the lamp 524 is emitted through the irradiation window 525 of the collimator 523. Due to an irradiation region 590 of light from the lamp 524, an image IM100 of the irradiation window 525 may be formed on an object 10. The image of the irradiation window 525 formed on the object 10 may also be referred to as an “irradiation window image IM100” on the object 10. The image acquirer 510 may acquire an object image by imaging the object 10. Because the irradiation window image IM100 is formed on the object 10, the object image acquired by the image acquirer 510 may include an image area corresponding to the irradiation window image IM100. FIG. 8 is a diagram showing an example of an object image 30 acquired by the X-ray apparatus 500 of FIG. 7, according to an exemplary embodiment. Referring to FIGS. 7 and 8, the object image 30 includes an image area 31 corresponding to the irradiation window image IM100 formed on the object 10. Hereinafter, the image area 31 corresponding to the irradiation window image IM100 in the object image 30 will be referred to as “collimation region” or “irradiation region of a collimator” of the object image 30. That is, a collimation region 31 is included in the object image 30 and corresponds to the irradiation region 590 of light from the lamp 524 of the collimator 523 of FIG. 5. The object image 30 may indicate 2-dimensional (2D) data including pixel values of pixels that are discrete image components. The pixel values may include at least one piece of information, such as brightness or color. In the object image 30, the collimation region 31 may be a group of pixels. Referring back to FIGS. 5 to 8, the controller 550 may detect the collimation region 31 in the object image 30. The controller 550 may acquire an object distance SOD based on a size of the collimation region 31. The controller 550 may detect the collimation region 31 based on brightness information of the object image 30. The collimation region 31 may be brighter than other areas in the object image 30. That is, pixel values of pixels in the collimation region 31 may have higher brightness than those of other areas. Furthermore, the controller 550 may detect the collimation region 31 based on a shape of the irradiation window 525 of the collimator 523. The shape of the collimation region 31 may vary according to the shape of the irradiation window 525. For example, when the irradiation window 525 is quadrilateral-shaped as in FIG. 6, the collimation region 31 may also be quadrilateral-shaped. Also, when the irradiation window 525 has crossing lines as in FIG. 6, the collimation region 31 may also have crossing lines L1 and L2 as shown in FIG. 8. Therefore, the controller 550 may use a pattern recognition algorithm based on the shape of the irradiation window 525 to detect the collimation region 31. For example, when the irradiation window 525 is quadrilateral-shaped, the controller 550 may use a quadrilateral pattern recognition algorithm. The controller 550 may set a predetermined error range related to the shape of the collimation region 31 that is based on the shape of the irradiation window 525 of the collimator 523. Due to curves of the object 10, the irradiation window image IM100 on the object 10 may be slightly distorted compared to an actual shape of the irradiation window 525. Accordingly, the shape of the collimation region 31 in the object image 30 may also be distorted. Therefore, the controller 550 may set a predetermined error range related to the shape of the collimation region 31. For example, when the irradiation window 525 is rectangular-shaped, the shape of the collimation region 31 may be a quadrilateral such as a trapezoid. Also, the controller 550 may reduce the size of the irradiation window 525 by using the shutter 526 so as to reduce distortion of the shape of the collimation region 31. In this case, the collimation region 31 may also be reduced in the object image 30, and thus, the shape of the collimation region 31 may be less distorted. However, as the collimation region 31 decreases in size, accuracy of the object distance SOD acquired by the controller 550 may decrease. Therefore, the controller 550 may adjust the size of the irradiation window 525 of FIG. 6 based on trade-off with the accuracy of the object distance SOD. Accordingly, the controller 550 may detect the collimation region 31 based on brightness information of the object image 30, the shape of the irradiation window 525, and the like. The controller 550 may acquire the object distance SOD based on the size of the collimation region 31. The size of the collimation region 31 may correspond to the number of pixels in the collimation region 31. Alternatively, the size of the collimation region 31 may correspond to the area size of the collimation region 31. The controller 550 may detect crossing lines L1 and L2 of the object image 30 that correspond to crossing lines of the irradiation window 525, and acquire the size of the collimation region 31 based on the crossing lines L1 and L2. The controller 550 may detect the crossing lines L1 and L2 based on the brightness information of the object image 30, the shape of the irradiation window 525, and the like. The controller 550 may detect respective lengths of the crossing lines L1 and L2. For example, the respective lengths of the crossing lines L1 and L2 may correspond to the number of pixels that form each of the crossing lines L1 and L2. The controller 550 may multiply the respective lengths of the crossing lines L1 and L2 and thus acquire the size of the collimation region 31. Alternatively, the size of the collimation region 31 may be estimated based on a length of one of the crossing lines L1 and L2. The controller 550 may acquire the size of the collimation region 31 based on a length of one of the crossing lines L1 and L2 of the irradiation window 525. The controller 550 may acquire the object distance SOD based on the size of the collimation region 31. However, the descriptions above are only examples of a method of acquiring the size of the collimation region 31, and the method is not limited thereto. The size of the collimation region 31 in the object image 30 may vary according to the object distance SOD. Therefore, when the controller 550 acquires relationship information that indicates relationship between the size of the collimation region 31 and the object distance SOD, the object distance SOD may be acquired based on the relationship information. FIG. 9 is a graph of an example of a relationship information between a size of a collimation region and an object distance, according to an exemplary embodiment. Referring to FIG. 9, an X-axis indicates the object distance, and a Y-axis indicates a size of a collimation region in an object image. The size of the collimation decreases as the object distance increases. In perspective, the size of the collimation region in the object image may decrease as the object distance increases. Therefore, when the size (OA) of the collimation region in the object image is acquired, the object distance SOD may be acquired based on the relationship information as shown in FIG. 9. Referring back to FIG. 7, the controller 550 of FIG. 5 may acquire the object distance SOD based on relationship information (e.g., the relationship information of FIG. 9) that indicates a relationship between the size of the collimation region and the object distance. Also, the controller 550 of FIG. 5 may acquire an object thickness OT that indicates a thickness of the object 10, based on a detector distance SID (source to image receptor distance) and an object distance SOD. The object thickness OT may be equal to a difference between the detector distance SID and the object distance SOD. Therefore, according to an exemplary embodiment, the X-ray apparatus 500 may automatically acquire the object distance SOD, which is a distance between an X-ray source 525 and the object 10, based on an object image by imaging the object 10. Also, the X-ray apparatus 500 may acquire the object thickness OT based on the object distance SOD and the detector distance SID, which is a distance between the X-ray source 525 and the detector 530. According to an exemplary embodiment, the X-ray apparatus 500 may automatically acquire the object distance SOD or the object thickness OT without a separate sensor or a measuring instrument such as a tapeline. Also, the controller 550 of FIG. 5 may acquire the detector distance SID in a similar manner as the acquiring of the object distance SOD. This will be described with reference to FIG. 10. FIG. 10 is a diagram for describing an example of acquiring the detector distance SID by using the X-ray apparatus 500 of FIG. 7, according to an exemplary embodiment. The X-ray apparatus 500 of FIG. 10 may be another exemplary embodiment of the X-ray apparatus 500 of FIG. 5. The above-described features may also be applied to the X-ray apparatus 500. Referring to FIGS. 5 and 10, as shown there is no object between the X-ray radiator 520 and the detector 530. When the lamp 524 is turned on, light from the lamp is emitted through the irradiation window 525 of the collimator 523. Due to the irradiation region 590 of light from the lamp 524, an image IM200 of the irradiation window 525 may be formed on the detector 530. The image of the irradiation window 525 formed on the detector 530 may be referred to as “irradiation window image IM200.” The image acquirer 510 may acquire a detector image by imaging the detector 530. In this case, the irradiation window image IM200 may be formed on the detector 530. Therefore, the detector image acquired by the image acquirer 510 may include an image area corresponding to the irradiation window image IM200. FIG. 11 is a diagram showing an example of a detector image 20 acquired by the X-ray apparatus 500 of FIG. 10, according to an exemplary embodiment. Referring to FIGS. 10 and 11, the detector image 20 includes an image area 21 corresponding to the irradiation window image IM200 formed on the detector 530. Hereinafter, the image area 21 corresponding to the irradiation window image IM200 in the detector image 20 is referred to as “collimation region” of the detector image 20. That is, the collimation region 21 is included in the detector image 20 and corresponds to the irradiation region 590 of light emitted from the lamp 524 of the collimator 523 of FIG. 5. The controller 550 of the X-ray apparatus 500 of FIG. 5 may detect the collimation region 21 from the detector image 20. The controller 550 of FIG. 5 may detect the collimation region 21 based on brightness information of the detector image 20, the shape of the irradiation window 525, and the like. The controller 550 of FIG. 5 may acquire the detector distance SID based on a size of the collimation region 21. The size of the collimation region 21 may correspond to the number of pixels in the collimation region 21. Alternatively, the size of the collimation region 21 may correspond to the area size of the collimation region 21. The controller 550 of FIG. 5 may detect crossing lines L3 and L4 of the detector image 20 that correspond to the crossing lines of the irradiation window 525, and acquire the size of the collimation region 21 based on the crossing lines L3 and L4. The controller 550 of FIG. 5 may detect respective lengths of the crossing lines L3 and L4. For example, the respective lengths of the crossing lines L3 and L4 may correspond to the number of pixels that form each of the crossing lines L3 and L4. The controller 550 of FIG. 5 may multiply the respective lengths of the crossing lines L3 and L4 and thus acquire the size of the collimation region 21. Alternatively, the size of the collimation region 21 may be estimated based on a length of one of the crossing lines L3 and L4. The controller 550 of FIG. 5 may acquire the size of the collimation region 21 based on a length of one of the crossing lines L3 and L4. The controller 550 of FIG. 5 may acquire the detector distance SID based on the size of the collimation region 21. However, the descriptions above are only examples of a method of acquiring the size of the collimation region 21, and the method is not limited thereto. As in the acquiring of the object distance SOD, the controller 550 of FIG. 5 may acquire the detector distance SID based on relationship information that indicates a relationship between a size of a collimation region and a detector distance. The controller 550 of FIG. 5 may use the relationship information (e.g., the relationship information of FIG. 9) that indicates the relationship between the size of the collimation region and the object distance, which is used for the acquiring of the object distance SOD, to acquire the detector distance SID. The relationship information may be information that is acquired based on values that are measured in advance through experiments. In FIG. 5, the image acquirer 510 of the X-ray apparatus 500 may acquire target images by imaging a target at various distances while changing a distance between the X-ray source 522 and a target. The target may be the object or the detector 530. The X-ray apparatus 500 may detect a size of a collimation region of each of the target images acquired according to distances. By doing so, the X-ray apparatus 500 may acquire the relationship information (e.g., the relationship information of FIG. 9) between the size of the collimation region and the distance between the X-ray source 522 and the target in advance. Alternatively, the X-ray apparatus 500 may receive relationship information that is acquired by another external device through experiments. FIG. 12 is a diagram showing an example of a relationship between an object distance SOD, a detector distance SID, and a thickness OT of an object in the graph of FIG. 9 that shows relationship information, according to an exemplary embodiment. Referring to FIG. 12, when a size OA of the collimation region is acquired from the object image, the object distance SOD may be acquired based on the relationship information. Likewise, when a size DA of the collimation region of the detector image is acquired from the detector image, the detector distance SID may be acquired. The object thickness OT may be acquired based on a difference between the detector distance SID and the object distance SOD. As described above, the controller 550 of FIG. 5 may acquire the detector distance SID by using a method similar to the method of acquiring the object distance SOD. However, this is only an exemplary embodiment of the method of acquiring the detector distance SID. The controller 550 of FIG. 5 may acquire the detector distance SID in various ways. For example, a detector may be coupled to a receptor such as a table type receptor or a stand type receptor. An X-ray apparatus may adjust or automatically acquire a distance between an X-ray source and the receptor. In this case, the X-ray apparatus may acquire the detector distance SID by using a method different from the method of acquiring the object distance SOD. FIG. 13 is a block diagram of an example of an X-ray apparatus 600, according to an exemplary embodiment. The X-ray apparatus 600 of FIG. 13 may be another exemplary embodiment of the X-ray apparatus 500 of FIG. 5. Therefore, whether or not described below, the above-described features may be included in the X-ray apparatus 600 of FIG. 13. Referring to FIG. 13, the X-ray apparatus 600 includes an image acquirer 610, an X-ray radiator 620, and a controller 650. The X-ray radiator 620 may include an X-ray source 622 and a collimator 623. The collimator 623 includes a lamp 624. The X-ray apparatus 600 may further include a detector 630, a manipulator 640, and a memory 660. The manipulator 640 may include an output interface 641 and an input interface 642. The image acquirer 610 may acquire an object image by imaging an object while the lamp 624 is turned on. The controller 650 may acquire an object distance, which is a distance between the X-ray source 622 and the object, based on the object image acquired by the image acquirer 610. The controller 650 may detect a collimation region from the object image, and acquire the object distance based on a size of the collimation region. The controller 650 may acquire the object distance based on information stored in the memory 660, that is, information about a relationship between the size of the collimation region and a target distance which is a distance between an X-ray source 622 and a target. The target may be the object or the detector 630. The controller 650 may acquire an object thickness based on the object distance and a detector distance, which is a distance between the X-ray source 622 and the detector 630. Also, based on the object thickness, the controller 650 may acquire an irradiation condition that is information related to an X-ray radiation amount of the X-ray source 622. The irradiation condition may refer to information that may affect the X-ray radiation amount. For example, the irradiation condition may include a tube voltage, tube current, and an X-ray radiation time of the X-ray source 622. The irradiation condition may be thickness information based on a thickness of the object. The thickness information may include the thickness of the object, or a degree of thickness of the object based on the thickness of the object. An example of the degree of the thickness may include obesity. An appropriate amount of X-rays may increase as the thickness of the object increases. Therefore, the irradiation condition may include the thickness information. Alternatively, the irradiation condition may be radiation amount information related to an X-ray radiation amount. The radiation amount information may include an X-ray radiation amount, power or voltage necessary for irradiating X-rays according to the X-ray radiation amount, and the like. As described above, the irradiation condition may include at least one of the thickness information and the irradiation amount information. The memory 660 may store information necessary for operations and controlling of the X-ray apparatus 600. The memory 660 may store first relationship information (e.g., the relationship information of FIG. 9) that indicates a relationship between the size of the collimation region and the target distance. Also, the memory 660 may further store second relationship information that indicates a relationship between the thickness of the object and the X-ray radiation amount. The output interface 641 may output the irradiation condition related to the X-ray radiation amount. The user may input X-ray setting information for setting the X-ray radiation amount via the input interface 642. The user may see the irradiation condition that is output on the output interface 641, and then input the X-ray setting information. The X-ray setting information may include an X-ray radiation amount, power or voltage necessary to irradiate X-rays according to the X-ray radiation amount, and the like. That is, the X-ray setting information may include the same information as the irradiation condition. However, the irradiation condition is output via the output interface 641, whereas the X-ray setting information is input by the user via the input interface 642. When the user sets the X-ray radiation amount, the X-ray source 622 may emit X-rays according to the set X-ray radiation amount. FIG. 14 is a diagram of an example of an X-ray apparatus 700, according to an exemplary embodiment. The X-ray apparatus 700 of FIG. 14 may be another exemplary embodiment of the X-ray apparatus 600 of FIG. 13. Therefore, whether or not described below, the above-described features may also be applied to the X-ray apparatus 700 of FIG. 14. Components included in the X-ray apparatus 700 of FIG. 14 that are the same as those of the X-ray apparatus 600 of FIG. 13 use the same reference numerals as those used in FIG. 13, and a repeated description thereof will be omitted. Also, the components of FIG. 13 that are not illustrated in FIG. 14 may be included in the X-ray apparatus 700 of FIG. 14. Referring to FIGS. 13 and 14, the example X-ray apparatus 700 includes a guide rail 720, a moving carriage 730, and a post frame 740 for moving the X-ray radiator 620. Although not illustrated in FIG. 14, the X-ray radiator 620 includes the X-ray source 622 and the collimator 623 including the lamp 624, as in FIG. 13. Although the detector 630 of FIG. 14 is illustrated as being coupled to a table type receptor 690, the detector 630 may also be coupled to a stand type receptor. Alternatively, the detector 630 may be a portable detector that is not coupled to any receptor and located at any desired location. When the lamp 624 of the collimator 623 in the X-ray radiator 620 is turned on, light from the lamp 524 is radiated in a light irradiation region 750. The image acquirer 610 may acquire an object image by imaging the object 10. The controller 650 may acquire an object distance SOD based on the object image. The controller 650 may acquire an object thickness OT based on a detector distance SID and the object distance SOD. The controller 650 may acquire the detector distance SID by using various methods. For example, the controller 650 may acquire the detector distance SID based on a moving distance of the post frame 740. The guide rail 720 may be installed at a ceiling of an examination room. A height of the guide rail 720 and a height of the table type receptor 690 may be fixed. A length of the post frame 740 may increase or decrease in the third direction D3. Therefore, the controller 650 may acquire the detector distance SID when a moving distance of the post frame 740 is acquired. This example may not only be applied to a case of the detector 630 coupled to the table type receptor 690 shown in FIG. 14, but also be applied to a detector coupled to a stand type receptor. As another example, the controller 650 may acquire the detector distance SID according to a selection of the user. The user may input distance setting information for setting the detector distance SID via the input interface 642. The controller 650 may move the post frame 740 according to the input of the user to move the X-ray radiator 620 to a location corresponding to the detector distance SID that is set. The distance setting information that is input to the input interface 642 may be the detector distance SID that the user desires, but is not limited thereto. For example, the distance setting information that is input to the input interface 642 may include an initialization instruction or an imaging preparation instruction. The detector distance SID that corresponds to the initialization instruction or the imaging preparation instruction may be a preset value. According to the initialization instruction or the imaging preparation instruction, the X-ray radiator 620 may be moved to a location that corresponds to the detector distance SID that is preset. This example may also be applied to the case of the detector 630 coupled to the table type receptor 690 as well as the detector coupled to the stand type receptor. In some exemplary embodiments, as described above, the controller 650 may acquire the detector distance SID by using a method similar to the method of acquiring the object distance SOD. This will be described with reference to FIG. 15. FIG. 15 is a diagram for describing an example of acquiring of a detector distance SID by the X-ray apparatus 700 of FIG. 14, according to an exemplary embodiment. Referring to FIGS. 13 and 15, as shown there is no object between the X-ray radiator 620 and the detector 630. The image acquirer 610 may acquire a detector image by imaging the detector 630 while the lamp 624 is turned on. The image acquirer 610 of FIG. 15 may acquire the detector image by imaging a receptor 690 that is coupled to the detector 630. The controller 650 may acquire a detector distance SID based on the detector image acquired by the image acquirer 610. The detector distance SID is a distance between the X-ray source 622 and the detector 630. A method of acquiring the detector distance SID based on the detector image may be applied to not only the detector 630 coupled to the table type receptor 690 as shown in FIG. 15, but also a detector that is coupled to a stand type receptor. Alternatively, the method may be applied to a portable detector that may be located at any desired location. After acquiring the detector distance SID based on the detector image, the controller 650 may adjust the acquired detector distance SID again. For example, a desired distance between the X-ray source 622 and the detector 530 selected by the user may be 100 cm, and the detector distance SID acquired by the controller 650 may be 80 cm. In this case, the controller 650 may move the post frame 740 upward by 20 cm in the third direction D3. As described above, the controller 650 may acquire an irradiation condition based on an object thickness OT that is acquired based on an object distance SOD and the detector distance SID. The irradiation condition may be information related to an X-ray radiation amount of the X-ray source 622. The output interface 641 may output the irradiation condition. FIGS. 16 to 18 are diagrams of examples of irradiation conditions that may be output on the manipulator 640 of FIG. 13, according to an exemplary embodiment. The manipulator 640 includes the output interface 641 and the input interface 642. Although FIGS. 16 to 18 illustrate that the output interface 641 and the input interface 642 in the manipulator 640 are spaced apart, the output interface 641 and the input interface 642 are not limited thereto. The input interface 642 or a portion of the input interface 642 may be provided in the output interface 641. For example, when the input interface 642 includes a touch screen, the touch screen may be provided in the output interface 641. Referring to FIG. 16, an irradiation condition 50 that is output on the output interface 641 may be a thickness of an object. The irradiation condition 50 may be output in text and numbers, for example, “THICKNESS OF OBJECT: 19.6 CM” as shown in FIG. 16. Referring to FIG. 17, an irradiation condition 50a that is output on the output interface 641 may be obesity of the object. For example, the controller 650 of FIG. 13 may acquire the obesity of the object based on an object thickness. The obesity may be classified into a plurality of levels, such as “high, intermediate, and low.” For example, the irradiation condition 50a may be output in text, “OBESITY OF OBJECT: HIGH” as shown in FIG. 17. FIGS. 16 and 17 are only examples of when the irradiation conditions 50 and 50a on the output interface 641 correspond to thickness information. The output interface 641 may output the irradiation condition in various ways such that the user may recognize the thickness of the object, the degree of the thickness. The user may input X-ray setting information for setting an X-ray radiation amount via the input interface 642 of FIGS. 16 and 17. The user may see the irradiation conditions 50 and 50a via the output interface 641, and then input the X-ray setting information. For example, when the user determines that the thickness of the object is high based on the thickness information output via the irradiation conditions 50 and 50a, the user may input the X-ray setting information such that the X-ray radiation amount increases. Referring to FIG. 18, an irradiation condition 70 output on the output interface 641 may include at least one of thickness information 71 and radiation amount information 72. The radiation amount information 72 may be related to the X-ray radiation amount. The radiation amount information 72 may include the X-ray radiation amount, power or voltage necessary for irradiating X-rays according to the X-ray radiation amount, and the like. For example, the irradiation condition may include a tube voltage, tube current, and an X-ray radiation time of an X-ray source. The user may input the X-ray setting information for setting the X-ray radiation amount via the input interface 642. The user may see the irradiation condition 70 via the output interface 641, and then input the X-ray setting information. As shown in FIG. 18, the input interface 642 may include a touch screen, and a user 90 may input the X-ray setting information by touching the radiation amount information 72 in the irradiation condition 70 that is displayed on the output interface 641. For example, the user 90 may input the X-ray setting information by approving the output radiation amount information 72 or readjusting the radiation amount information 72. However, FIG. 18 is only an example of inputting the X-ray setting information. The method of inputting the X-ray setting information may be modified in various ways. Referring to FIG. 13, the memory 660 of the X-ray apparatus 600 may store first relationship information (e.g., the relationship information of FIG. 9) that indicates a relationship between a size of a collimation region and a target distance. Also, the memory 660 may further store second relationship information that indicates a relationship between the thickness of the object and the X-ray radiation amount. FIG. 19 is an example table of first relationship information 40 that may be stored in the memory 660 of the X-ray apparatus 600 of FIG. 13, according to an exemplary embodiment. Referring to FIG. 19, the first relationship information 40 may be table type information in which an SID 41, which indicates distance information between an X-ray source and a target, is matched with a region size 42, which indicates size information of a collimation region. In FIG. 19, the target may be a detector. The first relationship information 40 may store relationships between detector distances SID and respective sizes of collimation regions in a detector image. That is, when the detector distance SID is a ‘first distance,’ the detector image is acquired and ‘first size’ is acquired as a size of a collimation region in the detector image. Accordingly, the first relationship information 40 may be acquired through experiments. Here, it is assumed that the controller 650 of the X-ray apparatus 600 of FIG. 13 detects a size of a collimation region in an object image or a detector image as ‘second size.’ The controller 650 may acquire that an object distance or a detector distance is a ‘second distance’ based on the first relationship information 40 stored in the memory 660. FIG. 19 is only an example of the first relationship information 40. As another example, the first relationship information 40 stored in the memory 660 of FIG. 13 may be a relation formula of the x-axis and the y-axis in the graph as in FIG. 9. FIG. 20 is an example of a table of second relationship information 60 that may be stored in the memory 660 of the X-ray apparatus 600 of FIG. 13, according to an exemplary embodiment. Referring to FIG. 20, the second relationship information 60 may be a relationship between thickness information 61 acquired based on a thickness of an object and an irradiation condition 62 of an X-ray source. The thickness information 61 and the irradiation condition 62 of FIG. 20 are only examples. The thickness information 61 may include the thickness of the object, a thickness range of the object, and a degree of thickness of the object. The irradiation condition 62 may include an X-ray radiation amount, power or voltage necessary for irradiating X-rays according to the X-ray radiation amount, and the like. For example, the irradiation condition may include a tube voltage, tube current, and an X-ray radiation time of an X-ray source. Here, it is assumed that the controller 650 of the X-ray apparatus 600 of FIG. 13 detects the thickness of the object as ‘third thickness.’ The controller 650 may acquire that radiation amount information 62 is ‘third radiation amount’ based on the second relationship information 60 stored in the memory 660. The output interface 641 may output the irradiation condition that includes at least one of the thickness information 61 and the radiation amount information 62. The user may input X-ray setting information via the input interface 642. The X-ray source 622 may radiate X-rays according to an X-ray radiation amount that is set by the user. However, the first relationship information 40 of FIG. 19 stored in the memory 660 may only apply when a size of the irradiation window 525 of FIG. 6 of the collimator 623 is limited to a specific size. The size of the irradiation window 525 of FIG. 6 may be adjusted by using the shutter 526. However, due to a limit of the memory 660, the first relationship information 40 may include respective sizes of collimation regions according to target distances, which are acquired through experiments only when the size of the irradiation window 525 of FIG. 6 is specified. Therefore, in some exemplary embodiments the collimator 623 may adjust the size of the irradiation window 525 of FIG. 6 to a first size while the object is being imaged. The first size may be a certain size at which the first relationship information is applied. Next, the collimator 623 may adjust the size of the irradiation window 525 of FIG. 6 to a second size while the X-ray source 622 radiates X-rays. The second size may be selected by the user. Therefore, the irradiation window 525 of FIG. 6 may have different sizes while the object is imaged and while the object is captured by using X-rays. As described above, according to an exemplary embodiment, the X-ray apparatus 600 may acquire the thickness of the object based on the object image. Also, the X-ray apparatus 600 may acquire information related to the X-ray radiation amount, i.e., the irradiation condition, based on the thickness of the object, and output the irradiation condition. Accordingly, the user may set the X-ray radiation amount of the X-ray source 622 that is appropriate for the object thickness by using the output irradiation condition. That is, according to an exemplary embodiment, the X-ray apparatus 600 may automatically detect the thickness of the object so as to guide the user to set the X-ray radiation amount that is appropriate for the thickness of the object. Thus, the user may use the X-ray apparatus more conveniently. The X-ray apparatus 600 may detect a collimation region from the object image to acquire the thickness of the object. FIG. 21 is a diagram for describing an example of acquiring of a collimation region in an object image by using the X-ray apparatus 600 of FIG. 6, according to an exemplary embodiment. Referring to FIGS. 13 and 21, the image acquirer 610 may acquire a first object image 81 by imaging an object while the lamp 624 is turned off. Also, the image acquirer 610 may acquire a second object image 82 by imaging the same object while the lamp 624 is turned on. FIG. 21 is an example in which the object is a phantom, but exemplary embodiments are not limited thereto. The controller 650 may acquire a difference image 83 by performing subtraction on the first object image 81 and the second object image 82. The controller 650 may detect a collimation region 84 from the difference image 83. In the difference image 83, an area other than the collimation region 84, i.e., a peripheral area may have very low brightness. The peripheral area may be substantially removed by subtraction because respective peripheral areas of the first and second object images 81 and 82 have almost no difference in brightness. In the difference image 83, because respective areas of the first and second object images 81 and 82 corresponding to the collimation region 84 have different brightness, brightness of the collimation region 84 may be increased by performing subtraction. When a surrounding environment of the X-ray apparatus 600 is bright, the brightness of the collimation region 84 in the second object image 82 may be indifferent from that of the peripheral area. In this case, the controller 650 may detect the collimation region 84 from the difference image 83 based on not only the second object image 82 but also the first object image 81. The controller 650 may monochromatize the first and second object images 81 and 82. For example, through image processing, the controller 650 may remove color information from the first and second object images 81 and 82 so that only bright information remains. Next, the controller 650 may acquire the difference image 83 from a monochromatized first object image and a monochromatized second object. Also, in order to detect the collimation region 84, the controller 650 may perform an additional image processing on the difference image 83, for example, thresholding or filtering. Also, when the irradiation window 525 of FIG. 6 is quadrilateral-shaped, the controller 650 may detect the collimation region 84 by using a quadrilateral pattern recognition algorithm. FIG. 21 shows only an exemplary embodiment of a method of detecting a collimation region from an object image, and the method of detecting the collimation region is not limited thereto. Heretofore, an X-ray apparatus according to an exemplary embodiment acquires an object thickness from an object image and outputs an irradiation condition. However, the exemplary embodiment may also be performed in a workstation. That is, the above-described features may also be applied to a workstation. FIG. 22 is a block diagram of an example of an X-ray system 8000, according to an exemplary embodiment. Referring to FIG. 22, the X-ray system 8000 includes an X-ray apparatus 800 and a workstation 860. The example X-ray apparatus 800 includes an image acquirer 810 and an X-ray radiator 820. Also, the X-ray apparatus 800 may further include a detector 830. The X-ray radiator 820 includes an X-ray source 822 and a collimator 823. The collimator 823 includes a lamp 824. The X-ray apparatus 800 may include the features of the above-described X-ray apparatuses. Although not illustrated in FIG. 22, the X-ray apparatus 800 may also include a manipulator or a controller as in the above-described X-ray apparatuses. The workstation 860 may include a controller 813 and a manipulator 840 that provides a user interface (UI). The manipulator 840 may include an output interface 841 and an input interface 842. The controller 813 and the manipulator 840 of the workstation 860 may include the above-described features of the controllers and the manipulators of the X-ray apparatuses. A UI applied to the manipulator 840 of the workstation 860 may be the same as a UI applied to a manipulator of an X-ray apparatus. Therefore, a simple and intuitive UI may be provided, and the user may intuitively and conveniently operate and control the X-ray apparatus 800. The image acquirer 810 of the X-ray apparatus 800 may acquire an object image by imaging an object while the lamp 824 is turned on. The controller 813 of the workstation 860 may receive the object image from the X-ray apparatus 800. The workstation 860 may further include a communicator that receives the object image from the X-ray apparatus 800. The controller 813 of the workstation 860 may turn on or off the lamp 824 of the collimator 823. Also, the controller 813 may control a size of an irradiation window of the collimator 823. Based on the object image, the controller 813 may acquire an object distance that is a distance between the X-ray source 822 and the object. The controller 813 may acquire a thickness of the object based on the object distance and a detector distance that is a distance between the X-ray source 822 and the detector 830. Based on the thickness of the object, the controller 813 may acquire an irradiation condition that is information related to an X-ray radiation amount of the X-ray source 822. The output interface 641 of the workstation 860 may output the irradiation condition. The user may input X-ray setting information for setting the X-ray radiation amount via the input interface 842. The controller 813 of the workstation 860 may control the X-ray source 822 of the X-ray apparatus 800 such that the X-ray source 822 radiates X-rays according to the X-ray radiation amount. The controller 813 may adjust the size of the irradiation window of the collimator 823 to a first size while the object is being imaged, and adjust the size of the irradiation window to a second size while the X-ray source 822 radiates X-rays. Although not illustrated in FIG. 22, the workstation 860 may further include a memory. The memory of the workstation 860 may store relationship information (e.g., the relationship information of FIG. 19) that indicates a relationship between the size of the collimation region and the target distance. Also, the memory may further store second relationship information (for example, the relationship information of FIG. 20) that indicates a relationship between the thickness of the object and the X-ray radiation amount. FIGS. 23 and 24 show examples of the manipulator 840 of the workstation 860 of FIG. 22, according to an exemplary embodiment. Referring to FIG. 23, the manipulator 840 may output thickness information as an irradiation condition 51. Referring to FIG. 24, the manipulator 840 may output at least one of thickness information 76 and radiation amount information 77 as an irradiation condition 75. The user 90 may input X-ray setting information to the manipulator 840. FIGS. 23 and 24 are only examples of the irradiation conditions that are output via the workstation 860. The irradiation conditions are not limited thereto. FIG. 25 is a flowchart of an example of an operation method S100 of an X-ray system, according to an exemplary embodiment. Referring to FIG. 25, the X-ray system may acquire an object distance based on an object image that is acquired by imaging an object while a lamp of a collimator is turned on (S110). The object distance is a distance between an X-ray source and the object. The X-ray system may acquire an object thickness based on the object distance and a detector distance that is a distance between the X-ray source and a detector (S120). FIG. 26 is a flowchart of an example of an operation method S200 of an X-ray system, according to an exemplary embodiment. Referring to FIG. 26, the X-ray system may acquire an object distance based on an object image (S210). The X-ray system may acquire an object thickness based on the object distance and a detector distance (S220). Based on the object thickness, the X-ray system may acquire an irradiation condition that is information related to an X-ray radiation amount of an X-ray source (S230). The X-ray system may output the irradiation condition (S240). FIG. 27 is a flowchart of an example of an operation method S300 of an X-ray system, according to an exemplary embodiment. Referring to FIG. 27, the X-ray system may acquire an object distance based on an object image (S310). The X-ray system may acquire an object thickness based on the object distance and a detector distance (S320). The X-ray system may acquire an irradiation condition based on the object thickness (S330). The X-ray system may output the irradiation condition (S340). The X-ray system may receive X-ray setting information for setting an X-ray radiation amount from a user (S350). The X-ray system may control the X-ray source such that the X-ray source radiates X-rays according to the X-ray radiation amount (S360). FIG. 28 is a flowchart of an example of an operation method S400 of an X-ray system, according to an exemplary embodiment. Referring to FIG. 28, the X-ray system acquires a detector distance based on a detector image that is acquired by imaging a detector while a lamp is turned on (S410). The detector distance is a distance between an X-ray source and the detector. While imaging the detector, an object does not exist between the detector and an X-ray radiator. Also, the X-ray system may readjust the distance between the X-ray source and the detector based on the acquired detector distance. The X-ray system may acquire an object distance based on an object image (S420). The object image may be acquired by imaging an object between the detector and the X-ray radiator while the lamp is turned on. The X-ray system may acquire an object thickness based on the object distance and the detector distance (S430). FIG. 29 is a flowchart of an example of an operation method S500 of an X-ray system, according to an exemplary embodiment. Referring to FIG. 29, the X-ray system may adjust a size of an irradiation window of a collimator to a first size (S510). The X-ray system may acquire an object image by imaging an object while a lamp of the collimator is turned on (S520). The X-ray system may acquire an object distance based on the object image (S530). The X-ray system may acquire an object thickness based on the object distance and a detector distance (S540). The X-ray system may acquire an irradiation condition based on the object thickness (S550). The X-ray system may output the irradiation condition (S560). The X-ray system may receive X-ray setting information from a user (S570). The X-ray system may adjust the size of the irradiation window of the collimator to a second size (S580). The X-ray system may control an X-ray source such that the X-ray source radiates X-rays according to a set X-ray radiation amount (S590). The operation methods of the X-ray systems described with reference to FIGS. 25 to 29 may be performed by an X-ray apparatus or a workstation configured to control the X-ray apparatus. Also, the above-described features may also be applied to the each step of the operation methods. Next, referring to FIGS. 30 to 32, according to an exemplary embodiment, a method of acquiring an object distance or a detector distance based on an object image acquired by imaging an object or a detector image acquired by imaging a detector. The exemplary embodiments described below may be applied to the above-described examples in which the object distance or the detector distance is acquired based on the object image or the detector image. FIG. 30 is a diagram of an example of an X-ray apparatus 900, according to an exemplary embodiment. Referring to FIG. 30, the X-ray apparatus 900 may include an image acquirer 910, an X-ray radiator 920, and a detector 930. Although not illustrated in FIG. 30, the X-ray apparatus 900 may include the components included in the X-ray apparatuses described above. 930-1, 930-2, and 930-3 are reference numerals indicating the detector 930 at different positions. Also, SID-1, SID-2, and SID-3 reference numerals indicating detector distances according to the positions of the detector 930. The detector distance may refer to a distance between the detector 930 and the X-ray radiator 920. For convenience, the following terms will be used: first detector 930-1, second detector 930-2, third detector 930-3, first detector distance SID-1, second detector distance SID-2, and third detector distance SID-3. The image acquirer 910 may be located at a boundary of a side of the X-ray radiator 920. In this case, as shown in FIG. 30, a line of sight (LOS) of the image acquirer 910 may be inclined, and a virtual camera area 990 of the image acquirer 910 may also be inclined. FIGS. 31A to 31C are examples of detector images acquired by the image acquirer 910 of FIG. 30. FIG. 31A is a first detector image 85-1 acquired by capturing the first detector 930-1 of FIG. 30 at the first detector distance SID-1 from the image acquirer 910, FIG. 31B is a second detector image 85-2 acquired by capturing the second detector 930-2 at the second detector distance SID-2 from the image acquirer 910, and FIG. 31C is a third detector image 85-3 acquired by capturing the third detector 930-3 at the third detector distance SID-3 from the image acquirer 910. Referring to FIG. 30, the first detector distance SID-1 is the shortest, and the third detector distance SID-3 is the longest. Referring to FIG. 31, a collimation region 80-1 of the first detector image 85-1 is the largest, and a collimation region 80-3 of the third detector image 85-3 is the smallest. That is, as the detector distances SID-1, SID-2, and SID-3 increase, sizes of the collimation regions 80-1, 80-2, and 80-3 decrease, respectively. Therefore, the detector distances SID-1, SID-2, and SID-3 may be acquired based on the collimation regions 80-1, 80-2, and 80-3. Details regarding this are described above. However, when the LOS of the image acquirer 910 is inclined as shown in FIG. 30, respective locations of centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and 80-3 in the detector images 85-1, 85-2, and 85-3 may change. That is, as the detector distances SID-1, SID-2, and SID-3 increase, the respective locations of the centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and 80-3 in the detector images 85-1, 85-2, and 85-3 may be biased toward the left. Therefore, the X-ray apparatus 900 may detect the respective locations of the centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and 80-3 in the detector images 85-1, 85-2, and 85-3, and may acquire the detector distances SID-1, SID-2, and SID-3 based on the respective locations of the detected centers P1, P2, and P3. Also, the X-ray apparatus 900 may store, in a memory (e.g., the memory 660 of FIG. 13), a database of location-distance information that indicates a relationship between the respective locations of the centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and 80-3 and the detector distances SID-1, SID-2, and SID-3. The X-ray apparatus 900 may perform experiments in advance to generate the database. For example, the X-ray apparatus 900 may acquire detector images by changing a detector distance, acquire a location of a center of a collimation region of each of the detector images, and store a relationship between the detector distance and the respective locations of the centers as location-distance information. When a collimator of the X-ray radiator 920 of FIG. 30 includes an irradiation window 525 with crossing lines as in FIG. 6, the collimation regions 80-1, 80-2, and 80-3 of the detector images 85-1, 85-2, and 85-3 may also have crossing lines. The centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and 80-3 may be the same as the center of the crossing lines. In this case, the X-ray apparatus 900 may detect the centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and 80-3 by detecting respective centers of the crossing lines in the detector image 85-1, 85-2, and 85-3. However, exemplary embodiments are not limited thereto. FIGS. 32A to 32C are examples of detector images and an object image. FIGS. 32A and 32B respectively show a detector image 97 and an object image 98 having an identical detector distance. An X-ray apparatus may acquire a thickness of an object based on a difference between a location of a center P4 of a collimation region 91 of the detector image 97 and a location of a center P5 of a collimation region 92 of the object image 98. Alternatively, the X-ray apparatus may acquire a detector distance based on a location of a center P4 of the collimation region 91 of the detector image 97, and acquire an object distance based on a location of a center P5 of the collimation region 92 of the object image 98. Then, the X-ray apparatus may acquire a difference between the detector distance and the object distance as the thickness of the object. FIG. 32C is a detector image 99 acquired by imaging a detector at a detector distance that is the same as the object distance of FIG. 32B. For example, the detector distance of FIGS. 32A and 32B may both be 100 cm, the object distance of FIG. 32B may be 80 cm, and the detector distance of FIG. 32C may be 80 cm. A location of a center P6 of a collimation region 93 of the detector image 99 may be substantially the same as the location of the center P5 of the collimation region 92 of the object image 98. That is, whether the target is an object or a detector, a distance from an X-ray source to the target may be acquired based on a location of a center of a collimation region in a target image. The above-described X-ray apparatus or a workstation that controls the X-ray apparatus may acquire a target distance by detecting a center of a collimation region from a target image. The exemplary embodiments above may be created as computer-executable programs and implemented in a general digital computer executing the programs by using a computer-readable recording medium. The computer-readable medium may include recording media, such as magnetic storage media (e.g., ROM, floppy disks, or hard disks) and optical recording media (e.g., CD-ROMs, or DVDs). It should be understood that exemplary embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each exemplary embodiment should typically be considered as available for other similar features or aspects in other exemplary embodiments. While one or more exemplary embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.
056082231	abstract	An ion implantation device is equipped with a high-speed driving device which causes rotation of a disk that supports semiconductor wafers around its outer periphery. A center position of the disk is the axis of the high-speed rotation. A low-speed driving device causes relative movement of the disk in a radial direction. The ion implantation device calculates the movement speed of the low-speed driving device with reference to different spacings between wafers about the outer periphery and the distance from the center of the disk to the ion implantation position and controls the low speed scan speed so that ions are uniformly implanted into the wafers.
059206020	summary	The invention relates to an underground storage facility for the interim storage of waste transportable in a container, in particular radioactive waste such as spent fuel elements, with transport gallery diving access to a storage gallery for interim storage of the waste. The invention further relates to a method for interim storage of waste, in particular of spent fuel elements, in an underground storage facility with transport gallery giving access to a storage gallery, the waste being transported to the storage facility in an inner container of a transport container. Before radioactive waste such as spent fuel elements reach a final storage facility, they are frequently kept for many years in an interim storage facility. The latter is in particular an underground storage facility located inside a mountain. In the known storage facilities, storage galleries lead off from a transport gallery and the waste is deposited inside these in transport containers. Since these transport containers are very expensive, considerable financial resources are bound up in a storage facility. The dimensions of the transport containers mean that the storage galleries have to be designed fairly wide. This has the drawback that cooling air cannot flow through the storage galleries by connection at the required rate, and instead it is necessary to install special equipment in order to achieve the necessary control of the flow. Since the transport containers are arranged one behind the other inside a storage gallery, it is rather difficult to transfer the transport containers or to remove a transport container located at the front of a storage gallery, since in this case the containers at the front (when viewed from the transport gallery) have to be removed first of all. An underground storage facility for spent nuclear reactor fuel elements is known from DE 33 40 101 A1.The storage areas are inside a cavern area of elliptical cross-section. Inside this storage area the fuel elements are arranged in individual horizontal storage pipes. Cooling air lows vertically upwards through the storage area. The lower part of the cavern area of elliptical cross-section is used for air supply, and the upper part for air removal. Individual pipes branch off from the main air supply and removal pipes in order to supply the individual storage areas with cooling air. DE 39 4 65C1 describes a storage facility in which radioactive wastes are deposited in a borehole. Corresponding proposals to solve the problem can be found in WO 88/08608, EP 0 093 671B1 and DE 28 39 759A1. According to DE 24 33 168B2, caverns extend from a transverse gallery designated as the transport gallery and are used for the storage of radioactive wastes. To transport or transfer radioactive materials, loading machinery or shielding bells are known from DE 32 48 592C2 and DE 40 34 710A1. The problem underlying the present invention is to develop an underground storage facility and a method for interim storage of waste of the type mentioned at the outset such that inexpensive yet safe interim storage is possible, where a simple introduction or rapid transfer has to be possible. Cooling of the waste by convection should also be possible without any problem. The problem is solved in accordance with the invention by an underground storage facility characterized mainly in that the storage gallery runs underneath the transport gallery and is separated from the latter by a floor designed as a transport level having closable openings intended for introduction and removal of the waste. The openings are closed with locking covers having a shielding function and separating the storage gallery from the transport gallery in respect of the effects of radiation. The storage gallery has an approximately rectangular cross-section and the transport gallery an approximately semi-elliptical or semi-oval cross-section, with the width of the storage gallery being less than that of the transport gallery. Cooling of the containers containing radioactive materials and stored in the storage gallery, such as fuel element containers, is achieved by passing cooling air through the storage gallery of rectangular cross-section running underneath the floor of the transport gallery. Accordingly, cooling is achieved by a horizontally directed air flow around the stored containers. It is of course also possible for at least one storage gallery to lead off from the side of the transport gallery. Unlike in the prior art, the storage gallery and the transport gallery are arranged one above the other, allowing easy introduction or removal and hence transfer of waste via the floor openings in the transport gallery. The floor itself is preferably of concrete here, with the openings being closable with cylindrical closing covers also made of concrete. To keep rock thrusts well away from the storage gallery/galleries, a further development of the invention provides for the width of the storage gallery of preferably rectangular cross-section to be less than that of the transport gallery of approximately semi-elliptical or semi-oval cross-section. Since the storage gallery is shielded from the transport gallery, it is only necessary for the waste to be stored in an inner container, and no longer in the transport container itself once inside the storage gallery. This has the advantage that the transport container can be reused immediately after removal of the inner container. Furthermore, the width of the storage gallery compared with those in which transport containers are stored can be designed more narrow. This allows the possibility of designing the storage gallery itself as a section of the convection air duct without additional construction measures, with the storage gallery having at its end filtering devices in order to keep microorganisms or dust, for example, out of the storage area. Vertical ventilation ducts lead off from the storage gallery itself, so that a strong updraught results from the heated air. The air is heated here by the heat-generating waste such as spent fuel elements or other highly active waste. The fact that the inner containers are introduced into the storage gallery via the opening in the transport gallery means that the inner containers can be transferred inside the storage gallery in a simple manner, allowing new waste for storage to be positioned initially in the air flow that is not yet heated, hence ensuring optimum cooling possibilities and minimum waste temperatures. Cooling in accordance with the invention is achieved by the air flow passing horizontally through the storage gallery. Since the storage gallery is loaded from above, it can be designed fairly narrow, i.e. only slightly wider than the diameter of a container to be stored. This has in particular the advantage that favorable air flows result, leading to good cooling of the waste. If necessary, the storage gallery can have filtering equipment at the end. In a further noteworthy embodiment of the invention, it is provided that the waste present in an inner container is surrounded inside the transport gallery by a conveying container closing at the bottom, using which the inner container can be deposited into the storage gallery through one of the floor openings of the transport gallery. The conveying container here can have a lifting/lowering or holding device for the inner container only its inside. The covers closing the floor opening are themselves lifted/lowered by a transport carriage movable alone the floor and controllable independently of the conveying container. A method for interim storage of waste, in particular of spent fuel elements, in an underground storage facility faith transport gallery giving access to a storage gallery, where the waste is transported to the storage facility inside an inner container of a transport container, is characterized in that the inner container containing the waste is picked up in the facility or in its immediate vicinity by a movable conveying container on its floor side that moves inside the transport gallery along a floor closing the storage gallery at the top, in that after introduction of the inner container into the conveying container the latter is closed on the floor side and moved to an opening closed by a lid in the floor of the transport gallery, and in that the cover is removed, the conveying container then aligned with the opening and its floor opened, and the inner container is passed by conveying elements provided in the conveying container through the opening and into the storage gallery, then the opening is closed and the conveying container is moved to a transport container to pick up an inner container or to a further opening in the transport gallery floor to remove or transfer the inner container placed in the storage gallery. Independently of this, it is possible for the inner container to be provided with corrosion protection after removal from the storage facility so that it can then be transported to a final storage facility. Finally, it is possible once the afterheat has receded sufficiently to fill the storage gallery with bentonite, for example, so that the interim storage facility is converted into a final storage facility. Further details, advantages and features of the invention are shown not only in the claims and in the features they contain--singly and/or in combination--but also in the following description of a preferred design example shown in the drawing.
	claims	1. A stable startup system, comprising:a nuclear reactor vessel;a reactor core housed in the nuclear reactor vessel, wherein the reactor core is submerged in a primary coolant of the nuclear reactor vessel;a riser located at least partially above the reactor core;a heat sink configured to remove heat from the primary coolant after the primary coolant has passed through the riser; anda heating system configured to introduce heat to the primary coolant prior to an initialization of the reactor core, wherein the initialization comprises at least a partial withdrawal of one or more control rods from the reactor core, and wherein the heat is introduced at one or more insertion points located within the riser at an elevation between the heat sink and the reactor core. 2. The stable startup system of claim 1, wherein the heating system comprises:one or more heaters configured to generate heated water from the heat; andone or more nozzles configured to introduce the heated water directly to the primary coolant located within the riser. 3. The stable startup system of claim 2, wherein the one or more heaters are located external to the nuclear reactor vessel, and wherein the one or more nozzles are at least partially located within the riser and are operably connected to the one or more heaters via one or more fluid distribution lines. 4. The stable startup system of claim 2, wherein the one or more heaters are located in a pressurizer system located in an upper head space of the nuclear reactor vessel, wherein the pressurizer system is configured to control a system pressure in the nuclear reactor vessel, and wherein the one or more nozzles are least partially located within the riser and are operably connected to the upper head space via one or more extraction lines. 5. The stable startup system of claim 1, wherein the introduction of heat into the riser causes a density difference between the primary coolant in the riser and in an annulus that drives the primary coolant through the reactor core via natural circulation prior to the initialization of the reactor core. 6. The stable startup system of claim 5, wherein the heat ink comprises a heat exchanger configured to remove at least a portion of the heat from the primary coolant in the annulus, and wherein the annulus is located outside of the riser. 7. The stable startup system of claim 1, wherein the initialization of the reactor core comprises removing control rods from the reactor core to achieve reactor criticality, and wherein the heat is introduced to the primary coolant prior to removing the control rods. 8. The stable startup system of claim 1, wherein the heating system comprises a pressurizer system configured to control pressure within the nuclear reactor vessel after the initialization of the reactor core. 9. The stable startup system of claim 1, wherein the heating system is configured to heat the primary coolant to an operating temperature that provides for circulation of the primary coolant from the riser to the heat sink and through the reactor core, and wherein the operating temperature identifies a coolant temperature associated with a low power steady state condition of an initialized reactor core. 10. The stable startup system of claim 1, wherein the heating system comprises one or more electric heaters configured to generate the heat introduced into the primary coolant. 11. An apparatus, comprising:a nuclear reactor vessel;a reactor core housed in the nuclear reactor vessel, wherein the reactor core is submerged in a primary coolant of the nuclear reactor vessel;a riser located at least partially above the reactor core;means for removing heat from the primary coolant after the primary coolant has passed through the riser; andmeans for introducing heat to the primary coolant prior to an initialization of the reactor core, wherein the initialization comprises at least a partial withdrawal of one or more control rods from the reactor core, and wherein the heat is introduced at one or more insertion points located within the riser at an elevation above the reactor core. 12. The apparatus of claim 11, further comprising one or more control rods configured to initialize the reactor core, wherein the reactor core is initialized after the means for introducing heat is deactivated. 13. The apparatus of claim 12, wherein the means for introducing heat is part of a pressurizer system, and wherein the means for introducing heat is reactivated to control an operating pressure of the nuclear reactor vessel after the reactor core has achieved criticality. 14. The apparatus of claim 12, wherein the means for introducing heat is deactivated after the primary coolant has achieved an operating temperature associated with a low power steady state condition of an initialized reactor core. 15. The apparatus of claim 12, wherein the one or more control rods are configured to be at least partially withdrawn from the reactor core, and wherein the heat is introduced to the primary coolant prior to withdrawing the control rods. 16. The apparatus of claim 12, wherein a difference in liquid density of the primary coolant in the riser and at the means for removing heat results in a circulation of the primary coolant through the reactor core prior to the initialization. 17. The apparatus of claim 11, wherein the means for removing heat is located above the elevation where the heat is introduced into the riser. 18. The apparatus of claim 11, wherein the nuclear reactor vessel comprises a pressurized vessel, wherein the reactor core is located in the pressurized reactor vessel, and wherein the means for introducing heat comprises one or more heaters located external to the pressurized reactor vessel. 19. The apparatus of claim 18, wherein the means for introducing heat further comprises one or more nozzles operatively connected to the one or more heaters, wherein the one or more nozzles are at least partially located within the riser, and wherein the one or more nozzles introduce the heat directly to the primary coolant located within the riser. 20. The apparatus of claim 11, wherein the means for introducing heat comprises one or more nozzles that are at least partially located in the riser and are configured to introduce the heat directly to the primary coolant located within the riser.
050698630	description	DESCRIPTION OF THE PREFERRED EMBODIMENT Nuclear Plant With Fuel Transfer System More particularly, there is shown in FIG. 1 a nuclear power plant 30, in this case a boiling water reactor plant, for which there are provided a containment building 32 for the reactor (not shown) and an auxiliary building 34 where pools 35 and 37 of water are located for fuel storage. A thick solid concrete containment wall 36 separates the containment and auxiliary buildings 32 and 34. An operating floor 33 extends across the two buildings 32 and 34 and the containment wall 36. A fuel transfer system 38 includes a car 40 that operates on a track 42 having spaced rails 42A and 42B extending from a canal 43 within the auxiliary building 34 through a transfer tube 44 within the containment wall 36 into the containment building 32. The transfer tube 44 may be about fifteen feet long. Within the transfer tube 44, the rails 42A and 42B are bolted to supports 43C which in turn are welded to the transfer tube 44. Respective gaps 45 and 47 exist in the car railing at the entry to the transfer tube 44 on both sides of the containment wall 36. However, the car 40 is provided with wheels that are appropriately located so that the car 40 bridges the rail gaps 45 and 47 when it moves along the track 42. Isolation is provided for the containment building 32 by a hatch 46. An isolation valve 48 can be used to close off the transfer tube 44 from the auxiliary building 34. A conventional upending mechanism 50 (FIG. 1B) in the containment building 32 is employed to turn a basket 51 pivotally supported by the car 40 into the vertical position where fuel transfer apparatus (not shown) can either take a fuel assembly (not shown) from the car basket 51 and install it in the fuel core or it can deposit a spent fuel assembly in the car basket 51 that had previously been obtained from the fuel core. When the car 40 is located at the containment end of the track 42, the leftmost end of the car 40 is located inside the transfer tube 44 thereby facilitating a structuring of a car drive system 60 for bidirectional operation from the auxiliary side of the containment wall 38. The containment building 32 is flooded during shutdown to reduce radiation exposure as fuel assemblies are relocated. In this boiling water reactor case, the containment building 32 is also flooded during normal reactor operation. Another upending mechanism 52 (FIG. 1A) similarly upends the car basket 51 for fuel transfers to and from the storage pool in the auxiliary building 34. Another fuel transfer apparatus (not shown) located in the auxiliary building 34 handles these transfers through a gate area 53 (FIG. 1C) to the storage pool. The auxiliary building is also flooded to a level above the reactor vessel during fuel transfer operations so that the fuel assemblies are always handled at a water depth of 15 to 20 feet. Fuel Transfer Drive System The fuel transfer drive system 60 is preferably unilateral in the sense that it is located on one side of the containment wall 36, yet it is capable of providing bidirectional drive force for the car 40 even though the car 40 is largely located within the containment building 34 at the containment end of the car travel. In accordance with the invention, the drive system 60 operates the car 40 under water with significantly improved operating reliability, fuel transfer performance and manufacturing economy. Preferably, the drive system 60 includes a pair of winches 62 and 64 (FIGS. 1A, 2A, 2B, 2D) supported on a plate 63 (FIG. 1C) above the track 42 at the leftmost end of the canal 43. Cabling 66 is coupled to the car 40 and operated by the winches 62 and 64 to drive the car 40 in one direction or the other direction over the track 42. The winch 62 operates a pair of cables 62A and 62B (FIGS. 4 and 6) that extend vertically downward through slot 62S in the winch support plate 63 to the track level. Similarly, the winch 64 operates a pair of cables 64A and 64B that extend vertically downward through support plate slot 64S to the track level. Cable pairs are employed so that substantially equally applied drive forces can be applied to the two sides of the car 40 in each direction of travel. The cables 62A and 62B are connected to the car 40 to pull the car 40 in the leftward direction as the winch 62 reels in the cables 62A and 62B. The cables 64A and 64B are connected to the car 40 to pull the car 40 in the rightward direction as the winch 64 reels in the cables 64A and 64B. The winches 62 and 64 are coordinated in operation in accordance with the invention so that desired cable tension is substantially continuously maintained as one or the other of the two winches operates as a master drive to reel in cable as the slave winch pays out cable. At the track level, four vertical sheaves 62S and 64S (FIGS. 1A, 6 and 7) are used to redirect the vertical cabling from the winches 62 and 64 to the horizontal direction along the track 42. Generally, the cables 62A and 64A pass over the sheaves 62SA and 64SA which are located within but toward one side of the track and thereafter extend along that side of the track for securance to the underside of the car 40. Similarly, the cables 62B and 64B pass over the sheaves 62SB and 64SB which are located within but toward the other side of the track and thereafter extend along the other side of the track for securance to the underside of the car 40. The cables 64A and 64B pass over the two outermost vertical sheaves 64SA and 64SB to facilitate placing them more closely toward the track rails since they extend along the track 42 to the containment end of the transfer tube 44 where they are directed in the reverse direction to extend back to the car 40 for securance thereto. The spacing between the cables 64A and 64B within the track 42 and to the containment side of the transfer tube 44 is generally sufficient to enable use of a center pivoted car basket without drive cable interference. In some embodiments, however, as in the present one, it may be desirable to provide special cable spreading action to facilitate car basket operation as subsequently described more fully herein. The cables 62A and 62B are secured to the underside of the car 40 to provide leftward drive force for the car 40. The cables 64A and 64B extend to the rightmost end of the track within the transfer tube 44 and return in the opposite direction for securance to the underside of the car 40 to provide rightward drive force for the car 40. A pair of horizontal sheaves 64LHS and 64HHS (FIGS. 8 and 10) are located at the containment end of the transfer tube 44 to redirect the cables 64A and 64B in the reverse direction for securance to the underside of the car 40. In operation, the winch 62 takes up the cables 62A and 62B to pull the car 40 toward the left and at the same time the winch 64 pays out the cables 64A and 64B to follow the leftward car movement. The opposite cable action occurs for rightward car movement. Cable securance to the underside of the car 40 is achieved with the use of a yoke 80 (FIGS. 6, 7 and 11) located near the leftmost end of the car 40. In operation, the yoke is always located to the left of the horizontal sheaves 64LHS and 64HHS. At the rightmost position of the car 40, i.e. when it is located for loading or unloading of the car basket in the containment building 38, the yoke 80 is located to the left of the horizontal sheaves as shown in FIG. 8. The yoke 80 (FIG. 11) preferably includes a shaft 82 supported from a car frame member 84 and by angle struts 84 and 86 through bracket 88. A yoke cross-piece 90 is supported for slight pivotal movement on the yoke shaft 82 in a horizontal plane so as to provide for equal load sharing by the paired cables secured to pivot arms 93 and 95 at the outer ends of cross-arms 92 and 94. The pivot arms 93 and 95 have a slight vertical offset so that they align respectively with the return cables 64A and 64B from the high and low horizontal sheaves 64HHS and 64LHS. As indicated by the reference character 96, each pivot arm 93 or 95 (FIG. 12) is pivotally supported relative to the yoke cross-arm 92 or 94 to provide cable spreading action when the car 40 is moved to its leftmost position in the auxiliary building for a fuel assembly transfer. In this embodiment, cable spreading action is provided since the horizontal return cables 64A and 64B angle slightly toward the center of the track 42 and thus need to be spread outwardly toward the rails 42A and 42B to assure clearance for upending of a center pivoted car basket as in this case. Each pivot arm 93 or 95 includes an extension 97 or 99 (FIG. 6) having a roller 100 or 102 at its end. As the car 40 approaches its auxiliary end of travel the two rollers 100 and 102 strike respective fixed spreader blocks 104 and 106 to move toward the center of the track 42. The pivot arms 93 and 95 thus pivot so that end portions 108 and 110 move outwardly toward the rails 42A and 42B thereby spreading the return cables 64A and 64B outwardly as needed for basket upending. Generally, the track rails 42A and 42B are sufficiently spaced to permit operation of a center pivoted car basket 47 (FIGS. 1A and 6). Additionally, the cables 64A and 64B have portions extending from the vertical sheaves toward the containment, and these are generally sufficiently spread toward the rails 42A and 42B to permit pivotal basket operation within the cable spread space. To this end, various cable guides 64G1 and 64G2 (FIG. 5) secure these portions of the cables 64A and 64B extending from the vertical sheaves to the horizontal sheaves in position toward the track rails. The return portions of the cables 64A and 64B that extend from the horizontal sheaves to the car yoke generally angle inwardly slightly toward the center of the track. The previously described yoke spreading action pushes these cable portions outwardly toward the track rails 42A and 42B to facilitate center pivoted car basket operation when the car 40 is positioned in the auxiliary building for fuel assembly loading and unloading. Each winch 62 or 64 preferably includes a drum 62D or 64D and a two speed electric motor 62M or 64M. A timing belt 112 (FIG. 4) is preferably interconnected between sprockets 62S and 64S to coordinate the operation of the winches for continuous maintenance of desired cable tension in the system. Thus, when the designated master drive winch is operating, the braking is released for the other winch and the cable payout from the released winch is held substantially equal to the cable takeup on the master winch as a result of the timing belt tie between the two winch shafts. The timing belt 112 can be released during system initializing to permit relative winch movement until cable tension is adjusted as desired. Idler pulleys 62P (not shown) and 64P (FIG. 2D) compensate for minor variations in cable tension during normal system operation. Respective slack cable switches 112 and 114 are operated by respective rollers 113 and 115 to deenergize the winches if cable tension is lost and cable slack develops. Respective load cells 116 and 118 sense winch loading and deenergize the winches if overloading develops. A programmable limit switch 120 (FIG. 5) is employed with one of the winches to provide drive system control. Thus, the switch operates in response to the output of a shaft resolver that in this case counts up to 64 shaft turns with 4096 counts per turn. Since the cable tension is essentially maintained constant, winch shaft position directly indicates the car position. Accordingly, to move the transfer car from the existing position to another position (usually from one end of travel to the other end of travel) one of the two motor speeds (13 fpm or 40 fpm in this case) is preset and the destination is entered. The limit switch 120 starts the winch motors designating one of them as the master drive and releasing the brake on the other according to the direction of travel and records shaft counts that measure travel distance as the car is pulled by the cabling 66. When the shaft counter indicates that the car has nearly reached its destination position, the programmable limit switch deenergizes the master winch motor and activates the winch braking system. Since the programmable limit switch 120 is located above water, system adjustments are greatly facilitated. With an actual fuel transfer drive system and its control structured in accordance with the invention as described, a fuel transfer car has been consistently brought to a stop within three sixty-fourths of an inch over a thirty-five foot path of travel. The present invention accordingly provides highly accurate operation. Further, with this drive control arrangement, underwater logic limit switches have been eliminated thereby significantly enhancing system reliability. For example, conventional underwater drive stop limit switches and drive home limit switches are unnecessary with use of the present invention. Just as importantly, reliability is enhanced significantly from a mechanical standpoint as a result of the overall structure and operation of the mechanical portion of the drive system. The structural character of the drive system also provides for economy of manufacture.
044141769	abstract	For a plasma device, a surface of a first wall or limiter with reduced loss of metal by erosion is provided by forming a monolayer of an alkali or alkaline earth metal on a substrate of a more negative metal. The surface exhibits a reduced loss of metal by erosion and particularly by sputtering and an increased secondary ion/neutral ratio resulting in a greater return of atoms escaping from the surface. In another aspect of the invention, the substrate includes a portion of the second metal and serves to replenish the surface layer with atoms of the second metal. In one process associated with self-generating desired surface, the metals as an alloy are selected to provide a first layer having a high concentration of the second metal in contrast to a very low concentration in the second layer and bulk to result in a surface with a monolayer of the second metal. When the combination of metals results in an intermetallic compound, selective removal of the first metal during an initial bombardment stage provides the surface layer with a predominance of the second metal.
	description	The present application claims the benefit of International Patent Application Number PCT/IB2010/052235, entitled “PROCESS FOR CO-PRODUCING SYNTHESIS GAS AND POWER,” filed on May 20, 2010, which is hereby incorporated by reference in its entirety for all purposes. This invention relates to a process for co-producing synthesis gas and power. Synthesis gas is a mixture which includes carbon monoxide (CO) and hydrogen (H2). Synthesis gas is typically produced by one of two processes, either from solid feedstocks, such as coal, by gasification with oxygen and steam, or from gaseous feedstocks, such as natural gas, by reforming with oxygen (known as partial oxidation reforming) or water (known as steam reforming). A combination of partial oxidation and steam reforming, namely autothermal reforming, is also commonly applied. The oxygen required for the production of synthesis gas is usually obtained from air using conventional cryogenic air separation technology. The synthesis gas produced is used to produce a wide range of carbon based chemicals, e.g. methanol and liquid hydrocarbons via Fischer-Tropsch synthesis. Synthesis gas production processes are energy intensive and contribute significantly to carbon dioxide emissions. Carbon dioxide is a major greenhouse gas, and its emission into the atmosphere is not environmentally friendly. The problem of carbon dioxide emissions can be dealt with in various ways e.g. by carbon dioxide capture and sequestration, reduction of carbon dioxide emissions via improvement of thermal efficiency and substitution of conventional carbon based power and heat generation facilities with a non-carbon source, e.g. nuclear energy. Synthesis gas production processes operate at elevated temperatures and, depending on the type of technology used to generate the synthesis gas, can produce a hot synthesis gas at a temperature above 900° C. Heat is typically recovered from the hot synthesis gas using waste heat boilers producing steam. This steam is typically used to drive steam turbines for cryogenic air separation units and/or to produce electrical power. It is important to note that conventional cryogenic air separation processes consume significant quantities of power. Heat recovery using waste heat boilers also contribute considerably to second law thermodynamic losses in processes producing the synthesis gas due to large temperature difference driving forces used in such waste heat boilers. In other words, the use of waste heat boilers downgrades high quality or high temperature heat to a lower quality or lower temperature heat which is undesirable, as heat at a higher temperature can be used to produce more power compared to the same amount of heat at a lower temperature. High temperature difference driving forces reduce overall thermal efficiency of a process and therefore potentially worsens the problem of carbon dioxide emissions. One way to reduce large temperature difference driving forces in waste heat boilers would be to raise the steam pressure or to superheat the steam. However, the fact that the critical temperature of water is 374° C. places an upper limit on the temperature at which saturated steam can be produced in waste heat boilers. Also, when using steam to generate power in e.g. a Rankine cycle, steam is typically not superheated to temperatures above 565° C. because of material of construction considerations. Attempts to reduce carbon dioxide emissions via thermal efficiency improvements should therefore focus on addressing the problem of high temperature difference driving forces and also on reducing the power consumption of cryogenic air separation processes. However, since cryogenic air separation is a mature technology, only incremental reductions in cost and power consumption are expected. An alternative process for separating oxygen from air is the use of Ion Transport Membranes (ITM's). The ITM oxygen process uses ceramic membranes operated at high temperature (typically 760-930° C.) to separate the oxygen from air. It is believed that the ITM oxygen technology could significantly lower the cost of oxygen production. This high temperature oxygen-producing process lends itself to integration with processes wherein oxygen, power and steam are required. In an ITM oxygen process ceramic membranes separate oxygen from air at high temperature in an electrochemically driven process. The oxygen in the air is ionized on an upstream surface of the ceramic and diffuses through the membrane as oxygen ions driven by an oxygen partial pressure gradient, forming oxygen molecules on a downstream side of the membrane. The ITM oxygen process produces a hot, substantially pure oxygen stream or permeate stream and a hot, pressurised oxygen-depleted stream or reject stream from which significant amounts of energy can be extracted. The effective use of this energy in the overall operation of an ITM oxygen process is necessary for the system to be competitive with conventional cryogenic air separation technology. The energy recovery and effective use thereof are possible by integration of compressors, gas turbines, hot gas expanders, steam turbines and heat exchangers with the membrane module. Research and development on nuclear-assisted synthesis gas generation processes have thus far attempted to match the synthesis gas generation process operating temperature with the highest temperature heat that can be made available from a nuclear reactor loop. High temperature gas cooled nuclear reactors are able to provide heat at temperatures of about 750-950° C. At these comparatively low temperatures, reasonable synthesis gas generation process options are limited, especially when a gasification process is employed. Synthesis gas generation processes typically form part of large-scale facilities producing carbon-based chemicals. Such facilities typically include further processing steps operating at temperatures below 800° C. or even more typically below 500° C. Although these further processing steps may be promising candidates for heat integration with nuclear heat sources, it was found that these further processing steps are also promising candidates for heat integration with hot synthesis gas produced in a synthesis gas generation process. It has also been found that in such facilities at temperatures below about 250° C. there typically is a number of sources and sinks of heat, with the heat sources becoming numerous with decreasing temperature. There is thus typically an excess of available lower grade heat. Consequently there is little incentive to rather provide low grade heat from a nuclear source. A more conventional light-water nuclear reactor would probably be the preferred choice for supplying low grade heat. There is thus a perceived lack of opportunities for integrating a nuclear heat source with large-scale facilities producing carbon-based chemicals, and particularly so for integrating a nuclear heat source with a synthesis gas generation process. This has led to significantly different strategies for using nuclear energy, most notably nuclear driven hydrogen production through water splitting. Embodiments of the present invention in contrast propose a new and different approach. According to the invention, there is provided a process for co-producing synthesis gas and power, the process including: in a synthesis gas generation stage, producing a synthesis gas comprising at least CO and H2 by reacting a hydrocarbonaceous feedstock with oxygen, the synthesis gas being at a first temperature; in an air separation stage, separating air from a compressed air stream by means of at least one ion transport membrane unit thereby producing a permeate stream consisting predominantly of oxygen and a reject stream of oxygen-depleted air at a second temperature which is lower than the first temperature; indirectly heating the reject stream of oxygen-depleted air with the synthesis gas and at least partially expanding said heated reject stream of oxygen-depleted air through at least one turbine to generate power, producing an at least partially expanded reject stream of oxygen-depleted air; and feeding at least a portion of the permeate stream consisting predominantly of oxygen to the synthesis gas generation stage to provide oxygen for production of synthesis gas. According to the invention, there is provided a process for co-producing synthesis gas and power, the process including: in a synthesis gas generation stage, producing a synthesis gas comprising at least CO and H2 by reacting a hydrocarbonaceous feedstock with oxygen, the synthesis gas being at a first temperature; in an air separation stage, separating air from a compressed air stream by means of at least one ion transport membrane unit thereby producing a permeate stream consisting predominantly of oxygen and a reject stream of oxygen-depleted air at a second temperature which is lower than the first temperature; indirectly heating the reject stream of oxygen-depleted air with the synthesis gas and at least partially expanding said heated reject stream of oxygen-depleted air through at least one turbine to generate power, producing an at least partially expanded reject stream of oxygen-depleted air; and feeding at least a portion of the permeate stream consisting predominantly of oxygen to the synthesis gas generation stage to provide oxygen for production of synthesis gas. Typically the synthesis gas produced in the synthesis gas generation stage is at a temperature of at least 900° C. Typically the reject stream of oxygen-depleted air is available at a temperature of at least 600° C., more typically at least 700° C., but less than the temperature of the synthesis gas produced in the synthesis gas generation stage. In this manner, the reject stream of oxygen-depleted air thus provides a heat sink for the high temperature heat available from the synthesis gas, with the high temperature difference driving forces typically encountered where waste heat boilers are employed as a heat sink being reduced. In this specification, it is intended that the term “turbine” includes the concept of a turbine stage, so that when there is a reference to more than one turbine, it is to be understood that the turbines may be separate units, or a single unit comprising more than one clearly identifiable turbine stage, or a combination of separate units and one or more single units comprising more than one clearly identifiable turbine stage. Also in this specification, indirect transfer of heat, e.g. “indirectly heating”, means that heat is transferred across a heat transfer surface from one fluid to another, so that the fluids are not in direct contact with each other and are therefore not mixed. The process may include heating the compressed air stream to a temperature of at least 700° C. prior to separation of the compressed air stream in the air separation stage. This heating may be done, for example, by burning a fuel such as a combustible gas or coal or any suitable combination of these methods. In a preferred embodiment of the invention, the compressed air stream is heated at least by transferring heat from a nuclear reaction stage. This preferred embodiment has the advantage of substituting conventional carbon based heating with a non-carbon source. The at least one ion transport membrane unit thus employs a selectively permeable non-porous ion transport membrane, typically a plurality of such membranes. These membranes are usually of an inorganic oxide ceramic material, such as zirconia or other materials known to those skilled in the art. Typically, the membranes are in the form of tubes, sheets or a monolithic honeycomb structure. It is expected that the invention will employ an oxygen partial pressure differential across the membranes thereby to cause oxygen ions to migrate through the membranes from a feed side to a permeate side, where the ions recombine to form electrons and oxygen gas. It is in principle however also possible to employ a voltage differential across the membranes, i.e. by using ion transport membranes of the electrically-driven type, in which the electrons flow from the permeate side to the feed side of the membrane in an external circuit driven by a voltage differential. As will be appreciated, any solid ceramic membrane material which selectively permeates oxygen in the form of oxygen ions, whether of a mixed conductor type using an oxygen partial pressure differential, or a solid electrolyte type using a voltage differential across the membrane, can be used in the invention. The reject stream of oxygen-depleted air is thus used as a working fluid. This working fluid may be expanded in a power generation stage of the process of the invention. The power generation stage thus employs the well-known Brayton cycle in which the working fluid is gaseous and is not condensed during the cycle. The Brayton cycle of the power generation stage thus effectively receives heat for power generation from at least the synthesis gas (this is the heat transferred to the reject stream of oxygen depleted air), and in some embodiments also from said nuclear reaction stage (this is the heat transferred to the compressed air stream prior to separation thereof. In embodiments including such heat transfer from a nuclear reaction stage, heat is typically transferred from a gaseous coolant of the nuclear reaction stage to the compressed air stream in indirect heat transfer fashion. This type of Brayton cycle is also referred to as being indirect, since the gaseous coolant of the nuclear reaction stage is typically re-circulated in a primary loop which is closed, with heat transferred from the primary loop to the compressed air stream of the indirect Brayton power cycle contained in a secondary loop. The secondary loop is an open loop cycle, i.e. a cycle in which the working fluid is used on a once-through basis with expanded working fluid being discharged from the process. In a preferred embodiment of the invention, the nuclear reaction stage employs a high temperature gas cooled nuclear reactor in which a gaseous coolant is used for the nuclear reactor. Helium under elevated pressure, e.g. 70 bar(g), is a gaseous coolant that is typically used. Thus, typically the gaseous coolant circulated in the primary loop is helium. Typically, the gaseous coolant is at a temperature between about 750 and about 950° C., preferably at a temperature between about 800 and about 900° C., e.g. about 900° C., at an inlet of a heat exchanger arrangement used to transfer heat from the gaseous coolant of the nuclear reaction stage to the compressed air stream in indirect heat transfer fashion. The process may include reheating the reject stream of oxygen-depleted air at least once, after partial expansion of the reject stream of oxygen-depleted air through said at least one turbine, and further expanding the reheated reject stream of oxygen-depleted air through at least one further turbine, in order to increase the efficiency of power generation. Reheating the reject stream of oxygen-depleted air thus typically involves heat addition to, and expansion of, the reject stream of oxygen-depleted air in steps, i.e. heating the reject stream of oxygen-depleted air with a portion of available heat and then expanding the reject stream of oxygen-depleted air to a first lower pressure, thereafter heating the reject stream of oxygen-depleted air again and expanding the reject stream of oxygen-depleted air again to a second lower pressure, with the second lower pressure being lower than the first lower pressure. Thus, in one embodiment of the invention, the concept of reheating is applied, i.e. the heating of the reject stream of oxygen-depleted air using synthesis gas is performed in multiple steps by staging the heating and the expansion of the heated or reheated reject stream of oxygen-depleted air. In such an embodiment, the power generation stage may thus employ at least two turbines, with at least a portion of the heat from the synthesis gas being transferred to the reject stream of oxygen-depleted air after the reject stream of oxygen-depleted air has passed through one turbine but before the reject stream of oxygen-depleted air passes through another turbine, thereby to reheat the reject stream of oxygen-depleted air. In another embodiment the reheating may also be done using a heat source other than the synthesis gas, e.g. nuclear energy or burning of fuel gas. The process may include cooling said at least partially expanded reject stream of oxygen-depleted air, after it has been used for power generation, in heat transfer relationship with the compressed air stream. In embodiments of the invention including heat transfer from a nuclear reaction stage to the compressed air stream as discussed hereinbefore, this cooling of said at least partially expanded reject stream of oxygen-depleted air thus may include preheating the compressed air stream before the compressed air stream is heated with heat from the nuclear reaction stage. In other words, the process of the invention may thus effectively employ a recuperative or regenerative Brayton power cycle. The process of the invention may thus include in the power generation stage, expanding said heated reject stream of oxygen-depleted air through at least one gas expander turbine producing an at least partially expanded reject stream of oxygen-depleted air at a lower temperature and a lower pressure than the heated reject stream of oxygen-depleted air. The at least one gas expander turbine may then be employed to generate electrical power, e.g. using a generator. The process of the invention may include compressing air to produce the compressed air stream. The at least one gas expander turbine may be employed to drive at least one compressor to produce the compressed air stream. Typically, the compressed air is at a pressure of at least 4 bar(g), more preferably between about 5.5 bar(g) and about 21 bar(g), e.g. about 15 bar(g). Preferably, the compressed air stream is at a temperature of at least about 750° C., more preferably at least about 800° C., most preferably at least about 825° C., e.g. about 850° C., prior to separation thereof in the air separation stage. As will be appreciated, the reject stream of oxygen-depleted air from the ion transport membrane unit will also be at substantially these temperatures, before being heated with the synthesis gas to form the heated reject stream of oxygen-depleted air. The heated reject stream of oxygen-depleted air may be at a temperature of at least 900° C., preferably at least about 1000° C., more preferably at least about 1100° C., most preferably at least about 1150° C., e.g. about 1200° C., before being at least partially expanded to generate power. As will be appreciated, the maximum temperature achievable for the heated reject stream of oxygen-depleted air is determined by the temperature of the synthesis gas. Preferably, the synthesis gas is thus at a temperature as high as practically possible, e.g. about 1300° C. In any event, the synthesis gas is preferably at a temperature sufficiently high to ensure that the heated reject stream of oxygen-depleted air is heated to a temperature of at least 900° C. Instead, or in addition, the process of the invention may include using said at least partially expanded reject stream of oxygen-depleted air to generate steam. The steam may be employed to generate additional power by means of a steam turbine. The power generation stage may thus be configured as a combined cycle. In a combined cycle heat is transferred from the expanded working fluid of the Brayton cycle (a so-called topping cycle) to the working fluid of a further power cycle (a so-called bottoming cycle). Typically the bottoming cycle is a Rankine cycle, typically using steam as working fluid. Combined cycle power systems are known to achieve increased efficiencies when compared to stand-alone Brayton cycles. When the power generation stage is configured as a combined cycle, the Rankine cycle may also be modified to include the step of reheating and/or superheating of the working fluid of the Rankine cycle to further increase efficiency. Reheating or superheating may be done using either synthesis gas or nuclear heat, or combustion of fuel gas. When the power generation stage is configured as a combined cycle, using steam as working fluid, a portion of the steam generated may be directed towards process heating, rendering the process of the invention a process for co-producing synthesis gas, power and heat. Alternatively, process steam generated in a facility utilising the synthesis gas may be fed into the Rankine cycle to supplement power production. The air may be compressed in one or more air compressors sized to compress air in addition to what is required to produce the permeate stream consisting predominantly of oxygen in the air separation stage for synthesis gas generation purposes. The additional compressed air typically bypasses the ion transport membrane unit and is heated before being used to produce additional power. The additional compressed air may receive heat from the nuclear reaction stage and/or from the synthesis gas. Typically, the additional compressed air, after having been heated, is then expanded to produce power. Alternatively, fuel gas may be burned with the additional compressed air producing combusted gas, with the combusted gas being expanded to produce power. The additional compressed air may first be mixed with the reject stream of oxygen-depleted air and fuel before the mixture is combusted to produce combusted gas, with the combusted gas then being expanded through a gas expansion turbine to generate power. Preferably, the process includes in such a case first mixing the additional compressed air and the reject stream of oxygen-depleted air and then heating the mixture using the synthesis gas, before the heated mixture is mixed with fuel gas for combustion. As will be appreciated, the permeate stream consisting predominantly of oxygen has a reduced pressure due to a pressure differential across the ion transport membrane unit. The process thus typically includes recompressing the permeate stream consisting predominantly of oxygen to a pressure suitable for use in the synthesis gas generation stage. The process of the invention may include in a hydrocarbon synthesis stage, producing hydrocarbons from the synthesis gas produced by the synthesis gas generation stage. Examples of such hydrocarbon synthesis include methanol synthesis and Fischer-Tropsch synthesis. The synthesis gas generation stage should thus produce synthesis gas at a pressure which is sufficiently high, taking into account pressure losses over process units to allow hydrocarbon synthesis at a suitably high pressure. Typically, the synthesis gas is at a pressure of between about 40 bar(g) and about 50 bar(g), e.g. about 45 bar(g). Synthesising hydrocarbons from the synthesis gas may be effected in any conventional fashion. Typically, the synthesising of hydrocarbons from the synthesis gas includes Fischer-Tropsch synthesis using one or more Fischer-Tropsch hydrocarbon synthesis stages, producing one or more hydrocarbon product streams and a Fischer-Tropsch tail gas which includes CO2, CO and H2. The one or more Fischer-Tropsch hydrocarbon synthesis stages may be provided with any suitable reactors such as one or more fixed bed reactors, slurry bed reactors, ebullating bed reactors or dry powder fluidised bed reactors. The pressure in the reactors may be between 1 bar(g) and 100 bar(g), typically below 45 bar(g), while the temperature may be between 160° C. and 380° C. One or more of the Fischer-Tropsch hydrocarbon synthesis stages may be a low temperature Fischer-Tropsch hydrocarbon synthesis stage operating at a temperature of less than 280° C. Typically, in such a low temperature Fischer-Tropsch hydrocarbon synthesis stage, the hydrocarbon synthesis stage operates at a temperature of between 160° C. and 280° C., preferably between 220° C. and 260° C., e.g. about 250° C. Such a low temperature Fischer-Tropsch hydrocarbon synthesis stage is thus a high chain growth, typically slurry bed, reaction stage, operating at a predetermined operating pressure in the range of 10 to 50 bar(g), typically below 45 bar(g). One or more of the Fischer-Tropsch hydrocarbon synthesis stages may be a high temperature Fischer-Tropsch hydrocarbon synthesis stage operating at a temperature of at least 320° C. Typically, such a high temperature Fischer-Tropsch hydrocarbon synthesis stage operates at a temperature of between 320° C. and 380° C., e.g. about 350° C., and at an operating pressure in the range of 10 to 50 bar(g), typically below 45 bar(g). Such a high temperature Fischer-Tropsch hydrocarbon synthesis stage is a low chain growth reaction stage, which typically employs a two-phase fluidised bed reactor. In contrast to the low temperature Fischer-Tropsch hydrocarbon synthesis stage, which may be characterised by its ability to maintain a continuous liquid product phase in a slurry bed reactor, the high temperature Fischer-Tropsch hydrocarbon synthesis stage cannot produce a continuous liquid product phase in a fluidised bed reactor. The synthesis gas generation stage may be a gasification stage gasifying a solid carbonaceous feedstock, e.g. coal. Any conventional gasification technology may be employed, although it is preferable that gasifiers with an exit gas temperature of at least 900° C. be used. Instead, the synthesis gas generation stage may be a reforming stage, reforming a gaseous hydrocarbonaceous feedstock, e.g. natural gas or associated gas. Any conventional reforming technology may be used. The process of the invention may include further cooling the synthesis gas after heat has been transferred from the hot synthesis gas to the reject stream of oxygen-depleted air. In this way, the synthesis gas can be cooled to a temperature suitable for further processing of the synthesis gas, e.g. in said hydrocarbon synthesis stage. Further cooling of the synthesis gas may include generating steam. Referring to FIG. 1 of the drawings, reference numeral 10 generally indicates a process in accordance with the invention for co-producing synthesis gas and power. The process 10 includes, broadly, a synthesis gas generation stage 12, a nuclear reaction stage 14 and an air-separation stage 16 comprising at least one ion transport membrane 16.1. The process 10 further includes an air-compressor 18, an air heater 20, an oxygen compressor 22, a synthesis gas cooler 24, a synthesis gas waste heat boiler 26, a gas turbine expander 28 and a hydrocarbon synthesis stage 30. The nuclear reaction stage 14 employs a high temperature gas cooled nuclear reactor 32 with helium as a gaseous coolant being circulated through the high temperature gas cooled nuclear reactor 32. The nuclear reaction stage 14 may be a typical or conventional high temperature gas cooled nuclear reaction stage operating with helium at a pressure of 70 bar(g) in a closed helium cycle 34. In the drawings, the nuclear reaction stage 14 is shown in a very simplified format with most of the detail of such a typical nuclear reaction stage not being shown. However, it is to be noted that the helium in the closed helium cycle 34 is heated in the high temperature gas cooled nuclear reactor 32 to a temperature sufficient such that the helium is at a temperature of about 900° C. where the helium enters the air heater 20. An air stream 36 is sucked into the air compressor 18 and compressed to a pressure of about 15 bar(g), producing a compressed air stream 38. In the air heater 20, heat is transferred from the closed helium cycle 34 of the nuclear reaction stage 14 to the compressed air stream 38, in indirect heat transfer fashion, producing a heated compressed air stream 40 at a temperature of at least about 700° C. Preferably, the heated compressed air stream 40 is however at a higher temperature, e.g. about 850° C. The heated compressed air stream 40 is separated in the air separation stage 16, by means of the ion transport membrane 16.1, to produce a permeate stream 42 consisting predominantly of oxygen, i.e. typically at least about 98% by volume oxygen, and a reject stream 44 of oxygen-depleted air. As will be appreciated, the reject stream of oxygen-depleted air 44 is substantially at the same pressure as the heated compressed air stream 40, i.e. at about 15 bar(g) minus the pressure drop across the air heater 20 and the air separation stage 16. The permeate stream 42 is at a pressure of about 1 bar(g) and is first cooled in a permeate stream cooler 43 before being compressed by means of the oxygen compressor 22 to a pressure suitable for use in the synthesis gas generation stage 12. Typically, the permeate stream 42 is thus compressed to a pressure between about 40 bar(g) and about 50 bar(g), e.g. about 45 bar(g). In the synthesis gas generation stage 12, coal from a coal feed 46 is gasified in the presence of oxygen, from the permeate stream 42 and in the presence of steam from a steam feed 48, to produce hot synthesis gas 50. The hot synthesis gas 50 is at a temperature of at least 900° C. The process of the invention is not restricted to a particular technology being employed to produce the hot synthesis gas 50, the only requirement being that the hot synthesis gas 50 must be at a sufficiently high temperature, e.g. at a temperature of at least 900° C. The synthesis gas generation stage 12 may thus generate synthesis gas from coal by gasification with oxygen and steam, as shown in FIG. 1, e.g. by using a fine coal high temperature gasifier, or instead the synthesis gas generation stage 12 may be a reforming stage in which methane is reformed with oxygen or with steam. The synthesis gas generation stage 12 may also be an autothermal reforming stage. For all of these technologies however, oxygen is required and for the process 10 would be provided by the permeate stream 42, once compressed by the oxygen compressor 22. The hot synthesis gas 50 is cooled in the synthesis gas cooler 24 in indirect heat transfer fashion, thereby heating the reject stream 44 of oxygen-depleted air. Preferably, the hot synthesis gas 50 is at a temperature of about 1300° C., with the reject stream 44 then being heated to a temperature of about 1200° C. A heated reject stream 52 of oxygen-depleted air is thus provided. As will be appreciated, the heated reject stream 52, at a temperature of about 1200° C. and a pressure of about 15 bar(g), can be used to generate power. The heated reject stream 52 is thus expanded through the gas turbine expander 28, for producing an at least partially expanded reject stream 54 of oxygen-depleted air. The gas turbine expander 28 is used to drive a generator 56, thereby generating electrical power. The hot synthesis gas 50 is cooled in the synthesis gas cooler 24. Cooled synthesis gas 58 is fed to the synthesis gas waste heat boiler 26 where it is further cooled, before the cooled synthesis gas 58 is fed to the hydrocarbon synthesis stage 30. The synthesis gas waste heat boiler 26 receives boiler feed water 60 and produces steam 62, which can be used to generate power or which can be used for process purposes, e.g. in the synthesis gas generation stage 12 as the steam feed 48. The hydrocarbon synthesis stage 30 may be any hydrocarbon synthesis stage employing a synthesis gas to synthesise hydrocarbons 64. For example, the hydrocarbon synthesis stage may be a methanol synthesis stage or a Fischer-Tropsch hydrocarbon synthesis stage. Referring to FIG. 2 of the drawings, reference numeral 100 shows another embodiment of a process in accordance with the invention for co-producing synthesis gas and power. The process 100 is similar to the process 10 and unless otherwise indicated, the same reference numerals are used in relation to the process 100 as were used in relation to the process 10, to indicate the same or similar process features. The process 100 employs reheating of the working fluid of the Brayton power cycle, i.e. the reject stream 44. The process 100 thus has a reject stream reheater 104 and another gas turbine expander 106. The hot synthesis gas 50 splits into two streams, one going to the synthesis gas cooler 24 and one going to the reject stream reheater 104, before rejoining and entering the hydrocarbon synthesis stage 30. In the process 100, the heated reject stream 52 is expanded in stages, first through the gas turbine expander 28 and then through the gas turbine expander 106, producing an expanded reject stream 108. One of the hot synthesis gas streams 50 is used to reheat the at least partially expanded reject stream 54 from the gas turbine expander 28 before the at least partially expanded reject stream 54 is expanded in the gas turbine expander 106. As shown in FIG. 2, the gas turbine expander 106 can be used to drive the air compressor 18. Such a drive arrangement would typically make use of a direct mechanical coupling between the gas turbine expander 106 and the air compressor 18. The use of the reheater 104 and expansion of the heated reject stream 52 in stages, increases the efficiency of the Brayton power cycle of the process 100. With reference to FIG. 3, reference numeral 200 shows an alternative embodiment of a process in accordance with the invention for co-producing synthesis gas and power, and heat. Again, as there are many similarities between the process 200 and the process 10, the same reference numerals have been used as far as possible to indicate the same process features. The process 200 includes a boiler 206, a superheater 208, a steam turbine 202 and a steam condensor 204. The steam turbine 202, condensor 204, boiler 206 and superheater 208 form part of a Rankine bottoming cycle which works with a Brayton topping cycle to generate steam (i.e. heat) and power, where the Brayton topping cycle includes the air heater 20, synthesis gas cooler 24 and gas turbine expander 28. In the process 200, the at least partially expanded reject stream 54 is cooled in the boiler 206, producing steam 210 and a cooled reject stream 211. The steam 210 is superheated in the superheater 208 in indirect heat transfer fashion with the cooled synthesis gas 58, producing a superheated steam 212. A portion of the superheated steam 212 is passed through the steam turbine 202 to generate power. This portion of the steam is fully condensed in the steam condensor 204 and condensate 214 is returned to the boiler 206. Boiler feed water make-up 216 is added to the condensate 214. A portion of the superheated steam 212, indicated by reference numeral 218, is withdrawn and used for process purposes, such as process heating. As also shown in FIG. 3, the air compressor 18 is sized to compress air in addition to what is required to produce the permeate stream 42, i.e. to compress air in addition to the oxygen requirement of the synthesis gas generation stage 12. The additional compressed air is not passed through the air separation stage 16, although the additional compressed air is heated in the air heater 20. In other words, a bypass stream 220 of the heated compressed air stream 40 bypasses the air separation stage 16. This bypass stream 220 is used to generate additional power in the gas turbine expander 28. FIG. 4 shows a further embodiment of a process in accordance with the invention for co-producing synthesis gas and power, the process generally being indicated by reference numeral 300. As with FIGS. 2 and 3, FIG. 4 also uses the same reference numerals as were used in FIG. 1 to indicate the same or similar process features, unless otherwise indicated. As is the case with the process 200, in the process 300 the air compressor 18 is sized to compress air in addition to what is required to produce the permeate stream 42 for oxygen supply to the synthesis gas generation stage 12. The additional compressed air is heated also in the air heater 20 and then bypasses the air separation stage 16, as a bypass stream 302, to join the reject stream 44. A combined hot gas stream 304, at a temperature of about 850° C., is then passed through the synthesis gas cooler 24 and heated to a temperature of about 1200° C. A heated combined hot gas stream 306 from the synthesis gas cooler 24 is fed to a combustor 308 where the heated combined hot gas stream 306 is mixed with fuel gas 310. This mixture is combusted in the combustor 308 to produce combusted gas 312 which is then expanded through a gas turbine expander 314 to produce additional power. A particular advantage of the process of the invention, as illustrated, is that it relies on well-established technology for power production, namely air compressors and gas turbines, and possibly entirely conventional nuclear reaction stages in the case of the preferred embodiment using nuclear heat. There is also economy of scale for production of power since one cycle uses heat from both the nuclear reaction stage and from the heat available in the hot synthesis gas, in contrast to a stand-alone nuclear plant and a stand-alone steam generation system used to cool hot synthesis gas. The process of the invention, as illustrated, provides a solution to more than one problem, namely the perceived lack of integration opportunities of nuclear energy with synthesis gas generation processes, the large temperature difference driving force associated with steam production using hot synthesis gas (i.e. by matching this heat available at temperatures above 900° C., with the hot, pressurised oxygen-depleted stream emanating from an ITM oxygen process to further increase the energy that can be extracted from this stream), the large power requirement of traditional cryogenic air separation units for oxygen production, the heating requirement for an ITM system as well as the carbon dioxide emission problem associated with synthesis gas production processes for large scale chemicals production. The reduced carbon dioxide emissions result from improvement of thermal efficiency and by substitution of conventional carbon based power and heat generation facilities with a non-carbon source, namely nuclear energy.
047284838	abstract	An apparatus for an integrated and automated fuel assembly inspection system includes a support base, an elongated fixture, top and bottom carriages and a pedestal. The top carriage is mounted to a pair of tracks on the fixture for vertical movement therealong. The pedestal is mounted on the base and aligned with the top carriage for supporting a nuclear fuel assembly therebetween. The bottom carriage has a central opening adapted to receive the fuel assembly therethrough such that the bottom carriage surrounds all sides of the fuel assembly. Also, the bottom carriage is mounted to the tracks for generally vertical movement along the fixture and the fuel assembly. D.C. stepping motors are mounted on the top and bottom carriages and coupled to a gear track for selectively driving the carriages along the fixture. Proximity sensors are movably disposed on the bottom carriage adjacent the sides of the fuel assembly for measuring its envelope when the bottom carriage is moved to and stationed at selected axial positions along the fuel assembly. Lasers and photodetectors are disposed on the top and bottom carriages for continuously monitoring fixture out-of-straightness and performing correction. Capacitive probes are disposed on the bottom carriage for measuring channel spacing between fuel rods of the fuel assembly, and photoswitches and an optical scale are disposed on the bottom carriage and the fixture for measuring fuel assembly length when the bottom carriage has been moved between the bottom and top nozzles of the fuel assembly.
	abstract	An object of the invention is to reduce the beam drift in which the orbit of the charged particle beam is deflected by a potential gradient generated by a nonuniform sample surface potential on a charged-particle-beam irradiation area surface, the nonuniform sample surface potential being generated by electrification made when observing an insulating-substance sample using a charged particle beam.
051715198	summary	BACKGROUND OF THE INVENT 1. Field Of The Invention The present invention relates to the field of decontamination of nuclear reactor primary systems. More specifically, it relates to a unique apparatus for integrating a chemical injection system, a clean-up subsystem and a resin replacement system into a nuclear reactor primary system for chemical decontamination of the entire primary system in which the process equipment is located outside of the containment chamber. 1. Description Of The Prior Art The problem of excessive personnel exposures caused by high background radiation levels in a nuclear reactor primary system, such as in pressurized water reactor (PWR) systems, and the resultant economic cost of requiring personnel rotation to minimize individual exposure is significant at many nuclear plants. These background levels are principally due to the buildup of deposits of radioactive corrosion products in certain areas of the plant. The buildup of corrosion products exposes workers to high radiation levels during routine maintenance and refueling outages. The long term prognosis is that personnel exposure levels will continue to increase. As a nuclear power plant operates, the surfaces in the core and primary system corrode. Corrosion products, referred to as crud, are activated during transport of the corroded material through the core region by the reactor coolant system (RCS). Subsequent deposition of the activated crud elsewhere in the system produces radiation fields in piping and components throughout the primary system, thus increasing radiation levels throughout the plant. The activity of the corrosion product deposits is predominately due to Cobalt 58 and Cobalt 60. It is estimated that 80-90% of personnel radiation exposure can be attributed to these elements. One way of controlling worker exposure, and of dealing with this problematic situation, is to periodically decontaminate the nuclear steam supply system using chemicals which remove a significant fraction of the corrosion product oxide films. Prior techniques had done very little to decontaminate the primary system as a whole, typically focusing only on the heat exchanger (steam generator) channel heads. Two different chemical processes, referred to as LOMI (developed in England under a joint program by EPRI and the Central Electricity Generating Board) and CANDEREM (developed by Atomic Energy of Canada, Ltd.), have been used for small scale decontamination in the past. These processes are multi-step operations, in which various chemicals are injected, recirculated, and then removed by ion-exchange. Although the chemicals are designed to dissolve the corrosion products, some particulates are also generated. One method of chemical decontamination, focusing on the chemistry of decontamination, is disclosed in U.K. Patent Application No. GB 2 085 215 A (Bradbury et al.). There is little disclosure, however, of the methodology t be used in applying that chemistry to system decontamination. While these chemical processes had typically been used on only a localized basis, use of these chemical processes has now been considered for possible application on a large scale, i.e. full system chemical decontamination. Such an application is disclosed generally in co-pending Application Ser. No. 07/621,120, filed Nov. 26, 1990, now U.S. Pat. No. 5,089,216, entitled "System For Chemical Decontamination Of Nuclear Reactor Primary Systems", and incorporated herein by reference. While some work has been done in the boiling water reactor (BWR) programs, the BWR scenarios examined by those in the field involved decontaminating fuel assemblies in sipping cans employing commercial processes at off-normal decontamination process conditions with little regard for the effects of temperature, pressure, and flow that would be mandated by an actual application of the process to the full RCS. The estimated collective radiation dose savings over a 10-year period following decontamination is on the order of 3500-4500 man rem, depending upon whether or not the fuel is removed during decontamination. At any reasonable assigning of cost per man-rem, the savings resulting from reduced dose levels will be in the tens of millions of dollars. As a result of the present examination of potential full system decontamination, and the resulting need for new sub-system methods, developments have been made by the assignor of this invention to use demineralizing resin beds in conjunction with the known chemical processes. Developments in resin replacement systems for the demineralizer resin beds have also been made by the assignor of this invention. These developments are set forth in co-pending Application Ser. No. 07/621,129, filed Nov. 26, 1990, now U.S. Pat. No. 5,089,217 entitled "Clean-up Sub-system for Chemical Decontamination of Nuclear Reactor Primary systems", and in Ser. No. 07/621,130, filed Nov. 26, 1990 entitled "Resin Processing System , which are both incorporated herein by reference. There exists a need for a design layout which incorporates these advanced full system decontamination systems and sub-systems and incorporates them into an existing or future reactor plant design. One such plant design would be an "outside of containment" design in which the plant processing units which constitute the chemical decontamination process would be installed outside of the containment chamber. SUMMARY OF THE INVENTION The present invention is directed to a chemical decontamination system to be used in conjunction with a nuclear reactor primary system to achieve full primary system decontamination. More specifically, the present invention is directed towards an "outside of containment" chemical decontamination system which locates the chemical decontamination equipment outside of the containment chamber. The present invention provides for locating the equipment systems necessary for the chemical decontamination process on modular skids which can be easily installed in a decontamination building when needed and easily removed from that building when not in use. The decontamination process equipment is primarily comprised of a demineralizer system, a resin fines filter system, and a spent resin storage system. The demineralizer system is comprised of a plurality of demineralizer vessels which are downstream of and flow coupled to the primary system. The resin fines filter system is comprised of a plurality of resin fines filters which are downstream of and flow coupled to the demineralizer vessels. The spent resin storage tank system is comprised of a plurality of spent resin storage tanks which are downstream of and flow coupled to said demineralizer vessels and which receive spent resin from the demineralizer vessels. It is an object of the present invention to provide a process design which allows for the connection of a chemical decontamination system into a nuclear reactor primary system to economically and chemically decontaminate substantially the entirety of the nuclear reactor primary system in which the decontamination system equipment is located within a decontamination building outside of the containment chamber. This and other aspects of the present invention are more fully appreciated from the detailed description of the invention.
	abstract	The installation is designed for loading a nuclear fuel assembly that comprises a skeleton structure defining parallel locations for receiving fuel rods distributed in sheets. The installation comprises a horizontal bench (22) for receiving a skeleton structure, a magazine (16) for receiving rods for loading in a disposition that corresponds to that of the rods in the assembly, and a pulling bench (26) having a block of pulling or pushing elements enabling a plurality of rods to be slid simultaneously from the magazine into the skeleton structure. The bench makes it possible for a set of clamps from a plurality of sets each corresponding to a particular type of assembly to be fixed removably thereto by quick coupling and uncoupling means closed by actuators. The pulling bench (26) receives one out of a plurality of pulling element selector blocks, each block having a disposition of active pulling elements corresponding to a particular distribution of rods.
	claims	1. A non-resonance photo-neutralizer for neutral beam injectors comprisingfirst and second mirrors defining an open ended chamber, the first and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction between first and second ends of the open ended chamber, first ends of the first and second mirrors and seconds ends of the first and second mirrors being spaced apart and defining first and second openings at the first and second ends of the open ended chamber, the first mirror being concave along the first direction with the first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror,wherein the first mirror is concave in a second direction transverse to the first direction. 2. The photo-neutralizer of claim 1 wherein a space interposing the first and second mirrors comprises a confinement region adjacent a family of normals common to the opposing reflective surfaces of the first and second mirrors. 3. The photo-neutralizer of claim 1 wherein a mirror surface of the first mirror is concave and a mirror surface of the second mirror is flat. 4. The photo-neutralizer of claim 1 wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror. 5. A non-resonance photo-neutralizer for neutral beam injectors comprisingfirst and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction, the first mirror being concave along the first direction with first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror,wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror,wherein the central mirror is cylindrically shaped and the outer mirrors are conically shaped,wherein the first mirror is concave in a second direction transverse to the first direction. 6. A ion based neutral beam injector comprisinga negative ion source, anda non-resonance photo-neutralizer co-axially positioned with the ion source, wherein the photo-neutralizer including first and second mirrors defining an open ended chamber, the first and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction between first and second ends of the open ended chamber, first ends of the first and second mirrors and seconds ends of the first and second mirrors being spaced apart and defining first and second openings at the first and second ends of the open ended chamber, the first mirror being concave along the first direction with the first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror, wherein the first mirror is concave in a second direction transverse to the first direction. 7. The neutral beam injector of claim 6 wherein a space between the first and second mirrors comprises a confinement region adjacent a family of normals common to the opposing reflective surfaces of the first and second mirrors. 8. The neutral beam injector of claim 6 wherein one or more of the mirror surfaces of the first and second mirrors are concave. 9. The photo-neutralizer of claim 6 wherein a mirror surface of the first mirror is concave and a mirror surface of the second mirror is flat. 10. The neutral beam injector of claim 6 wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror. 11. A ion based neutral beam injector comprisinga negative ion source, anda non-resonance photo-neutralizer co-axially positioned with the ion source, wherein the photo-neutralizer includingfirst and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction, the first mirror being concave along the first direction with first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror,wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror,wherein the central mirror is cylindrically shaped and the outer mirrors are conically shaped,wherein the first mirror is concave in a second direction transverse to the first direction.
	claims	1. A method of storing radioactive materials, the method comprising:a) positioning a system comprising a shell forming a cavity and having an open top, and at least one inlet ventilation duct extending from an inlet to an outlet at a bottom portion of the cavity in a below grade hole so that the inlet of the inlet ventilation duct is above grade and the outlet of the inlet ventilation duct into the cavity is below grade;b) introducing engineered fill into the hole to circumferentially surround the shell;c) lowering a canister containing radioactive materials through the open top of the shell into the cavity; andd) subsequent to the canister being lowered into the cavity, placing a removable lid on the shell;wherein the shell is formed of steel and the inlet ventilation duct is seal joined to the shell and a bottom plate attached to the shell to form a self-supporting unitary structure. 2. The method of claim 1 wherein the system further comprises at least one outlet ventilation duct forming, a passageway from a to portion of the cavity to an ambient atmosphere. 3. The method of claim 2 wherein the lid comprises at least one outlet ventilation duct forming, a passageway from a top portion of the cavity to an ambient atmosphere. 4. The method of claim 1 wherein the system further comprises a concrete body circumferentially surrounding the shell, the engineered fill circumferentially surrounding the concrete body. 5. The method of claim 1 wherein step c) further comprises supporting the canister in the cavity so that an inlet air plenum exists between a floor of the cavity and a bottom surface of the canister and an outlet air plenum exists between a bottom surface of the lid and a top surface of the canister. 6. The method of claim 1 wherein the cavity extends along a longitudinal axis and has a transverse cross-sectional area that can accommodate no more than one of the canister. 7. A method of storing radioactive materials, the method comprising:a) providing a system comprising a structure having a metal shell forming a cavity and having an open top, the cavity having a top portion and a bottom portion, at least one inlet ventilation duct thrilling a passageway from an ambient air inlet to an outlet at the bottom portion of the cavity, and at least one outlet ventilation duct forming a passageway from the top portion of the cavity to ambient air;b) lowering a canister loaded with radioactive materials through the open top of the structure into the cavity until a bottom surface of the canister is lower than a top of the outlet of the at least one inlet ventilation duct;c) supporting the canister in the cavity in a position where the bottom surface of the canister is lower than the top of the outlet of the at least one inlet ventilation duct, wherein the inlet ventilation duct is shaped so that a line of sight does not, exist to the canister from the ambient air inlet through the at least one inlet ventilation duct; andd) placing a removable lid atop of the structure;wherein the inlet ventilation duct is seal joined to the shell and a bottom plate attached to the shell to form a self-supporting unitary structure. 8. The method of claim 7 wherein the lid comprises the at least one outlet ventilation duct. 9. The method of claim 7 wherein step a comprises positioning the system in a below grade hole so that at least a major portion of the structure and the cavity is located below grade, the outlet of the at least one inlet ventilation duct is located below grade, and the inlet of the at least one inlet ventilation duct is above grade. 10. The method of claim 7 wherein the structure is a metal shell and the system further comprises a concrete body surrounding the metal shell. 11. The method of claim 7 wherein the cavity extends along a longitudinal axis and has a transverse cross-sectional area that can accommodate no more than one of the canister. 12. The method of claim 7 wherein step c) further comprises supporting the canister in the cavity so that an inlet air plenum exists between a floor of the cavity and a bottom surface of the canister and an outlet air plenum exists between a bottom surface of the lid and a top surface of the canister.
042776880	description	With reference to FIG. 1, a cask 1 has a pair of trunnions 2 for suspending the cask 1 and a large number of annular cooling fins 3. With this cask 1, the trunnions 2 are disposed near the open upper end thereof, with almost all the annular fins 3 positioned below the trunnions 2. A bagging device 10 covering the outer surface of the cask 1, especially the finned portion thereof, comprises a bag 11 in the form of a tubular sheet closed at one end and an annular tube 12 attached to the open end of the bag 11. To facilitate the disposal of the device after use, the bag 11 and the annular tube 12 are preferably made from a combustible material such as rubber, synthetic resin or composite material made of rubber and resin. The annular tube 12, which has relatively high flexibility so as to be deformable in section, is fitted in the space between a pair of adjacent upper fins among the multiplicity of fins 3, as somewhat flattened in section as seen in FIG. 2. A pressure gas, when fed to the annular tube 12, holds the tube 12 in pressing contact with the pair of fins 3 to seal off the opening of the bag 11. In order to assure proper liquid tightness with the strength of fins 3 considered, it is desired that the width of contact, A, between the tube 12 and the fins 3 radially of the cask 1 be at least 30 mm and that the internal pressure of the tube 12 be set at a value P.sub.S which is 1.2 to 1.5 kg/cm.sup.2. When a fuel is to be accommodated in the cask 1, the bagging device 10, namely the bag 11 with the annular tube 12 attached to its open end, is fitted over the cask 1, and the annular tube 12 is fitted into the space between the uppermost pair of annular fins 3 as seen in FIG. 1. Subsequently a pressure gas is fed to the annular tube 12 to seal off the opening of the bag 11, while a specified negative pressure is applied to the interior of the bag 11 to hold the bag 11 in intimate contact with the outer surface of the cask 1. The cask 1 thus made ready for use is immersed into the fuel pool, the fuel is placed into the cask 1 as immersed in the water, the lid (not shown) of the cask 1 is closed for sealing, and the cask is withdrawn from the fuel pool. With the pressure gas thereafter released and the bag 11 opened to the atmosphere, the bagging device 10 is removed from the cask 1. The above operation is carried out while the cask 1 is held suspended from a crane. The bagging device 10 removed from the cask 1 may be used again but is usually burned immediately for disposal. On the other hand, the cask 1 is decontaminated over the portion left uncovered with the bag and other desired portion and then transported to the destination contemplated. The fuel is withdrawn from the cask 1 substantially in the same manner as above. For the transport of other radioactive fissionable materials, the cask 1 and the present device 10 are used similarly when accommodating the material in the cask and withdrawing the same therefrom. FIGS. 3 to 6 show another embodiment for use with a cask 1 having trunnions 2 at an axially intermediate portion thereof and a number of fins 3 positioned above and below the trunnions 2. Indicated at 4 is a flange for attaching a lid to the cask 1. A bagging device 20 useful for this embodiment comprises a bag 21, a first annular tube 22 fittable to the outer periphery of the flange 4, and a pair of second annular tubes 23 fittable around the trunnions 2. The bag 21 has a rubber bottom plate 24, a tubular sheet 25 extending upward from the bottom plate 24 and surrounding the body of the cask 1, and a pair of auxiliary tubular sheets 27 each having one end integral with the tubular sheet 25 and the other end apertured as at 26 to fit around the trunnion 2. The tubular sheet 25 and auxiliary tubular sheets 27 are both bellows-shaped. Of the folds of major and minor diameters of the tubular sheet 25, the annular folds 25a of major diameter are each internally provided with a synthetic resin annular rib 28. Similarly the annular folds 27a of minor diameter of each auxiliary tubular sheet 27 is internally provided with an annular rib 29. The peripheral edge portion 25b of the tubular sheet 25 defining its opening is fitted around the flange 4, with the first annular tube 22 fitting around the edge portion 25b. The apertured portion 27b of each auxiliary tubular sheet 27 is fitted around the base portion of each trunnion 2, with the second annular tube 23 fitting to the apertured portion 27b from outside. As shown in FIGS. 5 and 6, the annular tubes 22, 23 comprise deformable and inflatable annular tubular members 22a, 23a provided with plate coatings 22b, 23b of high rigidity respectively over the radially outer surface of the outer periphery of the member except where the tube is pressed against the cask, i.e. against the flange 4 or trunnion 2. Accordingly the annular tubes 22, 23, when subjected to the internal pressure of the gas supplied thereto, will inflate radially inwardly thereof as indicated in phantom lines in FIG. 5. When a fuel is to be placed into the cask, the bag 21 and the first and second annular tubes 22, 23 are fitted to the cask 1 as shown in FIG. 3, and pressure gas is fed to the annular tubes 22, 23 to seal off the openings of the bag 21. When the cask 1 is immersed into the fuel pool, the interior of the bag 21 is pressurized. The fuel is placed into the cask 1 in the same manner as in the first embodiment, the cask 1 is then withdrawn from the pool, the annular tubes 22 and 23 are thereafter allowed to contract, and the annular tubes 22, 23 and bag 21 are removed from the cask 1. The same procedure as in the first embodiment subsequently follows. The pressure thus applied to the space between the bag 21 and the cask 1 eliminates any likelihood of the contaminated water penetrating into the bag 21, rendering the cask free from contamination with improved effectiveness. The tubular sheet 25 of the bag 21, when held away from the outer peripheries of the fins 3 on the cask 1 in this way, is unlikely to be damaged by contact with the fins 3. The bellows-shaped construction further makes the bag 21 fittable to and removable from the cask with greater ease. FIGS. 7 to 10 show a third embodiment for use with a cask 1 which is similar in concept to the one used in combination with the second embodiment. Trunnions 2 are positioned slightly higher with some annular fins 3 also disposed above the trunnions 2. A bagging device 30 comprises a lower bag segment 31 in the form of a bottomed tubular sheet for covering the portion of the cask 1 below the trunnions 2 and an upper bag segment 32 in the form of a tubular sheet extending from the upper end of the cask 1 to the upper end of the lower bag segment 31 for covering the upper portion of the cask 1. The lower bag segment 31 is integral with a first annular tube 33 at the open end thereof, while the upper bag segment 32 is integral with a second annular tube 34 at its open end corresponding to the open upper end of the cask 1. As seen in FIG. 10, the upper bag segment 32 has apertures 35 for passing the trunnions 2 therethrough, and a tacky or adhesive coating 36 is formed on the rear surface of the peripheral portion defining each of the apertures 35. FIG. 9 shows an annular fastening member 37 attached to the upper end of the cask 1 by screws 38 and formed on the under side of its outer periphery with an annular recess 39 semicircular in cross section for the second annular tube 34 to fit in. When the cask 1 is to be covered with the bag, the cask 1 is placed on the bottom of the lower bag segment 31 spread over the floor, and the upper bag segment 32 is fitted over the upper portion of the cask 1 with the trunnions 2 passed through the apertures 35. The release paper affixed to the adhesive coatings 36 is removed therefrom, and the inner peripheral portions of the segment 32 defining the apertures 35 are attached to the outer surface of the cask 1 with the adhesive coatings 36. The lower end of the upper bag segment 32 is made to extend over the two fins 3 immediately below the trunnions 2. The second annular tube 34 at the upper end of the segment 32 is placed on the top of the cask 1 along its outer periphery. Subsequently the fastening member 37 is placed on the top of the cask 1 with the second annular tube 34 fitted in the annular recess 39, and fastened to the top of the cask 1 with the screws 38. A pressure gas is thereafter forced into the second annular tube 34 to inflate the tube 34 into pressing contact with the top of the cask 1 and with the fastening member 37, causing the tube 34 to seal off the bag opening. The first annular tube 33 at the upper end of the lower bag segment 31 is then lifted with a jig and inserted into the space between the two fins 3 immediately below the trunnions 2. With the lower end of the upper bag segment 32 positioned inside the lower bag segment 31, the first annular tube 33 opposes the two fins 3 with the lower end held therebetween. The first annular tube 33 is then inflated with the pressure gas forced thereinto and thereby pressed against the fins 3 with the lower end of the segment 32 interposed therebetween, thus sealing the joint between the upper and lower bag segments 32 and 31. A fuel is placed into or out of the cask 1 in the same manner as is the case with the first embodiment. The bag of the third embodiment which comprises the divided upper and lower segments 32 and 31 is fittable over the cask 1 with greater ease than a single elongated bag and will not be broken by engagement of the bag with the fin. Even if one of the bag segments should be broken, the contaminated water will not ingress into the other bag segment. The lower bag segment 31, which need not be passed over the trunnions 2, has only to be made diametrically slightly larger than the outside diameter of the fins 3. Preferably the bags 11, 12 and bag segments 31, 32 may be made from a composite material comprising two synthetic resin films 41a and 41b, a synthetic resin fiber fabric 42 sandwiched between the films, and a lining 43 of natural rubber or like soft rubber formed over the film 41b to be positioned closer to the cask 1. Needless to say, also useful are other highly flexible sheets of rubber or synthetic resin which are impermeable and combustible. With reference to FIGS. 12 to 14, a control system will be described below for effecting pressure compensation against the pressure of water to be exerted on the annular tube, or on the annular tube and the bag. The control system will be described as used for the first embodiment of FIG. 1 in which the interior of the annular tube is set to a specified sealing pressure (for example, of 1.5 kg/cm.sup.2) and the bag is set to a specified internal negative pressure (for example, of -0.04 kg/cm.sup.2). The application of the system for the other embodiments will be apparent and will not be described. FIGS. 12 and 13 show a pressure control unit 51 comprising a casing 53 housing a pressure supply container 52, and a main body casing 54 housing a control system. The casings are joined together in a compact arrangement and attached to an upper portion of the cask by a fitting band 55. The main body casing 54 has a connecting outlet 56 and another connecting outlet 57 which are adapted for communication with the interior of the bag 11 and the interior of the annular tube 12 by suitable flexible pipes (not shown) respectively. The main body casing 54 further has an outlet 58 for connection to a vacuum pump which outlet is in communication with the bag connecting outlet 56 by way of the internal space of the main body casing 54. The main body casing 54 has a pressure detecting port 60 through which the pressure of water is detected in accordance with the depth after the port has started to submerge. The result is fed through a pressure detecting line 61 to a tube pressure control valve 62 and to a bag pressure control valve 63. The valve 62 is connected to a line 64 for applying internal pressure to the tube, while the internal pressure of the main body casing 54 is fed to the control valve 63. Accordingly the pressure control valve 62 opens its valve channel 65 in accordance with the variation of the difference between the pressure of water, P.sub.H, detected and the sum of the initial set pressure P.sub.S or subsequent internal pressure of the annular tube 12 and an increment .DELTA.P.sub.H of the internal pressure due to the deformation of the tube 12 resulting from an increase in the water pressure (see FIG. 2). Indicated at 66 is a spring for compensating for the initial set pressure P.sub.S. On the other hand, the pressure control valve 63 opens its valve channel 67 in accordance with the variation in the difference between the detected water pressure and the specified negative pressure within the bag 12 or subsequent internal pressure of the bag. A pressure supply line 68 extending from the pressure supply container 52 communicates with a line 69 through which pressure is supplied to or released from the annular tube 12. A line 71 for supplying pressure to the bag branches off from the pressure line 68, has an intermediate start valve 70 and communicates with the valve channel 67 of the pressure control valve 63. The valve channel 67 has an opening 72 to the interior of the main body casing 54. The start valve 70 has a resistivity-sensitive gas generator 73, which operates simultaneously with immersion into the body of water, generating a gas and breaking a shield 74 to open a valve channel 75. A check valve 76 for releasing pressure from the annular tube is in communication with the pressure supply-release line 69 by way of a line 78 for releasing pressure from the annular tube, the line 78 having a trap 77. A check valve 79 for releasing pressure from the bag is in communication with the interior of the main body casing 54 via a line 81 for releasing pressure from the bag, the line 81 having a trap 80. The check valves 76 and 79 are provided outside the main body casing 54. When the interior of the bag 12 is maintained at a negative pressure relative to the external pressure, the check valve 79 is positioned above the pressure detecting port 60 by a head corresponding to the negative pressure. Indicated at 82 and 83 are pressure gauges for indicating the internal pressures of the annular tube 12 and bag 11 respectively. The control system operates in the following manner. With reference to FIG. 14, designated at P.sub.S0 is the initially set internal pressure of the annular tube required for sealing, and at -P.sub.b0 the negative set pressure within the bag. It is now assumed that the cask 1 is immersed in the fuel pool under the above pressure conditions and that the annular tube 12 and the pressure detecting port 60 of the control system are both positioned at a depth H.sub.1 for the convenience of description. When the head at the depth H.sub.1 is P.sub.H1, the pressure P.sub.H1 acts externally on the annular tube 12, slightly deforming the tube 12 in cross section, with the result that the interior of the tube 12 is subjected to the sum of P.sub.S0 and a small increment .DELTA.P.sub.H1 in proportion with the external pressure P.sub.H1, namely P.sub.S0 +.DELTA.P.sub.H1 (see FIG. 2). Thus the difference in pressure between outside and inside the tube 12, which has been P.sub.S0 while the tube is in the atmosphere, is P.sub.S0 -(P.sub.H1 -.DELTA.P.sub.H1) at the depth H.sub.1, thus impairing the reliability of the seal. It is noted that the combined internal pressure of the tube, P.sub.S0 +.DELTA.P.sub.H1, and the water pressure P.sub.H1 detected at this time are fed to the tube pressure control valve 62 described with reference to FIG. 13, with the pressure P.sub.S0 compensated for by the spring 66, so that the valve channel 65 is opened in accordance with the difference between P.sub.H1 and .DELTA.P.sub.H1, permitting the pressure supply container 52 to supply the pressure gas to the tube 12 via the pressure line 68, reducing valve 68a, valve channel 65, pressure supply-release line 69 and connecting outlet 57 until the internal pressure, P.sub.S1, of the tube 12 reaches P.sub.S0 +P.sub.H1, whereupon the valve channel 65 is closed. In this way, the internal-external pressure difference P.sub.S0 is established for the tube 12, thus assuring a reliable sealing effect. When the cask 1 is further lowered to bring the annular tube 12 to a depth H.sub.2, the control system operates similarly, supplying the pressure gas to the tube 12 until the internal pressure P.sub.S2 equals to P.sub.S0 +P.sub.H2 to give the internal-external pressure difference P.sub.S0 to the tube 12 for reliable sealing action. Conversely if the cask 1 is raised with the tube 12 shifted from the depth H.sub.2 to the depth H.sub.1, an excess of pressure corresponding to P.sub.H2 -P.sub.H1 is released into the water via the supply-release line 69, release line 78 and check valve 76, because the valve 76 has such a pressure compensation spring that the valve is opened when subjected to the pressure of the sealing pressure P.sub.S0 plus a small pressure .DELTA.P, namely P.sub.S0 +.DELTA.P, the valve further being so adapted that the external water pressure exerted thereon acts to close the valve. Consequently the valve 76 maintains the internal-external pressure difference involved in the tube 12 at a value of up to P.sub.S0 +.DELTA.P at all times. The external pressure on the bag 11 will now be discussed with reference to the right-end section of the diagram of FIG. 14. The bag 11, while in the atmosphere, is subjected to an external pressure P.sub.b0 corresponding to the absolute value of the negative pressure -P.sub.b0 to which the bag is set. It is now assumed that the pressure detecting port 60, namely the upper end of the bag 11, is positioned at the depth H.sub.1. Unless a compensation pressure is fed to the interior of the bag 11, the upper end will be subjected to an external pressure of P.sub.b0 +P.sub.H1, and the lower end to an external pressure of P.sub.b0 +P.sub.l +P.sub.H1 where l is the length of the bag 11, and P.sub.l is the head difference. With the internal pressure, -P.sub.b0, of the bag 11 and the pressure of water, P.sub.H1, detected fed to the bag pressure control valve 63, the valve channel 67 is opened in accordance with the pressure difference between P.sub.H1 and -P.sub.b0, with the result that the pressure gas is sent out from the pressure supply container 52 to the bag 11 by way of the pressure line 68, pressure line 71, start valve channel 75, pressure control valve channel 67, opening 72, interior space of the main body casing 54 and connecting outlet 56 until the internal bag pressure reaches P.sub.H1 -P.sub.b0. Thus the external pressure on the bag 11 is limited to P.sub.b0 at its upper end and to P.sub.b0 +P.sub.l at its lower end. The control system operates similarly when the cask 1 is further lowered to bring the upper end of the bag 11 to the depth H.sub.2, supplying the pressure gas until the internal bag pressure reaches P.sub.H2 -P.sub.b0 and limiting the external pressure on the bag 11 similarly as above. Conversely if the bag 11 is raised from the depth H.sub.2 to the depth H.sub.1, an excess of pressure corresponding to P.sub.H2 -P.sub.H1 is released into the water via the interior space of the main body casing 54, bag pressure release line 81 and check valve 79. Since the check valve 79 is positioned above the upper end of the bag 11 by a head corresponding to -P.sub.b0, the internal pressure of the bag 11 is limited at all times to a level slightly higher than P.sub.H -P.sub.b0. Apparently, however, the initial negative internal pressure of the bag 11 in the atmosphere must be given forcibly from outside. Further when the submerged cask 1 is raised to the atmosphere, a positive pressure will be applied to the interior of the bag, so that it is impossible to reduce the internal bag pressure to a level lower than the atmospheric pressure by the check valve 79, whereas even at this time the bag will not inflate in the atmosphere since the bag 11 has been maintained at the specified negative pressure relative to the external water pressure and in intimate contact with the cask outer surface, with the interior of the bag 11 sealed off from outside by the check valve 79. Thus the bag can be held in contact with the cask when raised to the atmosphere, causing no trouble to the operation. In any case, the pressure gas is fed to the bag 11 in accordance with the pressure of water, permitting a substantially uniform external pressure to act on the bag 11 irrespective of the depth of water without producing any adverse effect on the strength of the bag and allowing the bag to retain the specified negative pressure relative to the external pressure throughout the entire operation. This enables the bag to retain the initial shape in the cask covering state throughout the whole operation. The traps 77 and 80 provided for the tube pressure release line 78 and the bag pressure release line 81 respectively serve to prevent the contaminated water of the fuel pool from flowing reversely through the check valves 76 and 79 into the tube pressure control valve 62 and the bag pressure control valve 63, thus precluding the possible contamination of these parts. Indicated at X in FIG. 13 is a pressure source on the ground. Alternatively a pressure source of the submerged type may be usable when so desired. Although the foregoing embodiments each comprise a characteristic combination of the components, the present invention also includes various changes of the components and modified combinations of the elements disclosed within the scope and spirit of the invention.
	claims	1. A vehicle operation data collection apparatus comprising:a memory configured to store operation data of a plurality of vehicles acquired from the plurality of vehicles; anda processor programmed toevaluate excess or deficiency of operation data of the plurality of vehicles stored in the memory for each of abnormality types, on the basis of accuracy information of classification obtained when classifying the abnormality types occurring in the plurality of vehicles by machine learning, using operation data of the plurality of vehicles stored in the memory;extract, from the plurality of vehicles, a vehicle suitable for acquiring data of an abnormality type evaluated as data deficiency from a database accumulating maintenance history information of the plurality of vehicles as a collection target vehicle; anddistribute a collection command instructing collection of operation data to the extracted collection target vehicle; andreceive the operation data from the extracted collection target vehicle. 2. A vehicle operation data collection system comprising:a memory configured to store operation data of a plurality of vehicles acquired from the plurality of vehicles; anda vehicle operation data collection apparatus which has a processor programmed to evaluate excess and deficiency of the operation data of the plurality of vehicles accumulated in the memory for each of abnormality types, on the basis of accuracy information of classification obtained when classifying the abnormality types occurring in the plurality of vehicles by machine learning, using the operation data of the plurality of vehicles accumulated in the memory, extract, from the plurality of vehicles, a vehicle suitable for acquiring data of an abnormality type evaluated as data deficiency from a database accumulating maintenance history information of the plurality of vehicles as a collection target vehicle, distribute an operation data collection command instructing collection of operation data to the extracted collection target vehicle, and receive the operation data from the extracted collection target vehicle; andthe plurality of vehicles which has a communication unit which communicates with the vehicle operation data collection apparatus, one or more sensors attached to one or more components constituting the plurality of vehicles, and an in-vehicle terminal which acquires sensor data from the sensor specified by the operation data collection command and collects the acquired sensor data as operation data of the plurality of vehicles when receiving the operation data collection command. 3. A vehicle operation data collection method which causes a computer connected communicably to a plurality of vehicles to execute the steps of:accumulating operation data of a plurality of vehicles acquired from the plurality of vehicles in a storage device;evaluating excess or deficiency of operation data of the plurality of vehicles accumulated in the storage device for each of abnormality types, on the basis of accuracy information of classification obtained when classifying the abnormality types occurring in the plurality of vehicles by machine learning, using operation data of the plurality of vehicles accumulated in the storage device;extracting, from the plurality of vehicles, a vehicle suitable for acquiring data of an abnormality type evaluated as data deficiency in the evaluating excess or deficiency of operation data of the plurality of vehicles from a database accumulating maintenance history information of the plurality of vehicles, as a collection target vehicle; anddistributing a collection command instructing collection of operation data to the extracted collection target vehicle; andreceiving the operation data from the extracted collection target vehicle.
047770139	claims	1. A nuclear reactor, in particular a high-temperature reactor, with a reactor protecting building and therein a reactor pressure container in particular made of concrete, which is provided with at least one valve designed as a spring valve to limit the pressure in the reactor pressure container in the event of nuclear reactor overheating and which is provided with a liner on its inside and associated with cooling ducts communicating with at least one liner cooling equipment, characterized in that the valve spring (44) of a valve 38 consists of a material with a spring constant decreasing as the temperature rises and is subject to the heat of the gas flowing out when the valve 38 is open and that at least one cooling apparatus (25) is provided to cool at least one of the valve spring (44) and the gas before if flows out, said apparatus being connected to at least one liner cooling equipment (12, 13). characterized in that each liner cooling equipment (12, 13) is provided with at least one valve (30, 31) in the discharge conduit (16, 17). 2. Nuclear reactor per claim 1, characterized in that the cooling apparatus (25) is connected to all liner cooling equipment (12, 13). 3. Nuclear reactor per claim 1, characterized in that the cooling apparatus (25) is connected to the particular intake (14, 15) of the particular liner cooling equipment (12, 13). 4. Nuclear reactor per claim 1, characterized in that the valve is designed in such a manner that any excess pressure in the reactor pressure container (5) leads to closing the valve (38) no sooner than after one hour. 5. Nuclear reactor per claim 1, characterized in that the material for the valve spring (44) evinces a spring-constant which drops markedly at temperatures above 150.degree. C. 6. Nuclear reactor per claim 1, characterized in that the valve spring (44) of the valve is designed in such a manner that the closing force in the event of failure of either or both of the liner cooling equipment (12, 13) and open valve (38) will be in the range of the pressure level of either or both of the liner cooling equipment (12, 13). 7. Nuclear reactor per claim 1, characterized in that the valve (38) is designed in such a manner that the valve spring (44) is heated by the gas flowing out of the reactor pressure container (5) only after it is open. 8. Nuclear reactor per claim 1, characterized in that the valve (38) is enclosed by a thermally insulating housing (24). 9. Nuclear reactor per claim 1 characterized in that there is a plurality of valves and associated housings and each housing of one of the valves (38) is surrounded in the region of the valve spring (44) by welded-on cooling coils (49) of the cooling apparatus (25). 10. A high-temperature reactor with a reactor protecting housing and therein a reactor pressure container made of concrete and with an inside liner, associated with cooling ducts connected to at least one liner cooling equipment, as defined by claim 1, 11. A nuclear reactor per claim 10, characterized in that the valve (30, 31) evinces a closing force somewhat above the operational pressure of the particular liner cooling equipment (12, 13). 12. Nuclear reactor per claim 10, characterized in that there is a plurality of valves (30, 31) and each valve (30, 31) is provided with a venting conduit (34, 35) issuing into a water seal (37). 13. Nuclear reactor per claim 10, characterized in that there is a plurality of valves (30, 31) and each valve (30, 31) is bridged by a remote-controlled bypass valve (32, 33).
	summary
045004870	claims	1. A pressure surge attenuating system for piping which carries liquid coolant for a nuclear reactor and which attenuating system is operable to attenuate maximum expected pressure surges while maintaining the integrity of said piping to prevent escape of coolant from said piping, said attenuating system comprising: a pipe section of said piping having a wall portion with a fluted cross-sectional configuration which can deform by radially expanding without plastic deformation under pressure surges which could be hazardous; an enlarged container surrounding said fluted wall pipe section and spaced from said fluted wall pipe section; and a crushable metal foam filling the space between said fluted wall pipe section and said surrounding container, said crushable metal foam exhibiting controlled energy absorption upon crushing thereof, and said pressure surge attenuating system operable to attenuate the maximum expected pressure surges which may be encountered while limiting the expansion of said fluted wall section so that it does not exhibit plastic deformation. 2. The pressure surge attenuating system as specified in claim 1, wherein said fluted wall portion, when subjected to pressure surges which could be hazardous, deforms by radial expansion to crush said metal foam which in turn absorbs the energy of deformation to attenuate the original pressure surge. 3. The pressure surge attenuating system as specified in claim 2, wherein said coolant is liquid metal. 4. The pressure surge attenuating system as specified in claim 3, wherein said coolant is liquid sodium.
	description	FIG. 1 is a sectional illustration of a conventional nuclear reactor fuel assembly 10 typically used in commercial light water nuclear reactors for electricity generation throughout the world. Several fuel assemblies 10 are shipped to and placed in a reactor in close proximity to sustain a nuclear chain reaction. A fluid moderator and/or coolant conventionally passes through fuel assembly 10 in an axial direction, enhancing the chain reaction and/or transporting heat away from the assembly 10. As shown in FIG. 1, fuel assembly 10 includes multiple fuel rods 14 containing fissile material and extending in the axial direction within the assembly 10. Fuel rods 14 are bounded by a channel 12 that forms an exterior of the assembly 10, maintaining fluid flow within assembly 10 throughout the axial length of assembly 10. Conventional fuel assembly 10 also includes one or more conventional fuel spacers 18 at various axial positions. Fuel spacer 18 permits fuel rods 14 to pass through grid-like openings in spacer 18, thereby aligning and spacing fuel rods 14. One or more water rods 16 or other assembly features may also pass through spacer 18, and grid size and shape, and the overall shape of spacer 18 may vary across different designs of assembly 10. FIG. 2 is an illustration of a related art fuel spacer 18 from an axial direction. As shown in FIG. 2, conventional spacer 18 includes several grid openings 41, which may be formed by several unioned internal spans 42. Perimeter band 49 may enclose spacer 18 and include one or more bathtubs 44 that contact channel 12 (FIG. 1). As shown in FIG. 2, several fuel rods 14 may pass through spacer 18 through corresponding grid openings 41, when used in an assembly. Grid openings 41 may be of a substantially similar size and positioned in rectilinear fashion as shown in FIG. 2, or may be positioned and sized differently to accommodate other fuel designs. For example, grid openings 41 for water rods 16 may be larger than grid openings 41 for smaller fuel rods 14. Alternatively, all grid openings 41 may be a same size, and one or more rod contacts 46 may be used to bring fuel rods 14 into rigid contact with spacer 18 if grid openings 41 are larger than a diameter of fuel rod 14. For example, rod contacts 46 may be attached to one or more sidewalls 45 of grid opening 41 and extend inward to contact fuel rod 14 and rigidly connect fuel rod 14 to spacer 18 in a transverse direction. Example embodiments include nuclear fuel spacers that sit along axial positions of a fuel assembly and surround/align fuel rods that pass therethrough. Example embodiment spacers include a specialized rod contact with an elastic component and an associated limiting component that limits deflection of the elastic component. The elastic component may be embodied in several diverse ways, including as a curved protrusion with a length to minimally contact the fuel rod. Limiting components are similarly diverse, and may include a curved protrusion with a length shorter than the elastic component to allow some movement of the fuel rod against the elastic component before being halted, such as by contact with the deflection component. The degree of permitted movement may be approximately a threshold for plastic deformation of the elastic component or any other desired criteria. Elastic and deflection-limiting components may be arranged and related in several different ways in example embodiments, including a central, axial extending elastic component connecting at two axial ends to the spacer, with deflection limiters at either axial end. Example embodiment fuel spacers may further include a rigid stop without any corresponding elastic component. Example embodiment fuel spacers may include specialized rod contacts in any number and pattern based on fuel assembly design, desired operating characteristics, and anticipated loads and shocks. Example embodiment fuel spacers may be rectilinear with square grid openings having specialized rod contacts extending in fours from each inner wall of each opening, for example. In such an example, specialized rod contacts may include a combination of rigid stops and elastic components positioned around each fuel rod. Example embodiments include nuclear fuel assemblies with spacers through which several rods pass, each contacted by a desired combination of deflection-limited and rigid contacts at different points about each rod. Example methods include fabricating and using nuclear fuel assemblies and spacers with deflection-limited elastic components. Example methods may include stamping internal pieces of spacers to form the piece and elastic and/or rigid/deflection-limiting pieces together, so that a simplified fabrication method is achieved and spacer internals are integral and continuous. Various components can be further stamped or thinned to provide rigidity and desired levels of elasticity based on fuel needs. This is a patent document, and general broad rules of construction should be applied when reading and understanding it. Everything described and shown in this document is an example of subject matter falling within the scope of the appended claims. Any specific structural and functional details disclosed herein are merely for purposes of describing how to make and use example embodiments. Several different embodiments not specifically disclosed herein fall within the claim scope; as such, the claims may be embodied in many alternate forms and should not be construed as limited to only example embodiments set forth herein. It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being “connected,” “coupled,” “mated,” “attached,” or “fixed” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between”, “adjacent” versus “directly adjacent”, etc.). Similarly, a term such as “communicatively connected” includes all variations of information exchange routes between two devices, including intermediary devices, networks, etc., connected wirelessly or not. As used herein, the singular forms “a”, “an” and “the” are intended to include both the singular and plural forms, unless the language explicitly indicates otherwise with words like “only,” “single,” and/or “one.” It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, steps, operations, elements, ideas, and/or components, but do not themselves preclude the presence or addition of one or more other features, steps, operations, elements, components, ideas, and/or groups thereof. It should also be noted that the structures and operations discussed below may occur out of the order described and/or noted in the figures. For example, two operations and/or figures shown in succession may in fact be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Similarly, individual operations within example methods described below may be executed repetitively, individually or sequentially, so as to provide looping or other series of operations aside from the single operations described below. It should be presumed that any embodiment having features and functionality described below, in any workable combination, falls within the scope of example embodiments. Applicants have recognized that fuel assemblies are subjected to a variety of shocks and strains over their lifetime, including shipping, installation, handling, seismic events, and power generation, that cover a wide array of transverse force profiles on the assembly. As such, although it is desirable to maintain fuel rods in a particular positions in a fuel assembly for fluid flow, neutronics, and handling purposes, rigid and direct contact between the spacer and fuel rods may increase the risk of damage to the spacer or fuel rods when the assembly is subjected to certain transverse loads, such as sudden impact events or intense vibration, for example. Further, Applicants have recognized that a rigid connection between spacer and fuel rods may cause damage during axial movement of the spacer relative to the fuel rods during fuel assembly and disassembly processes, and/or may result in plastic deformation of internal spacer features or fuel rods during certain transverse load events, potentially damaging the assembly. On the other hand, purely elastic connections between spacer and fuel rods may result in less predictable spacing of the fuel rods when the assembly is subjected to certain transverse loads, resulting in plastic deformation of such elastic connections and/or poor fuel rod positioning. Elastic connections may also have unacceptably large transverse cross-sections in order to provide necessary elastic force, reducing coolant flow and rod-coolant heat transfer. Example embodiments described below address these and other problems recognized by Applicants with unique solutions enabled by example embodiments. The present invention is fuel spacers, fuel assemblies having spacers, and methods of forming and using the same, where the spacers include a rod contact that provides elastic force to a fuel rod to a degree and is deflection limited thereafter. This may avoid permanent deformation of the elastic member, achieve desired fuel rod spacing, simplify fabrication, and/or achieve several other desired characteristics. Specific example embodiments are discussed below that illustrate examples of how this may be done. FIG. 3 is an illustration of a section of a profile of an example embodiment fuel spacer 100. As shown in FIG. 3, example embodiment fuel spacer 100 may include several features of, and be useable with or in place of, related fuel spacers, such as those shown in FIGS. 1 and 2. Fuel spacer may include several internal grid openings 141 formed by internal spans 142 within an outer perimeter band 149. Fuel rods 14 may pass through example embodiment fuel spacer 100 through grid openings 141, with one or more internal walls 145 of grid openings 141 not directly contacting a corresponding rod 14. Non-shown portions of example embodiment fuel spacer 100 may be similar to the portion shown in FIG. 3, so as to convey all of example embodiment spacer 100 with any arbitrary number of grids 141 and fuel rods 14. Although the specific example of FIG. 3 is shown in a rectilinear shape and layout like related art spacers of FIGS. 1 and 2, it is understood that other geometries, sizes, and grid opening layouts are understood and useable as example embodiments. Example embodiment fuel spacer 100 may include other features, such as flow tabs, swirl vane mixers, debris filters, bathtubs etc. that permit the spacer to be useable with several types of fuel assemblies through appropriate or known variation. As shown in FIG. 3, example embodiment fuel spacer 100 includes an example embodiment rod contact 146 that contacts fuel rod 14 by extending transversely (the horizontal or vertical direction in the example of FIG. 3) from inner wall 145 of grid opening 141. Example embodiment rod contact 146 includes at least one of a rigid stop 462 and a deflection-limited elastic contact 461. Rigid stop 462 generally prevents relative movement of a contacted fuel rod 14 toward a nearest inner wall 145 from which rigid stop 462 extends. Deflection-limited elastic contact 461 is flexible and provides some, but not complete, movement of a contacted fuel rod 14 toward a nearest inner wall 145 from which deflection-limited elastic contact 461 extends. That is, deflection-limited elastic contact 146 provides a distance or clearance that fuel rod 14 may move toward an internal wall 145 while being subject to only restorative, elastic force but beyond which fuel rod 14 is subject to a rigid blocking force. This clearance or degree of movement may be selected based on a spring constant of deflection-limited elastic contact 461, a desired minimum distance between fuel rod 14 and inner wall 145, shocking forces expected to be encountered by a fuel assembly including the same in transport, use, or accident, and/or the plastic threshold of deflection-limited elastic contact 461. Any number of specialized rod contacts 146 may be placed in a grid opening 141. For example, if a grid opening 141 has four inner walls 145, one specialized rod contact 146 may extend from each wall 145 to provide four specialized rod contacts 146 in contact with a fuel rod 14. Alternatively, multiple or no specialized rod contacts 146 may also be present on any given inner wall 145, and any number of inner walls 145, including a single, circular ferrule-like inner wall 145, may be used in example embodiment spacers. As such, a single specialized rod contact 146 in a single grid opening 141 may be present in example embodiment spacers, up to dozens of specialized rod contacts 146 in up to every grid opening 141 in other example embodiments. Specialized rod contacts 146 may be arranged to provide fuel rods 14 with desired damping characteristics. For example, as shown in FIG. 3, two deflection-limited elastic contacts 461 may extend from two perpendicular walls 145, while two rigid stops 462 may extend from opposite perpendicular walls 145 in a given grid opening 141. The example arrangement of FIG. 3 may thus provide deflection-limited elastic forces in two perpendicular transverse directions and rigid forces in two other perpendicular directions. Of course, other arrangements, including all deflection-limited elastic resistance from deflection-limited elastic contacts 461 in one or all directions, a single rigid contact from a single direction, and/or different mixes of elastic, rigid, and/or no contact from any number of sides across different grid openings 141 are useable in example embodiment spacers. Nuclear fuel engineers can use example embodiment spacers with varying rigid and elastic rod contacts to achieve a wide degree of support and response to fuel rods spaced by example embodiments, achieving desired levels of support and/or damping based on rod position within a spacer, bundle, and/or core, based on anticipated operating and shipping shock magnitudes and direction, based on steady-state vibration conditions, etc. If specialized rod contacts 146 uses two opposite contacts, such as both a deflection-limited elastic contact 461 and a rigid stop 462 as shown in FIG. 3, specialized rod contact 146 may contact a plurality of fuel rods 14 in different grid openings 141 extending on both sides of an internal span 142. In the example of FIG. 3, specialized rod contact includes a rigid stop 462 providing a rigid contact to one fuel rod 14 in one grid opening 141 and an opposite deflection-limited elastic contact 461 providing a flexible, restorative contact to another fuel rod 14 in an adjacent grid opening 141. Specialized rod contact 146 may be embodied in several ways in to provide desired rigid and/or deflection-limited elastic contact characteristics to fuel rods supported thereby. FIG. 4 is an example embodiment showing a particular arrangement for a specialized rod contact 146 that provides both rigid contact and deflection-limited elastic contact to adjacent fuel rods. As shown in FIG. 4, example embodiment specialized rod contact 146 includes an elastic contact 461a that may be a spring or extension having a transverse length sufficient to contact a fuel rod positioned in a cell with specialized rod contact 146. Elastic contact 461a may be have rounded edges and have a relatively thin profile so as to have minimal debris capture and/or blocking effect on fluid flowing over a rod and specialized rod contact 146 in the axial direction. Elastic contact 461a may further be shaped to minimize a hydraulic profile of example spacers in which it is useable by being thin and elongated in the axial direction (the vertical direction in the example of FIG. 4) while extending minimally in the transverse direction (the horizontal direction in the example of FIG. 5) so as to minimally block fluid flow while still providing the desired resistive force. Elastic rod contact 461a may be formed of any material compatible with an operating nuclear reactor environment, including zircaloys, aluminum alloys, stainless steels, and/or nickel alloys such as X-750. Elastic contact 461a may be formed to a thinness and other dimensions to provide a desired spring constant and/or plastic deformation threshold based on any number of criteria including position in core, fuel rod characteristics, anticipated loads and vibrations, etc. Because elastic contact 461a may provide a flexible, restorative force to a contacting fuel rod with only a relatively narrow/thin curved contact area, the potential for fouling, corrosion, and/or debris capture between elastic contact 461a and a fuel rod can be minimized. Example embodiment specialized rod contact 146 also includes a deflection limiter 461b extending in the transverse direction from interior span 142. Deflection limiter 461b is comparatively rigid, and, if pushed into contact with a fuel rod, will largely prevent any further movement of fuel rod toward an inner wall 145 (FIG. 3) of a spacer in which it is used. As shown in FIG. 5, deflection limiter 461b extends toward a fuel rod a shorter distance than a corresponding elastic contact 461a. In this way, deflection limiter 461b provides a clearance d that fuel rod 14 may move toward an internal wall 145 of an example embodiment spacer while being subject to only the restorative force of elastic resistive contact 461a. Clearance d may be selected based on a spring constant of elastic contact 461a, a desired minimum distance between example embodiment spacers and fuel rods 14, shocking forces expected to be encountered by a fuel assembly including the same in transport, use, or accident, and/or the plastic deformation threshold of elastic contact 461a. For example, d may be a distance less than a plastic deformation threshold of elastic contact 461a, such that elastic contact 461a will maintain a sufficient spring constant and length, and thus functionality, even following a severe transverse force that causes deflection limiter 461b to come into direct contact with fuel rod 14. In the alternative or additive, for example, d may be a maximum distance between an internal span 142 in an example embodiment spacer and an internal surface of fuel rod 14 in order to preserve desired levels of flow or other thermo-hydraulic properties of a fuel assembly containing the same. As shown in FIG. 4, multiple deflection limiters 461b may be used, one on each axial side of elastic contact 461a. In all these and other ways, deflection limiter 461b may rigidly prevent further relative movement between spacer elements and fuel rods 14 in desired combinations with permitted relative movement between the same that is resisted and reversed by elastic contact 461a. Example embodiment specialized rod contact 146 may further include a rigid stop 462 that provides a rigid, secure contact to a fuel rod. As shown in FIGS. 4 and 5, rigid stop 462 may be similar to deflection limited 461b but unpaired with any elastic member that contacts a same fuel rod. For example, rigid stop 462 may also be a thin, rounded extension of a transverse length to provide rigid support to a fuel rod 14 contacted thereby. In this way, rigid stop 462 may also present a minimal flow blockage and/or debris entrapment profile while contacting a minimal area of fuel rod 14. For example, as shown in FIG. 5, a lateral width of rigid stop 462, elastic contact 461a, and deflection limiter 461b may be approximately 0.1 inches or less. Rigid stop 462 and deflection limiter 461b may extend in relatively opposite transverse directions to provide respective minimum required spacing between fuel rods 14 in adjacent grid openings 141. Rigid stop 462 and deflection limiter 461b may be relatively thicker than elastic contact 461a and supported more directly from inner span 142 in order to have relatively little elasticity and provide desired rigidity and movement limitation. Similarly, rigid stop 462 and/or deflection limiter 461b, along with other parts of example embodiment specialized rod contact 146 may be fabricated from any material compatible with an operating nuclear reactor environment, including zircaloys, aluminum alloys, stainless steels, and/or nickel alloys such as X-750. Specialized rod contacts 146 may be formed from inner spans 142 through a stamping or molding fabrication process that requires no additional parts or connections to inner spans 142 and thus creates a simplified, lighter-weight example embodiment spacer 100. For example, inner spans 142 may be fabricated through a stamping process that provides an amount of material and sets a thickness of inner spans 142 at, for example, approximately 0.010 inch thickness or greater. Elastic contact 462 may be formed thereafter by expanding, stamping, and/or thinning desired portions of inner span 142 and or removing portions of inner span 142, such as in the case of example embodiment specialized rod contact 146 shown in FIGS. 4 and 5 having sections of inner span 142 removed about elastic contact 462. Or, for example, elastic contact 461a may be formed by welding a leaf spring to inner span 142 or otherwise attached to inner span 142. Specialized rod contacts 146 and other elements of example embodiment fuel spacers 100 may be heat treated or age-hardened following fabrication. Deflection limiter 461b and rigid stop 462, like elastic contact 461a, may be formed by stamping or molding inner spans 142 during manufacturing of example embodiment spacers. In this way, the manufacturing process may be simplified, requiring no additional parts or connectors and minimizing weight of example embodiment spacers using specialized rod contacts. Deflection limiters 461b and rigid stops 462 may be stamped with formation of inner span 142 so as to retain an original thickness, with little or no thinning of the material. Alternatively, deflection limiters 461b and rigid stops 462 may be separate rigid pieces welded or otherwise attached to inner spans 142. Although shown in a specific arrangement in FIGS. 4 and 5, and in a layout within an example embodiment spacer 100 in FIG. 3, deflection-limited elastic contact 461 may have elastic and deflection-limiting members arranged in several different configurations, and example embodiment specialized rod contacts 462 can be positioned and oriented in several different manners and include different components. For example, example embodiment spacers may include a ring-type deflection limiter 462 encircling an elastic contact 461, deflection limiters 462 spaced at regular intervals between elastic contacts 461a on inner span 142, etc. Thus, as long as a desired inner wall 145 includes an elastic contact 461a and deflection limiter 461b operable together to prevent plastic deformation of elastic contact 461a, the spacer includes a deflection-limited elastic rod contact 146. Example embodiments and methods thus being described, it will be appreciated by one skilled in the art that example embodiments may be varied and substituted through routine experimentation while still falling within the scope of the following claims. For example, although some example embodiments are described with specialized rod contacts in certain positions and with rigid and elastic features in opposite rectilinear grid openings, it is understood that example embodiment spacers may include any combination and positioning of an elastic member and deflection limiter. Further, it is understood that example embodiments and methods can be used in connection with any type of fuel and reactor where axial spacers are used to align fuel rods. Such variations are not to be regarded as departure from the scope of the following claims.
042382882	claims	1. A drive for driving a control element of a nuclear reactor having a coolant contained therein, said drive comprising: an electromotor having a housing and having a supply voltage applied thereto; said electromotor including a stator accommodated in said housing, insulated from the coolant of said nuclear reactor, and producing an electromagnetic field as said supply voltage is applied to said electromotor, said stator including an active part of given length; said electromotor further including a rotor also accommodated in said housing so that said stator encompasses said rotor with a certain clearance between them, said rotor comprising two lengthwise parts, a first part and a second part, the total length of said two parts being equal to the given length of the active part of said stator; securing means for securing said rotor in said housing; the first part of said rotor comprising a solid cylinder-shaped member secured in said housing by said securing means; a drive screw having a shaft extending inside said solid cylinder-shaped member, said drive screw being coupled to said control element; the second part of said rotor comprising at least three double-arm rocking levers, each having a first arm, a second arm and a pivot axle coupled to and intermediate said first arm and said second arm; said first arm, said second arm and said pivot axle being parallel to said shaft of said drive screw and secured in said housing by said securing means, the first arm of each said lever acting as a pole of said rotor; and rollers, one for each double-arm rocking lever, each said roller having an axle of rotation and mounted on corresponding said second arm of said each double-arm rocking lever so that said axle of rotation is parallel to said shaft of said drive screw, each said roller comprising detachable roller nut means rotatably mounted with axis parallel to said shaft of said drive screw for interacting with said drive screw under the action of said electromagnetic field of said stator.
	description	This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2013-037608 filed Feb. 27, 2013, the entire contents of which are incorporated herein by reference. 1. Field of the Invention The present invention relates to an inspection method and inspection device for inspecting the inner surface of a nozzle provided in a reactor vessel of a nuclear power plant. 2. Description of the Related Art For example, a nuclear power plant having a pressurized water reactor (PWR) uses light water, which serves as primary cooling water, as a reactor coolant and neutron moderator, and makes it into a high-temperature and high-pressure water that does not boil throughout the reactor internal, and causes the high-temperature and high-pressure water to flow into a steam generator, so that steam is generated by heat exchange, and this steam is caused to flow into a turbine generator to generate power. In such nuclear power plant, various kinds of structural objects in the pressurized water reactor are required to be inspected with a regular interval in order to ensure sufficient level of safety and reliability. When each inspection is carried out, and a defect is found, then the required portions related to the defect are repaired. For example, in the pressurized water reactor, the main body of the reactor vessel has an outlet nozzle for providing the primary cooling water to the steam generator and an inlet nozzle for retrieving the primary cooling water of which heat has been exchanged by the steam generator. These nozzles are connected, by means of welding, with the primary cooling water tube which is in communication with the steam generator. Since the nozzles and the primary cooling water tube are made of different materials, safe-end tubes are connected therebetween by means of welding. With a cutting method and a cutting device for an inner surface of a nozzle of a reactor vessel as described in Patent Literature 1 (Japanese Patent No. 4444168), when a welded portion of the nozzle is determined to have defective surface such as crack due to secular change, a cutting device is inserted into the inside of the nozzle, and is positioned at a cutting position, and the cutting device cuts the welded portion. During the cutting process, the cutting position is determined with an eddy-current flaw detection sensor, and the inner surface shape of the nozzle is recorded with a displacement detection sensor, and the inner surface of the nozzle is cut on the basis of such data. Patent Literature 1 indicates that the inner surface of the nozzle of the reactor vessel is repaired, and the device is hoisted by a crane and is inserted into the nozzle, and the cutting position is determined with the eddy-current flaw detection sensor. When the eddy-current flaw detection sensor is calibrated in such repairing method, the device is needed to be calibrated on a work floor of a nuclear reactor building of a nuclear power plant before the device is inserted into the inside of the nozzle, and thereafter, the device is needed to be hoisted by a crane and inserted into the inside of the nozzle, and the cutting position is determined with the eddy-current flaw detection sensor at that position, and thereafter, the device is needed to be hoisted by the crane to bring the device back to the work floor, and the device is needed to be calibrated. In this case, as described above, the reactor vessel forms a loop having the inlet nozzle and the outlet nozzle and connected to one steam generator. Alternatively, in a nuclear power plant having multiple steam generators, the reactor vessel includes multiple inlet nozzles and outlet nozzles so as to form as many loops as the number of steam generators. More specifically, it is necessary to perform the work for the multiple nozzles, which includes hoisting the device with a crane and inserting the device into the inside of the nozzle, and returning the device back to the work floor, and therefore, it takes a lot of time and the work efficiency may be reduced. In an under-water eddy-current test device described in Patent Literature 2 (Japanese Laid-open Patent Publication No. 7-218474), a test coil and a normal coil are attached to an operation head that moves in the upper/lower vertical direction along a fixed fuel rod and that moves in the forward/backward direction and the horizontal direction perpendicular to the upper/lower vertical direction, and a sensitivity calibration test piece is provided in proximity thereto. During the measuring process, the test coil is pushed out to the forward position, and is brought into contact with the fuel rod. On the other hand, when the sensitivity of the test coil is calibrated before the measurement process, the sensitivity calibration test piece is fixed with respect to the horizontal direction movement of the operation head, and the test coil is moved in the horizontal direction, so that it is brought into contact with the sensitivity calibration test piece in a face to face manner. An eddy-current inspection device for fuel cladding described in Patent Literature 3 (Japanese Patent No. 3378500) includes a chuck unit for holding a fuel cladding, a sensor holder unit for pushing an inspection sensor against the center of the fuel cladding so as to be perpendicular thereto, and a zero calibration test piece unit for an inspection sensor, wherein the zero calibration test piece unit includes a rotation mechanism, and during the calibration process, it is provided to be able to move to the forward side of the inspection sensor. In Patent Literature 2 and Patent Literature 3, the calibration test piece is provided on the device, and therefore, the calibration can be performed in the under-water environment where the inspection is performed. However, in Patent Literature 2, during the measurement process, the test coil is pushed forward to be in contact with the fuel rod, and when the sensitivity of the test coil is calibrated, the test coil is moved in the horizontal direction, and is brought into contact with the sensitivity calibration test piece in a face to face manner. For this reason, the position of the test coil may be out of the position where it faces the fuel rod, and when each environment has changed, the calibration may not be performed accurately. In Patent Literature 3, the zero calibration test piece unit has the rotation mechanism and is arranged to be able to move to the forward side of the inspection sensor during the calibration process. Therefore, when the device is arranged at the position where the inspection is performed, the zero calibration test piece unit cannot be arranged at the forward side of the inspection sensor, and therefore, as a result, during the calibration process, the position of the device needs to be changed from the forward side of the fuel cladding, and the environment would be changed, which may make it impossible to accurately perform the calibration. The present invention is to solve the above problems, and it is an object of the present invention to provide an inspection method and an inspection device capable of performing inspection and calibration without moving the device from the processed position. According to a first aspect of the present invention, there is provided a According to a second aspect of the present invention, there is provided an inspection method for inspecting an inner surface of a nozzle provided in a reactor vessel, the inspection method including: inserting an inspection device including an inspection unit and a calibration test unit into inside of the nozzle; subsequently moving the calibration test unit forward or backward with regard to a track where the inspection unit makes push-out movement to the inner surface of the nozzle at a reference position where the inspection device is inserted into the inside of the nozzle, and calibrating the inspection unit; and subsequently causing the inspection unit to inspect the inner surface of the nozzle. According to a third aspect of the present invention, there is provided an inspection device for inspecting a body which is to be inspected, the body being provided in a nuclear power plant, the inspection device including: a device frame installed at the reference position for inspecting the body; an inspection unit provided on the device frame, for inspecting the inspection target portion of the body; an inspection unit push-out moving mechanism for pushing out and moving the inspection unit to the inspection target portion while the device frame is installed at the reference position; a calibration test unit provided on the device frame, for calibrating the inspection unit; and a calibration test unit forward/backward moving mechanism for moving the calibration test unit forward or backward with regard to a track where the inspection unit makes push-out movement in such a state that the inspection unit is installed at the reference position. According to a fourth aspect of the present invention, there is provided an inspection device for inspecting an inner surface of a nozzle provided in a reactor vessel, the inspection device including: a device frame inserted into inside of the nozzle; an inspection unit provided on the device frame, for inspecting the inner surface of the nozzle; an inspection unit push-out moving mechanism for pushing out and moving the inspection unit to the inner surface of the nozzle while the device frame is installed in the inside of the nozzle; a rotation moving mechanism for rotating and moving the inspection unit about a predetermined central axis along a peripheral direction of the nozzle while the device frame is installed in the inside of the nozzle; a calibration test unit arranged on the device frame for calibrating the inspection unit; and a calibration test unit forward/backward moving mechanism for moving the calibration test unit forward or backward in the direction along the central axis with regard to a track where the inspection unit makes push-out movement. Hereinafter, an embodiment according to the present invention will be explained in detail with reference to drawings. It should be noted that this invention is not limited by the embodiment. Constituent elements in the embodiment include those that can be easily replaced by a person skilled in the art or those that are substantially the same. FIG. 1 is a schematic configuration diagram illustrating an example of a nuclear power plant. The nuclear power plant as illustrated in FIG. 1 includes a pressurized water reactor (PWR). This nuclear power plant is configured such that a reactor vessel 101 for a pressurized water reactor, a pressurizing device 102, a steam generator 103, and a primary cooling water pump 104 in a reactor vessel 100 are connected in order by a primary cooling water tube 105, so that a circulation path for primary cooling water is made. The reactor vessel 101 has a fuel assembly 120 contained therein in a sealed manner, and is constituted by a main body of a reactor vessel 101a and a reactor vessel lid 101b attached to the upper side thereof, so that the fuel assembly 120 can be inserted thereinto or removed therefrom. The main body of the reactor vessel 101a has an inlet nozzle 101c and an outlet nozzle 101d, which are provided at the upper side thereof, for feeding and discharging the light water serving as primary cooling water. The outlet nozzle 101d is connected to the primary cooling water tube 105 so as to be in communication with an inlet water chamber 103a of a steam generator 103. The inlet nozzle 101c is connected to the primary cooling water tube 105 so as to be in communication with an outlet water chamber 103b of the steam generator 103. The steam generator 103 is provided in such a manner that, at the lower portion formed in a hemisphere shape, the inlet water chamber 103a and the outlet water chamber 103b are separated by a separation plate 103c. The inlet water chamber 103a and the outlet water chamber 103b are separated from the upper side of the steam generator 103 by a tube plate 103d provided at a ceiling portion thereof. At the upper side of the steam generator 103, a heat transmission tube 103e in an inverse U shape is provided. The end portions of the heat transmission tube 103e are supported by the tube plate 103d so as to connect the inlet water chamber 103a and the outlet water chamber 103b. The inlet water chamber 103a is connected to the primary cooling water tube 105 at the entrance side, and the outlet water chamber 103b is connected to the primary cooling water tube 105 at the outlet side. The steam generator 103 is configured such that the upper end of the upper side of the steam generator 103 separated by the tube plate 103d is connected to a secondary cooling water tube 106a at the outlet side, and the side portion of the upper side of the steam generator 103 is connected to a secondary cooling water tube 106b at the entrance side. In the nuclear power plant, the steam generator 103 is connected, outside of the reactor vessel 100, to a steam turbine 107 via secondary cooling water tubes 106a, 106b, so that the circulation path for the secondary cooling water is made. The steam turbine 107 includes a high pressure turbine 108 and a low pressure turbine 109, and is connected to an electric power generator 110. The high pressure turbine 108 and the low pressure turbine 109 are connected to a moisture separator reheater 111 which branches off from the secondary cooling water tube 106a. The low pressure turbine 109 is connected to a condenser 112. The condenser 112 is connected to a secondary cooling water tube 106b. As described above, the secondary cooling water tube 106b is connected to the steam generator 103, and the secondary cooling water tube 106b extends from the condenser 112 to the steam generator 103, and the secondary cooling water tube 106b includes a condenser pump 113, a low pressure feed heater 114, a deaerator 115, a main feed pump 116, and a high pressure feed heater 117. Therefore, in the nuclear power plant, the primary cooling water is heated in the reactor vessel 101 to be of a high temperature and high pressure, and while it is pressurized by the pressurizing device 102 so that the pressure is maintained at a constant level, it is provided via the primary cooling water tube 105 to the steam generator 103. In the steam generator 103, heat is exchanged between the primary cooling water and the secondary cooling water, so that the secondary cooling water is evaporated to become steam. The primary cooling water having been cooled after the heat exchange is recovered by the primary cooling water pump 104 via the primary cooling water tube 105, and is returned back to the reactor vessel 101. On the other hand, the secondary cooling water which is made into steam as a result of the heat exchange is provided to the steam turbine 107. With regard to the steam turbine 107, the moisture separator reheater 111 removes moisture from the exhaust discharged from the high pressure turbine 108, and further heats it to make it into superheated state, and thereafter, feeds it into the low pressure turbine 109. The steam turbine 107 is driven by the steam of the secondary cooling water, and the force of the steam turbine 107 is transmitted to the electric power generator 110, so that the electric power is generated. The steam used for driving the turbine is discharged to the condenser 112. The condenser 112 exchanges heat between cooling water (for example, seawater) retrieved by a pump 112b via a water intake tube 112a and the steam discharged from the low pressure turbine 109, and the steam is condensed, so that it becomes back to saturated liquid of a low pressure. The cooling water used for the heat exchange is discharged from a discharge tube 112c. The saturated liquid which has been condensed becomes the secondary cooling water, and is pumped to the outside of the condenser 112 by the condenser pump 113 via the secondary cooling water tube 106b. Further, the secondary cooling water passing the secondary cooling water tube 106b is heated by the low pressure feed heater 114 with, for example, the low pressure steam bled from the low pressure turbine 109, and after the deaerator 115 removes impurities such as dissolved oxygen and non-condensable gas (ammonia gas), the secondary cooling water is fed by the main feed pump 116, and the high pressure feed heater 117 heats the secondary cooling water with, for example, high pressure steam bled from the high pressure turbine 108, and thereafter, high pressure steam is returned back to the steam generator 103. In the pressurized water reactor of the nuclear power plant configured as described above, the reactor vessel 101 is configured such that the inlet nozzle 101c and the outlet nozzle 101d is connected to the primary cooling water tube 105 as described above. Since the inlet nozzle 101c and the outlet nozzle 101d and the primary cooling water tube 105 are made of different materials, a safe-end tube 121 is connected therebetween by welding (groove welded portion 122) (see FIG. 3 and FIG. 4). For this reason, tensile stress may remain in the groove welded portion 122 and the peripheral portion thereof, and it is necessary to alleviate the stress. Therefore, a water jet peening device serving as a reactor repairing device alleviates the tensile residual stress on the inner surfaces of the nozzles 101c, 101d which are the groove welded portion 122 and the peripheral portion thereof, i.e., the target, thus making the tensile residual stress into compressive residual stress and preventing stress corrosion crack. This water jet peening device emits high pressure water including cavitation bubbles onto the surface of the metal member in the water, and alleviates the tensile residual stress of the surface of the metal member, thus making the tensile residual stress into the compressive residual stress. When the water jet peening device alleviates the tensile residual stress on the inner surfaces of the nozzles 101c, 101d which are the groove welded portion 122 and the peripheral portion thereof and making the tensile residual stress into the compressive residual stress, work is performed by inserting this water jet peening device into the inside of the nozzles 101c, 101d. When the water jet peening is performed, the position to which the water jet is emitted is inspected in order to identify the position of the surface which is to be processed. In the present embodiment, the inspection device and the water jet peening device are integrally provided. It should be noted that the inspection device may be provided with any repairing device other than the water jet peening device. FIG. 2 is a schematic diagram illustrating installation state of the inspection device according to the present embodiment. FIG. 3 is a sectional side view illustrating the inspection device according to the present embodiment. FIG. 4 is a sectional side view illustrating another usage form of the inspection device according to the present embodiment. FIG. 5 is a top view illustrating the inspection device according to the present embodiment. FIG. 6 is a sectional view taken along A-A of FIG. 3 and FIG. 5. FIG. 7 is a sectional view taken along B-B of FIG. 4. FIG. 8 is a sectional view taken along C-C of FIG. 3. FIG. 9 is a view taken along D-D of FIG. 3. FIG. 10 is a view taken along E-E of FIG. 3. FIGS. 11 to 15 are schematic views illustrating inspection procedure with the inspection device according to the present embodiment. As illustrated in FIG. 2, an inspection device (water jet peening device) 1 is installed upon being inserted into the inside of the inlet nozzle 101c or the outlet nozzle 101d of the reactor vessel 101 (the main body of the reactor vessel 101a) which is the body which is to be inspected. In the present embodiment, the inlet nozzle 101c and the outlet nozzle 101d are examples of bodies which are to be inspected by the inspection device, but the bodies which are to be inspected by the inspection device are not limited thereto. In the nuclear power plant, a nuclear reactor building (not shown) is provided with a work floor 151, and a cavity 152 is provided below the work floor 151, and cooling water is accumulated in the cavity 152. The cavity 152 has the reactor vessel 101 provided therein, and the reactor vessel 101 is suspended and supported. In the nuclear reactor building, a pair of guide rails 155 which are parallel to both sides of the cavity 152 are installed, and a mobile crane 156 is supported by the guide rails 155 in a movable manner. The mobile crane 156 is provided with an electric hoist 157 that can move in one direction in the horizontal direction (the horizontal direction in FIG. 2) and that can move in the other direction crossing (perpendicular to) the one direction in the horizontal direction (direction perpendicular to FIG. 2). This electric hoist 157 has a hook 158 that can ascend and descend along the vertical direction. An installation pole 159 is suspended via this hook 158. The installation pole 159 is a long-length member that has a predetermined length, and the lower end portion of the installation pole 159 can be connected to the inspection device 1. This installation pole 159 is constituted by multiple divided poles, and both of them can be fastened with multiple swing bolts by bringing the flange units of the upper and lower ends thereof into contact with each other. As illustrated in FIGS. 3 to 5, the nozzles 101c, 101d have an opening portion 101f in a wall surface 101e which is inside of the reactor vessel 101, and is arranged to extend in the horizontal direction (or including some component of the horizontal direction). The inspection device 1 is inserted from the opening portion 101f into the inside of the nozzles 101c, 101d and installed there. In the present embodiment, the installation pole 159 is used as an installation jig used for installing the inspection device 1, but the configuration is not limited thereto. For example, wires, cables, ropes, and the like may be used. This inspection device 1 has a device frame 2 coupled with the installation pole 159. The device frame 2 has such an external shape that can be inserted into the inside of the nozzles 101c, 101d, and is formed to have a cylindrical shape extending along the insertion direction T. The device frame 2 mainly includes external abutment members 3, an internal abutment member 4, a suction unit 5, an abutment detection unit 6, an image-capturing unit 7, an injection nozzle 8, a nozzle push-out moving mechanism 9, a rotation moving mechanism 15, a slide moving mechanism 18, an inspection unit 20, an inspection unit push-out moving mechanism 21, a calibration test unit 22, and a calibration test unit forward/backward moving mechanism 23. As illustrated in FIGS. 3 to 5, the external abutment member 3 comes into contact with the wall surface 101e when the device frame 2 is inserted into a predetermined position in the inside of the nozzles 101c, 101d. As illustrated in FIGS. 3 to 6, the external abutment member 3 is attached to a support member 13 fixed in an extending manner to the outside of the device frame 2, and the external abutment member 3 is attached so that the front end of the external abutment member 3 faces the front end side at which the device frame 2 is inserted (in the insertion direction T) in a protruding manner. In the present embodiment, two external abutment members 3 are provided at the upper side of the support member 13 in such a manner that each one of the two external abutment members 3 is arranged at the right and the left, and four external abutment members 3 are provided at the lower side of the support member 13 in such a manner that two external abutment members 3 are arranged at each of the right and the left, which means that there are totally six external abutment members 3 provided. As illustrated in FIGS. 3 and 5, by providing spacers 3a or not providing the spacers 3a, the upper two external abutment members 3 and the slightly upper two of the lower external abutment members 3 are configured to be able to change the position of the front end to the front end side at which the device frame 2 is inserted. As illustrated in FIGS. 3 to 5, the slightly lower two of the lower external abutment members 3 are configured to be movable so that the position of the front end to the front end side at which the device frame 2 is inserted can be changed by an actuator (air pressure cylinder) 3b. This is because the shapes of the opening portions 101f of the inlet nozzle 101c and the outlet nozzle 101d are different, and the outlet nozzle 101d is formed with a protrusion 101g, and the slightly lower two of the lower external abutment members 3 are thus configured to be able to cope with the presence of the protrusion 101g and the absence of the protrusion 101g. As described above, the external abutment members 3 are provided, thus being able to determine the position in the state where the device frame 2 is inserted into the predetermined position inside of the nozzles 101c, 101d. As illustrated in FIGS. 3 to 5, 7, and 8, the internal abutment member 4 is a portion where the device frame 2 is inserted into the inside of the nozzles 101c, 101d. The internal abutment members 4 are provided at multiple positions around the device frame 2 (central axis S), and the internal abutment members 4 are provided to protrude so that the front end faces the outside in the radial direction. As illustrated in FIG. 5, in the present embodiment, four internal abutment members 4 are provided at the right and the left of the upper side with respect to the center of the device frame 2 in such a manner that two internal abutment members 4 are each arranged at the front and the back in the insertion direction T of the device frame 2, and two internal abutment members 4 are provided in such a manner that each one of the two internal abutment members 4 is arranged at either side of the device frame 2 at a height close to the central position, and as illustrated in FIGS. 4 and 7, one internal abutment member 4 is provided at the lower side of the central position of the device frame 2, which means that there are totally seven internal abutment members 4 provided. These internal abutment members 4 are configured to be able to move forward and backward in the radius direction about the device frame 2 by an actuator (air pressure cylinder) 4a. The internal abutment member 4 moved forward by the actuator 4a comes into contact with the inner surfaces of the nozzles 101c, 101d. As illustrated in FIGS. 4 and 7, the internal abutment member 4 provided at the lower side of the central position of the device frame 2 is located below the two internal abutment members 4 arranged at the front in the insertion direction T of the device frame 2 which are provided at each of the right and the left at the upper side, and when inserted into the inlet nozzle 101c with the five portions including the two internal abutment members 4 arranged at both sides at the height close to the central position of the device frame 2, the internal abutment member 4 provided at the lower side of the central position of the device frame 2 is used so that the central position of the device frame 2 is aligned with the central position of the inlet nozzle 101c. On the other hand, as illustrated in FIGS. 3 and 8, at the back side of the internal abutment member 4 at the lower side of the central position of the device frame 2, a tire 4b rotating in the insertion direction T is provided at the internal abutment member 4 that does not move forward or backward. This tire 4b located below the two internal abutment members 4 at the rear in the insertion direction T of the device frame 2 which are provided at the right and the left of the upper side, and when inserted into the outlet nozzle 101d with the five portions including the two internal abutment members 4 arranged at both sides at the height close to the central position of the device frame 2, this tire 4b is used so that the central position of the device frame 2 is aligned with the central position of the outlet nozzle 101d. This is because the shape of the hole of the inlet nozzle 101c and the shape of the hole of the outlet nozzle 101d are different, and an inclination is formed on the inner surface of the inlet nozzle 101c so that the diameter becomes smaller in the inside, but the outlet nozzle 101d does not have this inclination, and the central position of the device frame 2 is aligned with the central position of the nozzles 101c, 101d in accordance with the presence of this inclination or the absence of this inclination. As described above, since the internal abutment members 4 are provided, the central position of the device frame 2 can be aligned with the central position of the nozzles 101c, 101d. As illustrated in FIG. 5, the suction unit 5 is provided so that the suction unit 5 can be adhered to the wall surface 101e when the device frame 2 is inserted into the predetermined position inside of the nozzles 101c, 101d. As illustrated in FIGS. 5 and 6, the suction unit 5 is attached to the support member 13 in such a manner that the suction surface faces the front end side to which the device frame 2 is inserted (insertion direction T). In the present embodiment, two suction units 5 are provided in such a manner that each of the two suction units 5 is arranged at the right and the left of the upper side of the support member 13, and two suction units 5 are provided in such a manner that each of the two suction units 5 is arranged at the right and the left of the lower side of the support member 13, which means that there are totally four suction units 5 provided. As illustrated in FIG. 5, the suction unit 5 is provided to be able to move along the insertion direction T by an actuator (air pressure cylinder) 5a. As illustrated in FIG. 5, the suction unit 5 is arranged to be able to swing in the right and left direction with respect to a rod 5b of the actuator 5a so as to cope with the inclination of the wall surface 101e. As described above, since the suction unit 5 is provided, the device frame 2 can be maintained in such a state that the device frame 2 inserted into the inside of the nozzles 101c, 101d is positioned by the external abutment members 3, and the device frame 2 can be maintained in such a state that the central position of the device frame 2 is aligned with the central position of the nozzles 101c, 101d by the internal abutment members 4. As illustrated in FIG. 5, when the external abutment member 3 comes into contact with the wall surface 101e, the abutment detection unit 6 detects this. As illustrated in FIGS. 5 and 6, the abutment detection unit 6 is arranged at the side portion of the upper external abutment member 3 with respect to the support member 13, and is attached in such a manner that the front end of a contact shoe 6a faces the front end side to which the device frame 2 is inserted (insertion direction T). The contact shoe 6a is provided to be able to move along the insertion direction T with respect to a casing 6b, and is urged by a spring (not shown) so as to protrude in the insertion direction T at all times. The casing 6b has a proximity sensor (not shown) provided therein, and when the contact shoe 6a moves in a direction opposite to the insertion direction T, the proximity sensor detects the contact shoe 6a thus moved. The abutment detection unit 6 is configured such that, when the external abutment member 3 comes into contact with the wall surface 101e, the contact shoe 6a comes into abutment with the wall surface 10e at the same time and moves in the direction opposite to the insertion direction T, and this is detected by the proximity sensor, and the abutment detection unit 6 detects this as the abutment of the external abutment member 3 onto the wall surface 101e. As described above, since the abutment detection unit 6 is provided, the state of abutment of the external abutment member 3 onto the wall surface 101e can be recognized. More specifically, the fact that the device frame 2 inserted into the inside of the nozzles 101c, 101d is positioned by the external abutment members 3 can be recognized. As illustrated in FIGS. 3, 4 and 6, totally four image-capturing units 7 are provided on the support member 13 in such a manner that each one of the four image-capturing units 7 is arranged at the upper side, the lower side, the left, and the right of the device frame 2. The image-capturing unit 7 includes a camera 7a and an illumination 7b, and each is arranged to face the front end side to which the device frame 2 is inserted (insertion direction T). This image-capturing unit 7 captures, from the rear end side from which the device frame is inserted, an image of the front end side to which the device frame 2 is inserted into the nozzles 101c, 101d. As described above, since the image-capturing unit 7 is provided, the state of the device frame 2 inserted into the nozzles 101c, 101d can be monitored. Therefore, when the device frame 2 is inserted into the nozzles 101c, 101d, such work is done while a video taken by the image-capturing unit 7 is watched on a monitor (not shown) provided on the work floor 151, and when a detection signal of the abutment detection unit 6 is input, it is recognized that the external abutment member 3 comes into contact with the wall surface 101e. Thereafter, the internal abutment members 4 are brought into contact with the inner surfaces of the nozzles 101c, 101d, and the suction unit 5 is adhered to the wall surface 101e of the nozzles 101c, 101d. The injection nozzle 8 emits water jet onto the inner surfaces of the nozzles 101c, 101d. As illustrated in FIGS. 3, 4 and 9, the injection nozzle 8 is arranged on the support unit 14 provided at the front end side to which the device frame 2 is inserted, so that an injection port 8a emitting the water jet faces the inner surfaces of the nozzles 101c, 101d. As illustrated in FIGS. 3 and 4, the support unit 14 is supported on the device frame 2 so as to be able to rotate about the central axis S (the central axis of the nozzles 101c, 101d) of the device frame 2. More specifically, the support unit 14 is supported by the rotation moving mechanism 15. The rotation moving mechanism 15 has a rotation shaft unit 15a. This rotation shaft unit 15a is attached to the support unit 14, and is supported by the device frame 2 so as to be able to rotate about the central axis S. The rotation shaft unit 15a is formed in a cylindrical shape extending along the central axis S, and a driven gear wheel 15b is attached to the external periphery thereof. The driven gear wheel 15b meshes with a driving gear wheel 15d provided on the output shaft of a rotation motor 15c fixed to the device frame 2. The rotation moving mechanism 15 rotates the rotation shaft unit 15a when the rotation of the driving gear wheel 15d is transmitted to the driven gear wheel 15b thanks to the rotation motor 15c driving. Therefore, the support unit 14 supported by the rotation shaft unit 15a rotates with the injection nozzle 8. As a result, the injection nozzle 8 rotates and moves along a predetermined movement track about the central axis S. As described above, the injection nozzle 8 is provided the support unit 14 so that the injection port 8a emitting water jet faces the inner surfaces of the nozzles 101c, 101d. Therefore, the injection nozzle 8 rotated and moved by the rotation moving mechanism 15 rotates and moves along the predetermined movement track along the peripheral direction of the nozzles 101c, 101d while the injection port 8a faces the inner surfaces of the nozzles 101c, 101d. More specifically, when the rotation angle in the vertically downward direction is zero degrees, the direction of the injection port 8a of the injection nozzle 8 passes a rotation angle of 180 degrees in the vertically upward direction, and rotates 360 degrees along the peripheral direction of the nozzles 101c, 101d. The movement position of the injection port 8a and the inspection unit 20 explained later (flaw detection sensor 20A and image-capturing sensor 20B) in this movement track are detected by a nozzle position detection unit (not shown) provided in the rotation moving mechanism 15. In the present embodiment, the nozzle position detection unit is such that the rotation motor 15c is configured as the servo motor, and therefore, the movement position of the injection port 8a and the inspection unit 20 (the flaw detection sensor 20A and the image-capturing sensor 20B) along the movement track is detected. As illustrated in FIGS. 3 and 4, in the rotation moving mechanism 15 explained above, a high pressure water providing tube 16 for providing high pressure water to the injection nozzle 8 is arranged inside of the rotation shaft unit 15a. This high pressure water providing tube 16 is provided in the rotation shaft unit 15a to extend along the central axis S from the rear end side from which the device frame 2 is inserted, and a swivel bearing 17 is interposed at the extension end portion thereof. The high pressure water providing tube 16 extends from the swivel bearing 17 to the upper side, and as illustrated in FIG. 2, the high pressure water providing tube 16 is connected to a high pressure water pump 160 for feeding the high pressure water installed on the work floor 151. More specifically, the high pressure water fed by the high pressure water pump 160 passes the high pressure water providing tube 16, and is provided to the injection nozzle 8, and the high pressure water is emitted as water jet from the injection port 8a to the inner surfaces of the nozzles 101c, 101d. Then, the injection nozzle 8 is rotated about the central axis S by the rotation moving mechanism 15, so that the water jet is emitted onto the inner surface along the peripheral direction of the nozzles 101c, 101d. When the rotation shaft unit 15a is rotated by the rotation moving mechanism 15, the high pressure water providing tube 16 provided therein also rotates therewith, but since the swivel bearing 17 is interposed therein, this can prevent the high pressure water providing tube 16 from being kinked. As illustrated in FIGS. 3 and 4, the support unit 14 is supported on the device frame 2 so as to be able to slide and move along the central axis S of the device frame 2 (the central axis of the nozzles 101c, 101d). More specifically, the support unit 14 is supported by the slide moving mechanism 18 provided inside of the device frame 2. As illustrated in FIGS. 3 to 5, 7, and 8, the slide moving mechanism 18 includes a slide rail 18a, a slide base 18b, a slider 18c, a ball screw 18d, a nut unit 18e, and a slide motor 18f. The slide rails 18a extend in parallel to the central axis S of the device frame 2, and the pair of slide rails 18a are provided at the right and the left. The slide base 18b is supported by the slide rail 18a in such a manner that the slide base 18b can move in the direction in which the slide rail 18a extends. The slider 18c is attached via the slide rail 18a, and is fixed to the slide base 18b. The ball screw 18d is provided to extend along the central axis S of the device frame 2 in parallel to the slide rail 18a, and is supported on the device frame 2 to be able to rotate about the center of an axis parallel to the central axis S. The nut unit 18e is screwed to this ball screw 18d. The slide motor 18f is coupled with the ball screw 18d, and the ball screw 18d is rotated. The slide moving mechanism 18 drives the slide motor 18f to rotate the ball screw 18d, whereby the nut unit 18e as well as the slider 18c move in the direction in which the ball screw 18d extends (the direction parallel to the central axis S) with the slide base 18b. This slide base 18b is attached to the rotation shaft unit 15a of the rotation moving mechanism 15 described above supporting the support unit 14. More specifically, the rotation shaft unit 15a moves in the direction parallel to the central axis S together with the slide base 18b and with the support unit 14 supporting the injection nozzle 8. As a result, the injection nozzle 8 slides and moves along the central axis S. By the way, as described above, the rotation shaft unit 15a rotates about the central axis S, and is attached in such a manner as to allow rotation with respect to the slide base 18b. The rotation shaft unit 15a is provided in such a manner that the driven gear wheel 15b can move along the central axis S. The driven gear wheel 15b is restricted from moving along the central axis S while meshing with the driving gear wheel 15d is maintained. For this reason, the transmission of driving for rotating the rotation shaft unit 15a is maintained at all time when the slide moving mechanism 18 slides and moves the rotation shaft unit 15a. More specifically, the rotation shaft unit 15a is provided to be able to rotate itself and slide and move along the central axis S. The nozzle push-out moving mechanism 9 is to push out and move the injection nozzle 8 along the direction in which the water jet is emitted from the injection port 8a. As illustrated in FIG. 9, the nozzle push-out moving mechanism 9 is provided on the support unit 14, and includes slide rails 9a, sliders 9b, a slide base 9c, and actuators 9d. The pair of slide rails 9a are provided to extend in the direction perpendicular to the central axis S. The slider 9b is supported so as to be able to move in the direction in which the slide rails 9a extend. The slide base 9c is supported by the sliders 9b, and is provided to be able to move in the direction in which the slide rails 9a extend. The injection nozzle 8 is fixed to the slide base 9c in such a manner that the injection port 8a is in the direction in which the slide rails 9a extend. The actuators 9d are provided on the support unit 14 so that the actuators 9d are arranged on the slide rails 9a, respectively, and the actuators 9d are coupled with the slide base 9c. The actuators 9d are to move the slide base 9c in the direction in which the slide rails 9a extend, and in the present embodiment, the actuator 9d is made of an air pressure cylinder. However, the actuator 9d is not limited to the air pressure cylinder. Anything may be employed as long as it moves the slide base 9c in the direction in which the slide rails 9a extend. The nozzle push-out moving mechanism 9 drives the actuators 9d to move the slide base 9c with the injection nozzle 8 in the direction perpendicular to the central axis S. More specifically, the nozzle push-out moving mechanism 9 pushes out and moves the injection port 8a of the injection nozzle 8 so as to bring the injection port 8a of the injection nozzle 8 close to the inner surfaces of the nozzles 101c, 101d or move the injection port 8a of the injection nozzle 8 away from the inner surfaces of the nozzles 101c, 101d in such a state that the injection port 8a of the injection nozzle 8 faces the inner surfaces of the nozzles 101c, 101d. As a result, the emission distance of the water jet which is the distance from the injection port 8a to the inner surfaces of the nozzles 101c, 101d is configured. With regard to this emission distance of the water jet, 130 mm±10 mm is a predetermined distance. Therefore, while the device frame 2 is inserted into the inside of the nozzles 101c, 101d by the external abutment members 3, the internal abutment members 4, and the suction units 5, the slide moving mechanism 18 moves the injection nozzle 8 forward or backward so that the injection port 8a is at the position where it faces a predetermined inner surfaces of the nozzles 101c, 101d where the water jet peening is performed. Thereafter, the nozzle push-out moving mechanism 9 pushes out and moves the injection nozzle 8 so as to attain the emission distance. Thereafter, while the water jet is emitted from the injection port 8a of the injection nozzle 8, the rotation moving mechanism 15 rotates and moves the injection nozzle 8. Accordingly, the water jet peening is performed on the predetermined inner surfaces of the nozzles 101c, 101d. In the present embodiment, the inspection unit 20 inspects the predetermined inner surface (groove welded portion 122) of the nozzles 101c, 101d where the water jet peening is performed. As illustrated in FIGS. 3 to 5, the inspection unit 20 is provided on the support unit 14. Therefore, the inspection unit 20 is rotated and moved about the central axis S by the rotation moving mechanism 15 explained above, and is slid and moved about the central axis S by the slide moving mechanism 18. This inspection unit 20 includes flaw detection sensors 20A and an image-capturing sensor 20B. The flaw detection sensor 20A comes into contact with the inner surfaces of the nozzles 101c, 101d and performs flaw detection inspection, and in the present embodiment, the flaw detection sensor 20A is an eddy-current flaw detection sensor, and the flaw detection sensor 20A is rotated and moved about the central axis S by the rotation moving mechanism 15, so that the flaw detection sensor 20A moves along the peripheral direction with respect to the inner surfaces of the nozzles 101c, 101d to perform flaw detection. In the present embodiment, multiple flaw detection sensors 20A (two flaw detection sensors 20A) are provided in a row so as to be along the peripheral direction of the inner surfaces of the nozzles 101c, 101d which are to be inspected in the present embodiment. The image-capturing sensor 20B captures images of the inner surfaces of the nozzles 101c, 101d so as to visually inspect them, and the image-capturing sensor 20B is rotated and moved about the central axis S by the rotation moving mechanism 15, so that the image-capturing sensor 20B captures images upon moving along the peripheral direction with respect to the inner surfaces of the nozzles 101c, 101d. Although not clearly shown in the drawings, the inspection unit 20 has an illumination for illuminating the portion where images are taken by the image-capturing sensor 20B. The inspection unit push-out moving mechanism 21 pushes out and moves the inspection unit 20 to the inner surfaces of the nozzles 101c, 101d. As illustrated in FIG. 9, the inspection unit push-out moving mechanism 21 is provided on the support unit 14, and includes slide rails 21a, a slider 21b, a slide base 21c, and an actuator 21d. The pair of slide rails 21a are provided to extend the direction perpendicular to the central axis S, and are formed by extending the slide rails 9a of the nozzle push-out moving mechanism 9 explained above. The slider 21b is supported to be able to move in the direction in which the slide rails 21a extend. The slide base 21c is supported by the slider 21b, and is provided to be able to move in the direction in which the slide rails 21a extend. The flaw detection sensor 20A (see FIG. 10) and the image-capturing sensor 20B which are the inspection unit 20 are attached to the slide base 21c. The actuator 21d is arranged on the support unit 14 so as to be arranged at a side portion of one of the slide rails 21a, and is coupled with the slide base 21c. The actuator 21d is to move the slide base 21c in the direction in which the slide rails 21a extend, and in the present embodiment, the actuator 21d is made of an air pressure cylinder. However, the actuator 21d is not limited to the air pressure cylinder. Anything may be employed as long as it moves the slide base 21c in the direction in which the slide rails 21a extend. The inspection unit push-out moving mechanism 21 drives the actuator 21d to move the slide base 21c as well as the inspection unit 20 (the flaw detection sensor 20A and the image-capturing sensor 20B) in the direction perpendicular to the central axis S. The direction of this push-out movement is a direction in which the inspection unit 20 performs the inspection. In a case of the flaw detection sensor 20A, the direction of this push-out movement is a direction in which the surface in contact with the inner surfaces of the nozzles 101c, 101d faces. In a case of the image-capturing sensor 20B, the direction of this push-out movement is a direction in which images of the inner surfaces of the nozzles 101c, 101d are taken. More specifically, the inspection unit push-out moving mechanism 21 pushes out and moves the inspection unit 20 so that the inspection unit 20 comes closer to the inner surfaces of the nozzles 101c, 101d or the inspection unit 20 moves away from the inner surfaces of the nozzles 101c, 101d. As illustrated in FIGS. 9 and 10, the inspection unit push-out moving mechanism 21 includes a flaw detection sensor push-out moving mechanism 21A for pushing out and moves the flaw detection sensors 20A alone and an image-capturing sensor push-out moving mechanism 21B for pushing out and moves the image-capturing sensor 20B alone. As illustrated in FIG. 10, the flaw detection sensor push-out moving mechanism 21A is provided on the slide base 21c, and includes a fixed base 21Aa, slide rails 21Ab, sliders 21Ac, actuators 21Ad, and a slide base 21Ae. The fixed base 21Aa is fixed to the slide base 21c. The slide rails 21Ab are in parallel to the slide rails 9a, and the pair of slide rails 21Ab are provided to extend in the direction perpendicular to the central axis S (see FIG. 3 to FIG. 5). The sliders 21Ac are supported to be able to move in the direction in which the slide rails 21Ab extend. The actuator 21Ad is fixed to the fixed base 21Aa, and is coupled with the slide base 21Ae. The actuator 21Ad is to move the slide base 21Ae in the direction in which the slide rails 21Ab extend, and in the present embodiment, the actuator 21Ad is made of an air pressure cylinder. However, the actuator 21Ad is not limited to the air pressure cylinder. Anything may be employed as long as it moves the slide base 21Ae in the direction in which the slide rails 21Ab extend. The slide base 21Ae supports the flaw detection sensors 20A. Multiple flaw detection sensors 20A (two flaw detection sensors 20A) are provided in a row along the peripheral direction of the inner surfaces of the nozzles 101c, 101d which is the inspection target portion as described above, and the flaw detection sensors 20A are supported on a sensor first support units 20Aa, respectively, so that each of the flaw detection sensors 20A incline in the peripheral direction. Each of the sensor first support units 20Aa is integrally attached to a sensor base 20Ab. The sensor base 20Ab is supported so that both ends of the sensor base 20Ab is supported by a sensor second support units 20Ac so that the sensor base 20Ab inclines about the axial center perpendicular to the slide rail 21Ab and in the direction in which the central axis S extends. The sensor second support units 20Ac are attached to the slide base 21Ae. The sensor second support units 20Ac are supported on the slide base 21Ae with elasticity given by a spring (not shown) and so as to be able to move in the direction in which the slide rails 21Ab extend. More specifically, the flaw detection sensors 20A freely incline in the direction in which the central axis S extends and in the peripheral direction thanks to the sensor first support unit 20Aa and the sensor second support unit 20Ac, and are supported in such a manner as to be urged by the spring to be in contact with the inner surfaces of the nozzles 101c, 101d by following the shapes of the inner surfaces of the nozzles 101c, 101d. The flaw detection sensor push-out moving mechanism 21A drives the actuator 21Ad to push out and move the slide base 21Ae as well as the flaw detection sensors 20A in the direction perpendicular to the central axis S. As illustrated in FIG. 9, the image-capturing sensor push-out moving mechanism 21B is provided on the slide base 21c, and includes an actuator 21Ba and a slide base 21Bb. The actuator 21Ba is fixed to the slide base 21c, and is coupled with the slide base 21Bb. The actuator 21Ba is to move the slide base 21Bb in the direction in which the slide rails 21a extend, and in the present embodiment, the actuator 21Ba is made of an air pressure cylinder. However, the actuator 21Ba is not limited to the air pressure cylinder. Anything may be employed as long as it moves the slide base 21Bb in the direction in which the slide rails 21a extend. The slide base 21Bb supports the image-capturing sensor 20B. The image-capturing sensor push-out moving mechanism 21B drives the actuator 21Ba to push out and move the slide base 21Bb as well as the image-capturing sensor 20B in the direction perpendicular to the central axis S. The calibration test unit 22 is to calibrate and examine the inspection unit 20 (the flaw detection sensor 20A and the image-capturing sensor 20B). As illustrated in FIGS. 3 to 5, the calibration test unit 22 is provided on the calibration test unit forward/backward moving mechanism 23. This calibration test unit 22 includes the calibration test piece for the flaw detection sensor 22A calibrating each of the flaw detection sensors 20A and the calibration test piece for the image-capturing sensor 22B calibrating the image-capturing sensor 20B. The calibration test unit forward/backward moving mechanism 23 moves the calibration test unit 22 to the forward or the backward in the direction along the central axis S. As illustrated in FIGS. 3 to 5, the calibration test unit forward/backward moving mechanism 23 is provided on the device frame 2. Therefore, the calibration test unit forward/backward moving mechanism 23 and the calibration test unit 22 do not affect rotation movement and slide movement of the rotation moving mechanism 15 and the slide moving mechanism 18 explained above. The calibration test unit forward/backward moving mechanism 23 includes a fixed base 23a, slide rails 23b, a slide base 23c, and an actuator 23d. The fixed base 23a is fixed to the device frame 2. The pair of slide rails 23b are provided to extend in parallel to the central axis S. The slide base 23c supports the calibration test unit 22, and is provided to be able to move in the direction in which the slide rails 23b extend. The actuator 23d is fixed to the fixed base 23a, and is coupled with the slide base 23c. The actuator 23d is to move the slide base 23c in the direction in which the slide rails 23b extend, and in the present embodiment, the actuator 23d is made of an air pressure cylinder. However, the actuator 23d is not limited to the air pressure cylinder. Anything may be employed as long as it moves the slide base 23c in the direction in which the slide rails 23b extend. The calibration test unit forward/backward moving mechanism 23 drives the actuator 23d to move, to the forward or the backward, the slide base 23c as well as the calibration test unit 22 (each of the calibration test piece for the flaw detection sensor 22A and the calibration test piece for the image-capturing sensor 22B) in a straight track parallel to the central axis S (see FIG. 11 to FIG. 15). In this case, the calibration test unit 22 supported by the slide base 23c arranges the position of each of the calibration test piece for the flaw detection sensor 22A and the calibration test piece for the image-capturing sensor 22B in such a manner that the position of each of the calibration test piece for the flaw detection sensor 22A and the calibration test piece for the image-capturing sensor 22B is aligned with the position where each of the flaw detection sensors 20A and the image-capturing sensor 20B of the inspection unit 20 explained above is above the device frame 2 in the vertical direction and faces the inner surfaces of the nozzles 101c, 101d which is the inspection target portion. For this reason, as illustrated in FIGS. 11 and 14, in the forward-moved state with the calibration test unit forward/backward moving mechanism 23, each of the calibration test piece for the flaw detection sensor 22A and the calibration test piece for the image-capturing sensor 22B matches the position where each of the flaw detection sensor 20A and the image-capturing sensor 20B faces the inner surfaces of the nozzles 101c, 101d which is the inspection target portion with regard to the track of the push-out movement of the inspection unit 20 (the flaw detection sensor 20A and the image-capturing sensor 20B). As illustrated in FIGS. 14 and 15, in the forward-moved state with the calibration test unit forward/backward moving mechanism 23, the calibration test unit 22 is arranged to be aligned with the position of a distance L2 which is the same as a distance L1 when the image-capturing sensor 20B captures images of the inner surfaces of the nozzles 101c, 101d. Hereinafter, inspection procedure (inspection method) with the inspection device 1 will be explained. FIGS. 11 to 15 illustrate that the device frame 2 inserted into the predetermined position inside of the nozzles 101c, 101d is positioned by the external abutment members 3, and the central (central axis S) position of the device frame 2 is aligned with the central position of the nozzles 101c, 101d by the internal abutment members 4, and this state is maintained by the suction units 5. The rotation moving mechanism 15 is set so that each of the flaw detection sensors 20A and the image-capturing sensor 20B of the inspection unit 20 is at a position (reference position) where they face the upper side of the device frame 2 in the vertical direction. Then, when the flaw detection sensor 20A performs the flaw detection inspection, the slide moving mechanism 18 makes slide movement in parallel to the central axis S, so that each of the flaw detection sensors 20A of the inspection unit 20 is at the position below the groove welded portion 122 in the vertical direction as illustrated in FIG. 11. In this state, the calibration test unit forward/backward moving mechanism 23 moves the calibration test unit 22 forward. Accordingly, at the reference position where the inspection device 1 is inserted into the inside of the nozzles 101c, 101d, each of the calibration test pieces for the flaw detection sensors 22A are arranged on the track where each of the flaw detection sensors 20A makes push-out movement to the inner surfaces of the nozzles 101c, 101d. Subsequently, as illustrated in FIG. 12, the flaw detection sensor push-out moving mechanism 21A pushes out and moves the flaw detection sensors 20A in the direction perpendicular to the central axis S to make the flaw detection sensors 20A be in contact with the calibration test pieces for the flaw detection sensors 22A, respectively. Subsequently, the rotation moving mechanism 15 rotates and moves the flaw detection sensors 20A about the central axis S and perform flaw detection on the calibration test pieces for the flaw detection sensors 22A. Accordingly, on the basis of each of the calibration test pieces for the flaw detection sensors 22A, each of the flaw detection sensors 20A is calibrated and tested. Subsequently, as illustrated in FIG. 13, the calibration test unit forward/backward moving mechanism 23 moves the calibration test unit 22 backward. Subsequently, the inspection unit push-out moving mechanism 21 and flaw detection sensor push-out moving mechanism 21A pushes out and moves each of the flaw detection sensors 20A in the direction perpendicular to the central axis S to make each of the flaw detection sensors 20A be in contact with the inner surfaces of the nozzles 101c, 101d (groove welded portion 122). Subsequently, the rotation moving mechanism 15 rotates and moves each of the flaw detection sensors 20A about the central axis S, and the flaw detection is performed on the inner surfaces of the nozzles 101c, 101d. Therefore, each of the flaw detection sensors 20A performs the flaw detection inspection. Subsequently, as illustrated in FIGS. 11 and 12, on the basis of each of the calibration test pieces for the flaw detection sensors 22A, each of the flaw detection sensors 20A is calibrated and tested after the inspection. When the visual inspection is performed with image-capturing sensor 20B, the slide moving mechanism 18 makes slide movement in parallel to the central axis S so that the image-capturing sensor 20B of the inspection unit 20 is at the position below the groove welded portion 122 in the vertical direction as illustrated in FIG. 14. In this state, the calibration test unit forward/backward moving mechanism 23 moves the calibration test unit 22 forward. Accordingly, at the reference position where the inspection device 1 is inserted into the inside of the nozzles 101c, 101d, the calibration test piece for the image-capturing sensor 22B is arranged on the track where the image-capturing sensor 20B makes push-out movement to the inner surfaces of the nozzles 101c, 101d. Therefore, on the basis of the calibration test piece for the image-capturing sensor 22B, the image-capturing sensor 20B is calibrated and tested. Subsequently, as illustrated in FIG. 15, the calibration test unit forward/backward moving mechanism 23 moves the calibration test unit 22 backward. Subsequently, the inspection unit push-out moving mechanism 21 and the image-capturing sensor push-out moving mechanism 21B push out and move the image-capturing sensor 20B in the direction perpendicular to the central axis S. Subsequently, the rotation moving mechanism 15 rotates and moves the image-capturing sensor 20B about the central axis S, and images of the inner surfaces of the nozzles 101c, 101d are captured. Accordingly, visual inspection is performed with video taken by the image-capturing sensor 20B. Subsequently, as illustrated in FIG. 14, on the basis of the calibration test piece for the image-capturing sensor 22B, the image-capturing sensor 20B is calibrated and tested after the inspection. As described above, an inspection method of the present embodiment is an inspection method for inspecting a body, which is to be inspected, which is provided in the nuclear power plant, and the inspection method includes a step of arranging the inspection device 1 having the inspection unit 20 and the calibration test unit 22 at the reference position where the body which is to be inspected is inspected, a step of subsequently moving the calibration test unit 22 forward or backward with regard to the track where the inspection unit 20 makes push-out movement to the inspection target portion of the body which is to be inspected, and calibrating the inspection unit 20, and a step of subsequently causing the inspection unit 20 to inspect the inspection target portion. According to the inspection method, when the inspection target portion of the body which is to be inspected is inspected, the inspection unit 20 can be calibrated and tested on the track where the inspection unit 20 makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device 1 from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. Moreover, since the inspection unit 20 is calibrated and tested within the range that the inspection unit 20 can make push-out movement, the inspection unit 20 can be calibrated and tested even in a location where the condition is limited in which the inspection unit 20 can make push-out movement. An inspection method of the present embodiment is an inspection method for inspecting the inner surfaces of the nozzles 101c, 101d provided in the reactor vessel 101, and the inspection method includes a step of inserting the inspection device 1 including the inspection unit 20 and the calibration test unit 22 into the inside of the nozzles 101c, 101d, a step of subsequently moving the calibration test unit 22 forward or backward with regard to the track where the inspection unit 20 makes push-out movement to the inner surfaces of the nozzles 101c, 101d at the reference position where the inspection device 1 is inserted into the inside of the nozzles 101c, 101d, and calibrating the inspection unit 20, and a step of subsequently causing the inspection unit 20 to inspect the inner surfaces of the nozzles 101c, 101d. According to the inspection method, when the inner surfaces of the nozzles 101c, 101d provided on the reactor vessel 101 is inspected, the inspection unit 20 can be calibrated and tested on the track where the inspection unit 20 makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device 1 from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. The inspection method of the present embodiment further includes, after the step of causing the inspection unit 20 to inspect the inner surfaces of the nozzles 101c, 101d, a step of moving the calibration test unit 22 forward or backward with regard to the track where the inspection unit 20 makes push-out movement to the inner surfaces of the nozzles 101c, 101d at the reference position and calibrating the inspection unit 20 after the inspection. According to the inspection method, after the inner surfaces of the nozzles 101c, 101d provided in the reactor vessel 101 are inspected, the inspection unit 20 can be calibrated and tested on the track where the inspection unit 20 makes push-out movement. As a result, the calibration can be performed after the inspection without moving the inspection device 1 from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. The inspection device 1 of the present embodiment is an inspection device for inspecting a body, which is to be inspected, provided in the nuclear power plant, and the inspection device 1 includes the device frame 2 installed at the reference position for inspecting the body which is to be inspected, the inspection unit 20 provided on the device frame 2 for inspecting the inspection target portion of the body which is to be inspected, the inspection unit push-out moving mechanism 21 for pushing out and moving the inspection unit 20 to the inspection target portion while the device frame 2 is installed at the reference position, the calibration test unit 22 provided on the device frame 2 for calibrating the inspection unit 20, and the calibration test unit forward/backward moving mechanism 23 for moving the calibration test unit 22 forward or backward with regard to the track where the inspection unit 20 makes push-out movement in such a state that the inspection unit 20 is installed at the reference position. According to this inspection device, when the inspection target portion of the body which is to be inspected is inspected, the inspection unit 20 can be calibrated and tested on the track where the inspection unit 20 makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device 1 from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. Moreover, since the inspection unit 20 is calibrated and tested within the range that the inspection unit 20 can make push-out movement, the footprint is reduced, and the inspection unit 20 can be calibrated and tested even in a location where the condition is limited in which the inspection unit 20 can make push-out movement. Further, the calibration test unit 22 can be moved forward and backward with regard to the track where the inspection unit 20 makes push-out movement, and therefore, the device configuration is simplified, and the footprint is reduced, and the size of the device can be reduced. The inspection device 1 of the present embodiment is the inspection device 1 for inspecting the inner surfaces of the nozzles 101c, 101d provided in the reactor vessel 101, and the inspection device 1 includes the device frame 2 inserted into the inside of the nozzles 101c, 101d, the inspection unit 20 provided on the device frame 2 for inspecting the inner surfaces of the nozzles 101c, 101d, the inspection unit push-out moving mechanism 21 for pushing out and moving the inspection unit 20 to the inner surfaces of the nozzles 101c, 101d while the device frame 2 is installed in the inside of the nozzles 101c, 101d, the rotation moving mechanism 15 for rotating and moving the inspection unit 20 about a predetermined central axis S along a peripheral direction of the nozzles 101c, 101d while the device frame 2 is installed in the inside of the nozzles 101c, 101d, the calibration test unit 22 arranged on the device frame 2 for calibrating the inspection unit 20, and a calibration test unit forward/backward moving mechanism 23 for moving the calibration test unit 22 forward or backward in the direction along the central axis S with regard to the track where the inspection unit 20 makes push-out movement. According to this inspection device 1, when the inner surfaces of the nozzles 101c, 101d provided in the reactor vessel 101 are inspected, the inspection unit 20 can be calibrated and tested on the track where the inspection unit 20 makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device 1 from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. In the inspection device 1 of the present embodiment, the inspection unit 20 has at least one of the flaw detection sensor 20A coming into contact with the inner surfaces of the nozzles 101c, 101d and performing flaw detection and the image-capturing sensor 20B for capturing an image of the inner surfaces of the nozzles 101c, 101d, and the calibration test unit 22 has at least one of the calibration test piece for the flaw detection sensor 22A for calibrating the flaw detection sensor 20A and the calibration test piece for the image-capturing sensor 22B for calibrating the image-capturing sensor 20B. According to this inspection device 1, in at least one of the flaw detection inspection with the flaw detection sensor 20A and the visual inspection with the image-capturing sensor 20B, the inspection and calibration can be performed without moving the inspection device 1 from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. In the inspection device 1 of the present embodiment, the inspection unit 20 has the flaw detection sensor 20A that comes into contact with the inner surfaces of the nozzles 101c, 101d and performs flaw detection and the image-capturing sensor 20B for capturing images of the inner surfaces of the nozzles 101c, 101d, which are arranged in a row along the central axis S, and the calibration test unit 22 has the calibration test piece for the flaw detection sensor 22A for calibrating the flaw detection sensor 20A and the calibration test piece for the image-capturing sensor 22B for calibrating the image-capturing sensor 20B, which are arranged along the central axis S in alignment with the position where the flaw detection sensor 20A and the image-capturing sensor 20B are arranged in a row. According to this inspection device 1, the calibration test piece for the flaw detection sensor 22A and the calibration test piece for the image-capturing sensor 22B are arranged along the central axis S in alignment with the position where the flaw detection sensor 20A and the image-capturing sensor 20B are arranged in a row, and therefore, the calibration test unit forward/backward moving mechanism 23 for moving them forward or backward can be provided as a common configuration, so that both calibration tests can be performed with one mechanism and with one operation, and in addition, this can reduce the size of the device. In the inspection device 1 of the present embodiment, the calibration test unit 22 is arranged to be aligned with the position of a distance L2 which is the same as a distance L1 when the image-capturing sensor 20B captures images of the inner surfaces of the nozzles 101c, 101d, while the inspection device 1 is installed in the inside of the nozzles 101c, 101d. According to this inspection device 1, the image-capturing sensor 20B can be calibrated under the same condition as the case of the visual inspection performed with the image-capturing sensor 20B, and still more highly reliable inspection result can be obtained from still more accurate calibration. By the way, FIG. 16 is a top view illustrating the calibration test piece for the flaw detection sensor. FIG. 17 is a side view illustrating the calibration test piece for the flaw detection sensor. FIG. 18 is a side view illustrating the calibration test piece for the flaw detection sensor. FIG. 19 is a top view illustrating another example of the calibration test piece for the flaw detection sensor. FIG. 20 is a top view illustrating another example of the calibration test piece for the flaw detection sensor. FIG. 21 is a top view illustrating the calibration test piece for the image-capturing sensor. FIG. 22 is a side view illustrating the calibration test piece for the image-capturing sensor. The calibration test piece for the flaw detection sensor 22A as shown in FIGS. 16 to 20 corresponds to one flaw detection sensor 20A. The calibration test piece for the flaw detection sensor 22A as shown in FIGS. 16 and 17 has a test surface 22Aa having such a curvature that the central axis S is the center. The test surface 22Aa is a surface with which the flaw detection sensor 20A comes into contact, and the calibration groove 22Ab is a surface formed perpendicular to the scanning direction of the flaw detection sensor 20A. When the calibration test unit forward/backward moving mechanism 23 moves the calibration test unit 22 forward, the groove 22Ab is formed to be arranged in the center of the scanning direction of the flaw detection sensor 20A. Therefore, sufficient scanning space for the flaw detection sensor 20A can be ensured from the groove 22Ab to both ends of the test surface 22Aa. Therefore, when the test surface 22Aa having such a curvature that the central axis S is the center is provided just like the calibration test piece for the flaw detection sensor 22A as shown in FIGS. 16 and 17, the scanning of the inner surfaces of the nozzles 101c, 101d with the flaw detection sensor 20A and the scanning of the calibration test piece for the flaw detection sensor 22A are of the same condition. As a result, still more highly reliable inspection result can be obtained from still more accurate calibration. In the inspection device 1 of the present embodiment, two flaw detection sensors 20A are provided in a row along the peripheral direction of the inner surfaces of the nozzles 101c, 101d which is the inspection target portion. Therefore, as illustrated in FIG. 18, two calibration test pieces for the flaw detection sensors 22A are arranged in a row in association with the flaw detection sensors 20A, and each has the test surface 22Aa having such a curvature that the central axis S is the center with the two of them. Therefore, the scanning of the inner surfaces of the nozzles 101c, 101d with each of the flaw detection sensors 20A and the scanning of each of the calibration test pieces for the flaw detection sensors 22A are of the same condition. As a result, still more highly reliable inspection result can be obtained from still more accurate calibration. This can also be applied to the calibration test piece for the flaw detection sensor 22A as shown in FIGS. 19 and 20. In the calibration test piece for the flaw detection sensor 22A as shown in FIG. 19, the inspection target portion is a welded portion (groove welded portion 122) of the inner surfaces of the nozzles 101c, 101d, and the calibration test piece is formed to imitate the material and the form of the welded portion and the portion therearound. More specifically, as illustrated in FIG. 19, on the surface of the groove welded portion 122, there is a safe-end tube 121 made of stainless steel at one side in the direction along the central axis S, and there is a buttering welded portion 123 at the other side, and there is an overlay welded portion 124 at the still other side of the buttering welded portion 123. Inside of the cross section of the overlay welded portion 124, there is low-alloy steel which is the material of the nozzles 101c, 101d. The calibration test piece for the flaw detection sensor 22A as shown in FIG. 19 is formed to imitate the material and the form of the groove welded portion 122 and the portion therearound. Therefore, when the material and the form of the welded portion and the portion therearound are imitated just like the calibration test piece for the flaw detection sensor 22A as shown in FIG. 19, calibration is performed in a state similar to actual inspection. When the groove 22Ac is also formed around the welded portion (groove welded portion 122) as indicated by an alternate long and short dashed line of FIG. 19, evaluation can be performed even when failure (crack) is found around the welded portion. In FIG. 20, the calibration test piece for the flaw detection sensor 22A is formed with multiple types of grooves 22Ab, 22Ad of which depths and extension directions are different. For example, the groove 22Ab is formed perpendicular to the scanning direction of the flaw detection sensor 20A, and the groove 22Ad is formed along the scanning direction of the flaw detection sensor 20A. Both sides of the grooves 22Ab are grooves which are considered to have ordinary failure (crack) having, e.g., a width of 0.5 mm, the second from the left is a groove which is considered to have deep failure (crack) having, e.g., a width of 1.0 mm, and the second from the right is a groove which is considered to have still deeper failure (crack) having, e.g., a width of 3.0 mm. It should be noted that the calibration test piece for the flaw detection sensor 22A as shown in FIG. 20 imitates the material and the form of the welded portion and the portion therearound just like FIG. 19. However, the calibration test piece for the flaw detection sensor 22A as shown in FIG. 20 may not imitate the material and the form of the welded portion and the portion therearound just like FIG. 19. Therefore, when multiple types of grooves 22Ab, 22Ad of which depths and extension directions are different are formed just like the calibration test piece for the flaw detection sensor 22A as shown in FIG. 20, evaluation can be performed even when unexpected failure (crack) is found. The calibration test piece for the image-capturing sensor 22B as shown in FIGS. 21 and 22 has the test surface 22Ba having such a curvature that the central axis S is the center. The test surface 22Ba is a surface of which image is captured by the image-capturing sensor 20B, and is a surface formed with a scale 22Bc which is an index of size and one mm wire 22Bb which is an image-capturing range (indicated by a chain double-dashed line) of the image-capturing sensor 20B. Therefore, when the test surface 22Ba having such a curvature that the central axis S is the center is provided just like the calibration test piece for the image-capturing sensor 22B as shown in FIGS. 21 and 22, the inner surfaces of the nozzles 101c, 101d captured by the image-capturing sensor 20B and the test surface 22Ba of the calibration test piece for the image-capturing sensor 22B are of the same condition. As a result, still more highly reliable inspection result can be obtained from still more accurate calibration. According to an embodiment of inspection method, when the inspection target portion of the body which is to be inspected is inspected, the inspection unit can be calibrated and tested on the track where the inspection unit makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. Moreover, since the inspection unit is calibrated and tested within the range that the inspection unit can make push-out movement, the inspection unit can be calibrated and tested even in a location where the condition is limited in which the inspection unit can make push-out movement. According to an embodiment of inspection method, when the inner surfaces of the nozzles provided on the reactor vessel is inspected, the inspection unit can be calibrated and tested on the track where the inspection unit makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. According to an embodiment of inspection method, after the inner surfaces of the nozzles provided in the reactor vessel are inspected, the inspection unit can be calibrated and tested on the track where the inspection unit makes push-out movement. As a result, the calibration can be performed after the inspection without moving the inspection device from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. According to an embodiment of inspection device, when the inspection target portion of the body which is to be inspected is inspected, the inspection unit can be calibrated and tested on the track where the inspection unit makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. Moreover, since the inspection unit is calibrated and tested within the range that the inspection unit can make push-out movement, the footprint is reduced, and the inspection unit can be calibrated and tested even in a location where the condition is limited in which the inspection unit can make push-out movement. Further, the calibration test unit can be moved forward and backward with regard to the track where the inspection unit makes push-out movement, and therefore, the device configuration is simplified, and the footprint is reduced, and the size of the device can be reduced. According to an embodiment of inspection device, when the inner surfaces of the nozzles provided in the reactor vessel are inspected, the inspection unit can be calibrated and tested on the track where the inspection unit makes push-out movement. As a result, the inspection and calibration can be performed without moving the inspection device from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. According to an embodiment of inspection device, in at least one of the flaw detection inspection with the flaw detection sensor and the visual inspection with the image-capturing sensor, the inspection and calibration can be performed without moving the inspection device from the processed position. Therefore, highly reliable inspection result can be obtained from accurate calibration. According to an embodiment of inspection device, the calibration test piece for the flaw detection sensor and the calibration test piece for the image-capturing sensor are arranged along the central axis in alignment with the position where the flaw detection sensor and the image-capturing sensor are arranged in a row, and therefore, the calibration test unit forward/backward moving mechanism for moving them forward or backward can be provided as a common configuration, so that both calibration tests can be performed with one mechanism and with one operation, and in addition, this can reduce the size of the device. According to an embodiment of inspection device, the image-capturing sensor can be calibrated under the same condition as the case of the visual inspection performed with the image-capturing sensor, and still more highly reliable inspection result can be obtained from still more accurate calibration. According to an embodiment of inspection device, when the test surface having such a curvature that the central axis is the center is provided, the inspection of the inner surfaces of the nozzles with the inspection unit and the calibration test with the calibration test unit are of the same condition. As a result, still more highly reliable inspection result can be obtained from still more accurate calibration. According to an embodiment of inspection device, when the material and the form of the welded portion and the portion therearound are imitated, calibration can be performed in a state similar to actual inspection. According to an embodiment of inspection device, when multiple types of grooves of which depths and extension directions are different are formed, evaluation can be performed even when unexpected failure (crack) is found. According to the embodiments of the present invention, the inspection and calibration can be performed without moving the device from the processed position. 1 inspection device 2 device frame 3 external abutment member 4 internal abutment member 5 suction unit 6 abutment detection unit 7 image-capturing unit 15 rotation moving mechanism 18 slide moving mechanism 20 inspection unit 20A flaw detection sensor 20B image-capturing sensor 21 inspection unit push-out moving mechanism 21A flaw detection sensor push-out moving mechanism 21B image-capturing sensor push-out moving mechanism 22 calibration test unit 22A calibration test piece for flaw detection sensor 22Aa test surface 22B the calibration test piece for the image-capturing sensor 22Ba test surface 23 calibration test unit forward/backward moving mechanism 101 reactor vessel 101c, 101d nozzle
	description	The inventors found that a specific combination of a gel type cation exchange resin and a porous type anion exchange resin can be used to stabilize for a long period of time the performance of the ion exchange resins in a condensate water demineralizer. Specifically, porous type cation exchange resins such as AMBERLITE 200C from Rohm and Haas Co. and DIAION PK228 from Mitsubishi Chemicals Inc., which are typically used in a pressurized water reactor nuclear power plant, have levels of crosslinkage of 20% and 14%, respectively. The inventors observed that even though these cation exchange resins exhibit good resistance to oxidation due to their high levels of crosslinkage, leachables from these cation exchange resins still affect the anion exchange resins and significantly deteriorate the performance of the anion exchange resins. This is likely caused, not by macromolecular leachables which are released by the oxidation of the resin, but by resin fines produced by attrition (physical loading) to which porous type ion exchange resins are liable. To the condensate water in a pressurized water reactor nuclear power plant is added ammonia as a rust preventing reagent and hydrazine as a deoxidizing reagent. While in a once-through boiler of a thermal power plant, because hydrazine is completely decomposed at the boiler, hydrazine is not transported to the vapor side, and thus, hydrazine will not be entrained to the condensate water, in a pressurized water reactor nuclear power plant, on the other hand, part of hydrazine is carried to the condensate water demineralizer. A regeneration operation is performed periodically in the condensate water demineralizer, and during this periodic operation air scrubbing is performed to remove a small amount of metal oxides in the condensed water which have deposited on the ion exchange resins. In the scrubbing operation, air is blown in, the resins are agitated by bubbles, the metal oxides are dislodged from the resins, and the isolated metal oxides are removed by water backwash. During the air scrubbing, hydrazine, small amounts of metals, and air are mixed, and hydrazine decomposes through auto oxidation using the metals as catalysts to thereby generate hydrogen peroxide. The cation exchange resin is then oxidized by the hydrogen peroxide, and PSS or the like will eventually leach out. In a boiling water reactor nuclear power plant, no reagent such as a rust-preventing reagent is added to the condensate water and demineralized water as such is used, and thus, normally, the ion exchange resins at the condensate water demineralizer are not oxidized. However, during periodic maintenance, the water within the nuclear reactor is radiation decomposed and hydrogen peroxide is generated. The water within the nuclear reactor is then passed through the condensate water demineralizer when the operation is restarted. Because of this, the water supplied to the condensate water demineralizer in a boiling water reactor nuclear power plant contains hydrogen peroxide, which bring about oxidation decomposition of the cation exchange resin, with a result similar to the case with a pressurized water reactor nuclear power plant. In the present invention, a gel type cation exchange resin is used. In particular, considering the characteristics of the resins, it is preferable to use a gel type cation exchange resin which has a moisture holding capacity of 41% or less or a crosslinkage of 12% or greater. More preferably, the moisture holding capacity is between 30% and 38% or the crosslinkage is between 14% and 16%. The moisture holding capacity to be used in the above described criteria is a value determined when the ion form is a standard form (sodium form) as will be described later. When the moisture holding capacity is represented for a case in a regenerated form (hydrogen form), it is preferable to have a moisture holding capacity of 49% or less, and more preferably in a range between 37% and 46%. The gel type cation exchange resin used in the present invention can be any of the known gel type cation exchange resins. The resin can, for example, be manufactured by copolymerizing an aromatic monovinyl monomer such as styrene, vinyltoluene, vinylxylene, ethylstyrene, and chlorstyrene, with an aromatic polyvinyl monomer such as divinylbenzene and divinyltoluene, and then introducing cation exchange radicals. It is possible to use both aromatic polyvinyl monomer and ester polyvinyl monomer as a polyvinyl monomer, and it is preferable to use a gel type cation exchange resin derived from such polyvinyl monomers. As an ester polyvinyl monomer, for example, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylol propane trimethacrylate, or the like, or an equivalent acrylate can be used independently or as a mixture. Moisture holding capacity as used in the present specification refers to the ratio of water content measured when the water within the resin capillary is adjusted to a state of saturation equilibrium. In the specification, the moisture holding capacity refers to a value for a gel type strong acid cation exchange resin with a standard ion form (sodium form). In the examples described later in this specification, this value was measured by the following procedure. (a) A sample resin having a standard form (sodium form) and moisture content at an equilibrium was prepared. (b) Approximately 5 g of the sample resin prepared as in (a) above was placed into each of two flat balance bins adjusted to a constant weight to weigh the sample weight to an accuracy of 1 mg. (c) Each sample was placed in a drying container pre-adjusted to 110xc2x15xc2x0 C., and allowed to dry for 24 hours. (d) Each sample was allowed to cool for approximately 30 minutes in a desiccator. (e) The measurement bin was sealed and the mass of each bin was measured, and then the differences (a g) between the bins before drying and the bins after drying, that is, between the weight of the resin in which the moisture content is at an equilibrium and the weight of the resin after the drying, was found and used to calculate the moisture holding capacity (%) using the following formula. M1=a/Wxc3x97100 where M1 is the moisture holding capacity (%) and W is the weight (g) of the resin in which the water content is at an equilibrium. The measurement of the weights of the resin with the moisture content at an equilibrium and after the drying was simultaneously made for two samples of the identical resin, and, if the two results differed by more than 0.5%, the examination was repeated until two results coinciding with each other within a difference of 0.5% were obtained. When the two results match within 0.5% difference, the average value of these results was adopted as the examination result. The level of crosslinkage in the present invention refers to the degree of crosslinkage by the polyvinyl monomer, and specifically, refers to the weight ratio (%) of divinylbenzene with respect to all the vinyl monomers. When an aromatic polyvinyl monomer and ester polyvinyl monomer are both used for the resin, however, the level of crosslinkage cannot be determined by the above definition of the level of crosslinkage. In such cases, a preferable gel type cation exchange resin can be selected and determined based on the moisture holding capacity. In a gel type ion exchange resin, the moisture holding capacity and the degree of crosslinkage have a close relationship to each other, and, generally, as the degree of crosslinkage increases, the moisture holding capacity decreases in a gel type ion exchange resin. When the moisture holding capacity exceeds 41% or the degree of crosslinkage is below 12% in a gel type cation exchange resin, the resistance to oxidation is low, and such a gel type cation exchange resin is therefore not preferred. As a gel type cation exchange resin for use in the present invention, any commercially available cation exchange resin which has a moisture holding of 41% or less or a degree of crosslinkage of 12% or greater can be used. Examples of suitable commercially available gel type cation exchange resins includes AMBERLITE IR-124, AMBERLITE XT-1006 (trade name, Rohm and Haas Co.), DIAION SK112, and DIAION SK116 (trade name, Mitsubishi Chemicals Inc.). In the present invention, porous type anion exchange resins to be used with the gel type cation exchange resin includes both MR (macroreticular) type and MP (macroporous) types. In the present invention, a porous type anion exchange resin is used because, in general, a porous type anion exchange resin has a better resistance to fouling than a gel type anion exchange resin. Any known and/or commercially available porous type anion exchange resin with a diameter between 100 and 1000 xcexcm can be used in the present invention, and can be either strong by basic or weakly basic. Examples of suitable commercially available porous type anion exchange resins include AMBERLITE IRA-900, AMBERLITE IRA-910 (trade name, Rohm and Haas Co.), DIAION PA308, DIAION PA312, DIAION PA316, DIAION PA408, DIAION PA412, DIAION PA418 (trade name, Mitsubishi Chemicals, Inc.), DOWEX MSA-1, DOWEX MSA-2 (trade name, Dow Co.), and LEWATIT MP500 (trade name, Bayer Co.). It is preferable that a porous type anion exchange resin employed in the present invention has a specific surface area of 1 m2/g or more. If the specific surface area is less than 1 m2/g, the capability for adsorbing leachables from the gel type cation exchange resin is low while the reduction in reactivity still high even when the quantity of leachables is small, and therefore not preferred. The ratio of the gel type cation exchange resin and the porous type anion exchange resin to be used in the present invention, (gel type cation exchange resin):(porous type anion exchange resin), is preferably within a range of 1:2 to 3:1 (volume ratio in standard form). The gel type cation exchange resin is usually used in an H type, and the porous type anion exchange resin is usually used in OH type. The condensate water demineralizer of the present invention is effective in applications where the ion exchange resins come in contact with oxidizing materials, especially hydrogen peroxide. In other words, the demineralizer can be preferably used as a condensate water demineralizer in pressurized water reactor nuclear power plants and in boiling water demineralizer nuclear power plants. The condensate water demineralizer is effective for cases where the cation exchange resin comes in contact with hydrogen peroxide. The condensate water demineralizer of the present invention is characterized by the combination of the ion exchange resins to be used, but the overall structure is equivalent to that of the conventional condensate water demineralizers, and thus, its structure will not be described in detail. xe2x80x9cDemineralizer Structurexe2x80x9d Operational flow of the condensate water demineralizer used in pressurized water reactor nuclear power plants will now be described by referring to FIG. 1. In a pressurized water reactor nuclear power plant, steam is supplied to a turbine 11 which is driven by the steam to generate power. The steam discharged from the turbine 11 is introduced to a condenser 1, where the steam is cooled and becomes condensate water. Sea water or the like is used for cooling the condenser 1. The condensate water obtained at the condenser is supplied to a condensate water filtering apparatus 3 by a condensate water pump 2, where solid materials are filtered out. There are some cases where no condensate water filtering apparatus is provided. The filtrate flowing out of the condensate water filtering apparatus 3 is fed to a condensate water demineralizer 4 of the present invention where the condensate water is purified (demineralized). In other words, the condensate water demineralizer 4 is filled with a gel type cation exchange resin and a porous type anion exchange resin, and various ions included in the condensate water are removed. The condensate water which is purified (demineralized) at the condensate water demineralizer 4 is then heated at a low pressure feed water heater 5 and degassed at a degasifier 6. The degassed condensate water is pressurized to a predetermined pressure by a feed pump 7, heated at a high pressure feed water heater 8, and fed to a steam generator 9. At the steam generator 9, heat is exchanged with a high temperature and high pressure water supplied from a nuclear reactor 10, so that the condensate water becomes a steam, which is then supplied to the turbine 11, where a power generator 12 is driven to generate power. In the power generation cycle, ammonia and hydrazine are added downstream (at a point near the steam generator 9) of the condensate water demineralizer 4 for preventing rust. These compounds are then circulated via the steam generator 9 forward to the condensate water demineralizer 4. In particular, the steam generator 9 is typically operated at approximately 270xc2x0 C. which is lower than the temperature in a boiler at a fossil-fueled power plant. Because of this, only a portion of hydrazine is decomposed, and there will be some hydrazine remaining in the condensate water, which is sent to the condensate water demineralizer 4. The condensate water demineralization 4 is regenerated when its ion exchange capacity is exhausted. Regeneration is effected by passing a hydrochloric acid solution for the cation resin and a sodium hydroxide solution for the anion resin. During the regeneration, air scrubbing is carried out to dislodge small amounts of metal oxides from the resin surfaces. The dislodged metal oxides are then removed from the system by water backwash. During the air scrubbing, hydrazine oxidizes itself (autooxidation) with the small amounts of metal as a catalyst, and hydrogen peroxide is generated. While in a conventional system a cation exchange resin is generally vulnerable to hydrogen peroxide and normally liable to degradation, in the present invention, a gel type cation exchange resin with a predetermined degree of crosslinkage is used, and therefore, the cation exchange resin is resistant to decomposition by hydrogen peroxide, thereby increasing the lifetime of the cation exchange resin. Moreover, because the cation exchange resin does not decompose as easily, the lifetime of the anion exchange resin can also be elongated. In particular, because a porous type resin is used as the anion exchange resin, the anion exchange resin has a larger surface area, resulting in reduction of lifetime degradation due to PSS or the like adhering to the resin. Because blowdown water in the steam generator 9 is generally also sent to the condenser 1, hydrazine also flows into the condensate water demineralizer 4 from this route. FIG. 2 shows the flow of a condensate water demineralizer used in a boiling water reactor nuclear power plant. In a boiling water reactor nuclear power plant, the plant structure is basically identical to the pressurized water reactor nuclear power plant, with the exception that the condensate water is directly supplied to a nuclear reactor 20 where the condensate water is heated and vaporized. In other words, the steam generated at the nuclear reactor 20 is supplied to a turbine 11 where a power generator 12 is driven to generate power. The steam from the turbine 11 is then circulated to the nuclear reactor 20 via a condenser 1, a condensate water pump 2, a condensate water filter 3, a condensate water demineralizer 4, a low pressure feed water heater 5, feed water pump 7, and high pressure feed water heater 8. In such a boiling water reactor nuclear power plant, water within the nuclear reactor 20 is decomposed by radiation when the power generation is interrupted, resulting in generation of hydrogen peroxide. The steam generated in the nuclear reactor 20 is eventually transferred to the condenser 1, and thus, water containing hydrogen peroxide flows in to the condensate water demineralizer 4. Therefore, just as in the case of the pressurized water reactor nuclear power plant example described above, degradation of the cation exchange resin tends to occur at the condensate water demineralizer 4. In the present embodiment, the effects and damages due to hydrogen peroxide are inhibited by using a gel type cation exchange resin with a given degree of crosslinkage. The results of various experiments will now be explained. The experiments were performed using each of the ion exchange resins shown in Tables 1 (showing cation exchange resins) and 2 (showing anion exchange resins). 100 ml each of the five types of cation exchange resins and 100 ml of anion exchange resin Amberlite IRA 400 were measured. Each of the cation exchange resins was mixed with the anion exchange resin and filled in an acrylic column with an inside diameter of 25 mm. Scrubbing air was introduced from the bottom of the column to create an environment where the resins are rubbed. Because iron rust (commonly called cruds) is present in the condensate water, 1 g/L-resin of iron oxide was added to simulate this, and scrubbing was performed for 16 hours. Then, in order to check any effect of the cation exchange resin on the fouling of the anion exchange resin, the mass transfer coefficient (hereinafter abbreviated to xe2x80x9cMTCxe2x80x9d) of the anion exchange resin was measured. The results are shown in Table 3. The measurement of MTC of the anion exchange resin was made as follows. New cation exchange resins regenerated under the conditions shown in Table 4 were prepared, each of these resins was mixed with an anion exchange resin which is treated as described above, separated and regenerated, in a mixing ratio of 2/1, and the mixture was charged into a column. Feed water with an NH3 concentration of 1500 ppb and an Na2SO4 concentration of 300 ppb was passed through the column with a linear velocity (LV) of 120 m/hour, and the SO4 concentration of the outlet (treated) water from the column was measured. Then, the SO4 concentration of the treated water at the time when this SO4 concentration had stabilized and the SO4 concentration of the feed water at the column inlet were measured. Finally, the MTC value was calculated by the following formula using these measured SO4 concentration values, and void ratios of the anion exchange resin and the particle size of the resin which were separately measured. xe2x80x83K={⅙(1xe2x88x92xcex5)R}xc2x7{F/(Axc3x97L)}xc2x7dxc2x7ln (C0/C) where K is the mass transfer coefficient (m/sec.), xcex5 is the void ratio, R is the ratio of anion exchange resin, F is the flow rate of feed water (m3/sec.), A is the cross sectional area of the column (m2), L is the height of the resin layer (m), d is the particle size of the resin (m), C0 is the SO4 concentration at the column inlet, and C is the SO4 concentration at the column outlet. As is apparent from the results shown in Table 3, porous cation exchange resins 200CP and PK228 led to significant drops in the MTC of the anion resin, which serves as an indicator of the reactivity of the anion exchange resin, from the value 2.0xc3x9710xe2x88x924 m/sec. for a new resin. The gel type cation exchange resins, on the other hand, resulted in no significant drop in the MTC value of the anion resin, and thus, considered to be good for use in the condensate water demineralizer in accordance with the present invention. 100 ml each of the five types of cation exchange resins as described above and 200 ml of anion exchange resin Amberlite IRA400 were measured. Each of the five cation exchange resins mixed with the anion exchange resin was charged into an acrylic column with an inside diameter of 25 mm. Feed water containing hydrogen peroxide with a concentration of 3 ppm was passed through the column with a flow rate of 40 m/h. Iron ions were added beforehand so that the cation exchange resin was loaded with 20 g Fe/L-resin. The feed water was passed for 16 hours under the above-mentioned conditions. Then, the MTC value of the anion exchange resin was measured in order to check any fouling effect of the cation exchange resins on the anion exchange resin. The results are shown in Table 5. As can be seen from Table 5, the effects of oxidizing agents depend on the degree of crosslinkage of the cation exchange resins. The results indicate that the effect starts to decrease around at a level of crosslinkage of 12% and then stabilizes. Example 3 was performed with identical conditions as in example 1 except that Amberlite IR124 was used as a cation exchange resin, two types of anion exchange resins, porous type Amberlite IRA900 and gel type Amberlite IRA400 were used for combining with the cation exchange resin, and the resistance to fouling of the anion exchange resin was evaluated using the MTC value as a indicator. The results are shown in Table 6. As is apparent from Table 6, a porous type anion exchange resin is better in the resistance to fouling the pollution resistivity than a gel type anion exchange resin when combined with the cation exchange resin. As described, according to the present invention, the condensate water demineralizer performance and the ion exchange resin performance can be maintained for a longer period of time, and thus, the demineralizer is particularly suitable for processing condensate water within a pressurized water reactor or boiling water reactor nuclear power plant.
	abstract	A deflector array includes a plurality of deflectors, which deflect charged particle beams, arrayed on a substrate. Each of the plurality of deflectors includes a single opening formed in the substrate, and each of the plurality of deflectors includes a pair of electrodes that oppose each other through the opening and are configured to deflect a single charged particle beam. The plurality of deflectors are arrayed such that a length of the pair of electrodes in a longitudinal direction thereof is not less than a distance between centers of two of the plurality of deflectors that are located nearest to each other. The plurality of deflectors is arrayed to form a checkerboard lattice, and two openings of the two of the plurality of deflectors overlap in the longitudinal direction.
047117559	abstract	A handling tool for selectively removable cruciforms employed in ice baskets of the type employed with nuclear power generator systems. The tool includes clamping means for engaging a compressible central portion of the removable cruciform to retract same inwardly and permit moving same, in a horizontal orientation, throughout the axial height of the interior of the ice basket. When at a desired elevation, selective actuating means moves previously retracted guide means to an extended or projected position for engaging a retaining ring of the ice basket and supporting the tool on the ring. The clamping means is selectively actuated to the disengaged position for releasing the cruciform whereupon the same expands, projecting legs associated therewith radially outwardly and engaging the retaining ring, to support the cruciform on the ring. The tool may thereafter be removed. For removing a cruciform, the tool is lowered and the clamping means actuated to engage and compress the central portion thereof for releasing these from the ring and, in that condition, is raised for removing the cruciform from the ice basket.
	summary
	description	1. Field of the Invention The present invention relates to an LPP (laser produced plasma) type EUV (extreme ultra violet) light source apparatus which generates extreme ultra violet light to be used for exposing semiconductor wafers, etc. 2. Description of a Related Art Recent years, as semiconductor processes become finer, photolithography has been making rapid progress to finer fabrication. In the next generation, microfabrication at 60 nm to 45 nm, further, microfabrication at 32 nm and beyond will be required. Accordingly, in order to fulfill the requirement for microfabrication at 32 nm and beyond, for example, exposure equipment is expected to be developed by combining an EUV light source generating EUV light having a wavelength of about 13 nm and reduced projection reflective optics. As the EUV light source, there are three kinds of light sources, which include an LPP (laser produced plasma) light source using plasma generated by applying a laser beam to a target, a DPP (discharge produced plasma) light source using plasma generated by discharge, and an SR (synchrotron radiation) light source using orbital radiation. Among them, the LPP light source has advantages that extremely high intensity close to black body radiation can be obtained because plasma density can be considerably made larger, that the light emission of only the necessary waveband can be performed by selecting the target material, and that an extremely large collection solid angle of 2π to 5π steradian can be ensured because it is a point light source having substantially isotropic angle distribution and there is no structure surrounding the light source such as electrodes. Therefore, the LPP light source is considered to be predominant as a light source for EUV lithography requiring power of more than 100 watts. FIG. 35 shows the outline of a conventional LPP type EUV light source apparatus. As shown in FIG. 35, the EUV light source apparatus includes a driver laser 101, an EUV light generating chamber 102, a target material supply unit 103, and laser beam focusing optics 104. The driver laser 101 is a master oscillator power amplifier type laser apparatus which generates a drive laser beam to be used for exciting a target material. The EUV light generating chamber 102 is a chamber in which EUV light is generated and which is evacuated by a vacuum pump 105 to facilitate turning the target material into plasma and prevent the EUV light from being absorbed. Furthermore, a window 106 for passing a laser beam 120 generated by the driver laser 101 into the EUV light generating chamber 102 is attached to the EUV light generating chamber 102. In addition, a target injection nozzle 103a, a target collecting cylinder 107, and an EUV light collector mirror 108 are located in the EUV light generating chamber 102. The target material supply unit 103 supplies the target material to be used for generating EUV light into the EUV light generating chamber 102 through the target injection nozzle 103a which is a part of the target material supply unit 103. Target material, which has become unnecessary without laser beam irradiation, among the supplied target material is collected by the target collecting cylinder 107. The laser beam focusing optics 104 includes a mirror 104a for reflecting the laser beam 120 emitted from the driver laser 101 toward the EUV light generating chamber 102, a mirror adjusting mechanism 104b for adjusting the position and angle (tilt angle) of the mirror 104a, a focusing element 104c for focusing the laser beam 120 reflected by the mirror 104a, and a focusing element adjusting mechanism 104d for moving the focusing element 104c along the optical axis of the laser beam. The laser beam 120 focused by the laser beam focusing optics 104 reaches the trajectory of target material through the window 106 and a hole formed in the midsection of the EUV light collector mirror 108. Thus, the laser beam focusing optics 104 focuses a laser beam 120 so as to make a focus on the trajectory of target material. As a result, the target material 109 is excited and turned into plasma, and EUV light 121 is generated from the plasma. The EUV light collector mirror 108 is a concave mirror on the surface of which an Mo/Si film reflecting light having a wavelength of 13.5 nm, for example, at a high reflectance is formed, and reflects the generated EUV light 121 to focus it on an IF (intermediate focusing point). The EUV light 121 reflected by the EUV light collector mirror 108 passes through a gate valve 110 provided to the EUV light generating chamber 102 and a filter 111 which eliminates unnecessary light (electromagnetic waves (light) having a shorter wavelength than EUV light, and light having a longer wavelength than EUV light, e.g. ultra violet light, visible light, infrared light, etc.) from the light generated from the plasma to allow passage of only desired EUV light, e.g. light having a wavelength of 13.5 nm. EUV light 121 focused on the IF (intermediate focusing point) is then guided to an exposure unit or the like through transmission optics. Since large energy is radiated from plasma generated in the EUV light generating chamber 102, temperature of the components in the EUV light generating chamber 102 rises due to this radiation. A technology of preventing such temperature rise of components is known (see Japanese Unexamined Patent Application Publication JP-P 2003-229298A, for example). JP-P2003-229298A describes an X-ray generator including an X-ray source which turns a target material into plasma and radiates X-ray from the plasma, and a vacuum vessel which accommodates the X-ray source, and the X-ray generator is characterized by an inner wall made of a material having high absorption ratio for electromagnetic waves in a range from infrared to X-ray inside the vacuum vessel. According to the X-ray generator, the components in the vacuum vessel can be prevented from being heated unnecessarily due to radiation energy reflected and scattered by the inner wall of the vacuum vessel. By the way, the plasma generated in the EUV light generating chamber 102 as shown in FIG. 35 diffuses with the passage of time, and a part of the diffused plasma scatters as atoms and ions. These atoms and ions are called debris and irradiated to the inner wall and structure of the EUV light generating chamber 102. Due to the irradiation of debris scattered from the plasma as described above and electromagnetic waves generated from the plasma, the following phenomena may occur. (a) Atoms scattered from the plasma adhere to the surface of the window 106 on the internal side of the EUV light generating chamber 102. The atoms adhered to the surface of the window 106 on the internal side of the EUV light generating chamber 102 absorb a laser beam 120. (b) Ions scattered from the plasma are applied to the surface of the window 106 on the internal side of the EUV light generating chamber 102, and the surface of the window 106 on the internal side of the EUV light generating chamber 102 is deteriorated (the surface becomes rough and not smooth). As a result, the window 106 becomes to absorb a laser beam 120 emitted from the driver laser 101. (c) Ions scattered from the plasma are applied to the inner wall and structures of the EUV light generating chamber 102. Atoms scattered from the inner wall and structures of the EUV light generating chamber 102 by this spattering adhere to the surface of the window 106 on the internal side of the EUV light generating chamber 102. Atoms adhered to the surface of the window 106 on the internal side of the EUV light generating chamber 102 absorb a laser beam 120. (d) The window 106 absorbs electromagnetic waves (light) having a short wavelength generated from plasma, and thereby, quality of its material is deteriorated. As a result, the window 106 becomes to absorb a laser beam 120. (e) When the operation period of the EUV light source apparatus becomes long to some extent, the material of the window 106 is deteriorated or damaged by the irradiation of the laser beam 120 during this period. As a result, the window 106 becomes to absorb a laser beam 120. When the phenomena of (a) through (e) have occurred, the energy for turning target material into plasma decreases and the efficiency of generation of EUV light 121 decreases. Furthermore, when the window 106 and/or atoms adhered to the window 106 absorb laser beam 120, the temperature of the window 106 rises, and distortion occurs on the substrate of the window 106, and therefore, the focusing property decreases. Such reduction in the focusing property results in more reduction in the efficiency of generation of EUV light 121. In addition, when the distortion of the substrate of the window 106 grows, the distortion, in turn, results in damage of the window 106. Furthermore, there is a case where a part (e.g. lens, mirror, etc.) of the laser beam focusing optics 104 is located inside the EUV light generating chamber 102. In such a case, the phenomena (a) through (e) may occur also on the part of the laser beam focusing optics 104 located in the EUV light generating chamber 102. In particular, in the case where a mirror which reflects the laser beam is located in the EUV light generating chamber 102, when the phenomena (a) through (e) occur on the mirror, the laser beam reflectance of the reflection-increasing coating on the reflecting surface of the mirror decreases. As a result, the energy for turning target material into plasma decreases and the efficiency of generation of EUV light 121 decreases. When the phenomena (a) through (e) have occurred and the window 106 and/or the laser beam focusing optics 104 have been deteriorated, the deteriorated optical elements need to be replaced with new optical elements. However, there has been a problem that since a laser beam 120 is focused on a plasma generating position (the trajectory of target material) in the EUV light generating chamber 102, it is not easy to know whether the window 106 and/or the laser beam focusing optics 104 have been deteriorated and therefore it is difficult to take prompt countermeasure (optical element replacement). On the other hand, as factors responsible for destabilizing generation of the plasma and eventually fluctuating or decreasing efficiency of generation of EUV light 121, there is a problem of displacement of focusing point (focus) of the laser beam 120, in addition to deterioration of the window 106 and the laser beam focusing optics 104. The displacement of focusing point of the laser beam 120 is caused by alignment deviation of the laser beam focusing optics 104, pointing deviation of the driver laser 101, and so on. Alignment deviation of the laser beam focusing optics 104 is mainly caused by deformation of the optical elements included in the laser beam focusing optics 104 or deformation of the optical element holders holding such optical elements because heat load is applied to the optical elements and the optical element holders along with operation of the EUV light source apparatus. Furthermore, pointing deviation of the driver laser 101 is mainly caused by deformation of the elements or the components in the driver laser 101 because heat load is applied to the elements and the components along with operation of the EUV light source apparatus. When displacement of focusing point of the laser beam 120 as described above occurs, a focusing spot size or an intensity distribution in the plasma generating position (on the trajectory of target material) becomes inadequate or the laser beam 120 deviates from target material, and the generation of plasma is destabilized, and eventually, the efficiency of generation of EUV light 121 is fluctuated or decreased. Focusing point displacement of the laser beam 120 can be corrected by readjusting the alignment of the laser beam focusing optics 104 without replacement of optical elements. Thereby, the focusing point of the laser beam 120 can be restored to the original position (plasma generating position), plasma generation can be stabilized, and, in turn, the efficiency of generation of EUV light 121 can be restored to the original value. However, there has been a problem that since the laser beam 120 is focused in the EUV light generating chamber 102 (plasma generation position) it is not easy to know whether focusing point displacement of the laser beam 120 occurred and therefore it is difficult to take prompt countermeasure (readjusting the alignment of the laser beam focusing optics 104). Furthermore, in particular, as the light output of the EUV light source apparatus increases, the amount of generated debris increases, and the surfaces of various optical elements such as the concave mirror 108 of the EUV light collecting optics become contaminated easily as well as the window 106, and therefore, the deterioration state should be adequately known and the optical elements should be cleaned or replaced. In view of the about point, an object of the present invention is to provide an extreme ultra violet light source apparatus capable of promptly coping with reduction or fluctuation of an efficiency in EUV light generation caused by deterioration of the window for a driver laser and/or deterioration of the optical element of laser beam focusing optics located in the EUV light generating chamber. In order to achieve the above object, an extreme ultra violet light source apparatus according to a first aspect of the present invention is an apparatus for generating extreme ultra violet light by applying a laser beam to a target material to turn the target material into plasma, and the apparatus includes: an extreme ultra violet light generating chamber in which extreme ultra violet light is generated; a target material supply unit for injecting a target material into the extreme ultra violet light generating chamber when the extreme ultra violet light is generated; a driver laser for emitting a laser beam; a window provided to the extreme ultra violet light generating chamber, for passing a laser beam into the extreme ultra violet light generating chamber; laser beam focusing optics including at least one optical element, the laser beam focusing optics focusing the laser beam emitted from the driver laser onto a trajectory of the target material injected into the extreme ultra violet light generating chamber to generate plasma; extreme ultra violet light collecting optics for collecting and outputting extreme ultra violet light radiated from the plasma; a temperature sensor for detecting a temperature of the window and/or optical elements provided in the extreme ultra violet light generating chamber; and a processing unit for determining deterioration of the window and/or the optical elements provided in the extreme ultra violet light generating chamber based on the temperature of the window and/or the optical elements detected by the temperature sensor when extreme ultra violet light is generated. Furthermore, an extreme ultra violet light source apparatus according to a second aspect of the present invention is an apparatus for generating extreme ultra violet light by applying a laser beam to a target material to turn the target material into plasma, and the apparatus includes: an extreme ultra violet light generating chamber in which extreme ultra violet light is generated; a target material supply unit for injecting a target material into the extreme ultra violet light generating chamber when extreme ultra violet light is generated; a driver laser for emitting a laser beam; a window provided to the extreme ultra violet light generating chamber, for passing the laser beam into the extreme ultra violet light generating chamber; laser beam focusing optics including an optical element provided in the extreme ultra violet light generating chamber, the laser beam focusing optics focusing the laser beam emitted from the driver laser onto a trajectory of the target material injected into the extreme ultra violet light generating chamber to generate plasma; extreme ultra violet light collecting optics for collecting and outputting extreme ultra violet light radiated from the plasma; a cooling channel for supplying cooling water to the window and/or the optical element; a temperature sensor provided at a cooling water back-flow position of the cooling channel, for detecting a temperature of back-flow water; and a processing unit for obtaining an amount of waste heat carried by the cooling water based on the temperature detected by the temperature sensor when extreme ultra violet light is generated, and determining deterioration of the window and/or the optical element based on the amount of waste heat. Incidentally, the driver laser may have a main pulse laser and a pre-pulse laser. According to the present invention, deterioration, etc. of the window and/or the optical element of the EUV light generating chamber can be easily detected. Thereby, the reduction or fluctuation of the efficiency in EUV light generation can be promptly handled. Embodiments of the present invention will be described in detail below with reference to the drawings. The same reference numerals are attached to the same components to omit a description of them. FIG. 1 is a schematic diagram showing the outline of an extreme ultra violet light source apparatus (simply referred to as “EUV light source apparatus” hereinafter) according to the present invention. As shown in FIG. 1 the EUV light source apparatus includes a driver laser 1, an EUV light generating chamber 2, a target material supply unit 3, and laser beam focusing optics 4. The driver laser 1 is a master oscillator power amplifier type laser apparatus which generates a drive laser beam to be used for exciting a target material. As the driver laser 1, publicly known various lasers (for example, ultra violet lasers such as KrF and XeF lasers and infrared lasers such as Ar, CO2, and YAG lasers) can be used. The EUV light generating chamber 2 is a vacuum chamber in which EUV light is generated. A window 6 for passing a laser beam 20 generated by the driver laser 1 into the EUV light generating chamber 2 is attached to the EUV light generating chamber 2. In addition, a target injection nozzle 3a, a target collecting cylinder 7, and an EUV light collector mirror 8 are located in the EUV light generating chamber 2. The target material supply unit 3 supplies a target material to be used for generating EUV light into the EUV light generating chamber 2 through the target injection nozzle 3a which is part of the target material supply unit 3. Target material, which has become unnecessary without being irradiated with a laser beam, among the supplied target material is collected by the target collecting cylinder 7. As a target material, publicly known various material (e.g. tin (Sn), xenon (Xe), etc.) can be used. Furthermore, the state of the target material may be any one of solid, liquid, and gas, and may be supplied to the space in the EUV light generating chamber 2 in any publicly known state such as a continuous flow (target injection flow) or a droplet. For example, when liquid xenon (Xe) target is used as the target material, the target material supply unit 3 includes a gas cylinder which supplies high purity xenon gas, a mass flow controller, a cooling apparatus for liquefying xenon gas, a target injection nozzle, etc. Furthermore, when a droplet is generated, a vibrator such as a piezoelectric element is added to the configuration including them. The target material supply unit 3 supplies the target material into the EUV light generating chamber 2 when the EUV light source apparatus generates EUV light, while not supplying the target material into the EUV light generating chamber 2 when the EUV light source apparatus does not generate EUV light. The laser beam focusing optics 4 focuses a laser beam 20 emitted from the driver laser 1 so as to make a focus on the trajectory of the target material. As a result, the target material 9 is excited and turned into plasma, and EUV light 21 is generated from the plasma. The laser beam focusing optics 4 may be composed of one optical element (e.g. one convex lens or the like) or may be composed of two or more optical elements. When the laser beam focusing optics 4 is composed of two or more optical elements, at least one of them can be located in the EUV light generating chamber 2. The EUV light collector mirror 8 is, for example, a concave mirror having an Mo/Si film formed on the surface thereof, for reflecting light having a wavelength of 13.5 nm at a high reflectance, and collects the generated EUV light 21 by reflecting it and guides it to transmission optics. The EUV light 21 is further guided to an exposure unit or the like through the transmission optics. In FIG. 1, the EUV light collector mirror 8 collects the EUV light 21 toward the front of the paper. Next, an EUV light source apparatus according to the first embodiment of the present invention will be described. FIG. 2 is a schematic diagram showing an EUV light source apparatus according to this embodiment. In FIG. 2, the target material supply unit 3 and the target material collecting cylinder 7 (see FIG. 1) are omitted, and the target material is assumed to be injected in a direction perpendicular to the paper. As shown in FIG. 2, a laser beam 20 emitted upward in the figure from the driver laser 1 enters the laser beam focusing optics 4. The laser beam focusing optics 4 includes a lens barrel 4a, a concave lens 4b and convex lenses 4c and 4d located in the lens barrel 4a, and a lens barrel adjusting mechanism 4e. The laser beam 20 having entered the laser beam focusing optics 4 is diverged by the concave lens 4b, collimated by the convex lens 4c, and focused by the convex lens 4d. The laser beam 20 focused by the convex lens 4d passes through the window 6 and enters the EUV light generating chamber 2. As the material of the concave lens 4b, the convex lenses 4c and 4d, and the window 6, such materials are desirable that little absorbs a laser beam 20 like synthetic quartz, CaF2, MgF2, or the like. When an infrared laser such as a CO2 laser is used as the driver laser 1, ZnSe, GaAs, Ge, Si, etc. are suitable for the material of the concave lens 4b, the convex lenses 4c and 4d, and the window 6. Furthermore, it is desirable that an anti-reflection (AR) coating by a dielectric multilayer film is applied to the surfaces of the concave lens 4b, the convex lenses 4c and 4d, and the window 6. Furthermore, the lens barrel adjusting mechanism 4e can adjust the position and angle (tilt angle) of the lens barrel 4a. FIGS. 3A and 3B show an example of the lens barrel adjusting mechanism 4e. It is desirable that, as shown in FIGS. 3A and 3B, the lens barrel adjusting mechanism 4e is able to adjust the tilt angles of the lens barrel 4a in the directions of θx and θy in the figures in order to adjust the angle of the optical axis of a laser beam and is able to move the lens barrel 4a in the directions of x-axis, y-axis, and z-axis as shown in the figures while keeping the tilt angles of the lens barrel 4a. Referring to FIG. 2 again, a temperature sensor 82 for detecting the temperature of the window 6 is attached to the window 6. As the temperature sensor 82, a sheath type thermocouple or the like, for example, can be used so as to maintain the vacuum state and clean state in the EUV light generating chamber 2. A signal or data representing the temperature of the window 6 detected by the temperature sensor 82 is sent to a laser beam optics deterioration determination processing unit 80 which executes processing for determining whether the window 6 is deteriorated or not. The laser beam optics deterioration determination processing unit 80 can be realized with a personal computer (PC) and a program. The laser beam optics deterioration determination processing unit 80 is connected with a warning light 81 for notifying, when the window 6 is determined to be deteriorated, a user (operator) of the fact. A laser beam 20 having passed through the window 6 and entered the EUV light generating chamber 2 is focused on the trajectory of the target material. As a result, the target material is excited and turned into plasma, and EUV light 21 is generated. In this way, incident light is once diverged and then focused, and thereby, the back focal distance can be made longer than the focal distance. Such optics is referred to as a retro-focus. The EUV light collector mirror 8 is, for example, a concave mirror having an Mo/Si film formed on the surface thereof, for reflecting light having a wavelength of 13.5 nm at a high reflectance, and reflects the generated EUV light 21 to the right in the figure to focus it on an IF (intermediate focusing point). The EUV light 21 reflected by the EUV light collector mirror 8 passes through a gate valve 10 provided on the EUV light generating chamber 2 and a filter 11 which eliminates unnecessary light (electromagnetic waves (light) having a shorter wavelength than EUV light, and light having a longer wavelength than EUV light, e.g. ultra violet light, visible light, infrared light, etc.) among light generated from plasma so as to pass only desired EUV light (e.g. light having the wavelength of 13.5 nm). The EUV light 21 focused on the IF (intermediate focusing point) is then guided to an exposure unit or the like through transmission optics. The EUV light source apparatus further includes a purge gas supply unit 31 for injecting and supplying purge gas, and a purge gas guiding path 37 for guiding the purge gas injected from the purge gas supply unit 31 to the surface of the window 6 on the internal side of the EUV light generating chamber 2. As the purge gas, inert gas (e.g. Ar, He, N2, Kr, or the like) is desirable. When the EUV light source apparatus does not generate EUV light, the purge gas supply unit 31 may not inject purge gas. Furthermore, a purge gas chamber 53 surrounding the window 6 is attached to the inner wall of the EUV light generating chamber 2. The upper side in the figure of the purge gas chamber 53 has a shape of a tapered cylinder, and on the tip (upper side in the figure) thereof is formed with an opening 53a to pass a laser beam 20 having transmitted through the window 6. Next, processing executed by the laser beam optics deterioration determination processing unit 80 will be described. FIG. 4 is a flow chart showing processing executed by the laser beam optics deterioration determination processing unit 80 when the EUV light source apparatus according to this embodiment generates EUV light. First, the laser beam optics deterioration determination processing unit 80 receives a signal or data representing the temperature T of the window 6 from the temperature sensor 82 (step S11). As previously described, when the window 6 is deteriorated, the window 6 absorbs a laser beam 20 and thereby the temperature of the window 6 rises. Hence, at step S12, the laser beam optics deterioration determination processing unit 80 determines whether the temperature T of the window 6 is equal to or less than a predetermined threshold Tth. When the temperature T of the window 6 is equal to or less than the predetermined threshold Tth, the processing unit 80 determines that the window 6 is not deteriorated, and returns the processing to step S11. When the temperature T of the window 6 is larger than the predetermined threshold Tth, the processing unit 80 determines that the window 6 is deteriorated, and advances the processing to step S13. When the temperature T of the window 6 is larger than the predetermined threshold Tth, in other words, when determining that the window 6 is deteriorated, the laser beam optics deterioration determination processing unit 80 notifies a user (operator) of the fact (step S13). The fact that the window 6 is deteriorated may be notified by lighting or flashing the warning light 81 or changing the flashing pattern of it, by sounding a buzzer or the like, or by displaying characters or images on a display device such as an LCD. Furthermore, at that time, the laser beam optics deterioration determination processing unit 80 may output an operation stop control signal to the driver laser 1 to stop the operation of the driver laser 1. As described above, according to this embodiment, when EUV light is generated, it can be easily detected and notified to a user (operator) that the window 6 is deteriorated, so that the user (operator) is able to appropriately determine whether the window 6 should be replaced or not. As a result, it becomes possible to generate EUV light with stability. In this embodiment, three lenses (concave lens 4b and convex lenses 4c and 4d) are used in the laser beam focusing optics 4, but four or more lenses may be used to reduce the aberration. Next, an EUV light source apparatus according to the second embodiment of the present invention will be described. FIGS. 5 and 6 are schematic diagrams showing an EUV light source apparatus according to this embodiment. FIG. 5 is a schematic diagram showing the state at EUV light generation of the EUV light source apparatus according to this embodiment, and FIG. 6 is a schematic diagram showing the state at EUV light non-generation of the EUV light source apparatus according to this embodiment. In FIGS. 5 and 6, the target material supply unit 3 and the target material collecting cylinder 7 (see FIG. 1) are omitted, and the target material is assumed to be injected in a direction perpendicular to the paper. As shown in FIGS. 5 and 6, the EUV light source apparatus includes a gate valve 16 and a laser beam detector 61 in addition to the EUV light source apparatus according to the first embodiment previously described (see FIG. 2). The gate valve 16 is closed when the EUV light source apparatus generates EUV light, and is opened when the EUV light source apparatus does not generate EUV light (see FIG. 6). For this reason, when the EUV light source apparatus generates EUV light, plasma, materials which have scattered from the inner wall, etc. of the EUV light generating chamber 12 because the wall, etc. have been cutaway (or sputtered) by the plasma, and the EUV light are not output to the outside of the EUV light generating chamber 12, being shielded by the gate valve 16. The operation at EUV light generation (see FIG. 5) of the EUV light source apparatus according to this embodiment is the same as that at EUV light generation of the EUV light source apparatus according to the first embodiment previously described, and in that case, the laser beam optics deterioration determination processing unit 80 executes the processing shown in the flow chart of FIG. 4 previously described. Next, the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment will be described with reference to FIG. 6. When the EUV light source apparatus does not generate EUV light, the target material supply unit 3 does not supply the target material into the EUV light chamber 12 and the gate valve 16 is opened, as previously described. For this reason, a laser beam which has transmitted through the window 6 and entered the EUV light generating chamber 12 passes through the gate valve 16 and exits upward in the figure from the EUV light generating chamber 12 while being dispersed without being applied to the target material. On the upper side in the figure of the gate valve 16, a laser beam detector 61 for detecting a laser beam which passes through the gate valve 16 and exits from the EUV light generating chamber 12 is located. For the laser beam detector 61, a pyroelectric sensor is suitable, from the viewpoint of resistance to a laser beam. A laser beam having passed through the gate valve 16 enters the laser beam detector 61, which detects the intensity of the incident laser beam. A signal or data representing the intensity of the laser beam detected by the laser beam detector 61 is sent to the laser beam optics deterioration determination processing unit 80. FIG. 7 is a flow chart showing processing executed by the laser beam optics deterioration determination processing unit 80. The laser beam optics deterioration determination processing unit 80 executes the processing shown in FIG. 7 when the EUV light source apparatus does not emit EUV light. First, the laser beam optics deterioration determination processing unit 80 receives a signal or data representing the intensity W of a laser beam from the laser beam detector 61 (step S21). As previously described, when the window 6 is deteriorated, the transmittance of the window 6 for a laser beam 20 decreases and thereby the intensity of a laser beam incident on the EUV light generating chamber 12 decreases. Hence, at step S22, the laser beam optics deterioration determination processing unit 80 determines whether the intensity W of a laser beam is equal to or larger than a predetermined threshold Wth. When the intensity W of the laser beam is equal to or larger than the predetermined threshold Wth, the processing unit 80 determines that the window 6 is not deteriorated, and finishes the processing. When the intensity W of the laser beam is less than the predetermined threshold Wth, the processing unit 80 determines that the window 6 is deteriorated, and advances the processing to step S23. When the intensity W of a laser beam is equal to or larger than the predetermined threshold Wth, the processing unit may return the processing to step S21 so as to repeatedly execute the laser beam intensity determination. When the intensity W of a laser beam is less than the predetermined threshold Wth, in other words, when determining that window 6 is deteriorated, the laser beam optics deterioration determination processing unit 80 notifies a user (operator) of the fact (step 823). The fact that the window 6 is deteriorated may be notified by lighting or flashing the warning light 81 or changing the flashing pattern of it, by sounding a buzzer or the like, or by displaying characters or images on a display device such as an LCD. As described above, according to this embodiment, also when EUV light is not generated, it can be easily detected and notified to a user (operator) that the window 6 is deteriorated. As a result, it can be determined more surely whether the window 6 is deteriorated or not. Furthermore, in this embodiment, the gate valve 16 is closed when the EUV light source apparatus generates EUV light (see FIG. 5), so that the laser beam detector 61 can be prevented from being destroyed by plasma, materials, which have scattered from the inner wall, etc. of the EUV light generating chamber 12 because the inner wall, etc. are cut away by the plasma, or the EUV light. Incidentally, a neutral density (ND) filter may be located on an optical path between the gate valve 16 and the laser beam detector 61 to adjust the intensity of a laser beam incident on the laser beam detector 61. Next, an EUV light source apparatus according to the third embodiment of the present invention will be described. FIGS. 8 and 9 are schematic diagrams showing an EUV light source apparatus according to this embodiment. FIG. 8 is a schematic diagram showing the state at EUV light generation of the EUV light source apparatus according to this embodiment, and FIG. 9 is a schematic diagram showing the state at EUV light non-generation of the EUV light source apparatus according to this embodiment. In FIGS. 8 and 9, the target material supply unit 3 and the target material collecting cylinder 7 (see FIG. 1) are omitted, and the target material is assumed to be injected in a direction perpendicular to the paper. First, the operation at EUV light generation of the EUV light source apparatus according to this embodiment will be described mainly with reference to FIG. 8, and then the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment will be described mainly with reference to FIG. 9. As shown in FIG. 8, a laser beam 20 emitted to the right in the figure from a driver laser 1 is diverged by a concave lens 41 and collimated by a convex lens 42, transmits through a window 6, and enters an EUV light generating chamber 13. In the EUV light generating chamber 13, a parabolic concave mirror 43 and a parabolic concave mirror adjusting mechanism 44 adjusting the position and angle (tilt angle) of the parabolic concave mirror 43 are located. As the substrate material of the parabolic concave mirror 43, synthetic quartz, CaF2, Si, Zerodur (registered trademark), Al, Cu, Mo, or the like may be used, and it is desirable that a reflective coating by a dielectric multilayer film is applied to the surface of such a substrate. Furthermore, as the parabolic concave mirror adjusting mechanism 44, a mechanism similar to that shown in FIGS. 3A and 3B may be used. The laser beam 20 having transmitted through the window 6 and entered the EUV light generating chamber 13 is reflected upward in the figure and focused on the trajectory of the target material by the parabolic concave mirror 43. As a result, the target material is excited and turned into plasma, and EUV light 21 is generated from the plasma. An EUV light collector mirror 8 reflects the generated EUV light 21 to the right in the figure to focus it on an intermediate focusing point (IF). The EUV light 21 reflected by the EUV light collector mirror 8 passes through a gate valve 10 and a filter 11. The EUV light 21 focused on the intermediate focusing point (IF) is then guided to an exposure unit or the like through transmission optics. The EUV light source apparatus further includes purge gas supply units 31 and 32, a purge gas guiding path 33 for guiding purge gas injected from the purge gas supply unit 31 to the surface of the window 6 on the internal side of the EUV light generating chamber 13, and a purge gas guiding path 34 for guiding purge gas injected from the purge gas supply unit 32 to the reflecting surface of the parabolic concave mirror 43. Furthermore, a purge gas chamber 50 which surrounds the window 6, the parabolic concave mirror 43, and the parabolic concave mirror driving mechanism 44 is attached to the inner wall of the EUV light generating chamber 13. The upper side in the figure of the purge gas chamber 50 has a shape of a tapered cylinder, and on the tip (upper side in the figure) thereof has an opening 50a to pass a laser beam 20 reflected by the parabolic concave mirror 43. On the upper part in the figure of the EUV light generating chamber 13, a gate valve 16 is located. When the EUV light source apparatus according to this embodiment generates EUV light (see FIG. 8), a laser beam optics deterioration determination processing unit 80 executes the processing shown in the flow chart of FIG. 4 previously described, using a signal or data from a temperature sensor 82 attached to the window 6. Next, the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment will be described with reference to FIG. 9. When the EUV light source apparatus does not generate EUV light, the target material supply unit 3 does not supply the target material into the EUV light generating chamber 13 and the gate valve 16 is opened as previously described. For this reason, a laser beam focused by the parabolic concave mirror 43 passes through the gate valve 16 and exits upward in the figure from the EUV light generating chamber 13 while dispersing without being applied to the target material. On the upper side in the figure of the gate valve 16, a laser beam detector 61 is located, and a laser beam having passed through the gate valve 16 enters the laser beam detector 61, which detects the intensity of the incident laser beam. A signal or data representing the intensity of the laser beam detected by the laser beam detector 61 is sent to the laser beam optics deterioration determination processing unit 80. When the EUV light source apparatus according to this embodiment does not generate EUV light (see FIG. 9), the laser beam optics deterioration determination processing unit 80 executes the processing shown in the flow chart of FIG. 7 previously described, using a signal or data from the laser beam detector 61. In this embodiment, the parabolic concave mirror 43 which is one of two or more optical elements constituting laser beam focusing optics is located in the EUV light generating chamber 13. Also when the reflecting surface of the parabolic concave mirror 43 is deteriorated, the reflectance of the parabolic concave mirror 43 for a laser beam decreases, and thereby the intensity of a laser beam irradiated onto the target material decreases. For this reason, when the intensity W of a laser beam detected by the laser beam detector 61 is less than the threshold Wth (see step S22 of FIG. 7), the laser beam optics deterioration determination processing unit 80 notifies that the window 6 and/or the parabolic concave mirror 43 are/is deteriorated (see step S23 of FIG. 7). As described above, according to this embodiment, when EUV light is not generated, it can be easily detected and notified to a user (operator) that the window 6 and/or the parabolic concave mirror 43 are/is deteriorated, so that the user (operator) is able to appropriately determine whether the window 6 and/or the parabolic concave mirror 43 should be replaced or not. As a result, it becomes possible to generate EUV light with stability. It is desirable that the concave lens 41, the convex lens 42, the window 6, and the parabolic concave mirror 43 are manufactured integrally as a unit to adjust the alignment (position and tilt angle) of the parabolic concave mirror 43 close to a design value, and the alignment of the parabolic concave mirror 43 has been finished so as to be able to obtain a designed laser beam focusing performance before the unit is built in the EUV light generating chamber 13. Furthermore, in this embodiment, two lenses (the concave lens 41 and the convex lens 42) are used in the laser beam focusing optics, but three or more lenses may be used. Next, an EUV light source apparatus according to the fourth embodiment of the present invention will be described. FIGS. 10 and 11 are schematic diagrams showing an EUV light source apparatus according to this embodiment. FIG. 10 is a schematic diagram showing the state at EUV light generation of the EUV light source apparatus according to this embodiment, and FIG. 11 is a schematic diagram showing the state at EUV light non-generation of the EUV light source apparatus according to this embodiment. In FIGS. 10 and 11, the target material supply unit 3 and the target material collecting cylinder 7 (see FIG. 1) are omitted, and the target material is assumed to be injected in a direction perpendicular to the paper. As shown in FIGS. 10 and 11, the EUV light source apparatus includes a convex lens 63 focusing a laser beam passed through the gate valve 16 in addition to the EUV light source apparatus according to the third embodiment (see FIGS. 8 and 9) previously described. Furthermore, the EUV light source apparatus according to this embodiment includes a laser beam detector 64 instead of the laser beam detector 61 of the EUV light source apparatuses according to the second and third embodiments previously described. The laser beam detector 64 has smaller size than the laser beam detector 61. The operation at EUV light generation of the EUV light source apparatus according to this embodiment (see FIG. 10) is the same as the operation at EUV light generation of the EUV light source apparatus according to the third embodiment previously described (see FIG. 8). Next, the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment (see FIG. 11) will be described. As shown in FIG. 11, when the EUV light source apparatus according to this embodiment does not generate EUV light, a laser beam passed through the gate valve 16 is focused by the convex lens 63 and enters the laser beam detector 64. At that time, the laser beam optics deterioration determination processing unit 80 executes the processing shown in the flow chart of FIG. 7 previously described, using a signal or data from the laser beam detector 64. According to this embodiment, the size of the laser beam detector 64 can be made smaller than that of the laser beam detector 61 in the second and third embodiments previously described by further providing the convex lens 63 focusing a laser beam passed through the gate valve 16. Next, an EUV light source apparatus according to the fifth embodiment of the present invention will be described. FIGS. 12 and 13 are schematic diagrams showing an EUV light source apparatus according to this embodiment. FIG. 12 is a schematic diagram showing the state at EUV light generation of the EUV light source apparatus according to this embodiment, and FIG. 13 is a schematic diagram showing the state at EUV light non-generation of the EUV light source apparatus according to this embodiment. In FIGS. 12 and 13, the target material supply unit 3 and the target material collecting cylinder 7 (see FIG. 1) are omitted, and the target material is assumed to be injected in a direction perpendicular to the paper. As shown in FIGS. 12 and 13, the EUV light source apparatus includes an area sensor 67 capable of detecting a two-dimensional image of a laser beam instead of the laser beam detector 64 of the EUV light source apparatus according to the fourth embodiment (see FIGS. 10 and 11) previously described. As the area sensor 67, a CCD area sensor, a CMOS area sensor, or the like maybe used. A convex lens 63 focuses a laser beam focused and then diverged by the parabolic concave mirror 43 so as to make a focus on the light-receiving surface of the area sensor 67. The area sensor 67 detects a two-dimensional image of an incident laser beam and sends an image signal representing the two-dimensional image to a laser beam optics deterioration determination processing unit 80. In this embodiment, the area sensor 67 is assumed to send an image signal of (N×M) pixels to the laser beam optics deterioration determination processing unit 80 (N and M are integers of two or larger). The operation at EUV light generation of the EUV light source apparatus according to this embodiment (see FIG. 12) is the same as the operation of the EUV light source apparatus according to the fourth embodiment previously described. Next, the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment will be described with reference to FIG. 13. As shown in FIG. 13, when the EUV light source apparatus according to this embodiment does not generate EUV light, a laser beam passed through a gate valve 16 is focused by the convex lens 63 and the image of the laser beam is formed on the light-receiving surface of the area sensor 67. FIG. 14 is a flow chart showing the processing executed by the laser beam optics deterioration determination processing unit 80 when the EUV light source apparatus according to this embodiment does not generate EUV light (see FIG. 13). First, the laser beam optics deterioration determination processing unit 80 receives an image signal (referred to as “image data” hereinafter) representing the two-dimensional image of a laser beam from the area sensor 67 (step 31). FIG. 15A shows an example of image data which the laser beam optics deterioration determination processing unit 80 receives from the area sensor 67. Next, the laser beam optics deterioration determination processing unit 80 performs pattern matching processing using a normalized cross-correlation function for predetermined template image data and shot image data, obtains the center coordinate P (x, y) of the focal spot of a laser beam in the shot image data, and calculates a correlation coefficient R at the time (step S32). In this embodiment, the template image data is image data of the focal spot of a laser beam at a normal state where the window 6 and the parabolic concave mirror 43 are not deteriorated and not deviated in alignment, and is assumed to be of (n×m) pixels (where n<N, m<M). FIG. 15B shows an example of template image. In the template image data shown in FIG. 15B, an offset in the direction of i-axis between the coordinate (0, 0) and the center coordinate of the focal spot is assumed to be ioff, and an offset in the direction of j-axis between them is assumed to be joff. Next, the pattern matching processing using a normalized cross-correlation function will be described. The pattern matching processing using a normalized cross-correlation function is processing of searching for an area having the highest correlation with the template image data (an area of (n×m) pixels in this embodiment) in shot image data by calculating a normalized cross-correlation coefficient NR(u, v) of each coordinate (u, v) of the shot image data with the following equation (1) and searching for the maximum value of the normalized cross-correlation coefficient NR(u, v) where each of the pixel values constituting the template image data is assumed to be T(i, j) (where 0≦i≦n−1 and 0≦j≦m−1) and each of the pixels constituting the shot image data is assumed to be F(u, v) (where 0≦u≦N−1 and 0≦v≦M−1) NR ⁡ ( u , v ) = ∑ i = 0 n - 1 ⁢ ∑ j = 0 m - 1 ⁢ ( F ⁡ ( i + u , j + v ) - F _ ⁡ ( u , v ) ) ⁢ ( T ⁡ ( i , j ) - T _ ) ∑ i = 0 n - 1 ⁢ ∑ j = 0 m - 1 ⁢ ( F ⁢ ( i + u , j + v ) - F _ ⁡ ( u , v ) ) 2 ∑ i = 0 n - 1 ⁢ ∑ j = 0 m - 1 ⁢ ( T ⁡ ( i , j ) - T _ ) 2 ⁢ ⁢ where ( 1 ) F _ ⁡ ( u , v ) = ∑ i = 0 n - 1 ⁢ ∑ j = 0 m - 1 ⁢ F ⁡ ( i + u , j + v ) n · m ( 2 ) T _ = ∑ i = 0 n - 1 ⁢ ∑ j = 0 m - 1 ⁢ T ⁡ ( i , j ) n · m ( 3 ) A value is assumed to be x which is obtained by adding the offset ioff previously described to the u-axis component umax of the coordinate (umax, vmax) of the shot image data by which the value of the equation (1) becomes the maximum, a value is assumed to be y which is obtained by adding the offset joff previously described to the v-axis component vmax of the coordinate (umax, vmax), and the coordinate (x, y) is assumed to be the center coordinate P (x, y) of a focal spot. Furthermore, NR(umax, vmax) is assumed to be a correlation coefficient R. In other words,x=umax+ioff (4)y=vmax+joff (5)R=NR(umax, vmax) (6) Referring to FIG. 14 again, the laser beam optics deterioration determination processing unit 80 integrates the pixel values of pixels lying within a predetermined radius r centering on the center coordinate P(x, y) of the focal spot and assumes the integrated value to be the intensity W of the laser beam (step S33). Next, at step S34, the laser beam optics deterioration determination processing unit 80 determines whether the intensity W of the laser beam is equal to or larger than a predetermined threshold Wth. When the intensity W of the laser beam is less than the predetermined threshold Wth, the processing unit 80 determines that the window 6 and/or the parabolic concave mirror 43 are/is deteriorated, and advances the processing to step S35. When the intensity W of the laser beam is equal to or larger than the predetermined threshold Wth, the processing unit 80 determines that the window 6 and the parabolic concave mirror 43 are not deteriorated, and advances the processing to step S38. In step S35, the laser beam optics deterioration determination processing unit 80 further determines whether the correlation coefficient R is equal to or larger than a predetermined threshold Rth. When the correlation b coefficient R is less than the predetermined threshold Rth, the processing unit 80 determines that the distribution of the focal point is abnormal, and that the window 6 and/or the parabolic concave mirror 43 are/is distorted, and advances the processing to step S36. When the correlation coefficient R is equal to or larger than the predetermined threshold Rth, the processing unit 80 determines that the distribution of the focal point is normal, and that the window 6 and the parabolic concave mirror 43 are not distorted, and advances the processing to step S37. When the intensity W of the laser beam is less than the predetermined threshold Wth and the correlation coefficient R is less than the predetermined threshold Rth, the laser beam optics deterioration determination processing unit 80 determines that the window 6 and/or the parabolic concave mirror 43 are/is deteriorated and that the window 6 and/or the parabolic concave mirror 43 is distorted, and notifies a user (operator) of the fact (step S36). In this case, the user (operator) is able to make the EUV light source apparatus normally generate EUV light by replacing the window 6 and/or the parabolic concave mirror 43. The fact that the window 6 and/or the parabolic concave mirror 43 are/is deteriorated and distorted may be notified by lighting or flashing a warning light 81 or changing the flashing pattern of it, by sounding a buzzer or the like, or by displaying characters or images on a display device such as an LCD. On the other hand, when the intensity W of the laser beam is less than the predetermined threshold Wth and the correlation coefficient R is equal to or larger than the predetermined threshold Rth, the laser beam optics deterioration determination processing unit 80 determines that the window 6 and/or the parabolic concave mirror 43 are/is deteriorated, and notifies the user (operator) of the fact (step S37). In this case also, the user (operator) is able to make the EUV light source apparatus normally generate EUV light by replacing the window 6 and/or the parabolic concave mirror 43. In step S38, the laser beam optics deterioration determination processing unit 80 determines whether the correlation coefficient R is equal to or larger than the predetermined threshold Rth also when the intensity W of the laser beam is equal to or larger than the predetermined threshold Wth. When the correlation coefficient R is less than the predetermined threshold Rth, the processing unit 80 determines that the focus of the laser beam is deviated in the direction of the optical axis of the laser beam (the direction of z-axis in FIGS. 3A and 3B), and advances the processing to step S39. When the correlation coefficient R is equal to or larger than the predetermined threshold Rth, the processing unit 80 determines that the focus of the laser beam is not deviated in the direction of the optical axis, and advances the processing to step S40. When the intensity W of the laser beam is equal to or larger than the predetermined threshold Wth and the correlation coefficient R is less than the predetermined threshold Rth, the laser beam optics deterioration determination processing unit 80 determines that the focus of the laser beam is deviated in the direction of the optical axis of the laser beam (the direction of z-axis in FIGS. 3A and 3B), and notifies a user (operator) of the fact (step S39). In this case, the user (operator) is able to make the EUV light source apparatus generate desired EUV light by operating the parabolic concave mirror adjusting mechanism 44 to move the parabolic concave mirror 43 in the direction of z-axis in FIGS. 3A and 3B. On the other hand, when the intensity W of the laser beam is equal to or larger than the predetermined threshold Wth and the correlation coefficient R is equal to or larger than the predetermined threshold Rth, the laser beam optics deterioration determination processing unit 80 further determines whether the center coordinate P (x, y) of the focal spot is located within a predetermined range (step S40). The processing unit 80 is able to determine whether the center coordinate P(x, y) of the focal spot is located within the predetermined range by determining whether x is located between predetermined thresholds xl and xh (see FIG. 15A), in other words, whether xl<x<xh holds, and by determining whether y is located between predetermined thresholds yl and yh (see FIG. 15A), in other wards, whether yl<y<yh holds. In step S40, the laser beam optics deterioration determination processing unit 80 determines that the window 6 and/or the parabolic concave mirror 43 are/is not deteriorated, distorted, nor deviated in alignment, and finishes the processing, when the center coordinate P(x, y) of the focal spot is located in the predetermined range, while The processing unit 80 determines that the focus of the laser beam is deviated in a direction different from the optical axis of the laser beam and the parabolic concave mirror 43 is deviated in x, y alignment, and advances the processing to step S41, when the center coordinate P(x, y) of the focal spot is not located in the predetermined range. When the parabolic concave mirror 43 is deviated in x, y alignment, the parabolic concave mirror 43 may be deviated in the direction of x-axis and/or the direction of y-axis in FIGS. 3A and 3B, or the tilt angle of the parabolic concave mirror 43 may be deviated in the θx direction and/or the θy direction in FIGS. 3A and 3B. While the window 6 and the parabolic concave mirror 43 have no abnormality, the processing unit 80 may return the processing to step S31 to repeatedly make determinations about the intensity of the laser beam. In step S41, the laser beam optics deterioration determination processing unit 80 notifies a user (operator) that the parabolic concave mirror 43 has been deviated in x, y alignment. In this case, the user (operator) is able to make the EUV light source apparatus generate desired EUV light by operating the parabolic concave mirror adjusting mechanism 44 to move the parabolic concave mirror 43 in the direction of x-axis and/or the direction of y-axis in FIGS. 3A and 3B and adjust the tilt angle of the parabolic concave mirror 43. As described above, according to this embodiment, when EUV light is not generated, it can be easily detected and notified to a user (operator) that the window 6 and/or the parabolic concave mirror 43 are/is deteriorated and/or distorted, and/or that the focus of the laser beam is deviated, so that the user (operator) is able to appropriately determine whether the window 6 and/or the parabolic concave mirror 43 should be replaced, and/or whether alignment adjustment should be made. As a result, EUV light can be generated with stability. In this embodiment, although it is assumed that a laser beam focused by the convex lens 63 is made directly enter the area sensor 67, the laser beam focused by the convex lens 63 may be made directly enter a visible fluorescent screen 68 to be converted to a visible beam, which may be focused by the convex lens 69 and entered in a common area sensor 70 which is sensitive to visible light. Thus, an inexpensive area sensor 70 which is sensitive to visible light can be used instead of the expensive area sensor 67 which is sensitive to a laser beam. Furthermore, even if the EUV light source apparatus according to this embodiment has been used for a long term and the visible fluorescent screen 68 is deteriorated, the area sensor 70 can be restricted from being deteriorated. In that case, only the visible fluorescent screen 68 which is cheaper than the area sensor 70 needs to be replaced while the area sensor 70 does not need to be replaced. Next, an EUV light source apparatus according to the sixth embodiment of the present invention will be described. FIGS. 17 and 18 are schematic diagrams showing an EUV light source apparatus according to this embodiment. FIG. 17 is a schematic diagram showing the state at EUV light generation of the EUV light source apparatus according to this embodiment, and FIG. 18 is a schematic diagram showing the state at EUV light non-generation of the EUV light source apparatus according to this embodiment. In FIGS. 17 and 18, the target material supply unit 3 and the target material collecting cylinder 7 (see FIG. 1) are omitted, and the target material is assumed to be injected in a direction perpendicular to the paper. As shown in FIGS. 17 and 18, the EUV light source apparatus includes a beam splitter 71 splitting a laser beam focused by the convex lens 63, and an area sensor 67 in the EUV light source apparatus according to the fifth embodiment (see FIGS. 12 and 13) previously described in addition to the EUV light source apparatus according to the fourth embodiment (see FIGS. 10 and 11) previously described. The operation at EUV light generation of the EUV light source apparatus according to this embodiment (see FIG. 17) is the same as that of the EUV light source apparatus according to the fifth embodiment previously described. Next, the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment will be described with reference to FIG. 18. When the EUV light source apparatus according to this embodiment does not generate EUV light, a laser beam passed through the gate valve 16 is focused by the convex lens 63 and split in a first direction (upward in the figure) and a second direction (rightward in the figure) by the beam splitter 71. A laser beam passed through the beam splitter 71 in the first direction enters the laser beam detector 64, and a laser beam passed through the beam splitter 71 in the second direction enters the area sensor 67. When the EUV light source apparatus according to this embodiment does not generate EUV light, the laser beam optics deterioration determination processing unit 80 executes the processing shown in the flow chart of FIG. 7 using a signal or data from the laser beam detector 64, and executes the processing shown in the flow chart of FIG. 14 using image data from the area sensor 67. As described above, according to this embodiment, the intensity of a laser beam can be detected by the laser beam detector 64, and the center coordinate, etc. of the laser beam can be detected by the area sensor 67. As a result, it can be determined more surely whether the window 6 and/or the parabolic concave mirror 43 are/is deteriorated and so on. Next, an EUV light source apparatus according to the seventh embodiment of the present invention will be described. FIGS. 19 and 20 are schematic diagrams showing an EUV light source apparatus according to this embodiment. FIG. 19 is a schematic diagram showing the state at EUV light generation of the EUV light source apparatus according to this embodiment, and FIG. 20 is a schematic diagram showing the state at EUV light non-generation of the EUV light source apparatus according to this embodiment. In FIGS. 19 and 20, the target material supply unit 3 and the target material collecting cylinder 7 (see FIG. 1) are omitted, and the target material is assumed to be injected in a direction perpendicular to the paper. First, the operation at EUV light generation of the EUV light source apparatus according to this embodiment will be described with reference to mainly FIG. 19, and then the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment will be described with reference to mainly FIG. 20. As shown in FIG. 19, a laser beam 20 emitted upward in the figure from a driver laser 1 is diverged by a concave lens 45 and collimated by a convex lens 46, passes through a beam splitter 72 and a window 6, and enters an EUV light generating chamber 14. In the EUV light generating chamber 14, a spherical concave mirror 47 and a spherical concave mirror adjusting mechanism 48 adjusting the position and angle (tilt angle) of the spherical concave mirror 47 are located. The laser beam 20 passed through the window 6 and entered the EUV light generating chamber 14 is reflected downward in the figure by the spherical concave mirror 47 to be focused on the trajectory of the target material. As a result, the target material is excited and turned into plasma, and EUV light 21 is generated. An EUV light collector mirror 8 reflects the generated EUV light 21 to the right in the figure to focus it on an intermediate focusing point (IF). The EUV light 21 reflected by the EUV light collector mirror 8 passes through a gate valve 10 provided in the EUV light generating chamber 14, and a filter 11. The SIN light 21 focused on the intermediate focusing point (IF) is then guided to an exposure unit or the like through transmission optics. The EUV light source apparatus further includes purge gas supply units 31 and 32, a purge gas guiding path 35 for guiding purge gas injected from the purge gas supply unit 31 to a surface of the window 6 on the internal side of the EUV light generating chamber 14, and a purge gas guiding path 36 for guiding purge gas injected from the purge gas supply unit 32 to a reflecting surface of the spherical concave mirror 47. In addition, a purge gas chamber 51 which surrounds the window 6, and a purge gas chamber 52 which surrounds the spherical concave mirror 47 and the spherical concave mirror driving mechanism 48, are located in the EUV light generating chamber 14. The upper side in the figure of the purge gas chamber 51 has shape of a tapered cylinder, and on the tip (upper side in the figure) thereof has an opening 51a for passing a laser beam 20 passed through the window 6. Furthermore, the lower side in the figure of the purge gas chamber 52 has shape of a tapered cylinder, on the tip (lower side in the figure) thereof has an opening 52a for passing a laser beam 20 passed through the window 6 and a laser beam 20 reflected by the spherical concave mirror 47. When the EUV light source apparatus according to this embodiment generates EUV light (see FIG. 19), a laser beam optics deterioration determination processing unit 80 executes the processing shown in the flow chart of FIG. 4 previously described, using a signal or data from a temperature sensor 82 attached to the window 6. Next, the operation at EUV light non-generation of the EUV light source apparatus according to this embodiment will be described with reference to FIG. 20. When the EUV light source apparatus does not generate EUV light, the target material supply unit 3 does not supply the target material into the EUV light generating chamber 14 as previously described. For this reason, a laser beam focused by the spherical concave mirror 47 passes through the window 6 and exits downward in the figure from the EUV light generating chamber 14 while being dispersing without irradiating onto the target material. The laser beam which is emitted downward in the figure from the EUV light generating chamber is reflected to the left in the figure by the beam splitter 72 and focused by the convex lens 63, and enters the laser beam detector 64. When the EUV light source apparatus according to this embodiment does not generate EUV light, the laser beam optics deterioration determination processing unit 80 executes the processing shown in the flow chart of FIG. 7 previously described. According to this embodiment, the spherical concave mirror 47 may correct the chromatic aberrations of the concave lens 45 and the convex lens 46 and therefore the laser beam 20 may be focused more efficiently comparing to the case where a parabolic concave mirror is used. As a result, EUV light can be efficiently generated. In stead of or in addition to the laser beam detector 64, an area sensor 67 maybe provided. In that case, the laser beam optics deterioration determination processing unit 80 may execute the processing shown in the flow chart of FIG. 14 when the EUV light source apparatus according to this embodiment does not generate EUV light. Next, an EUV light source apparatus according to the eighth embodiment of the present invention will be described. FIG. 21 is a schematic plan view showing the outline of an EUV light source apparatus according to this embodiment, and FIG. 22 is its schematic elevation view. The EUV light source apparatus of this embodiment is characterized in that it is able to accurately detect deterioration, etc. in laser beam focusing optics of an EUV light generating chamber and thereby promptly cope with a reduction and a fluctuation in the efficiency of EUV light generation. The EUV light source apparatus of this embodiment includes, as shown in the figures, a driver laser 1, an EUV light generating chamber 2, a target material supply unit 3, and laser beam focusing optics including a beam expander 41a. The EUV light source apparatus of this embodiment is a system efficiently causing plasma emission by irradiating a target droplet with a pre-pulse laser beam to expand the target or turn the target into plasma and irradiating the target which has been expanded or turned into plasma with a main pulse laser beam. The driver laser 1 is a master oscillator power amplifier type laser apparatus generating a drive laser beam used for exciting the target material, and includes a main pulse laser 17 and a pre-pulse laser 18 as shown in FIG. 21 with a chain line. As the driver laser 1, publicly known various lasers (for example, ultra violet lasers such as KrF and XeF and infrared lasers such as Ar, CO2, and YAG) can be used. The EUV light generating chamber 2 is a vacuum chamber in which EUV light is generated. Windows 6a and 6b to pass laser beams generated by the main pulse laser 17 and the pre-pulse laser 18 of the driver laser 1 to the inside of the EUV light generating chamber 2 are attached to the EUV light generating chamber 2. In addition, a target injection nozzle of the target material supply unit 3, a target collecting cylinder 7, and an EUV light collector mirror 8 are located in the EUV light generating chamber 2. The target material supply unit 3 supplies the target material used to generate EUV light into the EUV light generating chamber 2 through the target injection nozzle. Target material which has remained without being irradiated with a laser beam of the supplied target material is collected by the target collecting cylinder 7. As a target material, publicly known various material (e.g. tin (Sn), xenon (Xe), etc.) can be used. Furthermore, the state of the target material may be any one of solid, liquid, and gas, and may be supplied to the space in the EUV light generating chamber 2 in any publicly known state such as a continuous flow (target injection flow) or a droplet. For example, when liquid xenon (Xe) target is used as the target material, the target material supply unit 3 is composed of a gas cylinder which supplies high purity xenon gas, a mass flow controller, a cooling apparatus to liquefy xenon gas, a target injection nozzle, etc. On the other hand, when tin (Sn) is used as the target material, the target material supply unit 3 is composed of a heating apparatus for heating to liquefy Sn, a target injection nozzle, etc. Furthermore, when droplets are to be generated, a vibrator such as a piezoelectric element is added to the configuration. The target material supply unit 3 is controlled by a droplet controller 30 and supplies the target material into the EUV light generating chamber 2 when the EUV light source apparatus generates EUV light, while the target material supply unit 3 does not supply the target material into the EUV light generating chamber 2 when the EUV light source apparatus does not generate EUV light. Pre-pulse laser beam focusing optics is composed of a beam expander 41b, a window 6b, and a parabolic concave mirror 43b, and focuses a laser beam emitted from the pre-pulse laser 18 so as to make a focus on the trajectory of the target material through an opening 54b. Furthermore, main pulse laser beam focusing optics is composed of a beam expander 41a, a window 6a, and a parabolic concave mirror 43a, and focuses a laser beam emitted from the main pulse laser 17 so as to make a focus on the target material 9 expanded by a pre-pulse laser beam. As a result, the target material 9 is excited and turned into plasma, and EUV light is generated. The laser beam focusing optics may be composed of one optical element (e.g. one piece of convex lens, or the like), and may be composed of two or more optical elements. When laser beam focusing optics is composed of two or more optical elements, some of them may be located in the EUV light generating chamber 2. When an excimer laser, a harmonic light of a YAG laser, or a fundamental wave YAG laser is used as the main pulse laser 17 or the pre-pulse laser 18, the material of the concave lenses and the convex lenses constituting the expanders 41a and 41b, and the windows 6 is desirable to be selected from material absorbing little of a laser beam, such as synthetic quartz, CaF2, MgF2, or the like. When an infrared laser such as a CO2 laser is used as the main pulse laser 17, ZnSe, GaAs, Ge, Si, diamond, etc. are suitable for the material of the concave lenses, the convex lenses, and the windows 6. Furthermore, it is desirable that an anti-reflection (AR) coating by a dielectric multilayer film is applied to the surfaces of the concave lenses, the convex lenses, and the windows 6. The EUV light collector mirror 8 is an elliptical concave mirror having an Mo/Si film formed on the surface thereof for reflecting light having a wavelength of 13.5 nm, for example, at a high reflectance, and focuses the EUV light generated from plasma by reflecting the EUV light and guides it to transmission optics. Thereafter, the EUV light is guided to an exposure unit or the like through the transmission optics. As shown in FIG. 21, a pre-pulse laser beam is expanded by the beam expander 41b, part of the expanded laser beam is branched by a beam splitter 71b and enters a power meter 25b through a convex lens 26b, and thus an output Wp0 of the pre-pulse laser before entering the EUV light generating chamber 2 is monitored. On the other hand, a pre-pulse laser beam transmitted through the beam splitter 71b passes through the window 6b, enters the EUV light generating chamber 2, is incident and reflected by an off-axis parabolic concave mirror 43b, and is focused and irradiated onto a droplet 9 supplied from the target material supply unit 3 in synchronization with the timing of the droplet 9 arriving at a predetermined position. Then, the droplet 9 onto which the laser beam has been irradiated is instantaneously expanded or turned into plasma. On the other hand, a main pulse laser beam is expanded by the beam expander 41a and split by a beam splitter 71a, split part of the expanded laser beam enters a power meter 25a through a convex lens 26a, and thus an output Wm0 of the main pulse laser before entering the EUV light generating chamber 2 is monitored. The remainder after the split transmits through the window 6a, enters the EUV light generating chamber 2, is incident and reflected by an off-axis parabolic concave mirror 43a, and is focused and irradiated onto a target which has been expanded by a pre-pulse laser beam through an opening 54a. Since the main pulse laser beam irradiates a droplet 9 which has been expanded or turned into plasma by being irradiated with the pre-pulse laser beam, EUV light generation with a high efficiency of conversion to EUV can be achieved. As the substrate material of the parabolic concave mirror 43b for focusing a pre-pulse laser beam, synthetic quartz, CaF2, Si, Zerodur (registered trademark), Al, Cu, Mo, or the like may be used, and it is desirable that a high reflective coating by a dielectric multilayer film is applied to the surface of such a substrate. Furthermore, when the main pulse laser 17 is a CO2 laser, Cu or the like in which a cooling apparatus is built may be used as the substrate material of the parabolic concave mirror 43a for focusing a main pulse laser beam, and it is desirable that a high reflective coating by Au is applied to the surface of such a substrate. The EUV light source apparatus of this embodiment includes temperature monitors installed on laser optical elements. Temperature sensors 82a, 82b, 82c, and 82d such as thermometers, platinum resistance temperature detectors, or radiation thermometers are installed on the window 6a and the parabolic concave mirror 43a for the main pulse laser and the window 6b and the parabolic concave mirror 43b for the pre-pulse laser. If these optical elements are deteriorated, they absorb the laser beam, generate heat, and rise in temperature. For this reason, the temperature sensors are provided to detect deterioration of the optical elements by detecting the temperatures thereof. The EUV light source apparatus of this embodiment further includes a laser dumper-calorimeter 35a for the main pulse laser beam and a laser dumper-calorimeter 35b for the pre-pulse laser beam, and is able to measure energies in a target position (focal point 15) of the pre-pulse laser beam and the main pulse laser beam. When the energy in the target position (focal point 15) of the laser beam is measured, the laser beam optics deterioration determination processing unit 80 sends a command to the droplet controller 30 and the main pulse laser 17 or the pre-pulse laser 18 so that there is no droplet in the focal point 15 position at a time when the laser beam is focused and irradiated thereto. The pre-pulse laser beam is once focused on the focal point 15 by the parabolic concave mirror 43b, and passes through the focal point 15 without colliding with a droplet. After that, while spreading, the pre-pulse laser beam passes through the opening 55a, passes through the window 6c, enters the laser dumper-calorimeter 35b, and is absorbed by the laser dumper-calorimeter 35b. The energy Wp at the focal point 15 of the pre-pulse laser beam is detected by a calorimeter part of the laser dumper-calorimeter 35b. Furthermore, the main pulse laser beam is once focused on the focal point 15 by the parabolic concave mirror 43a, and passes through the focal point 15 without colliding with a droplet. After that, while spreading, it enters the laser dumper-calorimeter 35a and is absorbed by the laser dumper-calorimeter 35a. The energy Wm at the focal point 15 of the main pulse laser beam is detected by a calorimeter part of the laser dumper-calorimeter 35a. It is desirable that debris shields surrounded with walls excluding portions which open in the shape of a funnel toward the focal point 15 are installed in order to protect the windows 6a, 6b, and 6c and the parabolic concave mirrors 43a and 43b from debris. As shown in FIG. 21, the focal point 15 of the laser beam is a point where the optical path of the main pulse laser beam traveling in parallel with the paper in the figure and the optical path of the pre-pulse laser beam traveling in a direction perpendicular to the main pulse laser beam cross the trajectory of a droplet 9 perpendicular to the paper. In the case of metal target such as Sn, when the target is expanded or turned into plasma by the pre-pulse laser beam, the center position of the target expanded or turned into plasma may be somewhat displaced. In such a case, the focal point of the pre-pulse laser beam does not always meet the focal point of the main pulse laser beam. However, the displacement between two of the focal points is very small, so that no error is caused in detecting the energies of both of the laser beams. In this specification, it is described that the focal points 15 meet each other. However, even if there is a distance between two of the focal points, it is so small that there is no problem in applying this embodiment. Methods of preventing any droplet from existing on a focal point 15 when measuring irradiated energy of laser beams include the following three methods. (a) A method of measuring energies of the main pulse laser beam and the pre-pulse laser beam while stopping generation of droplets. This method has an advantage of measuring energies without changing the optical axes of both of the laser beams. (b) A method of measuring energies of the laser beams while avoiding a collision between a droplet and the pulse laser beam by shifting the droplet generation timing or the oscillation timing of the main pulse laser beam or the pre-pulse laser beam. If generation of droplets is once stopped, considerable time is needed until droplets are regularly generated. This method has an advantage of needing only short time to return to a normal state because only the timing of droplet generation is shifted. Furthermore, the optical axes of the laser beams are not changed. On the other hand, the method of measuring energies of the laser beams while avoiding collision between droplets and the laser beams by shifting the oscillation timing of the main pulse laser beam or the pre-pulse laser beam has an advantage that the rise time of EUV light can be short enough because it is not necessary to change the droplet generation timing, but only the laser oscillation timing should be changed, and therefore a very stable state can be maintained with respect to the optical axes of both of the lasers and the droplet generation timing. (c) A method of measuring energy of the laser beams in such a way that the generation of droplets is left as it is and the optical axes of the main pulse laser beam and the pre-pulse laser beam are slightly shifted from a target so that each of them does not contact with the droplet or the target expanded or turned into plasma. This method has an advantage that the rise time at the re-start can be short because the energies of laser beams are detected while steady generation of the droplets without stopping falls of the droplets. FIG. 23 is a main flow chart illustrating an example of a procedure of detecting laser optics deterioration executed by the laser beam optics deterioration determination processing unit 80 in the EUV light source apparatus of this embodiment. The laser beam optics deterioration determination processing unit 80 first executes a laser optical element abnormality diagnosis necessity determination subroutine (S101), and determines whether a deterioration diagnosis for laser optical element is made or not. When it is determined that the diagnosis is not made (in the case of NO), the procedure returns to S101 and executes the subroutine again and again until the deterioration diagnosis is to be made. On the other hand, when it is determined that an optical element deterioration diagnosis is to be made (in the case of YES), the procedure goes to the next step, and a droplet non-radiation control subroutine (S102) is executed. Subsequently, a laser optical element deterioration detection subroutine (S103) is executed. Based on the result of the subroutine, a laser optical element deterioration determination subroutine (S104) is executed with respect to the pre-pulse laser and the main pulse laser. When it is determined that there is deterioration (YES), the procedure goes to step S105, where an output is sent to the warning light to notify an operator and an exposure equipment controller that optical element deterioration has occurred. After that the EUV light source apparatus is stopped (S107). On the other hand, when the laser optical element deterioration determination subroutine (S104) is executed with respect to the pre-pulse laser and the main pulse laser and it is determined that the deterioration is in an allowable range (NO), the procedure goes to a laser optical element no-abnormality subroutine (S106). After that, the procedure returns to the first step S101 and repeats this routine. FIGS. 24 and 25 are flow charts showing the contents of the laser optical element abnormality diagnosis necessity determination subroutine (S101). As criteria of determining whether an abnormality diagnosis of optical element is necessary or not, a criterion based on an elapsed time from the last diagnosis, a criterion based on EUV light output, a criterion based on a cumulative value of the number of laser beam pulses after the last diagnosis, and a criterion based on the temperatures of optical elements of the laser beam focusing optics provided in the EUV light generating chamber are used. Some of these criteria may be selected and used, or all of them may be used, and if any one of them is not satisfied, an abnormality diagnosis may be made. An optical element temperature management routine (a) is shown in FIG. 24, and a time management routine (b), an EUV light output management routine (c), and a pulse number management routine (d) are shown in FIG. 25. These routines are shown to be executed individually. If these routines are connected in series and the procedure goes to the next routine when one routine is executed and the result of NO is obtained, an abnormality diagnosis may be made when all conditions are checked and any one of them is satisfied. The optical element temperature management routine (a) is a routine for managing the temperatures of optical elements and determining that an abnormality diagnosis is made when the temperature of any one of the optical elements each of which is managed in temperature exceeds a predetermined threshold. First, it is determined whether the temperature T1 of the window 6a for the main pulse laser exceeds its threshold T1th,whether the temperature T2 of the parabolic concave mirror 43a for the main pulse laser exceeds its threshold T2th,whether the temperature T3 of the window 6b for the pre-pulse laser exceeds its threshold T3th,or whether the temperature T4 of the parabolic concave mirror 43b for the pre-pulse laser exceeds its threshold T4th (S131). When any one of the temperatures exceeds its threshold, it is notified an operator or external equipment such as exposure equipment that abnormality has occurred on any optical element for the lasers (S132), and it is determined that an abnormality diagnosis is necessary (YES) (S113), and the processing exits the temperature management routine. On the other hand, when all of the temperatures of optical elements to be managed do not exceed their threshold at step S131, it is determined that no abnormality diagnosis is necessary (NO) (S134), and the processing exits the temperature management routine. When either a window or a parabolic concave mirror which is located in the EUV light generating chamber and may be contaminated by debris, of optical elements in focusing optics for a driver laser, is deteriorated in the optical characteristic, the window or the parabolic concave mirror excessively absorbs a laser beam to become hotter than the normal state. So that when the temperature rise is detected with a temperature sensor by the optical element temperature management routine, the presence of abnormality can be confirmed by further executing an abnormality diagnosis procedure. If a temperature sensor which measures a higher temperature than a threshold is identified, an optical element which is possibly deteriorated can be identified. In addition, it is not determined by the optical element temperature management routine whether an abnormality diagnosis is necessary or not, but a deteriorated optical element may be identified directly from a result obtained by executing this routine and may be given with a warning. The time management routine (b) is a routine for making an abnormality diagnosis in a fixed cycle. It is determined using a timer whether measured time has reached time K which is a diagnosis cycle (S201). When the measured time is less than time K, it is determined that no abnormality diagnosis is necessary (NO), and the processing exits this routine. When time K has passed, the timer is reset (S202) and it is determined that an abnormality diagnosis is necessary (YES) (S203), and the processing exits the time management routine. The EUV light output management routine (c) is a routine for monitoring an EUV light output and making an abnormal diagnosis if the EUV light output does not reach a predetermined value. An EUV light output Eeuv measured by an EUV light output measuring device is compared with a predetermined threshold Eeuvth (S211). When Eeuv is not less than Eeuvth, it is determined that no abnormality diagnosis is necessary (NO) (S212), and the processing exits this routine. When Eeuv is less than Eeuvth, it is determined that an abnormality diagnosis is necessary (YES) (S212), and the processing exits the EUV light output management routine. The pulse number management routine (d) is a routine for making an abnormality diagnosis whenever the number of EUV light irradiation pulses reaches a predetermined number. The number of EUV light pulses N is counted by a counter and the counter value is compared with a preset threshold Nth (S221). When N does not exceed Nth, it is determined that no abnormality diagnosis is necessary (NO) (S224), and the processing exits this routine. When N exceeds Nth, the counter is reset (S222) and it is determined that an abnormality diagnosis is necessary (YES) (S223), and the processing exits the pulse number management routine. FIG. 26 is a flow chart showing the contents of the droplet non-radiation control subroutine (S102). The laser beam optics deterioration determination processing unit 80 previously selects and executes one of three methods of preventing any droplet from existing on a focal point 15 of a laser beam in order to measure the application energy of the laser beam on the fecal point 15. Thus, the droplet non-radiation control subroutine (S102) has a droplet generation stop routine (a), a droplet/laser beam timing changing routine (b), and a pulse laser optical axis changing routine (c), and the laser beam optics deterioration determination processing unit 80 executes any one of the routines previously selected. The droplet generation stop routine (a) is a routine for outputting a droplet generation stop signal to the target material supply unit 3 through the droplet controller 30 (S301) to stop the droplet generation and then returning. Since no droplet come to exist on the focal point 15 of the laser beam by executing this routine, a pre-pulse laser beam and a main pulse laser beam come to enter the calorimeter without being applied to a droplet. The drop/laser beam timing changing routine (b) is a routine for shifting the droplet generation timing of the target material supply unit 3 from the pre-pulse laser beam oscillation timing and the main pulse laser beam oscillation timing through the droplet controller 30, or shifting these pulse laser oscillation timings from the droplet generation timing through the pre-pulse laser controller and the main pulse laser controller so as to apply no pulse laser beam to a droplet (S311) and then returning. The pulse laser optical axis changing routine (c) is a routine for slightly changing the optical axis of the pre-pulse laser and the optical axis of the main pulse laser from the trajectory of a droplet (S321) to make both of the pulse laser beams enter the calorimeter without contacting with the droplet and then returning. Since the diameter of a droplet is the order of 30 to 100 μm, it is sufficient to shift the optical axes by about several hundreds of μm, and the shift of the optical axes does not influence the energy measurements of both of the pulse lasers. FIG. 27 is a flow chart showing the contents of a first example of the laser optical element deterioration detection subroutine (S103). The laser beam optics deterioration determination processing unit 80 measures the application energy of a laser beam on a focal point 15, and detects a laser optical element deterioration state based on decline of the energy output. The laser optical element deterioration detection subroutine (S103) is composed of a routine for detecting deterioration about main pulse laser optical elements (a) and a routine for detecting deterioration about pre-pulse laser optical elements (b). The main pulse laser optical element deterioration detection routine (a) first detects an output Wm0 of the main pulse laser before entering the EUV light generating chamber 2 with the power meter 25a for the main pulse laser (S401). Next, the main pulse laser optical element deterioration detection routine (a) measures an output Wm at the focal point 15 of the main pulse laser with the laser dumper-calorimeter 35a for the main pulse laser (S402), and then advances to the next pre-pulse laser optical element deterioration detection routine. The pre-pulse laser optical element deterioration detection routine (b) first detects an output Wp0 of the pre-pulse laser before entering the EUV light generating chamber 2 with the power meter 25b for the pre-pulse laser (S403). Next, the pre-pulse laser optical element deterioration detection routine (b) measures an output Wp at the focal point 15 of the pre-pulse laser with the laser dumper-calorimeter 35b for the pre-pulse laser, and then returns to the main routine. The measurements of the output Wm0 of the main pulse laser before entering the EUV light generating chamber 2 and the output Wp0 of the pre-pulse laser before entering the EUV light generating chamber 2 may be substituted with the outputs of the power monitors contained in the lasers. FIG. 28 is a flow chart showing the contents of the laser optical element deterioration determination subroutine (S104). The laser beam optics deterioration determination processing unit 80 calculates the transmittances of optical elements installed in the EUV light generating chamber 2 among optical elements used for the pre-pulse laser and the main pulse laser, and determines the deterioration states of them. The laser optical element deterioration determination subroutine (S104) first calculates the total transmittances Tm and Tp of optical elements used for the main pulse laser and the pre-pulse laser according to the following formulas using the laser outputs Wm0 and Wp0 before entering the EUV light generating chamber 2 and the laser outputs Wm and Wp at the focal point 15 (S501).Tm=Wm/Wm0Tp=Wp/Wp0 Next, this subroutine compares the total transmittances Tm and Tp with the transmittance lower limit thresholds Tmt and Tpt (S502) to determine the deterioration states of the optical elements. If any of the total transmittances Tm and Tp of the main pulse laser and the pre-pulse laser is less than the respective lower limit thresholds Tmt and Tpt, this subroutine determines that any optical element is deteriorated, notifies abnormality (S503) determines that there is any deterioration (YES) (S504), and returns to the main routine. If any of the total transmittances Tm and Tp does not reach the respective lower limit threshold Tmt and Tpt, this routine determines that there is no deterioration (NO) (S505), and returns to the main routine. When the laser optical element deterioration determination subroutine (S104) determines that the deterioration of the optical elements of the pre-pulse laser and the main pulse laser is in an allowable range, the laser beam optics deterioration determination processing unit 80 executes the laser optical element no-abnormality notification subroutine (S106). FIG. 29 is a flow chart showing the contents of the laser optical element no-abnormality notification subroutine (S106). This subroutine first notifies an operator or exposure equipment that there is no abnormality in the optical elements for the lasers (S601). Then, this subroutine substitutes the respective total transmittances Tmc and Tpc of the optical elements of the main pulse laser and the pre-pulse laser with the latest measured values Tm and Tp, (S602) so as to make a determination indicator accurately reflect the current status.Tmc=TmTpc=Tp This subroutine may store transmittance changes of the optics of the lasers with time. In addition, this subroutine calculates output energies Em and Ep required for the pulse lasers from the total transmittances and the laser beam energies Emt and Ept needed at the focal point 15 using the following formulas (S603), and then returns to the main flow.Em=Emt/Tmc Ep=Ept/Tpc The laser beam optics deterioration determination processing unit 80 adjusts the outputs of the lasers based on this result, which is not shown in the flow chart. In the main flow, the energies of the main pulse laser 17 and the pre-pulse laser 18 are controlled using the latest total transmittances Tmc and Tpc of the optical elements of the main pulse laser and the pre-pulse laser, respectively. The following advantages can be expected by the above processing. (1) Since laser beams can be focused and applied to a droplet based the latest transmittances of the optics for the lasers, the pulse energy of EUV light can be stabilized. (2) Deterioration of the optics of the lasers can be predicted by measuring the transmittance variations with time of the optics of the both lasers, and preventive maintenance can be performed. For example, the EUV light source apparatus can be prevented from suddenly stopping and replaced and repaired at a convenient time for maintenance by warning in advance, and therefore the downtime of the apparatus decreases. FIG. 30 is a schematic diagram showing the outline of an EUV light source apparatus according to the ninth embodiment of the present invention. The EUV light source apparatus of this embodiment is different from the EUV light source of the eighth embodiment only in that a calorimeter for a main pulse laser beam is located so as to be protected against debris, and other components are almost the same. In other words, a laser dumper-calorimeter 35c for the main pulse laser beam is located outside an opening 56a provided on the wall of the EUV light generating chamber 2, instead of being located close to the focal point 15. Then, the main pulse laser beam which is once focused on the focal point 15 and then disperses is reflected and focused again by a concave mirror 27, passes through a hole of the opening 56a forming a debris shield and through a window 6d, and reaches the laser dumper-calorimeter 35c. In addition, the concave mirror 27 is stored in usual in a protection housing of a focusing (or collimating) mirror exchanging device 28 and protected against debris, and is inserted into the path of the main pulse laser beam by a mirror exchanging actuator 29 only at measurement. Thus, the concave mirror 27 is not contaminated by debris and little deteriorated. Furthermore, the laser dumper-calorimeter 35c is effectively prevented by the debris shield and the window 6d from being deteriorated by debris. When the total transmittance of the optical elements for the main pulse laser is measured, the concave mirror 27 which is not contaminated and not deteriorated is drawn out and used, so that an accurate measurement result can be obtained. Power meters which measure outputs before the main pulse laser beam and the pre-pulse laser beam enter the EUV light generating chamber 2 are not shown in FIG. 30. The power meters can be substituted by the laser output monitors contained in the lasers and the measured values of the laser output monitors can be assumed to be Wm0 and Wp0. Furthermore, after the energy of the main pulse laser beam has been measured, the concave mirror 27 which is not deteriorated may be returned into the housing of the focusing (or collimating) mirror exchanging device 28, and a regularly used original concave mirror may be used to dump the main pulse laser beam incident on the mirror to the laser dumper-calorimeter 35c. Furthermore, a laser dump may be provided in the downstream of the concave mirror 27 and dump the laser beam to the laser dump after the concave mirror 27 is retracted. FIG. 31 is a flow chart showing the contents of the laser optical element deterioration detection subroutine of the second example (S103) which is applied instead of the laser optical element deterioration detection subroutine of the first example, when the main flow chart of the EUV light source apparatus of the present invention is applied to the ninth embodiment. The subroutine of the second example is mainly different from the subroutine of the first example in the main pulse laser optical element deterioration detection routine (a), and there is little difference in other parts between them. The laser optical element deterioration detection subroutine (S103) of the second example will be described below. The main pulse laser optical element deterioration detection routine (a) of the laser optical element deterioration detection subroutine (S103) of the second example, first conducts the work of drawing the reference concave mirror 27 which has not been contaminated with debris from the housing of the focusing (or collimating) mirror exchanging device 28 and placing it in a measurement optical path (S411). Next, this routine uses the power monitor contained in the main pulse laser to output main pulse laser beam fixed with the power at Wm0 (S412). This routine measures an output Wm of the main pulse laser at the focal point 15 with the laser dumper-calorimeter 35c for the main pulse laser (S413), replaces the reference concave mirror 27 with the original mirror (S414), and goes to the next pre-pulse laser optical element deterioration detection routine (b). In the pre-pulse laser optical element deterioration detection routine (b), the pre-pulse laser apparatus first outputs pre-pulse laser beam fixed with the power at Wp0 (S415). The laser dumper-calorimeter 35b for the pre-pulse laser then measures an output Wp at the focal point 15 of the pre-pulse laser in this routine (S416) and the routine returns to the main routine. FIG. 32 is a schematic diagram showing the outline of an EUV light source apparatus according to the tenth embodiment of the present invention, and FIG. 33 is a cooling water circulation circuit diagram in the tenth embodiment. The EUV light source apparatus of this embodiment is characterized in that cooling water is supplied to the laser optical elements to perform waste heat amount management as compared with the EUV light source apparatus of the ninth embodiment shown in FIG. 30. Other components are almost the same. Since the output of the main pulse laser is 10 to 20 kW, even if surface deterioration has not occurred on the optical elements, the wave front is distorted because of heat generation, so that it is desirable that the optical elements are cooled to maintain the focusing performance. Hence, in the EUV light source apparatus according to this embodiment, cooling water is supplied to the window 6a and the parabolic concave mirror 43a for the main pulse laser and the window 6b and the parabolic concave mirror 43b for the pre-pulse laser so that the optical elements are not distorted by thermal stress, etc. Since the output of the pre-pulse laser is between 100 and 200 W, if the optical elements are not deteriorated by debris, it is not necessary to cool them. However, even when the optical elements are somewhat deteriorated and absorb heat, cooling of the optical elements makes the distortion of the wave front suppressed to maintain the focusing performance. Thus, it is also desirable for the focusing performance to cool the optical elements for the lasers. As shown in FIG. 33, cooling water output from a chiller 40 is distributed in parallel and supplied to optical elements including the windows 6a and 6b and the parabolic concave mirrors 43a and 43b, and after cooling down the optical elements, the cooling water is discharged to a return pipe to the chiller 40 in parallel. With respect to each of the optical elements, a cooling water inlet temperature Tin (T1in, T2in, T3in, T4in), a cooling water outlet temperature Tout (T1out, T2out, T3out, T4out), and a cooling water flow rate V (V1, V2, V3, V4) are measured, a waste heat amount is calculated to detect the deterioration state of the concerned optical elements, and thus an appropriate management is performed on optical elements. When cooling water of a constant temperature is supplied to the optical elements, waste heat amounts can be calculated using the measured values of cooling water flow rates and outlet temperatures. A system in which cooling water is circulated in parallel through all the related optical elements is shown in the figure. However, it is needless to say that without limitation to this example, pipes may be installed in series for all of the optical elements, or series piping arrangement and parallel piping arrangement may be combined, for example. In short, any piping arrangement which does not influence the focusing performance of the main pulse laser and the pre-pulse laser may be provided to measure inlet and outlet temperatures and a cooling water flow rate with respect to each of the optical elements. Furthermore, for example, if a series piping arrangement is provided so that cooling water flow rates for all of the optical elements become the same value, only the inlet and outlet temperatures of each of the optical elements may be measured. FIG. 34 is a flow chart showing an optical element waste heat amount management routine (e) which is used as a routine for determining whether an optical element abnormality diagnosis is necessary in the laser optical element abnormality diagnosis necessity determination subroutine (S101) of the tenth embodiment. The optical element waste heat amount management routine (e) is a subroutine for determining whether an abnormality diagnosis is made based on the waste heat amount of each of the optical elements taken out by cooling water. The waste heat amount Q of each of the optical elements can be obtained according to the formula of Q=V(Tout−Tin) using a cooling water flow rate V, a cooling water inlet temperature Tin, and a cooling water outlet temperature Tout. First, the waste heat amount Q (Q1, Q2, Q3, Q4) is obtained using the measured values of cooling water flow rates V, cooling water inlet temperatures Tin, and cooling water outlet temperatures Tout with respect to each of the window 6a and the parabolic concave mirror 43a for the main pulse laser and the window 6b and the parabolic concave mirror 43b for the pre-pulse laser (S141). Next, it is determined whether the waste heat amount Q1 of the window 6a for the main pulse laser exceeds its threshold Q1th, whether the waste heat amount Q2 of the parabolic concave mirror 43a for the main pulse laser exceeds its threshold Q2th, whether the waste heat amount Q3 of the window 6b for the pre-pulse laser exceeds its threshold Q3th, or whether the waste heat amount Q4 of the parabolic concave mirror 43b for the pre-pulse laser exceeds its threshold Q4th (S142). When any one of the waste heat amounts exceeds its threshold, it is notified to an operator or external equipment such as exposure equipment that abnormality has occurred on any optical element for the lasers (S143), and it is determined that an abnormality diagnosis is necessary (YES) (S144). Then the processing exits the optical element waste heat management routine. On the other hand, when any of the waste heat amounts of optical elements to be managed does not exceed its threshold at step S142, it is determined that no abnormality diagnosis is necessary (NO) (S145) and the processing exits the waste heat amount management routine. In the above description, the cooling water inlet temperature Tin, the cooling water outlet temperature Tout, and the cooling water flow rate V are measured and the waste heat amount Q is obtained for each of the optical elements, and it is determined whether a diagnosis is necessary or not. However, without limitation to this example, it can be determined whether an abnormality diagnosis is necessary or not based on other measured values corresponding to the waste heat amounts. For example, when the cooling water is supplied in series, flow rate measurement may be conducted only at one point. Furthermore, when a flow rate is controlled to be a predetermined value, flow rate measurement is not necessary and the management may be performed using differences in temperature between inlets and outlets of the cooling water. Furthermore, when cooling water inlet temperatures and flow rates at the optical elements are controlled to be identical, the management may be performed only using cooling water outlet temperatures Tout at the optical elements. Furthermore, in the embodiments of FIGS. 30 and 32, a main laser beam is focused by the concave mirror 21, 27 and guided to the opening 56a. However, without limitation to these embodiments, the opening 56a maybe somewhat widened and the main laser beam may be once collimated by the concave mirror to be guided to the opening 56a. In addition, when a plane mirror is used instead of the concave mirror 21, 27, there is no problem if a spread main laser beam can be guided to the opening 56a and the laser dumper-calorimeter a 35c. Thus, any optical element which only does reflect the main pulse laser beam and guide it to the laser dumper-calorimeter may be used. However, when the main pulse laser beam is once focused by the concave mirror 21, 27 to be guided to the small opening 56a like the embodiments of FIGS. 30 and 32, the contamination of the window 6d by debris can be prevented and therefore a great effect can be obtained. Furthermore, an optical element may also be used to guide the pre-pulse laser beam to a laser dumper-calorimeter.
	description	The present invention relates generally to focused charged particle systems and in particular to reducing damage and contamination in detectors for secondary particles. In charged particle systems, comprising both electron microscopes and focused ion beam systems, a column is typically used to focus a charged particle beam onto the surface of a target to be imaged and (optionally) processed using the beam. To form an image of the target, it is necessary to deflect the beam across the target surface, usually in a raster pattern. Due to the impact of the charged particle beam with the target, secondary particles are emitted and may be collected to form an imaging signal. As an example, an electron beam will stimulate the emission of secondary electrons from the target. A focused ion beam will stimulate the emission of both secondary electrons and secondary ions (usually positively-charged). A secondary particle detector is employed in these systems to generate the necessary imaging signal—these detectors may be characterized by their collection efficiency, i.e., the fraction of emitted secondary particles which are actually collected by the detector. To enhance this collection efficiency, a “collection” grid is often positioned between the target and the detector. A voltage applied to this grid creates an electric field between the target and grid to attract secondary particles, which then pass through the grid (a sparse mesh or other nearly transparent structure) and then to the detector. Unfortunately, it is found that over time, secondary detectors may exhibit a loss in efficiency due to either damage to the detector and/or a build-up of contamination on the detector surface. This damage results from the energetic bombardment of the detector by incoming secondary particles, which can disrupt the detector material. Contamination covers the detector with a thin film such as polymerized hydrocarbons arising from the interaction of the charged particle beam with trace gases in the vacuum system—often these gases arise from the interaction of the charged particle beam with the target, and thus are difficult to avoid even in systems with very low base pressures. Typically this damage is non-uniform over the detector surface. This non-uniformity arises because the emission pattern of secondary particles from the target is concentrated in a direction upwards (following a cosine law) from the target. If the detector is an annulus surrounding the primary charged particle beam, then the majority of the collected secondary particles will strike the detector near the center. Thus, the accumulated damage and/or contamination on the detector will also be concentrated near the center. Detector lifetime is determined by the most damaged or contaminated area (even if the majority of the detector area is still functional), so when the center of the detector becomes unusable due to damage and/or contamination, the entire detector must be replaced, reconditioned, or cleaned. Thus, it would be advantageous in charged particle systems to improve the detector lifetime by making the damage and/or contamination rate more uniform over the area of a charged particle detector to improve the overall detector lifetime. An object of the invention is to improve the lifetime of secondary particle detectors in charged particle systems. The present invention increases the useful life of secondary particle detectors by providing a detector assembly that spreads the secondary particles more evenly over the detector, thereby reducing the damage to parts of the detector that would otherwise degrade more quickly because of the disproportionately large number of secondary particles impinging on those portions of the detector. In some embodiments, a grid positioned between the target and the detector provides a field that spreads the secondary particles more evenly over the detector. The grid can comprise multiple sections, each at a different potential, or a resistive grid can provide different potentials across a single grid section. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The present invention provides a field that that deflects secondary charged particles before they impact on a detector to reduce the maximum current density of the charged particles impinging on the charged particle detector, thereby prolonging the useful life of the charged particle detector. By “maximum current density” is meant the highest current density on any area of the detector. The distribution of the secondary charged particles is more uniform that it would be in the absence of the provided field. In one embodiment, the invention positions a multiplicity of secondary particle collection grids between a target and the secondary particle detector. The voltage on each grid is independently controllable in order to create an electric field between the target and the array of collection grids which deflects the secondary particles farther off-axis. This deflection of the secondary particles makes the distribution of secondary particles which reach the detector more spatially uniform that would be the case with a single collection grid. The term “secondary particle” as used herein includes backscattered particles from the primary beam. In a second embodiment, a resistive grid is used in place of the array of grids. A voltage is applied across the resistive grid to create approximately the same electric field as was induced in the first embodiment using the separate grids. In a third embodiment, a multiplicity of deflector electrodes is positioned between the collection grid and the target, again with the purpose of creating an electric field needed to make the secondary particle distribution at the detector more uniform. Embodiments of the present invention may also be used in cases where the detector is used in an imaging mode, as illustrated herein for a transmission electron microscope (TEM—FIG. 9) and a scanning transmission electron microscope (STEM—FIG. 10). In these applications, it is often the case that the full detector area cannot be used for imaging due to considerations in the optical designs of the columns. Thus, the particle distributions at the detector are again non-uniform (often more concentrated around the symmetry axis of the column). Embodiments of the present invention may enable more of the detector area (typically areas farther from the symmetry axis of the column) to be used for imaging, thereby increasing the detector lifetime. For these imaging applications, it may not be possible to make the signal current fully uniform at the detector since the spatial distribution of particles striking the detector conveys image information. Positional information is maintained by expanding the secondary charged particle spatial distribution, that is, maintaining the relative position of the secondary particles from the optical axis of the column. An additional benefit for imaging detectors may be an increase in the imaging resolution—this arises from the fact that spreading the imaging signal over a larger area of the detector may enable the use of a larger number of detector elements within the detector array to form the image. A further benefit of some embodiments of the present invention is the potential for higher signal gains in cases where local saturation of the detector gain would otherwise occur. For example, it is well known that multichannel plates (MCPs) amplify the input signal current by as much as 106-107—this amplification occurs within the many channels of the MCP. If a large input signal current strikes only a small area of the MCP, it is possible to saturate the local gain that region of the MCP, while other areas of the MCP (receiving lower input currents) still retain their original (higher) gains. This saturation in MCPs occurs due to “current loading” effects in which the inherent resistivity of the MCP prevents enough supply current from reaching the saturated area of the MCP to provide the normal level of signal amplification. Since the present invention spreads the input current over a larger and more uniform area of the detector, these local saturation effects should be reduced or eliminated. This corresponds to a wider range of linearity (i.e., higher gain before saturation) in the overall detector response. Although those of ordinary skill in the art will readily recognize many alternative embodiments, especially in light of the illustrations provided herein, this detailed description is exemplary of the preferred embodiments of the present invention, the scope of which is limited only by the appended claims. The present invention derives from the recognition that the lifetime of secondary particle detectors in charged particle systems may be adversely affected by two factors: 1) Damage to the detector due to bombardment by secondary particles, and 2) Contamination of the detector due to polymerization and deposition of materials on the detector arising from bombardment by secondary particles.Typical types of secondary electron detectors comprise: 1) Multichannel plates (MCPs)—these types of detectors have a large number of very small channels operating in parallel across the collection area of the detector. Each channel operates independently of the others, amplifying the incoming secondary particle current by factors of as much as 106-107 in a process of cascade multiplication within each channel. This amplified current is then collected on one or more anodes positioned on the far side of the MCP (i.e., the opposite side from the side receiving the input signal current). Often, to avoid “ion feedback”, a two-stage structure is employed in which the channels in the first stage have a different angle than those in the second-stage, thereby eliminating “line-of-sight” travel of positive ions from the exit back to the entrance of the MCP. 2) PIN diodes—these types of detectors are essentially a diode within which the incoming secondary particle produces a cascade of electron-hole pairs. The gain of the PIN diode detector is proportional to the energy of the incoming secondary particle. 3) Scintillator+Light Pipe+PMT—this common type of detector operates by the initial generation of light within the scintillator material (typically either a crystal or plastic) due to the impact of a secondary particle. This light is then transmitted through the light pipe to a photomultiplier tube (PMT), usually located outside the vacuum enclosure of the charged particle system comprising the secondary particle detector.All three of these detectors have this characteristic in common: the entire detector will become unusable if any part of the detector becomes unusable. Since the rates of damage and/or contamination for each specific area of a detector are generally proportional to the integrated total dose of input signal into that specific area, it is clearly advantageous to ensure that all areas of the detector receive similar dose rates to ensure that the detector lifetime is maximized (i.e., the entire detector becomes unusable at approximately the same time). When only a small area of a detector receives a disproportionately large fraction of the overall secondary particle flux, clearly that area will be damaged and/or contaminated more quickly than would be the case if the secondary particle flux were more evenly distributed over the full collection area of the detector. In addition, for MCPs, if a small area of the MCP detector receives a disproportionately large fraction of the input signal current, local gain saturation may occur, resulting in non-linearity across the detector area. FIG. 1A shows a prior art charged particle detector 100, wherein a charged particle column 102 focuses a charged particle beam 104 onto a location 106 on the surface of a target 108. Due to the impact of the charged particle beam 104 with the target 108, secondary particles 118, 119, 120 and 152 may be emitted from the target. For the case where charged particle beam 104 is an electron beam, these secondary particles will be secondary electrons. For the case where charged particle beam 104 is a focused ion beam (FIB), both secondary electrons and secondary ions (mostly positive) may be emitted from the target 108. Generally, the emission pattern of secondary particles (in the case of a normally-incident primary beam 104), tends to follow a Lambert, or cosine, law angular distribution concentrated around an axis perpendicular to the surface of the target 108 at the point 106 of impact of the primary charged particle beam 104 with the target 108. In the prior art, an annular detector 110 (shown here as a two-stage multichannel plate) providing current gain and a collection anode 111 typically are mounted on the bottom of the charged particle column 102 as illustrated in FIG. 1. To enhance collection of secondary particles, a collection grid 112, supported by an inner ring 114 and an outer ring 116, may be employed. A single voltage is applied to the collection grid 112 to draw secondary particles towards the grid 112 which is largely transparent to secondary particles that mostly pass through grid 112 and are subsequently collected by detector 110 and collection anode 111. Detector 110 may comprise a multi-channel plate (MCP), in which case the signal current is collected on an anode 111, as shown. Alternatively, detector 110 may comprise a PIN diode detector, a scintillator connected to a light pipe and photomultiplier tube (see FIG. 8), or possibly other types of charged particle detector—in these cases, anode 111 may not be necessary, since the signal is derived by the detector 110 itself. Details of the detector 110 and anode design 111 are well-known in the art. Due to the cosine emission pattern of the secondary particles, some particles 152 will be emitted too close to the axis of column 102 to be collected by grid 112, and thus will pass up the bore of the charged particle column 102, and will not be detected. Those secondary particles 118 which were emitted from target 108 at slightly larger angles than particles 152 pass through grid 112 to be collected near the center of detector 110, as shown. A smaller portion of secondary particles 120 which are emitted at much larger angles pass through collection grid 112 much farther off-axis and are collected near the outer edge of detector 110. It is well known in the art that many types of detectors, such as both multichannel plates, PIN diodes, and scintillators, demonstrate damage mechanisms which are functions of the total integrated signal current into each area of the detector. Thus, for an MCP detector 110, the region near the central hole (required to allow passage of the primary beam 104 to the target 108) will be damaged before the outer regions of the MCP 110. A similar situation applies to PIN diodes and scintillators. In addition to damage, detectors may also become contaminated with polymerized hydrocarbons from a poor vacuum between the target and detector—note that this may occur due to beam-target interactions, even in cases where the base vacuum level would have been adequate to prevent contamination. In either case, the lifetime of an entire detector is determined by when a certain level of damage and/or contamination has occurred anywhere on the detector, even if the remainder of the detector is not yet damaged and/or contaminated to an unusable degree. The lifetime of detector 110 in the prior art configuration illustrated in FIG. 1 may be substantially reduced compared with the case where secondary particles were more uniformly distributed over the detector 110 surface. FIG. 1B shows a portion of the prior art charged particle detector 100 from FIG. 1A. Detector 110 is shown in a view looking up at the input signal collection surface (lower surface of detector 110 in FIG. 1A). The concentration of the input signal current near the center of detector 110 is illustrated using progressively-heavier cross-hatched shading from the edge to the center of detector 110. Three regions 140, 142, and 144, of the detector 110 at the center, middle, and edge, respectively, are indicated by the circles with arrows to the corresponding graphs, below. Starting at the inner edge 140 of the central hole in detector 110 (where ring 114 in FIG. 1A is attached), graph 170 is a plot of the local signal gain 172 as a function of the time-integral 171 of the output (i.e., amplified) signal current from region 140 over the lifetime of detector 110. As shown, gain curve 174 has an initial high level 176, which is maintained over a certain total time-integral of output signal current (i.e., to a certain total output signal charge), then gain curve 174 drops to a lower level 178 at the right of graph 170. Because the input signal current at region 140 is relatively high, the cross-hatched shading representing the time-integral of the output signal current extends to line 179, nearly at the point at which the gain curve 174 will start to drop. Thus, the useful lifetime of detector 110 is nearly over. At the middle region 142 in detector 110, the input signal current is at a medium level. Graph 160 is a plot of the local signal gain 162 as a function of the time-integral 161 of the output signal current from region 142 over the lifetime of detector 110. As shown, gain curve 164 has an initial high level 166, which is maintained over a certain total time-integral of output signal current, then gain curve 164 drops to a lower level 168 at the right of graph 160. The key difference from graph 170 is that the cross-hatched shading extends only to line 169, a substantial distance from the point at which the gain 164 will drop—thus, at region 142, detector 110 still has a substantial useful lifetime remaining. Of course, since the detector lifetime depends on all areas being usable, this localized residual lifetime of region 142 cannot be used due to region 140 having essentially no residual lifetime. Similar considerations apply at the outer region 144 of detector 110—where graph 150 is a plot of the local signal gain 152 as a function of the time-integral 151 of the output signal current from region 144 over the lifetime of detector 110. As shown, the gain curve 154 has an initial high level 156, which is maintained over a certain total time-integral of output signal current, then gain curve 154 drops to a lower level 158 at the right of graph 150. Because the input signal current at region 144 is relatively low compared to the input signal currents at regions 142 and 140, the edge 159 of the cross-hatched area is farther to the left, showing that most of the detector lifetime at region 144 at the edge of detector 110 has not been used by the time area 140 is close to becoming unusable. Comparison of graphs 150, 160, and 170 illustrates how the lifetime of detector 110 may be substantially reduced when the input signal currents between regions 140, 142 and 144 are unequal. FIG. 2A shows a first embodiment 200 of the invention, comprising a multiplicity of annular collection grids 222, 224, 226, and 228, supported by an inner ring 214 and an outer ring 216. The exact number of grids would be determined by the degree of electric field uniformity desired. The number of grids is preferably between 2 and about 20, more preferably between 2 and 8, and most preferably between 3 and 5. A charged particle column 202 focuses a charged particle beam 204 onto a location 206 on the surface of a target 208. Due to the impact of the beam 204 with the target 208, secondary particles may be emitted from the target 208. FIGS. 6 and 7, below, discuss two electrical circuits which may be used to apply differing bias voltages to the inner ring 214, annular grids 222, 224, 226, and 228, as well as the outer ring 216. The bias voltages are set to create an electric field which pulls secondary particles away from the symmetry axis of the column 202, detector 210 and collection anode 211. Thus, under the influence of the electric field, secondary particles 232 pass through grid 222, secondary particles 234 pass through grid 224, secondary particles 236 pass through grid 226, and secondary particles 238 pass through grid 228. Secondary particles 252 which are emitted near the symmetry axis are not collected. Comparison of FIGS. 1A and 2A shows that the radial distribution of secondary particles entering the grids 222, 224, 226, and 228, is now less concentrated near the symmetry axis of detector 210 and collection anode 211. The net result is that now a larger fraction of the collection area of detector 210 is utilized effectively in providing signal gain, potentially reducing or eliminating signal gain saturation effects as discussed above. Because the distribution of current into detector 210 is more uniform, the damage and/or contamination mechanisms discussed in FIG. 1A will also occur more uniformly over the entire collection area of detector 210. The lifetime of detector 210 with respect to damage and/or contamination should thus be increased, reducing maintenance costs for the system comprising this detector system 200. FIG. 2B shows a portion of the charged particle detector 200 of a first embodiment of the present invention from FIG. 2A. Detector 210 is shown in a view looking up at the input signal collection surface (lower surface of detector 210 in FIG. 2A). The relative uniformity of the input signal current across the collection area of detector 210 enabled by the present invention is illustrated using uniform cross-hatched shading across the full collection area of detector 110 (compare with FIG. 1B). Three regions 240, 242, and 244, of the detector 210 at the center, middle and edge, respectively, are highlighted. Starting at the inner edge 240 of the central hole in detector 210 (where ring 214 in FIG. 2A is attached), graph 270 is a plot of the local signal gain 272 as a function of the time-integral 271 of the output (i.e., amplified) signal current from region 240 over the lifetime of detector 210. As shown, gain curve 274 has an initial high level 276, which is maintained over a certain total time-integral of output signal current (i.e., to a certain total output signal charge), then gain curve 274 drops to a lower level 278 at the right of graph 270. Because the input signal current at region 240 is lower than for the comparable graph 170 in FIG. 1B, the cross-hatched shading representing the time-integral of the output signal current extends to line 279, which is only about half of the way to the point at which the gain curve 274 will start to drop. Thus, about half of the useful lifetime of detector 210 remains, in contrast with the case in FIG. 1B. At the middle region 242 in detector 210, the input signal current is at roughly the same level as for area 240. Graph 260 is a plot of the local signal gain 262 as a function of the time-integral 261 of the output signal current from region 242 over the lifetime of detector 210. As shown, gain curve 264 has an initial high level 266, which is maintained over a certain total time-integral of output signal current, then gain curve 264 drops to a lower level 268 at the right of graph 260. Note that the cross-hatched shading extends to line 269, at roughly the same position along axis 261 as line 279 is along axis 271 in graph 270—thus, at region 242, detector 210 still has about the same useful lifetime remaining as at region 240. Similar considerations apply at the outer region 244 of detector 210—where graph 250 is a plot of the local signal gain 252 as a function of the time-integral 251 of the output (signal current from region 244 over the lifetime of the detector 210. As shown, gain curve 254 has an initial high level 256, which is maintained over a certain total time-integral of output signal current, then gain curve 254 drops to a lower level 258 at the right of graph 250. Because the input signal current at region 244 is similar to the input signal currents at regions 240 and 242, the edge 259 of the cross-hatched area is roughly at the same location along axis 251 as lines 269 and 279 are along axes 261 and 271, respectively. Comparison of the cross-hatched areas in graphs 250, 260, and 270 illustrates how the lifetime of detector 210 may be substantially increased when the input signal currents between regions 240, 242 and 244 are equalized by the present invention. FIG. 3 shows a second embodiment 300 of the invention, comprising a single resistive annular collection grid 312, supported by an inner ring 314 and an outer ring 316. A charged particle column 302 focuses a charged particle beam 304 onto a location 306 on the surface of a target 308. As in FIGS. 1 and 2, the impact of the charged particle beam 304 with the target 308 may induce the emission of secondary particles. The first embodiment in FIG. 2 utilized a series of concentric annular grids to produce an electric field to draw secondary particles away from the axis and out to regions of the detector which would normally receive lower secondary particle currents. The second embodiment of the present invention illustrated in FIG. 3 utilizes a resistive grid 312 upon which a radial voltage gradient is applied arising from a voltage difference between the inner ring 314 and the outer ring 316. In the case of secondary electron collection by detector 310, the radial force vector 324 would correspond to a more positive voltage on the outer ring 316 and a less positive voltage on the inner ring 314. In the case of (positive) secondary ion collection by detector 310, the relative voltages on the inner ring 314 and outer ring 316 would be reversed. Since some portion of the secondary particles (either electrons or ions) will strike the resistive grid 312, it is necessary to ensure that the resulting current in grid 312 does not affect the radial voltage gradient desired in grid 312 to establish the correct electric field needed to equalize the radial distribution of secondary particles reaching the detector 310 and collection anode 311. This is a similar situation to that found in photomultiplier tubes (PMTs), where typically the current in the resistor chain used to generate the voltages on the dynodes is specified to be at least ten times higher than the largest internal currents within the PMT. When this condition is not met, the voltage distribution within the resistive grid 312 may not produce the desired distribution of trajectories 332, 334, 336, and 338 passing through resistive grid 312 shown in FIG. 3. Detector 310 (shown here as an annular two-stage multichannel plate providing current gain) and the collection anode 311 typically are mounted on the bottom of the charged particle column 302. As in FIGS. 1 and 2, a small portion 352 of secondary particles emitted near the symmetry axis of the column 302, detector 310, and collection anode 311, will pass up the bore of column 302 and will not be detected. FIG. 4 shows a third embodiment 400 of the invention, comprising a multiplicity of deflector electrodes 424 for attracting secondary particles away from the symmetry axis of the column 404, detector 410, and collection anode 411. A charged particle column 402 focuses a charged particle beam 404 onto a location 406 on the surface of a target 408. As in FIGS. 1 through 3, the impact of the charged particle beam 404 with the target 408 may induce the emission of secondary particles which may be secondary electrons and/or secondary ions. A collection grid 412 is supported by an inner ring 414 and an outer ring 416. In one version of the third embodiment, the inner ring 414, grid 412 and outer ring 416 may have the same voltage—in this case, the deflector electrodes 424 generate a more uniform distribution of secondary particles at detector 510 and collection anode 511. In another version of the third embodiment, the multiplicity of grids of the first embodiment may be substituted for conductive grid 412, thereby enabling the generation of a radial electric field by means of both deflector electrodes 424 and a multiplicity of concentric annular collection grids such as grids 222, 224, 226, and 228 in FIG. 2. In still another version of the third embodiment, the resistive collection grid 312 of the second embodiment (see FIG. 3) may be substituted for conductive grid 412, thereby enabling the generation of a radial electric field by means of both the added deflector electrodes 424 and the resistive grid 312. In the case of secondary electron collection, deflector electrodes 424 would have a positive bias applied to attract the secondary electrons radially outwards as shown by force vectors 460, and hence through grid 412 and onto detector 410 at a larger radius than would otherwise have been the case. For (positive) secondary ions, a negative bias would be applied to deflector electrodes 424, again making force vectors 460 point radially outwards. Secondary particles 452 which are emitted near the symmetry axis are not collected. Detector 410 (shown here as an annular two-stage multichannel plate providing current gain) and the collection anode 411 typically are mounted on the bottom of the charged particle column 402. FIG. 5 shows a fourth embodiment 500 of the invention, comprising an off-axis charged particle detector with a multiplicity of collection grids 522, 524, 526, and 528, supported by an inner electrode 514 and an outer electrode 516—details of the mechanical support for grids 522, 524, 526, and 528 are not part of the present invention and are not shown. Note that there is no circular symmetry assumed or required for this fourth embodiment. A charged particle column 502 focuses a charged particle beam 504 onto a location 506 on the surface of a target 508. As in FIGS. 1 through 4, due to the impact of the beam 504 with the target 508, secondary particles may be emitted from the target 508. The differing bias voltages on the grids 522, 524, 526, and 528, are adjusted to create an electric field which pulls secondary particles away from the symmetry axis of the column 502 (although the detector has no required symmetry for this embodiment, the column 502 will still typically retain circular symmetry with respect to the beam-forming optics)—toward the right of FIG. 5, in this example. Thus, under the influence of the electric field, secondary particles 532 pass through grid 522, secondary particles 534 pass through grid 524, secondary particles 536 pass through grid 526, and secondary particles 538 pass through grid 528. The same considerations apply to this non-circularly symmetric detector system as applied in FIGS. 2 through 4 for the circularly-symmetric detectors of the first three embodiments—the voltages on grids 522, 524, 526, and 528 may be adjusted to spread out the distribution of secondary particles entering detector 510 and collection anode 511, thereby making any damage and/or contamination mechanisms also more uniform. Secondary particles 552 which are emitted near the symmetry axis are not collected. Detector 510 (shown here as a two-stage multichannel plate providing current gain) and the collection anode 511 typically are mounted on the bottom of the charged particle column 502. FIG. 6 shows an electrical schematic diagram 600 for a first biasing circuit for a multiplicity of grids 622, 624, 626, and 628, supported by an inner electrode 614 (corresponding to inner ring 214 in FIG. 2 or inner electrode 514 in FIG. 5) and an outer electrode 616 (corresponding to outer ring 216 in FIG. 2 or outer electrode 516 in FIG. 5). Circuit 600 is applicable to the detector systems illustrated in FIGS. 2 and 5, and would also be applicable if the detector system in FIG. 4 were combined with the segmented grid structures from FIG. 2. Detector 610 may represent one side of an annular detector such as detector 210 in FIG. 2, or an off-axis detector such as detector 510 in FIG. 5. In either case, the symmetry axis 640 represents the optical axis for the charged particle column generating the secondary particles entering detector 610 and collection anode 611. A dc power supply 602 is connected through a first wire 604 to electrode 614 and through a second wire 606 to electrode 616. The voltage bias connections for the detector 610 and collection anode 611 are not part of the present invention and are not shown. The collection grid assembly comprises four grids 622, 624, 626, and 628, connected in series between electrode 614 and electrode 616 by resistors 632, 634, 636, 638 and 640. The exact number of grids would be determined by the degree of electric field uniformity desired and is not part of the present invention. The same considerations which were discussed in FIG. 3 apply here—it is preferable to ensure that the current flowing from dc power supply 602 through electrodes 614 and 616, grids 622, 624, 626, and 628, and resistors 632, 634, 636, 638, and 640 is substantially higher (typically ten times) than any anticipated secondary particle currents which might strike any of the grids 622, 624, 626, and 628 to ensure that there is no “current loading”, causing unwanted deviations in the electric field distribution between the target (not shown) and detector 610. A potential problem with circuit 600 is the requirement that the resistors 634, 636, and 638 (but not necessarily resistors 632 and 640) be mounted between the successive grids to which they attach—this may be undesirable since resistors 634, 636 and 638 would then be exposed to a portion of the secondary particle flux from the target. This may cause charging of the exterior surfaces of the resistors which could perturb the desired electric field distribution. It is also possible that the secondary particle flux could damage the resistors, causing incorrect resistance values or even shorts between neighboring collector grids. FIG. 7 shows an electrical schematic diagram 700 for a second biasing circuit for a multiplicity of grids 722, 724, 726, and 728, supported by an inner electrode 714 (corresponding to inner ring 214 in FIG. 2) and an outer electrode 716 (corresponding to outer ring 216 in FIG. 2). Circuit 700 is applicable to the detector system illustrated in FIG. 2, and would also be applicable if the detector system in FIG. 4 were combined with the segmented grid structures from FIG. 2. The off-axis detector system illustrated in FIG. 5 may not need circuit 700 since a non-circularly symmetric detector system has room for the grading resistors without the need for the shielded cable configuration illustrated here. Detector 710 may represent one side of an annular detector such as detector 210 in FIG. 2. The symmetry axis 740 represents the optical axis for the charged particle column generating the secondary particles entering detector 710 and collection anode 711. A dc power supply 702 is connected through a first wire 704 to electrode 714 and through a second wire 706 to electrode 716. The voltage bias connections for the detector 710 and collection anode 711 are not part of the present invention and are not shown. The collection grid assembly comprises four grids 722, 724, 726, and 728, connected in series between electrode 714 and electrode 716 by resistors 732, 734, 736, 738 and 740. The exact number of grids would be determined by the degree of electric field uniformity desired and is not part of the present invention. Note that electrically, FIG. 7 is the same as FIG. 6—the difference is the physical locations for the five voltage divider resistors 732, 734, 736, 738, and 740 and the addition of coaxial shields 752, 754, 756, 758, 760, and 762. As discussed in FIG. 6, it may be problematic to locate the voltage divider resistors between the successive grids in the grid assembly. FIG. 7 illustrates an alternative architecture in which the resistors 732, 734, 736, 738, and 740 may be located outside the grid assembly, thereby avoiding the problems discussed in FIG. 6. However, simply connecting unshielded wires to each of the grids would present a new problem—since these wires necessarily must extend outwards from each annular grid, there will be overlaps between the wires from inner annular grids (such as 722, 724 and 726) and all the annular grids which are outside of the particular annular grid being connected to (such as grids 724, 726, and 728 for grid 722). One potential solution to this problem is illustrated here—the wire connecting to the inner annular grid 722 passes through a series of coaxial shields 752, 754, and 756, and then connects to resistors 732 and 734 in the voltage divider comprising resistors 732, 734, 736, 738 and 740, connected between the output wires 704 and 706 of dc power supply 702. Similarly, the wire connecting to annular grid 724 passes through coaxial shields 758 and 760, and then connects to resistors 734 and 736 in the voltage divider. In the same way, the wire from grid 726 passes through coaxial shield 762 and then connects to resistors 736 and 738 in the voltage divider. The wire connecting to the outer annular grid 728 can directly connect to resistors 738 and 740 in the voltage divider. The electrical connection between annular grid 722 and inner ring 714 is completed outside through resistor 732 as shown. All of the shields 752, 754, 756, 758, 760, and 762 represent essentially short sections of coaxial cable. The outer conductors of each shield are electrically (and, optionally, also mechanically) connected to the respective grids (e.g., shield 752 connected to grid 724) so that as each wire passes across an annular grid, there is no electric field induced by the center wire which is, of course, at a different voltage since each grid voltage has been set to a desired value for optimum charged particle collection. The short sections of wire between successive shields (e.g., between shields 752 and 754) will probably need to be stripped of the coaxial cable insulation (thus leaving a short section of the center wire exposed, e.g., the wire from grid 722 being exposed between shields 752 and 754) to avoid possible charging effects which might occur due to secondary particles collecting on exposed insulation. FIG. 8 shows a version 800 of a first embodiment of the invention, comprising a scintillator 860, light pipe 862 and photomultiplier 864, as well as a multiplicity of annular collection grids 822, 824, 826, and 828, supported by an inner ring 814 and an outer ring 816—details of the mechanical support for grids 822, 824, 826, and 828 are not part of the present invention and are not shown. A charged particle column 802 focuses a charged particle beam 804 onto a location 806 on the surface of a target 808. FIGS. 6 and 7, above, discuss two electrical circuits which may be used to apply differing bias voltages to the inner ring 814, annular grids 822, 824, 826, and 828, as well as the outer ring 816. Secondary particles 832 pass through grid 822, secondary particles 834 pass through grid 824, secondary particles 836 pass through grid 826, and secondary particles 838 pass through grid 828. The key difference in FIG. 8 relative to FIG. 2 is the substitution of a scintillator 860, light pipe 862, and photomultiplier 864 in place of the multichannel plate (MCP) detector 210 and collection anode 211 shown in FIG. 2. Like multichannel plates, scintillators also exhibit long-term damage resulting from changes in the scintillator molecular or crystal structure as a result of bombardment by charged particles. Scintillators may also become contaminated by polymerized hydrocarbons, etc. Thus, the same damage and/or contamination issues apply here as were discussed above. Scintillator 860 emits light 866 when bombarded by energetic charged particles 832, 834, 836, and 838. Light 866 passes through, and undergoes total internal reflection at the walls of, light pipe 862, then passing into photomultiplier 864. Secondary particles 852 which are emitted near the symmetry axis are not collected. A number of combinations of different detector types and grid geometries have been illustrated in FIGS. 2 through 5, and 8. Table I lists a number of detector system configurations—other detector types and electrical biasing circuits are also possible within the scope of the present invention TABLE IDifferent detector system configurations and the correspondingdetectors and electrical connections.Types of DetectorsElectricalDetector SystemPINScintillator +ConnectionsConfigurationMCPDiodePMTFIG. 6FIG. 7Embodiment 1 -YesYesYesYesYesConcentricAnnularGridsEmbodiment 2 -YesYesYesYesYesAnnularResistiveGridEmbodiment 3 -YesYesYesYesYesAddedDeflectorElectrodesEmbodimentsYesYesYesYesYes1 + 3 -AnnularGrids +DeflectorElectrodesEmbodimentsYesYesYesYesYes2 + 3 -ResistiveGrid +DeflectorElectrodesEmbodiment 1 -YesYesYesYesProbably NotMultiplicityNeededof Grids(No circularSymmetry)Embodiment 2 -YesYesYesYesProbably NotResistiveNeededGrid(No circularSymmetry)Embodiment 3 -YesYesYesYesProbably NotAddedNeededDeflectorElectrodes(No circularSymmetry)EmbodimentsYesYesYesYesProbably Not1 + 3 -NeededGrids +DeflectorElectrodes(No CircularSymmetry)EmbodimentsYesYesYesYesProbably Not2 + 3 -NeededResistiveGrid +DeflectorElectrodes(No CircularSymmetry) The various embodiments of the present invention discussed in FIGS. 2 through 5 apply to non-imaging detectors, i.e., where the imaging signal arriving at the detector and then conveyed to the collection anode (if the detector is a multichannel plate) carries no positional information. The entire detector in these examples generated a single imaging signal, no matter where the secondary particle (carrying the imaging information) strikes the detector and collection anode surface. Thus, the design of the multiplicity of grids, the resistive grid, or the deflector electrodes could be optimized solely for more uniform current into the detector and collection anode. Embodiments of the present invention are also applicable for those alternative situations in which the imaging particles carry both intensity and positional information. In these cases, we are not free to ignore where on the detector the secondary particle strikes, and the collection anode will generally comprise multiple individual detectors, each collecting (amplified) current from a small region of the multichannel plate. This contrasts with the detector system 200 in FIG. 2, where a single collection anode 211 receives all the amplified signal current generated by detector 210, regardless of where on detector 210 the original secondary particle arrived. FIGS. 9 and 10 discuss two exemplary cases of the application of the present invention to imaging detectors—other cases also fall within the scope of the present invention. FIG. 9 shows an application of the present invention to a detector system 900 of a transmission electron microscope (TEM). In a TEM, a condenser and projector optics system projects a beam 902 of primary electrons onto the surface of a sample 904 to be imaged. As shown in FIG. 9, electrons 906 and 907 are scattered from various locations within sample 904. For simplicity, electrons 906 and 907 represent particular electron trajectories which are deflected within sample 904 at angles such that electrons 906 and 907 pass undeflected through lens 908, then travel downwards to the detector system comprising multiple annular grids (including outermost grid 932 and innermost grid 933) supported by ring electrode 930, and then into a two-stage multichannel plate 934, and finally to collection anode assembly 936, comprising multiple collection elements (including elements 914 and 924). Not all electrons emerging from sample 904 pass through the center of lens 908—electrons 904 and 942 illustrate a typical envelope of scattered electrons which would pass through objective lens 908, then being focused by lens 908 onto annular grid 932. Due to the voltages applied to the annular grids, an outward radial force 950 on the secondary particles between lens 908 and the multiple annular grids is generated. As an example, trajectory 906 emerging from the bottom of sample 904 passes through lens 908, becoming trajectory 910 which is then deflected outwards by force 950 to become trajectory 912 entering the outermost annular grid 932. Trajectories 940 and 942 emerging from the same location on sample 904 become trajectories 944 and 946, respectively, after focusing by lens 908, arriving at approximately the same location on grid 932 as trajectory 912. After current amplification by the two-stage multichannel plate 934, a current proportional to the current passing through grid 932 is collected on element 914 of the collection anode assembly 936—note that the positional information carried by the input signal passing through grid 932 is preserved by using a collection anode assembly 936, instead of a single collector anode (such as collector anode 211 in FIG. 2). Electron trajectory 907, much nearer the axis, passes through lens 908, becoming trajectory 920 which is then deflected outward by force vector 950 to become trajectory 922 entering the innermost annular grid 933, and then, after current amplification, the signal current is collected by element 924 of collection anode assembly 936. Again, the positional information in the input signal reaching the grid has been preserved (it has just been stretched radially outwards in a 1:1 mapping that can be calibrated or calculated in advance). FIG. 9 shows an imaging detector embodiment of the present invention—in the absence of the segmented collection grid assembly, the electron trajectories reaching the multichannel plate 934 and collection anode assembly 936 would be more concentrated near the center of the MCP 934. This can be seen by extrapolating trajectories 910 and 920 without radial outward force vectors 950 all the way to the entrance plane of the grid assembly. Clearly, then, the imaging signals generated from collection anode assembly 936 would arise from a smaller number of collection elements near element 924, and elements 914 at the outer edge of the collection anode assembly would not receive any current at all. Two potential advantages of some embodiments of the present invention for imaging detector applications can now be seen: 1) The damage and/or contamination of the detector 934 will be more uniform, leading to longer detector lifetimes—this is the same benefit as was found above for non-imaging detectors. 2) The imaging resolution is potentially increased, since now a larger number of collection elements are used (such as outer element 914) than would be the case for a beam which was more concentrated near the center of the detector assembly 934 and collection anode assembly 936. FIG. 10 shows an embodiment of the present invention applied to a detector system 1000 of a scanning transmission electron microscope (STEM). In a STEM, a beam 1002 of electrons is focused onto the surface of a sample 1004 and scanned in a raster pattern by a deflection system to generate an image, similar to the imaging process in a scanning electron microscope (SEM). As the electron beam 1002 passes through the sample 1004, electrons in the beam are scattered by nuclei in the sample 1004 (leading to “elastic scattering”) and electrons in the sample 1004 (leading to “inelastic scattering”). As an example, electrons 1008 are scattered at larger angles, characteristic of elastically-scattered electrons. Electrons 1011 have small scattering angles, and may be inelastically-scattered. Both types of electrons contain important structural and compositional information about the sample 1004, and it is preferred to configure the detector system 1000 to simultaneously collect both imaging signals. It is well known in the art that the ratio of the elastic signal to the inelastic signal is proportional to the local atomic number of the sample. Typically, the STEM detector optics will comprise a lens 1010 below the sample 1004 (often this lens is formed by that portion of the objective lens magnetic field which is below the sample plane, but additional lenses may also contribute to the net focusing effect illustrated by the single lens 1010 in FIG. 10). Off-axis trajectory 1008 is focused by lens 1010, resulting in trajectory 1009. Similarly, near-axis trajectory 1011 is focused by lens 1010, resulting in trajectory 1012 (aberrations in lens 1010 are neglected here). In the absence of the radial outward forces 1050, trajectories 1009 and 1012 would reach the collection grid near the axis (at the center). With radial outward forces 1050 generated by the voltages on the annular grids (such as grids 1032 and 1033) in the collection grid assembly, the input signal currents reaching the two-stage multichannel plate 1034 and then the collection anode assembly 1036 fill a larger portion of the respective available detector and collection areas. For example, trajectory 1009 is deflected outwards, becoming trajectory 1014 which passes through outermost annular grid 1032, and then the corresponding (amplified) current reaches outermost collection element 1016. Similarly, trajectory 1012 is deflected outwards, becoming trajectory 1024 which passes through innermost annular grid 1033, and then the corresponding (amplified) current reaches innermost collection element 1026. Again, note that the scattering angle information carried by signals 1008 and 1011 is preserved, along with the image intensity information carried in the relative currents in signals 1008 and 1011. As in all scanning systems (such as SEMs and STEMs), positional information is in the time that the signal is collected, being correlated with the (known) position of the beam during raster scanning. The same two benefits discussed for FIG. 9 also apply here—increased detector lifetime and potentially improved imaging resolution. With a small modification, FIG. 10 can also apply to the case of electron diffraction in the STEM. If the primary beam 1002 is made nearly parallel and illuminates a somewhat larger area of the sample 1004, while not being raster scanned across sample 1004, it is possible to acquire an electron diffraction image—in this case, the various trajectories 1008 and 1010 would correspond to different scattering angles. All other considerations discussed above would apply to this example, as well. Although embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made to the embodiments described herein without departing from the spirit and scope of the invention as defined by the appended claims. The voltage source for the grids may come from a single power source and use a voltage divider, separate power sources can be used for each grid, or some combination of voltage drivers and power sources may be used. While the examples provide an electric field to alter the trajectories of the secondary particles, a magnetic field could be used, although the effect of the magnetic field on the primary beam must be considered. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
	description	The subject matter disclosed herein relates generally to imaging systems, and more particularly, to pinhole collimators for nuclear medicine imaging systems and determining a system matrix for the pinhole collimator imaging systems. Nuclear medicine imaging systems, for example, single photon emission computed tomography (SPECT) imaging systems, use one or more image detectors, sometimes many image detectors, such as gamma cameras to acquire image data (e.g., gamma ray or photon image data). Collimators are used in combination with the image detectors to select the direction from which incident gamma rays are accepted and reduce the effects, for example, of radiation from other parts of the body that can degrade image quality (e.g., cause image artifacts). Thus, collimators can improve spatial resolution. Nuclear imaging systems with gamma cameras and pinhole collimators are increasingly being used for small animal and organ specific imaging in humans. A point spread function (PSF) of the gamma cameras is used to describe the photon count density distribution at the detector surface when a point source is imaged. Accurate modeling of the PSF is important for performing accurate image reconstruction, for example, of SPECT images. Accordingly, accurate modeling is important for resolution recovery, as well as for improving the quantitative accuracy of the reconstructed image. However, accurately determining the PSF of pinhole collimators is challenging as the PSF is a function of source location (shift-variant). One factor that contributes to the shift-variant nature of the PSF is the penetration of photons through the pinhole aperture. Conventional reconstruction algorithms are either ray-driven or voxel driven. In these reconstruction algorithms, the PSF of the pinholes are usually modeled using a simpler shift-invariant PSF. The simplifications can cause distortions in the reconstructed images, as well as affect the quantification in the images. Different methods are also known to calculate a system matrix for a nuclear medicine imaging system. The system matrix generally defines the physics of the system. The known methods perform physical measurements to determine the system matrix. The measurements are acquired by moving a point source to different locations in the image space and saving multiple acquired projections. However, in order to obtain sufficient counts in the projection data, the total acquisition time to calculate the system matrix can be from four hours up to eighteen hours. In order to speed up the process, the system matrix is sometimes measured for intermediate points (e.g., 400 intermediate points) and the system matrix for the intermediate grid is determined using interpolation. This process is not capable of exactly determining the PSF for any point in the image space and can introduce errors. Other known Monte-Carlo based methods are used wherein the pinhole is assumed to be formed from discrete steps. The photon flux through the pinhole aperture, as well as the collimator material, is then measured and stored as a system matrix. However, this method is computationally demanding and time consuming, resulting in a slow process that can also have discretization errors. The accuracy of the system matrix depends greatly on the model used to define the pinhole aperture. In accordance with an embodiment of the invention, a method for determining a system matrix for a medical imaging system is provided. The method includes using a closed form expression to determine a penetration term for a collimator of the medical imaging system and determining a point spread function of the collimator based on the penetration term. The method further includes calculating the system matrix for the medical imaging system based on the determined point spread function. In accordance with another embodiment of the invention, a method for determining a system matrix for a medical imaging system is provided. The method includes determining a penetration term for a collimator of the medical imaging system without performing any measurements using the medical imaging system and determining a sensitivity term, including a geometric term and a penetration term, for shape of a point spread function for the collimator based on the penetration term. The method further includes calculating the system matrix for the medical imaging system based on the determined point spread function. In accordance with yet another embodiment, a method for determining a system matrix for a medical imaging system is provided. The method includes determining parametric values where a plurality of planes that contain a voxel in an image space intersect a collimator and a detector of the imaging system and marking a location where the plurality of planes intersect a surface of the collimator as end points on the detector. The method further includes calculating the system matrix for the medical imaging system based on based on an inner most shape through which photons from a point source pass through the collimator and are detected. In accordance with still another embodiment of the invention, a method for reducing the size of a system matrix for a medical imaging system is provided. The method includes calculating the system matrix for one or more geometric configurations of a collimator and detector of a medical imaging system, wherein the calculated system matrix for all locations in an image space based on one of linear and non-linear transformations is used. The method further includes recomputing a reduced system matrix for all angular views at one position of a table of the medical imaging system. In accordance with another embodiment of the invention, a medical imaging system is provided that includes a plurality of nuclear medicine imaging detectors and a plurality of pinhole collimators attached to the plurality of nuclear medicine imaging detectors. The medical imaging system further includes an image reconstruction processor configured to reconstruct an image using a system matrix calculated based on an analytically derived pinhole penetration term. The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. To the extent that the figures illustrate diagrams of the functional blocks of various embodiments, the functional blocks are not necessarily indicative of the division between hardware circuitry. Thus, for example, one or more of the functional blocks (e.g., processors or memories) may be implemented in a single piece of hardware (e.g., a general purpose signal processor or a block of random access memory, hard disk, or the like). Similarly, the programs may be stand alone programs, may be incorporated as subroutines in an operating system, may be functions in an installed software package, and the like. It should be understood that the various embodiments are not limited to the arrangements and instrumentality shown in the drawings. As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. Various embodiments of the invention provide diagnostic imaging systems with imaging detectors and methods for determining the system matrix for the imaging systems. In particular, the various embodiments provide system matrix based reconstruction of pinhole collimator nuclear medicine imaging systems, in particular, single photon emission computed tomography (SPECT) imaging systems. The system matrix is determined based on the calculation of an analytical expression for the pinhole penetration term. FIG. 1 is a perspective view of an exemplary embodiment of a medical imaging system 10 constructed in accordance with various embodiments of the invention, which in this embodiment is a nuclear medicine imaging system, and more particularly, a single photon emission computed tomography (SPECT) imaging system. The system 10 includes an integrated gantry 12 that further includes a rotor 14 oriented about a gantry central bore 32. The rotor 14 is configured to support one or more nuclear medicine (NM) cameras 18 (two cameras 18 are shown), such as, but not limited to gamma cameras or SPECT detectors. In various embodiments, the cameras 18 are formed from detectors, such as pixelated detectors. The rotors 14 are further configured to rotate axially about an examination axis 19. A patient table 20 may include a bed 22 slidingly coupled to a bed support system 24, which may be coupled directly to a floor or may be coupled to the gantry 12 through a base 26 coupled to the gantry 12. The bed 22 may include a stretcher 28 slidingly coupled to an upper surface 30 of the bed 22. The patient table 20 is configured to facilitate ingress and egress of a patient (not shown) into an examination position that is substantially aligned with examination axis 19. During an imaging scan, the patient table 20 may be controlled to move the bed 22 and/or stretcher 28 axially into and out of a bore 32. The operation and control of the imaging system 10 may be performed in any manner known in the art. It should be noted that the various embodiments may be implemented in connection with imaging systems that include rotating gantries or stationary gantries. FIG. 2 is a schematic illustration of an NM imaging system 100 that has a plurality of imaging detectors mounted on a gantry. In various embodiments, more than two imaging detectors are provided and are dimensionally smaller than the cameras 18 of the system 10 of FIG. 1. In FIG. 2, and for example, first, second, third through N imaging detectors 102, 104, 106 and 108 are mounted on a gantry 110. The cameras 18 of the system 10 are large enough to image most or all of a width of a patient's body at one time and may have a diameter of approximately 40 centimeters (cm) or more. Each of the first, second, third through N imaging detectors 102, 104, 106 and 108 are smaller than the cameras 18. Each of the first through N imaging detectors 102-108 may have a diameter of 1 cm to 50 cm and may be formed for example, of cadmium zinc telluride (CZT) tiles to define, for example, pixelated detectors. The first through N imaging detectors 102-108 may be of different sizes and/or shapes with respect to each other, such as square, rectangular, circular or other shapes. By positioning multiple imaging detectors at multiple positions with respect to a patient 116, radiation or imaging data specific to a structure of interest within the patient 116 may be acquired while limiting the amount of motion needed, or even without moving the imaging detectors relative to the patient 116. Each of the first through N imaging detectors 102-108 may include, for example, 32×32 pixels. Each of the detectors 102-108 in one embodiment are stationary, viewing the structure of interest from one particular direction. However, the detectors 102-108 also may rotate about the gantry 110. Optionally, the detectors 102-108 are stationary and one or more collimators are rotated in front of one or more of the detectors 102-108. The collimators also may be stationary relative to the detectors 102-108. Different types of collimators are described in more detail below. Each detector captures a 1D or 2D image that may be defined by the x and y location of the pixel and the detector number. The measured data can also be in a list-mode format where each detected event is stored along with the time at which the event was detected. Each of the first through N imaging detectors 102-108 has a radiation detection face (not shown) that is directed towards, for example, a structure of interest within the patient 116. One or more of the radiation detection faces are covered by a collimator (see FIGS. 3 through 6). An actual field of view (FOV) of each of the first through N imaging detectors 102-108 may be directly proportional to the size and shape of the respective imaging detector 102-108, or may be changed using a collimator. The gantry 110 may have a bore 112 therethrough. A patient table 114 is configured with a support mechanism (not shown) to support and carry the patient 116, optionally, in a plurality of viewing positions within the bore 112 and relative to the first through N imaging detectors 102-108. Alternatively, the gantry 110 may include a plurality of gantry segments (not shown), each of which may independently move one imaging detector or a subset of imaging detectors. The gantry 110 also may be configured in other shapes, for example, as a “C” or “L”, and may be rotatable about the patient 116. A controller unit 120 may control the movement and positioning of the patient table 114, the gantry 110 and/or the first through N imaging detectors 102-108 with respect to each other to position the desired anatomy of the patient 116 within the FOVs of the first through N imaging detectors 102-108 prior to acquiring an image of the anatomy of interest. The controller unit 120 may have a table controller 122 and gantry motor controller 124 that may be automatically commanded by a processing unit 130, manually controlled by an operator, or a combination thereof. The gantry motor controller 124 may move the first through N imaging detectors 102-108 with respect to the patient 116 individually, in segments or simultaneously in a fixed relationship to one another. The table controller 122 may move the patient table 114 to position the patient 116 relative to the FOV of one or more of the first through N imaging detectors 102-108. Optionally, one or more collimators may be moved relative to the first through N imaging detectors 102-108. The first through N imaging detectors 102-108, gantry 110, and patient table 114 remain stationary after being initially positioned, and imaging data is acquired and processed as discussed below. The imaging data may be combined and reconstructed into a composite image, which may comprise two-dimensional (2D) images, a three-dimensional (3D) volume or a 3D volume over time (4D). A data acquisition system (DAS) 126 receives electrical signal data produced by the first through N imaging detectors 102-108 and converts the data into digital signals for subsequent processing. An image reconstruction processor 128 receives the data from the DAS 126 and reconstructs an image using an image reconstruction process. The image reconstruction process uses a system matrix of the various embodiments as described in more detail below. A data storage device 132 may be provided to store data from the DAS 126 or reconstructed image data. An input device 134 also may be provided to receive user inputs and a display 136 may be provided to display reconstructed images. The NM imaging system 100 also includes a system matrix processor 138 that determines a system matrix for use when reconstructing an image. The system matrix processor 138 uses an analytically derived pinhole penetration term calculated from a point spread function having a closed form expression (which also may be referred to as a closed form equation). In various embodiments, the cameras 18 and the first through N imaging detectors 102-108 may be formed, for example, from photon detectors having one or more corresponding collimators. The various embodiments of determining a system matrix may be used to determine the point spread function (PSF) of imaging systems having different types of collimators. The photon detectors may be any type of photon detecting elements known in the art (e.g., pixelated detectors) and may be formed from different materials. In some embodiments, and for example as shown in FIGS. 3 through 6, a photon detector 150 may be provided. The detectors 150a-150d may be formed of any material. For example, any semiconductor material as known in the art, such as, cadmium zinc telluride (CdZnTe), often referred to as CZT, gallium arsenide (GaAs) and silicon (Si), among others. Specifically, the detectors 150a-150d each include a crystal 152 formed, for example, from a semiconductor material. A collimator, for example, a parallel hole collimator 154 may be attached to the detector 150a as shown in FIG. 3. The parallel hole collimator 154 may be formed, for example, from a flat sheet or cylindrical tube with multiple holes through the sheet. In some embodiments, the parallel hole collimator 154 is connected to a lead base (not shown), which is attached to the crystal 152. As another example, as shown in FIG. 4, a pinhole collimator 156 may be attached to the crystal 152 of the detector 150b. As still other examples, focusing collimators may be used, such as a diverging collimator 158 as shown in FIG. 5 in connection with detector 150c or a converging collimator 160 as shown in FIG. 6 in connection with detector 150d. Parallel hole collimators 154 generally produce images having a one to one relation to the object being imaged. Diverging collimators 158 generally are used to acquire images of reduced size relative to the object being imaged and converging collimators 160 are used to acquire images of magnified size relative to the object being imaged. The number of openings in the collimators or the number of collimators may be varied as desired or needed. It should be noted that the collimators may be made of different types of materials. In general, the collimators are formed from a material having a high atomic number, for example, tungsten or lead, with lead or lead alloys used in some embodiments. Various embodiments of the invention determine the system matrix for a nuclear medicine imaging system, for example, the system 10 or 100. For example, the system matrix for a pinhole SPECT system may be determined using a closed form expression, for example, for defining the PSF of focusing collimators (e.g., collimators 158 and 160). The calculation of the system matrix generally includes combining a closed form expression for the PSF, the distance driven effect of the pixel onto the three-dimensional (3D) image space, the sensitivity of the voxel, calibration parameters and the effects of attenuation. System matrix based reconstruction accordingly can be performed using a system matrix determined in accordance with various embodiments of the invention. It should be noted that when reference is made herein to a system matrix, this generally refers to a matrix that describes the probability that activity in a particular voxel in the image space is recorded by a particular pixel in the detector space. The system matrix is essentially a mathematical description of the physics of the system (e.g., physics of collimators of an imaging system, attenuation, geometrical calibration, etc.). Specifically, a method 170 for determining a system matrix, for example, for a pinhole SPECT imaging system is shown in FIG. 7. More particularly, at 172 a closed form expression is used to determine the path length of a penetrating photon through a collimator, for example, a focusing pinhole collimator. The closed form expression may be any analytically derived expression modeling the collimator to determine the path length. For example, one closed form expression is described in “Analytical derivation of the point spread function for pinhole collimators” by Girish Bal and Paul D. Acton, Phys. Med. Biol. 51 (2006), pages 4923-4950 (hereafter Bal Article), the entire disclosure of which is hereby incorporated by reference herein. The path length ΔL of a photon through a collimator may be determined using the following closed form expression of the Bal Article: Δ ⁢ ⁢ L = Δ ⁢ ⁢ t sin ⁢ ⁢ θ a = d f ⁢ ⁢ tan ⁢ ⁢ α ⁢ ⁢ ( N ⁢ ⁢ sin ⁢ ⁢ γ ⁢ + cos ⁢ ⁢ γ ) - ( Q 1 2 - PR 1 ) 1 / 2 - ( Q 2 2 - PR 2 ) 1 / 2 P ( csc 2 ⁢ θ - 2 ⁢ ρ ⁢ ⁢ cot ⁢ ⁢ θ ⁢ ⁢ cos ⁡ ( β - ϕ / h + ρ 2 / h 2 ) - 1 / 2 ,whereP=M2+AN2−2BN+C; M=cot θ cos φ−ρ cos β/h N=cot θ sin φ−ρ sin β/h; A=cos2 γ−sin2 γ tan2 α;B=cos γ sin γ(1+tan2 α); C=sin2 γ=cos2 γ tan2 α;R1=ρ2(cos2 β+A sin2 β)−ρdf sin β sin γ tan α−0.25df2;R2=ρ2(cos2 β+A sin2 β)+ρdf sin β sin γ tan α−0.25df2;Q1=Mρ cos β+ρ sin β(AN−B)−0.5df tan α(N sin γ+cos γ);Q2=Mρ cos β+ρ sin β(AN−B)+0.5df tan α(N sin γ+cos γ). It should be noted that a positive value for ΔL means that the photon passes through the pinhole collimator and a negative value for ΔL means that the photon is passing through the pinhole aperture. Thereafter, at 174 the PSF is determined based on one or more of the determined path length of the photon through the collimator as determined, for example, from the closed form expression, incident angle, calibration values, energy of incident photon, etc. For example, and as described in the Bal Article, initializing all the negative values of ΔL to zero, the two-dimensional PSF for a focusing pinhole collimator may be determined using:PSF≡sin3 θae−μΔL/4πh2. It should be noted that the equations used herein to determine ΔL and the PSF are only exemplary and other equations may be derived by one of skill in the art. For example, the PSF can be approximated by an elliptical shape with a certain direction and magnitude of major and minor axes, and corresponding tapering of the penetration term towards these axes, respectively. Such a PSF is a slowly varying function of position and the coefficients of the PSF may be pre-computed and stored for a number of locations in the image space. Actual values of the PSF then can be quickly computed on the fly (e.g., while data is being acquired) by interpolating the coefficients. The system matrix is then calculated (if possible) at 176 based on the PSF, and more particularly, the penetration term of the PSF, which may be based on ΔL. A system matrix is formed that includes penetration term values based on the PSF, for example, for a plurality of different angles of incidence relative to each of the collimators. The system matrix defines, for example, correction terms for the penetration of photon through each collimator as determined by the PSF. Other parameters also may be included as part of the system matrix, as are known, may be added into the calculation of the PSF. In some embodiments, calibration parameters (as are known) are added to the PSF equation, for example, as error terms for the various spatial parameters defining the image and detector space. The system matrix from every voxel may be calculated by convolving the calculated PSF with a corresponding distance-driven based rect function. For example, as shown in FIG. 8, a schematic representation 200 of the PSF component 202 is illustrated after being convolved with a distance driven effect 204. The combined effect determines the shape of the PSF for any voxel in the image space. It should be noted that this determination can be extended to the volume space by combining the effect of the volume of a voxel in the image space onto the pixels in the projection space. Thus, at 178, different effects may be incorporated into the system matrix, such as the effects of attenuation, detector response function, sensitivity, uniformity, etc. For example, a matrix multiplication may be performed to the system matrix using the stored matrix and acquired or calculated attenuation terms. It should be noted that this incorporation of the effects of attenuation to the system matrix is performed only once per imaging scenario in the various embodiments. Thereafter, if the system matrix is too large, for example, to store or use as part of the image reconstruction process (e.g., slows down the image reconstruction process to an unacceptable level to a user), then memory reduction methods are performed at 180. For example, the system matrix may be (i) determined for just the targeted volume of interest (VOI) and calculated on the fly for voxels outside the field of view, (ii) calculated for just one location of the table (e.g., patient table) and all angular views, with the thereafter stored system matrix modified based on table translation and used in the reconstruction, (3) stored as a set of parameters or (4) stored such that different elements of the system matrix are stored within a memory element (e.g., within a float, store the u,v and sensitivity values). After the system matrix is calculated (an optionally reduced in size), the system matrix is stored with the analytically derived pinhole penetration term at 182. For example, the system matrix may be stored in a memory of a nuclear medicine imaging system. If an image is to be displayed, then at 184 an image is reconstructed using the precalculated system matrix stored in memory. It should be noted that some of the major parameters that make the PSF of a pinhole collimator shift-variant are (1) the focusing angle of the pinhole collimator, (2) the attenuation coefficient of the collimator material and (3) the incidence angle of the photon. The various embodiments use a closed form expression to determine the path length of the penetrated photon through the collimator and hence determine the shape and PSF. This determination is particularly important for small pinholes (e.g., pinholes less than 1 mm in diameter) and high energy photons such as I-123 where more than 50 percent of the detected photons may be due to penetration. The effect of penetrated photons is even larger for isotopes such as I-131, where the contribution of the penetrated photons may be as high as 90 percent of the detected counts depending on the pinhole diameter, acceptance angle and material of the pinhole. Using the various embodiments and the closed form expression in the calculation of the system matrix, the sensitivity of the pinhole system can be determined. This sensitivity term combines the effects of both the geometrically accepted as well as penetration photons. In the system matrix approach of the various embodiments, calibration parameters can be added into the PSF equation thereby eliminating, for example, multiple tri-linear interpolations during image reconstruction. Thus, in accordance with some embodiments of the invention pinhole sensitivity can be determined as shown in FIGS. 9 and 10. Specifically, as shown in the graph 210 of FIG. 9 and the diagram of a sphere 220 as shown in FIG. 10, the pinhole sensitivity can be determined as: a solid angle subtended/4π. More particularly, in order to determine the pinhole sensitivity the following method may be performed: 1. Take a number of planar sections through the pinhole 212, and find intersections with edges. 2. Find the edge that is limiting sensitivity. 3. Project the limiting points onto a unit sphere. 4. Compute the solid angle as follows: tan ⁡ ( 1 2 ⁢ Ω ) = [ R 1 ⁢ R 2 ⁢ R 3 ] R 1 ⁢ R 2 ⁢ R 3 + ( R 1 · R 2 ) ⁢ R 3 + ( R 1 · R 3 ) ⁢ R 2 + ( R 2 · R 3 ) ⁢ R 1 Moreover, the shape of the pinhole “shadow” may be determined as illustrated in FIGS. 11 and 12. In particular, FIG. 11 is a graph 230 illustrating a pinhole shadow and FIG. 12 is a graph 240 illustrating a detector model. The “limiting edge” of the pinhole is projected onto the detector in some embodiments as follows: 1. Starting from the central ray, find the limiting intersections and project onto the detector. 2. Repeat the determination for pixel edges until no intersection is found. 3. Determine pixels that are “partially” and “fully” inside the shadow. 4. Compute the area of “partial” pixels inside the shadow. 5. Convert area into a solid angle. 6. Return the results to detector model. Thus, the detector PSF may be determined as a function of angle as shown in FIG. 13. Specifically, as shown in the graphs 250, 252, 254, 256, 258 and 260 corresponding to different angles, namely 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees and 50 degrees, respectively, various embodiments may determine the detector PSF as a function of angle, which takes into account the direction and angle of incidence, the detector resolution and the crystal penetration. Accordingly, with various embodiments described herein, the PSF, loss of sensitivity and point spread displacement may be calculated. The value for the displacement for each of the different angles is also shown in FIG. 13. At least one technical effect of the various embodiments is reducing the time to determine the system matrix for an imaging system, such as a nuclear medicine imaging system, using a pre-calculated system matrix determined based on a penetration term calculated from a closed term expression. Image reconstruction time is thereby reduced. Calibration errors may be incorporated into the system matrix to reduce the number of interpolation errors. Additionally, after the effects of the PSF and attenuation have been pre-computed, resolution recovery and attenuation correction can be applied in a single step. It should be noted that modifications and variations to the various embodiments are contemplated. For example, the falloff term of the PSF (i.e., the half maximum of the penetration term) may be approximated as an elliptical shape and expressed, for example, as a parabolic or third order polynomial equation. The radial distance and angle of incidence may be determined using the polynomial and based on the minor and major axes of the elliptical shape. During estimation of the PSF, the pinhole may be modeled accordingly as using the various embodiments of the invention. It also should be noted that a major drawback of using the system matrix based reconstruction is that the memory size needed to store the system matrix can be very large. In certain cases the memory may have to be about 60 GB and hence impossible to store in the computer Random Access Memory (RAM). To overcome this drawback, the system matrix can be calculated for certain geometric configurations of the collimator and detector. For example, in a helical acquisition the system matrix needs to be calculated for one circular rotation of the collimator/gantry. Then, the system matrix for the translation of the patient/animal table can modeled during reconstruction. This method will enable fast reconstruction as the number of terms needed to be calculated on the fly is very small. In one embodiment of the algorithm, the algorithm is the variable pitch helical acquisition. In this geometry the collimator/gantry is rotated such that the measured angle between views are as far apart as possible (e.g., increased step size for adjacent views) or as a combination of some pseudo-random angle, leading to better angular sampling of the image space towards the start and end of the helical scan, thereby resulting in improved reconstructed images of the entire image space. Further the table increment can be varied so that the volume of interest (VOI) can be sampled for a longer acquisition time. The system matrix for the variable pitch-helical acquisition can be pre-computed for just a few angular views. Then, the system matrix of different table translations along the z-axis can be recomputed using the z-shift of the table and used in the reconstruction. In another embodiment, the system matrix is pre-computed and stored only for certain voxels (e.g., voxels within the VOI). In this case, for the voxels not having the system matrix pre-computed (e.g., voxels outside the VOI), the projector/backprojector of the reconstruction algorithm is calculated on the fly. Accordingly, the reconstructed image has a high resolution and less quantitative errors within the VOI and at the same time the memory requirement is reduced. Additionally, in some embodiments, to reduce the memory size needed for storing the system matrix, the values of the different elements of the system matrix can be approximated using a set of parameters. For example the shape of the point spread function can be approximated using geometric shapes or a combination of geometric shapes, such as a circle, ellipse and/or Gaussian, exponential function. Additional parameters such as radius, offset values, aspect ratios and amplitude of the function can be used to represent the system matrix. In yet another embodiment, the image space is sequentially sampled in the same order both during the generation of the system matrix as well as during the reconstruction. In this way, the system avoids saving the voxel locations in the image space along with the system matrix, thereby reducing the memory needed. The system matrix elements or the parameters can be stored using fewer memory elements by saving multiple parameters in the same byte, for example, by placing the horizontal and vertical location on the detector along with the sensitivity value of the system matrix as one unsigned long integer (or float, character, etc). Accordingly, the number of individual bits in the memory element can be predetermined to represent the various parameters of the system matrix. Apart from reducing the memory size, this approach can speed up reconstruction as multiple parameters are can be retrieved in the same memory call. In still another embodiment, the system matrix can be calculated and stored for a certain number of predetermined locations in the image space. The system matrix in the intermediate region can be either calculated on the fly analytically/numerically or can be approximated using a set of parameters. Further, the system matrix can be calculated for a higher resolution (sampling) and based on the location of where the photons from the voxel strike the detector, and the highly sampled system matrix can be down sampled to that used on detector. One approach to determine the parametric values of the system matrix is to consider multiple planes that contain a voxel in the image space and intersect the collimator (such as pinhole, keel hole, slit hole, parallel hole, fan beam cone beam, etc.) and the detector. The locations where these planes intersect the surface of the collimator are determined and the corresponding locations were marked as end points on the detector. The point spread function is determined as the inner most shape through which the photons from the point source passes through the collimator and is detected. The counts in this region are integrated to give the sensitivity term. In addition, the penetration of the photons through the material can be modeled and added to the system matrix. Specifically, because the location on the detector where the edge of the different parts of the collimator intersect the plane (containing the point source) is known, the penetration of photons through the collimator material can be determined. For example, the path length of the photons through the collimator material can be calculated from the shape of the object for every location on the detector surface that lies between the projection of the edges of the collimator. This numerically calculated system matrix can be parameterized if desired as a combination of different functions and used during the reconstruction. Thus, in accordance with various embodiments of the invention, system matrix based reconstruction may be provided using an exact equation, using a numerical approach and/or using memory reduction methods. For example, using an exact equation can include using the closed for expression as described herein and incorporating different effects, such as the effects of attenuation, detector response function, sensitivity, calibration parameters, etc. With a numerical approach, parametric values are used to define a combination of different shapes that can result in the measured point spread function, for example the short and long axis of an ellipse, an offset value of the central ray, the location of the centroid, a vector direction of the incident photon, amplitude, etc, Thereafter the projection space is divided into a set of lines. Using a point source in the image space, planes that contain the point source and pass through the lines on the detector are determined. Then, the locations where the planes intersect the surface of the collimator holes are determined. The locations where the planes intersect the surface of the collimator holes can be marked on the detector. Polynomials that are common to all the marked points then may be determined. It should be noted that the geometrically accepted photons are the photons that lie within the inner most part of the different shapes on the detector. Because the location on the detector where the edge of the different parts of the collimator intersect the plane (containing the point source) is known, the penetration of photons through the collimator can be determined. For example, the path length of the photons through the collimator material can be calculated from the shape of the object for every location on the detector surface that lies between the projection of the edges of the collimator. With the memory reduction methods, targeted VOI imaging may be performed, for example, by determining the system matrix for just the targeted VOI (which is precomputed and stored). The system matrix outside the VOI is calculated “on the fly”, namely not predetermined or precalculated, but determined as factors or circumstances change, such as the patient table moves. An imaging geometry method optionally may be performed, for example, by calculating the system matrix for all angular location, but just one patient table location. Thereafter the system matrix is modified for various patient table locations as the patient table moves. The parametric values optionally may be stored “on the fly” try to determine the point spread function from the parametric values. Additionally, one memory element optionally may be used to store different parts of the system matrix. For example, if a ‘float’ element is stored as 64 bits in a computer memory, the first 16 bits can be used to save the u-axis location, the next 16 bits to store the v-axis location, the next 16 bits to store the sensitivity term, and the last 16 bits to store the scatter component for a photon emitted from a point in the image space. Some embodiments of the present invention provide a machine-readable medium or media having instructions recorded thereon for a processor or computer to operate an imaging apparatus to perform one or more embodiments of the methods described herein. The medium or media may be any type of CD-ROM, DVD, floppy disk, hard disk, optical disk, flash RAM drive, or other type of computer-readable medium or a combination thereof. The various embodiments and/or components, for example, the processors, or components and controllers therein, also may be implemented as part of one or more computers or processors. The computer or processor may include a computing device, an input device, a display unit and an interface, for example, for accessing the Internet. The computer or processor may include a microprocessor. The microprocessor may be connected to a communication bus. The computer or processor may also include a memory. The memory may include RAM and Read Only Memory (ROM). The computer or processor further may include a storage device, which may be a hard disk drive or a removable storage drive such as a floppy disk drive, optical disk drive, and the like. The storage device may also be other similar means for loading computer programs or other instructions into the computer or processor. As used herein, the term “computer” may include any processor-based or microprocessor-based system including systems using microcontrollers, reduced instruction set computers (RISC), application specific integrated circuits (ASICs), logic circuits, and any other circuit or processor capable of executing the functions described herein. The above examples are exemplary only, and are thus not intended to limit in any way the definition and/or meaning of the term “computer”. The computer or processor executes a set of instructions that are stored in one or more storage elements, in order to process input data. The storage elements may also store data or other information as desired or needed. The storage element may be in the form of an information source or a physical memory element within a processing machine. The set of instructions may include various commands that instruct the computer or processor as a processing machine to perform specific operations such as the methods and processes of the various embodiments of the invention. The set of instructions may be in the form of a software program. The software may be in various forms such as system software or application software. Further, the software may be in the form of a collection of separate programs, a program module within a larger program or a portion of a program module. The software also may include modular programming in the form of object-oriented programming. The processing of input data by the processing machine may be in response to user commands, or in response to results of previous processing, or in response to a request made by another processing machine. As used herein, the terms “software” and “firmware” are interchangeable, and include any computer program stored in memory for execution by a computer, including RAM memory, ROM memory, EPROM memory, EEPROM memory, and non-volatile RAM (NVRAM) memory. The above memory types are exemplary only, and are thus not limiting as to the types of memory usable for storage of a computer program. It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. For example, the ordering of steps recited in a method need not be performed in a particular order unless explicitly stated or implicitly required (e.g., one step requires the results or a product of a previous step to be available). While the dimensions and types of materials described herein are intended to define the parameters of the invention, they are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing and understanding the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure. 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.
	summary
	description	This application is a continuation-in-part of U.S. patent application Ser. No. 10/282,324, filed on Oct. 10th, 2002, entitled “ELECTRON BEAM PATTERN GENERATOR WITH PHOTOCATHODE COMPRISING LOW WORK FUNCTION CESIUM HALIDE”, by Maldonado et al., which is incorporated herein by reference in its entirety. At least a portion of the work related to the invention described herein was performed with Government support under Contract Number N581-99C-8624. The Government has certain rights in these portions of the invention. Embodiments of the present invention relate to the generation of electron beams and their applications. Electron beams are used in a number of different applications. For example, electron beams can be modulated and directed onto an electron sensitive resist on a workpiece, such as a semiconductor wafer or mask, to generate an electron beam pattern on the workpiece. Electron beams can also be used to inspect a workpiece by, for example, detecting electrons emerging or reflected from the workpiece, to detect defects, anomalies or undesirable objects. Electron beams can also be used to irradiate a workpiece, such as a postal envelope, to destroy toxic chemicals or harmful microorganisms therein. A typical electron beam apparatus comprises an electron beam column that includes an electron beam source to generate one or more electron beams and electron beam elements to focus or deflect the electron beams across a workpiece, which is held on a movable support. The electron beam source typically comprises a photocathode and wavelength matched radiation beam source. The photocathode can be a radiation transparent workpiece coated with an electron-emitting material. The electron-emitting material has an electron work function, which is the minimum electron emission energy level required to emit an electron from the surface of the material. A beam source directs radiation onto the backside of the transparent workpiece, the radiation having an energy level that is at least as high as the electron work function. When photons of the beam impinge on the electron-emitting material they excite electrons to a suitable energy level that emits the electrons from the electron-emitting material. For example, one photocathode-laser combination comprises an argon-ion laser, a frequency multiplier crystal, and a photocathode comprising a electron-emitting material of Mg or MgO. The argon-ion laser has a fundamental wavelength of 514 nm, which is reduced to 257 nm by the frequency multiplier crystal, to generate a laser beam having an energy level of about 4.8 eV. The frequency multiplied 4.8 eV laser beam has a higher energy than the workfunction of the Mg or MgO electron-emitting material, which is 3 to 4 eV, thus, the laser system and the electron-emitting material are suitably matched. Electron-emitting materials used in such conventional photocathode systems have several limitations. For example, electron-emitting magnesium gradually oxidizes from exposure to residual oxygen in a low-pressure environment. MgO emitters often gives rise to deleterious blanking effects when the incident laser beam is blanked, i.e., turned on after an off period, when modulating the electron beams. In another example, the emission spot of a CsTe electron-emitting material often grows in size in operation, requiring the electron-emitting material to be patterned or covered with a protective anti-oxidation layer of CsBr, as described in commonly assigned U.S. patent application publication no. US 2003/0042434A1, which is incorporated herein by reference in its entirety. Cesium antimonide electron-emitting materials also have to be covered with a protective layer of CsBr to minimize attenuation of the quantum efficiency of the electron-emitting over time in an oxygen environment, as described in U.S. Pat. No. 6,531,816 B1, which is also incorporated herein by reference in its entirety. A further problem with conventional electron beam apparatus arises from their throughput versus resolution trade-off. Conventional apparatus that use a single electron beam to scan across a workpiece provide relatively low throughput when used at high resolutions. For example, at current line width resolutions of 100 to 130 nm, a single electron beam system takes about 6 hours to scan across the entire surface of a 200 mm workpiece; however, at resolutions of 35 to 50 nm, the same system would take about 50 hours to scan the same workpiece. This problem is reduced in multiple electron beam apparatus, which use a plurality of electron beams drawn from one or more electron sources as separate and well-defined beams. The multi-beam systems provide higher throughput and speed even at high resolutions. However, even these multi-beam systems are limited by the degradation, low beam current and electron cross-over limitations of conventional photocathodes. Thus, it is desirable to have an electron generating system that can generate a consistent stream of electrons without deleterious changes in operation. It is further desirable to have a properly matched photocathode and beam source capable of generating electrons with good efficiency and consistent emissivity. It is also desirable to have a stable photocathode that does not degrade due to oxidation in the vacuum environment. It is further desirable to have an electron beam apparatus capable of providing good throughput at high resolutions. An electron beam apparatus comprises a radiation beam source to generate a radiation beam and a photocathode comprising an electron-emitting material composed of activated alkali halide having a minimum electron emission energy level that is less than 75% of the minimum electron emission energy level of the un-activated alkali halide. The electron-emitting material emits electrons when the radiation beam is incident thereon. Electron beam elements are provided to form an electron beam from the emitted electrons and direct the electron beam onto a workpiece. A support is provided to support the workpiece. In one version, the photocathode comprises an electron-emitting material composed of activated alkali halide having a minimum electron emission energy level that is less than about 5 eV, such that the electron-emitting material emits electrons when a laser beam having a wavelength of from about 190 to about 532 nm is incident thereon. In another version, an electron beam pattern generator generates a pattern of electrons on a workpiece. The pattern generator comprises the aforementioned photocathode, and a laser beam source to generate the laser beam having a wavelength of from about 190 to about 532 nm. A beam modulator is provided to modulate the intensity of the laser beam according to a pattern and direct the modulated laser beam onto the photocathode. Electron beam elements are used to form an electron beam from the emitted electrons and direct the electron beam onto a workpiece. A support is provided to support the workpiece. Yet another version comprises an electron beam inspection apparatus that is used to inspect a workpiece with electron beams. The apparatus comprises the aforementioned photocathode and a laser beam source to generate a laser beam having a wavelength of from about 190 to about 532 nm. Electron beam elements are used to form an electron beam from the emitted electrons and direct the electron beam onto a workpiece. A support supports the workpiece. An electron detector is used to detect electrons backscattered from the workpiece to inspect the workpiece. In an electron generating method, an electron-emitting material composed of alkali halide is provided. The alkali halide is activated to form an activated alkali halide having a minimum electron emission energy level that is less than 75% of the minimum electron emission energy level of the un-activated alkali halide. A first radiation beam is directed on the activated alkali halide, the first radiation beam having photons with an energy level that is higher than the energy level of the activated alkali halide to cause electrons to be emitted therefrom. A method of manufacturing a photocathode for an electron beam apparatus comprises providing a substratum in a process zone, evacuating the process zone, evaporating an alkali halide in the process zone to deposit alkali halide on the workpiece, and activating the deposited alkali halide to have a minimum electron emission energy level that is less than 50% of the electron emission minimum electron emission energy level of the un-activated alkali halide by directing radiation onto the deposited alkali halide for a sufficient time period to develop an interior region having a first alkali concentration and a surface region having a second alkali concentration. The second alkali concentration results from a capping layer of alkali formed on the surface of the material. Electrons are generated from a photocathode 20 comprising a substratum 22 supporting an electron-emitting material 24, as illustrated in FIG. 1. The photocathode 20 is typically a negatively biased electrode, but may also be at a floating or ground potential. The electron-emitting material 24 absorbs photons that excite electrons above the energy level of a surrounding vacuum environment, and a portion of the electrons that are sufficiently excited are emitted into the vacuum. Thus, the electron-emitting material 24 is a material has a minimum electron emission energy level that is sufficiently low to emit electrons when photons having an energy greater than the minimum electron emission energy level are incident upon and absorbed by the electron-emitting material 24. The substratum 22 typically comprises a radiation permeable material that is permeable to radiation in a predefined band of wavelengths, so that the radiation can pass through the substratum 22 to reach the electron-emitting material 24. For example, the substratum 22 may comprise sapphire. The photocathode 20 can also have a conductive layer 26 between the substratum 22 and the electron-emitting material 24 to provide a good adhesion layer that also serves as an electrode to complete the photocurrent circuit and is substantially transparent to the radiation. If the radiation is impinging from the photocathode side, the conductive layer may be opaque to the incident radiation wavelength. The conductive layer may also include materials with good adhesion and low chemical reactivity with the photocathode like Mo, Cr and Ta. While an illustrative embodiment of the photocathode is described, it should be understood that other embodiments are also possible, such as embodiments in which there is no substratum and the photocathode is made entirely from the electron emitting material, or others which have different shapes or which use different layers, thus, the scope of the claims should not be limited to the illustrative embodiments. The photocathode 20 comprises an electron-emitting material 24 composed of an activated alkali halide that emits electrons when excited with radiation, the activated alkali halide material having a minimum electron emission energy level that is lower than the minimum electron emission energy level of the un-activated material. The alkali metals, found in Group I of the periodic table (formerly known as group IA), are reactive metals that have only one electron in their outer shell, and can lose that one electron in ionic bonding with other elements. The alkali metals include lithium, sodium, potassium, rubidium, cesium and francium. The halogens of Group VII of the periodic table include chlorine, fluorine, bromine and iodine. The alkali halide material comprises at least one alkali metal and at least one halogen in a ratio that may be a stochiometric or non-stoichiometric ratio. Of the alkali halides, cesium halide materials have been found to have good results, although the other alkali halides may also be used. The cesium halide material comprises at least one cesium atom and at least one halogen atom. The cesium halide is not necessarily limited to particular stoichiometric formulations of conventional cesium halides, but can include non-stochiometric formulations that provide a desirable minimum electron emission energy level. In addition, the cesium halide material can also contain other materials, beside cesium and halogen. The alkali halide has to be activated before it can emit electrons at the desired efficiency and yield levels, and to have a lower minimum electron emission energy level than the theoretical minimum electron emission energy of the same but untreated alkali halide material. The activation treatment reduces the minimum electron emission energy level of the alkali halide by at least 75%, and can even lower the energy level by at least 50%. For example, without activation, the theoretically determined energy gap of an exemplary alkali halide such as CsBr is 7.8 eV, however, after activation the minimum emission energy of the same CsBr material can be reduced to less than about 5 eV, for example, about 4.8 eV, and can even be about 3 eV. The significantly lower minimum electron emission energy level makes it practicable to use the electron-emitting material in conventional applications. In one version of the activation method, the electron-emitting material 24 is activated by irradiating the alkali halide material with a radiation having a sufficiently high energy level and for a sufficiently long time period to create an activated material having a lower minimum electron emission energy level. The radiation may be, for example, UV, X-ray, visible light, or electron beams. During irradiation, it is believed that the reduced minimum electron emission energy level is achieved by the migration of alkali metal atoms to form color centers in the bulk of the alkali halide material and a capping layer on its surface. A color center (or F-center) is a lattice defect in a crystalline solid comprising a vacant negative ion site and an electron bound to the site. Such defects absorb radiation having a wavelength that corresponds to the band gap energy level created by the defect, and can make certain normally transparent crystals appear colored, or can make colored crystals change color. The color centers and their corresponding radiation absorption bands may be caused by one or more of hole center, electron centers, di-vacancy and di-hole centers, and even Frenkel defects. The presence of the color centers can be detected by observing a change in a color of the material, if such a color change is in the observable visible spectrum. Scanning a series of sequentially incremented wavelengths across a specimen of the activated material and detecting the resultant absorption spectrum can be used to detect the color centers. The detected absorption spectrum has absorption peaks corresponding to the wavelengths of the incident radiation that is absorbed by the color centers. Thus, the un-activated alkali halide absorbs a first level of a radiation having a wavelength that falls in the absorption band of color centers to form the activated alkali halide, which then absorbs a second level of the same radiation to emit electrons. Photoelectron spectroscopy can also be used to probe the electronically excited states of alkali-halide material with excess electrons, in which the excess electrons are pumped up to their excited states by one laser pulse before being driven into the continuum by a second laser pulse. Activation of the alkali halide material is affected during irradiation when the alkali halide material is heated to a temperature of from about 60 to about 300° C. At relatively low temperatures of less than about 100° C., the heat increases the diffusion of alkali metal atoms, such as the cesium, to the surface of the alkali halide film to form a capping surface layer having a higher concentration of alkali-atoms than that present in the bulk of the interior region of the activated material. However, the material can be deactivated when it is heated to a sufficiently high temperature. The higher surface concentration of alkali metal atoms in the surface reduces the effective work function of the alkali halide material by lowering the energy required to excite electrons out of the surface. Typically, directing a laser beam having an output of a few mWatts for a time period of a few hours, such as about 180 minutes (3 hours), on the electron-emitting material is sufficient to generate the surface activated layer. In the activation process, the incident radiation causes the alkali metal atoms, such as the cesium atoms, to migrate to the surface of the electron-emitting material 24 to form a thin capping layer having a higher concentration of alkali metal than the surrounding bulk material. The capping layer can have a thickness from at least a fraction of a monolayer to several monolayers of atoms. It is believed that the capping surface layer of alkali metal cooperates with the underlying bulk of the alkali halide material to form a dipole that reduces the electron emission energy at the surface of the resultant electron-emitting material 24. For example, in an electron-emitting material 24 comprising cesium halide, the cesium halide material is deposited as a layer on a substratum and then activated to have a capping layer of cesium atoms 28 on its surface. When photons irradiate the electron-emitting material 24, the emission surface 30 with the higher cesium concentration of the capping layer provides an effectively lowered minimum electron emission energy level at the surface of the material 24 that allows longer-wavelength (lower energy) photons to generate electron emission from the activated material. For example, by deep-UV light activation, the minimum electron emission energy level at the emission surface 30 of a cesium bromide or cesium iodide layer can be reduced to less than 5 eV, such as about 4.8 eV or 3.6 eV or even about 2.1 eV. Then, a photon source such as an argon-ion laser beam 32 with a wavelength of at least about 257 nm, for example, the laser beam 32 can have a wavelength of about 364 or 532 nm can be used to irradiate and cause electron emissions from such an electron-emitting material 24. The photoyield of the 532 nm laser beam is significantly lower than the corresponding one for the smaller-wavelength laser beam, such as the 257 nm laser beam. In one version, the electron-emitting material 24 comprises activated cesium bromide material. This activated cesium bromide material can yield a quantum efficiency of at least about 0.1% when irradiated with approximately 4.8 eV photons (257 nm), and an energy spread of about 1 eV. This version is advantageous because conventional photoemitters like Au have a much lower efficiency and are susceptible to surfacecontamination. In another version, the electron-emitting material 24 comprises cesium iodide material. The cesium iodide material is advantageous because it may be more stable in terms of temperature resistance or corrosion resistance. The activated alkali halide electron-emitting material also provides good photoyields that exhibit low degradation over time in a vacuum environment. The photoyield is a measure of the electron emitting efficiency of the electron emitter layer. An activated alkali halide, for example, activated CsBr, provides a photoemission electron yield at least about 20 nA/mW, and more typically, even about 200 nA/mW. In contrast, the same un-activated CsBr photocathode generally provides no yields or yields of less than about 2 nA/mW. This demonstrates an improvement in yield of a factor of 10 to about 100 times. Furthermore, unlike conventional photocathode materials, the electron yield reduces only marginally after operation for extended periods in vacuum environments. For example, a photocathode having an activated CsBr electron-emitting material with an argon ion laser can provide a photoyield of greater than 200 nA/mW that remains stable at these levels in a vacuum environment for an extended time period, as shown in FIG. 8. The output was found to remain stable for more than 150 hours without appreciable degradation. The lower minimum electron emission energy level of the activated material also allows use of activated beam sources that are well characterized and commonly used systems, such as an argon ion laser. An argon ion laser has a fundamental wavelength of at least about 514 nm, which can be frequency multiplied by the BBO crystal to have a divided wavelength of at least about 257 nm. The divided wavelength is equivalent to an energy level of about 4.8 eV, which is higher than the minimum electron emission energy level of activated CsBr of about 2 eV. The same argon ion laser cannot be used to generate electrons using un-activated CsBr, which in its untreated form has an energy gap of 7.8 eV that would require a laser source having a wavelength smaller than 158 nm, which is smaller than that being produced by the argon ion laser. For these reasons, activated electron-emitting material 24 comprising CsBr, emits electrons more reliably and with better yields than the un-activated material. The electron emitter layer of the photocathode 20 can be manufactured in a photocathode deposition system 50, an embodiment of which is illustrated in FIG. 2. The photocathode deposition system 50 comprises a sublimator chamber 51 to deposit both a conductor film 26 and an electron-emitting material 24 on a substratum 20. A transfer or analysis chamber (not shown) can also be used for post-deposition analysis of the photocathode 20. The substratum 22 is placed in the sublimator chamber 51, and effusion cells 52 are used to sublimate alkali halide material for deposition on the substratum 22. Channels 53 are provided between the chambers to allow transfer of the substratum 22 between the chambers without exposure to the external atmosphere. The sublimator chamber 51 has stainless steel walls 54 and an ultra-high vacuum pump 55, such as an ion pump, to maintain an ultrahigh vacuum of from about 10−8 to about 10−11 Torr. Liquid nitrogen shrouding is used to provide cold surfaces within the sublimator chamber 51 to reduce unwanted contaminants. The substratum 22 is mounted on a holder 58, which is maintained at a selected temperature for film growth by a power supply 56. A temperature instrument (not shown) may also be provided. An optical pyrometer or thermocouple can be used to measure the temperature of the substratum 22. An electron beam evaporator 57 is provided in the sublimator chamber 51 to evaporate material onto the substratum 22 to form the conductor film 26. The conductor film that transmits the photon beams 32 with sufficiently low attenuation to allow the beams to pass through and still irradiate the electron-emitting material with sufficient energy. The conductor film can be a molybdenum film having a thickness of less than about 10 nm to provide an attenuation of less than about 20% at 257 nm. The evaporator 57 operates by directing a beam of electrons onto a metal wire. The conductor film can also be made of other metals, such as Mo, Cr, Ta, that have low ultraviolet attenuation, good wetting, and strong adhesion. The effusion cell 52 also has a crucible 59 for sublimating alkali halide material 60 placed therein. The crucible 59 is made of a high temperature material, such as ceramic, graphite, tantalum, molybdenum, or pyrolytic boron nitride. The crucible 59 is secured to a frame 63 connected to a flange 64 for attachment of the effusion cell 52 to the sublimator chamber 51. The sublimator chamber 51 is evacuated to form an ultra-high vacuum oxygen-free environment in which the effusion cell 52 can operate. A heating assembly 62 surrounding the crucible 59 heats the material 60 in the crucible 59 to control the sublimation of the source material 60 from solid to vapor form. For example, in one embodiment, the source material 60 is heated to a temperature of from about 60 to about 300°C. The evaporated molecules 61 generated by evaporation of the alkali halide material 60 in the crucible 59 deposits on the conductor film 26 to form an epitaxial film of alkali halide material. After deposition of the halide material 60 on the substratum 22, the deposited material is activated to form an electron-emitting material 24 having a reduced minimum electron emission energy level at its surface. In one activation method, the deposited alkali halide material is irradiated with a radiation such as ultra-violet radiation having a wavelength <300 nm, such as deep-ultraviolet radiation having a wavelength in the range of from about 190 to about 532 nm. A suitable radiation source for an electron emitter layer comprising CsBr is, for example, an argon-ion laser. The activation is performed by directing the argon-ion laser beam onto the deposited electron-emitting material, in vacuum, for a time period of from about 120 to about 240 minutes. An example of the progress of the activation process is illustrated in FIG. 1. The activation can be performed insitu in an electron generating apparatus or the photocathode may be activated in a separate vacuum chamber and transferred to the operating chamber under vacuum. In the irradiation step, a lower minimum electron emission energy level is achieved by the migration of alkali metal atoms to form residual color centers and a surface-capping layer having a higher alkali metal atom concentration. An embodiment of an electron beam apparatus 100 having a photocathode with an activated electron-emitting material is illustrated in FIG. 3. The apparatus generates multiple electron beams 34 that are scanned across a workpiece 105. The workpiece 105 can be a blank mask; a silicon wafer; a compound semiconductor wafer; a printed circuit board (PCB); or a multichip module (MCM). In one embodiment, the electron beam pattern is imprinted in a mask comprising an electron-sensitive resist coating 115 on a workpiece 105 comprising glass or quartz, which is used in the fabrication of integrated circuits (IC). After exposing the workpiece mask to electron beams 34, the exposed resist layer 115 is developed to form a resist pattern on the mask. The embodiments of the apparatus 100 and workpiece 105 illustrated herein are examples, and should not be used to limit the scope of the invention, and the invention encompasses equivalent or alternative versions, as would be apparent to one of ordinary skill in the art. The electron beam apparatus 100 includes a photon source section 120 coupled to an electron beam section 125. The photon source section 120 may include a beam source 130, a beam modulator 135, optical system 140, and beam splitter 150, as illustrated in FIG. 4. In one version, the beam source 130 comprises a laser 131, such as an argon ion laser. The beam source 130 may also comprise a frequency multiplier 132 to increase the frequency of the laser beam 32 emitted by the laser 131. For example, the frequency multiplier 132 may comprise a beta barium borate (BBO) crystal that approximately doubles the frequency of the laser beam 32. For an argonion produced laser beam having a fundamental wavelength of about 514 nm, a BBO crystal can receive the laser beam and double its frequency; in other words, halve its wavelength to about 257 nm. Alternatively, the beam source 130 may also comprise a frequency doubled diode-pumped laser source. In one example, the diode-pumped laser source operates at a fundamental wavelength of about 532 nm. A laser having a wavelength of 364 nm can also be used. The beam source may also comprise a laser having a wavelength of from about 190 to about 532 nm. In operation, a laser beam 32 is generated by the laser 131 is split by a beam splitter 150 into an array of spaced apart individual laser beams. The laser beam array is then directed to a beam modulator 135 that modulates the intensities of each of the laser beams 32. For example, the beam modulator 135 may comprise an array of acousto-optic modulators (AOM), which switch the laser beams 32 on or off by acoustically diffracting the laser beams in response to an RF signal, or set the transmitted photon flux of each individual beam to a predetermined intermediate value. In one embodiment, the laser beam 32 is split by a beam splitter 150 into an array comprising 32 individual beams, and a beam modulator 135 comprising a matching number of 32 AOM beam modulator elements is used to modulate the split beams. In an AOM array, the modulation of the photon intensity is achieved by applying RF power to the individual AOM channels. Applying different levels of RF power can be used for fine modulation of the light intensity. In another embodiment, the beam modulator 135 comprises a spatial light modulator (SLM) such as a micromechanical diffracting device. SLMs can be advantageous because they can modulate a larger number of laser beams, such as at least about 100 laser beams. A multiple gray level, multiple pass writing strategy may also be used, in beam modulation. Furthermore, another beam modulator (not shown) may be inserted in the optical system upstream of the beam splitter 150 to act as a fast auxiliary blanker. This additional beam modulator may be used during scan retrace when additional modulation is needed. In one illustrative embodiment, a 300 MHz carrier frequency is used to diffract the laser beams with an approximately 10 nsec pixel time. The beam splitter 150 may include optical light lenses focused on a desired plane of the electron beam section 125. The laser beam 32 from the laser beam source 130 may also be actively controlled by automatic beam centering mirrors 160 so that alignment to the optical train, both in position and angle, is maintained. An attenuator 165, which may comprise a combination polarization-rotating element and polarizing beam splitter, adjusts the laser power to a range suitable for operation of the system while allowing the beam source 130 to operate in a power range optimized for reliability and stability. A spatial filter 170 can remove undesirable sections of the laser beams intensity profile. An anamorphic relay 172 can be provided to create a round beam exiting this aperture and relay it to the diffractive optical element (DOE) 175 inside a brush module 180. The DOE 175 is a grating that produces a plurality of laser beams 32. The laser beams 32 are focused by lenses of the brush module 180 to a region typically underneath the additional beam modulator. A mechanical shutter 185 before the brush module 180 is used to block radiation from reaching the electron beam section 125 when the electron beam apparatus 100 is not exposing the workpiece 105. The individual modulated laser beams 32 are demagnified by the optical system 140. A K-mirror 190 allows for rotational adjustment of the linear array of laser beams 32 exiting the additional beam modulator. A wave plate 195 aligns the polarization of the beams for optimal focusing through birefringent substratums such as sapphire. A lens element 200 after the wave plate 195 focuses the laser beam array onto a focal spot on a steering mirror 205. Before reaching the steering mirror 205, the zero-order (undiffracted) light from the beam modulator 135 is blocked by a zero-order beam stop 210. The steering mirror 205 allows for small positional adjustment of the spot array at the final image plane of an objective lens 215. The zoom optics and stigmator 220 relay the focal spot into the pupil of the objective lens 215. Tilted plates inside the zoom optics and stigmator 220 provide adjustment capability to ensure that the focus of the spots onto the electron beam section 125 occurs in the same plane whether measured along the direction of the array of spots or perpendicular to it. Movable lenses within the zoom optics and stigmator 220 allow for slight magnification adjustment of the array of laser beams 32. Referring to FIGS. 3 and 5, below the photon source section 120, the electron beam section 125 converts the photon beam image generated by the photon source section 120 into a corresponding electron beam image. The electron beam section 125 may comprise a vacuum column 225 containing a vacuum environment in which electron beams 34 can be generated to expose the workpiece 105 to an electron beam image. The vacuum column 225 comprises walls 230 that are substantially vacuum-tight and are typically made of a material such as aluminum. One or more vacuum pumps (not shown) are provided to evacuate the vacuum column 225 to create and maintain the vacuum environment. In one embodiment, the vacuum pumps provide a first vacuum environment at the top portion of the vacuum column 225, and a second vacuum environment, which may have a different vacuum pressure at the bottom portion of the vacuum column 225. For example, the first vacuum environment may be at a gas pressure of about 109 Torr and the second vacuum environment may be at a gas pressure of about 10−6 Torr. A pressure barrier may also be provided between the vacuum environments to maintain the pressure difference. The electron beam section 125 includes a photocathode 20 according to the present invention, and electron beam elements such as an anode 240 and electron optics 245. During installation of the photocathode 20 in the electron beam apparatus 100, the photocathode 20 may be transferred within a continuous vacuum environment into the electron beam section 125. In operation, the optical system 140 focuses the array of laser beams 32 exiting the beam modulator 135 onto a photocathode 20. The photocathode 20 receives the laser beam image and generates corresponding multiple electron beams 34 that form an electron beam image. The photocathode 20 forms an extraction field between itself and the anode 240 to draw the electron beams 34 from the photocathode 20 and accelerate the electron beams 34 toward the workpiece 105. For example, the extraction field may have a strength of from about 5 to about 10 kV/mm. The electrons are accelerated to an initial energy level to form defined electron beams 34. The energy level is selected to be sufficiently high to substantially prevent interactions between the electron beams 34. When the electron beams 34 are moving vertically at a higher velocity, lateral interactions between the electron beams 34 are typically less significant than when the electron beams 34 are moving at lower velocities. In one embodiment, the electron beams 34 are accelerated to energies of from 1 keV to, about 60 keV, such as about 50 keV. The electron beams 34 may have a brush width of from about 40 to about 90 microns, such as about 65 microns. Each electron beam 34 has a width of from about 270 to about 330 nm. When a voltage is applied to the anode 240, the electrons are accelerated and focused to form a multibeam virtual electron image of the photocathode emission surface corresponding to the laser beam image generated by the laser beam source 131. In one embodiment, the photocathode 20 is biased at about −50 kV, and is separated from a grounded anode 240 by an accelerating gap. The anode 240 is typically a planar electrode with an aperture in the center. The electron optics 245 shape the electron beams 34 to focus, demagnify, stigmate, or align the electrons. Optionally, an electron field lens 260 near the photocathode 20 is used to reduce off-axis aberrations in demagnification lenses 265 that follow. A version of exemplary electron optics is described in commonly-assigned U.S, Pat. No. 6,215,128 by Mankos et al., entitled “Compact Photoemission Source, Field and Objective Lens Arrangement for High Throughput Electron Beam Lithography”, filed on Mar. 18, 1999, which is hereby incorporated by reference in its entirety. The field lens 260 collimates the electrons exiting the accelerating region above the anode 240 and forms a crossover in the plane of a beam-limiting aperture 270. The virtual image created by the field lens 260 is then subsequently demagnified by the demagnification and objective magnetic lenses 265, 280 to form an array 285 of focused electron beams 34. Sets of alignment coils 290 are used to center and stigmate the electron beam array 285 in the beam-limiting aperture 270 and in the objective lens 280. In one embodiment, a beam scanner 295 comprising a set of magnetic beam deflection coils is used to scan the array 285 of individually modulated electron beams 34 across the workpiece 105. Another set of magnetic deflection coils 300 performs dynamic stigmation and focus as the electron beam array 285 is scanned across a field of the workpiece 105. This allows dynamic stigmation, focus, or x/y deflection corrections to be applied to different parts of the scan field. The electron beam pathway traversed by the electron beams 34 can be along a straight pathway, a curved pathway, or a series of redirected pathways. Thus, the apparatus components may be vertically oriented in a column above the workpiece 105, or oriented in an angled configuration (not shown), such as a right-angled configuration, or may be oriented in a curved configuration (also not shown). The electron beam apparatus 100 further comprises a workpiece support capable of supporting the workpiece 105. The support 305 may comprise an electrostatic chuck (not shown) capable of holding the workpiece 105 against the support 305. The electron bean generator 100 may also comprise support motors capable of moving the support 305 to precisely position the workpiece 105 in relation to the electron optics 245 or to move the workpiece 105 to scan the electron beams 34 across the workpiece 105. For example, the support motors may comprise electric motors that translate the support 305 in the >x= and >y= directions along an x-y plane parallel to the workpiece surface, rotate the support 305, elevate or lower the support 305, or tilt the support 305. The electron beam apparatus 100 may further comprise support position sensors capable of precisely determining the position of the support 305. For example, the support position sensors may reflect a light beam (not shown) from the support 305 and detect the intensity of the reflected beam, where interferometric analysis indicates the distance between the workpiece support 305 and the support position sensors. When generating a pattern in an electron-sensitive resist 115 of a workpiece 105, exposure throughput refers to the area of the pattern exposed on the workpiece 105 per unit time, and determines the speed of pattern generation. A first factor affecting throughput is the total current needed to generate the pattern. A certain fraction of the electron-sensitive resist 115 is to be exposed. To a first approximation, this exposure occurs after a particular electron dose, which can be calculated for a resist 115 of given sensitivity. The throughput is determined by the time required to deliver this dose, which is proportional to the maximum total electron current. This total current is proportional to the number of electron beams Nb and the current Ib delivered by each electron beam 34 of the array 285. Thus the time ô to expose a given area is ô =AS/NbIb, where A is the area to be patterned and S is the resist sensitivity (charge density required to expose the resist). High throughput can be achieved by using a sufficiently large number of electron beams 34 and a sufficiently large current in each electron beam 34. The electron beam apparatus 100 further comprises a controller 400 comprising a suitable configuration of hardware and software to operate the components of the electron beam apparatus 100 to generate an electron beam pattern on the workpiece 105. An exemplary controller 400 is illustrated in FIG. 3. For example, the controller 400 may comprise a central processing unit (CPU) 405 that is connected to a memory 410 and other components. The CPU 405 comprises a microprocessor, such as a complex instruction set computer (CISC) microprocessor, for example a Pentium (TM) microprocessor commercially available from Intel Corporation, Santa Clara, Calif., or a reduced instruction set computer (RISC) microprocessor, capable of executing a computer-readable program 415. The memory 410 may comprise a computer-readable medium such as hard disks 420 in a redundant array of independent disks (RAID) configuration, removable storage 425 such as an optical compact disc (CD) or floppy disk, random access memory (RAM) 430, and/or other types of volatile or non-volatile memory. The interface between a human operator and the controller 400 can be, for example, via a display 435, such as a cathode ray tube (CRT) monitor, and an input device, such as a keyboard 440. The controller 400 may also include drive electronics 445 such as analog and digital input/output boards, linear motor driver boards, or stepper motor controller boards. The computer-readable program 415 generally comprises software comprising sets of instructions to operate the apparatus components, and an apparatus manager 450 to manage the instruction sets, as illustrated in the exemplary version of FIG. 6. The computer-readable program 415 can be written in any conventional programming language, such as for example, assembly language, C, C++ or Pascal. Suitable program code is entered into a single file, or multiple files, using a conventional text editor and stored or embodied in the memory 410 of the controller 400. If the entered code text is in a high level language, the code is compiled, and the resultant compiler code is then linked with an object code of pre-compiled library routines. To execute the linked, compiled object code, the user invokes the feature code, causing the CPU 405 to read and execute the code to perform the tasks identified in the computer-readable program 415. Using a keyboard interface, a human user enters commands or registration parameters into the computer-readable program 415 in response to menus or screens displayed on the display 435. The computer-readable program 415 may include instruction sets to, for example, control the positioning of the workpiece support 305 (instruction set 455), locate fiducial marks on the workpiece 105 (instruction set 460), control beam modulation (instruction set 465), control data compression (instruction set 470), and control the retarding of the electron beams 34 (instruction set 473). If the electron beam apparatus 100 is used to inspect the workpiece 105, the computer-readable program 415 may further comprise an instruction set to evaluate a signal from the detectors 342 to generate a pattern representative of the structure of the workpiece 105 (instruction set 477). This workpiece inspection instruction set 477 may also comprise program code to determine a property of the workpiece 105, such as a defect or critical dimension, from the evaluated signals. The instruction sets may receive parameters, such as a data file corresponding to the support position, the fiducial mark locations, the electron beam pattern, properties of the workpiece 105, or instructions entered by the human operator. The controller 400 is adapted to generate, send, and receive signals to operate the apparatus components to generate a pattern by directing electron beams 34 onto the workpiece 105. For example, the controller 400 may send signals to the beam modulator 135 to control modulation of the electron beams 34 to the desired intensity levels, such as in correspondence to electron beam pattern data to write a corresponding pattern on the workpiece 105. The beam modulator 135 may also be controlled to scale the electron beam pattern in the scanning direction by timing the beam pulses, and the support motors may also receive real-time instructions from the controller 400 to control the position of the workpiece 105 to scale, rotate, or offset the pattern generated by the electron beams 34. As another example, the controller 400 may also operate a fiducial mark locator 340 by receiving measured locations of fiducial marks on the workpiece 105 and comparing them to intended locations to determine the deviation of each fiducial mark, thereby calculating the position of the workpiece 105. The controller 400 may control the beam modulator 135 and beam scanner 295 of the electron beam apparatus 100 to scan the electron beams 34 across the workpiece 105 according to a raster method, or alternatively according to a vector method. Depending on the scanning method used in generating a pattern on the workpiece 105, pattern data that are stored in the memory 410 and communicated to the beam modulator 135 are also different. FIG. 7 is a block diagram showing a data processing path for a raster scanned electron pattern. In a raster method, the pattern data 475 are processed into a bitmap 480 by a rasterizer 485 and the bitmap 480 is stored in the memory 410. An exemplary rasterizer 485 is described in commonly-assigned U.S. Pat. No. 5,533,170 by Teitzel et al., entitled “Rasterizer for a Pattern Generation Apparatus”, filed on Nov. 22, 1994, which is hereby incorporated by reference in its entirety. Thereafter, a corrector 490 corrects the bitmap to compensate for proximity effects, heating effects, or other undesirable effects. A sequencer 495 then sequences the corrections to apply to the sequenced bitmap to modulate the electron beams 34. Control of pixel dosage is determined by the modulation of the electron beams 34 as a function of time. The electron beams 34 are scanned across the workpiece 105 in a substantially predetermined sequence of parallel scan lines to generate the pattern on the workpiece 105. In a vector scanning method, in contrast, the pattern data are stored as vectors. For example, data corresponding to a line can be stored as a vector comprising a starting position, a length, and a direction. Additionally, certain other shapes may be stored in a way that refers to the characteristic dimensions of the shapes. The electron beams 34 are scanned across the workpiece 105 along paths that correspond to the pattern vectors. For example, to draw a line, the beam scanner 295 could deflect an electron beam 34 to the starting position in a first step, the beam modulator 135 turns on the electron beam 34 in a second step, the beam scanner 295 deflects the turned-on electron beam 34 through the length of the line in a third step, and the beam modulator 135 turns off the electron beam 34 in a fourth step. Typically, the electron beams 34 are spatially distributed such that optical interference and other crosstalk between them are reduced or eliminated. However, typically a final exposed pattern in the resist layer 115 produced by raster scanning is composed of overlapping spots, which can be accomplished by employing an interlaced scan print strategy and writing with multiple passes. The controller 400 may contain pattern data in the memory 410 in either flat or hierarchical formats. The flat formats contain the pattern information in a raw form that is not organized by hierarchy or otherwise compressed. In contrast, the hierarchical formats contain the pattern information in a compressed hierarchical organization that expedites transmission from the memory 410 to the beam modulator 135. An exemplary embodiment of an electron beam inspection apparatus 500 is schematically illustrated in FIG. 9. The illustration is provided as an exemplary embodiment and should not be used to limit scope of the invention or this embodiment. Generally, the apparatus 500 directs electron beam 34 toward a substrate 105 and subsequently detects back-scattered electrons 537, secondary electrons 539, and transmitted electrons 541. The detected electrons can be used to generate an image representative of the substrate 105. For example, electron beams reflected from the substrate 105 can be used to determine a surface topography of the substrate 105, or electrons can be transmitted through the substrate 105 to determine an internal composition of the substrate 105 or to irradiate the substrate 105. Any electron generated image can be used to determine properties of the substrate 105, such as to accurately locate defects, measure dimensions of features of the substrate 105, or measure distances between two or more points on the substrate 105. For example, after manufacturing, a substrate 105 can be inspected to determine whether critical dimensions of features formed on the substrate are within a preselected tolerance range or are properly shaped. The electron beam inspection apparatus 500 is capable of inspecting semiconductor substrates, X-ray masks and other conductive substrates. The apparatus 500 can also be used in various modes of operation, for example, images from two sections of the same substrate 105 can be compared with each other, or the image from the substrate 105 can be compared with an image from a database that represents the design goal. The electron beam inspection apparatus 500 comprises enclosing walls 501 to contain a vacuum environment generated by vacuum pumps (not shown). The apparatus 500 comprises a photon source section 503 and an electron beam inspection section 505. The photon source section 503 produces and delivers a single beam or multiple, independently-controllable radiation beams 502 to the electron beam inspection section 505. The section 503 may comprise the photon source section 120 from the apparatus 100 as previously discussed, or other photon sources, such as a lamp that produces photons with energies above at least about 3 eV. Disposed below the photon source section 503 is the electron beam inspection section 505, comprising a photocathode 20 to receive the radiation beam 502 and generate an electron beam 34. The photocathode 20 comprises an activated alkali halide material that emits electrons when excited with radiation as described. Power supplies 507, 509 deliver bias conditions to the photocathode 20 and the anode 240 to form an extraction field between the photocathode 20 and the anode 240. For example, the extraction field may have a strength of from about 0.1 to 5 kV/mm. In one embodiment, the photocathode 20 is biased at about 1 kV. The anode 240 is typically a planar electrode with an aperture in the center. The electron beam inspection section 505 also comprises electron optics to focus, control, deflect, and otherwise shape the electron beam 34 emitted by the photocathode 20, which is also referred to as the primary beam 34. An upper lens 513 may be disposed below the photocathode 20 and anode 240 to collimate the electron beam 34. An upper deflector 515 may also be optionally disposed near the upper lens 513 for alignment, stigmation, and blanking of the electron beam 34. The upper deflector 515 may be, for example, an electrostatic deflector. A beam limiting aperture 517 is disposed below the upper lens 513 and upper deflectors 515 to provide further beam shaping and comprises several holes. A pair of electrostatic beam deflectors 519 are disposed below the beam limiting aperture 517 to control the deflection of the beam 34 as it scans the substrate 105. The beam deflectors 519 may also be used to control the incident primary beam 34 such that interference with other electrons generated by the incidence of the primary beam 34 on the substrate 105 are minimized. A lens 521 is disposed below the beam deflectors 519 to refocus the electron beam 34. The substrate 105 to be inspected is held and positioned by an x-y stage 523 disposed below the lens 521. The stage 523 is controlled by a stage servo 525. Interferometers 527 disposed about the stage 523 and substrate 105 are used for positioning and alignment of the substrate 105. Communication between the stage 523, stage servo 525, and the interferometers 527 is performed by a system controller 529. The electron beam inspection apparatus 500 can detect one or more of secondary 539, back-scattered 537, and transmission electrons 541. To detect secondary electrons 539, the apparatus 500 comprises secondary electron deflectors 531 and a secondary electron detector 533. The secondary electron deflector 531 is disposed near the lens 521 and is capable of deflecting secondary electrons 539 to the secondary electron detector 533 based on their energy levels. In one version, the secondary electron deflector 531 comprises a Wien filter that only allows charged particles having a threshold energy to pass uninhibited and deflects the path of particles at other energies. The Wien filter is tuned to the incident primary electron beam energy to deflect the lower energy secondary electrons 539. The secondary electron detector 533 receives deflected secondary electrons 539, and may be a reverse biased high frequency Schottky barrier detector. Other types of semiconductor detectors may also be used. The stage 523, substrate 105, and portions of the lens 521 may be biased in such a way as to increase the energy levels of secondary electrons 539 to allow their efficient collection, and bias conditions are coordinated with the tuning of the Wien filter. The back-scattered electron detector 535 is disposed annularly about, and above the lens 521, and comprises a hole in the center to allow passage of the primary electron beam 34. Back-scattered electrons 537 typically have a higher energy than secondary electrons 539, and may be further accelerated by bias conditions on the stage 523, substrate 105, and lens 521, to allow them to pass relatively uninhibited by the secondary electron deflector 531. The apparatus 500 may also be operated such that the secondary electron deflector 531 is turned off and thus only back-scattered electrons 537 will be detected. The back-scattered electron detector 535 may be a Schottkey barrier detector similar to other detectors, but with the above mentioned hole in the center. To allow inspection of partially transparent substrates, a transmission electron detector 543 is located below the stage 523. A transmission lens 545 is disposed below the stage 523 and above the transmission electron detector 543. The transmission electrostatic lens 545 is used to spread the transmitted electron beam 541 to a diameter suitable for detection by the transmitted electron detector 543, which may also be a Schottky barrier detector. The system controller 529 coordinates the operation of the apparatus 500 and its subsystems, which include deflector controllers 547, the stage servo 525, lens controllers 549, an inspection apparatus computer readable program 555, and an operator interface 551. The system controller 529, as illustrated in FIG. 10, comprises memory 410, CPU 405, drive electronics 445, and hardware modules 553. The memory 410 may further comprise hard disks, RAM, and removable storage (all of which are not shown). The drive electronics 445 function as the interface between the system controller 529 and the various other subsystems of the apparatus 500. The hardware modules 553 may comprise specialized hardware to facilitate the function of the system controller 529. The hardware modules 553 are removable and may be periodically exchanged for updated modules. The deflection controllers 547 control the operation of the various beam deflectors. The inspection apparatus computer readable program 555 includes instruction sets that the system controller 529 may use to operate the apparatus 500. The instruction sets comprise image analysis instructions 557, defection controller instructions 559, stage servo instructions 561, and lens controller instructions 563. The image analysis instructions 557 comprise image database instructions 565, image comparison instructions 567, image processing instructions 569. The image analysis instruction sets 557 include instructions for such purposes as storing image scan data, reading and retrieving image data from a database, comparing scanned image data with images from the image database or other scanned data, and high level image processing algorithms. The operator interface 551 comprises at least a keyboard 440 and a display 435 and relays information to a human operator and accepts commands. The interface 551 may also comprise other input and output devices such as a mouse, floppy disk drive, compact disc drive, and a printer (all not shown). During operation of the apparatus, the substrate 105 to be inspected is placed beneath the electron beam 34 on the x-y stage 523. Alignment of the substrate 105 is achieved by scanning the substrate 105 with the electron beam 34 and observing the image on the display 435. The apparatus 500 then directs an electron beam 34 at the substrate 105 and detects secondary electrons 539 generated by the beam 34, the back-scattered electrons 537 from the beam 34 and transmitted electrons 541 which pass through the substrate 105. Data collection and analysis of the scan is performed by the system controller 529 and the inspection apparatus computer readable program 555. The position and movement of the stage 523 during the inspection of the substrate 105 is controlled by the stage servo 525, interferometers 527, and the system controller 529. When comparing the substrate 105 to a database image, data from the scan is stored in the memory 410, and a comparison to the database image is performed by the system controller 529 using the image analysis instructions 557. Likewise, when comparing two sections of the same substrate 105, the stage servo 525 moves the stage 523 so that the electron beam 34 alternately scans each section or subsections. The scan data of the first section or subsection is stored in the memory 410, and then this data, along with the scan data of the second section or subsection is processed by the system controller 529 and the image analysis instructions 557. Various defect detection algorithms may be implemented via the image analysis instructions 557, which may interpret the comparison of the image data according to algorithms. After the substrate 105 has been inspected, a list of defects, together with their locations, is displayed on the display 435 and the operator can then initiate a defect review via the keyboard 440. In response to operator commands, the apparatus 500 may locate and provide scans of the neighborhood of each defect and displays the image to the operator on the display 435. Two important applications of the electron beam inspection apparatus 500 are the detection of small physical defects and the detection of defects buried well beneath the surface of the substrate 105. Detection of small physical defects is becoming increasingly difficult. Shrinking feature sizes and increasing aspect ratios are pushing inspection of substrates beyond the inherent limits of optical inspection. The electron beam inspection device 500 can typically achieve higher resolution and higher depth of field than optical inspection devices, making electron beam inspection an increasingly important tool for the processing of substrates. Defects buried well beneath the surface of the substrate 105 are also an important application and are essentially invisible to optical devices. Voids in contact and via plugs can often be hidden beneath several layers of subsequently deposited material. Incomplete etch or excess polymer buildup during the formation of holes for contacts and vias are also a concern. Buried defects can be discovered by electron beam inspection even if the electron beam inspection apparatus 500 can not form a direct image of the area of concern. Buried defects can be identified using a technique known as voltage contrast. Upon illumination by an electron beam 34, a defective hole charges up differently than a non-defective hole. The bad hole either glows more or less, depending on image conditions, than the good ones do in the electron beam image. A defective plug can also be found this way. Upon illumination by the electron beam 34, the higher resistance of the defective plug causes it to glow either more or less brightly in the image, thus identifying itself. Although the present invention has been described in considerable detail with regard to certain preferred versions thereof, other versions are possible. The present invention could be used with other electron beam apparatuses 100 or other equivalent configurations as would be apparent to one of ordinary skill in the art. For example, the electron beam apparatus 100 may generate a pattern by generating and modulating the electron beams 34 directly rather than in the photon source section 120. Also, the electron beam apparatus 100 may generate the electron beams 34 by illuminating the photocathode 20 with other electron beams from an electron beam source rather than with the laser beams 32 from the photon source section 120. Thus, the appended claims should not be limited to the description of the preferred versions contained herein.
048805955	description	DETAILED DESCRIPTION OF THE INVENTION FIG. 3 shows a case where cooling water 3 containing no leaked ion exchange resin, but only non-radioactive metal ions dissolved from pipings, etc. such as cobalt ions, etc. flows into a nuclear reactor. In the nuclear reactor, fuel rods 8 whose surfaces are covered by an oxide film are provided. When an electrically charged state of metal ions 7 flowing into the nuclear reactor and the surfaces of fuel rods 8 are taken into account, the metal ions are, needless to say, positively charged, and the surfaces of fuel rods 8 also have a positive surface potential, because the zeta potential of the oxide film is positive in water at pH 5 to 8. In such a state, the metal ions 7 and the surfaces of fuel rods 8 are positively charged, and thus the metal ions 7 are substantially not deposited on the surfaces of fuel rods 8, as shown in FIG. 3. FIG. 4 shows a case where the ion exchange resins (cation exchange resins 9 and anion exchange resins 10) leaked from the filtration desalter enter into the cooling water. The cation exchange resins 9 are negatively charged, whereas the anion exchange resins 10 are positively charged. Since the surfaces of fuel rods 8 are positively charged, a portion of the negatively charged cation exchange resins 9 deposits onto the surfaces of fuel rods 8. Non-radioactive metal ions such as cobalt ions, etc. are ionically adsorbed on the deposited cation exchange resins 9. Usually, the cation exchange resins 9 are not saturated with the adsorbed metal ions, and thus will also ionically adsorb metal ions 7 suspended in the cooling water 3. Thus, it has been found that, once cation exchange resins leak into the cooling water, the amount of non-radioactive metal ions deposited on the surfaces of fuel rods 8 will be increased. That is, it has been found that, when cation exchange resins leak into the cooling water, the average residence time of the non-radioactive metal ions in the nuclear reactor will be prolonged. Cobalt 59 (.sup.59 Co) is typical of non-radioactive metal ions contained in the cooling water 3, but the .sup.59 Co will be partially converted to cobalt 60 (.sup.60 Co) when subjected to neutron irradiation in the nuclear reactor. It has been found that, when the cation exchange resins 9 leak into the cooling water 3, .sup.59 Co, etc. will stay in the nuclear reactor for a prolonged residence time, and consequently the yield of radioactive metals such as .sup.60 Co, etc. will be increased. That is, the radiation exposure of operators will be increased. The yield of radioactive metals in the nuclear reactor will be increased by leakage of cation exchange resins from the filtration desalter, and a portion of radioactivated metals peels from the fuel rods 8 and again dissolves into the cooling water. As a result, the radioactive density of cooling water will be increased. Since a portion of the radioactive metal ions in the cooling water deposits on the piping, the dosage of piping will be increased. For the same reasons as explained, referring to FIGS. 3 and 4, the amount of radioactive metal ions deposited on the piping will be increased by the presence of cation exchange resins. When the cation exchange resins leak into the cooling water, the yield of radioactive metals will be increased and the amount of radioactive metals deposited on the piping will be increased in this manner, resulting in increasing radiation exposure of operators. The anion exchange resins 10 are positively charged and thus hardly deposit on the surfaces of fuel rod or piping, because these surfaces are positively charged. The present inventors have obtained the foregoing finding through the following test, using a test apparatus shown in FIG. 5. A circumstance corresponding to the core water conditions for a boiling water-type nuclear reactor was made by heating pure water 11 containing about 1 ppb of .sup.60 Co to 280.degree. C. under 70 atmospheres by a heater 12, and passing the heated water through a piping 14 by a pump 13. The amount of .sup.60 Co deposited on the piping 14 was determined after the passage through the piping 14. When the pure water contained about 0.01 ppm of cation exchange resins, it was found that the amount of .sup.60 Co deposited on the piping was 1.5-2-fold increased, as compared with that when the pure water contained no cation exchange resins. Furthermore, when the pure water contained the anion exchange resins, no increase was found in the amount of .sup.60 Co deposited on the piping 14. It is seen from the foregoing results that it is effective to prevent leakage of cation exchange resins into the cooling water to reduce the radiation exposure of operators. The ion exchange resins are used in both filtration desalter and desalter, which constitute an apparatus for cleaning nuclear reactor cooling water, and a mixture of cation exchange resins and anion exchange resins is used in these two units. In the desalter, granular ion exchange resins having particle sizes as large as about 500 .mu.m are used, and leakage of the ion exchange resin into the cooling water hardly occurs, whereas in the filtration desalter the average particle size of ion exchange resin is as small as about 30 .mu.m with a broad particle size distribution of from a few .mu.m to about 100 .mu.m, and thus ion exchange resins having smaller particle sizes are liable to leak into the cooling water. Thus, it is necessary to provide a means for preventing the cation exchange resin leakage from the filtration desalter. Such a means would be use of only powdery ion exchange resins having particle sizes above a predetermined size, for example, above 5 .mu.m, and is indeed effective for the leakage prevention, but disadvantageous from the viewpoint of cost, because the powdery ion exchange resins are prepared by pulverizing granular ion exchange resins, and thus inevitably contain those having particle sizes as small as 1 .mu.m, and when only those having particle sizes above the predetermined size are to be used, it is necessary to single them out from the thus prepared powdery ion exchange resins by screening. Furthermore, such singling-out becomes much complicated and costly, because the particle size to be singled out is as small as a few .mu.m. The present inventors have studied the presence of cation exchange resins incapable of increasing the radiation exposure of operators even if the cation exchange resins leak into the cooling water and have found that it is effective to use cation exchange resins whose ion-exchanging groups are bonded to other elements than the carbon atoms constituting a benzene ring. When the cation exchange resins leak into the cooling water 3, they will deposit on the surfaces of fuel rods and the average residence time of the non-radioactive metal ions such as .sup.59 Co, etc, in the nuclear reactor will be prolonged thereby, and the yield of radioactive metals will be increased, as already described above. Heretofore, benzenesulfonic acid-based resins whose ion-exchanging groups (SO.sub.3.sup.-) are directly bonded to the benzene ring have been used as cation exchange resins, and it has been found that such resins have a high heat resistance and a high radiation resistance, and are hardly decomposed even used in the primary system of a nuclear reactor. The reasons why the cation exchange resins are liable to deposit on the fuel rods 8 are that the cation exchange resins 9 are negatively charged, and the reasons why the cation exchange resins are negatively charged are as follows: the polymer body (copolymer of styrene and divinylbenzene) is electrically neutral, but the ion-exchanging groups are negatively charged as their property, and thus the cation exchange resins are negatively charged on the whole. When the cation exchange resins enter into a nuclear reactor, they are exposed to a higher temperature and an intense radiation, and thus are more susceptible to decomposition. Decomposition of cation exchange resin starts at first at the positions of the ion-exchanging groups having the lowest chemical bonding energy, as given by the following chemical equation: ##STR2## If it is presumed that a cation exchange resin is decomposed as shown by the foregoing equation, an electrically neutral polymer body and a negatively charged sulfite ion (SO.sub.3.sup.2-) are formed. The sulfite ion migrates into the cooling water 3 owing to its solubility, whereas the remaining polymer body becomes electrically neutral, and thus hardly deposits onto the surfaces of fuel rods 8. Even if the polymer body deposits thereon, it has no more ion-exchanging capacity, and thus the non-radioactive metal ions in the cooling water are not retained on the surfaces of fuel rod for a prolonged period. Furthermore, the cation exchange resin whose ion-exchanging groups have been decomposed is electrically neutral, and thus hardly deposits even on the piping. Consequently, deposition of radioactive metals such as .sup.60 Co, etc. is no more promoted thereby. In the foregoing, the case of liberating the ion-exchanging groups from the cation exchange resin by decomposition has been described. Heretofore, benzenesulfonic acid-based resins having a high heat resistance and a high radiation resistance have been used as cation exchange resins. That is, the ion-exchanging groups have been hard to liberate from such cation exchange resins by decomposition, and the said effect of reducing radiation exposure of operators has not been obtained. In other words, the effect of reducing the radiation exposure of operators can be obtained by using cation exchange resins readily susceptible to thermal decomposition. Cation exchange resins readily susceptible to thermal decomposition will be described below. Cation exchange resins can be classified into the following two large groups on the basis of species of elements to which the ion-exchanging groups are bonded: one is the group where the ion-exchanging groups are bonded to the carbon atoms constituting a benzene ring, as will be hereinafter referred to as "benzene ring type", and another is the group where the ion-exchanging groups are bonded to other elements than the carbon atoms constituting a benzene ring, as will be hereinafter referred to as "straight chain type". Table 1 shows examples of benzene ring type and straight chain type cation exchange resins. TABLE 1 __________________________________________________________________________ Bonding energy Group Molecular structure (KJ/mol.) __________________________________________________________________________ Benzene ring type .circle.A ##STR3## 339 .circle.B ##STR4## -- .circle.C ##STR5## 447 .circle.D ##STR6## -- Straight chain type .circle.E ##STR7## 289 .circle.F ##STR8## 260 .circle.G ##STR9## 293 __________________________________________________________________________ Remark: ##STR10## Seven kinds of cation exchange resins given in Table 1 were subjected to a test to find out thermally weak resins. The test was carried out in the following manner. Seven kinds of the cation exchange resins were dipped in hot water at 280.degree. C. under 70 atmospheres to show changes in ion exchange capacity to investigate how the ion-exchanging groups were liberated by decomposition with time. FIG. 6 shows the test results, where the axis of abscissa shows a dipping time in the hot water and the axis of ordinate logarithmically shows changes in ion exchange capacity. It is seen from the test results that cation exchange resins readily susceptible to thermal decomposition are .circle.E , .circle.F and .circle.G , that is, the straight chain type ion exchange resins given in Table 1. Ready susceptability to thermal decomposition of the straight chain type ion exchange resins seems due to the bonding energy of the ion-exchanging groups to the polymer body (see Table 1). That is, it seems that the ion-exchanging groups bonded to the carbon atoms in a benzene ring (benzene ring type) has such a large bonding energy that they are hard to liberate by thermal decomposition, whereas the ion-exchanging groups bonded to other elements than the carbon atoms in the benzene ring (straight chain type) has such a small bonding energy that they are easy to liberate by thermal decomposition. FIG. 7 shows the time t.sub.1/10 until the ion exchange capacity becomes 1/10 for the respective ion exchange resins, obtained from changes in the ion exchange capacity shown in FIG. 6, where the axis of ordinate shows t.sub.1/10 and the axis of abscissa shows the bonding energy of the ion-exchanging group in the corresponding ion exchange resin. It is seen from FIG. 7 that, when the bonding energy is not more than 300 KJ/mol, t.sub.1/10 will be not more than one hour, and the ion exchange resins are readily susceptible to thermal decomposition. Particularly, straight chain type ion exchange resins are readily susceptible to thermal decomposition, because their bonding energy is usually not more than 300 KJ/mol, and even benzene ring type ion exchange resins can readily undergo thermal decomposition, so long as their bonding energy is not more than 300 KJ/mol. It can be seen from the foregoing that it is effective for reducing the radiation exposure of operators to use straight chain type cation exchange resins or cation exchange resins whose ion-exchanging groups have a low bonding energy as cation exchange resins for the filtration desalter. Up to now, more than 100 kinds of cation exchange resins have been known, and most of the resins now in use belong to the benzene ring type, and the straight chain types are not so many. Particularly, there have been no examples of using a straight chain type cation exchange resin in an apparatus for cleaning nuclear reactor cooling water. The straight chain type cation exchange resins include the following types: (1) Oxybenzylsulfonic acid type: as shown by .circle.E in Table 1. (2) Acrylic carboxylic acid type: as shown by .circle.F in Table 1. (3) Methacrylic carboxylic acid type: molecular structure of this type is as follows: ##STR11## (4) Aromatic carboxylic acid type: molecular structure of this type is as follows: ##STR12## (5) So called chelate resin: as shown by .circle.G in Table 1, and those having the following molecular structures: ##STR13## When cation exchange resin containing divinylbenzene as a molecule-constituting member is used in the present invention, the content of the divinylbenzene in the resin is 1 to 20% by weight, preferably 2 to 16% by weight, on the basis of the resin. Which ion exchange resin is most preferable for a filtration desalter 4 shown in FIG. 2 or a desalter 5 shown in FIG. 1 will be described in detail below. Impurities contained in the cooling water include fine granular materials such as cruds, etc., which will be hereinafter referred to as impurities a, cations produced by corrosion of materials such as Co.sup.2+, Fe.sup.2+, Mn.sup.2+, etc., which will be hereinafter referred to as impurities b, and anions such as carbonate ions, silicate ions, etc., which will be hereinafter referred to as impurities c, and furthermore include neutral salts such as NaCl, etc., when sea water leaks into the cooling water from the condenser 2 as shown in FIG. 1 (the neutral salt will be hereinafter referred to as impurities d). According to the prior art, a mixture of benzenesulfonic acid-based resin as a strongly acidic ion exchange resin and a quaternary ammonium-based ion exchange resin as a strongly basic ion exchange resin is used in the filtration desalter, as described earlier, and all of the said impurities a to d can be removed in the filtration desalter. That is, the desalter is provided in an auxiliary sense. In the present invention, on the other hand, a desalter 5 as shown in FIG. 1 plays an important role, because the straight chain type cation exchange resin generally belongs to a weakly acidic ion exchange resin, and thus has a low ability of decomposing the impurities d (neutral salt) (NaCl.fwdarw.Na.sup.+ +Cl.sup.-) to adsorb these ions. Thus, when sea water leaks into the cooling water from the condenser 2 as shown in FIG. 1, and when straight chain type ion exchange resin is used as cation exchange resin in the filtration desalter 4, the neutral salt cannot be completely removed in the filtration desalter. Thus, if there is a possibility of leakage of sea water from the condenser 2, it is preferable to use a mixture of strongly acidic granular ion exchange resin such as benzenesulfonic acid-based resin, etc., and a strongly basic granular ion exchange resin such as quaternary ammonium-based resin in the desalter 5. The neutral salts can be completely removed in the desalter 5 thereby. In the foregoing description, mention has been not substantially made of anion exchange resin among the powdery ion exchange resins to be used in the filtration desalter 4. Even if the anion exchange resin leaks in the cooling water 3, it will not increase the radiation exposure of operators, and thus the same quaternary ammonium-based resin as so far used, or any other resins can be used satisfactorily. Other anion exchange resins than the foregoing include primary to tertiary amine-based anion exchange resins, as given below: ##STR14## Heretofore, quaternary ammonium-based resins have been used as anion exchange resin for use in the filtration desalter, because the quaternary ammonium-based resins are strongly basic resins, and thus have a high percent removal of the neutral salts in the filtration desalter when used in mixture with the strongly acidic benzenesulfonic acid-based resin. In the present invention, however, removal of the neutral salts (impurities d) is carried out in the desalter 5, and thus the anion exchange resin for use in the filtration desalter 4 is not limited to the quaternary ammonium-based resins. As already described above, the radiation exposure of operators can be considerably reduced by using cation exchange resins whose ion-exchanging groups are bonded to other elements than the carbon atoms constituting a benzene ring in the filtration desalter 4 using the powdery ion exchange resins. Furthermore, the following effects can be obtained with the said structure of the present invention. When the powdery ion exchange resin precoated in the filtration desalter 4 is used for a prolonged period, for example, 10 to 50 days, the resin layer undergoes clogging as a result of trapping the cruds in the cooling water 3, and the pressure drop through the resin layer will be increased. When the pressure drop reaches a predetermined value, the resin layer is back-washed and the ion exchange resin is exchanged with fresh one. The used ion exchange resin is handled as a radioactive waste. About half of the radioactive wastes now discharged from the boiling water-type nuclear reactor is the used ion exchange resins discharged from the filtration desalter 4 (the used ion exchange resin will be hereinafter to as "waste resin"). As means for reducing the volume of waste resin, there has been developed a process for thermal decomposition or incineration, as disclosed in Japanese Patent Application Kokai (Laid-open) No. 59-107,300. The waste ion exchange resin according to the present invention can be readily treated by the said process for thermal decomposition or incineration. The reasons will be described below, referring to thermal decomposition treatment of benzenesulfonic acid-based resin ( .circle.A in Table 1) and acrylic carboxylic acid resin ( .circle.F in Table 1) in comparison. FIG. 8 is a diagram showing changes in weight by heating when the benzenesulfonic acid-based resin (curve .circle.A ) and the acrylic carboxylic acid resin (curve .circle.F ) were subjected to thermal decomposition treatment in a nitrogen gas atmosphere. As is apparent from FIG. 8, the benzenesulfonic acid-based resin produces about 50% by weight of residues, even if subjected to the thermal decomposition at 500.degree. C. or higher, owing to its high heat resistance, whereas more than 95% by weight of the acrylic carboxylic acid resin can be decomposed, producing only small amount of the residues, when subjected to the thermal decomposition at 450.degree. C. or higher, owing to its low heat resistance. That is, it is evident therefrom that, when the waste resin used in the present invention is subjected to a thermal decomposition treatment, the amount of the wastes can be considerably reduced. As a result of investigations of thermal decomposition characteristics of other cation exchange resins according to the present invention, it has been found that more than 95% by weight of methacrylic carboxylic acid resin, aromatic carboxylic resin and chelate resin are decomposed and even about 70% by weight of oxybenzylsulfonic acid is decomposed when subjected to thermal decomposition at 500.degree. C. in a nitrogen gas atmosphere. That is, any of the cation exchange resins for use in the present invention is more readily susceptible to thermal decomposition than the benzenesulfonic acid-based resin. The same results were obtained when they were subjected to an incineration treatment in an oxygen-containing atmosphere. That is, the conventional benzenesulfonic acid-based resin was hardly incinerated owing to its high heat resistance, and a portion of the residues deposited onto the furnace wall shortened the life of the furnace material, because the incineration was carried out at 800.degree. C. or higher, and thus a portion of the ion exchange resin was melted, and was much liable to deposit on the furnace wall. On the other hand, the cation exchange resins for use in the present invention could be readily incinerated. Furthermore, when the conventional benzenesulfonic acid-based resin is subjected to thermal decomposition or incineration, harmful gases, such as H.sub.2 S, SO.sub.x, etc. are evolved, because the resin contains sulfur atom. In the present invention, on the other hand, no such harmful gases as H.sub.2 S and SO.sub.x are evolved at all, even if the acrylic carboxylic acid resin, aromatic carboxylic resin, etc. according to the present invention are subjected to thermal decomposition or incineration treatment, because they contain no sulfur atom. Thus, the gas treatment system can be simplified, and also corrosion of materials by H.sub.2 S, etc. can be prevented. When the cation exchange resins according to the present invention are used in the filtration desalter 4, not only the radiation exposure of operators can be reduced, but also the radioactive waste disposal can be facilitated. The conventional benzenesulfonic acid-based resin is used as granular cation exchange resin in the desalter 5 also in the present invention, and thus no effect of facilitating the waste disposal can be obtained, but there is no serious problem at all, because the amount of the wastes discharged from the desalter 5 is not more than 1/10 of the amount of the wastes discharged from the filtration desalter 4. Furthermore, a trouble at the disposal of the benzenesulfonic acid-based resin discharged from the desalter 5 can be eased by treating the waste resin discharged from the desalter 5 together with the waste resin discharged from the filtration desalter 4 simultaneously, for example, by thermal decomposition or incineration. The concentration of SO.sub.x or H.sub.2 S evolved from the benzenesulfonic acid-based resin can be relatively lowered by the simultaneous treatment, and thus the problems such as corrosion of materials, etc. can be eased, as compared with the single treatment of the benzenesulfonic acid-based resin. In the foregoing, it has been described that the desirable powdery cation exchange resins for use in the filtration desalter 4 are those whose ion-exchanging groups are bonded to other elements than the carbon atoms constituting a benzene ring, but it is inevitable to use those whose ion-exchanging groups are partly bonded to the carbon atoms in the benzene ring directly on account of process conditions, etc. In summary, the preferable modes of the present invention are as follows: (1) Powdery cation exchange resins whose ion-exchanging groups are bonded to other elements than the carbon atoms constituting a benzene ring (straight chain type) are used in a filtration desalter in an apparatus for cleaning nuclear reactor cooling water. (2) A mixture of benzenesulfonic acid-based cation exchange resin and quaternary ammonium-based anion exchange resin is used as granular ion exchange resins in a desalter in an apparatus for cleaning nuclear reactor cooling water. PREFERRED EMBODIMENTS OF THE INVENTION The present invention will be described in detail below, referring to Examples and Drawings. EXAMPLE 1 A first embodiment of the present invention is shown in FIGS. 1 and 2, where FIG. 1 shows a flow diagram of an apparatus for cleaning cooling water in a boiling water-type nuclear reactor, and FIG. 2 shows a partially cutaway view of a filtration desalter used in the apparatus for cleaning cooling water shown in FIG. 1. Cooling water 3 recovered by a condensor 2 after driving a turbine 1 is cleaned by a filtration desalter 4 and a desalter 5, and returned to a nuclear reactor 6 through a feedwater heater 16 by a feedwater pump 15. In the desalter 5 a mixture of the said granular benzenesulfonic acid-based resin and quaternary ammonium-based resin in a mixing ratio of 2:1 by weight is packed. In the filtration desalter 4, powdery ion exchange resin is precoated. That is, acrylic carboxylic acid resin ( .circle.F in Table 1) having an average particle size of about 30 .mu.m as powdery cation exchange resin and quaternary ammonium-based resin having an average particle size of about 30 .mu.m as powdery anion exchange resin are charged in a ratio of 2:1 by weight of the former to the latter into a precoat tank 17 at first, and further about 0.05 to about 1% by weight of a water-soluble polymeric electrolyte such as polyacrylic acid, polymerized maleic acid, etc. is added therto. Then, the mixture is stirred by a stirrer 18. As a result, flocs composed of the mixture of cation exchange resins 9 and anion exchange resins 10 are formed. The flocs are supplied to the filtration desalter 4 through a valve 19 by a precoat pump 20. Nylon or stainless steel filtration elements 21 are provided in the filtration desalter 4, as shown in FIG. 2, and are precoated with the flocs 22. The boiling water-type nuclear reactor provided with the apparatus for cleaning cooling water, as described above, was operated for one year, and the surface dosages of various pipings were measured. It was found that the dosage of recycle piping 23 was highest and was 20 mR/h. When a conventional apparatus for cleaning cooling water, using benzenesulfonic acid-based resin and quaternary ammonium-based resin in the filtration desalter 4, was used, the surface dosage of recycle piping 23 was 30 mR/h. The nuclear reactor 6 was operated while changing the species of the powdery ion exchange resin in the filtration desalter 4, and the surface dosage of recycle piping 23 was measured. The results are shown in Table 2. TABLE 2 ______________________________________ Surface Filtration desalter dosage of Cation exchange Anion exchange recycle resin resin piping (mR/h) ______________________________________ Benzenesulfonic Quaternary Conven- acid-based ammonium-based 30 tional resin resin Acrylic Quaternary carboxylic ammonium-based 20 acid resin resin Oxybenzyl- Quaternary sulfonic acid ammonium-based 25 resin resin The Methacrylic Tertiary amine- Inven- carboxylic acid based resin 20 tion resin Aromatic Secondary carboxylic amine-based 20 acid resin resin Primary amine- Chelate resin based resin 25 ______________________________________ As is obvious from Table 2, the radiation exposure of operators according to the present invention can be reduced to 1/3-1/6 of that according to the prior art. For example, when the surface dosage of recycle piping is 20 mR/h, the annual radiation exposure of operators amounts to about 60 to about 100 man.rem. In the present invention, it has been found that the life of powdery ion exchange resin for use in the filtration desalter 4 can be prolonged, as will be described below, referring to FIG. 9, where the dotted line curve A shows changes in differential pressure when cooling water 3 was cleaned by a precoat of a mixture of acrylic carboxylic acid resin and quaternary ammonium-based resin in a mixing ratio of 2:1 by weight of the former to the latter, and the full line curve B shows changes in differential pressure when a precoat of a mixture of the conventional powdery ion exchange resins (benzenesulfonic acid-based resin and quaternary amine-based resin) was used. It is obvious from FIG. 9 that the differential pressure curve of the present invention rises much later than that of the prior art, and the life can be about 1.5-fold prolonged. Thus, in the present invention, the filtration life of the powdery ion exchange resin can be prolonged, and not only the cost can be reduced, but also the resin can be used for a longer time, and consequently the amount of the waste resin can be decreased. That is, the amount of the radioactive wastes can be effectively reduced. In the foregoing description, a combination of acrylic carboxylic acid resin and quaternary ammonium-based resin has been exemplified as the powdery ion exchange resins for use in the filtration desalter 4. Equivalent effects can be also obtained from combinations of other kinds of ion exchange resins according to the present invention. That is, 5 kinds of powdery cation exchange resins, such as oxybenzylsulfonic acid resin, acrylic carboxylic acid resin, methacrylic carboxylic resin, etc., and 4 kinds of powdery anion exchange resins such as quaternary ammonium-based resin, tertiary amine resin, etc. were selected, and their filtration lives were experimentally determined on the basis of combinations thereof. The results are shown in Table 3, where the filtration lives on the basis of various combinations according to the present invention are shown as relative values to the filtration life of the conventional powdery ion exchange resin as unity. TABLE 3 ______________________________________ Quaternary Tertiary Secondary Primary Filtration ammonium- amine-based amine-based amine-based Life based resin resin resin resin ______________________________________ Oxybonzyl- sulfonic 1.2 1.2 1.1 1.1 acid resin Acrylic carboxylic 1.5 1.6 1.4 1.5 acid resin Methacrylic carboxylic 1.8 1.6 1.6 1.4 acid resin Aromatic carboxylic 1.4 1.2 1.3 1.3 acid resin Chelate 1.4 1.3 1.2 1.4 resin ______________________________________ *Filtration life: Relative to the conventional resin as unity. As is obvious from Table 3, any of the combinations according to the present invention can make the filtration life 1.1 to 1.8-fold longer. In the present embodiment, not only the radiation exposure of operators can be reduced to 1/3-1/6 of that of the prior art, but also the life of ion exchange resin in the filtration desalter can be made about 1.5-fold longer, as described above, and thus cost and the amount of discharged radioactive waste can be reduced to about 1/3. Tests were carried out in the present apparatus on the condition that sea water leaked into the cooling water 3 from the condenser 2, but no trouble appeared. When sea water leaked in the cooling water from the condenser 2, neutral salts such as NaCl, etc. in the cooling water could be removed in the filtration desalter 4 in the conventional apparatus, whereas in the present invention the neutral salts could not be removed, because weakly acidic cation exchange resin was used in the filtration desalter 4. However, in this embodiment of the present invention, the strongly acidic benzenesulfonic acid-based resin and the strongly basic quaternary ammonium-based resin were used in the desalter 5 and thus the neutral salts that could not be removed in the filtration desalter 4 could be completely removed in the desalter 5. That is, there was no problem at all, even when sea water leakage took place. In this embodiment of the present invention, three components, i.e. cation exchange resin, anion exchange resin and polymeric electrolyte, were mixed in the precoat tank 17, but when both or any one of the cation exchange resin and the anion exchange resin, to which the polymeric electrolyte has been added in advance, for example, by surface treatment, etc., are used, only two components, i.e. the cation exchange resin and the anion exchange resin, are to be mixed in the precoat tank 17. EXAMPLE 2 This embodiment had the same basic structure as in Example 1, but the mixing ratio of powdery cation exchange resin to the cation exchange resin to be used in the filtration desalter 4 was changed from that of Example 1. In Example 1, it was shown that the life of the powdery ion exchange resins to be used in the filtration desalter 4 could be prolonged in the present invention. In this embodiment changes in the life of the powdery ion exchange resins were investigated by changing the mixing ratio of the powdery cation exchange resin to the powdery anion exchange resin. The same test procedure as shown in FIG. 9 was used, where the differential pressure changing curves were experimentally plotted to determine the life of the resins. The test results are shown in FIG. 10, where the axis of abscissa shows the resin proportion and the axis of ordinate shows the filtration life. The filtration life on the axis of ordinate shows a life relative to the life of the powdery ion exchange resins used in the filtration desalter in the conventional apparatus, i.e. a mixture of 67% by weight benzenesulfonic acid-based resin and 33% by weight of quaternary ammonium-based resin, as unity. In FIG. 10, the full line curve C shows powdery ion exchange resins based on combinations of acrylic carboxylic acid resin and quaternary ammonium-based resin, and the dotted line curve D shows powdery ion exchange resins based on combinations of methacrylic carboxylic acid resin and tertiary amine resin. As is obvious from FIG. 10, the filtration life could be prolonged by setting the ratio of the cation exchange resin to the anion exchange resin to 50:50- 90:10% by weight. The reasons why the filtration life depended on the mixing ratio of the cation exchange resin to the anion exchange resin seems as follows: there are much more cations such as Co.sup.2+, Fe.sup.2+, etc. as impurities in the cooling water 3 than anions, and if the cation exchange resin and the anion exchange resin are used in equal weights, the cation exchange resin will adsorb such a larger number of ions than the anion exchange resin. Once at least any one of the cation exchange resin and the anion exchange resin adsorbs much more ions, the filtration capacity seems to be lowered. In order to prolong the filtration life, the ratio of the cation exchange resin must be 50% or more. According to the prior art, neutral salts such as NaCl, etc. from sea water leakage is designed to be removed in the filtration desalter 4, where equal equivalent weights of cations (Na.sup.+) and anions (Cl.sup.-) must be removed. Thus, the ratio of the cation exchange resin cannot be made too large. However, in the present invention, the neutral salts are designed to be removed not in the filtration desalter 4, but in the desalter 5, and thus the ratio of the cation exchange resin in the filtration desalter can be made considerably larger without any problem. It is also seen from FIG. 10 that the filtration life will be shortened when the ratio of the cation exchange resin exceeds 90% by weight. This is because no suitable flocs (coagulates of cation exchange resin and anion exchange resin) for the filtration can be formed owing to too small an amount of the anion exchange resin. As described above, it is desirable that the ratio of the powdery cation exchange resin to the powdery anion exchange resin is 50:50 to 90:10% by weight, preferably 60:40 to 85:15% by weight, whereby the filtration life can be considerably prolonged. EXAMPLE 3 This embodiment shows a case of applying the present invention to an apparatus for cleaning cooling water in a pressurized water-type nuclear reactor, whose flow diagram is shown in FIG. 11. Cooling water 3 heated in nuclear reactor 6 is recycled to the nuclear reactor 6 through a steam generator 24 by a primary cooling water pump 25, but a portion of the cooling water 3 is supplied to a filtration desalter 4 through a heat exchanger 26. In the filtration desalter 4, a mixture of cation exchange resin and anion exchange resin having the following molecular structures is used in a ratio of the former to the latter of 3:1 by weight as powdery ion exchange resins: ##STR15## According to the prior art, the pressurized water-type nuclear reactor uses a mixed bed desalter using granular ion exchange resins in place of the filtration desalter 4, but the capacity of removing cruds in the cooling water can be considerably increased by using the filtration desalter of this Example, and also the radiation exposure of operators can be largely reduced. The present apparatus for cleaning cooling water can be applied also to a core water-cleaning system in a boiling water-type nuclear reactor. According to the prior art, a portion of cooling water in the nuclear reactor recycle system is cleaned in the filtration desalter in the boiling water-type nuclear reactor, and a mixture of benzenesulfonic acid-based resin and quaternary amine-based resin is used as powdery ion exchange resins for the filtration desalter. However, a portion of the ion exchange resins leaks in the cooling water even in the filtration desalter, and there is a consequent possibility to increase the radiation exposure of operators. When the ion exchange resins according to the present invention are used in the filtration desalter in the core water-cleaning system for cleaning a portion of the cooling water in the recycle system, an increase in the radiation exposure of operators can be minimized, even if the ion exchange resin leakage takes place. Furthermore, the life of the filtration desalter in the core water-cleaning system can be prolonged as in Example 2, and the waste disposal can be also facilitated thereby. EXAMPLE 4 In Example 1, a combination of the filtration desalter 4 and the desalter 5 arranged in series as an apparatus for cleaning nuclear reactor cooling water is exemplified, but the desalter 5 is not always required, and only the filtration desalter 4 can perform the required duty. That is, the filtration desalter 4 also uses ion exchange resins as in the desalter 5, and most of ions and cruds can be removed in the filtration desalter 4, because the desalter has only a backing function. When the ion exchange resins according to the present invention are used in the filtration desalter 4, the neutral salts are not completely removed therein, and thus the desalter 5 can be only omitted when there is a very low possibility for the sea water leakage from the condenser 2, or when corrosion-resistant materials, such as stainless steel, etc. are used in the condenser 2, or when there is no possibility at all for the sea water leakage, for example, when river water or well water is used in place of the sea water as the condenser cooling water. According to this embodiment of the present invention, the same effect as in Example 1 can be obtained, and the cost can be much more reduced by omitting the desalter 5. EXAMPLE 5 When the ion exchange resins used in the apparatus for cleaning nuclear reactor cooling water run down, the waste ion exchange resins are treated as radioactive wastes. The radioactive wastes are now stored and preserved in atomic power plants, and the amount of such wastes is increasing year after year. This embodiment concerns a thermal decomposition treatment of waste ion exchange resins (waste resins) discharged from the filtration desalter 4 shown in Example 1, and will be explained, referring to the flow diagram shown in FIG. 12. Waste resins 27 are in a slurry state, because they are discharged from the filtration desalter 4 by backwashing, and are stored in a waste resin tank 28 for a while. The waste resins in the waste resin tank 28 are supplied in the slurry state at a concentration of about 10% by weight through a valve 29 at a constant flow rate to a thermal decomposition unit 31 by a slurry pump 30. The waste resins used in this embodiment are composed of 60% by weight of acrylic carboxylic acid resin, 30% by weight of quaternary ammonium-based resin, and 10% by weight of impurities such as cruds, etc. The thermal decomposition unit 31 is a rotary kiln of continuous treatment type, operated at 500.degree. C. In the thermal decomposition unit 31 an inert gas atmosphere is kept by nitroge gas purging. The waste resins 27 supplied to the thermal decomposition unit 31 are subjected to drying and thermal decomposition at the same time, and the thermal decomposition residues are stored in a powder hopper 35 for a while. A flue gas evolved at the thermal decomposition is composed mainly of steam and hydrocarbons, and led through a valve 33 to a flue gas-treating unit 34 and treated. After the thermal decomposition residues 32 are stored in the powder hopper 35 for a while, they are mixed with cement 37 or plastics, or the like in a mixer 36 and then poured into a drum 39 through a valve 38, and solidified. The functions and effects of this embodiment will be described below: By thermal decomposition of the waste resins 27 in the thermal decomposition unit 31, the waste resins 27 can be reduced to 20% by weight and 10% by volume of the charged entire waste resins, whereas the waste resins 27 whose cation exchange resin is the conventional benzenesulfonic acid-based resin is reduced only to 40% by weight and 25% by volume of the charged entire waste resins by the thermal decomposition. In the case of the waste resins according to this embodiment the flue gas evolved by the thermal decomposition contains only steam and hydrocarbons, whereas in the case of the waste resins containing the benzenesulfonic acid-based resin SO.sub.x or H.sub.2 S is evolved by the thermal decomposition in addition to the steam and the hydrocarbons owing to the sulfur atoms contained therein, as is obvious from the said structure. SO.sub.x or H.sub.2 S is a harmful gas component, and its removal requires an alkali scrubber, etc., complicating the flue gas-treating unit 34. The present invention has no such problems. Thus, such effects as considerable reduction in the volume of waste resins and simplification of the flue gas-treating unit can be obtained by using the ion exchange resins according to the present invention and by thermal decomposition of the waste resins. In this embodiment, the waste resins discharged from the filtration desalter in the boiling water-type nuclear reactor have been exemplified, but the waste resins discharged from the filtration desalter in the pressurized water-type nuclear reactor shown in Example 3 can be likewise treated according to the present invention. EXAMPLE 6 In Example 5, the waste resins 27 are treated by thermal decomposition, but the same effects as in Example 5 can be obtained by incineration treatment in place of the thermal decomposition. In this case an incineration furnace is used in place of the thermal decomposition unit 31, and the waste resins are incinerated at 600.degree. C. or higher in the air. So far as the ion exchange resins according to the present invention are used, a considerable reduction in the volume can be attained, and also the flue gas-treating unit can be simplified. In this embodiment, the following effects can be further obtained. In the case of incineration, waste resins are treated at 600.degree. C. or higher, usually at 800.degree. to 1,500.degree. C., and thus a portion of the waste resins is melted and the melted resin deposits on the furnace wall, shortening the life of the incineration furnace. The ion exchange resins according to the present invention have a low heat resistance, and thus can be readily gasified below 600.degree. C. That is, the present ion exchange resins are not substantially melted. Thus, the trouble of waste resin deposition on the furnace wall can be considerably reduced, and the life of the incineration furnace can be prolonged. EXAMPLE 7 In the foregoing embodiments, the straight chain type cation exchange resins are used in the filtration desalter, but a filter of membrane structure capable of mechanically removing cruds, such as hollow fiber filter, etc. can be used as a filtration desalter. In this embodiment, there is no leakage of ion exchange resin into the cooling water or no function to increase the surface dosage of pipings as in the case of the powdery ion exchange resins. Furthermore, when polymers whose ion-exchanging groups are bonded to other elements than carbon atoms constituting the benzene rings are used as the filter of membrane structure having ion-exchanging groups, a high volume reduction effect can be obtained at the disposal of the resulting waste polymers. That is, the same functions and effects as in Examples 5 and 6 can be obtained owing to the use of straight chain type polymers as .circle.E , .circle.F and .circle.G in Table 1. Thus, in this embodiment of using polymers whose ion-exchanging groups are bonded to the straight chains, equivalent or superior effects to those of the foregoing Examples can be obtained. In Example 1, powdery straight chain type cation exchange resins having an average particle size of about 30 .mu.m are used, but the present invention is not limited to the said particle size. For example, fibrous straight chain type cation exchange resins, which are extended in one direction, can be used. Such fibrous straight chain type cation exchange resin is effective for reducing the resin leakage from the filtration desalter. Both or any one of cation exchange resin and anion exchange resin can be such a fibrous ion exchange resin. When the fibrous cation exchange resin is long enough not to pass through nylon or stainless steel filtration elements, the cation exchange resin can be used alone. That is, since the cruds to be removed are positively charged and also ion species such as Co, etc. are positively charged, they can be removed only by the cation exchange resin. The amount of waste resins can be largely reduced in this manner without using the anion exchange resins. Furthermore, the straight chain type cation exchange resins have a lower degree of dissociation (smaller .sub.P K.sub.A, where .sub.P K.sub.A is a logarithm of the reciprocal of the dissociation constant) than the sulfonic acid bonded to the benzene ring, and are of weakly acidic type. Thus, their ability to decompose the neutral salts is lowered, as already described, and it is hard to remove NaCl when sea water leaks into the cooling water. In other words, if the straight chain type ion exchange resins can have ion exchanging groups of higher degree of dissociation (.sub.P K.sub.A of less than 3), removal of NaCl can be made without providing a condensate desalter on the downstream side. That is, when a possibility of large sea water leakage is substantially eliminated by an increased reliability of apparatuses and machinery of an atomic power plant in the future, the condensate desalter 5 as shown in FIG. 1 can be omitted by using the straight chain type cation exchange resins having ion exchanging groups of high degree of dissociation in the filtration desalter. EXAMPLE 8 Characteristics of filtration desalter 4 can be further improved by optimizing the particle size of the ion exchange resin according to the present invention, or by adding fibers thereto. Characteristics required for the filtration desalter 4 are the following two: The first is a longer filtration life. The longer the filtration time, the more the amount of cruds adsorbed in and removed by the precoat layer. Thus, clogging takes place in the precoat layer, increasing the filtration differential pressure (pressure drop). When the differential pressure reaches a predetermined value (usually 1.75 kg/cm.sup.2), the powdery ion exchange resins as a precoat material is back-washed, and discharged, and exchanged with a new precoat material. Thus, in order to reduce the cost and the amount of the discharged wastes, it is desirable that the differential pressure increases slowly, that is, the filtration life is longer. The second characteristic as required is a higher percent removal of cruds from the cooling water to be treated, and usually percent removal of 90% or higher is required. The present inventors have found, as a result of basic tests, that when the cation exchange resins according to the present invention are used, a longer filtration life can be obtained as desired than that of the conventional strongly acidic sulfonic acid-based resin, but sometime cracks are developed in the precoat layer during the filtration, lowering the percent removal of cruds to 60-90%, and continuous use of the filtration desalter in such a state becomes inappropriate. The cation exchange resins according to the present invention include carboxylic acid-based resin, chelate resin, etc., and at first the case of using carboxylic acid-based resin will be described below: Methacrylic carboxylic acid resin, acrylic carboxylic acid resin, etc. are known as the carboxylic acid-based resin. Characteristics of these resins used as the precoat material are substantially equal to one another, and thus will be hereinafter referred to all together as "carboxylic acid-based resin". The known carboxylic acid-based resin is the so called granular resin having particle sizes of about 500 .mu.m, but such granular resin is not suitable for the precoat and has an insufficient filtration effect owing to the larger particle size, and is also not practical owing to the low efficiency in ion exchange reaction. Thus, the carboxylic acid-based resin is pulverized to prepare powdery carboxylic acid-based resin having an average particle size of about 50 .mu.m. The thus prepared resin is mixed with powdery anion exchange resin in a ratio of the former to the latter of 2:1 by weight, and a small amount of a polymeric coagulating agent such as polyacrylamide, etc. is added to the mixture to prepare a precoat material. Water containing cruds is treated with the thus obtained precoat material. The results are shown in FIG. 13, as compared with the results of using the conventional sulfonic acid-based resin as cation exchange resin. As is obvious from FIG. 13, the filtration differential pressure increases with filtration time, but the filtration differential pressure of carboxylic acid-based resin increases more slowly than that of sulfonic acid-based resin. The filtration life of the carboxylic acid-based resin is about 1.5 times as long as that of sulfonic acid-based resin, where the filtration time is defined as the filtration time or the trapped crud amount at the time when the filtration differential pressure reaches 1.75 kg/cm.sup.2, and thus a better result can be obtained in the present invention. However, the percent crud removal decreases with filtration time, and reaches about 75% in the case of carboxylic acid-based resin at the time when the filtration differnetial pressure reaches 1.75 kg/cm.sup.2, and the percent crud removal of 90% or higher as generally required cannot be attained. It has been found that the low percent crud removal is caused by development of cracks in the precoat layer with increasing filtration time. The detail will be described below, referring to FIG. 14. Generally, water 42 is filtered after a precoat layer 41 having a thickness of 2 to 20 mm has been formed on a filtration element 21, as shown in FIG. 14(a). The precoat layer is shrunk with increasing filtration time, and thus cracks 43 are developed, as shown in FIG. 14(b), lowering the percent crud removal. Such phenomena are known also in the case of the conventional sulfonic acid-based resin, and known effective means for preventing development of cracks 43 is addition of fibers thereto. The results of sulfonic acid-based resin shown in FIG. 13 are based on the precoat layer containing fibers. It is known that in the case of the conventional sulfonic acid-based resin it is appropriate to add 30 to 60% by weight, preferably 50% by weight, of fibers thereto. The present inventors carried out filtration tests in the following manner. After mixing carboxylic acid-based resin with anion exchange resin, 50% by weight of acrylic fibers (size: about 10 .mu.m, length: about 100 .mu.m) was added to the mixture on the total basis to prepare a precoat material. The results are shown in FIG. 15, together with the results obtained without any addition of the fibers. It is obvious from FIG. 15 that the percent crud removal can be considerably improved by the addition of fibers, and crack development in the precoat layer can be prevented. However, even in the proportion of fibers of 50% by weight, which is deemed most appropriate in the case of the sulfonic acid-based resin, percent crud removal of more than 90% as generally required could not always be obtained, as in obvious from FIG. 15. The present inventors tried to clarify its causes and find out a step for solving this problem. To clarify the causes for crack development in the precoat layer in the case of carboxylic acid-based resin, the present inventors at first investigated causes for crack development in the case of the conventional sulfonic acid-based resins. As a result, it was found that the crack development was caused by shrinkage of precoat layer 41, and the cause for the shrinkage of precoat layer 41 was due to the synergistic effect of the following two factors. That is, the first factor is that, among ion exchange resins, cation exchange resin particles have negatively charged surfaces, whereas anion exchange resin particles have positively charged particles, and the precoat layer composed of a mixture of these two is a loose layer of so called flocs by electric repulsive forces. When cruds are adsorbed on the precoat layer, the surface electric charges are offset, and the electric repulsive forces are reduced, whereby the precoat layer is shrunk and turns into a dense layer. The second factor is that the conventional sulfonic acid-based resin is a shrinkable resins in which the resin particles shrink when they adsorb the cruds, and thus the precoat layer is shrunk thereby, causing crack development. In the case of the conventional sulfonic acid-based resin, cracks develop by reduction in the electric repulsive forces by the crud adsorption and shrinkage of the resin itself, and fibers are added thereto to prevent the crack developments. In the case of carboxylic acid-based resin, on the other hand, the mechanism of crack development was found to be quite different from the foregoing. That is, the said first factor (reduction in the electric repulsive force) was quite identical with the foregoing, but the second factor was quite different. That is, even if the carboxylic acid-based resin adsorbs cruds, the resin particles are not shrunk, but rather expand. That is, the carboxylic acid-based resin is an expandable resin. Thus, the second factor acts to lessen the shrinkage of the precoat layer, and it has been found that the carboxylic acid-based resin has less precoat layer shrinkage than the sulfonic acid-based resin. The present inventors presumed that, in contrast to the appropriate proportion of fibers of 30 to 60% by weight (dry basis) in the case of sulfonic acid-based resin, crack development in the precoat layer could be prevented by a much small proportion of fibers in the case of carboxylic acid-based resin. The present inventors conducted filtration tests by changing the proportion of fibers. The results are shown in FIG. 16, where the percent crud removal is shown as a function of proportion of fibers when the filtration differential pressure reaches 1.75 kg/cm.sup.2 in the precoat layer. It has been found that in the case of sulfonic acid-based resin, cracks develop in the precoat layer in a proportion of below 30% by weight (dry basis), and the percent crud removal is drastically lowered, whereas in the case of carboxylic acid-based resin no cracks develop even in a smaller proportion of fibers, as presumed, and the percent crud removal of 90% can be obtained even in the proportion of fibers of 10% by weight (dry basis). On the other hand, the percent crud removal is again lowered even in the region of a larger proportion of fibers, as shown in FIG. 16. The cause for such lowering is that the proportion of ion exchange resin having a high filtrability is decreased with increasing proportion of fibers. In the case of sulfonic acid-based resin, the percent crud removal becomes less than 90% in the proportion of fibers above 60% by weight (dry basis), whereas in the case of carboxylic acid-based resin the percent crud removal becomes less than 90% in the proportion of fibers above 40% by weight (dry basis). The reasons are that the sulfonic acid-based resin is a strongly acidic resin and thus has a high ability to remove cruds, and the desired ability can be maintained even if the proportion of fibers is rather increased, whereas the carboxylic acid-based resin is a weakly acidic resin, and has a rather low ability to remove cruds, and thus the proportion of fibers cannot be made too large. As described above, it has been found that the carboxylic acid-based resin and the sulfonic acid-based resin have different optimum proportions of fibers from each other owing to different physical properties. That is, in the case of carboxylic acid-based resin, percent crud removal of 90% or higher can be obtained, if the proportion of fibers is in a range of 10 to 40% by weight (dry basis), and such a range is quite preferable when applied to a filtration desalter. Any of acrylic fibers, nylon fibers, plant fibers, carbon fibers, etc. can be used as fibers for use in the present invention, and the fiber size can be in a range of a few .mu.m to a few tens .mu.m and the length can be in a range of a few tens .mu.m to a few mm, as in the conventional size and length. The optimum proportion of fibers has been clarified in the foregoing, and the carboxylic acid-based resin has such an essential defect that the ability to remove cruds is rather low, as already mentioned above. That is, in the case of carboxylic acid-based resin, the percent crud removal reaches maximum 93% when the proportion of fibers is about 20% by weight (dry basis), whereas in the case of sulfonic acid-based resin maximum 97% crud removal can be obtained, as is obvious from FIG. 16. To investigate the reason fully, the present inventors investigated distribution of cruds adsorbed through the precoat layer. The results are shown in FIG. 17, where the axis of ordinate shows the concentration of adsorbed cruds, and the axis of abscissa shows the depth of precoat layer 41 from the surface toward the filtration element 21. It is seen therefrom that, since the sulfonic acid-based resin is a highly acidic resin, it has a high ability to remove cruds, and thus most of cruds are adsorbed near the surface of the precoat layer 41, whereas the carboxylic acid-based resin is a weakly acidic resin, cruds are adsorbed throughout the precoat layer, and a portion of cruds reaches even the filtration element 21. That is, since the carboxylic acid-based resin is weakly acidic, cruds cannot be completely adsorbed in the precoat layer, and a portion of the cruds reaches the filtration element. That is, the percent crud removal is low. To give such carboxylic acid-based resin an equivalent ability to remove cruds to that of the conventional sulfonic acid-based resin, the present inventors presumed that reduction in particle size of the resin would be a preferable step. In the conventional sulfonic acid-based resin, powdery resins having particle sizes of 60 to 400 meshes, that is, an average particle size of 50 to 150 .mu.m have been used from the viewpoint of precoatability, etc. In the case of carboxylic acid-based resin having a rather low ability to remove cruds, the present inventors presumed that an effective ability to remove cruds could be increased by reducing the particle size, thereby increasing the reactive surface area, and consequently a higher percent crud removal than that of the sulfonic acid-based resin could be obtained. Thus, the present inventors conducted filtration tests by changing the particle sizes of carboxylic acid-based resins. The results are shown in FIG. 18, where the proportion of fibers was always kept at 20% by weight. The percent crud removal shown in FIG. 18 shows values obtained when the filtration differential pressure reaches 1.75 kg/cm.sup.2, and the filtration life is defined as follows. In the conventional sulfonic acid-based resin, powdery resin having particle sizes of 60 to 400 meshes, preferably 100 to 200 meshes, that is, an average particle size of about 80 .mu.m, as disclosed in Japanese Patent Publication No. 47-44903, are used. Thus, the filtration life of sulfonic acid-based resin having an average particle size of 80 .mu.m is presumed to be unity, and the filtration life of carboxylic acid-based resin is shown as a relative value thereto. As is obvious from FIG. 18, the smaller the average particle size, the larger the reactive surface area and the higher the percent crud removal. To obtain percent crud removal of 90% or higher, it has been found that it is desirable that the average particle size is not more than 60 .mu.m. On the other hand, the larger the average particle size, the longer the filtration life. The reasons are that the smaller the average particle size is, the more often clogging takes place in the precoat layer at the crud adsorption, and consequently the increase in the filtration differential pressure is accelerated. Thus, to make the filtration life equal or superior to that of the conventional sulfonic acid-based resin, it is desirable that the average particle size of carboxylic acid-based resin is 30 .mu.m or larger. That is, to obtain percent crud removal of 90% or higher and make the filtration life equal or superior to that of the conventional sulfonic acid-based resin, it is desirable that the average particle size of carboxylic acid-based resin is 30 to 60 .mu.m. The reasons why an average particle size of 50 to 150 .mu.m (60 to 400 meshes) is desirable in the case of the conventional sulfonic acid-based resin, whereas 30 to 60 .mu.m is desirable in the case of carboxylic acid-based resin can be summarized as follows: that is, to obtain a high percent crud removal, the carboxylic acid-based resin must have a larger reactive surface area owing to the weak acidity (whereas the sulfonic acid-based resin is strongly acidic), and thus it is desirable that the average particle size is smaller than that of the conventional sulfonic acid-based resin. Sulfonic acid-based resin is a shrinkable resin in which the resin particles shrink when they absorb cruds, and thus the filtration life is drastically shortened when the average particle size is less than 50 .mu.m, whereas the carboxylic acid-based resin is an expandable resin to the contrary, the filtration life equal to that of the conventional sulfonic acid-based resin can be obtained even if the average particle size is about 30 .mu.m. In FIG. 18, the cases with the proportion of fibers of 20% by weight are shown, but the present inventors have found that a high filtrability can be obtained in proportions of fibers ranging from 10 to 40% by weight shown in FIG. 16 by making the average particle size 30 to 60 .mu.m. This will be explained, referring to FIG. 19. When the proportion of fibers shown on the axis of abscissa is less than 10% by weight, cracks develop, and the percent crud removal becomes less than 90%, whereas above 40% by weight the proportion of ion exchange resin is lowered, and the percent crud removal is lowered. When the average particle size shown on the axis of ordinate is more than 60 .mu.m, the reactive surface area is insufficient, and the percent crud removal is low, whereas below 30 .mu.m clogging takes place in the precoat layer, and the filtration life becomes short. Since the carboxylic acid-based resin is expandable and weakly acidic, and is different in the physical properties from the conventional sulfonic acid-based resin, the optimum conditions for powdery ion exchange resins are quite different therebetween. In the foregoing, carboxylic acid-based resin has been exemplified, but the same results can be obtained from other ion exchange resins, so long as they are the resins according to the present invention. One example is a chelate resin shown as .circle.G in Table 1. Test results obtained by mixing the cation exchange resin shown as .circle.G in Table 1 with anion exchange resin in a mixing ratio of the former to the latter of 1:1 by weight, and adding fibers thereto are shown in FIG. 20, where percent crud removal at the time when the filtration differential pressure reaches 1.75 kg/cm.sup.2 is shown for chelate cation exchange resins having average particle sizes of 30, 60 and 100 .mu.m when the proportion of plant fibers having a size of about 5 .mu.m and a length of a few tens .mu.m are changed in a range from 0 to 60% by weight. In this case, higher percent crud removal can be obtained in proportions of fibers from 10 to 40% by weight as in FIG. 16, and percent crud removal of 90% or higher can be obtained when the particle size of the cation exchange resin is from 30 to 60 .mu.m, as is obvious from FIG. 20. When the powdery ion exchange resin is used as a precoat material, the weakly acidic cation exchange resin and anion exchange resin are used in a mixture in a predetermined ratio (usually the ratio of the cation exchange resin to the anion exchange resin is in a range of 4:1 to 1:2), and powdery quaternary, tertiary, secondary and primary amine-based resins, etc. can be used as the anion exchange resin, as in the prior art. According to the present invention, the following effects can be obtained: (1) Non-radioactive metals such as .sup.59 Co, etc. are not retained in a nuclear reactor for a long time, and thus formation of .sup.60 Co, etc. is suppressed and deposition of radioactive metals onto pipings can be also suppressed. That is, radiation exposure of operators in an atomic power station can be considerably reduced. (2) Even if the ions or cruds are trapped from nuclear reactor cooling water, an increase in the filtration differential pressure or crack development can be suppressed, and thus the life of a filtration desalter can be prolonged. That is, not only the cost, but also the amount of discharged wastes can be reduced. (3) The cation exchange resins for use in the present invention have ion-exchanging groups of low bonding energy, and thus can be thermally decomposed simply. That is, the waste disposal can be readily made, and a considerable reduction in the waste volume can be attained without generation of harmful gas components at the waste disposal and the waste disposal facility can be simplified.
	summary
	claims	1. A fabrication method of burnable absorber nuclear fuel pellets, comprising:adding a boron compound, which is one or more of compounds selected from the group consisting of boron carbide (B4C), titanium diboride (TiB2), zirconium diboride (ZrB2) and boron nitride (BN) and a manganese compound to one or more of nuclear fuel powders selected from the group consisting of uranium dioxide (UO2), plutonium dioxide (PuO2) and thorium dioxide (ThO2) and mixing the same (step 1);compacting the mixed powder of step 1 into compacts (step 2); andsintering the compacts of step 2 under a hydrogen atmosphere (step 3) performed at a temperature range of between about 1000° C. and about 1500° C., wherein, upon sintering, the nuclear fuel pellets have a density of 90% TD (theoretical density) or above, wherein the boron compound of step 1 is added in an amount of 0.01 to 5 wt. % per nuclear fuel powder, and the manganese compound of step 1 is added in an amount of 0.01 to 1 wt. % per nuclear fuel powder, and mixed therein,wherein the boron compound and the manganese compound are uniformly dispersed in the compacts of step 2. 2. The fabrication method of claim 1, wherein the boron compound of step 1 is boron nitride (BN). 3. The fabrication method of claim 1, wherein the manganese compound of step 1 is one or more of compounds selected from the group consisting of manganese oxide (MnO), manganese dioxide (MnO2), manganese sulfide, manganese fluoride, and manganese chloride. 4. The fabrication method of claim 1, wherein the manganese compound of step 1 is manganese oxide (MnO). 5. The fabrication method of claim 1, wherein the compacts of step 2 are formed under pressure of 1 to 5 ton/cm2. 6. The fabrication method of claim 1, wherein the sintering of step 3 is performed at a temperature range of 1000 to 1200 degree C. 7. The fabrication method of claim 1, wherein the hydrogen atmosphere further comprises one or more of gases selected from the group consisting of argon, nitrogen, carbon dioxide and water vapor.
	summary
	summary
	claims	1. Method for determining friction forces occurring on a moving object in a guide, using a speed sensor, comprising the following steps of a calculation process: V 1 =f 1 ( t ), V 2 =f 2 ( t ); V 4 =g 4 ( d ); V 5 =V 4 xe2x88x92V 3 =g 5 ( d ); F additional =M (xcex35xe2x88x92xcex34)= f ( d ), wherein 1) measuring and recording changes in the velocity V 1 of the object initially before the occurrence of friction: xe2x80x83wherein f 1 is a function of time (t); 2) calculating distance of travel d 1 with integrated change in velocity of the object before the onset of friction, to obtain the change in velocity, V 1 =g 1 (d) in relation to distance of travel: xe2x80x83wheein g 1 is a second function of distance (d), and (u) is a time value; 3) measuring and recording the change in velocity V 2 of the object after the onset of friction: 4) calculating distance of travel d 2 with integrated change in velocity of the object, after onset of friction, to obtain the change in velocity V 2 =g 2 (d) relation to distance of travel; 5) calculating the difference of velocity V 3 between the two velocities V 1 and V 2 in relation to travel before and after onset of additional friction, F additional ; 6) calculating the change in velocity V 4 of the object in relation to distance of travel, before the onset of friction, using a predetermined calculation program, wherein 7) subtracting the difference of velocity V 3 from this change in velocity V 4 , the difference V 3 in measured velocity changes: xe2x80x83to obtain the difference of velocity V 5 ; and 8) deducing, by differentiation between V 4 and V 5 and multiplication by the weight M, the additional friction forces acting on the movement of the object; xe2x80x83and wherein xcex3 is the acceleration of the object, and subscripts 4, 5 represent successive values in the said calculation process. 2. Method according to claim 1 , applied to a pressurized water nuclear reactor, the moving object being a mobile assembly formed of a control rod and control cluster, the guide being the lowering channel, the speed sensor being a rod position indicator (RPI) used to measure velocity. claim 1
	abstract	A method for forming a solid immersion lens (SIL) includes generating a focused ion beam, and projecting the focused ion beam onto an optical medium at locations defined by a binary bitmap milling pattern, wherein the locations at which the focused ion beam impact a surface of the optical medium are randomized over successive raster scans of the surface of the optical medium to form at least a portion of a hemispherical structure in the optical medium.
	claims	1. A system for particle beam therapy, the system comprising, as seen in a flow direction of a particle beam:a) an adjustable gantry for beam delivery to a target volume, said gantry including:a1) a beam coupling section for an incoming particle beam, the incoming particle beam being oriented substantially horizontally and defining a horizontal plane;a2) a first beam bending section having a plurality of beam deflection and/or focusing magnets, said first beam bending section being configured to either bend the particle beam with an adjustable angle into a vertical plane, or with 90 degrees in the horizontal plane, but with mechanical rotatability about an adjustable angle along an axis of the incoming particle beam;a3) a beam transport section disposed to receive the particle beam leaving said first beam bending section and guiding the particle beam to a second beam bending section;a4) said second beam bending section having a plurality of beam deflection magnets and/or beam focusing magnets; anda5) a beam nozzle formed with a window for an exit of the particle beam; andb) a patient support mounted for rotation and/or shifting in the horizontal plane or in a plane parallel to the horizontal plane;c) a tilting mechanism supporting said gantry to enable said gantry to be tilted vertically by a tilting angle Φ1, where Φ1ε[−90°; +90°], about a pivot disposed in a region of said first beam bending section; andd) a rotation mechanism disposed to enable said second beam bending section and said beam nozzle to rotate by an angle Φ2, where Φ2ε[−180°; +180°], around a direction given by the tilting angle Φ1. 2. The system according to claim 1, comprising the following basic settings:a) maximum of Φ1 and Φ2=0°, leading to a particle beam pointing from the vertical direction downwards to said patient support;b) minimum of Φ1 and Φ2=180°, leading to a particle beam pointing from the vertical direction upwards to said patient support;c) Φ1=0°and Φ2=−90°, leading to a particle beam pointing in the horizontal direction from one side to said patient support; andd) Φ1=0°and Φ2=+90°, leading to a particle beam pointing in the horizontal direction from an opposite side to said patient support. 3. The system according to claim 1, wherein said tilting mechanism comprises a telescope arm. 4. The system according to claim 1 wherein said beam transport section comprises a telescope section. 5. The system according to claim 4, wherein said beam transport section is adjustable in length in order to compensate for a change in a horizontal component of said gantry due to the tilting angle Φ1. 6. The system according to claim 1, wherein said first beam bending section comprises a set of magnets in order to deflect the incoming beam into a direction given by the tilting angle Φ1. 7. The system according to claim 1, which comprises a beam spreading system configured to spread the beam in a lateral direction, which is perpendicular to a direction of the beam leaving said second bending section. 8. The system according to claim 7, wherein said beam spreading system comprises a scattering system configured to increase a beam diameter and/or a system of fast deflection magnets configured to scan the beam in the transversal direction. 9. The system according to claim 8, wherein said beam spreading is collated upstream of or downstream of said second bending section in the flow direction of the beam. 10. The system according to claim 1, wherein a treatment angle of the particle beam at the isocenter with respect to a patient orientation is determined by a combination of the tilting angle Φ1, the angle Φ2, and an orientation of the patient support.
	summary
062691457	claims	1. A compound refractive lens for x-rays, comprising: a plurality of individual unit lenses comprising a total of N in number, said unit lenses hereinafter designated individually with numbers i=1 through N, said unit lenses substantially aligned along an axis, said i-th lens having a displacement t.sub.i orthogonal to said axis, with said axis located such that ##EQU77## wherein each of said unit lenses comprises a lens material having a refractive index decrement .delta.<1 at a wavelength .lambda.<100 Angstroms. 2. A compound refractive lens as in claim 1, wherein said displacements t.sub.i are distributed such that there is a standard deviation .sigma..sub.t of said displacements t.sub.i about said axis, and wherein each of said unit lenses is a spherical lens and has an absorption aperture radius r.sub.a, a mechanical aperture radius r.sub.m, a radius of curvature R.sub.s, and a minimum effective aperture radius r.sub.e =MIN(r.sub.a,r.sub.m), such that .sigma..sub.t is less than r.sub.e and also less than R.sub.s /2. 3. A compound refractive lens as in claim 1 wherein said displacements t.sub.i are distributed such that there is a standard deviation .sigma..sub.t of said displacements t.sub.i about said axis, and wherein each of said unit lenses is a parabolic lens, and has an absorption aperture radius r.sub.a, a mechanical aperture radius r.sub.m, and a minimum effective aperture radius r.sub.e =MIN(r.sub.a,r.sub.m), such that .sigma..sub.t is less than r.sub.e. 4. A compound refractive lens as in claim 1 wherein said displacements t.sub.i are distributed such that there is a standard deviation .sigma..sub.t of said displacements t.sub.i about said axis, and wherein each of said unit lenses is a Fresnel refractive lens having a mechanical aperture radius r.sub.m such that .sigma..sub.t is less than r.sub.m. 5. A compound refractive lens as in claim 2, wherein said spherical lens has a radius of curvature of R.sub.s and is made of material having a linear absorption coefficient .mu., and wherein said absorption radius ##EQU78## 6. A compound refractive lens as in claim 3, wherein said parabolic lens has a latus rectum of 2R.sub.p and is made of material having a linear absorption coefficient .mu., and wherein said absorption radius ##EQU80## 7. A compound refractive lens according to any one of claims 2, 3, or 4 wherein .lambda./4N.delta..ltoreq..sigma..sub.t <r.sub.e. 8. A compound refractive lens according to any one of claims 1, 2, 3, 4, 5, or 6 wherein each of said unit lenses has an average thickness d.sub.ave such that d.sub.ave <<1N.mu.. 9. A compound refractive lens according to claim 8, wherein d.sub.ave.ltoreq.25 .mu.m. 10. A compound refractive lens according to any of claims 1, 2, 3, 4, 5, or 6, wherein said unit lenses are fabricated separately and do not have a common substrate. 11. A compound refractive lens according to any of claims 1 through 6 wherein each of the unit lenses is selected from a group of lenses consisting of a plano-concave lens, a bi-concave lens, a plano-convex lens, a bi-convex lens, and a Fresnel lens. 12. A compound refractive lens according to any of claims 1 through 6 wherein the plurality of the unit lenses are cylindrical and focus in one dimension. 13. A compound refractive lens according to any of claims 1 through 6 wherein the plurality of the unit lenses have a round or rectangular mechanical aperture and focus in two dimensions. 14. A compound refractive lens according to any of claims 1, 2, 3, 4, 5, or 6 wherein each unit lens is rigidified by a thicker contiguous support structure. 15. A compound refractive lens according to any of claims 1, 2, 3, 4, 5, or 6 wherein the unit lenses are made using injection or compression molding manufacturing techniques. 16. A compound refractive lens according to any of claims 1, 2, 3, 4, 5, or 6 wherein the unit lens structure shape is fabricated on top of and supported by a thin plastic film and by a contiguous structure which supports and rigidifies the unit lens. 17. A compound refractive lens according to any of claims 1, 2, or 3 wherein the unit lens structure shape is fabricated by molding the lens using spherical shaping means such as stainless steel ball or balls or a parabolic shaping means supported by a contiguous structure which supports and rigidifies the lens. 18. A compound refractive lens according to any of claims 1, 2, or 3 wherein the unit lens structure shape is fabricated in a thin metal substrate utilizing spherical shaping tool such as a ball end mill, or a parabolic shaping tool. 19. A compound refractive lens according to any of claims 1, or 4 wherein the plurality of thin unit lenses have refractive Fresnel shapes, are made of plastic and are of a single material. 20. A compound refractive lens according to any one of claims 1, or 4 wherein the plurality of thin unit lenses have refractive Fresnel shapes, are made of plastic, are of a single material, and supported and rigidified by thicker contiguous support structure. 21. A compound refractive lens according to any one of claims 1, or 4 wherein the plurality of thin unit lenses have refractive a Fresnel shape wherein said Fresnel shape fabricated on or in a thin support film by lithographic techniques or compression molding techniques; and whereas said thin support film is supported and rigidified by thicker contiguous support structure. 22. A compound refractive lens according to any one of claims 1, or 4 wherein the plurality of thin unit lenses have a refractive Fresnel shape that are fabricated by compression or injection molding techniques wherein said compression and injection molding techniques include utilizing molds fabricated using diamond lathe turning or lithographic techniques. 23. A compound refractive lens according to any one of claims 1, 2, 3, 4, 5, or 6 wherein the unit lenses are held by a cylindrical alignment and support element whereby the lenses have an average optical axis. 24. A compound refractive lens according to any one of claims 1, 2, 3, 4, 5, or 6 wherein the unit lenses are held and aligned by two or more alignment pins or rods whereby the lenses have an average optical axis. 25. A compound refractive lens according to any one of claims 1, 2, 3, 4, 5, or 6, wherein the unit lenses are aligned with an alignment means and then held together using an adhesive, an epoxy, a metal bonding means or any other fastening means. 26. A compound refractive lens according to any one of claims 1, 2, 3, 4, 5, or 6, further comprising the number of lenses, N, arranged as a succession of elements to form a compound refractive lens, the individual lenses being constructed of a material having atomic weight A, an atomic number Z, and a density .rho..gtoreq.3 gm/cm.sup.3. 27. A compound refractive lens according to any one of claims 1, 2, 3, 4, 5, or 6, further comprising the number of lenses, N, arranged as a succession of elements to form a compound refractive lens, wherein N.ltoreq.1/.mu.(.omega..sub.k)d, where d is the minimum thickness of the individual lenses; .mu.(.omega.) is the linear absorption coefficient of the lens material at frequency .omega..sub.k, where .omega..sub.k is the K-shell, L-shell or M-shell photoabsorption edge frequency of the lens material. 28. A compound refractive lens system composed of lenses manufactured as described in claims 1, 2, 3, 4, 5, or 6 forming an achromatic x-ray lens, a telescope, a microscope or lens systems for the manipulation and use of x-rays. 29. A plurality of compound refractive lens composed of lenses manufactured as described in claims 1, 2, 3, 4, 5, or 6 whose focal lengths and separation are adjusted such that the focal length of the entire lens system is the same over a wide range of x-ray photon energies that is greater than any of the individual compound refractive lenses that compose the lens system. 30. A compound refractive lens as in claim 4, wherein .sigma..sub.t less than the smallest zone (r.sub.m -r.sub.m-1).
	claims	1. A deflector array comprising:a plurality of deflectors, which deflect charged particle beams, arrayed on a substrate,wherein each of said plurality of deflectors includes a single opening formed in the substrate, and each of said plurality of deflectors including a pair of electrodes that oppose each other through the opening and being configured to deflect a single charged particle beam, andwherein said plurality of deflectors are arrayed such that a length of said pair of electrodes in a longitudinal direction thereof is not less than a distance between centers of two of said plurality of deflectors that are located nearest to each other, said plurality of deflectors being arrayed to form a rectangular lattice, the longitudinal direction being tilted with respect to a direction of a side of a rectangle in the rectangular lattice. 2. The deflector array according to claim 1, wherein a direction of a line connecting the centers forms an angle of 45° with respect to a direction in which each of said plurality of deflectors deflects the charged particle beam. 3. The deflector array according to claim 1, wherein a direction of a line connecting the centers forms an angle of 63.4° with respect to a direction in which each of the plurality of deflectors deflects the charged particle beam. 4. The deflector array according to claim 1, wherein a direction in which each of the plurality of deflectors deflects the charged particle beam is perpendicular to the longitudinal direction of said pair of electrodes. 5. The deflector array according to claim 1, wherein said pair of electrodes are parallel to each other. 6. The deflector array according to claim 1, wherein said pair of electrodes are formed such that a distance between said pair of electrodes shortens from centers toward end portions of said pair of electrodes. 7. An exposure apparatus which exposes a wafer with a charged particle beam, the apparatus comprising:a charged particle source which emits the charged particle beam;a first electron optical system which forms a plurality of intermediate images of said charged particle source;a second electron optical system which projects the plurality of intermediate images formed by said first electron optical system onto the wafer; anda positioning apparatus which holds and positions the wafer,wherein said first electron optical system includes a deflector array defined in claim 1. 8. A method of manufacturing a device, the method comprising:exposing a wafer with a charged particle beam using an exposure apparatus defined in claim 7;developing the exposed wafer; andprocessing the developed wafer to manufacture the device. 9. The deflector array according to claim 1, wherein the deflector array includes deflectors with three rows and three columns.
	summary
059011920	description	DETAILED DESCRIPTION FIG. 1 is a perspective view with parts cut away of a reactor pressure vessel (RPV) 10. RPV 10 includes a shroud 11, core spray lateral pipes 12A and 12B, core spray line risers 14A and 14B, a T-box junction 16, a T-box 18, and core spray spargers (not shown in FIG. 1). Core spray line risers 14A and 14B each include a lower elbow 20A and 20B. Elbows 20A and 20B each include an opening (not shown). Core spray line riser 14A is configured to couple core spray pipe 12A and T-box 18. Referring to FIG. 2, T-box 18 includes a substantially cylindrical pipe 30 having a bore 34 extending therethrough, two core spray sparger openings 38 (only one shown), and an end plate (which has been machined off in the FIG. 2 illustration). Core spray line lower elbow 20A is secured to T-box 18, typically with a lower weld (not shown). Core spray line riser 14A may, for example, be secured to T-box 18 in various manners, including, inserting pipe 30 into elbow 20A and welding, or inserting elbow 20A into pipe 30 and welding, as well as abutting elbow 20A to pipe 30 and welding. Core spray spargers 44A and 44B are coupled to T-box openings 38, for example by welding. Referring to FIGS. 2 and 3, repair apparatus 48 includes a substantially cylindrical sleeve 50, a draw bolt 54, and a block 58. Cylindrical sleeve 50 includes a flange 62 at one end 64, and a main cylinder body 68 having an axial bore 72 extending therethrough. Opposing water flow openings 76A and 76B are located in sleeve main body 68. Main body 68 is sized to be inserted within T-box pipe 30 so that sleeve flange 62 engages T-box 18. Flange 62 outer diameter is greater than the outer diameter of T-box pipe 30 and includes an opening (not shown) sized to receive draw bolt 54. Flange 62, may for example, be integral or welded to main body 68. Water flow openings 76A and 76B are configured to provide a fluid passage from core spray spargers 44A and 44B to T-box 18. Draw bolt 54 is of sufficient length to extend through flange opening, main body bore 72, elbow opening (not shown), and block 58. Draw bolt 54 is threaded and configured to engage block 58. Block 58 includes a threaded opening (not shown) and is configured to threadedly engage bolt 54 to draw block 58 into tight engagement with riser lower elbow 20A or 20B. Sleeve 50 may, for example, be fabricated from type 304L or 316L stainless steel. Bolt 54 and block 58 may be fabricated from type XM-19 stainless steel. After replacing core spray riser 14A, repair apparatus 48 is coupled between T-box 18 and core spray line riser 14A. Specifically, in one embodiment, core spray line riser elbow 20A is coupled to T-box 18, for example with a weld. T-box end plate (not shown) is removed, for example by machining. Main cylindrical body 68 is inserted into T-box pipe 30 until flange 62 fully engages T-box 18. Draw bolt 54 is inserted through flange opening, main body bore 72, and core spray line riser elbow opening. Block 58 is engaged to draw bolt 54 and engaged with lower elbow 20A. Sleeve 50 is rotated to ensure that sleeve water flow openings 76A and 76B are substantially aligned with core spray spargers 44A and 44B attached to T-box 18. An opening (not shown) in lower elbow 20A corresponds to a centerline of sleeve 50. The lower elbow opening is formed, for example, by machining or drilling. Draw bolt 54 is inserted through flange opening, bore 72, and elbow opening. Bolt 54 is then engaged to block 58. Draw bolt 54 is torqued until block 58 fully engages lower elbow 20A and locked into place. The resulting connection provides a fluid passage from T-box junction 16 to core spray spargers 44A and 44B. Repair apparatus 48 provides axial restraint for core spray line riser 14A and T-box 18 connection. Additionally, because draw bolt 54 is positioned within T-box bore 34, draw bolt 54 is exposed to the injection waters temperature only and would, therefore, be expected to contract at the same rate or slightly less than core spray riser 14A and 14B and T-box 22, which facilitates minimizing leakage. From the preceding description of various embodiments of the present invention, it is evident that the objects of the invention are attained. Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is intended by way of illustration and example only and is not to be taken by way of limitation. Accordingly, the spirit and scope of the invention are to be limited only by the terms of the appended claims.
054066115	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows a radiation apparatus in which the gating device disclosed herein can be used that, for example, is in the form of a computer tomography apparatus. In this radiation apparatus, an X-ray radiator 1 transmits an x-ray beam 2 to a radiation detector 3 that is arcuately fashioned and comprises individual detector elements adjoining one another. For gating the beam 2, a slotted diaphragm 4 is provided in the region of the X-ray radiator 1. A pre-diaphragm 5, a first diaphragm 6 and a second diaphragm 7 immediately in front of the radiation detector 3 for setting the slice widths are provided over the course of the further beam path. In this radiation apparatus, the aforementioned arrangement rotates around a measurement field 8 in which an examination subject can be disposed. Dependent on the radiation penetrating through the examination subject, signals corresponding to the radiation intensity incident on the individual detectors are obtained at the respective outputs of the individual detectors. These signals are supplied to an image processor 50 whose output signals can be portrayed on a monitor 51 as an image of the examination subject. FIG. 2 shows a gating device 9 of the invention in plan view for gating radiation from a radiation source, for example, the x-ray radiator 1. This gating device 9 has first and second diaphragm plates 10 and 11 having respective longitudinal axes 12 and 13 aligned parallel to one another, so that the first and second diaphragm plates 10 and 11 form a slot-shaped opening 14. Each diaphragm plate 10 and 11 has at least one guide. In the embodiment of FIG. 2, the plates 10 and 11 each have two guides, referenced 15 and 16, and 17 and 18. In the exemplary embodiment, the guides 15 and 16 parallel to one another and are disposed obliquely relative to the longitudinal axis 12 as are the guides 17 and 18 relative to the longitudinal axis 13. The guides 15 and 16 are respectively formed by recesses 19 and 20 in the diaphragm plate 10 and first and second pin 23, 24 and 25, 26 respective engaging into the recesses 19 and 20. Similarly, the guides 17 and 18 are respectively formed by recesses 21 and 22 in the diaphragm plate 11 into which first and second pins 27, 28 and 29, 30 extend. The diaphragm plates 10 and 11 can be adjusted especially easily at their guides 15, 16, 17 and 18 when the pins 23-30 are provided with a bearing implemented as, for example, a rolling bearing, whereby the bearing of each first pin 23, 25, 27 and 29 engages a long side of its recess 19, 20, 21, or 22 and the bearing of each second pin 24, 26, 28 and 30 engages the opposite long side of the same recess 19, 20, 21 or 22. The bearings can operate without play if eccentrically mounted on the pins 23-30. Within the context of the invention, the guides 15, 16, 17 and 18 can, of course, each be executed with only one pin, but are then less precise. The pins 23-30 are part of the housing 49 of the device 9. Longitudinal movement of the first and second diaphragm plates 10 and 11 thus also causes the plates 10 and 11 to move in a direction perpendicular to their longitudinal axes 12 and 13 to make the slot-shaped opening 14 is larger or smaller. Such movement ensues with an adjustment mechanism 31. This adjustment mechanism 31 includes a threaded spindle 32 rotatable in a threaded bore or bushing of a carriage 35 movable on rails 33 and 34. One end of each of first and second articulations 36 and 37 is pivotally attached at the carriage 35; the other ends thereof are respectively connected to the first and second diaphragms plates 10 and 11. In the illustrated position, the diaphragm plates 10 and 11 are in a position in which a medium-sized slot-shaped opening 14 is established. When the slot-shaped opening 14 is to be enlarged, the spindle 32 is rotated around its longitudinal axis so that the carriage 35 is displaced toward the left in the plane of the drawing. The diaphragm plates 10 and 11 are thereby adjusted by the guides 15, 16, 17 and 18 via the first and second articulations 36 and 37, as a result of which the spacing between the diaphragm plates 10 and 11 increases. The diaphragm plates 10 and 11 are thereby preferably adjusted simultaneously and symmetrically relative to the central longitudinal axis of the radiation receiver. Within the context of the invention, however, one diaphragm plate can be stationary, while the other diaphragm plate is adjustable for varying the slot-shaped opening 14. It is also possible that the guides of diaphragm plates arranged opposite one another exhibit a different pitch, so that the diaphragm plates are asymmetrically adjustable relative to the central longitudinal axis of the radiation receiver 3. Dependent on the angle that the guides 15, 16, 17 and 18 describe relative to the longitudinal axes 12 and 13 and dependent on their lengths, the maximum spacing between the diaphragm plates 10 and 11 which can be achieved can be predetermined. If the angle becomes obtuse, then a high exertion of force is required for the adjustment of the diaphragm plates 10 and 11 and the precision with which a spacing can be set between the diaphragm plates 10 and 11 is low. With an acute angle, the adjustability of the first and second diaphragm plates 10 and 11 is facilitated and the precision with which a predetermined spacing of the diaphragm plates 10 and 11 can be set is high. It has proven advantageous when the guides 15, 16 17 and 18 describe an angle of approximately 15.degree.-45.degree., preferably 25.degree. relative to the respective longitudinal axis 12 and 13 of the diaphragm plates 10 and 11. Within the context of the invention, the guide can be executed not only as a recess and pin but also as a channel into which a ridge (or web) engages. A ridge (or web) can also be provided with roller bearings. FIG. 3 shows a preferred exemplary embodiment of an adjustment mechanism 38 for the first and second diaphragm plates 10 and 11. Differing from the above-described adjustment mechanism 31, wherein a threaded bushing or bore into which the spindle 32 extends must be provided at the carriage 35, the adjustment mechanism 38 of FIG. 3 has a spindle 39 having threads at a pitch such that bearing means held in the carriage 40 and preferably executed as a roller bearing 41 and 42 can engage the threads. The roller bearings 41 and 42 can be adjusted such via eccentric mounts such that no play occurs between the carriage 40 and the spindle 39. The first and second articulations 36 and 37 described with reference to FIG. 2 attach at the carriage 40 for adjusting the first and second diaphragm plates 10 and 11. Also shown in FIG. 3 is a motor 43, which can be a stepping motor or DC motor, is attached to the spindle 39, for example via a chain or via a toothed belt 44. In addition to the absence of play in the bearings of the adjustment mechanism 38, it should be emphasized that it is extremely rugged and insensitive to dirt. The spindle 32 according to FIG. 2 can, for example, be provided with a thread according to DIN13 as a commercially available spindle. In order to reduce the play between the carriage 35 and the spindle 32 (or the carriage 40 and the spindle 39) the spindle 32 or 39 can also be provided with a trapezoidal thread that engages a bushing of the carriage 35 (or 40) that is provided with a corresponding thread. The bushing can be executed as a nut. In order to reduce play, the bushing is axially divided and is prestressed via a spring element, for example a rubber ring. The bearing play is also considerably reduced as a result of this measure. Adjustment of the diaphragm plates at their guides 15, 16, 17 and 18, can alternatively ensue via an adjustable eccentric attached to at least one of the diaphragm plates 10 and 11. For identifying the position of the diaphragm plates 10 and 11, a position sensor 45 as shown in FIGS. 2 and 4 can be provided, such as an encoder, potentiometer or resolver. When the gating device of the invention is to be utilized in a computer tomography apparatus and, in particular, as a diaphragm in front of the individual detector elements, then it is advantageous when, as shown in FIG. 4, a plurality of diaphragm plates 10 and 11 according to FIG. 2 adjoin one another and are fashioned arcuately. Due to the connection of the diaphragm plates 10 and 11 to one another, only one adjustment mechanism 31 or 38 is required via which the adjustment of the diaphragm plates 10 and 11 can ensue. The diaphragm plates can be entirely composed of a material having high radiation absorption. Within the context of the invention, however, it is an alternative to provide diaphragm plates with carrier plates 46 and 47 composed, for example, of aluminum and having the guides described above, so that a material having high radiation absorption must be provided only in the region of one end face of each plate. When such diaphragm plates are to be arcuately joined to one another, preferably two or more carrier plates 46 and 47 are arranged at a distance from one another, joined to one another via a ring segment or a ring 48 composed of a material having high radiation absorption. The individual carrier plates 46 and 47 can include one or more guides as described above. An advantage of this embodiment is that the mass to be moved given an adjustment of the diaphragm plates is extremely low. The described gating device, of course, can be utilized not only in a computer tomography apparatus but also in other radiation systems, for example, x-ray diagnostics installations, electron beam devices, radiation therapy devices and in light sources for gating the beam. The gating device can have only one diaphragm plate, or a plurality of diaphragm plates. Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
	summary
	summary
060375973	summary	BACKGROUND OF THE INVENTION The present invention relates generally to non-destructive testing, and more specifically to a non-destructive detection system of novel, inexpensive construction utilizing epithermal neutrons and characteristic energies generated by the same upon interacting with an object under study. As further background, a variety of non-destructive detection systems are known for use in applications such as the detection of explosives in luggage or other packages. Current technologies utilized in such detection systems include principles derived from NMR, atomic adsorption, X-ray fluorescence, neutron activation analysis, and X-ray analysis. In addition, a few attempts have been made to utilize CT technology and quadripole moment techniques in such systems. Additional relevant background as to known techniques for non-destructive detection can be found, for instance, in U.S. Pat. Nos: 2,270,373; 2,288,717; 2,297,478; 2,344,043; 3,124,679; 3,146,349; 3,255,352; 3,670,715; 3,832,545; 4,266,132 4,853,550; 4,864,142; 4,882,121; 5,006,299; 5,080,856; 5,098,640; 5,124,554; 5,144,140; 5,153,439; and 5,200,626. Drawbacks of known systems, however, include relatively high construction and operation expense and complexity of the devices utilized both to bombard the sample and receive characteristic signals from an object or sample. The present invention is addressed to the need for a relatively simple, inexpensive device and system which can be utilized to non-destructively interrogate materials, including for example luggage or other packages, and to determine the presence or absence of a given substance in the materials. SUMMARY OF THE INVENTION Accordingly, the invention provides in one preferred embodiment a device for delivering epithermal neutrons, which is a laminate of several polymer layers, e.g. wherein the polymer is high density polyethylene. In particular, the preferred device includes a first polymer layer having embedded therein a source of alpha-radiation, and a second polymer layer which is generally non-permeable or opaque to alpha-radiation and having defined therein a diffraction opening for passing alpha-radiation from the source of alpha-radiation embedded in the first polymer layer. The device further includes a third polymer layer having embedded therein a chemical source of boron, the third polymer layer being positioned relative to the second polymer layer such that alpha-radiation from the source of alpha-radiation impinges upon the source of boron, thereby generating epithermal neutrons. The device further includes a fourth polymer layer which is generally impermeable to the epithermal neutrons and defines a diffraction opening for passing the generated epithermal neutrons. Another embodiment of the invention includes a source/detector array device useful for interrogating an object. In accordance with the invention the array device includes a non-conductive layer such as mylar having affixed thereto an array of self-contained radiation sources selected for thermal neutron sources, infrared radiation sources, and X-ray sources. Also attached to the non-conductive layer in the array are a plurality of signal detectors selected from X-ray detectors, neutron detectors, infrared detectors, and gamma ray detectors. Further, the non-conductive layer includes an imprinted pattern of conductive material electrically connected to the detectors in the array, for transmitting signals generated by the detector, e.g. for immediate analysis or to memory storage for later analysis. Still another preferred embodiment of the invention provides a method for interrogating an object, comprising disposing the object next to an array device such as that described in the paragraph above. The object is bombarded with radiant energy (e.g. x-rays, infrared radiation and/or epithermal neutrons) generated by the self-contained sources, and characteristic radiant signals are generated by the interaction of the radiant energy and the object. The signals can then be analyzed to determine the presence or absence of a predetermined substance in the object. The present invention provides non-destructive detection systems and methods, and component devices useful therein, which are relatively simple in construction and relatively inexpensive in manufacture. Additional objects, features and advantages of the invention will be apparent from the following description.
	claims	1. A sample holder apparatus for reducing the energy of charged particles entering an annular-acceptance analyzer, the apparatus comprising:an electrically isolated sample support member having a sample receiving surface to receive a sample and electrically connect the sample to the sample support member, wherein the sample support member is configured for application of a retarding bias potential; anda grounded sample aperture member defining an aperture, wherein the grounded sample aperture member is positioned relative to the sample support member but electrically isolated therefrom such that the aperture is proximate the sample receiving surface to expose at least a portion of a surface of a sample received thereon to be analyzed, wherein the grounded sample aperture member along with the sample support member produce an electrical retarding field about the aperture when a retarding bias potential is applied thereto that reduces the energy of emitted particles from a sample before they enter the annular-acceptance analyzer. 2. The apparatus of claim 1, wherein the grounded sample aperture member along with the sample support member produce an electrical retarding field about the aperture when a retarding bias potential is applied thereto that reduces the energy of emitted particles from a sample before they enter the annular-acceptance analyzer and further that modifies the trajectories of such emitted particles such that they enter the annular-acceptance analyzer in a predetermined range of input elevation angles. 3. The apparatus of claim 1, wherein the retarding bias potential is a positive retarding bias potential provided by a voltage source. 4. The apparatus of claim 1, wherein the aperture is a circular aperture. 5. The apparatus of claim 1, wherein the electrically isolated sample support member comprises a body member extending along an axis terminating in the sample receiving surface configured to receive a sample, and further wherein the grounded sample aperture member comprises a wall surrounding the body member but electrically isolated therefrom, wherein the wall is terminated by an end portion defining a circular aperture, wherein the end portion is positioned relative to the sample receiving surface but electrically isolated therefrom such that the aperture is proximate the sample receiving surface to expose at least a portion of a surface of a sample received thereon to be analyzed. 6. The apparatus of claim 1, wherein the sample aperture member comprises an aperture plate defining the aperture, wherein the aperture plate is configured to allow movement between the aperture and the sample receiving surface. 7. A method for reducing the energy of charged particles entering an annular-acceptance analyzer, the method comprising:providing an electrically isolated sample support member having a sample receiving surface to receive a sample and electrically connect the sample to the sample support member, wherein the sample support member is configured for application of a retarding bias potential;positioning a grounded sample aperture member defining an aperture relative to the sample support member but electrically isolated therefrom such that the aperture is proximate the sample receiving surface to expose at least a portion of a surface of a sample received thereon to be analyzed; andapplying a retarding bias potential to the sample support member to produce an electrical retarding field about the aperture that reduces the energy of emitted particles from a sample before they enter the annular-acceptance analyzer. 8. The method of claim 7, wherein applying a retarding bias potential to the sample support member comprises applying a retarding bias potential to the sample support member to produce an electrical retarding field about the aperture that reduces the energy of emitted particles from a sample before they enter the annular-acceptance analyzer and further that modifies the trajectories of such emitted particles such that they enter the cylindrical mirror analyzer in a predetermined range of input elevation angles. 9. The method of claim 7, wherein the electrical retarding field about the aperture comprises a planar portion proximate the surface of the sample to be analyzed and a spherical portion farther from the surface of the sample to be analyzed. 10. The method of claim 9, wherein the method further comprises controlling the relative amounts of the planar portion of electrical retarding field and spherical portion of the electrical retarding field. 11. The method of claim 7, wherein the retarding bias potential is a positive retarding bias potential. 12. The method of claim 7, wherein the electrical retarding field is confined to a region in proximity to the aperture. 13. The method of claim 7, wherein the method further comprises providing a sample on the sample receiving surface that includes a surface to be analyzed that protrudes through and above the aperture. 14. The method of claim 7, wherein the method further comprises providing a sample on the sample receiving surface that includes a surface to be analyzed that is flush with the aperture. 15. The method of claim 7, wherein the method further comprises providing a sample on the sample receiving surface that includes a surface to be analyzed that is below the aperture. 16. The method of claim 7, wherein the method further comprises moving one of the aperture defined by the grounded sample aperture member and the sample receiving surface relative to the other. 17. The method of claim 7, wherein applying a retarding bias potential to the sample support member comprises applying a retarding bias potential to the sample support member to produce an electrical retarding field about the aperture that reduces the energy of high energy emitted particles having kinetic energies greater than 3200 eV such that the energy of at least a portion of the high energy emitted particles is less than 3200 eV before they enter the annular-acceptance analyzer. 18. An analyzer system for use in analyzing a sample, wherein the system comprises:an analyzer apparatus comprising a full or partial annular-acceptance input opening to receive emitted particles from the sample;an electrically isolated sample support member having a sample receiving surface to receive a sample and electrically connect the sample to the sample support member, wherein the sample support member is configured for application of a retarding bias potential from a source; anda grounded sample aperture member defining an aperture, wherein at least a portion of the grounded sample aperture member is positioned between the annular-acceptance input opening of the analyzer apparatus and the sample support member such that the aperture is proximate the sample receiving surface to expose at least a portion of a surface of a sample received thereon to be analyzed, wherein the sample support member is electrically isolated from the grounded sample aperture member, and further wherein the grounded sample aperture member along with the sample support member produce an electrical retarding field about the aperture when a retarding bias potential is applied thereto that reduces the energy of emitted particles from a sample before they enter the annular-acceptance opening. 19. The system of claim 18, wherein the grounded sample aperture member along with the sample support member produce an electrical retarding field about the aperture when a retarding bias potential is applied thereto that reduces the energy of emitted particles from a sample before they enter the annular-acceptance analyzer and further that modifies the trajectories of such emitted particles such that they enter the annular-acceptance analyzer in a predetermined range of input elevation angles. 20. The system of claim 18, wherein the aperture is a circular aperture.
	description	The principal of the invention relates to all types of electromagnetic radiation, i.e., electronically produced X-ray and also gamma-quanta emitted after radioactive decay of naturally radioactive isotopes like Cesium-137, Cobalt-57, Cobalt-60 and all other X-ray emitters. The inventive system is constructed such that the irradiation interacts with the low Z material to obtain as much back scattered radiation as feasible, and with as little absorption of the radiation as practical. The reflector used in the inventive system may be any low Z, high density material; in the various embodiments of the invention, boron carbide, boron and carbon have been used since these three materials appear to be the best for the purpose of the invention. In the embodiment of the invention depicted in FIG. 1, relatively thick (bulk) material from one inch to several inches in thickness is used as the reflector in order to utilize the entire spectrum, i.e., all energies up to 160 keV. In the embodiment where mono-energy gamma-quanta from radioactive decay is used the thickness of the reflector can be precisely calculated to obtain maximum effectiveness. In the embodiment of the inventive system and method as depicted in FIG. 1, an X-ray tube 21 of any suitable known type provides X-rays 22 to irradiate a product/object 23. As described above, the invention is applicable to the other type of irradiation as described above, the principal of the invention is to effectively reuse the photons produced by a source to re-irradiate the product to thereby provide more efficient irradiation system and process. That is, the invention is applicable to various sources of the electromagnetic radiation. The description of the embodiment of FIG. 1 is thus generally inclusive for the other sources mentioned. Referring still to FIG. 1, X-rays 22 are directed to enter (penetrate) the upper surface (as oriented in the drawing) of the product. A portion of the radiation (rays), indicated at 22A, penetrates and exits the product at the opposite or lower surface of product 23. Also, as will be appreciated some of the X-rays also exit at the sides of the product. A radiation reflector 24, comprising a low Z (atomic number), high density material such as boron carbide, boron or carbon is positioned to reflect a major portion of the radiation 22B exiting the product 23 back to irradiate the product, effectively from the bottom upwardly. Note that the term, xe2x80x9chigh density materialxe2x80x9d referred to herein, comprises boron, boron carbide, carbon or the like wherein the density is about 2 to 2.5 gr/cm3. These materials have the highest density amongst the low Z chemical elements. A low Z material is chosen because of lower absorption of the irradiating rays. It is known from physics that the absorption of X-rays and gamma-quanta rises as Z to the 5th power and diminishes by energy as E to the 3.5 power where Z is the atomic number of the absorber and E is the energy of the photons. This means that the low energy photons like X-rays or gramma rays would be highly absorbed by high Z materials. The best absorbers are high Z chemical elements and the best scattering materials, i.e., material with low absorption capability are low Z chemical elements. It is an additional feature of the high density material used that it diminishes the depth of penetration into the reflector material layer thereby permitting the thickness of the reflecting layer to be decreased. The reflector 24 can comprise a planar surface, and/or the reflector 24 may be contoured to better direct the reflected X-rays back to the product, as depicted in FIG. 1. The reflector should be at least three quarters (xc2xe) of an inch in thickness, and in the embodiment described with relation to FIGS. 1, the reflector is 10 cm in thickness (2.54 cms equals to 1 inch). Reflectors of boron carbide, boron and carbon have been used in the inventive system. In one embodiment boron carbide used as the material for the reflector 24 since it is readily available in the marketplace. All three materials mentioned provide excellent results as a reflector of irradiation rays. Importantly, all three materials are quite stable and will not deteriorate with use. Stated in another way, all three materials can withstand the bombardment of the radiation without any substantial alteration in their photon-reflective characteristics. A comparison was made of the outputs of reflectors made from each of the mentioned materials, i.e., and it has been found that the outputs from a pure boron reflector as well as from a carbon reflector follow essentially the output curves of boron carbide. The boron and carbon reflectors actually provide slightly higher peak outputs at the lower energy levels with carbon providing the highest peak outputs. However, as mentioned above boron carbide is used in the embodiment shown because it is generally available, durable and practical. Boron carbide has the highest density (2.52) amongst the three materials noted herein. In the embodiment of FIG. 1, the reflector 24 has its sides or ends 25 angled upwardly, such that the reflected beam is directed to the bottom surface of the product 23, and also to the sides of the product to provide a more uniform irradiation to the entire product. It should be understood that the reflector 24 can be configured to accommodate products of different sizes and shapes. As depicted in FIG. 1A, if the product is circular, the reflector 24 can be configured to have a circular recess 26 and vertical sides 25A of selected thickness, to receive the product and more evenly reflect and re-irradiate its bottom, sides and even the top surface. In the case of electronically produced X-rays, the thickness of the reflector is chosen to effectively reflect the high energy in the broad X-ray spectrum. In the case of a gamma-ray source, it is easier to determine the proper thickness of the reflector, because the thickness can be adjusted (tuned) to only one energy. FIGS. 2 and 3 show the results of tests conducted to quantify the improvement provided by the inventive method and apparatus. The test set-up was modeled to obtain results over a wide band of voltages, i.e., for commercially useful types of systems. It is, of course, known that water is a standard by which useful X-ray irradiation can be measured, particularly when considering irradiation of blood transfusion bags or containers, meat food products and vegetables. The analysis to be described in connection with FIG. 2 and FIG. 3 was on a system such as shown in FIG. 1. Specifically, a four (4) cm thick water equivalent phantom 23 comprising water equivalent polystyrene layers was positioned to receive the radiation provided from the tungsten anode of the X-ray tube 21. The results shown in FIG. 2, were obtained when the product was positioned 10 inches from the output port of tube 21. The layers were located between the X-ray tube and the reflector 24 comprised a 10 cm thick flat boron carbide member. A standard aluminum or copper filter, not shown, filtered the X-rays from X-ray tube 21. In FIG. 1, for purposes of depiction of the X-rays 22 penetrating the product 23 and the depiction of the reflected X-rays 22A, the space between the product 23 and reflector 24 has been exaggerated. Preferably, the upper surface of reflector 24 is placed in a position closely adjacent the bottom surface of the product. For example, when the product is mounted on a conveyor belt, the reflector is mounted immediately below the belt. The test results obtained in FIGS. 2-4, were obtained with the upper surface of the reflector 24 in position essentially abutting the bottom of the phantom product. For the comparisons indicated in FIGS. 2 and 3, the system was first operated without the reflector 24 and readings taken of the data obtained. Next, the reflector 24 was mounted in the system and readings taken of this data. FIG. 2 is a table showing the dose distribution in the 4 cm thick water equivalent phantom product (standard layered phantom comprising suitable layers of plastic) irradiated by a 160 kV X-ray tube. It was found that the dose distribution decreases almost linearly from the top surface to the bottom surface of the phantom. Without a reflector 24 and assigning the value of 100% to the dosage at the top surface, it was found that the dosage at the middle (at the 2 cm thickness) of the phantom was 76% of the dosage at the top of the phantom, and the dosage at the bottom surface was 49%. With the boron carbide reflector 24 placed in position in accordance with the invention as indicated in FIG. 1, the dosage at the middle of the phantom was 90% percent of the dosage at the top surface, and the dosage at the bottom surface was 70% of the dosage at the top surface. That is, the dosage distribution was improved by about 14% at the middle of the phantom and 21% at the bottom of the phantom. The table of FIG. 2 shows the actual increase in the dosage (when using a 160 kV tube) as a result of providing the reflector 24. The graph of FIG. 3 shows the results of calculations indicating the percentage increase as X-ray sources operating at higher kV""s are used. As is known, X-ray tube sources are used in the 160-300 kV range; above 300 kV, electron accelerators are used as the source. In the graph of FIG. 3, the axis of abscissas indicates the kV (voltages) of respective X-ray sources having accelerating voltages varying from 160 kV to 10 MV. The axis of ordinates shows the dose increase in percentage. At a voltage of 160 kV, the percentage increase is about 72.5%; at 300 kV the percentage increase is about 42.5%; and at 1 MV the increase is about 37.5%. Note that the percentage of increase is calculated to remain essentially constant from 1 MV to 10 MV. The table of FIG. 4 shows the dose distribution in a 4-cm water phantom positioned between a 160 kV X-ray tube and a boron carbide reflector. The table shows that, for the system depicted, the reflector compensates for distance variation between the tube and the product. Note that the dose ratio (dose at the top surface/dose at the bottom surface of the product) remains quite level for the distances from 8 inches to 16 inches. In the prior art systems, i.e., systems not using the inventive reflector system, the effective dosage varies as the reciprocal of the square of the distance between the product and the source. Thus a significant feature and an advantage of the inventive system and method are that it compensates for the influence of the increase in distance by between the source and the product by using a radiation reflector. As mentioned above, in prior art systems the effective dosage varies as the reciprocal of the square of the distance (1/r2) i.e., low rxe2x80x94high dose, and high rxe2x80x94low dose where r is the distance between the source and the item or product being irradiated. This of course means that in prior art systems, when the product being irradiated is positioned close to the source, the surface of the product closest to the source receives quite different amounts of radiation than the surface of the product farthest from the source i.e., the uniformity of irradiation becomes worse as the distance between the source and the item is decreased. It can be readily appreciated that in prior art systems, the dose uniformity between the top and bottom surfaces of a product is better when the product is positioned at a greater distance than when it is positioned closely to the source, as can be readily determined mathematically. In such prior art systems there are several variables which may not vary linearly. For example as mentioned, the effective dosage varies as the square of the distance between the tube and the product, the thickness of the product affects the dosage. In contrast to the prior art, in the inventive system the product can be positioned closer to the source and get more radiation in the entire volume of the product without worsening the top/bottom ratio; this is due to the fact that the reflector provides a compensating factor in that the reflector helps the bottom surface obtain more absorbed dose. In the inventive system, the thickness of the reflector also affects the dosage but can also provide a compensating factor. The specific data shown in the tables of FIGS. 2 and 4 may vary somewhat for different voltages, distances, and the thicknesses of the product and reflector. However, calculations indicate the compensating effect indicated in the table is generally applicable when a reflector in accordance with the invention is utilized. It should be understood that the inventive system applies to reflectors using any low Z, high density material although boron, boron carbide and carbon are the best materials to use for the inventive purposes. An important advantage provided by the inventive system and method is that the product is more uniformly irradiated throughout the thickness of the product. Further, the inventive system provides a more even irradiation throughout the surface area of the product, i.e., the inventive system equalizes the doses absorbed by the central area of the product surface and the doses absorbed by the peripheral area of the surface which may be at different distances from the source (see FIG. 1). Federal regulations require that the surface of the product that is farthest away from the ray source be irradiated within a certain range of the irradiation effective at the surface of the product closest to the ray source. The basis for this requirement is that the irradiation applied to various products must be effective to filly penetrate the thickness of the product, and must provide a uniform dose, within prescribed ranges, throughout the thickness of the product. In compliance with these regulations, the inventive system and method provide irradiation to the product from multiple sides by using a unique system and method comprising a single source of radiation and a radiation reflector which provides a more uniform dose to the product, i.e., it tends to equalize and balance the irradiation of the product from a single ray source throughout the surface area and thickness of the product. At present, certain prior art equipment includes two X-ray sources for irradiating a blood transfusion bag. By utilizing the present unique inventive scheme, the same equipment can use one X-ray source with a reflector, rather than two X-ray sources; the advantages are obvious. While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
053612922	claims	1. A condenser system for use with a ring field camera comprising: a small diameter source of radiation; at least three substantially equal radial segments of a parent aspheric mirror, each having one focus at the radiation source and the other focus at the radius of a ring field and each producing a beam of radiation; a number of sets of correcting mirror means, each correcting mirror means comprising correcting mirrors which both translate and rotate, which is one less than the number of aspheric mirror segments, such that one of the beams, an unrotated beam of radiation passes through the real entrance pupil of the camera without interaction with a set of correcting mirrors to form a first segment of a ring image at the ring field radius and the other beams individually interact with one each of the respective sets of correcting mirrors wherein each of the other beams is individually rotated and translated into substantial coincidence with the first segment at the ring field radius. a small diameter source of radiation; at least three substantially equal radial segments of a parent aspheric mirror, each having one focus at the radiation source and the other focus at the radius of a ring field and each producing a beam of radiation; a corresponding number of sets of correcting mirror means which are capable of translation or rotation or both such that all of the beams of radiation pass through the real entrance pupil of the camera about one of the beams to form a coincident ring image at the ring field radius. 2. The system of claim 1 wherein each of the rotated and translated beams passes through the entrance pupil of the camera about the one unrotated beam. 3. The system of claim 1 wherein each of the rotated and translated beams passes through the real entrance pupil of the camera about the one unrotated beam without interferring with another beam. 4. The system of claim 1 wherein the correcting mirrors are located in the beamline between the aspheric mirror segments and the real entrance pupil of the camera. 5. The system of claim 1 wherein the radiation comprises soft x-rays. 6. The system of claim 1 wherein there are five aspheric mirror segments, each of which images about 60 degrees of arc at the ring field radius. 7. The system of claim 1 further including powered imaging mirror means acting upon the one uncorrected and the other corrected beams to locate the combined coincident position of the beams at a specific position at the ring field radius. 8. The system of claim 7 wherein the specific position is onto a reflective mask. 9. The system of claim 1 wherein the correcting mirrors are sets of three grazing-incident mirrors each. 10. The system of claim 1 wherein the correcting mirrors are sets of two mirrors arrayed as roof mirror pairs. 11. The system of claim 10 wherein the uncorrected beam is translated by a set of two mirrors arrayed as a roof mirror pair. 12. The system of claim 1 wherein the aspheric mirror segments reflect their beams through the system centerline. 13. The system of claim 9 wherein the aspheric mirror segments reflect their beams through the system centerline. 14. The system of claim 11 wherein the aspheric mirror segments reflect all their beams but one parallel to the system centerline. 15. The system of claim 1 wherein all the beams are at or near their minimum cross-sections at the point where they pass through the real entrance pupil of the camera. 16. A condenser system for use with a ring field camera comprising: 17. The system of claim 16 wherein the beams pass through the real entrance pupil without overlapping. 18. The system of claim 17 wherein all the beams are at or near their minimum cross-sections at the point where they pass through the real entrance pupil of the camera.
	claims	1. A nuclear power plant comprising:a nuclear reactor containment structure defining an interior space in which a nuclear reactor is located;a cooling vessel comprising a water tank located outside the nuclear reactor containment structure, wherein the water tank comprises a portion that is lower than the bottom of the interior space of the nuclear reactor containment structure;water contained in the water tank:a vapor release pipe connecting between the interior space of the nuclear reactor containment structure and the water tank, the vapor release pipe being configured to transfer vapor from the interior space to the water tank based on a pressure difference between the interior space and the water tank; anda water return pipe connecting between the water tank and the interior space of the nuclear reactor containment structure, the water return pipe being configured to transfer water from the water tank to the interior space of the nuclear reactor containment structure based on a water head difference between water contained in the water tank and water in the interior space of the nuclear reactor containment structure,wherein the water is contained in the water tank only in the portion such that the water head in the water tank is lower than the bottom of the interior space of the nuclear reactor containment structure such that the water would not automatically flow from the water tank to the nuclear reactor containment structure during normal operation of the nuclear power plant,wherein in the event of an accident, the vapor release pipe is configured to transfer vapor from the interior space to the water tank where it condenses, which causes the water head in the water tank to rise to a level higher than the bottom of the interior space of the nuclear reactor containment structure such that is automatically returned to the interior space of the nuclear reactor containment structure from the water tank even in the absence of pumping. 2. The nuclear power plant of claim 1, wherein the water tank has a bottom surface lower than the bottom of the interior space such that the water tank has a volume configured to contain water under the level of the bottom surface of the interior space sufficient to maintain the water head in the water tank lower than the bottom surface of the interior space for about 3 hours after vapor begins to be transferred from the nuclear reactor containment structure to the water tank. 3. A cooling system of a nuclear power plant, comprising:a pressure vessel located outside a nuclear reactor containment structure, the pressure vessel having a water tank, the nuclear reactor containment structure defining an interior space for housing a nuclear reactor, wherein the water tank comprises a portion that is lower than the bottom of the interior space of the nuclear reactor containment structure;water contained in the water tank;a release pipe connecting between the interior space of the nuclear reactor containment structure and the water tank, the release pipe being configured to transfer water vapor and fission products generated in the nuclear reactor containment structure in the event of an accident to the water tank;a water return pipe connecting between the water tank and the interior space of the nuclear reactor containment structure, the water return pipe being configured to transfer water from the water tank to the interior space based on a water head difference between water contained in the water tank and water in the interior space of the containment structure,wherein the water is contained in the water tank only in the portion such that the water head in the water tank is lower than the bottom of the interior space of the nuclear reactor containment structure such that the water would not automatically flow from the water tank to the nuclear reactor containment structure during normal operation of the nuclear power plant,wherein in the event of an accident, the release pipe is configured to transfer vapor from the interior space to the water tank where it condenses, which causes the water head in the water tank to rise to a level higher than the bottom of the interior space of the nuclear reactor containment structure such that water is automatically transferred to the interior space of the nuclear reactor containment structure from the water tank even in the absence of pumping. 4. The cooling system of claim 3, wherein the pressure vessel is provided with one or more heat-radiation fins. 5. The cooling system of claim 3, wherein a cooling pool containing water for cooling the pressure vessel is formed around a lower portion of the pressure vessel. 6. The cooling system of claim 3, further comprising an exhaust pipe connected to the pressure vessel such that gas generated within the pressure vessel is discharged out thereof through the exhaust pipe. 7. The cooling system of claim 6, wherein the pressure vessel comprises a filter for removal of fission products. 8. The cooling system of claim 7, wherein the pressure vessel comprises a moisture separator located beneath the filter. 9. The cooling system of claim 3, wherein the release pipe is provided with a release isolation valve located inside the containment structure and a release valve located outside the containment structure. 10. The cooling system of claim 3, wherein the water return pipe is provided with a recovery isolation valve located inside the containment structure, and a recovery valve located outside the containment structure. 11. The cooling system of claim 3, further comprising a supply tank connected to the pressure vessel by a supply pipe, the supply pipe configured to supply water to the water tank of the pressure vessel. 12. The cooling system of claim 11, wherein:the supply tank comprises a temperature sensor configured for sensing a temperature in the water tank; andthe supply pipe is provided with a supply valve which is configured to open the supply pipe when the temperature in the water tank is equal to or greater than a set temperature. 13. The cooling system of claim 3, further comprising a gas recovery pipe connected to the pressure vessel and the containment structure such that gas generated within the pressure vessel flows into the containment structure. 14. The cooling system of claim 3, further comprising:a gas tank containing non-condensable gas and connected to the release pipe, wherein in the event of an accident, the gas tank is configured to release the non-condensable gas into a flow of water vapor and fission products from the containment structure such that the non-condensable gas is released into water contained in the water tank together with the water vapor and fission products for preventing undesirable water hammer from occurring; anda bypass pipe connecting between the containment structure and the pressure vessel while bypassing the gas tank. 15. The cooling system of claim 14, wherein the bypass pipe further comprises a bypass valve to control opening and closing of the bypass pipe. 16. The cooling system of claim 14, wherein the bypass pipe is connected to a position higher than the level of the condensed water in the pressure vessel. 17. The cooling system of claim 14, wherein the release pipe comprises a second release valve located between a portion from which the bypass pipe diverges and a portion to which the pressure vessel is connected. 18. The nuclear power plant of claim 14, wherein the non-condensable gas is nitrogen gas.
	abstract	A heat transfer (exchange) composition comprising a halide salt matrix having dispersed therein nanoparticles comprising elemental carbon in the absence of water and surfactants, wherein said halide is fluoride or chloride, wherein the halide salt may be an alkali halide salt (e.g., lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, sodium chloride, potassium chloride, rubidium chloride, and eutectic mixtures thereof) or an alkaline earth halide salt (e.g., fluoride or chloride salt of beryllium, magnesium, calcium, strontium, or barium), and wherein the nanoparticles comprising elemental carbon may be solid or hollow, and wherein the composition may further include nanoparticles comprising a fissile material (e.g., U, Th, or Pu) dispersed within the composition. Molten salt reactors (MSRs) containing these heat transfer compositions in coolant loops in thermal exchange with a reactor core, as well operation of such MSRs, are also described.
	abstract	A radiation collimator for use in either radiation-emitting devices (e.g., radiation therapy) or radiation-sensing imagery devices (i.e., gamma/X-ray cameras) is disclosed. The collimator's interior surface is basically a cylinder or a truncated cone, whereas its exterior shape is generated by the revolution of the graph of a function about the cylinder's symmetry axis, that function being determined such that the attenuation in the center of the sensor is constant as seen from any direction. The collimator is a body of revolution. The said collimator improves collimation and image resolution when compared to cylindrical, pinhole, laminar, or to other art collimators.
	description	1. Technical Field This invention pertains generally to a nuclear reactor internals structure and more particularly to components such as fuel rods that employ an active ingredient within a cladding that is held in position by a plenum spring. 2. Related Art The primary side of nuclear reactor power generating systems which are cooled with water under pressure comprise a closed circuit which is isolated and in heat exchange relationship with a secondary side for the production of useful energy. The primary side comprises the reactor vessel enclosing a core internal structure that supports a plurality of fuel assemblies containing fissile material, the primary circuit within heat exchange steam generators, the inner volume of a pressurizer, pumps and pipes for circulating pressurized water; the pipes connecting each of the steam generators and pumps to the reactor vessel independently. Each of the parts of the primary side comprising a steam generator, a pump, and a system of pipes which are connected to the vessel form a loop of the primary side. For the purpose of illustration, FIG. 1 shows a simplified nuclear reactor primary system, including a generally cylindrical reactor pressure vessel 10 having a closure head 12 enclosing a nuclear core 14. A liquid reactor coolant, such as water, is pumped into the vessel 10 by pump 16 through the core 14 where heat energy is absorbed and is discharged to a heat exchanger 18, typically referred to as the steam generator, in which heat is transferred to a utilization circuit (not shown), such as a steam driven turbine generator. The reactor coolant is then returned to the pump 16, completing the primary loop. Typically, the plurality of the above described loops are connected to a single reactor vessel 10 by reactor coolant piping 20. An exemplary reactor design is shown in more detail in FIG. 2. In addition to the core 14 comprised of a plurality of parallel, vertical, co-extending fuel assemblies 22, for purposes of this description, the other vessel internal structures can be divided into the lower internals 24 and the upper internals 26. In conventional designs, the lower internals' function is to support, align and guide core components and instrumentation as well as direct flow within the vessel. The upper internals restrain or provide a secondary restraint for the fuel assemblies 22 (only two of which are shown for simplicity in this figure), and support and guide instrumentation and components, such as control rods 28. In the exemplary reactor shown in FIG. 2, coolant enters the reactor vessel 10 through one or more inlet nozzles 30, flows down through an annulus between the vessel and the core barrel 32, is turned 180° in a lower plenum 34, passes upwardly through a lower support plate 37 and a lower core plate 36 upon which the fuel assemblies 22 are seated and through and about the assemblies. In some designs, the lower support plate 37 and the lower core plate 36 are replaced by a single structure, the lower core support plate, at the same elevation as 37. The coolant flow through the core and surrounding area 38 is typically large on the order of 400,000 gallons per minute for a four loop plant (generally, the flow rate is approximately 100,000 gallons per minute per loop), at a velocity of approximately 20 feet per second. The resulting pressure drop and frictional forces tend to cause the fuel assemblies to rise which movement is restrained by the upper internals, including a circular upper core plate 40. Coolant exiting the core 14 flows along the underside of the upper core plate 40 and upwardly through a plurality of perforations 42. The coolant then flows upwardly and radially to one or more outlet nozzles 44. The upper internals 26 can be supported from the vessel or the vessel head and include an upper support assembly 46. Loads are transmitted between the upper support assembly 46 and the upper core plate 40 primarily by a plurality of support columns 48. A support column is aligned above a selected fuel assembly 22 and perforations 42 in the upper core plate 40. The rectilinearly moveable control rods 28 typically include a drive shaft 50 and a spider assembly 52 of neutron poison rods that are guided through the upper internals 26 and into aligned fuel assemblies 22 by control rod guide tubes 54. The guide tubes are fixedly joined at one end to the upper support assembly 46 and connected at the other end to the top of the upper core plate 40 by a split pin force fit into the top of the upper core plate 40. The pin configuration provides for ease of guide tube assembly and replacement if ever necessary and assures that the core loads, particularly under seismic or other high loading accident conditions are taken primarily by the support columns 48 and not the guide tubes 54. This support column arrangement assists in retarding guide tube deformation under accident conditions which could detrimentally affect control rod insertion capability. FIG. 3 is an elevational view, represented in vertically shortened form, of a fuel assembly being generally designated by reference character 22. The fuel assembly 22 is the type used in a pressurized water reactor and has a structural skeleton which, at its lower end, includes a bottom nozzle 58. The bottom nozzle 58 supports the fuel assembly 22 on a lower core support plate 36 in the core region of the nuclear reactor. In addition to the bottom nozzle 58, the structural skeleton of the fuel assembly 22 also includes a top nozzle 62 at its upper end and a number of guide thimbles 54, which extend longitudinally between the bottom and top nozzles 58 and 62 and at opposite ends are rigidly attached thereto. The fuel assembly 22 further includes a plurality of transverse grids 64 axially spaced along and mounted to the guide thimbles 54 (also referred to as guide tubes) and an organized, array of elongated fuel rods 66 transversely spaced and supported by the grids 64. Although it cannot be seen in FIG. 3, the grids 64 are conventionally formed from orthogonal straps that are interleaved in an egg-crate pattern with the adjacent interface of four straps defining approximately square support cells through which the fuel rods 66 are supported in transversely spaced relationship with each other. In many conventional designs, springs and dimples are stamped into the opposing walls of the straps that form the support cells. The springs and dimples extend radially into the support cells and capture the fuel rods there between; exerting pressure on the fuel rod cladding to hold the rods in position. Also, the assembly 22 has an instrumentation tube 68 located in the center thereof that extends between and is mounted to the bottom and top nozzles 58 and 62. With such an arrangement of parts, fuel assembly 22 forms an integral unit capable of being conveniently handled without damaging the assembly of parts. As mentioned above, the fuel rods 66 in the array thereof in the assembly 22 are held in spaced relationship with one another by the grids 64 spaced along the fuel assembly length. Each fuel rod 66 includes a plurality of nuclear fuel pellets 70 and is closed at its opposite ends by upper and lower end plugs 72 and 74. The pellets 70 are maintained in a stack by a plenum spring 76 disposed between the upper end plug 72 and the top of the pellet stack. The fuel pellets 70, composed of fissile material, are responsible for creating the reactive power of the reactor. The cladding which surrounds the pellets functions as a barrier to prevent the fission byproducts from entering the coolant and further contaminating the reactor system. To control the fission process, a number of control rods 78 are reciprocally moveable in the guide thimbles 54 located at predetermined positions in the fuel assembly 22. Specifically, a rod cluster control mechanism 80, positioned above the top nozzle 62, supports the control rods 78. The control mechanism has an internally threaded cylindrical hub member 82 with a plurality of radially extending flukes or arms 52. Each arm 52 is interconnected to the control rods 78 such that the control rod mechanism 80 is operable to move the control rods vertically in the guide thimbles 54 to thereby control the fission process in the fuel assembly 22, under the motive power of control rod drive shafts 50 which are coupled to the control rod hubs 80, all in a well known manner. As previously mentioned, the fuel assemblies are subject to hydraulic forces that exceed the weight of the fuel rods and thereby exert significant forces on the fuel rods and the fuel assemblies. In addition, there is significant turbulence in the coolant in the core caused by mixing vanes on the upper surfaces of the straps of many grids, which promote the transfer of heat from the fuel rod cladding to the coolant. The substantial flow forces and turbulence can result in severe vibration of the fuel rod cladding if motion of the fuel rods is not restrained. Recently, a concern has been expressed about small pellet chips found in the fuel rod plenum in a fraction of fuel rods following back fill and sealing during manufacture. An investigation suggests that one mechanism responsible for top pellet chipping is non-uniform pressure distribution on the top surface of the fuel pellets. It was concluded that the end coil of the plenum spring does not make perfect contact with the top pellet. This leads to some part of the top pellet surface experiencing a significant axial load which could cause chipping. This affect was confirmed during pressure tests. It should be noted that the plenum spring design cannot provide uniform pressure distribution on the top surface of the pellet that it interfaces with due to limited contact area corresponding to the end coil spring geometry. A better view of the plenum spring 76 can be had by reference to FIG. 4 which clearly shows the end coil geometry 84. Accordingly, an improved means of holding down the fuel pellets within the fuel element cladding is desired that will provide uniform pressure on the upper surface of the top pellet. Furthermore, such an improved design is desired that will facilitate installation, limit consequences of unlikely installation mistakes and minimize potential performance issues. These and other objects are achieved by an improved elongated reactive member, such as a fuel element or control rod, for use in a nuclear core. The reactive member is formed from a tubular cladding substantially extending the elongated length of the reactive member with a top end plug sealing off a top end of a central hollow cavity of the tubular cladding and a bottom end plug sealing off a bottom end of the central hollow cavity of the tubular cladding. An active element substantially occupies a lower portion of the central hollow cavity and a spring substantially extends between the top end plug and an upper surface of the active element, pressuring the active element toward the lower end plug. A spacer is positioned between a lower end of the spring and the upper surface of the active element, spreading the force of the spring over a larger portion of the upper surface of the active element than would be applied by the spring directly. In one embodiment, the spring is a ground torsion spring and preferably the spring is either mechanically or metallurgically attached to the spacer. Preferably, the spacer has a substantially flat head facing the upper surface of the active element and an opposite side that extends in an axial direction of the elongated dimension of the cladding with the opposite side being attached to the spring. Desirably, a distal portion of the opposite side has a width that is smaller than the width of the head and a fillet is formed between the width of the head and the width of the distal portion. In another embodiment, an opening extends through the head from a side facing the upper surface of the active element through the spacer and out the distal end of the opposite side. Preferably, at least a portion of the opening has a hex contour. In one embodiment where the spring is mechanically attached to the spacer, a spiral thread extends axially along a radial surface of the opposite end of the spacer and a lower portion of the spring is wound around the spiral thread. In another embodiment, where the spring is mechanically attached to the spacer, an upper portion of the opposite side of the spacer is a split tube with an outwardly, radially extending lip that mechanically attaches to the spring. In one embodiment the reactive member is a nuclear fuel element and in still another embodiment, the reactive member is a nuclear control rod. Preferably, the spacer is substantially round and spaced from the inner wall of the cladding. To achieve the foregoing objectives, this invention introduces an intermediate part between the plenum spring and top pellet of the fuel pellet stack to create a uniform contact distribution and reduce chip migration potential between the fuel rod plenum and the pellet stack. The new intermediate element between the top pellet and the spring end coil is designed to provide a uniform pressure distribution and reduce chip migration potential. Desirably, this element is attached to the existing plenum spring. In one embodiment, illustrated in FIGS. 5 and 6, the intermediate element is a threaded spacer 86 that forms an interface between the plenum spring and the top surface of the top pellet. The spacer 86 is designed to provide a uniform contact pressure over its substantially flat head 88, on the top surface of the top pellet and reduce the potential for small pellet chip migration. The threaded spacer also has features to facilitate the spacer to spring assembly process. The threaded spacer 86 has a central hole 90 to facilitate proper fuel rod pressurization in an unlikely event where the plenum spring assembly is incorrectly installed and to prevent any related performance issues. If the fuel rod is not properly pressurized with He it could experience a reduction in diameter due to the high system external operating pressure that is not compensated by the proper fuel rod internal pressure, which could reduce the holding forces applied by the fuel assembly grid springs. Also, improper pressurization can lead to increased fuel element operating temperatures, due to lower thermal conductivity between the pellets and the cladding, possibly resulting in excessive clad corrosion and potential fuel melting. Any of these performance issues can lead to fuel rod failure resulting in an undesirable fission product release into the coolant. The central hole 90 has a hex contour 92 at its opening in the flat head 88 to facilitate coupling the rear tubular portion of the spacer 86 to the spring 76. The rear tubular portion has a spiral thread 94 that extends from the opposite end 96 just short of the rear side of the head 88. A hexed tool can be inserted in the hex opening 92 to wind the spacer 86 onto the plenum spring 76 until the end coil seats snuggly on the back of the head 88. Desirably, the threaded spacer 86 is one machined piece that basically comprises two functional regions in the fuel element axial direction: a pellet/clad interface region 88 and a spring interface region 98. Preferably, the total length of the spacer 86 should prevent rotation of the spacer inside of the cladding. The pellet/clad interface 88 maximum diameter of the spacer should be less than the pellet minimum outside diameter under all conditions to ensure that the spacer does not compromise clad structural integrity. Preferably, the pellet/clad interface 88 maximum length, i.e., the dimension in the fuel element axial direction, should be as minimal as practically possible. The pellet/clad interface length minimum value is limited by the ability to uniformly distribute the spring force and distortion during manufacturing. The maximum value of the pellet/clad interface length is limited by the additional spring compression and rod internal pressure penalty. Generally, the plenum spring is compressed during fuel rod fabrication to a pre-determined force within a range of forces for each fuel rod type. The maximum force within the range is established to assure the structural integrity of the fuel rod welds and pellets. A force above the maximum set by the range could impair the ability to produce a proper end plug weld. The amount of compression of the plenum spring is controlled by the plenum length. The free volume within the fuel element cladding has to accommodate the fission gases released during reactor operation. Therefore, any reduction in plenum volume will result in increases in fuel rod internal pressure over its operating life, which may lead to an unpredicted fuel rod outer diameter increase resulting in a decrease in thermal conductivity between the cladding and the pellets. The pellet/clad interface region 88 will reduce the plenum length and plenum volume and increase the plenum spring deflection/force and rod internal pressure. It was confirmed that the length of the pellet/clad region of the spacer is acceptable so long as it is factored into the design of the spring. A fillet radius 100 should be present between the back side of the head 88 and the tubular section 102 to prevent pressure concentration at the pellet to spacer bearing surface. The thread dimensions and profile on the spring interface 98 depends upon the spring design to allow for proper fit between the spring wire and the thread profile. The thread vanish zone is the area between the thread 94 and the fillet 100 and the thread vanish zone diameter plus two times the spring interface fillet radius should not exceed the minimum spring inner diameter to ensure proper interface between the spring end coil and the spacer 86. The central hole 90 diameter should be present to allow for fuel rod pressurization in case of “incorrect” assembly installation and the hex size should be sufficient to apply the required torque during assembly. The torque should be sufficient to prevent the spacer “from becoming” loose during shipping and handling and to mitigate spring damage during installation. Pressure tests have demonstrated that the spacer is able to provide a uniform pressure distribution and confirm that the spacer design reduces small pellet chipping frequency. Additionally, the fuel rod plenum spring assembly design of this embodiment is capable of meeting the design objectives to provide a uniform pressure distribution in pellet-to-spacer contact and to reduce the potential for small pellet chip migration. The design also includes features to facilitate spacer installation, limit consequences of unlikely installation mistakes and minimize potential performance issues. FIGS. 7, 8 and 9 show alternate embodiments to the threaded spacer illustrated in FIGS. 5 and 6. The embodiments illustrated in FIGS. 7, 8 and 9 each have the same flat head 88 as was previously described with regard to the threaded spacer shown in FIGS. 5 and 6. In FIGS. 7 and 8, the rear side of the spacer is a slotted tubular member 106 with the embodiment shown in FIG. 7 having the slots spaced 180° apart while the embodiment in FIG. 8 has the slots spaced 90° apart. Each of the two embodiments has a lip 108 that fits over a rung of the spring 76 to secure the spacer to the spring. In the embodiment shown in FIG. 9, the head 88 is welded directly to the end coil of the plenum spring 76. 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. For example, though the previous embodiments have described as being applied to a nuclear fuel element, the spring and spacer assembly taught herein can be applied to control rods as well, wherein the active element will be a neutron absorber rather than the fissile fuel pellets. Accordingly, the particular embodiments 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.
052971821	description	DETAILED DESCRIPTION Referring now to the drawings in detail and initially to FIG. 1, a nuclear reactor is indicated generally at 10. The nuclear reactor 10 comprises a vessel, indicated generally at 12, defining a chamber 13, a fuel core 14 situated within the chamber 13, and reactor internals 18 also situated within the chamber 13. The vessel 12 includes a main body portion 20 and a top closure head 22 coupled thereto. The illustrated vertical orientation of the vessel 12 is maintained by a bracing system which includes legs 24 mounted on the floor of the reactor building. The main body portion 20 of the vessel 12 includes inlet/outlet nozzles 26 which are surrounded by thick flanges 27 for integrity purposes and which are connected to the appropriate plant lines 28. In FIG. 2, the nuclear reactor 10 is shown after preparatory steps of the decommissioning process have been completed. These preparatory steps include uncoupling the top closure head 22 from the main body portion 20 and draining the fluid from the reactor chamber 13 through the appropriate nozzle(s) 26. Additionally, the fuel core 14 is removed in any suitable manner, and probably in the same manner as that used during annual replacements. Still further, the plant lines 28 are severed from their respective nozzles 26 and metal plates 30 are welded over the severed open ends of the nozzles 26. Referring now to FIGS. 3-8, a method of decommissioning the nuclear reactor 10 according to the present invention is shown. This method includes the steps of encapsulating portions of the vessel 12 and reactor internals 18 into a solid reactor capsule 50 and then converting this reactor capsule 50 into a plurality of decommissioned segments 100. The conversion step of this decommissioning process includes a cutting stage in which the reactor capsule 50 is cut into transportable-size segments and an encasing stage in which the transportable-size segments are encased to form the decommissioned segments. In some situations, the cutting stage will comprise a primary "capsule-cutting" procedures in which the reactor capsule 50 is cut, preferably sequentially, into a series of sections 50A-50L and a secondary cutting procedures in which each of these sections is further cut into a plurality of transportable-size segments. It should be noted that "cut" in this context corresponds to any sectioning, segmenting, or dividing process in which a component is converted into a plurality of pieces. Decommissioning the nuclear reactor 10 according to the present invention provides several advantages over prior art decommissioning processes. For example, the cutting of the vessel 12 and the reactor internals 18 occurs substantially simultaneously thereby reducing the decommissioning time and cost. In fact, the preferred method provides for removal of both the reactor vessel 12 and the reactor internals 18 for essentially the same cost as individually removing either of these components. Additionally, during the cutting steps, and during all subsequent steps of the decommissioning process, the reactor internals 18 are embedded in a material which functions as a radioactive shield whereby worker interaction and environmental exposure to contaminated components is minimized when compared to prior art procedures involving the cutting of isolated reactor internals. Still further, "in-house" lifting equipment may be used instead of specially fabricated units which will usually substantially reduce the overall cost of the decommissioning project. The encasing step of the method will eliminate the need for shipping casks in many situations thereby reducing total disposal cost. These advantages will become more apparent in the following detailed discussions of the stages of the preferred decommissioning process. i. Encapsulating Stage In the "encapsulating" stage of the decommissioning process, the relevant portions of the vessel 12 and the reactor internals 18 are encapsulated to create the solid reactor capsule 50 shown in FIG. 3. "Encapsulate" in this context corresponds to converting the relevant portions of the nuclear reactor 10 into a solid, substantially integral mass. In the illustrated and preferred embodiment, the relevant portions of the vessel 12 include substantially all of the main body portion 20 and all of the reactor internals 18. The encapsulating stage of the process preferably includes a matrix-forming step in which a matrix 51 is formed within the relevant portions of the reactor chamber 13. This matrix 51 integrally attaches to the vessel 12 and integrally embeds the reactor internals 18 to create the solid reactor capsule 50. When the capsule 50 is created in this manner, it will have an outer shell 52 which substantially encases a solid center 54. The shell 52 is formed from the main body portion 20 of the vessel 12 and the center 54 is formed from the matrix 51 and the reactor internals 18 embedded therein. The matrix 51 is preferably formed by providing a fluidized matrix-creating material which may be predictably solidified and which functions as a radioactive shield in its solid state. The matrix-creating material is introduced into the chamber 13 by pouring it through the open top of the main body portion 20 or, alternatively, by pumping it through one or more of the nozzles 26. The introduced matrix-creating material is then solidified in such a manner that it integrally attaches to the vessel 12 and integrally embeds the reactor internals 18. (In some instances the integral attachment to the vessel may be accomplished simply by the "tight fit" of the matrix material within the vessel). Concrete is the illustrated and preferred matrix-creating material because it performs well as a matrix, it is compatible with the subsequent cutting steps and, perhaps most importantly, it functions quite effectively as a radioactive shield. When concrete is used as the matrix-creating material, the "solidifying" step entails simply waiting for the concrete to cure. The relevant portions of the nuclear reactor 10, such as the main body portion 20 of the vessel 12 and the reactor internals 18, preferably remain in their operating orientation and operating location during the encapsulating stage. For these reasons, applicants believe that in most, if not all, nuclear settings, the support system of the nuclear reactor will be sufficient to securely hold the capsule 50 in this position. In this regard, it is interesting to note that reactor capsule 50, although carrying the additional burden of the matrix 51, will be relieved of the weight of the reactor core and the circulating fluid sustained by the reactor 10 during on-line operation. Consequently, the weight differential between the on-line nuclear reactor 10 and the reactor capsule 50 will be substantially less than the weight of the matrix 51. Moreover, nuclear regulatory codes consistently require that reactors be supported in a manner which is capable of withstanding pressures substantially exceeding operating parameters and seismic loading. In any event, the encapsulating step of the decommissioning process creates a solid reactor capsule 50 having a shell 52, which is formed from a portion of the vessel 12, and a solid center 54 which is formed from the radioactive shielding matrix 51 and the reactor internals 18 embedded therein. ii. Capsule-Cutting Stage After completion of the encapsulating stage of the decommissioning process, the reactor capsule 50 is cut into sections 50A-50L as is shown schematically in FIG. 4. It is important to note that during this cutting step, and during all subsequent steps of the decommissioning process, the reactor internals 18 are encased in the matrix 51 which functions as a radioactive shield in its solid state. Thus, worker interaction and environmental exposure to contaminated components is minimized when compared to prior art procedures involving the cutting of isolated reactor internals. As is shown in FIG. 4, the sections are essentially "coin-shaped38 and the size, or more particularly, thickness, of these sections is preferably chosen so that they may be manipulated within the reactor building with existing equipment. Thus, in most instances, the size of the sections will be determined by the lifting capacity of a semi-permanent building crane, which in a typical nuclear power plant would probably be less than 400 tons. The use of "in-house" lifting equipment, rather than specially fabricated units, will usually serve to substantially reduce the overall cost of the decommissioning project. The preferred relative size and shape of the sections 50A-50L is illustrated schematically in FIG. 4, and, as shown, the sections 50A, 50B, 50D, 50E, 50F, 50H, 50I, 50J and 50K are formed by substantially horizontal cutting lines. In such a cutting arrangement, the shell 52 of the reactor capsule 50 (which is formed by the portions of the vessel 12) and the matrix 51 of the capsule 50 (which includes the reactor internals 18) will both be cut by a single cutting line. Thus, in contrast to prior art decommissioning methods, the cutting of the vessel 12 and the reactor internals 18 occurs substantially simultaneously. The remaining illustrated sections 50C, 50G and 50L are also formed by substantially horizontal cutting lines which create coin-shaped sections. However, the sections 50C, 50G, and 50L, which are substantially thicker than the other sections, are then cut into semi-sections by vertical cutting lines. More particularly, section 50C is cut into semi-sections 50C.sub.1 and 50C.sub.2, section 50G is cut into semi-sections 50G.sub.1 and 50G.sub.2, and section 50L is cut into semi-sections 50L.sub.1 and 50L.sub.2. The reason for the different treatment of these sections 50C, 50G and 50L, is that they each contain at least one inlet/outlet nozzle 26 and thus, a corresponding annular flange 27. The cutting of the sections 50C, 50G and 50L into semi-sections eliminates the need to cut directly through the sometimes massive flanges 27. The capsule-cutting steps are preferably accomplished with a diamond wire cutting system such as that marketed under the name "Trentec." The Trentec diamond wire system comprises a diamond matrix wire made to length for each individual cut and a hydraulic drive apparatus. The diamond wire is routed to envelope the cut area and then the wire is guided back to a drive wheel located on the hydraulic drive apparatus. The drive wheel rotates and pulls the wire through the cut area. The Trentec cutting system is particularly suited for the present method because it lends to substantially remote operation whereby worker interaction with contaminated components may be minimized. Additionally, the dust and/or particles created by the Trentec cutting system are practically nonexistent when compared to other conventionally used cutting techniques. Consequently, HEPA ventilation and the need to wear respirators during cutting operations is eliminated because airborne contamination will not be generated. Furthermore, because the equipment may be lubricated solely with a small volume of cooling water, any liquid radioactive waste may be minimized by recirculating the cooling water through settling drums designed to collect any radioactive debris. Still further, the illustrated cutting arrangement coordinates very efficiently with the Trentec cutting technique. More particularly, the cutting wire may be positioned at a predetermined location or level on the capsule 50 and appropriately pulled to cut the capsule 50 and form the first section 50A. Thereafter, the cutting wire may be moved downwardly by a pulley-system to the next "cutting" level to perform a subsequent cut and form the second section 50B. The same pulleys may be rearranged and used for the vertical cuts on sections 50C, 50G and 50L. When concrete is used as the matrix-creating material, the material make-up of the reactor capsule 50 will be extremely compatible with the Trentec cutting system which is specifically designed for the removal of concrete. It may be additionally noted that in the "water platform" decommissioning method, the Trentec diamond cutting wire was not used to cut the submerged reactor internals because their mounting allowed them to vibrate, or "wobble", during the cutting process. Consequently, the benefits of the Trentec cutting system, such as low airborne contamination and uncomplicated lubrication, could not be enjoyed in the past. However, in the present invention, the embedding of the reactor internals 18 in the matrix material eliminates any vibration whereby the advantages of the Trentec cutting system may be realized. Moreover, a concrete matrix appears to additionally facilitate the sawing process because it provides a substantially uniform density across the cutting line and extremely compatible surface qualities. In the preferred method of decommissioning the nuclear reactor 10, the primary-cutting stage of the process will begin with the capsule 50 being cut to create the top, or first, section 50A. This first section 50A is then transferred to a location away from the direct locality of the remaining portion of the capsule, such as an appropriate secondary cutting station within the reactor building. Upon transfer of the first section 50A, the remaining portion of the reactor capsule 50 is cut to form the second section 50B, and this section is then transferred away from the direct locality of the now remaining portion of the capsule 50. This sequence is repeated until all of the sections 50A-50L have been created and transferred. The transfer of the sections/semi-sections 50A-50H will preferably be performed with existing equipment, such as the building crane discussed above. As such, the sections 50A-50L will have to be rigged to accommodate the crane, or supplied with lifting lugs which may be coupled to the crane. Although the lugs could possibly be attached after a particular section has been cut from the reactor capsule 50, they are preferably attached prior to this cutting step after the location of the cutting lines has been determined. More particularly, the lugs may be welded to the capsule shell 52 prior to the capsule-cutting and/or they may be welded to the vessel 12 prior to the encapsulating step. A representative section, namely the second section 50B, is illustrated in detail in FIG. 5 and, as shown, the section 50B includes an outer annular ring 52B, or more generally a parametrial frame, having an integral filling 54B. The annular ring 52B is formed from a slice of the capsule shell 52, and thus was originally part of the reactor vessel 12. The integral filling 54B is formed from a slab of the capsule center 54, and thus includes a layer of the radioactive shielding matrix 51 and pieces 18B of reactor internals embedded therein. It may be noted for future reference that the exposed surfaces of the filling 54B, namely the axial end faces 56B, are substantially planar. iii. Secondary-Cutting Stage As was indicated above, the size and shape of the sections/semi-sections 50A-50L will usually be chosen to maximize the efficiency of the primary lifting equipment, i.e., the building crane. However, this particular geometry may substantially exceed the parameters necessary to safely transport the decommissioned reactor components to a disposal site. For example, if the lifting capacity of the utilized crane is 120 tons, this will be reflected in the cutting of the reactor capsule 50 whereby each section/semi-section will preferably weigh approximately 120 tons. At the same time, shipping requirements could very well dictate that the transported pieces weigh a maximum of approximately 30 tons. Additionally, a sometimes related, but often independent, consideration is the sizing of the section to be transported relative to the available access openings in the reactor building, the loading dock area and/or the transporting vehicle. For this reason, the decommissioning method may include secondary-cutting steps in which the sections/semi-sections 50A-50L are further cut into transportable segments. For the purposes of this discussion, it is assumed that the representative section 50B is too heavy/wide for transportation purposes and that segments of approximately a quarter of this weight/width would be transportable. Accordingly, as is shown in FIG. 6, the section 50B is cut, preferably equally, into four segments 50B.sub.1, 50B.sub.2, 50B.sub.3, and 50B.sub.4 at an appropriate cutting station. The appropriate cutting station for the section 50B, as well as sections 50A, 50C-50G and 50L would probably be a dry cutting station. The appropriate cutting station for sections 50H-50K, which correspond to the fuel-containing area of the nuclear reactor 10, would probably be a wet cutting station. In either event, the secondary cutting is preferably accomplished by the Trentec cutting technique due to its low air/water contamination and undemanding lubrication needs. The geometry of the segment 50B.sub.1 is probably best described as being shaped like a "pie-piece." The segment 50B.sub.1 includes a 90.degree. ringlet 52B.sub.1 and a quadrant 54B.sub.1 projecting therefrom, or, in more general terms, a frame fragment 52B.sub.1 and an integral extension 54B.sub.1. The ringlet 52B.sub.1 is formed from a piece of the annular ring 52B of the segment 50B, and thus is formed from the reactor vessel 12. The quadrant 54B.sub.1 is formed by cutting a quarter piece of the integral filling 54B and thus is formed from the radioactive matrix 51 and the reactor internal pieces 18B.sub.1 embedded therein. The ringlet 52B.sub.1 surrounds and covers the curved circumferential surface of the quadrant 54B.sub.1 while its axial end faces 56B.sub.1, as well as its radial side faces 58B.sub.1, are exposed. These exposed surfaces 56B.sub.1 and 58B.sub.1 are all substantially flat or planar, and each is bordered by edges of the ringlet 52B.sub.1. The remaining segments 50B.sub.2, 50B.sub.3, and 50B.sub.4 will have essentially identical characteristics. In the illustrated example, the size and shape of the segments 50B.sub.1, 50B.sub.2, 50B.sub.3, and 50B.sub.4 is assumed to meet transporting requirements whereby no further cutting is necessary. However, in the event that a further reduction in size/weight was necessary, the segments would be further cut until an appropriate geometry was achieved. The secondary cutting steps are preferably performed in a similar manner on the other sections of the reactor capsule 50 so that the exposed surfaces of the respective matrix slabs are all substantially flat or planar, and each is bordered by edges of a ringlet formed from the reactor vessel 12. In other words, the further cutting would result in transportable-size segments which are shaped like a "pie-piece." iv. Encasing Stage The final stage of the conversion of the reactor capsule 50 into a plurality of decommissioned segments entails encasing the transportable-size segments. This encasing stage particularly involves covering the exposed surfaces of the integral extension 54B.sub.1 so that the transportable-size segment is fully encased, or decommissioned. The preferred encasing procedure is shown in FIGS. 7A-7C in which the transportable-size segment 52B.sub.1 is used for the purposes of explanation. The encasing procedure particularly includes providing rectangular steel sheets 60B.sub.1 dimensioned to cover the radial surfaces 58B.sub.1 of the segment 52B.sub.1. (See FIG. 7A). Each of the sheets 60B.sub.1 includes a first pair of opposite edges 62B.sub.1 and a second pair of opposite edges 64B.sub.1. Because the exposed surfaces 58B.sub.1 are flat, the sheets 60B.sub.1 may likewise be flat whereby their formation is uncomplicated. The steel sheets 60B.sub.1 are then welded to the segment 52B.sub.1 to cover the exposed surfaces 58B.sub.1. More particularly, one of the sheets 60B.sub.1 is placed over one of the surfaces 58B.sub.1 and the edge 62B.sub.1 abutting the ringlet 52B.sub.1 is welded thereto, and the other sheet 60B.sub.1 is placed over the other surface 58B.sub.1 and its edge 62B.sub.1 abutting the ringlet 52B.sub.1 is welded thereto. In this arrangement, the opposite edges 62B.sub.1 of each of the rectangular sheets will meet at a corner and are welded to each other at this corner. (See FIG. 7B). The encasing procedure further includes providing steel sheets 66B.sub.1 which are shaped and sized to cover the axial end faces 56B.sub.1 of the segment 52B.sub.1. (Again, because the exposed surfaces 56B.sub.1 are flat, the sheets 66B.sub.1 may likewise be flat whereby their formation is uncomplicated.) In the illustrated embodiment, this shape will be in the form of a triangle having two equal sides 68B.sub.1 and a rounded base 69B.sub.1. One sheet 66B.sub.1 is placed over each of the faces 56B.sub.1, and its sides 68B.sub.1 are welded to the abutting edges 64B.sub.1 of the rectangular sheets 60B.sub.1. Additionally, the rounded bases 69B.sub.1 of the sheets 66B.sub.1 will be welded to the abutting edges of the ringlet 52B.sub.1. In this manner, the integral extension 54B.sub.1, and thus the pieces 18B.sub.1 of the reactor internals embedded therein, are totally encased to form the decommissioned segment 100 shown in FIG. 8. If the preferred cutting steps are used, the encasing procedure will be conceptually the same regardless of the sectioning needed to create transportable segments. For example, if further cutting of the segment 52B.sub.1 is necessary to meet transporting requirements, the encasing procedure for the resulting "pie-piece" segments would be essentially identical to that described above, except that the dimensions of the base side 69B.sub.1 of the top/bottom sheets 66B.sub.1 would be appropriately reduced. (The dimensions of the sides 68B.sub.1 of the sheets 66B.sub.1 and the overall shape and size of the rectangular sheets 60B.sub.1 would remain the same). Likewise, if "semi-sections" of the section 50B were of an appropriate transportable size, a single rectangular sheet (which is approximately twice as long as each of the rectangular sheets 60B.sub.1) and two semi-circle sheets would be used in the encasing procedure. Additionally, in the event that section 50B was of a transportable size (and thus itself constituted a transportable-size segment), the encasing procedure would entail placing circular sheets over the exposed faces 56B and the circumferential edges of these circular sheets would be welded to the abutting edges of the ring 52B. Thus, regardless of the size and shape of the transportable segment, the encasing procedure will produce a decommissioned segment 100 having a casing 102 which totally encases a solid interior chamber 104. The casing 102 will include at least one wall 52B.sub.1 which is formed from a portion of the vessel 12 and the interior chamber 104 will include a chunk of the matrix 51 which is integrally attached to the wall 52B.sub.1 and which integrally embeds pieces of the reactor internals 18 therein. This encasing step maintains the intactness of the segment and/or provides radiation shielding of the reactor internals contained therein. In many situations, this encasing in combination with the matrix 51 will eliminate the need for shipping casks thereby reducing total disposal cost. v. Closing One may now appreciate that the present invention provides a method of decommissioning a nuclear reactor 10 which may significantly reduce man-rem exposure and may substantially decrease the time and capital expenditure of a decommissioning project. The cutting of the vessel 12 and the reactor internals 18 occurs substantially simultaneously thereby reducing the decommissioning time and cost. Additionally, during the cutting steps, and during all subsequent steps of the decommissioning process, the reactor internals 18 are embedded in the radioactive shield matrix 51 whereby exposure to contaminated components is minimized. Still further, the method allows the use of "in-house" lifting equipment and eliminates the need for separate shipping casks in many situations. Although the invention has been shown and described with respect to a certain preferred embodiment, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. For example, the method could be used for disassembling any nuclear device, (such as a steam generator used in conjunction with a pressurized water reactor) which includes a receptacle defining a cavity and radiation-exposed internal components positioned within the cavity. The present invention includes all such equivalent alterations and modifications and is limited only by the scope of the following claims.
	abstract	Lightweight and rigid, leaded or lead-free integral radiation shielding structural compositions comprising two or more radiation attenuating elements or compounds thereof, selected for having compatible radiation attenuating characteristics, dispersed in a thermoplastic or thermoset resin. The radiation shielding structural compositions of the present invention can be used to functionally and structurally replace lead-lined structures in medical and industrial x-ray systems. The radiation shielding structural compositions of the present invention can also be formulated to minimize the density of the resulting structure.
	claims	1. A nuclear reactor plant which includesa helium cooled nuclear reactor positioned in a cavity defined by a shell; anda closed loop liquid cooling system which includesat least one coolant chamber defined by a wall having ends which are sealed off respectively by a top and a bottom and positioned in the cavity adjacent to the nuclear reactor;a pump having an inlet side and an outlet side;a coolant inlet pipe which is connected in flow communication with the outlet side of the pump and which enters the coolant chamber through the top and extends downwardly through the coolant chamber to a discharge end positioned within the coolant chamber; an outlet leading from the coolant chamber which is connected in flow communication with the inlet side of the pump; andat least one anti-siphon bleed opening provided in that portion of the coolant inlet pipe positioned in the coolant chamber at a position spaced from the discharge end whereby the coolant inlet pipe and the coolant chamber are connected or connectable in flow communication. 2. A nuclear reactor plant as claimed in claim 1, which includes an anti-siphon valve mounted in the inlet pipe. 3. A nuclear reactor plant as claimed in claim 1, in which a plurality of anti-siphon bleed openings are provided in that portion of the coolant inlet pipe which is positioned at the highest level within the coolant chamber. 4. A nuclear reactor plant as claimed in claim 3, in which the anti-siphon bleed openings are in the form of holes in the coolant inlet pipe, said holes having a combined area of between 1% and 10% of the cross-sectional area of the coolant inlet pipe. 5. A nuclear reactor plant as claimed in claim 3, in which the inlet pipe has a nominal diameter of 100 mm and between four and eight anti-siphon bleed openings are provided therein. 6. A nuclear reactor plant as claimed in claim 3, in which the bleed openings are circular and have a diameter of between 5 mm and 10 mm.
052532780	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to fuel assembly, channel box, production method of the channel box and core of nuclear reactor. More particularly, the present invention relates to fuel assembly, channel box, production method of the channel box and core of nuclear reactor which will be suitable for a boiling water reactor. 2. Description of the Prior Art Each fuel assembly used in a boiling water reactor is equipped with upper and lower tie plates, a plurality of fuel rods whose both end portions are supported by these tie plates, fuel spacers for bundling these fuel rods and a channel box encompassing the bundle of fuel rods and fitted to the upper tie plate. The fuel assembly is loaded into the core of the nuclear reactor. A pressure loss is different inside and outside the fuel assembly during the reactor operation and a pressure difference occurs between the inner and outer surfaces of the channel box. This pressure difference is greater at the lower end portion of the fuel assembly and the pressure acting on the inner surface of the channel box is greater than the pressure acting on its outer surface. Therefore, the channel box expands outward and undergoes large creep deformation with the passage of the operation time of the nuclear reactor. This creep deformation will possibly result in the increase in a flow rate of leaking cooling water from between the channel box and the lower tie plate and in the trouble of a control rod operation. One of the methods to cope with creep deformation of the channel box disposes recesses (or projections) on the sidewalls of the channel box as described in Japanese Patent Laid-Open Nos. 58487/1975 and 13894/1979 and in U.S. Pat. No. 3,715,274. Japanese Patent Laid-Open No. 58487/1975 discloses a channel box equipped on its sidewalls with projections that project inward and thinly in a horizontal direction. Rigidity of this channel box is improved in a direction orthogonal to an axis. U.S. Pat. No. 3,715,274 teaches to dispose corrugated portions having concavo-convexities that repeat in an axial direction, on the sidewall portions of the channel box opposing the lower tie plate. Japanese Patent Laid-Open No. 13894/1979 shows in its FIGS. 3 and 4 a channel box equipped with projections which project inward and are disposed above, and in the proximity of, the upper surface of the lower tie plate and at a position of 1/3 of the full length of a fuel rod from the lower end of the fuel rod. The number of these projections is the same as that of a large number of tabs disposed on a band of a fuel spacer, and they are disposed at the same level and have a width capable of passing through the tabs. These tabs come into contact with the inner surface of the channel box and support the fuel spacer in a horizontal direction. FIGS. 7 and 8 of Japanese Patent Laid-Open No. 13894/1979 show the structure wherein a large number of projections described above are disposed on the sidewall portions of the channel box facing the lower tie plate. The lower tie plate is equipped on its outer side surface with a large number of grooves into which the projections described above are fitted. In accordance with Japanese Patent Laid-Open No. 58487/1975 and U.S. Pat. No. 3,715,274, the height of the projections from the inner surface of the channel box in a direction vertical to an axis is limited to a range such that the projections can pass through the gap between the inner surface of the channel box and the support tabs disposed on the fuel spacer. When outwardly projecting projections are dispose on the channel box, too, the height of the projections cannot be much increased in order to avoid interference with a control rod. As higher burnup of a fuel assembly and reutilization of a channerl box have been attempted recently, the residence time of the channel box inside a core tends to remarkably increase. Therefore, the increase in strength for inhibiting creep deformation of the channel box has been all the more desired than in the prior art. The channel box disclosed in Japanese Patent Laid-Open No. 58487/1975 and U.S. Pat. No. 3,715,274 cannot satisfy this requirement because the height of the projections cannot be increased much more than the height described above. The projection disclosed in Japanese Patent Laid-Open No. 13894/1979 has a width such that the projection can pass through the gap between the tabs disposed on the fuel spacer. Accordingly, the height of this projection can be made greater than that of the two prior art references described above. However, the width of each projection positioned at the same level is limited by the gap between the tabs in the horizontal direction. Therefore, the degree of the increase in strength by the projection in Japanese Patent Laid-Open No. 13894/1979 is not much great and fails to satisfy the requirement described above. Furthermore, in accordance with the structure disclosed in Japanese Patent Laid-Open No. 13894/1979, each of the projections disposed on the channel box must be passed through the gap between the tabs disposed on each of a plurality of fuel spacers disposed in an axial direction when the channel box is fitted to a fuel bundle. Therefore, fitting of the channel box is troublesome and time-consuming. SUMMARY OF THE INVENTION It is a first object of the present invention to provide a fuel assembly, a channel box and a core of a nuclear reactor capable of reducing further creep deformation of a channel box. The object described above can be accomplished by a channel box which has spacer support means projecting inward and supporting a fuel spacer in a direction vertical to an axis. Since the channel box is equipped with the spacer support means, the height of creep deformation inhibition portions (the height in the direction vertical to the axis) formed on the channel box can be increased and moreover, the width of the creep deformation inhibition portions in the transverse direction of the sidewalls of the channel box can be increased without being limited by the spacer support means. Accordingly, strength of the channel box can be increased remarkably and creep deformation of the channel box can be drastically reduced.
062467395	description	DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a schematic side view of a nuclear reactor 10 which includes a reactor pressure vessel 12 supported by a reactor support 14. Pressure vessel 12 and reactor support 14 separate a lower drywell 16 from an upper drywell 18. A plurality of connecting vents 20 (two shown in FIG. 1) extend through reactor support 14 and are located circumferentially around reactor support 14. Each connecting vent 20 includes an outer wall 22 which defines a bore 24 extending through connecting vent 20. Connecting vent bore 24 provides for flow communication between lower drywell 16 and upper drywell 18. During a theoretical severe accident condition, for example, a melt down outside reactor pressure vessel 12, radioactive aerosols may be formed, primarily in lower drywell 16. These radioactive aerosols are transported to upper drywell 18 through connecting vents 20. To minimize the migration of these aerosols from lower drywell 16 to upper drywell 18, a passive aerosol retention apparatus 30, illustrated in FIG. 2, is positioned in each connecting vent 20. Referring to FIG. 2, aerosol retention apparatus 30 includes a substantially cylindrical housing 32 and a flow modulator 34 positioned inside housing 32 and extending at least partially from a first end 35 to a second end 37 of housing 32. Flow modulator 34 includes a helically shaped baffle 36 positioned inside housing 32 so as to be coaxial with housing 32. Helical baffle 36 is coupled at each end to housing 32 by attachment bars 38. Particularly, helical baffle 36 is attached at each end to an attachment bar 38, usually by welding. Attachment bars 38 are coupled at each end to housing 32. Attachment bars 38 are coupled to housing 32 by welding, mechanical fasteners, or the like. In one embodiment, the diameter of helical baffle 36 is less than the inside diameter of housing 32. Typically, an angle A, formed by the intersection of helical baffle 36 and a radial plane B extending perpendicular to a longitudinal plane passing through the longitudinal axis of housing 32, is about 30 to about 60 degrees. In an alternative embodiment, housing 32 is connecting vent outer wall 22. Aerosol retention apparatus 30 is fabricated from any suitable material, for example, stainless steel and INCONEL Ni--Cr--Fe alloy. In one embodiment, aerosol retention apparatus 30 is fabricated from stainless steel. In operation, aerosol retention apparatus 30 are positioned in connecting vents 20 that are located between lower and upper drywell 16 and 18. Helical baffle 36 of aerosol retention apparatus 30 imparts a rotational component to the steam, gas and aerosol mixture as the mixture flows from lower drywell 16 to upper drywell 18. The resulting tangential acceleration imparted to the aerosol particles causes the aerosol particles to be thrown against an inside surface 40 of housing 32 of apparatus 30. The insoluble aerosol particles then may adhere to inside surface 40 of housing 32 or drop back into lower drywell 18. The aerosol particles that impact housing 32, agglomerate and build-up on inside surface 40 of housing 32 and then are transported back into lower drywell 18 because only a thin layer of aerosol particles can be maintained on the vertical inside surface 40 of housing 32 due to gravity and the tendency of the agglomerated particles to be transported by sedimentation flows. FIG. 3 is a perspective side view, with parts cut away, of an aerosol retention apparatus 42 in accordance with another embodiment of the present invention. Similar to aerosol retention apparatus 30 described above, apparatus 42 includes a substantially cylindrical housing 44 and a flow modulator 46 positioned inside housing 44. Cylindrical housing 44 includes an inside surface 48. Flow modulator 46 includes a first section 50 and a second section 52. First section 50 of flow modulator 46 includes a helical shaped baffle 54 similar to helical baffle 36 described above. Helical baffle 54 is positioned inside housing 44 and extends from a first end 56 of housing 44 through a first portion 58 of housing 44. Helical baffle 54 is coupled at each end to housing 44 by attachment bars 60. Second section 52 of flow modulator 46 includes a plurality of baffle plates 62 (three shown in FIG. 3) extending inwardly from inside surface 48 of housing 44. Baffle plates 62 are spaced axially and longitudinally from each other. Each baffle plate 62 is an arced segment ranging from about 90 to about 120 degrees as measured from the longitudinal axis. Each baffle plate 62 extends at a right angle from inside surface 48 of housing 44. Specifically, each baffle plate 62 extends from inside surface so as to be within a radial plane perpendicular to a longitudinal plane passing through the longitudinal axis of housing 44. In an alternative embodiment, housing 44 is connecting vent outer wall 22. FIG. 4 is a side schematic view, with parts cut away, of a passive aerosol retention device 64 in accordance with still another embodiment of the present invention. Similar to aerosol retention apparatus 42 described above, apparatus 64 includes a substantially cylindrical housing 66 and a flow modulator 68 positioned inside housing 66. Cylindrical housing 66 includes an inside surface 70. Flow modulator 68 includes a first section 72 and a second section 74. First section 72 of flow modulator 68 includes an inlet swirler 76. FIG. 5 shows a perspective view of inlet swirler 76. Referring to FIGS. 4 and 5, inlet swirler 76 includes a central conical shaped portion 78 and a plurality of curved vanes 80 extending from central conical portion 78. Each vane 80 extends longitudinally from a first end 82 to a second end 84 of conical portion 78. Second end 84 of conical portion 78 is adjacent to second portion 74 of flow modulator 68. Also, each vane 80 extends radially from central conical portion 78 to inside surface 70 of housing 66. Curved vanes 80 impart a spin to the steam, gas, and aerosol mixture, as the mixture flows from the lower drywell to the upper drywell, causing the aerosol particles to be separated from the mixture. Inlet swirler 76 is coupled to housing 66 by attachment collar 86 and vanes 80. Particularly, central conical portion 78 is coupled to attachment collar 86 by vanes 80 and collar 86 is attached to housing 66. Also, vanes 80 are coupled to housing 66. Housing 66 is configured so that the diameter at a first end 88 is less than the diameter of housing 66 at second section 74 of flow modulator 68. Similar to flow modulator 46, described above, second section 74 of flow modulator 68 includes a plurality of baffle plates 90 (four shown in FIG. 4) extending inwardly from inside surface 70 of housing 66. Baffle plates 90 are spaced axially and longitudinally from each other. Each baffle plate 90 is an arced segment ranging from about 90 to about 120 degrees as measured from the longitudinal axis. Each baffle plate 90 extends at a right angle from inside surface 70 of housing 66. Specifically, each baffle plate 90 extends from inside surface so as to be within a radial plane perpendicular to a longitudinal plane passing through the longitudinal axis of housing 66. In an alternative embodiment, housing 66 is connecting vent outer wall 22. From the preceding description of various embodiments of the present invention, it is evident that the objects of the invention are attained. Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is intended by way of illustration and example only and is not to be taken by way of limitation. Accordingly, the spirit and scope of the invention are to be limited only by the terms of the appended claims.
	claims	1. A method for producing 225Ac using an accelerator, the method comprisinga. producing a beam of particles along an axis, whereby the beam is maintained at between about 70 and 8000 MeV;b. impinging the particles on a plurality of target sheets, each target sheet containing 232Th, wherein each of said plurality of target sheets is arranged such that surfaces of each of said plurality of target sheets is spaced apart and approximately parallel to each other, and the surfaces are arranged at an angle greater than 0 and less than 10 degrees relative to the beam's axis; andc. producing approximately 10 Ci of 225Ac per 100 grams of 232Th in the plurality of target sheets during each day of irradiation. 2. The method as recited in claim 1 wherein the each of the target sheets of 232Th comprise a thorium metal, or a thorium compound, or a combination of the two. 3. The method as recited in claim 1 wherein the particles are subatomic entities or elements selected from the group consisting of ions of hydrogen, hydrogen isotopes, helium, helium isotopes and combinations thereof. 4. The method as recited in claim 1 wherein the beam is produced at a power level of from about 1 kW to 1 MW. 5. The method as recited in claim 1 wherein the beam is maintained at 200 MeV energy, the particles are protons, and a net yield of approximately 1.4 Ci of 225Ac are produced per gram of 232Th in the plurality of target sheets after 15 days of irradiation. 6. The method as recited in claim 1 wherein the energy imparted to the particles is varied while the ion current of the particles remains constant. 7. The method as recited in claim 1 wherein the rate of 225Ac production is about 8E12 per second at a beam power level of 100 kW and 200 MeV proton beams. 8. The method as recited in claim 1 wherein the plurality of target sheets is contacted with proton particles maintained at from 100 to 250 kW each. 9. The method as recited in claim 1 further comprising a heat sink interlineated with the plurality of target sheets. 10. The method as recited in claim 9 wherein the heat sink is a fluid which contacts the surfaces of the target sheets. 11. The method as recited in claim 9 wherein the heat sink is a fluid selected from the group consisting of liquid water, helium gas, liquid metal and combinations thereof. 12. The method as recited in claim 1 wherein a cross section of each target sheet is sized close to the cross section of the particle beam such that substantially the entire cross section of each target sheet opposes the beam. 13. The method as recited in claim 1 wherein the beam energy is 100 MeV, the beam power is 100 kW and about 1500 curies per year are produced. 14. The method as recited in claim 1, wherein each target sheet has a substantially uniform thickness of between zero and one millimeter and each target sheet is spaced apart from each other by a space of up to one millimeter.
	description	This application is a divisional application of U.S. patent application Ser. No. 12/617,051, “Mixed-Layered Bismuth-Oxygen-Iodine Materials For Capture And Waste Disposal of Radioactive Iodine”, filed Nov. 13, 2009, which claims the benefit of U.S. Provisional Application No. 61/114,113, “Mixed Bismuth Compounds for Iodine Capture”, filed Nov. 13, 2008; which is incorporated by reference herein. The United States Government has rights in this invention pursuant to Department of Energy Contract No. DE-AC04-94AL85000 with Sandia Corporation. The invention relates generally to methods and materials for disposal of radioactive iodine wastes from nuclear reactor fuel cycles, as well as capture and immobilization of non-radioactive iodine species. Radioactive 129I is one of the longer-lived fission products (1.6×107 years) resulting from the generation of nuclear energy, and it is also one that is associated with considerable public concern by virtue of the obvious mechanism whereby it may become concentrated in the human body. Historically, 129I was simply discharged to the atmosphere. Currently, iodine is discharged to the ocean (principally the seas around Europe) for isotope dilution with the natural iodine in seawater. With the growth of research on advanced fuel cycles in the United States and abroad, there is a strong interest in the separations and waste form development for all radioisotopes that are isolated in the developing nuclear cycles. This includes the initial trapping of gaseous iodine radioisotopes, and their incorporation into waste forms. Whether wastes are slated for above ground storage, or underground burial, a serious need is that the radionuclides (129I, in our case) exist in chemical forms that will not be readily dissolved should water gain access to the site. A second major consideration is that the wastes not exist as powders, since an accident during storage or handling could produce a cloud of radioactive dust with the potential for causing widespread contamination. A number of research groups have investigated the complex crystal structures of layered bismuth oxy-iodide compounds. In particular, the researchers focused on the subtle, yet related, differences in the topography of the bismuth oxide layers, and the stacking around the iodine complexes located between the layers (see FIG. 1). Due to the high measured stability limits of bismuth carbonates and iodides with respect to saline groundwater, recent research in Canada has focused on the use of individual bismuth oxyiodide compounds as candidates for radioactive iodine waste forms. Hence, a need exists for improved methods of synthesizing mixed-layer bismuth oxyiodine and oxy-iodate materials for use in the in-situ recovery of radioactive iodine from caustic waste streams and/or final waste form. In particular, we are focused on the use of these mixed-layer Bi—O—I waste forms if repository conditions are at temperatures at, or below, those under which the iodine was initially captured. The invention relates to materials and methods of synthesis of mixed-layered bismuth oxy-iodine materials, in an effort to develop materials for iodine recovery from caustic waste streams (e.g., NaOH or KOH) and/or for final waste disposal; in particular, if repository conditions included ambient temperatures similar to those under which the iodine was initially captured. The results presented involve the in-situ crystallization of layered bismuth oxide compounds with aqueous dissolved iodine (which resides as both iodide (I−) and iodate (IO3−) forms in solution). Although individual bismuth oxy-iodide compounds (e.g., BiOI) have already been described in the context of capturing radioiodine, our contribution is the unexpected discovery that there are mixed-layered bismuth oxy-iodine materials that optimize both the uptake of iodine and the degree of insolubility (and un-leachability) of iodine in water. These optimized mixed-layered Bi—O—I materials are suitable as a durable waste form for repository conditions such as are predicted at the Yucca Mountain repository (YMP), or in a similar type of repository that could be developed in coordination with iodine production via DOE/Nuclear Energy-Fuel Cycle R&D Program (FCR&D) and Global Nuclear Energy Program (GNEP, currently focused on US-foreign interactions only) production cycles. This technology provides a one-step process for both iodine sequestration and storage for nuclear fuel cycles or non-nuclear industrial processes. By properly controlling reactant concentrations, optimized compositions of the mixed-layered bismuth oxy-iodine materials can be made that have both a high iodine weight percentage and a low solubility in normal groundwater environments. The general term “bismuth oxy-iodine compounds” is broadly defined herein to include both the iodide (I−) and iodate (IO3−) forms of iodine. The term “mixed-layered Bi—O—I materials” and “mixed-layered bismuth oxy-iodine materials” are interchangeable. Our novel technology generally involves the in-situ crystallization of layered bismuth oxide compounds (See FIG. 1) with aqueous dissolved iodine (which resides as both iodide and iodate in solution). Although individual bismuth oxy-iodide compounds (e.g., BiOI) have already been described in the context of capturing radioiodine, our unique contribution is the unexpected discovery that there are mixed-layered Bi—O—I materials, not described in the prior work, which optimize both the uptake of iodine and the degree of insolubility (and un-leachability) of iodine. When optimized, these mixed-layered Bi—O—I materials are durable materials that are especially suitable as a waste forms for repository conditions, such as are predicted at the Yucca Mountain repository (YMP) or in a similar type of repository that could be developed in coordination with iodine production via advanced nuclear fuel production cycles (or other fuel storage and reprocessing technologies). In this work, we identified two (known) layered bismuth oxy-iodide lattice types (lattice phases), i.e., BiOI and Bi5O7I, as primary building blocks in our synthesized mixed-layered Bi—O—I materials. The proportions (relative to each other) of the known lattice phases, BiOI and Bi5O7I, (and possibly additional, unknown Bi—O—I lattice phases) was optimized by to produce a series of intimately mixed layered Bi—O—I materials that have both high iodine uptake in aqueous solutions, and minimal leachability of the iodine component. Leachability concerns in predicted repository conditions include temperatures below 100° C., and in contact with groundwater (aqueous environment) containing competing ions of chloride and carbonate. The meaning of our term “mixed-layered Bi—O—I materials” is different than a simple mechanical mixture (i.e., combination) of individual BiOI or Bi5O7I particles. Instead, the term “mixed-layered Bi—O—I materials” means a “chemical assemblage at an atomistic or molecular scale of at least two different Bi—O—I lattice types or lattice phases.” The “at least two different Bi—O—I lattice types or lattice phases” could be BiOI, or Bi5O7I, or they could be other Bi—O—I lattice phases that haven't yet been identified. The optimized mixed-layered Bi—O—I materials that we made were synthesized under the general mild precipitation method of adding a mixture of Bi(NO3)3+HNO3+KI (or KIO3) into a basic solution (e.g., with NaOH or KOH). The resultant precipitates were aged at elevated temperature (e.g., 70-90° C. for 24 hours, and they ranged in color from yellow to orange depending on composition ranges. The heated solution begins at mild basic pH (approximately >7), and then falls with time to become acidic (pH≈3-4). The solid settles and the solution is decanted off. The solids were repeatedly washed/soaked with DI water until the ionic strength drops and the solids remain in suspension. At this point, the wet slurry was dried at 90° C. for 12 hours, or until completely dry. The methodology we developed for this discovery used a series of varying bismuth-to-iodine ratios in the different mixes that were progressively increased in 10% increments. Ideally, the sample with the greatest content of iodine should have had a Bi:I molar ratio of 1:1, conducive to forming the compound BiOI, if all of the iodine had reacted with the bismuth. In reality, complete uptake of iodine stopped in the mixture of lattice phases in the series at sample #7, and synthesis of pure BiOI was never achieved. Unexpectedly, we discovered that the optimum composition of the mixed-layered Bi—O—I materials fell in the middle of the “1-10” series, (i.e., samples 4, 5, 6), rather than at either end of the spectrum. These three optimized materials incorporated 17-22 wt % iodine into their structures. The relative representations of Bi5O7I and BiOI lattices in the optimized materials were determined by X-Ray Diffraction, XRD, and the elemental compositions were established by X-Ray Fluorescence (XRF). In the optimized materials (samples 4, 5, 6) the relative contributions of the two known bismuth oxyiodide lattice phases were calculated to be: 15-20 mole % Bi5O7I and 85-80 mole % BiOI. Also, the three samples, which had the highest amount of incorporated iodine, also had the lowest solubility of all the materials' combinations when exposed to chloride, sulfate, and carbonate-containing solutions (simulants for possible groundwater contaminants). This last result is quite surprising, because according to Taylor and Lopata, in “Stability of Bismuth Oxyiodides in Aqueous Solutions at 25° C.”, CAN. J. CHEM. Vol. 64, 1986, pp. 290-294, they found: “From the viewpoint of radioactive iodine immobilization, the most important conclusion is that Bi5O7I is seven orders of magnitude more stable than BiOI towards hydrolysis.” However, in our synthesized optimum materials, the highest stability (lowest iodine solubility) was achieved with a very different proportion, i.e., 15-20 mole % Bi5O7I and 85-80 mole % of BiOI (opposite from what Taylor would have predicted from their work). Method of Synthesis All chemicals were used as received without further purification from Fisher Scientific—Certified. In house analytical testing used for characterizing the composition and solubility of the iodine loaded on inorganic bismuth waste forms include: (1) Orion specific ion electrode, (2) PerkinElmer Elan 6100 ICP-MS (3) X-ray fluorescence ARL (Thermo) QUANT'X EDXRF Analyzer, (4) TA Instruments STD Q666 Simultaneous DTA-TGA, (5) Powder X-ray (XRD) Bruker AXS-D8 Advance powder diffractometer. Leaching studies were carried out by a generalized deionized water solubility test (similar to the modified Product Consistency Test Procedure B (PCT test, American Society for Testing and Materials Standards. Standard Test Method for Determining Chemical Durability of Nuclear, Hazardous, and Mixed Waste and Glasses. The Product Consistency Test (PCT), 2008 Annual Book of ASTM Standards. American Society for Testing and Materials Standards, West Conshohocken, Pa., 2008.) method in which powders of the resultant bismuth oxyiodide mixtures were leached in deionized water. A 10 wt % (10 g water/1 g solid) solution of the bismuth powdery material is suspended in DI H2O, and heated at 90° C. for 24 hours in a screw top Teflon container. The resultant liquid was analyzed by ICP-MS (or specific iodine electrode) for leached iodine, and the pH was measured on the cooled solution using a standard pH electrode. Three series of samples (i.e., the “41” series, the “42” series, and the “1-10” series) were prepared by dissolving bismuth nitrate (e.g., as Bi(NO3)3.5H2O) and potassium iodide, mixing them in various ways, and then causing a precipitate to form by occasionally adding a basic solution made with sodium hydroxide (or with any alkali or alkaline earth oxide or hydroxide). Other bismuth salts can be used in place of bismuth nitrate (e.g., bismuth trichloride). Specific details of preparation are given below: Appropriate amounts of solid bismuth nitrate and potassium iodide (KI) salts were added dry to a bottle. Samples 41A and 41B had Bi-to-I ratios appropriate to making Bi5O7I (Bi:I=5); 41C and 41D appropriate to making Bi7O9I3 (Bi:I=2.33); and 41E and 41F appropriate to making Bi4O5I2 (Bi:I=2.00). Then, DI water (˜50 ml) was added and the mixes put on a shaker at room temperature for about an hour. Finally, alternately in every other sample, an aliquot (˜22 ml) of 1 M NaOH (samples 41 B, D, F), or an approximately equal amount of deionized water (samples 41 A, C, E), was added. The mixes were then set back on the shaker overnight. The next afternoon they went into the oven (along with the “42 Series” mixes) to age over the weekend at 90° C. After three days, the samples were cooled to room temperature, the supernate was decanted off, and the heated solids were rinsed repeatedly with deionized water. At the end of the process the supernates from 41B, 41D and 41F were still strongly basic (blue pH paper), while 41A, 41C and 41E were quite acid (red pH paper). Table 1 summarizes the composition and XRD results. TABLE 1Composition and Characteristics of Series “41” and “42” Samples:Chemical AnalysisPrep:25-35by XRFby XRFbyNaOHdeg.I/BiBi/IDesignAdded~8.6 A2-ThetamolarmolarBi:IIntensityColor?PeakPeaks41A0.0061595lightbrownnomajor5, 1 major41B0.2144.685mediumorangeyestrace6, 3 major41C0.011912.33darkorangenomajor4, 1 major41D0.4332.312.33darkorangeyestrace,3 majorshifted41E0.0071402lightbrownnosmall4, 3 major41F0.5201.922darkorangeyestrace,6, 5 majorshifted42A0.0091145mediumbrownnomajor5, 3 major42B0.2134.695lightyellowyesnone5, 3 major42C0.015682.33darkbrownnomajor5, 3 major42D0.4052.472.33lightorangeyesnone5, 1 major42E0.024422darkbrownnomajor5, 1 major42F0.5211.922lightorangeyesnone2 major Mixes 42 A-F were designed to have the same Bi:I ratios as in the “41 Series”, but the order in which the constituents were mixed was different. First, the appropriate amounts of bismuth nitrate salts were placed in the bottles, and then an aliquot (˜22 ml) of either 1 M NaOH (samples 42 B, D, F) or deionized water (samples 42 A, C, E) was added. Then, 50 ml of deionized water was added to each bottle, and the mixes put on a (room temperature) shaker for 15 minutes. Generally, a white, milky slurry formed as the bismuth nitrate dissolved and hydrolyzed. Finally, the appropriate amounts of KI were added as a solid salt, and the bottles returned to the shaker for about two hours. Samples were then placed in the 90° C. oven over the weekend. The following Monday, the samples were cooled to room temperature, the supernate was decanted off, and the heated solids were rinsed repeatedly with deionized water. At the end of the process the supernates from 42B, 42D and 42F were still strongly basic (blue pH paper), while 42A, 42C and 42E were quite acid (red pH paper). See results in Table 1. The “1-10” series samples were prepared as follows. In this instance, rather than trying to mix Bi and I in specific proportions chosen to mimic known bismuth oxyiodine compounds, the Bi to I ratio was stepped up progressively in small (i.e., 10%) increments. As shown in Recipe #1, these samples were prepared by dissolving bismuth nitrate and potassium iodide in deionized water, and then bringing the pH to near 7 by adding sodium hydroxide (and occasionally back titrating with a little acetic acid when adding the standard aliquot of NaOH resulted in a pH significantly above 7). Samples were then incubated in the 90° C. oven overnight. The bismuth to iodine ratios in the different mixes (samples 1-10) were increased by 10% increments, so that the sample with the greatest content of iodine would have had a Bi:I molar ratio of 1.4 (conducive to forming the compound Bi7O8I5), if all of the iodine had reacted with the bismuth. However, analysis of the post-synthesis fluids indicated, however, that complete uptake of iodine stopped with the 7th sample in the “1-10” series, so that the synthesis of Bi7O8I5 was not actually achieved in samples #8, 9, or 10. The results are shown in Table 2. 1. Label sample bottles #1 through 10; 2. Add 4 g (+/−0.1 g) of Bismuth Nitrate, Bi(NO3)3.5H2O, into each of the ten bottles; 3. Add 50 ml of deionized water to each bottle; 4. Put them on a shaker for 20-40 minutes; 5. Add X grams of potassium iodide (KI) individually to the appropriate bottle, according to the following: Sample No.X grams of KI10.13720.27430.41140.54850.68460.82170.95881.09591.232101.369 6. Shake, record the color produced, then shake for 30 minutes, record color; 7. Add 20 ml of 1 M NaOH to each bottle, shake for 1 hour or overnight, and record color; 8. Place in oven and heat at 90° C. for overnight or over the weekend; 9. Cool the bottles to room temperature, decant the supernate off (save the supernate); and 10. Rinse the remaining precipitated solids repeatedly with deionized water and dry. TABLE 2Composition and Characteristics of the “1-10 ” Series Sampleswt %wt %molarmolarmoleswt %% I in pH BiII:BiBi:IOIthe supernateafter heating179.404.620.118.791.444.98 0.41%2.1272.226.450.175.731.417.45 0.31%2.3377.9914.210.362.811.3214.19 0.32%2.3474.8017.990.472.131.2617.98 0.30%4.7569.9021.800.611.641.2022.22 0.27%5.2657.3717.700.601.661.2022.03 0.29%6.5767.7228.100.811.231.0927.69 0.27%6.8861.3324.330.781.291.1126.7712.86%6.9963.7727.380.841.191.0828.4015.55%6.81066.1625.870.761.311.1226.4826.50%6.7 The rational for carrying out the “1-10 Series” synthesis experiments was to approach the matter of synthesis in a more controlled manner. Toward this end, more system variables were assessed; as well as having the Bi:I proportions in the starting mixes incremented in smaller steps. After synthesis, two parameters were measured on the remaining supernate: the pH and the residual iodine left in the solution from which the solids had precipitated (See Table 2). Although the pH of the synthesis fluid was nearly neutral in all samples prior to the final incubation at 90° C., the heating process resulted in further reactions in samples 1-3, which lowered the pH. A post-test iodide analysis of the supernate in samples #1-7 revealed that effectively all of the iodine added in the initial mix was taken up by the solid precipitates. In contrast, for samples 8-10, an analysis of the post-heating supernate suggests that not all of the iodine provided in the synthesis ended up on the solids. This picture was confirmed by the XRF analysis of the solids (FIG. 2), which showed that after sample 7 (i.e., in samples 8, 9, 10) the iodine content of the solids no longer increased, in spite of the fact that additional iodine was provided by the synthesis recipe. The actual weight percent of iodine in the samples, of course, depends on all of the components in the compound (i.e., Bi, O, I, plus any contaminants). In this case the amount of oxygen assumed to be present was computed based on what would be needed to maintain charge balance in a compound containing only oxygen, iodine (as iodide), and bismuth. Earlier FTIR studies on similar compounds had confirmed that neither hydroxide nor carbonate (as a contaminant in the NaOH used in the preparation) were present in significant amounts. Also, the XRF (SEM-EDS) studies confirmed that neither Na nor K (from the base used to precipitate the compounds) was incorporated to a significant degree in the solid precipitates. So, this is a reasonable assumption. X-Ray Diffraction (XRD) Studies on Bismuth Oxyiodine Materials Powder X-ray diffraction patterns (XRD) were obtained for all of the materials described above. Many of the patterns exhibit similar features, although in detail there are significant differences, which have entailed some effort to resolve. FIGS. 3 and 4 provide diffraction data on the three “41” and “42” samples (respectively) which exhibited significant uptake of iodine (e.g., B, D, and F). FIG. 5 provides a full display of all ten traces from the “1-10” series materials. These traces ultimately provided the basis for characterizing the materials that were the most stable, and contained the highest proportions of iodine (and hence make the most attractive targets for potential waste form development). Solubility Studies on Bismuth Oxyiodine Materials The solubility of our novel mixed-layered bismuth oxy-iodine materials can be approached from two directions; solubility in pure deionized water using a PCT-type test protocol, and the solubility in normal groundwaters (e.g., with Na+, K+, Ca2+, Mg2+, Cl−, HCO3−, SO42−). Fortunately, basic thermodynamic data is available for both BiOI and Bi5O7I. Calculations involving these data indicate that both HCO3− and Cl− will quantitatively displace iodide from the waste, even if only present at concentrations of just a few tens of parts per million. Thermodynamic data for the sulfate solubility is not available. Thus, to model the performance of a repository, one can simply equate the outward iodide flux to the incoming flux of chloride plus bicarbonate (and maybe sulfate), provided that the basic solubility of the waste form is significantly less than the indigenous concentrations of the common groundwater anions. In our leaching tests, the level of iodine leached from the various materials is a few parts per million. FIG. 7 clearly demonstrates that there is a significant difference in the overall stability of the different materials, with the materials giving relatively well-defined patterns for BiOI holding a distinct advantage (e.g. lower solubility and, hence, greater stability) over materials at either end of the compositional spectrum. In a general sense, this picture is also supported by the series “41-42” samples (FIG. 6), though, since these experiments did not explore the low-iodine end of the spectrum curves analogous to ASH3-#2 in FIG. 7. Tables 3-5 summarize the solubility test data. (Note: The sample designated “ASH3-#2” is the same as sample 2; “ASH3-#4” is the same as sample 4, “JLK-41B” is the same as sample 41B, etc.) It is noteworthy that these solubility results are quite different from predictions based on thermochemical properties of BiOI3 and Bi5O7I; and that this distinction serves to emphasize the difference between our mixed-layered Bi—O—I materials and the two end-member compositions (BiOI and Bi5O7I); or simple mechanical mixtures thereof. TABLE 3Solubility (ppm iodine) of bismuth oxyiodinematerials in deionized water.Temp - ° C.ASH3-#2ASH3-#4ASH3-#6ASH3-#8250.030.010.040.52470.070.010.011.03750.760.070.012.61902.620.210.043.69Temp - ° C.ASH3-#10JLK-41BJLK-41DJLK-41F250.910.080.060.10471.300.240.120.41752.670.220.311.81903.620.270.552.19Temp - ° C.JLK-42BJLK-42DJLK-42F250.050.140.68470.040.490.43750.020.301.39900.060.421.99 TABLE 4Post-test quench pH values of solubility experimentfluids after sitting for 2-3 weeks at RT.Temp - ° C.ASH3-#2ASH3-#4ASH3-#6ASH3-#8253.103.463.7 4.54472.983.523.604.54753.703.353.614.20903.083.153.564.04Temp - ° C.ASH3-#10JLK-41BJLK-41DJLK-41F254.454.193.814.29474.553.923.764.18754.173.733.653.91904.053.663.64no spl. leftTemp - ° C.JLK-42BJLK-42DJLK-42F253.923.723.98473.883.663.82753.683.363.69903.713.443.67 TABLE 5Solubility (ppb iodine) of “1-10” series materials in deionized water.Temp ° C.#2#4#6#8#102510.204.6911.70178.47333.624723.624.933.71388.52385.3077260.4621.452.61930.37576.8894856.8177.6212.671110.021191.63(ppb)iodine In summary, we unexpectedly discovered a set of closely-related mixed-layered Bi—O—I materials (samples #4-6, Table 2), containing 17-22 weight % iodine, and having X-ray diffraction patterns related to BiOI, (see FIG. 8), which leaches out significantly less iodine than materials synthesized with either more, or less, iodine (relative to the amounts of Bi in the mix). In terms of sample identification, we calculated, for example, that the sample #10 X-ray diffraction pattern could be best matched by assuming a scaled mix of 2 “parts” of the Bi5O7I XRD pattern and 5 “parts” of the BiOI XRD pattern (See FIG. 9). For the optimized materials (samples 4, 5, 6), the relative contributions to the total XRD pattern from the XRD patterns of the two known bismuth oxyiodide lattice phases was calculated to be: 15-20 mole % Bi5O7I and 85-80 mole % BiOI. FIG. 10 shows the amounts of iodine released (leached) from exposure to deionized water for 3 days at various temperatures. FIG. 11 shows the amounts of iodine released (leached) from exposure to deionized water for 3 days at various temperatures with 0.005 M of common groundwater anions (i.e., sulfate, carbonate, and chloride) added to the water. It can be seen that sample #6 was more stable than sample #8 with respect to iodine leaching. The presence of carbonate ion (HCO3−) produced the greatest amount of iodine leaching. FIG. 12 shows the amounts of iodine released (ppb) for samples 2, 4, 6, 8, and 10 after 3 days exposure to deionized water at 94° C. (see Table 5). One would normally expect there to be a smooth, linear change in solubility as a function of varying composition (wt % iodine), based on a simple rule-of-mixtures behavior, in the samples tested (i.e., there would be a straight line between sample 2 and 10). However, what we unexpectedly found was a strong minimum in the solubility curve at samples 4 and 6 (i.e., at about 18% wt % iodine), where the solubility was reduced a factor of 100× at the minimum, compared to the maximum (for samples 8 and 10). This was a very unexpected result, and supports our belief that our synthesized mixed-layered Bi—O—I materials are not simple mechanical mixtures of the two known, layered end-member compositions (BiOI, and Bi5O7I), but, rather, are a much more complex chemical assemblage, intimately-mixed at an atomistic-scale of two or more layered Bi—O—I lattice phases, possibly more, whose structure is much more stable to dissolution by water than either of the two end-member compositions (BiOI, and Bi5O7I) by themselves. This assessment is further supported by Scanning Electron Microscope (SEM) photomicrographs. FIG. 13 shows a 1000× magnification of sample #1. Long, rectangularly-shaped crystalline blocks can be seen, along with thin plates (flakes) and balls made of flakes (“flakey” balls). FIG. 14 shows a 1000× magnification of sample #6. A few crystalline blocks can be seen, but most of the image shows balls made of thin flakes (“flakey” balls). FIG. 15 shows a 1000× magnification of sample #10. The image shows both balls made of thin flakes (“flakey” balls), and long, thin spikes (needles). Clearly, the microstructure of the three different samples (1, 6 and 10) are vastly different, and are not simple mechanical mixtures of the two known, layered end-member compositions (BiOI, and Bi5O7I). The SEM micrographs in FIGS. 13-15 also show that our synthesized mixed-layered Bi—O—I materials have a very high specific surface area (see, e.g., FIG. 13). It is rather remarkable that, despite the high specific surface area microstructure, any of these materials could have a very low solubility in ground water (e.g., the middle series samples 4, 5, & 6). By using these optimized mixed-layered bismuth oxy-iodine materials, the greatest cost savings can be realized from: (1) the ability to implement this technology into processing wastes from civilian and defense nuclear power cycles and reactors, and by (2) reducing energy consumption plus reduced potential radiological exposure to workers by combined sequestration and waste form materials processing. This process can be applied across the United States and world wide for the removal and storage (for decay) of radioactive iodine compounds. It can be used for both defense and civilian nuclear power cycle productions of iodine gas and iodine aqueous compounds. With respect to the iodine leaching tests shown in FIG. 11, it can be seen that carbonate is apparently the anion of greatest concern in groundwater (i.e., greatest leaching). This raises the interesting possibility of synthesizing even more stable compounds that deliberately incorporate the same carbonate species along with the iodine to make a mixed-layered bismuth-oxygen-carbonate-iodine material. The particular examples discussed above are cited to illustrate particular embodiments of the invention. Other applications and embodiments of the apparatus and method of the present invention will become evident to those skilled in the art. It is to be understood that the invention is not limited in its application to the details of construction, materials used, and the arrangements of components set forth in the following description or illustrated in the drawings. The scope of the invention is defined by the claims appended hereto.
	description	The invention is related to containment of radioactive energy. There has been and continues to be a need for a techniques to safely encapsulate and to store hazardous nuclear waste generated from either defense, utility, or medical uses that both shields the environment from gamma, neutron, and x-ray particles. It is generally agreed that exposure to even low-level radioactive emission is highly undesirable. The use of medicinal grade radioactive solutions is undergoing great expansion. Furthermore, Military defense use of radioactive materials in submarines and other areas creates additional levels of toxic radioactive materials. Safety issues exist today in the uranium enrichment plants, which have been decommissioned leaving behind a plethora of contaminated soils, equipment, and wastes that have to be properly disposed of. Moreover, utilities continue to create significant amounts of nuclear waste from power generation plants. To date, the waste disposal process has largely been associated with the casking of waste into concrete castings, which have been dosed with absorbing materials such as fly ash or others. However, the absorbing materials can leach into the environment, if the concrete is damaged or cracked. Concrete is a hard and brittle material, which has a high potential for cracking, even when shrinkage naturally occurs as moisture escapes from it during a curing process. Cracking permits the escape of gamma radiation and the potential for radiation leaks. Concrete castings are being utilized as safe storage techniques for radioactive waste at the disposal facilities and are optimistically expected to perform for hundreds of years as the radioactive materials decay to safe levels. The excessive weight of concrete and its thicknesses create transportation issues and further places limits on the practical size of storage containers. In addition, the use of flyash in concrete (referred to as flyash concrete) has been the staple of the radioactive material shielding/absorption systems to date, since concrete has limits on the amount of solids, which may be added without effecting the structural integrity of the cement. Concrete has a degree of porosity, which allows for any moisture to eventually escape or permeate its structure, and many types of radioactive wastes have high levels of acidity, which can quickly attack concrete. Accordingly, there continues to be a strong need for techniques, compositions, and materials that offer improved and cost effective radiation shielding. The techniques and compositions should improve the safety of handling, storing, transporting, managing, and disposing of radioactive waste. Briefly and in general terms, a radioactive shielding composition is formed or otherwise provided. The composition includes a hydrocarbon component and a radiation shielding and absorbing material or additive. In one embodiment, the composition also includes a polymer and/or a crosslinking or curing agent. In various embodiments, the composition is sprayed, brushed, rolled, or otherwise coated onto substrates. In other instances, the composition is sprayed, brushed or otherwise coated onto radioactive material. In still other cases, the composition is mixed with raw materials of other products. The composition provides novel non-leaching gamma and neutron radiation shielding or absorbing properties. While concrete castings are conventionally used in the industry for radioactive containment, there still exists many shortcomings with concrete castings and therefore a need for a more permanent and safer method of encapsulating radioactive waste. Embodiments of the present inventions use leaded glass and various other neutron absorption agents in combination with a hydrocarbon component, such as asphalt (bitumen) to form novel radioactive shielding compositions. The novel radioactive shielding compositions presented with various embodiments of this invention teach improved alternatives to concrete castings. Asphalt based materials are extensively used in a wide variety of applications. For example, asphaltic material is widely employed as a primary ingredient in coating compositions for structures, in sealants, and in waterproofing agents. Asphalt compositions have been used in paving mixtures with considerable advantage for many years. Many manufactured roofing materials, such as in roofing shingles, impregnated felts, tars, mastics, and cements are also based upon asphalt or compositions thereof. All applications rely on the wide range performance of asphalt to waterproof and seal while being flexible and able to adapt with the incorporation of modifiers into a wide range of climatic conditions and loading stresses. In the case of paving asphalt, a typical paving asphalt mixture comprises a mixture of components, principal ingredients of the paving asphalt mixture being an asphalt composition or cement and aggregate or aggregate material. In such mixtures, the ratio of asphalt composition to aggregate material varies, for example, according to aggregate material type and the nature of the asphalt composition. Generally, asphalt compositions in paving mixtures are less than 10% by weight and are usually in the range of 4-7% by weight of the composition. As used herein, the terms “Asphalt Composition” or “Asphalt Cement” are understood to refer to any of a variety of organic materials, either solid or semi-solid at room temperature, which gradually liquefy when heated, and in which the predominate constituents are naturally occurring bitumens or residues commonly obtained in petroleum, synthetic petroleum, or shale oil refining, from coal tar, or the like. For example, vacuum tower bottoms produced during the refining of conventional or synthetic petroleum oils are a common residue material useful as asphalt composition. A “Paving Asphalt Composition” or “Paving Asphalt Cement” is an asphalt composition or asphalt cement having characteristics, which dispose the composition to use as a paving material, as contrasted for example, with an asphalt composition suited for use as a roofing material. “Roofing Asphalts”, for example, usually have a higher softening point, and are thus more resistant to flow from heat on roofs, the higher softening point generally being imparted by the air blowing processes by which they are commonly produced. Paving asphalt mixtures may be formed and applied in a variety of ways, as are commonly produced. For example, the paving asphalt composition and the aggregate can be mixed and applied at elevated temperatures at the fluid state of the paving asphalt composition to form the pavement or road surface. There exist numerous modifiers, which may be added to the asphalt cement to impart higher softening points, greater levels of elasticity, and resistance to aging and cold temperature cracking. Various polymers, antioxidants, surfactants or antistripping agents as well as many other additives have been employed in paving, roofing, and industrial applications. Radioactive wastes, as a natural result of their time-dependent decay and fission of radionuclides, emit alpha, beta, gamma, and neutron radiation. Of those types of radiation, the neutron and gamma radiation are extremely harmful to the environment and human life. Wastes of radioactive materials may be in found in three distinct types commonly in either solid, liquid or sludge forms. High-level radioactive wastes contain gamma emitting long-half life radionuclides, such as Plutonium (Pu-238, Pu239, Pu-240, and Pu-242) and Uranium (U-234, U-235, and U-236). High-level wastes include spent or used nuclear fuel and wastes from commercial and defense related nuclear reactors resulting from reprocessing of spent nuclear fuel. Most spent nuclear fuel in the United States is currently located in pools of water at nuclear generating plants across the country to protect workers from radiation. Spent fuel is also stored in large concrete casks as described above. High-level wastes are also generated from reprocessing of fuel from weapons production reactors to obtain materials to make nuclear weapons. These wastes are primarily in liquid form and can be either vitrified into a glass or solidified. Transuranic (TRU) waste contains such radionuclides as Californium (Cf-249-Cf252), Americium (Am-241, AM-242, and AM-243), Curium (Cm242-Cm250), Neptunium (Np-235, Np-236), Plutonium (Pu-236-PU-242) and Berkelium (Bk-247, Bk-250). The half-life of TRU wastes are generally in the range of about 20 years. TRU wastes are commonly generated by defense nuclear research and development activities, such as those encountered during the development and fabrication of nuclear weapons. TRU waste is classified as either “Contact-Handled” (CH) or “Remote-Handled” (RH), which are highly radioactive with high radiation Neutron and Gamma fluxes. CH-TRU waste emits mostly alpha radiation and therefore this type of radiation does not require a heavy lead shielding. Low-Level radioactive wastes do not include either High-Level or Transuranic waste materials. Most low-level wastes, classified by the Nuclear Regulatory Commission (NRC) as A, B, or C emit relatively low levels of radiation from radioactive decay of short half-life radionuclides, such as Strontium-90, Cesium-137, Krypton-85, Barium-133, and Beryllium-7 and Beryllium-10. Generally these wastes have radioactivity that decays to background levels in less than 500 years and about 95 percent of the waste decays to background levels in less than 100 years. Commercial and university laboratories, pharmaceutical industries and hospitals, as well as nuclear power plants generate low-level radioactive wastes, which can be addressed by the current invention. Low-level wastes include both solid and liquid wastes. High-level wastes are very radioactive and emit extremely harmful Gamma and Neutron radiation. RH-TRU wastes are primarily Gamma and Neutron emitters and consequently, they use heavy shielding and should be handled robotically. CH-TRU wastes are also very radioactive and emit harmful Alpha radiation in addition to Neutron radiation. One of the main hazards of this type of radiation is its potential for exposure by inhalation or ingestion. Inhalation of certain transuranic materials, such as plutonium, even in very small quantities, can deliver a significant internal radiation dose. Among Transuranic wastes; RH-TRU waste poses a significantly more hazardous risk than CH-TRU due to its emission of Gamma and Neutron radiation. Radiation emitted by Low-Level radioactive waste is significantly lower than that emitted by either High-Level or TRU radioactive wastes. Exposure to Gamma and Neutron radiation, as well as Alpha and Beta radiation, which are associated with these wastes, can induce chronic, carcinogenic and mutagenic health effects that lead to cancer, birth defects, and death. Thousands of tons of both solid, liquid, and sludge radioactive wastes have been generated in the past and they will continue to be generated in the future by commercial and private industries as well as government agencies. Unless they are safely and cost effectively shielded, managed, and disposed, these wastes may pose serious health and economic consequences to the global environment. The techniques and compositions presented herein are adapted to address these issues. Shielding from exposure to radiation varies with the type of waste and the type of radiation emission. Paper, skin or clothes can easily shield alpha radiation. Beta radiation on the other hand passes directly through paper, skin, or clothes but can be shielded by a thin layer of plastic, aluminum, or wood. Gamma and Neutron radiation, the most dangerous of all, are very penetrating with Neutron having the highest level of penetration potential. Gamma radiation can be blocked by heavy shielding materials such as lead, steel and Ducrete (depleted Uranium mixed with concrete). Neutron radiation easily penetrates through heavy metal shielding and only specially engineered and chemically formulated concrete blocks can shield penetration of Neutron radiation from its source. High-Level radioactive wastes are currently stored at nuclear power plants and Department of Energy (DOE) facilities across the country. The DOE's Office of Civilian Radioactive Waste Management (OCRWM) is charged with identifying and developing a suitable site for deep geologic disposal of this waste. The OCRWM is currently conducting research and testing to determine the suitability of the Yucca Mountain, Nevada site for long-term storage and safe disposal of these wastes. Much concern continues to exist from Nevada and its citizens on the ability to safely store these materials. Citizens and environmental groups across the country also have concerns as to how this material can be contained for secure and safe transportation to these storage depots. The embodiments of the present invention address these safety and storage concerns. Transuranic wastes are destined to be disposed into an already existing geologic repository at the WIPP site in Carlsbad, N. Mex. Class A and B low-level radioactive wastes are currently disposed in isolated shallow burial grounds. Greater than Class C low-level wastes use deep geologic disposal in specially licensed facilities. Management and disposal of high-level, transuranic and low-level radioactive wastes are very risky and use safe and cost-effective radiation shielding materials and techniques to minimize or prevent exposure to radiation, especially neutron and gamma radiation. Management activities, prior to disposal, include handling, solidification of liquid wastes, loading, storage, radiation monitoring, reloading of wastes into transportable containers, and transport of the radioactive wastes and waste containers to disposal sites. During these activities, if effective shielding is not applied, exposure to radiation can occur and cause devastating, irreversible health damage to workers. Management of these wastes prior to disposal consists of containing them in storage casks, canisters, and other forms of containments with conventional radiation shielding technologies. Currently conventional radiation shielding technologies, such as concrete-based technology, vitrification technology, synthetic-rock technology and ducrete technology are used for management and disposal of these radioactive wastes. These technologies are made up of either single or double component shielding materials and have limitations in terms of their effectiveness in full radiation (i.e. both neutron and gamma radiation) shielding, stability of the shielding materials, and ease of application and cost effectiveness. Concrete technology fails due to its inherent brittleness and inability to withstand impact. Once cracked, radiation easily penetrates through its once continuous encapsulation. Concrete also fails due to its inherent weight, which limits the amount and size of the encapsulation that can be easily handled or transported. The shielding effectiveness is limited in concrete compositions which are currently used for encapsulating and shielding. Embodiments of the current invention provide for a much higher level of shielding materials to be incorporated into the encapsulating medium and provide a medium which remains flexible and elastomeric over a wide range of temperatures. This improved shielding material provides significantly higher radiation shielding performance. Alternatives to the embodiments of this invention, such as sufficient size lead (Pb) containment vessels of suitable sizes would be too heavy and bulky for ease of handling and cost prohibitive. It is also unclear if an adequate supply of lead is available to provide enough containers to capture the currently existing waste stockpiles. FIG. 1 illustrates a block diagram of a radioactive shielding composition 100, according to an example embodiment of the invention. The radioactive shielding composition 100 minimally includes a hydrocarbon component 101 and a radiation shielding and absorbing material 102. In an embodiment, the radioactive shielding composition 100 may also include a crosslinking or curing agent 103 and/or other additional materials or additives 104. In an embodiment, the hydrocarbon component or medium 101 is petroleum asphalt. The radioactive shielding composition 100 may also include a stabilizing amount of polymer(s) (additional materials or additives 104), a reactive amount of curing agents 103, crosslinkers 103, or reactants so as to stabilize the polymer and incorporate it intimately with the asphalt. The radioactive shielding composition 100 may also include fillers or extenders to provide body and additional shielding or absorption, a stabilizing amount of antioxidants or stabilizers, and an amount of virgin or recycled radioactive shielding or absorptive additives or materials 102 suitable to provide the degree of shielding and absorption so desired for the application, including but not limited to alpha, beta, gamma and neutron shielding mediums. The radioactive shielding composition 100 may be used in a wide variety of applications for containing, managing, handling, storage and disposal of nuclear wastes. They are particularly unique in that they remain functional over a wide range of temperatures, provide Alpha, Beta, Gamma and Neutron shielding capabilities as well as function as a barrier and shielding material for many other types of radiation including but not limited to X-rays, Radon, and other types commonly known to those skilled in the art. The use of the hydrocarbon medium or component 101 with the radioactive shielding and absorptive mediums or materials 102 provides for a synergistic effect due to the presence of polar constituents and the presence of a significant number of hydrogen molecules present in the hydrocarbon medium 101. In an embodiment, the natural occurring elements within the asphalt component (hydrocarbon component 101) help to both shield and absorb various types of radiation emissions. Further, the addition of additional metals, their alloys, additives and minerals, both synthesized and naturally occurring can provide additional levels of shielding and absorption (additional materials or additives 104). The composition 100 and various instances of combinations of the composition 100 may be incorporated in and/or used as encapsulants, used as stabilizers, used as shields, and used to prevent any leaching of the radioactive materials from a containment system. This may be achieved by shielding fillers for cask type multi-wall shipping containers with the composition 100, thereby forming protective barrier sheets, coatings, and binders thereof. The composition 100 may be also be applied or incorporated into radioactive shielding applications or into the radioactive waste handling and storage applications by hot melt application, reactive one and two component systems, used as solvent cutbacks, or used as emulsions which solidify upon application to satisfy a variety of needs for protecting workers and the environment when handling and disposing of nuclear waste and/or radioactive materials. The composition 100 may be provided as a material which can be used to waterproof nuclear waste storage sites, incorporated into the storage containers themselves, line drainage ditches and troughs to provide a barrier to the soil underneath so as to prevent further contamination, or be applied to underlying soils prior to pouring concrete flooring slabs to prevent the migration of Radon gas into basements or living areas. The hydrocarbon component 101 or the composition 100 may include Asphalt, Petroleum Pitch, SDA (Solvent De-asphalted Pitch), hydrocarbon resins, heavy hydrocarbon bottoms, or recycled lube oil bottoms, and/or any mixtures thereof. Coal tar may be incorporated, but from a health effects and leachability standpoint, its use may be limited. In an example embodiment, the hydrocarbon component 101 is asphalt. The term “asphalt” (sometimes referred to as “bitumen”) refers to all types of asphalts (bitumen), including those that occur in nature and those obtained in petroleum processing. The choice depends essentially on the particular application intended for the resulting asphalt composition. In an embodiment, the hydrocarbon component 101 has an initial viscosity at 140° F. (60° C.) of 50 to 10,000 poise (measured by ASTM method D-2170 for absolute viscosity). The initial penetration range of the base asphalt at 77° F. (25° C.) is 0 to 500 dmm, such as 25 to 200 dmm, when the intended use is for preparing the radioactive shielding composition 100. In some embodiments, asphalt, which does not contain any polymer, additives, or modifications, etc., may sometimes herein be referred to as “Base Asphalt”. Suitable asphalt components include a variety of organic materials either solid or semi-solid at room temperature. These materials gradually liquefy when heated, and in which the predominate constituents are naturally occurring bitumens, e.g. Trinidad Lake Asphalt, or residues commonly obtained in petroleum, synthetic petroleum, shale oil refining, tar sands refining, or from coal tar or the like. For example, vacuum tower bottoms produced during the refining of conventional or synthetic petroleum oils are a common residue material useful as asphalt composition. Solvent deasphalting or distillation may also product the asphalt. Solvent deasphalting (SDA) bottoms, or alternatively, those derived from the ROSE™ process, may be used as part or all of the asphalt of the hydrocarbon component 101 blends. SDA bottoms are obtained from suitable feeds such as vacuum tower bottoms, reduced crude (atmospheric), topped crude and hydrocarbons comprising an initial boiling point of about 450° C.(850° F.) or above. In an embodiment, the solvent deasphalted bottoms are obtained from vacuum tower bottoms, boiling above 538° C. (1000° F.). Solvent deasphalting can be carried out at temperatures of 93-148° C. (200-300° F.). After solvent deasphalting, the resulting SDA bottoms have a boiling point above 510° C. (950° F.), above 538° C.(1000° F.), and a penetration of 0 to 100 dmm at 25° C. (77° F.), 0 to 70 dmm at 25° C.(77° F.). In an embodiment, the asphalt hydrocarbon composition 101 may be vacuum tower bottoms or heavy residuum solely or partly material produced by distillation of oils, with or without any solvent extraction step. Such materials sometimes referred to as “asphalt cement”, have a reduced viscosity relative to the SDA bottoms. Such asphalt cement component can have a viscosity of 100 to 5000 poise at 60° C. (140° F.), 250 to 4000 poise, e.g. 500 poise for AC5 or PG52-28 asphalt cements. The asphalt cement component is added in amounts of sufficient quantities to provide the resulting asphalt or hydrocarbon compositions 101 with the desired viscosities for their intended application, e.g. asphalt cement may be blended with SDA bottoms to produce asphalts having a viscosity of 500 to 2000 poise at 60° C. (140° F.). Additionally, in an embodiment, Performance Graded(PG) asphalt binders may be employed with the composition 100 and may be selected from the group including PG46-34, PG52-34, PG52-28, PG58-28, PG58-22, PG64-28, PG64-22, PG70-22, PG70-28, PG76-22 and any combination thereof so as to provide a composition 100 with the desired properties for the desired application of the composition 100. PG asphalts are produced in accordance with the guidelines established by the American Association of State and Highway Transportation Officials (AASHTO) specification M-312. Other hydrocarbon materials, media, or components 101 may include petroleum pitch produced under U.S. Pat. No. 4,671,848 (Ashland), Pat. No. 4,243,513 (Witco) or Pat. No. 3,140,248 (Mobil). Commercially available pitch products available from Marathon Ashland Petroleum and sold under the designations of A-240, A-225, A-170 or A-40 or from British Petroleum sold under the designation of Trolumen 250. Coal tar and Coal tar pitch may also be utilized with instances of the radioactive shielding composition 100. Generally, the shielding, binding, and encapsulating instances of the composition 100 may contain from approximately about 0.0 to approximately about 95.0% by weight, with from approximately about 0.0 to approximately about 35% by weight of a hydrocarbon component 101. The radiation shielding and absorption material 102 may include a variety of materials configured in such a manner that their compositions when combined with the hydrocarbon component 101 (such as an asphalt binder) provide a desired level of shielding and absorption protection for the particular radioactive or radioactive waste material desired to be managed, handled, stored or contained. In an embodiment, the radiation shielding and absorption material 102 includes virgin and/or recycled glass which contains lead, iron, titanium, or other metals and minerals commonly know to those skilled in the art, naturally occurring or synthesized minerals and their compounds selected from Boron, Aluminum, Coal, Titanium, Sulfur and Sulfates, Iron, or Lithium. Boron compounds may include one or more of the following: Borax, Boron Carbide, Boron Nitride, or any mixtures or combinations thereof. Aluminum chemical and mineralogical compounds may include one or more of the following Bauxite, Cryolite, Boehmite, Gibbsite, Diaspore, Alumina Trihydrates, Aluminum Silicate, or any mixtures or combinations thereof. The Coaliferous compounds may include one or more of bituminous or anthracite coal materials and any mixtures thereof. Titanium compounds include, but are not limited to, one or more of ilmenite, rutile, brookite, anatase, titano-magnetite, or any mixtures thereof. Sulfur compounds include in particular sulfates consisting of one or more selected from gypsum, anhydrite, barite, or any mixtures thereof. Iron chemical and mineralogical compounds include one or more selected from hematite, magnetite, siderite, goethite, limonite, or any mixtures thereof. Lithium compounds may include one or more of the following including lepidolite, spodumene, petalite, amblygonite, or any combination of mixtures thereof. Other elemental additives may include Beryllium, Lead, Cobalt, Nickel, Copper, Zinc, Strontium, Zirconium, Tin, depleted Uranium or any of the alkali or alkaline earth metals, transitional metals or any compounds or mixtures thereof. Other shielding additives may include plastics such as polyethylene, polypropylene, parafinnic and microcrystalline waxes, fischer-tropsch waxes, water, ground concrete, recycled crumb and ground tire rubbers, and hydrated lime. The radiation shielding and absorbing materials 102 and their compositions, which may be employed, may be selected from virgin and/or recycled materials. In an embodiment, the radiation shielding and absorbing material 102 comprises approximately about 0.5 to approximately about 70% virgin or recycled, non-leachable, leaded glass, which contains from approximately about 0.1 to approximately about 60.0% by weight of lead and which has been processed to a particle size which is suitable for uniform distribution throughout a hydrocarbon binder system. Uniform distribution provides a continuous gamma, neutron, alpha and beta radiation absorbing and shielding composition. Recycled radiation shielding and absorbing materials 102 may be recovered from waste glass including CRT (Cathode Ray Tube) scrap which has been recovered from computer monitors, television screens and the like. Such recycled material shall be processed so as to remove any leachable materials, which may be present in or on the recycled particles of the material, as described in U.S. Pat. Nos. 6,666,904 and 6,669,757. In some embodiments, the radioactive shielding composition 100 also includes additional materials or additives 104. Such additives 104 are added in amounts comprising from approximately about 0.1 to approximately about 95% by weight, with approximately about 0.5 to about 75% by weight of the composition 100. One additive 104 may be surfactants selected from anionic, cationic, or nonionic commercially available products for emulsifying asphalt or other compositions which are widely known to one of ordinary skill in the art. In emulsified forms, surfactants are generally added in amounts comprising from approximately about 0.1 to approximately about 5% by weight, with approximately about 0.2 to approximately about 2.5% by weight of the composition 100. Another additive 104 may be dispersants added to the composition 100 in order to speed dispersion and to increase the amount of the shielding materials 102 added into instances of the composition 100. Commercially available dispersants from Rohm and Haas under the brand name Tamol, R. T. Vanderbilt under the designation Darvan, as well as many others available from a wide range of vendors are suitable for use with instances of the composition 100. In an embodiment, the composition 100 comprises from approximately about 0.0 to 5% by weight, from approximately about 0.0 to about 2.5% by weight of a dispersant. Still other materials 104 that may be added to instances of the composition 100 include polymers. Elastomeric or plastomeric polymer modifiers or mixtures thereof may be employed in instances of the composition 100. As used herein, “elastomeric” refers to a composition or compound having “Elastic” or “Rubbery” type memory properties, which remains intact, but gives with stress. That is, it regains its shape once the stress is removed. Elastomers are commonly a member of the class of polymers known as block copolymers, natural rubber, recycled rubber, ground tire rubber, urethanes, polyurethanes, or polysiloxanes. As used herein, the term “plastomeric” refers to those polymers normally chosen from either polymers or copolymers, which tend to stiffen a mixture but do not offer an elastic or elastomeric benefit. Polymers are elastomers, selected so as to provide the highly elastomeric and high softening point compositions which remain flexible down to sub zero temperatures while meeting the specific encapsulating and shielding requirements for the particular radioactive material or waste involved with instances of the composition 100. Plastomers may also be used in conjunction with the elastomers for tailoring desired stiffness, and shielding qualities. The amount of each specific type of polymer(s) will vary with the compositional characteristics desired for the intended purpose. Some of examples of Polymers which may be used as additional material 104 for instances of the composition 100 where the hydrocarbon component 101 is asphalt include Elastomers of Styrene-Butadiene (SB) diblock polymers, Styrene-Butadiene-Styrene (SBS), triblock polymers which may be linear or radial in form, Styrene-Isoprene-Styrene (SIS), diblocked polymers, hydrotreated SBS, Styrene-Ethylene Butadiene-Styrene (SEBS), Styrene-Butadiene Rubber (SBR), Polychloroprene rubber, natural latex rubber, Plastomers employed in the present invention may include polyacrylamide, polyacrylates, methyl methacrylates, Glycidyl-containing ethylene copolymers such as those described in U.S. Pat. No. 5,331,028, polyethylene, oxidized polyethylene, ethylene acrylic acid, ethylene vinyl acetate, ethylene terpolymers and others commonly available under the trade names Elvax, Elvaloy, Polybuilt, Vestoplast, EE-2, etc. It may be particularly beneficial to add individually or in combination SB, SBS, or SIS copolymers, 2-ethyl-1,3-hexandiol, various glycols including but not limited to polyether and polyester polyols, or hydroxyl terminated polybutadiene polymers (the hydroxyl terminated polybutadiene resins typically have a hydroxyl number of 20-100 and a Mn (molecular weight ) of between 1000 and 5000), copolymers thereof with acrylonitrile, castor oil, various vegetable oils, or epoxies and combinations thereof as modifiers to the hydrocarbon component 101 of the composition 100. In an embodiment, polymers are added in amounts comprising approximately about 0.0. to approximately about 100% by weight, or from approximately about 0.5 to approximately about 75% by weight polymers. The hydroxyl terminated polybutadiene resins typically will have a hydroxyl number of approximately 40-60 and a Mn (molecular weight) of approximately between 1000 and 5000. The composition 100 also may also include crosslinking or curing agents 103. Curing agents 103 are well know to those of ordinary skill in the art and include, but are not limited to, crosslinkers, accelerators, and catalysts comprising one or more of the following: elemental sulfur, sulfur donors such as various thiurams and dithiocarbamates, zinc 2-mercaptobenzothiasole (ZMBT), Zinc Oxide, Dibutyl Tin Dilaurate, Dioctyltin dilaurate, different tertiary amines, and organometallic compounds of tin, lead, cobalt, and zinc, peroxides, polycarbodiimide-modified diphenylmethane diisocyanates, 2,4 Toluene Diisocyanate, and 2,6-Toluene Diisocyanate, hexamethylene diisocyanates, and isophorone diisocyanates, in one embodiment having a functionality of two or greater. As examples, U.S. Pat. Nos. 5,017,230; 5,756,565; 5,795,929; 6,538,060; and 5,605,946 disclose, and refer to various other patents that disclose various crosslinking and curing agent compositions. For various reasons including costs, environmental impact, and ease of use, elemental sulfur with organic zinc compounds are employed for lower demand systems and compositions. In special situations, the sulfur can be added with a sulfur donor such as dithiodimorpholine, zinc thiuram disulfide, or any compound with two or more sulfur atoms bonded together. The zinc is added as zinc 2-mercaptobenzothiasole, zinc tetraalkylthiuram disulfide, zinc oxide, zinc dialkyl-2-benzosulfenamide, or other suitable zinc compound or mixtures thereof. In some instances of the compositions 100, where situational conditions demand the highest performance for the widest range of thermal stability and impact resistance, the curing agent 103 is a polycarbodiimide-modified diphenylmethane diisocyanate with or without the addition of a dibutyl-tin dilaurate. Other materials or additives 104 that may be added to instances or mixtures of the composition 100 include oils or other agents. For example, fluxing or extender oils may be added to mixtures or instances of the composition 100 so as to improve the flow properties of an asphalt component (hydrocarbon component 101) and to provide the finished composition 100 with the degree of flexibility and properties necessary for the particular application of the composition 100. Fluxing oils may be added to improve the properties of a base asphalt (hydrocarbon component 101) and polymer blend so as to balance the flexibility and softening point of the finished composition 100. Such fluxing components can include parafinnic and/or napthenic, as well as aromatic materials, e.g. gas oils (which can contain both isoparaffins and monoaromatics). Gas oils include neutral oils, including hydrotreated, hydrocracked, or isodewaxed neutral oils. Suitable parafinnic fluxing components include parafinnic oils having at least 50 wt % parafinnic's content (isoparaffins and normal paraffins) such as footes oil (which is highly parafinnic and obtained from deoiling slack waxes in refineries) as well as slack wax itself. Polyalphaolefins (PAO's) are also suited for use as fluxing components. Aromatic oils such as lube plant extracts may also be used, but may not be desired due to their high aromatic content and inherent health hazards. Hydrotreated napthenic and parafinnic oils are desired in some embodiments. Esters of tallow and vegetable fats and oils are also suitable for extenders and fluxing agents as well as for solvents which may be used in coating applications. The primary constraints on the fluxing components are stability, safety and compatibility. The material should be relatively non-volatile, i.e. have an initial boiling point above 300° F. The oil should be chosen so as to minimize health effects. There is no upper limit, per se, on boiling point and many suitable oils will have distillation end points above 538° C. (1000° F.). The material has a viscosity similar to that of neutral oils or higher. Higher viscosity helps keep the finished compositions 100 of the invention in suitable range so as to not melt and so as to flow under heat yet also so as to be flexible during low temperature exposures. Other suitable extender or flux oils may include FCC Light Cycle Oil, FCC Heavy Naptha, and FCC Slurry Oil or clarified slurry oil, Vegetable oils, esters of fatty acids, Gas Oil, Vacuum Gas Oil, Coker Naptha, Coker Gas Oil, and Aromatic Extracts. In an embodiment, a hydrotreated napthenic or parafinnic oil is employed in some mixtures of the composition 100 in an amount comprising from approximately about 0.0 to 40% by weight, from approximately about 0.0 to 30% by weight. A wide variety of chain extending diols can be employed and the choice may affect the cure rate and the physical properties of mixtures of the composition 100. Particularly useful diols are 2-ethyl 1,3 hexanediol, phenyl diisopropanolamine, and bis-hydroxyethyl dimerate. The use of a short chain diol in conjunction with an additional isocyanate increases the urethane concentration in the final composition 100 and this combination leads to increased hydrogen bonding between polymer chains and thus higher strength properties in the final composition. The increased hydrogen bonding further adds to the shielding capabilities for mixtures of the compositions 100. Still other additional materials or additives that may be included in mixtures of the composition 100 include plasticizers. Plasticisers may be added to mixtures of the composition 100 to impart flexibility, low temperature cracking and impact resistance. They may also include any of the above mentioned extenders or flux oils, Phthalates including but not limited to Dibutylpthalate (DBP) and/or Dioctylpthalate (DOP), various Phosphates, Citrates, polybutadienes, polybutenes, low molecular weight SB, SBS, SEBS, SBR, functional BD Resins, or blends thereof. In an embodiment, where plasticisers are incorporated into mixtures of the composition 100, they may be included in a range from approximately about 0.0 to about 10.0% by weight, from approximately about 0.0 to approximately about 6.0% by weight. Still more additional materials or additives 104 that may be added to mixtures of the composition include gellants. Gellants may include chemical gellants such as metallic soaps formed by the neutralization of fatty acids and/or rosin acids; organoclays, e.g. bentonites, hectorites, ball clays, kaolin clays, attapulgus clays, silicas, silicates including but not limited to calcium, magnesium, and/or aluminum, etc.; hydrogenated castor oils, oligomers; siloxanes; or others well known to those of ordinary skill in the art. As used herein “gellants” are typically used in the range from approximately about 0.0 to about 10.0% by weight, from approximately about 0.0 to about 6.0% by weight. Other additional materials or additives that may be included in mixtures of the composition 100 include antioxidants. Antioxidants are an oxidation inhibiting or stabilizing amount of a composition selected from metal hydrocarbyl dithiophosphates, and mixtures thereof and a composition selected from antioxidant butylated phenols, and mixtures thereof, or others commercially available such as those under the trade names Vanox, Irganox, Cyanox. Antioxidants added into mixtures of the composition are generally added in the range from approximately about 0.0 to about 10.0% by weight or from approximately about 0.0 to about 3.0% by weight. Miscellaneous additives 104 may also be added to mixtures of the composition 100. The additives 104 may include flame retardants such as Antimony Oxide, calcined aluminum, aluminum trihydrate, chlorinated oils or paraffins, or other flame retardants commonly know to one of ordinary skill in the art. Reinforcement additives such as Kevlar® fiber, cellulose fibers, or polyester fibers may be added to impart mechanical strength to mixtures of the composition 100. Other fillers may include Sepiolite clays, silicas, carbon blacks, or Wollastonite which also add reinforcement and strength to mixtures of the composition 100. Many other additives 104 known to those or ordinary skill in the art are not listed herein but assumed to be included in the invention as modifiers for use as desired to impart specific desired properties. In an embodiment, additives 104 may be incorporated into the mixtures of the composition 100 in ranges from approximately about 0.0 to 45% by weight or from approximately about 0.0 to about 20% by weight. In some embodiments, water is also added to mixtures of the composition 100. In an embodiment, deionized or distilled water is used when making emulsions from the hydrocarbon component 101 but standard tap or well (naturally occurring) water may be used. Water with high ionic contents should be avoided so as to produce more stable emulsions for use when spray applying coatings, dust pallatives/binders or membranes of mixtures of the composition 100. In an embodiment, water when used in emulsions for mixtures of the composition 100 may be incorporated in a range from approximately about 0.1 to about 70% by weight or from approximately about 10.0 to approximately about 50.0% by weight. In an embodiment where the hydrocarbon component 101 is asphalt, then hydrocarbon solvents may be added to mixtures of the composition 100 to reduce the viscosity of the asphalt. This may be useful when the mixtures are being applied as coatings, liners, binders, or dust pallatives. Some hydrocarbon solvents include mineral spirits; napthas; aromatic solvents; kerosenes; compounds of D'Limolene, methyl esters of fatty acids, biodiesel compounds, and fuel oils. In an embodiment, hydrocarbon solvents may be utilized to reduce viscosity for application in the range from approximately about 1.0 to 95% by weight or from approximately about 5.0 to approximately about 50% by weight. In various embodiments, sufficient or desired heating is applied to or achieved with the mixtures of the composition 100 in order to maintain a fluidity of the mixture for mixing, pumping, application and/or flow of the composition. In a like manner, pressure is an optional control parameter when constructing mixtures of the composition 100, and thus, in one embodiment, the pressure during initial formation of the composition 100 is normal atmospheric pressure. Furthermore, in one embodiment, mixtures of the composition 100 are formed as a batch process. In another embodiment, the mixtures of the composition are formed with continuous processing with continuous mixing of the ingredients as they are pumped or fed into casks, containers, reservoirs, piping, vessels, or as coatings, binders, pallatives, lines, or the like. Mixtures of the composition 100 provide for novel impact and temperature resistant radioactive shielding and absorptive modified compositions containing a radiation shielding and absorptive improvement additive or material 102 of (a) a composition selected from virgin or recycled radiation shielding and/or absorption additives, optionally (b) an Elastomeric or polymeric polymer modifier 104 composition and combinations thereof, (c) a hydrocarbon component 101, and (d) a crosslinking and/or curing agent 103. Ingredients (a), (b),(c) and (d) may all be present in mixtures of the composition 100 or may be present in part. Generally, the modified radioactive shielding and absorption materials 102 of the invention comprise, (a) from approximately about 0.1 to approximately about 85 wt. % of a virgin or recycled radioactive shielding and/or absorption additive(s) and mixtures thereof, and (b) from approximately about 0.0 to about 95 wt. % of a composition selected from Elastomeric and/or plastomeric polymer modifiers 104 and combinations thereof, (c) from about 0.0 to approximately about 95 wt. % a hydrocarbon component 101 selected from naturally occurring or refinery produced asphalt, petroleum pitch, SDA or ROSE bottoms, vacuum tower bottoms, coal tar or coal tar pitch, and (d) from approximately about 0.0 to about 50 wt. % of a crosslinking and/or curing agent 103 or mixtures thereof. Unless indicated otherwise, all compositions percentages given herein are by weight, based upon the total weight of the composition. The virgin or recycled radiation shielding and absorbing additive 102 may be present in an amount from approximately about 10 to 85 wt. %. The Elastomeric and/or plastomeric polymer modifiers 104 and combinations thereof may be present in an amount from approximately about 0.0 to approximately about 85 wt. %. The hydrocarbon component 101 of the invention may be present in an amount from approximately about 0.0 to 80 wt. %. The crosslinking and/or curing agents 104 and combinations thereof may be present in an amount from approximately about 0.0 to about 40.0 wt. %. In some embodiments, other additives 104 such as extender oils, extender diols, fillers, antioxidants, and fire retardants may be added so as to tailor the composition 100 to meet specific application requirements for the radioactive shielding composition 100. All percents are by weight of the total composition and are provided for purposes of illustration only. FIG. 2 illustrates a block diagram of another radioactive shielding composition 200, according to an example embodiment of the invention. The radioactive shielding composition 200 includes asphalt 201 and a radiation shielding and absorbing additive 202. In one embodiment, the radioactive shielding composition 200 also includes polymer modifiers 203. In an embodiment, the composition 200 includes a radiation shielding and absorbing additive 202 that is leaded glass particles. The leaded glass particles may be derived from recycled glass waste or virgin glass. In an embodiment, the glass particles are manufactured or supplied to the composition with diameter sizes of 2 millimeters or less. In this manner, the lead and other heavy metals are not practically capable of leaching from the glass particles. Moreover, the remaining non-leachable lead and other heavy metals act as a good radiation shielding and absorbing additive 202 for the composition 200. Furthermore, the asphalt 201 may be custom blended from naturally occurring bitumen or as bitumen derived from petroleum processing. Moreover, a desired viscosity for the asphalt 201 may be achieved with other additives or other materials mixed within the custom blended asphalt 201. In an embodiment, the composition 200 also includes an elastomeric or plastomeric polymer modifier 203. Other mixtures of the composition 200 may include crosslinking or curing agents. Mixtures of the composition 200 may be manufactured in various forms such as liquids, aerosols, solids, and incorporated as coatings on radioactive waste or as coatings on substrates that interface with radioactive waste. Additionally, the composition 200 may be integrated into raw materials associated with products that interface with radioactive waste, such as containers, etc. FIG. 3 is a diagram of a method 300 for forming a radioactive shielding composition and applying or integrating the composition, according to an example embodiment of the invention. In an embodiment, the method 300 is adapted to produce mixtures or instances of the compositions 100 and 200 of FIGS. 1 and 2. Initially, at 310, a hydrocarbon component is liquefied. That is, a hydrocarbon component, such as asphalt, is heated or otherwise acquired in a form that is fluid or liquid. Next, at 320, the hydrocarbon component is blending or mixed with a radiation shielding additive, a polymer, and a crosslinking or curing agent. At 330, a radioactive shielding composition is formed from at the conclusion of the blending. In an embodiment, at 340, the formed radioactive shielding composition is sprayed, rolled, brushed, and/or coated onto a substrate. In some embodiments, the substrate is a container made of plastic, metal, cement, rubber, and the like. In other embodiments, the substrate is rock, cement, sand, gravel, dirt, and the like. The coating of the radioactive shielding composition on the substrate forms a durable, weather-resistant radiation absorber and shield. In another embodiment, at 350, a substrate is dipped or submersed into a bath of the formed radioactive shielding composition, such that all sides and surfaces of the substrate are coated with the composition. In yet other embodiments, at 360, the formed radioactive shielding composition is sprayed, rolled, brushed, and/or coated onto one or more surfaces of radioactive waste material. In other cases, at 370, the radioactive waste material is dipped or submersed into a bath of the composition. In still more embodiments, at 380, the radioactive shielding composition is mixed with raw materials of manufactured products, such that the manufactured products exhibit radiation shielding and absorbing properties and characteristics associated with the composition. In this manner, containers and other products may be manufactured with a portion of their composition including the radioactive shielding composition. The method 300 improves the radioactive emission shielding performance, radioactive emission absorbing performance, impact resistance, and temperature susceptibility of radioactive emission shielding and absorbing compositions produced by blending the ingredients at a temperature sufficient to liquefy the hydrocarbon component, a virgin or recycled radiation shielding and absorbing additive or mixtures thereof, an elastomeric and/or plastomeric polymer modifier and/or combinations thereof, a naturally occurring or refined hydrocarbon component and/or mixtures thereof, a crosslinking and/or curing agent in a configurable ratio to the elastomeric or plastomeric additives, as described more fully hereinafter. In an embodiment, the components or ingredients are added so that the radiation shielding composition comprises from approximately about 0.1 to 85.0 wt. % of a composition selected from virgin and/or recycled radiation absorbing and shielding additives and/or mixtures thereof, from approximately about 0.0 to 95.0 wt. % of an elastomeric and/or plastomeric polymer modifier and/or combinations thereof, from approximately about 0.0 to 95.0 wt. % of a naturally occurring or refined hydrocarbon component and/or mixtures thereof, and from approximately about 0.0 to 5.0 wt. % of a crosslinking and/or curing agent or mixtures thereof in a specified ratio to the elastomeric or plastomeric polymer modifiers as described more fully hereinafter. In another embodiment, the virgin or recycled radioactive shielding and/or absorbing additives or mixtures thereof is supplied in an amount from approximately about 10.0 to 85 wt. %, the elastomeric and/or plastomeric polymer modifier or mixtures thereof supplied in an amount from approximately about 0.0 to 85.0 wt. %, the naturally occurring or refined hydrocarbon components and/or mixtures thereof is supplied in an amount from approximately about 0.0 to 80.0 wt. %, and the crosslinking and/or curing agents or mixtures thereof are supplied in an amount from approximately about 0.0 to 40.0 wt. %. All percentages are percent by weight of the total composition. In yet another embodiment, the method 300 relates to a novel impact and temperature resistant radiation shielding and absorbing compositions which may be spray, brushed, or flow applied to various substrates and radioactive emitting sources comprising a virgin or recycled radiation shielding and absorbing additive or mixtures thereof, an elastomeric and/or plastomeric polymer modifier and/or combinations thereof, a naturally occurring or refined hydrocarbon component and/or mixtures thereof, a crosslinking and/or curing agent in a specified ratio to the elastomeric or plastomeric additives, and a dilution solvent suitable for reducing viscosity of the composition so as to render it easily sprayable, brushable, or flowable onto the desired substrate to be protected or into a containment vessel or shielding vessel as described more fully hereinafter. For example, the components are added so that the radiation shielding composition comprises from approximately about 0.1 to 85 wt. % of a composition selected from virgin and/or recycled radiation absorbing and shielding additives and/or mixtures thereof, from approximately about 0.0 to 95.0 wt. % of an elastomeric and/or plastomeric polymer modifier and/or combinations thereof, from approximately about 0.0 to 95.0 wt. % of a naturally occurring or refined hydrocarbon component and/or mixtures thereof, and from approximately about 0.0 to 50.0 wt. % of a crosslinking and/or curing agent or mixtures thereof in a specified ratio to the elastomeric or plastomeric polymer modifiers as described more fully hereinafter. In another example, the virgin or recycled radioactive shielding and/or absorbing additives or mixtures thereof is supplied in an amount from approximately about 10.0 to 85 wt. %, the elastomeric and/or plastomeric polymer modifier or mixtures thereof supplied in an amount from approximately about 0.0 to 85.0 wt. %, the naturally occurring or refined hydrocarbon components and/or mixtures thereof is supplied in an amount from approximately about 0.0 to 80.0 wt. %, the crosslinking and/or curing agents or mixtures thereof are supplied in an amount from approximately about 0.0 to 40.0 wt. %, and the hydrocarbon solvents and/or mixtures thereof are supplied in an amount from approximately about 0.5 to about 95.0 wt. %. The percentages are percentages by weight for the total composition produced by the method 300. In still other embodiments, the method 300 relates to a novel, impact and temperature resistant radiation shielding and absorbing emulsified compositions which may be spray, brushed, or flow applied to various substrates and radioactive emitting sources comprising a virgin or recycled radiation shielding and absorbing additive or mixtures thereof, an elastomeric and/or plastomeric polymer modifier and/or combinations thereof, a naturally occurring or refined hydrocarbon component and/or mixtures thereof, a crosslinking and/or curing agent in a configurable ratio to the elastomeric or plastomeric additives, an anionic, cationic, or nonionic emulsifier composition and/or mixtures thereof, and an amount of water suitable for reducing viscosity of the composition so as to render it easily sprayable, brushable, or flowable onto the desired substrate to be protected or into a containment vessel or shielding vessel as described more fully hereinafter. For example, the components may be added so that the radiation shielding composition comprises from approximately about 0.1 to 85.0 wt. % of a composition selected from virgin and/or recycled radiation absorbing and shielding additives and/or mixtures thereof, from approximately about 0.0 to 95.0 wt. % of an elastomeric and/or plastomeric polymer modifier and/or combinations thereof, from approximately about 0.0 to 95.0 wt. % of a naturally occurring or refined hydrocarbon component and/or mixtures thereof, and from approximately about 0.0 to 40.0 wt. % of a crosslinking and/or curing agent or mixtures thereof in a specified ratio to the elastomeric or plastomeric polymer modifiers as described more fully hereinafter. In another example, the virgin or recycled radioactive shielding and/or absorbing additives or mixtures thereof is supplied in an amount from approximately about 1.0 to 85 wt. %, the elastomeric and/or plastomeric polymer modifier or mixtures thereof supplied in an amount from approximately about 0.0 to 85.0 wt. %, the naturally occurring or refined hydrocarbon components and/or mixtures thereof is supplied in an amount from approximately about 0.0 to 80.0 wt. %, the crosslinking and/or curing agents or mixtures thereof are supplied in an amount from approximately about 0.0 to 40.0 wt. %, the anionic, cationic, and/or nonionic emulsifiers and/or mixtures thereof are supplied in an amount from approximately about 0.1 to approximately about 10.0 wt. %., and water in an amount from approximately about 0.5 to 80.0 wt. %. The percentages are percentages by weight of the total composition. In an embodiment, the method 300 relates to novel, impact and temperature resistant, radiation shielding and absorbing encapsulant and filler compositions, comprising an nuclear radiation emitting source and from about 10.0 to 99% of the novel modified radiation shielding and absorbing compositions described herein. In more particular embodiments, the method 300 is directed to specific methods of applications and compositions thereof, such as novel shielding/absorbing fillers for cask type multi-wall shipping containers, protective barrier sheets, shielding and absorbing coatings, and binders for radioactive materials and wastes thereof. Compositions produced from the method 300 may be incorporated into radioactive shielding/absorption applications or in the radioactive waste handling and storage applications by hot melt application, use as solvent cutbacks, or as emulsions for a variety of applications for protecting workers and the environment when handling and disposing of nuclear waste and radioactive materials. The compositions of the method 300 further provide for a material which can be used to line and waterproof nuclear waste storage sites or facilities using nuclear materials, used to fill cracks in the structures thereof, incorporated into the radioactive material storage containers themselves, line drainage ditches and troughs to provide a barrier from the soil underneath so as to prevent further contamination from leaching and runoff, be applied to underlying soils prior to pouring concrete slabs to prevent the migration of Radon gas into basements or living areas, or pumped through contaminated piping so as to bind and contain any loose particles or dust into a solid mass for collection and disposal. The method 300 also provides for a process whereby the compositions of the method 300 may be used to bind and solidify contaminated waste materials to be extruded into containers for disposal. Accordingly, embodiments of the present invention provide novel compositions comprising the use of at least approximately about 5.0 to 95.0% of a hydrocarbon medium or component, wherein an example hydrocarbon medium is petroleum asphalt, into which has been incorporated a stabilizing amount of polymer(s), a reactive amount of curing agents, crosslinkers, or reactants so as to stabilize the polymer and incorporate it intimately with the asphalt, fillers or extenders to provide body and additional shielding or absorption, a stabilizing amount of antioxidants or stabilizers, and an amount of virgin or recycled radioactive shielding or absorptive additives suitable to provide the degree of shielding and absorption so desired for the application, including but not limited to alpha, beta, gamma and neutron shielding mediums. The novel compositions of the present invention may be used in a wide variety of applications for containing, managing, handling, storage and disposal of nuclear wastes. They are particularly unique in that they remain functional over a wide range of temperatures, provide Alpha, Beta, Gamma and Neutron shielding capabilities as well as function as a barrier and shielding material for many other types of radiation including but not limited to X-rays, Radon, and other types commonly known to those of ordinary skill in the art. The use of the hydrocarbon medium with the radioactive shielding and absorptive mediums provides for a synergistic effect due to the presence of polar constituents and the presence of a significant number of hydrogen molecules present in the hydrocarbon medium. As natural occurring elements within the asphalt component, they help to both shield and absorb various types of radiation emissions. Further, the addition of additional metals, their alloys, additives and minerals, both synthesized and naturally occurring can provide additional levels of shielding and absorption. The invention further provides for method(s) 300 whereby the compositions of the invention may be incorporated in or used as encapsulants, stabilizing, shielding, and preventing any leaching of the radioactive materials from the containment system, shielding fillers for cask type multi-wall shipping containers, protective barrier sheets, coatings, and binders thereof. They may be applied or incorporated into radioactive shielding applications or into the radioactive waste handling and storage applications by hot melt application, reactive one and two component systems, use as solverit cutbacks, or as emulsions which solidify upon application to satisfy a variety of needs for protecting workers and the environment when handling and disposing of nuclear waste and/or radioactive materials. They further provide for a material which can be used to waterproof the nuclear waste storage sites, incorporated into the storage containers themselves, line drainage ditches and troughs to provide a barrier to the soil underneath so as to prevent further contamination, or be applied to underlying soils prior to pouring concrete flooring slabs to prevent the migration of Radon gas into basements or living areas. Any suitable hydrocarbon component or asphalt cement may be employed for producing mixtures of the radiation shielding and absorbing compositions of the invention. For example, industrial asphalts used for coatings, sealants, roofing materials, adhesives, and other applications may be used. Paving grade asphalt compositions are employed in some embodiments. Asphalt compositions may be derived, as previously indicated, from any well known bituminous or asphaltic substance obtained from natural sources or derived from a number of sources such as petroleum, shale oil, coal tar, tar sands, and the like, as well as mixtures of two or more of such materials. Typical of such asphalts are the straight run asphalts derived from atmospheric, steam and/or vacuum distillation of crude oils, or those asphalts derived from solvent precipitation treatments of raw lubricating oils and their fractions. Also included are the thermal or “Cracked” asphalts which are separated as cracker bottom residues from refinery cracking operations and the asphalts produced as byproducts in hydro refining operations. Example asphalt is the vacuum tower bottoms that is produced during the refining of synthetic or petroleum oils. The asphalt may be treated or modified before use in the invention; so called “Blown” or “Oxidized” asphalts are used in roofing shielding compositions but may be also employed for encapsulant and filler applications when modified according to the invention. As indicated, for encapsulating and filler as well as coating compositions, any suitable paving grade asphalt may be employed as the hydrocarbon component for the compositions of the invention. Such paving grade asphalt compositions are often referred to as viscosity, penetration graded or performance graded (PG) asphalts having penetrations up to 500 as measured by ASTM method D5. Some example asphalts include the performance-graded asphalts such as PG46-40, PG46-34, PG46-28, PG52-40, PG52-34, PG52-28, PG52-22, PG58-40, PG58-34, PG58-28, PG58-22, PG64-40, PG64-34, PG64-28, PG64-22, PG64-16, PG70-34, PG70-28, PG70-22, PG70-16, PG70-10, PG76-34, PG76-28, PG76-22, PG76-16, PG76-10, PG82-34, PG82-28, PG82-22, PG82-16, or PG82-10. The PG in the title referring to Performance Grade, the first numeric designation referring to the binder's high temperature resistance range, and the last numeric designation referring to the binder's low temperature thermal cracking resistance range. Complete specification requirements are outlined under AASHTO Performance Graded Asphalt Binder Specifications. AASHTO is the designation for the American Association of State and Highway Transportation Officials. In an example manufacturing environment, the method 300 may be performed as follows. A mixing vessel equipped with air and nitrogen purging, agitation, and circulation are added in order 23.31 parts by weight of molten PG64-22 asphalt cement at a temperature sufficient to maintain pumpability and adequate mixing capability, 23.31 parts by weight of a Hydroxyl Terminated Polybutadiene polymer manufactured by Sartomer Corporation and marketed under the trade name R45HTLO. The polybutadiene polymer is allowed to pre-wet into the asphalt cement under agitation and mixing at temperatures between 180 and 280° F. Once the polymer is pre-wet and mixture is smooth and homogeneous, 2.33 parts by weight of napthenic extender oil is added, and the mixture continues to mix until homogeneous. The mixture is then stored at 200-250° F. with or without nitrogen purging as desired to minimize any moisture in the mixing vessel until it is pumped to an external mixing vessel where 46.62 parts of the radiation shielding and absorption additive is added under mixing and allowed to completely wet into the asphalt and polymer composition. Once mixed and homogeneous, the material is pumped through an inline mixing apparatus where it is mixed till homogeneous with 4.43 parts of a polycarbodiimide-modified diphenylmethane diisocyanate as the material is applied as a liner/filler material to radiation shielding storage casks for handling radiation emitting materials and wastes. Compositions produced according to the example will provide flexible, impact absorbing, temperature resistant, radioactive emission shielding and absorbing fillers and encapsulants for radioactive storage containers. Various other equipment and techniques and portions of the ingredients may be deployed to practice the method 300 and to produce the compositions 100 and 200. As more examples, compositions may be produced with ratios and/or ingredient combinations as follows: 4 parts asphalt to 1 part polymer; asphalt and radiation shielding and absorbing material without polymers; 1 part PG58-28 Base Asphalt to 1 part Polymer; PG64-22 asphalt and coarse sieve size radiation shielding and absorbing material; PG64-22 and an Extender Polyol; SBS and asphalt and radiation shielding and absorbing material; SBS, Sulfur Crosslinker, and asphalt and radiation shielding and absorbing material; SBS Peroxide Crosslinker and asphalt and radiation shielding and absorbing material; composition with Kevlar Fibers; composition with Fire Retardants(aluminum trihydrates); and Comparative Asphalt without Polymer and asphalt and radiation shielding and absorbing material. Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same purpose can be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments of the invention. It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combinations of the above embodiments, and other embodiments not specifically described herein will be apparent to one of ordinary skill in the art upon reviewing the above description. The scope of various embodiments of the invention includes any other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled. It is emphasized, that the Abstract is provided in order to comply with 37 C.F.R. §1.72(b). This requires that the Abstract allow a reader to quickly ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In the foregoing Detailed Description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate independent embodiment.
	summary
	description	The present disclosure relates generally to medical monitors and, more particularly, to certification of computers that are used in conjunction with medical devices. This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. In the field of healthcare, caregivers (e.g., doctors and other healthcare professionals) often desire to monitor certain physiological characteristics of their patients. Accordingly, a wide variety of devices have been developed for monitoring many such characteristics of a patient. Such devices provide doctors and other healthcare personnel with the information they need to provide the best possible healthcare for their patients. As a result, such monitoring devices have become an indispensable part of modern medicine. Monitoring devices are often configured as dedicated monitoring units (e.g., a stand-alone pulse oximetry monitor) with integral processing circuitry for receiving measurements from medical devices and converting these measurements into medical information that is meaningful to a clinician. However, certain types of medical devices are capable of being used with configurable personal computers that are loaded with software that communicates with the medical device. For example, a medical sensor may be capable of communicating directly with a personal computer, which, with the appropriate software, is able to receive the sensor measurements and process and display information related to the sensed data. In this manner, an off-the shelf computer may act as a medical monitor. In contrast to dedicated monitoring devices, which are limited-purpose machines, a personal computer (e.g., a general purpose computer) may be used for a variety of tasks and, as such, may run a variety of different software programs. Different end users may select different brands and/or computer models depending on their own needs. Accordingly, different types of computers may have differing levels of compatibility with particular medical devices. Further, an individual computer may be frequently upgraded or changed from its factory condition according to the needs of the user, and these updates often occur automatically in response software or operating system changes. In certain instances, these changes may cause certain incompatibilities with installed software for receiving medical device information. One or more embodiments of the present techniques will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. Medical monitors are built according to FDA or other regulatory specifications and undergo quality testing by the manufacturer. However, in the case of medical devices that may be used with personal or off-the-shelf computers, while the medical devices themselves are subjected to quality testing by the manufacturer, the computers may be purchased by an end user and, thus, are not necessarily tested by the medical device manufacturer for compatibility with the medical device. In such cases, a particular model of computer may be certified by a technician as being compatible with a particular type of medical device and the device's associated software for processing data or measurements. This certification may involve having a technician run diagnostic tests on an individual model of a computer to verify that the device and installed software are compatible and that accurate readings and data processing are performed. Such certifications are time-consuming and involve skilled personnel. In addition, the certification must be repeated for different brands and different models of computers. Because computer vendors frequently change their offerings as technology changes and improves, a particular computer model that has been certified for use with a particular medical device may become obsolete and no longer available on the market. In addition, end users may change the functionality of their own computers, which may introduce device incompatibilities. Provided herein is an automatic certification technique for a computer configured to be used in conjunction with a medical device. In addition, provided herein are systems and computers that include certification functionality (e.g., a certification module). The certification may involve using the computer to process stored data representative of data collected by the medical device and comparing the processed results to an expected result. In this manner, the computer may be certified as performing according to expectations. In certain embodiments, the certification module as well as the data representative of the medical device may be installed directly on the computer (e.g., bundled with software for receiving and processing the medical device signal) so that the certification may take place without any outside input from the medical device. In other embodiments, an input from an associated device may trigger the certification process. It should be understood that the certification techniques may be used in conjunction with medical devices for diagnosis and/or therapy. Such devices may include devices for sensing physiological parameters, collecting medical data (e.g., imaging data), delivering therapy, and performing procedures. The devices may include blood or tissue constituent sensors (e.g., pulse oximetry sensors, carbon dioxide sensors, or aquametry sensors), patient temperature sensors, transvascular fluid exchange sensors, blood flow, cardiovascular effort, glucose levels, total hematocrit, electrocardiography, electroencephalograpy, airway products and ventilation devices, infusion pumps, blood pressure devices, apnea masks, ultrasound transducers, and cardiac defibrillators. In addition, the certification techniques may be used with computers having installed software for receiving and processing signals from a medical device to generate medical information. Such computers may include personal computers, off-the-shelf computers, multi-purpose computers, laptops, desktop computers, notebooks, mobile communication devices, or any suitable computing device. Turning now to the figures, FIG. 1 depicts an embodiment of a computer certification system 10 that includes a computer 12 configured to be used on conjunction with a medical device 14. The computer 12 includes a processor 18 for executing routines or instructions stored in mass storage 20, such as instructions for implementing the techniques discussed herein and instructions associated with medical device operating software. Additionally, the computer 12 may include a display 22 coupled to the processor 18 via internal bus 23 and configured to display information regarding the output generated by the medical device, such as physiological parameters and/or alarm or operating indications. In certain embodiments, the computer 12 is a multi-purpose computer that is configured to run any number of software programs, such as word processing, database programs, and internet access. While installation of the medical device operating software may disable or prevent operation of particular types of programs, other maintenance programs may be configured to operate in the background. As such, the display 22 may also be used for display of other information, e.g., in addition to medical device information, according to the inputs provided by the user, and the computer 12 may include various input components 24, such as knobs, switches, keys and keypads, buttons, etc., to provide for operation and configuration of the computer 12. The computer 12 may also include an input port 26 for coupling to the medical device 14. For example, the computer may include a USB port for coupling to an external device. In other embodiments, the computer 12 may include a transceiver for coupling to wireless medical devices. FIG. 2 is a process flow diagram illustrating a method 40 for certifying the computer 12. The method may be performed as an automated procedure by a system, such as a system 10 that includes the computer 12 and the medical device 14, or by the computer 12 without an associated medical device 14. In addition, certain steps of the method may be performed by a processor, e.g., processor 18, that executes stored instructions for implementing certain steps of the method 40. According to a particular embodiment, instructions for certification stored on the computer 12 access stored data that is representative of data generated by the medical device 14 at step 44. It is envisioned that, in the depicted embodiment, the stored data may be stored in computer memory 20 or a portable memory device (e.g., a flash memory device). Accordingly, the stored data may be accessed when the computer 12 is not coupled to the medical device 14. The certification instructions may be part of medical device software for receiving signals from the medical device 14 and generating medical information. In particular implementations, installation of the medical device software is accompanied by executing the method 40 to complete the installation. For example, the installation and/or certification may be performed by an end user. In other embodiments, the installation and certification may be performed by a vendor of the software and medical device. The vendor may purchase an off-the-shelf computer, install the software, and initiate the steps of the method 40 to certify the computer 12. In other embodiments, the certification process 40 may begin upon computer startup or when the medical device software is accessed. That is, regardless of whether the initial certification was initiated by a vendor or the end user, additional certifications may be completed during the operation of the computer 12. At step 46, the stored data is processed according to the instructions installed on the computer 12 for processing incoming signals from the medical device 14. The processed output of the medical device operating software is compared to an expected result at step 48. At decision step 49, if the processed output is within an acceptable deviation from the expected result, the method 40 proceeds to step 50, and the computer is certified to be used with the medical device 14. If the processed output is outside of an acceptable deviation from the expected result, the method 40 proceeds to step 52, and the computer is not certified or is rejected. Optionally, the method 40 may prevent incoming signals from the medical device 14 and/or coupling of the medical device 14 to the computer 12 if the computer 12 is rejected. In other embodiments, the medical device software may be prevented from completing installation if the computer 12 is rejected. The stored data is representative of a typical medical device output when the medical device 14 is in operation (e.g., coupled to a patient). In particular embodiments, the stored data may be historical data that has been collected (e.g., recorded or stored) from a test device and that provides sufficient information for generating medical information about a patient. A test device may be a version of the medical device 14 that has been verified to generate a representative signal for a particular physiological parameter or other medical data. In other embodiments, the stored data may be simulated data that simulates the incoming signal of the medical device 14. By using data from a test device or simulated data, the certification process may provide information about the functionality of the computer 12 and its installed software that is isolated from any variations or irregularities in a particular medical device 14. That is, because the stored data is not generated by the medical device 14 itself, the certification may be specific to the computer 12. In other implementations, it may be advantageous to provide stored data that has been collected by the medical device 14 in question. For example, if the medical device 14 has been customized for a particular end use, the stored data may be generated from the medical device 14 for use in certification. In certain embodiments, the medical device 14 may be configured to generate an analog signal or a digital signal that is further processed via hardware and/or software to condition the signal and generate an output representative of medical information. For example, if the medical device 14 is a temperature sensor, the stored data representative of the medical device signal may be stored in the form of an analog signal in which the voltage varies according to the sensed temperature. In other embodiments, the data representative of an analog signal may be converted to a digital signal, and the certification process may include a digital-to-analog conversion step. The analog signal or digital signal may be processed according to instructions encoded in the installed software, which may include correlating particular voltages to particular temperature readings and providing an indication of the sensed temperatures. The calculated temperatures may be compared to the expected results, e.g., results from a test run or results that were independently confirmed, to determine if the computer 12 is compatible with the medical device 14. If the calculated temperatures deviate from the expected temperatures by less than a predetermined amount (e.g., less than a standard deviation), the computer 12 may be certified. Certification or rejection of the computer 12 may trigger one or more audible or visual indicators. For example, the display of an indicator or text message may be triggered upon certification of the computer 12. The indicator may be a green light, a check mark, and/or a message that refers to successful certification. Rejection of the computer 12 (e.g., a failure to be certified) may trigger an alarm, a red light, a message related to unsuccessful certification, and/or an inability to open or access the medical device software. The certification information may be provided to a regulatory agency, such as the Food and Drug Administration (FDA), as part of the certification process. Computer certification, such as certification via method 40, may be provided as part of the guidelines for approval of the medical device 14. In addition, all or part of a certification process may form part of text-based instructions or other training materials for the medical device 14. The device manufacturer may designate particular computer hardware specifications, including processor specifications, (manufacturer, speed, and features), RAM (memory size), hard disk size, other storage, communications, display, etc., and software specifications, such as operating system, drivers, utilities, etc as being compatible with the medical device software in question. These specifications may be provided as part of a software requirements specifications (SRS) document. As part of this or other submitted documentation for approval, the device manufacturer may specify how the use of the medical device software by an end user may be regulated or monitored, including any certification of the computer 12 to be used with the medical device 14. For example, the specifications may include guidelines for the frequency of the certification, such as every time the computer 12 is booted or after every update to the computer 12. In one embodiment, installation of new software or computer updates will trigger certification, such as via method 40, either automatically or through a pop-up window or reminder on the computer display Certification information for the computer 12 may be automatically provided to the FDA, or may be stored in the computer's memory 20 for later review or submission. FIG. 3 illustrates a block diagram of a system 54 for assembling certification information. The system 54 includes a central station 56 completion of certification of the computer 12 may be accompanied by entry of the certification date, time, or other information in a log file or database 58. The database 58 may compile certification information from several computers (e.g., computers 12a, 12b, and 12c) that are configured to couple to medical devices (e.g., medical devices 14a, 14b, and 14c). The central station 56 may store certification information to be accessed during an audit or review of a medical facility. In a specific embodiment, the certification techniques may be used in conjunction with a pulse oximetry system. FIG. 4 is a perspective view of a pulse oximetry system 62 with the computer 12 that may couple to a pulse oximetry sensor 64. The sensor 64 may include optical components such as a light emitter (e.g., a light emitting diode) and a light detector (e.g., a photodetector) that are applied to a patient and may be used to generate a plethysmographic waveform, which may be further processed by the computer 12. The sensor 64 may be coupled to the computer 12 wirelessly, or via a cable 66 that terminates in a connector 68 that is configured to couple to the computer. In a specific embodiment, the sensor 64 may be pulse oximetry sensor available from Nellcor-Puritan Bennett LLC, including a clip-type sensor suitable for placement on an appendage of a patient, e.g., a digit, an ear, etc. In other embodiments, the sensor 64 may be a bandage-type sensor having a generally flexible sensor body to enable conformable application of the sensor to a sensor site on a patient. In yet other embodiments, the sensor 64 may be secured to a patient via adhesive (e.g., in an embodiment having an electrode sensor) on the underside of the sensor body or by an external device, such as headband or other elastic tension device. In yet other embodiments, the sensor 64 may be configurable sensors capable of being configured or modified for placement at different sites (e.g., multiple tissue sites, such as a digit, a forehead of a patient, etc.). In embodiments in which the sensor 64 is wireless, wireless communication with the computer 12 may be accomplished using any suitable wireless standard, such as the ZigBee standard, WirelessHART standard, Bluetooth standard, IEEE 802.11x standards, or MiWi standard. FIG. 5 is a block diagram of the system 62. The computer 12 includes microprocessor 70 coupled to an internal bus 72. Also connected to the bus 72 may be a mass storage device 74, a display 76, and a user input 78. As depicted, the computer 12 may include functional modules, such as an oximetry module 80 and a certification module 82. In other embodiments, the functionality of the oximetry module 80 and certification module 82 may be achieved via the microprocessor 70 executing routines stored in the mass storage device 74. In addition, the computer 12 includes a sensor drive 84 coupled to a sensor input port 86. The sensor drive 84 may include a time processing unit (TPU) to provide timing control signals to light drive circuitry, which controls when the optical components of the sensor 64, such as light emitter 88 and light detector 90, are activated, and, if multiple light sources are used, the multiplexed timing for the different light sources. The sensor drive 84 may also control the gating-in of signals from sensor 64 through one or more switching circuits. The received signal from the pulse oximetry sensor 64 may be passed to the oximetry module 80, which may include one or more signal conditioning elements that may be hardware or software-enabled, including an amplifier, a low pass filter, and an analog-to-digital converter. Based at least in part upon the received signals, the oximetry module 80 may calculate the oxygen saturation and/or heart rate using various algorithms, such as those employed by the Nellcor™ N-600x™ pulse oximetry monitor, which may be used in conjunction with various Nellcor™ pulse oximetry sensors, such as OxiMax™ sensors. These algorithms may employ certain coefficients, which may be empirically determined, and may correspond to the wavelengths of light used. In one embodiment, the correction coefficients may be provided as a lookup table. In the depicted embodiment, a memory element 94 associated with the sensor 64 is configured to store certain information that is accessed by the certification module 82, such as stored data representative of output by the detector 90. The memory element 94 may also store calibration and identification information, including compatibility information for the computer 12. For example, the memory element 94 may store compatible medical device software version information that may be accessed by the calibration module 82 as part of the certification process. The memory element 94 may be associated with the sensor body, the cable 66, or the connector 68. In other embodiments, data representative of detector output may be stored on the computer 12 as part of the certification module 82. The computer 12 is capable of reading the information from the memory element 94 to as part of the certification process. FIG. 6 is a process flow diagram illustrating a method 100 for certifying the computer 12 in conjunction with the sensor 64, on which data representative of sensor data is stored. According to an embodiment, the method 100 begins at step 102 by coupling the pulse oximetry sensor 64 to the computer 12 and starting the computer 12 (e.g., booting the computer or opening the medical device software installed on the computer) at step 104. The computer 12 reads the initialization requirements based on information stored in the memory element 94 at step 106 to determine if the computer 12 passes an initialization test at step 108. The initialization requirements may include software and sensor compatibility requirements (e.g., if the sensor is from a manufacturer that is supported by the software), software and hardware specifications, and software version specifications. The stored information may include explicit initialization information, or may include identification information for the sensor that may be further analyzed by the certification module 82 to determine compatibility. If the computer 12 is not compatible with the medical device (e.g., sensor 64), the computer 12 is rejected at step 110. If the computer 12 passes the initialization requirements, the method 100 moves to step 112 to read simulated data stored on the memory element 94. The simulated data may be processed by the oximetry module 80 at step 114 and the results compared with expected results at step 116. If the results do not match, the computer is rejected at step 120. If the results match expected results, the computer 12 is certified and the software may continue operating at step 122. An indication of successful certification may be provided at step 124. The embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.
	description	A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. The present invention relates generally to interactive test and/or measurement environments and more particularly to methods and systems for controlling interactive test and/or measurement environments. Computers may include software tools that run on the computers and perform desired functions. For example, computers may include software tools that provide programming environments. The programming tools enable users to create programs that can be executed on the computers to perform specific functions designed by the users. The programming tools may provide textual and graphical environments for generating the programs. MATLAB® and Simulink®, both from The MathWorks Inc. of Natick, Mass., are exemplary software tools that provide textual and graphical programming environments, respectively. MATLAB® integrates mathematical computing, visualization, and a powerful language to provide a flexible environment for technical computing. Simulink® enables users to design a block diagram for a target system, simulate the system's behavior, analyze the performance of the system, and refine the design of the system. Computers may also include software tools that provide other functions, such as reading/writing data from/to external devices. MATLAB® Toolboxes, from The MathWorks Inc. of Natick, Mass., provide exemplary software tools that enable the computers to perform a plurality of functions, including interfacing with the external devices. The fields of Test & Measurement and Industrial Automation often involve interfacing with hardware devices, such as external devices, in the form of instruments or other devices from which data is imported into the software environment. Historically, because of a wide variety of instruments and protocols for communication for hardware devices, establishing and maintaining an interface to many types of hardware devices has resulted in an inordinate amount of effort on the part of the user and/or very limited interface capabilities available to the user. Oftentimes, even if an interface to one hardware device is established, difficulties can arise in establishing additional interfaces or organizing several interfaces for the many hardware devices that may be accessible to a computer. The present invention provides a graphical interface capable of indicating available hardware and software devices. The present invention can also provide opportunities for enhanced control and simplified operation of hardware and software devices accessible to an electronic device, such as a computer. Such devices may include a wide variety of hardware and software devices. The graphical communication interface can create objects that are associated with hardware or software devices. The objects are representative of the device and are depicted in the graphical interface. The objects are configured to be interactive with the device and enable communication between the graphical interface and the hardware device. The graphical interface can include both software objects and hardware objects, and the objects can include user-defined protocols to communicate with the device, allowing communications with a wide variety of devices. According to one embodiment of the invention, a method is provided having the steps of providing a graphical interface and providing at least one hardware object. The hardware object is representative of a hardware device and is depicted in the graphical interface. The hardware object is configured to be interactive with the hardware device and to enable communication between the graphical interface and the hardware device. A software object and/or an analysis object is also be provided. The software object is representative of a software device and is depicted in the graphical interface. The software object is configured to be interactive with the software device and to enable communication between the graphical interface and the software device. The analysis object is adapted to communicate with the hardware object and/or the software object. Optionally, a medium may be provided holding electronic device executable steps for the methods of the invention. An illustrative embodiment of the present invention provides a graphical interface for managing interfaces with hardware and software devices in a measurement system. The graphical interface provides a view of hardware objects that represent the hardware devices and software objects that represent the software devices. Analysis objects may also be displayed via the graphical interface. The analysis objects represent analyses that may be performed relative to the hardware and software objects. The graphical interface can be operated on an electronic device to simplify management of one or more interfaces of hardware and/or software devices located locally or remotely. Measurement systems are often created for use in the Test & Measurement and Industrial Automation fields to enable test and/or control one or more devices. The measurement system, illustrated by way of example in FIG. 1, may include a unit under test 110, hardware 120, such as an instrument, to measure the unit under test 110, an electronic device 130, such as a computer, with an interface 140 to the hardware 120 and software 150 to send to and receive data from the hardware. It is understood that the unit under test may be a process being controlled. In an alternative embodiment, the hardware 120 may be incorporated in the unit under test 110. According to an illustrative embodiment of the invention, a graphical interface 200 is provided to access various types of hardware and software by the use of hardware and/or software objects. FIG. 2 illustrates an example of a graphical interface 200 according to the illustrative embodiment of the invention. The graphical interface 200 may include a tree view 210, a detail view 220 and a help panel 230. It is understood that a wide variety of graphical configurations are within the scope of the invention, and the various views and/or panels may be added, deleted or modified. The various views may also be configured in multiple windows. The tree view may be configured as an expandable tree, grouping similar types of components. A further example of a tree view 210 is provided in FIG. 3. The graphical interface 200 of the illustrative embodiment can provide access to hardware accessible to the electronic device and software accessible by the electronic device. The graphical interface 200 provides access to such hardware by the use of hardware objects depicted in the interface 200. In the same interface, software objects may also be depicted and provide access to software accessible by the electronic device. The graphical interface 200 allows multiple configurations for the same piece of hardware, such as by the use of multiple hardware objects corresponding to a specific unit of hardware. The interface 200 can display all configurations that have been defined and provides an opportunity to select what configuration is used to communicate with a piece of hardware by the selection of the desired hardware object and/or the opportunity to edit the properties of the hardware object. The graphical interface 200 can provide access to any type of hardware device capable of receiving a signal from an electronic device and/or providing a signal to an electronic device. Examples of hardware devices can include, but are not limited to, any type of input/output device, industrial control and/or monitoring hardware, data acquisition cards, data transmission cards, instruments and image acquisition and transmission hardware. The hardware object may interface with a driver for communication with the hardware device. The interface to the hardware can be independent of the vendor of the hardware. For example, the interface supports GPIB cards by Agilent Technologies, Keithley, Measurement Computing Corporation, and others. When communicating with GPIB instruments, the graphical interface 200 may allow users to define the type of driver that the software object uses for communicating with the hardware. By way of example, the hardware object may support either the VISA driver or the vendor-supplied driver that comes with the GPIB board. The graphical interface 200 also can provide access to software devices. A software device is a unit of code capable of receiving an input and/or sending an output. Examples of inputs and outputs can include, but are not limited to, signals, data or other types of information. Examples of receiving and sending can consist of writing information to a memory location or passing information to a communications port, such as a serial port, or a buffer. Examples of software devices include, but are not limited to, DLLs, objects, subroutines, and databases. FIG. 4 illustrates one example embodiment of an electronic device 130 suitable for practicing the illustrative embodiment of the present invention. The electronic device 130 is representative of a number of different technologies, such as mainframes, personal computers (PCs), laptop computers, workstations, personal digital assistants (PDAs), Internet appliances, cellular telephones, and the like. In the illustrated embodiment, the electronic device 130 includes a central processing unit (CPU) 13 and a display device 15. The display device 15 enables the electronic device 130 to communicate directly with a user through a visual display. The graphical interface 200 may be displayed on the display device 15. The electronic device 130 may further include a keyboard 17 and a mouse 19. Other potential input devices not depicted include a stylus, trackball, joystick, touch pad, touch screen, and the like. The electronic device 130 may include primary storage 21 and/or secondary storage 23 for storing data and instructions. The storage devices 21 and 23 can include such technologies as a floppy drive, hard drive, tape drive, optical drive, read only memory (ROM), random access memory (RAM), and the like. Applications such as browsers, JAVA virtual machines, and other utilities and applications can be resident on one or both of the storage devices 21 and 23. JAVA is available from Sun Microsystems, Inc. of Santa Clara, Calif. The electronic device 130 may also include a network interface 25 for communicating with one or more electronic devices external to the electronic device 130. A modem (not shown) is one form of establishing a connection with an external electronic device or network. The CPU 13 may have coupled thereto one or more of the aforementioned components, either internally or externally. The graphical interface 200 can be configured to operate on multiple platforms. Although the invention is not so limited, examples of platforms include MICROSOFT WINDOWS, available from Microsoft Corporation of Redmond, Wash. and Unix. The graphical interface 200 may allow the definition of analysis objects that couple with hardware and software objects. The analysis objects can be used for a wide variety of programmatic applications, such as analysis of results from hardware and/or software. Examples of applications of analysis objects include, but are not limited to: interfacing with hardware and/or software objects and/or databases, interfacing with financial data sources such as Bloomberg, IDC and HyperFeed, analyzing financial market data, performing general and large-scale optimization, simulation, visualization and analysis of neural networks, reading, writing, filtering and/or plotting data, including data from examples such as a file, an environment, another object or a workspace variable. By way of further example, the analysis objects can be used to enable the graphical interface 200 to be modified to support any of the capabilities of MATLAB and its toolboxes. According to one embodiment of the invention as illustrated in FIG. 5, a method 400 is provided having the steps of providing a graphical interface 200, step 410. At least one hardware object is also provided, step 420. The hardware object is representative of a hardware device, is depicted in the graphical interface, and is configured to be interactive with the hardware device and enable communication between the graphical interface and the hardware device. Optionally, at least one software object may also be provided, step 430. The software object is representative of a software device and is depicted in the graphical interface. The software object is configured to be interactive with the software device and to enable communication between the graphical interface and the software device. Also, an analysis object may optionally be provided, step 440, and adapted to communicate with the hardware object and/or the software object for analysis of data from the hardware object and/or the software object. Any number of modular components 240 can appear in the graphical interface 200. There may be a component that represents and interacts with instruments and another component that represents and interacts with data acquisition hardware. In the illustrative embodiment, each modular component is defined as a client of the graphical interface 200. A component generally performs tasks similar to those grouped with it, although a group may be formed of a single component, as illustrated by both the localhost:4000 component 240C and GPIB0-5 component 240D of FIG. 3. According to the illustrative embodiment, in order for a client to appear in the graphical interface 200, the client implements a specific API. This API defines routines that each client defines. These routines may include, for example, defining what tree nodes appear in the graphical interface 200, defining what graphical panels are shown when a tree node is selected, defining the actions that occur when the graphical interface 200 scans for available hardware and defining what information is saved between sessions of the graphical interface 200. The graphical interface 200 may be implemented with an extensible API. This allows other developers or users to define custom objects to appear in the graphical interface 200. Also, according to the illustrative embodiment, a client can optionally extend a base client. The base client defines default implementations for the methods in the API. This can assist client writers since the client writer then need only have to write those methods that they are interested in. For example, if the client does not interact with hardware, the client does not need to implement the method that scans for available hardware. Instead, the client can use the base client scan for hardware implementation which may be configured to do nothing. In the illustrative embodiment of the invention, the API can specify how to define a root node. In this embodiment of the invention, each browser client should include all it's tree nodes underneath a root node. To define the root node, the browser client implements the getRootNode method. This method takes no input arguments and returns a BrowserTreeNode. For example: public BrowserTreeNode getRootNode( ){ return new BrowserTreeNode(“Instrument Control”, this); } A browser client's root node may have a list of sub-folders that the remaining nodes are grouped into. These nodes can be defined with the getLevelOneNodes method. This method takes no input arguments and returns a BrowserTreeNode[ ] of nodes. For example: private BrowserTreeNode level1=new BrowserTreeNode(“Instrument Hardware”, this); private BrowserTreeNode level2=new BrowserTreeNode(“Instrument Control Objects”, this); private BrowserTreeNode[ ] levelNodes={level1, level2}; public BrowserTreeNode[ ] getLevelOneNodes( ){ return levelNodes; } © 2003 The MathWorks, Inc. To avoid removal of the node when it's children nodes are removed, the node may be defined as a level-one node. Further according to the illustrative embodiment, each browser client can add new top-level menus and menu items beneath existing menus. To define the menu items, a client implements three methods: getHelpMenuItem, which returns the Toolbox Help JMenuItem; getAboutMenuItem, which returns the About Toolbox JMenuItem; and getMenus, which returns an array of JMenus to be added to the menubar. The getHelpMenuItem method returns a JMenuItem for displaying the Toolbox Help. For example: private JMenuItem helpMenuItem=new JMenuItem(“Instrument Control Toolbox”); public JMenuItem getHelpMenuItem( ){ return helpMenuItem; } © 2003 The MathWorks, Inc. The getAboutMenuItem returns a JMenuItem for displaying the About Toolbox dialog. For example: private JMenuItem aboutMenuItem=new JMenuItem(“About Instrument Control”); public JMenuItem getAboutMenuItem( ){ return aboutMenuItem; } © 2003 The MathWorks, Inc. Additional menu items can be added with the getMenus method. For example: private JMenu[ ] menus=null; public JMenu[ ] getMenus( ){ if (menus=null) { //Create the View menu items. JMenu view=new JMenu(“View”); JMenuItem icView=new JMenu(“Instrument Control Toolbox”); view.add(icView); JCheckBoxMenuItem hardware=new JCheckBoxMenuItem(“Hardware”, true); JCheckBoxMenuItem instrObj=new JCheckBoxMenuItem(“Instrument Objects”, true); JCheckBoxMenuItem instrDriver=new JCheckBoxMenuItem(“Instrument Drivers”, true); icView.add(hardware); icView.add(instrObj); icView.add(instrDriver); //Create the Tools menu items. JMenu tools=new JMenu(“Tools”); JMenu icTools=new JMenu(“Instrument Control Toolbox”); tools.add(icTools); JMenuItem newObject=new JMenuItem(“New Instrument Control Object . . . ”); JMenuItem scan=new JMenuItem(“Scan for Instrument Hardware”); icTools.add(newObject); icTools.add(scan); //Create output. menus=new JMenu[2]; menus[0]=view; menus[1]=tools; } return menus; } © 2003 The MathWorks, Inc. The detail view 220 may be updated based on the node selected in the tree view 210 when the user left clicks on a node in a tree. To define what JPanel is added to the Detail View, the browser client implements the getPanel method. This method takes three input arguments: the node that was selected; the node that was previously selected; and an array of nodes that are selected. Based on the previous node selected and the node that is currently selected, the client may decide that the detail view 220 does not need to be updated. Each node has an okToUpdatePanel property. If okToUpdatePanel is configured to false, then the detail view 220 will not be repainted. If okToUpdatePanel is configured to true, the panel in the detail view 220 will be removed and the new panel will be added. The okToUpdatePanel Boolean is configured with the updatePanel method. The getPanel method returns a JPanel that will be added to the detail view 220 (if okToUpdatePanel is true). If the getPanel method returns null, the detail view 220 will be cleared. The third input argument may be a list of nodes that are selected. If the client allows multiple selection, the client should return the correct panel based on all the nodes selected. If the client does not allow multiple selection and more than one node is selected, the client should return null. In the illustrative embodiment, it can be assumed that the first argument passed to the getPanel method is the node that is currently selected. There are three methods in the illustrative embodiment for adding a node to the tree view. To add a node, the browser client may implement the postNodeAddedEvent method. The input arguments taken by postNodeAddedEvent method are dependent upon the method used to add the node. The postNodeAddedEvent method may post the event to all its listeners. According to the first illustrative method for adding a node to the tree view, a node is added based on the node's path. This method takes the following input arguments: the node name, e.g. GPM-NI-01; the path to the node that is being added, e.g. Instrument Control-Instrument Control Objects; the node that is being added (BrowserTreeNode); the mode for adding a node; and a Boolean variable indicating if the node should be selected after it is added. There are four modes for adding a node. In the first mode, if the path exists and the node does not exist, the node is added. If the path exists and the node exists, the node is added. There will be two nodes with the same name. If the path does not exist, the node is not added. In the second mode, if the path exists and the node does not exist, add the node. If the path exists and the node does exist, do not add the node. If the path does not exist, the elements in the path that do not exist are added and the node is added. According to the third mode, if the path exists and the node does not exist, the node is added. If the path exists and the node does exist, the node name is incremented and the node is added. If the path does not exist, the elements in the path are added that do not exist and the node is added. In the fourth mode, the node is always added as is. According to the illustrative embodiment, in all of the modes, the node is always added to the end of the parent list. The second illustrative method for adding a node to the tree view is similar to the first method, except that the position the node is inserted is a sixth input argument. For example, if the parent node contains three nodes, and the position for insertion of the node is greater than 3, the node is appended to the parent's child list. The third illustrative method for adding a node to the tree view is slightly different than the first two methods in that the client defines the parent node that the child node is inserted to. This method takes the following input arguments: the parent node (BrowserTreeNode); the child node, i.e. the node that is being inserted (BrowserTreeNode); a Boolean variable indicating if the node should be selected after it is added; and the position that the node should be inserted. According to the illustrative embodiment, there are four methods that will remove a node from a tree view. To remove a node, the browser client may implement the postNodeRemovedEvent method. The input arguments taken by postNodeRemovedEvent method are dependent upon the method used to remove the node. The postNodeRemovedEvent method may post the event to all its listeners. For an example, refer to BaseBrowserClient. In all methods of the illustrative embodiment, after the node(s) are removed, the parent node of the last node removed is selected. According to the first method, the node is removed based on the node's name. The following input arguments are used: the node name; the path to the node that is being deleted; and the mode for deleting a node. In the illustrative embodiment, there are four modes for deleting a node. In the first mode, if the specified path and node exist, the node is removed. In the second mode, if the specified path and node exist, the node is removed. If the parent node of the node removed contains no other nodes, the parent node is removed. This continues until there are no more parent nodes or a non-empty parent node is encountered. According to the third mode, if the specified path and node exist, the node is removed. If the parent node of the node removed contains no other nodes, it is removed. The fourth mode provides that if the specified path and node exist, the node is removed. If the parent node of the node removed is empty and is not a root or level-one node, such as may be defined by the getRootNode and getLevelOneNodes methods, the node is removed. This continues until a parent node is encountered that is non-empty or is a root node or is a level-one node. According to the second mode for deleting a node, the node is removed based on the node's UserData. In summary, the node that matches the given UserData is removed. The following input arguments are used: the path to the node that is being deleted; the UserData of the node that is to be deleted; and the mode for deleting a node. This method should be used if the name of the node may be modified, such as incremented, when it is added. Or, it is possible to have two or more nodes with the same name. The third mode for deleting a node defines the node that is to be removed based on the node itself and it's parent. The following input arguments are used: the parent node and the child node that is being deleted. The fourth mode defines the node that is to be removed based on the node itself. The input argument of the node that is being deleted is used. If the client changes the node's name, it may post an event to the tree view 210 to refresh itself. To refresh a node, the browser client may implement the postNodeUpdatedEvent method according to the illustrative embodiment. The node that has been updated is passed as an input argument to the postNodeUpdatedEvent method. The postNodeUpdatedEvent method may post the event to all its listeners. When a node is selected in the tree view 210, the client may add additional menu items to the existing menus. To do this, the browser client may implement the getMenus method. The getMenus method takes the following input arguments: the BrowserTreeNode that is currently selected; the BrowserTreeNode that was previously selected; and an array of all the selected nodes. Based on the input arguments, the browser client may decide to return menu items. If no menus are to be added, the getMenus method should return null and the node's updateMenu method should be called with true, which may be the default value. If the menu items from the previously selected node apply to the node that is currently selected, the node's updateMenu method should be called with false and the getMenu method should return null. Otherwise, the getMenus method should return a JMenu[ ] of menus to add. For example: public JMenu[ ] getMenus(BrowserTreeNode node, BrowserTreeNode oldNode) { if (node.getClient( )!=oldNode.getClient( )){ //The previously selected node was this client's node. //Define the menu items to add. JMenu fileMenu=new JMenu(“File”); JMenuItem export=new JMenuItem(“Export”); JMenuItem test=new JMenuItem(“Test”); fileMenu.add(export); fileMenu.add(test); fileMenu.addSeparator( ) //Construct the output. nodeMenus=new JMenu[1]; nodeMenus[0]=fileMenu; //Indicate that the menu items need to be updated. node.updateMenu(true); return nodeMenus; } else { //The previously selected node was this client's node therefore the //menus do not need to be updated. node.updateMenu(false); } return null; } © 2003 The MathWorks, Inc. The menu items are added to the top of the JMenu specified. Therefore, the client may add a separator after the menu items that is being added. It may not be permissible to add a JMenu that does not already exist. For example, if the menubar contains only File and Help menus, the client may be prevented from adding a Demo menu to the menubar. The graphical interface 200 can save information between sessions of using the graphical interface 200. For example, the hardware, software and analysis objects created may be saved for use in future sessions, thereby noting hardware devices and the drivers found. This allows users to pick up where they left off when using the graphical interface 200 without having to re-scan for information. The graphical interface 200 may also save information about actions the user took, such as software objects that were created between sessions of using the graphical interface 200. For example, before the browser is closed, the client may want to save the hardware that is found so that the next time the browser is opened, the tree can be populated with the information from the previous session. In order to do this, the client may implement the save and load methods. A cleanup client method may be called after the save method. The save method takes the following arguments: BrowserConfigFileWriter and an XML element. The file that contains the data is an XML file. The BrowserConfigFileWriter creates the XML file and contains some helper methods for adding nodes to the XML file. The second argument, the XML element, is the element that is specific to the client currently being saved. All nodes that are added to the XML file should be added to this element. The following example saves some information from a hardware device found on a serial port. public void save(BrowserConfigFile file, Element parent){ for (int i=0;i<data.length;i++){ Element instr=file.addNode(parent, “Instrument”); instr.setAttribute(“Type”, “serial”); instr.setAttribute(“Identification”, (String)data[i][1]); instr.setAttribute(“Port”, (String)data[i][0]); } } © 2003 The MathWorks, Inc. The load method takes the following arguments: BrowserConfigFileReader and an XML node. The XML node contains the information that the client saved. public void load(BrowserConfigFileReader bf, Node node) { if (node=null) { return; } NodeList children=node.getChildNodes( ) for (int i=0;i<children.getLength( )i++){ String name=children.item(i).getNodeName( ) if (name.equals(“Instrument”)) { String type=((Element)children.item(i)).getAttribute(“Type”); String id=((Element)children.item(i)).getAttribute(“Identification”); String port=((Element)children.item(i)).getAttribute(“Port”); } } } © 2003 The MathWorks, Inc. In this example, the BrowserConfigFileReader does not contain any helper methods for reading the XML file. It is understood that if helper methods are desired, they may be added. To get the frame to the hardware browser, the browser client may open additional dialogs from menu items, right-click menus, a double-click or from the detail view panel. If the dialog is modal, the dialog may be handed a frame that the dialog is attached to. To get the Browser frame, the browser client may implement the setBrowserFrame method. The Browser Client could store the frame in a local variable to be used as needed. A browser client can be defined according to the illustrative embodiment of the invention as follows. First, an XML file is created. In the present example, the file is named tmgui.xml. The tmgui.xml file may contain information about other graphical user interfaces that may be used with the present invention. The tmgui.xml file may be placed in a toolbox root directory, e.g. matlabroot/toolbox/instrument/instrument. The tmgui.xml file may include the following: <tmguiinfo> <gui> <name>Browser</name> <client>com.mathworks.toolbox.instrument.browser.InstrumentControlBrowser</client> </gui> </tmguiinfo> © 2003 The MathWorks, Inc. As illustrated in FIG. 6, when the graphical interface 200 is instantiated, step 510, the graphical interface 200 may scan for clients, step 520. In the illustrative embodiment, the graphical interface 200 is used with MATLAB, although the invention is not so limited. In this embodiment, the MATLAB path is scanned for clients. When scanning for clients, the graphical interface 200 looks for all tmgui.xml files on the MATLAB path. According to the illustrative method 500, the XML file is read, step 530, to determine the class name of the client. If the client list is to be altered, step 540, this approach allows clients to be added or removed, step 550, from the graphical interface 200 based on the user's choice. For example, a tmgui.xml file could be removed or renamed if the component it represents should not be shown in the graphical interface 200. Or the client names can be supplied, step 560, to the graphical interface 200 and only those clients would be instantiated. In the illustrative embodiment, the clients that are found are instantiated and stored within the graphical interface 200. The tree nodes that have been defined by each client are added to the tree view 210 of the graphical interface 200. Each tree node is defined by a java class that extends the java DefaultMutableTreeNode class. This allows for some additional information to be stored with the tree node. This information includes the client that created the tree node, the panel that is shown in the detail view when the tree node is selected, a flag indicating if the tree node is editable, etc. This assists clients in managing what occurs when a tree node is selected. As shown by way of example in the method 600 of FIG. 7, when a tree node is selected, step 710, the graphical interface 200 determines, step 720, what client added the selected tree node to the graphical interface 200. The graphical interface 200 then calls the client, step 730, to determine how the graphical interface 200 should be updated, step 740. For example, the client returns instructions on what menu items should be added, what panel should be shown in the detail view 220 and what help text should be shown in the help panel 230. As noted above, the graphical interface 200 also contains instances of the tree view 210, detail view 220 and help panel 230. Based on the instructions returned by the client, the graphical interface 200 instructs the tree view 210, detail view 220 and help panel 230 on how to update. The graphical interface 200 also controls the menu bar, frame, toolbar and status bar. The menu bar is also updated based on the client's instructions. Since the client defines the menus and panels that are shown in the graphical interface 200 of the illustrative embodiment, when a user interacts with one of them, the client can define what occurs, for example, the client can define what happens when a button is selected and the graphical interface 200 is not involved. However, the client can post events to the graphical interface 200 if it should be updated based on the user actions. For example, the client can post an event to have a tree node added to the graphical interface 200 or to have the status bar updated with status information. According to the illustrative embodiment, the user may optionally define what hardware is available in the graphical interface 200. Once a hardware device has been added, the hardware device can be identified using the same scan routine as other hardware devices. The hardware device that was added may also be saved between graphical interface 200 sessions. Software objects, hardware objects and analysis objects may be on a local or remote machine. If on a remote machine, the objects may optionally be accessed through a web page that, in the illustrative embodiment, shows the same graphical interface 200. With reference to FIG. 8, according to the illustrative embodiment, the graphical interface 200 provides live interaction with an array-based environment 250. Examples of array-based environments can include MATLAB or other interpretive programming environments capable of interfacing with one or more arrays. Changes that are made to the software objects, hardware objects and analysis objects in the array-based environment 250 are reflected in the graphical interface 200. For example, if the hardware object is disconnected from an associated hardware device from within the array-based environment 250, the graphical interface 200 is updated to indicate that the hardware object is no longer connected to the hardware device. Similarly, if a software object is created in the array-based environment 250, the graphical interface 200 may be updated to include the software object. The user may interact with the software object, hardware object and analysis object from either the array-based environment 250 or the graphical interface 200. Results obtained with the graphical interface 200 may be exported from the graphical interface 200 to the array-based environment. This allows further analysis to be done on the data in the array-based environment 250. The graphical interface 200 of the illustrative embodiment provides an option to scan for available hardware. Available hardware can include any hardware that the electronic device is able to communicate with. Communication can be in many forms, including digital and/or analog signals and signals in wired, wireless, electrical and/or optical form, or other forms or methods apparent to one of skill in the art. In scanning for available hardware, the illustrative embodiment first attempts to identify hardware. For example, when identifying instruments, various commands are sent to the instrument to try to identify it. Different hardware devices respond to different commands. The commands that are used to identify the hardware devices may be user-definable. This can enable any hardware device, such as any instrument, able to communicate with the electronic device to be identified and represented in the graphical interface 200. The graphical interface 200 can provide embedded procedural help in the help panel 230 to assist users with the graphical interface 200. The help can be hidden from the graphical interface 200 giving the user more space for interacting with the graphical interface 200. According to the illustrative embodiment, clients of the graphical interface 200 can control what help is included based on the root node or tree node that is selected. The graphical interface 200 and the clients may be implemented using JAVA. Using the JAVA-to-MATLAB interface, the graphical interface 200 and its clients can pass information from the JAVA side to the MATLAB side. Similarly, when something occurs on the MATLAB side, an event can be posted that the client is listening for. This allows the graphical interface 200 to be updated based on user actions on the MATLAB side. The software 150 operating on the electronic device 130 may include software tools, such as MATLAB®, Simulink®, MATLAB® Toolboxes, and Simulink® Blocksets, all from The MathWorks, Inc. of Natick, Mass. One of skill in the art will appreciate that the described software tools are merely illustrative and the invention is applicable to use with other software tools. Another example of software tools that may be used with embodiments of the invention include those related to OLE for Process Control (OPC). Built-in interfaces of MATLAB® enable users to access and import data from instruments, files, and external databases and programs. In addition, MATLAB® enables the users to integrate external routines written in C, C++, Fortran, and Java with the MATLAB® applications. In the illustrative embodiment, the software objects and/or hardware objects that are created with the graphical interface 200 can be converted to MATLAB® code, or other types of code, such as C, C++, Fortran, and Java, or saved to a binary file. The software objects and/or hardware objects can be re-created from either the MATLAB® code or from loading the binary file. According to the illustrative embodiment, an ability to record user actions with the graphical interface 200 and optionally convert the user actions to MATLAB® code in order to later recreate or automate the user actions. Examples of these user actions can include, but are not limited to: connecting/disconnecting to/from hardware by selecting a button, sending data to and receiving data from the hardware by selecting buttons and entering text strings. These interactions with the graphical interface are converted to code that creates a software object, hardware object or analysis object, configures the object and writes and reads data from the object. The code is created by incorporating the relevant characteristics of the graphical interface at the time of the user action in order to properly specify the code. This code can be executed from within the MATLAB® environment. The code can also be modified to include analysis routines. The code that is generated can also be used to develop a deployable solution. Simulink® provides a graphical user interface (GUI) component that allows drafting of block diagram models by users. The visual representation of the target systems in the block diagrams allows for a convenient interpretation of the target systems and provides an intuitive notion of the behavior of the target systems. Simulink® also allows users to simulate the designed target systems to determine the behavior of the systems. The graphical interface 200 of the present invention may interact with Simulink® as described above in relation to MATLAB®. According to an illustrative embodiment, the graphical interface 200 can be used from within Simulink® and/or objects created by the graphical interface 200 can be exported and used by Simulink®. MATLAB® Toolboxes include a plurality of Toolboxes, such as Instrument Control Toolbox, Data Acquisition Toolbox and Image Acquisition Toolbox. The Instrument Control Toolbox provides communications with instruments, such as oscilloscopes and function generators, directly from MATLAB. Instrument Control Toolbox supports for GPIB, VISA, TCP/IP, and UDP communication protocols. Users may generate data to send out to an instrument, or read data for analysis and visualization. The transferred data can be binary or ASCII. The Instrument Control Toolbox supports both synchronous and asynchronous read and write functions. A synchronous operation blocks access to the command line until the read or write is completed. An asynchronous operation does not block access to the command line, and additional MATLAB® commands can be issued while the read or write operation executes. According to the illustrative embodiment, the components 240 shown in the graphical interface 200 can change based on the MATLAB® Toolbox capabilities installed on the electronic device. Simulink® Blocksets contain application specific blocks that support the modeling and simulation of systems in the block diagram environment provided by Simulink®. Simulink® Blocksets provide blocks that are incorporated into the models of the systems, and include subsets, such as DSP Blockset, Fixed-point Blockset and Communications Blockset, from The MathWorks, Inc. of Natick, Mass. The Blocksets provide utilities for the development and integration of models for the systems and sub-systems of the systems. According to the illustrative embodiment, the components 240 shown in the graphical interface 200 can change based on the Simulink® Blockset capabilities installed on the electronic device. The present invention has been described by way of example, and modifications and variations of the described embodiments will suggest themselves to skilled artisans in this field without departing from the spirit of the invention. Aspects and characteristics of the above-described embodiments may be used in combination. The described embodiments are merely illustrative and should not be considered restrictive in any way. The scope of the invention is to be measured by the appended claims, rather than the preceding description, and all variations and equivalents that fall within the range of the claims are intended to be embraced therein.
	abstract	The present invention provides devices and methods that protect against exposure to remote sources of electromagnetic radiation (EMR). As such, the devices provide protection against a plurality of electrical equipment used in ordinary households and employment settings. The device includes a housing, a solenoid operably connected to a driver and a polymer. The solenoid generates incident radiation which results in the polymer emitting electromagnetic oscillations at frequencies that counter adverse effects associated with the subject's exposure to the electromagnetic radiation.

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