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056339038	claims	1. A method for dismantling bulky parts of pressure-vessel fittings of a nuclear plant into transportable parts of smaller sizes, which comprises: a) setting down a bottom part of an open transport container on a bottom of a water tank; b) inserting a bulky part into the bottom part of the open transport container; c) moving a casing part of the open transport container over the inserted bulky part like a sleeve until the casing part contacts the bottom part and the bulky part projects a predeterminable amount above an end surface of the casing part; d) connecting the casing part to the bottom part; e) supporting a separating device on the end surface of the transport container and fixing the separating device relative to the transport container; and f) separating the bulky part above the end surface of the casing part with the separating device.
	description	The present application claims priority based on Korean Patent Application No. 10-2019-0178096, filed Dec. 30, 2020, the entire content of which is incorporated herein for all purposes by this reference. The present invention relates to an nuclear-fuel pellets based on uranium dioxide in which a plate-type fine precipitate material in a base of a sintered pellet based on uranium dioxide, used as nuclear fuel in nuclear power plants, is uniformly dispersed in a matrix of nuclear-fuel sintered pellet thereof so as to form a donut-shaped precipitate cluster, and to a method of manufacturing the same. More particularly, the present invention relates to an nuclear-fuel pellet based on uranium dioxide in which a plate-type fine precipitate material is uniformly precipitated in a matrix of nuclear-fuel sintered pellets thereof or forms a donut-shaped precipitate cluster having a two-dimensional structure by dispersion in order to improve the thermal and physical performance of the uranium dioxide nuclear-fuel pellet, whereby the creep deformation rate and thermal conductivity of the nuclear-fuel sintered pellets are improved, thus overcoming the problem of reduced safety due to the low creep deformation rate and thermal conductivity characteristics of the uranium dioxide nuclear-fuel sintered pellets, and to a method of manufacturing the same. The nuclear-fuel sintered pellets are capable of reducing the Pellet-Clad Interaction (PCI) failure and the core temperature of nuclear fuel when an accident occurs, thereby significantly improving the safety of a nuclear reactor. In nuclear power generation, heat generated through nuclear fission is used. Nuclear fuel assemblies are manufactured by bundling hundreds of fuel rods loaded with the uranium dioxide nuclear-fuel sintered pellet, which is a nuclear fuel material. The nuclear fuel assembles are loaded and used in the core of pressurized-water-reactor-type and pressurized-heavy-water-reactor-type nuclear reactors, and the heat generated due to nuclear fission in the sintered pellet is transferred via the sintered pellet to the cooling water flowing around the fuel rods through a clad tube. The nuclear fuel pellet, which is the heat source of a nuclear power plant, is manufactured in the form of a cylindrical sintered pellet by molding and sintering oxides of uranium, plutonium, and thorium or mixed materials thereof. Currently, uranium dioxide is used as a nuclear-fuel sintered pellet for commercial nuclear power plants around the world. In the case of the above-described uranium oxide sintered pellet, uranium dioxide powder is used as a starting material, and a lubricant is added thereto, followed by mixing and pre-molding at a pressure of about 1 ton/cm2, thus manufacturing a slug. The slug is crushed to manufacture granules. A lubricant is added to the granules that are manufactured and mixed therewith, followed by uniaxial compression molding. The fabricated green pellet is sintered in a hydrogen-containing gas atmosphere at a sintering temperature of up to 1780° C., thus manufacturing the sintered body. The uranium oxide sintered pellet manufactured through the above process is typically cylindrical, and has a density satisfying about 95% of a theoretical density. Further, plutonium oxide or thorium oxide powder may be mixed with uranium dioxide powder, and the same procedure as in the method of manufacturing the uranium oxide may then be performed, thus manufacturing (U, Pu)O2 and (U, Th)O2 sintered pellets. Gadolinia oxide powder may be mixed with the uranium oxide powder, and a procedure similar to that of the method of manufacturing uranium oxide may then be performed, thus manufacturing a (U, Gd)O2 sintered pellet, which is a nuclear fuel as a burn-able absorber. Meanwhile, uranium dioxide (UO2), which is nuclear fuel for commercial nuclear power plants, has a very high melting point of about 2850° C. and very low reactivity with cooling water, and thus has been widely used as a nuclear fuel to date. However, uranium dioxide has a very low thermal conductivity of about 2 to 3 W/mK in the operating temperature range of the nuclear power plant, and the crystal grain size thereof is small, so the fracturing of fuel rods may be promoted due to a nuclear fission gas release rate and pellet-clad interaction. In particular, because of the low thermal conductivity of uranium dioxide, when the heat produced due to nuclear fission is not easily transferred to the cooling water, the nuclear fuel sintered pellet has a temperature that is much higher than that of the cooling water, the center temperature of the sintered body is increased, and a steep temperature gradient occurs in the sintered body. Due to this thermal characteristic, all temperature-dependent reactions are accelerated, and the performance of the material is remarkably reduced, resulting in a lower margin for the safety of nuclear power plants. Further, damage to fuel rods caused by PCI occurs when the clad tube and the sintered body come into contact with each other at 30 GWD/MTU or higher, and from this time, the sintered body exerts external force in the radial direction of the clad tube, which causes mechanical deformation, resulting in breakage. However, in the case of nuclear fuel sintered pellets having large grain microstructure resulting from added oxides, before the occurrence of deformation of the clad tube, plastic deformation of a nuclear-fuel sintered pellet occurs, and mutual stress with the clad tube resulting from volume expansion due to heat is relieved. In addition, the area of the crystal grain boundary, acting as a channel through which various types of nuclear fission gases generated in the course of the nuclear reaction are capable of escaping, is reduced, thereby reducing the rate of release of nuclear fission gas to the outside of the nuclear fuel pellet. Therefore, the nuclear fission gas that deteriorates the inner surface of the fuel rod may be collected into the nuclear fuel pellet, thereby weakening the damage behavior caused by stress corrosion cracking. The role of the sintering additive in reducing PCI damage is basically to enlarge the crystal grains of the uranium dioxide sintered pellet. This occurs because the oxide additive promotes the migration of uranium cations at the sintering temperature when uranium dioxide is sintered, and the developed microstructure serves to improve safety and the operation margin of power plants during combustion in the furnace of nuclear power plants. Accordingly, in order to improve the thermal conductivity of uranium dioxide as described above, Korean Patent No. 10-0609217 discloses a nuclear fuel containing a tungsten metal network and a method of manufacturing the same. In detail, the patent discloses a method of manufacturing a nuclear-fuel sintered body including a tungsten metal network, and the method includes heating a molded body containing nuclear fuel powder and tungsten oxide in a reducing gas atmosphere to thus manufacture a pre-sintered pellet, heating the pre-sintered pellet in an oxidative gas atmosphere to thus form a liquid network of tungsten oxide in the pre-sintered pellet, and reducing the liquid network of tungsten oxide. Further, Korean Patent No. 10-1652729 discloses a method of manufacturing a nuclear-fuel sintered pellet, and in the method, a thermally conductive micro-sized metal powder is used so that oxidation of the metal material occurring during the manufacture of the sintered pellet is prevented, thereby overcoming the problem of reduced thermal conductivity of the sintered pellet. Further, a plate-type metal powder is used to further improve the homogeneity of the microstructure of the sintered pellet, thereby manufacturing a nuclear-fuel sintered pellet having excellent thermal conductivity. However, in a conventional technology of homogenously distributing oxides, which are formed in a liquid phase, along the crystal grain boundary of the sintered pellet, the oxidation characteristics of the added metal are not taken into consideration. Accordingly, there is the possibility of volatilization, and poor microstructure may be formed on the surface of the sintered pellet. From the aspect of commercial manufacture, it is almost impossible to manufacture the sintered pellet in large quantities. Accordingly, the present inventors have studied a method capable of improving both the mechanical and thermal properties of a nuclear-fuel sintered pellet based on uranium dioxide, and have found that the thermal conductivity is improved and the grain size is increased by 30 μm or more by uniformly dispersing a plate-type fine precipitate material in a circumferential direction in the base of uranium dioxide and by disposing the precipitate material so as to form a donut-shaped two-dimensional cluster, whereby the compression creep properties of the sintered pellet are greatly improved, thus greatly increasing PCI resistance. Thereby, the present invention was accomplished. Korean Patent No. 10-0609217 (Registration date: 2006 Jul. 27) Korean Patent No. 10-1652729 (Registration date: 2016 Aug. 25) The present invention provides a nuclear-fuel sintered pellet having a microstructure in which a plate-type fine precipitate material is dispersed in a circumferential direction and also having a donut-shaped two-dimensional cluster so as to satisfy both resistance to creep deformation and excellent thermal conductivity, and a method of manufacturing the same. An aspect of the present invention is a nuclear-fuel sintered pellet manufactured using an oxide to which at least one of a group including uranium (U), plutonium (Pu), gadolinium (Gd), and thorium (Th) is added. The nuclear-fuel sintered pellet includes a precipitate material, generated due to a sintering additive during a sintering process, in the microstructure of sintered pellet thereof. The precipitate material is uniformly dispersed in a circumferential direction. The precipitate material may form a donut-shaped two-dimensional precipitate cluster. The precipitate material may be disposed along a crystal grain boundary of uranium dioxide. The precipitate material may have a length of 3 to 30 μm and a thickness of 1 to 10 μm. The sintering additive may include at least one of a group including copper (I) oxide (CuO), copper (II) oxide (Cu2O), chromium carbide (Cr23C6), molybdenum dioxide (MoO2), molybdenum trioxide (MoO3), molybdenum carbide (Mo2C), and molybdenum disilicide (MoSi2). The sintering additive may further include titanium dioxide (TiO2). The content of titanium dioxide (TiO2) may be 0.05 to 0.70 wt % based on an oxide for the nuclear-fuel sintered pellet. The addition amount of the sintering additive may be 0.5 to 10.0 wt % based on the oxide for the nuclear-fuel sintered pellet. The nuclear-fuel sintered pellet may further include a metal aluminum (Al) powder. The content of the metal-aluminum powder may be 0.01 to 0.10 wt % based on the oxide for the nuclear-fuel sintered pellet. Another aspect of the present invention provides a method of manufacturing an oxide nuclear-fuel sintered pellet in which a plate-type fine precipitate material is dispersed in a circumferential direction. The method includes mixing an oxide powder, including at least one of a group including uranium (U), plutonium (Pu), gadolinium (Gd), and thorium (Th), with a sintering additive powder, thus manufacturing a mixed powder (first step), manufacturing a granulated powder using a sieve after pre-compressing and crushing the mixed powder (second step), uniaxially compressing the granulated powder at 300 to 500 MPa, thus manufacturing a nuclear-fuel green pellet (third step), performing primary sintering of the manufactured nuclear-fuel green pellet in a hydrogen-containing reducing gas atmosphere at a sintering temperature of about 700 to 1100° C. (fourth step), and performing secondary sintering in a hydrogen-containing reducing gas atmosphere at a sintering temperature of 1700 to 1800° C. successively after the primary sintering is completed (fifth step). The sintering additive powder may include at least one of a group including copper (I) oxide (CuO), copper (II) oxide (Cu2O), chromium carbide (Cr23C6), molybdenum dioxide (MoO2), molybdenum trioxide (MoO3), molybdenum carbide (Mo2C), and molybdenum disilicide (MoSi2). A sintering additive may further include titanium dioxide (TiO2). Titanium dioxide (TiO2) may be included in a content of 0.05 to 0.70 wt % based on the oxide for the nuclear-fuel sintered pellet. In the method of manufacturing the oxidative nuclear-fuel sintered pellet, a metal-aluminum (Al) oxide powder may be further added. In the primary sintering, heating may be performed at a heating rate of 1 to 10° C./min so that sintering is performed at a condition of 300 to 1100° C. for 30 to 120 minutes, thereby maintaining a sintering additive in a liquid state. In the secondary sintering, after completion of the primary sintering, sintering may be performed at a condition of 1700 to 1800° C. for 60 to 240 minutes at a heating rate of 1 to 10° C./min without cooling so that a sintering additive in a liquid state is precipitated into a plate-type fine precipitate material and then disposed homogeneously in a circumferential direction while crystal grains of the nuclear-fuel sintered pellet based on uranium dioxide grow. When the sintering additive powder is copper (I) oxide (CuO) or copper (II) oxide (Cu2O), in the primary sintering (fourth step), the sintering temperature may be 300 to 500° C. and the sintering time may be 30 to 120 minutes. The hydrogen-containing reducing gas may contain at least one of a group including carbon dioxide, nitrogen, argon, and helium gases. The hydrogen-containing reducing gas may contain only a hydrogen gas. According to an nuclear-fuel sintered pellet based on oxide and a method of manufacturing the same according to the present invention, the nuclear-fuel sintered pellet has a microstructure in which a plate-type fine precipitate material is dispersed in a circumferential direction and also has a donut-shaped two-dimensional cluster. Accordingly, it is possible to satisfy both very high creep deformation and excellent thermal conductivity characteristics. The specific structural or functional descriptions presented in the embodiments of the present invention are provided for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention may be implemented in various forms. Also, the present invention should not be construed as being limited to the embodiments described herein, but should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. An aspect of the present invention is a nuclear-fuel sintered pellet manufactured using an oxide to which at least one of a group including uranium (U), plutonium (Pu), gadolinium (Gd), and thorium (Th) is added. The nuclear-fuel sintered pellet includes a precipitate material, generated due to a sintering additive during a sintering process, in the microstructure of uranium dioxide thereof. The precipitate material is uniformly dispersed in a circumferential direction. The precipitate material may form a donut-shaped two-dimensional precipitate cluster. The precipitate material may be disposed along a crystal grain boundary. The precipitate material may have a length of 3 to 30 μm and a thickness of 1 to 10 μm. The sintering additive may include at least one of a group including copper(I) oxide (CuO), copper(II) oxide (Cu2O), chromium carbide (Cr23C6), molybdenum dioxide (MoO2), molybdenum trioxide (MoO3), molybdenum carbide (Mo2C), and molybdenum disilicide (MoSi2). The sintering additive is reduced together with uranium dioxide in the process of sintering uranium dioxide in a reducing atmosphere, so that the sintering additive remains in the form of a precipitate material in the sintered pellet, thus increasing the thermal conductivity of the sintered pellet. Preferably, the addition amount of the sintering additive may be 0.5 to 10.0 wt % based on the oxide for the nuclear-fuel sintered pellet. The sintering additive may further include titanium dioxide (TiO2). Titanium dioxide may increase the size of crystal grains in the sintered pellet, thus increasing the compression creep deformation rate at high temperatures and improving the PCI characteristic, which expands the sintered body to thus effectively reduce the pressure applied to the clad tube. Preferably, the content of titanium dioxide (TiO2) may be 0.05 to 0.70 wt % based on the oxide for the nuclear-fuel sintered pellet. The nuclear-fuel sintered pellet based on oxide may further include metal aluminum (Al) powder. The sintering additives that are reduced and then precipitated in the uranium oxide sintered pellet serve to increase the thermal conductivity. However, the reduced precipitate material is oxidized again under a condition of high oxygen partial pressure, thus losing its function. The metal aluminum powder is reacted with oxygen to generate aluminum oxide (Al2O3) and reduce the oxygen partial pressure, thereby preventing oxidation of the reduced precipitate material. Preferably, the metal aluminum powder may be included in a content of 0.01 to 0.10 wt % based on the oxide for the nuclear-fuel sintered pellet. Another aspect of the present invention provides a method of manufacturing nuclear-fuel sintered pellet based on oxide in which a plate-type fine precipitate material is dispersed in a circumferential direction. The method includes mixing an oxide powder, including at least one of a group including uranium (U), plutonium (Pu), gadolinium (Gd), and thorium (Th), with a sintering additive powder, thus manufacturing a mixed powder (first step), manufacturing a granulated powder using a sieve after pre-compressing and crushing the mixed powder (second step), uniaxially compressing the granulated powder at 300 to 500 MPa, thus manufacturing a nuclear-fuel green pellet (third step), performing primary sintering of the manufactured nuclear-fuel green pellet in a hydrogen-containing reducing gas atmosphere at a sintering temperature of about 700 to 1100° C. (fourth step), and performing secondary sintering in a hydrogen-containing reducing gas atmosphere at a sintering temperature of 1700 to 1800° C. successively after the primary sintering is completed (fifth step). The sintering additive powder may include at least one of a group including copper (I) oxide (CuO), copper (II) oxide (Cu2O), chromium carbide (Cr23C6), molybdenum dioxide (MoO2), molybdenum trioxide (MoO3), molybdenum carbide (Mo2C), and molybdenum disilicide (MoSi2). A sintering additive may further include titanium dioxide (TiO2). Titanium dioxide (TiO2) may be included in a content of 0.05 to 0.70 wt % based on the oxide for the nuclear-fuel sintered pellet. In the method of manufacturing the nuclear-fuel sintered pellet based on oxide, a metal-aluminum (Al) oxide powder may be further added. In the primary sintering, heating may be performed at a heating rate of 1 to 10° C./min so that sintering is performed at a condition of 300 to 1100° C. for 30 to 120 minutes, thereby maintaining a sintering additive in a liquid state. In the secondary sintering, after completion of the primary sintering, sintering may be performed at a condition of 1700 to 1800° C. for 60 to 240 minutes at a heating rate of 1 to 10° C./min without cooling so that a sintering additive in a liquid state is precipitated into a plate-type fine precipitate material and is then disposed homogeneously in a circumferential direction while crystal grains of an nuclear-fuel sintered pellet based on oxide grow. When the sintering additive powder is copper (I) oxide (CuO) or copper (II) oxide (Cu2O), in the primary sintering (fourth step), the sintering temperature may be 300 to 500° C. and the sintering time may be 30 to 120 minutes. The hydrogen-containing reducing gas may contain at least one of a group including carbon dioxide, nitrogen, argon, and helium gases. The hydrogen-containing reducing gas may contain only a hydrogen gas. The present invention will be described in detail with reference to Examples and Experimental Examples. However, this is only illustrative and does not limit the present invention in any form. First step: In a method of manufacturing an nuclear-fuel sintered pellet based on oxide in which a plate-type fine precipitate material was dispersed in a circumferential direction, an oxide powder, to which at least one of a group including uranium (U), plutonium (Pu), gadolinium (Gd), and thorium (Th) was added, was mixed with a sintering additive powder, thus manufacturing a mixed powder. Uranium dioxide powder was used as the oxide powder used in the Example, and the addition amount of the sintering additive is shown in Table 1. Second step: The mixed powder in the first step was subjected to pre-compressing (100 MPa), thus manufacturing a pre-compaction green pellet. The pre-compaction green pellet was crushed to manufacture a granulated powder using a sieve. The granulated powder had a particle size of about 400 to 800 μm. Third step: The granulated powder manufactured in the second step was placed in a standardized mold and uniaxially compressed at 300 to 400 MPa, thus manufacturing a nuclear-fuel green pellet. Fourth step: The uranium dioxide green pellet manufactured in the third step was subjected to primary sintering in a hydrogen-containing reducing gas atmosphere at a sintering temperature of about 700 to 1100° C. for about 30 to 120 minutes. Fifth step: After the primary sintering was completed in the fourth step, secondary sintering was performed under a sintering temperature condition of 1700 to 1800° C. at a heating rate of 1 to 10° C./min for 60 to 240 minutes without cooling, thus manufacturing a uranium dioxide sintered pellet. An nuclear-fuel sintered pellet based on oxide in which a plate-type fine precipitate material was dispersed in a circumferential direction was manufactured using the same method as in Example 1, except for the chemical compositions of the uranium dioxide powder and the sintering additive. The chemical composition of the sintering additive added to the nuclear-fuel sintered pellet based on oxide in which the fine precipitate material was dispersed in a circumferential direction is shown in Table 1. TABLE 1ClassificationMoO2Mo2CCr23C6CuOCu2OTiO2AlExample 15————0.10.01Example 23————0.10.05Example 3—5———0.1—Example 4—3———0.1—Example 5————30.1—Example 6————50.1—Example 7——5————Example 8——3————Example 9———5—0.1—Example 10———3—0.1— In the case of a commercially available uranium dioxide sintered pellet used as nuclear fuel in a commercial nuclear power plant, a uranium dioxide sintered pellet, manufactured using a process for manufacturing commercially available uranium dioxide sintered pellets in recent years, was used. The uranium dioxide sintered pellet was manufactured using the same method as in Example 1, except that aluminum was not added to the composition of the sintering additive. In order to analyze the microstructure of an nuclear-fuel sintered pellet based on oxide in which a plate-type fine precipitate material was dispersed in a circumferential direction according to Example 1 of the present invention, an optical microscope and a scanning electron microscope were used for the purpose of microstructure analysis. FIGS. 1 and 2 show the microstructure of a sintered pellet to which molybdenum dioxide, titanium dioxide, and metal aluminum are added. As shown in FIGS. 1 and 2, it was confirmed that when the added molybdenum dioxide was sintered, a plate-type metal molybdenum was precipitated along a crystal grain boundary due to the crystal grain growth in the UO2 sintered pellet, caused by titanium dioxide and a chemical reaction between molybdenum dioxide and hydrogen. In particular, with respect to the arrangement of the precipitate from the plate-type metal molybdenum, the precipitate material was uniformly dispersed in a two-dimensional donut shape, and thermal conductivity was improved due to the two-dimensional donut shape and the metal molybdenum. FIG. 3 shows the analysis of the microstructure and the elements of precipitate material using a scanning electron microscope (SEM/EDS) and XRD, and it was confirmed that the plate-type molybdenum was precipitated along the crystal grain boundary of uranium dioxide. Further, from the result of XRD analysis, which uses an analytical device for analyzing a small amount of impurities and crystal structures, it was confirmed that molybdenum dioxide, that is, the additive, was completely precipitated into metal molybdenum, thus forming the precipitate materials in the uranium dioxide base. In order to evaluate the integrity of the precipitate material of an oxide nuclear-fuel sintered body in which a plate-type fine precipitate material was dispersed in a circumferential direction according to Comparative Example 1 and Example 1 of the present invention, the integrity of the precipitate material depending on the sintering atmosphere was evaluated. FIG. 4 shows the precipitate materials in the uranium dioxide microstructure of Comparative Example 1, manufactured under a sintering atmosphere condition in which the oxygen partial pressure of CO2/H2 was 3% and 5%. As shown in FIG. 4, there was a problem in that, as the oxygen partial pressure was increased, the precipitated molybdenum was oxidized and volatilized. This is because molybdenum, which is precipitated due to an increase in the oxygen partial pressure caused by a small amount of oxygen in residual oxygen and uranium dioxide in a sintering furnace, is oxidized into molybdenum oxides such as molybdenum trioxide (MoO3) or molybdenum dioxide (MoO2), thus being volatilized. Therefore, in order to prevent oxidation of the precipitate from the metal molybdenum due to residual oxygen, a small amount of metal aluminum may be added so that the residual oxygen is first reacted with metal aluminum using an aluminothermic method to thus significantly reduce the oxygen partial pressure in a sintering furnace, thereby preventing the oxidation of molybdenum. FIG. 5 shows the results of the test of maintaining the integrity of the precipitate material by adding a small amount of metal aluminum as in Example 1. The dark part in black denotes molybdenum oxide, and the light part in white denotes molybdenum. Unlike FIG. 4, in FIG. 5, from the distribution of a large number of white dots denoting molybdenum, it was confirmed that the oxidation of molybdenum was prevented by adding aluminum. In order to investigate the high-temperature deformation characteristic of an nuclear-fuel sintered pellet based on oxide in which a plate-type fine precipitate material was dispersed in a circumferential direction according to Examples 1 to 4 and Comparative Example 1 of the present invention, the following high-temperature compression creep test was performed. After the uranium dioxide sintered bodies having the compositions of Examples 1 to 4 and Comparative Example 1 were manufactured, high-temperature compression creep test specimens were manufactured. After the cross sections of the two terminal ends of the manufactured sintered pellet specimen were uniformly cut, the diameter and length of the specimen were measured in order to evaluate the amount of deformation of the specimen after the high-temperature compression creep test. In the high-temperature compression creep test, a compression load of 40 MPa was applied in a hydrogen gas atmosphere at a temperature of 1450° C. for about 20 hours using high-temperature creep test equipment manufactured for that purpose by Zwick/Roell in Germany. In the high-temperature compression creep test, the deformation amount depending on time is measured and then stored in real time using a non-contact laser extensometer when a compressive load of 40 MPa is applied thereto. As shown in FIG. 6, it was confirmed that the high-temperature compression creep deformation amounts of Examples 1 to 4 of the present invention were at least 5 to 20 times as large as the high-temperature compression creep deformation amount of the commercial uranium dioxide sintered body provided in Comparative Example 1. The thermal conductivity of the uranium dioxide sintered pellet depends on density, porosity, chemical equivalents, temperature, and the concentration of impurities. Thermal conductivity, which is a thermal property, is an intrinsic property of a material, and is calculated as a function of the density, specific heat capacity, and thermal diffusivity of the material. The thermal conductivity of the uranium dioxide sintered body depends on density, porosity, chemical equivalents, temperature, and the concentration of impurities. In order to evaluate the thermal conductivity of uranium dioxide, it is necessary to obtain the thermal diffusivity using a laser flash method. The thermal diffusivity value was measured using an LFA 427 model manufactured by Netzsch company in Germany, the density was measured using the Archimedes method, and the specific heat value was calculated using a specific-heat calculation method in the composites. The density, the specific heat, and the thermal diffusivity were multiplied to calculate the thermal conductivity depending on the temperature. FIG. 7 shows the comparative evaluation of the thermal conductivities of the sintered pellets of Examples 1 to 5 and Comparative Example 1 of the present invention. As shown in the drawing, the thermal conductivities of Examples 1 to 5 were about 40 to 70% higher than that of Comparative Example 1. This result is believed to be because molybdenum oxides and chromium carbides were completely precipitated into metal molybdenum to form a uniform plate shape during the sintering process and because the thermal conductivity was greatly improved due to the effect of dispersion of a two-dimensional donut shape. The present invention described above is not limited by the above-described embodiments and the accompanying drawings, and those skilled in the art will appreciate that various substitutions, modifications, and changes are possible, without departing from the technical spirit of the present invention.
	description	The present invention relates to a nuclear fuel assembly, to be used in a nuclear power reactor. The fuel assembly contains fuel pellets having a boron-containing compound in admixture with the nuclear fuel. In a typical nuclear reactor, such as a pressurized water (PWR), heavy water or a boiling water reactor (BWR), the reactor core includes a large number of fuel assemblies, each of which is composed of a plurality of elongated fuel elements or rods. The fuel rods each contain fissile material such as uranium dioxide (UO2) or plutonium dioxide (PUO2), or mixtures of these, usually in the form of a stack of nuclear fuel pellets, although annular or particle forms of fuel are also used. The fuel rods are grouped together in an array which is organized to provide a neutron flux in the core sufficient to support a high rate of nuclear fission and thus the release of a large amount of energy in the form of heat. A coolant, such as water, is pumped through the core in order to extract some of the heat generated in the core for the production of useful work. Fuel assemblies vary in size and design depending on the desired size of the core and the size of the reactor. When a new reactor starts, its core is often divided into a plurality, e.g. three or more groups of assemblies which can be distinguished by their position in the core and/or their enrichment level. For example, a first batch or region may be enriched to an isotopic content of 2.0% uranium-235. A second batch or region may be enriched to 2.5% uranium-235, and a third batch may be enriched to 3.5% uranium-235. After about 10–24 months of operation, the reactor is typically shut down and the first fuel batch is removed and replaced by a new batch, usually of a higher level of enrichment (up to a preferred maximum level of enrichment). Subsequent cycles repeat this sequence at intervals in the range of from about 8–24 months. Refueling as described above is required because the reactor can operate as a nuclear device only so long as it remains a critical mass. Thus, nuclear reactors are provided with sufficient excess reactivity at the beginning of a fuel cycle to allow operation for a specified time period, usually between about six to eighteen months. Since a reactor operates only slightly supercritical, the excess reactivity supplied at the beginning of a cycle must be counteracted. Various methods to counteract the initial excess reactivity have been devised, including insertion of control rods in the reactor core and the addition of neutron absorbing elements to the fuel. Such neutron absorbers, known in the art and referred to herein as “burnable poisons” or “burnable absorbers”, include, for example, boron, gadolinium, cadmium, samarium, erbium and europium compounds. Burnable poisons absorb the initial excess amount of neutrons while (in the best case) producing no new or additional neutrons or changing into new poisons as a result of neutron absorption. During the early stages of operation of such a fuel element, excess neutrons are absorbed by the burnable poison, which preferably undergoes transformation to elements of low neutron cross section, which do not substantially affect the reactivity of the fuel element in the later period of its life when the neutron availability is lower. Sintered pellets of nuclear fuel having an admixture of a boron-containing compound or other burnable poison are known. See, for example, U.S. Pat. Nos. 3,349,152; 3,520,958; and 4,774,051. However, nuclear fuel pellets containing an admixture of a boron burnable absorber with the fuel have not been used in large land-based reactors due to concerns that boron would react with the fuel, and because the use of boron was thought to create high internal rod pressurization from the accumulation of helium in the reaction:10B+1n→11B(excited state)→4He+7Li Current practice is to coat the surface of the pellets with a boron-containing compound such as ZrB2, which avoids any potential reaction with the fuel. However, this does not solve the pressurization problem, which limits the amount of coating that can be contained within each rod. More rods with a lower 10B loading must be used, thus necessitating the handling and coating of a large number of fuel pellets, which is very expensive and results in high overhead costs. Complex manufacturing operations also result from the need to separate the coated and non-coated fuel manufacturing and assembly operations. In practice, the cost of coating the pellets limits their use, and they are used in as few rods as possible, taking into account the pressurization problem described above. Historically this was acceptable, because fuel cycles were shorter, levels of 235U enrichment were lower, and overall thermal output of a reactor was lower. Other compounds such as Gd2O3 and Er2O3 can be added directly to the pellets, but these are less preferred than boron because they leave a long-lived, high cross-section residual reactive material. Nuclear reactor core configurations having burnable poisons have been described in the art. For example, U.S. Pat. No. 5,075,075 discloses a nuclear reactor core having a first group of rods containing fissionable material and no burnable absorber and a second group of rods containing fissionable material with a burnable absorber, wherein the number of rods in the first group is larger than the number of rods in the second group. The burnable absorber comprises a combination of an erbium compound and a boron compound. U.S. Pat. No. 5,337,337 discloses a fuel assembly where fuel rods containing a burnable poison element having a smaller neutron absorption cross-section (such as boron) are placed in a region of the core having soft neutron energy and a large thermal neutron flux, while rods having a burnable poison element having a larger neutron absorption cross-section (such as gadolinium) are placed in regions of the core having average neutron energy spectrum. Neither of these prior patents disclose an arrangement of fuel rods in fuel assmeblies in which a majority of fuel rods contain boron alone, as the burnable poison. Neither disclose assembly arrangements suitable for reactors producing over 500 megawatts thermal power. With the use of longer fuel cycles and higher levels of 235U enrichment, there remains a need for the development of nuclear fuels and fuel assemblies having integral burnable absorbers that are cost-effective and can extend the life of the fuel without creating additional reactive materials. The present invention solves the above need by providing a fuel assembly comprising a plurality of fuel rods, each fuel rod containing a plurality of nuclear fuel pellets, wherein at least one fuel pellet in more than 50% of the fuel rods in the fuel assembly comprises a sintered admixture of an actinide oxide, actinide carbide or actinide nitride and a boron-containing compound. Due to the fact that boron has a relatively low parasitic cross-section as compared to other burnable absorbers, it will typically be necessary to put boron-containing fuel pellets in more than 50% of the rods. It has been found, contrary to previous assumptions, that boron does not interact with the nuclear fuel, and is not the primary cause of pressure in the fuel rods, when the amount of helium produced is compared to the amounts of other fission gases released during fuel use. Preparing fuel with an admixture of boron is much less expensive. Therefore, a greater number of rods can have the boron-containing fuel pellets, providing a greater amount of boron in the core but with less boron in each rod, thus avoiding the pressurization problem. For example, with the use of coated pellets fuel rods will contain about 2 mg boron per inch, whereas with the use of boron directly in the pellet fuel rods will contain about 1–1.5 mg boron per inch, a 25–50% reduction. By adding either natural or enriched boron to at least one fuel pellet in a majority of the rods in a fuel assembly, reactivity hold-down that is equivalent or superior to that provided by current methods is provided, at much lower cost. Additionally, increasing the number of rods containing boron can reduce the internal fuel rod pressure by a factor of 2 or 3 over that found in current practice. Thus, using lower levels of a boron-containing compound, in combination with its distribution more widely among the fuel rods, provides the benefits of the present invention. As will be appreciated by one skilled in the art, these benefits are most advantageous when the thermal output of the reactor core is above 500 megawatts thermal, in the case of water-cooled reactors, or above 200 megawatts thermal in the case of gas-cooled reactors. The use of boron in boiling water reactor fuel as a substitute for the currently employed Gd2O3 and Er2O3 provides even greater benefits. In addition to simplifying manufacturing and reducing rod pressurization, the space that is taken up by the Gd2O3 and Er2O3 in the fuel pellets can be replaced by more UO2 (or other actinide oxide, carbide or nitride), thus allowing more fuel to be loaded in a given size core. Enrichment constraints currently applied on a rod-by-rod basis due to poor thermal conductivity of these rare-earth oxides can be completely avoided, thus yielding a significant simplification in the manufacture of nuclear fuels. Accordingly, the present invention provides a fuel assembly comprising a plurality of fuel rods, each fuel rod containing a plurality of nuclear fuel pellets, wherein at least one fuel pellet in more than 50% of said fuel rods in said fuel assembly comprises a sintered admixture of a metal oxide or metal nitride and a boron-containing compound. The boron-containing compound functions as the burnable poison in the fuel. The term “fuel pellet” is used herein to denote the individual sintered pellets of fuel that are loaded into a fuel rod. Preferably, at least one fuel pellet in more than 60% of the fuel rods in the fuel assembly contains a boron-containing compound. Even more preferably, at least one fuel pellet in more than 70–80% of the fuel rods in the fuel assembly contains a boron-containing compound. When referring to any numerical range of values herein, such ranges are understood to include each and every number and/or fraction between the stated range minimum and maximum. A range of more than 50% of the fuel rods in a fuel assembly, for example, would expressly include all intermediate values between 50 and 100%, including, by way of example only, 51%, 52%, 53%, 60%, 70%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 100%, and all other intermediate values there between. In one embodiment, at least one fuel pellet in more than 50% of the fuel rods in the fuel assembly comprises an admixture of a boron-containing compound and the nuclear fuel. In other embodiments, at least one fuel pellet in at least 60%, 70%, 80%, 90% or more of the fuel rods in the fuel assembly contain the boron compound. In the rods having at least one boron-containing fuel pellet, any number of boron-containing fuel pellets can be used, to a maximum of 100% of all the pellets in the rod. Typically, the number of fuel pellets containing boron in a rod will be greater than 50%, but the number of boron-containing pellets in a particular rod will be determined based on all aspects of fuel design, as discussed further below. Any suitable boron-containing compound can be used, so long as it is compatible with the particular nuclear fuel selected and meets fuel specifications as to density, thermal stability, physical stability, and the like. Suitable boron-containing compounds include, but are not limited to, ZrB2, TiB2, MoB2, UB2, UB3, UB4, B2O3, ThB4, UB12, B4C, PuB2, PuB4, PuB12, ThB2, and combinations thereof. Preferred boron-containing compounds are UB4 and UB12. The boron-containing compound and actinide oxide, carbide or nitride are prepared as an admixture and then sintered to produce a fuel pellet. Such methods of preparing nuclear fuel pellets are known in the art; as described above, see U.S. Pat. Nos. 3,349,152; 3,520,958; and 4,774,051. Natural boron or boron enriched in the 10B isotope can be used, and any level of enrichment of 10B above natural levels is suitable, depending on certain factors. With the use of more enriched boron; the amount of boron-containing compound needed overall decreases, allowing a concomitant increase in fuel loading. However, enriched boron is more expensive than natural boron, and the amount of boron enrichment used will be a cost consideration balanced with other aspects of fuel design. Accordingly, the amount of boron-containing compound present in a fuel pellet will range between about 5 ppm to about 5 wt %, more preferably between about 10 ppm and 20,000 ppm, based on the total amount of fuel in the fuel pellet, and the amount used will vary depending on the level of uranium enrichment, the level of boron enrichment, and other factors. One skilled in the art of fuel design can easily determine the desired amount of boron-containing compound to use in a fuel pellet, and how many fuel pellets with this desired amount of boron-containing compound to place in a particular number of rods in a fuel assembly. Such calculations are routinely done in design of a fuel load, which must take into account the age of the fuel, the use pattern and activity of the surrounding fuel, the level of uranium-235 in the fuel and the number of neutrons given off. By way of example only, the use of an equal amount of natural boron in all the rods of a batch (if neutronically acceptable) will require boron levels between about 66 and 7,000 ppm, while the use of 100% enriched boron would reduce the level of boron needed to between about 13 and 1200 ppm. It is recognized that the selective boration of individual rods might be preferable neutronically, similar to current poison distribution methods. Fuel rods having fuel pellets with natural boron only, enriched boron only, or a combination of pellets with natural and enriched boron, are all contemplated as being embraced by the present invention. The boron-containing compound can be used with any suitable nuclear fuel. Examples of suitable nuclear fuels include actinide oxides, actinide carbides and actinide nitrides. Exemplary fuels include, but are not limited to, UO2, PuO2, ThO2, UN, (U, P)O2, (U, P, Th)O2, and (U, Th)O2, other actinide oxides, actinide carbides and actinide nitrides, mixtures of actinide oxides, mixtures of actinide carbides, and mixtures of actinide nitrides. The above described fuel assembly is suitable and economical for use in fast breeder reactors, as well as reactors that are substantially based on thermal fission such as light or heavy water nuclear reactors, including pressurized water reactors (PWR), boiling water reactors (BWR) and pressurized heavy water reactors (PHWR or CANDU). The fuel assembly is also suitable for use in gas-cooled reactors. Preferrably, the thermal output of the reactor core of any of the above reactor types will be above 500 megawatts thermal in the case of water-cooled reactors, and above 200 megawatts thermal in the case of gas-cooled reactors. In the following description, like reference numbers designate like or corresponding parts throughout the several views. Also in the following description, it is to be understood that such terms as “forward”, “rearward”, “left”, “right”, “upwardly”, “downwardly”, and the like, are words of convenience and are not to be construed as limiting terms. Referring now to the drawings, and particularly to FIGS. 1 and 2, there is shown an embodiment of the present invention, by way of example only and one of many suitable reactor types, a pressurized water nuclear reactor (PWR), being generally designated by the numeral 10. The PWR 10 includes a reactor pressure vessel 12 which houses a nuclear reactor core 14 composed of a plurality of elongated fuel assemblies 16. The relatively few fuel assemblies 16 shown in FIG. 1 is for purposes of simplicity only. In reality, as schematically illustrated in FIG. 2, the core 14 is composed of a great number of fuel assemblies. Spaced radially inwardly from the reactor vessel 12 is a generally cylindrical core barrel 18 and within the barrel 18 is a former and baffle system, hereinafter called a baffle structure 20, which permits transition from the cylindrical barrel 18 to a squared off periphery of the reactor core 14 formed by the plurality of fuel assemblies 16 being arrayed therein. The baffle structure 20 surrounds the fuel assemblies 16 of the reactor core 14. Typically, the baffle structure 20 is made of plates 22 joined together by bolts (not shown). The reactor core 14 and the baffle structure 20 are disposed between upper and lower core plates 24, 26 which, in turn, are supported by the core barrel 18. The upper end of the reactor pressure vessel 12 is hermetically sealed by a removable closure head 28 upon which are mounted a plurality of control rod drive mechanisms 30. Again, for simplicity, only a few of the many control rod drive mechanisms 30 are shown. Each drive mechanism 30 selectively positions a rod cluster control mechanism 32 above and within some of the fuel assemblies 16. A nuclear fission process carried out in the fuel assemblies 16 of the reactor core 14 produces heat which is removed during operation of the PWR 10 by circulating a coolant fluid, such as light water with soluble boron, through the core 14. More specifically, the coolant fluid is typically pumped into the reactor pressure vessel 12 through a plurality of inlet nozzles 34 (only one of which is shown in FIG. 1). The coolant fluid passes downward through an annular region 36 defined between the reactor vessel 12 and core barrel 18 (and a thermal shield 38 on the core barrel) until it reaches the bottom of the reactor vessel 12 where it turns 180 degrees prior to following up through the lower core plate 26 and then up through the reactor core 14. On flowing upwardly through the fuel assemblies 16 of the reactor core 14, the coolant fluid is heated to reactor operating temperatures by the transfer of heat energy from the fuel assemblies 16 to the fluid. The hot coolant fluid then exits the reactor vessel 12 through a plurality of outlet nozzles 40 (only one being shown in FIG. 1) extending through the core barrel 18. Thus, heat energy which the fuel assemblies 16 impart to the coolant fluid is carried off by the fluid from the pressure vessel 12. Due to the existence of holes (not shown) in the core barrel 18, coolant fluid is also present between the barrel 18 and the baffle structure 20 and at a higher pressure than within the core 14. However, the baffle structure 20 together with the core barrel 18 do separate the coolant fluid from the fuel assemblies 16 as the fluid flows downwardly through the annular region 36 between the reactor vessel 12 and core barrel 18. As briefly mentioned above, the reactor core 14 is composed of a large number of elongated fuel assemblies 16. Turning to FIG. 3, each fuel assembly 16, being of the type used in the PWR 10, basically includes a lower end structure or bottom nozzle 42 which supports the assembly on the lower core plate 26 and a number of longitudinally extending guide tubes or thimbles 44 which project upwardly from the bottom nozzle 42. The assembly 16 further includes a plurality of transverse support grids 46 axially spaced along the lengths of the guide thimbles 44 and attached thereto. The grids 46 transversely space and support a plurality of fuel rods 48 in an organized array thereof. Also, the assembly 16 has an instrumentation tube 50 located in the center thereof and an upper end structure or top nozzle 52 attached to the upper ends of the guide thimbles 44. With such an arrangement of parts, the fuel assembly 16 forms a integral unit capable of being conveniently handled without damaging the assembly parts. As seen in FIGS. 3 and 4, each of the fuel rods 48 of the fuel assembly 16 has an identical construction insofar as each includes an elongated hollow cladding tube 54 with a top end plug 56 and a bottom end plug 58 attached to and sealing opposite ends of the tube 54 defining a sealed chamber 60 therein. A plurality of nuclear fuel pellets 62 are placed in an end-to-end abutting arrangement or stack within the chamber 60 and biased against the bottom end plug 58 by the action of a spring 64 placed in the chamber 60 between the top of the pellet stack and the top end plug 56. In the operation of a PWR, it is desirable to prolong the life of the reactor core 14 as long as feasible to better utilize the uranium fuel and thereby reduce fuel costs. To attain this objective, it is common practice to provide an excess of reactivity initially in the reactor core 14 and, at the same time, provide means to maintain the reactivity relatively constant over its lifetime. FIGS. 2, 3 and 4 illustrate a preferred embodiment of the present invention, to achieve this objective. As can be seen in FIGS. 3 and 4, a fuel rod 48 has some end-to-end arrangements, or strings, of fuel pellets 62A containing no boron compound, provided at upper and lower end sections of the fuel pellet stack of the fuel rod 48 as an axial blanket. The fuel rod 48 also has a string of the fuel pellets 62B with the boron-containing compound provided at the middle section of the stack. Referring to FIG. 2, there is shown one preferred embodiment of an arrangement in the nuclear reactor core 14 in accordance with the present invention, of assemblies with fuel rods having no boron-containing compound, denoted by an “o” in FIG. 2, and assemblies in which all the fuel rods in the assembly have at least one pellet of fuel with a boron-containing compound, denoted by an “x” in FIG. 2. By way of example only, Table 1 below provides information comparing an assembly of the present invention with prior art practice. TABLE 1Original RodsRods withWith IFBA-coatedUB4Fuel (ZrB2)(present invention)Boron loading10 mg/inch325.5 ppmPercent of all rods coated60%100%With ZrB2 or containing UB4Pellet diameter0.37 inches0.37 inchesUO2 density10.47 gm/cm310.47 gm/cm3UO2 loading18.43 gm UO2/inch18.43 gm UO2/inch10B loading108.5 ppm65.1 ppm10B level in total20%20%amount of BoronSmeared 10B loading65.1 ppm65.1 ppmTotal B loading524.5 ppm325.5 ppmUB4 loading2119 ppm UB4% of pellets with IFBA or100%100%UB4 Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.
	description	This is a National Stage Application of International Patent Application No. PCT/KR2018/004009, filed Apr. 5, 2018, which claims the benefit of and priority to Korean Application No. 10-2018-0010619, filed Jan. 29, 2018, the entirety of which are incorporated fully herein by reference. The present invention relates to a nuclear fuel rod end distance adjusting device and, more particularly, to a nuclear fuel rod end distance adjusting device improving convenience and accuracy of an adjustment of a nuclear fuel rod end distance. A nuclear power plant is configured to heat primary coolant using energy generated during nuclear fission by using nuclear fuel inside a nuclear reactor, to transfer energy to secondary coolant using heated energy to generate steam at a steam generator, and to produce electricity in a generator by converting rotational energy at a steam turbine by using steam generated at the steam generator At this time, the nuclear reactor refers to an apparatus made to be used for various purposes such as generating heat, producing radioactive isotopes and plutonium, providing a radiation field, or the like, by artificially controlling the fission reaction of fissile material. In general, enriched uranium in which the ratio of uranium-235 is raised to 2-5% is used in light water reactors, and in order to process uranium into nuclear fuel used in nuclear reactors, a molding process to make the uranium into a cylindrical pellet weighing about 5 g is performed. Meanwhile, an energy source for nuclear fission is provided through nuclear fuel. The nuclear fuel arranged inside the nuclear reactor is composed of a unit of a nuclear fuel assembly 10 as shown in FIG. 1, and the nuclear fuel assembly 10 includes: a skeleton including a top nozzle 11, a bottom nozzle 12, and spacer grids 13; and fuel rods 20 inserted inside the spacer grids 13 and supported by springs and dimples provided in the spacer grids 13. At this time, each nuclear fuel rod 20 includes uranium of a unit of pellets 21 and a zirconium alloy cladding tube 22 to protect the uranium and to prevent radioactive leakage and is provided in a shape of a long bar. In order to manufacture such a nuclear fuel assembly 10, and in order to prevent scratches on a surface of the nuclear fuel rod 20 and to prevent damage to the spacer grids 13, a lacquer is applied on the surface of the fuel rod 20, the fuel rod 20 is inserted into the skeleton, and then the fuel rod 20 is attached and fixed by the top nozzle 11 and bottom nozzle 12, whereby assembling the nuclear fuel assembly 10 is finished. On the other hand, an insertion process of the nuclear fuel rods 20 into the fuel assembly 10 is carried out in units of rows in the spacer grid 13, and due to characteristics of the insertion process, the difference (no greater than 5 mm) occurs in an insertion length of the nuclear fuel rods 20 after the insertion process. Accordingly, in order to satisfy design requirements for a fuel rod 20 end distance, an adjustment of the insertion length of the fuel rod 20 is made using a nuclear fuel rod end distance adjusting device. At this time, the conventional nuclear fuel rod 20 end distance adjusting device 30 for the adjustment of the insertion length of the nuclear fuel rod 20, as shown in FIG. 2, includes fuel rod tongs 31, an insertion rod 32, and an insertion weight 33. A process for the adjustment of the insertion length of the nuclear fuel rod 20 using the nuclear fuel rod end distance adjusting device 30 is as follows. The distance adjusting device 30 is coupled to an end portion of the nuclear fuel rod 20 that requires adjustment of the insertion length using the fuel rod tongs 31. Thereafter, an impact is applied to the insertion weight 33 toward an opposite direction in which the nuclear fuel rod 20 is coupled. At this time, the insertion rod 32 is moved in an impacting direction, whereby the fuel rod tongs 31 installed on the insertion rod 32 pull the nuclear fuel rod 20. Thereafter, after the insertion weight 33 is returned to an original position, again, an impact is applied to the insertion weight 33 toward the opposite direction in which the nuclear fuel rod 20 is coupled. Through this repeating process, the insertion length of the nuclear fuel rod 20 is adjusted, and through this series of processes, the insertion length of a plurality of nuclear fuel rods 20 constituting the nuclear fuel assembly 10 is adjusted. However, the conventional nuclear fuel rod end distance adjusting device 30 described above has the following problems. First, the adjustment of the conventional nuclear fuel rod end distance adjusting device 30 through a method of impacting the insertion weight 33 has a problem in which a fine adjustment of the insertion length of the nuclear fuel rod 20 is difficult to be accomplished. That is, the difference in a degree of movement of the insertion weight 33 according to a degree of impact may occur greatly, so it is difficult to precisely adjust the insertion length of the nuclear fuel rod 20. Second, there is a problem in which the impact generated in the insertion weight 33 when the impact is applied to the insertion weight 33 may be transmitted to the nuclear fuel rod 20, whereby the nuclear fuel rod 20 may be damaged. Third, in the process of returning the insertion weight 33 having been applied the impact, the insertion weight 33 may push the insertion rod 32 instead of pulling the insertion rod 32 due to the carelessness of a worker, thereby eventually causing problems of pushing the nuclear fuel rod 20. Korean Patent No. KR 10-0982297 Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an objective of the present invention is to provide a nuclear fuel rod end distance adjusting device that enables an adjustment of the insertion length of a nuclear fuel rod to be more precisely and conveniently performed by using a method of converting a rotational motion into a linear motion and, in parallel therewith, allows the adjustment of the nuclear fuel rod end distance to be stably and efficiently performed by preventing the rotational movement from being transmitted to the charging rod. In order to accomplish the above objective, the present invention may provide a nuclear fuel rod end distance adjusting device, the device including: an insertion rod including nuclear fuel rod tongs and linearly moving forward and backward; a housing having a hollow space; insertion power means installed inside the housing and moving in a longitudinal direction of the housing by converting a rotational motion into a linear motion; a connector connected between the insertion power means and the insertion rod; and an anti-rotation tool installed between the insertion power means and the connector, being capable of moving in the longitudinal direction of the housing by being interlocked with the linear motion of the insertion power means, but preventing rotational force of the insertion power means from being transmitted to the connector. At this time, the insertion power means may be composed of a ball screw, a rotation space in which one end portion of a male screw of the ball screw is idled may be provided at one end portion of the anti-rotation tool, and the connector may be fixed to an opposite end portion of the anti-rotation tool. In addition, a guide long-hole may be provided in the longitudinal direction of the housing in the housing, and a moving pin guided along the guide long-hole may be installed in the anti-rotation tool. In addition, the nuclear fuel rod tongs may be screwed to the insertion rod, and the insertion rod may screwed to the connector, wherein the nuclear fuel rod tongs may be configured to be screwed to the connector. As described above, a nuclear fuel rod end distance adjusting device according to the present invention has following effects. First, the device according to the present invention is configured to pull the nuclear fuel rod by converting a rotational motion into a linear motion using a ball screw method, thereby giving an effect in which insertion length of the nuclear fuel rod can be more finely adjusted. In particular, by adjusting the insertion length of the nuclear fuel rod through a rotation method, there is an effect in which convenience for an adjustment of the insertion length of the nuclear fuel rod can be increased. Second, when adjusting the insertion length of the nuclear fuel rod, there is an effect in which the nuclear fuel rod can be prevented from being damaged by an external force such as an impact applied thereto and the like. Third, there is an effect in which the distance adjusting device can be easily used through a guide pin regardless of fuel types. Fourth, the insertion rod can be interlocked only with the linear motion of a ball screw, thereby giving an effect that movement of the nuclear fuel rod can be stably and efficiently accomplished. The terms or words used in the present specification and claims are not to be construed as being limited to ordinary or lexical meanings. In addition, on the basis of the principle that the concept of terms may be properly defined in order to best describe his or her invention, it should be interpreted in a sense and concept consistent with the technical idea of the present invention. Hereinafter, a nuclear fuel rod end distance adjusting device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3 to 7. The nuclear fuel rod end distance adjusting device has a technical feature that allows an adjustment of the nuclear fuel rod end distance to be finely accomplished using the principle of ball screw operation and increases convenience of an adjustment of a nuclear fuel rod end distance. The nuclear fuel end distance adjusting device is configured to include an insertion rod 100, a housing 200, insertion power means 300, a connector 400, and an anti-rotation tool 500. The insertion rod 100 is medium means for pulling a nuclear fuel rod 20 by being coupled to the nuclear fuel rod 20 of a nuclear fuel assembly 10 and includes nuclear fuel rod tongs 110. The nuclear fuel rod tongs 110 are configured to be directly coupled to the nuclear fuel rod 20, and attachment and detachment means is provided at an end of the nuclear fuel rod tongs 110 so as to be detachably attached to the insertion rod 100. At this time, the attachment and detachment means is not specifically provided but may be configured to allow the nuclear fuel rod tongs 110 to be screwed to the insertion rod 100. For example, an end portion of the nuclear fuel rod tongs 110 is configured in a shape of tongs capable of gripping the nuclear fuel rod 20, and an opposite end portion of the nuclear fuel rod tongs 110 may be configured to be a male screw or a female screw. Accordingly, a female screw or a male screw corresponding to the male screw or female screw of the nuclear fuel rod tongs 110 is provided to the insertion rod 100 so that the nuclear fuel rod tongs 110 are detachably attached to the insertion rod 100. With this configuration, the insertion rod 100 may be adjusted in length depending on the attachment and detachment of the nuclear fuel rod tongs 110. Next, the housing 200 is configured to allow various parts for linearly moving the insertion rod 100 to be installed and may be provided in a shape of a hollow cylinder. At this time, opposite sides of the housing 200 are open. Next, a front cover 210 is installed at an end of the housing 200, and the insertion power means 300 is installed at an opposite end of the housing 200. A guide tube 211 in which the connector 400 is moved is provided in the front cover 210, and a plurality of coupling grooves 212 to which the guide pin 220 is coupled are provided at an edge of the front cover 210. The guide pin 220 is inserted into a hole of an FR guide plate and is configured to prevent the adjusting device from being rotated when a male screw part 320 for the adjustment of the nuclear fuel rod end distance is rotated. This may be understood through FIG. 7. At this time, a plurality of the guide pins 220 is provided in various diameters and is detachably attached to the coupling groove 212 of the front cover 210 as described above. At this time, a tip portion of the guide pin 220 may be provided in a streamlined shape as shown in FIGS. 3 and 4. By such a configuration, the guide pin 220 of various diameters may be selectively positioned in the coupling groove 212 of the front cover 210, so that the nuclear fuel rod end distance adjusting device may be installed regardless of fuel types. Meanwhile, a guide long-hole 230 communicating with an inside of the housing 200 is provided in the housing 200. The guide long-hole 230 is a configured to guide a movement path when the anti-rotation tool 500 moves by the insertion power means 300 and is provided in a shape of the long-hole in a longitudinal direction of the housing 200. Next, the insertion power means 300 generates power to move the insertion rod 100 straight and is installed at a rear of the housing 200. The insertion power means 300 may be configured to allow an adjustment of the insertion length of the insertion rod 100 to be more precisely accomplished. To this end, the insertion power means 300 may be configured to convert the rotational motion into a linear motion. Accordingly, the insertion power means 300 is not particularly limited but may be provided as a ball screw assembly as shown in FIG. 4. The ball screw assembly 300 is configured to include a female screw part 310, a male screw part 320, a plug 330, and a bearing 340. The female screw part 310 is provided so that the male screw part 320 may be screwed and includes a plurality of steel balls (not shown) that roll along a female thread. The female screw part 310 is fixed to the housing 200 while shielding the open rear of the housing 200. The female screw part 310 is provided in a cylinder shape corresponding to the inner diameter of the housing 200. In addition, the male screw part 320 is screwed to the female screw part 310 and rotates, with the female screw part 310 as a reference, to perform a linear motion in a longitudinal direction of the housing 200. At this time, one end of the male screw part 320 is located inside the housing 200, and an opposite end of the male screw part 320 is located outside the housing 200. At this time, a handle 321 may be provided at the opposite end of the male screw part 320 so that the male screw part 320 may be easily gripped. In addition, the plug 330 serves to push or pull the anti-rotation tool 500 by interfering with the anti-rotation tool 500 during a linear motion according to the rotational motion of the male screw part 320 and is coupled to the one end portion of the male screw part 320. The plug 330 may be provided with a diameter larger than the diameter of the male screw part 320 and may be provided in a circular shape. At this time, between the plug 330 and the one end of the male screw part 320, a bearing 340 for smoothly rotating the male screw part 320 may be installed. Next, the connector 400 serves to connect the insertion rod 100 and the insertion power means 300. That is, one end portion of the connector 400 is connected to the insertion rod 100 side, and an opposite end portion of the connector 400 is connected to the insertion power means 300 side. At this time, a male screw or a female screw for screwing the insertion rod 100 or the nuclear fuel rod tongs 110 is provided at the one end portion of the connector 400. The one end portion of the connector 400 is disposed on the outside of the housing 200 through a guide tube 211 so as to be connected to the insertion rod 100, and the opposite end portion of the connector 400 is located at the inside of the housing 200. Next, the anti-rotation tool 500 serves to prevent the rotational force of the male screw part 320 of the insertion power means 300 from being transmitted to the insertion rod 100. That is, the linear motion of the insertion power means 300 is generated through the rotational motion of the male screw part 320. When the insertion rod 100 is directly connected to the male screw part 320, the insertion rod 100 also rotates together with a male screw portion 320, so the nuclear fuel rod 20 may be damaged. Accordingly, the anti-rotation tool 500 prevents the rotation of the insertion rod 100 and allows the insertion rod 100 to move straight. Accordingly, the anti-rotation tool 500 is moved inside the longitudinal direction of the housing 200 by being interlocked with the linear motion, generated by the rotational motion, of the male screw part 320. The male screw part 320 is coupled to one end portion of the anti-rotation tool 500, and the connector 400 is coupled to an opposite end portion of the anti-rotation tool 500. Looking in detail with respect to the anti-rotation tool 500 is as follows. A rotation space 510, in which the plug 330 of the insertion power means 300 is located and is idled, is provided at the one end portion of the anti-rotation tool 500 and is provided in a cylinder shape corresponding to the inner diameter of the housing 200. At this time, a shielding cap 520 that shields the rotation space 510 is coupled to the anti-rotation tool 500, and a through-hole 521 through which the male screw part passes is provided in the shielding cap 520. That is, by such a configuration, the plug 330 and the bearing 340 are located in the rotation space 510 of the anti-rotation tool 500 and are shielded by the shielding cap 520. In addition, a fixing means for fixing the connector 400 is provided at the opposite end of the anti-rotation tool 500. The fixing means may also be provided in a configuration in which the connector 400 may be screwed but is not limited to such a configuration. In addition, a moving pin 530 that may be guided along the guide long-hole 230 of the housing 200 in a process of moving inside the housing 200 is installed in the anti-rotation tool 500. Hereinafter, a process of adjusting the insertion length of the nuclear fuel rod using the nuclear fuel rod end distance adjusting device having the above-described configuration will be described. A plurality of the nuclear fuel rods 20 is inserted into the spacer grids 13 of the nuclear fuel assembly 10. At this time, the end distance of the inserted nuclear fuel rods 20 may not be uniform with each other, and an operator adjusts the end distance of the nuclear fuel rods 20 using a nuclear fuel rod distance adjusting device. To this end, a guide pin 220 is mounted on the front cover 210 of the housing 200, and the guide pin 220 is coupled to the FR guide plate of the assembly bench of the nuclear fuel assembly as shown in FIG. 7. Accordingly, the nuclear fuel rod end distance adjusting device is fixed to the FR guide plate of the assembly bench of the nuclear fuel assembly, as shown in FIG. 7, and the insertion rod 100 faces the nuclear fuel rod 20 correspondingly. At this time, it is understood that the size of the guide pin 220, and the location of the guide pin 220 on the front cover 210 of the housing 200 may be adjusted according to the type of the nuclear fuel. In addition, in consideration of a distance between the FR guide plate of the assembly bench of the nuclear fuel assembly and the fuel rod 20, the length of the insertion rod 100 may also be adjusted. As opposite ends of the insertion rod 100 are screwed to the nuclear fuel rod tongs 110 and the connector 400 through attachment and detachment means, respectively, the length of the insertion rod 100 may be shortened by allowing the nuclear fuel rod tongs 110 to be directly screwed to the connector 400. That is, it is possible to make the length of the insertion rod 100 long or short to be appropriate to the distance between the FR guide plate of the assembly bench of the nuclear fuel assembly and the fuel rod 20. Next, an end portion of the nuclear fuel rod 20 to be inserted is gripped by using the nuclear fuel rod tongs 110 of the insertion rod 100 corresponding to the nuclear fuel rod 20. Next, the operator rotates the male screw part 320 by grabbing the handle 321 of the male screw part 320 of the ball screw that is the insertion power means 300. At this time, a rotation direction of the male screw part 320 refers to a direction in which the insertion rod 100 may be pulled to the right in the drawing, as shown in FIGS. 5 and 6. On the other hand, when being rotated, the male screw part 320 moves in the linear motion along the spiral of the female screw part 310. At this time, the plug 330 coupled to the end portion of the male screw part 320 pulls the shielding cap 520 of the anti-rotation tool 500 while idling in the rotation space of the anti-rotation tool 500. Accordingly, as shown in FIG. 6, the anti-rotation tool 500 is interlocked along the linear motion direction of the male screw part 320 and is moved in the longitudinal direction of the housing 200. At this time, the moving pin 530 of the anti-rotation tool 500 guides the stable movement of the anti-rotation tool 500 while moving along the guide long-hole 230. On the other hand, by the movement of the anti-rotation tool 500, the connector 400 coupled to the anti-rotation tool 500 moves the insertion rod 100 in the moving direction of the male screw portion 320. At this time, the connector 400 is not directly coupled to the male screw part 320, but is configured to be coupled to the anti-rotation tool 500, so it is not interlocked with the rotation of the male screw part 320. Accordingly, only the linear motion may be accomplished according to the linear motion of the male screw part 320. Accordingly, the nuclear fuel rod 20 connected to the insertion rod 100 also only moves straight in accordance with the movement of the connector 400. At this time, it is understood that the rotation range of the male screw part 320 for the adjustment of the nuclear fuel rod 20 end distance may be determined by the operator. Accordingly, since the movement of the insertion rod 100 may be finely controlled through the rotational motion of the male screw part 320, it is possible to increase the accuracy of adjustment of the nuclear fuel rod 20 end distance. As described so far, the nuclear fuel rod end distance adjusting device according to the present invention has a technical feature that enables detailed adjustment of the nuclear fuel rod end distance to be performed by applying a configuration of the insertion power means that converts the rotational motion into the linear motion. In particular, in the case of a conversion into the linear motion according to the rotational motion, the insertion rod combined with the nuclear fuel rod is allowed to perform only the linear motion without the rotational motion, so the adjustment of the nuclear fuel rod end distance may be stably and efficiently performed without causing damage to the nuclear fuel rod. Accordingly, convenience and accuracy for the adjustment of the nuclear fuel rod end distance may be enhanced. In the above, the present invention has been described in detail with respect to the described embodiments, but it is apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and it is natural that such modifications and modifications belong to the appended claims. 100: Insertion rod110: Nuclear fuel rod tongs200: Housing210: Front cover211: Guide tube212: Coupling groove220: Guide pin230: Guide long-hole300: Insertion power means310: Female screw part320: Male screw part330: Plug340: Bearing400: Connector500: Anti-rotation tool510: Rotation space520: Shielding cap521: Through-hole530: Moving pin
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	description	This invention relates to plant and weed control or eradication using two component illumination trauma. More specifically, it relates to a relatively low energy unnatural illumination protocol of duration less than one minute to induce plant death, or induce stress, by altering cellular metabolism, causing plant component damage, hormonal changes, damage to photosynthetic apparatus, possible interruption of healthy symbiosis of a plant root with rhizosphere microorganisms surrounding the root, and photooxidative stress. The invention does not use mutagenic or high radiative energy transfers in any energy or wavelength for eradication or destruction by severe scalding, thermally-induced leaf and plant component failure, incineration, or the like. In performing lawn care, groundskeeping and landscape care, in nearly all climates, at airports, military bases, corporate parks, industrial zones and facilities, and all manner of public and private facilities nationwide and worldwide, there is a great need for plant or weed control without the application of herbicides or toxic substances. There is also a need in agriculture for stressing plants for strength and selection. Reducing the use of pesticides for weed and plant control has become an issue of national importance. Ground water is vitally important and the use of herbicides to prevent weeds from growing in homeowner and commercial lawns adversely impacts the quality of ground water. Most herbicides are persistent, soluble in water, and ingestion at high toxicity levels can be carcinogenic, affecting the human nervous system and causing endocrine disruption. To protect water quality, simple removal methods not relying on pesticides are widely sought. Ninety-five percent of fresh water on earth is ground water. Ground water is found in natural rock formations called aquifers, and are a vital natural resource with many uses. Over 50% of the USA population relies on ground water as a source of drinking water, especially in rural areas. In the USA, concerns about the potential impacts of herbicides on human health, as well as on terrestrial and aquatic ecosystems, have led to a wide range of monitoring and management programs by state and federal agencies, such as the U.S. Environmental Protection Agency (USEPA). For example, atrazine is a toxic, white, crystalline solid organic compound widely used as an herbicide for control of broadleaf and grassy weeds, and has been detected in concentrations problematic for human and animal health. Mechanical and thermal phenomena marshaled against undesirable plants by prior art devices, methods and teachings are not effective overall, and this is due in large part to the natural robustness of plants, due to their physiology and responses to natural trauma. The role of repair, regrowth, and the beneficial effects of soil-borne microbes all play a role in the hardiness of plants to prior art thermal and mechanical methods for plant control. Evaluation of effective methods for plant control using largely non-invasive phenomena is a difficult subject area to evaluate for general effectiveness because of many and varied biologic and environmental factors, including plant species, condition, type, environmental history, solar insolation, weather, and varied actions of insects, animals and microbiotica. Relevant to this is that a key component for nearly all plants, including nuisance vegetation, is its root system. A typical root comprises various internal layers, including a xylem layer which operates essentially to transport water and provide, when needed, healing substances that repair wounds, such as burn wounds or severing, lacerations, and the like. Surrounding the xylem layer is a phloem layer, typically a living transport layer, which transports organic substances such as glucose and other sugars, amino acids and hormones. Surrounding phloem layer is a cortex, which is in turn surrounded by an epidermis, which acts like a skin which sheds dead cells. In the immediate vicinity of the root of a plant, or on the root itself, is what is known as rhizospheric soil, which acts as a key root-soil interface of supreme importance for plant health. It is well known that soil-borne microbes interact with plant roots and soil constituents at this root-soil interface. This produces a dynamic environment of root-microbe interactions known as the rhizosphere, whose character and effect on the life of a plant varies widely with differing physical, chemical, and biological properties of the root-associated soil. Root-free soil without such organisms is known as bulk soil. Releasing of root exudates, such as epidermis flakes and other secretions, is sometimes called rhizodeposition and provides growth material, structural material or signals for root-associated microbiota. These microbiota feed on proteins and sugars released by roots. Protozoa and nematodes that feed on bacteria are also present in the rhizosphere, and provide nutrient cycling and disease suppression by warding off pathogens. [Ref: Oxford Journals Journal of Experimental Botany Volume 56, Number 417 Pp. 1761-1778, hereby incorporated in this disclosure in its entirety]. The balance of populations in a healthy symbiotic rhizosphere is important, because, in part, the bacteria which provide disease suppression interact with pathogens in a variety of ways, including mechanisms of antagonism, such as by competition for nutrients, parasitism, predation and antibiosis. Fungi, too, can be involved, and their actions, when turned from symbiotic to antagonistic, can be lethal for a plant. There are three separate, but interacting, components recognized in the rhizosphere: the rhizospheric soil, the rhizoplane, and the root itself. The rhizosphere is soil influenced by roots via release of substances that affect microbial activity. The rhizoplane is the root surface, including the strongly adhering soil particles. The root itself also participates, because certain micro-organisms, known as endophytes, are able to colonize root tissues. Any method to eradicate nuisance vegetation is typically influenced by the overall effect—and possible later influence—on the plant roots, and the rhizosheric soil. Interactions of a plant with electromagnetic radiation have been explored, but easy, safe, clean and efficient eradication meeting certain requirements has been heretofore elusive. In this disclosure, the plant root crown, as discussed below, figures importantly. In the prior art, basic thermal and mechanical techniques to eliminate nuisance vegetation are not sufficiently effective for use as a commercially viable eradication program or system. This includes [1] basic pulling of plant stems, roots, or other plant components to induce tensile failure, such as by natural events like feeding of cows and other ruminants; [2] tensile failure below ground surface or soil grade; [3] severing action or cut action, such as by gnawing or eating by an animal; [4] cutting using a cutting tool or machine such as a chain saw; [5] surface trauma delivered to plant root epidermis and cortex, such as lacerating or abrasion of the epidermis and possibly the cortex of a root, such as done by a gnawing animal, or by trauma delivered by a shovel blade or other tool; or [6] needle wounds, which lend themselves to repair using latex or other healing substances that are dispatched to the scene of the wound, often originating from the xylem layer to transport needed enzymes and healing tars. Biological responses to unnatural illumination can be counter-intuitive and complex, and there are many phenomenological findings discovered. Now referring to FIG. 1, a schematic representation of a general electromagnetic spectrum for wavelengths of radiation of significance that are potentially incident upon a plant, with wavelengths ranging from 1 mm to less than 100 nm is shown. In the infrared portion, or heat radiation portion of the electromagnetic spectrum, there are subdivisions for Far-Infrared (FAR), mid or Medium Wavelength Infrared (MWIR) and near-infrared (NEAR) all in total ranging from 1 mm to 700 nm or 0.7 microns. Visible light (Visible Light) is commonly taken to range from 700 nm to 400 nm. Ultraviolet (Ultraviolet) radiation is generally taken to be of wavelength less than 400 nm, with near-ultraviolet further divided according to some consensus into known portions UV-A (400-320 nm), UV-B (320-280 nm) and finally, UV-C (280 nm-100 nm) which is extremely dangerous for humans and is often used as a germicidal radiation to purify water and kill bacteria, viruses, and other organisms. There are competing standards for labeling portions of the electromagnetic spectrum, as promulgated by ISO (International Organization for Standardization); DIN, Deutsches Institut für Normung e.V. (German Institute for Standardization) and others. It is important to note that in this disclosure and the appended claims, these and certain other subdivisions shall have particular meanings assigned here and will be defined herein in the Definitions Section. Now referring to FIG. 2, a cartesian plot of both unfiltered solar radiation and net (ground) solar radiation is shown, with spectral radiance in watts per square meter per nanometer versus wavelength in nanometers (nm) is shown. Photosynthesis in plants makes use of visible light, especially blue and red visible light, and ultraviolet light, to varying degrees, depending on a host of factors including plant species and type, radiation exposure history, chloroplast type, internal plant signaling, light exposure history, and other factors. Nearly all the infrared radiation in sunlight is essentially in the region in or about near infrared (NIR), and shorter than 4 micrometers. Approximately seven percent of the raw electromagnetic radiation emitted from the sun is in a UV range of about 200-400 nm wavelengths. As the solar radiation passes through the atmosphere, ultraviolet or UV radiation flux is reduced, allowing that UV-C (“shortwave”) radiation (200-280 nm) is completely absorbed by atmospheric gases, while much of the UV-B radiation (280-320 nm) is additionally absorbed by stratospheric ozone, with a small amount transmitted to the Earth's surface. Solar UV-A radiation (320-400 nm) is essentially, for practical purposes, not absorbed by the ozone layer. As mentioned below, UV-B and UV-C radiation have been suggested to effect eradication of plants. Plants tend to respond to UV-B irradiation and also to excessive visible light by stimulating protection mechanisms or by activating repair mechanisms to reduce injury and perform repair. A common protective mechanism against potentially damaging irradiation is the biosynthesis of UV absorbing compounds, which include secondary metabolites, mainly phenolic compounds, flavonoids, and hydroxycinnamate esters that accumulate in the vacuoles of epidermal cells in response to UV-B irradiation. These compounds attenuate UV-B range radiation and protect the inner or deeper cell layers, with little absorptive effect on visible light. UV-B radiation is considered highly mutagenic, with plant DNA particularly sensitive. UV-B radiation causes deleterious phototransformations and can result in production of cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidinone dimers (6-4 Pps). DNA and RNA polymerases are generally not able to read through these photoproducts and the elimination of these cytotoxic compounds is essential for DNA replication and transcription and for plant survival. To cope, most plants have developed repair mechanisms including photoreactivation, excision, and recombination repair. Photoreactivation is a light-dependent enzymatic process using UV-A and blue light to monomerize pyrimidine dimers: Photolyase binds to the photoproducts and then uses light energy to initiate electron transfer to break the chemical bonds of cyclobutane rings and restore integrity of the bases. It is now known that plant roots also are simply generally sensitive to UV-B light levels, such as via the action of the gene RUS1, and can pass this information on to other parts of a plant responsible for growth and development. Low dosages of UV-B light can provide important signals to the rest of the plant and can be beneficial to plant growth, helping young plants develop in a timely way, and helping promote seedling morphogenesis. For long term exposure of weeks' duration, too much UV-B light can be toxic to some plants. However, any resulting lethality is not suited for meeting the purposes served by the instant invention, as discussed below. The allelopathic behavior of plants can be influenced by exposure to added (artificial) UV-B radiation [ref: “Allelopathic Influence of Houndstongue (Cynoglossum officinale) and Its Modification by UV-B Radiation,” Nancy H. Furness, Barbara Adomas, Qiujie Dai, Shixin Li, and Mahesh K. Upadhyaya; Weed Technology 2008 22:101-107]. Importantly, UV-B radiation can trigger biochemical steps to activate internals processes such as wax production to provide a plant with protection against further ultraviolet radiation [ref: “A UV-B-specific signaling component orchestrates plant UV protection,” Brown B A, Cloix C, Jiang G H, Kaiserli E, Herzyk P, Kliebenstein D J, Jenkins G I; Proc Natl Acad Sci USA. 2005 Dec. 13; 102(50):18225-30. Epub 2005 Dec. 5]. Plant epidermal flavonoids can protect the photosynthetic apparatus from UVB-mediated damage [ref: “Protection of the D1 photosystem II reaction center protein from degradation in ultraviolet radiation following adaptation of Brassica napus L. to growth in ultraviolet-B,” Wilson, M. I. and B. M. Greenberg (1993) Photochem. Photobiol. 57, 556-563] [ref: “A flavonoid mutant of barley (Hordeum vulgare L.) exhibits increased sensitivity to UV-B radiation in the primary leaf,” Reuber, S., J. F. Bornman and G. Weissenböck (1996) Plant Cell Environ. 19, 593-601]. It is illustrative to examine how plants deal with large infrared and ultrviolet/visible light exposures. Now referring to FIG. 3, a partial schematic representation of a class of prior art plant eradication using various large infrared radiative transfers is shown. A plant Y with root R is shown receiving a large infrared radiative transfer from a forest fire, or any number of prior art infrared radiation-producing processes listed as shown, such as via a flame, an incandescent body, a hot gas, vapor (e.g., steam) or fluid, or via contact with a hot body, or via ordinary high intensity destructive exposure to known IR or infrared radiators. Because of the their inherited ability to withstand forest fires and lightning strikes, most plants do not respond in large numbers to application of heat as given in the prior art. Application of thermal contactors or applicators have not met with success. The heat thus delivered is ineffective or can be sometimes be beneficial or stimulative, with any resultant subsequent repair to a root often making the root and plant more robust to future thermal trauma. Application of thermal energy and high doses of radiant energy have been shown in the prior art to burn, incinerate, discolor, or render useless above-ground plant components. Whether or not those same plants grew back, however, is often left unstated in prior art disclosures. FIG. 3, which shows schematically as an example a FIRE impinging upon plant Y and/or root R, is followed by FIG. 4 showing a burned root with a burned stump as shown, such as might be found after a forest fire, with combustion byproducts, volatilized proteins or smoke SS rising from the stump as shown. Even obliterating plant Y above ground in this manner typically results in the response shown in FIG. 5, which shows Regrowth as shown. It is not sufficient merely to damage certain components of a plant, such as causing senescence or incineration of above-surface foliage. While visible above-ground damage may be desirable or gratifying for an operator of a eradication machine, actual lethality can be short of expectations and short of what is required for a successful eradication system, particularly for agricultural applications where fast-growing species can regenerate in a matter of weeks. For example, prior art U.S. Pat. No. 5,189,832 to Hoek et al., discloses gas-fired burners which are directed at nuisance vegetation along a ground plane. This and other prior art methods which burn or heat plant parts usually fail, because plants have evolved to tolerate—and sometimes be stimulated by, forest fires and lightning strikes. Similarly, when propane burners and heated ceramics burn off foliage, root structure remains among plants, and many plants regrow. Soil is an excellent thermal insulator both because of the presence of what are essentially refractory materials such as silica, sand, igneous rock particles, and the like—and also because of air content, moisture content, and because of its high thermal mass. It has been found through experimentation that It takes approximately one hour for a 8000 btu/hour output propane torch to have significant thermal effects 2.5 cm into bulk soil. Common nuisance vegetation such as Digitaris sanguinalis in the crabgrass family, for example, is difficult to kill, regenerates easily after pulling, and is resistant to chemicals and thermal trauma. Many weeds such as crabgrass are fairly transparent to UV-C and the lethality of UV-B for short term applications of low energy is small in degree and not sufficient for a commercially successfully eradication method. Now referring to FIGS. 6 and 7, there is depicted one typical class of prior art eradication processes or occurrences whereby extreme ultraviolet light induced trauma is delivered with a large UV radiative transfer via general illumination or flash onto a naturally grown species Digitaria sanguinalis rooted into a soil grade as shown. The radiation shown in FIG. 6 is shown for illustrative purposes, ranging from visible light, through UV-A, UV-B and UV-C and beyond, into what is known as Far Ultraviolet, extremely virulent and dangerous forms of radiation. First, it should be noted that with the various protection mechanisms that plants employ, added amounts of UV radiation are quite often ineffective, either wholly or in practice, for a suitable eradication process. When plants are normally in sunlight, they tend to develop a waxy layer on their leaves and other similarly exposed components. These plants tend to be resistant to UV radiation. In particular, monocots and dicots have protective cells, including a well-developed epidermis which comprises a waxy layer on top, called the cuticle. This waxy surface protects the leaves from sunburn, dessication (drying out) and reduces attacks by fungi, bacteria, virus particles and insects. This layer prevents what is called sunscald. When moderate levels of UV radiation are used to attempt to clear nuisance vegetation, leaves can turn white in color as the radiation breaks down connections of layers, and as a result, the leaf is unable to conduct photosynthesis. Leaf components can die. However, the root structure remains, and the plant usually is able to adapt as after a forest fire, which inflicts similar radiation damage. Evaluating the effect of artificial illumination on nuisance plants can be complex, with competing and conflicting effects and factors. Prior art techniques have not been successful, overall. In many cases, added illumination in the form of general UV rays containing UV-A, UV—B and UV-C frequencies has been found to give benefits. Inconsistencies in prior art research findings are due to differing plant biology and genetics; soil conditions; and ambient light, e.g., shady versus sunny conditions. There are many engineering considerations that figure importantly in determining the success of an eradication system using illumination. Among the many other factors in play when using artificial illumination to attempt eradication of nuisance plants are: [1] Actual operative (beneficial versus detrimental) result from illumination stress [2] Effectiveness, such as expressed lethality in percent dead after 30 days [3] Total required input energy [4] Time of Exposure and speed of operations. Increased speed is part of the subject of this disclosure. [5] Infrared levels, visible light levels, UV-A levels, UV-B levels, and UV-C levels [6] Lamp or light source system complexity, cost, the need for controls, ballasts, and operator safety guards [7] Operator and bystander safety, specifically often regarding infrared and UV exposure danger. This is a significant disadvantage for prior art methods such as that disclosed in U.S. Pat. No. 5,929,455 to Jensen, which discloses an eradication method using high energy radiation, high in UV-B and especially UV-C radiation, which is dangerous and mutating. Jensen '455 uses very high applied power.[8] Mutagenic effects from UV-B and UV-C to life forms at ground surface and into bulk soil. Although some mutagenic activity has been observed for even visible light, there is a steep exponential drop in mutagenic activity and effect for radiation over 320 nm wavelength.[8] Ignition hazards, lamp unit operating temperatures, and cost of operation A successful eradication system will develop and meet high benchmarks regarding these factors. While some effectiveness has been found using prior art methods, it has only been effective for very large and dangerous radiative transfers. The reason why these dangerous and very high energy transfers have been used is because prior art low energy methods have not worked. The method described by Kaj Jensen in U.S. Pat. No. 5,929,455 uses an extremely high energy, dangerous process, specifically using UV-B and UV-C which have very high and special, qualitatively different, lethality. Interestingly, certain species such as crabgrass are fairly transparent to it for low dosages. Jensen '455 uses no other kind of light and employs a high pressure mercury (Hg) vapor lamp with a strong 254 nm UV-C emission line and no intervening phosphor. Such emissions, including similar emissions lines from other selected arc discharge lamps are very dangerous, expensive and require extensive controls and safeguards. Jensen '455 uses dosages very far greater than 10,000 joules per square meter merely to stop or retard growth dependent on the type and size of the plant. Actual attempts at lethality for a successful eradication process for the type of radiation Jensen '455 arrays involves many tens of thousands of Joules per square meter exposure. This type of high energy exposure of UV rays, along with infrared and visible light, to kill life, including plant life, is known since at least the mid-20th century. During World War II and also during tests in decades after, it became known that certain high energy depositions of UV-B and UV-C radiation onto land kills vegetation—and it is energies in this regime, in terms of total Joules of deposited UV energy—that Jensen '455 uses. The world's first hydrogen bomb test, conducted by the United States in the Bikini Atoll in March, 1954, had unprecedented explosive power, an equivalent explosive yield of as high as 15 Megatons of TNT (Trinitrotoluene). By contrast, the blasts at Hiroshima and Nagasaki in Japan in August, 1945 yielded an estimated 16,000 tons and 21,000 tons, respectively. Radiation effects from these blasts received very high attention and study. According the Radiation Effects Research Foundation (RERF), a non-profit organization conducted in accord with an agreement between the governments of Japan and the United States, initial radiation effects were assessed by the Atomic Bomb Casualty Commission (ABCC) established in 1947, which was later re-organized into the RERF in 1975. This included extremely extensive and detailed epidemiological studies of health and longevity on more than 120,000 affected individuals, with research conducted for over fifty years. It also included detailed observations of effects on plants and animal life. From the discoveries made after the bombing of Hiroshima and Nagasaki, regarding the effects on plant life from the measured emissions of electromagnetic (light) radiation, the application of a high amount of UV, including UV-A, UV-B and UV-C, to kill plants appears to be known. Generally, the energy of a typical atomic bomb is distributed roughly as 50% blast pressure, 35% as heat, and 15% as radiation (all types). During the two atomic bomb blasts of 1945, the greatest number of radiation injuries was deemed to be due to ultraviolet rays. The origination of the ultraviolet rays comes from the extremely high temperature flash of the initial reaction in the detonated atomic bomb. These rays cause very severe flash burns and they were well known to have killed plant life. The radiation comes in two bursts: an extremely intense “flash” discharge lasting only 3 milliseconds, and a less intense one of longer duration, lasting several seconds. The second burst contains by far the larger fraction of total light energy, over ninety percent. The first flash or discharge is especially rich in ultraviolet radiation, which is very biologically destructive. The total deposition energy of the initial flash alone is such that, with no time for heat dissipation, the temperature of a person's skin would have been raised 50 C by the flash of visible and ultraviolet rays in the first millisecond at a distance of just under 4000 meters from the blast zone. This research was conducted by the Manhattan Atomic Bomb Investigating Group, formed on 11 Aug. 1945, two days after the bombing of Nagasaki, via a message from Major General Leslie R. Groves to Brigadier General Thomas F. Farrell. The biological effects of high amounts of UV radiation on plant life were especially obvious and pronounced by examining the aftermath of the first hydrogen bomb test on the Bikini Atoll. Young naval officers on deck of the USS Bairoko witnessed, while in the Bikini Atoll about 50 km from the hydrogen bomb blast site, an intense flash followed by a longer radiation burst of some seconds duration, in turn followed by heavy, warm, blast-driven winds. The ultraviolet radiation from the flashes was sufficient to kill fish deep underwater, as evidenced by many varied fish floating to the surface, with bodies burned on one side or region, from incident UV rays. The ultraviolet radiation also killed plant life over a very large area. Various measurements were retained even though the blast destroyed many instruments that were set up in permanent buildings to measure it. From the standpoint of acceptable lethality for a success eradication process, all low energy previous prior art techniques have fallen short and have not been acceptably effective. Speed of application and overall success rate are very important. Generally, the delivery of trauma which resembles natural trauma (e.g., severing, pulling, application of heat etc.) is not effective as bona fide reliable eradication methods, because the plants so treated tend to heal and regenerate, probably as a result of centuries of evolution. The delivery of illumination trauma in the low energy regime as attempted in the prior art is similarly not effective. High dosages of radiation that serve to scald, burn or incinerate a plant ironically result in regrowth as shown in the instant FIGS. 3-5, as they resemble a forest fire, addressed by centuries of evolution among plants. Also, many prior art discoveries regarding application of artificial radiation to plants often exist ostensibly to serve another other objective, such as benefitting the plant, by stimulating growth, removing pathogens or insects, etc. Reference is now made to U.S. Pat. No. 8,872,136, issued 28 Oct. 2014 to Jackson, et. al., application Ser. No. 13/553,79. The entire disclosure of this prior issued patent, Jackson U.S. Pat. No. 8,872,136 is hereby incorporated herein by reference in its entirety and its subject matter arises from the same owner and obligation to assign. In U.S. Pat. No. 8,872,136 to Jackson et al., a substantially non-invasive low-energy low irradiance non-mutating method is taught and claimed for eradicating a plant in a time under one minute, using a Rapid Unnatural Dual Component Illumination Protocol (RUDCIP) with illumination about the plant—but a different eradication method is given from that disclosed and claimed in the instant disclosure—different aiming, different wavelengths, and different protocol are given. Jackson U.S. Pat. No. 8,872,136 discloses an above-ground foliage and root crown damage illumination component comprising exposure using near-IR radiation directed to the foliage of the plant and/or its root crown—along with a ground-penetrating UV-A illumination component, with UV-A radiation directed to the root crown of the plant and/or the soil grade immediately adjacent the root crown of the plant. Of further interest and relevance in the instant disclosure are metabolic and signaling processes associated with photosynthesis and plant regulation, growth and self-protection. One main organelle, the chloroplast, figures importantly. Chloroplasts, the organelles responsible for photosynthesis, are metabolic generators, contain self-supporting genetic systems, and they can replicate. They are also highly dynamic and circulate within plant cells, and their operative metabolic behavior is strongly influenced by light color and intensity. Plant chloroplasts are large organelles (typically 5 to 10 microns (μm) in their longest dimension and comprise a double membrane chloroplast envelope, and also a third internal envelope, the thylakoid membrane. The thylakoid membrane forms a network of flattened thylakoids, which frequently are arranged in stacks. It is well known that plants use blue and red light as primary drivers for photosynthesis, as well as to serve as signals and alarms for needed internal changes. A plant blue light response was documented as early as 1881 by Charles Darwin when he discovered what is now known as the blue light-induced phototropic response. Commercially available “grow” lamps use blue light as part of a distribution of wavelengths for maximum growth and viability. If excess light is given to a plant, stress can occur. Generally, inside chloroplasts, abiotic stresses such as drought, high light, high temperatures, and salinity induce a reduction in CO2 takeup, and increased reactive oxygen species (ROS), which can lead to leaf senescence and yield loss. Plants have multiple mechanisms to either prevent the formation of ROS or eliminate them. However, it is important to note that leaf senescence is not same as plant senescence, dying, or eradication. Reactive oxygen species are eliminated rapidly by internal antioxidative systems, and the chloroplast uses hydrogen peroxide levels to regulate thermal dissipation or elimination of excess light input energy, as managed by known photosynthetic electron transport mechanisms. Reactive oxygen species are also used to signal alarms inside plants, to regulate metabolism, gene expression and other factors to deal with stresses, including exposure to UV-A radiation. There are other mechanisms that employ light in plants, such as by various photoreceptors. Phytochromes are sensitive to red and infrared light and may act as temperature sensors. Phytochromes regulate the germination of seeds, synthesis of chlorophyll itself, and growth and development of seedlings, and onset of flowering. Cryptochromes are flavoproteins that are respond to blue and UV-A light, and influence circadian rhythms. Finally, phototropins are flavoproteins that mediate phototropism responses in higher plants, such as those notably observed by Charles Darwin in 1881. Red light plays a role in many plants but regarding the instant invention, red light irradiation was found not effective, and addition of red wavelengths to the protocol taught and claimed in the instant disclosure had no perceptible increase in effectiveness when compared to a control group. A different, subtle but effective way to eradicate or stress plants with optical and thermal/optical trauma with high effective lethality was discovered using unexpectedly low input energy and short exposure times using safe radiation. The invention uses specific aiming and a combination of irradiances not taught or suggested by the prior art. The instant invention uses a dual component, low energy, unnatural set of irradiances, with an Indigo Region Illumination Distribution of light that can extend from 300 nm (UV-A) to midway in the visible spectrum (550 nm) to be directed to plant foliage and/or a plant root crown, and a Medium Wavelength Infrared distribution of light, ranging from 2-20 microns wavelength to be directed to the ground, to a plant root crown and/or soil immediately adjacent to the root crown. This represents a wholly new discovery distinct from Jackson 8,872,136, and allows eradication and/or control to be accomplished in half the time, e.g., 5 seconds instead of ten. In addition to quicker application and faster operation, the teachings of the instant invention use less energy. For certain embodiments, energy used has been reduced from 400 watts to 120 watts. The invention also provides for preferred embodiments that allow for novel compact configurations, such as a proximity pass-through configuration and a proximity reflect-through configuration, that provide both irradiances together in a compact illuminator package, as disclosed further below. The instant invention uses Medium Wavelength Infrared radiation, with wavelength most broadly from 2-20 microns, preferably 2.4-8 microns and more preferably for certain embodiments, 3-5 microns. Photoreceptors in the human eye have low sensitivity to this type of infrared radiation. The invention comprises a high speed, substantially non-invasive, low-irradiance method for eradicating a plant via signaling in a treatment time under one minute, using indigo region illumination and medium wavelength infrared illumination about the plant, the method comprising any of [A], [B], [C] and [D]: [A] a full IRID twin component exposure, directed for eradicating a plant that is in a vegetative or later phase, comprising: [A1] Exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID between 0.125 W/cm2 and 2 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination A1 exposure;[A2] Exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR between 0.045 W/cm2 and 0.72 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination A2 exposure; the exposures A1 and A2 for respective times that together allow the signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures;[B] a low IRID summed twin component exposure, with compensating MWIR, directed for eradicating a plant that is in a vegetative or later phase, comprising:[B1] Exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID between 0.05 W/cm2 and 0.125 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination B1 exposure;[B2] Exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR such that the sum of the Indigo Region Illumination Distribution average irradiance EIRID from step [B1] and the Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR is at least 0.25 W/cm2 and less than 7 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination B2 exposure; the exposures B1 and B2 for respective times that together allow the signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures;[C] a saturation twin component exposure, directed for eradicating a plant that is in a vegetative or later phase, comprising:[C1] Exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID of at least 0.125 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination C1 exposure;[C2] Exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR such that the sum of the Indigo Region Illumination Distribution average irradiance EIRID from step [C1] and the Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR is at least 0.125 W/cm2 and less than 7 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination C2 exposure; the exposures C1 and C2 for respective times that together allow the signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures;[D] a twin component exposure, directed for eradicating a seedling, comprising:[D1] Exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID between 0.1 W/cm2 and 1 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination D1 exposure;[D2] Exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR between 0.035 W/cm2 and 0.35 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination D2 exposure; the exposures D1 and D2 for respective times that together allow the signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures. The method can also additionally comprise heating an MWIR emitter (E) to produce at least a portion of the Medium Wavelength Infrared radiation, and the MWIR emitter can also be heated to a temperature between 400 F and 1000 F to produce at least a portion of the Medium Wavelength Infrared radiation. The MWIR emitter can comprise glass such as selected from borosilicate glass, and soda lime glass. The exposures of [A], [B], [C] and [D] can have a duration of 7 seconds or less in total, or 2 seconds or less in total. The Indigo Region Illumination Distribution can comprise radiation in the range of 420-480 nm wavelength, or alternatively, 400-500 nm wavelength, and additionally, one can superpose at least a portion of Indigo Region Illumination Distribution and the Medium Wavelength Infrared radiation to allow them to be so directed at least partly together. The method also can comprise creating a proximity pass-through configuration by passing a portion of the Indigo Region Illumination Distribution through a MWIR emitter (E) that provides at least some of the Medium Wavelength Infrared radiation. The method can also comprise directing at least a portion of the Indigo Region Illumination Distribution so as to reflect off a surface before emerging to be so directed. Also, a proximity reflect-through configuration can be achieved using the invention by making at least a portion of the Indigo Region Illumination Distribution reflect off a surface before emerging to be so directed and superposing at least a portion of the Indigo Region Illumination Distribution and the Medium Wavelength Infrared radiation to allow them to be directed at least partly together. The invention can also additionally comprise heating an MWIR emitter to produce at least a portion of the Medium Wavelength Infrared radiation, where the MWIR emitter comprises a powder coat, and the powder coat can be optically excited via a radiant source (HL) external thereto. The powder coat can comprise a glass, such as glass selected from borosilicate glass, and soda lime glass. The method can also comprise directing the exposures for the Indigo Region Illumination Distribution and the Medium Wavelength Infrared radiation at least partly simultaneously. The method also can comprise locating the plant using machine recognition, and performing the method on the plant so located. The invention also relates to a high speed, substantially non-invasive, low irradiance method to apply stress to a plant in a time under one minute, using indigo region illumination and medium wavelength infrared illumination about the plant, the method comprising any of exposures [A], [B], [C] and [D], as given above, and similarly can be supplemented by the additional optional method features listed above following the descriptions of exposures [A], [B], [C] and [D]. Also, this method can additionally comprise an additional step whereby, based upon a plant response to exposures corresponding to any of [A], [B], [C] and [D], one can further select a plant for one of retention, treatment, eradication or neglect. The invention also includes a non-invasive, low-irradiance proximity illuminator (10) providing an Indigo Region Illumination Distribution (IRID) and Medium Wavelength Infrared (MWIR) radiation about a plant, the illuminator comprising: [a] A foliage and root crown illumination source comprising an IRID emitter (88); [b] A root crown and soil grade illumination source comprising an MWIR emitter (E); the IRID emitter and the MWIR emitter each so sized, positioned and oriented to allow that at least some light output from each of the IRID emitter and MWIR emitter to be substantially superposed for directing to the plant. As in the method, the illuminator can have the IRID emitter and the MWIR emitter further each so sized, positioned and oriented to offer a proximity pass-through configuration whereby at least some of the light output from the IRID emitter passes through the MWIR emitter. The illuminator can comprise a thermal shield so sized, positioned and oriented to reduce thermal back-emission from the MWIR emitter to the IRID emitter, the thermal shield comprising at least one of an IR-reflector and an IR-insulator, and the MWIR emitter additionally can also comprise a glass selected from borosilicate glass, and soda lime glass, as well as additionally comprise a heater in thermal communication with the glass. The illuminator can also be configured wherein the IRID emitter is further positioned to allow at least some of the light output therefrom to reflect off a surface before emerging from the illuminator, and that surface can optionally comprise at least part of the MWIR emitter. The MWIR emitter can comprise a powder coat, and can optionally be excited by a radiant source to heat the powder coat. The powder coat itself can comprise a glass selected from borosilicate glass, and soda lime glass. The following definitions shall be used throughout: —Average Irradiance—shall refer to a power level of irradiance at taught for the instant invention which is achieved at some time, such as a sub-portion of the total treatment time and not necessarily all the time, during exposure treatment of a plant or use of the instant invention. It is understood that those of ordinary skill in the art can modulate power levels to achieve many varied objectives, and flashes or low level or high level exposures can be used. For example, during a 2 second treatment, an exposure consisting of four flashes active during 1/10 of the exposure time, such as four 0.05 second duration flashes for a total of 0.2 seconds at a 10 W/cm2 irradiance would work out to 1 W/cm2 average irradiance, if calculated over the whole time of 2 seconds. This definition shall thus preclude the avoidance of claims by merely changing exposure levels to avoid the average irradiances for Indigo Region Illumination Distribution IRID and Medium Wavelength Infrared MWIR as taught and claimed.—Directed, directing—shall denote any net transmission of electromagnetic radiation as taught and claimed here, whether by direct illumination or via reflection or indirect transmission, such as via use of mirrors, light guides, via refraction, or incidental reflection or absorption and re-transmission through any material body, or through a plant under treatment, or a plant adjacent to a plant under treatment, such as light passing between or through foliage of one plant to another plant, seed, or seedling.—Eradicate—can include death, eventual death, damage or stress to an adult plant, seedling or seed, and at least partial disruption or delay of the germination of a plant or seed. Multiple applications of the instant invention, such as lower dose applications can be contemplated whereby desired eradication yield increases upon multiple applications or passes.—Exposure—shall be that due to radiative transfer over and above that provided by natural sunlight or equivalent ordinary ambient light received by plants unassisted by use of the instant invention.—Foliage—shall denote all parts of a plant above soil grade, generally excluding root structures, and shall include components such as stems and leaves.—Heater/Heating—shall include all thermal production and transfer, from any heat source, via contact or conduction; convection; or radiation.—Illumination—shall be interpreted broadly and shall include all manner of radiative processes as defined by the appended claims, and shall not be limited to lamp outputs, but rather shall encompass any and all radiation afforded by physical processes such as incandescence or any light emission process such as from a light emitting diode (LED); flames; or incandescence from hot masses, such as gases, fluids, steam, metal knives or hot infrared emitters—and can encompass multiple sources.—IRID—Indigo Region Illumination Distribution (“blue”)—shall denote a preferred range of frequencies, such as emitted by commercially available blue LED (light emitting diode) light sources with emission peaks named “royal blue” that denote a possible range of wavelengths that serve the instant invention. This definition shall include an Indigo Region Illumination Distribution to be defined to be any of the following wavelength ranges:[1] A preferred range: 420-450 nm; [2] a larger preferred range of 420-480 nm; [3] a larger preferred range of 400-500 nm; [4] a yet larger preferred range of 400-550 nm; [5] and a broad range of 300-550 nm. This “indigo band” does not have to include indigo or blue or any particular “color” and does not have to include wavelengths in the preferred range of—wavelengths of 420-450 nm that are commonly assigned to indigo or near indigo as human perceptions. The addition of light for any reason, including for a trademark or appearance effect, e.g., aquamarine, shall not affect this definition. The frequency range as defined interestingly typically includes a first common photochemical efficiency peak for plants, as discussed in the description for FIGS. 11 and 12. An Indigo Region Illumination Distribution IRID can include monochromatic, multichromatic frequency/wavelength lines or bands, continuous or non-continuous distributions, and distributions that comprise one of more emission lines, or distributions that are absent the general wavelength or frequency for which it is named, i.e., a distribution that is absent wavelengths generally given for indigo, that is, absent approximately 420-450 nm. Metamerism and the response of the human visual system to identify or form color perceptions shall not narrow this definition. —IRID Emitter (88)—shall denote any light producing device that has the requisite electromagnetic output properties to help produce an Indigo Region Illumination Distribution IRID that allows service to the instant invention as described in the appended claims, and can be an LED array IRID emitter 88, a laser, or an excited material body. An IRID emitter and a MWIR emitter can be combined into one body or component, or device.—Medium Wavelength Infrared—MWIR—has been variously defined by different organizational bodies, sometimes using different terms. For example In the CIE division scheme (International Commission on Illumination), CIE recommended the division of infrared radiation into the following three bands using letter abbreviations: IR-A, from 700 nm-1400 nm (0.7 μm-1.4 μm); IR-B, from 1400 nm-3000 nm (1.4 μm-3 μm); and IR-C from 3000 nm-1 mm (3 μm-1000 μm). ISO (International Organization for Standardization) established a standard, ISO20473 that defines the term mid-IR to mean radiation with wavelengths from 3-50 nm. In common literature infrared generally has been divided into near infrared (0.7 to 1.4 microns IRA, IR-A DIN), short wavelength infrared (SWIR or 1.4-3.0 microns IR-B DIN), mid-wavelength (or medium wavelength) infrared at 3-8 microns (MWIR/midlR 3-8 microns IR-C DIN) to long wavelength infrared (LWIR, IR-C DIN) 8-15 microns to far infrared 15-1000 microns. In this disclosure, throughout the specification, drawings and in the appended claims, MWIR in particular shall have a meaning assigned, and the wavelengths for MWIR shall span from 2-20 microns, and with preferred embodiments in a range of 2.4-8 microns and more preferably in a range of 3-5 microns. Source emissions can include emissions from an MWIR emitter E that is formed from materials with known emissivity functions useful in service of the invention, such as known borosilicate glass. —MWIR Emitter (E)—shall denote any glass or material body that has the requisite optical properties or electromagnetic emissivity properties that allow service to the instant invention as described in the appended claims. This can include glass known under the trade name Pyrex® such as borosilicate glass, which is preferred, or Pyrex Glass Code 7740, as well as Pyrex® soda lime glass or other materials. Any material body which serves the invention with useful emissivity as an MWIR emitter when stimulated, excited, or heated shall meet this definition. An IRID emitter and a MWIR emitter can be combined into one body or component.—Minute of total operation—“under one minute of total operation”—“Time under one minute”—shall denote a process of illumination that shall include stepwise, piecemeal, segmented, separated, sequential, variable, or modulated exposures that when totaled, have a summed duration or the equivalent of under one minute, such as four 10-second exposures/flashes over a three minute time, or four ¼ second flashes in one hour.—Near-IR (near infrared)—is defined in varied ways by multiple sources and organizations, such as the International Commission on Illumination (CIE), and as given by ISO standard 20473. In the instant disclosure and appended claims, near-IR shall be assigned to extend from 700 nm to 2 microns (2000 nm) wavelength.—Non-invasive—shall include the attributes of not requiring uprooting, stabbing, cutting, striking or significant mechanical stressing, except for contact with hot bodies or hot fluids such as hot gases or steam when used as a thermal equivalent of general IR (infrared) radiation as taught here.—Non-mutating—shall be construed as relatively non-mutating, such as UV-A radiation being relatively non-mutating when compared to the effect of UV-B radiation.—Plant—shall include any biological organism that succumbs to or is controlled by the instant invention. The can include bacteria, and organisms in the plant and animal kingdoms, and seeds and seedlings.—Powder coat—shall include any and all coverings, coatings, surface treatments, appliques, and depositions to a surface.—Rhizosphere—shall include all microorganisms in contact with, in the vicinity of, or interacting with a plant root system, such as nitrogen-fixing bacteria, fungi, and mycorrhizae, such as arbuscular mycorrhizae which can inhabit root structure.—Root—can comprise any number of root types, such as a tap root, a fibrous root, a prop root, an aeria root, an aerating or knee root, a buttress root, or a tuberous root system.—Root crown—shall comprise the portion of a plant root which is above, at, or near the surface established by a soil grade. This shall include the root collar or root neck from which a plant stem arises. Root crown shall also comprise any portion of a seed or seedling which has not affixed itself to a soil grade, but is the root in development or is biological tissue associated with root development.—Seedling, Seed—A seedling shall include any young plant or sporophyte emerging or developing out of a plant embryo or seed, whether before or after germination of any seed. This shall apply to a young plant regardless of stage of development, for any stage of a radicle (embryonic root) of a seed, as well as to any stage for any hypocotyl (embryonic shoot) and any seed leaves, such as with one-leaf monocotyledons and two leaf dicotyledons, or multiple leaf cotyledons, or no cotyledons, such as acotyledons. Any stage of photomorphogenesis shall be included. This definition shall apply even with assistance from natural processes that weaken seed coats to assist with germination, such as heat of a fire, moisture exposure or water immersion, history of passing through an animal's digestive tract, or extreme swings in ambient natural temperature or light levels.—Soil grade—shall include any prevailing soil grade, or any immediately effective soil grade, such as after disturbing of soil.—UV-A radiation—shall denote ultraviolet radiation of wavelength from 300-400 nm.—Vegetative stage or phase—shall denote the growth phase of a plant that occurs after germination and before flowering, during which time the plant has distinct, viable foliage. The term “later stage” associated with “vegetative phase or later” as used in this disclosure and in the appended claims shall include phases more advanced, such as a flowering phase or later stages such as a ripening phase. The instant invention shall be applied as taught and claimed even though a mixture of plants of different phases, including seeds and seedlings, can be under its application. The scope of the amended claims shall not be narrowed by virtue of types or phases of development of plants serving as a target of the instant teachings. Now referring to FIG. 8, a schematic representation of a process is shown according to the invention to eradicate or stress a plant that can be an adult plant, or a seedling, but it is shown illustratively in a vegetative or later phase. The invention employs a dual component illumination protocol that is shown schematically for two portions of the electromagnetic spectrum as shown in FIG. 1 being directed upon parts of an illustrative plant (Dandelion Taraxacum Offinale) resting upon a soil grade. In this protocol, a high speed, substantially non-invasive, low-irradiance method for eradicating a plant in a vegetative or later phase is accomplished in a time under one minute, using dual component indigo region illumination and Medium Wavelength Infrared radiation or illumination about the plant. Described very briefly and qualitatively, the method comprises: [1] A foliage and root crown damage illumination component comprising exposure to an an Indigo Region Illumination Distribution (IRID) directed to the foliage and/or the root crown of a plant, with representative IRID rays as shown by dashed arrows in the Figure; and[2] A ground illumination component, comprising exposure to an Medium Wavelength Infrared (MWIR) radiation directed to the root crown and/or a soil grade immediately adjacent the root crown, with representative MWIR rays as shown by solid arrows in the Figure. Both exposures are of under one minute duration, and preferably under 20 seconds, and most preferably in the range of ½-7 seconds. Now referring to FIG. 9, a close-up view of the bottom portion of FIG. 8 is shown. An Indigo Region Illumination Distribution IRID is shown (dashed arrows) directed upon the foliage and/or a root crown of a plant (e.g., Dandelion Taraxacum Offinale) while a Medium Wavelength Infrared radiation MWIR is shown directed to the root crown and/or a soil grade immediately adjacent same (shown). The root crown is shown inside the circled area. The ground penetrating MWIR illumination component, when directed to a soil grade immediately adjacent the root crown, typically shows a deep penetration of the MWIR rays. This targeted and specifically directed use of Medium Wavelength Infrared MWIR is very important and represents a departure from the prior art. The method discovered helps provide very effective lethality, an unanticipated finding. It is interesting to note that root-crown temperature has been found to affect plant growth and physiology in various ways. Root crowns need to be exposed for oxygen and gas interchange. Further, a number of pests and diseases affect specifically this part of the plant, including root-crown rot/fungus and various species of root-crown weevil. The root crown area can appear swollen, tapered, constricted or very thin—as well as a combination of these. The root crown is usually located around or at the soil level and can be vaguely or clearly apparent. Now referring to FIG. 10, a cartesian plot of known relative optical absorption and photochemical efficiency for a typical plant is shown as a function of wavelength from 400 to 700 nm. The plot shows relative absorption for Chlorophyll a and Chlorophyll b, and also actual photochemical (photosynthetic conversion) for a typical plant, as well as the overall (optical) absorption spectrum of the plant overall. As can be seen there are two relative peaks centered about blue/violet and red light and this is the regime operation for the bulk of the excitation that fuel photosynthesis and internal regulation in plants, generally. Referring now to FIG. 11, the cartesian plot of FIG. 10 is shown, with the span of a Indigo Region Illumination Distribution in service to the instant invention is shown. As can be seen, the Indigo Region Illumination Distribution IRID can extend from 300 nm to a relative low between the two absorption peaks for a typical plant that are due to photochemical action of Chlorophyll a and Chlorophyll b. Specifically, the wavelength regime 1 shown in the Figure to the left of the vertical dotted line depicting 550 nm is that for use as the Indigo Region Illumination Distribution IRID according to the invention. The wavelength regime 2 shown to the right of the 550 nm line that includes yellow, orange and red was found from research and experimentation using controls to be not effective. Addition of this type of light from regime 2 is optional and may serve aesthetic or other purposes, but was discovered to be operationally ineffective for eradication and control. For example, it is notable that known red 650 nm peak LEDs (light emitting diodes) at the same power level as those used to form a Indigo Region Illumination Distribution to meet the protocol of the invention had no measurable effectiveness. However the actual spectral or wavelength distribution of light used to construct a Indigo Region Illumination Distribution IRID can vary. Now referring to FIG. 12, a schematic representation across this range of 300 nm to 550 nm for an Indigo Region Illumination Distribution is shown with various illustrative possible distribution patterns that are possible. This Figure does not show spectral intensity, or spectral irradiance, that is, W/cm2 per unit wavelength—which can vary. The Figure shows only the presence of radiation in particular wavelength, without intensity information. The first distribution depicted, s1, shows a near full span of the range between 300 and 550 nm, continuous and solid. The second distribution s2 shows another possible distribution from 400 to 550 nn, not continuous and absent UV-A radiation. A third distribution s3 shows various spectral lines of output, with the highest energy radiation at about 480 nm, and consisting of only six emission lines as shown. This can arise from various light sources, such as lasers, and especially ion discharge lamps with no intervening phosphor, etc. A fourth distribution s4 is continuous in part like distribution s1, but is absent mid-wavelengths, and notably is absent wavelengths associated with indigo, for which the Indigo Region Illumination Distribution IRID is named. All these, and other similar distributions are possible in service of the instant invention. However from testing and experimentation, radiation at and around 430 nm appears to be the best for biological effectiveness in eradication and control. Appearance of the Indigo Region Illumination Distribution IRID to the human eye shall not be indicative of suitability, A Indigo Region Illumination Distribution may not appear “blue” or ‘indigo” to the human eye because of the effect of constituent wavelength components—and response of the human eye to light distributions, including known effects of metamerism, shall not limit or narrow the scope of the appended claims, nor narrow the instant teachings. As stated above, a Indigo Region Illumination Distribution IRID contains wavelengths of light substantially coincident with a short wavelength absorption relative peak (generally of wavelength less than 550 nm) of a plant. Without narrowing the scope of the disclosure or claims, it is believed as a theory that certain processes at this low wavelength peak shown in FIGS. 10 and 11 contribute to the unexpected success of the invention. Known commercially available high output “blue” LEDs (light emitting diodes) can be used to provide necessary light for Indigo Region Illumination Distribution IRID, providing light generally in a wavelength range from 400 to 550 nm. For example, known SiC (silicon carbide) based LEDs with output from 430-505 nm (appearance blue) are available and have a Forward Voltage of 3.6 volts; GaN (Gallium Nitride) and InGaN (Indium Gallium Nitride) based diodes are also available. Mixture of GaN with In (InGaN) or Al (AlGaN) with a band gap dependent on alloy ratios allows manufacture of light-emitting diodes (LEDs) with varied output peaks. Some LED devices using Aluminium Gallium Nitride (AlGaN) produce ultraviolet (UV-A) light also suitable for a Indigo Region Illumination Distribution, and known phosphors can be used to extend spectral range or to serve another objective such as making a trademark color splash without departing from the scope of the invention and appended claims. To construct a Indigo Region Illumination Distribution IRID source, commercially available high power UV/violet LED chips are thus available in varied peak distribution wavelengths such as 365 nm, 370 nm, 375 nm, 385 nm, 390 nm 395 nm, 400 nm, 405 nm, and 425 nm with input power ranging from 3 to 100 watts, such as available from Shenzhen Chanzon Technology Co., Ltd., ShenZhen, Guangdong, China. The embodiments shown in Figures which follow employ a 100 watt array, 450 nm peak output. Larger arrays can be built up from constituent chips to serve the requirements of the instant invention for larger scale applications. From experimentation on plants in different life stages, a number of effective operating regimes or exposures for the instant invention were discovered, with treatments as follows: Method A: A full IRID twin component exposure, directed for eradicating or stressing a plant that is in a vegetative or later phase, is accomplished by [A1] exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID between 0.125 W/cm2 and 2 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination A1 exposure; and [A2] exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR between 0.045 W/cm2 and 0.72 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination A2 exposure; the exposures A1 and A2 for respective times that together allow signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures. Method B: A low IRID summed twin component exposure, with compensating MWIR, directed for eradicating or stressing a plant that is in a vegetative or later phase, is accomplished by [B1] exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID between 0.05 W/cm2 and 0.125 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination B1 exposure; and [B2] exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR such that the sum of the Indigo Region Illumination Distribution average irradiance EIRID and the Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR is at least 0.25 W/cm2 and less than 7 W/cm2, that is0.25 W/cm2≤EIRID+EMWIR<7 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination B2 exposure; the exposures B1 and B2 for respective times that together allow signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures. Method C: A saturation twin component exposure, directed for eradicating or stressing a plant that is in a vegetative or later phase, is accomplished by [C1] exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID of at least 0.125 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination C1 exposure; and [C2] exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR such that the sum of the Indigo Region Illumination Distribution average irradiance EIRID from step [C1] and the Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR is at least 0.125 W/cm2 and less than 7 W/cm2, that is0.125 W/cm2≤EIRIDEMWIR<7 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination C2 exposure; the exposures C1 and C2 for respective times that together allow signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures. Method D: A twin component exposure, directed to eradicate or stress a plant that is in the seedling phase or stage, is accomplished by [D1] exposing any of a foliage of the plant and a root crown of the plant to an Indigo Region Illumination Distribution (IRID) of an average irradiance EIRID between 0.1 W/cm2 and 1 W/cm2 during at least a portion of the treatment time, to provide a foliage and root crown illumination D1 exposure; and [D2] exposing any of a root crown of the plant and a soil grade immediately adjacent the root crown to infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation of an average irradiance EMWIR between 0.035 W/cm2 and 0.35 W/cm2 during at least a portion of the treatment time, to provide a root crown and soil grade illumination D2 exposure; the exposures D1 and D2 for respective times that together allow signaling, but not sufficient together to cause substantial high temperature thermally-induced leaf and plant component failure during the exposures. Medium Wavelength Infrared MWIR wavelengths can be in a distribution, with similar variability as that of the Indigo Region Illumination Distribution IRID as discussed above for FIG. 12. Medium Wavelength Infrared according to the invention can range from infrared wavelengths of 2-20 microns (2000-20,000 nm); a preferred range is 2.4-8 microns (2400 nm-8000 nm) and more preferred is the vicinity of 3-5 microns (3000-5000 nm). The method of the invention allows for many different possible lighting and beam forming configurations. Beam forming and reflector-endowed lamp sets can be devised to allow both [1] the above-ground foliage and root crown damage illumination component that directs Indigo Region Illumination Distribution IRID to the foliage and/or the root crown of a plant, and [2] the ground-penetrating Medium Wavelength Infrared MWIR component that directs Medium Wavelength Infrared radiation directed to the root crown and/or a soil grade immediately adjacent the root crown—to happen or operate simultaneously, if desired, and also if desired, originate within the same general lamp or photo-emissive device or lamp housing. Now referring to FIGS. 13-19, various pass-through, shrouded lamp and reflector configurations that may be used to practice some embodiments of the instant invention are shown. In FIGS. 13 and 14, simple schematic cross-sectional representations of an advantageous, compact proximity pass-through configuration illuminator 10 (PROXIMITY PASS-THROUGH CONFIGURATION ILLUMINATOR) according to the invention are shown. Inside a housing 6, are a IRID emitter 88 and a MWIR emitter E. As can be seen, the IRID emitter and the MWIR emitter are sized, positioned and oriented to allow light output from each of said IRID emitter and MWIR emitter to be substantially superposed for directing to said plant, with rays of type shown in FIGS. 8 and 9 being directed to a plant to the left on the Figure. Light generated as shown emerging from IRID emitter 88 passes through the physical MWIR emitter E. MWIR emitter E can comprise glass in various forms, such as plate glass, and be can selected from borosilicate glass, Pyrex® Glass Code 7740, soda lime glass, and other material, such as that having high thermal emissivity in the range of Medium Wavelength Infrared wavelengths as defined herein. This can include materials having coatings or surface treatments that have favorable MWIR emission characteristics. MWIR emitter E is heated using a heater (shown in later Figures), assisted by a heating ring Hr as shown, in thermal communication with illustrative glass (e.g., borosilicate glass) of MWIR emitter E. Borosilicate glass and other similar materials conduct heat across themselves, and this heated glass allows efficient coupling into MWIR wavelengths and allows a pass-through of Indigo Region Illumination Distribution IRID light as shown. Now referring to FIG. 15, an oblique surface view of a proximity pass-through configuration illuminator 10 of FIGS. 13 and 14 according to the invention is shown. As shown, mounting pipe 11 supports the illuminator 10, with IRID emitter 88 located behind transparent glass MWIR emitter E in the Figure, which can be an LED array. Indigo Region Illumination Distribution IRID radiation from IRID emitter 88 passes through MWIR emitter E and joins MWIR rays for directing to a plant, as shown. MWIR emitter E is heated with assistance from heat ring Hr, and a heat sink 77 is sized, positioned, and oriented to be in thermal communication with IRID emitter 88 to cool the IRID emitter. Not shown in this Figure is a thermal insulator Y and thermal reflector Z that thermally separate MWIR emitter E from IRID emitter 88, but an aperture 9 in those thermal barriers is shown, to allow the Indigo Region Illumination Distribution IRID to pass through the glass of MWIR emitter E. Indigo Region Illumination Distribution IRID and Medium Wavelength Infrared MWIR can thus be directed at a plant. Aiming can be of the spillover type of exposure. Spillover can naturally occur to many areas as can be expected when illuminating plant of different sizes, stem stiffness, and foliage arrays, with differing orientations. This spillover will not affect aiming of an operatively effective portion of the light is as directed by the instant teachings and appended claims. In practicing the invention, a small gap is preferred between the MWIR emitter E and the plant root or base because of attenuation and r-squared losses, and those of ordinary skill in the art will be able to position, size, and move the illuminator appropriately. FIG. 16 shows a split cross-sectional view of a proximity pass-through configuration illuminator according to the invention, with distinct upper and lower plane views. LED array IRID emitter 88 is shown inboard of MWIR emitter E, which is in contact with, or thermal communication with a known 100 watt Kapton heater H, assisted by heat ring Hr affixed to housing 6. Heat sink 77 in thermal communication with LED array IRID emitter 88 for cooling same. MWIR emitter E can be heated to a temperature of 400 F to 1000 F for efficacity and safety when in service of the instant invention. Guards (not shown) can be added. FIG. 17 shows a cross-sectional close-up partial schematic view of elements of the proximity pass-through configuration illuminator shown in FIGS. 13-16. Thermal protection can be arranged to protect LED array IRID emitter 88 from heat generated from MWIR emitter E, which can optionally comprise on its inboard surface a thermal reflector Z, which in turn can have at its inboard surface a thermal insulator Y. An aperture 9, previously shown in FIG. 15, can be sized, and positioned to allow LED array IRID emitter 88 to emit the desired Indigo Region Illumination Distribution IRID through MWIR emitter E. Thermal reflector Z can be fabricated from known aluminum foil 1 mil thick. Thermal insulator Y can be 0.005 inch (5 mil, 0.2 mm) thick film made from known polycarbonate, or PFA (Perfluoroalkoxy alkane). Commercially available LED arrays can have lifetimes of 50,000 hours if the working temperature history is kept under 60 C. Now referring to FIG. 18, an oblique view of a proximity pass-through configuration illuminator of FIG. 15 according to the invention, with a ¼ cylindrical cut-out showing cross-sections (PROXIMITY PASS-THROUGH CONFIGURATION). LED array IRID emitter 88 illustratively comprises as shown a 100 watt Chanzon® 1DGL-JC-100W-440 Royal Blue chip-on-board (COB) surface mounted device (SMD), with peak emission at 440-450 nm, drawing 3000 mA at 30-34 volts DC. Individual LED cells in LED array IRID emitter 88 and an array mount m can be seen behind glass MWIR emitter E, which is not explicitly visible except for line hatching in the Figure adjacent the reference character indicator lines for E and the MWIR ray. Kapton heater H is in thermal communication with heat ring Hr and MWIR emitter E. Very close approach to plants can be achieved with this proximity pass-through configuration, and MWIR emitter E can be kept at 400 F to 1000 F with appropriate guards known in the art to prevent ignition of biomass and materials. Additional known optics can be added, such as outer reflectors whose shape comprises compound parabolic curves, or other advantageous light handling to suit a particular application. A baseline (“midlevel”) exposure that typifies operation for many applications is average irradiances (see Definitions section) of 0.5 W/cm2 of Indigo Region Illumination Distribution IRID radiation and 0.18 W/cm2 of Medium Wavelength Infrared MWIR radiation. The average power levels are important and must be delivered in seconds, not minutes, hours, or days for efficacity, according to the discoveries made. Lethality is pronounced, with many yields at 100% with no regrowth after two weeks. With this baseline exposure, for a first test, on 1 inch tall rye grass, less than 4 months since germination, lethality of 100% was obtained with a 2 second exposure. For a second test, on 8 inch tall cereal rye grass, 6 months since germination, lethality of 85% was obtained with a 5 second exposure. For a third test, dandelion (Dandelion Taraxacum Offinale) with less than a 6 inch rosette at the root crown, and greater than 1 year but less than two since germination, 83% lethality was obtained with a 10 second exposure. For a fourth test, dandelion less than 4 inches in rosette diameter, and 6 months since germination, 100% lethality was obtained with a 5 second exposure. With a fifth test, dandelion with rosettes more than 6 inches in diameter and more than 2 years since germination, 75% lethality was obtained with a 15 second exposure. MWIR emitter E can be heated with varying temperatures from a minimum of 250 F, to 400 F to past the Draper Point (977 F) to 1000 F. According to the Stefan-Boltzmann law, a black body at the Draper point emits 23 kilowatts/m2 radiation, nearly all infrared. The embodiments disclosed herein allow for substantially superposed Indigo Region Illumination Distribution IRID and Medium Wavelength Infrared MWIR radiation for illumination at a target plant, and are especially advantageous for this purpose. However, as will be mentioned below, both component radiations can arise from different sources not in a unitary housing or device. The use of the instant invention can be particularly helpful in agriculture. Referring now to FIG. 19, the proximity pass-through configuration illuminator of FIG. 18 is shown, with Indigo Region Illumination Distribution and Medium Wavelength Infrared rays trained upon a seedling, shown as Amaranthus Tuberculatus, and known commonly as waterhemp, a plant of concern to farmers. Seedlings are fast developing organisms with special characteristics and the teachings of the instant invention apply differently to achieve efficacity. There are different structural developing components in various seedlings as they develop a root system and differentiate physically. In this sense the root crown shall include the root collar or root neck from which a plant stem arises. The root crown shall also comprise any portion of a seedling which has not affixed itself to a soil grade, but is the root in development or is biological tissue associated with root development. Monocotyledons (one-seed leaves) and dicotlydons (two-seed leaves) differ in early seedling development. In monocotyledons, a primary root is protected by a coating, a coleorhiza, which ejects itself to yield to allow seedling leaves to appear, which are in turn protected by another coating, a coleoptile. Wth dicotyledons a primary root radicle grows, anchoring the seedling to the ground, and further growth of leaves occurs. Amaranthus Tuberculatus or waterhemp, has gone herbicide resistant and creating a economic and productivity problems for farmers in the United States. Waterhemp seedlings are known to grow as much as 1- to 1¼-inches per day, while another weed that is a threat to agriculture, Palmer amaranth, has been known to grow 1½- to 2-inches per day. Farmers need to spend capital to control weeds like Palmer amaranth and waterhemp. As a result, in North America, tall waterhemp is considered a major weed of agricultural fields and other disturbed habitats. Because of a long germination window, single herbicide applications are not considered effective. Tall waterhemp have been reported resistant to acetolactate synthase inhibiting (ALS) herbicides and the triazines, and resistance to acifluorfen and other diphenyl ether herbicides has been reported. Now referring to FIG. 20 shown is a logarithmic cartesian plot representation of Illumination Wavelength versus Total Illumination Irradiance indicated by closed figure for a typical illustrative approximate regime of operation for the instant invention applied to plants in a vegetative stage or later, using an Indigo Region Illumination Distribution and a Medium Wavelength Infrared illumination distribution—with contrast shown to the dangerous prior art high radiative transfer depicted in FIGS. 6 and 7, shown on this plot in closed figure. As shown, the instant invention is in a different regime. Average irradiances for Indigo Region Illumination Distribution IRID radiation and Medium Wavelength Infrared MWIR radiation are on the order of single digit or fractional W/cm2, while the high radiative transfer of the prior art is higher by 1-5 orders of magnitude (factors of ten), such as radiative transfer of 50 W/cm2. Now referring to FIG. 21, a listing of operative attributes is shown for a class of prior art large radiative and large UV radiative transfers as depicted in FIGS. 6, 7, and 8. Specifically, the use of energy distributions such as those high in UV-B and UV-C radiation—have effects on plant life, such as scalding, burning, an ultraviolet burn similar to extreme sun burn in humans called UV burn, leaf and plant component failure, and dehydration. Ironically, it is evident that the more destructive the radiative transfer, the more plants appear to be equipped to regrow, likely so because of evolution dealing with fire, flood, windstorms, trampling by animals, disease, pestilence, drought, landslides, etc. Now referring to FIG. 22, a logarithmic cartesian plot representation similar to that of FIG. 20 is shown, depicting Illumination Wavelength versus Total Illumination Irradiance indicated by closed figure for a typical illustrative approximate regime of operation for the instant invention applied to seedlings, using an Indigo Region Illumination Distribution and a Medium Wavelength Infrared illumination distribution, with contrast again shown to the prior art high radiative transfer depicted in FIGS. 6 and 7, shown on this plot in closed figure. Again, as shown, the instant invention applied to seedlings is in a different regime. Average irradiances for Indigo Region Illumination Distribution IRID radiation and Medium Wavelength Infrared MWIR radiation for seedlings are again on the order of single digit or fractional W/cm2, while the high radiative transfer of the prior art is higher by orders of magnitude. Use of the invention does not lead to ignition of biomass or burning or thermal failure of plant components. Now referring to FIG. 23, a cross-sectional schematic view is shown of another type of illustrative preferred proximity pass-through configuration illuminator according to the invention, with a shrouded Indigo Region Illumination Distribution IRID emitter 88 preferably comprising a LED array, which is sized, positioned, and oriented to allow light output therefrom to reflect off a surface before emerging from the illuminator. That surface S has been chosen illustratively to be Spectralon®, a durable fluoropolymer available from Labsphere® of North Sutton NH, USA. Housing 6 can comprise inner cup surface S as shown, and LED array IRID emitter 88 direct light output upward in the figure into this cup or surface. Rays (dotted) as shown or Indigo Region Illumination Distribution IRID reflect from this surface S and emerge directly through MWIR emitter E as before, with the MWIR emitter E employing heated glass (borosilicate glass preferred) assisted by action of Kapton heater H (not shown) and heat ring Hr. In this embodiment reduced heating of the MWIR emitter E can be needed because the Indigo Region Illumination Distribution IRID pass-through can assist with heating of the glass, and tinting or other treatment of MWIR emitter E can enhance this effect. Surface S optional Spectralon® material has a hardness roughly equal to that of high-density polyethylene and is thermally stable to 350 C or 662 F. It exhibits absorption at 2800 nm, then absorbs strongly (less than 20% reflectance) from 5400 to 8000 nm, thus giving it a corresponding high emissivity in the range of 5400 nm to 8000 nm (5.4-8.0 microns), putting its emissivity in range for MWIR emitter E according to the invention. Borosilicate glass or other MWIR emitter E is optional as can be seen in the discussion for FIG. 24 where a fluoropolymer like Spectralon® can act as an MWIR emitter. Now referring to FIG. 24, a cross-sectional schematic view similar to that shown in FIG. 23 is shown, as another alternate illustrative embodiment using a proximity reflect-through configuration illuminator according to the invention, with a shrouded Indigo Region Illumination Distribution (IRID) emitter and illustratively shown with a non-glass MWIR emitter E. This is a PROXIMITY REFLECT-THROUGH CONFIGURATION as shown, so named because in essence the “blue” splash component or Indigo Region Illumination Distribution IRID is reflected off a MWIR emitter E on surface S before emerging directly to be directed upon a plant, as opposed to prior Figures where the Indigo Region Illumination Distribution IRID first passes directly through the MWIR emitter E. LED array IRID emitter 88 is shown putting light output upward in the Figure, but it can be also, if desired, turned face down so light output is directly downward in the Figure. Kapton heater H is in thermal communication with at least a portion of surface S which becomes an MWIR emitter E. No heated glass (e.g., borosilicate glass) is needed, although a transparent cover can still be affixed for physical protection from soil, dirt, etc. Kapton heater H can have portions spaced to allow a cooler environment in the vicinity of LED array IRID emitter 88. Although the Figure indicates “NO HEATED GLASS” for this illustrative example of an alternate embodiment, the hot surface S can be replaced with borosilicate glass or other materials in service of the invention to produce Medium Wavelength Infrared (MWIR). This open design allows for air flow, as the “cup” formed by housing 6 can be open to air, not necessarily blocked off by borosilicate glass, other glass or other cover. FIG. 25 shows a cross-sectional schematic view of a Medium Wavelength Infrared (MWIR) emitter that comprises an emissive powder coat for enhanced emission. A powder coat MWIR emitter, e.g., ground or powdered borosilicate glass, can be put onto a surface which is heated for operation according to the invention. Specifically, as shown, powder coat MWIR emitter E+ is affixed or coated upon a heated substrate E′, which derives heat from heat ring Hr and associated Kapton heater H, not shown. Rays from any Indigo Region Illumination Distribution IRID passing though powder coat MWIR emitter E+ are not shown for clarity. This embodiment can reduce costs and weight, and can allow for optimization of output. One can use known powdered, sintered, or particulate materials, comprising borosilicate glass or other glasses or MWIR emissive materials, to provide a source for Medium Wavelength Infrared MWIR. If desired, underlying heated substrate E′ can itself be a MWIR emitter E as well. FIG. 26 shows a cross-sectional schematic view similar to that of FIG. 25, showing the emissive powder coat MWIR emitter E+ being externally optically energized or heated with a lamp or source HL. This allows the powder coat to be illuminated independently to provide heating. This excitation can include optical radiation (in a variety of possible wavelengths) such as from lamps; glowing filaments or other bodies, microwave radiation, laser light, and flood and spot lamps, such as high intensity halogen enhance filament lamps, or LED lamps, using known reflector or other optics. Arrays can be used that are proximate the powder coat MWIR emitter E+ along a length, or a spot beam, such as that illustratively shown, can be used. In this illustrative example, a simple substrate D which is not an Medium Wavelength Infrared emitter, can be used. As shown in FIG. 27, schematic arrangement is shown using separate MWIR and IRID sources used to irradiate a plant or seedling. Illustratively shown powder coat MWIR emitter E+ and LED array IRID emitter 88 are separately housed and light output is not undergoing superposition as in the previous Figures. Guide optics can be provided using known reflectors, transmitters, light guides, refractors, etc. to direct Medium Wavelength Infrared MWIR and Indigo Region Illumination Distribution IRID as taught and claimed. The guide optics can include moveable parts such as reflector flaps that respond yieldingly to being passed to over a plant, for ease of motion and application across a field. Possible Medium Wavelength Infrared MWIR sources can include known CO2 (carbon dioxide) lasers, and infrared LEDs (Light Emitting Diodes). CO2 lasers can produce a beam of infrared light with the principal wavelength bands centering on 9.4 and 10.6 micrometers (μm). Now referring to FIG. 28, a schematic series of apparatus and process components is shown for using the teachings of the instant invention with machine recognition and automated processes. Machine vision and recognition of undesirable plants is possible using known techniques and can be used with the instant invention to provide automated detection and eradication of nuisance vegetation. Field leaf reflectance may vary with environmental parameters like soil type, light conditions, irregular terrain, and maintenance inputs (fertilizer, watering, etc.); as well as, plant variables such as irregular/dense sowing patterns, different plant species, growth stages, leaf moisture, and similar color of crop and weeds. Machine vision to distinguish weeds in lawns, for example, can operate despite lawn condition variables such as soil characteristics and maintenance variables such as fertilizer and cut frequencies. Spectral reflectance variables can be detected using known methods to distinguish growth habits and differences in plant canopies, such as differences in an erectophile canopy versus a planophile canopy. FIG. 28 shows known ultraviolet (UV) or visible (VIS) lights which illuminate a Field as shown. An image is received with a known Imager as shown, such as an imager system using a CCD (Charge Coupled Device) camera. The optical system can be controlled by a known electronic system that will flash UV/Visible lights (Image Capture Light) for a specific time in rapid succession. A known Light flash controller (shown) also triggers the CCD camera to capture an image shown (Image Capture) that uses Image pattern recognition, employing known techniques, to send signals to a Controller that selectively operates a Weed Disruptor that uses the teachings and methods given here. Using known techniques, selected spectral regions for gathering information can processed. The wavelengths can be chosen based on weed reflection characteristics that distinguish them from grass or any desired crop. The images can be processed to register them with one another and determine the optical responses at each pixel. Automatic recognition of weeds will also include displaying edge effects for plant morphology determination and pinpointing root position. A known algorithm can include segmenting the scene for rapid identification and classification. Known electronics for post-processing images can be simple designs using graphics processing units (GPUs), field-programmable gated arrays and smart phones. Once a weed has been identified, the position of the target plant is passed to the controller that positions a device to act according to the instant teachings. Such a machine recognition system can be a module positioned in front of the weed treatment mobile unit as depicted in the schematic shown in FIG. 29. Wheels on the mobile unit can record track positions and store information in a memory, whose construction, fabrication and interfacing is known in the art. During each flash of UV/visible light, the reflected light is collected by a CCD camera with high dynamic range. Images can be processed onboard the mobile unit and the controller can be used to place appropriate components as disclosed here over a target weed for processing. The imager as shown in FIG. 29 can be mounted in front of a carriage that houses electronics. This carriage can be part of the mobile unit. The position of the carriage can be encoded by a known digital sensing system synchronized with the rotation of the wheels. This information is used in by a control algorithm constructed by those with ordinary skill in the art, with image ID results to automatically place desired operative components over the weed root position or turn on the appropriate near-IR and UV-A light heads of known design, if multiple IR/UV heads are to be used. A weed region segmentation algorithm can be based on a known adaptive progressive thresholding (APT) approach which automatically estimates the threshold value to accurately differentiate the weed region from the desired crop or grass. This technique employs a recursive procedure to obtain a coarse region of interest (ROI), which is then subjected to an adaptive filter operation so that a smaller enhanced region can be identified. This enhanced region is subjected to the APT procedure again and then the process of performing the filtering operation is repeated as before. Repetition of this process in an iterative manner facilitates the rapid identification of the weed region accurately. The iterative procedure can be stopped by employing a pre-computed cumulative limiting factor (CLF), which depends on the complexity of the images due to the unpredictable reflection characteristics of the environment, leading to the extraction of accurate weed regions in the images. Known techniques can use this to advantage in segmentation and classification of broadleaf and grass weeds. Known feature extraction can be achieved using Gabor wavelets. Gabor wavelet features indicate the frequency content in localized frequency regions in the spatial domain. A Gabor wavelet transform can be obtained by convolving the signal with a filter bank in a known manner, whose impulse response in the time domain can be Gaussian-modulated by sine and cosine waves. Different choices of frequency and orientation provide a set of filters. A feed forward neural network with error back-propagation learning algorithm can be employed for weed classification based on the extracted Gabor wavelet features. These algorithms can be developed for rapid post processing of the imagery captured by the CCD cameras. FIG. 30 shows a listing of possible adaptive stress vectors upon a plant including those which can arise while practicing the instant invention. Although no theory is given here and the following is not to be limiting, these are possible stress factors which may contribute to the unexpected degree of success using the invention. Plants subjected to the protocol as taught and claimed herein may be stressed by four simultaneous factors, including stresses delivered by the methods of the invention that constitute in some senses, a Forest Fire (above ground); High Intensity unprecedented MWIR signaling at root crown/below soil grade, High Intensity unprecedented IRID signaling at root crown/foliage, and a General high velocity shift in illumination exposure levels as a result of practicing the invention. This unnatural and simultaneous set of possible stresses may cause a plant to perish because it has not evolved to meet those stresses simultaneously. While the illumination as taught herein and expressed in the appended claims can be used to eliminated, eradicate, or damage a plant, it can also be used for other purposes. There can arise situations where one wants to induce stress in a plant, to act as a signal for a sought after change in the plant, to enhance a kind of immunity or protection from common similar stresses, or to select strong plants for survival. To this end, one can, using the instant invention, use the protocols taught and claimed, and based on findings, further select a plant for one of retention, treatment, eradication or neglect. The instant invention can be practiced using partial exposure times or shortened flashes to accomplish these objectives. Regarding exposures as taught and claimed herein, there are many possible factors which would require a practitioner of the method of the invention to change exposures, such as the varied effectiveness of the invention on many varied different plant species; plant environmental history, plant health, prior sun exposure, history of rain or water uptake, degree of past built-up plant protection, such as waxy layers on leaves and other physiological changes; rhizospheric and bulk soil MWIR transmissivity; miscellaneous species factors; plant condition; soil factors; special rhizospheric factors such as symbiotic effect of macrobiotica; plant life cycle/stage factors such as whether the plants to be eliminated are in early growth stage, maturity, giving off seeds, etcetera; the presence of ground debris which might block MWIR radiation from root crowns and nearby soil grade; and geographic location and climate, including average historical ambient UV levels. “Over-driven” states are possible where excess exposures are used for good measure to insure results. The combination of the targeted IRID exposure to foliage and/or root crowns and the MWIR exposure to root crowns and/or the soil immediately adjacent root crowns provides unexpected results that are a departure from what was known previously. Testing was successfully completed for trials of various durations, including 5, 10, 15, and 20 seconds. The method is effective, with actual lethality, with no regrowth later. When a plant dies, it can be a complex process. Oxygen uptakes levels typically start to plummet, certain hormone levels go up, and the death process overall in the field of botany is not particularly well known. However, plants undergoing testing died as given by the protocol, with the statistical outliers that can be expected from any natural interaction. In a group of 100 plants, occasionally one plant would take as much as 2 weeks to die. During testing, immediate dieback was an observable, but death cannot and was not often ascertained immediately. The dual component exposures according to the invention may be simultaneous, or partially simultaneous, and individually may be paused, stepwise or otherwise modulated. For example, a series of exposures or flashes can be used to achieve the method taught here. All total respective exposure times can total under 20 seconds, preferably; or more preferably, under 5 seconds, or more preferably, under one second. Illustrative emphasis in this disclosure is on herbaceous, non-woody stalk plants, and the instant invention seeks to eradicate plants of a certain size, as well as seedlings. However, the methods and teachings here can be applied to eradication and control of certain tap-root or woody stalk plants. The methods taught and claimed here are not dependent on the existence of a particular species or organism. Not shown herein are known solid or telescopic pipes or other elements which retain or position an illuminator using the instant invention which those of ordinary skill will be able to devise. The invention can be set in motion using known means to accomplish the same objectives over a wide area. Autonomous, non-autonomous, powered, or non-powered vehicles can be used to scan, survey or treat a field, using illumination as taught and claimed, or using communication to other, external light sources. Imaging optics can be added to practice the protocol of the invention, including parabolic curved sections, or sections that resemble a compound parabolic curve; non-imaging optics can also be used. If desired, one can redirect all electromagnetic emissions as taught and claimed in the instant disclosure using mirrors, lenses, foil arrays, or light guides and pipes without departing from the scope of the invention. Similarly, those of ordinary skill can add light wavelengths to the exposure protocols without departing from the invention or the appended claims. Addition of white or red light was found to have no perceptible increase in effectiveness, but other objectives can be served if desired, namely, one can add power, i.e., over-expose without departing from the scope of the invention or claims. Measurement units were chosen illustratively and in the appended claims include irradiance in W/cm2 but radiance or other measures can be used and would by fair conversion read upon the appended claims if equivalent. For clarity, the invention has been described in structural and functional terms. Those reading the appended claims will appreciate that those skilled in the art can formulate, based on the teachings herein, embodiments not specifically presented here. Production, whether intentional or not, of irradiance levels that are under the magnitude of powers as given in the appended claims shall not be considered a departure from the claims if a power level as claimed is used at any time during treatment. The illumination protocol disclosed and claimed here can be supplemented with visible light, which can enhance user safety by increasing avoidance and can allow for pupil contraction of the eye of an operator; other radiations can be added with without departing from the appended claims. There is obviously much freedom to exercise the elements or steps of the invention. The description is given here to enable those of ordinary skill in the art to practice the invention. Many configurations are possible using the instant teachings, and the configurations and arrangements given here are only illustrative. Those with ordinary skill in the art will, based on these teachings, be able to modify the invention as shown. The invention as disclosed using the above examples may be practiced using only some of the optional features mentioned above. Also, nothing as taught and claimed here shall preclude addition of other structures, functional elements, or systems. Obviously, many modifications and variations of the present invention are possible in light of the above teaching. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described or suggested here.
052415694	summary	The present invention relates in general to imaging radionuclide analysis apparatus and method and more particularly to imaging neutron activation analysis apparatus and method. BACKGROUND OF THE INVENTION Normal neutron activation analysis measures the average concentration of one or more analytes in a single analysis volume. Neutron activation analysis is an extremely powerful method for measuring major, minor, and trace element concentrations in a wide variety of samples. Analyte elements absorb a neutron to form a radionuclide which usually decays by emitting a .beta.-particle and a .gamma.-ray. The .gamma.-ray energies are characteristic of the analyte element and they are normally measured with a germanium detector. Modern germanium crystal .gamma.-ray detectors have excellent energy resolution which provides for simultaneous in situ determination of many elements. This procedure, performed without chemical separations, is called instrumental neutron activation analysis (INAA). Although the INAA takes place on elements located in situ within unaltered samples, information on the three-dimensional locations of the elements is never acquired. Beta-electrons provide a method for gathering lateral position information for individual radionuclide decompositions in thin samples or particles. Neutron activated nuclides usually decompose by .beta.-decay, effectively producing a nucleus in which a neutron has been converted to a proton. The nucleus emits a neutrino, and usually a .gamma.-ray in addition to the .beta.-electron. The emitted electrons have substantial energies which are largely expended in the production of secondary electrons. Secondary electrons with energies of a few electron volts can be imaged if they pass out of the sample. BRIEF SUMMARY OF THE INVENTION Broadly stated, the present invention, to be described in greater detail below is directed to radionuclide imaging method and apparatus wherein the time when and the energy of .gamma.-rays emitted from the sample are detected and the presence of certain elements in the sample established from the detected ray energies. Secondary electrons emitted from the sample are detected and imaged showing the location on the sample from which the secondary electrons were emitted. Coincidence between detection of .gamma.-rays and secondary electrons is determined to establish the location of certain elements on the sample. In accordance with a principle aspect of the present invention, the location of the certain elements on the sample is established by producing a distribution image of the certain elements of the sample from the determined coincidence of the detected rays and the detected secondary electrons and the established ray energies and the image of the location on the sample from which the secondary electrons are emitted. Thus, when .gamma.-rays and .beta.-particle induced secondary electrons are detected in coincidence, the .gamma.-ray energy answers the question of "what" and the secondary electron position answers the question "where" for individual radionuclide disintegrations. In accordance with another aspect of the present invention, the secondary electrons are detected and imaged using an image intensifier and a resistive anode encoder. The features and advantages of the present invention will be appreciated by a perusal of the following specification taken in conjunction with the accompanying drawings wherein similar characters of reference refer to similar elements in each of the several views. DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view, partially in broken away elevational sectional form and partially in block diagram form. FIG. 2 is a schematic elevational sectional view of the charged particle optics for electron extraction and imaging of secondary electrons arising where energetic .beta.-particles pass out of the sample. FIG. 3 is an enlarged sectional view of the charged particle optics for electron extraction shown in FIG. 2. FIG. 4 is a graph of electron counts plotted against energy level of detected .gamma.-rays in an operative example of use of the present invention. FIGS. 5A and 5B illustrate the distributions of gold and nickel, respectively, on a portion of a particle sample.
	claims	1. A method of producing a nuclear fuel product, the method comprising:providing a core comprising aluminium and low-enriched uranium, the low-enriched uranium having a proportion of U235 below 20 wt %; andsealing the core in a cladding;the core comprising a first composition including more than 80 wt % of a mixture of UAl3 phase and UAl4 phase, and the mixture having a weight fraction of UAl3 phase higher than or equal to 50%, orthe core comprising a second composition including more than 50 wt % of UAl2 phase,the core having a low-enriched uranium loading higher than 3.0 gU/cm3, the core comprising less than 10 wt % in total of one or several material(s) taken from the list consisting of aluminium phase and aluminium compounds other than UAl2 phase, than UAl3 phase, and than UAl4 phase. 2. The method as recited in claim 1 wherein the cladding comprises one or several of an aluminium alloy, a zirconium alloy, a Ni-based alloy and a stainless steel. 3. The method as recited in claim 2 wherein the aluminium alloy comprises more than 95 wt % of aluminium, the zirconium alloy is Zircaloy-2, Zircaloy-4 or a Zr—Nb alloy, the Ni-based alloy is Alloy 600 and the stainless steel is AISI 304L or AISI 316L. 4. The method as recited in claim 1 wherein the core comprises the second composition. 5. The method as recited in claim 4 wherein the core comprises more than 80 wt % of UAl3 phase. 6. The method as recited in claim 1 wherein the core comprises the second composition preferably more than 80 wt % of UAl2 phase. 7. The method as recited in claim 1 wherein the step of providing the core comprises the substep of melting low-enriched uranium and aluminium in a furnace to form a melt, the proportion of low-enriched uranium in the melt being higher than or equal to 68 wt % and lower than or equal to 82 wt %. 8. The method as recited in claim 7 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 71 wt % and lower than or equal to 75 wt %, wherein the core comprises the first composition. 9. The method as recited in claim 7 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 73 wt % and lower than or equal to 75 wt %, wherein the core comprises more than 80 wt % of UAl3 phase. 10. The method as recited in claim 7 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 75 wt % and lower than or equal to 82 wt % wherein the core comprises the second composition. 11. The method as recited in claim 7 wherein the step of providing the core comprises the substeps of:providing a ingot from the melt;grinding the ingot to produce a powder;compacting the powder to produce a compact; andsintering the compact to obtain the core. 12. The method as recited in claim 11 wherein the step of providing the core comprises:prior to the substep of compacting the powder, the substep of adding aluminium to the powder, the weight proportion of aluminium in the powder being lower than or equal to 10 wt %. 13. The method as recited in claim 1 wherein the step of sealing the core in the cladding comprises the substeps of:enclosing the core in framing elements to obtain a sandwich; androlling the sandwich in order to extend a core length along a rolling direction R by a factor between 1% and 50%. 14. The method as recited in claim 10 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 78 wt % and lower than or equal to 82 wt %. 15. The method as recited in claim 10 wherein the core comprises more than 80 wt % of UAl2 phase. 16. The method as recited in claim 13 wherein the rolling of the sandwich extends the core length by between 5% and 30% and more preferably around 10%. 17. The method as recited in claim 6 wherein the core comprises more than 80% of UAl2 phase. 18. A nuclear fuel product comprising:a core comprising aluminium and low-enriched uranium, the low-enriched uranium having a proportion of U235 below 20 wt %; anda cladding sealing the core;the core comprising a first composition including more than 80 wt % of a mixture of UAl3 phase and UAl4 phase, and the mixture having a weight fraction of UAl3 phase higher than or equal to 50%, orthe core comprising a second composition including more than 50 wt % of UAl2 phase,the core having a low-enriched uranium loading higher than 3.0 gU/cm3 and comprises less than 10 wt % in total of one or several material(s) taken from the list consisting of aluminium phase and aluminium compounds other than UAl2 phase, than UAl3 phase, and than UAl4 phase. 19. The nuclear fuel product as recited in claim 18 wherein the cladding comprises one or several of an aluminium alloy, a zirconium alloy, a Ni-based alloy and a stainless steel. 20. The nuclear fuel product as recited in claim 19 wherein the aluminium alloy comprises more than 95 wt % of aluminium, the zirconium alloy is Zircaloy-2, Zircaloy-4 or a Zr—Nb alloy, the Ni-based alloy includes Alloy 600 and the stainless steel is AISI 304L or AISI 316L. 21. The nuclear fuel product as recited in claim 18 wherein the core comprises the first composition. 22. The nuclear fuel product as recited in claim 21 wherein the core comprises more than 80 wt % of UAl3 phase. 23. The nuclear fuel product as recited in claim 18 wherein the core comprises the second composition. 24. The method as recited in claim 16 wherein the rolling of the sandwich extends the core length by around 10%. 25. The nuclear fuel product as recited in claim 23 wherein the core comprises more than 80 wt % of UAl2 phase.
047388200	summary	CROSS REFERENCE TO RELATED APPLICATIONS Reference is hereby made to the following copending applications dealing with related subject matter and assigned to the assignee of the present invention: 1. "Nuclear Reactor" by H. M. Ferrari et al, assigned U.S. Ser. No. 732,220 and filed May 9, 1985 (W. E. 52,520). BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to fuel assemblies for nuclear reactors and, more particularly, is concerned with a nuclear fuel assembly bottom nozzle to control rod guide thimble attachment system which allows for bottom nozzle fuel assembly reconstitution. 2. Description of the Prior Art In a typical nuclear reactor, the reactor core includes a large number of fuel assemblies each of which is composed of top and bottom nozzles with a plurality of elongated transversely spaced guide thimbles extending longitudinally between the nozzles and a plurality of transverse support grids axially spaced along and attached to the guide thimbles. Also, each fuel assembly is composed of a plurality of elongated fuel rods transversely spaced apart from one another and from the guide thimbles and supported by the transverse grids between the top and bottom nozzles. The fuel rods each contain fissile material and are grouped together in an array which is organized so as to provide a neutron flux in the core sufficient to support a high rate of nuclear fission. The reactor also has control rods which can be inserted into the guide thimbles to control the fission reaction. The fission reaction releases a large amount of energy in the form of heat. A liquid coolant is pumped upwardly through the core in order to extract some of the heat generated in the core for the production of useful work. During operation in the nuclear reactor, the fuel rods may occasionally develop cracks along their lengths resulting primarily from internal stresses. These defective fuel rods must be replaced in the fuel assemblies, and this replacement must occur under water as the fuel assemblies become highly radioactive during their operation in the reactor. To gain access to a defective fuel rod, it is necessary to remove the top and/or bottom nozzle of the fuel assembly. Reconstitutable fuel assemblies exist which are designed with removable nozzles. Typical removable top nozzles have been attached to the top of the guide thimbles using a threaded or bulge/groove arrangement. Typical removable bottom nozzles have been attached to the bottom of the guide thimbles using a threaded arrangement. Heretofore, bottom nozzle removal and replacement has required inverting the fuel assembly, such as disclosed in U.S. Pat. No. 4,522,780, hereby incorporated by reference. There is a concern that inverting an irradiated fuel assembly may damage the fuel pellets in the fuel rods. SUMMARY OF THE INVENTION The present invention provides a nuclear fuel assembly with an improved attaching arrangement for the removal and replacement of its bottom nozzle without inverting the fuel assembly. Briefly stated, a first embodiment of the invention is directed towards a nuclear fuel assembly bottom nozzle adaptor plate is attached to the guide thimble bottom end plug with a two-headed bolt. The bolt has a first head large enough to be blocked by the adaptor plate's bore, and has a second head small enough to pass through the bore and the bottom end plug's threaded axial passageway. The bolt is threaded to the bottom end plug. The first head is located near the adaptor plate, and the second head is located near the end plug. In a second embodiment of the invention, involving a nuclear fuel assembly bottom nozzle to guide thimble attachment system, the bottom nozzle adaptor plate is attached to the guide thimble bottom end plug with a bolt fastener. The bolt fastener has a head large enough to be blocked by the end plug's axial passageway. The bolt fastener is threaded to the adaptor plate. The head is located near the end plug. In a third embodiment of the invention, there is disclosed a method to reconstitute a nuclear fuel assembly which has its bottom nozzle attached by the two-headed bolts of the first embodiment previously discussed. In the method, the fuel assembly is placed with its top nozzle higher than its bottom nozzle, and the bolts are unthreaded from the top. The unthreaded bolts are removed from the bottom, and the bottom nozzle is removed. A lower nozzle is obtained in which the adaptor plate has a threaded bore. Bolt fasteners, of the second embodiment previously discussed, are inserted through the guide thimbles from the top, through the end plugs and into the threaded bore of the adaptor plate.
043483526	claims	1. A storage rack for fuel element bundles, said rack comprising, a bottom plate; a plurality of vertically disposed square receiving tubes, each tube having an inwardly directed flange resting on said plate and defining a bore for centering a fuel element bundle; and screws passing through each flange and into said plate to secure said tubes to said plate. 2. A storage rack as set forth in claim 1 wherein said plate has passage openings aligned with each rack said bore. 3. A storage rack as set forth in claim 2 which further comprises a plurality of ribs secured to an underside of said plate to stiffen said plate. 4. A storage rack as set forth in claim 1 which further comprises vertically adjustable screws secured to said plate for vertically adjusting said plate. 5. A storage rack as set forth in claim 1 wherein each tube has lateral inlet openings for the passage of circulating water. 6. A storage rack as set forth in claim 1 which further comprises a cover plate mounted over said tubes and having square openings coaxially of said tubes, a depending frame secured to said plate and vertical angle sections securing said frame to said bottom plate. 7. A storage rack as set forth in claim 6 which further comprises diagonally disposed flat rods secured at each end to an end of an adjacent pair of angle sections. 8. A storage rack as set forth in claim 7 wherein said rack is sub-divided into a plurality of units, each unit having a bottom plate, a cover plate and a plurality of tubes between said plates, and connecting elements screwed into adjacent cover plates to secure adjacent units together. 9. A storage rack as set forth in claim 8 wherein said connecting elements are guides for installation and removal of fuel element bundles. 10. A storage rack as set forth in claim 6 which further comprises a latticework of ribs secured to said cover plate within said frame.
	claims	1. A computerized nuclear power station monitoring system, comprising:a memory configured to store a database comprising a task category database comprising plurality of task category information elements comprising a safety function information element and a reactor protection information element, each task category information element being associated with at least one technical functional requirement and at least one technical design principle, each technical design principle being comprised in a technical design principle list, the technical design principle list comprising redundancy, diversity, separation and isolation, each functional requirement being comprised in a functional requirement list, the functional requirement list comprising reactivity control, core cooling and safe shut-down, and an equipment database configured to store at least one equipment information element, andat least one processor configured to, responsive to receipt in the computerized monitoring system of a failure notification concerning a first equipment information element, determine, using the database, a set comprising each technical design principle associated with each task category information element associated, via database relations, with the first equipment information element, and to identify, based on each technical design principle comprised in the set, a technical constraint of an equipment replacement action compensating, at least partly, effects of a failure identified in the failure notification and to provide information to personnel concerning the technical constraint. 2. The computerized monitoring system of claim 1, wherein the at least one processor is configured to determine a constraint of increased unit count responsive to the set comprising the technical design principle redundancy. 3. The computerized monitoring system of claim 1, wherein the at least one processor is configured to determine a constraint of principle of action responsive to the set comprising the technical design principle diversity. 4. The computerized monitoring system of claim 1, wherein the at least one processor is configured to determine a constraint of location responsive to the set comprising the technical design principle separation. 5. The computerized monitoring system of claim 1, wherein the at least one processor is configured to determine a constraint of physical separation responsive to the set comprising the technical design principle isolation. 6. The computerized monitoring system of claim 1, wherein the at least one processor is further configured to provide an indication of the determined constraints. 7. A method in a computerized nuclear power station monitoring system, comprising:storing a database comprising a task category database comprising a plurality of task category information elements comprising a safety function information element and a reactor protection information element, each task category information element being associated with at least one technical functional requirement and at least one technical design principle, each technical design principle being comprised in a technical design principle list, the technical design principle list comprising redundancy, diversity, separation and isolation, each functional requirement being comprised in a functional requirement list, the functional requirement list comprising reactivity control, core cooling and safe shut-down, and an equipment database configured to store at least one equipment information element;determining, responsive to receipt in the computerized monitoring system of a failure notification concerning a first equipment information element, using the database, a set comprising each technical design principle associated with each task category information element associated, via database relations, with the first equipment information element, andidentifying, based on each technical design principle comprised in the set, a technical constraint of an equipment replacement action compensating, at least partly, effects of a failure identified in the failure notification and providing information to personnel concerning the technical constraint. 8. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:store a database comprising a task category database comprising a plurality of task category information elements comprising a safety function information element and a reactor protection information element, each task category information element being associated with at least one technical functional requirement and at least one technical design principle, each technical design principle being comprised in a technical design principle list, the technical design principle list comprising redundancy, diversity, separation and isolation, each functional requirement being comprised in a functional requirement list, the functional requirement list comprising reactivity control, core cooling and safe shut-down, and an equipment database configured to store at least one equipment information element;determine, responsive to receipt in the computerized monitoring system of a failure notification concerning a first equipment information element, using the database, a set comprising each technical design principle associated with each task category information element associated, via database relations, with the first equipment information element, andidentify, based on each technical design principle comprised in the set, a technical constraint of an equipment replacement action compensating, at least partly, effects of a failure identified in the failure notification and provide information to personnel concerning the technical constraint.
	summary
	claims	1. A method of fabricating a liquid-metal coolant for a nuclear reactor, the method comprising:adding nanoparticles to the liquid-metal coolant to change neutronic properties of the liquid-metal coolant,the nanoparticles including a metal having neutronic properties different from that of the liquid-metal coolant prior to the adding nanoparticles, the metal including one of hafnium, boron and gadolinium. 2. The method of claim 1, wherein the adding nanoparticles includes adding the metal having the neutronic properties including at least one of a neutron cross-section and an atomic weight different from a metal of the liquid-metal coolant. 3. The method of claim 2, wherein the adding a metal to the liquid-metal coolant includes adding the metal to one of a liquid sodium coolant, a lead-bismuth coolant and a sodium-potassium coolant. 4. The method of claim 1, wherein the neutronic properties include one of neutron absorption cross-section, neutron moderation characteristics, and a neutron scattering cross-section. 5. The method of claim 1, wherein the adding nanoparticles includes measuring a concentration of the nanoparticles by one of direct methods and continuous on-line methods. 6. The method of claim 5, wherein the measuring a concentration of the nanoparticles includes sampling the liquid-metal coolant using a mass spectrometer. 7. The method of claim 5, wherein the measuring a concentration of the nanoparticles includes measuring intensity of a gamma signal from decay of a metal present in the nanoparticles to determine the content of the metal in the liquid-metal coolant. 8. The method of claim 1, wherein the metal includes one of boron and gadolinium. 9. The method of claim 1, wherein the nanoparticles consist essentially of the metal.
049960172	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a neutron generating system. More specifically, the invention relates to a new and improved neutron generator tube especially adapted to traverse the narrow confines of a well or borehole for well logging purposes. 2. Description of the Prior Art Over four decades have passed since F. M. Penning disclosed a neutron generator in U. S. Pat. No. 2,211,668 constructed of a low pressure deuterium-filled envelope containing a cathode and anode with an axially oriented magnetic field ion source, a nuclear reaction producing target and one or more acceleration electrodes. For the last three decades this "Penning" ion source has been employed extensively in various neutron generator tubes for downhole oil and gas well neutron logging. During this period extensive modifications and improvements have been suggested with varying degrees of commercial success, yet specific problems still remain, particularly during well logging in deep wells at high temperatures. It is generally known that the permanent magnetic materials used in the conventional neutron generator tubes tend to lose their magnetic properties when subjected to temperatures such as 400.degree. C. or greater (see U.S. Pat. Nos. 3,546,512 and 3,756,682). Because of the small confines of a well borehole, the neutron generator tube must have extremely high magnetic field capabilities in a relatively high vacuum in order to have significant ion production. In order to prevent or eliminate outgassing within the tube during use in deep, high temperature wells, an ultra high temperature bake out is necessary during fabrication of the tube. This creates the pragmatic dilemma; i.e., if an external magnet or field is employed (separate from the neutron generator tube) the physical dimensions of the resulting well logging tool restricts its utility, and if an internal permanent magnet is employed, the bake out procedure again will either restrict the physical size or deleteriously affect the magnetic field strength. Another historically recognized problem which continues to pragmatically limit the contemporary neutron generator tube is the removal of thermal energy from the target surface of the tube. Thus it is known that the energy of the ion beam striking the target and inducing the desired nuclear reaction, if too intense, will result in high temperature sputtering and thermal failure of the target and thus failure of the neutron generator tube. Various methods of modifying the composition and the thickness of the hydrogen occluding target film have been proposed to compensate for this problem. In a recent U.S. Pat. No. 3,784,824, vapor deposition or sputtering of a non-occluder for hydrogen onto the target during operation was suggested; yet, the problem essentially remains as a critical limitation. It is also generally recognized that shielding or confining the magnetic field to the ion source by encapsulating the permanent magnet and ion source and allowing the ion to escape through an aperture creating a narrow intense ion beam (see U.S. Pat. No. 3,112,401) is a desirable practice. In contrast, U.S. Pat. Nos. 3,141,975 and 3,401,264 employ one or more ion beam grids (with and without variable potential) placed between the ion source and target. In this approach the ion beam optics are manipulated across a relatively large cross-sectional ion beam such that the ion path is completely defocused and linear, thus allowing for a low energy acceleration of the positive ions. However, up to this time the combination of optimum thermal energy removal from the target surface and uniform distribution of the ion beam energy impinging on the target per unit surface area has been beyond contemporary technology. SUMMARY OF THE INVENTION In view of the prior art methods and apparatus and their associated limitations, I have discovered a neutron generating system and an associated improved neutron generator tube comprising: (a) a hermetically sealed housing containing an ionizable gas; (b) an axial recess in one end of the housing to accept a removable magnet; (c) a ring anode axially oriented within the housing adjacent to the recessed end for accepting the magnet; (d) an axially oriented thermal conductor cathode penetrating through the other end of the housing wherein the inner surface of the cathode contains a target; (e) an ion screen near the anode ring and between the anode ring and cathode target wherein the ion screen contains an axially positioned gridded aperture; and (f) an electron shield near the cathode target and between the ion screen and cathode target wherein the electron shield contains an axially positioned aperture. The neutron generating system of the present invention further comprises a removable magnet adapted to fit into the axial recess which in the preferred embodiment is a samarium/cobalt magnet. The invention also provides that the thermal conductor cathode have a cross-sectional area of substantially the same size as the target, and that the end of the cathode containing the target be within the housing such as to remove thermal energy from the target. The present invention further provides that the ion screen be an electrically conductive, grounded surface and in a preferred embodiment the gridded aperture be a screen of etched tungsten of about 0.002 to 0.005 inch thick with the openings representing about 90 percent of the surface area. In an alternative embodiment, a means is provided to vary the electrical potential on the ion screen relative to the potentials of the ring anode and cathode such as to assist in ignition of the ion source. It is a primary object of the present invention to provide a neutron generating system and tube that is compatible with the hostile high temperatures and pressures associated with downhole well logging. It is a further object that the device be compatible with extremely small diameter well casing and borehole diameter of deep wells. It is an object of the invention to provide a removable magnet such that the tube can be baked out under vacuum and hermetically sealed without subjecting the permanent magnet to ultra-high temperatures. It is also an object of the invention to provide a means for removing thermal energy from the target thus reducing thermal effects on the neutron output. And it is an object of the invention to provide a means of producing a broad ion beam of reduced power per unit area impinging on the target. Fulfillment of these objects and the presence and fulfillment of other objects shall be apparent upon complete reading of the specification and claims in conjunction with the attached drawing.
	claims	1. Method for the production of spherical fuel or breeder material particles from an oxide consisting of the heavy metals uranium and plutonium, the method comprising the steps of:producing a starting solution of nitrates of the heavy metals,adding a first reagent from the group of urea and/or ammonium carbonate and/or ammonium hydrogen carbonate and/or ammonium cyanate and/or biuret,adding at least one second reagent comprising PVA and THFA in order to adjust the viscosity of the solution, transforming the solution into droplets to form microspherules,solidifying the microspherules, at least in a surface region, in an atmosphere containing ammonia,collecting the microspherules in a solution containing ammonia and subsequent rinsing, drying and thermal treatment, characterized in that:the first reagent of the starting solution is added at room temperature and the solution thus prepared is heated to a temperature T where 80° C.≦T<Ts, where Ts=boiling temperature of the solution and is maintained at said temperature over a period of time t, where 2 h≦t≦8 h, the solution is subsequently cooled to a temperature TA, where TA=room temperature, and finally, the second reagent is added. 2. Method according to claim 1, characterized in that the solution is cooled to room temperature prior to adding the second reagent. 3. Method according to claim 1, characterized in that the first reagent from the group of urea and/or ammonium carbonate and/or ammonium hydrogen carbonate and/or ammonium cyanate and/or biuret is dissolved in solid form in the starting solution. 4. Method according to claim 1, characterized in that the solution is maintained at a temperature T where T≈90° C. over a period of time t. 5. Method according to claim 1, characterized in that the solution is maintained at a temperature T over a period of time t where 3 h≦t≦6 h. 6. Method according to claim 1, characterized in that a 1 to 2.5 molar nitrate solution is used as the starting solution. 7. Method according to claim 1, characterized in that the rinsed microspherules are subjected to subsequent treatment without using alcohol. 8. Method according to claim 1, characterized in that after rinsing of the microspherules water present in the latter is removed by further treatment in a reduced pressure atmosphere. 9. Method according to claim 1, characterized in that the further treatment for removing water is performed at a pressure p where 0.07 MPa≦p≦0.09 MPa. 10. Method according to claim 1, characterized in that the PVA and THFA are added to the solution in a quantitative ratio of about 1:10.
	abstract	Embodiments of a radiation shield are disclosed. One non-limiting embodiment of the radiation shield may comprise a first layer, a second layer, and a third layer. The first layer may include a neutron moderating material. The second layer may be adjacent the first layer and may include a neutron absorbing material. The third layer may be adjacent the second layer, and may include a photonic radiation attenuating material. At least the first layer and the second layer may be removable from the radiation shield.
	abstract	Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.
044118589	abstract	Direct power shape monitoring in parallel with precision power monitoring is effected by use of gamma sensors in the fuel core and signal processing that includes compensation for slow signal response and takes advantage of a substantially direct relationship of sensor signal to linear power generation rate. Continous readout from the direct power shape monitor is available during readout interruptions in the precision monitor.
	summary
	claims	1. A passively-cooled spent nuclear fuel pool system comprising:a spent nuclear fuel pool comprising:a body of liquid water having a surface level, at least one spent nuclear fuel rod submerged in the body of liquid water that heats the body of liquid water;a lid covering the spent nuclear fuel pool to form a hermetically sealed vapor space between the surface level of the body of liquid water and the lid, the vapor space including a first vapor space section and a second vapor space section, the lid comprising a first lid section and a second lid section; anda passive heat exchange sub-system comprising:a riser conduit comprising a first riser inlet section having a first inlet positioned within the first vapor space section, a second riser inlet section having a second inlet positioned within the second vapor space section and a primary riser section, wherein the primary riser section receives water vapor from the first and second vapor space sections;at least one downcomer fluidly coupled to the primary riser section for receiving the water vapor from the primary riser section, the water vapor condensing within the at least one downcomer to form a condensed water vapor; andat least one return conduit fluidly coupled to the at least one downcomer, the at least one return conduit having an outlet located within the body of liquid water for returning the condensed water vapor to the body of liquid water. 2. The system according to claim 1 further comprising a containment vessel comprising a cylindrical shell having an inner surface defining an interior cavity, the spent nuclear fuel pool housed within the interior cavity of the containment vessel. 3. The system according to claim 2 further comprising a containment enclosure surrounding the containment vessel, a heat sink space formed between the containment vessel and the containment enclosure. 4. The system according to claim 3 wherein the heat sink space contains water, and wherein the at least one downcomer is coupled to the inner surface of the containment vessel such that thermal energy from the water vapor is transferred to the water in the heat sink space through the at least one downcomer conduit and the containment vessel. 5. The system according to claim 1 further comprising a plurality of the downcomer conduits arranged in a circumferentially spaced apart manner about the inner surface of the containment vessel, and wherein each of the plurality of downcomer conduits is in intimate surface contact with the inner surface of the containment vessel. 6. The system according to claim 1 wherein the riser conduit comprises a thermal insulating layer. 7. The system according to claim 1 wherein the condensed water vapor mixes with the body of liquid water within the spent nuclear fuel pool. 8. The system according to claim 1 further comprising a first divider extending from the lid a partial distance into the body of liquid water to divide the vapor space into the first vapor space section located between the first lid section and the body of liquid water and the second vapor space section located between the second lid section and the body of liquid water. 9. The system according to claim 8 wherein the first and second vapor space sections are hermetically isolated from one another by the first divider and the first and second lid sections so that the water vapor in the first vapor space section cannot flow into the second vapor space section and the water vapor in the second vapor space section cannot flow into the first vapor space section. 10. The system according to claim 1 wherein each of the first and second vapor space sections is a hermetically sealed space. 11. The system according to claim 1 further comprising a gasket coupled to each of the first and second lid sections to create the hermetically sealed vapor space. 12. The system according to claim 8 wherein the spent nuclear fuel pool further comprises:a third lid section; anda second divider extending from the lid a partial distance into the body of liquid water, the first and second dividers dividing the vapor space into the first vapor space section, the second vapor space section and a third vapor space section, the third vapor space section located between the third lid section and the body of liquid water. 13. The system according to claim 12 wherein the riser conduit further comprises a third riser inlet section having a third inlet positioned within the third vapor space section, the third riser inlet section extending from the primary riser section to the third vapor space section. 14. The system according to claim 1 wherein a peripheral wall of the spent nuclear fuel pool is formed of concrete, and wherein the first and second riser inlet sections extend through the concrete. 15. The system according to claim 1 wherein each of the first and second vapor space sections is at a sub-atmospheric pressure. 16. The system according to claim 1 wherein the passive heat exchange sub-system further comprises an inlet manifold fluidly coupling the riser conduit to the at least one downcomer conduit and an outlet manifold fluidly coupling the at least one downcomer conduit to the at least one return conduit. 17. The system according to claim 1 wherein the passive heat exchange sub-system comprises a closed-loop fluid circuit. 18. The system according to claim 1 further comprising:a nuclear reactor; andthe nuclear reactor, the spent nuclear fuel pool and the passive heat exchange sub-system housed within a thermally conductive containment vessel, the at least one downcomer conduit coupled to the thermally conductive containment vessel such that thermal energy from the water vapor is transferred through the at least one downcomer conduit and the thermally conductive containment vessel to a heat sink. 19. A passively-cooled spent nuclear fuel pool system comprising:a spent nuclear fuel pool comprising a body of liquid water having a surface level, at least one spent nuclear fuel rod submerged in the body of liquid water that heats the body of liquid water;a lid covering the spent nuclear fuel pool to create a hermetically sealed vapor space between the surface level of the body of liquid water and the lid; anda passive heat exchange sub-system fluidly coupled to the vapor space, the passive heat exchange sub-system configured to: (1) receive water vapor from the vapor space; (2) remove thermal energy from the received water vapor, thereby condensing the water vapor to form a condensed water vapor; and (3) return the condensed water vapor to the body of liquid water;a heat sink;wherein the passive heat exchange sub-system comprises at least one riser conduit receiving the water vapor from the vapor space and at least one downcomer conduit receiving the water vapor from the at least one riser conduit, the at least one downcomer conduit being in thermal cooperation with the heat sink to transfer thermal energy from the water vapor to the heat sink, thereby condensing the water vapor in the at least one downcomer conduit and facilitating thermosiphon flow of the water vapor through the passive heat exchange sub-system;a thermally conductive containment vessel enclosing the spent nuclear fuel pool, the heat sink located outside of the thermally conductive containment vessel; andthe at least one downcomer conduit coupled to the thermally conductive containment vessel such that the thermal energy from the water vapor is transferred to the heat sink through the at least one downcomer conduit and the thermally conductive containment vessel. 20. The system according to claim 19 wherein the passive heat exchange sub-system comprises at least one inlet located in the vapor space and at least one outlet located in the body of liquid water. 21. The system according to claim 19 further comprising:a containment enclosure at least partially surrounding the thermally conductive containment vessel to form a heat sink space therebetween; andthe heat sink being a liquid reservoir located within the heat sink space. 22. The system according to claim 21 wherein the heat sink space is an annular space circumferentially surrounding the thermally conductive containment vessel. 23. The system according to claim 21 wherein the containment enclosure has an open top end. 24. The system according to claim 21 further comprising a plurality of heat exchange fins extending from an outer surface of the thermally conductive containment vessel into the liquid reservoir.
	abstract	A component for conducting or receiving a fluid, in particular a component of a fluid-conducting line system of an industrial plant, especially of a line system of a tertiary cooling circuit of a nuclear power plant, includes a wall having a supporting structure made of a glass-fiber-reinforced plastic. Electrically insulating inner and outer protective layers are disposed on respective inner and outer surfaces of the supporting structure. An electrically conductive inner intermediate layer lies between the inner protective layer and the supporting structure and is provided with an electrical terminal. An electrically conductive outer intermediate layer lies between the outer protective layer and the supporting structure, is provided with an electrical terminal and is electrically insulated from the inner intermediate layer. A method for testing the component is also provided.
	abstract	A system and method for determining a cross sectional feature of a measured structural element having a sub-micron cross section, the cross section is defined by an intermediate section that is located between a first and a second traverse sections. The method starts by a first step of scanning, at a first tilt state, a first portion of a reference structural element and at least the first traverse section of the measured structural element, to determine a first relationship between the reference structural element and the first traverse section. The first step is followed by a second step of scanning, at a second tilt state, a second portion of a reference structural element and at least the second traverse section of the measured structural element, to determine a second relationship between the reference structural element and the second traverse section. The method ends by a third step of determining a cross sectional feature of the measured structural element in response to the first and second relationships.
046506330	abstract	A control apparatus and method for restricting liquid flow in a liquid moving pump, usually of the centrifugal type, to prevent pump cavitation and pump prime mover overloading. The control apparatus includes sensors to detect liquid temperature and pressure at the inlet of the pump. It may further include a device such as a current transformer to develop a signal indicative of power consumed by the prime mover of the pump where the prime mover is an electrical motor. The liquid pressure and temperature indications are used to generate a specific indication of the subcooling of the liquid. The temperature indication is used to derive an indication of the instantaneous required subcooling of the pump. The subcooling indication and the required subcooling indication are introduced to a comparator. Should the subcooling of the liquid fail to exceed the required subcooling, a first control signal is generated. Simultaneously, a signal indicating power consumption may be fed to a second comparator along with a power limit signal. Should power consumption exceed the power consumption limit, a second control signal is generated. As long as either control signal is generated, progressive restriction of liquid flow through the pump is effected.
	description	The invention relates to systems and methods for measuring overlay errors on objects such as wafers, reticles and the like, and especially system and methods that use charged particle beams to observe said overlay errors. Overlay Error Measurements Integrated circuits are very complex devices that include multiple layers. Each layer may include conductive material, isolating material while other layers may include semi-conductive materials. These various materials are arranged in patterns, usually in accordance with the expected functionality of the integrated circuit. The patterns also reflect the manufacturing process of the integrated circuits. Each layer is formed by a sequence of steps that usually includes depositing a resistive material on a substrate/layer, exposing the resistive material by a photolithographic process, and developing the exposed resistive material to produce a pattern that defines some areas to be later etched. Ideally, each layer is perfectly aligned to previously existing layer. Typically, the layers are misaligned, thus a misalignment or overlay error exists between each pair of layers. Various techniques evolved for observing overlay errors, some using optical instruments and some using scanning electron microscopes. U.S. Pat. No. 6,407,396 of Mih et al., U.S. Pat. No. 6,489,068 of Kye, U.S. Pat. No. 6,463,184 of Gould et al., U.S. Pat. No. 6,589,385 of Minami et al, all being incorporated herein by reference, provide a good indication about the state of art overlay error measurement techniques. FIGS. 3a and 3b illustrate a commonly used overlay measurement target 90 that facilitates overlay measurements. Target 90 includes a first feature 91 formed in a first layer 92, a second feature 93 formed in a second layer 94 positioned under an aperture 95 that is formed in the first layer 92 and in an intermediate layer 96 positioned between the first and second layers. Both features 91 and 93 are visible to illuminating charged particle beams or optical beams. The formation of apertures is further subjected to inaccuracies and overlay errors and also may change the electrical properties of the integrated circuit. Optical overlay measurement methods require relatively large targets that may exceed tens of microns. Usually, said overlay targets are positioned at the scribe lines that are positioned between different dices of the wafer. Due to various reasons, such as manufacturing process fluctuations and inaccuracies, the manufacturing process parameters (and as a result the overlay errors) may differ across the wafer, and especially may differ from scribe lines to the dices and especially to central regions of the dices. Accordingly, measuring overlay errors at the scribe lines may not reflect the status of overlay errors of the dice. Due to the large cost of dice estate the amount of large overlay targets is usually limited. Optical overlay measurements are subjected to various errors such as lens aberrations of the optical system. Mih states that in some cases Atomic Force Microscopy or Scanning Electron Microscopy metrology techniques may be necessary to verify the optical overlay measurement accuracy. Interaction Between Charged Electron Beam and an Inspected Object Once an electron beam hits an inspected object various interaction processes occur. A detailed description of these processes can be found at “Scanning electron microscopy”, L. Reimer, second edition, 1998, which is incorporated herein by reference. FIG. 1 illustrates the important interaction process and various information volumes. An information volume is a space in which interaction process occur and result in scattering or reflection of electrons that may be eventually detected to provide information about the information volume. FIG. 1 illustrates the important interaction processes and various information volumes. An information volume is a space in which interaction processes occur and result in scattering or reflection of electrons that may be eventually detected to provide information about the information volume. Secondary electrons are easy to detect as their trajectory can be relatively easily changed such that they are directed toward a detector. The trajectory of backscattered electrons is relatively straight and is slightly affected by electrostatic fields. Multi-Perspective Scanning Electron Microscopes There are various prior art types of multi-perspective scanning electron microscopes. FIG. 2a illustrates a first type of a multi-perspective SEM 10 that includes multiple detectors. SEM 10 includes an electron gun (not shown) for generating a primary electron beam, as well as multiple control and voltage supply units (not shown), an objective lens 12, in-lens detector 14 and external detectors 16. System 10 also includes deflection coils and a processor (not shown). Such a system is described at U.S. Pat. No. 5,659,172 of Wagner. In system 10 the primary electron beam is directed through an aperture 18 within the in-lens detector 14 to be focused by the objective lens 12 onto an inspected wafer 20. The primary electron beam interacts with wafer 20 and as a result various types of electrons, such as secondary electrons, back-scattered electrons, Auger electrons and X-ray quanta are reflected or scattered. Secondary electrons can be collected easily and most SEMs mainly detect these secondary electrons. System 10 is capable of detecting some of the emitted secondary electrons by in-lens detector 14 and by external detectors 16. Objective lens 12 includes an electrostatic lens and a magnetic lens that introduce an electrostatic field and a magnetic field that leak from the lens towards the wafer. The collection of secondary electrons is highly responsive to the leaked electrostatic field while it hardly influenced by the leaked magnetic field. The leaked electrostatic field attracts low energy secondary electrons and very low energy secondary electrons into the column. A significant part of the very low energy secondary electrons are directed through the aperture of in-lens detector 14 and are not detected. Low energy secondary electrons are directed towards the in-lens detector 14. High-energy secondary electrons are detected if their initial trajectory is aimed towards one of the detectors. Effective defect review tool requires both types of detectors in order to capture all types of defects. In-lens detector 14 is usually used for determining a contrast between different materials, and is also useful in voltage contract mode as well as in HAR mode. HAR mode is used to inspect cavities that are characterized by a High Aspect Ratio (in other words—cavities that are narrow and deep). During HAR mode the area that surrounds the cavity is usually charged to allow electrons from the lower portion of the cavity to reach the detector. The In-lens detector 14 is also very sensitive to pattern edges. External detectors 16 are much more sensitive to the topography of the wafer. The external detectors are also less susceptible to wafer charging, which is significant when imaging highly resistive layers. Another U.S. Pat. No. 6,555,819 of Suzuki et al (which is incorporated herein by reference) describes a multi-detector SEM having magnetic leakage type objective lens where the magnetic field largely influences the trajectory of emitted secondary electrons. This SEM has various disadvantages, such as not being capable of providing tilted images and is not efficient to provide images from holes of high aspect ratio. Suzuki has a reflector that includes an aperture through which the primary electron beam passes, thus reflected electrons may pass through this aperture and remain un-detected. There is a need to provide a simple system and method that facilitated seamless overlay measurements of different types. There is a need to provide a system and method for expanding the capabilities of electron beam based overlay measurements. Detecting Second Feature by First Layer Topography Detection The invention provides a system and method for measuring overlay errors in response to a relative displacement between a first feature formed on a first layer of an object and a second feature formed on a second layer of an object. The second feature is buried under the first layer. According to an embodiment of the invention the second feature affects the shape (topography) of the first layer. Thus, the second feature can be detected in response to interactions with the first layer. This detection requires attracting towards one or more detectors electrons that are scattered or reflected at small angle in relation to the inspected object. The detection of electrons that are scattered or reflected at relatively small angles (and even at angles the range between few degrees and about eighty degrees) can be achieved by using multiple-detector SEM. According to an embodiment of the invention that SEM may include external as well as internal detectors. The external detectors are more sensitive to the topography of the inspected object as they can detect electrons reflected or scattered at angles that deviate from the normal to the inspected object. According to another embodiment of the invention the multi-detector SEM has a magnetic leakage type objective lens where the magnetic field largely influences the trajectory of emitted secondary electrons. The detectors are all in-lens detectors. According to a further embodiment of the SEM has an electrostatic type objective lens and at least one in-lens detector as well as at least one inner-lens detector. Detecting Second Feature by Interacting with the Second Feature According to another embodiment of the invention the second feature is detected by interactions with the second feature itself. This can be achieved by directing high kinetic energy electrons towards the inspected object. At certain kinetic energy layers enough electrons will interact with the second feature and will be eventually detected. The high kinetic energy can be introduced by subjecting the electrons to strong electrostatic fields. According to an embodiment of the invention the electrons are accelerated by a high acceleration voltage towards the object. Typically, this acceleration voltage may range between 5 kV to 15 kV, but this is not necessarily so. It is noted that the second feature can be detected by combining both detection based upon interaction with second feature and monitoring the first layer topography. According to another aspect of the invention the detection of second feature can involve controlling the penetration depth of the electrons in response to the depth of the second feature. This may involve directing electrons to penetrate through the first layer (and even the intermediate layer) such as to be reflected by the second feature, when such a feature is illuminated by the beam. According to another embodiment of the invention the scanning of the inspected object charges the second layer that may be detected by implementing capacitance voltage contract methods. Improving Second Feature Detection by Pre-Charging According to yet a further embodiment of the invention the detection is further improved by a preliminary step of charging the second feature. This may improve the detection when using either one of the mentioned above detection methods. It is further noted that overlay measurement errors can utilize both Multi Perspective Overlay Measurement FIG. 2b is an illustration of a portion 10′ of multiple-detector SEM in accordance to an embodiment of the invention. FIG. 2b also illustrates an exemplary path of a primary electron beam, as well as the paths of electrons that are scattered or reflected from an inspected object, such as but not limited to a wafer or a reticle. The primary electron beam propagates along an optical axis and is then (i) tilted in a first direction, (ii) tilted in an opposite direction such as to propagate along a secondary optical axis that is parallel to the optical axis but spaced apart from the optical axis, (iii) tilted, in a second direction, towards the optical axis and then (iv) tilted, in a direction opposing the second direction, such as to propagate along the optical axis. The above-mentioned tilt operations may be generated by magnetic deflection coils 32-36. A system and method for double tilt is described at patent application Ser. No. 10/146,218 filed 13 May 2002, and is incorporated herein by reference. The electron beams are subjected to an electrostatic field that can be introduced by multiple electrodes of various shapes and arrangements. Some of the embodiments are illustrated in U.S. patent application Ser. No. 10/423,289 titled “objective lens arrangement for use in a charged particle beam column”, that is incorporated herein by reference. It is noted that other tilt schemes may be implemented, such as performing only the fist two tilts, such that the primary electron beam interacts with the inspected object while propagating along the secondary axis. In system 10′ the primary electron beam is directed through an aperture 18 within the in-lens detector 14 to be focused by the objective lens 12 onto an inspected wafer 20. Secondary electrons that propagate through the aperture of in-lens detector 14 are eventually tilted in a second direction towards an inner-lens detector 40. The in-lens detector is located at the final part of the propagation path, where the primary electron beam propagates along the optical axis. The in-lens detector has an aperture that is positioned such as to surround the optical axis. Once electrons are emitted/scattered as a result of an interaction between the primary beam and the inspected object they are attracted, due to a strong electromagnetic field, towards the in-lens detector and to the aperture of that detector. The strength of the electrostatic field determines which secondary electrons are attracted to the in-lens detector and which are attracted to the aperture of the in-lens detector. Secondary electrons that propagate through the aperture of in-lens detector 14 are eventually tilted in a second direction towards an inner-lens detector 40. By applying a relatively strong electrostatic field the inner lens detector detects electrons that were once either not detected (passed through the aperture) or detected by the in-lens detector, while the in-lens detector detects electrons that once were detected by the external detectors. FIGS. 4a and 4b illustrate an overlay measurement target 110 that facilitates overlay measurements. Target 110 differs than prior art target 90 by not having an aperture that exposes the second feature. When using the invention the size of the overlay target 110 may be about tens of nanometers and even less. Target 110 includes a first feature 111 formed in a first layer 112, a second feature 113 formed in a second layer 114. Target 110 also includes an intermediate layer 116 that is positioned between the first and second layers. While first feature 111 is visible to optical beams, second feature 113 is buried under first and intermediate layers 112 and 116. The second feature can be detected by detecting its effect upon the topography of the first layer (according to a first embodiment of the invention) and/or by detecting electrons that interact with the second feature itself (according to a second embodiment of the invention). When the detection depends upon interaction with the second feature then the kinetic energy of the electrons is such that the second feature is included within a second information volume, such as the relatively large second information volume 5 of FIG. 1. The small size of the overlay target enables positioning it within the die, to use multiple targets and even to use die patterns as targets. FIGS. 5-7 illustrate methods 200-250 for overlay error detection. Method 200 starts by step 202 of directing a primary electron beam to interact with an inspected object. The inspected object includes a first feature formed on a first layer of the inspected object and a second feature formed on a second layer of the object, wherein the second feature is buried under the first layer and wherein the second feature affects a shape of an area of the first layer. As illustrated at FIGS. 4a-4b an intermediate layer is usually formed between the first and second layer. Step 202 is followed by step 204 of detecting electrons reflected or scattered from the inspected objects, and especially from the area. According to an aspect of the invention at least some of the directed electrons are reflected or scattered at small angle in relation to the inspected object. Secondary electrons may be directed towards external detectors 16 of FIG. 1 or in-lens detector 40 of FIG. 2b by introducing an electrostatic field and/or a magnetic field. The electrostatic field attracts the secondary electrons emitted from the first layer, and especially from an area of the first layer that is affected by the second feature. Usually, the first layer surface is deformed as a result of the second layer. For example, an ideally planar area of the first layer will include bumps positioned above the second pattern. These bumps are usually much smaller than the first and second feature and cannot be detected by usual top-view inspection. On the other hand, the edges of the bumps can be detected by collecting electrons at small angles in relation to the first layer. In a sense such a detection resembles “dark field” detection schemes that are very sensitive to scattered radiation. Step 204 is followed by step 206 of receiving detection signals from at least one detector and determining overlay errors. Step 206 usually includes calculating the relative displacement between the first and second features, and comparing the relative displacement to an expected displacement to determine the overlay error. FIG. 6 illustrates method 210 for detecting overlay errors. Method 210 starts at step 212 of directing a primary electron beam to interact with a first feature and a second feature of an inspected object. The first feature is formed on a first layer of the inspected object and the second feature formed on a second layer of the object. The second feature is buried under the first layer. Step 212 is followed by step 214 of directing electrons reflected or scattered from the first and second features towards at least one detector. At least some of the directed electrons may be reflected or scattered at small angle in relation to the inspected object, but this is not necessarily so. Step 214 is followed by step 216 of receiving detection signals from at least one detector and determining overlay errors. Each of methods 200 and 210 may further include a preliminary step of charging the second layer. This step may include scanning the inspected object with an electron beam. According to an embodiment of the invention the overlay errors are measured as deviations from a required spatial relationship between the first and second feature. According to an aspect of the invention measuring buried features, without creating an aperture allows measurement of overlay error by inspecting features of the integrated circuit that were not intended to be overlay measurement targets. A search of the integrated circuit CAD file and/or layout may indicate the presence of non-overlapping first and second features that may be inspected in order to detect overlay errors. The present invention can be practiced by employing conventional tools, methodology and components. Accordingly, the details of such tools, components and methodology are not set forth herein in detail. In the previous descriptions, numerous specific details are set forth, such as shapes of cross sections of typical lines, amount of deflection units, etc., in order to provide a thorough understanding of the present invention. However, it should be recognized that the present invention might be practiced without resorting to the details specifically set forth. Only exemplary embodiments of the present invention and but a few examples of its versatility are shown and described in the present disclosure. It is to be understood that the present invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
	claims	1. A lithographic apparatus comprising:an illumination system configured to condition a radiation beam;a projection system configured to project the radiation beam onto a substrate; anda filter system for filtering debris particles out of the radiation beam, wherein the filter system comprisesa plurality of foils for trapping the debris particles,a support for holding the plurality of foils, anda cooling system having a surface that is arranged to be cooled, the cooling system and the support being positioned with respect to each other such that a gap is formed between the surface of the cooling system and the support, andwherein the cooling system is arranged to inject gas into the gap. 2. A lithographic apparatus according to claim 1, wherein a path between an entrance position at which the gas enters the gap and an exit position from which the gas exits the gap forms a meandering path. 3. A lithographic apparatus according to claim 1, wherein the gap is such that a smallest distance between the surface of the cooling system and the support is in a range that varies from about 20 micrometers to about 200 micrometers. 4. A lithographic apparatus according to claim 3, wherein the gap is such that a smallest distance between the surface of the cooling system and the support is in a range that varies from about 40 micrometers to about 100 micrometers. 5. A lithographic apparatus according to claim 1, wherein the support is ring-shaped. 6. A lithographic apparatus according to claim 5, wherein the support is rotatable around its axis. 7. A lithographic apparatus according to claim 1, wherein the surface of the cooling system is arranged to be stationary with respect to the support. 8. A lithographic apparatus according to claim 5, wherein the surface of the cooling system is substantially ring-shaped, sharing its axis with the support. 9. A lithographic apparatus according to claim 1, wherein the surface of the cooling system is arranged to be cooled with a fluid. 10. A lithographic apparatus according to claim 9, wherein the fluid is water. 11. A lithographic apparatus according to claim 1, wherein the gas is argon. 12. A lithographic apparatus according to claim 1, wherein the support is provided with a recess for holding the gas before the gas exits the gap. 13. A lithographic apparatus according to claim 1, wherein the cooling system is arranged to cool the gas before injecting the gas into the gap. 14. A lithographic apparatus according to claim 1, wherein at least a part of the support and at least a part of the cooling system form together a heat sink to which a number of first foils of the plurality of foils are connected, the first foils substantially freely extending within the filter system such that heat is conducted substantially towards that heat sink through each first foil. 15. A lithographic apparatus according to claim 14, wherein at least another part of the support and at least another part of the cooling system form together an additional heat sink to which a number of second foils of the plurality of foils are connected, the second foils substantially freely extending within the filter system such that heat is conducted substantially towards that additional heat sink through each second foil, wherein the filter system is arranged to filter debris particles out of a predetermined cross-section of the radiation as emitted by a source, wherein the number of first foils extend substantially in a first section of the predetermined cross-section, and wherein the number of second foils extend substantially in a second section of the predetermined cross-section, the first section and the second section being substantially non-overlapping. 16. A lithographic apparatus according to claim 15, wherein at least one of the first foils and/or at least one of the second foils is apart from its connection with the respective heat sink, and unconnected with respect to any other part of the filter system. 17. A lithographic apparatus according to claim 15, wherein the filter system is arranged such that all of the filter system remains below a predetermined maximum temperature when exposed to the radiation beam. 18. A lithographic apparatus according to claim 15, wherein at least one of the first foils and at least one of the second foils extend in substantially the same virtual plane. 19. A lithographic apparatus according to claim 18, wherein a distance in that virtual plane between the respective first foil and the respective second foil is selected so as to maintain a gap between that first foil and that second foil when that first foil and that second foil reach their respective maximum temperatures. 20. A lithographic apparatus according to claim 18, wherein that virtual plane extends through a predetermined position that is intended to coincide with a source from which the radiation is generated. 21. A lithographic apparatus according to claim 15, wherein at least one of the first foils extends between two of the second foils. 22. A lithographic apparatus according to claim 1, wherein at least one foil of the plurality of foils comprises at least two parts that are connected along a substantially straight connection line, wherein each of the two parts coincide with a virtual plane that extends through a predetermined position that is intended to substantially coincide with a source from which the radiation is generated, the straight connection line coinciding with a virtual straight line that also extends through the predetermined position. 23. A lithographic apparatus according to claim 22, wherein a first part of the at least two parts is connected at a first position of the support and a second part of the at least two parts is connected at a second position of the support. 24. A lithographic apparatus according to claim 23, wherein a distance between the first and second position is fixed. 25. A lithographic apparatus according to claim 22, wherein at least one of the at least two parts coincides with a virtual plane that is a straight plane. 26. A lithographic apparatus according to claim 1, wherein at least one foil of the plurality of foils substantially coincides with a virtual plane that extends through a predetermined position that is in use intended to substantially coincide with a source from which the radiation is generated, and wherein a tensed wire extends within the virtual plane between the at least one foil and the predetermined position. 27. A lithographic apparatus according to claim 26, wherein the tensed wire is connected to the at least one foil. 28. A lithographic apparatus according to claim 26, wherein the tensed wire is held tight by at least one spring element. 29. A lithographic apparatus according to claim 26, wherein the tensed wire is thermally insulated from the at least one foil. 30. A lithographic apparatus according to claim 26, wherein the tensed wire is made out of a material that comprises at least one of the metals of the group consisting of tantalum and tungsten.
048209295	summary	TECHNICAL FIELD The present invention relates to devices for transforming visible images into infrared images. More particularly, the present invention relates to devices for the production of infrared images through the use of a layered structure having a photoconductive layer. BACKGROUND ART Infrared light is that portion of the electromagnetic spectrum adjacent to the long wavelength, or red end of the visible light range. Invisible to the eye, it can be detected as a sensation of warmth on the skin. The infrared range is usually divided into three regions: near infrared (nearest the visible spectrum), with wavelengths 0.78 to 3.0 microns; middle infrared, with wavelengths 3 to 30 microns; and far infrared, with wavelengths 30 to 300 microns. Most of the radiation emitted by a moderately heated surface is infrared light; it forms a continuous spectrum. Molecular excitation also produces copious infrared radiation but in a discreet spectrum of lines or bands. In application, infrared sensors on the ground, or in aircraft or spacecraft, can detect such hot spots as motor-vehicle engines, hot jet engines, missile exhaust, and even campfires. They generally have good location accuracy and high sensitivity to signals, without registering such false targets as sun reflections. Infrared imaging detectors are also used. In the very near infrared region, specially sensitized photographic film forms camouflaged-revealing images. More important are the detectors used in the far infrared region; objects at room temperature radiate sufficient energy for detection at ranges of several miles. Infrared imagery can have longer range than image intensifiers and can operate without starlight. While the prior art has shown a vast assortment of devices that can detect infrared radiation, there is little known in the prior art for the conversion of visible light into infrared radiation. Typically, in military exercises, objects must be individually heated in order to produce infrared radiation. Another apparatus used is the Bly Cell. The Bly Cell projects an image onto a polymer sheet at great intensity such that the light itself serves to heat the sheet. An image is produced since the most intense portions of the light will elevate the temperature of the polymer sheet a greater amount than the less intensely illuminated portions of the projected image. The Bly Cell, however, requires a large amount of power for image generation. In addition, the spatial and temporal resolution of the image is poor. It is an object of the present invention to provide a dynamic infrared simulation cell which is capable of converting a light image into an infrared image. It is another object of the present invention to provide an infrared simulation cell that operates with low amounts of power and energy consumption. It is another object of the present invention to provide an infrared simulation cell that offers a high level of spatial and temporal resolution. It is still another object of the present invention to provide an infrared simulation cell that is capable of operating at realtime speeds for the projection of "moving" infrared pictures. These and other objects and advantages of the present invention will become apparent from a reading of the attached Specification and appended claims. DISCLOSURE OF THE INVENTION The present invention is an infrared simulation device comprising: a photoconductive layer, a first conductiive layer affixed to the photoconductive layer, a second conductive layer affixed to the other side of the photoconductive layer, and an external energy source connecting to the first conductive layer and the second conductive layer. The photoconductive layer is a layer of silicon material. This layer of silicon material is made up of a plurality of separate segments. These segments of the photoconductive material generally act as the pixels of the projected infrared images. The photoconductive layer further includes insulative material affixed between the segments of photoconductive material. The first conductive layer is a transparent layer of gold material. This first conductive layer includes a conductive band extending about the outer edges of the conductive layer. This band serves to transmit energy from the external energy source to the first conductive layer. The second conductive layer serves to remove heat from the photoconductive layer. This cooling effect may be accomplished by making the second conductive layer of a material having strong heat sink properties. For example, this may be a layer of aluminum. Alternatively, the cooling may be a cooling fluid communicating with and circulating within the interior of this conductive layer. The present invention also includes an enclosure for maintaining the layered structure in a generally darkened environment. A source of imaging radiation is directed toward the first conductive layer within the enclosure. This source of imaging radiation may be either a two-dimensional light image directed onto the photoconductive layer or it may have a modulated light beam directed in a raster scanning pattern onto the layered structure. The enclosure includes suitable optics for the transmission of imaging radiation into the enclosure and for the emission of infrared radiation from the enclosure.
	description	The present patent application claims benefit from and incorporates by reference from Ser. No. 60/731,971, filed Oct. 31, 2005. A. Field of the Invention Embodiments herein relate to the field of charged particle storage and transportation. More particularly, embodiments relate to apparatus and method of storing and transporting charged particles, as well as preparing, filling, and transporting a bottle capable of storing and transporting charged particles utilizing electrostatic containment. More specifically, the present invention addresses the collection and storage of antiprotons; and the transport of antiprotons. B. Background of the Invention Antiprotons are annihilated upon contacting matter, and containers (e.g., Penning traps) include: “Container for Transporting Antiprotons,” U.S. Pat. No. 5,977,554 issued to Gerald A. Smith, et al. on Nov. 2, 1999; “Container for Transporting Antiprotons,” U.S. Pat. No. 6,160,263 issued to Gerald A. Smith, et al. on Dec. 12, 2000. See also Smith et al's. related U.S. Pat. Nos. 6,414,331 and 6,576,916, all of which are incorporated by reference. U.S. Pat. No. 5,977,554, for example, teaches containing with “means for providing the necessary magnetic fields”; “cryogen or cold wall”; and antiprotons are trapped in a potential well formed between the first and second electric fields (italics added herein.) While embodiments herein stand on their own, some embodiments reflect removal of that which has previously been considered necessary or otherwise contradict prior teachings. 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. While these experimental studies of particle physics use antiprotons with very high energies and momenta, other uses of antiprotons, such as the medical use, have relatively small energies and momenta. If the existing sources of antiprotons at such accelerators are to be used as sources of antiprotons for these other fields, the antiprotons have to 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. One embodiment provides means for storing charged particles, such as antiprotons. The means for storing can include an electrostatic means, such as a bottle, and preferably the means for storing can be utilized as a means for transporting. The means for storing can facilitate applications: For example, the treatment of cancerous tissue, the generation of radioisotopes within the body (useful for imaging techniques and therapeutic treatment). An electrostatic bottle can be comprised of one or more electrodes through which charged particles flow. Each electrode has applied to it a specific voltage. The combination of electrode spacing, voltage, and aperture diameter, coupled with the motion of the charged particles within the bottle, creates a focusing force which constrains the particles from striking any surfaces within the bottle. As to the particle motion dynamics of the stored antiprotons, the design of charged particle storage rings can rely on the employment of piecewise uniform (and hence integrable) optical elements such as dipole and quadrupole magnets. By using such linear optical elements which have analytic solutions for particle trajectories and amplitude independent stability parameters, particle loss effects such as resonant extraction and dynamic aperture can be controlled or avoided at the design stage of the optical system. In some embodiments, it can be preferable to sharpen the edges of the discrete focusing and defocusing lenses, depending on the preferred integrable solution desired for predicting long-term storage. By way of a prophetic teaching, a design can employ an optical system composed of tens or hundreds of electrodes. A representative design can be simulated to illustrate synthesis of piecewise integrable electrostatic optical systems. The choice of electrode voltages utilize an accelerator physics approach to storage ring design in which a piecewise integrable optical system can be used to minimize dynamical sources of particle loss. By way of another prophetic teaching, the optical system can be comprised of axisymmetric electrodes. Alternatively, the optical system can be comprised of electrostatic quadrupoles, employing strong-focusing to generate a net focusing force on charged particles that are moving within the bottle. Also, the optical system can be comprised of both axisymmetric electrodes and electrostatic quadrupoles. By way of another prophetic teaching, the geometry of the bottle can incorporate a linear array of electrodes, in which the charged particles oscillate across the bottle along the axis of the electrodes. Alternatively, the bottle can contain a ring of electrodes, in which the charged particles continuously circulated round the ring in toroidal geometry. In order to maximize the storage life of the charged particles within the bottle, the voltage on the electrodes can be slowly modified. This modification can be based on measured properties of the stored charged particles, such as their oscillation frequencies within the focusing electric field. A vacuum can be used to prevent the stored particles from being lost through chemical reactions, nuclear reactions, or particle-antiparticle annihilation. In order to keep the weight of the bottle low, the skin of the primary vacuum system can be quite thin. If exposed to air, which contains a hydrogen partial pressure of 1.4×10−4 Torr liter/cm3, this skin would allow diffusion of hydrogen into the ultra-high vacuum system and reduce the charged particle lifetime in the bottle. A representative solution is to surround a primary vacuum region with a second high vacuum system that is pumped, e.g., with a miniature sputter-ion pump. By reducing the concentration of hydrogen, e.g., nine orders of magnitude, the problem of hydrogen diffusion can be minimized or eliminated. Near the charged particles, a highly aggressive method of removing residual gas molecules can be surface gettering. The electrodes and other conducting surfaces of the bottle can be comprised of titanium, which is a good getter material. Just before filling the bottle with the charged particles, the getter material can be heated to outgas the material and generate clean surfaces capable of adsorbing sufficient numbers of gas molecules to maintain the vacuum for weeks or months. To fill bottles, the injection of charged particles can be accomplished by first attaching the bottle to an existing charged particle source, such as an ion source or a particle accelerator. A vacuum gate valve can be used to merge the bottle vacuum with the particle source vacuum. The charged particles are then directed toward the bottle. In order to hold the charged particles within the bottle, the electric field (which prevents stored charged particles from again exiting the bottle) can be briefly modified during the incoming passage of the injected charged particles. Briefly reducing the voltages on the electrodes near the bottle entrance can be a modification that enables charged particle injection. Extraction of charge particles stored in the bottle can occur with a procedure inverse to that used for charged particle injection. Another embodiment is to slowly lower the electrode voltages near the bottle entrance, allowing the stored charged particles to slowly spill out. These extracted charged particles can be directed into a particle accelerator. The extracted charged particles can be used in medical therapies, for isotope detection, for isotope generation, for the induction of nuclear fission or fusion, for imaging, of for catalyzing chemical reactions. In some embodiments, antiprotons are stored and transported in the bottle. However, there are applications wherein the antiprotons do not need to be extracted, but rather annihilated within the bottle itself. One way to accomplish such annihilation is by injecting a gas into the bottle. The gas can be hydrogen. Byproducts of this antiproton annihilation are secondary particles and rays. Embodiments herein can use these secondary particles in interrogating a shielded container for nuclear materials. When a source of electrons is added, the properties of the bottle can be improved. First, an ion-sputter pump functionality is created by ionizing the residual air molecules in the vacuum chamber. Second, the electrons cool the charged particles in order to overcome the intrabeam scattering. Third, the electrons create a space-charge counter-force which allows more charged particles to be stored in the electrostatic bottle. In addition to the use of electrons to control the temperature of the stored charged particles, changes to select electrode voltages based on measured charged particle positions and velocities can also be used to reduce and maintain the temperature of the stored charged particles. Power can be used to maintain the electrode voltages, maintain the vacuum within the bottle, and implement technologies for maintaining the temperature of the stored charged particles. Batteries can be used to provide sufficient power to operate the bottle without external power. Under some conditions the operational power level can be less than ten Watts. The apparatus can be used for transporting charged particles, again herein exemplified as including antiprotons. Because vibrations can occur when transporting on a vehicle or a person, steps can be taken to minimize the relative motion of electrodes within the bottle. This minimization of structural deflections is useful at the oscillatory frequencies of the stored charged particles. The vehicles used for transport can include automobiles, trains, aircraft, and rockets. Representatively, one way of viewing the teachings herein is as an apparatus used in storing and transporting charged particles. The apparatus can include: an electric field within the apparatus capable of preventing or controlling the charged particles from striking a surface within the apparatus; and a means for maintaining a vacuum within the apparatus in the region of the charged particles. In another way of viewing the teachings herein, there can be a method of storing and transporting charged particles. The method can include generating an electric field within a bottle capable of preventing or controlling the charged particles from striking a surface within the bottle; and maintaining a vacuum within the bottle in the region of the charged particles. Another embodiment can be phrased as an apparatus for storing (and in some cases transporting) antiprotons. The apparatus can include an electric field within the apparatus capable of preventing or limiting the antiprotons from striking the surface within the apparatus; and a means for maintaining a vacuum within the apparatus in the region of the antiprotons. Yet another embodiment can be articulated as a method of storing and transporting antiprotons, including: generating an electric field within a bottle capable of preventing the antiprotons from striking a surface within the bottle; and maintaining a vacuum within the bottle in the region of the antiprotons. Representatively, another way of viewing the teachings herein is as an apparatus and/or method of storing charged particles that is devoid of a controllable magnetic field or need therefore. 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. The realization that the magnetic field used in Penning traps is not required leads to important improvements in container weight and size. Representatively, yet another way of viewing the teachings herein is an apparatus and/or method of storing charged particles that is devoid of a cryogenic temperature, and/or a container with a cold wall, (and associated thermally conductive supports in thermal connection with said cold wall), and/or dewar associated with the container or need therefore. 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. In the teachings herein a vacuum is maintained through any of a number of means, including gettering, ion-sputter pumping, and the employment of an envelope vacuum. The realization that cold walls and cryogenic temperatures used in Penning traps are not required leads to important improvements in container weight and size. Representatively, yet another way of viewing the teachings herein is as an apparatus and/or method of storing charged particles that is devoid of multiple electric fields or need therefore. 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. In the teachings herein a single electric field, generated by multiple electrodes, can be handled as a single integrated field. The realization that the cryogenic temperatures used in Penning traps is not required leads to important improvements in container weight and size. Another embodiment can be phrased as an apparatus and/or method of storing and/or transporting antiprotons. These antiprotons are generated when high energy ions strike a target, colliding the ions against the atoms in the target. These collisions cause fragmentation of the ions and atoms, which sometimes re-coalesce in the form of antiprotons. Because of the radiation levels, energy difference between the incident protons and exiting antiprotons, and system complexity of the antiproton capture system, this target is not found within a synchrotron (see, e.g., U.S. Pat. Nos. 5,977,554, 6,160,263, etc.) but rather a separate location within the accelerator complex. These antiprotons can then be decelerated and injected into a portable container. As a prophetic teaching, this portable container with injected antiprotons can be used to generated biomedically useful radioisotopes at the bedside of a patient. Compare this teaching 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. 1 shows a group of electrodes 100 surrounding a dense distribution of charged particles 102. An apparatus for, and a method of, storing (and transporting) charged particles is illustrated in a teaching manner. FIG. 2 shows the electric field 200 generated by the electrodes 100. The electric field in FIG. 2 is represented by contours of constant electric potential. FIG. 3 shows a schematic representation of a possible bottle 300 or other container suitable for storing and transporting those charged particles 102. This apparatus can include one or more electrodes 100 that shape an electric field 200 which, coupled with the motion of the charged particles 102, focuses the charged particles and constrains them from striking any internal surfaces within the bottle 300, such as the electrodes 100 themselves. The voltage on each electrode can be generated by a high voltage power source 302, which in turn can draw the electrical power it needs from a battery 304. If the charged particles 102 that are stored in the bottle come into contact with residual gas molecules within the vacuum maintained in the bottle, they can be lost through chemical, nuclear, or annihilation reactions. In this embodiment a second vacuum system 306 that acts as a protective envelope around the central primary vacuum system 308 can be implemented. This envelope vacuum system 306 prevents atmospheric hydrogen and other gases from inducing charged particle losses. A gate valve 310 can be used to separate these two vacuum systems. The envelope vacuum can be maintained using a miniature ion-sputter pump 312. The high voltage needed to operate the ion-sputter pump 312 can be generated by a high voltage power source 314, which in turn can draw the electrical power it needs from a battery 304. In order to inject or extract charged particles from the bottle, the internal gate valve 310 and an external gate valve 316 can be opened to allow passage of the charged particles. In this embodiment of the invention, the methods of injection and extraction can take place with these gate valve(s) cycling open and closed just long enough to allow passage of the charged particles. Within this embodiment, the apparatus can include a gate valve(s) that are fast acting. The primary vacuum 308 can be maintained by constructing the electrodes 100 and primary vacuum vessel 318 from a material that getters residual gas molecules. In this embodiment, the material is titanium. In this embodiment, the bottle is protected from extreme temperature fluctuations and physical shock by an external shield 320 that can be comprised of soft, thermally insulating material. The electrodes should also be mounted such that they are insulated from external vibrations. In one embodiment, the radial focusing of the charged particles is generated by axisymmetric radial electric fields 400 that are a direct result of a voltage gradient along the axis of the electrodes 100. FIG. 4 shows a possible radial electric field pattern as a function of distance along the axis of the electrodes 100. In another embodiment, radial focusing is accomplished through the use of alternating gradient electrostatic quadrupoles 500 such as those illustrated in FIG. 5. The stored charged particles 102 oscillate within the electric field that constrains their motion, such that there are well defined resonant frequencies associated with this motion. Mechanical and electric vibrations and modulations with a non-zero power spectrum near these resonant frequencies can cause these charged particle oscillations to increase in amplitude, which is described as an increase in the charged particle temperature. Different approaches can be used to limit or reverse this temperature rise. In one embodiment, the stored charged particles 102 include electrons which interact with the other stored particles. By continuously replacing hot electrons and allowing thermodynamic interactions between all stored charged particles via Coulomb scattering, the temperature of the stored charged particles can be controlled. In another embodiment, measurement of the oscillatory particle signal on one or more electrodes can be electrically amplified and applied to one or more electrodes to reduce that signal. Continuous application of this procedure can reduce the temperature of stored charged particles, and is called stochastic cooling. In some embodiments, stored antiprotons 600 are not extracted, but rather annihilated within the bottle itself. One way to accomplish such annihilation is by injecting a gas into the bottle. The gas can be hydrogen. As illustrated in FIG. 6, annihilation occurs when the antiproton interacts with a gas molecule 602. Byproducts of this antiproton annihilation are gamma-rays 604, pi-mesons 606, neutrons 608, and other secondary particles and rays 610. A container 300 storing charged particles 302 can be used for many applications. Because the charged particle 302 have very low velocities, it is often necessary to extract them from the container 300 and accelerate them in a particle accelerator 700. A preferred embodiment of this invention is to store and transport antiprotons 600 for use in these many applications. As illustrated in FIG. 7, examples of these applications are medical therapies 702, the detection of individual isotopes 704, the generation of isotopes 706, the induction of fission in a variety of materials 708, the induction of fusion in a variety of materials 710, imaging 712, and catalyzing chemical reactions 714. Each of these applications can be performed using charged particles 102 directly from the container 300, or using these charged particles 302 after acceleration in the particle accelerator 700. The container 300 storing charged particles can be transported in many ways. As illustrated in FIG. 8, a motorized vehicle 800 of some kind can be used. Motorized vehicles with one or more wheels, including automobiles, motorcycles, trucks, and trains can be used. Motorized vehicles such as ships and aircraft can also be used. The transportation of containers 300 storing charged particles can also be implemented using rockets 802 or other vehicles capable of reaching outer space. The transportation of container 300 storing charged particles can also be performed by one or more persons or animals 804 carrying the container 300. 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.
	description	While the present invention is described below with reference to a syringe shield, a practitioner in the art will recognize the principles of the present invention are applicable elsewhere. As can be seen in FIG. 5, apparatus 10 is illustrated in a cross-section view of the syringe shield and transporter with dose applicator 18. The apparatus 10 transports a radiopharmaceutical 26 and protects individuals from radiation generated therefrom. A first body 11 releasably communicates with a second body 12 and a third body 13. The second edge first body 11e provides a releasably first communication means 33 with the first edge second body 12h between the first body 11 and the second body 12. The first edge first body 11f provides a releasably second communication means 34 with the first edge third body 13j between the first body 11 and the third body 13. A disposable insert device 20 containing a hypodermic syringe 25 is internally positioned (housed) by the first hollow core 23a in the first body 11. The first hollow core 23a is open on a first edge first body 11f and second edge first body 11e. A disposable insert device 20 containing a hypodermic syringe 25 is internally positioned (housed) by the second hollow core 23b in the second body 12. The second hollow core 23b is open on a first edge second body 12h and closed on the second edge second body 12d. A disposable insert device 20 containing a hypodermic syringe 25 is internally positioned (housed) by the third hollow core 23c in the third body 13. The third hollow core 23c is open on an first edge third body 13j and fixedly communicates with a hollow stem 23d that is open on a second edge third body 13i. A first connection means 33 releasably communicates the first body 11 with the second body 12 to provide protection from radiation emitted by the radiopharmaceutical 26. A second connection means 34 releasably communicates the first body 11 with the third body 13 to provide protection from radiation emitted by the radiopharmaceutical 26. A third connection means 35 releasably communicates the third body 13 with the locking nut 15 of the dose measuring applicator 18 or cap 14 shown in FIG. 1. An applicator rod 16 of the dose measuring applicator 18 is connected to the disposable insert 20 by a fifth female thread 16b at the first end 16d of the applicator rod 16. The applicator rod 16 slideably communicates with the third body 13 within the hollow stem 23d which is located between the fourth edge third body 13f and the third hollow core 23c of the third body 13. This allows the hypodermic syringe 25 with the radiopharmaceutical 26 to be positioned into and out of the first body 11 and third body 13 when the second body 12 is removed from the apparatus 10. A third connection means 35 includes a locking nut 15 that releasably secures the rod 16 of the dose applicator 18 to the third body 13. The third connection means 35 releasably communicates the locking nut inner recessed edge 15d and the locking nut inner edge 15e to the second edge third body 13i and the fourth edge third body 13f of the third body 13. The locking nut 15 releasably secures the dose applicator 18 to the third body 13 and provides an additional radiation shield 29 stopping radiation leakage from the hollow stem 23d. The radiation shield 29 is provided by various radiation shielding material used in the construction of the first body 11, the second body 12, the third body 13 and the locking nut 15. In the preferred embodiment of the invention the radiation shielding material is typically lead. However, in many applications although lead is an excellent radiation shielding material it is unsuitable because it is too heavy and insufficiently flexible. Consequently, as is known by the practitioner in the art, the radiation shielding material is any material that will attenuate the photons released from the radioactive agent. For example, a radiation shielding material is obtainable from lead acrylate or lead methacrylate combined by polymerizing it at a temperature above the melting point in admixture with a copolymerizable monomer such as methyl methacrylate. Furthermore, another radiation shielding material comprises an elastomeric or rubbery plastics material filled with lead particles. These materials combine the excellent radiation shielding properties of lead with other materials that weigh less than lead to provide a good radiation shield that is flexible and not too heavy. Another commonly utilized radiation shielding material is tungsten. When tungsten, a tungsten compound or a tungsten based alloy is used as the material with high radiation absorptivity, where the xcex3-ray absorption coefficient of tungsten is not less than about 1 when the energy of the xcex3-ray is 511 KeV or greater, there is provided a safe radiation shielding material. For example, one such tungsten compound with high radiation absorptivity is a tungsten powder that is not less than 80% by weight or greater than 95% by weight combined with vulcanized rubber. The tungsten powder in combination with the vulcanized rubber has particle sizes in the range of about 4 xcexcg to 100 xcexcm. When a tungsten alloy is used for the radiation shielding material a typical combination includes but is not limited to a hard-fine grained internally stressed material of tungsten and carbon or tungsten, carbon and oxygen. Now referring to FIG. 1 the apparatus 10 is illustrated with the first body 11 communicating with the second body 12 and the first body 11 communicating with the third body 13 and a cap 14. The cap 14 communicates with the third body 13. The hypodermic syringe and disposable insert (FIG. 5) are not shown. The first body 11 has a first hollow core 23a that is machined all the way through body 11 from the first edge first body 11f to the second edge first body 11e. The diameter of the first hollow core 23a that forms the first inner surface 11b is a variety of sizes depending on the hypodermic syringe to be used. The first body 11 shape is defined by the first outer surface 11a and is typically machined. However, as is know by the practitioner of the art that machining the first body 11 first inner surface 11b and first outer surface 11a is substitutable by casting the first body 11. Furthermore, the first edge first body 11f and second edge first body 11e are typically formed in parallel planes. The connection means at the first edge first body 11f is typically a first male thread 11d that is formed starting at the first edge first body 11f at a diameter that is smaller than the first outer surface 11a and larger than the diameter of the first inner surface 11b. Typically, the first male thread 11d diameter is formed in the range of about 70% of the diameter of the first outer surface 11a and machined back from the first edge first body 11f about 15% the overall length of the first body 11. The connection means at the second edge first body 11e is typically a second male thread 11c that is formed starting at the second edge first body 11e at a diameter that is smaller than the first outer surface 11a and larger than the diameter of the first inner surface 11b. Typically, the second male thread 11c diameter is formed in the range of about 70% of the diameter of the first outer surface 11a and machined back from the second edge first body 11e about 15% the overall length of the first body 11. The first male thread 11d and the second male thread 11c are typically and unified fine thread or a unified coarse thread. Depending on the application the male thread connection means are substitutable for female threads, a locking nut arrangement or a compression flange arrangement. Finally, the first outer surface 11a is cylindrical in shape with a diameter that provides enough radiation shielding material between itself and the first inner surface 11b to protect against radiation exposure. The cylindrical shape is substitutable for any circular or polyhedron shape. The second body 12 has a second hollow core 23b that is machined from the third edge second body 12e to a point that is about 25% of the length of the second body 12 from the second edge second body 12d. The diameter of the second hollow core 23b that forms the second inner surface 12b is a variety of sizes depending on the hypodermic syringe to be used. The second body 12 shape is defined by the first tapered outer surface 12a and second outer surface 12g and is typically machined. However, as is know by the practitioner of the art that machining the second body 12 second inner surface 12b, first tapered outer surface 12a and second outer surface 12g is substitutable by casting the second body 12. Furthermore, the third edge second body 12e and the second edge 12d second body are typically formed in parallel planes. The second connection means 34 at the third edge second body 12e is typically a first female thread 12f that is formed starting at the third edge second body 12e at a diameter that is smaller than the first tapered outer surface 12a and larger than the diameter of the second inner surface 12b. Typically, the first female thread 12f diameter is formed in the range of about 70% of the diameter of the first tapered outer surface 12a and machined back from the third edge second body 12e about 15% the overall length of the second body 12. The first female thread 12f is typically and unified fine thread or a unified coarse thread. However, depending on the application the female thread connection means are substitutable for a male thread, a locking nut arrangement or a compression flange arrangement. There is an annular ridge 23e that is formed to provide a means for the disposable insert (shown in FIG. 5) to be coaxially secured to the third inner surface 12c. The diameter of the third inner surface 12c depends on the size of the hypodermic syringe (shown in FIG. 5) to be used. The diameter is typically the size to fit a disposable insert that accepts 3 cc and 5 cc syringes. Finally, the first tapered outer surface 12a and second outer surface 12g are cylindrical in shape with a diameter that provides enough radiation shielding material between itself and the second inner surface 12b to protect against radiation exposure. The cylindrical shape is substitutable for any circular or polyhedron shape. The third body 13 has a third hollow core 23c that is machined from the third edge third body 13e to a point that is about 25% of the length of the third body 13 from the second edge third body 13i. The diameter of the third hollow core 23c that forms the fourth inner surface 13b is a variety of sizes depending on the hypodermic syringe to be used. The third body 13 shape is defined by the second tapered outer surface 13a and the third outer surface 13g and is typically machined. However, as is know by the practitioner of the art that machining the third body 13 fourth inner surface 13b, second tapered outer surface 13a and the third outer surface 13g is substitutable by casting the third body 13. Furthermore, the third edge third body 13e, the fourth edge third body 13f, the second edge third body 13i and the first edge third body 13j are typically formed in parallel planes. The third connection 35 means at the third edge third body 13e is typically a second female thread 13h that is formed starting at the third edge third body 13e at a diameter that is smaller than the third outer surface 13g and larger than the diameter of the fourth inner surface 13b. Typically, the second female thread 13h diameter is formed in the range of about 70% of the diameter of the third outer surface 13g and machined back from the third edge third body 13e about 15% the overall length of the third body 13. The third connection means 35 at the second edge third body 13i is typically a third male thread 13d that is formed starting at the second edge third body 13i at a diameter that is smaller than the second tapered outer surface 13a and larger than the diameter of the fourth inner surface 13b. Typically, the third male thread 13d diameter is formed in the range of about 35% of the diameter of the third outer surface 13g and machined back from the second edge third body 13i about 15% the overall length of the third body 13. The second female thread 13h and the third male thread 13d are typically and unified fine thread or a unified coarse thread. However, depending on the application the male thread connection means is substitutable for female threads, a locking nut arrangement or a compression flange arrangement. Also, the female thread connection means is substitutable for male threads, a locking nut arrangement or a compression flange arrangement. The hollow stem 23d that is formed by the fifth inner surface 13c is machined slightly larger than the application rod 16 that is shown in FIG. 2. The hollow stem 23d extends from the seventh edge 13i back into the third hollow core 23c. Furthermore, the second tapered outer surface 13a and the third outer surface 13g are cylindrical in shape with a diameter that provides enough radiation shielding material between itself and the fourth inner surface 13b to protect against radiation exposure. Finally, the cylindrical shape is substitutable for any circular or polyhedron shape. The cap 14 has a cap outer surface 14a that is less in diameter than the narrowest diameter of the second tapered outer surface 13a. The cap 14 has an overall length extending from the cap inner edge 14d to the cap outer edge 14b. This length is typically about 30% of the length of the first body 11. A third connection means 35 extends from the cap inner edge 14d to the cap recessed edge 14e. The third connection means 35 is typically a third female thread 14c and is recessed into the cap 14 about 30% of the overall length of cap 14. However, as is known by the practitioner in the art the female thread is substitutable for a male thread, lock nut arrangement or a compression flange arrangement depending on the application. The material of cap 14 is various radiation shielding material including but not limited to, for example, tungsten or lead. The amount of material required is that which provides little or no leaking of radiation from the second edge third body 13i. The syringe shield (pig), apparatus 10, as illustrated in FIG. 1 shows the cap 14 communicating with the third body 13, the third body 13 communicating with the first body 11 and the first body 11 communicating with the second body 12. The first edge first body 11f, the second edge first body 11e, the second edge second body 12d, the third edge second body 12e, the third edge third body 13e, the fourth edge third body 13f, the second edge third body 13i, the first edge third body 13j and the first edge second body 12h are all formed in a parallel plane to one another. The cap 14 is securely fastened to the third body 13 by axially threading the third male thread 13d into the third female thread 14c until the fourth edge third body 13f and the cap inner edge 14d are in snug-fitting contact. The third body 13 is securely fastened to the first body 11 by axially threading the first male thread 11d into the second female thread 13h until the first edge first body 11f and the first edge third body 13j are in snug-fitting contact. The first body 11 is securely fastened to the second body 12 by axially threading the second male thread 11c into the first female thread 12f until the first edge second body 12h and the second edge first body 11e are in snug-fitting contact. FIG. 1 does not show the hypodermic syringe 25 and the disposable insert 20 that is shown in FIG. 5. The cap 14 is used when only transporting the hypodermic syringe 25. Finally, in the preferred embodiment of the invention the first outer surface 11a, the second outer surface 12g and the third outer surface 13g are in alignment with their surface peripheries radially flush. FIG. 2 shows the dose measuring applicator 18 communicating with and securely fastened to the third body 13. The dose applicator 18 is used when it is desired to load the hypodermic syringe 25 (shown in FIG. 5) into a well counter allowing continued radiation shielding. The dose applicator 18 consists of an applicator rod 16, a connector 16a and a locking nut 15. The connector 16a is typically an eye bolt or some other suitable connection structure such as a clip, flange, threaded pipe or the like. The connector 16a is attached to the rod 16 at the second end 16e. The outer rod surface 16c defines the periphery and the size of rod 16. The diameter of the outer rod surface 16c and the length of rod 16 varies depending on the application. At the first end 16d of the rod 16 is a fourth connection means 36 that is a fifth female thread 16b and a second section male thread 21c located on the disposable insert 20. Alternately, the female thread 16b is substitutable for a male thread in a different application. Likewise, the second section male thread 21c is substitutable for a female thread in a different application. The 5th inner surface 13c diameter is always greater in diameter than the fifth female thread connector outside surface 16f diameter. This allows the rod 16 to be slideably removed or inserted into the third hollow core 23c of the third body 13. At the third connection means 35, a locking nut 15 connects the applicator rod 16 of the dose applicator 18 to the third body 13 allowing the rod 16 to slide but not allow the rod 16 to be completely removed from the third body 13. The locking nut 15 varies in size depending on the application with the locking nut outer surface 15a having a diameter that is about 60% greater than the diameter of the third make thread 13d. The locking nut outer edge 15f and the locking nut inner edge 15e are formed in the same parallel plane and match the parallel plane of the fourth edge third body 13f. A fourth female thread 15c is formed with a diameter that is about twice as large as the diameter of the fifth inner surface 13c. The depth of the fourth female thread 15c matches the length of the third male thread 13d and is formed to the locking nut inner recessed edge 15d. A locking nut inner surface 15b diameter is formed with a diameter that is slightly larger than the applicator rod outer surface 16c diameter. This produces a small gap 19 and because the gap is small the locking nut 15 provides additional shielding of the radiation from the radionuclide contained in the third hollow core 23c of the third body 13. It also allows the dose measuring applicator 18 to slideably extend into or retract from the third hollow core 23c of the third body 13. An o-ring 37 fits snuggly into an annular recess 38 that is formed in the locking nut inner surface 15b at the locking nut inner recessed edge 15d. The annular recess 38 is formed by machining it into the locking nut 15. However, the machining of the annular recess 38 is substitutable for casting the annular recess 38 into the locking nut 15. The o-ring 37 prevents slippage of the applicator rod 16 because the o-ring internal surface 37a is positioned providing a snug-fit against the applicator rod outer surface 16c. After the dose measuring applicator 18 (rod 16) is inserted into the third hollow core 23c of the third body 13, the locking nut 15 is rotated on the third male thread 13d. This occurs until the fourth edge third body 13f tightly contacts the locking nut inner edge 15e and the fourth edge third body 13f tightly contacts the locking nut inner recessed edge 15d. FIG. 3 is a cross-section illustration of the disposable insert 20. The disposable insert 20 consists of a first section 21 and a second section 22. The first section 21 is separable from the second section 22 at the insert perforation 21b. The first section inner surface 21d has a diameter large enough to allow a 3 cc or 5 cc hypodermic syringe to be inserted. The second section inner surface 22b has a diameter large enough to allow a 3 cc or 5 cc hypodermic syringe to be inserted. The first section inner surface 21d and the second section inner surface 22b typically have the same diameter that allows the first section inner surface to be radially flush with the second section inner surface. As is know in the art the first section inner surface 21d diameter and the second section inner surface 22b diameter are substitutable for various sizes depending on the size of the hypodermic syringe to be inserted into the first section 21 and the second section 22. The first section outer surface 21a diameter is radially flush with the second section outer surface 22a. The first section second outer surface 21f diameter is greater than the first section first outer surface 21a. The transition from the first section first outer surface 21a to the first section second outer surface 21f is in the shape of a tapered cylinder or a cone. The length of the cone is equivalent to the distance between the disposable insert annular ridge 23e and the ninth edge 12h as shown in FIG. 1. The first section second outer surface 21f is about the same diameter as the diameter of the third inner surface 12c. The first section first outer surface 21a and the second section outer surface 22a is about the same diameter as the first inner surface 11b and the fourth inner surface 13b. The fit between the first section first outer surface 21a and the second section outer surface 22a is a snug-fit with the first inner surface 11b and the fourth inner surface 13b. A cover 30 is positioned on the second end 22d with a cover outer surface 30a and cover inner surface 30b defining the thickness of the cover 30. The cover inner surface 30b diameter is slightly larger than the first section second outer surface 21f diameter providing a snug-fit when the cover 30 is positioned on the second end 22d. A first section annular lip 21e is located on the first section inner surface 21d where the first section first outer surface 21a begins transitioning to the first section second outer surface 21f. The first section annular lip 21e allows the hypodermic syringe 25, as shown in FIG. 5, to snugly-fit into the disposable insert 20. Finally, on the first end 22c there is a connection means that in the preferred embodiment of the invention is a second section male thread 21c. This second section male thread 21c is rotatably positioned into the fifth female thread 16b of the dose measuring applicator 18 as shown in FIG. 2. The second section male thread 21c is rotatably positioned until there is a snug-fit between it and the fifth female thread 16b. Alternately, the second section male thread 21c is substitutable for a female thread in another application. FIG. 4 shows the end view of the disposable insert with the second end 22d and the first section annular lip 21e. A hypodermic syringe (not shown) is inserted into the disposable insert 20 until it snugly-fits against the first section annular lip 21e. FIG. 6 shows apparatus 10 being loaded into a well counter 28. The well counter 28 typically has an insert 27 that the apparatus 10 is set into to allow the hypodermic syringe 25 to be loaded and measured at the well counter 28. The dose measuring applicator 18 is attached to the disposable insert 20 that has a hypodermic syringe 25 loaded into it. The apparatus 10 has the second body (not shown) removed from the first body 11 and the third body 13 before being loaded into the well counter 28. The radiation emitted from the radiopharniaceutical 26 in the hypodermic syringe is still shielded by apparatus 10 as the hypodermic syringe 25 is being loaded into the well counter 28. The dose measuring applicator 18 is pushed in the direction of the arrow 31 to load the syringe 25 into the well counter 28. The well counter typically contains shielding of radiation from the radiopharmaceutical. When the radiation from the radiopharnaceutical 26 has been measured in the well counter 28 the dose measuring applicator 18 is pulled in the opposite direction of arrow 31 inserting the disposable insert 20 that contains the hypodermic syringe back into the protective shielding of apparatus 10. FIG. 7 illustrates apparatus 10 with the hypodermic syringe 25 in another embodiment of the invention where the radiopharmaceutical 26 in hypodermic syringe 25 can be injected into a patient. The first body 11 is the radionuclei shield surrounding the disposable insert 20 with the hypodermic syringe 25 filled with a radiopharmaceutical 26. The radiation shield is constructed of various radiation shielding materials including, but not limited to, lead and tungsten. When the radiopharmaceutical 26 is going to be injected into a patient the second section 22 of the disposable insert 20 is removed from the first section 21 at insert perforation 21b. This is accomplished without exposing anyone to the radiation emanating from the radiopharmaceutical 26. The hypodermic syringe is ready to be injected into a patient once the needle cover 32 is removed. While there has been illustrated and described what is at present considered to be the preferred embodiment of the invention, it should be appreciated that numerous changes and modifications are likely to occur to those skilled in the art. It is intended in the appended claims to cover all those changes and modifications that fall within the spirit and scope of the present invention.
	claims	1. A nuclear reactor steam generator, comprising:three or four plenums proximate with a first plane;three or four plenums proximate with a second plane; anda plurality of steam-generating tubes that form a coolant flowpath from one of the three or four plenums located proximate with the first plane to at least one of the three or four plenums proximate with the second plane,wherein the steam generator is configured to be installed in a reactor vessel such that the first plane intersects a bottom portion of a riser column positioned in the reactor vessel and the second plane intersects a top portion of the riser column,wherein each of the three or four plenums proximate with the first plane and each of the three or four plenums proximate with the second plane includes an approximately flat tubesheet that faces in a direction of a middle portion of the riser column, andwherein the approximately flat tubesheet includes a plurality of perforations, the perforations being of lower density near an edge closer to the riser column than near an edge closer to a reactor vessel wall. 2. The nuclear reactor steam generator of claim 1, wherein each of the three or four plenums proximate with the second plane is directly above a corresponding one of the three or four plenums proximate with the first plane. 3. The nuclear reactor steam generator of claim 1, wherein at least some of the plurality of perforations include an orifice for reducing pressure at an inlet of a steam-generating tube. 4. The nuclear reactor steam generator of claim 3, wherein the orifice included with the at least some of the plurality of perforations introduces a pressure drop of at least 15.0% of an overall pressure drop brought about by a length of steam generator tubing extending between a first plenum located at the first plane and a second plenum located at the second plane. 5. The nuclear reactor steam generator of claim 1, wherein certain ones of the plurality of steam-generating tubes are interleaved with certain other ones of the plurality of steam-generating tubes. 6. A nuclear reactor steam generator, comprising:a top portion having three or four plenums disposed in a plane around a riser column, wherein:each of the three or four plenums includes an approximately flat tubesheet that faces a bottom portion of the steam generator, andwherein the approximately flat tubesheets of the plenums include a plurality of perforations, andwherein the plurality of perforations changes in density between an area near an inner edge of the plenums and an area near an outer edge of the plenums. 7. The nuclear reactor steam generator of claim 6, wherein the density of the perforations changes from a smaller number at the area near the inner edge of the at least one plenums to a larger number near the outer edge of the at least one plenums. 8. The nuclear reactor steam generator of claim 6, wherein the plurality of perforations is arranged into a plurality of concentric arcs. 9. The nuclear reactor steam generator of claim 6, wherein each perforation of the plurality of perforations is between 15.0 and 20.0 mm in diameter. 10. A nuclear reactor steam generator, comprising:three or four means for inletting a working fluid, wherein each of the means for inletting the working fluid are disposed around a riser column at a first height and are each approximately perpendicular to a longitudinal axis of the riser column;three or four means for outletting a working fluid, wherein each of the means for outletting the working fluid are disposed around the riser column at a second height and are each approximately perpendicular to the longitudinal axis of the rise column; andmeans for conducting heat to the working fluid from a reactor coolant and conveying the working fluid from at least one of the means for inletting to at least one of the means for outletting,wherein each of means for inletting comprise approximately flat tubesheets that face a bottom portion of the steam generator, andwherein the approximately flat tubesheets of the means for inletting each include a plurality of perforations, and a number of the plurality of perforations per unit of area of at least one of the approximately flat tubesheets changes between an area near an inner edge of each respective means for inletting and an area near an outer edge of each respective means for inletting. 11. The nuclear reactor steam generator of claim 10, wherein the means for inletting and the means for outletting comprise means for reducing a pressure of the working fluid. 12. The nuclear reactor steam generator of claim 10, wherein the approximately flat tubesheets couple the means for inletting to the means for conducting heat to and conveying the working fluid. 13. The nuclear reactor steam generator of claim 10, wherein each of the means for outletting comprise approximately flat tubesheets that face the top portion of the steam generator. 14. The nuclear reactor steam generator of claim 13, wherein the approximately flat tubesheets couple the means for outletting to the means for conducting heat to and conveying the working fluid. 15. The nuclear reactor steam generator of claim 13, wherein the approximately flat tubesheets of the means for outletting each include a plurality of perforations, and a number of the plurality of perforations per unit of area of at least one of the approximately flat tubesheets changes between an area near an inner edge of each respective means for outletting and an area near an outer edge of each respective means for outletting. 16. A nuclear reactor steam generating system, comprising:a nuclear reactor comprising a riser column; anda steam generator installed around the riser column, the steam generator comprising:first, second, and third plenums proximate with a first plane, the first plane intersecting a bottom portion of the rise column,first, second, and third plenums proximate with a second plane, the second plane being approximately parallel with the first plane and intersecting a top portion of the riser column; anda plurality of steam-generating tubes that form a coolant flowpath from one of the first, second, and third plenums located proximate with the first plane to at least one of the fourth, fifth, and sixth plenums proximate with the second plane,wherein the first, second, and third plenums proximate with the first plane and the first, second, and third plenums proximate with the second plane include approximately flat tubesheets that faces in a direction of a middle portion of the column, andwherein the approximately flat tubesheets include a plurality of perforations, the perforations being of lower density near an edge closer to the riser column than near an edge closer to a reactor vessel wall.
	description	This application is a continuation of U.S. patent application Ser. No. 15/225,571, entitled “High Efficiency Power Generation System and System Upgrades,” filed Aug. 1, 2016, which is a continuation-in-part of U.S. patent application Ser. No. 14/742,760, entitled “High Efficiency Power Generation System and System Upgrades,” filed Jun. 18, 2015, now U.S. Pat. No. 9,404,394, issued Aug. 2, 2016, which is a continuation of U.S. patent application Ser. No. 14/451,863, entitled “High Efficiency Power Generation System and System Upgrades”, now U.S. Pat. No. 9,068,468, issued Jun. 30, 2015, which is a continuation of U.S. patent application Ser. No. 13/971,273, entitled “High Efficiency Power Generation System and System Upgrades,” now U.S. Pat. No. 8,826,639, issued Sep. 9, 2014, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/691,955, entitled “HiEff Mod.” filed on Aug. 22, 2012, which applications are incorporated herein by reference. The present invention is directed, in general, to power generation systems and, more specifically, to a system and method for employing a Brayton closed-cycle power generator to produce electricity and provide a thermal source for a thermally driven load. Burning coal to produce electrical power is one of the critical 21st century power generation dilemmas. Fifty-five percent of global power comes from burning coal. The resulting flue gas emissions from burning coal contain a broad spectrum of intractable climate-change and health-compromising compounds. For instance, carbon dioxide, a climate changing gas, is virtually impossible to economically eliminate in power-generating facilities. The use of natural gas instead of coal reduces, but does not eliminate the carbon dioxide. Both coal and natural gas also discharge ozone-producing gasses and soot particulates, which are costly to extract from exhaust and flue gas. Natural gas infrastructure for domestic space and water heating is fully developed as a preferred fuel source. It is advantageous for ground transportation and as feedstock for a broad range of chemical processing. The available natural gas stores, however, are much more limited than coal. The use of natural gas for electrical power generation appears to be misguided in the long term. To provide a perspective, the Tennessee Valley Authority (“TVA”) Kingston Fossil Plant, burns about 14,000 tons of coal a day, but produces over 50,000 tons of carbon dioxide per day. Their discharge of ozone and particulate emissions is not stated. This plant powers 700,000 homes, but requires daily delivery of 140 freight-car loads of coal that must be dug out of the ground and transported to Kingston. Coal extraction, cross country delivery, on site handling and burning can be directly related to human costs, and can be directly related to mounting environmental degradation for just this one plant. About twenty percent of world power is produced from water-cooled nuclear fission with varying degrees of public acceptance, from passive but reluctant acceptance to hysterical fear and absolute demands for nuclear power elimination. Existing nuclear power plants provide inherent risks, but are engineered and operated to exceptional safety standards. Nuclear power plants were originally designed for a 20-year life. An increasing number of nuclear plants are approaching an age of 60 years. Ten- and 20-year operating license extensions have been repeatedly granted after comprehensive examinations and analysis. Satisfying solutions to plant aging are elusive. Population growth, rising standards of living and economic growth are putting worldwide electrical grid generating capacity margins at risk. Conservation and alternative generating sources are helpful, but are not expected to meet the growing demand. In addition, electrical demand growth to power the growing worldwide demand for air conditioning and the anticipated demand for electric cars are projected to further over stress the capacity of existing grids. Clearly, there is a growing demand for more electrical power, but current methods of power generation are problematic and unsustainable. In 1824, Sadi Carnot described the ultimate heat engine efficiency limit of a perfect engine dependent on the highest heat-input temperature and the lowest waste-heat rejection temperature. Rankine, Diesel, Otto and Brayton conceived basic power-generation engine cycles and others have refined these basic engines. The Atkinson cycle is a recent improvement of the Otto and Diesel cycles. General Electric (“GE”) and Siemens have developed open gas turbine/steam combined-cycle power plants. Each has made unique contributions to power production technology. Steam-based Rankine cycle engines dominate electric power generation. A Rankine-cycle engine has two possible energy sources, burning coal or other fossil fuels, and nuclear fission. In both, superheated steam at high pressure drives a turbine that in turn drives an electrical alternator. A steady, continuous, recirculating flow of water and steam flows through a boiler, turbine, condenser and water pump in this closed system. The heat source is external combustion of coal, sub-grade hydrocarbons or natural gas, or from a boiling-water nuclear reactor. Waste heat is rejected from the turbine exhaust at or near ambient dew-point temperatures in a steam-condensing heat exchanger. This low temperature waste heat rejection temperature is key to normal cycle efficiencies in the 35 percent (“%”) to 40% range. However, the continuous, superheated, steam turbine inlet temperature is limited to about 1000 degrees (“°”) Fahrenheit (“F”) to avoid hydrogen embrittlement of the turbine blades. This material limitation precludes higher efficiencies from operating at higher superheated steam temperatures. This superheated steam temperature limit exists for both combustion and nuclear heat sources. Coal-fired units produce electricity by burning coal in a boiler to heat water to produce steam, generally employing a coal/fossil fueled, closed Rankine cycle (steam) power plant. Steam, at tremendous pressure, flows into a turbine, which spins a generator to produce electricity. The steam is cooled, condensed back into water, and the water is pumped back to the boiler to continue the process. For example, the coal-fired boilers at TVA's Kingston Fossil Plant near Knoxville, Tenn., heat water to about 1000° F. (540° Celsius (“C”)) to create steam. The steam is piped to turbines at pressures of more than 1,800 pounds per square inch (130 kilograms per square centimeter). The turbines are connected to the generators and spin them at 3600 revolutions per minute to make alternating current electricity at, e.g., 20,000 volts. River water is pumped through tubes in a condenser to cool and condense the steam discharging from the turbines. The Kingston plant generates about 10 billion kilowatt-hours a year, or enough electricity to supply 700,000 homes. As mentioned previously hereinabove, to meet this demand Kingston burns about 14,000 tons of coal day, an amount that would fill 140 railroad cars daily. The open Brayton cycle is generally used in gas turbine and combined-cycle power plants that burn liquid or gaseous fossil fuels, and produce refractory environmental stressors. The turbine blades and other structures formed of superalloy materials to limit oxidation and creep temperature properties, however, limit turbine operating temperatures to about 2000° to 2100° F. Complex internal turbine blade cooling systems enable turbine inlet gas temperatures to exceed 2500° F., but these high temperatures produce a full range of harmful ozone activators and high levels of nitrous and nitric oxides (“NOx”). Typical turbine exhaust temperatures of 500° to 700° F. compromise efficiency to mid-40 percent range. In conventional fossil-fueled power plants, whether designed for steam or gas turbines, the combustion products are ozone-producing gases, carbon dioxide, and particulate soot that are environmental stressors. These toxic exhaust products cannot be easily eliminated, and are costly to reduce. Climate stability-challenging carbon dioxide removal from coal fired boilers is not practical at this time. In nuclear powered power-generating plants, high-pressure steam is produced by contact cooling of water with fission-reacting fuel rods. In the heating process, the circulating water and steam become radioactive. This large mass of radioactively contaminated water is an unavoidable and an unfortunate side effect in all existing nuclear power plants. Consequently, all existing nuclear plants must absolutely prevent water and steam venting or leakage. They must also be actively controlled in all operating modes to prevent “melt down” and accompanying water dissociation, hydrogen explosions, and uncontrolled spread of radioactive gases, liquids, and particles. Prevention of these types of failures is a high tribute to comprehensive and exhaustive excellence in engineering, manufacturing, and vigilant operation in a safety culture. Notwithstanding these precautions, three reactor meltdowns have happened in the past half century including Three Mile Island without injuries. Another incident occurred at Chernobyl with 31 on-site deaths and long-term evacuation of a 1000 square mile region, plus undisclosed, high human and animal sickness and early deaths. In 2011, multiple melt downs at the Japanese Fukushima power plants followed a tsunami with monumental tragedies. Limitations of conventional power generation approaches have now become substantial hindrances for wide-scale power generation with high efficiency and low levels of undesirable environmental pollutants. No satisfactory strategy has emerged to provide a sustainable, long-term solution for these issues. Accordingly, what is needed in the art is a new approach that overcomes the deficiencies in the current solutions. These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by advantageous embodiments of the present invention, in which a power generation system includes an inert gas power source, a thermal/electrical power converter and a power plant. The inert gas power source is formed with an input and an output. The thermal/electrical power converter includes a compressor with an output coupled to the input of the inert gas power source. The power plant has an input coupled in series with an output of the thermal/electrical power converter. The thermal/electrical power converter and the power plant are configured to serially convert thermal power produced at the output of the inert gas power source into electricity. The thermal/electrical power converter includes an inert gas reservoir tank coupled to an input of the compressor via a reservoir tank control valve and to the output of the compressor via another reservoir tank control valve. The reservoir tank control valve and the another reservoir tank control valve are configured to regulate a temperature and/or pressure of the output of the thermal/electrical power converter. 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, which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes 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. Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated, and may not be redescribed in the interest of brevity after the first instance. The FIGUREs are drawn to illustrate the relevant aspects of exemplary embodiments. The making and usage of the present exemplary embodiments are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the systems, subsystems and modules associated with a process for producing a thermal power source. Combined gas/steam cycle power generation employing open Brayton-closed Rankine combined cycles includes both fuel-burning gas turbine and fuel-burning steam turbine generators. Hot turbine exhaust energy is recovered in a boiler to partially generate steam and superheated steam of a steam power plant. A combined-cycle power generation arrangement, however, requires a full complement of complex and costly components and controls, with full facility costs of both a high performance gas turbine and a complete steam power plant. There remains a complex and broad range of ultra-high temperature combustion and environmental stressors that offset or diminish some of the value of combined-cycle power generation arrangements. U.S. Pat. No. 5,431,016, entitled “A High Efficiency Power Generation,” to W. E. Simpkin, issued Jul. 11, 1995, (hereinafter “Simpkin 1”), which is incorporated herein by reference, describes a power generating system formed with a light gas reactor powered by a closed Brayton cycle that discharges waste heat to supply energy for a steam-based Rankine cycle. The physical application is directed to specifying carbon-carbon materials in all ultra-high temperature locations. Simpkin 1 employs an ultra-high temperature light gas to benefit from energy efficiency advantages of the two cycles while reducing limitations of each. Simpkin 1 is an advance using Carnot's principles to produce higher efficiency power generation. A holistic approach is described that enhances overall, compound-cycle efficiency. Simpkin 1 also includes design concepts for piping and pressure vessels containing very high temperatures within a conventional steel structure. A portion of Simpkin 1 was issued later as U.S. Pat. No. 5,896,895, entitled “Radiation Convection Conduction Heat Flow Insulation Barriers,” to W. E. Simpkin, issued Apr. 27, 1999, (hereinafter “Simpkin 2”), which is incorporated herein by reference. The original insulation concept is retained in the “High Efficiency Power Generation” descriptions disclosed in Simpkin 1. Light gas (e.g., helium, “He”) reactors are generally referred to as Generation IV Emerging Nuclear Power Reactors, which have a long Research and Development (“R&D”) history motivated by inherent safety aspects. Helium is a unique, totally stable gas at all pressures and temperatures encountered in the reactor designs. Helium does not become radioactive, even in high intensity radiation or at very high temperatures. It does not change state and is absolutely inert. Helium does not interact chemically with organic or inorganic atoms or molecules. Its inertness is absolute even to surface effects. Helium does not ionize at temperatures encountered in reactor-cooling applications and does not change its atomic structure. Advanced nuclear technology is globally coordinated by the Generation IV International Forum. Two of the six Generation IV nuclear reactor development programs are helium cooled. The Very High Temperature Reactor (“VHTR”) is a thermal reactor in full scale prototype build in 2013, and the Gas Cooled Fast Neutron Breeder Reactor (“GFR”) now undergoing component testing and development is seven to ten years later for deployment than the VHTR. These two helium-cooled reactors are significantly different in their neutron action processes and life cycles. As producers of very high temperature helium flows, they are quite similar. Applications using the VHTR and the GFR are described herein as functionally interchangeable for providing a thermal source of very high temperature helium. The GFR has been projected to beneficially reduce the difficult and costly nuclear waste storage problem. Existing nuclear waste could provide a very low cost fuel supply for decades, if not centuries, in GFR power production. The GFR is a fast neutron breeder reactor that extracts nearly all of the potentially fissionable material, leaving low-level residual radiation waste. Fourth Generation nuclear power plants include helium-cooled (light gas) reactors because they are inherently safer and environmentally benign. A thermal-version VHTR and a GFR provide probable further growth potential beyond today's high performance for both reactors. The VHTR is a graphite-moderated, helium-cooled reactor with a thermal neutron spectrum. The VHTR is designed to be a high-efficiency system, which can supply electricity and process heat to a broad spectrum of high-temperature and energy-intensive processes. A U.S. Department of Energy (“DOE”) reference reactor formed with a 600 megawatt thermal (“MWth”) core connected to an intermediate heat exchanger can deliver process heat, e.g., up to 900° C. (1652° F.). The reactor core can be a prismatic block core or a pebble-bed core according to a structure of the fuel particles. Fuel particles are coated with successive material layers that are high-temperature resistant, and are then formed either into fuel compacts or rods that are embedded into hexagonal graphite blocks for a prismatic block-type core reactor, or are formed into graphite coated pebbles for a pebble-bed core. The reactor produces heat with core outlet helium temperatures up to about 1000° C. The closed helium circuit can enable non-power producing applications such as hydrogen production or process heat for the petrochemical industry. Thermal processes requiring lower temperature than that supplied by a reactor supply could be configured to supply an application-specific compressor-turbine-generator set providing an application-specified turbine discharge temperature. As an application of a nuclear heat-generating process, hydrogen can be efficiently produced from only heat and water by using a thermochemical iodine-sulfur process, or a high temperature electrolysis process, with additional natural gas, by applying a steam-reformer technology. A prototype VHTR is being fabricated in 2013 for demonstration trials in the mid-2010s, and component and sub-system testing have demonstrated inherent safety characteristics of a GFR. Thus, a VHTR offers a thermal source for high-efficiency electricity production and a broad range of process heat applications while retaining desirable safety characteristics in normal as well as off-normal events. The basic technology for the VHTR has been well established in former high temperature gas reactor plants such as the United States Fort Saint Vrain and Peach Bottom prototypes, and the German AVR and THTR prototypes. The technology is being advanced through near- or medium-term projects lead by several plant vendors and national laboratories, such as PBMR, GTHTR300C, ANTARES, NHDD, GT-MHR, and NGNP in South Africa, Japan, France, Republic of Korea, and the United States. Experimental reactors such as the HTTR in Japan (30 MWth) and the HTR-10 in China (10 MWth) support advanced concept development, as well as cogeneration of electricity and nuclear heat production applications. The GFR system employs a fast-neutron spectrum, helium-cooled reactor and a closed fuel cycle. The DOE Generation IV GFR demonstration project uses a direct-cycle helium turbine for electricity generation, or can optionally use its process heat for production of hydrogen. Through the combination of a fast neutron spectrum and full recycling of actinides, the GFR reduces the production of long-lived radioactive waste. The fast neutron spectrum of the GFR also makes it possible to use available fissile and fertile materials (including depleted uranium) much more efficiently than thermal spectrum gas reactors that employ once-through fuel cycles. Several fuel forms are candidates that hold the potential for operating at very high temperatures and ensure excellent retention of fission products. The fuel forms include composite ceramic fuel, advanced fuel particles, or ceramic-clad elements of actinide compounds. Core configurations can be based on pin- or plate-based assemblies or on prismatic blocks. A DOE Generation IV GFR reference cites an integrated on-site “nuclear waste” refabrication plant GFR fuel supply. Through the combination of a fast neutron spectrum and full recycling of actinides, the GFR develops very low-cost power and reduces the production of long-lived radioactive waste. As introduced herein, a compound electrical power generator is formed having two interdependent closed-cycle turbine-driven alternators. A closed-cycle Brayton inert (e.g., helium) gas turbine/alternator power generation system is coupled to and supplies superheated steam to a closed-cycle Rankine steam turbine/generator. An overhauled candidate, a retired or new Rankine steam turbine/generator, is employed for the Rankine power-generation process. The Rankine steam turbine/generator receives steam at controlled quantities, pressure, and temperature from energy extracted from heat exchangers from high temperature, helium turbine outflow gas produced by the Brayton power generation system. A Brayton-cycle gas turbine is powered by an inert light gas reactor (e.g., a VHTR or GFR). The steam temperature supplied to the Rankine steam turbine/generator system is set and controlled to an application-dependent temperature level sufficient to power the Rankine steam turbine/generator load. The turbine employed in the Brayton power generation system has a low, tailored pressure ratio, and a low-cost compressor and gas turbine. Thus, the Brayton power generation system produces power and provides superheated steam according to specification for integration into an existing steam turbine generator to form a compound power plant. In an embodiment, the Brayton power generation system provides power for a thermally driven chemical or refining process such as hydrogen production or petroleum refining. Such chemical or refining process can be endothermic or exothermic. The power-generation architectures introduced herein come at a time in technology development in which safety, health, and environmental factors are of greater consequence than achieving record system efficiencies. Profound advances in health and safety, and elimination of environmental stressors can be achieved with described modifications of an existing utility power plant. In addition, the modifications introduced herein can readily increase existing plant capacities by 40% or more, with potential for further capacity growth. The power generation modifications are equally suitable for either fossil-fuel fired or nuclear power plants. The heat source system and boiler of an existing fossil-fueled or nuclear power plant would be removed. The remainder of the plant, steam turbine, alternator, condenser, pumps, and electrical- and control-system elements continue in use as before. Additional large economic savings come from using the same site, the same electrical distribution system, the same support and physical infrastructure, and unchanged cooling water supply and steam condenser systems. As introduced herein, modifications of a steam generator provide a large increase in compound plant capacity and efficiency. Re-fabricated “nuclear waste” can provide an abundant supply of low-cost fuel for the GFR. These economic leverages provide incentives for implementing a high efficiency modification of a moth-balled plant or in lieu of a necessary major overhaul. A modified power plant can provide substantial financial benefits to a utility. Valuable assets can be reclaimed, including the site, rotating systems, cooling condensing system, electrical infrastructure/grid connections, and functional elements of the business infrastructure. Thus, a substantial plant capacity increase can be obtained that uses abundant, low-cost fuel, thereby providing a safer and cleaner power-generation solution than previously employed. Turning now to FIG. 1, illustrated is a diagram of an embodiment of a power generation system. The power generation system includes two, interdependent, closed-loop thermal/electrical power systems with a Brayton closed-loop power generation and processing system, and a Rankine closed-loop power processing system. The elements illustrated in FIG. 1 are not drawn to scale. A thermal/electrical power converter 102 is formed with a generator (such as an alternator) 110, a gas turbine 112, and a compressor 114, all mechanically coupled via a rotatable shaft 130. An electrical power output 111 of the generator 110 may be coupled through switchgear and an optional power converter 113 to a power grid 106, such as an alternating current (“ac”) or a direct current (“dc”) power grid. The generator 110 is an electro-mechanical device that can produce either an ac output or a dc output according to its design. The term “alternator” will be used herein to refer to an electro-mechanical device that can produce an ac output. The switchgear and an optional power converter 113 may include an ac transformer and an inverter. In an embodiment, the optional power converter 113 can be employed to convert a dc output of the generator 110 to ac at a frequency suitable for connection to the power grid 106. In an embodiment, the optional power converter 113 can be employed to convert an ac output of the generator 110 at one frequency to another frequency suitable for connection to the power grid 106. An optional gear box may be coupled between the gas turbine 112 and the generator 110 to provide a different rotation rate of the generator 110 relative to that of the gas turbine 112. An input 124 of the gas turbine 112 is coupled to a high-temperature, high-pressure, inert gas thermal power source (referred to as an “inert gas power source” or “inert gas thermal power source”) 101, such as a VHTR or GFR helium-cooled, light gas reactor. An example high-temperature, high-pressure helium cooled gas power source is illustrated and described hereinbelow with reference to FIG. 4. Other inert gases such as, without limitation, argon, xenon, and neon, are contemplated within the broad scope of the present invention as a heat-transfer/working fluid medium for an inert gas power source. Also, other power sources such as a source of combusted fossil fuel (see, e.g., U.S. Pat. No. 5,431,016, previously incorporated by reference) can also be used for the power generation system. A low-pressure output 128 of the gas turbine 112 is coupled to a high-temperature input 129 of a heat exchanger 140. A low-pressure output 126 of the heat exchanger 140 is coupled to a low-pressure input 123 of the compressor 114. A high-pressure output 121 of the compressor 114 is coupled to an input of the inert gas power source 101 via return line 122. An inert gas reactor such as a VHTR or a GFR can introduce dust particles into the inert gas flow, particularly with a pebble-bed reactor. Over time, dust particles can erode gas turbine and compressor blades, and even inert gas piping at piping bends. To remove such dust particles from the inert gas flow, a filter 131 can be installed between the low-pressure output 126 of the heat exchanger 140 and the low-pressure input 123 of the compressor 114, which is a low temperature position to install a filter 131. In an embodiment, such filter 131 can have a minimum equivalent reporting value (“MERV”) of 7. The thermal/electrical power converter 102 is assumed herein to be operable between its input and a combined output that includes the electrical power output 111 of the generator 110 and a thermal output between a high-temperature steam output 142 and a low-temperature, liquid-water input 144 of the heat exchanger 140 with very highly efficient power conversion. This assumes that the generator 110 is operable with substantially 100% power conversion efficiency. A practical generator operable to convert mechanical shaft power to an electrical output in a high-power plant can generally achieve a power conversion efficiency in the mid- to high-90% range, and the slightly imperfect power conversion efficiency of such a high-power generator is ignored herein. Such mechanical-to-electrical power conversion plants are not limited by a second-law efficiency constraint imposed by a Carnot cycle. The high-temperature steam output 142 of the heat exchanger 140 is coupled to an input 143 of a thermally driven Rankine-cycle power plant (also referred to as a “power plant”) 104. In an embodiment, the thermal energy produced at the high-temperature steam output 142 of the heat exchanger 140 provides the power input to the power plant 104, which can be an existing, modified steam-driven plant. A high-pressure, cooled-water output 145 of the power plant 104 is coupled to the low-temperature, liquid-water input 144 of the heat exchanger 140. Thus, substantially the entire thermal output of thermal/electrical power converter 102 is supplied to the power plant 104, with exception of the small inefficiency of the generator 110. No substantial thermal sink need be coupled to the thermal/electrical power converter 102 with exception of modest cooling for the generator 110. Pipeline pressure losses are included in calculating heat exchanger pressure drops for convenience in calculating system performance evaluations. A small pressure drop at the input side of the heat exchanger 140 does not contribute to system inefficiency. The small pressure drop of the heat exchanger 140 is simply accommodated by operating pressure differences between the compressor 114 and the gas turbine 112. Thermal content of heated water or other heated fluid that may be employed to cool the generator 110 (or other system elements) may be employed to preheat the low pressure, cooled helium at the high-temperature steam output 142 of the heat exchanger 140 before being supplied to the compressor 114 to provide a further efficiency enhancement to the thermal/electrical power converter 102. The power plant 104 is operable in a conventional way. High-pressure, high-temperature steam from the high-temperature steam output 142 of the heat exchanger 140 is coupled to a high-pressure, high-temperature input of a gas turbine 152 of the power plant 104. A generator 150 of the power plant 104 is mechanically coupled to a rotatable shaft of the gas turbine 152, and an electrical power output 151 of the generator 150 may be coupled to the power grid 106 through a switchgear and an optional power converter 153 that may be similar in function to the switchgear and optional power converter 113 described previously hereinabove. The power grid to which the generator 150 is coupled can be the same or different power grid to which the generator 110 of the thermal/electrical power converter 102 is coupled. A low-pressure, steam output 154 of the gas turbine 152 is coupled to an input of a heat exchanger/condenser 156 of the power plant 104. A low-temperature output 155 of the heat exchanger/condenser 156 conducting low-pressure, cooled water is coupled to a low-pressure input of a water pump 160 of the power plant 104. A high-pressure water output of the water pump 160 is coupled to the low-temperature, liquid-water input 144 of the heat exchanger 140. A high-temperature water output 158 of the heat exchanger/condenser 156 is coupled to a low-temperature thermal sink such as cooling water supplied from a river. A low-temperature (e.g., 40 to 80° F.) liquid-water input 159 of the heat exchanger/condenser 156 is coupled to the low-temperature thermal sink. The heat exchanger/condenser 156 can be an unchanged steam condenser for waste heat rejection to a cooling water subsystem in a thermally-driven process. In a manner similar to that described hereinabove for the helium filter 131 installed after the low-pressure output 126 of the heat exchanger 140, a water filter can be introduced into the cold water return between the heat exchanger/condenser 156 and the heat exchanger 140 to remove suspended particles. The overall power-conversion efficiency of the power generation system illustrated in FIG. 1 is the summed electrical outputs of the generators 110, 150 divided by the thermal input measured between the input 124 of the gas turbine 112 and the high-pressure output 121 of the compressor 114 (to the inert gas power source 101), and can be of the order of 45 to 50% or more in a practical plant. The overall thermal efficiency of a typical nuclear-, natural gas-, oil-, or coal-fueled power plant is typically in the mid-thirties percent, and is limited by the Carnot efficiency of practical Rankine cycle gas turbine/compressor power converters. Overall efficiency of a front-end thermal/electrical power converter 102 as introduced herein is not so limited. In an example embodiment, the inert gas power source 101 provides an inert gas thermal source at a temperature of about 1650° F. with an energy flow of about 1100 MWth to the input 124 of the gas turbine 112. It is contemplated that the inert gas power source 101 can produce an inert gas at a temperature as high as 2500° F. or more (1650° F. in an example), and that left-over thermal energy at a lower temperature produced by the inert gas power source 101 can be fully utilized to power a thermally driven, closed-loop, Rankine cycle steam power system or other thermally powered process such as, for example, a chemical reactor that produces gaseous hydrogen. The shaft output power in this example of the gas turbine 112 is about 230 thermal megawatts (“MWth”), which is assumed for this example to be converted with 100% efficiency to about 230 electrical megawatts (“MWe”). The heat exchanger 140 produces about 870 MWth, which is the difference between the 1100 MWth produced by the inert gas power source 101 and the 230 MWe produced by the generator 110. It is also contemplated that efficient gas turbine-compressor-generator sets will rotate at controlled rotational speeds of 20,000 revolutions per minute or more. It is further contemplated that gas turbine blades formed of carbon-carbon composite materials or superalloys such as Hastelloy, Inconel, Waspaloy, and Rene alloys will be able to sustain such rotational speeds at temperatures as high as 2800° F. Nonetheless, a practical highly efficient thermal/electrical power converter plant can be formed with lower rotational speeds and lower operating temperatures. The low-pressure output 128 of the gas turbine 112 is regulated to a temperature of about 960° F. by controlling the amount of inert gas in the inert gas power source 101 with a first reservoir tank control valve 117 and a second reservoir tank control valve 118, each reservoir tank control valve coupled to and in series with an inert gas (e.g., helium) reservoir tank (also referred to as a “reservoir tank”) 116. The reservoir tank 116 provides a thermal sizing function for matching the helium mass flow in the thermal/electrical power converter 102 to the thermal power requirement of the thermally driven process load coupled thereto, which can be an existing, functioning system that was previously powered by a carbon combustion-based or a nuclear power-based power source. The reservoir tank 116 is coupled to the low-pressure input 123 of the compressor 114 via the first reservoir tank control valve 117 and the high-pressure output 121 of the compressor 114 via the second reservoir tank control valve 118 and is configured to regulate a power output and/or a temperature of the inert gas power source 101 and/or the thermal/electrical power converter 102. As an example, if a 900 MWe steam plant is supported by three manifolded thermal/electrical power converters 102, the helium supply for each provided by the reservoir tank 116 would be “vernier” trimmed employing respective first and second reservoir tank control valves 117, 118 for substantially perfect load sharing while providing a specified temperature at the output 128 of the gas turbine 112. In a variable turbine speed plant that provides a dc output, the first and second reservoir tank control valves 117, 118 could be employed to vary the temperature or the output power at the output 128 of the gas turbine 112. In a system employing a fixed rotation rate for the gas turbine 112, the first and second reservoir tank control valves 117, 118 could be employed for load following. This is unique because all system temperatures would be fixed and part load efficiency would be a substantially invariant over a range of the electrical load coupled to the system. In an embodiment, the gas turbine 112 is operated at substantially a constant speed of rotation so that the generator 110 coupled to the rotatable shaft 130 of the gas turbine 112 can produce an ac output at a substantially fixed frequency (e.g., 60 Hertz (“Hz”)). A temperature of the low-pressure cooled helium coupled to the low-pressure input 123 of the compressor 114 is about 100° F. The first reservoir tank control valve 117 is coupled to the low-pressure output 126 of the heat exchanger 140. The second reservoir tank control valve 118 is coupled to the return line 122 from the high-pressure output 121 of the compressor 114. Pressure of the helium gas in the reservoir tank 116 is intermediate between the helium pressure at the low-pressure input 123 to the compressor 114 and the helium pressure at the high-pressure output 121 of the compressor 114. By opening the first reservoir tank control valve 117, helium from reservoir tank 116 flows into the closed-cycle helium loop that supplies the inert gas power source 101, thereby increasing the overall helium pressure in the closed-cycle helium loop. By opening the second reservoir tank control valve 118, helium is returned to the reservoir tank 116 from the return line 122, thereby decreasing the overall helium pressure in the closed-cycle helium loop. In this manner, temperature of helium output flow from the inert gas power source 101 is controlled. In an example system, the high-pressure, high-temperature steam produced at the high-temperature steam output 142 of the heat exchanger 140 is about 900° F. The high-pressure steam supplied to the input of the gas turbine 152 is reduced by the gas turbine 152 to low-pressure steam at a temperature of about 80 to 100° F. at the low-pressure, steam output 154 of the gas turbine 152. The generator 150 is mechanically coupled to the rotatable shaft of the gas turbine 152 and produces 300 MWe. The remaining thermal output is transferred to the thermal sink (i.e., cooling water supplied from a river or other substantial body of water). The low-pressure steam at the low-pressure, steam output 154 of the gas turbine 152 is condensed to low-pressure water of about the same temperature in the heat exchanger/condenser 156. The water pump 160 repressurizes the water at its output at substantially the same temperature. The overall compound system efficiency of the power generation system performed by the thermal/electrical power converter 102 illustrated in FIG. 1 is about 230 MWe (produced by the generator 110) plus 300 MWe (produced by the generator 150) divided by 1100 MWth (produced thermally by the inert gas power source 101), which is about 45 to 50%, almost double that of a conventional fuel-burning or nuclear-powered power plant. Turning now to FIG. 2, illustrated is a diagram of an embodiment of a power generation system. The power generation system is formed with a closed-loop thermal/electrical power system with a Brayton closed-loop power generator. The elements illustrated in FIG. 2 are not drawn to scale. Analogous to the power generation system of FIG. 1, the power generation system includes the thermal/electrical power converter 102 formed with the generator 110, the gas turbine 112, and the compressor 114, all mechanically coupled via a rotatable shaft 130. The electrical power output 111 of the generator 110 is coupled through switchgear and the optional power converter 113 to the ac power grid 106. Descriptions of remaining elements of the thermal/electrical power converter 102 that are similar to those describe hereinabove with reference to FIG. 1 will not be repeated in the interest of brevity. The high-temperature steam output 142 of heat exchanger 140 is coupled to a high-temperature thermal input of an endothermic process load (also referred to as a “thermally driven process load”) 240, such as a chemical processing or refining process. In an embodiment, a low-temperature, liquid-water input 144 of heat exchanger 140 is coupled to a cooling water source 258 such as a river or a screen that may provide cooling water at a temperature in the range of 40° F. to 80° F. In an embodiment, the low-temperature, liquid-water input 144 of the heat exchanger 140 is coupled to a low-temperature water output of the thermally driven process load 240. In either case, the low-temperature, liquid-water input 144 can be circulated by a liquid-water pump 260. The endothermic process load 240 is thus substantially wholly powered by the power generation system, with exception of the relatively quite small power required by the liquid-water pump 260 (or, similarly, by liquid-water pump 160 illustrated in FIG. 1). The endothermic process load 240, which can be, without limitation, a chemical or refining endothermic system, can, in an embodiment, be functionally incorporated into the process represented by the heat exchanger 140. In such an arrangement, the endothermic process load 240 can directly use as a thermal source the high-temperature steam (or other working fluid) provided by the process represented by the heat exchanger 140. The output 142 and the input 144 of the heat exchanger 140 could carry a process fluid. In an embodiment, waste heat of the endothermic process load 240 can be directly discharged to a thermal sink, such as a river, or to the atmosphere, with or without a further heat exchanger. The thermally driven process load 240 will generally produce high-temperature steam that can be cooled and condensed in a heat exchanger (e.g., the heat exchanger/condenser 156 illustrated and described hereinabove with reference to FIG. 1). Alternatively, according to the needs of the thermally driven process load 240, the high-temperature steam can be discharged to the atmosphere. Thus, the thermal/electrical power converter 102 can be employed to provide high-temperature steam or other working fluid to a thermally driven process load 240, and at the same time, produce locally generated electricity, all in an environmentally sensitive and safe manner. A power output of (or a temperature in) the power generation system illustrated in FIG. 2 can be regulated in a manner analogous to that described previously hereinabove for the power generation system of FIG. 1 via reservoir tank control valves coupled respectively between an inert gas reservoir tank and an input and an output of the compressor 114. Turning now to FIG. 3, illustrated is a diagram of an embodiment of a heat exchanger 140 of a power generation system. The heat exchanger 140 is formed with a super-heater heat exchanger 310, a boiler heat exchanger 320, and a water preheater heat exchanger 330 coupled in series. The super heater heat exchanger 310 is coupled to a high-temperature input 129 and a high-temperature steam output 142 of the heat exchanger 140. The super-heater heat exchanger 310 is configured to extract thermal energy from the high-temperature inert gas presented at the high-temperature input 129 to super-heated steam at the high-temperature steam output 142. An example temperature of the inert gas presented at the high-temperature input 129 is 960° F. In an embodiment, the inert gas is helium. The temperature of the super-heated steam produced at the high-temperature steam output 142 is 900° F. or higher, depending on the efficiency of the super-heater heat exchanger 310. The super-heater heat exchanger 310 is thus a gas-to-gas heat exchanger. A high-temperature, inert gas input of the boiler heat exchanger 320 is coupled to a reduced temperature, inert gas output of the super-heater heat exchanger 310. A high-temperature steam output of the boiler heat exchanger 320 is coupled to a steam input of the super-heater heat exchanger 310. An example temperature of fluids at these inputs and outputs is about 650° F. The boiler heat exchanger 320 is thus a gas-to-boiling liquid heat exchanger. A further-reduced temperature, inert gas input of the pre-heater heat exchanger 330 is coupled to a low-temperature inert gas output of the boiler heat exchanger 320. A high-temperature water output of the pre-heater heat exchanger 330 is coupled to a hot-water input of the boiler heat exchanger 320. An example temperature of fluids at these inputs and outputs is about 600 to 650° F. A low-temperature, liquid-water input 144 of the heat exchanger 140 is coupled to a low-temperature input of the pre-heater heat exchanger 330, and a low-pressure, low temperature inert gas output of the pre-heater heat exchanger 330 is coupled to a low-pressure output 126 of the heat exchanger 140. An example temperature of fluids at these inputs and outputs is about 80 to 100° F. The pre-heater exchanger 330 is thus a gas-to-liquid heat exchanger. By constructing the heat exchanger 140 with three heat exchangers forming three heat-exchanger stages as described previously hereinabove, high overall heat-exchanger efficiency can be achieved. A practical pressure drop of the inert gas helium of about 4% can be achieved in each of these heat-exchanger stages. The overall pressure drop through the heat exchanger assembly would thus be about (1−0.04)3, which is about 11-12%. The pressure drop of the inert gas flowing through the inert gas power source 101 (see FIG. 1) could be about 5%. The total pressure drop of the three heat-exchanger stages and the inert gas power source 101 (about 16%) is made up by a difference in pressure produced by compressor 114 and that absorbed by gas turbine 112 (again, see FIG. 1). There is no net loss of energy, because the respective inefficiencies due to these pressure drops produce heat that it is ultimately absorbed by the thermally driven process load coupled to the high-temperature steam output 142 of the heat exchanger 140. Turning now to FIG. 4, illustrated is an elevation view of an embodiment of an inert gas power source (e.g., a GFR) 101. A GFR is a fast-neutron breeder reactor operable with a Brayton closed-cycle gas turbine. A GFR employs helium as a core coolant within a containment vessel 405 capable of sustaining high pressure at high temperature. A reactor core 420 is force-convection cooled by helium as a working-fluid that is admitted at a low temperature, such as 460° F., at a low-temperature input 422 of the inert gas power source 101 and is exhausted at a high temperature such as 1650° F. at a high-temperature output 424 of the inert gas power source 101. A power level of the reactor core 420 is controlled by control rods 430. Power levels approaching a gigawatt or more are expected to be achieved in practical designs. The reactor core 420 operates with a fast-neutron spectrum for efficient utilization of uranium and other fissile fuel sources such as thorium that can produce a high gas temperature (e.g., 2000° F. or higher) at the high-temperature output 424. Helium is a preferred coolant because it has a low neutron capture cross-section and does not produce an explosive gas such as hydrogen, which can be produced by dissociation of steam at a high temperature in a water-cooled reactor. Helium has other advantages as a coolant in that it does not condense into droplets at lower temperatures in a turbine, which can erode the surface of turbine blades, and does not produce radioactive isotopes in a nuclear environment. A GFR has attractive fuel-breeding properties, and is operable for many years without a need to recharge the fuel. A new era for standardizing power plant unit production is thus enabled by utilization of a thermal/electrical power converter powered by an inert gas reactor such as a GFR or a VHTR to power a new or existing thermally driven process load. Economically affordable cost to build or renew a power plant by adopting multiple, standardized, high-efficiency modifications adds further advantage. Turning now to FIG. 5, illustrated is a flow diagram of an embodiment of a method for providing power for a thermally-driven process load. The method begins in a start step or module 500. In a step or module 505, an input of a gas turbine is coupled to a high-temperature output of an inert gas power source. In a step or module 510, a super-heater heat exchanger, a boiler heat exchanger, and a water preheater heat exchanger are coupled in series to form a heat exchanger. In a step or module 515, a low-pressure output of the gas turbine is coupled to a high-temperature input of the heat exchanger. In a step or module 520, a low-pressure input of a compressor is coupled to a low-pressure output of the heat exchanger. In a step or module 525, a high-pressure output of the compressor is coupled to a low-temperature input of an inert gas power source. In a step or module 530, a rotatable shaft of the compressor is mechanically coupled to a rotatable shaft of the gas turbine. In a step or module 535, the rotatable shaft of the gas turbine is mechanically coupled to a rotatable shaft of a generator. In a step or module 540, a high-temperature steam output of the heat exchanger is coupled to a high-temperature input of the thermally-driven process load. In a step or module 545, a low-temperature output of the thermally-driven process load is coupled to a low-temperature, liquid-water input of the heat exchanger. In a step or module 550, a reservoir tank (an inert gas reservoir tank such as a helium gas tank) is coupled to a low-pressure input of the compressor via a first reservoir tank control valve and the high-pressure output of the compressor via a second reservoir tank control valve. The reservoir tank is also coupled to the low-temperature input of the inert gas power source via a return line between the compressor and the inert gas power source. In a step or module 555, a power output and/or optionally a gas temperature of inert gas thermal power is controlled with the first and second reservoir tank control valves. In a step or module 560, the method ends. Although the high-efficiency modifications as discussed herein have been oriented to a greatly needed, clean overhaul of a depleted, coal fired power plant, the high-efficiency modifications are equally applicable to substantially eliminate the hazards of today's nuclear power plants. This could be accomplished within the context of a modification of the steam supply to the existing nuclear power plant steam turbine generation plant. The water-cooled reactor would be shut down. The high-efficiency modifications to provide a steam generator would be connected to the steam supply piping coupled to the steam turbine. For turbine steam supply flow rate and temperature matching, multiple standard high efficiency inert gas modification units could be manifolded. This process would be performed following purge of all radioactive water from the generating system including the condenser water. Through the purging, the remnant hazards of radioactive water are permanently eliminated. The prior conventional nuclear power plant would then become safe from melt-down, explosions, and release of radioactive gases, liquids and particles. The original turbine/generator, physical, thermal, and electrical infrastructure may again be retained in service, with an increase in electrical generating capacity, and with no increase in cooling water supply. Many of the major components of a previously functioning coal or fossil-fuel powered steam power plant including grid connection can be re-used, except the steam generation sub-system, which includes the previously used fuel supply and handling, firebox, boiler, and combustion gas exhaust chimney stacks. A water-cooled nuclear fission reactor could be similarly replaced. A number of design variables influence compound plant performance. As a non-limiting example, the following assumptions are made, and computed performance results are shown in Table I below for a rescued steam plant design: TABLE IAn Example Compound Systemthermal generating capacity of new1100 MWthinert gas reactororiginal plant electrical capacity300 MWe outputfrom 1500 psi/900° F.inputadded plant electrical capacity230 MWetotal electrical capacity of modified530 MWeplantthermal discharge of nuclear reactornegligibleto environmentreactor inert gas input pressure500 psiareactor inert gas output pressure475 psiacore reactor He output temperature900° C. (1650° F.)gas turbine He output temperature515° C. (960° F.)He compressor efficiency86%He gas turbine efficiency88%pressure drop ratio in each of three∂P/P = .04heat exchangerspressure drop ratio in core reactor∂P/P = .05compressor pressure ratio3.2:1gas turbine pressure ratio2.7:1He-to-steam mass ratio in heat1.28 lb He/lb steamexchanger arrangementoverall efficiency of modified,47%combined plant As indicated above, the resulting capacity of the modified plant is about 1.75 times the previously existing capacity with no increased thermal load on the environment. In an embodiment, the compressor 114, the gas turbine 112, and the generator 110 can be set to operate at a variable speed of rotation. This enables variation and control of the output temperature of the gas turbine gas flow to the high-temperature input 129 to the heat exchanger 140. A unique characteristic of the modifications introduced herein is flexibility to change the helium cycle power output at constant temperature by changing the helium pressure level within operating limits. This can maintain thermal efficiency of the gas turbine generator at different power levels. Additionally, this characteristic could be used to maintain steam temperature at a varying water/steam flow rate, or to vary the steam temperature at the same steam flow rate. Within GFR/VHTR operating pressure and flow limits, plant modifications coupled with its variable operating characteristic enable application of a given physical sized high-efficiency power and steam producing unit to be thermodynamically sized to match a range of steam turbine power plant sizes. By steam output and return pressurized water pipe manifolding of one or more high efficiency modified gas turbine/steam producing units, a broad range of steam turbine plant sizes can be accommodated. Thus, a power generation system has been introduced herein. In one embodiment, the power generation system includes an inert gas thermal power source, a thermal/electrical power converter and a thermally-driven process load. The thermal/electrical power converter includes a closed-cycle gas turbine engine having a gas turbine with an inert gas input couplable to an inert gas output of the inert gas thermal power source, a compressor, mechanically coupled to the gas turbine, including an inert gas output couplable to an inert gas input of the inert gas thermal power source, and a generator mechanically coupled to the gas turbine. The thermal/electrical power converter also includes a heat exchanger with an input coupled to an inert gas output of the gas turbine and an inert gas output coupled to an input of the compressor. The heat exchanger includes a series-coupled super-heater heat exchanger, a boiler heat exchanger and a water preheater heat exchanger. The thermal/electrical power converter also includes an inert gas reservoir tank coupled to the inert gas input of the compressor via a reservoir tank control valve and to an inert gas output of the compressor via another reservoir tank control valve. The reservoir tank control valve and the another reservoir tank control valve are configured to regulate a power output of the thermal/electrical power converter. The thermally-driven process load includes an input coupled to another output of the heat exchanger and an output coupled to another input of the heat exchanger. The thermally-driven process load is powered by the thermal/electrical power converter, which in turn is powered by the inert gas thermal power source. In an embodiment, the thermally-driven process load is wholly powered by the thermal/electrical power converter, which in turn is wholly powered by the inert gas thermal power source. Electrical power generation systems may be constrained by an underlying inefficiency of Carnot-cycle thermal engines (as universally used in electrical power plants), which depends on a temperature difference between a hot source that supplies energy to the plant and a cold-side thermal sink or cold sink that absorbs remaining energy. The higher the input temperature, the greater the possible power conversion efficiency for a fixed cold-side temperature provided by, for example, a lake or a stream. As a result of this observation, additional energy can be obtained from a heat source embodied in a nuclear reactor beyond that obtained by a cooler fossil fuel burning power plant by utilizing a higher temperature of a nuclear reactor core, such as 1600° F. or more, as a heat source for a first stage. The cold-side output of the first stage, which might be 900° F., is then used as the thermal input for a conventional power plant. The conventional power plant effectively becomes the heat sink for the first stage. The operating temperature of the nuclear reactor core can be substantially higher than that produced by a fossil fuel burning power plant by using an inert gas coolant such as helium to extract thermal energy from the reactor core. The inert gas coolants typically do not chemically attack the blades of a turbine that converts the thermal energy produced by the reactor core to a mechanical output. The net result of using a reactor core as a thermal source cooled by an inert gas is a substantial improvement in plant energy efficiency that enables additional useful electrical energy to be produced without increasing the energy dumped into a lake or stream that acts as the cold-side thermal sink. The fossil fuel burning power plant may be eliminated. The lake or stream or other thermal sink is still used to absorb heat from a second stage, but no additional thermal load is presented to the lake or stream while producing a higher level of electrical power output. The Carnot efficiency, which presents a maximum theoretical plant efficiency, can be computed using the expression 1−(Tc/Th) where Tc is the temperature of the cold sink and Th is the temperature of the hot source, both measured relative to absolute zero temperature (e.g., in degrees Kelvin or Rankin, not Celsius or Fahrenheit). As the temperature of the hot source becomes very high, the Carnot efficiency approaches unity. Of course, the attainable efficiency in practice is less than that computed by the Carnot expression due to practical equipment design limitations. Taking advantage of a large temperature difference between a nuclear reactor core and a thermal sink such as a lake or stream, as introduced herein, a power generation system is formed with a thermal/electrical power converter that employs helium as a coolant for a nuclear reactor core. Helium, unlike other reactor coolants such as water, liquid sodium, air, or other inert gases such as argon, doesn't exhibit radioactivity upon exposure to radiation produced in the reactor core. No radioactive byproducts are produced by helium itself, unlike water and other possible reactor coolants. The nuclear reactor core still produces its own spent radioactive fuel, but the absence of radioactive products that are produced when using helium as a coolant provides significant design and operational advantages. In addition, helium is entirely chemically unreactive with turbine blades, even at quite high temperatures such as 1600° F. Using steam as a working fluid limits turbine input temperatures to about 900° F. Due to its very low atomic weight and its monoatomic gas structure, helium may employ a multi-stage mechanical design for the turbine and compressor versus a cooling system that employs a higher molecular weight gas such as steam, carbon dioxide, or air. For example, a turbine operating with helium and operating with a 3:1 pressure ratio between its input and output may employ about 20-stage compressor and turbine designs. A 20-stage turbine operating with argon and rotating at a same rotational rate could operate with about a 40:1 pressure ratio. As introduced herein, substantial redesign of conventional turbines and compressors can be avoided by using, without limitation, argon or a mixture of argon and helium as the working fluid in the turbine and compressor. Helium has a molecular weight of about four. Argon has a higher molecular weight of about 40 versus about 18 for steam and 29 for air, thereby facilitating the turbine and compressor design. Steam (water) and air, however, produce radioactive byproducts upon exposure to radiation in the nuclear reactor core and, as mentioned above, chemically react with the turbine blades at high temperatures. It is contemplated that nitrogen as an inert gas can be substituted for the argon. Thus, a disadvantage of using argon as a coolant/working fluid in the nuclear reactor core is its production of radioactive byproducts upon exposure to radiation in the reactor core. Helium is a desirable reactor coolant because it does not become radioactive upon exposure to a nuclear core and has excellent heat-transfer properties. Argon is desirable because of its higher atomic weight and associated advantages related to design of turbines and compressors. Neither helium nor argon, being noble gases, is chemically reactive at high temperatures with the turbine blades. Thus, a thermal/electrical power system is formed with a nuclear reactor core cooled with helium as a working fluid. Thermal energy is extracted from the helium heated in the reactor core employing a counterflow heat exchanger positioned external to the reactor core and acting as a thermal source for an electrical power system. The counterflow heat exchanger employs argon or a mixture of argon and helium as the working fluid on its output side to simplify the design of the compressor and the turbine. As a result, helium cools the reactor core while not producing radioactive byproducts and argon, or mixture (which can produce radioactive byproducts) is not exposed to radiation in the core of the reactor. In an embodiment, the counterflow heat exchanger employs a mixture of helium and argon as the working fluid on its output side. A mixture of helium and another inert gas such as nitrogen can also be used. The counterflow heat exchanger extracts heat from the helium heated in the nuclear reactor core and provides the extracted heat to argon or other inert gas, or to an inert gas mixture. Argon or, alternatively, a mixture of helium and argon (or other higher molecular weight inert gas) does not degrade the turbine blades at high temperatures and admits the use of a turbine that can operate at temperatures higher than those used in conventional steam-driven power plants. Thus, the thermal input to a thermal/electrical power plant is also the heat sink for the first stage of the combined process. The input to the thermal/electrical power plant becomes both a heat sink for the first stage and a heat source for the second stage. The thermal/electrical power plant is reused with little modification and power derating as the second stage, and radioactive byproducts are avoided by using helium to cool the nuclear reactor core in the first stage. The first stage produces power that can be added to that produced by the second stage that is already installed. The combined system produces about 40 percent more electrical power than the original conventional power plant with no added thermal burden on a nearby lake or stream, and no discharge of carbon dioxide and other contaminants to the atmosphere. Turning now to FIG. 6, illustrated is a diagram of an embodiment of a power generation system. The power generation system includes two, interdependent, closed-loop thermal/electrical power systems with a first stage Brayton closed-loop power generation and processing system, and a second stage Rankine closed-loop power processing system. The elements illustrated in FIG. 6 are not drawn to scale. Analogous to the power generation system of FIG. 1, the first stage is the thermal/electrical power converter 102 and the second stage is the power plant 104. The thermal/electrical power converter 102 is powered by the inert gas power source 101 (e.g., see FIGS. 1 and 4) via a counterflow heat exchanger 600. Again, other power sources such as a source of combusted fossil fuel (see, e.g., U.S. Pat. No. 5,431,016, previously incorporated by reference) can used for the inert gas power source 101 within the power generation system. A high-temperature output 424 of the inert gas power source 101 is coupled to a thermal input 610 of the counterflow heat exchanger 600. A thermal output 620 of the counterflow heat exchanger 600 is coupled to the input 124 of the gas turbine 112 of the thermal/electrical power converter 102. On the return side, the high-pressure output 121 of the compressor 114 of the thermal/electrical power converter 102 is coupled to an input 625 of the counterflow heat exchanger 600. A low-temperature output 630 of the counterflow heat exchanger 600 is coupled to a low-pressure input 635 of a circulating pump 640 via a filter 645. A high-pressure output 650 of the circulating pump 640 is coupled to a low-temperature input 422 of the inert gas power source 101 via a return line 122. The inert gas power source 101 such as a VHTR or a GFR can introduce dust particles into the inert gas flow, particularly with a pebble-bed reactor. Over time, dust particles can erode gas turbine and compressor blades, and even inert gas piping at piping bends. To remove such dust particles from the inert gas flow, the filter 645 can be installed between the low-temperature output 630 of the counterflow heat exchanger 600 and the low-pressure input 635 of the circulating pump 640, which is a low temperature position to install such a filter 645. In an embodiment, such a filter 645 can have a minimum equivalent reporting value (“MERV”) of seven. A reservoir tank 655 is coupled to the return line 122 via a valving and pumping apparatus 660. The valving and pumping apparatus 660 is employed to maintain a pressure of an inert gas such as helium inside the inert gas power source 101 to regulate a temperature (such as 1600° F.) and/or a pressure (such as a few dozen atmospheres or more) at the high-temperature output 424 of the inert gas power source 101 in view of a fluctuating electrical load on the two-stage power generation system. The thermal/electrical power converter 102 is assumed herein to be operable between its input and a combined output that includes the electrical power output 111 of the generator 110 and a thermal output between a high-temperature steam output 142 and a low-temperature, liquid-water input 144 of the heat exchanger 140 with highly efficient power conversion. This assumes that the generator 110 is operable with substantially 100 percent power conversion efficiency. A practical generator operable to convert mechanical shaft power to an electrical output in a power plant can generally achieve a power conversion efficiency in the mid- to high-90 percent range, and the slightly imperfect power conversion efficiency of such a high-power generator is ignored herein. Such mechanical-to-electrical power conversion plants are not limited by a second-law efficiency constraint imposed by a Carnot cycle. It is contemplated that heat produced in the generator 110 by its imperfect power conversion efficiency can be recaptured in the cold-side thermal loop, for instance, before the filter 131. The high-temperature steam output 142 of the heat exchanger 140 is coupled to an input 143 of the power plant 104. In an embodiment, the thermal energy produced at the high-temperature steam output 142 of the heat exchanger 140 provides the power input to the power plant 104, which can be an existing, modified steam-driven plant. A high-pressure, cooled-water output 145 of the power plant 104 is coupled to the low-temperature, liquid-water input 144 of the heat exchanger 140. Thus, substantially the entire thermal output of thermal/electrical power converter 102 is supplied to the power plant 104, with possible exception of the small inefficiency of the generator 110 and modest inefficiency of the counterflow heat exchanger 600. No substantial thermal sink need be coupled to the thermal/electrical power converter 102 with exception of modest cooling for the generator 110. In an embodiment, thermal energy obtained from cooling the generator 110 is recovered at the heat exchanger 140. Pipeline pressure losses are included in calculating heat exchanger pressure drops for convenience in calculating system performance evaluations. A small pressure drop at the input side of the heat exchanger 140 does not contribute to system inefficiency. The small pressure drop of the heat exchanger 140 is simply accommodated by operating pressure differences between the compressor 114 and the gas turbine 112. Thermal content of heated water or other heated fluid that may be employed to cool the generator 110 (or other system elements) may be employed to preheat the low pressure, cooled inert gas at the high-temperature steam output 142 of the heat exchanger 140 before being supplied to the compressor 114 to provide a further efficiency enhancement to the thermal/electrical power converter 102. The power plant 104 is operable as described previously hereinabove with reference to FIG. 1. The overall power-conversion efficiency of the power generation system illustrated in FIG. 6 is similar to that described hereinabove with reference to FIG. 1 and won't be repeated in the interest of brevity. Turning now to FIG. 7, illustrated is a diagram of an embodiment of a power generation system. The power generation system of FIG. 7 is analogous to the power generation system of FIG. 6, but more clearly demonstrates the relationships between the stages thereof. As illustrated, an output of the thermal/electrical power converter 102 (the first stage) is thermally coupled in series to a thermal input of the power plant 104. The high-temperature water output 158 of the power plant 104 is thermally coupled to a cold sink such as a lake or a stream. Electrical power outputs of the thermal/electrical power converter 102 and the power plant 104 are electrically coupled in parallel as demonstrated by the connection to the power grid 106. The remaining items illustrated in FIG. 7 have been described previously hereinabove and will not be redescribed in the interest of brevity. Thus, as introduced herein, a counterflow heat exchanger is inserted between an inert gas power source employing an inert gas such as helium and a cascaded arrangement of a thermal/electrical power converter and a power plant. By positioning the counterflow heat exchanger between the helium-cooled inert gas power source and the cascaded arrangement of the thermal/electrical power converter and the power plant, beneficial thermal and radioactive aspects of the power generation system are realized. Helium is a desirable coolant for the inert gas power source because it does not become radioactive upon exposure to a nuclear core and has excellent heat-transfer properties. Employing a second inert gas such as argon, an inert gas mixture such as argon and helium, or air (or mixture of air and an inert gas) with a higher molecular weight in the first stage of the cascaded arrangement (the thermal/electrical power converter) simplifies design of a compressor and turbine. The architecture further allows a reservoir tank arrangement containing the inert gas mixture and coupled to two control valves to control the temperature and pressure of the inert gas mixture that is discharged from a turbine in the first stage of the cascade arrangement of thermal/electrical power converter coupled to a generator. The result enables the temperature of a working fluid fed to the second stage (a power plant) to be controlled. Turning now to FIG. 8, illustrated is a flow diagram of an embodiment of a method for providing power for a thermally-driven process load. The method begins in a start step or module 805. In a step or module 810, a high-temperature output of the inert gas power source employing a first inert gas such as helium is coupled to a thermal input of the counterflow heat exchanger. The counterflow heat exchanger is configured to transfer thermal energy from the inert gas power source to a first stage of the power generation system. In a step or module 815, an input of a gas turbine of the first stage of the power generation system is coupled to a thermal output of the counterflow heat exchanger. The first stage of the power generation system conducts a second inert gas such as argon, air or a mixture. In a step or module 820, a super-heater heat exchanger, a boiler heat exchanger, and a water preheater heat exchanger are coupled in series to form another heat exchanger. In a step or module 825, a low-pressure output of the gas turbine is coupled to a high-temperature input of the another heat exchanger. In a step or module 830, a low-pressure input of a compressor is coupled to a low-pressure output of the another heat exchanger. In a step or module 835, a high-pressure output of the compressor is coupled to an input of the counterflow heat exchanger. In a step or module 840, another output of the counterflow heat exchanger is coupled to a low-pressure input of a circulating pump via a filter. In a step or module 845, a high-pressure output of the circulating pump is coupled to a low-temperature input of the inert gas power source via a valving and pumping apparatus and a reservoir tank (an inert gas reservoir tank such as a helium gas tank). The circulating pump enables an inert gas such as helium to circulate between the inert gas power source and the counterflow exchanger. The reservoir tank coupled to the inert gas power source by the valving and pumping apparatus is configured to regulate a temperature and/or pressure at the output of the inert gas power source. In a step or module 850, a rotatable shaft of the compressor is mechanically coupled to a rotatable shaft of the gas turbine. In a step or module 855, the rotatable shaft of the gas turbine is mechanically coupled to a rotatable shaft of a generator. In a step or module 860, a high-temperature steam output of the another heat exchanger is coupled to a high-temperature input of the thermally-driven process load. In a step or module 865, a low-temperature output of the thermally-driven process load is coupled to a low-temperature, liquid-water input of the another heat exchanger. In a step or module 870, another reservoir tank (an inert gas reservoir tank such as an argon or mixture gas tank) is coupled across the compressor via a first reservoir tank control valve and a second reservoir tank control valve. In a step or module 875, a power output and/or optionally a gas temperature of the inert gas power source is controlled with at least one valve coupled to the reservoir tanks. In a step or module 880, the method ends. A power generation system and related method of forming and operating the same has been introduced herein. In one embodiment, the power generation system includes an inert gas power source (101) having an input (422, 122) and an output (424), and a thermal/electrical power converter (102) including a compressor (114) with an output (121) coupled to the input (422, 122) of the inert gas power source (101). The power generation system also includes a power plant (104) with an input (143) coupled in series with an output (142) of the thermal/electrical power converter (102), wherein the thermal/electrical power converter (102) and the power plant (104) are configured to serially convert thermal power produced at the output (424) of the inert gas power source (101) into electricity. The power generation system may also include an inert gas reservoir tank (116) coupled to an input (123) of the compressor (114) via a reservoir tank control valve (117) and to the output (121) of the compressor (114) via another reservoir tank control valve (118). The reservoir tank control valve (117) and the another reservoir tank control valve (118) are configured to regulate a temperature and/or pressure of the output (142) of the thermal/electrical power converter (102). The power generation system may also include a heat exchanger (140) having an input (129) coupled to an output (128) of a gas turbine, an output (126) coupled to the input (123) of the compressor (114), and the output (142) coupled to the power plant (104). The thermal/electrical power converter (102) and the power plant (104) are thermally coupled in series and electrically coupled in parallel. The power generation system may also include a counterflow heat exchanger (600) with an input (610) coupled to the output (424) of the inert gas power source (101), and an output (620) coupled to an input (124) of a gas turbine (112) of the thermal/electrical power converter (102). The inert gas power source (101) provides a first inert gas (e.g., helium) to the input (610) of the counterflow heat exchanger (600) to transfer thermal energy to a second inert gas (e.g., argon or a mixture of argon and helium) or air (or a mixture of air and an inert gas) at the output (620) of the counterflow heat exchanger (600). The second inert gas may have an average molecular weight equal to or greater than an average molecular weight of air. The power generation system may also include a circulating pump (640) configured to circulate the first inert gas between the inert gas power source (101) and the counterflow heat exchanger (600). A filter (645) of the power generation system is coupled between another output (630) of the counterflow heat exchanger (600) and an input (635) of the circulating pump (640). The power generation system may also include another inert gas reservoir tank (655) coupled to the inert gas power source (101) by a valving and pumping apparatus (660) configured to regulate a temperature and/or pressure at the output (424) of the inert gas power source (101). As described above, the exemplary embodiment provides both a method and corresponding systems consisting of various modules providing functionality for performing the steps of the method. The modules may be implemented as hardware, software or combinations thereof. Although the embodiments and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the conceptual spirit and scope thereof as defined by the appended claims. Also, many of the features, functions, and steps of operating the same may be reordered, omitted, added, etc., and still fall within the broad scope of the various embodiments. Moreover, the scope of the various embodiments 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, 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 as well. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
	summary
	claims	1. A jet pump inspection apparatus comprising:a body;a probe driver configured to provide axial movement of a probe along a length of the apparatus; anda guide funnel configured to guide the probe into the apparatus to a given depth,wherein the probe driver and the guide funnel are located on the body. 2. The jet pump inspection apparatus of claim 1, wherein the body includes a calibration tube portion, further comprising:a pole attachment connected to the probe driver on the body above the calibration tube portion, the pole attachment configured to connect to at least one handling pole; anda guide latch on the body below the calibration tube portion, the guide latch configured to secure the apparatus to a jet pump. 3. The jet pump inspection apparatus of claim 2, wherein the guide latch and the body are detachably attached by the calibration tube. 4. The jet pump inspection apparatus of claim 1, wherein the probe driver includes a set of wheels configured to contact a cable including a probe head in order to control a location of the probe head within the body. 5. The jet pump inspection apparatus of claim 2, wherein a thickness of a plate of the pole attachment is up to one-half an inch. 6. The jet pump inspection apparatus of claim 2, wherein the body is made of aluminum. 7. The jet pump inspection apparatus of claim 2, wherein the guide latch is an air-actuated clamp configured to secure the apparatus to a jet pump. 8. The jet pump inspection apparatus of claim 7, wherein the guide latch further comprises:one or more engagement members including a gap therebetween; anda latching actuator configured to engage at least one of the engagement members to clamp an object or surface in the gap. 9. The jet pump inspection apparatus of claim 1, wherein the probe driver includes an encoder configured to determine a location of a probe head. 10. The jet pump inspection apparatus of claim 9, wherein the probe driver is configured to control an elevation of the probe head based on the location established by the encoder. 11. A jet pump inspection apparatus comprising:a body having a calibration tube portion;a probe driver on the body above the calibration tube portion, the probe driver configured to provide axial movement of a probe along a length of the apparatus;a pole attachment connected to the probe driver and configured to connect to the at least one handling pole;a guide funnel on the body above the calibration tube portion and below the probe driver, the guide funnel configured to guide the probe into the jet pump inspection apparatus to a given depth; anda guide latch on the body below the calibration tube portion, the guide latch configured to secure the apparatus to a jet pump inlet. 12. The jet pump inspection apparatus of claim 11, wherein the probe driver includes an encoder configured to determine a location of a probe head. 13. The jet pump inspection apparatus of claim 12, wherein the probe driver is configured to control an elevation of the probe head based on the location established by the encoder. 14. The jet pump inspection apparatus of claim 11, wherein the guide latch and the body are detachably attached by the calibration tube. 15. The jet pump inspection apparatus of claim 11, wherein the probe driver includes a set of wheels configured to contact a cable including a probe head in order to control a location of the probe head within the body. 16. The jet pump inspection apparatus of claim 11, wherein a thickness of a plate of the pole attachment is up to one-half an inch. 17. The jet pump inspection apparatus of claim 11, wherein the body is made of aluminum. 18. The jet pump inspection apparatus of claim 11, wherein the guide latch is an air-actuated clamp configured to secure the apparatus to a jet pump. 19. The jet pump inspection apparatus of claim 18, wherein the guide latch further comprises:one or more engagement members including a gap therebetween; anda latching actuator configured to engage at least one of the engagement members to clamp an object or surface in the gap.
	claims	1. A method to characterize a power transfer of a heating surface of a component with a layer of material placed on a side of the component, comprising;obtaining a sample of a deposit layer on the side of the heating component;obtaining a scanning electron microscope image of a surface of the sample;obtaining a scanning electron microscope image of another surface of the sample;analyzing the scanning electron microscope images of the surface and the another surface of the sample for a presence of capillaries and steam chimneys;determining a number of capillaries and steam chimneys for the surface and the another surface;determining a diameter of capillaries and steam chimneys for the surface and the another surface; andcalculating the power transfer of the heating component based on the number of steam chimneys in the deposit layer. 2. The method according to claim 1, wherein the step of obtaining a sample of the deposit layer includes scraping a side of the component to obtain a flake. 3. The method according to claim 1, wherein the step of determining the number of capillaries and steam chimneys for the surface and the another surface further comprises preparing a graph of a number of openings on the surface and the another surface; andestablishing a threshold point on the graph separating a number of capillaries from a number of steam chimneys, based on a comparison of a diameter versus number representation for each of the examined surfaces. 4. The method according to claim 3, wherein the threshold point on the graph of capillary and steam chimney diameters verses number is based on a size of a vapor bubble. 5. The method according to claim 3, wherein the step of determining the number of capillaries and steam chimneys for the surface and the another surface is performed such that the number of steam chimneys and the capillaries is performed on a per unit of area basis. 6. The method according to claim 4, wherein the step of obtaining a sample of a deposit layer on the side of the component includes identifying an inner surface of the flake and an outer surface of the flake. 7. The method according to claim 1, wherein the step of calculating the power transfer of the component based on a number of steam chimneys in the deposit layer is performed by an equation Nv=a x(q0)b. 8. The method according to claim 1, wherein the heating surface of the component is a fuel rod of a light water reactor. 9. The method according to claim 8, wherein the fuel rod is from one of a boiling water reactor and a pressurized water reactor. 10. The method according to claim 1, wherein the layer of material placed upon the side of the component is Chalk River Unidentified Deposits (CRUD). 11. The method according to claim 1, wherein the deposit layer of material obtained from one of solids and dissolved substances in a cooling fluid is placed upon the heating surface. 12. The method according to claim 1, wherein the step of calculating the power transfer of the component is based on the number of steam chimneys in the deposit layer calculates the average power transfer for a given time interval. 13. The method according to claim 1, wherein the step of calculating the power transfer of the component is based on the number of steam chimneys in the deposit layer further calculates an average power transfer of the component for a nuclear fuel cycle. 14. The method according to claim 1, further comprising:comparing local power density readings from in-core monitors to the calculated power transfer after the step of calculating the power transfer of the fuel element based on the number of steam chimneys in the deposit layer. 15. A method to characterize a power transfer of a heating surface of a component with a layer of deposit material placed on a surface of the component obtained from one of solids and dissolved substances in a cooling fluid, comprising;obtaining a sample of a deposit layer on a side of the component;obtaining an image of at least two surfaces of the sample;analyzing the digital images of the outside and inside surfaces of the sample for a presence of capillaries and steam chimneys;determining a number of capillaries and steam chimneys for the surfaces;determining a diameter of the capillaries and the steam chimneys for the surfaces; andcalculating the power transfer of the component based on the number of steam chimneys in the deposit layer. 16. The method according to claim 15, wherein the step of obtaining a sample of the deposit layer on the side of the component includes scraping a side of the heating surface to obtain a flake. 17. The method according to claim 15, wherein the step of determining the number of capillaries and steam chimneys for the outside surface and the inside surface further comprises preparing a graph of a number of openings on the inside surface and the outside surface; andestablishing a threshold point on the graph separating a number of capillaries from a number of steam chimneys, based on a comparison of a diameter versus number representation for each of the examined surfaces. 18. The method according to claim 17, wherein the step of determining the threshold point on the graph between capillaries and steam chimneys is based on a size of a vapor bubble.
052573052	claims	1. A method for producing absorptione elements for a slit radiography assembly, which comprises: forming a template of a cross-sectional shape for said absorption elements by defining at least two cut lines between two equidistant lines of absorption thickness of absorption material, said cut lines being non perpendicularly transverse to said equidistant lines; by defining two edge regions with a boundary line on either side of each cut line, each of said edge regions being bounded by said cut lines, said boundary line extending transversely to said equidistant lines and a part of at least one of said equidistant lines; and by moving said edge regions on either side of each said cut lines a distance in an opposite direction along said boundary lines to produce a gap at a position of each of said cut lines thereby forming said cross-sectional shape between respective gaps; and forming an absorption element of said cross-sectional shape from said template. 2. The method for producing absorption elements as defined in claim 1 wherein straight shoulders produced by movement at the position of said boundary lines are chamfered by displacing a projecting angular section near one equidistant line to an oppositely situated angular section near the other equidistant line. 3. The method for producing absorption elements as defined in claim 1 wherein at least one of said cut lines is kinked having a first section extending between an intersection thereof with one of said equidistant lines and a point of inflection and having a second section extending between said point of inflection and a second of said equidistant lines and wherein said boundary line is drawn transversely through said point of inflection and wherein a region formed by said boundary line, said first section and a part of a first of said equidistant lines is moved in a first direction transversely to said equidistant lines and wherein a region formed by said boundary line, said second section and a second of said equidistant lines is moved in said opposite direction and the thus-produced projecting corners at a position of said intersection of said boundary line with said equidistant lines is filled by triangular sections removed at the level of the original point of inflection.
051577003	summary	FIELD OF THE INVENTION AND RELATED ART The present invention relates to a mask pattern transferring exposure apparatus used in manufacturing semiconductor devices, and more particularly to an exposure apparatus which uses as a radiation source a synchrotron radiation source. An exposure apparatus, which uses synchrotron radiation emitted when high energy electrons make a circular orbit motion, is known. The synchrotron radiation has a wide and uniform intensity distribution in a horizontal plane that is in a plane including the circular orbit. However, the beam width measured in the vertical direction is very much limited. In order to expand the beam width in the vertical direction, there are proposed various methods. In one method, a mirror is disposed in an optical path between the synchrotron radiation source and the member to be exposed to the radiation, and the mirror is swung to scan the member to be exposed (Japanese Laid-Open Patent Applications Nos. 45026/1981 and 113065/1986; "Investigation of X-ray exposure using plane scanning mirrors" J. Vac. Sci. Techol. vol. 31, (4) p.1271, 1983, by M. Bieber, H. U. Sheunemann, H. Betz, A. Heuberger). In another example, the electron orbit in the accumulation ring of the radiation source is vertically swung by application of a magnetic field ("stationary large area exposure in synchrotron radiation lithography utilizing a new arrangement of magnets applied to the storage ring", Jpn. Appl. Phys., 22; L718-L720, 1983, H. Tanio, K. Hoh). A further example is that a fixed mirror is disposed in an optical path from the radiation source to the member to be exposed to provide a large exposure area having a uniform beam intensity (variation of the beam intensity is not more than .+-.5% in an area of 3.times.3 cm.sup.2) ("Design of Stationary Troidal Mirror for Large Area Synchrotron Radiation Exposure", preprint for the 31st Applied Physics Meeting, 282, 1984, by Koji Tanino and Ohtori Koichiro, and Japanese Laid-Open Patent Application No. 84814/1985). Referring to FIG. 1, an example of an exposure apparatus using synchrotron radiation is shown. In FIG. 1, reference numerals 1, 5 and 6 are respectively a synchrotron radiation beam, a mask and a semiconductor wafer which is to be exposed to the radiation. The apparatus comprises a stationary or fixed mirror 2 for expanding the synchrotron beam, an exposure chamber 3 filled with helium gas or the like, a window 4 of the exposure chamber 3 made of beryllium, a wafer stage 7, a spring 8, a wafer stage driver 9 and a frame 10. The apparatus further comprises movable aperture steps 11 and 12, supporting members 13 and 14 for the movable aperture steps and drivers 15 and 16 for the movable aperture steps. The movable apertures 11 and 12, the supporting members 13 and 14 and the drivers 15 and 16 constitute an exposure control means. Designated by a reference 17 is an ultra-high vacuum chamber which is isolated from the exposure chamber 3 containing the helium gas by the window 4. In operation, light (radiation) 1 travels through the ultra-high vacuum chamber 17 and is expanded by the mirror 2, and is passed through the window 4. The exposure control means controlled by a shutter controller 20 limits the light 1, and the limited light is projected onto the semicondutor wafer 6 through the mask 5, by which the pattern of the mask is transferred onto the semiconductor wafer 6. SUMMARY OF THE INVENTION In the exposure apparatus using the synchrotron radiation source, the strength or intensity distribution of the radiation beam is narrow in the direction perpendicular to the plane of the accumulation ring. Therefore, it is preferable to expand the intensity distribution in this direction by one method or another. For the purpose of this expansion, Japanese Laid-Open Patent Applications Nos. 141135/1986 and 59828/1986 disclose that the synchrotron radiation is passed through a monocrystal or a diffraction grating so as to expand the divergence angle measured in the vertical plane. The beam provided thereby, as it is, involves non-uniformity and variation in the spectral distribution in the vertical direction, so that it is still not possible to project the mask pattern onto the wafer with a uniform exposure amount. Then, Japanese Laid-Open Patent Application No. 104438/1981 discloses that a shutter is driven with a control to make uniform the exposure amount over each of many shot areas on the basis of exposure beam profiles predicted beforehand. However, in the conventional art, since there is no practical sequential operation for determining a profile of the synchrotron radiation incident on the mask, the data for determining the profile is not accurate. Accordingly, the first object of the present invention is to provide an exposure apparatus wherein the exposure control is possible on the basis of synchrotron radiation profile data which is accurately obtained and which is high in the S/N ratio (signal/noise ratio). According to an aspect of the present invention, the synchrotron radiation beam profile is measured or sensed when the intensity of the radiation from the synchrotron radiation generator is substantially highest, that is, when the transmissivity of the radiation through the window disposed in the radiation path from the synchrotron radiation generator to a mask in the exposure apparatus, by which the exposure control can be performed, on the basis of the radiation beam profile data having substantially the highest S/N ratio. With the increase of the pattern density in integrated circuit devices, the line width of the pattern transferred by the exposure decreases, and the control of the line width in the resist becomes more severe. As is well known, the line width formed in the resist changes greatly depending on variation in the exposure amount. Therefore, it is important that the actual amount of exposure is controlled correctly to be the desired amount. As for the system for correctly controlling the amount of exposure, Japanese Laid-Open Applications Nos. 101839/1982 and 198726/1984 disclose that the intensity of the exposure radiation during the exposure operation is detected by a detector disposed adjacent to the mask, and upon the desired amount of exposure reached, a shutter is closed. However, it is difficult to use the conventional art of the X-ray exposure for the synchrotron radiation (SOR). This is because, in the conventional apparatus, the area in which the intensity of the exposure radiation is uniform is relatively wide, and therefore, a measurement at the marginal area of the mask is not much different from the intensity in the exposure area, but in the SOR exposure, the region in which the intensity of the SOR is uniform is narrow, so that the X-ray intensity is different at the marginal measuring position than at the exposure area. To obviate this problem, it is considered that a retractable X-ray detector is advanced into the exposure area when the exposure operation is not carried out, and it detects the X-ray intensity, whereas during the exposure, the detector is retracted so as not to block the X-rays. However, when the X-ray intensity varies with time as in SOR, it is possible that the X-ray intensity is different at the time of the exposure than at the time of measurement, with the result of an additional error. Accordingly, a second object of the present invention is to provide an X-ray exposure apparatus which can determine the X-ray intensity with high accuracy even if the SOR is used. According to an aspect of the present invention, after the electron is injected into the SOR ring to generate the synchrotron radiation, the intensity of X-rays is measured, and the X-ray intensity during the exposure operation is determined on the basis of the measurement and on an attenuation curve of the injected electron. In this system, the X-ray intensity during an exposure operation for a shot can be correctly predicted both from one or more X-ray measurements after the orbit electron injection and from the attenuation curve of the orbit electron amount. Further, in order to achieve the second object, in the X-ray exposure apparatus according to an embodiment of the present invention, the X-ray or light intensities are simultaneously measured within the exposure area and outside the exposure area after the electron injection into the SOR ring, and thereafter, the exposure control is performed on the basis of an output of the measuring device disposed outside the exposure area. In the X-ray exposure apparatus, the desired amount of exposure is provided by controlling the exposure period. The following methods are considered for accomplishing this: (1) The exposure period is determined on the basis of the sensitivity, to the X-rays, of the sensitive resist applied on the wafer and the X-ray illuminance empirically determined: and (2) As disclosed in Japanese Laid-Open Patent Application 198726/1985, an X-ray detector is disposed at a proper position in the X-ray illumination area, by which the variation of the X-ray illuminance with time is detected, and on the basis of the detection, the exposure period is controlled. However, in those methods, the exposure period is uniform over the entire exposure area on the wafer surface, and therefore, when, for example, the radiation source is a synchrotron radiation source, non-uniformness results in the exposure area of the wafer, and in addition, the correction thereof is not possible. Accordingly, a third object of the present invention is to provide an exposure apparatus wherein the exposure operation can be performed with a uniform amount of exposure over the entire wafer even if the synchrotron radiation or the like is used. According to an aspect of the present invention, the exposure apparatus according to an embodiment of the present invention includes aperture means (shutter), disposed between the radiation source and the member to be exposed and movable in a direction crossing the direction of illumination of the radiation rays, control means (controlling the opening and closing of the shutter) for controlling movement of the aperture means so as to provide a uniform radiation intensity distribution on the member to be exposed, a radiation sensor for measuring the exposure amount by the radiation rays, and feed-back means for feeding the result of the measurement to the control means. By this, the exposure amount becomes uniform over the entire exposure area even if the radiation source is a synchrotron radiation source. In an illuminance measuring system for light using a semiconductor, when a high measurement accuracy is required, a chopper is used adjacent the light source to block the light pulsewisely in order to correct for dark current which is a problem from the standpoint of the measurement correctness. The chopped light is received by an illuminance sensor. The dark current component inherent to the semiconductor sensor is corrected by measuring the AC component of the illuminance sensor output. However, as for the illuminance measurement in the exposure apparatus using variable wavelength light, even if the semiconductor sensor is used, the variation in the dark current is very small, and therefore, it is practically not necessary to correct it, and it will suffice if the DC component is measured. However, in the exposure apparatus using high energy radiation such as X-rays, when the semiconductor sensor is used for the purpose of measurement of the illuminance, the temperature of the semiconductor sensor itself increases by the illumination with the exposure radiation, by which the dark current varies, with the result that the correct illuminance is not obtained. Referring to FIG. 2, there is shown a relation in a graph between the sensor output current with time when the semiconductor sensor is exposed to X-rays having a constant intensity. As will be understood from this Figure, even if the X-ray intensity does not change, the dark current increases due to the temperature rise of the sensor, and therefore, the output of the sensor is as if the X-ray intensity changes. In order to avoid this, it would be possible to use the above-described method wherein the dark current is corrected, which, however, necessitates the sensor to be provided with a chopper. This results in an inconvenience of an increased number of drivers. Accordingly, a fourth object of the present invention is to provide an exposure apparatus wherein the dark current of the semiconductor components can be corrected, and therefore, the illuminance of the exposure radiation can be measured with high accuracy without a necessity of an additional driving mechanism. According to an embodiment of the present invention, there is provided an exposure apparatus wherein a semiconductor sensor for measuring the illuminance is disposed behind the exposure shutter with respect to the radiation source; upon measurement, an exposure shutter is opened and closed, and an output of the sensor is produced in synchronism with the opening and closing of the shutter; and the output is signal-processed to calculate the illuminance of the exposure radiation. Therefore, the high measurement accuracy can be accomplished without the necessity of increasing the number of driving parts in the exposure apparatus. As disclosed in Japanese Laid-Open Patent Application No. 276223/1986, it is known that in an exposure apparatus wherein the light from a light source is reflected by a mirror and is then projected onto a mask, the mirror is vibrated to control the amount of exposure within the exposure angle in the mask to be a given or constant amount. In this case, it is necessary to determine a driving profile for controlling the swinging vibration of the mirror. The driving profile has to be produced in consideration of an intensity distribution of the light incident on the mirror, intensity variation of the emergent light due to a change in the angle of incidence, the change in the spectral distribution or the like when the light source is, for example, a synchrotron radiation source, the intensity of the radiation attenuates at least during several hours as periods, and therefore, various driving profiles have to be produced for respective shots meeting the attenuation. This places a heavy burden on the controller for controlling the exposure apparatus. Accordingly, it is a fifth object of the present invention to provide an exposure apparatus wherein the driving profile is compensated for in accordance with the radiation intensity characteristics change of the radiation source with time to assure the uniformity of exposure amount on the exposure surface without much burden imparted on the controller. According to an embodiment of the present invention, an absolute intensity of the radiation provided by the radiation source is measured, and in accordance with the change of the detected intensity, the time axis of the driving profile is proportionally expanded or contracted, thus eliminating the necessity for the process of producing a new driving profile for each change in the intensity of the radiation by the radiation source. Therefore, the controller is not given the heavy burden. More particularly, the exposure apparatus according to this embodiment includes an exposure radiation source, a stage for supporting a member to be exposed; optical control means for controlling the radiation projected from the radiation source to the member to be exposed; optical measurement means for measuring the intensity of the radiation provided by the exposure radiation source or the illuminance on the surface to be exposed; driving profile determining means for determining the driving profile of the optical control means, wherein the profile determining means is coupled with the optical control means and optical measuring means, and provides a uniform exposure amount on the surface to be exposed in consideration of the illuminance on the surface to be exposed as a function of a position of the surface to be exposed and the radiation intensity characteristics of the radiation source; and driving profile compensating means for expanding and contracting the time axis of the driving profile in accordance with a change of the radiation intensity characteristics of the radiation source. In a preferred embodiment, the exposure radiation source is a synchrotron radiation source, and the optical control means includes a movable aperture. In another preferred embodiment, the exposure radiation source is a synchrotron, and the optical control means includes an actuator for swingingly driving a mirror. Referring to FIG. 3, there is shown a movable aperture, in an enlarged scale, employed in the apparatus of FIG. 1. In this Figure, aperture limiting members 11 and 12 are movable in a y direction, and an aperture limiting member 20 is movable in an x direction constitute the movable aperture. More particularly, the edge surfaces 18 and 19 define the aperture. The synchrotron radiation passes through the limited opening or aperture in the z direction to within the view angle 21. As shown in FIG. 4, if the beam intensity at the aperture position is uniformly constant also in the y direction, the edge surface 18 of the aperture limiting member is moved in the y direction at a constant speed determined by (y.sub.z -y.sub.1)/.DELTA.T in accordance with the operation curve (1) in FIG. 5 during the time period of .DELTA.T from the point of time T1 at which the aperture limiting members 11 and 12 are contacted to close the aperture. Thereafter, it is stopped at the position indicated in FIG. 3. Then, the edge surface 19 of the aperture limiting member is moved in accordance with the operation line (2) in the +y direction at a constant speed determined by (y.sub.1 -y.sub.1)/.DELTA.T during the period of .DELTA.T from the point of time (T1+.DELTA.T). Then, it is brought into contact with the aperture limiting member 11 which has advanced and stopped. Thus, the exposure amount in the view angle 21 is constant, so that the wafer is uniformly exposed. If the strength of the beam is constant at the position of the aperture, the exposure amount of the view angle 21 is constant, and the member to be exposed is uniformly exposed. Actually, however, it is not constant, and in addition, the radiation intensity attenuates with time due to collisions of the electrons to the inside wall of the accumulation ring or gas molecules. For this reason, the exposure amount is not uniform within the angle of view, and therefore, there is a problem that the pattern of the mask is not uniformly formed on the wafer with high resolution. Accordingly, it is a sixth object of the present invention to provide an exposure apparatus wherein the exposure amount within the angle of view is made uniform, thus assuring the uniform exposure. According to an embodiment of the present invention, a driving speed of a movable member of an exposure control means for making uniform the exposure amount of the member to be exposed is determined in accordance with the attenuation characteristics with time of the illumination intensity to the member to be exposed, and the movable member of the exposure means or the stage supporting the member to be exposed is driven at the speed thus determined. More particularly, according to the embodiment of the present invention, there is provided an exposure apparatus, including an illumination source, a stage for supporting a member to be illuminated, exposure control means including a movable member for selectively limiting the light from the illumination source to the member to be illuminated, means for determining the driving speed in accordance with the attenuation (with time) characteristics of the illumination intensity to the member to be illuminated to provide a constant amount of exposure, and driving means for driving the movable member of the exposure control means or the stage at a speed thus determined. In a preferred embodiment, the exposure control means includes a movable aperture stop or a movable mirror. These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
	abstract	A sample transfer system for nuclear irradiation and a method of automatically irradiating sample containers is disclosed. The sample transfer system includes a conduit which may define a passage for transferring a plurality of sample containers, an input assembly which may be configured to allow the plurality of sample containers to pass through the conduit in a predefined order, and an exposure assembly which may be configured to receive the sample containers via the conduit and rotate the sample containers in front of a radiation source.
	abstract	A method of forming photo masks having rectangular patterns and a method for forming a semiconductor structure using the photo masks is provided. The method for forming the photo masks includes determining a minimum spacing and identifying vertical conductive feature patterns having a spacing less than the minimum spacing value. The method further includes determining a first direction to expand and a second direction to shrink, and checking against design rules to see if the design rules are violated for each of the vertical conductive feature patterns identified. If designed rules are not violated, the identified vertical conductive feature pattern is replaced with a revised vertical conductive feature pattern having a rectangular shape. The photo masks are then formed. The semiconductor structure can be formed using the photo masks.
062298771	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will hereinbelow be described in further detail with reference to the accompanying drawings. Firstly, embodiments of the improved direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention will be described hereinbelow. FIG. 1A is a schematic view showing an embodiment of the improved direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention. As illustrated in FIG. 1A, an improved direct conversion type of radiation image recording and read-out apparatus 1 comprises a radiation source 8, which produces radiation, an improved direct conversion type of solid-state radiation detector 10, which acts as two-dimensional image read-out means, and a grid plate 16, which is located between the radiation source 8 and the two-dimensional image read-out means. The grid plate 16 guides only the radiation, which comes from a specific direction, to the two-dimensional image read-out means. The improved direct conversion type of solid-state radiation detector 10 comprises a first electrical conductor layer 11 having permeability to recording radiation, and a recording photo-conductive layer 12, which exhibits photo-conductivity when it is exposed to the recording radiation having passed through the first electrical conductor layer. The solid-state radiation detector 10 also comprises a charge transporting layer 13, which acts approximately as an insulator with respect to electric charges having a polarity identical with the polarity of electric charges occurring in the first electrical conductor layer 11, and which acts approximately as a conductor with respect to electric charges having a polarity opposite to the polarity of the electric charges occurring in the first electrical conductor layer 11. The solid-state radiation detector 10 further comprises a reading photo-conductive layer 14, which exhibits photo-conductivity when it is exposed to a reading electromagnetic wave, and a second electrical conductor layer 15 having permeability to the reading electromagnetic wave. The layers 11, 12, 13, 14, and 15 are overlaid in this order. FIG. 1B is a plan view showing the solid-state radiation detector 10, as viewed from the side of the second electrical conductor layer 15. As indicated by the hatching in FIG. 1B, the second electrical conductor layer 15 is constituted as stripe-shaped electrodes 15a, 15a, . . . having comb tooth-like shapes. The stripe-shaped electrodes 15a, 15a, . . . are arrayed at a predetermined pitch PC (mm) so as to stand side by side in a direction, which is approximately normal to a longitudinal direction of each stripe-shaped electrode 15a. FIG. 1C is a plan view showing the solid-state radiation detector 10, as viewed from the side of the grid plate 16. The grid plate 16 is constituted of radiation absorbing substance regions 16a, 16a, . . . (formed from lead, or the like) and radiation-permeable substance regions 16b, 16b, . . . (formed from aluminum, or the like), which are arrayed alternately at a predetermined grid pitch PG (mm) so as to stand side by side in the direction approximately normal to the longitudinal direction of each stripe-shaped electrode 15a. Specifically, the stripe-shaped electrodes 15a, 15a, . . . and the radiation absorbing substance regions 16a, 16a, . . . of the grid plate 16 are arrayed in parallel with each other. Also, the radiation-permeable substance regions 16b, 16b, . . . of the grid plate 16 are arrayed in parallel with the stripe-shaped electrodes 15a, 15a, . . . With the radiation image recording and read-out apparatus 1, a radiation image is recorded with the solid-state radiation detector 10 and read out in the manner described below. Specifically, firstly, a D.C. voltage is applied across the first electrical conductor layer 11 and the stripe-shaped electrodes 15a, 15a, . . . of the second electrical conductor layer 15, and the two electrical conductor layers are electrically charged. The solid-state radiation detector 10 is located such that the surface on the side of the first electrical conductor layer 11 may stand facing the radiation source 8, and radiation carrying image information of an object 9 is irradiated to the first electrical conductor layer 11. The radiation, which has passed through the first electrical conductor layer 11, impinges upon the recording photo-conductive layer 12. As a result, electric charge pairs of electrons (negative charges) and holes (positive charges) occur in the recording photo-conductive layer 12. The negative charges or the positive charges are accumulated as latent image charges, which carry the radiation image information, at the interface between the recording photo-conductive layer 12 and the charge transporting layer 13. Thereafter, the stripe-shaped electrodes 15a, 15a, . . . are scanned with a (line-like) reading electromagnetic wave along the longitudinal direction of each stripe-shaped electrode 15a. As a result, electric charge pairs of electrons (negative charges) and holes (positive charges) occur in the reading photoconductive layer 14. Also, electric charges (transported polarity charges) having the polarity opposite to the polarity of the latent image charges move through the charge transporting layer 13 toward the recording photo-conductive layer 12. When the transported polarity charges arrive at the interface between the recording photo-conductive layer 12 and the charge transporting layer 13, charge recombination occurs between the accumulated latent image charges and the transported polarity charges. As a result, an electric current in accordance with the latent image charges flows. The electric current occurring from the charge recombination is detected by a signal processing circuit (not shown), and an image signal is thereby obtained. A signal detected from the respective stripe-shaped electrodes 15a, 15a, . . . is the signal in the main scanning direction. The scanning with the (line-like) reading electromagnetic wave in the longitudinal direction of each stripe-shaped electrode 15a corresponds to the sub-scanning. The radiation, which has been produced by the radiation source 8, is irradiated to the object 9 (such as a human body). At this time, absorption, scattering, and passage of the radiation occur in accordance with substances contained in the object 9, and the radiation carrying image information of the object 9 travels toward the grid plate 16. The grid plate 16 acts to prevent image information from becoming bad due to the scattered radiation. Specifically, only the radiation traveling in a specific direction (in this case, in the cross-sectional direction of the grid plate 16) passes through the radiation-permeable substance regions 16b, 16b, . . . , and the radiation scattered in the object 9 is absorbed by the radiation absorbing substance regions 16a, 16a, . . . Therefore, the problems concerning the image quality do not occur in that signal components corresponding to the scattered radiation mix in the image signal representing the image information of the object 9 and therefore a high signal-to-noise ratio cannot be obtained or the resolution cannot be kept high. In cases where the spatial frequency fC of the pitch of the stripe-shaped electrodes 15a, 15a, . . . , which is represented by the formula of fC=1/PC (cycle/mm), is set to be at least two times as high as the spatial frequency fG of the grid pitch, which is represented by the formula of fG=1/PG (cycle/mm), as will be estimated from the sampling theorem, a moire phenomenon forming a periodical (perceptible) striped pattern in the image does not occur theoretically. In such cases, signal components representing the pattern of the grid plate 16 are detected. Therefore, an image pattern representing the grid plate 16 is superposed upon the object image, and the object image becomes hard to see. Accordingly, such that the signal components representing the pattern of the grid plate 16 may be eliminated, the signal components SG, which are contained in the image signal having been detected by the two-dimensional image read-out means (in this embodiment, the solid-state radiation detector 10) and which carry the spatial frequency fG of the grid pitch, are suppressed. In this manner, the grid pattern occurring in the image can be rendered visually imperceptible. FIG. 2A is a block diagram showing a radiation image recording and read-out apparatus 7 provided with image processing means 70 for eliminating the signal components representing the pattern of the grid plate 16. As illustrated in FIG. 2A, the radiation image recording and read-out apparatus 7 comprises the radiation image recording and read-out apparatus 1 described above and the image processing means 70 connected to the radiation image recording and read-out apparatus 1. The image processing means 70 comprises an analog-to-digital converter 71 for converting an analog output signal, which has been obtained from the solid-state radiation detector 10, into a digital signal, and a frame memory 72 for storing the digital signal. The image processing means 70 also comprises a digital filter 73 for suppressing the signal components SG, which are contained in the signal received from the frame memory 72 and which carry the spatial frequency fG of the grid pitch. The image processing means 70 further comprises a frame memory 74 for storing an output signal obtained from the digital filter 73. With the radiation image recording and read-out apparatus 7, the output signal obtained from the solid-state radiation detector 10 is stored in the frame memory 72. The output signal contains the signal components representing the pattern of the grid plate 16. If an image is reproduced from the output signal, an image "c" shown in FIG. 2B will be obtained. As illustrated in FIG. 2B, in the image "c," an image "a" of a vertical stripe patterns representing the grid plate 16 and standing side by side in the main scanning direction is superposed upon an object image "b." The digital filter 73 suppresses the signal components representing the striped image "a" of the grid plate 16, i.e. the signal components SG carrying the spatial frequency fG of the grid pitch. FIG. 2C shows an example of amplitude characteristics of the digital filter 73. Since the signal components SG carrying the spatial frequency fG of the grid pitch have been suppressed by the digital filter 73, the output signal obtained from the digital filter 73 contains approximately only the signal representing the object image "b" shown in FIG. 2B. The thus obtained signal is stored in the frame memory 74, and the stored signal is read when it is to be used for making a diagnosis, or the like. In this embodiment, as the means for suppressing the signal components SG carrying the spatial frequency fG of the grid pitch, the digital filter 73 is employed. Alternatively, an analog filter may be employed for such purposes. Specifically, in the embodiment described above, the radiation absorbing substance regions 16a, 16a, . . . and the radiation-permeable substance regions 16b, 16b, . . . of the grid plate 16 are arrayed so as to stand side by side in the main scanning direction. Therefore, a simple trap (a band elimination filter) for suppressing the signal components SG carrying the spatial frequency fG of the grid pitch may be employed. In cases where the spatial frequency fG of the grid pitch cannot be set so as to satisfy the relationship described above, the difference between the spatial frequency fC of the pitch of the stripe-shaped electrodes 15a, 15a, . . . , which is represented by the formula of fC=1/PC (cycle/mm), and the spatial frequency fG of the grid pitch, which is represented by the formula of fG=1/PG (cycle/mm), the difference representing the moire frequency, may be set to be at least 1 cycle/mm. In this manner, the number of stripes periodically occurring in the image due to the moire phenomenon can be decreased, and the striped pattern can be rendered visually imperceptible. In such cases, the signal components SM, which are contained in the image signal having been detected by the two-dimensional image read-out means (in this embodiment, the solid-state radiation detector 10) and which carry the moire frequency occurring due to the grid plate 16, may be suppressed. In this manner, the moire occurring in the image can be rendered visually imperceptible. In such cases, there is no risk that the important components of at most 1 cycle/mm, which are contained in the image information, are lost. For such purposes, for example, the digital filter 73 of the image processing means 70 shown in FIG. 2A may be set so as to suppress the signal components SM carrying the moire frequency occurring due to the grid plate 16. FIG. 2D shows an example of amplitude characteristics of the digital filter 73 which is set for such purposes. A different embodiment of the improved direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention will be described hereinbelow with reference to FIGS. 3A, 3B, and 3C. As illustrated in FIG. 3A, in an improved direct conversion type of radiation image recording and read-out apparatus 2, a grid plate 26 comprises radiation absorbing substance regions 26a, 26a, . . . and radiation-permeable substance regions 26b, 26b, . . . , which are arrayed alternately so as to stand side by side in the longitudinal direction of each stripe-shaped electrode 15a. FIG. 3A is a schematic view showing the improved direct conversion type of radiation image recording and read-out apparatus 2. As illustrated in FIG. 3A, basically, the radiation image recording and read-out apparatus 2 has the same constitution as that in the radiation image recording and read-out apparatus 1 described above, except that the grid array direction of the grid plate is varied. FIG. 3B is a plan view showing the solid-state radiation detector 10 in the embodiment of FIG. 3A, as viewed from the side of the second electrical conductor layer 15. The second electrical conductor layer 15 is constituted as stripe-shaped electrodes 15a, 15a, . . . having comb tooth-like shapes. The stripe-shaped electrodes 15a, 15a, . . . are arrayed at the predetermined pitch PC (mm) so as to stand side by side in the direction, which is approximately normal to the longitudinal direction of each stripe-shaped electrode 15a. FIG. 3C is a plan view showing the solid-state radiation detector 10 in the embodiment of FIG. 3A, as viewed from the side of the grid plate 26. The grid plate 26 is constituted of the radiation absorbing substance regions 26a, 26a, . . . and the radiation-permeable substance regions 26b, 26b, . . . , which are arrayed alternately at the predetermined grid pitch PG (mm) so as to stand side by side in the longitudinal direction of each stripe-shaped electrode 15a. Specifically, the stripe-shaped electrodes 15a, 15a, . . . and the radiation absorbing substance regions 26a, 26a, . . . of the grid plate 26 are arrayed so as to intersect perpendicularly to each other. Also, the radiation-permeable substance regions 26b, 26b, . . . of the grid plate 26 are arrayed so as to intersect perpendicularly to the stripe-shaped electrodes 15a, 15a, . . . With the radiation image recording and read-out apparatus 2, a radiation image is recorded with the solid-state radiation detector 10 and read out in the same manner as that in the radiation image recording and read-out apparatus 1 described above. With the radiation image recording and read-out apparatus 2, wherein the grid plate 26 is employed, the problems concerning the deterioration of the image quality due to the scattered radiation can be eliminated. In cases where the spatial frequency fS of a sampling pitch, at which the latent image charges are read with scanning in the longitudinal direction of each stripe-shaped electrode 15a, which is represented by the formula of fS=1/PS (cycle/mm), is set to be at least two times as high as the spatial frequency fG of the grid pitch, which is represented by the formula of fG=1/PG (cycle/mm), as will be estimated from the sampling theorem, a moire phenomenon forming a periodical (perceptible) striped pattern in the image does not occur theoretically. In cases where the spatial frequency fG of the grid pitch cannot be set so as to satisfy the relationship described above, the difference between the spatial frequency fS of the sampling pitch, at which the latent image charges are read with scanning in the longitudinal direction of each stripe-shaped electrode 15a, which is represented by the formula of fS=1/PS (cycle/mm), and the spatial frequency fG of the grid pitch, which is represented by the formula of fG=1/PG (cycle/mm), the difference representing the moire frequency, may be set to be at least 1 cycle/mm. In this manner, the number of stripes periodically occurring in the image due to the moire phenomenon can be decreased, and the striped pattern can be rendered visually imperceptible. In the embodiment of FIG. 3A, as described above with reference to FIGS. 2A, 2B, 2C, and 2D, the radiation image recording and read-out apparatus 2 may be provided with the image processing means for suppressing the signal components SG, which are contained in the image signal having been detected by the solid-state radiation detector 10 and which carry the spatial frequency fG of the grid pitch, or the image processing means for suppressing the signal components SM, which are contained in the image signal having been detected by the solid-state radiation detector 10 and which carry the moire frequency occurring due to the grid plate 26. In this manner, the grid pattern occurring in the image or the moire occurring in the image can be rendered visually imperceptible. In the radiation image recording and read-out apparatuses 1 and 2 described above, the radiation absorbing substance regions and the radiation-permeable substance regions of the grid plate are arrayed in one direction. However, in the improved direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention, the grid array direction is not limited to one direction. Specifically, the improved direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention reads out a two-dimensional image. Therefore, as illustrated in FIG. 4, a checkered grid plate 17 comprising radiation absorbing substance regions 17a, 17a, . . . and radiation-permeable substance regions 17b, 17b, . . . , which are arrayed in a two-dimensional pattern, may be employed. In the grid plate 17, the radiation absorbing substance regions 17a, 17a, . . . and the radiation-permeable substance regions 17b, 17b, . . . are arrayed alternately such that they may stand side by side in the longitudinal direction of each stripe-shaped electrode 15a and in the direction approximately normal to the longitudinal direction. In cases where the grid plate 17 is employed, the effects of the improved direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention can be obtained with respect to both the longitudinal direction of each stripe-shaped electrode 15a and the direction approximately normal to the longitudinal direction. In the embodiments described above, the solid-state radiation detector 10 comprises the first electrical conductor layer 11 having permeability to recording radiation, the recording photo-conductive layer 12, which exhibits photo-conductivity when it is exposed to the recording radiation having passed through the first electrical conductor layer, the charge transporting layer 13, which acts approximately as an insulator with respect to electric charges having a polarity identical with the polarity of electric charges occurring in the first electrical conductor layer 11, and which acts approximately as a conductor with respect to electric charges having a polarity opposite to the polarity of the electric charges occurring in the first electrical conductor layer 11, the reading photo-conductive layer 14, which exhibits photo-conductivity when it is exposed to a reading electromagnetic wave, and the second electrical conductor layer 15 having permeability to the reading electromagnetic wave, the layers 11, 12, 13, 14, and 15 being overlaid in this order. However, the two-dimensional image read-out means is not limited to the solid-state radiation detector 10 described above and may be one of various other means constituted such that the latent image charges carrying image information can be read with stripe-shaped electrodes. Also, in the radiation image recording and read-out apparatuses 1 and 2 described above, the second electrical conductor layer 15 is constituted of the stripe-shaped electrodes 15a, 15a, . . . Alternatively, the second electrical conductor layer 15 may be formed as a flat plate-like layer and may be scanned with spot-like reading light, such as a laser beam, for reading the latent image charges. In such cases, the spatial frequency fS of the sampling pitch, at which the latent image charges are read with scanning with the reading light, may be set to be at least two times as high as the spatial frequency fG of the grid pitch. In this manner, a moire phenomenon forming a periodical (perceptible) striped pattern in the image does not occur. Also, the difference between the spatial frequency fS of the sampling pitch and the spatial frequency fG of the grid pitch, the difference representing the moire frequency, may be set to be at least 1 cycle/mm. In this manner, the number of stripes periodically occurring in the image due to the moire phenomenon can be decreased, and the striped pattern can be rendered visually imperceptible. The spatial frequency fS of the sampling pitch may be of either one or both of the main scanning direction and the sub-scanning direction. An embodiment of the direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention will be described hereinbelow with reference to FIG. 5. FIG. 5 is a schematic view showing a direct conversion type of radiation image recording and read-out apparatus 3 in accordance with the present invention, which is provided with a solid-state radiation detector 30. As illustrated in FIG. 5, the direct conversion type of radiation image recording and read-out apparatus 3 comprises the radiation source 8, which produces radiation, the direct conversion type of solid-state radiation detector 30, and a grid plate 36, which is located between the radiation source 8 and a radio-conductive material 31 of the solid-state radiation detector 30. The grid plate 36 guides only the radiation, which comes from a specific direction, to the radio-conductive material 31. The solid-state radiation detector 30 is provided with two-dimensional image read-out means 32. The two-dimensional image read-out means 32 comprises an insulating substrate (not shown), which is formed from, for example, quartz glass having a thickness of 3 mm, and a plurality of charge collecting electrodes 33, 33, . . . , which are formed on the insulating substrate and each of which corresponds to a single pixel. The charge collecting electrodes 33, 33, . . . are arrayed at a predetermined pitch PD (mm) in a matrix-like pattern in an X direction and a Y direction. The two-dimensional image read-out means 32 also comprises capacitors 34, 34, . . . Each of the capacitors 34, 34, . . . accumulates signal charges, which have been collected by the corresponding charge collecting electrode 33, as latent image charges. The two-dimensional image read-out means 32 further comprises switching devices 35, 35, . . . , which may be constituted of TFT's, or the like. Each of the switching devices 35, 35, . . . transfers the latent image charges, which have been accumulated by the corresponding capacitor 34, to the side of a signal processing circuit. The two-dimensional image read-out means 32 still further comprises a plurality of signal lines and scanning lines (not shown), which are connected to the switching devices 35, 35, . . . and are formed in a matrix-like pattern so as to intersect perpendicularly to each other. A first electrode 37 is formed on the side of the upper surface of the radio-conductive material 31. A second electrode 38 is formed on the side of the lower surfaces of the switching devices 35, 35, . . . The grid plate 36 is constituted of radiation absorbing substance regions 36a, 36a, . . . and radiation-permeable substance regions 36b, 36b, . . . , which are arrayed alternately at a predetermined grid pitch PG (mm) so as to stand side by side in at least either one of the X direction and the Y direction. (In FIG. 5, the grid array in only one specific direction is shown.) With the radiation image recording and read-out apparatus 3, a radiation image is recorded with the solid-state radiation detector 30 and read out in the manner described below. Specifically, firstly, a D.C. voltage is applied across the first electrode 37 and the second electrode 38, and the two electrodes are electrically charged. The solid-state radiation detector 30 is located such that the surface on the side of the radio-conductive material 31 may stand facing the side of the radiation source 8, and radiation carrying image information of the object 9 is irradiated to the radio-conductive material 31. As a result, electric charge pairs of electrons (negative charges) and holes (positive charges) occur in the radio-conductive material 31. The negative charges or the positive charges are collected by the charge collecting electrodes 33, 33, . . . and are accumulated as latent image charges, which carry the radiation image information, by the capacitors 34, 34, . . . The latent image charges are transferred by the switching devices 35, 35, . . . , which are located so as to correspond to the charge collecting electrodes 33, 33,. . . , to the signal processing circuit (not shown) and are outputted as an image signal. With the radiation image recording and read-out apparatus 3, wherein the grid plate 36 is employed, as in the improved direct conversion types of radiation image recording and read-out apparatuses 1 and 2 described above, the problems concerning the deterioration of the image quality due to the scattered radiation can be eliminated. In cases where the spatial frequency fD of the charge collecting electrodes 33, 33, . . . in the grid array direction, which is represented by the formula of fD=1/PD (cycle/mm), is set to be at least two times as high as the spatial frequency fG of the grid pitch, which is represented by the formula of fG=1/PG (cycle/mm), as in the improved direct conversion types of radiation image recording and read-out apparatuses 1 and 2 described above, a moire phenomenon forming a periodical (perceptible) striped pattern in the image does not occur theoretically. In cases where the spatial frequency fG of the grid pitch cannot be set so as to satisfy the relationship described above, the difference between the spatial frequency fD of the charge collecting electrodes 33, 33, . . . in the grid array direction, which is represented by the formula of fD=1/PD (cycle/mm), and the spatial frequency fG of the grid pitch, which is represented by the formula of fG=1/PG (cycle/mm), the difference representing the moire frequency, may be set to be at least 1 cycle/mm. In this manner, the number of stripes periodically occurring in the image due to the moire phenomenon can be decreased, and the striped pattern can be rendered visually imperceptible. In the embodiment of FIG. 5, as described above with reference to FIGS. 2A, 2B, 2C, and 2D, the radiation image recording and read-out apparatus 3 may be provided with the image processing means for suppressing the signal components SG, which are contained in the image signal having been detected by the two-dimensional image read-out means 32 and which carry the spatial frequency fG of the grid pitch, or the image processing means for suppressing the signal components SM, which are contained in the image signal having been detected by the two-dimensional image read-out means 32 and which carry the moire frequency occurring due to the grid plate 36. In this manner, the grid pattern occurring in the image or the moire occurring in the image can be rendered visually imperceptible. In FIG. 5, the specific cross-section of the solid-state radiation detector 30 of the radiation image recording and read-out apparatus 3 is illustrated, and the grid plate 36 is illustrated so as to comprise the radiation absorbing substance regions 36a, 36a, . . . and the radiation-permeable substance regions 36b, 36b, . . . , which are arrayed alternately so as to stand side by side in either one of the X direction and the Y direction. However, in the direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention, the grid array direction is not limited to one direction. Specifically, the direct conversion type of radiation image recording and read-out apparatus in accordance with the a present invention reads out a two-dimensional image. Therefore, as illustrated in FIG. 4, the checkered grid plate 17 comprising the radiation absorbing substance regions 17a, 17a, . . . and the radiation-permeable substance regions 17b, 17b, . . . , which are arrayed in a two-dimensional pattern, may be employed. In the grid plate 17, the radiation absorbing substance regions 17a, 17a, . . . and the radiation-permeable substance regions 17b, 17b, . . . are arrayed alternately such that they may stand side by side in the X direction and in the Y direction. In cases where the grid plate 17 is employed, the effects of the direct conversion type of radiation image recording and read-out apparatus in accordance with the present invention can be obtained with respect to both the X direction and the Y direction. An embodiment of the photo conversion type of radiation image recording and read-out apparatus in accordance with the present invention will be described hereinbelow with reference to FIG. 6. FIG. 6 is a schematic view showing a photo conversion type of radiation image recording and read-out apparatus 4 in accordance with the present invention, which is provided with a solid-state radiation detector 40. As illustrated in FIG. 6, the photo conversion type of radiation image recording and read-out apparatus 4 comprises the radiation source 8, which produces radiation, the photo conversion type of solid-state radiation detector 40, and a grid plate 46, which is located between the radiation source 8 and a fluorescent material (i.e., a scintillator 41) of the solid-state radiation detector 40. The grid plate 46 guides only the radiation, which comes from a specific direction, to the scintillator 41. The photo conversion type of solid-state radiation detector 40 is provided with two-dimensional image read-out means 42. The two-dimensional image read-out means 42 comprises an insulating substrate (not shown), which is formed from, for example, quartz glass having a thickness of 3 mm, and a plurality of photoelectric conversion devices 44, 44, . . . , which are formed on the insulating substrate and each of which corresponds to a single pixel. The photoelectric conversion devices 44, 44, . . . are arrayed at a predetermined pitch PD (mm) in a matrix-like pattern in an X direction and a Y direction. The two-dimensional image read-out means 42 also comprises switching devices 45, 45, . . . , which may be constituted of TFT's, or the like. Each of the switching devices 45, 45, . . . transfers signal charges, which have been obtained from photoelectric conversion performed by the corresponding photoelectric conversion device 44, to the side of a signal processing circuit (not shown). The two-dimensional image read-out means 42 still further comprises a plurality of signal lines and scanning lines (not shown), which are connected to the switching devices 45, 45, . . . and are formed in a matrix-like pattern so as to intersect perpendicularly to each other. The photoelectric conversion devices 44, 44, . . . are formed from a dielectric and act also as capacity devices. Specifically, the signal charges obtained from the photoelectric conversion performed by each photoelectric conversion device 44 are accumulated as the latent image charges in the photoelectric conversion device 44. The grid plate 46 is constituted of radiation absorbing substance regions 46a, 46a, . . . and radiation-permeable substance regions 46b, 46b, . . . , which are arrayed alternately at a predetermined grid pitch PG (mm) so as to stand side by side in at least either one of the X direction and the Y direction. (In FIG. 6, the grid array in only one specific direction is shown.) With the radiation image recording and read-out apparatus 4, a radiation image is recorded with the solid-state radiation detector 40 and read out in the manner described below. Specifically, firstly, the solid-state radiation detector 40 is located such that the scintillator 41 may stand facing the side of the radiation source 8, and radiation carrying image information of the object 9 is irradiated to the scintillator 41. As a result,the radiation impinges directly upon the scintillator 41 and is converted into visible light. The visible light is photoelectrically converted by the photoelectric conversion devices 44, 44, . . . into signal charges, and the signal charges are accumulated as the latent image charges, which carry the radiation image information, by the photoelectric conversion devices 44, 44, . . . The latent image charges are transferred by the switching devices 45, 45, . . . , which are located so as to correspond to the photoelectric conversion devices 44, 44, . . . , to the signal processing circuit (not shown) and are outputted as an image signal. With the radiation image recording and read-out apparatus 4, wherein the grid plate 46 is employed, as in the improved direct conversion types of radiation image recording and read-out apparatuses 1 and 2 or the direct conversion types of radiation image recording and read-out apparatus 3 described above, the problems concerning the deterioration of the image quality due to the scattered radiation can be eliminated. The radiation absorbing substance regions 46a, 46a, . . . and the radiation-permeable substance regions 46b, 46b, . . . of the grid plate 46 may be arrayed in the same manner as that in the direct conversion type of radiation image recording and read-out apparatus 3 described above. In cases where the relationship between the spatial frequency fP of the photoelectric conversion devices 44, 44, . . . . in the grid array direction, which is represented by the formula of fP=1/PP (cycle/mm), and the spatial frequency fG of the grid pitch, which is represented by the formula of fG=1/PG (cycle/mm), is set in the same manner as that in the radiation image recording and read-out apparatus 3, the same effects as those with the grid array of the grid plate 36 in the direct conversion type of radiation image recording and read-out apparatus 3 described above, can be obtained with the radiation image recording and read-out apparatus 4. Also, in the embodiment of FIG. 6, as described above with reference to FIGS. 2A, 2B, 2C, and 2D, the radiation image recording and read-out apparatus 4 may be provided with the image processing means for suppressing the signal components SG, which are contained in the image signal having been detected by the two-dimensional image read-out means 42 and which carry the spatial frequency fG of the grid pitch, or the image processing means for suppressing the signal components SM, which are contained in the image signal having been detected by the two-dimensional image read-out means 42 and which carry the moire frequency occurring due to the grid plate 46. In this manner, the grid pattern occurring in the image or the moire occurring in the image can be rendered visually imperceptible. FIG. 7 is a plan view showing two-dimensional image read-out means 52, the view serving as an aid in facilitating the explanation of the two-dimensional image read-out means 42 constituting the photo conversion type of solid-state radiation detector 40. In FIG. 7, photoelectric conversion devices and switching devices corresponding to four pixels are shown. In FIG. 7, hatched areas 53, 53, . . . are light receiving surfaces for receiving the fluorescence produced by the scintillator 41. The two-dimensional image read-out means 52 comprises photoelectric conversion devices 54, 54, . . . , and switching devices 55, 55, . . . for transferring the signal charges, which have been obtained from the photoelectric conversion performed by the photoelectric conversion devices 54, 54, . . . , to the side of the signal processing circuit. The two-dimensional image read-out means 52 also comprises scanning lines 56, 56, . . . for controlling the switching devices 55, 55, . . . , and signal lines 57, 57, . . . connected to the signal processing circuit. The two-dimensional image read-out means 52 further comprises electric source lines 58, 58, . . . for giving a bias to the photoelectric conversion devices 54, 54, . . . , and contact holes 59, 59, . . . for connecting the photoelectric conversion devices 54, 54, . . . and the switching devices 55, 55, . . . to each other. FIG. 8 is a sectional view taken on line A-B of FIG. 7. How the two-dimensional image read-out means 52 is produced will be described hereinbelow with reference to FIG. 8. Firstly, a first thin metal film layer 61 having a thickness of approximately 500 angstroms is formed from chromium Cr on an insulating substrate 60 with a sputtering process or a resistance heating process. Patterning is then performed with photolithography, and unnecessary regions are removed with an etching process. The first thin metal film layer 61 acts as a lower electrode of each photoelectric conversion device 54 and a gate electrode of each switching device 55. Thereafter, an amorphous silicon nitride insulation layer (a-SiN.sub.x) 62 for blocking the passage of electrons and holes and having a thickness of approximately 2,000 angstroms, a hydrogenated amorphous silicon photoelectric conversion layer (a-Si:H) 63 having a thickness of approximately 5,000 angstroms, and an n-type injection blocking layer (N+ layer) 64 for blocking the injection of hole carriers and having a thickness of approximately 500 angstroms are overlaid in the same vacuum with a CVD process. The layers 62, 63, and 64 constitute an insulation layer, a photoelectric conversion semiconductor layer, and a hole injection blocking layer of each photoelectric conversion device 54. The layers 62, 63, and 64 also constitute a gate insulation film, a semiconductor layer, and an ohmic contact layer of each switching device 55. The layers 62, 63, and 64 are further utilized as insulation layers at crossing areas (indicated by the reference numeral 51 in FIG. 7) of the first thin metal film layer 61 and a second thin metal film layer 65. After the layers have been overlaid, the regions acting as the contact holes 59, 59, . . . are etched with a dry etching process, such as an RIE process or a CDE process. Thereafter, the second thin metal film layer 65 having a thickness of approximately 10,000 angstroms is formed from aluminum Al with the sputtering process or the resistance heating process. Patterning is then performed with photolithography, and unnecessary regions are removed with an etching process. The second thin metal film layer 65 acts as an upper electrode of each photoelectric conversion device 54, source and drain electrodes of each switching device 55, and wiring (the scanning line 56, the signal line 57, and the electric source line 58). Simultaneously with the formation of the second thin metal film layer 65, the first thin metal film layer 61 and the second thin metal film layer 65 are connected. In order for a channel area of each switching device 55 to be formed, a portion of the area between the source electrode and the drain electrode is etched with the RIE process. Thereafter, unnecessary areas of the a-SiN.sub.x layer, the a-Si:H layer, and the N+ layer are etched with the RIE process, and the respective devices are separated from one another. In this manner, the photoelectric conversion devices 54, the switching device 55, and scanning line 56, the signal line 57, and the electric source line 58 are formed. In FIG. 8, the constitution of only two pixels is illustrated. However, a plurality of pixels are formed simultaneously on the insulating substrate 60. Finally, in order for moisture resistance to be enhanced, the respective devices and the wiring are covered with a passivation film (i.e., a protective film) 66. In the manner described above, the photoelectric conversion devices 54, 54, . . . , the switching devices 55, 55, . . . , and the wiring can be formed simply by etching the first thinmetal film layer 61, the a-SiN.sub.x layer 62, the a-Si:H layer 63, the N+ layer 64, and the second thin metal film layer 65, which have been overlaid simultaneously. At this time, only one injection blocking layer (the N+ layer) 64 is contained in each photoelectric conversion device 54 and can be formed in the same vacuum. Therefore, the photo conversion type of two-dimensional image read-out means having a large area and high performance can be produced with an ordinary thin film forming apparatus, such as the CVD apparatus or the sputtering apparatus. Also, the two-dimensional image read-out means can be produced with a small number of simple processes, at a high yield, and at a low cost. In the constitution described above, the relationship between holes and electrons may be reversed. For example, the injection blocking layer may be a p-type layer. In such cases, the application of the voltage and the electric field may be reversed, and the other constituents may be constituted. In this manner, the same operation can be achieved. Also, it is sufficient for the photoelectric conversion semiconductor layer to have the photoelectric conversion functions for generating electron-hole pairs. The photoelectric conversion semiconductor layer may be constituted of a single layer or a plurality of layers. Further, it is sufficient for the switching device to have a gate electrode, a gate insulation film, a semiconductor layer allowing channel formation, an ohmic contact layer, and a main electrode. For example, the ohmic contact layer may be a p-type layer. In such cases, the voltage for the control of the gate electrode may be reversed, and holes may be utilized as the carriers. As described above, with the radiation image recording and read-out apparatuses in accordance with the present invention, the grid plate is located between the radiation source and the solid-state radiation detector, the grid plate guiding only the radiation, which comes from a specific direction, to the solid-state radiation detector. Therefore, the radiation scattered in the object is absorbed by the radiation absorbing substance regions of the grid plate. As a result, the problems can be prevented from occurring in that the image quality becomes bad due to the scattered radiation. Also, in cases where the spatial frequency f0 of the sensor is at least two times as high as the spatial frequency fG of the grid pitch, the striped pattern occurring in the image due to the moire phenomenon can be rendered imperceptible in accordance with the sampling theorem. Further, in cases where the radiation image recording and read-out apparatuses are not constituted such that the spatial frequency f0 of the sensor is at least two times as high as the spatial frequency fG of the grid pitch, the moire frequency may be rendered to be at least 1 cycle/mm, and the number of stripes periodically occurring in the image due to the moire phenomenon may thereby be decreased. In this manner, the striped pattern can be rendered visually imperceptible. In cases where the radiation image recording and read-out apparatuses in accordance with the present invention are not constituted such that the spatial frequency f0 of the sensor is at least two times as high as the spatial frequency fG of the grid pitch, the signal components SM, which are contained in the image signal having been detected by the two-dimensional image read-out means and which carry the moire frequency occurring due to the grid, may be suppressed. In this manner, the moire occurring in the image can be rendered visually imperceptible. In such cases, there is no risk that the important components of at most 1 cycle/mm, which are contained in the image information, are lost. Furthermore, in cases where the signal components SG, which are contained in the image signal having been detected by the two-dimensional image read-out means and which carry the spatial frequency fG of the grid pitch, are suppressed, the grid pattern occurring in the image can be rendered visually imperceptible. Also, the photo conversion type of two-dimensional image read-out means having a large area and high performance can be produced with an ordinary thin film forming apparatus, such as the CVD apparatus or the sputtering apparatus. Further, the two-dimensional image read-out means can be produced with a small number of simple processes, at a high yield, and at a low cost.
042591554	claims	1. A fuel assembly for gas-cooled nuclear reactors, comprising a plurality of fuel rods having metal cladding containing nuclear fuel, said cladding having outer metal surfaces, spacer grids having interspaced openings through which said rods are inserted and rigid elements extending from said grids and having metal surfaces contacting the rods' said surfaces, in each instance one of said surfaces being roughened. 2. The assembly of claim 1 in which said one of said surfaces is roughened by having threads cut in the surface. 3. The assembly of claim 1 in which said one of said surfaces has transversely extending grooves.
059096543	claims	1. A method for the volume reduction of solid organic waste from nuclear facilities, said method comprising: (a) subjecting said organic waste to pyrolysis to form a gas which comprises organic compounds, said pyrolysis further forming a solid pyrolysis residue comprising residual carbon from said organic waste; and (b) gasifying via steam reforming solid pyrolysis residue to extract at least a portion of said residual carbon. (a) subjecting said organic waste to pyrolysis to form a first gas comprising organic compounds, said pyrolysis further forming a solid pyrolysis residue comprising residual carbon from said organic waste; (b) gasifying via steam reforming said solid pyrolysis residue to extract at least a portion of said residual carbon, said gasification forming a second gas and a solid waste residue; and (c) oxidizing said first gas and said second gas. (a) adding iron powder to said solid organic waste; (b) subjecting said organic waste to pyrolysis to form a gas which comprises organic compounds, said pyrolysis further forming a solid pyrolysis residue comprising residual carbon from said organic waste; and (c) gasifying said solid pyrolysis residue to extract at least a portion of said residual carbon. (a) subjecting said organic waste to pyrolysis to form a first gas comprising organic compounds, said pyrolysis further forming a solid pyrolysis residue comprising residual carbon from said organic waste; (b) gasifying said solid pyrolysis residue to extract at least a portion of said residual carbon, said gasification forming a second gas and a solid waste residue; and (c) oxidizing said first gas and said second gas in a submerged bed heater. (a) subjecting said organic waste to pyrolysis to form a first gas comprising organic compounds, said pyrolysis further forming a solid pyrolysis residue comprising residual carbon from said organic waste; (b) gasifying said solid pyrolysis residue to extract at least a portion of said residual carbon, said gasification forming a second gas and a solid waste residue; (c) oxidizing said first gas and said second gas; and (d) removing residual acid gases from said oxidized gases wherein said removal is performed by a fiber bed scrubber. 2. The method of claim 1 wherein said gasifying of said solid pyrolysis residue forms carbon dioxide and carbon monoxide. 3. The method for the volume reduction of solid organic waste of claim 1 wherein said pyrolysis is performed at a temperature of no more than 700.degree. C. 4. The method for the volume reduction of solid organic waste of claim 1 wherein said pyrolysis is carried out in the absence of a catalyst for the breaking down of carbon compounds that are present in said organic waste. 5. The method for the volume reduction of solid organic waste of claim 1 wherein said solid organic waste is an ion exchange medium. 6. The method for the volume reduction of solid organic waste of claim 3 wherein said pyrolysis is performed at a temperature of no more than 600.degree. C. 7. The method for the volume reduction of solid organic waste of claim 6 wherein said pyrolysis is performed at a temperature in the range of 450.degree. C. to 550.degree. C. 8. The method for the volume reduction of solid organic waste of claim 1 wherein said pyrolysis of said solid organic waste is performed for a residence time of less than 10 seconds. 9. The method for the volume reduction of solid organic waste of claim 8 wherein said pyrolysis of said solid organic waste is performed for a residence time of 5 to 8 seconds. 10. The method for the volume reduction of solid organic waste of claim 1 wherein said gasification of said solid pyrolysis residue reduces said solid pyrolysis residue by a factor of about 2 to 5 times. 11. The method of claim 1 further comprising the step of grinding said solid organic waste prior to pyrolysis. 12. The method of claim 11 further comprising the step of drying said ground organic waste prior to pyrolysis. 13. The method of claim 11 further comprising the step of adding iron powder to the ground organic waste prior to pyrolysis. 14. The method of claim 12 further comprising the step of adding iron powder to the dried ground organic waste powder prior to pyrolysis. 15. The method of claim 14 wherein said organic waste contains chlorine which combines with said iron powder to form FeCl.sub.2. 16. The method of claim 14 wherein said organic waste contains sulfur which combines with said iron powder to form FeS and FeS.sub.2. 17. The method for the volume reduction of solid organic waste of claim 1 wherein said solid pyrolysis residue comprises radioactive material. 18. A method for the processing of solid organic waste from nuclear facilities, said method comprising: 19. The method of claim 18 wherein said oxidizing step is performed in a submerged bed heater. 20. The method of claim 18 further comprising the step of grinding said organic waste. 21. The method of claim 20 further comprising the step of drying said organic waste. 22. The method of claim 20 further comprising the step of adding iron powder to said ground organic waste. 23. The method of claim 22 wherein said organic waste contains sulfur which combines with said iron powder to form FeS. 24. The method of claim 22 wherein said organic waste contains sulfur which combines with said iron powder to form FeS.sub.2. 25. The method of claim 22 wherein said organic waste contains chlorine which combines with said iron powder to form FeCl. 26. The method of claim 18 further comprising the step of quickly reducing the temperature of the oxidized gases of step (c). 27. The method of claim 26 further comprising the step of removing residual acid gases from said reduced temperature oxidized gases. 28. The method of claim 27 wherein said removal of residual acid gases is performed by a fiber bed scrubber. 29. The method for the volume reduction of solid organic waste of claim 1, wherein said organic waste contains up to about 50 percent moisture content. 30. The method for the volume reduction of solid organic waste of claim 29, wherein said organic waste contains from about 10 to about 30 percent moisture content. 31. The method for the volume reduction of solid organic waste of claim 1, wherein said pyrolysis of said organic waste is performed in the presence of substoichiometric quantities of oxygen. 32. A method for the volume reduction of solid organic waste from nuclear facilities, said method comprising: 33. The method of claim 32 further comprising the step of grinding said solid organic waste prior to pyrolysis. 34. The method of claim 32 further comprising the step of drying said solid organic waste prior to pyrolysis. 35. The method of claim 32 wherein said organic waste contains chlorine which combines with said iron powder to form FeCl.sub.2. 36. The method of claim 32 wherein said organic waste contains sulfur which combines with said iron powder to form FeS and FeS.sub.2. 37. A method for the processing of solid organic waste from nuclear facilities, said method comprising: 38. A method for the processing of solid organic waste from nuclear facilities, said method comprising: 39. The method of claim 38 further comprising the step of quickly reducing the temperature of the oxidized gases.
	summary
	summary
	abstract	An electron beam column comprises a thermal field emission electron source to generate an electron beam, an electron beam blanker, a beam shaping module, and electron beam optics comprising a plurality of electron beam lenses. In one version, the optical parameters of the electron beam blanker, beam shaping module, and electron beam optics are set to achieve an acceptance semi-angle β of from about ¼ to about 3 mrads, where the acceptance semi-angle β is half the angle subtended by the electron beam at the writing plane. The beam-shaping module can also operate as a single lens using upper and lower projection lenses. A multifunction module for an electron beam column is also described.
	abstract	The present disclosure relates to a method of performing an optical proximity correction (OPC) procedure that provides for a high degree of freedom by using an approximation design layer. In some embodiments, the method is performed by forming an integrated chip (IC) design having an original design layer with one or more original design shapes. An approximation design layer, which is different from the original design layer, is generated from the original design layer. The approximation design layer is a design layer that has been adjusted to remove features that may cause optical proximity correction (OPC) problems. An optical proximity correction (OPC) procedure is then performed on the approximation design layer. By performing the OPC procedure on the approximation design layer rather than on the original design layer, characteristics of the OPC procedure can be improved.
043449158	claims	1. A system for removably attaching a nuclear reactor fuel rod to a support member comprising: a. A reusable locking cap, secured to said nuclear reactor fuel rod, having opposing, resiliently deflectable fingers defining a socket having a body, throat, and mouth portion, said socket also having a narrowing decoupling-aiding tapered section from said body portion to said throat portion and a narrowing coupling-aiding tapered section from said mouth portion to said throat portion; and b. A reusable locking strip, secured to said support member, having an extension which fixedly engages said body portion of said socket, said extension comprising a top section which, upon application of a coupling force, engages said coupling-aiding tapered section to deflect open said fingers to widen said throat portion for receiving said extension into said body portion of said socket, and said extension also comprising a bottom section which, upon application of a decoupling force, engages said decoupling-aiding tapered section to deflect open said fingers without distortion to widen said throat portion for removing said extension from said body portion of said socket. (A) Said socket has a longitudinal axis, and said body portion has rotation-preventing generally planar finger surfaces generally parallel to said longitudinal axis; and (B) Said extension has a middle section having generally planar surfaces, generally parallel to said longitudinal axis, which engage, upon application of a torque, said rotation-preventing generally planar finger surfaces when said extension is attached to said socket. a. A reusable locking cap, secured to said support member, having opposing, resiliently deflectable fingers defining a socket having a body, throat, and mouth portion, said socket also having a narrowing decoupling-aiding tapered section from said body portion to said throat portion and a narrowing coupling-aiding tapered section from said mouth portion to said throat portion; and b. A reusable locking strip, secured to said nuclear reactor fuel rod, having an extension which fixedly engages said body portion of said socket, said extension comprising a top section which, upon application of a coupling force, engages said coupling-aiding tapered section to deflect open without distortion said fingers to widen said throat portion for receiving said extension into said body portion of said socket, and said extension also comprising a bottom section which, upon application of a decoupling force, engages said decoupling-aiding tapered section to deflect open said fingers to widen said throat portion for removing said extension from said body portion of said socket. a. A reusable locking cap, secured to said nuclear reactor fuel rod, having opposing fingers defining a socket having a body, throat, and mouth portion, said socket also having a narrowing decoupling-aiding tapered section from said body portion to said throat portion and a narrowing coupling-aided tapered section from said mouth portion to said throat portion; and b. A reusable locking strip, secured to said support member, having a resiliently transversely compressible extension which fixedly engages said body portion of said socket, said extension, upon application of a coupling force, engaging said coupling-aiding tapered section to transversely compress said extension for receiving said extension through said throat portion into said body portion of said socket, and said extension, upon application of a decoupling force, engaging said decoupling-aiding tapered section to transversely compress said extension for removing said extension from said body portion of said socket without distortion. a. A reusable locking cap, secured to said support member, having opposing fingers defining a socket having a body, throat, and mouth portion, said socket also having a narrowing decoupling-aiding tapered section from said body portion to said throat portion and a narrowing coupling-aiding tapered section from said mouth portion to said throat portion; and b. A reusable locking strip, secured to said nuclear reactor fuel rod, having a resiliently transversely compressible extension which fixedly engages said body portion of said socket, said extension, upon application of a coupling force, engaging said coupling-aiding tapered section to transversely compress said extension for receiving said extension through said throat portion into said body portion of said socket, and said extension, upon application of a decoupling force, engaging said decoupling-aiding tapered section to transversely compress said extension for removing said extension from said body portion of said socket without distortion. 2. The system of claim 1, wherein said locking strip's extension fixedly engages said body portion of said socket when said fingers are generally relaxed. 3. The system of claim 2, wherein: 4. The system of claim 3, also including an additional said locking cap secured to an additional said fuel rod, and wherein said locking caps each have two fingers and said locking strip has a widened said extension to also accommodate said additional locking cap. 5. The system of claim 4, wherein said coupling-aiding tapered section has generally planar finger surfaces. 6. The system of claim 5, wherein said top section has a convex area which, upon application of said coupling force, engages said coupling-aiding tapered section. 7. The system of claim 6, wherein said extension generally fills said socket when said extension is attached to said socket. 8. The system of claim 7, wherein said coupling-aiding tapered section has a more gradual taper than that of said decoupling-aiding tapered section, and said decoupling force is greater than said coupling force. 9. A system for removably attaching a nuclear reactor fuel rod to support member, comprising: 10. A system for removably attaching a nuclear reactor fuel rod to a support member, comprising: 11. A system for removably attaching a nuclear reactor fuel rod to a support member, comprising:
	claims	1. A method of producing cesium-131, comprising:dissolving at least one non-irradiated barium source in water or a nitric acid solution to produce a barium target solution;subjecting the barium target solution to neutron radiation to produce cesium-131; andremoving the cesium-131 from the barium target solution. 2. The method of claim 1, wherein dissolving at least one non-irradiated barium source in water or a nitric acid solution comprises dissolving at least one nonirradiated barium compound selected from the group consisting of barium carbonate (BaCO3), barium chlorate (Ba(ClO3)2.H2O), barium chloride (BaCl2), barium formate (Ba(CHO2)2), barium fluoride (BaF2), barium nitrate (Ba(NO3)2), barium metal, and barium oxide (BaO) in the water or nitric acid solution. 3. The method of claim 1, wherein dissolving at least one non-irradiated barium compound in water or a nitric acid solution comprises dissolving at least one of a non-irradiated, natural barium compound and a non-irradiated, enriched barium compound in the water or nitric acid solution. 4. The method of claim 1, wherein dissolving at least one non-irradiated barium source in water or a nitric acid solution to produce a barium target solution comprises dissolving an amount of the at least one non-irradiated barium source in the water or nitric acid solution to provide a concentration of the at least one non-irradiated barium source of greater than or equal to approximately 0.5 M. 5. The method of claim 1, wherein dissolving at least one non-irradiated barium source in water or a nitric acid solution comprises dissolving an amount of the at least one non-irradiated barium source in the water or nitric acid solution to provide a concentration of the at least one non-irradiated barium source of from approximately 0.5 M to approximately 1 M. 6. The method of claim 1, wherein dissolving at least one non-irradiated barium source in water or a nitric acid solution comprises dissolving the at least one nonirradiated barium source in from approximately 1 M to approximately 3 M nitric acid. 7. The method of claim 1, wherein removing the cesium-131 from the barium target solution comprises flowing the barium target solution through a separation device comprising a calixarene compound. 8. A method of producing cesium-131, comprising:irradiating a barium target solution comprising nitric acid and at least one non-irradiated barium-130 compound to produce cesium-131;complexing the cesium-131 with a calixarene compound; andseparating the cesium-131 from the irradiated barium target solution. 9. The method of claim 8, wherein irradiating a barium target solution comprising at least one non-irradiated barium-130 compound comprises irradiating the barium target solution comprising at least one naturally occurring barium-130 compound or at least one barium compound enriched in barium-130. 10. The method of claim 8, wherein separating the cesium-131 from the irradiated barium target solution comprises removing the cesium-131 by liquid-liquid extraction. 11. The method of claim 8, wherein separating the cesium-131 from the irradiated barium target solution comprises removing the cesium-131 by extraction chromatography. 12. A method of producing cesium-131, comprising:irradiating a target solution comprising barium and nitric acid to produce an irradiated barium target solution;enabling the irradiated barium target solution to decay for an amount of time sufficient to produce cesium-131; andcontinuously separating the cesium-131 from the irradiated barium target solution. 13. The method of claim 12, wherein irradiating a barium target solution to produce an irradiated barium target solution comprises exposing the barium target solution to neutron irradiation. 14. The method of claim 12, wherein continuously separating the cesium-131 from the irradiated barium target solution comprises continuously circulating the irradiated barium target solution through an isotope production system. 15. The method of claim 12, wherein continuously separating the cesium-131 from the irradiated barium target solution comprises continuously contacting the irradiated barium target solution with a calixarene extractant solution comprising at least one calixarene compound, at least one modifier, and a diluent. 16. The method of claim 12, wherein continuously separating the cesium-131 from the irradiated barium target solution comprises complexing the cesium-131 with a calixarene compound selected from the group consisting of: calix[4]arene-bis-(tert-octylbenzo)-crown-6, 1,3-alternate-25,27-di(octyloxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(decyloxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(dodecyloxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(2-ethylhexyl-l-oxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(3,7-dimethyloctyl-1-oxy)calix[4]arenebenzocrown-6, and 1,3-alternate-25,27-di(4-butyloctyl-l-oxy)calix[4]arenebenzocrown-6. 17. The method of claim 12, wherein continuously separating the cesium-131 from the irradiated barium target solution comprises continuously flowing the irradiated barium target solution through an extraction column comprising at least one calixarene compound supported on a solid support. 18. A method of producing cesium-131, comprising:dissolving at least one non-irradiated barium source in nitric acid to produce a barium target solution;irradiating the barium target solution in a nuclear reactor to produce cesium-131; andflowing the irradiated barium target solution through at least one separation device to remove the cesium-131. 19. The method of claim 18, further comprising continuously flowing the irradiated barium target solution through the nuclear reactor and the at least one separation device.
	summary
	summary
	description	This application is the U.S. National Phase under 35 U.S.C. § 371 of International Application No. PCT/JP2018/012576, filed Mar. 27, 2018, designating the U.S., which claims priority to International Application No. PCT/JP2017/013684, filed Mar. 31, 2017, the entire contents of which are incorporated herein by reference. The present invention relates to a dosimeter container and a dosage measuring body for measuring a dosage of radiation other than neutron radiation, such as gamma radiation. In recent years, Boron Neutron Capture Therapy (BNCT) has been under extensive research and development as a rapidly emerging therapy for cancer. Boron Neutron Capture Therapy represents a radiotherapy that uses neutron radiation. First, a boron compound designed to be specifically incorporated into cancer cells is administered to a patient. Then, cancer cells in which the boron compound has been accumulated are irradiated with neutron radiation controlled to have an energy within a predetermined range. A collision of the neutron radiation with the boron compound will generate an α ray. That α ray will kill the cancer cells. Boron Neutron Capture Therapy is a promising method of treating cancer, and is on the verge of advancing to the clinical trial stage. A neutron radiation irradiation apparatus used for Boron Neutron Capture Therapy is designed to achieve a therapeutic effect by taking advantage of radiation such as thermal neutron radiation and epithermal neutron radiation. A neutron radiation irradiation environment may be viewed as a field where types of radiation having energies within a certain range coexist. Considering the above view of the neutron radiation irradiation environment, required is a step of selectively measuring only gamma radiation as isolated as possible to ensure the safety of the apparatus and other factors. To date, a neutron radiation generator for use in the neutron radiation irradiation apparatus has always been a nuclear reactor. However, in recent years, a small neutron generator for in-hospital use has been emerging. The small neutron generator is configured to allow protons and deuterons accelerated in an accelerator to collide against a target of beryllium or lithium. The resulting neutron radiation, which includes a higher proportion of thermal and epithermal neutrons as compared with those generated by a conventional generator, is decelerated with a moderator to provide a neutron radiation irradiation environment having less negative effects on the human body. In a neutron radiation irradiation environment, there coexist types of radiation having effects on the human body such as gamma radiation, including gamma radiation radioactivated by irradiation with neutron radiation, in addition to neutron radiation. When gamma radiation is measured in the presence of neutron radiation, the dosage of gamma radiation may not be accurately determined due to the influence of the neutron radiation even when a dedicated dosimeter is used for detection. As an approach for enhancing the measurement accuracy of a dosage of gamma radiation, a gamma radiation measuring device has been proposed, the gamma radiation measuring device including a first detector, the first detector including a filter, the filter being arranged around a radiation dosimeter of the same type as a radiation dosimeter constituting a second detector to be used together, and being made of lead or a lead alloy and having a thickness such that the decay of neutrons and the correction coefficient of gamma radiation fall within an acceptable range for measuring gamma radiation (see Patent Document 1). However, lead blocks gamma radiation, but not neutron radiation. Further, lead and lead alloys themselves may emit gamma radiation due to radioactivation when exposed to neutron radiation. Therefore, the dosage of gamma radiation needs to be calculated from the difference between a detection result from a radiation detector provided in the inside of a filter made of lead or a lead alloy and a detection result from a radiation detector provided outside of the filter. Consequently, the approach described in Patent Document 1 may result in complicated procedures as well as a radiation dosimeter that is larger in size. Moreover, in view of demands for a neutron-radiation shielding material, a shape-formable composition for forming radiation protection equipment has been proposed, in which a radiation shielding material such as lithium fluoride is kneaded with a thermoplastic resin having a melting point of 40 to 80° C. (see Patent Document 2). However, in the shape-formable composition described in Patent Document 2, a limited range of the ratio of a radiation shielding material such as a lithium compound which can be mixed with a resin requires a shielding material having a larger thickness in order to obtain a sufficient shielding effect. Moreover, a resin component may be slightly radioactivated to emit gamma radiation when irradiated with neutron radiation. This may affect measurement results from a dosimeter. Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2016-3892 Patent Document 2: Japanese Unexamined Patent Application, Publication No. H08-201581 The present invention is made in view of the aforementioned actual circumstances. An object of the present invention is to provide a dosimeter container which contributes to both an improvement in measurement accuracy of a radiation dosage and a downsizing of a measuring apparatus. The present inventors conducted extensive studies to achieve the above object. As a result, the present inventors have found that a dosimeter container which contributes to both an improvement in measurement accuracy of a radiation dosage and a downsizing of a measuring apparatus can be obtained when the dosimeter container includes: a housing portion for housing a specific radiation dosage measuring device; and a shield portion surrounding the housing portion and including at least a member made of a specific material capable of blocking neutron radiation. The present invention was then completed. That is, the present invention can provide the followings. (1) A first embodiment of the present invention is a dosimeter container including: a housing portion for housing a radiation dosage measuring device for measuring a dosage of predetermined radiation other than neutron radiation; and a shield portion surrounding the housing portion and including at least a LiF sintered body, the LiF sintered body transmitting the predetermined radiation to be measured with the radiation dosage measuring device, but blocking neutron radiation. (2) A second embodiment of the present invention is the dosimeter container according to the first embodiment, in which the LiF sintered body is a 6LiF sintered body. (3) A third embodiment of the present invention is the dosimeter container according to the second embodiment, in which the 6LiF sintered body includes 6LiF, and has a relative density of 83% or more to 90% or less, and has a good appearance with the occurrence of cracks and/or blisters being reduced on an outer surface. (4) A fourth embodiment of the present invention is the dosimeter container according to any one of the first to third embodiments, in which the predetermined radiation is gamma radiation. (5) A fifth embodiment of the present invention is the dosimeter container according to any one of the first to fourth embodiments, in which the shield portion includes at least two or more shield portion components, and the adjacent shield portion components of the at least two or more shield portion components that have mutually abuttable structures. (6) A sixth embodiment of the present invention is the dosimeter container according to the fifth embodiment, in which the adjacent shield portion components have mutually fittable structures. (7) A seventh embodiment of the present invention is the dosimeter container according to the fifth or sixth embodiment, in which the housing portion has a size substantially the same as or larger than the size of the radiation dosage measuring device, and the housing portion extends over the entirety of the shield portion components. (8) An eighth embodiment of the present invention is the dosimeter container according to any one of the fifth to seventh embodiments, in which a shortest distance from an inner surface of the housing portion to outer surfaces of the shield portion components is constant. (9) A ninth embodiment of the present invention is a dosage measuring body comprising the radiation dosage measuring device housed in the housing portion of the dosimeter container according to any one of the first to eighth embodiments. The present invention can provide a dosimeter container which contributes to both an improvement in measurement accuracy of a radiation dosage and a downsizing of a measuring apparatus. Below, the specific embodiments of the dosimeter container according to the present invention will be described in detail, but the present invention shall not be limited to the following embodiments in any sense. Modifications may be appropriately made without departing from the spirit and scope of the present invention. <Dosimeter Container 10> FIG. 1 schematically shows an example of a dosimeter container 10 according to the first embodiment of the present invention. More specifically, FIG. 1A shows a perspective view of the dosimeter container 10. FIG. 1B shows a front view of the dosimeter container 10, and FIG. 1C shows a cross-sectional view at the A-A section of FIG. 1B. FIG. 1D shows a perspective view of a body portion 12A of the dosimeter container 10, and FIG. 1E shows a perspective view of a lid portion 12B of the dosimeter container 10. Further, FIG. 1F schematically shows a state where a radiation dosage measuring device 51 is housed in a housing portion 11 of the dosimeter container 10. The dosimeter container 10 according to the present embodiment includes the housing portion 11 for housing a radiation dosage measuring device and a shield portion 12 surrounding the housing portion 11. [Housing Portion 11] The housing portion 11 has a space for storing the radiation dosage measuring device. The radiation dosage measuring device is an element which measures a dosage of predetermined radiation other than neutron radiation. The predetermined radiation may be selected from any type of radiation other than neutron radiation. However, the predetermined radiation is preferably gamma radiation in the view of an application to Boron Neutron Capture Therapy (BNCT). It is noted that the term “radiation dosage measuring device” as used herein shall encompass dosimeters in various forms, including a fluorescent glass element itself of a glass dosimeter, a fluorescent glass element of a glass dosimeter contained in a resin holder, and the like. There is no particular limitation on the type of the element. Examples of the element include a fluorescent glass element of a glass dosimeter, ferrous sulfate or ferrous ammonium sulfate used in a Fricke dosimeter, and the like. There is no particular limitation on the size of the housing portion 11, but it is preferred to be substantially the same as the size of a radiation dosage measuring device in view of downsizing the dosimeter container 10. For example, when the radiation dosage measuring device is a fluorescent glass element of a glass dosimeter, the housing portion 11 has a cylindrical shape with φ2.5 mm to 3 mm, and a length of 10 mm to 15 mm. [Shield Portion 12] The shield portion 12 surrounds the housing portion 11, and is configured so as to enable neutron radiation which reaches the dosimeter container 10 to be blocked. The shield portion 12 includes a member made of a material which blocks neutron radiation, but transmits at least radiation to be measured with a radiation dosage measuring device housed in the housing portion 11. This configuration enables a single radiation dosage measuring device housed alone in the housing portion 11 of the dosimeter container 10 to accurately measure the target radiation even when no radiation dosage measuring device is provided outside of the dosimeter container 10. Therefore, procedures of calculating a radiation dosage of the target radiation can be simplified, and the dosimeter container 10 can be downsized. A material of the shield portion 12 will be described in detail below. There is no particular limitation on the lower limit of the size of the shield portion 12, provided that it is sized so as to be able to appropriately block neutron radiation which reaches the shield portion 12, but appropriately transmit radiation to be measured with a radiation dosage measuring device. For example, the shield portion 12 preferably has a thickness of 2 mm or more, more preferably 3 mm or more, around the housing portion 11. There is no particular limitation on the upper limit of the size of the shield portion 12, but the shield portion 12 preferably has a thickness of 8 mm or less, more preferably 5 mm or less, around the housing portion 11, in view of obtaining a thinner and smaller dosimeter as compared with a conventional one. Moreover, the shield portion 12 has at least two or more shield portion components. In the present embodiment, the shield portion 12 has a body portion 12A and a lid portion 12B as the two or more shield portion components. As shown in FIGS. 1C, 1D, and 1E, the body portion 12A and the lid portion 12B, which are shield portion components adjacent to each other, have mutually abuttable structures. The shield portion 12 includes two or more shield portion components, and adjacent shield portion components of the two or more shield portion components are configured to be able to abut to each other. This configuration enables easy mutual attachment and detachment of the shield portion components, which in turn enables a radiation dosage measuring device to be easily housed in and removed from the housing portion 11. There is no particular limitation on the types of mutually abuttable structures. For Example, the body portion 12A and the lid portion 12B may be configured to have mutually fittable structures as shown in FIGS. 1C, 1D, and 1E. Alternatively, the body portion 12A and the lid portion 12B may be configured to be abutted to each other, and fixed with a fixing member at the outside of a joint region. In particular, the body portion 12A and the lid portion 12B as adjacent shield portion components preferably have mutually fittable structures. When configured to have fittable structures, the body portion 12A and the lid portion 12B can be united together without fixing them with a fixing member at the outside of a joint region. Moreover, effects which may occur due to irradiation of the fixing member with neutron radiation and radiation other than neutron radiation can be disregarded. There is no particular limitation on the types of fittable structures. For example, as shown in FIGS. 1C, 1D, and 1E, one shield portion component (the body portion 12A in this case) may be configured to have a protruded shape, and the other shield portion component (the lid portion 12B in this case) may be configured to have a depressed shape. Alternatively, one shield portion component may be an inclined member inclined in a predetermined direction, and the other shield portion component may be another inclined member having a shape symmetrical to the one shield portion component. In particular, in view of suitably blocking neutron radiation with which the dosimeter container 10 is directly irradiated, and suitably transmitting the target radiation, the fittable structures are preferably configured such that one shield portion component (the body portion 12A in this case) has a protruded shape, and the other shield portion component (the lid portion 12B in this case) has a depressed shape, as shown in FIGS. 1C, 1D, and 1E. Further, a length LA from the base of the body portion 12A to the apex portion of the protruded member is preferably the same as a length LB from the base of the lid portion 12B to the apex portion of the depressed member. When LA is the same as LB, both the body portion 12A and the lid portion 12B can be obtained from a plate-like material having the same thickness, allowing for efficient manufacture of the dosimeter container 10 and reduced losses due to the cutting of raw materials. As described above, the housing portion 11 preferably has a size substantially the same as that of a radiation dosage measuring device. In addition, the housing portion 11 preferably extends over the entirety of the shield portion components (the body portion 12A and the lid portion 12B in the present embodiment). When the housing portion 11 has a size substantially the same as that of a radiation dosage measuring device, and the housing portion 11 extends over the entirety of the shield portion components, the radiation dosage measuring device housed in the housing portion 11 itself can serve as a fixing member for fixing the shield portion components abutted together. When the body portion 12A has a protruded shape, and the lid portion 12B has a depressed shape so that the body portion 12A can be fitted to the lid portion 12B, the length where the body portion 12A is protruded in a protruding manner and the depth where the lid portion 12B is depressed in a depressing manner may be appropriately selected in view of easy abutting and detachment of the body portion 12A and the lid portion 12B as well as in view of the fixing strength of the abutted shield portion components. For example, when a radiation dosage measuring device is a fluorescent glass element of a glass dosimeter, the lower limit of the length where the body portion 12A is protruded in a protruding manner and the depth where the lid portion 12B is depressed in a depressing manner is preferably 1 mm or more, more preferably 1.5 mm or more, and even more preferably 2 mm or more. When the length where the body portion 12A is protruded in a protruding manner and the depth where the lid portion 12B is depressed in a depressing manner are too short, the lid portion 12B may detach from the body portion 12A during use of the dosimeter container 10 even when the body portion 12A is fitted to the lid portion 12B. On the other hand, when a radiation dosage measuring device is a fluorescent glass element of a glass dosimeter, the upper limit of the length where the body portion 12A is protruded in a protruding manner and the depth where the lid portion 12B is depressed in a depressing manner is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. When the length where the body portion 12A is protruded in a protruding manner and the depth where the lid portion 12B is depressed in a depressing manner are too long, loss of raw materials due to cutting may be significant, resulting in increased costs. The shield portion components are each preferably configured to have a thickness so that the shortest distance from the inner surface of the housing portion to the outer surfaces of the shield portion components is constant. This configuration can allow a radiation dosage measuring device housed in the housing portion to be uniformly covered with the shield portion components, ensuring that neutron radiation from all directions can be blocked at an equal proportion. Therefore, a dosage measuring body can be placed according to a desired arrangement pattern in the container regardless of the irradiation directions of neutron radiation. For example, in a case where the thickness of the shield portion components is 5 mm as shown in FIG. 5, both end portions of the shield portion components may be curved with a radius of R5 as viewed in a cross-section at the corners of the end portions of the housing portion. This enables the shortest distance from the corners of the end portions of the housing portion to the outer surfaces of the shield portion components to be maintained equally at 5 mm. When the curvatures of R portions at the end portions of the shield portion components are appropriately designed according to the thicknesses of the shield portion components as described above, the shortest distance from the inner surface of the housing portion to the outer surfaces of the shield portion components can be configured to be constant. Materials having the aforementioned properties include LiF-containing materials. Among these, a LiF sintered body is preferably used as a LiF-containing material because it has a high content of LiF with other ingredients that are unaffected by neutron radiation passing therethrough, and can contribute to obtaining a smaller and thinner dosimeter container 10. It is worth noting that Li includes two stable isotopes, 6Li and 7Li, and their natural abundance percentages are 92.5 atom % and 7.5 atom % for 7Li and 6Li, respectively. Among these, 6Li contributes to blockage of neutron radiation, and thus the use of 6LiF in which 6Li is enriched can block neutron radiation at a higher efficiency. In view of the above, a 6LiF sintered body is more preferably used as the LiF sintered body. Below, a 6LiF sintered body will be described. (6LiF Sintered Body) (1) Ingredient: 6LiF The 6LiF sintered body includes 6LiF as the main raw material, and has a higher neutron shielding performance as compared with other neutron moderators/shielding materials (for example, CaF2, MgF2, MgF2—CaF2 binary system, MgF2—CaF2—LiF ternary system, and the like). Moreover, the 6LiF sintered body includes 6LiF, but does not include other inorganic compounds as sintering aids or composite ingredients, and further is not a mixture with a thermoplastic resin and the like. Therefore, the 6LiF sintered body according to the present embodiment has a very high neutron shielding performance, and can contribute to obtaining a thinner and smaller shield portion 12. The purity of 6Li in the 6LiF sintered body is preferably 95.0 atom or more, and the purity of LiF is preferably 99 wt % or more. If a large number of impurities such as metal ingredients (elements) are present in the 6LiF sintered body, these impurities may be radioactivated to emit gamma radiation when the 6LiF sintered body is irradiated with neutron radiation. 6LiF does not undergo radioactivation even when irradiated with neutron radiation. Therefore, the 6LiF sintered body according to the present embodiment having 95.0 atom % or more of 6Li and a LiF purity of 99 wt % has excellent neutron shielding performance, and in addition, advantageously reduces the effects of radiation exposure on the human body. Further, 6LiF is prepared as a sintered body. Approaches to manufacturing a 6LiF sintered body include the single crystal growth method, a method involving solidifying from a melt, the sintering method, and the like. However, the single crystal growth method requires precise control over a manufacturing process, and suffers from inferior quality stability, resulting in very expensive product prices. In addition, the resulting compact, which is a single crystal, has cleavability, resulting in problems such as susceptibility to cracking during processing. Further, a method involving solidifying from a melt requires strict temperature control when cooling, and also requires a prolonged cooling time. Therefore, it is difficult to obtain a uniform and sound solidified material throughout the entirety of a relatively large size. The 6LiF sintered body herein is obtained by the sintering method. Therefore, neutron shielding materials having high neutron shielding performance can be stably supplied. (2) Relative Density The 6LiF sintered body preferably has a relative density of 83% or more to 90% or less. As used in the present embodiment, the term “relative density” refers to a value obtained by dividing the density of a sintered body by the theoretical density (2.64 g/cm3) of LiF, and then multiplying the resulting value by 100. A relative density of 83% or more to 90% or less means that the 6LiF sintered body is not highly densified. Advantageously, this leads to excellent cutting workability of the 6LiF sintered body. A relative density that is too small may not be able to confer sufficient neutron shielding performance on the 6LiF sintered body. Further, a relative density that is too small may mean a higher cavity rate within the sintered body, resulting in inferior mechanical strength. This may cause breakage during processing and other problems. On the other hand, a relative density that is too large results in a high degree of densification, and thus the residual stress inside the material may be released during processing of the sintered body even if sufficient neutron shielding ability is given to the 6LiF sintered body. This may generate a crack or the like. (3) Thickness There is no particular limitation on the thickness of the 6LiF sintered body as long as it is thick enough to suitably block neutron radiation. Specifically, the thickness of the 6LiF sintered body is preferably 2 mm or more, more preferably 3 mm or more. There is no particular limitation on the upper limit of the thickness of the 6LiF sintered body, but the 6LiF sintered body is preferably thinner within a range where it can suitably block neutron radiation in view of obtaining a smaller and lighter shield portion 12. Specifically, the thickness of the 6LiF sintered body is preferably 8 mm or less, more preferably 5 mm or less. (Method of Manufacturing 6LiF Sintered Body) A method of manufacturing a 6LiF sintered body according to the present embodiment includes: a pressurizing step of pressurizing a 6LiF composition containing a 6LiF powder and an organic-based molding aid to obtain a pressed compact; and a firing step of firing the pressed compact at 630° C. or more to 830° C. or less. Further, the method may include a preliminary firing step of performing preliminary firing at 250° C. or more to 350° C. or less before the firing step. <Dosage Measuring Body 1> FIG. 1F schematically shows an example of a dosage measuring body 1 according to the first embodiment of the present invention. For a dosage measuring body 1, the radiation dosage measuring device 51 is housed in the housing portion 11 of the dosimeter container 10. According to the present embodiment, sufficient neutron shielding performance can be obtained even when the thickness of the dosimeter container 10 is thin. This enables the dosimeter container 10 to be designed to have a small size. Therefore, the dosimeter container 10 can be easily handled. For example, if the dosimeter container 10 is small, a plurality of dosimeter containers 10 may be arranged at a neutron radiation irradiation area in a measurement site so as to detect the presence of and/or difference in the strength of gamma radiation at the neutron radiation irradiation area (or by fewer measuring steps). Further, the shield portion 12 as a component of the dosimeter container 10 includes a member made of a material which blocks neutron radiation but transmits at least radiation to be measured with a radiation dosage measuring device housed in the housing portion 11. This enables the radiation dosage measuring device housed in the housing portion 11 to accurately measure the target radiation. Therefore, procedures of calculating a radiation dosage of the target radiation can be simplified, contributing to the downsizing of the dosimeter container 10. FIG. 2 schematically shows an example of a dosimeter container 20 according to the second embodiment of the present invention. More specifically, FIG. 2A shows a perspective view of the dosimeter container 10. FIG. 2B shows a front view of the dosimeter container 20, and FIG. 2C shows a cross-sectional view at the A-A section of FIG. 2B. FIG. 2D shows a perspective view of a body portion 22A of the dosimeter container 20, and FIG. 2E shows a perspective view of a lid portion 22B of the dosimeter container 20. Further, FIG. 2F schematically shows an example of a dosage measuring body 2 according to the second embodiment of the present invention, in which the radiation dosage measuring device 51 is housed in a housing portion 21 of the dosimeter container 20. The dosimeter container 20 includes the housing portion 21 and a shield portion 22. The housing portion 21 is a member for storing a radiation dosage measuring device for measuring a dosage of predetermined radiation other than neutron radiation, and has similar functions as the housing portion 11 unless otherwise stated. The shield portion 22 is a member surrounding the housing portion 21, and has similar functions as the shield portion 12 unless otherwise stated. The second embodiment differs from the first embodiment in the following points. In the first embodiment, the dosimeter container 10 has a capsule-like overall shape in which both end portions having hemispherical shapes are provided at both ends of a cylindrically shaped peripheral wall. In contrast, in the second embodiment, the dosimeter container 20 basically has a quadrangular prism-like overall shape with rounded corners. Further, in the first embodiment, the housing portion 21 has a cylindrical shape which corresponds to the shape of the radiation dosage measuring device 51 (for example, a fluorescent glass element). In contrast, in the second embodiment, the housing portion 21 has a quadrangular prism-like shape in which the length of a side of the base of the housing portion 21 coincides with the length of the outer diameter of the base of the radiation dosage measuring device 51, and the height of the housing portion 21 is substantially the same as that of the radiation dosage measuring device 51. As described above, there is no particular limitation on the shape of the dosimeter container, and it can be selected in an appropriate manner. FIG. 3 schematically shows an example of a dosimeter container 30 according to the third embodiment of the present invention. More specifically, FIG. 3A shows a perspective view of the dosimeter container 30, and FIG. 3B shows a front view of the dosimeter container 30. FIG. 3C shows a top view of the dosimeter container 30, and FIG. 3D shows a cross-sectional view at the A-A section of FIG. 3C. FIG. 3E shows a perspective view of a body portion 32A of the dosimeter container 30, and FIG. 3F shows a perspective view of a lid portion 32B of the dosimeter container 30. Further, FIG. 3G schematically shows an example of a dosage measuring body 3 according to the third embodiment of the present invention, in which the radiation dosage measuring device 51 is housed in a housing portion 31 of the dosimeter container 30. The dosimeter container 30 includes the housing portion 31 and a shield portion 32. The housing portion 31 is a member for storing a radiation dosage measuring device for measuring a dosage of predetermined radiation other than neutron radiation, and has similar functions as the housing portion 11 unless otherwise stated. The shield portion 32 is a member surrounding the housing portion 31, and has similar functions as the shield portion 12 unless otherwise stated. The third embodiment differs from the first embodiment in the following points. The dosimeter container 10 has a capsule-like overall shape as described above in the first embodiment, while the dosimeter container 30 has a circular plate-like shape in the third embodiment. Further, in the first embodiment, the housing portion 21 has a cylindrical shape which corresponds to the shape of the radiation dosage measuring device 51 (for example, a fluorescent glass element). In contrast, in the third embodiment, the housing portion 31 has a circular plate-like shape having an inner diameter substantially the same as the length of the radiation dosage measuring device 51 in the longitudinal direction. Moreover, the housing portion 11 extends over the entirety of a shield portion component (the body portion 12A and the lid portion 12B in the present embodiment) while the housing portion 31 is provided only in the body portion 32A and not in the lid portion 32B in the third embodiment. As described above, there is no particular limitation on the shape of the dosimeter container, and it can be selected in an appropriate manner. In particular, the housing portion preferably extends over the entirety of the shield portion component as in the first embodiment considering that the shield portion component can serve as a fixing member when the body portion is fitted to the lid portion. FIG. 4 schematically shows an example of a dosimeter container 40 according to the fourth embodiment of the present invention. More specifically, FIG. 4A shows a perspective view of the dosimeter container 40, and FIG. 4B shows a front view of the dosimeter container 40. FIG. 4C shows a top view of the dosimeter container 40, and FIG. 4D shows a cross-sectional view at the A-A section of FIG. 4C. FIG. 4E shows a perspective view of a body portion 42A of the dosimeter container 40, and FIG. 4F shows a perspective view of a lid portion 42B of the dosimeter container 40. Further, FIG. 4G schematically shows an example of a dosage measuring body 4 according to the fourth embodiment of the present invention, in which the radiation dosage measuring device 51 is housed in a housing portion 41 of the dosimeter container 40. The dosimeter container 40 includes the housing portion 41 and a shield portion 42. The housing portion 41 is a member for storing a radiation dosage measuring device for measuring a dosage of predetermined radiation other than neutron radiation, and has similar functions as the housing portion 11 unless otherwise stated. The shield portion 42 is a member surrounding the housing portion 41, and has similar functions as the shield portion 42 unless otherwise stated. The fourth embodiment differs from the third embodiment as follows. The dosimeter container 30 has a circular plate-like overall shape in the third embodiment while the dosimeter container 40 has a substantively square plate-like shape in the fourth embodiment. As described above, there is no particular limitation on the shape of the dosimeter container, and it can be selected in an appropriate manner. Below, the present invention will be described in more detail with reference to an Example, but the present invention shall not be limited to the Example in any sense. <Manufacture of Dosimeter Container 10> A dosimeter container 10 was obtained via the following steps, has a similar shape as the dosimeter container 10 according to the first embodiment of the present invention, and has dimensions as shown in FIG. 5 at a cross-section as viewed from the front side (corresponding to FIG. 1C). [Manufacture of 6LiF Sintered Body] A cylindrical 6LiF sintered body having a height of about 16 mm was obtained via the following steps. First, 100 mass parts of a 6LiF powder (6Li purity: 95.0 atom % and LiF: 99%, Sigma-Aldrich) was mixed with 16 mass parts of a molding aid including stearic acid and cellulose to obtain a 6LiF composition. (1) Pressurizing Step Then, a mold with a diameter of 25 mm was filled with about 15.8 g of the 6LiF composition, and tapped to reduce voids where the 6LiF composition was not present. Subsequently, the cylindrical mold was mounted on a hydraulic pressing machine, and pressed at 100 MPa to obtain a pressed compact. (2) Preliminary Firing Step The pressed compact was placed in a furnace under air atmosphere. The temperature was increased to 300° C. at 100° C./hr, and then the temperature was maintained for 5 hours to allow the majority of the molding aid included in the pressed compact to be decomposed or vaporized. (3) Firing Step After the preliminary firing step, the pressed compact was heated to 650° C. at 100° C./hr, and then the temperature was maintained for 5 hours. After that, cooling (air cooling) was performed to obtain a 6LiF sintered body. [Processing of 6LiF Sintered Body] Next, the 6LiF sintered body was cut circumferentially and internally and bored by machining processing so as to obtain dimensions in a cross-section as shown in FIG. 5. Then the dosimeter container 10 according to the Example was obtained. <Evaluation> [Evaluation of Pressed Compact] The pressed compact obtained via the pressurizing step was found to have a relative density of 57.3% relative to 6LiF. Further, neither a blister nor a crack was observed when the appearance was visually inspected. [Evaluation of 6LiF Sintered Body] Further, the mass and relative density of the 6LiF sintered body obtained via the pressurizing step, the preliminary firing step, and the firing step were found to be 13.6 g and 86.2%, respectively. Moreover, neither a blister nor a crack was observed when the appearance was visually inspected. Furthermore, no internal defect such as a crack or a void was observed when a cut surface of the 6LiF sintered body cut with a precision cutting machine was visually inspected. [Evaluation of Dosimeter Container 10] A fluorescent glass element was housed in the housing portion 11 of the dosimeter container 10, and the shield portion 12 was irradiated with gamma radiation and neutron radiation from the outside of the dosimeter container 10. Results showed that the dosimeter container 10 had excellent neutron shielding ability while transmitting gamma radiation, demonstrating that the dosimeter container 10 is suitable for measuring gamma radiation. 1 Dosage measuring body according to the first embodiment 10 Dosimeter container according to the first embodiment 11 Housing portion 12 Shield Portion 12A Body portion 12B Lid portion 2 Dosage measuring body according to the second embodiment 20 Dosimeter container according to the second embodiment 3 Dosage measuring body according to the third embodiment 30 Dosimeter container according to the third embodiment 4 Dosage measuring body according to the fourth embodiment 40 Dosimeter container according to the fourth embodiment 51 Radiation dosage measuring device
	description	This application claims priority to U.S. Provisional Patent Application Ser. No. 61/940,581, filed Feb. 17, 2014, entitled Ultrasonic Phased Array Transducer for the NDE Inspection of the Jet Pump Riser Welds and Welded Attachments. 1. Field This invention relates generally to nondestructive examination transducers and, more particularly, to ultrasonic phased array transducers for inspecting components in restricted areas. 2. Related Art A boiling water reactor (BWR) produces electrical power by heating water in a reactor pressure vessel that contains a nuclear fuel core in order to generate steam which is used to drive a steam turbine. Various components and structures in a nuclear reactor are examined periodically to assess their structural integrity and determine the need for repair. Ultrasonic inspection is a known technique for detecting cracks in nuclear reactor components. A number of the inspection areas in a nuclear reactor, such as a BWR, have limited access and, therefore, are difficult to assess using an inspection tool. A jet pump in a BWR is one such component. The jet pump riser pipe welds are periodically inspected for cracking. The presence of cracking can diminish the structural integrity of the jet pump riser pipe and elbow; however, the jet pump riser pipe welds are difficult to access. Access to the jet pump riser pipe welds is limited to the annular space between the outside of the shroud and the inside of the reactor pressure vessel, between adjacent jet pumps. The ability to scan the pipe welds is additionally restricted within the narrow space between the jet pump riser pipe and vessel, shroud, or welded attachments such as the riser brace or restrainer brackets. The jet pump riser assembly is comprised of fillet welds in which attachments are welded to the riser pipe or butt welds in which elbows and pipes are amalgamated through welding. Weldments including the weld and the heat affected zone adjacent to the weld are ultrasonically inspected, otherwise referred to as the “weld volume.” Cracking orientation may be of two classifications; circumferential (parallel to the weld) or axial (perpendicular to the weld). The inspection of the weld volume for the detection of circumferential and axial orientated cracking is commonly performed by a combination of scans that involve transducer rotations or a combination of transducers positioned such that the ultrasonic sound beam(s) interrogates the weldment's heat affected zone in multiple directions (clockwise, counter-clockwise and perpendicular to the weld). Ultrasonic testing is a method of characterizing the internal structure of a test piece through the use of high frequency sound waves. The frequencies used for ultrasonic testing are many times higher than the limit of human hearing, most commonly in the range from 500 KHz to 20 MHz. High frequency sound waves are directional, and can travel through a steel medium until the beam strikes a boundary from another medium (such as a crack or void), at which point the beam is reflected back to be characterized. Previous ultrasonic weldment inspection technology typically employed a single or dual element piezoelectric crystal transducer that generates a single beam on a specified wedge to create a predetermined angle in which the beam would travel through the medium. Multiple probes would be necessary to examine the weld volume in varying directions, angles or require the complexity of remote tooling for individual transducer rotation. Phased array probes utilized for weld inspections are advantageous as fewer transducers are needed, and more importantly they require less transducer manipulation. Phased array transducers have the advantage of being able to generate numerous ultrasonic beams from a single transducer assembly containing a row or rows of sensor elements in which each can be pulsed separately creating a single beam or multiple beams at various angles (array) in a sweeping manner in a first direction. Some phased array technology enables the transducers to steer the beam(s) generation in a second direction without rotation of the phased array transducer. The phased array sweeping and steering capabilities are driven by an ultrasonic operating system, the number of piezoelectric elements and the element's positioning within the housing. Inspections using ultrasonic testing techniques can be difficult due to the complexity of the geometry of the object to be inspected or the limited access to the component. In such cases the transducer may be contoured to increase the coupling between the contact surface of the transducer and the component being inspected. Problems sometimes arise with the automated tooling that is used to maneuver the transducers and, more specifically, with the ability to maintain contact between the transducers and the component being examined. Maintaining contact between the flat surfaces of a transducer with the concave or convex surface of a pipe system can be challenging. Poor coupling may result in missed detection of a flaw or lack of data quality to satisfy the inspection requirements. Furthermore, inspecting and repairing nuclear reactors, such as boiling water reactors, typically can require complex tooling in order to position or move the phased array transducer to complete the examination. Plant utilities have a desire to reduce the number of manipulator installations and removals to reduce radiological exposure as well as cost and plant outage impact. Tooling with less complexity typically has the advantage of added reliability and a smaller tooling design enables access to areas with limited proximities. Accordingly, a new ultrasonic phased array transducer assembly is desired that is relatively small in size and uncomplicated. Additionally, such a transducer is desired that requires less movement to fully interrogate a jet pump weld. These and other objects are achieved by an ultrasonic phased array transducer assembly having a single housing in which a plurality of phased array transducer subassemblies are mounted at skewed angles relative to a leading face of the housing and to each other, with each transducer mounted on a composite wedge within the housing. Preferably, the housing has a contoured face to substantially match the surface of a pipe to be inspected. Desirably, a conductor from each of the phased array transducers are tethered together into a single cable assembly which exits the housing at a single port. In one embodiment the housing has at least one mounting hole or shoulder for gimbal attachments. The invention also contemplates a method of inspecting a jet pump riser pipe in a boiling water nuclear reactor with each riser pipe having at least one welded attachment such as a riser brace. The method positions at least one ultrasonic phased array probe assembly adjacent to the surface of the pipe wherein a front leading face of the probe assembly is positioned adjacent to a weld or weld volume to be inspected. The method then scans the jet pump riser with at least one ultrasonic phased array probe so that the scanned volume of the ultrasonic beam comprises an area extending from the weld down the pipe and extends from the scan surface down at least partially towards the opposing surface of the pipe. The ultrasonic phased array probe assembly contains at least two independent phased array transducers mounted on composite wedges and set at skewed angles relative to each other and the front leading face of the probe assembly. Preferably, the scanning angles are capable of detecting flaws oriented axially and circumferentially relative to the pipe welds without rotating the probe assembly. As can be seen in FIGS. 1-6, the phase array transducer assembly 10 of this invention contemplates a single housing 12 containing at least two independent phased array transducers utilized for the ultrasonic inspection of a jet pump riser pipe and associated riser pipe attachment welds in a boiling water reactor. An advantage of a single housing containing multiple phased array transducer subassemblies mounted in different positions and angles, whose outputs are coordinated, but independently controlled, is that such a design would eliminate the need to utilize multiple probes for the detection of various flaws which may differ in their orientation. This invention allows the number of tool reconfigurations, and the number of tools and/or probes required to perform inspections to be minimized. Further, when scanning on a contoured surface such as a pipe 36, the phased array transducer assembly 10 must have a contoured surface 18 to maintain a fixed sound path distance from the transducer elements within each of the subassemblies to the area to be inspected. This requirement further explains the desire to minimize the number of custom transducer housings that are needed to be employed for a weld inspection. In addition, due to the unique placement and orientation of the phased array subassemblies 22, 24, and 26, a compact overall housing 12 can be fabricated which allows maximum access to the weld around adjacent obstructions in the surrounding areas. The housing 12 includes a side wall and an opposing second side wall, an end wall and an opposing face 38. The side walls, the end wall and the face define a housing cavity 28 in which the phased array transducers are mounted. Phased array transducers contain a row or multiple rows of elements referred to as the phased array subassembly that establish the parameters of the ultrasonic sound beam's steering or sweeping capabilities. Phased array transducer housings typically contain phased array subassemblies that are mounted on individual wedges which classically function in unity with one another to generate the desired beams. A more detailed understanding of the operation of ultrasonic phased array transducers can be found in U.S. Pat. Nos. 4,149,420 and 5,563,346. The novel probe assembly 10 of this invention utilizes phased array subassemblies 22, 24 and 26 mounted on separate wedges 38 positioned at dissimilar orientations within the housing, functioning as independent transducers and is not reliant on a plural wedge combination to generate the desired ultrasonic beams. Alternately, the phased array subassemblies may be mounted on a single piece of material with individual wedge surfaces machined to orient the subassemblies in their proper position. The independent transducer conductors are tethered together in a joint cable 16 through a single port 14 in the housing 12. The port 14 is located such that it will not impede the face or front of the transducer from positioning at or near the weld toe. The housing 12 may contain shoulder mounts 20 for hardware gimbals on each side such that the face or front 18 of the transducer 10 can be positioned at or near a weld toe. The housing face 18 in contact with the surface of the jet pump piping 36 is a contoured such as to maximize coupling to the piping, as can be seen in FIG. 5. Each transducer 22, 24 and 26, contained within the housing cavity 28 is fixed on at least one composite wedge 38 such as to generate at least one ultrasonic sound beam. The wedge 38 provides a means to set the transducer array at an angle relative to the inspection surface such that different elements of the array are fixed at different elevations relative to the inspection surface. The transducer claimed herein has at least two phased array assemblies mounted at a skewed angle from each other and relative to the front leading edge 18 of the transducer housing 12. In one preferred embodiment, the single housing 12 contains three phased array transducers 22, 24 and 26. The center transducer 24 and the corresponding wedge is mounted such that its primary or center ultrasonic beam is directed in a plane perpendicular to the leading edge/face 18 of the housing 12. The two transducers 22 and 26 mounted on the clockwise and counter clockwise side of the centered transducer 24 are positioned inside the housing such that their primary or center ultrasonic beam is directed at an angle skewed from a plane perpendicular to the leading edge/face 18 of the housing 12, where the primary ultrasonic beams face away from each other, oriented approximately ninety degrees apart (at approximately reciprocal angles). Alternative configurations such as two, four, or more independent transducers can be utilized in a single housing 12 and would be considered to be within the concept claimed hereafter. In addition, alternative positions of each array may be utilized such that the array perpendicular to the leading edge/face is not the center array. FIG. 4 shows the phased array transducer assembly 10 positioned adjacent a weld volume, i.e., the weldment 34 and the heat effected zone 30. The base metal 32 of the pipe 36 is shown on either side of the weld volume. As previously mentioned FIG. 5 shows the face 18 of the transducer assembly 10 being closely matched with the curvature of the pipe 36. FIG. 6 shows the view of the transducer assembly 10, shown in FIG. 1, adjacent the pipe 36. While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular 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.
	description	This application is a National Phase of PCT Patent Application No. PCT/IL2012/050157 having International filing date of May 3, 2012, which claims the benefit of priority under 35 USC §119(e) of U.S. Provisional Patent Application No. 61/481,758 filed on May 3, 2011. The contents of the above applications are incorporated herein by reference in their entirety. The present invention, in some embodiments thereof, relates to an antenna system fabrication and, more particularly, but not exclusively, to an antenna system having two end-fire antenna elements facing each other. Optical radiation is typically manipulated by redirecting its wave front with lenses and mirrors, which are subject to diffraction. As a consequence of this diffraction, optical fields cannot be localized to dimensions which are much less than the optical wavelength. Nano-antennas provide a solution as they can efficiently couple the energy of free-space radiation to a confined region of sub-wavelength size. Although the use of radiofrequency (RF) antennas is widespread, such as in the radio- and microwave regimes, they are an emerging technology at optical frequencies. Heretofore, there have seen a considerable amount of work devoted to nano-antennas for the IR and optical frequencies [Crozier et al., J. Appl. Phys., 94, 4632 (2003); Derkacs et al., Appl. Phys. Lett., 89, 093103 (2006); Kuhn et al., Phys. Rev. Lett., 96, 017402 (2006); and Bouhelier et al.]. In terms of performances, conventional nano-antennas having a broad frequency band of operation are characterized by low radiation efficiency [Alù et al., Phys. Rev. Lett., 101, 043901 (2008)]. According to an aspect of some embodiments of the present invention there is provided an antenna system. The system comprises a first end-fire antenna element and a second end-fire antenna element facing each other in a planar arrangement, the antenna elements being configured such as to cause destructive interference between individual end-fire radiations of the elements, while maintaining constructive interference generally perpendicular to the planar arrangement. According to some embodiments of the invention the system wherein the first end-fire antenna element is identical to the second end-fire antenna. According to some embodiments of the invention each of the antenna elements is a slot antenna element having a tapered profile. According to some embodiments of the invention the tapered profile is characterized by an opening rate selected such that a ratio between an imaginary part and a real part of an impudence of the antenna system is less than 50%. According to some embodiments of the invention the opening rate is from about 0.0001 to about 0.01 nm−1. According to some embodiments of the invention each slot has a stub and an aperture and is symmetric with respect to a meridian line connecting the stub and aperture, perpendicularly to the aperture. According to some embodiments of the invention each slot has a stub and an aperture and is asymmetric with respect to a meridian line connecting the stub and aperture, perpendicularly to the aperture. According to some embodiments of the invention each of the antenna elements is a Vivaldi antenna element. According to some embodiments of the invention the first and the second antenna elements are made of a metal characterized by a skin depth for a predetermined optical frequency and wherein a thickness of the antenna elements is at least 2 times the skin depth. According to some embodiments of the invention the first and the second antenna elements are separated by at least one air gap. According to some embodiments of the invention a width of the gap is selected so as to allow emission of radiation in a transverse optical mode while suppressing higher optical modes. According to some embodiments of the invention a width of the gap is at least 10 nm. According to some embodiments of the invention the system comprises a waveguide coupled to the gap. According to some embodiments of the invention the waveguide is a parallel plate waveguide. According to some embodiments of the invention at least one of the first and the second end-fire antenna elements has a nanometric size along at least one dimension of the element. According to some embodiments of the invention at least one of the first and the second end-fire antenna elements has a nanometric size along a largest dimension of the element. According to an aspect of some embodiments of the present invention there is provided an antenna array. The array comprises a plurality of antenna systems as delineated above and optionally as further exemplified hereinbelow. According to some embodiments of the invention at least a portion of the antenna systems are connected in series with respect to a characteristic direction of the end-fire radiations. According to some embodiments of the invention at least a portion of the antenna systems are connected in parallel with respect to a characteristic direction of the end-fire radiations. According to some embodiments of the invention the antenna systems are connected via DC connection. According to an aspect of some embodiments of the present invention there is provided a method of detecting electromagnetic radiation. The method comprises generating condition for the radiation to interact with the antenna system or array as delineated above and optionally as further exemplified hereinbelow, and collecting electrical signals generated by the antenna system. According to an aspect of some embodiments of the present invention there is provided a method of emitting electromagnetic radiation, comprising applying voltage to the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to an aspect of some embodiments of the present invention there is provided a method of converting electromagnetic radiation into electricity, comprising generating condition for the radiation to interact with the antenna system or array as delineated above and optionally as further exemplified hereinbelow, and collecting electrical signals generated by the antenna system. According to some embodiments of the invention the electromagnetic radiation comprises radiation in the infrared range. According to some embodiments of the invention the electromagnetic radiation comprises radiation in the visible range. According to an aspect of some embodiments of the present invention there is provided an optical sensor system, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to an aspect of some embodiments of the present invention there is provided an optical communication system, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to an aspect of some embodiments of the present invention there is provided an imaging system, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to an aspect of some embodiments of the present invention there is provided a light projector, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to an aspect of some embodiments of the present invention there is provided a high harmonics generating system, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to an aspect of some embodiments of the present invention there is provided a wave mixing system, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to an aspect of some embodiments of the present invention there is provided a frequency conversion system, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. According to some embodiments of the invention the frequency conversion system is configured for up conversion. According to some embodiments of the invention the frequency conversion system configured for down conversion. According to an aspect of some embodiments of the present invention there is provided a phased array, comprising the antenna system or array as delineated above and optionally as further exemplified hereinbelow. Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. Implementation of the method and/or system of embodiments of the invention can involve performing or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of embodiments of the method and/or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware or by a combination thereof using an operating system. For example, hardware for performing selected tasks according to embodiments of the invention could be implemented as a chip or a circuit. As software, selected tasks according to embodiments of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In an exemplary embodiment of the invention, one or more tasks according to exemplary embodiments of method and/or system as described herein are performed by a data processor, such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes a volatile memory for storing instructions and/or data and/or a non-volatile storage, for example, a magnetic hard-disk and/or removable media, for storing instructions and/or data. Optionally, a network connection is provided as well. A display and/or a user input device such as a keyboard or mouse are optionally provided as well. The present invention, in some embodiments thereof, relates to an antenna system fabrication and, more particularly, but not exclusively, to an antenna system having two end-fire antenna elements facing each other. Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. The present inventors have devised efficient wideband antenna system. The antenna system of the present embodiments is useful in many applications, including, without limitation, precision tracking, radar, communications, energy harvesting, near-field optical microscopy, harmonic generation and sensing. In particular, the antenna system of the present embodiments is useful in applications utilizing ultra wideband (UWB) radiation. As used herein “UWB radiation” refers to radiation having a spectrum occupying a bandwidth of at least 15%, more preferably at least 20%, more preferably at least 25% of its center frequency. An antenna is oftentimes characterized by an impedance bandwidth which relates to the range Δf of frequencies for which the impedance of the antenna remains generally constant (e.g., impedance variations of less than 20% or less than 10% or less than 5%). The impedance bandwidth is typically expressed in percentage according to the formula 100×Δf/fc, where fc is the center frequency of the spectrum. In some embodiments of the present invention UWB radiation has an impedance bandwidth of at least 100% or at least 110% or at least 120%, e.g., 129%. In some embodiments of the present invention UWB radiation has a spectrum occupying a bandwidth of at least 2000 nm or at least 2100 nm or at least 2200 nm or at least 2300 nm or at least 2400 nm or at least 2500 nm, with return losses above −9.5 dB. The background art fails to teach antenna configurations which are both efficient and broad-band, particularly at IR frequencies. At RF, typically, metallic antenna thickness is significantly larger than the skin depth. Thus, overly thin conductors with high resistance leading to low radiation efficiency are avoided. However, in the IR range the skin depth does not decrease monotonically as the frequency increases. The skin depth is defined as δS=1/α where α is the real part of the complex propagation constant (also known as the absorption coefficient). For example, in gold, the skin depth remains at roughly 13 nm over a large part of the IR band and even increases at the beginning of the visible spectrum as shown in FIG. 1. Thus, for the IR frequency a 40-50 nm thick gold, which is several times the skin depth, nano-antenna elements are required in order to achieve sufficiently high radiation efficiency. The antenna system according some embodiments of the present invention is a traveling wave antenna. Unlike in resonant antennas, the traveling wave antenna of the present embodiments features a gradual transition from wave guiding to radiation. It was found by the present inventors that such gradual transition leads to a wide bandwidth and improved efficiency. In some embodiments of the present invention the antenna system has a tapered geometry. FIGS. 2A and 2B are schematic illustrations of a top view (FIG. 1A) and a side view (along line A—A of FIG. 1A) of an antenna system 10 according to some embodiments of the present invention. For clarity of presentation, a Cartesian coordinate system is also illustrated in FIGS. 2A and 2B. As shown, FIG. 2A is parallel to the x-z plane and FIG. 2B is parallel to the x-y plane. The direction parallel to the y axis is referred to as the thickness direction. Antenna system 10 optionally and preferably provide UWB radiation. System 10 comprises a first end-fire antenna element 12 and a second end-fire antenna element 14 facing each other in a planar configuration. As used herein, an end-fire antenna element refers to generally planar antenna element which emits radiation into free space or an adjacent substance, from, or in proximity to an edge of the antenna element, wherein the maximum radiation intensity is in the plane engaged by the element or substantially parallel to that plane. In some embodiments of the invention, more than 50% or more than 60% or more than 70% or more than 80% or more than 90% of the radiation energy is emitted from, or in proximity to the edge and is in the plane engaged by the element or substantially parallel to that plane Representative examples of end-fire antenna elements include, without limitation, tapered dielectric rod, Vivaldi antenna element, slot antenna element, dipole antenna element, and the like. Both elements 12 and 14 are generally planar and engage the same plane. Elements 12 and 14 are preferably made of metal, such as, but not limited to, gold and aluminum, and they can be deposited on a dielectric substrate 30, which can be made, for example, of Quartz, Silicon or any other dielectric material. In some embodiments of the present invention element 12 and 14 have similar shapes and sizes. For example, elements 12 and 14 can be identical to each other. In various exemplary embodiments of the invention at least one of elements 12 and 14, more preferably both elements 12 and 14 are nanometric in size. Specifically, the characteristic length of one or both elements 12 and 14 along at least one, more preferably at least two directions, is nanometric. In some embodiments of the present invention the largest dimension of element 12 and/or 14 is nanometric. As used herein, nanometric length refers to a length less than micron. The thickness of elements 12 and 14 is typically several times larger than the skin depth at the respective frequency. For IR radiation, the thickness is preferably from about 50 nm to about 500 nm or from about 60 nm to about 400 nm or from about 70 nm to about 300 nm or from about 80 nm to about less than 200 nm or from about 90 nm to about 150 nm. Each of the planar dimensions of elements 12 and 14 (namely the lengths as measured along the x and z axes) is typically of on the order of a few hundred nanometers (e.g., about 200 nm or about 300 nm or about 400 nm or about 500 nm or about 600 nm or about 700 nm or about 8 or about 900 nm). Elements 12 and 14 are positioned such as to form one or more air gaps therebetween. In the representative example illustrated in FIG. 2, two air gaps are shown at 16. In various exemplary embodiments of the invention the width of the gap is less than half the wavelength at the highest operational frequency of system 10. This is advantageous since it allows the system to emit the transverse electromagnetic (TEM) mode while suppressing higher optical modes. From performances standpoint, the gap between elements 12 and 14 is preferably sufficiently narrow so as not to reduce electric field enhancement when the antenna operates in the receive mode. From manufacturing standpoint, the width of the gap is selected above or at the minimal resolution of the fabrication technique. For example, E-beam lithography allows fabricating system 10 with an air gap of a few nanometers or more. A typical width of the air gap is from about 10 nm to about 40 nm or from about 20 nm to about 30 nm, e.g., about 25 nm. Each of elements 12 and 14 has ends (narrow side faces) parallel to their thickness direction (the y axis in the present example) and broadside faces perpendicular to their thickness direction (parallel to the x and axes in the present example). During transmission, elements 12 and 14 preferably emit radiation from their narrow side faces. Radiation emitted from the narrow side face of an antenna element is referred to herein as “end-fire radiation.” Radiation propagating along the thickness direction is referred to herein as “broadside radiation.” In various exemplary embodiments of the invention elements 12 and 14 are configured such as to cause destructive interference between their individual end-fire radiations, and constructive interference between their individual broadside radiations. Such configuration provides a bi-directional antenna pattern. In various exemplary embodiments of the invention one or both elements 12 and 14 is a slot antenna element having a slot characterized by a tapered profile. Also contemplated are other time of end-fire elements, including, without limitation, log-periodic and Yagi antenna elements. In the representative example illustrated in FIGS. 2A and 2B, system 10 comprises a pair of slot antenna elements. The slots are generally shown at 18 and 20. Each slot extends from a closed end, referred to as a stub, to an open end, referred to as an aperture, along a median line which is generally parallel to the x direction. The slots are tapered in the sense that the width of each slot widens from a minimum at the stub to a maximum at the aperture. The subs of slots 18 and 20 are respectively designated 22 and 24, and the apertures of slots 18 and 20 are respectively designated 26 and 28. The slots 18 and 20 can have any tapered profile. Specifically, any of the edges 18a, 18b, 20a and 20b can be linear, curved or a combination of linear and curved shapes. In some embodiments of the present invention one or both of slots 18 and 20 has a an exponential flare shape. An antenna element having such a slot is known as a Vivaldi antenna element and described in P. J. Gibson, “The Vivaldi Aerial,” in Proc. 9th European Microwave Conference, UK, June 1979, 101-105. For example, a slope edge (e.g., edge 18a) of a Vivaldi antenna element can have an upper part in the x-z plane described by:x=C1exp(Rz)+C2 where R is a constant referred to as an opening rate, and the C1 and C2 are constants defined by C 1 = x end - x start exp ⁡ ( R ⁢ ⁢ z end ) + exp ⁡ ( R ⁢ ⁢ z start ) C 2 = x start ⁢ exp ⁡ ( R ⁢ ⁢ z end ) - x end ⁢ exp ⁡ ( R ⁢ ⁢ z start ) exp ⁡ ( R ⁢ ⁢ z end ) + exp ⁡ ( R ⁢ ⁢ z start ) , where (xstart, zstart) and (xend, zend) are the coordinates of edge 18a at the aperture 26 and stub 22, respectively. In various exemplary embodiments of the invention the other edges are constructed as mirror images of edge 18a with respect to axes x and/or z. One of ordinary skill in the art would be able to obtain the expression for the other edges based on the above formulae. Unlike conventional Vivaldi antennas in which the pick gain is perpendicular to the thickness direction, system 10 produces its main radiation lobe parallel to the thickness direction, thus effectively serving as a broadside emitting system. This is advantageous since it allows integrating the antenna system in planar configurations, for example, using E-beam lithography process. In some embodiments of the present invention the antenna device poses fewer fabrication restrictions as compared to dipole and bow-tie antennas, in particular in terms of the gap size between the antenna terminals. It was found by the inventors of the present invention that the dimensional parameters of the antenna system, particularly the opening rate R, the length of the apertures 26 and 28 (along the z axis), and the distance between the stubs 22 and 24 (along the x axis) can be selected to tune the radiation pattern such as to provide the peak gain at the antenna broadside. The antenna of the present embodiments can be integrated with a waveguide 32, which can be connected to system 10 at gap 16 as shown in FIG. 3. Waveguide 32 can be a parallel plate waveguide. Use of parallel plate waveguides is advantageous since it allowed employing wider gaps compared to the gap required in conventional a dipole-like antennas. The configuration of the present embodiments allows combining multiple antenna systems in parallel at their terminals, thus providing more degrees of freedom in order to match the combined system to its load or excitation. The width and height of waveguide 30 are preferably the same or similar to the width of gap 16 and the thickness of the antenna elements, respectively. Preferably, impedance matching is employed between the parallel plate waveguide and the antenna system. For a parallel plate waveguide having width W1 and height h, the impedance can be approximated as Z0=ηW1/h, where η is the free space impedance. For example, for W1=25 nm, h=120 nm and η=377Ω, the impedance of a parallel waveguide is about 78.5Ω. Thus, in this embodiment, the impedance of antenna system 10 is preferably also about 78.5Ω. In various exemplary embodiments of the invention the ratio between the imaginary part of the impudence (the reactance) and the real part of the impudence (the resistance) of antenna system 10 is less than 50% or less than 40% or less than 30% or zero, for all of the operational bandwidth. This can be achieved by a judicious selection of the length of the apertures, the distance between the stubs and/or the opening rate R of the slots. Typically, but not exclusively, the opening rate is from about 0.0001 nm−1 to about 0.01 nm−1 or from about 0.0005 nm−1 to about 0.005 nm−1 or from about 0.001 nm−1 to about 0.003 nm−1, e.g., about 0.002 nm−1. Thus, the geometry of antenna system 10 is optionally and preferably selected based on the material properties of metals at the respective frequencies, e.g., IR frequencies. In some embodiments of the present invention the antenna has both high radiation efficiency and good impedance matching properties over a wide frequency band (more than 112%) in the IR frequency band. According to some embodiments of the invention the antenna device is characterized by radiation efficiency of at least X for any frequency from F1 to F2, wherein X equals 60% or 70% or 80%, e.g., 85%, F1 equals about 140 THz or about 130 THz or about 120 THz, and F2 equals about 390 THz, or about 400 THz, or about 410 THz. FIG. 4 is a schematic illustration of an appliance 40 which includes antenna system 10, according to some embodiments of the present invention. Appliance 40 communicates with the environment, via optical radiation transmitted and/or received by antenna system 10. The load on antenna system 10 can be non-linear. This is particularly useful when appliance 40 is used for rectification or second harmonic generation. The optical radiation is optionally and preferably in the IR range. Many types of appliances are contemplated, including, without limitation, an optical sensor system, an optical communication system, an imaging system, a light projector, a high harmonics generating system, a wave mixing system, a frequency conversion system (configured for up conversion and/or down conversion), a phased array and the like. It is expected that during the life of a patent maturing from this application many relevant appliances utilizing antennas will be developed and the scope of the term appliance is intended to include all such new technologies a priori. As used herein the term “about” refers to ±10%. The word “exemplary” is used herein to mean “serving as an example, instance or illustration.” Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments. The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments.” Any particular embodiment of the invention may include a plurality of “optional” features unless such features conflict. The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to”. The term “consisting of” means “including and limited to”. The term “consisting essentially of” means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure. As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof. Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range. Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging/ranges between” a first indicate number and a second indicate number and “ranging/ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples. Reference is now made to the following examples, which together with the above descriptions illustrate some embodiments of the invention in a non limiting fashion. A nano-antenna system was designed according to some embodiments of the present invention. The nano-antenna system included a pair of Vivaldi elements, as illustrated in FIG. 5. As shown the width W1 of the air gap was 25 nm, the distances between the stubs of the slots was 500 nm and the length of the apertures was 2L=500 nm. The thickness of the elements was 120 nm. The size of the gap was selected to facilitate fabrication in a standard E-beam lithography based process, and the thickness was about ten times the skin depth of gold for IR radiation (see FIG. 1). The antenna was designed to operate at wavelength of from 700 nm to 3250 nm. The resulting Dual Vivaldi antenna can be fabricated as a single metallic layer on planar substrate and has a bi-directional radiation pattern normal to the substrate surface. This is country to other designs, such as directive 3D Yagi-Uda antenna [Dregely et al., Nature Communications 2, 267, 2011], or nanoloop antenna [Ahmadi et al., Optics Letters, 35, 21, 2010] which involve considerably more complicated multi layered structures. In computer simulations performed by the present inventors, each of the Vivaldi elements was fed by integrated parallel plate waveguide, with a gap of W1=25 nm and thickness of h=120 nm. The parallel plate impedance Z0 was 78.5Ω, as calculated using the relation Z0=ηW1/h, with η=377. Impedance matching between the parallel plate waveguide and the nano-antenna for the above dimensions and wavelengths was achieved by selecting an opening rate R=0.002 nm−1. In the simulations, the antenna was simulated in the center of a Quartz substrate with lateral dimensions of 2×2 μm and thickness of 1 μm. These dimensions are sufficiently large to make the simulation results generally independent of the substrate size. The simulation were performed by using commercial software CST MWS, with the finite elements frequency domain solver. The gold complex index of refraction (N, K) database at the IR frequencies [E. Palik, Handbook of Optical Constants of Solids, vol. 1. New York: Academic, 1985] was defined in the simulation so that the correct measured index of refraction value was used at each frequency point. Both parallel plate waveguide gaps were excited coherently and in phase, using ports across the gaps. The electric field distribution at 1.58 μm over the antenna half thickness plane (y=0) is shown in FIG. 6A and the resulting far field pattern is shown in FIG. 6B. A three-dimensional illustration of the electric field distribution is shown in FIG. 6C. As shown in FIG. 6A, most of the electric field is concentrated in the air gap within the parallel plate waveguide starting at the antenna terminals. The smooth tapering of the antenna system generated gradually transition of the electric field from the guided mode to radiation as the gap increases. This leads to a highly efficient radiating antenna, because the dominant field remains normal to the conductor surface, thus reducing the conduction losses. FIG. 6B demonstrates non symmetric far field pattern due to the Quartz substrate effect. FIG. 7 shows the simulated input resistance and reactance. As shown, the return loss of the antenna system of the present embodiments is better than −9.5 dB for the range of 700 nm to 3250 nm (129% impedance bandwidth). Unlike a dipole antenna featuring a single resonance behavior, the antenna system of the present embodiments exhibits a multi resonance behavior characteristic for finite size traveling wave configurations. FIG. 7 demonstrates that the input resistance is relatively constant (at about 100Ω), and the input reactance oscillates around zero in the frequency band of operation. FIGS. 8A and 8B show the radiation efficiency (FIG. 8A) and peak and broadside realized gain (FIG. 8B). The radiation efficiency is defined as the radiated to accepted (input) power ratio. As shown in FIG. 8A, the radiation efficiency of the system of the present embodiments remains higher than 85% for all wavelengths ranging from 0.78 μm to 3.23 μm (122% efficiency bandwidth). Due to the Quartz substrate that operates as a lens, the far field pattern is not symmetric and the higher directivity is in the Quartz direction. At the lower wavelengths the Quartz substrate changes the antenna pattern and the peak gain is shifted from the antenna broadside. The maximum realized gain (including the mismatch loss) at the antenna broadside direction reaches 6 dBi, and the peak gain is about 7 dBi (see FIG. 8B). These values are significantly higher compared to conventional nano-antennas, especially if one takes into account that the system is a single layer structure, without a ground plane. According to the reciprocity theorem for an antenna comprising isotropic materials, the radiation pattern of such an antenna is equal to its receiving pattern. Arrays of nano-Antenna systems were fabricated using E-beam lithography. Two types of arrays were fabricated. In a first type, several sets of nano-antenna systems as described in Example 1 were fabricated, where the antenna systems at each set were connected in series along the x direction. In a second type, the antenna systems were arranged as in the first type, except that each individual antenna systems was devoid of air gaps between the Vivaldi elements. FIGS. 9A and 9B are electron microscope images of the fabricated first and second arrays. The fabricated antenna arrays were subjected to measurements using an experimental setup designed to characterize the antenna arrays. The experimental setup is schematically illustrated in FIG. 10A. The arrays were illuminated by a collimated beam, emitted by a tunable IR laser source in the 1450-1640 nm range. The light was linearly polarized in a direction that was parallel to the Vivaldi columns. The sample was placed on a fine rotation stage (θ-φ) which was mounted on a high resolution XYZ translation stage to allow control over the alignment and orientation of the sample relative to the incident light. Each array was positioned at the waist of the incident Gaussian beam, so as to equally excite all nano-antennas in the array in both amplitude and phase. Light emitted from the nano-antennas was detected by a high sensitivity InGaAs photodiode (NewFocus 2153), which was positioned 55 cm from the sample at an angle of 60° relative to the incident beam. The lateral pitch of the arrays was 1.79 μm, thus yielding the first-order Bragg diffraction lobe at 60° with respect to the incident beam at λ=1550.2 nm for a normally incident excitation beam. This configuration is advantageous from the standpoint of strong suppression of the direct reflection of the excitation beam from the substrate surface, which allows for convenient measurement of the radiation emitted from the nano-antennas. The radiation efficiency of the fabricated arrays was measured and compared to the theoretical predictions. The results for one lobe out of the 6 lobes (lobe +1) are shown in FIG. 10B. As shown, there is an excellent agreement between the simulations described above and the experimental measurements. Summing all the lobes resulted in efficiency higher than 90%. Additional exemplary configurations suitable for the antenna system according to some embodiments of the present invention are illustrated in FIGS. 11-14B. FIG. 11 illustrates an embodiment in which the system is fed from one side only, at the gap between the end-fire antenna elements, wherein at the opposite side, the elements are connected to each other. The feed is shown at 110 and the opposite side is shown at 112. Also contemplated are embodiments in which the opposite side 112 is open (namely a gap is present but no feed is connected thereto) and embodiments in which the opposite side 112 is connected to another load. FIG. 12 illustrates an embodiment in which the system comprises geometrically asymmetric end-fire antenna elements. In these embodiments, each slot is asymmetric with respect to a meridian line 122 connecting the stub 124 and aperture 126, perpendicularly to the aperture 126. The system can be fed from both gaps 128 and 130, as illustrated in FIG. 12, or at one gap only, as described above. FIG. 13 illustrates an embodiment in which a pair of antenna systems is arranged in parallel with respect to the direction of the end-fire radiation. In other words the two systems in the pair are arranged such that their apertures are generally collinear. The two systems are connected at the gaps 132a, 132b between their end-fire antenna elements. The pair can include a single feed 134, for example, at the gaps 132a, 132b or it can include a plurality of feeds, e.g., one feed at each gap. Also contemplated are similar arrangements with more than two antenna systems arranged in parallel. FIGS. 14A and 14B illustrate embodiments in which a plurality of antenna systems is arranged an array. In the representative example of FIG. 14A, the array comprises a set of linear arrays, wherein in each linear array, the antenna systems are arranged in series with respect to the end-fire radiation direction (the x axis). In other words the systems in the linear array are arranged such that their apertures are generally parallel and not collinear. The linear arrays are arranged parallel to each other. In the representative example of FIG. 14B, the array comprises a set of linear arrays, wherein each linear array comprises several pairs of parallel antenna systems each pair being similar to the pair illustrated in FIG. 13. The pairs in each linear array are arranged in series with respect to the end-fire radiation direction. The linear arrays are arranged parallel to each other. Note that the configurations in FIGS. 14A and 14B provide DC connection between the antenna systems in the array. This embodiment is particularly advantageous for energy harvesting and other applications. Also contemplated are other arrangements of the antenna systems in an arrays, optionally and preferably, but not necessarily, with a DC connection between individual antenna systems in the array. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.
	claims	1. An x-ray focusing device comprising:a slide pivotable about a pivot point defined at a forward end thereof;a rail unit fixed with respect to said slide;a forward crystal, for focusing x-rays, disposed at said forward end of said slide, said forward crystal defining a forward angle of incidence with respect to said pivot point; anda rearward crystals, for focusing x-rays, movably coupled to said slide and said rail unit at a distance rearward from said forward crystal, said rearward crystal defining a rearward angle of incidence with respect to said pivot point,wherein said slide extends in a straight line between said pivot point and said rearward crystal, and wherein pivoting of said slide about said pivot point changes said forward angle of incidence and said rearward angle of incidence of said forward and rearward crystals while simultaneously changing the distance between said forward and rearward crystals. 2. An x-ray focusing device as defined in claim 1, further comprising:a forward carriage fixed to said forward end of said slide for supporting said forward crystal; anda movable rearward carriage for supporting said rearward crystal, said movable rearward carriage being linearly translatable along said slide and along said rail unit and defining a fixed distance between said rearward crystal and said rail unit. 3. An x-ray focusing device as defined in claim 2, wherein said movable rearward carriage comprises a rotatable bearing to allow for varying angles between said slide and said rail unit. 4. An x-ray focusing device as defined in claim 1, wherein said rail unit comprises a linear translation device for linearly translating said rearward crystal along said slide. 5. An x-ray focusing device as defined in claim 4, wherein said linear translation device comprises:a lead screw coupled to said rearward crystal; anda motor for rotating said lead screw, wherein said rearward crystal is linearly translated along said slide. 6. An x-ray focusing device as defined in claim 5, wherein said linear translation device further comprises a translation arm threadably coupled to said lead screw, said translation arm defining a fixed distance between said rearward crystal and said lead screw. 7. An x-ray focusing device as defined in claim 1, wherein said forward and rearward crystals are sagittally bent Laue crystals having asymmetric lattice planes for focusing and diffracting x-rays. 8. An x-ray focusing device as defined in claim 7, further comprising forward and rearward bending units for respectively adjusting the sagittal bend of said forward and rearward crystals. 9. An x-ray focusing device as defined in claim 8, wherein at least one of said forward and rearward bending units comprises a pair of deflectable arms having said forward crystal or said rearward crystal attached therebetween, wherein deflection of at least one of said deflectable anus symmetrically bends said crystal about a centerline defined between said deflectable arms. 10. An x-ray focusing device comprising:a slide pivotable about a pivot point defined at a forward end thereof;a rail unit fixed with respect to said slide;a forward crystal, for focusing x-rays, disposed at said forward end of said slide, said forward crystal defining a forward angle of incidence with respect to said pivot point; anda rearward crystal, for focusing x-rays, movably coupled to said slide and said rail unit at a distance rearward from said forward crystal, said rearward crystal defining a rearward angle of incidence with respect to said pivot point,wherein pivoting of said slide about said pivot point changes said forward angle of incidence and said rearward angle of incidence of said forward and rearward crystals while simultaneously changing the distance between said forward and rearward crystals, andwherein said forward and rearward crystals are sagittally bent Laue crystals having asymmetric lattice planes for focusing and diffracting x-rays, andwherein said x-ray focusing device further comprises forward and rearward bending units for respectively adjusting the sagittal bend of said forward and rearward crystals, andwherein at least one of said forward and rearward bending units comprises a pair of deflectable arms having said forward crystal or said rearward crystal attached therebetween, wherein deflection of at least one of said deflectable arms symmetrically bends said crystal about a centerline defined between said deflectable arms, andwherein the at least one of said forward and rearward bending units further comprises:a base;a fixed support attached to said base and having one end of a first deflectable arm attached thereto;a movable support disposed on said base and having one end of a second deflectable arm attached thereto;a translation mechanism for moving said movable support with respect to said fixed support to deflect said second deflectable arm; anda pair of clamping members disposed on respective ends of said first and second deflectable arms opposite said fixed support and said movable support, said forward crystal or said rearward crystal being attached between said clamping members. 11. An x-ray focusing device as defined in claim 10, wherein said translation mechanism is a picomotor. 12. An x-ray focusing device as defined in claim 1, further comprising a base, said pivot point and said rail unit being fixed to said base. 13. An x-ray focusing device as defined in claim 1, wherein said forward angle of incidence and said rearward angle of incidence of said forward crystal and said rearward crystal are reciprocal angles, whereby an x-ray beam emerging from said rearward crystal is substantially parallel to an incident beam striking said forward crystal. 14. An x-ray focusing device comprising:a slide pivotable about a pivot point defined at a forward end thereof;a rail unit fixed with respect to said slide;a forward crystal, for focusing x-rays, disposed at said forward end of said slide, said forward crystal defining a forward angle of incidence with respect to said pivot point; anda rearward crystal, for focusing x-rays, movably coupled to said slide and said rail unit at a distance rearward from said forward crystal, said rearward crystal defining a rearward angle of incidence with respect to said pivot point,wherein pivoting of said slide about said pivot point changes said forward angle of incidence and said rearward angle of incidence of said forward and rearward crystals while simultaneously changing the distance between said forward and rearward crystals, andwherein said forward angle of incidence and said rearward angle of incidence of said forward crystal and said rearward crystal are reciprocal angles, whereby an x-ray beam emerging from said rearward crystal is substantially parallel to an incident beam striking said forward crystal, andwherein said pivot point is positioned about midway between said incident beam striking said forward crystal and said x-ray beam emerging from said rearward crystal. 15. A method for changing the energy of an x-ray beam focused in a device comprising:a slide pivotable about a pivot point defined at a forward end thereof;a rail unit fixed with respect to said slide;a forward crystals, for focusing x-rays, linearly fixed to said forward end of said slide, said forward crystal defining a forward angle of incidence with respect to said pivot point; anda rearward crystal, for focusing x-rays, movably coupled to said slide and said rail unit at a distance rearward from said forward crystal, said rearward crystal defining a rearward angle of incidence with respect to said pivot point, said slide extending in a straight line between said pivot point and said rearward crystal,the method comprising the step of translating said rearward crystal along said slide with respect to said forward crystal, while said forward crystal remains fixed with respect to said slide thereby changing the distance therebetween, wherein said step of translating simultaneously pivots said slide about said pivot point thereby changing the incidence angles of said forward and rearward crystals. 16. A method as defined in claim 15, wherein said rail unit comprises a lead screw and a motor, said lead screw being coupled between said motor and said rearward crystal, and wherein said step of translating comprises the step of rotating said lead screw with said motor to translate said rearward crystal along said slide. 17. A method as defined in claim 16, wherein said translating step comprises the step of maintaining a fixed distance between said lead screw and said rearward crystal. 18. A method as defined in claim 15, wherein said forward and rearward crystals are sagittally bent Laue crystals having asymmetric lattice planes for focusing and diffracting x-rays. 19. A method as defined in claim 18, further comprising the step of changing the bend of at least one crystal to adjust focusing of the x-rays. 20. A method as defined in claim 15, wherein said forward angle of incidence and said rearward angle of incidence of said forward crystal and said rearward crystal are reciprocal angles, whereby an x-ray beam emerging from said rearward crystal is substantially parallel to an incident beam striking said forward crystal. 21. A method for changing the energy of an x-ray beam focused in a device comprising:a slide pivotable about a pivot point defined at a forward end thereof;a rail unit fixed with respect to said slide;a forward crystal, for focusing x-rays, disposed at said forward end of said slide, said forward crystal defining a forward angle of incidence with respect to said pivot point; anda rearward crystal, for focusing x-rays, movably coupled to said slide and said unit at a distance rearward from said forward crystal, said rearward crystal defining a rearward angle of incidence with respect to said pivot point, wherein said forward angle of incidence and said rearward angle of incidence of said forward crystal and said rearward crystal are reciprocal angles, whereby an x-ray beam emerging from said rearward crystal is substantially parallel to an incident beam striking said forward crystal, and wherein said pivot point is positioned about midway between said incident beam striking said forward crystal and said x-ray beam emerging from said rearward crystal,the method comprising the step of translating said rearward crystal along said slide with respect to said forward crystal, thereby changing the distance therebetween, wherein said step of translating simultaneously pivots said slide about said pivot point thereby changing the incidence angles of said forward and rearward crystals.
	abstract	The present invention relates to a liquid radioactive waste treatment system. The liquid radioactive waste treatment system includes a plurality of evaporation plates and each of the evaporation plates has an uneven surface, in a housing comprised of a glass. A liquid radioactive waste is dispersed via a liquid waste dispersing unit to the evaporation plate, and the liquid radioactive waste is evaporated using solar heat and airflow in the housing.
	description	The present invention relates to digital environment monitor; more particularly, relates to stably setting a high-pressure chamber in a container by a supporting unit for reducing hardware wastage and false signal rate caused by saturated humidity, where the high-pressure chamber is prevented from dampness, thus, conquers environmental problems of temperature and humidity and effectively reduces failure rate. High-pressure chamber device is highly sensitive, reliable, energy-responsive, dose-responsive and environment-tolerant to be used in nuclear plants, nuclear emergency warning systems and civil defense departments. The chamber device coordinated with proper electronic design can obtain a measurement range of span over nine orders of magnitude about 0.1 μR/h˜100 R/h (i.e. 1 nGy/h˜1 Gy/h). Thus, even a little amount of radioactive contents can be shown to obtain a correct dose measurement for correct decision on protecting people's lives and property safety. A general high-pressure chamber device for environmental radiation monitor comprises a main body; a chamber set in the body; a plurality of emulsion bolsters separately set at top and bottom of the chamber; a monitor connected with the chamber; and a cover closing the main body. The chamber device can be used as a standard device for continuously monitoring environmental gamma radiation dose. However, owing to high temperature, high humidity and acid rain in different environments and climates, the chamber device has high damage rate and is hard to maintain. The bolsters at the top and bottom of the chamber are critical. In north America and Europe, porous foam rubbers are used to make the bolsters for resisting the dry and cold weather and the big temperature difference between day and night. But, in subtropical areas, it is muggy before noon and have thundershower in the afternoon. Consequently, the chamber device may be easily damaged. In a practical use for a rather long time, the bolsters may become permeable to water and the high-pressure chamber device becomes wet, which is caused by electrode leakage. The permeable bolsters may also cause high error rate to the chamber device. Besides, the chamber device is usually a dangerous product, which may lay heavy burden on users for maintenance or abandonment. In addition, a new chamber device may cost very high (˜US $20,000/pcs) and becomes uneasy in widely applying to corners of a country for radiation safety. Hence, the prior art does not fulfill all users' requests on actual use. The main purpose of the present invention is to stably set a high-pressure chamber in a container by a supporting unit for reducing hardware wastage and false signal rate caused by saturated humidity, where the high-pressure chamber is prevented from dampness, thus, conquers environmental problems of temperature and humidity and effectively reduces failure rate. To achieve the above purpose, the present invention is an apparatus of digital environment monitor having an easy-in-maintenance high-pressure chamber, comprising a container, a supporting unit, and a high-pressure chamber, where the container comprises a containing area and a cover; the cover closes the containing area; the supporting unit is set in the containing area; the high-pressure chamber is set in the supporting unit; the supporting unit comprises an upper supporter and a lower supporter; the upper supporter is set on an inner end of the containing area; the lower supporter is opposed and connected to the upper supporter; the high-pressure chamber is set between the upper supporter and the lower supporter; and the supporting unit and the high-pressure chamber are closed in the container with the cover; the lower supporter has a curved concave; the upper supporter has a hallowed area corresponding to the curved concave; and the high-pressure chamber is set between the curved concave and the hallowed area; and the upper supporter and the lower supporter are made of acrylics or a polymer material. Accordingly, a novel apparatus of digital environment monitor having an easy-in-maintenance high-pressure chamber is obtained. The following description of the preferred embodiment is provided to understand the features and the structures of the present invention. Please refer to FIG. 1 to FIG. 3, which are a perspective view and an explosive view showing a preferred embodiment according to the present invention; and a view showing a state of opening a cover. As shown in the figures, the present invention is an apparatus of digital environment monitor having a high-pressure chamber easy in maintenance, comprising a container 1, supporting unit 2 and high-pressure chamber 3. The container 1 comprises a containing area 11; and a cover 12 closing the containing area 11. A buckle 13 is set between the container 1 and the cover 12; and, a handle 14 is set on an end surface of the cover 12. The supporting unit 2 is set in the containing area 11. The supporting unit 2 comprises a lower supporter 21 set at bottom of the containing area 11; and an upper supporter 22 correspondingly connected with the lower supporter 21. Therein, the lower supporter 21 has a curved concave 211; the upper supporter 22 has a hallowed area 221 corresponding to the curved concave 211; at least two limit units 23,24 are set on top of the upper supporter 22; and, the upper and lower supporters 21,22 are made of acrylics or polymer materials. The high-pressure chamber 3 is set between the curved concave 211 and the hallowed area 221 of the lower and upper supporters 21,22 of the supporting unit 2; and, the supporting unit 2 and the high-pressure chamber 3 is closed in the container 1 by the cover 12. The high-pressure chamber 3 is further connected with an embedded main controller 31, a digital low-current meter/high-pressure generator 32 and a detector 33. The embedded main controller 31 and the digital low-current meter/high-pressure generator 32 are separately set in the limit units 23,24. The detector 33 is set on an outside surface of the cover 11. Thus, a novel apparatus of digital environment monitor having a high-pressure chamber easy in maintenance is obtained. On using the present invention, the high-pressure chamber 3 is coordinated with the supporting unit 2 to be set in the containing area 11 of the container 1. The high-pressure chamber 3 is set between the curved concave 211 and the hallowed area 221 of the lower and upper supporters 21,22 of the supporting unit 2. The cover is coordinated with the buckle 13 to close the supporting unit 2 and the high-pressure chamber 3 in the container 1. Thus, the whole apparatus can be carried with the handle 14 on the cover 12 to be set at a required position for radiation detection. Since the upper and lower supporters 21 of the supporting unit 2 are made of acrylics or a polymer material, the high-pressure chamber 3 is prevented from dampness. Hence, the high-pressure chamber 3 can conquer environmental problems of temperature and humidity and effectively reduce failure rate. To sum up, the present invention is an apparatus of digital environment monitor having a high-pressure chamber easy in maintenance, where a high-pressure chamber is stably set in a container by a supporting unit; the supporting unit reduces hardware wastage and false signal rate caused by saturated humidity; the high-pressure chamber is prevented from dampness; and, the high-pressure chamber can conquer environmental problems of temperature and humidity and effectively reduce failure rate. The preferred embodiment herein disclosed is not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.
	claims	1. An atom interferometer device for inertial sensing, comprising:one or more thermal atomic sources to provide one or more atomic beams;a state preparation laser disposed to provide a state preparation laser beam nominally perpendicular to each of the one or more atomic beams;a set of lasers disposed to provide interrogation laser beams that interrogate the one or more atomic beams to assist in generating atom interference;a detection laser disposed to provide a detection laser beam, which is angled at a first angle to each of the one or more atomic beams to enhance dynamic range by enabling velocity selectivity of atoms used in detecting the atom interference. 2. The device as in claim 1, wherein the velocity selectivity of atoms is achieved using an angle from perpendicular to one of the one or more atomic beams. 3. The device as in claim 2, wherein the angle from perpendicular comprises a less than ten degree angle from perpendicular. 4. The device as in claim 2, wherein the angle from perpendicular comprises a ten to less than twenty degree angle from perpendicular. 5. The device as in claim 2, wherein the angle from perpendicular comprises a twenty to less than thirty degree angle from perpendicular. 6. The device as in claim 2, wherein the angle from perpendicular comprises a thirty to less than fifty degree angle from perpendicular. 7. The device as in claim 2, wherein the angle is adjusted from perpendicular for each of the one or more atomic beams to adjust the dynamic range. 8. The device as in claim 2, wherein the detection laser beam is modulated for a Doppler shift associated with the angle from perpendicular to each of the one or more atom beams. 9. The device as in claim 2, wherein the detection laser beam is modulated for a plurality of Doppler shifts to address different populations in the one of the one or more atomic beams. 10. The device as in claim 2, wherein a detection beam steering mirror is adjusted dynamically to increase or decrease a dynamic range depending on sensor motion and a detection beam frequency is adjusted to an appropriate Doppler shift. 11. The device as in claim 2, where an optical power in the detection laser beam is adjusted dynamically to increase or decrease a dynamic range depending on a sensor motion. 12. The device as in claim 1, wherein a second detection laser beam is angled at a second angle to the one of the one or more atomic beams to enhance dynamic range by enabling velocity selectivity of atoms used in detecting the atom interference, wherein the first angle and the second angle are different. 13. The device as in claim 12, wherein the second detection laser beam is generated by the detection laser. 14. The device as in claim 1, wherein the thermal atomic source is collimated using a mechanical collimator. 15. The device as in claim 14, wherein the mechanical collimator achieves a collimation to one of the following ratio ranges: from 50:1 to less than 100:1, from 100:1 to less than 200:1, or from 200:1 to less than 300:1. 16. The device as in claim 1, wherein the laser interrogation beams assisting in generating atom interference comprise three Raman beams. 17. The device as in claim 16, wherein each of the three Raman beams are retroreflected. 18. The device as in claim 17, wherein retroreflection is achieved using a single mirror or three mirrors. 19. The device as in claim 16, wherein the set of lasers comprise three Raman lasers that produce the three Raman beams. 20. The device as in claim 16, wherein a first separation of a first interrogation region of a first Raman beam of the three Raman beams with the one of the one or more atomic beams to a second interrogation region of a second Raman beam of the three Raman beams with the one of the one or more atomic beams and a second separation of the second interrogation region of the second Raman beam of the three Raman beams with the one of the one or more atomic beams to a third interrogation region of a third Raman beam of the three Raman beams with the one of the one or more atomic beams are equivalent. 21. The device as in claim 1, wherein the state preparation laser beam is split to generate two state preparation laser beams for interaction with the one or more atomic beams in two separate interaction regions. 22. The device as in claim 1, wherein the detection laser beam is split to generate two detection laser beams for interaction with the one or more atomic beams in two separate detection regions. 23. The device as in claim 1, further comprising a processor configured to determine an inertial measurement based at least in part on the atom interference detected using the detection laser. 24. The device as in claim 1, wherein the one or more thermal atomic sources comprise two atomic sources that provide two atomic beams. 25. The device as in claim 1, wherein the set of lasers to provide interrogation laser beams comprise a set of Raman lasers to provide Raman interrogation laser beams. 26. A method for inertial sensing using an atom interferometer device, comprising:disposing one or more thermal atomic sources to provide one or more atomic beams;disposing a state preparation laser to provide a state preparation laser beam nominally perpendicular to one of the one or more atomic beams;disposing a set of lasers to provide interrogation laser beams that interrogate the one or more atomic beams to assist in generating atom interference; anddisposing a detection laser to provide a detection laser beam, which is angled at a first angle to each of the one or more atomic beams to enhance dynamic range by enabling velocity selectivity of atoms used in detecting the atom interference. 27. A method for inertial sensing using an atom interferometer device, comprising:providing one or more thermal atomic sources to provide one or more atomic beams;providing a state preparation laser to provide a state preparation laser beam nominally perpendicular to one of the one or more atomic beams;providing a set of lasers to provide interrogation laser beams that interrogate the one or more atomic beams to assist in generating atom interference;providing a detection laser to provide a detection laser beam, which is angled at a first angle to each of the one or more atomic beams to enhance dynamic range by enabling velocity selectivity of atoms used in detecting the atom interference; andproviding a processor to determine an inertial measurement based at least in part on the atom interference detected using the detection laser.
	abstract	An x-ray analysis apparatus for illuminating a sample spot with an x-ray beam. An x-ray tube is provided having a source spot from which a diverging x-ray beam is produced having a characteristic first energy, and bremsstrahlung energy; a first x-ray optic receives the diverging x-ray beam and directs the beam toward the sample spot, while monochromating the beam; and a second x-ray optic receives the diverging x-ray beam and directs the beam toward the sample spot, while monochromating the beam to a second energy. The first x-ray optic may monochromate characteristic energy from the source spot, and the second x-ray optic may monochromate bremsstrahlung energy from the source spot. The x-ray optics may be curved diffracting optics, for receiving the diverging x-ray beam from the x-ray tube and focusing the beam at the sample spot. Detection is also provided to detect and measure various toxins in, e.g., manufactured products including toys and electronics.
	claims	1. An electron beam writing apparatus which has a holding mechanism for holding a mask at a back surface thereof and applies an electron beam onto a surface of the mask held by the holding mechanism by electron beam applying means thereby writing a desired pattern, comprising:an XY stage movable in a direction orthogonal to the direction of an optical axis of the electron beam;an electron-beam focal adjusting mark table fixed onto the XY stage;a Z stage mounted onto the XY stage in avoidance of an area to which the mark table is fixed, and movable in the optical axis direction; andmeasuring means for measuring a height of the mark table and a height of the mask placed on the holding mechanism,wherein the electron beam applying means includes a focal adjustment mechanism for varying a focal height of the electron beam within a predetermined adjustable range and a middle value of the adjustable range coincides with the height of the mark table,wherein the mask holding mechanism includes difference calculating means placed on the Z stage for calculating a difference between the height of the mark table measured by the height measuring means and the height of the mask placed on the holding mechanism, and Z stage control means for moving the Z stage based on information about the calculated difference in such a manner that the height of the mask coincides with the height of the mark table, andwherein the height of the mask used in the calculation of the difference calculating means is a middle value between highest and lowest values of heights of a plurality of measurement points, which are obtained by measuring the plurality of measurement points on the mask by the height measuring means. 2. The electron beam writing apparatus according to claim 1, wherein the measurement points on the mask measured by the height measuring means are at least five spots corresponding to four corners of the mask and the center thereof. 3. The electron beam writing apparatus according to claim 1, further including inclination calculating means for calculating an inclination of the mask placed on the holding mechanism,wherein the Z stage includes inclination correcting means for correcting the inclination of the mask based on information about the calculated inclination in such a manner that the surface of the mask becomes orthogonal to the optical axis of the electron beam. 4. The electron beam writing apparatus according to claim 2, further including inclination calculating means for calculating an inclination of the mask placed on the holding mechanism,wherein the Z stage includes inclination correcting means for correcting the inclination of the mask based on information about the calculated inclination in such a manner that the surface of the mask becomes orthogonal to the optical axis of the electron beam. 5. The electron beam writing apparatus according to claim 3, wherein the Z stage equipped with the inclination correcting means comprises three or more support mechanisms movable independently with respect to the optical axis direction. 6. The electron beam writing apparatus according to claim 4, wherein the Z stage equipped with the inclination correcting means comprises three or more support mechanisms movable independently with respect to the optical axis direction. 7. The electron beam writing apparatus according to claim 1, wherein the holding mechanism comprises an electrostatic chuck for adsorbing the back surface of the mask. 8. An electron beam writing method for applying an electron beam to a surface of a mask held by a holding mechanism for holding the mask at a back surface thereof by electron beam applying means by writing a desired pattern, comprising the steps of:fixing an electron beam focal adjusting mark table to an XY stage movable in a direction orthogonal to the direction of an optical axis of the electron beam, mounting a Z stage movable in the optical axis direction on the XY stage in avoidance of an area to which the mark table is fixed, and placing the holding mechanism on the Z stage;adjusting the electron beam applying means in such a manner that a middle value of a predetermined adjustable range of a focal height of the electron beam, said range being varied by a focal adjustment mechanism provided in the electron beam applying means, coincides with a height of the mark table; andmeasuring the height of the mark table, measuring heights of a plurality of measurement points on the mask placed on the holding mechanism, setting a middle value between highest and lowest values of the heights of the measurement points as a measured height of the mask, comparing the measured height of mark table and the measured height of mask to calculate a difference therebetween, and movably controlling the Z stage based on information about the calculated difference in such a manner that the height of the mask coincides with the height of the mark table. 9. The electron beam writing method according to claim 8, wherein the plurality of measurement points are at least five spots corresponding to four corners of the mask and the center thereof. 10. The electron beam writing method according to claim 8, further including an inclination correcting step for calculating an inclination of the surface of the mask from the heights of the plurality of measurement points on the mask placed on the holding mechanism and controlling inclination correcting means provided in the Z stage, based on information about the calculated inclination in such a manner that the surface of the mask becomes orthogonal to the optical axis of the electron beam. 11. The electron beam writing method according to claim 9, further including a step for calculating an inclination of the surface of the mask from the heights of the plurality of measurement points on the mask placed on the holding mechanism, and controlling inclination correcting means provided in the Z stage, based on information about the calculated inclination in such a manner that the surface of the mask becomes orthogonal to the optical axis of the electron beam. 12. The electron beam writing method according to claim 10, wherein the inclination correcting step is performed after the height adjusting step. 13. The electron beam writing method according to claim 11, wherein the inclination correcting step is performed after the height adjusting step. 14. The electron beam writing method according to claim 10, wherein the height adjusting step is performed after the inclination correcting step. 15. The electron beam writing method according to claim 11, wherein the height adjusting step is performed after the inclination correcting step.
	description	This application claims the priority of Provisional Application Ser. No. 60/762,392, filed Jan. 26, 2006, entitled “PROCESS AND UNIQUE TOOLING FOR DISMANTLING, CASKING AND REMOVAL OF NUCLEAR REACTOR CORE.” 1. Field of the Invention The invention relates generally to nuclear reactors and, more particularly, to methods and tooling for dismantling, casking and removing nuclear reactor core structures from the containment building, for example, for on-site storage of transport off-site for disposal. 2. Background Information As nuclear reactors age, utility companies desired to extend plant life. There is also a desire for design upgrades in some circumstances. Accordingly, the replacement of reactor internals (e.g., core structures) is coming into prominence. To remove and replace radioactive structural members of the reactor internals efficiently and cost-effectively, a number of factors must be taken into account. Among them is the very important priority of minimizing the exposure of personnel to radiation. It is also necessary to minimize plant outage duration, and to limit the size and weight of the disposable segments of the internals. For example, to minimize costs, it is desirable that the capacity of the existing crane, which is typically present at the containment building for the nuclear reactor, is not exceeded. It is also desirable that the casked segments can exit the containment building through the existing equipment hatch. Unfortunately, prior proposals do not satisfy these criteria. Rather, they typically require the existing equipment hatch to be enlarged or an alternate opening to be provided which is sufficiently large in size, for example, by breaking through the concrete and rebar of the containment building. The building must then be restored after the task is completed, at great expense. This is because such proposals require a cask which is quite large, and thus heavy, in order to house and adequately shield the radioactive internals which are to be disposed therein. Specifically, the cask or casks which generally comprise thick walled cylinders that enclose the internals to provide the shielding function, must satisfy the allowable radiation dose level on the outer surfaces of the cask(s), as prescribed by well-established health physics guidelines. This generally results in the cask(s) having relatively thick walls, thus being large and heavy. Accordingly, a special, enlarged opening, and specialized lifting equipment, including a larger capacity crane than the existing on-site crane, are required. By way of example, one known project wherein the upper and lower internals of Shikoku Electric Power Company's Ikata Unit No. 1 were replaced, required a single cask which was large (e.g., about 12 m in height and 3.8 m in outer diameter) and heavy (e.g., about 450 tons). Such a large cask severely limits the number of manufacturing vendors who have the necessary equipment to cast, machine and handle thick walled cylinders of the magnitude necessary. Additional disadvantages included extended material procurement and manufacturing schedules. Accordingly, such a process is cost-intensive. There is a need, therefore, for an improved method and tooling for dismantling, casking and removing nuclear reactor core structures which overcomes the aforementioned disadvantages. Specifically, it is desirable to selectively dismantle highly radiated components and cask them in a fashion which significantly reduces the size and weight of disposal hardware. There is, therefore, room for improvement in methods and tooling for dismantling, casking and removing nuclear reactor core structures. These needs and others are met by embodiments of the invention, which are directed to an improved method and associated tooling for dismantling, casking and removing nuclear reactor core structures. As one aspect of the invention, a method is provided for removing radioactive internals structural members in the core of a reactor pressure vessel in a containment vessel. The reactor pressure vessel houses a core barrel assembly. The method comprises the steps of: removing the core barrel assembly from the reactor pressure vessel; placing a first cask in a first internals assembly; detaching radioactive first internals structural members from second internals structural members of the first internals assembly; placing the detached first internals structural members in the first cask; placing the first internals assembly in a second cask; and removing the second cask containing the first internals assembly and containing the casked detached radioactive first internals members from the containment vessel, for example, for transport or on-site storage. The first internal members may comprise radioactive baffle plates, and the second internals members may comprise former plates bolted to the radioactive baffle plates, wherein the step of detaching the radioactive first internals members from second internals members comprises unbolting the radioactive baffle plates from the former plates. The baffles plates may also have a plurality of segments, which are unbolted from the former plates. The bolts fastening the baffle plates to the former plates may be secured by lock bars which are welded to the baffles plates. Thus, the step of unbolting the radioactive baffle plates from the former plates may further comprises the steps of: placing a strong back near a baffle plate bolt; placing a tool between the strong back and the baffle plate bolt; placing a pneumatic cavity between the tool and the strong back; expanding the pneumatic cavity to urge the tool into engagement with the baffle plate bolt; cutting or breaking the lock bar securing the baffle plate bolt; and unbolting the baffle plate bolt with the tool. The strong back may be keyed with the first internals assembly to precisely position the strong back. The first internals assembly may have a plate member disposed at one end of a barrel member, and the step of placing the first cask in the first internals assembly may comprise: placing the first cask on the first internals assembly plate member in spaced relationship from the barrel member. The first internals assembly plate member may further include guide members, and the first cask may have a base plate member, wherein the step of placing the first cask on the first internals assembly plate member and in spaced relationship from the barrel member comprises: lowering the first cask base plate member over the guide members. The first cask may have a number of detachable side wall members, and the step of placing the detached first internals structural members in the first cask may include placing the detached first internals structural members on the first cask base plate member after the first cask base plate is lowered over the guide members, and attaching the number of first cask detachable side wall members to the first cask base member base plate after the detached first internals structural members have been placed on the first cask base plate member. The method may further comprise draining water from the first cask in the lower internals assembly, and/or positioning indexable guides in the first cask proximate the detached first members. The first cask and the second cask may each have a wall thickness, wherein the wall thickness of the first cask is greater than the wall thickness of the second cask. The wall thickness of the first cask may, for example, be at least twice the wall thickness of the second cask. The first cask and the second cask may also be made from substantially similar materials of construction. In one non-limiting embodiment of the invention, the detached first internals members may have radiation contact levels of at least 500,000 R/hr, and the second cask may be have an outside surface with a radiation level of about 800 mR/hr. or less. This level will allow the casked internals to be removed through the equipment hatch of the containment building and transferred to a storage bunker made, for example, from concrete and similar in concept to the bunkers that store casked spent fuel elements on site. The 800 mR/hr. contact level can be markedly reduced, if desired, by adding more shielding, without increasing the cask diameter. Removing the eight irradiation specimen baskets from the thermal shield outside diameter will permit the inside diameter of the lower cask to move radially inward by about 2.7 inches, increasing the cask wall thickness by this amount. As will be discussed hereinbelow, the upper cask can also increase shielding, again without increasing cask envelope diameter, if necessitated by the radiation levels on the upper core plate element in the upper internals. Additionally, the upper support plate of the upper internals can be vacuumed to remove radioactive crud and aggressive chemical decamination remains as another means of reducing radiation levels of non-activated elements of the internals. The method may further comprise: severing the first internals assembly into a first section and a second section; placing a second internals assembly into the severed first section of the first internals assembly; placing the severed first section of the first internals assembly containing the second internals assembly into a third cask; and removing the third cask containing the severed first section of the first internals assembly and the second internals assembly from the containment vessel. The second internals assembly may have extending members, and the method may further comprise severing the extending members from the second internals assembly before the step of placing the second internals assembly in the third cask. Tooling for use in facilitating the aforementioned method, is also disclosed. For purposes of illustration, embodiments of the invention will be described as applied to a standard 3-loop nuclear power plant (e.g., about 750 Megawatts) such as, for example and without limitation, a Westinghouse 3-loop nuclear power plant, although it will become apparent that they could also be adapted for implementation with nuclear power plants of any known or suitable size (e.g., without limitation, a 2-loop plant). Westinghouse Electric Company has a place of business in Pittsburgh, Pa. Directional phases used herein, such as, for example, left, right, top, bottom, upper, lower, front, back and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein. It will be appreciated that times, dimensions and other quantities discussed herein, are provided for example only, and are not meant to be limiting on the scope of the invention. As employed herein, the term “cask” refers to any known or suitable container or vessel, or combination of containers or vessels, suitably structured to receive, secure and/or shield components (e.g., without limitation, radioactive structural members) of a nuclear reactor for storage and/or transportation thereof. As employed herein, the term “casking” refers to the process of placing and/or storing nuclear reactor components within a suitable cask or combination of casks. As employed herein, the term “strong back” refers to any known or suitable structural member such as, for example and without limitation, a beam or a bar member, which is sufficiently robust and strong to accommodate strain and/or to serve as a mounting base or foundation on which to securely mount tooling. As employed herein, the term “internals” refers to the structures within the interior of a nuclear reactor such as, for example, the radioactive structural members of the reactor core that are located within the pressure vessel of the reactor. Accordingly, as used herein, the phrase “upper internals” refers to the interior structures of the reactor that are generally disposed in the top part of the pressure vessel (and above the mating line of the reactor flange and vessel head of the pressure vessel). Likewise, the phase “lower internals” refers to interior structures of the reactor that are generally disposed in the lower part of the pressure vessel (e.g., below the mating line). As employed herein, the term “segment” refers to a portion which comprises a group or collection of parts of a whole, and expressly includes, without limitation, a collection of baffle plates which are removed, detached, disassembled or otherwise severed from the baffle assembly of a nuclear reactor as a unit, as opposed to individual plates of the baffle assembly. As will be described hereinbelow, the exemplary baffle plate segments include A plate segments, B plate segments and C plate segments as opposed to, for example, the exemplary individual D plates and angle plates of the baffle assembly. As employed herein, the terms “key” and “keying” refer to any known or suitable interface configuration between two or more coupled components, wherein such interface configuration provides precise alignment between the components. As employed herein, the term “pneumatic cavity” refers to any known or suitable device or mechanism such as, for example and without limitation, an inflatable bladder or a volume of air, which is provided for the purpose of establishing a predetermined, desired spacing relationship between a number of components and/or for facilitating movement of one component with respect to another (e.g., by inflating the inflatable bladder). As employed herein, the statement that two or more parts are “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). FIG. 1 shows a non-limiting example of a pressurized water nuclear reactor (PWR) 10 of the type with which embodiments of the invention are employed. The PWR 10 includes a reactor pressure vessel 12 which houses a nuclear reactor core 14 composed of a plurality of elongated fuel assemblies 16. For simplicity of disclosure and ease of illustration, only two fuel assemblies 16 are shown in FIG. 1. In reality, however, the core 14 is composed of a great number of such fuel assemblies 16. Spaced radially inwardly from the reactor vessel 12 is a generally cylindrical core barrel 18, and within the core barrel 18 is a former and baffle system, hereinafter called a baffle assembly 20. The reactor core 14 and the baffle assembly 20 are disposed between upper and lower core plates 22,24 which, in turn, are supported by the core barrel 18. The baffle assembly 20, which is also shown at least in part in FIGS. 2A and 2B, provides a transition from the generally cylindrical core barrel 18 to the squared-off periphery of the reactor core 14, which is formed by the plurality of fuel assemblies 16 being arrayed therein. The baffle assembly 20 surrounds the fuel assemblies 16 of the reactor core 14, as shown in FIG. 2A. Specifically, the baffle assembly 20 includes a plurality of substantially vertical segments or plates, such as the A segments 26, B segments 28, C segments 30, D plates 32 and angle plates 34, shown in FIGS. 2A and 2B, which are fastened to generally horizontal former plates 35 by bolts 36. The baffle plate-to-former arrangement and fasteners (e.g., bolts) therefor, are described in further detail, for example, in U.S. Pat. Nos. 4,080,257 (Marhado et al.) and 6,055,288 (Schwirian), which are hereby incorporated herein by reference. Referring again to FIG. 1, the upper end of the reactor pressure vessel 12 is hermetically sealed by a removable closure head 38 upon which are mounted a plurality of control rod drive mechanisms 40. For simplicity of disclosure and ease of illustration, only a few of the many control rod drive mechanisms 40 are shown. Each control rod drive mechanism 40 selectively positions a corresponding rod cluster control mechanism 42 above and within some of the fuel assemblies 16. A nuclear fission process carried out in the fuel assemblies 16 of the reactor core 14 produces heat which is removed during operation of the PWR 10 by circulating a coolant fluid (e.g., without limitation, light water with soluble boron), through the core 14. More specifically, the coolant fluid is typically pumped into the reactor pressure vessel 12 through a plurality of inlet nozzles 44 (only one inlet nozzle 44 is shown in FIG. 1). As indicated generally by the arrows at FIG. 1, the coolant fluid passes downward through an annular region 46 defined between the reactor vessel 12 and core barrel 18, and a thermal shield 48 on the core barrel 18, until it reaches the bottom of the reactor vessel 12 where it turns 180 degrees prior to flowing up through the lower core plate 24 and then up through the reactor core 14. Upon flowing upwardly through the fuel assemblies 16 of the reactor core 14, the coolant fluid is heated to reactor operating temperatures by the transfer of heat energy from the fuel assemblies 16 to the fluid. The hot coolant fluid then exits the reactor vessel 12 through a plurality of outlet nozzles 50 (only one outlet nozzle 50 is shown in FIG. 1) extending through the core barrel 18. Thus, heat energy which the fuel assemblies 16 impart to the coolant fluid is carried off by the fluid from the pressure vessel 12. When it is time to replace reactor internals such as, for example and without limitation, the lower core barrel assembly 52 of FIGS. 1, 2A and 2B, it is necessary to dispose of the internals, which are highly irradiated (e.g., about 500,000 R/hr on contact), in a shielding container or cask. In order to minimize the radiation dose level on the outer surface of the shielding cask which contains the old internals, the wall of the cask, which typically comprises a carbon steel cylinder, can reach a thickness of about 11 inches to about 13 inches, depending on the size of the plant and the operating life of the core structures being replaced. In recent offshore programs, 2-loop size reactor internals were casked and removed, without being first dismantled, from the reactor containment building (see, for example, containment vessel (e.g., building) 2 of FIGS. 7 and 8) through the existing relatively large (e.g., about 252 inch diameter) equipment hatch opening. The shielding cask wall thickness was about 11 inches, and the loaded cask was about 41 feet long and weighed about 550 tons. In many circumstances, the equipment hatch will not be large enough for a single shielding cask which provides the necessary shielding attributes. Under such circumstances, a larger hole will have to be made in the containment building, and specialized equipment (e.g., heavy duty cranes) capable of lifting the huge cask will be necessary, as previously discussed. On a 2-loop plant with about 30 calendar years of operation (e.g., 24 effective full-power years), the following contact radiation readings were measured on the following components: 1.Baffle Plates (Core Side)−500,000 R/hr.2.Core Barrel. O.D.−100,000 R/hr.3.Thermal Shield, I.D. −40,000 R/hr.4.Thermal Shield. O.D. −6,000 R/hr.5.Lower core Plate−100,000 R/hr. The radiation level requirement for the outer diameter (O.D.) surface of the shielding cask is about 200 mR/hr. for over the road shipment (higher if the cask is stored on-site). Hence, the aforementioned 11 inch wall thickness is required, if the load is shipped. As will now be described, the invention provides an improved method for providing the requisite shielding, while simultaneously reducing the size and weight of the casked load. It will be appreciated that first casks 102 and 102′ represent two non-limiting alternative example embodiments of inner casks in accordance with the invention. Specially, as will be described herein, the disclosed method removes the highly irradiated baffle plates and/or segments 26,28,30,32,34 (FIGS. 2A-5) and disposes of them separately, positioned them within a novel first or inner cask 102 (FIGS. 4B-6 and 17A), 102′ (FIGS. 3, 7 and 16) which is spaced apart from the inside diameter of a second or outer shielding cask 104 to achieve the desired shielding in a compact configuration. It will be appreciated that first casks 102 and 102′ represent two non-limiting alternative example embodiments of inner casks in accordance with the invention. The baffle plates and/or segments 26,28,30,32,34 are dismantled by removing as few retaining bolts 36,36′ (FIG. 2B) as possible and securing the baffle plates and/or segments 26,28,30,32,34 within the individual inner shielding cask 102,102′, in an organized, compact array. In turn, the inner cask 102,102′ is stored, in a compact fashion, inside the internals (e.g., lower core barrel assembly 52). FIG. 2B illustrates a typical baffle plate-to-former bolting arrangement of the baffle assembly 20. Specifically, a plurality of bolts 36 couple the baffle plates and/or segments (a B segment 28, a D plate 32, and an angle plate 34 are shown in FIG. 2B) to former plates 35. As shown in FIG. 2C, the bolts 36 may be secured by lock bars 37 (one is shown) welded to the baffle plates 28. FIG. 3 shows all the baffle plates and/or segments 26,28,30,32,34 having between removed (e.g., unbolted) and stacked inside a remnant canister 103, which is generally octagonal in shape. The canister 103 and baffle plates and/or segments 26,28,30,32,34 therein, are then disposed within the inner cylindrical cask 102′. The inner cask 102′ has a wall thickness 116′ of about 7.5 inches. A receptacle 124′ is included within the remnant canister 103 for receiving the bolts 36,36′ of the baffle assembly 20 (FIGS. 1, 2A and 2B). FIGS. 4A-6 and 11A-16 show another method and configuration for securing the baffle plates and/or segments 26,28,30,32,34 in an inner cask 102 which, unlike the cylindrical cask 102′ of FIGS. 3, 7 and 16, is preferably generally octagonal in shape. More specifically, the inner cask 102 includes a base plate member 106 which is structured to be disposed on the lower core plate 24 (FIG. 1) which, in turn, bears the vertical load component of the cask 102. In particular, the inner cask 102 is disposed on the axial center line of the lower core plate 24, thereby positioning the highly irradiated baffle plates 26,28,30,32,34 well away from the cylindrical outer cask 102 (FIGS. 5-7) which shrouds the entire lower internals 52. This separation, and the wall thickness 116 of the inner cask 102, which is preferably about 7.5 inches, provides the requisite level of radiation shielding while simultaneously allowing for a relatively thin-walled outer cask 104 in comparison with the aforementioned example, which was about 11 inches thick. As a result, cost, size and weight savings are realized. Furthermore, as will be described hereinbelow, the baffle plates and/or segments 26,28,30,32,34 are preferably secured in an organized manner within a racking assembly 130, as shown in FIGS. 4A and 4B, in order to maximize the efficiency with which the interior space of the inner cask 102 is used, and thereby minimize the overall size of the inner cask 102. It will be appreciated that the casks 102, 102′ may have a wall or walls which are detachable or otherwise removable from the cask base plate member 106, in order to facilitate the process of the loading the racking assembly 130 of the cask 102,102′. FIG. 5 shows the generally octagonal inner cask 102, located in the lower internals 52, as described, with radial arms 112 (four are shown) deployed to stabilize the inner cask 102, and to absorb horizontal loads during the process of lifting, lowering, and moving out of the reactor containment vessel (e.g., containment building 2 of FIG. 8). These radial arms 112 have a first end 113 disposed at or about the outside of the cask 102, and a second end 114 which extends outwardly to engage the internals 52 and secure the inner cask 102 in a centralized position therein. It will be appreciated that such arms 112 may be disposed at two or three vertical levels (see, for example, arms 112 disposed at three vertical levels in FIG. 17A) in order to fully secure the inner cask 102. Accordingly, by way of example, with the baffle plates 26,28,30,32,34 relocated to the center of the core barrel 18, the shielding wall thickness 118 (FIG. 5) required, for example, for a cask having an outer diameter (O.D.) of about 157 inches, is only about 2.00 inches (about 3 inches locally). As shown in FIG. 5, additional panels which are about 1.00 inch thick, are preferably coupled to the cask 104 at or about the cardinal axes (e.g., 0, 90°, 180°, 270°) of the internals 52, where radiation levels are generally much higher than that of the 45° axes. The casked lower internals 52 culminates in what can be seen in FIG. 6, where the lower internals section 52 is within the outer cask 104 with top and bottom cask covers 105,106 in place, and the lift rig 126 (best shown in FIGS. 17A-17C) is assembled. This casked assembly will then be transported out of the reactor containment building 2, as shown in FIGS. 7 and 8. Specifically, the casked assembly is much smaller and lighter than would otherwise be necessary if a single cask were employed. The overall dimensions of the exemplary assembly are about 160 inches in maximum outer diameter (O.D.) and about 305 inches in length. The weight of the assembly is about 225 tons. Accordingly, such load can be handled using, for example, tie rods 128, and the on-site main crane (not shown) with modest motor and cable upgrades, and the addition of several vertical crane rail supports. Such modifications are common in the industry, making the disclosed method a very cost effective solution. Additionally, whereas many 2-loop plants have relatively large equipment hatch openings in the reactor containment structure, such as the 252 inch diameter hatch, in the 2-loop example previously discussed, most 3-loop plants feature openings of only about 176 inch in outer diameter (O.D.). As shown in FIG. 7, the 160 inch O.D. of the casked assembly in accordance with the invention will fit through such 176 inch equipment hatch 4. Specifically, FIG. 7 shows the 225 ton casked assembly loaded onto a transfer skid 6 and being moved through the equipment hatch 4. In the example of FIG. 7, the inner cask 102′ is of the generally cylindrical configuration described hereinabove with respect to FIG. 3. In this non-limiting example, which is representative of, for example and without limitation, Surry Unit 2, a clearance of about 2 inches is present at the top of the assembly, between the outer cask 104 and the hatch 4. FIG. 8 is provided for reference to show the type of “rail and truck” system 200 that is generally installed to facilitate movement of equipment through the equipment hatch 4. A pressure vessel head assembly 13 is shown, already through the hatch 4 and upended for transport to the pressure vessel 12 (FIG. 1). As previously discussed, if the outer cask 104 were larger, it would be necessary to create a larger opening by breaking through concerete and rebar of the containment building 2, and then restore the building 2 after the job was completed. Several plants have done this, out of necessity, for example, when changing out steam generators or pressure vessel head assemblies (see, for example, head assembly 13 of FIG. 8). Obviously, this option undesirably entails a significant added cost and additional plant outage time. A non-limiting EXAMPLE of an operation employing the method of the invention will now be discussed. Specifically, FIG. 9A shows the lower internals 52 residing in its storage stand 8 after the core barrel 18 has been removed from the pressure vessel 12. A number of head and vessel alignment pins 193 are provided at the mating surface. At an elevation of about 290 inches above the reactor cavity floor 3, the core barrel 18 is parted using a plasma torch 140 (shown in simplified form) mounted, for example, on a track assembly 142 such as, for example and without limitation, a BUGO TRACK®, which is affixed by clamps or suction cups to either the core barrel 18 or thermal shield outer diameter. A BUGO TRACK® is commercially available from BUG-O Systems, Inc. which has a place of business in Pittsburg, Pa. The torch 140 will track around the circumference of the core barrel 18 (a distance of about 430 inches), thereby severing the upper section 60. Depending on each specific plant layout, cutting can be performed from without (FIG. 9A) or within (FIG. 9C) the core barrel 18. For example, FIG. 9C shows an alternative embodiment in which a tool 134 having a plurality of gears 136 and a stylus 138, is employed to cut the core barrel 18 from inside. Specifically, an air cylinder 139 marks in conjunction with the gears 136 and stylus 138 to position the torch 140′ in the desired location and move it to cut the core barrel 18. A television camera 80′ can be employed to monitor the operation. The upper section 60 (see also FIG. 9B) can then be transported to, and inserted into the pressure vessel 12, sans the lower section 52, which remains in the storage stand 8. Removal of the aforementioned baffle plates and/or segments 26,28,30,32,34 is then commenced. Specifically, the underwater operation of removing the bolts 36 which fasten the baffle plates and/or segments 26,28,30,32,34 to the formers 35, and baffle-to-baffle edge bolts 36′ (FIG. 2B), will now be described. Referring back to FIG. 2B, and the example of a 3-loop plant, there are a total of about 1,088 baffle-to-former bolts 36, and about 1800 baffle edge bolts 36′. In accordance with the exemplary method, all of the baffle-to-former bolts 36 are removed, and only about 408 baffle edge bolts 36′ need to be removed. More specifically, by selective removal of edge bolts 36′, baffle plate segments, such as segments A, B, and C previously discussed, rather than individual plates 26,28,30 can, in most cases, be removed. There are, in addition four of the aforementioned D plates 32, and eight corner angle plates 34. As shown in FIG. 2C, and as previously discussed, the bolts 36 are secured with lock bars 37. The lock bars 37 fit into a slot in the bolt head, as shown, and after the bolts 36 are torqued, a weld is added at each end of the lock bar 37 to secure it to the counter bore of the bolt 36 (see also FIG. 2B). A novel bolt removal tool 56, which is shown in simplified form in FIG. 10 and is described below with respect thereto, is provided to accomplish the tasks of loosening and removing select bolts 36. Specifically, two such tools 56 (one is shown in FIG. 10) will be deployed in the baffle cavity (see FIGS. 1 and 2A), and spaced approximately 180 degrees apart from one another. In this manner, the tools 56 may work simultaneously in order to reduce plant outage time for the operation. As shown in FIG. 10, the exemplary tool 56 includes a strong back 54, which preferably keys into precise holes 23 in the lower core plate 24 (partially shown in simplified form in FIG. 10), and can be positioned to address every bolt 36, in every baffle plate and/or segment (an A baffle segment 26 is shown in FIG. 10). The strong back 54 is essentially a template which has a hole 62 for receiving a pilot (i.e., guide) pin 64 which is disposed on a torquing drive 66. More specifically, it is believed that the weld of lock bar 27 (FIG. 2C) can be broken with sufficient torque being applied with a breaker bar 68 (fitted with a socket head cap screw ejector in the example shown), and then the bolt 36 unscrewed with a nut runner 76 (e.g., a device for twisting a nut to loosen or tighten it) that is coupled to, and designed to rotate, a suitable wrench, such as the modified Allen wrench 78, both of which are shown in simplified form in FIG. 10. An air cylinder 76 can then be employed to retract the wrench 78 and draw out the loosened bolt 36 to be deposited into a chute (not shown) for disposal in the aforementioned receptacle 124 (shown in simplified form in FIG. 10; see also FIGS. 4A-5 and 11A). In the example of FIG. 10, a television camera 80 is positioned to monitor the operation. The exemplary tool 56 also includes a pneumatic cavity 58, as defined herein. The pneumatic cavity 58 which can comprise, for example and without limitation, an inflatable bladder 58 of the type generally shown in FIG. 10, is inflated pneumatically to ease the modified Allen wrench 78 into engagement with the head of the bolt 36. The Allen wrench 78 is shown spaced from the head of the bolt 36 in FIG. 10. It will, of course, be appreciated that additional equipment such as, for example and without limitation, lighting fixtures (not shown) and vacuum equipment (not shown), could be provided in order that the operation can be observed from a work platform or other suitable location, for example, positioned above the water level (see, for example, FIG. 9A). There are eight levels (e.g., in elevation) of formers 35 that must be addressed. The strong back 54, which also serves as a template, is designed to span two or perhaps three bolts 36 laterally, per setup of the tool 56. Thus, about 26 lateral moves, total, of each strong back setup 54, with an average of, for example and without limitation, about 18 minutes being spent to remove each bolt 36, is anticipated for the disassembly process. This includes movement of the torquing tool 66, but not movements of the strong backs 54. About 104 hours will be allotted for repositioning the strong back 54. In summary, the aforementioned tool 56 and method provide for efficient disassembly of the baffle assembly 20 (FIGS. 1, 2A and 2B) in to the desired plates and/or segments. As a result, minimal plant down time is achieved. It will be appreciated that various alternative to the aforementioned tool 56 and associated method for removing bolts 36, could be employed without departing from the scope of the invention. For example and without limitation, an alternative to breaking the welds lock bars 27 with just torque, would be to use a saw (not shown), for example, of the type commonly referred to as a “hole saw,” or any other known or suitable cutting device (not shown). Such saw could be, but need not necessarily be, an integral part of the untorquing tool 66, and be employed to first cut the welds and thereby reduce the amount of torque needed to undo the bolt 36. Additionally, in the unlikely event that the threads of the bolt 36 were to gall, a boring tool (not shown) could be attached to the torquing device and the bolt head could be removed, leaving the threaded end in the former 35. In the next step, once the baffle plates and/or segments 26,28,30,32,34 are uncoupled from the formers 35, they are transported to the center of the lower core plate 24 and positioned into the appropriate “niche” or rack of the aforementioned racking assembly 130 for storage within the inner cask 102, as shown in FIG. 4B. Specifically, the racking assembly 130 (FIGS. 4A-5 and 11A) includes a plurality of storage racks 144,146,148, which are an integral part of the inner cask base plate 106, and are structured to receive and secure the various plates and/or segments 26,28,30,32,34 in an organized array within the inner cask 102, as shown in FIG. 4B. More specifically, FIGS. 11A and 11B show the base plate member 106 (partially shown in FIG. 11B) for the inner cask 102 (FIGS. 4B-6 and 17A). As previously discussed, it is positioned in the center of the lower core plate 24 (FIG. 5). Specifically, precisely located pins 107 are permanently installed on the lower core plate 24 (FIG. 11B) and are structured to be received in the recesses of the base of fuel assemblies 16 (one fuel assembly is shown in phantom line drawing in FIG. 11B). A number of guide members 109 (e.g., protrusions 109) (best shown in FIG. 11B) are included on the base plate member 106 and are structured to engage the lower core plate 24 and maintain it in the desired centralized position thereon. This engagement also provides lateral restraint for the base plate 106. For example, there are about 314 pins 107 affixed to the lower core plate 24 in the aforementioned EXAMPLE. FIG. 11A also shows the racks 114,146,148, some of which comprise angle plate weldments affixed to the base plate member 106, for positioning and restraining the baffle pate segments 26,28,30 (FIGS. 4A and 4B) and individual plates 32 (FIGS. 4A and 4B) as they are moved into their storage positions. The segments 26,28,30 and plates 32 must be laterally transported to this position, for example, by a suitable clamping tool (not shown) suspended from the on-site crane (not shown). The baffles cannot be lifted substantially because they must remain well below the water level for adequate shielding. FIGS. 4A and 4B show the racks 144,146,148 of the racking assembly 130 fully loaded. FIGS. 14A through 15C show the storage racks 114,146,148 of the exemplary racking assembly 130 in greater detail. Specifically, FIGS. 12A and 12B show top plan and side elevation views, respectively, of the storage rack 144 for A plate segments 26 (FIGS. 4A and 4B) of the disassembled baffle assembly 20 (FIGS. 1, 2A and 2B). The rack 144 generally comprises four relatively long (e.g., without limitation, about 144inches) angle racks 150 which extend perpendicularly outwardly from the base plate member 106, and are joined by three cross members 152, for structural support. A plurality of shorter (e.g., without limitation, about 24 inches) angle racks 154 also extend outwardly from the base plate member 106 and are in staggered relation with respect to one another, as shown. In this manner, the rack 144 receives A plates segments 26 in the side-by-side arrangement shown in FIGS. 4A and 4B. The aforementioned receptacle 124 (e.g., box) for receiving bolts, is also shown. It will be appreciated that while one receptacle 124, which is generally square in shape, is shown, that any suitable number and/or configuration of receptacles could be employed. It will also be appreciated that the same is true with respect to the number and configuration of the angle members 150,154 and cross supports 152 of the rack 144, and with respect to the racks 146,148 and components thereof, discussed hereinbelow. FIGS. 13A-13C shows the storage rack 144 of the racking assembly 30 for receiving and securing C plate segments 30 in the manner shown in FIGS. 4A and 4B. Two relatively long (e.g., without limitation, 144 inches) angles 150 extend perpendicularly outwardly from the base plate member 106 and are joined by cross support 152. A plurality (e.g., without limitation, eight are shown) of shorter (e.g., without limitation, 24 inches) angles 154 are aligned with respect to angles 150, in parallel rows, as shown. FIGS. 14A-14C show a top plan and two-side elevation views, respectively, of the rack 146 of racking assembly 130 for receiving and securing D plates 32, in the manner shown in FIGS. 4A and 4B. Specifically, the rack 146 includes a first, relatively long (e.g., without limitation, 144 inches) racking element which extends perpendicularly outwardly from the base plate member 106 and includes a plurality (e.g., without limitation, five are shown) of parallel fins 160. A second, relatively short (e.g., without limitation, 24 inches) racking element 158 is disposed opposite and spaced from the first racking element 156, as shown. The second racking element 158 includes a corresponding number of parallel fins 162, which align with the fins 160 of the first racking element 156. In this manner, the first and second racking elements 156,158 receive opposing ends of the D planes 32 between adjacent pairs of fins 160,162, as shown in FIGS. 4A and 4B. FIGS. 15A-15C show a top plan view and two side elevation views, respectively, of a portion of the base plate member 106 and racking assembly 130 therefor, including storage rack 148, which is structured to receive and secure the corner angles or angle plates 34 (FIGS. 2B, 3, 4A and 4B) of the disassembled baffle assembly 20 (FIGS. 1, 2A and 2B), in the manner shown in FIGS. 4A and 4B. The exemplary rack 148 includes a generally rectangular (from a top plan perspective) receiving portion 164 which, as best shown in the side elevation view of FIG. 15C, comprises a receiving member 166 that is tilted or angled with respect to the base plate member 106 at an angle of, for example and without limitation, about 7 degrees from vertical. The upper (from the perspective of FIGS. 15B and 15C) end of the tilted member 166 includes a retaining member, such as the hinged retaining member 168 which pivotably coupled to tilted member 166 in the example of FIG. 15C. Accordingly, the receiving portion 164 and tilted member 166 thereof, of the storage rack 148, receive the corner plates 34 on an angle, with the upper ends of the corner plates 34 being secured beneath the retaining member 168, as shown in FIGS. 4A and 4B. FIGS. 16A, 16B and 16C show one non-limiting example of an optional indexable guide 110 for facilitating positioning of the baffle plate segments such as, for example, the B plate segment 28 and angle plates 34 shown in FIG. 16A, into a racking assembly 130′, in accordance with another aspect of the invention. Specifically, the exemplary indexable guide 110 includes opposing indexable guides in the form of shoe horns 170,171 which are structured to guide the plate segment 28 into the desired position in the racking assembly 130′. Specifically, one shoe horn 170 is fixed and one shoe horn 171 is movable. The shoe horns 170,171 include sloped surfaces 173,175, respectively, to guide (e.g., funnel) the plate segment 28 into the desired position (see, for example, plate segment 28 being funneled into position in FIG. 16B. In operation, once the first baffle segment 28 is inserted into the desired nesting position, the movable shoe horn 171 is lifted and moved to the next nearby location. Holes 172 are provided to accept pins 177,177′ of the shoe horn 171, in order that the shoe horn 171 is indexable to guide and next another baffle plate segment 28. In this manner, the operation continues until the plate segments 28 are arranged side-by-side in the desired position. The indexable guide 110 may also include a receptacle 179 (FIGS. 16A and 16C), for example, in the fixed shoe horn 170, in order to receive and store angle plates 34 (FIGS. 16A and 16C). It will, of course, be appreciated that a wide variety of other guidance devices (not shown) having any known or suitable configuration can be provided for the various baffle plates and/or segments 26,28,30,32,34 which will eventually fill the racking assembly 130′. See also racking assembly 130 of the inner cask 102, shown in FIGS. 4A and 4B. It should be noted, for example with respect to FIGS. 9A and 17A that the plates and/or segments 26,28,30,32,34 (FIGS. 2A-2B and 3-5) cannot be permitted to “break water” (e.g., be removed from the water) because of their relatively high radiation level. The elevation of the water level in the example of FIG. 9A is about 45 ft., 4 inches. It will, therefore, be appreciated that the plates and/or segments 26,28,30,32,34 can be lifted about 30 inches and still have about 12 inches of water coverage. Also, if necessary, the water level could be raised another 12 inches in the reactor cavity and still be 12 inches below the operating floor. A flotation device (not shown) can be used to shield the portion of the lower internals assembly 52, which has a much lower radiation level than the plates and/or segments 26,28,30,32,34, and which is above water when in the storage stand 8 (see, for example, FIG. 9A). FIGS. 6 and 17A-17D illustrate the exemplary lifting fixtures 126 for maneuvering the casked load, and their attachment to the casked load. For simplicity of illustration, only one such fixture 126 is shown and described in detail. Specifically, three generally C-shaped (from the perspective of FIG. 17C) lifting lugs 174 engage the thermal shield support blocks 21, of which there are six spaced around the circumference of the core barrel 18 (FIGS. 17A and 17B). These are fixed points that anchor the thermal shield to the core barrel 18, and three of them will be used for a tripod lift of the casked load (see also, for example, the top plan view of FIG. 3, and the three lifting devices 126′ thereof). With the lower internals section 52 still in the storage stand 8, and after attaching the top cover 105 to the inner cask 102, the outer cask 104 is lowered down over the internals 52. A tongue 176 of the C-shaped lifting lug 174 will pass up through a slot 115 in the top cover 111 of the outer cask 104. To restrain the lower internals package, threaded snubbers 178 (e.g., screws) are threaded in until they bear upon and put a compressive force on the outer diameter (O.D.) of the thermal shield, as shown in FIG. 17B. As best shown in FIG. 6, a jack-screw 180, shown located on the axial centerline of the top cover 111 of cask 104, will be threaded down to bear on the top cover 105 of the inner cask 102, thereby putting a compressive force on that cask 102. As many as five of these jack-screws 180 (one is shown) can be employed to secure the inner cask 102 in the vertical direction. Screw size for both snubbers 178 and jack screws 180 will preferably be on the order of about 2 to a bout 2.5 inches in diameter. With the base plate member 117 positioned at some convenient location on the floor of the reactor cavity, as shown in FIG. 6, or on the operating deck (not shown), the outer cask 104 is lowered onto the bottom plate member 117, as shown. Once satisfied that the engagement and alignment of the outer cask 104 are correct, the cask 104 and the base plate member 117 are fixed together, for example, and without limitation, by pneumatically activated shear pins 182 entering holes in blocks 184 attached to the base plate member 117, as shown in FIG. 6. The entire casked assembly can now be delivered to a predetermined location, for example, on the operating deck (not shown) of the containment building 2 (FIGS. 7 and 8) where it will be lowered onto and affixed to a skid 6, as previously described with respect to FIG. 7. The skid 6 resides on a suitable transfer vehicle such as, for example, the rail and train assembly 200 previously discussed with respect to FIG. 8. It will then be moved out of the containment. Further handling and final on-site storage or off-site disposal can then occur. Still to be disposed of, are the upper internals 74 and the upper section 60 of the lower internals 52. Specifically, when the lower internals assembly 52 was plasma cut, previously discussed with respect to FIG. 9A, the upper section 60 was placed in the pressure vessel 12, as shown in FIGS. 9B, 18 and 19. With the upper internals 74 situated in a storage stand (not shown), the operation of cutting or “demasting” the thermocouple support columns 61 must first be performed. As shown in FIGS. 18 and 19, these are located on the outer periphery of the upper internals assembly 74 where they are readily accessible for tooling. A cut will be made, for example and without limitation, with a large hydraulic shear (not shown), at an elevation on the thermocouple column 61 slightly below that of the top of the control rod guide tube extensions 63. The tops of the extensions 63 now establish the requisite height of the third shield cask 120. The exemplary third cask 120 has a height of about 190 inches. The severed portions (not shown) of the thermocouple columns 61, which have relatively low grade radiation levels, are placed in disposable containers (not shown) that will be supplied by the utility customer. Next, the standard left rig used to transfer the upper internals 74, moves them from their storage stand (not shown) and deposits them in the upper section of the lower internals 60 (see (FIG. 9B), which is residing in the pressure vessel 12. FIG. 18 depicts this situation, with the lifting rig removed. The lifting frame 186, which also serves as the shielding for the top of the upper internals 74, is lowered into position and set atop the lower internals top support plate 75, and is guided into position by the head and vessel alignment pins 71. These three elements, namely the lifting frame 186, the upper internals 74 and the section of lower internals 60, are clamped and secured together by at least four bolts 73 which pass through the flange 187 of the lifting frame 186 and upper internals support plate flange 77 and thread into the flange 65 of the lower internals sections 60. Threaded holes exist for attachment of the left rig which is used to transport the lower internals. Moving these three joined elements 186,74,60 into the cask 120, can be accomplished in at least two ways. The preferred embodiment is to position the cask 120 over the pressure vessel 12, supported on the operating deck floor. A lift rig (not shown) is then lowered to engage the lift points 188 on the lifting frame 186. The load is then lifted up into the cask 120 until it comes into contact with the cask flange 192. Adequate guide pins (not shown) are provided at the interface of 186 and 192 to cause the alignment of features which allow the cask 120 to be bolted to the lifting frame 186 at about 12 locations on the prescribe bolt circle. The cask bottom plate 190, which includes the cylindrical shielding element 191 can be attached in one of two preferred ways. First, it can be positioned beneath the cask 120 and hoisted (e.g., without limitation, with hydraulic jacks) into the final position shown in FIG. 19. Alternatively, the plate 190 can be placed at a location that is suitable and available, and the package of 186, 74, and 60 can be transported to a position above the plate 190 and lowered onto it. In either case, the casked package is completed by securing the plate 190 to the cask 120 with threaded suitable fasteners (not shown). The loaded cask 120 can now be lifted and moved out of containment in the same fashion as the other casked internals, previously described hereinabove. However, it will be appreciated that this latter casked load is shorter and weights considerably less than the aforementioned cask-in-cask package. It will be appreciated that the upper core plate 22 is the most highly radiation activated element in the package. Sufficient shielding is accomplished by making the plate 190 as thick as needed. In addition, the cylindrical shielding element 191 can be increased in diameter, and it can be extended upward (not shown) as high as necessary, for example, to pass through the gap between nozzles 46 and the cask 120 inside diameter. This gap is about 3.4 inches. This will increase the weight of the package, but it will pass through the equipment hatch (FIGS. 7 and 8). Portable cranes (not shown) can also be brought in to supplement the existing polar crane if required. It will also be appreciated that although the above steps have been described as if they were in series, that the method of disassembling, casking and/or removing internal structural members of the core in accordance with embodiments of the invention can be conducted in parallel to even further reduce costly plant outage time. For example, once the lower internals 52 have been sectioned (e.g., plasma cut), and the upper portion 60 has been transferred to the pressure vessel 12, the upper internals 74 can be transferred over and installed (see FIG. 18), and casking of that load could be accomplished while baffle bolts 36 (FIGS. 2B and 10) are being removed, in the manner described hereinabove. That cask 120 could then be removed from containment, leaving the pressure vessel 12 empty. This enables the customer to perform a mandatory in-service vessel inspection, for example, thus saving valuable time during the same outage, thereby avoiding or minimizing a future outage. Internals replacement implies new internals on-site to be installed during the same plant outage. Dimensions of critical features on the pressure vessel 12 will, therefore, need to be taken in order to custom machine interfacing features on the new lower internals. Special gauges, fixtures and inspection devices are required to do this. This process is disclosed, for example, in U.S. Pat. No. 5,864,594, which is hereby incorporated herein by reference. Such dimensions can be taken, for example, at the time when the baffle plates and/or segments 26,28,30,32,34 are being removed and casked. In this manner, outage time can be saved. Still further time may be saved by performing the final machining of the key components such as, for example and without limitation, the lower radial support keys 194 shown in FIGS. 1, 6, 9A and 17A. Once machined, final installation of such keys onto the lower internals can be performed with the replacement set being secured in a stand (not shown) located on the cavity operating floor 3. Trial fit-up of the new lower internals into the vessel 12 can be done while the lower cask 104 (e.g. lower section 52, inner cask 102, and baffle plates and/or segments 26,28,30,32,34) are being transported out of the containment building 2. It will be appreciated that the shielded casks 102,102′,104 described herein may be made from any known or suitable irradiation shielding material such as, for example and without limitation, painted carbon steel which may be rolled, or comprised of welded plate or castings and stacked one on top of the other and welded to form an extended cylinder or an octagonal shape, or formed in any other known or suitable manner. For example, as one non-limiting alternative, the casks 102,102′,104 might comprise concentric cylinders or octagons with an annulus filled with lead shot as a shielding medium. This alternative would reduce the size of cost of the resulting inner cask 102,104′ that contains the baffle plates and/or segments 26,28,30,32,34. It is believed that the entire operation of removing and replacing both the upper and lower internals 52,74 in accordance with the disclosed method can be accomplished in about 70 days or less of critical path in the outage. Such period begins once the existing internals are secured in their respective storage stands (under water), and ends when the plant is turned back over to the customers to begin the core refueling phase. In summary, an improved internals removal method is provided by the invention, which entails the selective dismantling of as few of the structural elements as possible, while establishing an end result of a small, light, disposable casked load capable of being removed through the plant's existing equipment hatch, and with all of the foregoing being achieved in a reasonable amount of time. More specifically, a unique combination of casks 102,102′,104,120 in a novel configuration achieves the remarkable result of reducing the necessary wall thickness 118 of the outer cask 104 from the known required dimension of about 11 inches to as little as about 2.0 inches. In particular, the highly irradiated core baffle plates and/or segments 26,28,30,32,34 are removed and isolated by placing them in an individual inner storage cask 102,102′ positioned at the axial centerline of the lower core plate 24. At this location, which is about 40 inches (on average) inboard of their normal position, and with them being shrouded in the inner cask 102, which has a wall thickness 18 of its own of about 7.5 inches, radiation levels on the outer diameter (O.D.) of the outer cask 104 can meet a prescribed mR/hr. contact level, for example, needed to move out of reactor containment and into a storage bunker (generally constructed of concrete) (not shown) on site. In addition, the resulting size and weight of the loaded outer cask 104 is reduced to the extent that it can be removed through the existing equipment hatch 4 and is within the lifting capability of the plant's on-site crane. It will further be appreciated that additional shielding can be provided, if necessary, be removing the eight specimen baskets 11 shown in FIG. 2A. Such removal can be accomplished by any known or suitable process such as, for example and without limitation, plasma burning. This would allow the inner diameter (I.D.) of the lower cask 104 to be reduced to the extent that the wall of the lower cask 104 can be increased from about 2.0 inches to about 4.7 inches. This thickness can comprise, for example, all carbon steel or concentric cylinders filled with lead. The resultant increase in weight could be accommodated by a portable crane (not shown) brought into containment to supplement the existing polar crane (not shown), if necessary. Most importantly, the casked internals could still be moved out of the existing equipment hatch 4 (FIGS. 7 and 8). Significant benefits result from the dramatic decrease in size and weight of the shielding casks in accordance with the invention, when compared, for example to the known prior art. Specifically, in addition to the already noted easement of handling and transporting the smaller casks, the number of qualified suppliers who can now manufacture these smaller components expands considerably. Accordingly, competitive pricing comes into play, and manufacturing time schedules are greatly reduced. While specific embodiment of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention is to be given the full breadth of the claims appended and any and all equivalents thereof.
	claims	1. A plant operation system configured to support operation of a plant, the system comprising:an operation monitoring system configured to acquire and monitor a plurality of measurement parameters which are output from a plurality of measuring instruments provided in the plant as plant operation data to control the operation of the plant based on the plant operation data;an operation history database configured to store the plant operation data;an abnormality indication monitoring system configured to monitor an indication of abnormality of the plant, based on history of the plant operation data stored in the operation history database;an abnormality diagnosis system configured to perform a diagnosis of abnormality of the plant, based on a result of the abnormality indication which is detected by the abnormality indication monitoring system to output a diagnosis result; anda maintenance system with a maintenance database which stores therein the diagnosis results from the abnormality diagnosis system as maintenance data for the plant configured to acquire the maintenance data from the maintenance data base to provide the acquired maintenance data to a maintenance worker of the plant and to store a maintenance inspection result obtained by inspection work by the maintenance worker in the maintenance database,whereinthe operation monitoring system, the abnormality indication monitoring system, and the abnormality diagnosis system are connected via unit bus to one another so as to be able to communicate from the operation monitoring system to the abnormality indication monitoring system and the abnormality diagnosis system,the abnormality diagnosis system and the maintenance system are connected via unit bus to each other so as to be able to communicate with each other, andthe abnormality diagnosis system is configured to compare an abnormality sign pattern generated by the current plant operation data with a plurality of abnormality model patterns of the past plant operation data stored in the operation history database, and when the abnormality sign pattern corresponds to one of the plurality of abnormality model patterns, configured to specify an occurrence probability corresponding to a cause of the specified abnormality as the diagnosis result and output the diagnosis result to the maintenance system, and when the abnormality sign pattern corresponds to some of the plurality of abnormality model patterns, configured to specify, using a Bayesian network as a statistical model, each of the occurrence probabilities corresponding to each of causes of the specified abnormalities as the diagnosis result and output the diagnosis result to the maintenance system. 2. The plant operation system according to claim 1, wherein the maintenance system hasa maintenance terminal configured to acquire the result of the abnormality diagnosis from the abnormality diagnosis system, anda maintenance mobile terminal configured to perform wireless communication with the maintenance terminal, andthe maintenance terminal is configured to provides the result of the abnormality diagnosis toward the maintenance mobile terminal. 3. The plant operation system according to claim 2, wherein the maintenance terminal and the maintenance mobile terminal are provided in a building in which the plant is installed. 4. A plant operation method for a plant operation system configured to support operation of a plant the plant operation system comprising;an operation monitoring system configured to control the operation of the plant;an operation history database configured to store the plant operation data;an abnormality indication monitoring system configured to monitor an indication of abnormality of the plant;an abnormality diagnosis system configured to perform a diagnosis of abnormality of the plant; anda maintenance system configured to store information for maintenance of the plant in a maintenance database and to provide the information to a maintenance worker of the plant; whereinthe operation monitoring system, the abnormality indication monitoring system, and the abnormality diagnosis system are connected via unit bus to one another so as to be able to communicate from the operation monitoring system to the abnormality indication monitoring system and the abnormality diagnosis system andthe abnormality diagnosis system and the maintenance system are connected via unit bus to each other so as to be able to communicate with each other; the method comprising;acquiring and monitoring, in the operation monitoring system, a plurality of measurement parameters which are output from a plurality of measuring instruments provided in the plant as plant operation data to control the operation of the plant based on the plant operation data;storing step, in the operation history database, the plant operation data;monitoring, in the abnormality indication monitoring system, an indication of abnormality of the plant, based on history of the plant operation data stored in the operation history database;performing, in the abnormality diagnosis system, a diagnosis of abnormality of the plant, based on a result of the abnormality indication which is detected by the abnormality indication monitoring system to output a diagnosis result; andacquiring, in the maintenance system, maintenance data from a maintenance database which stores therein the diagnosis results from the abnormality diagnosis system as the maintenance data for the plant, providing the acquired maintenance data to a maintenance worker of the plant and storing a maintenance inspection result obtained by inspection work by the maintenance worker in the maintenance database, characterized in thatthe method comprising;in performing the diagnosis of abnormality of the plant, comparing an abnormality sign pattern generated by the current plant operation data with a plurality of abnormality model patterns of the past plant operation data stored in the operation history database, and when the abnormality sign pattern corresponds to one of the plurality of abnormality model patterns, specifying an occurrence probability corresponding to a cause of the specified abnormality as the diagnosis result and outputting the diagnosis result to the maintenance system; andwhen the abnormality sign pattern corresponds to some of the plurality of abnormality model patterns, specifying, using a Bayesian network as a statistical model, each of the occurrence probabilities corresponding to each of causes of the specified abnormalities as the diagnosis result and outputting the diagnosis result to the maintenance system.
	abstract	A method and system for thermal-dynamic modeling and performance evaluation of a nuclear Boiling Water Reactor (BWR) core design is presented. A data processing system is used to execute specific program routines that simultaneously simulate the thermal operating characteristics of fuel rods within the reactor during a transient operational condition. The method employs a multi-dimensional approach for the simulation of postulated operational events or an anticipated operational occurrence (AOO) which produces a transient condition in the reactorxe2x80x94such as might be caused by single operator error or equipment malfunction. Based on a generic transient bias and uncertainty in the change in critical power ratio (xcex94CPR/ICPR), histograms of fuel rod critical power ratio (CPR) are generated. Ultimately, the operating limit minimum critical power ratio (OLMCPR) of the reactor is evaluated from a histogram of probability calculations representing the number of fuel rods subject to a boiling transition (NRSBT) during the transient condition. The histogram may be readily displayed by the data processing system and used to statistically demonstrate an OLMCPR compliance of the reactor core design with USNRC regulations.
	summary
	description	This application is a continuation combing the international application PCT/CN2020/076280 filed on Feb. 21, 2020, which claims priority to Chinese Application No. 201910109125.0 filed on Feb. 3, 2019, and the international application PCT/CN2020/076281 filed on Feb. 21, 2020, which claims priority to Chinese Application No. 201910109130.1 filed on Feb. 3, 2019, all of which are hereby incorporated by reference in its entireties. The present disclosure relates to the field of radiotherapy technologies, and in particular to, a source storing apparatus, a source guiding system, and a source guiding method. At present, for a radiotherapy device using a radioactive source box (e.g., a cobalt source box), a common source replacing approach is generally to assemble a source guiding tool outside the radiotherapy device to load and fill a radioactive source. Because the radioactive source is radioactive, the radioactive source is stored in a source tank in transit, such that the radioactive source is shielded using the source tank. When the source is loaded, it is necessary to first take out a shielding plug of the source tank using the tool, and then take out the radioactive source in a shielded environment whilst ensuring that the source tank is shielded. In this process, ray shielding is required in all aspects, but a current source guiding tool has a complex structure, such that the installation and operation processes are complex with high operation requirements, and are time-consuming and labor-consuming. Therefore, it is necessary to provide a novel technical solution to improve one or more problems existing in the above solution. It should be noted that the “BACKGROUND” is intended to provide a background or context for embodiments of the present disclosure provided in the appended CLAIMS. The description here is not recognized as existing technologies because of being included in the “BACKGROUND”. An object of the present disclosure is to provide a source storing apparatus, a source guiding system, and a source guiding method, and then overcome, at least to a certain extent, one or more problems caused by the limitations and defects of related technologies. According to a first aspect of the present disclosure, a source storing apparatus is provided, including: a source tank and a shielding plug, the source tank being provided with an opening and an accommodating cavity, the accommodating cavity being configured to accommodate a cobalt source box, the shielding plug being configured to close an opening of the accommodating cavity; where a first connecting structure is provided on the cobalt source box; a second connecting structure is provided on an outer side of the shielding plug, a pickup structure is provided on an inner side of the shielding plug, and the first connecting structure is detachably connected to the pickup structure. An embodiment of the present disclosure further provides a source guiding system configured to guide a cobalt source box from a first source storing apparatus into a second source storing apparatus, where the first source storing apparatus or the second source storing apparatus is a source storing apparatus provided in embodiments of the present disclosure; and the cobalt source box further includes a third connecting structure; and the source guiding system including: a source guiding tank, the source guiding tank including a tank body, a first pull rod and a first opening, a second pull rod and a second opening, where the tank body includes a source-carrying cavity, the first pull rod and the first opening are located on opposite sides of the source-carrying cavity along a first direction, the second pull rod and the second opening are located on opposite sides of the source-carrying cavity along a second direction, the first pull rod moves along the first direction and is connectable to a second connecting structure of a shielding plug of the first source storing apparatus; and the second pull rod moves along the second direction and is connectable to a third connecting structure of the cobalt source box. An embodiment of the present disclosure further provides a source guiding method, being applied to a source guiding system according to any one embodiment of the present disclosure and used for guiding a cobalt source box from a source storing apparatus into a radiotherapy device. The method includes: connecting a first connecting structure of the cobalt source box and a pickup structure of a shielding plug of the source storing apparatus; driving a first pull rod to connect the first pull rod to a second connecting structure of the shielding plug of the source storing apparatus, and lifting the shielding plug to a source-carrying cavity of a source guiding tank; driving a second pull rod to connect the second pull rod to a third connecting structure of the cobalt source box; driving the first pull rod to coordinate with the second pull rod, such that the first connecting structure of the cobalt source box is separated from the pickup structure; and driving the second pull rod to send the cobalt source box into the radiotherapy device and fix the cobalt source box with the radiotherapy device. An embodiment of the present disclosure further provides a source guiding method, being applied to a source guiding system provided in embodiments of the present disclosure and used for guiding a cobalt source box from a radiotherapy device into a source storing apparatus. The method includes: driving a first pull rod to connect the first pull rod to a second connecting structure of a shielding plug of the source storing apparatus, and lifting the shielding plug to a source-carrying cavity of a source guiding tank; driving a second pull rod to connect the second pull rod to a third connecting structure of the cobalt source box, and pulling the cobalt source box to the source-carrying cavity of the source guiding tank; driving the first pull rod to coordinate with the second pull rod, such that the first connecting structure of the cobalt source box is connected to a pickup structure; driving the second pull rod to separate the second pull rod from the cobalt source box; and driving the first pull rod to send the cobalt source box into the source storing apparatus. The technical solutions provided in the embodiments of the present disclosure may include the following beneficial effects: The present disclosure provides a source storing apparatus, a source guiding system, and a source guiding method. The source storing apparatus includes: a source tank and a shielding plug, a pickup structure is provided on the shielding plug, and a first connecting structure is provided on a cobalt source box. Then, the cobalt source box is connected to the shielding plug through the first connecting structure and the pickup structure, thereby taking out the shielding plug and the cobalt source box once during the source replacement, simplifying the operating apparatus and operation steps, and improving the operation safety. Through the above radioactive source guiding system and method, the structure of the source guiding tool is simplified; the installation and operation processes are simple with reduced operation requirements, and are time-consuming and labor-consuming; and the cost of the source guiding tool is also greatly reduced. It is noted that the elements shown in the figures may not be in proper proportion to each other. Example embodiments will now be described more comprehensively with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms, and should not be construed as being limited to the examples set forth herein; on the contrary, these embodiments are provided to make the present disclosure more comprehensive and complete, and fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in one or more embodiments in any suitable manner. In addition, the accompanying drawings are only schematic illustrations of the present disclosure, and are not necessarily drawn to scale. Identical reference numerals in the accompanying drawings represent identical or similar portions, and therefore repeated descriptions thereof will be omitted. Some of the block diagrams shown in the drawings are functional entities, and do not necessarily correspond to physically or logically independent entities. An embodiment of the present disclosure discloses a source storing apparatus 10. For example, as shown in FIG. 1, the source storing apparatus includes: a source tank 11 and a shielding plug 12, the source tank 11 is provided with an opening and an accommodating cavity 14, the accommodating cavity 14 is configured to accommodate a cobalt source box 15, the shielding plug 12 is configured to seal an opening of the accommodating cavity 14; where a first connecting structure 151 is provided on the cobalt source box 15; a second connecting structure 121 is provided on an outer side of the shielding plug 12, a pickup structure 122 is provided on an inner side of the shielding plug, and the first connecting structure 151 is detachably connected to the pickup structure 122. For example, in the embodiment of the present disclosure, the first connecting structure may be detachably connected to the pickup structure by a threaded connection or by a buckled connection. The specific structure and connection mode thereof are not limited in embodiments of the present disclosure. In the embodiment of the present disclosure, the second connecting structure is provided on the outer side of the shielding plug, and the second connecting structure may be connected to a pull rod of a source guiding system, thereby taking out the shielding plug and the cobalt source box simultaneously through the pull rod of the source guiding system. The connection mode between the second connecting structure and the pull rod is not limited in the embodiments of the present disclosure, e.g., may be a threaded connection or a snap fit. For a source storing apparatus provided in an embodiment of the present disclosure, a pickup structure is provided on the shielding plug, a first connecting structure is provided on a cobalt source box, and the cobalt source box is connected to the shielding plug through the first connecting structure and the pickup structure, thereby taking out the shielding plug and the cobalt source box once during the source replacement, simplifying the operating apparatus and operation steps, and improving the operation safety. The source storing apparatus in the embodiment of the present disclosure, e.g., may be a source tank. In a source storing apparatus provided in an embodiment of the present disclosure, for example, as shown in FIG. 2, the pickup structure 122 includes an elastic member 1221, the elastic member 1221 is snapped into the first connecting structure to realize a connection between the cobalt source box and the shielding plug. The pickup structure includes the elastic member, such that an external force may be applied to achieve a snap-fit of the elastic member, thereby facilitating the connection between and operation of the pickup structure and the first connecting structure. A specific structure of the elastic member is not limited in the embodiments of the present disclosure, and is described only with FIG. 2 as an example. Further, a plurality of, e.g., three or four, elastic members may be provided. For example, in a source storing apparatus provided in an embodiment of the present disclosure, the pickup structure 122 is directly and fixedly connected to the shielding plug 12. Alternatively, the pickup structure 122 is connected to the shielding plug 12 by a connecting rod. When the pickup structure is directly fixed on the shielding plug, a space of the pickup structure can be reduced. The connection between the pickup structure and the shielding plug may be determined based on specific settings of the source storing apparatus, and is not limited in the embodiments of the present disclosure. In a source storing apparatus provided in an embodiment of the present disclosure, as shown in FIG. 3, the first connecting structure 151 is a connecting slot. As shown in FIG. 4, the pickup structure 122 is snappable into the connecting slot. Specifically, the elastic member 1221 is snappable into the connecting slot. In a schematic diagram of a cobalt source box provided in an embodiment of the present disclosure, a connecting slot of the cobalt source slot includes a first opening and a second opening that are in communication, where the first opening is located in a first direction (e.g., X direction), and the second opening is located in a second direction (e.g., Y direction). As shown in FIG. 5, the first opening may be located at a top opening of the cobalt source box, and the second opening may be a side opening of the cobalt source box. The pickup structure may extend from the first opening into the connecting slot to be snapped to the connecting slot, and separate from the connecting slot from the second opening. It should be noted that FIG. 5 only illustrates the connecting slot of the cobalt source box, and does not show other structures of the cobalt source box. In the source storing apparatus provided in an embodiment of the present disclosure, as shown in FIG. 3, the connecting slot includes a clamping slot 1511 and a compressing slot 1512, where a maximum size of the clamping slot 1511 is larger than that of the first opening. The pickup structure is an elastic member, and a size of the clamping slot may be larger than or equal to a maximum size of the elastic member when the elastic member is not compressed, such that the elastic member is clampable within the clamping slot. For example, when the pickup structure includes the elastic member, the first opening is larger than a minimum compression size of the elastic member and smaller than a maximum extension size of the elastic member, so as to help the elastic member enter the connecting slot from the first opening, and prevent the elastic member from disengaging from the first opening. For example, a maximum size of the clamping slot is larger than the maximum extension size of the elastic member, to better implement the clamped connection. For example, a maximum size of the compressing slot is smaller than the maximum extension size of the elastic member, such that the elastic member separates from the second opening after being compressed at a position of the compressing slot. In an embodiment of the present disclosure, in order to prevent the pickup structure from separating from the cobalt source box, a bottom size of the second opening is larger than a top size of the second opening, and a maximum opening size of the second opening is larger than or equal to a minimum compression size of the pickup structure. In order to contributing more to compressing the elastic member at the second opening, such that the pickup structure separates, a size of the second opening at a position corresponding to the compressing slot is larger than or equal to the minimum compression size of the pickup structure in an embodiment of the present disclosure. An embodiment of the present disclosure provides a source guiding system configured to guide a cobalt source box from a first source storing apparatus into a second source storing apparatus, where the first source storing apparatus or the second source storing apparatus is a source storing apparatus provided in embodiments of the present disclosure; where the first source storing apparatus may be a source storing apparatus provided in the embodiments of the present disclosure, the second source storing apparatus may be a radiotherapy device, and the guiding a cobalt source box from a first source storing apparatus into a second source storing apparatus is loading a radioactive source into the radiotherapy device; or the first source storing apparatus is a radiotherapy device, the second source storing apparatus is a source storing apparatus provided in the embodiments of the present disclosure, and the guiding a cobalt source box from a first source storing apparatus into a second source storing apparatus is taking out a radioactive source from the radiotherapy device and loading the radioactive source into a source tank. In an embodiment of the present disclosure, description is provided, e.g., with the first source storing apparatus being a source storing apparatus provided in the embodiments of the present disclosure, e.g., a source tank, and with the second source storing apparatus being a radiotherapy device as an example. The source guiding system includes: a source guiding tank 20. As shown in FIG. 6, the source guiding tank 20 includes a tank body 21, a first pull rod 31 and a first opening 211, a second pull rod 32 and a second opening 212, where the tank body 21 includes a source-carrying cavity 213, the first pull rod 31 and the first opening 211 are located on opposite sides of the source-carrying cavity 213 along a first direction (e.g., X direction shown in FIG. 6), the second pull rod 32 and the second opening 212 are located on opposite sides of the source-carrying cavity 213 along a second direction (e.g., Z direction shown in FIG. 6), and the first pull rod 31 moves along the first direction and is connectable to a second connecting structure of the shielding plug 12 of the first source storing apparatus 10. In the source guiding system provided in the embodiment of the present disclosure, the cobalt source box further includes a third connecting structure; and the second pull rod 32 moves along the second direction and is connectable to the third connecting structure of the cobalt source box 15. In the source guiding system provided in the embodiment of the present disclosure, the first opening corresponds to a position of the first source storing apparatus, and then may be connected to the shielding plug through the first pull rod. The shielding plug may be connected to the cobalt source box, and then when the first pull rod is pulled up, the shielding plug and the cobalt source box can be pulled out together, such that the cobalt source box is located within the source-carrying cavity of the source guiding tank. The second opening corresponds to a source loading port of the radiotherapy device. After the second pull rod is connected to the cobalt source box, the shielding plug is disconnected from the cobalt source box, and the cobalt source box is sent into the radiotherapy device using the second pull rod, thus completing the source loading process. Likewise, when the cobalt source box needs to be taken out from the radiotherapy device, the second pull rod may be first connected to the cobalt source box, such that the cobalt source box is located within the source-carrying cavity of the source guiding tank. Then, the cobalt source box is connected to the shielding plug, and is loaded into the first source storing apparatus through the first pull rod. Then, the first pull rod is disconnected from the shielding plug, to realize the source removal process. For example, the connection between the cobalt source box and the shielding plug is disconnectable as described above. The source storing apparatus provided in the embodiment of the present disclosure may be referred to, which may be provided with the pickup structure on the shielding plug, and is snapped to the connecting slot on the cobalt source box. The pickup structure includes the elastic member. Specifically, as shown in FIG. 5 and FIG. 6, when the first pull rod is driven, such that the shielding plug moves downward along the X direction, the elastic member is clamped into the connecting slot of the cobalt source box, thereby realizing the connection between the shielding plug and the cobalt source box. The second pull rod is connected to the cobalt source box. When the shielding plug continues moving downward along the X direction, the elastic member is compressed at the position of the compressing slot. In this case, the second pull rod may be driven to move outward, such that the elastic member separates from the cobalt source box from the second opening, and then the cobalt source box is sent into the radiotherapy device through the second pull rod. The source removal process is the same as the source loading principle. The description will not be repeated here. The source guiding system provided in the embodiment of the present disclosure includes the source storing apparatus provided in the embodiment of the present disclosure. The source storing apparatus coordinates with the source guiding tank to realize the removal and assembly of the radioactive source, and no other shielding apparatus is required during the removal and assembly, thereby simplifying the radioactive source removal and assembly process, and improving the safety of the removal and assembly of the radioactive source. For example, in the embodiment of the present disclosure, the first direction is perpendicular to the second direction. In the source guiding system provided in the embodiment of the present disclosure, the source guiding system further includes a first shielding door configured to open and close the first opening; and/or, the source guiding system further includes a second shielding door configured to open and close the second opening. Specifically, the source guiding system may merely include the first shielding door, or the source guiding system may merely include the second shielding door, or the source guiding system may include both the first shielding door and the second shielding door. The source guiding system includes the shielding door, to further improve the shielding safety of the source guiding system. In the source guiding system provided in the embodiment of the present disclosure, the first pull rod and/or the second pull rod are/is provided with a limiting slot, and the source guiding system further includes a fastener fixable with the limiting slot to prevent the first pull rod and/or the second pull rod from rotating. For example, the first pull rod is provided with a limiting slot. After the first pull rod lifts the shielding plug and the cobalt source box to the source-carrying cavity, the fastener is inserted into the limiting slot, to prevent the shielding plug and the cobalt source box from rotating in the source-carrying cavity, and facilitate the connection between the second pull rod and the cobalt source box. In the source guiding system provided in the embodiment of the present disclosure, a glass window is provided on the source guiding tank; or a camera and/or a detection lamp are/is further provided within the source-carrying cavity of the source guiding tank, such that an operator can see the inside of the source-carrying cavity from the outside, so as to realize, e.g., connection or removal by adjusting the position of the pull rod. For example, in the source guiding system in the embodiment of the present disclosure, the source guiding tank includes a plurality of components, and the plurality of components is fixedly connected. For example, the source guiding tank includes a source guiding shield and a shielding cover, to facilitate the processing and transport of the source guiding tank. A source guiding method provided in an embodiment of the present disclosure is applied to a source guiding system provided in embodiments of the present disclosure, and is used for guiding a cobalt source box from a source storing apparatus into a radiotherapy device, i.e., a first source storing apparatus is a source storing apparatus provided in the embodiments of the present disclosure, and a second source storing apparatus is a radiotherapy device, i.e., the guiding a cobalt source box from a first source storing apparatus into a second source storing apparatus is loading a radioactive source into the radiotherapy device. The method includes: Step 101: connecting a first connecting structure of a cobalt source box and a pickup structure of a shielding plug of a source storing apparatus. Step 101 may realize the connection in other ways, e.g., realize the connection through a hot cell, or realize the connection through the source storing apparatus in the embodiments of the present disclosure. Description is provided below, e.g., with realizing the connection through the source storing apparatus in the embodiments of the present disclosure as an example. As shown in FIG. 6, the first connecting structure may be fixedly connected to the shielding plug 12 using the first pull rod 31, and then the shielding plug 12 moves downward using the pull rod, thereby the elastic member is snapped on the shielding plug 12 to the connecting slot on the cobalt source box 15, i.e., realizing the connection between the first connecting structure of the cobalt source box and the pickup structure of the shielding plug of the source storing apparatus. Step 102: driving a first pull rod to connect the first pull rod to a second connecting structure of the shielding plug of the source storing apparatus, and lifting the shielding plug to a source-carrying cavity of a source guiding tank. The driving the first pull rod may be implemented by motor drive or by manual pull. This is not limited in the embodiments of the present disclosure. Step 103: driving a second pull rod to connect the second pull rod to a third connecting structure of the cobalt source box. For example, the second pull rod may be threadedly connected to the cobalt source box, and the second pull rod is driven to rotate, thereby connecting a thread of the second pull rod to a threaded hole on the cobalt source box. Of course, a specific connection mode of the second pull rod and the third connecting structure is not limited in the embodiments of the present disclosure, and is merely illustrated with the above description as an example. Step 104: driving the first pull rod to coordinate with the second pull rod, such that the first connecting structure of the cobalt source box separates from the pickup structure. For example, step 104 specifically includes: driving the first pull rod to move along a first direction such that an elastic member is in a compressing slot; and driving the second pull rod to move along a second direction, such that the pickup structure separates from a connecting slot from a second opening. Specifically, as shown in FIG. 5 and FIG. 6, when the first pull rod is driven, such that the shielding plug moves downward along the X direction, the elastic member is clamped into the connecting slot of the cobalt source box, thereby realizing the connection between the shielding plug and the cobalt source box. The second pull rod is connected to the cobalt source box. When the shielding plug continues moving downward along the X direction, the elastic member is compressed at the position of the compressing slot. In this case, the second pull rod may be driven to move outward, such that the elastic member separates from the cobalt source box from the second opening. Step 105: driving the second pull rod to send the cobalt source box into the radiotherapy device and fix the cobalt source box with the radiotherapy device. The source guiding method provided in the embodiment of the present disclosure can realize the source removal and assembly only using the source guiding tank without the need of using other shielding apparatus, thereby simplifying the source guiding process and improving the source guiding safety. After sending the cobalt source box into the radiotherapy device, the source guiding method provided in the embodiment of the present disclosure further includes: driving the radiotherapy device to switch off and shield a radioactive source, i.e., directly switching off the source using the radiotherapy device, such that the operator removes, e.g., the source guiding tank. Of course, the source guiding method provided in the embodiment of the present disclosure further includes a process of taking out the radioactive source from the radiotherapy device and storing the radioactive source in the source storing apparatus. The principle of the process is similar to the above. An embodiment of the present disclosure discloses a source guiding method. The source guiding method is applied to a source guiding system in the embodiments of the present disclosure, and is used for guiding a cobalt source box from a radiotherapy device into a source storing apparatus. The method includes: Step 201: driving a first pull rod to connect the first pull rod to a second connecting structure of the shielding plug of the source storing apparatus, and lifting the shielding plug to a source-carrying cavity of a source guiding tank. Step 202: driving a second pull rod to connect the second pull rod to a third connecting structure of the cobalt source box, and pulling the cobalt source box to the source-carrying cavity of the source guiding tank. Step 203: driving the first pull rod to coordinate with the second pull rod, such that the first connecting structure of the cobalt source box is connected to the pickup structure. Step 204: driving the second pull rod to separate the second pull rod from the cobalt source box. Step 205: driving the first pull rod to send the cobalt source box into the source storing apparatus. That is, when the cobalt source box needs to be taken out from the radiotherapy device, the second pull rod may be first connected to the cobalt source box, such that the cobalt source box is located within the source-carrying cavity of the source guiding tank. Then, the cobalt source box is connected to the shielding plug, and is loaded into the first source storing apparatus through the first pull rod. Then, the first pull rod is disconnected from the shielding plug, to realize the source removal process. For example, FIG. 7 and FIG. 8 show a schematic structural diagram of a pull rod in an example embodiment of the present disclosure. FIG. 9 shows a schematic structural diagram of an adjusting member in an example embodiment of the present disclosure. The present disclosure provides a pull rod. As shown in FIG. 7, FIG. 8, and FIG. 9, the pull rod includes: a rod-shaped part 102 and an adjusting member 1012. The rod-shaped part 102 includes a pickup end and an operation end; and the adjusting member 1012 is located between the pickup end and the operation end of the rod-shaped part 102. For example, as shown in FIG. 8, the adjusting member 1012 includes a cambered surface, and the rod-shaped part 102 runs through the cambered surface 1023. An embodiment of the present disclosure provides a pull rod. The pull rod is connected to the adjusting member, and is adjustable and swingable along a direction of the cambered surface of the adjusting member, thereby improving the connection flexibility of the pull rod. For example, the pull rod may be a second pull rod. For example, the adjusting member 1022 may be spherical, or the adjusting member 1022 may be cylindrical. The adjusting member 1022 and the rod-shaped part 102 may be integrated, or the adjusting member 1022 is provided with an opening 1024, and the rod-shaped part 102 runs through the opening 1024. When the rod-shaped part 102 runs through the adjusting member 1022, the adjusting member 1022 may be fixedly connected to the rod-shaped part 102 by, but not limited to, a pin, to prevent the rod-shaped part 102 from rotating with respect to the adjusting member 1022. When the rod-shaped part is rotating, the rod-shaped part 102 is rotatable along the direction of the cambered surface 1023, thereby improving the flexibility of the pull rod. An embodiment of the present disclosure provides a pull rod. As shown in FIG. 9 and FIG. 10, the pull rod further includes a connector 101 and a rod-shaped part 102, where: a front end of the connector 101 is provided with a connecting structure 103; and the rod-shaped part 102 is provided with an opening 104 and an accommodating space 105, the connector 101 is provided in the accommodating space 105 of the rod-shaped part 102, the connecting structure 103 of the connector extends from the opening of the rod-shaped part into the accommodating space 105, the rod-shaped part 102 and a contactable part at a tail end of the connector are provided with a limiting structure 106, and the tail end of the connector 101 is movably assembled with the limiting structure 106, to limit the movement of the connector when the limiting structure is assembled with the tail end of the connector. The “movable” in this embodiment means that when the rod-shaped part is pushed toward the connector, the limiting structure can be assembled with the tail end of the connector; while when the rod-shaped part is away from the connector, the limiting structure can be removed from the tail end of the connector. An embodiment of the present disclosure provides a pull rod. When the rod-shaped part moves such that the limiting structure 106 is assembled and connected with the tail end of the connector, the rod-shaped part can be rotated to drive the connector to rotate; or the rod-shaped part can be moved to drive the connector to move, thereby connecting the connecting structure 103 of the connector to an external apparatus, e.g., a cobalt source box. When a relative position between the connecting structure 103 of the connector and the cobalt source box needs to be adjusted, the rod-shaped part can be pulled away from the cobalt source box, such that the tail end of the connector separates from the limiting structure 106 of the rod-shaped part 102, and then the pull rod is rotated or swung to adjust the relative position between the connecting structure 103 of the connector and the cobalt source box, thereby improving the flexibility and accuracy of the pull rod. For example, the front end of the connector 101 may be an end of the connector 101 close to a source carrier 107 of the source guiding apparatus. The connecting structure 103 may include a threaded connection unit configured to be threadedly connected to the source carrier 107. The source carrier 107 may include a threaded connection hole matching the threaded connection unit. When the connecting structure 103 is pushed to the vicinity of the source carrier 107, the threaded connection unit is aligned with the threaded connection hole, and the threaded connection unit is screwed into the threaded connection hole. For example, the rod-shaped part 102 may be rotated to drive the threaded connection unit to rotate, such that the threaded connection unit is screwed into the threaded connection hole. The threaded connection has a high reliability, can prevent the source carrier 107 from falling during the pushing and pulling, and can further prevent the radioactive source from leaking. Specifically, the tail end of the connector 101 refers to an end of the connector 101 close to the limiting structure 106. When the limiting structure 106 is assembled with the tail end of the connector, movement of the connector 101 can be limited. When the rod-shaped part 102 is pushed toward the connector 101, the limiting structure 106 can be assembled with the tail end of the connector; while when the rod-shaped part 102 is away from the connector 101, the limiting structure 106 can be removed from the tail end of the connector. For example, another pull rod 108 of the source guiding apparatus can lift the source carrier 107 from a source guiding tank 109 of the source guiding apparatus to an accommodating cavity 1010 of the source guiding apparatus. In this embodiment, the source carrier 107 is connected to a lead plug 1012 of the source guiding tank, the other pull rod 108 is externally connected to the lead plug 1012, the lead plug 1012 together with the source carrier 107 can be lifted to the accommodating cavity 1010 through the other pull rod 108, and then the rod-shaped part 102 can be pushed, such that the connector 1011 is close to the source carrier 107. When the connecting structure 103 of the connector 101 contacts with the source carrier 107, the tail end of the connector is assembled with the limiting structure 106 because of being blocked by the source carrier 107. In this case, the rod-shaped part 102 can be rotated to drive the connector 101 to be threadedly connected to the source carrier 107. Of course, the rod-shaped part 102 can be pulled backward, and the connecting structure 103 can separate from the limiting structure 106. In an embodiment, the connector 101 may further include a connecting rod 1013 and a swinging member 1014 located between a front end and a tail end of the connecting rod. A contact surface between the swinging member 1014 and the accommodating space 105 is an arc surface, the connector is rotatable along an arc surface of the swinging member, a diameter of the swinging member 1014 is larger than a maximum diameter of the connecting rod 1013, and the swinging member 1014 is in the accommodating space 105 of the rod-shaped part. Specifically, a front end of the connecting rod refers to an end of the connecting rod 1013 close to the connecting structure 103, and a tail end of the connecting rod refers to an end of the connecting rod 1013 close to the limiting structure 106. The arc surface of the swinging member 1014 matches a shape of the accommodating space 105, and in order to realize a function of the swinging member 1014 driving the connecting rod 1013 to rotate, the diameter of the swinging member 1014 may be larger than the maximum diameter of the connecting rod 1013. For example, the swinging member 1014 may be cylindrical or spherical. In FIG. 10, the swinging member 1014 being spherical is taken as an example. The swinging member may also be cylindrical as shown in FIG. 8, in which the rod-shaped part runs through a through hole of the swinging member. Specifically, in order to prevent the connector 101 from separating from the accommodating space 105, the diameter of the swinging member 1014 may be larger than a maximum diameter of the opening 104. Specifically, the swinging member 1014 and the connecting rod 1013 may be integrated, or the connecting rod 1013 may run through the swinging member 1014. When the connecting rod 1013 runs through the swinging member 1014, the connecting rod 1013 may be fixedly connected to the swinging member 1014 by, but not limited to, a pin, to prevent the swinging member 1014 from rotating with respect to the connecting rod 1013. Specifically, an inner wall of the accommodating space 105 may be arc-shaped, and the arc surface of the swinging member 1014 may match the arc-shaped inner wall of the accommodating space 105. A front end of the accommodating space 105 may include an arc-shaped slot 1015. The front end of the accommodating space 105 refers to an end of the accommodating space 105 close to the opening 104. In order to achieve a better rotation effect of the connector 101, the arc-shaped slot 1015 can match the arc surface of the swinging member 1014. In this embodiment, when the limiting structure 106 is removed from the tail end of the connector, the connector 101 can swing along the arc surface of the swinging member 1014. For example, as shown in FIG. 11A, FIG. 11A is a working principle diagram of a connector. When the connector 101 rotates in a counterclockwise direction, the source carrier 107 can be driven to move downward within a certain range. As shown in FIG. 11B, FIG. 11B is a working principle diagram of a connector. When the connector 101 rotates in a clockwise direction, the source carrier 107 can be driven to move upward within a certain range. When the swinging member 1014 is spherical, the rotation direction of the swinging member 1014 may be 360°. The rotation direction of the spherical swinging member is not limited in this embodiment in any way. When the pull rod is pushed to connect the source carrier 107 to the pull rod, the connector 101 is movable within a certain range, such that the source carrier 107 is connected to the pull rod. In the embodiment of the present disclosure, on the one hand, the connecting rod is connected to the source carrier 107 by a threaded connection, thereby preventing the source carrier 107 from falling, and improving the safety of the source replacement operation. In another embodiment, as show in FIG. 12, FIG. 12 is a schematic structural diagram of a pull rod. The rod-shaped part 102 may include a first rod-shaped part 1017 and a second rod-shaped part 1018 that are connected and fixed, and a front end of the first rod-shaped part 1017 is provided with the opening 104. Specifically, in order to facilitate the installation and replacement of the connector 101, an opening at a tail end of the first rod-shaped part 1017 may be larger than a maximum size of the connector 101, and the first rod-shaped part 1017 and the second rod-shaped part 1018 may be connected by, but not limited to, a connection mode, such as a buckle, or a pin, or may be integrated. For example, the first rod-shaped part 1017 may include a first accommodating cavity 1019, the second rod-shaped part 1018 may include a second accommodating cavity 1020, the limiting structure 106 may be provided within the second accommodating cavity 1020, and the first accommodating cavity 1019 and the second accommodating cavity 1020 constitute an accommodating space 105. For example, the limiting structure 106 may be provided on the second rod-shaped part 1018. For example, the limiting structure 106 may be a limiting slot, which is located within the second accommodating cavity 1020. The tail end of the connector 101 may further include a limiting unit 1021, and the limiting slot may be assembled with the limiting unit 1021. In an embodiment of the present disclosure, the limiting slot may be a quadrangular limiting slot or a hexagonal limiting slot. Accordingly, the limiting structure is quadrangular or hexagonal. In the embodiment of the present disclosure, the limiting slot and the limiting structure can prevent the connector from moving after being limited, and the specific structures and shapes of the limiting slot and the limiting structure are not limited. In an embodiment, a limiting slot may be provided on the surface of an end of the rod-shaped part 102 away from the connector 101, and a pin matching the limiting slot may be provided on the source guiding apparatus to prevent the rod-shaped part 102 from rotating when being pushed. In an embodiment, the rod-shaped part 102 may include at least 2 pull rods connected in sequence; where a diameter of each pull rod is increased successively from a pull rod connected to the connector 101. When diameters of two adjacent pull rods are different, radiation can be effectively shielded. When the diameter of each pull rod is increased successively from the pull rod connected to the connector 101, the radiation shielding effect is better. In an embodiment, at least one pull rod connected to the connector 101 among the at least 2 pull rods is made of a tungsten alloy. Because the tungsten alloy has high density and high shielding performance, the radiation shielding effect is better when at least one pull rod connected to the connector 101 is made of the tungsten alloy. This example embodiment further provides a source guiding apparatus. As show in FIG. 13, FIG. 13 is a schematic structural diagram of a source guiding apparatus. The source guiding apparatus may include the source guiding tank 109 and the pull rod in the above embodiments, where: the source guiding tank 109 includes an accommodating cavity 1010 capable of accommodating the source carrier 107; and a hole site 1025 is provided on the source guiding tank 109, and the pull rod can enter the accommodating cavity 1010 through the hole site 1025. For example, a shielding member 1026 is further included between the source guiding tank and the pull rod, and the pull rod is fixedly arranged with the source guiding tank 109 through the shielding member 1026. For example, the shielding member 1026 may include a base body 1027 and a tubular unit 1028, where an end of the base body 1027 has a groove, and a bottom surface of the groove has a through hole extending along an axial direction of the base body. The adjusting member 1022 is arranged within the through hole, the adjusting member 1022 is coaxial with the through hole, and the rod-shaped part 102 can pass through the through hole. For example, the shielding member may be composed of two parts that are connected to facilitate the installation of the adjusting member. Specifically, the tubular unit 1028 is sleeved on the rod-shaped part 102, an end of the tubular unit 1028 at least partially extends into the through hole and the opening 1024 of the adjusting member 1022, and a gap between the adjusting member 1022 and the rod-shaped part 102 and a gap between the through hole of the tubular unit 1028 and the rod-shaped part 102 can be filled, so as to prevent radiation from leaking from the gaps. Specifically, an outer surface of the tubular unit 1028 away from an end of the through hole has a protruding shielding block 1029 in a radial direction. The shielding block 1029 is located within the groove of the base body. A diameter of the shielding block 1029 may be larger than a diameter of the tubular unit 1028, to achieve a better radiation shielding effect. In the embodiment of the present disclosure, on the one hand, a gap position when the pull rod pushes the source carrier 107 from a source loading channel 1016 of the source guiding apparatus into a corresponding installation position of a radiotherapy device can be adjusted through the connector 101 or the adjusting member 1022 on the pull rod, thereby improving the flexibility and accuracy of the source replacement operation. On the other hand, the shielding member 1026 can be arranged to prevent radiation leakage and improve the safety of the source replacement operation. In the embodiments of the present disclosure, directions are defined only with what is shown in the accompanying drawings as an example, and the sequence of specific steps of the source guiding method provided in the embodiments of the present disclosure is not limited. In the description of the present disclosure, it should be understood that the directions or position relationships indicated by the terms, such as “center,” “longitudinal,” “transverse,” “length,” “width,” “thickness,” “above,” “below,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and “counterclockwise,” are based on the directions or position relationships shown in the accompanying drawings, are only provided to facilitate describing the present disclosure and simplifying the description, rather than indicating or implying that the apparatus or element referred to must have a specific direction, or be configured and operated in a specific direction, and therefore cannot be understood as limitations of the present disclosure. In addition, the terms “first” and “second” are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, features defined with “first” or “second” may explicitly or implicitly include one or more of the features. In the description of the present disclosure, “plurality” means two or more than two, unless otherwise specifically defined. In the present disclosure, unless otherwise clearly defined and limited, the terms, such as “installation,” “connected,” “connection,” and “fixed,” should be understood in a broad sense, for example, may be a fixed connection or a detachable connection, or an integration; may be a mechanical connection or an electrical connection; may be a direct connection, or an indirect connection through an intermediate medium, or may be an internal communication between two elements or an interaction relationship between two elements. For those of ordinary skills in the art, the specific meanings of the above terms in the present disclosure may be understood according to specific circumstances. In the present disclosure, unless otherwise clearly defined and limited, the first feature “above” or “below” the second feature may include the first feature in direct contact with the second feature, or may include the first feature not being in direct contact with the second feature, but in contact with the second feature through other features between them. Further, the first feature “above” the second feature includes the first feature being right above and above the second feature, or merely indicates that the first feature is horizontally above the second feature. The first feature “below” the second feature includes the first feature being right below and below the second feature, or merely indicates that the first feature is horizontally below the second feature. In the description of the present specification, descriptions with reference to the terms, such as “one embodiment,” “some embodiments,” “examples,” “specific examples,” or “some examples,” mean that specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the present specification, schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. In addition, the described specific features, structures, materials, or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may incorporate and combine different embodiments or examples described in the present specification. After considering the specification and practicing the disclosure disclosed herein, those skilled in the art will easily think of other embodiments of the present disclosure. The present disclosure is intended to cover any variations, uses, or adaptive changes of the present disclosure. These variations, uses, or adaptive changes follow the general principles of the present disclosure and include common knowledge or conventional technical means in the technical field that is not disclosed in the present disclosure. The specification and the embodiments are only regarded as examples, and the true scope and spirit of the present disclosure are indicated by the appended claims.
	summary
	description	1. Field of the Invention The present invention relates to a particle beam treatment system, and more particularly to a particle beam irradiation apparatus for treating an affected part by irradiating it with charged particle beams comprising proton ions, carbon ions, or the like, and a treatment planning unit using this particle beam irradiation apparatus, and a particle beam irradiation method. 2. Description of the Related Art A treatment method for treating a patient with cancer or the like by irradiating the affected part of the patient with charged particle beams such as proton beams is known. The treatment system used for this treatment includes a charged particle beam generating unit, beam transport system, and treatment room. The charged particle beam accelerated by the accelerator of the charged particle beam generating unit reaches the beam delivery apparatus beam delivery apparatus in the treatment room through the beam transport system, and after being scanned by scanning electromagnets provided in the beam delivery apparatus beam delivery apparatus, the charged particle beam is applied from a nozzle to the affected part of the patient. A treatment method using such a treatment system is known that includes the steps of: stopping the output of the charged particle beam from the beam delivery apparatus; and in a state where the output of the charged particle beam is stopped, controlling the scanning electromagnets to change the irradiation position (spot) of the charged particle beam (so-called “scanning”) and to start the output of the charged particle beam from the beam delivery apparatus after the aforementioned change (see, for example, European Patent Application No. 0779081A2 [FIG. 1 and the like]). In the above-described conventional particle beam treatment system, in order to reduce to a minimum the exposure of normal tissue to radiation and perform a proper treatment with neither too much nor too little irradiation, the beam delivery apparatus has an irradiation dose monitor and/or beam position monitor for estimating the irradiation dose distribution, located at the downstream side of the electromagnets and immediately in front of a patient to be irradiated. In many cases, this monitor is of a type that accumulates charges ionized by the passage of beams in a capacitor, and that reads the voltage induced by the capacitor after spot irradiation. The capacity of this capacitor is determined so as to permit the amount of ionized charges by the spot subjected to a largest irradiation dose. For the above-described capacitor, as the capacity decreases, the output voltage increases, thereby enhancing the resolution. Conversely, as the capacitor increases, the resolution decreases. Such being the situation, if the difference in irradiation dose between the spot subjected to the largest irradiation dose and that subjected to the smallest irradiation dose can be reduced, the capacity of the capacitor could be correspondingly reduced to enhance the resolution. This would effect the possibility of detecting more correctly an actual irradiation dose. However, the aforesaid conventional art does not particularly give consideration to the above-described reduction of the difference in irradiation dose, thus leaving room for improvement in the detection accuracy with respect to the actual irradiation dose. Meanwhile, when performing irradiation to each spot, a target irradiation dose is set on a spot-by-spot basis. Once an integrated value of irradiation dose detected by the irradiation dose monitor has reached the target value, a beam stop command is outputted to the accelerator, and in response to it, the accelerator stops the output of a charged particle beam. With typical accelerator such as a slow cycling synchrotron or a cyclotron, even if the beam stop command is inputted as described above, strictly speaking, it is not impossible that some amount of response delay occurs rather than the output of the charged particle beam immediately stops. In such a case, even after the aforementioned target value was reached, the charged particle beam continues to be applied to the pertinent spot for the time period during the response delay time. This leaves room for improvement in the control accuracy with respect to the irradiation dose of the charged particle beam. Since the irradiation dose monitor is an machine, it is difficult to perfectly eliminate the possibility that the irradiation dose monitor causes a malfunction or failure. Also, since the target irradiation dose for each spot is usually a value transmitted from a data base or a value calculated based on the transmitted value, it is not impossible that an improper value is inputted at the stage of the transmission or the calculation. However, the above-described conventional art does not particularly give consideration to such a monitor abnormality or an input error. This leaves room for improvement in the prevention of excessive irradiation of charged particle beams due to the aforementioned monitor abnormality or input error. Furthermore, when performing irradiation to each spot, a target irradiation dose is set on a spot-by-spot basis. Once the integrated value of irradiation dose by the irradiation dose monitor has reached the target value, a beam stop command is outputted to the accelerator, and in response to it, the accelerator stops the output of the charged particle beam. Regarding such a beam stopping function, it is not impossible that equipment associated with this function causes a malfunction or failure, as well. However, the above-described conventional art does not particularly take a malfunction of such a beam stopping function into consideration. This leaves room for improvement in the prevention of excessive irradiation of charged particle beams due to the above-described malfunction or failure of the beam stopping function. Accordingly, it is a first object of the present invention to provide a particle beam irradiation apparatus, treatment planning unit using this, and particle beam irradiation method that are capable of improving the detection accuracy with respect to an actual irradiation dose during treatment using charged particle beams. It is a second object of the present invention to provide a particle beam irradiation apparatus and particle beam irradiation method that are capable of enhancing the control accuracy with respect to the irradiation dose of charged particle beams. It is a third object of the present invention to provide a particle beam irradiation apparatus and particle beam irradiation method that are capable of reliably preventing the excessive irradiation of charged particle beams due to a monitor abnormality, input error, or the like. It is a fourth object of the present invention to provide a particle beam irradiation apparatus and particle beam irradiation method that are capable of reliably preventing the excessive irradiation of charged particle beams due to a malfunction or the like of a beam stopping function. It is a fifth object of the present invention to provide a particle beam irradiation apparatus and particle beam irradiation method that are capable of reducing the treatment time when performing irradiation of charged particle beams for each of a plurality of layer regions in a target. To achieve the above-described first object, the present invention provides a particle beam irradiation apparatus that includes an accelerator for extracting a charged particle beam; an beam delivery apparatus having a charged particle beam scanning unit and outputting the charged particle beam extacted from the accelerator; and a controller that stops the output of the charged particle beam from the beam delivery apparatus, and that, in a state where the output of the charged particle beam is stopped, controls the charged particle beam scanning unit to change the irradiation position of the charged particle beam, start the output of the charged particle beam from the beam delivery apparatus after the above-described change, and perform irradiations of the charged particle beam with respect to at least one irradiation position a plurality of times based on treatment planning information. In the present invention, the controller controls the charged particle beam scanning unit to perform irradiations of the charged particle beam with respect to at least one irradiation position a plurality of times. By virtue of this feature, regarding an irradiation position subjected to too much irradiation dose by one-time ion irradiation, it is possible to perform a divided irradiation so as to reduce an irradiation dose for each radiation. This allows the difference in irradiation dose between the irradiation position subjected to the largest dose and that subjected to the smallest dose to be reduced, thereby leveling off irradiation dose. As a result, the capacity of the capacitor of a position monitor can be correspondingly reduced to enhance the resolution, and therefore, the actual irradiation dose during treatment can be detected further correctly. To achieve the above-described second object, the present invention provides a particle beam irradiation apparatus including a controller that controls the irradiation of the charged particle beam to the irradiation position so that the irradiation dose applied to the irradiation position becomes a set irradiation dose, in a state where the irradiation dose applied to the irradiation position during the time period from the outputting of a beam extraction stop signal at the time when the irradiation dose detected by the irradiation dose detector reaches the set irradiation dose up to the extraction stop of the charged particle beam from the accelerator, is added. Even if the beam stop command is inputted, strictly speaking, it is not impossible that some amount of response delay occurs rather than the extraction of the charged particle beam from the accelerator immediately stops. In the present invention, the controller can perform an irradiation of the charged particle beam to an irradiation position so that the irradiation dose at the irradiation position becomes a set irradiation dose, in a state where the irradiation dose applied to the irradiation position during the time period from the outputting of a beam extraction stop signal up to the extraction stop of the charged particle beam from the accelerator, is added. This allows the irradiation dose at each irradiation position to become substantially the set irradiation dose, thereby enabling the charged particle beam to be applied to each irradiation position with high accuracy. To control the irradiation dose, even if there is time delay between the outputting of the beam extraction stop signal and the extraction stop of the charged particle beam from the accelerator, the irradiation dose at each irradiation position can be made to be a set irradiation dose, allowing for the irradiation dose for the time period during the time delay. This makes it possible to irradiate, with high degree of accuracy, any irradiation position with charged particle beams of a dose substantially equal to the set irradiation dose. To achieve the above-described third object, the present invention provides a particle beam irradiation apparatus including a controller that stops the output of the charged particle beam from the beam delivery apparatus, that, in a state where the output of the charged particle beam is stopped, controls the charged particle beam scanning unit to change the irradiation position of the charged particle beam and to start the output of the charged particle beam from the beam delivery apparatus after the above-described change, and that determines the occurrence of an abnormality based on an elapsed time from the irradiation start of the charged particle beam with respect to one irradiation position. In the present invention, the controller determines the occurrence of an abnormality based on an elapsed time from the irradiation start of the charged particle beam with respect to one irradiation position. Therefore, even if the irradiation time of the charged particle beam is likely to abnormally elongate due to the occurrence of a malfunction or failure of the irradiation dose detector, or an improper input value, the irradiation of the charged particle beam can be stopped after a certain time has elapsed. This reliably prevents an excessive irradiation to a target, and further improves the safety. To achieve the above-described fourth object, the present invention provides a particle beam irradiation apparatus including a controller that stops the output of the charged particle beam from the beam delivery apparatus, that, in a state where the output of the charged particle beam is stopped, controls the charged particle beam scanning unit to change the irradiation position of the charged particle beam and to start the output of the charged particle beam from the beam delivery apparatus after the above-described change, and that determines the occurrence of an abnormality using the irradiation dose detected by the irradiation detector and a second set irradiation dose larger than respective first set irradiation doses with respect to a plurality of irradiation positions in the target. In the present invention, the controller determines the occurrence of an abnormality, using the irradiation dose detected by the irradiation dose detector and the second set dose larger than respective first set doses with respect to a plurality of irradiation positions in the target. Therefore, even if, due to a malfunction or the like of the beam stopping function, the charged particle beam does not readily stop and the irradiation dose is likely to abnormally increase, the irradiation can be stopped at a certain upper limit irradiation dose, thereby reliably preventing an excessive irradiation to the target. This further enhances the safety. To achieve the above-described fifth object, the present invention provides a particle beam irradiation apparatus including a controller that performs control to decelerate the charged particle beam in the accelerator when the irradiation of the charged particle beam with respect to one of a plurality of layer regions that are different in irradiation energy from each other in a target to be irradiated with the charged particle beam from the beam delivery apparatus, has been completed. In the spot scanning irradiation according to the present invention, as the size of a target changes, the number of spots in a layer changes, and consequently, the time required to complete an irradiation to all spots in the layer changes. Regarding the allowable extraction period of the synchrotron, if it is set to be long with a large target assumed, the irradiations to all layers takes much time to complete, thereby elongating the treatment time for a patient. In the present invention, after the irradiation in a layer region has been completed, the charged particle beam in the accelerator is decelerated, and therefore, the allowable extraction period of the charged particle beams in the accelerator can be earlier terminated. As a result, even when it is necessary to irradiate a plurality of layer regions with charged particle beams, the treatment time can be made short. Hereinafter, a particle beam treatment system having a particle beam irradiation apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, a proton beam treatment system, which is a particle beam treatment system according to this embodiment, includes a charged particle beam generating unit 1 and a beam transport system 4 connected to the downstream side of the charged particle beam generating unit 1. The charged particle beam generating unit 1 comprises an ion source (not shown), a pre-stage charged particle beam generating unit (linear accelerator (linac)) 11, and a synchrotron (accelerator) 12. The synchrotron 12 includes a high-frequency applying unit 9 and acceleration unit 10. The high-frequency applying unit 9 is constructed by connecting a high-frequency applying electrode 93 disposed on the circulating orbit of the synchrotron 12 and a high-frequency power source 91 by an open/close switch 92. The acceleration unit (second element; charged particle beam energy changing unit) 10 comprises a high-frequency accelerating cavity (not shown) disposed on the circulating orbit thereof, and a high-frequency power source (not shown) for applying a high-frequency power to the high-frequency accelerating cavity. Ions generated in the ion source, e.g., hydrogen ions (protons) or carbon ions, are accelerated by the pre-stage charged particle beam generating unit (e.g., linear charged particle beam generating unit) 11. The ion beam (proton beam) emitted from the pre-stage charged particle beam generating unit 11 is injected into the synchrotron 12. In the synchrotron 12, this ion beam, which is a charged particle beam, is given energy and accelerated by the high-frequency power that is applied to the ion beam through the high-frequency accelerating cavity from the high-frequency power source 91. After the energy of the ion beam circulating through the synchrotron 12 has been increased up to a-set energy (e.g., 100 to 200 MeV), a high frequency for emission from the high-frequency power source 91 reaches the high-frequency applying electrode 93 through the open/close switch 92 in a closed state, and is applied to the ion beam from the high-frequency applying electrode 93. The application of this high-frequency causes the ion beam that is circulating within a stability limit to shift to the outside of the stability limit, thereby extracting the ion beam from the synchrotron 12 through an extraction deflector 8. At the extraction of the ion beam, currents supplied to quadrupole electromagnets 13 and bending electromagnets 14 are held at set values, and the stability limit is held substantially constant. Opening the open/close switch 92 to stop the application of the high frequency power to the high-frequency applying electrode 93, stops the extraction of the ion beam from the synchrotron 12. The ion beam extracted from the synchrotron 12 is transported to the downstream side of the beam transport system 4. The beam transport system 4 includes quadrupole electromagnets 18 and a deflection electromagnet 17; and quadrupole electromagnets 21 and 22, and deflection electromagnets 23 and 24 that are sequentially arranged on a beam path 62 communicating with the beam delivery apparatus 15 provided in a treatment room from the upstream side toward the beam traveling direction. Here, the aforementioned electromagnets each constitute a first element. The ion beam introduced into the beam transport system 4 is transported to the beam delivery apparatus 15 through the beam path 62. The treatment room has the beam delivery apparatus 15 affixed to a rotating gantry (not shown) provided therein. A beam transport unit having an inverse U-shape and including a part of the beam path 62 in the beam transport system 4, and the beam delivery apparatus 15 are disposed in a rotating drum (not shown) with a substantially cylindrical shape, of the rotating gantry (not shown). The rotating drum is configured so as to be rotated by a motor (not shown). A treatment gauge (not shown) is formed in the rotating drum. The beam delivery apparatus 15 has a casing (not shown) affixed to the rotating drum and connected to the aforementioned inverse U-shaped beam transport unit. Scanning electromagnets 5A and 5B for scanning a beam, a dose monitor 6A, a position monitor 6B and the like are disposed in the casing. The scanning electromagnets 5A and 5B are used for deflecting a beam, for example, in directions orthogonally intersecting each other (an X-direction and Y-direction) on a plane perpendicular to the beam-axis, and moving an irradiation position in the X-direction and Y-direction. Before an ion beam is applied from the beam delivery apparatus 15, a bed 29 for treatment is moved by a bed drive unit (not shown) and inserted into the aforementioned treatment gauge, and the positioning of the bed 29 for irradiation with respect to the beam delivery apparatus 15 is performed. The rotating drum is rotated by controlling the rotation of the motor by a gantry controller (not shown) so that the beam axis of the beam delivery apparatus 15 turns toward the affected part of a patient 30. The ion beam introduced into the beam delivery apparatus 15 from the inverse U-shaped beam transport unit through the beam path 62 is caused to sequentially scan irradiation positions by the scanning electromagnets (charged particle beam scanning unit) 5A and 5B, and applied to the affected part (e.g., occurrence region of cancer or tumor) of the patient 30. This ion beam releases its energy in the affected part, and forms a high dose region there. The scanning electromagnets 5A and 5B in the beam delivery apparatus 15 are controlled by a scanning controller 41 disposed, for example, in the gantry chamber in a treatment unit. A control system included in the proton beam treatment system according to this embodiment will be described with reference to FIG. 1. This control system 90 comprises a central control unit 100, storage unit 110 storing treatment planning database, scanning controller 41, and accelerator and transport system controller 40 (hereinafter referred to as an “accelerator controller”). Furthermore, the proton beam treatment system according to this embodiment has a treatment planning unit 140. While the aforementioned treatment planning data (patient data) stored in the storage unit 110 on a patient-by-patient basis is not particularly shown, the treatment planning data includes data such as patient ID numbers, irradiation doses (through a treatment and/or per fraction), irradiation energy, irradiation directions, irradiation positions, and others. The central control unit 100 has a CPU and memory 103. The CPU 100 reads the above-described treatment planning data concerning patients to be treated from the storage unit 110, using the inputted patient identification information. The control pattern with respect to the exciting power supply to each of the above-described electromagnets is determined by the value of irradiation energy out of the treatment planning data on a patient-by-patient basis. The memory 103 stores a power supply control table in advance. Specifically, for example, in accordance with various values of irradiation energy (70, 80, 90, . . . [MeV]), values of supply exciting power or their patterns with respect to a quadrupole electromagnet 13 and deflection electromagnet 14 in the charged particle beam generating unit 1 including the synchrotron 12; and the quadrupole electromagnets 18, deflection electromagnet 17, the quadrupole electromagnets 21 and 22, and deflection electromagnets 23 and 24 in the beam transport system 4, are preset. Also, using the above-described treatment planning data and power supply control table, the CPU 101 as a control information producing unit, produces control command data (control command information) for controlling the electromagnets provided on the charged particle beam generating unit 1 and the beam paths, regarding a patient to be treated. Then, the CPU 101 outputs the control command data produced in this manner to the scanning controller 41 and accelerator controller 40. One of the features of this embodiment lies in that, based on the treatment planning data created by the treatment planning unit 140, the central control unit 100, scanning controller 41, and accelerator controller 40 performs control operations in close liaison with one another as follows: (1) they stops the output of an ion beam from the beam delivery apparatus 150, and in a state where the output of the ion beam is stopped, they control the scanning electromagnets 5A and 5B to change the irradiation position (spot) of the ion beam and to start the output of the ion beam from the beam delivery apparatus 15 after the aforementioned change (so-called “scanning”); (2) in order to reduce variations in irradiation dose at a spot, they control the synchrotron 12 and beam delivery apparatus 15 to divide an irradiation of an ion beam with respect to at least one identical irradiation position (spot) at which the dose otherwise would exceed a division reference irradiation dose (discussed below), into a plurality of times of irradiations. Hereinafter, detailed explanation thereof will be provided with reference to FIGS. 2 to 18. First, the creation of a treatment plan by the treatment planning unit 140 is explained. The treatment planning unit 140 is, for example, constituted of a personal computer. While its illustration is omitted, the treatment planning unit 140 includes an input unit (e.g., keyboard) which can be operated by an operator and with which the operator can input; a computing unit (e.g., CPU) that performs a predetermined arithmetic processing based on an input result by the aforementioned input means and operation means; an input/output interface that performs the input/output of information, such as the input of external image data and the output of treatment planning data created by this computing unit; and a display unit. FIG. 2 is a flowchart showing arithmetic processing steps executed by the aforementioned computing means of the treatment planning unit 140. In FIG. 2, if an operator (usually a doctor or medical staff) inputs identification information (e.g., a name, ID number) about a patient to be treated via the input unit, the determination in step 101 is satisfied, and the processing advances to step 102, where a patient image file (file previously taken by extra imaging means such as CT scanner and stored in the database of the storage unit 110) of a pertinent patient is read. Here, the patient image file is tomography image information. Thereafter, in step 103, the read patient image file is outputted on a display unit as display signals, and a corresponding display is made. If the operator performs specification by filling in a target region to be irradiated with an ion beam via the input unit while watching the displayed patient image file, the determination in step 104 is satisfied, and the processing advances to step 105, where recognition processing is three-dimensionally performed regarding the filled-in region. In this situation, if the operator inputs a target dose to be applied to a corresponding target region via the input unit, the determination in step 106 is satisfied. Furthermore, if the operator inputs an irradiation direction of the ion beam, the determination in step 107 is satisfied, and the processing advances to step 108. Moreover, if the operator inputs, via the input unit, a division reference irradiation dose, which is a reference irradiation dose such that a divided irradiation is to be performed if an irradiation dose per unit spot exceeds this reference irradiation dose, the determination in step 108 is satisfied, and the processing advances to step 110. Here, description will be made of the relationship between the depth of a target and energy of an ion beam. The target is a region, including an affected part, to be irradiated with an ion beam, and is somewhat larger than the affected part. FIG. 3 shows the relationship between the depth of the target in a body and the irradiation dose of ion beam. The peak of dose as shown in FIG. 3 is referred to as a “Bragg peak”. The application of an ion beam to the target is performed in the position of the Bragg peak. The position of Bragg peak varies depending on the energy of ion beam. Therefore, dividing the target into a plurality of layers (slices) in the depth direction (traveling direction of ion beam in the body), and changing the energy of ion beam to the energy in correspondence with a depth (a layer) allows the ion beam to be irradiated throughout the entire target (target region) having a thickness in the depth direction as uniformly as possible. From this point of view, in step 110, the number of layers in the target region to be divided in the depth direction is determined. One possible determination method for determining the number of layers is to set the thickness of a layer, and to automatically determine the number of layers in accordance with the aforementioned thickness and a thickness of the target region in the depth direction. The thickness of layer may be a fixed value irrespective of the size of the target region, or alternatively may be automatically determined appropriately to the maximum depth of the target region. Still alternatively, the thickness of layer may be automatically determined in accordance with the spread of the energy of ion beam, or simply, the number itself of layers may be inputted by the operator via the input unit instead of determining the thickness of layer. FIG. 4 is a diagram showing an example of layers determined in the above-described manner. In this example, the number of layers is four: layers 1, 2, 3, and 4 in this order from the lowest layer. The layers 1 and 2 each have a spread of 10 cm in the X-direction and a spread of 10 cm in the Y-direction. The layers 3 and 4 each have a spread of 20 cm in the X-direction and a spread of 10 cm in the Y-direction. FIG. 3 represents an example of dose distribution in the depth direction as viewed from the line A–A′ in FIG. 4. On the other hand, FIG. 5 represents an example of dose distribution in the depth direction as viewed from the line B–B′ in FIG. 4. After the number of layers has been determined in this manner, the proceeding advances to step 111, where the number (and positions) of spots that divide each layer (target cross section) in the direction perpendicular to the depth direction, is determined. On this determination, like the above-described layers, one spot diameter is set, and the number of spots is automatically determined in accordance with the size of the spot and the size of the pertinent layer. The spot diameter may be a fixed value, or alternatively may be automatically determined appropriately to the target cross section. Still alternatively, the spot diameter may be automatically determined appropriately to -the size of ion beam (i.e., the beam diameter), or simply, spot positions themselves or the distances themselves between spot positions may be inputted by the operator via the input unit instead of determining the spot size. After step 111 has been completed, the processing advances to step 120, where the irradiation dose at each spot in all layers is determined. FIG. 6 is a flowchart showing detailed procedure in the aforementioned step 120. As described above, basically, the application of an ion beam to the target is performed in the position of the Bragg peak, and it is desirable that the ion beam be irradiated throughout the entire target (target region) having a thickness in the depth direction as uniformly as possible. On the determination in the irradiation dose at each spot, therefore, it is necessary to ultimately secure a uniform irradiation throughout the entire target region. In light of the above, in steps 121–123, firstly initial condition are determined in step 121. Specifically, by the accumulation of past calculation examples, the utilization of simple models or the like, the irradiation doses with respect to all spots on layer-by-layer basis that are deemed to correspond to the target doses, the irradiation direction of ion beam, and the numbers of layers that were inputted or determined in steps 106 to 111, are determined as temporary values. Thereafter, the processing advances to step 122, where, using a known method, a simulation calculation is performed as to how the actual dose distribution in the entire target region becomes, if an irradiation is performed using the values of irradiation doses with respect to all spots, the doses having been determined in step 121. Then, in step 123, it is determined whether the aforementioned calculated dose distribution is uniform throughout substantially the entire region of the target, namely, whether variations remain within a given limit. If not so, the processing advances to step 124, where a predetermined correction is made. This correction may be such that the irradiation doses at spots somewhat outstandingly higher/lower than an average dose value are automatically lowered/raised with a correction width, and that the correction width may be set by a manual operation. After such a correction, the processing returns to step 121 and the same procedure is repeated. Therefore, the correction in step 124 and the dose distribution calculation in step 122 are performed until the irradiation dose distribution becomes uniform to a certain extent. Thus, ultimately, the irradiation doses with respect all spots that allow substantially uniform dose distribution to be implemented in the entire target region, are determined. Thereafter, the processing advances to step 130. In this stage, although the irradiation doses to all spots have each been determined, each of all these spots is set to be irradiated with a pertinent allocated irradiation dose at one time. In step 130, if there are any irradiation doses exceeding the division reference irradiation dose inputted before in step 108, out of the irradiation doses determined with respect to all spots, the ion beam irradiation to each of such spots is not performed at one time, but is performed in the form of irradiations divided into a plurality of times (at least two times). Here, we assume the number N of irradiations to be a minimum natural number n that satisfies the relationship: n≧R/Rs, where R and Rs, respectively, denote the irradiation dose and the division reference irradiation dose at a pertinent spot. In other words, the number N of irradiations is assumed to be a value obtained by rounding-up the decimal places of R divided by Rs. Therefore, if N=1, then R≦Rs, and hence a plurality of times of divided irradiations are not performed (namely, the irradiation is performed at one time). If N=2, then R>Rs, and hence it is planned that irradiations divided into a plurality of times are performed. FIG. 7 shows an example (layers 1 to 4) of divided irradiations as described above with reference to FIGS. 4 and 5. In this example, the division reference dose is assumed to be 10 (a relative value without unit; the same shall apply hereinafter). As shown in FIG. 7, regarding the layer 1, before division processing (i.e., when the irradiation is performed at one time), the irradiation dose at each spot was 70. Such being the situation, it is planned that irradiations divided into seven times are performed, the irradiation dose for each divided irradiation being 10. Likewise, regarding the layers 2, 3, and 4, the irradiation doses at each spot before division processing were 25, 17.9, and 12.6, respectively. Accordingly, in the layers 2, 3, and 4, respectively, it is planned that irradiations divided into three, two, and two times were performed, the irradiation dose for each divided irradiation being 8.3, 9, and 6.3, respectively. More specific explanations of the above will be provided with reference to FIG. 8. As described above, regarding the layer 1 (the region corresponding to the right half of the layer 1 shown in FIG. 8; here, the right-left direction in FIG. 8 corresponds to that in FIG. 4), irradiations divided into seven times are performed, and it is planned that an irradiation with irradiation dose of 10 is repeated in each of the first-time to seventh-time irradiations. Regarding the layer 2 (the region corresponding to the right half of the layer 2 shown in FIG. 8), it is planned that an irradiation with irradiation dose of 8.3 is repeated three times. Regarding the layer 3, with respect to the region shown in the right half in FIG. 8, it is planned that an irradiation with irradiation dose of 9.0 is repeated two times, while with respect to the region shown in the left half in FIG. 8, it is planned that an irradiation with irradiation dose of 10 is repeated seven times. Regarding the layer 4, with respect to the region shown in the right half in FIG. 8, it is planned that an irradiation with an irradiation dose of 6.3 is repeated two times, while with respect to the region shown in the left half in FIG. 8, it is planned that an irradiation with irradiation dose of 8.3 is repeated three times. After step 130 has been completed, the processing advances to step 131, where the order of the irradiation with respect to spots in each of the layers is determined. Specifically, in the proton beam treatment system according to this embodiment, as described above, the output of an ion beam from the beam delivery apparatus 15 is stopped, and in the state the output of the ion beam is stopped, a scanning irradiation to change the irradiation position (spot) is performed. In step 131, it is determined how the ion beam is to be moved with respect to each spot in the scanning irradiation. Here, the ion beam to be applied to the target is narrow, and its diameter is a little larger than that of the spot diameter. FIGS. 9 and 10 each show an example of the setting of the order of spot irradiation. This order of spot irradiation order corresponds to the example described with reference to FIGS. 4, 3, 5, 7, and 8. FIG. 9 shows the setting of irradiation orders in both the layers 1 and 2 in a combined and simplified manner. As shown in FIG. 9, for each of the layers 1 and 2, 100 spots in total are set in a lattice shape of 10 rows and 10 columns. The application of an ion beam to the target (the square region in FIG. 9) of the layers 1 and 2 is performed, for example, in a manner as follows: an irradiation is performed on a spot-by-spot basis from one end (the left lower corner in FIG. 9) in the spot row (including ten spots) situated at one end of these layers toward the other end (the right lower corner in FIG. 9) of this spot row, i.e., from the left toward the right in FIG. 9. After the irradiation to the other end has been completed, the irradiation is performed on a spot-by-spot basis from one end (the right lower end in FIG. 9) in another spot row adjacent to the aforementioned spot row toward the other end (the left end in FIG. 9) of the other row, i.e., from the right toward the left in FIG. 9. After the irradiation to the other end in the other row has been completed, the ion beam moves to a next other spot row adjacent. In this manner, in this embodiment, it is planned that, in the horizontal surface of each of the layers 1 and 2, the ion beam is moved by inversing its traveling direction (i.e., by causing the ion beam to meander) for each of the adjacent spot rows, until the ion beam reaches the last spot (the left upper corner in FIG. 9) in the last spot row, thus completing an irradiation operation (one of a plurality of times of scanning operations) with respect to the layers 1 and 2. Regarding the layer 1, the irradiation dose at each of the total of 100 spots is 10 for each divided irradiation, and as described above, one meandering scanning operation for each of the spot rows is repeated seven times. From the first-time through seventh-time scanning operations, the same irradiation order setting may be applied. Alternatively, however, in order to speed up an irradiation, for example, the second-time scanning may be performed from the left upper corner toward the left lower corner in FIG. 9 along the reverse route (the same shall apply hereinafter). Also, regarding the layer 2, as described with reference to FIG. 8, it is planned that the irradiation dose at each of the total of 100 spots is 8.3 for each divided irradiation, and it is planned that one meandering scanning operation as described above is repeated three times. FIG. 10 shows the setting of irradiation orders in both the layers 3 and 4 in a combined and simplified manner, although this is an example of the first-time and second-time scanning operations. As shown in FIG. 10, for each of the layers 1 and 2, 200 spots in total are set in a lattice shape of 10 rows and 20 columns. The application of an ion beam to the target (the rectangular region in FIG. 9) of the layers 3 and 4 is performed, as is the case with the layers 1 and 2, for example, in a manner as follows: an irradiation is performed on a spot-by-spot basis from one end (the left lower corner in FIG. 10) in the spot row (including twenty spots) situated at one end of these layers toward another end (the right lower corner in FIG. 10) in this spot row. After the irradiation to the other end has been completed, the irradiation is performed from one end (the right lower end in FIG. 10) in another spot row adjacent to the aforementioned spot row toward the other end (the left end in FIG. 10) of the other row. After the irradiation to the other end in the other row has been completed, the ion beam moves to a next other spot row adjacent. In this way, in this embodiment, also for each of the layers 3 and 4, it is planned that, in the horizontal surface, the ion beam is moved by causing the ion beam to meander for each of the adjacent spot rows, and that one irradiation operation (one of two scanning operations) with respect to the layers 3 and 4 is completed. In the layer 3, as shown in FIG. 8, the irradiation dose for each divided irradiation with respect to each of the total of 200 spots is 9 for each of the 100 spots in the right half region in FIG. 10, and 10 for each of the 100 spots in the left half region in FIG. 10. It is planned, therefore, that one scanning operation that meanders for each of the spot rows while changing an irradiation dose at a midpoint in a spot row, is repeated two times. Likewise, in the layer 4, the irradiation dose for each divided irradiation with respect of each of the total of 200 spots is 6.3 for each of the 100 spots in the right half region in FIG. 10, and 8.3 for each of the 100 spots in the right half region in FIG. 10. It is planned, therefore, that one scanning operation that meanders for each of the spot rows while changing an irradiation dose at a midpoint in a spot row, is repeated two times. Regarding each of the layers 3 and 4, in irradiations at the third time and afterward, the irradiation to the 100 spots in the right half in FIG. 10 do not need, and the irradiation to the 100 spots in the left half alone is performed (see FIG. 8). Regarding the irradiation order then, although it is not particularly illustrated, for example, performing like the layers 1 and 2 shown in FIG. 9 suffices for the layers 3 and 4. Regarding the layer 3, the irradiation dose with respect of each of its 100 spots is 10 for each divided irradiation, and it is planned that in the left half region alone, for example, one meandering scanning operation is performed five times (in the third-time to seventh-time scanning operations). Likewise, in the layer 4, the irradiation dose with respect of each of its 100 spots is 8.3 for each divided irradiation, and it is planned that in the left half region alone, for example, one meandering scanning operation is performed (in the third-time scanning). After the spot irradiation order has been determined as described above, the processing advances to step 132, where the dose distribution at a target area that is estimated when irradiations are performed with the irradiation dose with respect to all layers and all spots and in the spot irradiation order that were each determined as described above, is calculated using a known method. This simulation uses a method with higher accuracy and requiring a little longer calculation time than a simplified method as shown before in FIG. 6. Hereafter, the processing advances to step 133, where the estimated dose distribution result calculated in step 132 is outputted on the display unit as display signals, together with a planning result. The display then may be, for example, a summary including a dose volume histogram (DVH) or the like. Preferably, a comment about influences on normal organs, and others can be displayed together. If the operator determines that this display is insufficient (improper) upon watching this display, he/she does not input “OK”, and hence, the processing returns to step 107 based on the determination by step 134. Until the determination in step 134 becomes “YES”, the processing of steps 107 to 134 is repeated. If the operator determines that the created treatment planning information is proper, he/she inputs “OK”, thereby satisfying the determination in step 134. Thereafter, the operator performs a registration instruction input (via a button on the screen display or keyboard) to permit the registration in the treatment planning information, thereby satisfying the determination in step 135. Then, in a next step 136, the operator performs registration processing for the treatment planning information at the storage unit 110, thus completing the processing shown in FIG. 2. Next, the central control unit 100 reads the treatment planning information, in which divided irradiations are planned as described above and which has been stored in the storage unit 110, and stores it into the memory 103. The CPU 101 transmits, to the memory 41M of the scanning controller 41, the treatment planning information stored in the memory 103 (i.e., information such as the number of layers, the number of irradiation positions (the numbers of spots), the irradiation order with respect to irradiation positions in each of the layers, a target irradiation dose (set irradiation dose) at each irradiation position, and current values of the scanning electromagnets 5A and 5B with respect to all spots in each of the layers). The scanning controller 41 stores this treatment planning information into the memory 41M. Also, the CPU 101 transmits, to the accelerator controller 40, all data of acceleration parameters of the synchrotron 12 with respect to all layers out of the treatment planning information. The data of acceleration parameters includes the value of an exciting current for each of the electromagnets for the synchrotron 12 and beam transport system, and the value of high-frequency power to be applied to the high-frequency accelerating cavity, which are each determined by the energy of ion beam applied to each of the layers. The data of these acceleration parameters is classified, for example, into a plurality of acceleration patterns in advance. FIG. 11 shows a part of the treatment planning information stored in the memory 41M of the scanning controller 41. The part of the information comprises irradiation parameters, that is, information on the irradiation index number (layer number and irradiation number), information on the X-direction position (X-position) and the Y-direction position (Y-position) of an irradiation position (spot), and information on a target irradiation dose (irradiation dose) for each divided irradiation. Furthermore, the irradiation parameters includes layer change flag information. The information on the irradiation number, for example, “2-2” means a “second-time irradiation in the layer 2, “2-3” means a “third-time irradiation in the layer 2”, and “3-1” means a “first-time irradiation in the layer 3”. The information on a X-direction position and Y-direction position is represented by current values of the scanning electromagnets 5A and 5B for scanning an ion beam to the irradiation position specified by the pertinent X-position and Y-position. Spot numbers j (described later) are given, in the irradiation order, to all divided irradiations with respect to the layer 2, i.e., “2-1” (not shown), “2-2”, and “2-3”. Likewise, spot numbers are given to all divided irradiations with respect to the other layers 1, 3, and 4. Next, with reference to FIG. 12, specific descriptions will be made of respective controls by the scanning controller 41 and the accelerator controller 40 in performing the spot scanning in this embodiment. If an irradiation start instructing unit (not shown) disposed in the treatment room is operated, then in step 201, the accelerator controller 40 correspondingly initializes an operator i denoting a layer number to 1, as well as initializes an operator j denoting a spot number to 1, and outputs signals to that effect. Upon being subjected to the initialization in step 201, the accelerator controller 40 reads and sets the accelerator parameters with respect to the i-th layer (i=1 at this point in time) out of the acceleration parameters of a plurality of patterns stored in the memory, in step 202. Then, in step 203, the accelerator controller 40 outputs it to the synchrotron 12. Also, in step 203, the accelerator controller 40 outputs exiting current information with respect to the electromagnets that is included in the i-th accelerator parameters, to the power source for each of the electromagnets of the synchrotron 12 and beam transport system 5, and controls a pertinent power source so that each of the electromagnets is excited by a predetermined current using this exiting current information. Furthermore, in step 203, the accelerator controller 40 controls the high-frequency power source for applying a high-frequency power to the high-frequency cavity to increase the frequency up to a predetermined value. This allows the energy of an ion beam circulating through the synchrotron 12 to increase up to the energy determined by the treatment plan. Thereafter, the processing advances to step 204, where accelerator controller 40 outputs an extraction preparation command to the scanning controller 41. Upon receipt of the information on initial setting in step 201 and the extraction preparation command in step 204 from the accelerator controller 40, in step 205, the scanning controller 41 reads and sets current value data and irradiation dose data of the j-th spot (j=1 at this point in time) out of the current value data (data shown in the “X-position and Y-position” columns in FIG. 11) and the irradiation dose data (data shown in the “irradiation dose” column in FIG. 11), which are already stored in the memory 41M as described above (see FIG. 13 shown later). Similarly, regarding the aforementioned target count number stored in the memory 41M, the scanning controller 41 reads and sets data of the j-th spot (j=1 at this point in time) as well. Here, the scanning controller 41 controls a pertinent power so that the electromagnets 5A and 5B are excited by the current value of the j-th spot. After the preparation for the irradiation to the pertinent spot has been completed in this manner, the scanning controller 41 outputs a beam extraction start signal in step 300, and controls the high-frequency applying unit 9 to extract an ion beam from the synchrotron. Specifically, the open/close switch 92 is closed by the beam extraction start signal passing through the accelerator controller 40 and a high frequency is applied to the ion beam, whereby the ion beam is extracted. Because the electromagnets 5A and 5B are excited so that the ion beam reaches the first spot position, the ion beam is applied to the first spot in a pertinent layer by the beam delivery apparatus 15. When the irradiation dose at the first spot reaches a pertinent target irradiation dose, the scanning controller 41 outputs a beam extraction stop signal in step 300. The beam extraction stop signal passes through the accelerator controller 40 and opens the open/close switch 92, thereby stopping the extraction of the ion beam. At this point in time, only the first-time irradiation to the first spot in the layer 1 has been completed. Since the determination in step 208 is “No”, the processing advances to step 209, where 1 is added to the spot number j (i.e., the irradiation position is moved to the next spot adjacent). Then, the processing of steps 205, 300, and 208 are repeated. Specifically, until the irradiation to all spots in the layer 1 is completed, the irradiation (scanning irradiation) of ion beam is performed while moving the ion beam to adjacent spots one after another by the scanning electromagnets 5A and 5B and stopping the irradiation during movement. If all divided irradiations to all spots in the layer 1 (seven-time irradiations in the above-described example) have been completed, the determination in step 208 becomes “Yes”. At this time, the scanning controller 41 outputs a layer change command to the CPU of the accelerator controller 40. Upon receipt of the layer change command, the CPU of the accelerator controller 40 adds 1 to the layer number i (i.e., changes the object to be irradiated to the layer 2) in step 213, and outputs a remaining beam deceleration command to the synchrotron 12 in step 214. By the output of the remaining beam deceleration command, the accelerator controller 40 controls the power source for each of the electromagnets in the synchrotron 12 to gradually reduce the exciting current of each of the electromagnets until it becomes the predetermined current such as the current appropriate for the beam injection from the pre-stage accelerator. This decelerates an ion beam circulating through the synchrotron 12. As a result, the time period during which a beam can be extracted varies depending on the number of spots and irradiation dose. At the point in time, since only the irradiation with respect to the layer 1 has been completed, the determination in step 215 becomes “No”. In step 202, the accelerator parameters for the second layer (layer 2) is read from the memory for the accelerator controller 40 and is set. Hereinafter, the processing of steps 203 to 215 is performed with respect to the layer 2. Also, until all divided irradiations to all spots in the layer 4 is completed, the processing of steps 202 to 215 is performed. If the determination in step 215 becomes “Yes” (i.e., if predetermined irradiations to all spots in all layers in the target of a patient 30 have been completed), the CPU of the accelerator controller 40 outputs an irradiation end signal to the CPU 101. As described above, under the acceleration by the synchrotron 12, an ion beam extracted from the synchrotron 12 is transported through the beam transport system. Then, the ion beam is applied to the target of the pertinent patient in an optimum mode as planned by a treatment plan, via the beam delivery apparatus 15 in the treatment room in which the patient to be irradiated is present. At this time, a detection signal of the dose monitor 6A provided in the nozzle of the beam delivery apparatus 15 is inputted to the scanning controller 41. Other features of this embodiment are: by using this detection signal, (1) to clear the integrated value of irradiation doses simultaneously with a beam-off signal; (2) to determine the occurrence of an abnormal operation in accordance with an elapsed time after beam extraction is started; and (3) to determine the occurrence of an abnormal operation based on the comparison between the integrated value of irradiation doses and a predetermined regulated value. More detailed explanations thereof will be provided below with reference to FIGS. 13 to 18. FIG. 13 is a detailed functional block diagram showing the functional construction of the scanning controller 41. As shown in FIG. 13, the scanning controller 41 comprises a preset counter 41a, recording counter 41b, and maximum dose counter 41c as ones related to the detection of an irradiation dose, and for controlling these counters, comprises a preset counter control section 41A, recording counter control section 41B, and maximum dose counter control section 41C. Here, the dose monitor 6A is a known one, and of a type that outputs pulses in accordance with the amount of electrical charges ionized by the passage of beam. Specifically, the dose monitor 6A outputs one pulse for each predetermined minute charge amount. The preset counter 41a and recording counter 41b determine the irradiation dose by counting the number of pulses outputted from the dose monitor 6A. Besides the above-described preset counter 41a, the preset counter control section 41A includes a spot timer 41Aa, difference calculating section 41Ab, determination section 41Ac, OR circuits 41Ad and 41Ae. The preset counter 41a includes a pulse input section 41aa, set value input section 41ab, initialization (clear) signal input section 41ac, operation start (START) signal input section 41ad, count value reading section 41ae, and set value comparison result output section 41af. Besides the above-described recording counter 41b, the recording counter control section 41B includes a first delay timer 41Ba, second delay timer 41Bb, first register 41Bc, second register 41Bd, difference calculating section 41Be, determination section 41Bf, NOT circuit 41Bg, and OR circuit 41Bh. The recording counter 41b includes a pulse input section 41ba, initialization (clear) signal input section 41bc, operation start (START) signal input section 41bd, and count value reading section 41be. As described above, the maximum dose counter control section 41C has a maximum dose counter 41c, which includes a pulse input section 41ca, set value input section 41cb, initialization (clear) signal input section 41cc, operation start (START) signal input section 41cd, and set value comparison result output section 41cf. Furthermore, the scanning controller 41 has a memory 41M and beam extraction start/stop signal producing section 41S. FIG. 14 is a flowchart showing the detailed procedures in steps 205 and 300 in FIGS. 12 executed by the scanning controller 41 with the above features. As described above, the operator i is initialized to 1, and the operator j is initialized to 1, in advance. In step 301, the scanning controller 41 outputs a preset count setting command corresponding to the target count number of the preset counter 41a already stored in the memory 41M, to the preset counter set value input section 41ab of the preset counter control section 41A. In step 302, the scanning controller 41 sets a target count number at the first spot in the layer 1 in accordance with the aforementioned set command. Here, the “target count number” refers to a value corresponding to the target irradiation dose of a pertinent spot in a pertinent layer in the column “radiation dose” shown in FIG. 11. This target count number is calculated by the scanning controller 41 based on the above-described target irradiation dose, before the start of ion beam irradiation. The calculation of the target count number using the target irradiation dose may be performed immediately after the preset counter control section 41A receives the aforementioned set command, or alternatively may be performed before the central control unit 100 transmits data to the scanning controller 41 if the central control unit 100 performs the calculation. Likewise, at this time, the scanning controller 41 outputs a maximum spot or layer dose counter setting command corresponding to the target count number (maximum dose count number) of the maximum dose counter 41c stored in the memory 41M, to the maximum dose counter set value input section 41cb of the maximum dose counter control section 41C. More details thereof will be described later. Upon completion of step 301, the processing advances to step 303, where the scanning controller 41 outputs a current setting command with respect to the electromagnets 5A and 5B regarding a pertinent spot, i.e., current data corresponding to each of X-position and Y-position in FIG. 11, to the power source for the electromagnets 5A and 5B. The electromagnets 5A and 5B generate a deflection electromagnetic force with pertinent current values, and output a current setting completion signal indicating that such a state has been accomplished, to the scanning controller 41. In step 304, this current setting completion signal is inputted to the beam extraction start/stop signal producing section 41S. On the other hand, in the preset counter control section 41A, when the target count number is set in step 302 as described above, this set value is inputted not only to the aforementioned preset counter set value input section 41ab but also to the difference calculation section 41Ab. Furthermore, the count number counted at this point in time (i.e., the count number at setting) is read from the preset counter count value reading section 41ae, and this is also inputted to the difference calculation section 41Ab. The difference calculation section 41Ab calculates the difference between these values: (count number at setting)−(target count number), and inputs it to the determination section 41Ac. In step 302A, the determination section 41Ac determines whether this difference is negative, namely, whether the count value at setting is less than the target count number. If this determination is satisfied, the determination section 41Ac outputs a target count number setting OK signal to the beam extraction start/stop signal producing section 41S. In step 305, the scanning controller 41 outputs a beam extraction (radiation) start signal from the beam extraction start/stop signal producing section 41S on the conditions that the target count number setting OK signal from the determination section 41Ac of the preset counter control section 41A, the current setting command in step 303, and the current setting completion signal from the scanning electromagnets 5A and 5B have been inputted. The beam extraction start signal passes through the accelerator controller 40 and closes the open/close switch 92. An ion beam is extracted from the synchrotron 12, and the ion beam is applied to a pertinent spot (e.g., the first spot in the layer 1). Next, the processing advances to step 306, where the beam extraction start/stop signal producing section 41S outputs a timer start command signal for starting the spot timer 41Aa of the preset counter control section 41A. If the elapsed time after this start that is measured by the spot timer 41Aa becomes a predetermined set time or more, (namely, if the beam extraction is performed for a predetermined time or more without being reset, as described later), a time excess signal is issued in step 307. In step 308, on the conditions that the time exceed signal has occurred and the timer start command signal has been inputted, a first abnormality signal is outputted to the central control unit 100. Upon receipt of the first abnormality signal, the central control unit 100 performs a predetermined abnormality processing, for example, an immediate forced stop with respect to beam extraction from the synchrotron 12, and recording to that effect through the intermediary of the scanning controller 41 and accelerator controller 41 (or alternatively, not through the intermediary thereof). On the other hand, when a beam irradiation is started by the output of the beam extraction start signal in step 305, detection signal of the dose monitor 6A is converted into a train of dose pulses by a current-frequency converter (i.e., I-F converter; not shown), and thereafter they are inputted to the preset counter pulse input section 41aa, recording counter pulse input section 41ba, maximum dose counter pulse input section 41ca of the scanning controller 41. These counters 41a, 41b, and 41c simultaneously count the pulses. This count number represents the irradiation dose from the start of counting. If the count value based on the input pulses from the pulse input section 41aa becomes a value of no less than the set value of the target count number set in step 302, the preset counter 41a issues an irradiation dose excess signal in step 309. In step 310, on the conditions that the irradiation dose excess signal has occurred and the target count number set in step 302 has been inputted, the preset counter 41a outputs a trigger signal from the set value comparison result output section 41af. As a first reset signal, this trigger signal is inputted to the initialization (clear) signal input section 41ac and operation start (START) signal input section 41ad of the preset counter 41a via the OR circuits 41Ad and 41Ae, and in step 311, the count number of the preset counter 41a is reset to start recounting. In step 312, based on the above-described trigger signal, the beam extraction start/stop signal producing section 41S of the scanning controller 41 produces a beam extraction start/stop signal and outputs it to the accelerator controller 40. The beam extraction start/stop signal passes through the accelerator controller 40 and reaches the open/close switch 92. Substantially by the beam extraction start/stop signal, the scanning controller 41 controls the open/close switch 92 to open. This stops the extraction of the ion beam from the synchrotron 12, and stops application of the ion beam to a patient. With the stoppage of the irradiation, the beam extraction start/stop signal producing section 41S outputs a command signal to stop or reset the spot timer 431Aa in step 313. The recording counter control section 41B of the scanning controller 41 has a first and second delay timers 41Ba and 41Bb. In step 314, the above-described beam extraction start/stop signal outputted by the beam extraction start/stop signal producing section 41S is inputted as a command signal for starting the first delay timer 41Ba in the form of converting beam ON→OFF switching into OFF→ON switching via the NOT circuit 41Bg. If the elapsed time after this start becomes a predetermined set time (i.e., first delay time, corresponding to the “delay” in FIG. 16 shown later), a first time arrival signal is sent to the first register 41Bc of the recording counter control section 41B, in step 315. In step 316, on the conditions that the first time arrival signal and a first delay timer start command signal have been inputted, a recording counter reading signal is outputted from the first register 41Bc to the recording counter 41Bc, and the count value then is inputted from the recording counter count value reading section 41be to the first register 41Bc. While not shown in FIG. 14 for the sake of simplification, the above-described time arrival signal is inputted as a signal for starting the second delay timer 41Bb. As in the case of the first delay timer, if the elapsed time after the start becomes a predetermined set time (i.e., a second delay time), a second time arrival signal is sent to the second register 41Bd of the recording counter control section 41B. On the conditions that the second time arrival signal and second delay timer start command signal have been inputted, a recording counter reading signal is outputted from the second register 41Bd to the recording counter 41b, and the count value then is inputted from the recording counter count value reading section 41be to the second register 41Bd. The count values at the first and second registers 41Bc and 41Bd are inputted to the difference calculation section 41Be, and after the difference therebetween is calculated, the difference is inputted to the determination section 41Bf. In step 317, the determination section 41Bf of the recording counter control section 41B determines whether the recording count value is a normal value, i.e., whether the above-described difference is within a predetermined proper range, and if the determination section 41Bf determines that the difference is an abnormal value, it outputs a second abnormality signal to the central control unit 100 in step 318. Upon receipt of the second abnormality signal, the central control unit 100 executes the predetermined abnormality processing as described above. If it is determined that the difference is a normal value in step 317, the determination section 41Bf inputs a second reset signal for resetting the recording counter 41b to the initialization (clear) signal input section 41bc and operation start (START) signal input section 41bd of the recording counter 41b via the OR circuit 41Bb, and after the resetting, starts recounting in step 319. Also, the count value then is outputted as an actual dose record from the determination section 41Bf to the central control unit 100. Furthermore, in step 320, the determination section 41Bf outputs a third reset signal for resetting the maximum dose counter control section 41C to the initialization (clear) signal input section 41cc and operation start (START) signal input section 41cd of the maximum dose counter 41c via the OR circuit 41Bb. On the other hand, based on the third reset signal inputted to the initialization (clear) signal input section 41cc and operation start (START) signal input section 41cd, the maximum dose counter 41c clears the count value and then starts recounting in step 321. If the beam extraction start signal is outputted in step 305, the maximum dose counter 41c counts pulses as a detection signal of the dose monitor 6A inputted to the pulse input section 41ca of the maximum dose counter 41c. This counter number represents the irradiation dose from the start of counting. In this time, in step 323, the maximum dose counter 41c has set a target count number (maximum dose count number) in a pertinent spot to be irradiated, in accordance with a maximum dose counter setting command inputted to the set value input section 41cb in the above-described step 301. If the above-described integrated value of irradiation dose becomes a value of no less than the set value of the target maximum count number set in the above step 323, the maximum dose counter 41c produces a count excess signal in step 322. Then, in step 324, on the conditions that the set target maximum count number (step 323) and the count excess signal has been inputted, the maximum dose counter 41c outputs a third abnormality signal from the set value comparison result output section 41cf to the central control unit 100 in step 324. Upon receipt of the third abnormality signal, the central control unit 100 executes the above-described predetermined abnormality processing. The target maximum count number refers to an irradiation dose set so as to be a little larger than the largest target dose in respective target irradiation doses with respective to all irradiation positions (all spots) in a target. FIG. 15 is a timing chart showing a series of operations of the preset counter 41a and recording counter 41b as described above. According to the particle beam treatment system of this embodiment with the above-described features, the following effects are provided. (1) Resolution Enhancing Effect by Divided Irradiations In general, the position monitor 6B is of a type that accumulates electric charges ionized by the passage of an ion beam in a capacitor and that reads a voltage induced in the capacitor after the spot irradiation. The capacity of this capacitor is determined so as to permit the amount of ionized electric charges by the spot subjected to the maximum irradiation dose. Regarding this capacitor, as the capacity decreases, the output voltage increases and the signal-to-noise ratio becomes higher, thereby enhancing the position measurement resolution. Conversely, as the capacity increases, the resolution decreases. Accordingly, in this embodiment, in a treatment plan using the treatment planning unit 140, it is planned that the irradiation to each spot in a layer is performed by dividing it into a plurality of times of irradiations (for example, in the example shown in FIG. 7, irradiations are performed seven times in the layer 1, three times in the layer 2, two times in the layer 3, and two times in the layer 4). The central control unit 100, accelerator controller 40, and scanning controller 41 control the synchrotron 12 and beam delivery apparatus 15 by using treatment information obtained by the above treatment plan. By virtue of this feature, regarding an irradiation position subjected to too much irradiation dose by one-time ion beam irradiation, it is possible to perform a divided irradiation so as to reduce an irradiation dose for each divided irradiation. This allows the difference in irradiation dose between the irradiation position subjected to the maximum dose and that subjected to the minimum dose to be reduced, thereby leveling off irradiation dose. In the example in FIG. 7, the maximum radiation dose is 10 at the spots in the layer 1, while the minimum radiation dose is 6.3 at the spots in the layer 4. As a result, the capacity of the capacitor of the position monitor 6B can be correspondingly reduced to enhance the resolution. This makes it possible to further correctly detect an actual beam position during treatment. (2) High-Accuracy Irradiation Effect by Preset Counter Clear In this type of particle beam irradiation apparatus, in order to reduce the exposure of normal tissue to radiation to a minimum and perform a proper treatment with neither too much nor too little irradiation, there is usually provided an irradiation dose monitor for measuring the irradiation dose of ion beam. When performing irradiation to each spot, a target irradiation dose is set on a spot-by-spot basis. Once the integrated value of irradiation doses detected by the dose monitor has reached the target value, a beam extraction stop command signal (beam stop command) is outputted to the accelerator, and in response to it, the accelerator stops the extraction of charged particle beam. With typical accelerator such as a slow cycling synchrotron or a cyclotron, even if the beam stop command is inputted, strictly speaking, it is not impossible that some amount of response delay occurs rather than the output of the charged particle beam immediately stops. In view of the above problem, in this embodiment, once the irradiation dose detected by the dose monitor 6A and counted by the preset counter 41a has reached a predetermined value, i.e., a target value (see step 309), the preset counter control section 41A outputs a trigger signal for triggering the scanning controller 41 to output the beam extraction stop signal to the high-frequency applying unit 9 (see step 312), and in step 311, clears the integrated count number of the preset counter 41a to restart integration, without waiting for the actual stop of the beam from the accelerator. FIG. 16 is a time chart showing the operations at this time. As shown in FIG. 16, a response delay can occur between the outputting of the beam extraction stop signal and the actual stoppage of the ion beam extraction from the synchrotron 12. During this response delay, the irradiation dose of ion beam extracted from the synchrotron 12 is integrated after the aforementioned clearing. After the extraction of ion beam has been actually stopped, the irradiation position is changed to a next irradiation position (spot) by the processing in steps 209 and 205 (see FIG. 12), and in step 302, the target count number is changed (in FIG. 16, for example, a change from the condition 1 (the target irradiation dose to be applied to the spot situated at a position) to the condition 2 (the target irradiation dose to be applied to the next spot) is made). Here, the target count number is a count number corresponding to a target irradiation dose. In step 303, the scanning electromagnets 5A and 5B are subjected to control, and in 305, the extraction of ion beam from the synchrotron 12 is restarted. At this time, the irradiation dose at the aforementioned next spot after the beam has moved there is detected by the dose monitor 6A and integrated by the preset counter 41a, like the foregoing. The integration of count number then includes previously, as an initial value, the count number with respect to an immediately preceding spot during the time period of the response delay of the accelerator, and the irradiation dose at the spot subsequent to the aforementioned spot is added to this initial value (see the part “condition 2 setting” in FIG. 16). As a result, irradiating the above-described subsequent spot with ion beam extracted from the synchrotron 12 until a target irradiation dose is reached, means irradiating this spot with the irradiation dose obtained by subtracting the aforementioned initial value from the target irradiation dose at this spot (i.e., the irradiation dose shown in “condition 2” in FIG. 16). Once the irradiation dose at this spot after the movement has reached a target irradiation dose, the preset counter control section 40A outputs a trigger signal for triggering the scanning controller 41 to output the beam extraction stop signal to the high-frequency applying unit 9, and clears the count number of the preset counter 41a, like the foregoing. The irradiation dose during the time period of the response delay of the synchrotron 12 is added as an initial value in irradiating the spot after a further subsequent movement, and the same is repeated hereinafter. Because the scanning controller 41 performs the above-described control, when attempting to irradiate each spot, an ion beam is always applied to the spot until the target dose of the spot is reached, on the assumption that an irradiation dose for the time period during a response delay of the synchrotron 12 occurring at irradiation to a spot is a part of irradiation dose at a subsequent spot. If irradiation dose control is performed without giving consideration to the response delay, an excessive irradiation corresponding to response delay is performed. This raises the possibility that the irradiation dose becomes, e.g., 1.2 at all spots (the intended irradiation dose is represented by 1.0 as shown in FIG. 17). In contrast, in this embodiment, by performing the above-described control, an ion beam dose (nearly equals 1.0) substantially equal to the target irradiation dose set with respect to a pertinent spot can be applied to all spots except the first spot to be irradiated (i.e., the spot at the left end in FIG. 18) with high accuracy, without an excessive irradiation corresponding to a response delay. In this embodiment, based on the assumption that the irradiation dose corresponding to a response delay of the synchrotron 12 occurring when irradiating a pertinent spot is a part of the irradiation dose at a next spot, an ion beam is applied to the pertinent spot until the target dose at the pertinent spot is reached. However, the same effect can be obtained using the following methods (1) and (2), as well. (1) To output a trigger signal in step 310 based on the conditions that, in step 309 in the preset counter control section 41A, when, from the target irradiation dose at a spot, the irradiation dose corresponding to the response delay occurring when irradiating immediately preceding spot is subtracted, and further when from the remaining irradiation dose, the count number with respect to the spot during irradiation is subtracted, remaining irradiation dose has become zero, and that the set target count number has been inputted in step 302.(2) To set the irradiation dose obtained by, from the target irradiation dose on a spot, subtracting the irradiation dose corresponding to the response delay occurring at the time of irradiating immediately preceding spot, as the target count number set in step 302 in the preset counter control section 41A.(3) Safety Enhancing Effect by Spot Timer Since the dose monitor 6A is an machine, it is difficult to perfectly eliminate the possibility that the irradiation dose monitor causes a malfunction or failure. Also, since the target irradiation dose for each spot is usually a value transmitted from a data base or a value calculated based on the transmitted value, it is not impossible that an improper value is inputted at the stage of the transmission or the calculation. In light of the above, in this embodiment, the scanning controller 41 has a spot timer, and determines whether an abnormal operation has occurred in accordance with the elapsed time after an ion beam started to be extracted to one spot (see steps 306 and 307 in FIG. 14). If the elapsed time after the extraction start becomes no less than a predetermined time, the scanning controller 41 outputs an abnormality signal for indicating the occurrence of an abnormal operation (the first abnormality signal) in step 308. Therefore, even if the extraction time of the charged particle beam is likely to abnormally elongate due to a malfunction or an occurrence of failure of the dose monitor 6A, or improper input value, the extraction of ion beam can be stopped after a certain time has elapsed. This reliably prevents excessive irradiation to an affected part, and further improves the safety. (4) Safety Enhancing Effect by Maximum Dose Counter Regarding the function of stopping the output of ion beam when the irradiation dose detected by the dose monitor reaches the target value, it is not impossible that equipment associated with this function causes a malfunction or failure. Also, it is not impossible that an error occurs in the setting of irradiation data. In view of the above problems, in this embodiment, the maximum dose counter control section 41C in the scanning controller 41 determines whether any abnormal operation has occurred (see steps 322 and 323 in FIG. 14) in accordance with the magnitude relation between the count number detected by the dose monitor 6A and integrated by the maximum dose counter control section 41C and a predetermined regulated value. If the count number becomes no less than a predetermined regulated value, the scanning controller 41 outputs a third abnormality signal in step 324. Therefore, even if the ion beam does not readily to stop due to a malfunction or the like of the beam stopping function and the irradiation dose is likely to abnormally increase, the irradiation can be stopped at a certain upper limit irradiation dose, thereby reliably preventing an excessive irradiation to an affected part. This further enhances the safety. Also, even if a target irradiation dose abnormally increases due to a malfunction or the like of data communications when an operator directly manually makes a regulated value a set value using, e.g., a hard switch, and the charged particle beam does not readily stop due to a malfunction or the like of the beam stopping function and the irradiation dose is likely to abnormally increase, the irradiation can be stopped at a certain upper limit irradiation dose, thereby reliably preventing an excessive irradiation to an affected part. This further enhances the safety. (5) Deceleration Effect of Ion Beam Remained in Synchrotron at Completion of Irradiation to All Spot in Layer In the spot scanning irradiation according to the present invention, as the size of a target changes, the number of spots in a layer changes, and consequently, the time required to complete an irradiation to all spots in the layer changes. Regarding the allowable extraction period of synchrotron, if it is set to be long with a large target assumed, the irradiation to all layers takes much time to complete, thereby elongating the treatment time for a patient. In view of the above, in this embodiment, after the irradiation to all spots in a layer has been completed, the charged particle beam in the accelerator is decelerated, quickly outputs a remaining beam deceleration command, thereby decelerating ion beams in the synchrotron. This terminates the allowable extraction period of the synchrotron. As a result, the allowable extraction period is controlled to a requisite minimum, thereby making the treatment time with respect to a patient short. The above-described ion beam irradiation by spot scanning can be applied to a proton beam treatment system using a cyclotron serving as an accelerator. This proton beam treatment system will be explained with reference to FIG. 19. The proton beam treatment system according to this embodiment has a construction where, in the proton beam treatment system shown in FIG. 19, the synchrotron is changed to a cyclotron 12A, and an energy changing unit (a second element and a charged particle beam energy changing unit) 42 is newly added. A charged particle beam generating unit 1A has a cyclotron 12A, which accelerates ion beams of the fixed energy. The cyclotron 12A has an acceleration unit 10A. The charged particle beam energy changing unit 42 is installed to a beam transport system 4 in the vicinity of the cyclotron 12A. The energy changing unit 42 comprises a plurality of planar degraders (not shown) for passing ion beams therethrough to cause the ion beams to lose energy, bending electromagnets (not shown) for deflecting the ion beams, which have been reduced in energy, and an aperture (not shown) for cutting out a part of the ion beams after passing the bending electromagnets. The energy changing unit 42 further includes a plurality of energy adjusting plates having thicknesses different from each other for changing energy value. Ion beams are changed in energy value by passing through the degraders. The plurality of degraders are made different in thickness from each other in order to obtain a plurality of energy values. As in the case of the embodiment shown in FIG. 1, the CPU 101 in the central control unit 100 reads the treatment planning information (see FIG. 11) stored in the memory 103 from the storage unit 110, and causes the memory (not shown) in the scanning controller 41 to store it. The CPU 101 transmits to an accelerator controller 40A all of data of operational parameters concerning all layers out of the treatment planning information. Here, the data of operational parameters comprises degrader numbers and an exciting current value of each electromagnets in the beam transport system, which are determined by the energy of ion beams applied to each of the layers. The control by the scanning controller 41 during the spot scanning according to this embodiment is performed similarly to the control illustrated in FIGS. 12 and 14 in the embodiment shown in FIG. 1. The control by the accelerator controller 40A is the control by the accelerator controller 40 shown in FIG. 12 except for step 214. Therefore, the accelerator controller 40A executes step 215 after step 213. Here, out of the control by the accelerator controller 40A, the control specific to this embodiment will be chiefly explained. In step 202, the aforementioned data of operational parameters with respect to an i-th layer (e.g., the layer 1) is set. In step 203, the accelerator controller 40A outputs degrader numbers to the energy changing unit 42, and outputs each exciting current value to a respective one of electromagnet power sources in the beam transport system 4. Specifically, the accelerator controller 40A performs control to insert a predetermined degrader in the energy changing unit 42 into beam path 62 based on the degrader number, and based on each of the exciting current values control, it perform to cause corresponding electromagnet power sources to excite a respective one of electromagnets (first element) in the beam transport system 4. The entrance of ion beam into the cyclotron 12A is performed by an ion source 11A. The beam extraction start signal outputted from the scanning controller 41 in step 300, and more specifically in step 305 (see FIG. 14), is inputted to the power source for the ion source 11A through the accelerator controller 40A. Based on the beam extraction start signal, the scanning controller 41 activates the ion source 11A to apply ion beams to the cyclotron 12A. When the beam extraction start signal passes through the inside of the accelerator control unit 40A, the accelerator control unit 40A outputs a predetermined high-frequency power set value to the high-frequency power source (not shown) of the acceleration unit 10A. Then, the ion beam in the cyclotron 12 is accelerated to the predetermined energy and extracted from the cyclotron 12A through an extraction deflector 8. The energy of the ion beam is reduced to the set energy by the degrader provided in the beam path 62, and reaches the beam delivery apparatus 15 through the beam path 62. These ion beam is applied to the pertinent spot in a pertinent layer in the target region of a patient 30 by scanning of the scanning electromagnets 5A and 5B. When the irradiation dose measured by the dose monitor 6A reaches a target dose of the pertinent spot, the scanning controller 41 outputs a beam extraction stop signal in step 300, and specifically in step 312 (see FIG. 14). The beam extraction stop signal is inputted to the power source for the ion source 11A through the accelerator controller 40A. Based on the beam extraction stop signal, the scanning controller 41 performs control to stop the ion source 11A and stop the application of the ion beam to the cyclotron 12A. When the beam extraction start signal passes through the inside of the accelerator control unit 40A, the accelerator control unit 40A controls the high-frequency power source for the acceleration unit 10A to stop the application of a high-frequency power to the acceleration unit 10A. This terminates the irradiation of ion beam with respect to the pertinent spot. Hereinafter, the irradiation of ion beam with respect to a subsequent spot is performed in the same manner as in the embodiment shown in FIG. 1. According to this embodiment, the effects (1) to (4) produced in the embodiment shown in FIG. 1 can be achieved. As is evident from the foregoing, according to the present invention, the detection accuracy with respect to an actual irradiation dose during treatment using charged particle beams can be enhanced. Also, according to the present invention, the control accuracy with respect to irradiation dose of charged particle beams can be improved. Furthermore, according to the present invention, the excessive irradiation of charged particle beams due to a monitor abnormality, input error, or the like can be reliably prevented. Moreover, according to the present invention, the excessive irradiation of charged particle beams due to a malfunction of a beam stopping function, or the like can be reliably prevented. Besides, according to the present invention, the treatment time with respect to a patient can be reduced.
	summary
043953816	abstract	A confinement enclosure, notably for a nuclear reactor, of the type consisting of reinforced, possibly prestressed concrete, comprising in the body of the wall a drainage network consisting of tubular channels provided in the concrete, wherein the tubular channels of the drainage network, which may be grouped in sub-groups, are connected to a system of filters located inside the enclosure.
	summary
	abstract	A riser cone has a lower end sized to engage a cylindrical lower riser section of a nuclear reactor and an upper end sized to engage a cylindrical upper riser section of the nuclear reactor. The riser cone defines a compression sealing ring that is compressed between the lower riser section and the upper riser section in the assembled nuclear reactor. In some embodiments the riser cone comprises: a lower element defining the lower end of the riser cone; an upper element defining the upper end of the riser cone; and a compliance spring compressed between the lower element and the upper element. In some embodiments the riser cone comprises a frustoconical compression sealing ring accommodating a reduced diameter of the upper riser section as compared with the diameter of the lower riser section.
055240429	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an exit window for an X-ray lithography beamline, and more particularly, to a thin beryllium exit window having a shape and thickness such that it can withstand a pressure differential of at least 14.7 psi and has X-rays above and below a desired energy band substantially attenuated. 2. Description of the Prior Art Since the first planar transistor was fabricated in the late 1950's the number of transistors on integrated circuits have doubled every year. The driving force behind this growth has been the ever increasing demand for higher speed communication in ever increasing chip sizes. The continuously increasing production and resolution requirements for manufacturing semiconductor devices will lead to performing microlithographic operations on 8-10 inch diameter wafers producing lithographed lines with 0.25 micron resolution in the mid 1990s. To meet the demands, these operations should be performed at a high production rate level, i.e., 30 to 60 wafers per hour per beamline. Although electron beam and focused ion beam techniques can meet critical dimension requirements, their low production rates make them unsuitable for high rate production. X-ray lithography was successfully utilized in 1989 to demonstrate the fabrication of functional NMOS and CMOS circuits with fully scaled 0.5 micron ground rules. The utilization of an electron storage ring (ESR) as the X-ray source, with its highly collimated X-ray flux at high intensity levels that can be delivered to many ports, has the necessary properties to satisfy both resolution and production volume needs of the future. The major subunits of an ESR based X-ray lithography system (XLS) include a preaccelerator, beam transport line, electron storage ring (synchrotron), lithography beamlines and exposure stations (aligner/stepper), where the actual lithography takes place. The lithography beamline performs a specialized role in the lithography system in that it connects the source to the lithography station. One basic ESR XLS performance requirement is to support 0.25 micron resolution lithography with the given stepper. One of the resolution related optical parameters is the lithography exposure window. The elements that form the exposure window in the beamline and the stepper include mirrors, filters and an exit window. The function of the exit window is to separate the beamline from the stepper (lithography chamber) and contribute to the formation of the exposure window. The lithography beamline connects the synchrotron to the exposure chamber. The beamline operates at an ultra high vacuum (UHV) while the exposure chamber operates at atmospheric pressure. In order to ensure the vacuum integrity of the beamline, the exit window must be able to withstand this pressure differential. The window material must also be transmissive to a desirable beam energy. This means the exit window material must behave as a high pass filter by providing minimum attenuation in that portion of the spectrum which is required for lithography, i.e. 800-1800 eV range, and maximum cutoff in the low energy interval of radiation. This absorption can be minimized with properly selected window materials and optimized material thickness. Beryllium is one of the possible exit window materials. The ideal window will have minimum power absorption in the exposure spectrum range and, therefore, minimum thickness. However, this minimum thickness will not be able to withhold the 1 Kg/cm.sup.2 pressure differential. It is clear that the power transmission and the mechanical strength of the window are competing factors that must be optimized. One basic future production lithography requirement dictates the manufacture of larger chip sizes with horizontal and vertical dimensions of 50 mm by 25 mm or larger. This defines the area to be illuminated with X-rays. The most practical way currently known in the prior art is to generate a "flat" (a few mm in the vertical dimension) X-ray beam with the required width (50 mm or wider) and to scan this beam over the field or move the wafer relative to the beam. This scanning type exit window is slightly larger than the beam cross section and it is synchronously moved with the scanning beam. The scanning exit window can be comprised of a flat beryllium sheet 4 mm.times.60 mm and 18 microns thick and will withstand the required pressure differential as well as be transmissive to the desired beam energy. However, the scanning exit window is a complicated subsystem of the beamline and makes the fabrication of the beamline expensive and its operation difficult. In addition, scanning the beam introduces difficulties in the optics of the lithography beamline including mechanical movement that generates uncompensated vibration. Further disadvantages include fatigue of connecting bellows which may trigger a major vacuum accident, higher thermal density load requiring additional cooling and an additional control system is required. Thus, there is a need to develop a stationary exit window that meets the requirements of pressure differential and beam energy transmission. SUMMARY OF THE INVENTION The present invention is directed to an exit window for an X-ray lithography beamline having a shape and a thickness such that the exit window can withstand a pressure differential of at least 14.7 psi between the ultra high vacuum of the X-ray lithography beamline and the pressure within the exposure chamber. In addition, the shape and thickness of the exit window are optimized so that the window is transmissive to X-rays within a desired energy band, typically between 800 eV and 1800 eV. The present invention allows the exit window to have an opening which is approximately equal to an exposure field on a wafer in the exposure chamber. In contrast to prior art exit windows which require a scanning exit window, the present invention allows a stationary exit window to be utilized. The exit window of the present invention includes a frame for securely mounting the exit window. The frame has an opening that can be equal to the size of an exposure field on the wafer. The exit window is comprised of a thin material having a window section disposed within the opening of the frame and a peripheral section which is integral with the window section and extends within the frame. The window section is exposed to the X-ray beam emitted from the beamline and has a shape that is substantially concave along its width and substantially linear along its length. The window section tapers to a flat surface at a periphery of the opening. This shape and a desired thickness allow the exit window of the present invention to withstand a pressure differential of at least one atmosphere and allow a desired energy band of X-rays to pass through the exit window. The exit window is preferably formed of beryllium having a thickness between 16 and 25 microns. By utilizing an exit window having a cross section that can be equal to the exposure field on the wafer, a stationary exit window can be used, which has a main advantage in that no mechanical movement is required. Alternatively, the cross section of the window can be made slightly larger than the cross section of the X-ray emitted from the beamline, in which case, the exit window can be synchronously scanned with the X-ray beam. The frame consists of first and second members each having an opening that is preferably rectangular and approximately equal to the exposure field on the wafer. Each member is tube shaped having a rectangular side view and an integral rectangular shoulder at one end thereof. The peripheral section of the window at the periphery of the opening extends between the first and second frame members. The exit window and frame members are held in place by two pins located on opposite ends of the shoulders of the first and second frame members. A vacuum seal is disposed within the first frame member completely surrounding the opening and abutting a part of the thin material sandwiched between the first and second frame members. The present invention is also directed to a method of scanning the X-ray beam emitted from the beamline onto the exposure field of the wafer. The first step is to position a stationary exit window having an opening that is approximately equal to the exposure field between the beamline and the wafer. The exit window has a shape and thickness that can withstand a pressure differential of at least 14.7 psi and is transmissive to the desirable energy band. Next, a vacuum is created within the beamline such that there is a pressure differential of at least 14.7 psi between the beamline and an exposure chamber containing the wafer. The X-ray beam is scanned up and down between first and second positions such that the X-ray beam passes through the exit window and is scanned over the entire exposure field on the wafer. The X-ray beam as passed through the exit window has X-rays above and below a desire energy band substantially attenuated.
	description	Referring now to the drawing figures, particularly to FIG. 1, there is illustrated a representative example of a fuel assembly, generally designated 10. Fuel assembly 10 includes a plurality of nuclear fuel rods 12 forming a nuclear fuel bundle 14 disposed with a fuel channel 16. The rods 12 are connected at their upper ends to an upper tie plate 18 and are supported at their lower ends in a lower tie plate grid 20 forming part of a lower tie plate 22. Spacers 18 are arranged at a plurality of vertically spaced locations along the fuel bundle to maintain lateral spacing of the fuel rods 12 relative to one another. The lower tie plate includes an inlet nozzle 24 for receiving coolant water for transmission through the lower tie plate 22, the tie plate grid 20 and upwardly therefrom for flow about the fuel rods for generating steam. Referring now to FIG. 2, there is illustrated a fuel rod support structure 29 comprised of a lower tie plate 30 constructed in accordance with a preferred embodiment of the present invention. The lower tie plate 30 includes a nozzle 31 adjacent its lower end for receiving water for flow upwardly through a transition structure 33 and through a tie plate grid 32 and for flow about the fuel rods 12. The tie plate grid 32 as illustrated in FIG. 2 lies adjacent the upper end of the tie plate 30 and is comprised of an array of cylindrical bosses 34 which extend between upper and lower surfaces of the tie plate grid 32 for receiving the cylindrical end plugs of the nuclear fuel rods for supporting the latter, as described hereinafter. The bosses 34 are arranged in a rectilinear array, a 10xc3x9710 array being illustrated. The centerlines of the bosses 34 are arranged at corners of substantially square matrices thereof. Interconnecting and forming the sides of the square matrices are webs 36 joining the adjacent cylindrical bosses 34. As will be appreciated from a review of FIG. 2, the upper edges 38 of the webs are recessed below the upper cylindrical edges 40 of the bosses. With this configuration, it will be seen that the webs 36 have portions formed along the sides of each square matrix and, together with convex outer portions of the cylindrical bosses 34, define coolant flow openings 42. Thus, coolant flow openings 42 extend between the upper and lower surfaces of the grid for flowing coolant from the inlet nozzle of the lower tie plate through the grid and upwardly about the fuel rods supported on the lower tie plate 30. The debris-catching function is performed by a filter plate 44 carried by the lower tie plate 30. As illustrated in FIG. 2, the filter plate 44 includes a plurality of holes 46 arranged in an identical array relative to the holes 48 of the bosses 34. Consequently, when the filter plate 44 overlies the lower tie plate grid, the holes 46 register with holes 48 through bosses 34, affording a combined opening for receiving the lower end plugs of the fuel rods. Also, registering holes are provided in the filter plate and the grid to receive end plugs of water rods 47. Referring now to FIG. 4, there is illustrated an enlarged view of the filter plate 44. As illustrated the filter plate 44 includes a plurality of apertures 50 between the holes 46. In a preferred embodiment of the present invention, the filter plate comprises a stainless steel plate having a thickness of 0.048 inches with staggered apertures 50 having diameters of 0.0625 inches on 0.094-inch centers. The number of apertures 50 through the filter plate is in excess of ten and preferably in excess of fifteen for each hole 46 through said filter plate 44. The cross-sectional area of each hole 46 is at least fifteen times and preferably twenty times the cross-sectional area of each aperture 50. As illustrated, each aperture 50 has six surrounding apertures in a hexagonal array of apertures. To provide perspective, the filter plate is preferably about 5.070 inches on a side, having holes 46 of 0.0287 inches diameter. The apertures 50 provide about at least 30% open area through the plate, with approximately 132 holes per square inch. The diameters of the holes 46 through plate 44 correspond to the inner diameters of the bosses 34 such that, upon application of the filter plate 44 in overlying relation to the tie plate grid, the plate 44 is wholly supported by the edges 40 of the bosses. Consequently, the flow openings 42 between the bosses and webs lie in direct alignment with the apertures 50. Additionally, because the upper edges of the webs are recessed below the upper edges of the bosses and hence the underside of the filter plate 44, the flow area through the filter plate includes each aperture 50 except those overlying the edges 40 of the bosses. The edges 38 of the webs 36 do not block the vertically registering apertures. It will be appreciated that the fuel rods of the fuel bundle are of different types. For example, certain of the fuel rods comprise tie rods for securing the fuel bundle to the lower tie plate. Those fuel rods comprising tie rods have end plugs at their lower ends which are threaded for threaded engagement with complementary female threads within associated bosses. Thus, as illustrated in FIG. 5, end plugs 58 of tie rods 56 have threaded male projections 57 for threaded engagement with the complementary female threads 59 of the bosses in which the end plugs reside. Additionally, part-length fuel rods, where applicable also have threaded end plugs. Consequently, a certain number of additional selected holes through the bosses are complementary threaded for receiving the threaded end plugs. The remaining holes 48 in the bosses 34 have smooth sides. Thus, the remaining fuel rods 55 have end plugs 60 having end projections 62 with smooth side surfaces for slidable reception within correspondingly smooth-sided bores. It will be appreciated that the end plugs 58, 60 pass through the registering holes 46 of the filter plate for reception in the holes of the bosses. For those fuel rods having smooth-sided end plugs 60, the end plugs are received through the registering holes 46 and 48 of the plate and grid, respectively, with the tapered side surfaces 61 of the end plugs bearing against the margins of the holes through the filter plate 44. This engagement and the weight of the fuel rods holds the filter plate 44 down on and against the upper edges 40 of the bosses 34 of the lower tie plate grid. The tapered surfaces 63 of the end plugs 58 having the threaded male extensions 57, however, are spaced from the margins of the holes 46 through the filter plate 44. That is, there is a discrete gap between the end plugs and the margins defining the holes through the filter plates which receive the threaded end plugs. This affords a tolerance for securing the threaded end plugs in the female threaded bosses. Consequently, there is provided a debris-catching filter plate with substantial reduction in hole size as compared with debris catchers of the prior art for minimizing or eliminating failure of the fuel bundles resulting from debris collection. Moreover, the assembly of the present invention is readily manufacturable and assembled with the tie plate without requiring additional parts. The prior art debris catcher integrally cast with the tie plate is thus eliminated, together with its associated problems. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
045307830	abstract	A composition of matter suitable for solidifying radioactive wastes is formed of unsaturated polyester resins comprising a polyester (I) obtained polycondensing (a) maleic anhydride and/or maleic and/or fumaric acid, (b) isophthalic and/or terephthalic acid, (c) neopentylglycol, (d) optionally one or more conventional glycols, wherein the amount of (c) is at least 50% by moles with respect to (c)+(d); another polyester (II) obtained polycondensing (a) maleic anhydride and/or maleic and/or fumaric acid, (b) isopropylidene-bis-(phenylene-oxypropanol-2), (c) optionally one or more conventional glycols, wherein the amount of (b) is at least 50% by moles with respect to (b)+(c); an ethylenically unsaturated monomer (III) capable of copolymerizing with (I) and (II); inhibitors, initiators, accelerators, glass fibers and other conventional additives and fillers the weight ratio of component (I) to (II) being from 100:0 to 20:80.
	abstract	A method is disclosed for producing a comb-like collimator element for a collimator arrangement. In at least one embodiment of the method, a collimator sheet extending in a first direction and made of an X-ray absorbing material is used as a support, onto which webs made of an X-ray absorbing material are formed in layers by way of a rapid prototyping technique and protrude transversely in respect of the support in a second direction.
046702130	claims	1. An improved top nozzle on a fuel assembly for aligning said fuel assembly with an upper core plate of a nuclear reactor core, said fuel assembly having a plurality of guide thimbles with respective upper end portions and said upper core plate having a lower side and a plurality of holes defined therein which open at said lower side, said top nozzle, comprising: (a) lower means being stationarily supported on said upper end portions of said guide thimbles; (b) an upper hold-down plate having a plurality of passageways defined therethrough in a pattern which matches that of said guide thimbles, said upper hold-down plate being adapted to abut said lower side of said upper core plate; (c) a plurality of upstanding bosses having respective central bores defined therethrough, each of said upstanding bosses being disposed above said upper hold-down plate and rigidly attached thereto with its central bore aligned with a respective one of said passageways of said upper hold-down plate, said each upstanding boss also being of a cross-sectional size adapted to interfit within one of said holes in said upper core plate when said upper hold-down plate abuts said lower side of said upper core plate; (d) a plurality of elongated tubular members having lower and upper ends and being releasably connected at their respective lower ends to said upper end portions of said guide thimbles and inserted at their respective upper ends into said passageways of said upper hold-down plate for slidable movement within said passageways of said upper hold-down plate and said corresponding aligned bores of said upstanding bosses; (e) a plurality of yieldable members disposed between said lower means and upper hold-down plate and supporting said upper hold-down plate in a spaced relation above said lower means at a stationary position in which said upper hold-down plate abuts said upper core plate with said upstanding bosses interfitted within said holes of said upper core plate; and (f) means interconnecting said spaced lower means and upper hold-down plate so as to accommodate movement of said lower means toward and away from said upper hold-down plate upon axial movement of said guide thimbles of said fuel assembly toward and away from said upper core plate, said interconnecting means also being effective to limit movement of said lower means away from said upper hold-down plate to maintain said yieldable members in a state of compression therebetween, whereby concurrently as alignment of said fuel assembly with said upper core plate is achieved through abutting of said upper hold-down palte with said upper core plate and interfitting of said upstanding bosses within said upper core plate holes, axial movement of said fuel assembly relative to said upper core plate is accommodated, without incurring wear thereof, through movement of said lower means and said plurality of tubular members relative to said upper hold-down plate without relative sliding engagement of either of said upper hold-down plate, said plurality of upstanding bosses and said plurality of tubular members of said improved top nozzle with said upper core plate. at least one wall structure connected to said lower means and extending upwardly therefrom; and at least one lug connected to said upper hold-down plate and extending downwardly therefrom, each of said lugs being coupled to said wall structure so as to accommodate movement of said lower means toward and away from said upper hold-down plate upon axial movement of said guide thimbles of said fuel assembly toward and away from said upper core plate. means defining a generally vertical slot in one of said wall structure and said lug; and a pin mounted to the other of said wall structure and said lug and extending into said slot in the one thereof, said pin being slidably moved along said slot as said lower means is moved toward and away from said upper hold-down plate, said slot having upper and lower ends which define upper and lower limits of said movement of said pin along said slot and thereby of said lower means toward and away from said upper hold-down plate. said lower means includes a lower adapter plate with a plurality of openings defined therethrough in a pattern which matches that of said guide thimbles for receiving said upper end portions of said guide thimbles therethrough and extending above said adapter plate; and said elongated tubular members releasably connected at their respective lower ends to said upper end portions of said guide thimbles extending above said lower adapter plate. said interconnecting means includes a plurality of lugs attached to said upper hold-down plate and extending downwardly from the periphery thereof, each of said lugs being coupled to said upstanding sidewall of said enclosure so as to accommodate movement of said lower adapter plate toward and away from said upper hold-down plate upon axial movement of said guide thimbles of said fuel assembly toward and away from said upper core plate, said coupling of said lugs with said enclosure sidewall also being effective to limit movement of said lower adapter plate away from said upper hold-down plate to maintain said hold-down springs in a state of compression therebetween. means defining a plurality of generally vertical slots in said sidewall; and a plurality of pins each of which being mounted to one of said lugs and extending into one of said slots, said each pin being slidably moved along its respective slot as said lower adapter plate and sidewall are moved toward and away from said upper hold-down plate, said each slot having upper and lower ends which define upper and lower limts of said movement of said pin along said slot and thereby of said lower adapter plate toward and away from said upper hold-down plate. (a) an enclosure having a lower adapter plate with a plurality of openings defined therethrough in a pattern which matches that of said guide thimbles for receiving said upper ends of said guide thimbles therethrough and an upstanding sidewall surrounding the periphery of said adapter plate; (b) a plurality of lower retainers being attached to said respective guide thimbles below said lower adapter plate for limiting downward slidable movement of said adapter plate relative to said guide thimbles and supporting said adapter plate on said guide thimbles with said upper ends thereof extending above said adapter plate; (c) an upper hold-down plate having a plurality of passageways defined therethrough in a pattern which matches that of said openings of said adapter plate, said upper hold-down plate being adapted to abut said lower side of said upper core plate; (d) a plurality of upstanding bosses having respective central bores, each of said bosses being disposed above said upper hold-down plate and attached thereto such that its central bore is aligned with a respective one of said passageways of said upper hold-down plate, said each boss being of a crosssectional size adapted to interfit within one of said holes in said upper core plate when said upper hold-down plate abuts said lower side of said upper core plate; (e) a plurality of elongated sleeves having upper and lower ends, said sleeves extending between said upper hold-down plate and lower adapter plate and being slidably inserted at their respective upper ends into said passageways of said upper hold-down plate and said corresponding aligned bores of said upstanding bosses and releasably connected at their respective lower ends to said upper ends of said guide thimbles so as to cooperate with said lower retainers in holding said lower adapter plate at a stationary position on said guide thimbles; (f) a plurality of hold-down springs disposed within said enclosure and about said respective elongated sleeves, said springs extending between said lower adapter plate and upper hold-down plate and supporting said upper hold-down plate in a spaced relation above said lower adapter plate at a stationary position in which said upper hold-down plate abuts said upper core plate with said upstanding bosses interfitted within said holes of said upper core plate, said sidewall of said enclosure substantially surrounding said springs so as to protect them from impingement by coolant cross-flow within said reactor core; and (g) a plurality of lugs attached to said upper hold-down plate and extending downwardly from the periphery thereof, each of said lugs being coupled to said upstanding sidewall of said enclosure so as to accommodate movement of said lower adapter plate toward and away from said upper hold-down plate upon axial movement of said guide thimbles of said fuel assembly toward and away from said upper core plate, said coupling of said lugs with said enclosure sidewall also being effective to limit movement of said lower adapter plate away from said upper hold-down plate to maintain said hold-down springs in a state of compression therebetween, whereby concurrently as alignment of said fuel assembly with said upper core plate is achieved through abutting of said upper hold-down plate against said lower side of said upper core plate and interfitting of said bosses within said upper core plate holes, axial movement of said fuel assembly relative to said upper core plate is accommodated, without incurring wear thereof, through movement of said enclosure and said plurality of elongated sleeves relative to said upper hold-down plate without relative sliding engagement of either of said upper hold-down plate, said plurality of upstanding bosses and said plurality of elongated sleeves of said improved top nozzle with said upper core plate. 2. The improved top nozzle as recited in claim 1, wherein said interconnecting means includes: 3. The improved top nozzle as recited in claim 2, wherein said interconnecting means further includes: 4. The improved top nozzle as recited in claim 3, wherein said pin is removable to aid in assembling said top nozzle. 5. The improved top nozzle as recited in claim 1, wherein: 6. The improved top nozzle as recited in claim 5, wherein each of said lower ends of said respective tubular members is internally threaded for releasable threaded connection to an externally threaded section on each of said upper end portions of said respective guide thimbles. 7. The improved top nozzle as recited in claim 5, wherein each of said tubular members has a lower portion of a cross-sectional size greater than an upper portion thereof and greater than the size of said passageway in said upper hold-down plate such that said tubular member remains captured between said upper hold-down plate and lower means when released from its connection with said respective one guide thimble. 8. The improved top nozzle as recited in claim 1, wherein said upper hold-down plate is composed of an array of hubs and ligaments extending between and interconnecting said hubs, each of said hubs having one of said passageways defined therethrough. 9. The improved top nozzle as recited in claim 8, wherein said interconnecting means includes at least one lug connected to each of at least several of said hubs and extending downwardly therefrom. 10. The improved top nozzle as recited in claim 8, wherein said interconnecting means includes at least one lug connected to each of at least several of said ligaments and extending downwardly therefrom. 11. The improved top nozzle as recited in claim 8, wherein said each upstanding boss is disposed above and connected to each of at least several of said hubs of said upper hold-down plate with said bore of said boss aligned with said passageway of said hub. 12. The improved top nozzle as recited in claim 1, wherein said each upstanding boss has an upper chamfered edge for mating thereof with a chamfered edge on said lower side of said upper core plate at the entrance to each of said holes defined in said lower side of said upper core plate so as to facilitate alignment and insertion of said each boss into one of said upper core plate holes. 13. The improved top nozzle as recited in claim 1, wherein said lower means includes an enclosure having a lower adapter plate and an upstanding sidewall surrounding the periphery of said lower adapter plate, said sidewall of said enclosure substantially surrounding said yieldable members so as to protect them from impingement by coolant cross-flow within said reactor core. 14. The improved top nozzle as recited in claim 13, wherein 15. The improved top nozzle as recited in claim 14, wherein said interconnecting means further includes: 16. An improved top nozzle on a fuel assembly for aligning said fuel assembly with an upper core plate of a nuclear reactor core, said fuel assembly having a plurality of guide thimbles with respective upper ends and said upper core plate having a lower side and a plurality of holes defined therein which open at said lower side, said top nozzle comprising: 17. The improved top nozzle as recited in claim 16, wherein each of said lower ends of said respective tubular sleeves is internally threaded for releasable threaded connection to an externally threaded section on each of said upper ends of said respective guide thimbles. 18. The improved top nozzle as recited in claim 16, wherein each of said tubular sleeves has a lower portion of a cross-sectional size greater than an upper portion thereof and greater than the size of said passageway in said upper hold-down plate such that said tubular sleeve remains captured between said upper hold-down plate and lower adapter plate when released from its connection with said respective one guide thimble. 19. The improved top nozzle as recited in claim 16, wherein said upper hold-down plate is composed of an array of hubs and ligaments extending between and interconnecting said hubs, each of said hubs having one of said passageways defined therethrough. 20. The improved top nozzle as recited in claim 19, wherein at least one of said lugs is connected to each of at least several of said hubs and extends downwardly therefrom. 21. The improved top nozzle as recited in claim 19, wherein at least one of said lugs is connected to each of at least several of said ligaments and extends downwardly therefrom. 22. The improved top nozzle as recited in claim 19, wherein said each upstanding boss is disposed above and connected to each of at least several of said hubs of said upper hold-down plate with said bore of said boss aligned with said passageway of said hub. 23. The improved top nozzle as recited in claim 16, wherein said each upstanding boss has an upper chamfered edge for mating thereof with a chamfered edge on said lower side of said upper core plate at the entrance to each of said holes defined in said lower side of said upper core plate so as to facilitate alignment and insertion of said each boss into one of said upper core plate holes.
	claims	1. An X-ray arrangement for obtaining quantitative X-ray images from a sample, comprising:a) an X-ray source;b) a set of at least two gratings;c) a position-sensitive detector with spatially modulated detection sensitivity having a plurality of individual pixels;d) a recorder connected to said detector for recording images of said detector;e) evaluation means for evaluating respective intensities for each pixel in a series of images in order to identify a characteristic of the object for each individual pixel as one or more of an absorption-dominated pixel or a differential phase contrast dominated pixel or an x-ray scattering dominated pixel;f) wherein the series of images is collected by continuously or stepwise rotating from 0 to π or 2π either the sample or the X-ray source relative to the sample;g) said set of gratings, or part of said gratings being manufactured with planar geometry where the X-rays pass through said gratings parallel to the substrate;h) said grating structures extending along an x-ray path which determines the phase shift and attenuation that said grating structures cause to the x-rays, not being given by the thickness of said structures, but by a length of said grating structures; andi) wherein a combination of said grating structures of said set of gratings are fabricated on a single substrate. 2. The arrangement according to claim 1, configured to be operated either in a “near field regime” or in a “Talbot-regime.” 3. The arrangement according to claim 1, wherein at least one of said gratings is a line grating forming an absorption grating or a phase grating. 4. The arrangement according to claim 1, wherein at least one of said gratings is a low absorption grating configured for generating an X-ray phase shift of it or odd multiples thereof. 5. The arrangement according to claim 3, wherein said gratings include a first grating (G1) and a second grating (G2), with the second grating being a line grating having a relatively high X-ray absorption contrast and a period corresponding to a self image of G1, and wherein G2 is placed closely in front of said detector with the lines of G2 parallel to those of G1. 6. The arrangement according to claim 1, wherein:for near-field-regime operation, a distance between said at least two gratings is chosen within the near-field regime; andfor Talbot-regime operation the distance is chosen according to D n , sph = L · D n L - D n = L · N · p 1 2 / 2 ⁢ η 2 ⁢ λ L - N · p 1 2 / 2 ⁢ η 2 ⁢ λ where n=1, 3, 5 . . . , and η = { 1 if ⁢ ⁢ the ⁢ ⁢ phase ⁢ ⁢ shift ⁢ ⁢ of ⁢ ⁢ G 1 ⁢ ⁢ is ⁢ ⁢ ( 2 ⁢ l - 1 ) ⁢ π 2 , p 2 = L + D n , sph L ⁢ p 1 2 if ⁢ ⁢ the ⁢ ⁢ phase ⁢ ⁢ shift ⁢ ⁢ of ⁢ ⁢ G 1 ⁢ ⁢ is ⁢ ⁢ ( 2 ⁢ l - 1 ) ⁢ π , p 2 = L + D n , sph L ⁢ p 1 2 where l=1, 2, 3, Dn is an odd fractional Talbot distance when the parallel X-ray beam is used, while Dn,sph is that when a fan or cone X-ray beam is used, L is a distance between the source and a grating G1. 7. The arrangement according to claim 1, wherein said grating structure is manufactured by planar technology. 8. The arrangement according to claim 1, wherein said grating structures are selected from the group consisting of absorption gratings and phase shift gratings and either or both are produced by a planar technology process. 9. The arrangement according to claim 1, wherein said line detector is fabricated on a common substrate with a second grating or on a common substrate with a first grating and a second grating. 10. The arrangement according to claim 1, wherein a geometry of said grating structure is adapted to a divergence of the X-ray beam. 11. The arrangement according to claim 1, wherein a multiplicity of structures obtained with planar fabrication techniques are stacked face-to-face on top of one another. 12. The arrangement according to claim 1, wherein multiple grating structures are stacked on-top of each other with mechanical or optical alignment. 13. The arrangement according to claim 12, wherein multiple grating structures are aligned by way of lithographically defined notches and grooves. 14. The arrangement according to claim 1, which comprises a collimator placed between said source and a first grating (G1) to limit a spatial extent of the illuminating X-rays to a fan beam, and wherein said detector is a line-array detector, and which further comprises a mechanism for rotating the sample, stepwise or continuously, relative to the apparatus, wherein a rotational axis of the rotation is perpendicular to an opening angle of the fan, and said mechanism is enabled to translate the sample, stepwise or continuously, relative to the apparatus along a direction parallel to the rotational axis. 15. The arrangement according to claim 1, which comprises a slit or a series of n slits disposed upstream of the object, in a beam direction, to minimize dose delivery to the object. 16. The arrangement according to claim 15, wherein said slit or series of n slits is integrated in a grating assembly with a first grating or a grating assembly with a second grating. 17. The arrangement according to claim 1, wherein phase stepping is effected by a mechanical shift of one of said gratings with respect to other said gratings. 18. The arrangement according to claim 1, wherein a phase relation between grating structures G1 and G2 corresponds exactly to a value for which an intensity curve can be expanded by a first order Taylor series. 19. An X-ray arrangement for obtaining quantitative X-ray images from a sample, comprising:a) an X-ray source;b) a set of at least two gratings;c) a position-sensitive detector with spatially modulated detection sensitivity having a plurality of individual pixels;d) a recorder connected to said detector for recording images of said detector;e) evaluation means for evaluating respective intensities for each pixel in a series of images in order to identify a characteristic of the object for each individual pixel as one or more of an absorption-dominated pixel or a differential phase contrast dominated pixel or an x-ray scattering dominated pixel;f) wherein the series of images is collected by continuously or stepwise rotating from 0 to π or 2π either the sample or the X-ray source relative to the sample;g) said set of gratings, or part of said gratings being manufactured with planar geometry where the X-rays pass through said gratings parallel to the substrate;h) said grating structures extending along the x-ray path which determines the phase shift and attenuation that said grating structures cause to the x-rays being given by a length of said grating structures;i) wherein phase stepping is effected by a mechanical shift of one of said gratings with respect to other said gratings; andj) wherein a first grating is stepped and second and third gratings are physically located on a common substrate and a phase relation between the second and third gratings is encoded within the planar structures. 20. An X-ray arrangement for obtaining quantitative X-ray images from a sample, comprising:a) an X-ray source;b) a set of at least two gratings;c) a position-sensitive detector with spatially modulated detection sensitivity having a plurality of individual pixels;d) a recorder connected to said detector for recording images of said detector;e) evaluation means for evaluating respective intensities for each pixel in a series of images in order to identify a characteristic of the object for each individual pixel as one or more of an absorption-dominated pixel or a differential phase contrast dominated pixel or an x-ray scattering dominated pixel;f) wherein the series of images is collected by continuously or stepwise rotating from 0 to π or 2π either the sample or the X-ray source relative to the sample;g) said set of gratings, or part of said gratings being manufactured with planar geometry where the X-rays pass through said gratings parallel to the substrate;h) said grating structures extending along the x-ray path which determines the phase shift and attenuation that said grating structures cause to the x-rays is given by a length of said grating structures; andi) wherein a set of n phase steps is obtained by using n sets of planar grating and n line detectors; each of the n sets being aligned with a different phase-stepping position, and wherein the object is scanned in n phase-step positions without moving any mechanical parts and only the object.
056278667	description	BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 is a cross-section of a fuel assembly for a boiling water nuclear reactor in accordance with the present invention. The fuel assembly 10 includes a plurality of fuel rods 12, a pair of coolant rods 14 (two coolant rods 14 are illustrated and described in the preferred embodiment, however, a single coolant rod is often used in such fuel assemblies), and a channel 16 surrounding the fuel rods 12 and coolant rods 14. The fuel rods 12 are preferably arranged in a 10.times.10 matrix and are secured against lateral movement in the channel by a plurality of spacers 18. The coolant rods 14 are generally centrally disposed in the fuel rod matrix. Small holes are provided at both the lower and upper ends of the coolant rods 14 allowing water to be driven through the rod, thus introducing moderating material within the fuel rod matrix. One water rod also serves as the spacer-capture rod being mechanically locked to each of the spacers 18, thereby fixing the axial position of each spacer 18. The fuel rod spacers 18 are equipped with InconeI-X springs to maintain rod to rod spacing. The fuel rods 12 and the coolant rods 14 are supported by a lower tie plate 20. An upper tie plate 22 receives the fuel rods 12 and the coolant rods 14 and restricts lateral movement. End plugs of the fuel rods have pins that fit into anchor holes in the tie plates 20, 22. An expansion space located over the top end plug of each fuel rod allows them to expand axially by sliding within the holes in the upper tie plate to accommodate differential axial thermal expansion. In contrast with the conventional structure, none of the fuel rods is threaded into the lower tie plate 20 or the upper tie plate 22. One or both of the coolant rods 14 may be securely threaded into the lower tie plate 20. As discussed above in connection with the prior art, it is not desirable to thread anything into the tie plates 20, 22 as the threads tend to seize over extended submersion times. In contrast with the fuel rods 12, however, the coolant rods 14 need not be removed from the bundle nearly as frequently as the fuel rods 12. Thus, in the present invention, the coolant rods 14 are threaded or otherwise securely attached to one or both of the tie plates 20, 22. A transition member 24 supports the lower tie plate 20 in the channel 16 and serves as a transition to the nose piece 26. The channel 16 is secured to the transition member 24 by any suitable structure. In the illustrated embodiment, a bolt 28 is threaded through the channel and into the transition member 24. Four bolts 28 are preferably threaded one each through each side of the substantially square cross-section of the channel 16. The transition member 24 has corresponding threaded bolt receiving holes 30 in each side of its corresponding square cross-section. The bolts 28 are preferably formed of alloy X-750. Integral with the upper tie plate :22 is a bail handle assembly 32. Referring to FIGS. 1 and 2, the bail handle assembly 32 includes a bail handle 33 and two boss members 34. FIG. 3 is a cross-section through line III--111 in FIG. 2. The boss members 34 include a channel 36 formed therein. A latch pin 38 is movably disposed in the channel 36. A latch pin cap 40 is fixed to an outer end of the latch pin 38 and has a first outermost diameter that is configured to be extendible through a latch pin aperture 42 in the channel 16 and a second innermost diameter that is larger than the latch pin aperture 42 in the channel 16 and that serves as a stop surface for the latch pin 38. An inside surface of the latch pin cap 40 delimits the channel 36 in the boss members 34. A spring 44 is disposed around the latch pin 38 in the channel 36 between the inside surface of the latch pin cap 40 and an end of the channel 36. The spring 44 urges the latch pin 38 to an extended position, engaging the latch pin aperture 42 in the channel 16. In operation, because the transition member 24 is rigidly secured to the channel 16 by means of the bolt 28 and because the latch pin 38 is inserted into the latch pin aperture 42 in the channel 16, when lifting the fuel assembly 10 with the bail handle assembly 32, the channel 16 bears the structural load of the fuel assembly 10. As noted above, the channel 16 has the highest volume to surface area of the components in the fuel assembly 10 and better avoids the effects of corrosion. With continued reference to FIG. 3, a bolt 43 is disposed between the water rods 14 in an aperture 45 in the upper tie plate 22. The bolt 43 extends into a channel 47. A substantially cylindrical member 51 is fixed to the end of the bolt 43 and delimits the channel 47. A spring 53 is disposed surrounding the bolt 43 in the space delimited by the cylindrical member 51 and the top of the channel 47. The spring 53 serves to maintain the upper tie plate 22 spaced from the water rod main spring supports 55 as illustrated in FIG. 3. Moreover, the spring 53 urges the upper tie plate 22 upward such that the latch pins engage an upper end of the latch pin apertures 42. Still further, preload forces of the water rod main springs are diverted from the upper tie plate 22. FIG. 4 is a cross sectional view through line IV--IV in FIG. 1. Through the channel 16 adjacent the transition member 24 are provided a plurality of end gussets or clips 48 that are attached to the channel 16 and that are inserted into corresponding slots 49 in the transition member 24. The clips 48 serve as a backup support for the assembly in the event that the bolts 28 fail. In a preferred embodiment, four end clips 48 are provided, one each attached to each corner of the channel 16. The end clips 48 are preferably welded to the channel. FIG. 5 illustrates a channel guide 50 according to the present invention. The channel guide 50 includes two channel guide arms 52 disposed substantially at 90.degree.. A center plate 54 is disposed substantially between the arms 52. The center plate 54 consists of a gusset having a threaded, aperture 56 therein. The channel guide 50 is configured to surround the channel 16 and is mounted by the aperture 56 in the center plate 54 to a corner post 35 of the upper tie plate 22 with a bolt 66. The corner post 35 is integral with the upper tie plate 22. The bolt 66 securing the channel guide 50 to the corner post 35 of the upper tie plate 22 is illustrated in FIG. 7. Referring to FIG. 6, two spring leaves 58 are disposed in the vicinity of the center plate 54 and are adapted to support the channel guide 50 along the channel 16. At an end of each of the arms 52 is provided a leg 60 configured to extend in the same direction along the channel 16 as the spring leaves 58. An ear 62 protrudes from each leg 60 toward the channel 16. Referring to FIG. 1, the channel also includes ear apertures 64 configured to receive the ears 62. The ear apertures 64 are sized slightly larger than the ears 62 both in the longitudinal direction and the axial direction to enable the ears 62 to be freely inserted into and removed from the ear apertures 64 and to accommodate differential axial thermal expansion. The ears 62 and ear apertures 64 thus provide a redundant support between the upper tie rod 22 and the channel 16 in the event that the spring loaded latch pins 38 fail. If it is desired to remove the upper tie plate from the assembly, the bolt 66 is removed from the corner post 35 of the upper tie plate 22, and the channel guide 50 is removed. The latch pins 38 are then compressed against the force of springs 44, either manually or using a tool, and the tie plate is lifted from the assembly using the bail handle 33. The fuel bundle can then be removed from the channel 16 by attaching a known grapple head to the coolant rod ends, which are specially shaped to facilitate an attachment tool. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
	claims	1. In an ion implantation apparatus including a source of charged particles for an ion beam, and for implantation of charged particles in the ion beam into a workpiece,the improvement comprising:first and second multicoil arrangements, wherein each said multicoil arrangement comprises a longitudinally extending ferromagnetic bar, and a plurality of first coil units wound independently and positioned adjacently on said bar;a pair of second coil units, said second coil units being wound independently and one of said pair of second coil units being positioned adjacent each end of a said bar;controllable power supplies for passing electrical current independently through each adjacently positioned coil unit on each of said longitudinally-extending bars of said first and second multicoil arrangements, whereby (a) each adjacently positioned coil unit becomes excited, (b) each excited coil unit independently generates a magnetic field extending orthogonally between said longitudinally-extending bars, (c) a plurality of said magnetic fields generated by said coils together form a magnetic field orthogonally extending between said first and second multicoil arrangements, and (d) the magnetic field generated by each of said coils be individually altered;electrical connections for passing electrical current independently through each of said second coil units adjacent an end of a said bar whereby said second coil units become excited and generate an orthogonally extending magnetic field adjacent each end of a said bar;an opening at least partially bounded by said multicoil arrangements for applying the magnetic field generated by said plurality of coils to an ion beam traveling therethrough. 2. The ion implantation apparatus as recited by claim 1 further comprising a collimator. 3. The ion implantation apparatus as recited by claim 1 wherein said independently wound and adjacently positioned coil units on a said bar are between nine and twenty-three in number. 4. The ion implantation apparatus as recited in claim 2 further comprising: power supplies for supplying an electric current independently to each coil unit on said first multicoil arrangement. 5. The ion implantation apparatus as recited in claim 1 further comprising power supplies for superimposing a constant electric current in a same direction to all said coil units on said multicoil arrangements sufficient to deflect a ribbon ion beam in a measurable degree. 6. The ion implantation apparatus as recited in claim 1 further comprising: a wrapping wound over the linear length of each said bar; and means of applying an identical current in the same orientation to each said wrapping effective to generate a constant magnetic field over the linear length of each longitudinally-extending bar and deflect a ribbon ion beam in a measurable degree. 7. In an apparatus for implanting charged particles in an ion ribbon beam into a workpiece,the improvement of a beam corrector comprising:upper and lower multicoil arrangements positioned to be on opposite sides of and extending a width of the ribbon beam, wherein each said multicoil arrangement comprises (i) a ferromagnetic bar having a long dimension, and (ii) a plurality of independently excitable coils positioned on said bar, controllable power supplies for independently exciting said plurality of independently excitable coils of said upper and lower multicoil arrangements such that each excited coil generates a magnetic field between said upper and lower ferromagnetic core members;whereby a plurality of adjacent magnetic fields generated by a plurality of excited coils form a magnetic field between said upper and lower multicoil arrangements, and whereby the magnetic field generated by each of said independently excitable coils can be individually altered;a pair of independently wound further coils positioned with one of the pair of further coils positioned adjacent each end of a said bar, the further coils being arranged such that the current through them is adjustable and the further coils being positioned on a said bar or on a further magnetic member extending between said bars;a channel bounded at least in part by said multicoil arrangements for applying the magnetic field to an ion beam traveling therethrough. 8. The ion implantation apparatus as recited by claim 7 wherein said independently wound and adjacently positioned coils on said ferromagnetic bar are between nine and twenty-three. 9. The ion implantation apparatus as recited by claim 7 wherein the number of said wire coils wound independently and positioned adjacently at pre-chosen sites on said ferromagnetic bar is nine, sixteen or twenty-three. 10. The ion implantation apparatus as recited by claim 7 wherein three independent winding sections are on each ferromagnetic core bar, and each winding section comprises at least two individually excited coils. 11. The ion implantation apparatus as recited by claim 7 further comprising: electrical apparatus for supplying a programmable electric current independently to each coil on said first ferromagnetic bar; and electrical apparatus for supplying an equal and opposite current independently to each coil deflector on said second ferromagnetic bar. 12. The ion implantation apparatus as recited in claim 7 further comprising electrical apparatus for superimposing a constant electric current in a same direction to all said coils sufficient to deflect a scanned ion beam. 13. The ion implantation apparatus as recited in claim 7 further comprising: a tubing around each said ferromagnetic bar; and means of applying a current in the same orientation to each said bar to generate a magnetic field over a linear length of each bar sufficient to deflect the ion beam. 14. The ion implantation apparatus as recited by claim 1 wherein said second coil units are positioned on a said bar. 15. The ion implantation apparatus as recited by claim 1 wherein each of said second coil units is positioned on a ferromagnetic member extending generally between said bars. 16. A method for adjusting and controlling the uniformity of charged particles in an ion beam, said method comprising the steps of:obtaining an ion implantation apparatus comprisinga source of charged particles for an ion beam,first and second multicoil arrangements, wherein each said multicoil arrangement comprises a longitudinally extending ferromagnetic bar, and a plurality of first coil units wound independently and positioned adjacently on said bar;a pair of second coil units, said second coil units being wound independently and one of said pair of second coil units being positioned adjacent each end of a said bar;controllable power supplies for passing electrical current independently through each adjacently positioned coil unit on each of said longitudinally-extending bars of said first and second multicoil arrangements, whereby (a) each adjacently positioned coil unit becomes excited, (b) each excited coil unit independently generates a magnetic field extending orthogonally between said longitudinally-extending bars, (c) a plurality of said magnetic fields generated by said coils together form a magnetic field orthogonally extending between said first and second multicoil arrangements, and (d) the magnetic field generated by each of said coils be individually altered;electrical connections for passing electrical current independently through each of said second coil units adjacent an end of a said bar whereby said second coil units become excited and generate an orthogonally extending magnetic field adjacent each end of a said bar;an opening at least partially bounded by said multicoil arrangements for applying the magnetic field generated by said plurality of coils to an ion beam traveling therethrough;directing an ion beam through said opening;passing current independently and concurrently through said multicoil arrangements on each of said bars of said first and second multicoil arrangements, whereby said coils independently and concurrently generate orthogonally extending and individually adjustable magnetic fields of limited breadth between said first and second multicoil arrangements,whereby said plurality of independently generated magnetic fields collectively form a magnetic field to adjust and control uniformity of the ion beam passing through the opening; andadjusting and controlling the uniformity of an ion beam passing through said opening. 17. A method for adjusting and controlling the uniformity of charged particles in an ion beam, said method comprising the steps of:obtaining an ion implantation apparatus comprising:upper and lower multicoil arrangements positioned to be on opposite sides of and extending a width of the ribbon beam, wherein each said multicoil arrangement comprises (i) a ferromagnetic bar having a long dimension, and (ii) a plurality of independently excitable coils positioned on said bar, controllable power supplies for independently exciting said plurality of independently excitable coils of said upper and lower multicoil arrangements such that each excited coil generates a magnetic field between said upper and lower ferromagnetic core members;whereby a plurality of adjacent magnetic fields generated by a plurality of excited coils-form a magnetic field between said upper and lower multicoil arrangements, and whereby the magnetic field generated by each of said independently excitable coils can be individually altered;a pair of independently wound further coils positioned with one of the pair of further coils positioned adjacent each end of a said bar, the further coils being arranged such that the current through them is adjustable and the further coils being positioned on a said bar or on a further magnetic member extending between said bars;a channel bounded at least in part by said multicoil arrangements for applying the magnetic field to an ion beam traveling therethrough;directing an ion beam through said channel;passing current independently and concurrently through said multicoil arrangements on each of said bars of said first and second multicoil arrangements, whereby said coils independently and concurrently generate orthogonally extending and individually adjustable magnetic fields of limited breadth between said first and second multicoil arrangements,whereby said plurality of independently generated magnetic fields collectively form a magnetic field to adjust and control uniformity of the ion beam passing through the channel; andadjusting and controlling the uniformity of an ion beam passing through said channel. 18. The ion implantation apparatus as recited by claim 7 wherein a pair of independently wound further coils is positioned with one of the pair of further coils adjacent each end of a said bar, the further coils being arranged such that the current through them is adjustable and the further coils being positioned on a said bar or on further magnetic members extending between said bars. 19. The ion implantation apparatus as recited by claim 7 wherein said second coil units are positioned on a said bar. 20. The ion implantation apparatus as recited by claim 7 wherein each of said second coil units is positioned on a ferromagnetic member extending generally between said bars. 21. The ion implantation apparatus as recited by claim 7, further comprising a current controller configured to actively adjust current passing through said coils to produce the magnetic field in the channel between said multicoil arrangements for correcting aberrations of the ion beam passing through the channel. 22. The ion implantation apparatus as recited by claim 7, further comprising a current controller configured to actively adjust current passing through said coils to produce the magnetic field in the channel between said multicoil arrangements in response to a condition of the ion beam passing through the channel. 23. The ion implantation apparatus as recited by claim 22, wherein the condition of the ion beam is an ion density of the ion beam. 24. The ion implantation apparatus as recited by claim 22, wherein the condition of the ion beam is a shape of the ion beam. 25. The ion implantation apparatus as recited by claim 22, wherein the controller is further configured to make active adjustments on a time scale limited only by a decay rate of eddy currents in said ferromagnetic bars. 26. The ion implantation apparatus as recited by claim 22, further comprising:faraday cups to measure an intensity and angle distribution of the ion beam passing through the channel between said multicoil arrangements, and wherein the current controller is further configured to actively adjust the magnetic field in response to the intensity and the angle distribution of the ion beam measured by the faraday cups, and wherein the current controller is further configured to make active adjustments on a time scale limited only by a decay rate of eddy currents in said ferromagnetic bars. 27. The ion implantation apparatus as recited by claim 1, further comprising a current controller configured to actively adjust current passing through said first and second coil units to produce the magnetic field in the opening for correcting aberrations of the ion beam passing through the opening. 28. The ion implantation apparatus as recited by claim 1, further comprising a current controller configured to actively adjust current passing through said first and second coil units to produce the magnetic field in the opening in response to a condition of the ion beam passing through the opening. 29. The ion implantation apparatus as recited by claim 28, wherein the condition of the ion beam is an ion density of the ion beam. 30. The ion implantation apparatus as recited by claim 28, wherein the condition of the ion beam is a shape of the ion beam. 31. The ion implantation apparatus as recited by claim 28, wherein the controller is further configured to make active adjustments on a time scale limited only by a decay rate of eddy currents in said longitudinally extending ferromagnetic bars. 32. The ion implantation apparatus as recited by claim 28, further comprising:faraday cups to measure an intensity and angle distribution of the ion beam passing through the opening, and wherein the current controller is further configured to actively adjust the magnetic field in response to the intensity and the angle distribution of the ion beam measured by the faraday cups, and wherein the current controller is further configured to make active adjustments on a time scale limited only by a decay rate of eddy currents in said longitudinally extending ferromagnetic bars.
	description	The present application is a Continuation of International Application No. PCT/EP2016/056617, filed Mar. 24, 2016, which claims the priority under 35 U.S.C. § 119(a) to German Patent Application DE 10 2015 207 140.5, filed on Apr. 20, 2015. The disclosures of both related applications are considered part of and are incorporated by reference into the disclosure of the present application in their respective entireties. The invention relates to a mirror, in particular for a microlithographic projection exposure apparatus. Microlithography is used for producing microstructured components, such as for example integrated circuits or LCDs. The microlithography process is carried out in a so-called projection exposure apparatus having an illumination device and a projection lens. The image of a mask (reticle) illuminated by the illumination device is in this case projected by the projection lens onto a substrate (for example a silicon wafer) coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection lens, in order to transfer the mask structure to the light-sensitive coating of the substrate. In projection lenses designed for the extreme ultraviolet (EUV) wavelength range, i.e. at wavelengths of e.g. approximately 13 nm or approximately 7 nm, owing to the lack of availability of suitable light-transmissive refractive materials, mirrors are used as optical components for the imaging process. Such EUV mirrors have a mirror substrate and a reflection layer system for reflecting the electromagnetic radiation impinging on the optically effective surface. In order to avoid damage to the chemically reactive layer materials of the reflection layer system by way of EUV radiation incident during operation, it is known, inter alia, to apply a capping layer onto the reflection layer system, which capping layer can be produced from e.g. a metallic material or an oxide or nitride and which can contribute, inter alia, to suppressing a diffusion of e.g. oxygen (O2) from the adjacent gaseous phase into the reflection layer system. A problem occurring in practice, in particular during transport, storage or operation, is that such capping layers are also susceptible to molecular contamination (e.g. by hydrocarbons), wherein corresponding contamination depositions on the respective mirror may lead to an impairment of the reflection properties thereof and hence to a reduction in the performance of the projection exposure apparatus overall. In respect of related background art, reference is made by way of example to US 2003/0064161 A1, WO 02/054115 A2, US 2007/0283591 A1, U.S. Pat. No. 8,764,905 B1 and U.S. Pat. No. 8,742,381 B2. It is an object of the present invention to provide a mirror, in particular for a microlithographic projection exposure apparatus, in which undesired contamination is avoided particularly effectively. A mirror according to one formulation of the invention has an optically effective surface and: a mirror substrate; a reflection layer system for reflecting electromagnetic radiation that is incident on the optically effective surface; and a capping layer, which is arranged on the side of the reflection layer system facing the optically effective surface and which is produced from a first material; wherein, either individually or in clusters, particles of a second material are applied onto this capping layer, wherein the second material differs from the first material. The reflection layer system can be a multiple layer system in the form of an alternating sequence of numerous individual layers or else an individual layer (wherein the mirror may have additional functional layers such as barrier layers, etc. in each case). In some embodiments, the mirror can be a mirror described as under grazing incidence (wherein the reflection layer system can have e.g. an individual layer made of ruthenium (Ru) with a purely exemplary typical layer thickness in the region of 30 nm). Such mirrors operated under grazing incidence are understood here and in the following to mean mirrors for which the reflection angles, which occur during the reflection of the EUV radiation and relate to the respective surface normal, are at least 65°. Sometimes, such mirrors are also referred to in an abbreviated fashion as GI mirrors (“grazing incidence”). Moreover, the mirror can also be a mirror operated under normal incidence (also referred to as an NI mirror, “normal incidence”) (wherein the reflection layer system can have e.g. an alternating succession of molybdenum and silicon layers). In particular, the invention is based on the concept of obtaining a reduction or elimination of contamination by virtue of a few particles of a further material (differing from the material of the capping layer) being applied onto the uppermost surface of the mirror in the direction of the EUV radiation incident during operation or onto a capping layer of the mirror. Here, the invention proceeds from the discovery, based on experience in the field of catalytic reactions, that adsorption and dissociation processes causing the contamination depositions, which are to be avoided or reduced according to the invention, typically occur predominantly in the region of surface defects (which, as it were, can be considered to be reaction centres for the contamination deposition). Proceeding from this consideration, the invention follows the approach of effectively blocking precisely these surface defects or “reaction centres”, with the consequence that the adsorption and/or dissociation processes and the contamination depositions accompanying these can no longer take place at the relevant positions. As a result of the fact that, according to the invention, the application of the particles mentioned above only takes place individually (in particular in the form of individual atoms) or in the form of clusters (e.g. in groups of no more than 25 atoms), the invention differs, in particular, from conventional approaches with an uppermost closed layer (on which there would in turn be a significant contamination deposition due to the surface defects which cannot be avoided as a matter of principle). As a result, an additional application according to the invention of a few particles of a further material brings about a lower reactivity and hence an increased contamination resistance of the uppermost capping layer. In accordance with one embodiment, the particles of the second material are applied in such a way that the particles preferably colonize defects in the surface structure of the capping layer. In accordance with one embodiment, the particles are applied in such a way that, compared to an analogous design without the particles, a contamination of the capping layer is reduced during operation or during transport of the mirror. In accordance with one embodiment, the first material is selected from the group containing metals (e.g. Ru, Mo or Zr), oxides (e.g. Nb2O5, ZrO2, TiO2), carbides (e.g. SiC), borides (e.g. ZrB, TiB), nitrides (e.g. SiN, ZrN) and mixtures thereof. In accordance with one embodiment, the first material is ruthenium (Ru). In accordance with one embodiment, the second material is selected from the group containing noble metals, in particular gold (Au), silver (Ag), palladium (Pd) and platinum (Pt), and sulphur (S). In accordance with one embodiment, the capping layer has a thickness in the range from 0.5 nm to 10 nm. In accordance with one embodiment, the number of particles is at most 50%, in particular at most 30%, more particularly at most 10% of the number corresponding to a monolayer of the second material. By contrast, if the number of particles of the second material corresponds to that of a monolayer, the embodiment of a closed layer—precisely explicitly unwanted according to the invention—made of the particles would be possible. In accordance with one embodiment, clusters of the second material comprise no more than 25 atoms, in particular no more than 20 atoms, more particularly no more than 15 atoms. The mirror can be designed in particular for an operating wavelength of less than 30 nm, in particular less than 15 nm. However, the invention is not in principle restricted thereto either and, in further embodiments, can also be realized in a mirror designed for operating wavelengths in the VUV range (e.g. less than 200 nm). The invention furthermore relates to an optical system of a microlithographic projection exposure apparatus, in particular an illumination device or a projection lens, wherein the optical system comprises at least one mirror having the features described above. Further configurations of the invention can be gathered from the description and the dependent claims. The invention is explained in greater detail below on the basis of exemplary embodiments illustrated in the accompanying figures. FIG. 1 shows a schematic illustration for elucidating the construction of a mirror 100 according to the invention in one embodiment of the invention. The mirror 100 can be in particular an EUV mirror of an optical system, in particular of the projection lens or of the illumination device of a microlithographic projection exposure apparatus (described in more detail below in conjunction with FIG. 5). Reference is made to the fact that, in particular, the layers relevant in conjunction with the explanation of the present invention are depicted in the layer construction of the mirror 100 depicted in FIG. 1 and that the mirror 100 can also have one or more additional layer(s) for providing different functionalities (e.g. adhesive layers, etc.) in embodiments of the invention. According to FIG. 1, the mirror 100 initially comprises a mirror substrate 101. A suitable mirror substrate material is e.g. titanium dioxide (TiO2)-doped quartz glass, wherein the materials sold under the trademarks ULE® or Zerodur® are known merely by way of example (and without the invention being restricted thereto). In further embodiments, it is also possible to use metallic mirror substrate materials. Furthermore, the mirror 100 comprises, in a manner known per se in principle, a reflection layer system 102, which, in the embodiment illustrated, merely by way of example, comprises a molybdenum-silicon (Mo—Si) layer stack (and, if appropriate, diffusion barrier layers, etc.). Without the invention being restricted to specific configurations of this reflection layer system 102, one suitable construction that is merely by way of example can comprise, for instance, 50 plies or layer packets of a layer system comprising molybdenum (Mo) layers having a layer thickness of in each case 2.8 nm and silicon (Si) layers having a layer thickness of in each case 4.2 nm. In further embodiments, the reflection layer system can also be an individual layer (e.g. made of ruthenium (Ru) with a thickness of e.g. 30 nm). Arranged on the reflection layer system 102 is, in accordance with FIG. 1, an (optional) diffusion barrier layer 103 (e.g. made of silicon nitride (Si3N4) or boron carbide (B4C)) and a capping layer 104 is arranged thereon. In the exemplary embodiment, the capping layer 104 consists of ruthenium (Ru) and it can have a typical thickness in the range from 0.5 nm to 10 nm (without the invention being restricted thereto). The capping layer 104 can be applied in a manner known per se, e.g. by way of magnetron sputtering, electron beam evaporation or atomic layer deposition (ALD). Moreover, the capping layer 104 can be monocrystalline, polycrystalline or else amorphous (optionally with crystalline inclusions). According to FIG. 1, particles 105 made of a material differing from the capping layer material, individual gold (Au) atoms in the exemplary embodiment, are applied onto the capping layer 104 in a scattered manner. The particles 105 can be applied in a manner known per se, e.g. by way of magnetron sputtering or electron beam evaporation. Moreover, the particles 105 can be applied at a substrate temperature of more than 100 K, in particular more than 300 K. As already indicated in FIG. 1, these particles 105 preferably colonize the defects in the surface structure of the capping layer 104 (on corners, edges or vacancies present there in the example). Below, the principle underlying the present invention is described with reference to the diagrams of FIG. 2-4, which are merely schematic and greatly simplified. FIG. 4A and FIG. 4B initially serve to elucidate the coming about of a contamination deposition on a conventional mirror (of which only the uppermost capping layer 404 is indicated in FIGS. 4A and 4B). In the situation depicted in FIG. 4A, contamination molecules 410 (e.g. hydrocarbon molecules) are incident on this capping layer 404 from the surrounding gaseous phase and said contamination molecules are—as indicated in FIG. 4A—adsorbed at defects (edges on the surface of the capping layer 404 in the example). The reason for this adsorption at defects is that adsorption at the terraces, denoted by “T”, of the surface structure of the capping layer 404 is not preferred thermodynamically. However—as indicated in FIG. 4B—there is subsequently dissociation of the contamination molecules 410, the dissociation products of which are denoted by 411 and 412 in FIG. 4B and in turn are distributed as contamination deposition over the whole surface of the capping layer 404 of the mirror. The terraces denoted by “T” can have a typical depth dimension in the range from (0.2-2) nm and a lateral extent in the range from (1-10) nm (without the disclosure being restricted thereto). Moreover, the regions at the terraces and between the terraces typically consist of the same material. FIG. 2 serves to elucidate the principle underlying the invention, in which the scenario described above on the basis of FIGS. 4A and 4B is prevented. According to FIG. 2, the particles 105 applied individually or in clusters on the capping layer 104 in accordance with the invention likewise preferably colonize the defects in the surface structure of the capping layer 104 (on edges, corners or vacancies present there in the example). As a result, no thermodynamically preferred adsorption space is available any more for contamination molecules 110 incident during transport, storage or operation of the mirror—as likewise indicated in FIG. 2 —, such that the contamination process described above on the basis of FIG. 4B can also no longer take place or only take place to a very small extent. The defects in the surface structure of the capping layer 104 blocked according to the invention by the particles 105 can be different types of defects (in particular defects with different dimensionality), with only schematic exemplary types of defects being indicated in FIG. 3. According to FIG. 3, a screw dislocation 302, a foreign atom 303, an edge 304, a vacancy 305 situated on an edge, a vacancy 306 situated in a corner and a vacancy 307 situated on a terrace are situated on or at an ideal surface or “terrace” denoted by “301”. FIG. 5 shows a schematic illustration of one exemplary projection exposure apparatus which is designed for operation in the EUV and in which the present invention can be realized. In accordance with FIG. 5, an illumination device in a projection exposure apparatus 500 designed for EUV comprises a field facet mirror 503 and a pupil facet mirror 504. The light from a light source unit comprising a plasma light source 501 and a collector mirror 502 is directed onto the field facet mirror 503. A first telescope mirror 505 and a second telescope mirror 506 are arranged in the light path downstream of the pupil facet mirror 504. A deflection mirror 507 is arranged downstream in the light path, said deflection mirror directing the radiation impinging on it onto an object field in the object plane of a projection lens comprising six mirrors 551-556. A reflective structure-bearing mask 521 on a mask stage 520 is arranged at the location of the object field, said mask being imaged into an image plane with the aid of the projection lens, in which image plane is situated a substrate 561 coated with a light-sensitive layer (photoresist) on a wafer stage 560. The avoidance or reduction according to the invention of the contamination leading to an impairment of the reflection properties can be implemented on any mirror within the illumination device or the projection lens of the projection exposure apparatus 500. Furthermore, the invention is not restricted to the application to a projection exposure apparatus, and so, in principle, other mirrors can also be configured in the manner according to the invention. Even though the invention has been described on the basis of specific embodiments, numerous variations and alternative embodiments are evident to the person skilled in the art, e.g. through combination and/or exchange of features of individual embodiments. Accordingly, such variations and alternative embodiments are concomitantly encompassed by the present invention, and the scope of the invention is restricted only within the meaning of the appended claims and equivalents thereof.
	summary
	abstract	A beam direct-writing apparatus for writing a pattern on a semiconductor substrate is provided with a head part for emitting an electron beam for direct writing and a computer for performing a computation. A program is installed in the computer in advance to obtain a path passing through a plurality of writing points on the substrate. The program divides a region (6) dotted with writing points (60) into a plurality of divided regions on the basis of the density of the points contained therein and sets a passing order among a plurality of divided regions by using an algorithm for generating the Hilbert Curve. Subsequently, the program sets a path in each of the divided regions by using a path setting algorithm and subsequently connects the path in one divided region to the path in another divided region according to the passing order, to obtain a final path (74). This allows an efficient beam direct-writing on a substrate (9).
045591709	claims	1. A process for reducing the volume of a bead ion exchange resin waste, said beads having a mean diameter of about 500 to 800 microns and said waste being contaminated with a member selected from the group consisting of the radionuclides Cs.sup.134, Cs.sup.137, Co.sup.58, Co.sup.60, I.sup.129, and mixtures thereof, said bead ion exchange resin waste containing water on the surface of ion exchange resin beads and water inside said ion exchange resin beads, which consists essentially of: introducing said bead ion exchange resin waste in the form of a finely atomized spray into a spray drying zone and contacting it with a hot gas stream within said zone, said gas stream having a temperature in the range of about 200.degree. to 450.degree. C. and sufficient to vaporize the water on the surface of said ion exchange resin beads and to remove the water inside said ion exchange resin beads, but insufficient to oxidize or combust said bead ion exchange resin waste or volatilize said radionuclides; maintaining said bead ion exchange resin waste in said spray drying zone for a residence time of about 3 to 12 seconds; removing from said zone dry ion exchange resin beads containing said radionuclides and containing substantially no water, and a gaseous nonradioactive product comprising water vapor, said gaseous product containing substantially no oxidation or combustion products of said bead ion exchange resin waste, the ratio of the volume of said bead ion exchange resin waste to said dry ion exchange resin beads being in the range of about 1.5:1 to 3:1; and separating said dry ion exchange resin beads from said gaseous nonradioactive product. introducing said bead ion exchange resin waste in the form of a finely atomized spray into a spray drying zone and contacting it with a hot gas stream, said stream having a temperature in the range of about 200.degree. to 450.degree. C. and sufficient to vaporize the water on the surface of said ion exchange resin beads and to remove the water inside said ion exchange resin beads, but insufficient to oxidize or combust said bead ion exchange resin waste or volatilize said radionuclides; maintaining said bead ion exchange resin waste in said spray drying zone for a residence time of about 3 to 12 seconds; removing from said zone dry ion exchange resin beads containing said radionuclides and containing substantially no water, and a gaseous nonradioactive product comprising water vapor, said gaseous product containing substantially no oxidation or combustion products of said bead ion exchange resin waste, the ratio of the volume of said bead ion exchange resin waste to said dry ion exchange resin beads being in the range of about 1.5:1 to 3:1; separating said dry ion exchange resion beads from said gaseous nonradioactive product; and mixing said dry ion exchange resin beads with a solid matrix-forming composition comprising a copolymer of styrene and vinyl ester; thereby forming a solid monolith containing said dry ion exchange resin beads and having a radionuclide leachability below about 10.sup.-2 g/cm.sup.2 /day. 2. A process according to claim 1 wherein said bead ion exchange resin waste comprises an aqueous slurry. 3. A process according to claim 1 wherein said temperature is in the range of about 300.degree. to 350.degree. C. 4. A process according to claim 3 wherein said residence time is about 3 to 6 seconds. 5. A process according to claim 1 wherein said temperature is in the range of about 275.degree. to 325.degree. C. and said residence time is about 5 to 10 seconds. 6. A process according to claim 1 wherein said hot gas is produced by burning a fuel in an excess of an oxygen-containing gas. 7. A process according to claim 1 wherein said hot gas is produced by burning fuel oil in an excess of an oxygen-containing gas. 8. A process according to claim 1 wherein said dry ion exchange resin beads are separated from said gaseous nonradioactive product by passing said mixture of dry beads and gaseous product through a dry cyclone. 9. A process according to claim 1 wherein said hot gas is produced by means of an electrically heated gas heater. 10. A process for disposing of a bead ion exchange resin waste, said beads having a mean diameter of about 500 to 800 microns and said waste being contaminated with a member selected from the group consisting of the radionuclides Cs.sup.134, Cs.sup.137, Co.sup.58, Co.sup.60, I.sup.129, and mixtures thereof, said bead ion exchange resin waste containing water on the surface of ion exchange resin beads and water inside said ion exchange resion beads, which consists essentially of: 11. A process according to claim 10 wherein said leachability is less than about 10.sup.-4 g/cm.sup.2 /day. 12. A process according to claim 10 wherein said dry ion exchange resin beads are mixed with said solid matrix-forming composition in a ratio of about 0.35:1 to 4:1. 13. A process according to claim 10 wherein said dry ion exchange resin beads are mixed with said solid matrix-forming composition in a ratio of about 1.5:1 to 2.5:1.
	claims	1. A particle beam target, comprising:a target body that receives coolant via a coolant inlet, the target body including a front side, a back side, and a lateral outer wall extending from the front side to the back side;a target cavity disposed in the target body configured such that a particle beam can be directed into the target cavity via a target window, the target cavity including a back inner wall, a lateral inner wall, and a cross-section bounded by the lateral inner wall, the back inner wall spaced from the back side relative to a lateral axis, and the lateral inner wall extending from the back inner wall toward the front side generally along the direction of the lateral axis;a plurality of parallel grooves formed in the back side, each groove including a first groove end and a second groove end and running along a transverse direction from the first groove end to the second groove end, the transverse direction being orthogonal to the lateral axis;a plurality of peripheral bores extending through the target body from the plurality of grooves toward the front side, the peripheral bores arranged to circumscribe the target cavity cross-section in proximity to the lateral inner wall, wherein each groove fluidly communicates with at least one peripheral bore at the first groove end and at least one other peripheral bore at the second groove end; anda plurality of radial outflow bores extending in respective radial directions relative to the lateral axis from the plurality of peripheral bores to the lateral outer wall, each radial outflow bore fluidly communicating with at least one of the peripheral bores,wherein the target body defines a plurality of separate liquid coolant flow paths, each liquid coolant flow path running from a respective groove to at least one of the first groove end and the second groove end of the groove, through at least one peripheral bore, and through at least one radial outflow bore to the lateral outer wall. 2. The particle beam target of claim 1, further comprising a target material inlet bore extending through the target body and into fluid communication with the target cavity. 3. The particle beam target of claim 2, wherein the target cavity has an inlet pocket formed in the lateral inner wall and circumscribing the target material inlet bore. 4. The particle beam target of claim 3, wherein the inlet pocket has a lateral dimension running in a direction generally toward the front side and a width transverse to the lateral dimension, and the width decreases along the lateral dimension in a direction away from the target material inlet bore. 5. The particle beam target of claim 3, wherein the inlet pocket has a lateral dimension running in a direction generally toward the front side and a width transverse to the lateral dimension, and the lateral dimension is elongated relative to the width. 6. The particle beam target of claim 1, further comprising a target material outlet bore extending radially through the target body from the target cavity to the lateral outer wall. 7. The particle beam target of claim 6, wherein the target cavity has an outlet pocket formed in the lateral inner wall and circumscribing the target material outlet bore. 8. The particle beam target of claim 1, wherein at least one of the plurality of parallel grooves fluidly communicates with more than one peripheral bore at the first groove end and more than one other peripheral bore at the second groove end, and the number of grooves is less than half of the number of peripheral bores. 9. The particle beam target of claim 1, wherein at least one of the plurality of radial outflow bores fluidly communicates with more than one peripheral bore, and the number of radial outflow bores is less than the number of peripheral bores. 10. The particle beam target of claim 1, wherein the cross-sectional flow area of each peripheral bore is less than the cross-sectional flow area of each radial outflow bore. 11. The particle beam target of claim 1, wherein each groove has a cross-sectional area defined by a width of the groove in the transverse direction and a height of the groove in a direction orthogonal to the transverse direction, and the height of the groove ranges from 0.01 inch to 0.125 inch. 12. The particle beam target of claim 1, wherein the target body includes a back portion disposed between the back inner wall and at least a majority of the plurality of grooves, and the back portion has a thickness along the lateral axis ranging from 0.002 inch to 0.5 inch. 13. The particle beam target of claim 1, wherein each groove is separated from at least one other adjacent groove by a groove wall, and the groove wall has a thickness between the adjacent grooves ranging from 0.002 inch to 0.125 inch. 14. The particle beam target of claim 1, wherein the target body includes an annular portion disposed between the lateral inner wall and the plurality of peripheral bores, and the annular portion has a thickness in a radial dimension relative to the lateral axis ranging from 0.002 inch to 0.5 inch. 15. The particle beam target of claim 1, wherein the plurality of radial outflow bores are located closer to the front side than to the back side. 16. The particle beam target of claim 1, wherein the plurality of radial outflow bores are located at a distance from the front side along the lateral axis ranging from 0.01 inch to 0.5 inch. 17. The particle beam target of claim 1, wherein the target cavity has a depth along the lateral axis, and the plurality of peripheral bores extend from the plurality of grooves along at least a majority of the depth. 18. The particle beam target of claim 1, wherein each peripheral bore has a diameter ranging from 0.01 inch to 0.25 inch. 19. The particle beam target of claim 1, wherein the plurality of peripheral bores extend in a direction parallel to the lateral inner wall. 20. The particle beam target of claim 1, wherein the plurality of peripheral bores include a first set of peripheral bores communicating with the first groove ends of the respective grooves and a second set of peripheral bores communicating with the second groove ends of the respective grooves, and each peripheral bore is spaced from an adjacent peripheral bore in the same first or second set by a distance ranging from 0.002 inch to 0.125 inch. 21. The particle beam target of claim 1, further comprising a coolant inlet body abutting the back side and covering the plurality of peripheral bores, the coolant inlet body including an elongated slot fluidly communicating with each of the grooves, wherein the coolant inlet body defines a liquid coolant inlet flow path running through the elongated slot and into each of the grooves such that the liquid coolant inlet flow path branches into each of the liquid coolant flow paths, and each liquid coolant flow path is divided into a first liquid coolant flow path running to the first groove end and a second liquid coolant flow path running to the second groove end. 22. The particle beam target of claim 21, wherein the elongated slot is positioned at a point over each groove equidistant to the first groove end and to the second groove end of the groove, and the coolant flow in the liquid coolant flow path for the respective groove is divided approximately equally into the first liquid coolant flow path and the second liquid coolant flow path. 23. The particle beam target of claim 21, wherein the elongated slot has a cross-sectional flow area defined by a length along which the slot is elongated and a width orthogonal to the length, and the width is non-uniform such that the coolant flow rate into at least one of the plurality of grooves is different than the coolant flow rate into at least one other groove. 24. A particle beam target, comprising:a target body that receives coolant via a coolant inlet, the target body including a front side, a back side, and a lateral outer wall extending from the front side to the back side;a target cavity disposed in the target body configured such that a particle beam can be directed into the target cavity via a target window, the target cavity bounded by a lateral inner wall of the target body, the lateral inner wall disposed about a lateral axis and extending from a target cavity opening at the front side toward the back side;a channel formed at the front side and circumscribing the target cavity opening;a plurality of peripheral bores extending through the target body from the back side toward the front side, the peripheral bores circumscribing the target cavity in proximity to the lateral inner wall, wherein the peripheral bores are arranged along a peripheral bore perimeter at a radial distance between the target cavity and the channel relative to the lateral axis; anda plurality of radial outflow bores extending in respective radial directions relative to the lateral axis from the plurality of peripheral bores to the lateral outer wall, each radial outflow bore fluidly communicating with at least one of the peripheral bores, wherein the target body defines a plurality of separate liquid coolant flow paths, each liquid coolant flow path running from the back side of the target body, through at least one peripheral bore, and through at least one radial outflow bore to the lateral outer wall. 25. The particle beam target of claim 24, further comprising a plurality of parallel grooves formed in the back side, each groove including a first groove end and a second groove end and running along a transverse direction from the first groove end to the second groove end, the transverse direction being orthogonal to the lateral axis, wherein each liquid coolant flow path running from a respective groove to at least one of the first groove end and the second groove end of the groove, through at least one peripheral bore, through at least one radial outflow bore, and to the lateral outer wall. 26. The particle beam target of claim 25, wherein at least one of the plurality of parallel grooves fluidly communicates with more than one peripheral bore at the first groove end and more than one other peripheral bore at the second groove end, and the number of grooves is less than half of the number of peripheral bores. 27. The particle beam target of claim 25, further comprising a coolant inlet body abutting the back side and covering the plurality of peripheral bores, the coolant inlet body including an elongated slot fluidly communicating with each of the grooves, wherein the coolant inlet body defines a liquid coolant inlet flow path running through the elongated slot and into each of the grooves such that the liquid coolant inlet flow path branches into each of the liquid coolant flow paths, and each liquid coolant flow path is divided into a first liquid coolant flow path running to the first groove end and a second liquid coolant flow path running to the second groove end. 28. The particle beam target of claim 24, wherein at least one of the plurality of radial outflow bores fluidly communicates with more than one peripheral bore, and the number of radial outflow bores is less than the number of peripheral bores. 29. The particle beam target of claim 24, wherein the target body includes an annular portion disposed between the lateral inner wall and the plurality of peripheral bores, and the annular portion has a thickness in a radial dimension relative to the lateral axis ranging from 0.002 inch to 0.5 inch. 30. The particle beam target of claim 24, wherein the plurality of radial outflow bores are located closer to the front side than to the back side. 31. The particle beam target of claim 24, wherein the target cavity has a depth along the lateral axis, and the plurality of peripheral bores extend from the plurality of grooves along at least a majority of the depth. 32. A particle beam target, comprising:a target body that receives coolant via a coolant inlet, the target body including a front side, a back side, and a lateral outer wall extending from the front side to the back side;a target cavity disposed in the target body configured such that a particle beam can be directed into the target cavity via a target window, the target cavity bounded by a lateral inner wall of the target body, the lateral inner wall disposed about a lateral axis and extending from a target cavity opening at the front side toward the back side;a plurality of peripheral bores extending through the target body from the back side toward the front side and circumscribing the target cavity, wherein the target body further includes an annular portion interposed between the lateral inner wall and the peripheral bores, and the annular portion has a radial thickness between the lateral inner wall and the peripheral bores ranging from 0.002 inch to 0.5 inch; anda plurality of radial outflow bores extending in respective radial directions relative to the lateral axis from the plurality of peripheral bores to the lateral outer wall, each radial outflow bore fluidly communicating with at least one of the peripheral bores, wherein the target body defines a plurality of separate liquid coolant flow paths, each liquid coolant flow path running from the back side of the target body, through at least one peripheral bore, and through at least one radial outflow bore to the lateral outer wall. 33. The particle beam target of claim 32, further comprising a plurality of parallel grooves formed in the back side, each groove including a first groove end and a second groove end and running along a transverse direction from the first groove end to the second groove end, the transverse direction being orthogonal to the lateral axis, wherein each liquid coolant flow path running from a respective groove to at least one of the first groove end and the second groove end of the groove, through at least one peripheral bore, through at least one radial outflow bore, and to the lateral outer wall. 34. The particle beam target of claim 33, wherein at least one of the plurality of parallel grooves fluidly communicates with more than one peripheral bore at the first groove end and more than one other peripheral bore at the second groove end, and the number of grooves is less than half of the number of peripheral bores. 35. The particle beam target of claim 33, further comprising a coolant inlet body abutting the back side and covering the plurality of peripheral bores, the coolant inlet body including an elongated slot fluidly communicating with each of the grooves, wherein the coolant inlet body defines a liquid coolant inlet flow path running through the elongated slot and into each of the grooves such that the liquid coolant inlet flow path branches into each of the liquid coolant flow paths, and each liquid coolant flow path is divided into a first liquid coolant flow path running to the first groove end and a second liquid coolant flow path running to the second groove end. 36. The particle beam target of claim 32, wherein at least one of the plurality of radial outflow bores fluidly communicates with more than one peripheral bore, and the number of radial outflow bores is less than the number of peripheral bores. 37. The particle beam target of claim 32, wherein the plurality of radial outflow bores are located closer to the front side than to the back side. 38. The particle beam target of claim 33, wherein the target cavity has a depth along the lateral axis, and the plurality of peripheral bores extend from the plurality of parallel grooves along at least a majority of the depth. 39. A particle beam target, comprising:a target body that receives coolant via a coolant inlet, the target body including a front side, a back side, and a lateral outer wall extending from the front side to the back side;a target cavity disposed in the target body and bounded by a lateral inner wall of the target body, the lateral inner wall disposed about a lateral axis and extending from a target cavity opening at the front side toward the back side;a target window disposed at the front side and covering the target cavity opening;a plurality of peripheral bores extending through the target body from the back side toward the front side, the peripheral bores circumscribing the target cavity in proximity to the lateral inner wall, wherein the peripheral bores are arranged along a peripheral bore perimeter at a radial distance between the target cavity and an outer perimeter of the target window relative to the lateral axis; anda plurality of radial outflow bores extending in respective radial directions relative to the lateral axis from the plurality of peripheral bores to the lateral outer wall, each radial outflow bore fluidly communicating with at least one of the peripheral bores, wherein the target body defines a plurality of separate liquid coolant flow paths, each liquid coolant flow path running from the back side of the target body, through at least one peripheral bore, and through at least one radial outflow bore to the lateral outer wall. 40. The particle beam target of claim 39, further comprising a plurality of parallel grooves formed in the back side, each groove including a first groove end and a second groove end and running along a transverse direction from the first groove end to the second groove end, the transverse direction being orthogonal to the lateral axis, wherein each liquid coolant flow path running from a respective groove to at least one of the first groove end and the second groove end of the groove, through at least one peripheral bore, through at least one radial outflow bore, and to the lateral outer wall. 41. The particle beam target of claim 40, wherein at least one of the plurality of grooves fluidly communicates with more than one peripheral bore at the first groove end and more than one other peripheral bore at the second groove end, and the number of grooves is less than half of the number of peripheral bores. 42. The particle beam target of claim 40, further comprising a coolant inlet body abutting the back side and covering the plurality of peripheral bores, the coolant inlet body including an elongated slot fluidly communicating with each of the grooves, wherein the coolant inlet body defines a liquid coolant inlet flow path running through the elongated slot and into each of the grooves such that the liquid coolant inlet flow path branches into each of the liquid coolant flow paths, and each liquid coolant flow path is divided into a first liquid coolant flow path running to the first groove end and a second liquid coolant flow path running to the second groove end. 43. The particle beam target of claim 39, wherein at least one of the plurality of radial outflow bores fluidly communicates with more than one peripheral bore, and the number of radial outflow bores is less than the number of peripheral bores. 44. The particle beam target of claim 39, wherein the target body includes an annular portion disposed between the lateral inner wall and the plurality of peripheral bores, and the annular portion has a thickness in a radial dimension relative to the lateral axis ranging from 0.002 inch to 0.5 inch. 45. The particle beam target of claim 39, wherein the plurality of radial outflow bores are located closer to the front side than to the back side. 46. The particle beam target of claim 40, wherein the target cavity has a depth along the lateral axis, and the plurality of peripheral bores extend from the plurality of grooves along at least a majority of the depth.
	summary
	summary
041526023	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 there is shown a plurality of nuclear fuel racks 10 positioned within a spent fuel storage pit 12. The racks are arranged within the pit or pool in a rectangular array, and each rack includes a plurality of cells 14 sized to receive a fuel assembly 16. Adjacent racks 10 are joined by lateral supports 18 so as to form a structure which moves essentially as a single mass under high loading conditions. The racks are also typically affixed to the bottom of the spent fuel pit by a bolted or welded structure (not shown). The spent fuel pit typically includes a concrete or other structural support 20 with a metallic sealed lining 22. The racks have sides 24, typically comprised of a plurality of metallic beams affixed in an open fashion to allow the flow of borated water therethrough. Between the sides 24 and the substantially parallel lining 22 are positioned a plurality of lateral support and restraint devices 26. The devices can be positioned at varying elevations along the sides of the fuel racks, although preferably positioned near the top of the racks. One embodiment of a lateral support and restraint device in accordance with this invention is shown in FIGS. 2 and 3. It includes one or more preferably ball jointed swivel pads 28 having a flat surface 30 that will seat against any surface substantially perpendicular to the axis of the arms 32 to which the pads 28 are affixed. The arms 32 can be affixed directly to a piston 34 or joined thereto by additional components as shown. The additional components can include a leveling foot 36 affixed to a piston extension 38 by a pinned connection 40. The piston 34 is slidably disposed within a cylinder 42 for reciprocating motion therein, and preferably extends through an open end 35 of the cylinder. Between the piston and the fuel rack, preferably contained within the cylinder, is an elastic compressible member such as the compression spring 44. The spring 44 is specifically sized to continuously apply a positioning force to the piston. Means are also provided for affixing the cylinder 42 to the fuel rack 10, such as the cylinder being welded to the rack support 46 by welds 48. Alternatively, as shown in FIG. 4, the pads 28 can be joined to the cylinder 42a which slides, through a predetermined clearance 56a, on stationary piston 34a. Piston 34a is affixed to the side 24 of the fuel rack, and spring 44a continuously acts upon cylinder 42a. Referring again to FIGS. 2 and 3, structure is also provided for selectively restraining the piston 34 in a retained position while the spring is compressed. This can include the opening 50 in the wall of the cylinder, a mating aperture 52 partially through the piston, and a ringed pin 54 insertable through the opening 50 into the aperture 52 upon alignment of the opening and aperture. The opening 50 is preferably positioned so that a portion of the piston is always aligned with the opening, thereby preventing undesirable flow paths into or out of the cylinder. Means are also provided for controlling the flow of fluid into or out of the portion of the cylinder between the piston and the fuel rack. This can include a preselected clearance 56 between the piston 34 and cylinder 42 or alternatively, one or more small openings through the cylinder wall or the end 58 adjacent the spring 44. As will be readily apparent, the device 26 can be easily installed. The piston can be loaded into the cylinder so as to compress the spring and locked into position by the ringed pin. The cylinder can then be affixed to the fuel rack side. The leveling foot and affixed components can than be attached to the piston or its extension, readying the device for final positioning. With properly sized components, the device can then be positioned merely by removing the ringed pin, allowing the spring to act on the piston, thereby forcing the piston laterally out of the cylinder and the joined pads against the spent fuel pool wall. The water in the pit flows, in a controlled fashion, into the area 60 within the cylinder and about the spring. For non-rapid relative motions, such as those brought about by differential thermal expansion between the pit wall and the rack, the piston will slide in the appropriate direction within the cylinder restrained or assisted as the case may be by the compression spring for rapid relative movements, such as seismic loading conditions, however, the hydraulic fluid within the cylinder cannot be rapidly discharged, and the support will accordingly react as a substantially rigid restraint or damper of the loading. The magnitude of the restraining force can be adjusted to any desired level by incorporating variously sized piston to cylinder clearances and/or variously sized and oriented flow relief openings 62. The device shown in FIG. 4 will operate similarly. It will be apparent that many modifications and additions are possible in view of the above teachings. It therefore is to be understood that within the scope of the appended claims, the invention can be practiced other than as specifically described.
045267138	claims	1. A process for treatment of waste liquid material including dissolved radioactive substances, comprising: heating the waste liquid material to vaporize the liquid and to deposit said radioactive substances on a heat transfer surface; wiping the radioactive substances deposited on the heat transfer surface to form a dry powder by rotary wiping blades; measuring the flow rate (W) of the entering waste liquid material and the concentration (C) of the radioactive substances to be powdered in the waste liquid material, thus determining the quantity of the radioactive substances to be powdered by the product of (W.times.C); and controlling the rotational speed of the wiping blade in accordance with the quantity of the radioactive substances to be powdered. 2. A process according to claim 1, wherein the rotational speed is controlled at a minimum speed necessary for powderizing the radioactive substances to be treated. 3. A process according to claim 1 or 2, wherein the rotational speed changes in proportion to the rate of change in the maximum quantity of radioactive substances to be powdered. 4. A process according to claim 3, wherein evaporation of the liquid and depositing of the radioactive substances on a heat transfer surface changes from a point where the maximum quantity of the radioactive substances to be powderized increases effectively with the increase of the wiping speed to a point where the maximum quantity of the radioactive substances to be powderized increases at a negligible rate with the increase of the wiping speed. 5. A process according to claim 4, further comprising steps of detecting a quantity of the waste liquid material to be treated and detecting a concentration of the radioactive substances in the waste liquid material. 6. A process according to claim 5, further comprising a step of calculating the maximum quantity of radioactive substances to be treated by an equation of thermal balance of heat energy required to vaporize water content in the waste liquid material and heat energy supplied for heating. 7. A process according to claim 3, further comprising steps of detecting a quantity of the waste liquid material to be treated and detecting a concentration of the radioactive substances in the waste liquid material. 8. A process according to claim 7, further comprising a step of calculating the maximum quantity of radioactive substances to be treated by an equation of thermal balance of heat energy required to vaporize water content in the waste liquid material and heat energy supplied for heating. 9. A process according to claim 1, wherein the wiping speed is kept constant and the flow rate of the waste liquid material and the concentration of the radioactive substances to be powderized in the waste liquid material are controlled to obtain an optimum operation condition. 10. A process according to claim 9, further comprising steps of detecting a quantity of the waste liquid material to be treated and detecting a concentration of the radioactive substances in the waste liquid material. 11. A system for treatment of waste liquid material including dissolved radioactive substances comprising a film evaporator having a cylindrical vessel with an inlet and outlet for the waste liquid material heating means for heating the waste liquid material in said vessel through a cylindrical heat transfer surface of said vessel to vaporize the liquid and to deposit said radioactive substances on the heat transfer surface, wiping means for wiping said heat transfer surface to remove the radioactive substances depositing thereon to obtain dry powder of the radioactive substances, measuring means for measuring the flow rate (W) of the entering waste liquid material and the concentration (C) of the radioactive substances to be powdered in the waste liquid material and determining the quantity of the radioactive substances to be powdered by the product of (W.times.C); and control means for controlling the wiping speed of said wiping means in accordance with the quantity of the radioactive substances to be powdered. 12. A system according to claim 11, further comprising detecting means for the quantity of the radioactive substances.
	description	The present invention relates to an operation stage of a charged particle beam apparatus which is employed in a scanning electron microscope for substrate (wafer) edge and backside defect inspection or defect review. However, it would be recognized that the invention has a much broader range of applicability. Charged particle beam apparatus are typically employed in scanning electron microscopy (SEM), which is a known technique used in semiconductor manufacturing. Traditionally, the wafer edge has been of secondary concern to semiconductor manufacturers, since it was considered a non-active area. However, there is a growing industry awareness that wafer edge and backside conditions impact yields, directly and indirectly. A 300 mm wafer may contain as much as 25% of the devices at its outer edge, and a recently published benchmark study has demonstrated that yield can decrease by as much as 50% at the wafer's edge. While there are varying causes for this yield loss, chipmakers are increasingly aware of the need to manage defect source at the wafer's edge. For instance, a scratch on the bottom of a wafer can cause a hot spot on the top. A large scratch or residual slurry on the bevel can flake or peel off, depositing particles on the topside that cause defects. In addition to affecting yield, defects may adversely impact the availability of the lithography equipment. The need for well characterized and methodical edge and bevel defect control becomes even greater with the introduction of immersion lithography for 45 nm technology node. Immersion increases the need for tighter edge control because of new edge defect creation mechanisms and because of higher risk of edge defects migrating to wafer patterned area with immersion liquid flow. The immersion fluid may pick up and deposit particles from the bevel region onto the wafer. Defects sources impacting yield include traditional films (silicon oxide, silicon nitride and polymers), new materials such as porous low-k and organic films. Porous low-k film often does not adhere as well as traditional silicon- or polymer-based films and, therefore, can be significant defect sources. Tensile films such as amorphous carbon also may adhere poorly at the edge of the wafer and can peel off in long strips that tend to ball up, creating particle sources. Although edge and bevel defects are typically large (several microns and above) and can be detected by optical microscope, comprehensive analysis of these defects requires the high resolution and image contrast provided by SEM. Optically, many of the defects appear as a small spot, whereas the SEM image reveals their true morphology. Understanding the defect's elemental composition can provide many clues to its origin and cause. Therefore, the ability to analyze the defect material has tremendous added value. A system and method in accordance with the present invention addresses defect and inspection review in an effective manner in a wafer edge. The present invention relates to an operation stage of a charged particle beam apparatus which is employed in a scanning electron microscope for substrate (wafer) edge and backside defect inspection or defect review. However, it would be recognized that the invention has a much broader range of applicability. A system and method in accordance with the present invention provides an operation stage for substrate edge inspection or review. The inspection region includes top near edge, to bevel, apex, and bottom bevel. The operation stage includes a supporting stand, a z-stage, an X-Y stage, an electrostatic chuck, a pendulum stage and a rotation track. The pendulum stage mount with the electrostatic chuck has the ability to swing from 0° to 180° while performing substrate top bevel, apex and bottom bevel inspection or review. In order to keep the substrate in focus and avoid a large position shift during altering the substrate observation angle by rotation the pendulum stage, one embodiment of the present invention discloses a method such that the rotation axis of the pendulum stage consist of the tangent of upper edge of the substrate to be inspected. The electrostatic chuck of the present invention has a diameter smaller than which of the substrate to be inspected. During the inspection process the substrate on the electrostatic chuck may be rotated about the central axis on the electrostatic chuck to a desired position, this design insures all position on the bevel and apex are able to be inspected. Reference will now be made in detail to specific embodiments of the invention. Examples of these embodiments are illustrated in accompanying drawings. While the invention will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a through understanding of the present invention. The present invention may be practiced without some or all of these specific details. In other instances, well known process operations are not been described in detail in order not to unnecessarily obscure the present invention. This invention presents an operation stage of a charged particle beam apparatus which is employed in a scanning electron microscope for substrate (wafer) edge and backside defect inspection and defect review. The metrology and stereo image of the defect can be revealed under the high resolution and high performance SEM. However, it would be recognized that the invention has a much broader range of applicability. As device architecture line width becomes finer, the wafer's edge cannot be disregarded when inspecting and reviewing the architecture for defects. A prime mover behind detecting these defects is the need to reduce progressively worse surface contamination that may migrate from a rough, pitted or fractured edge. Also it is realized that 5 to 7% of the wafer surface area is missed if edge inspection is not done. The edge is composed of three sections: the top bevel 120, the apex 140, and the bottom bevel 160 as illustrated in FIG. 1. The bevel and apex make up the area of the wafer beyond the pattern and process usually at least 2 to 3 mm from the physical edge of the wafer. Contrary to the wafer patterned surface which is well characterized, monitored and controlled through inspection (optical or e-beam based) and review (usually e-beam based), the defect identification ability beyond the wafer's edge is a new frontier for yield enhancement. The defect inspection around the wafer edge was done mostly by an optical device, for example, as described in U.S. Pat. No. 7,161,667 by Meeks et al. However, there is only limited paper reported that defect around the edge analyzed by SEM (Porat et al. 2008 IEEE/SEMI Advanced Semiconductor Manufacturing Conference, “SEM-based methodology for root cause analysis of wafer and bevel defects”). The reason is as follows. In order to have a good image quality from the top bevel to the apex then to the bottom bevel, the inspecting source (UV light or e-beam) should rotate around and keep normal to or within a range of normal to the substrate surface. It is much easier to move or rotate an optical device around the wafer edge to have a quality image than moving a heavy e-beam column without increasing vibration and background noise to the image. Currently, the best an e-beam system can provide is by tilting the column by 45°. One embodiment of the present invention discloses an operation stage of an e-beam system that can rotate between 0° and 180° to have the inspecting area always face to the electron beam. FIG. 2 illustrates the operation stage with an e-beam column on the system. The operation stage includes a supporting stand 620 that may sustain the weight of the system; a z-stage 640 that may provides the stage degree of freedom in vertical direction respect to the ground; an X-Y stage 320 that may provides the stage degree of freedom in the two horizontal direction respect to the ground; an electrostatic chuck 340 that holds the substrate 360 to be inspect or review by electrostatic force; and most of all a pendulum stage 380 for mounting the electrostatic chuck 340 on and have the ability to swing from 0° to 180° while performing top bevel, apex and bottom bevel inspection or review. FIG. 3 illustrates a top view of the operation stage at the normal position. In this position, the system can loading or unloading the substrate to be inspected 360 and the system can performing the top near edge 110, top bevel 120 inspection. Since the bevel gradually altering its slope, the pendulum stage 380 may also vary its rotation degree respectively during top bevel 120 and bottom bevel 160 inspection. A rotation track 660 is designed for the pendulum stage 380 to provide support increase stabilization and reduce vibration during bevel inspection. FIG. 4 illustrates the top view of the operation stage while performing apex 140 inspection or review. At this position, the pendulum stage 380 is rotating to 90° angle respect to the original starting position. In order to keep the substrate in focus and avoid a large position shift during altering the substrate observation angle by rotation the pendulum stage 380, one embodiment of the present invention discloses a method such that the rotation axis 420 of the pendulum stage 380 consists of the tangent of upper edge of the substrate to be inspected 360. With this design the vertical distance shift during the 90° rotation is about the thickness of the substrate, for example 775 micron for a 300 mm wafer. The horizontal distance shift from 0° to 180° is about 2 thickness of the substrate, for example 1.55 mm for a 300 mm wafer. These distance shift can be easily compensated by a regular z-stage and X-Y stage. FIG. 5 illustrates another top view of the operation stage position while performing bottom bevel 160 inspection or review. In order to reveal the backside or the bottom bevel of the wafer, one embodiment of the present invention includes a round shaped electrostatic chuck 340 that has a diameter smaller than which of the substrate to be inspected. Of course the shape of the electrostatic chuck could be any shape but must reveal the portion the substrate to be inspected. During the inspection process the substrate on the electrostatic chuck may be rotated about the central axis 720 of the electrostatic chuck 340 to a desired position, which may be connected to a suitable motor (not show) or other drive assembly for inducing rotational motion to the electrostatic chuck 340. With this design all the position on the top near edge 110, top bevel 120, apex 140, bottom bevel 160 and bottom near edge 170 could be inspected. FIG. 7 illustrates relationship between the pendulum stage, the electrostatic chuck, wafer and the rotation axis. The operation stage of the present invention combines with a review or inspection column become a system that can perform substrate edge inspection or review. For example, equipped with the column disclosed by Chen et al., U.S. patent application Ser. No. 12/257,304 filed in Oct. 23, 2008 entitled “Electron Beam Apparatus”, the present invention will become an edge review station with high resolution, high throughput and able to do material analysis. Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended.
	description	This application claims priority from German patent application DE 10 2014 018 810.8, filed on Dec. 19, 2014 which is incorporated in its entirety by this reference. The invention relates to a nuclear power plant including: a containment vessel including a reactor pressure vessel for receiving fissionable nuclear fuel an aerosol filter stage a pressure relief conduit through which a gas volume flow which is filtered in the aerosol filter stage is releasable to the ambient through a pass through opening in the containment vessel, and an iodine filter stage through which the gas volume flow that is filtered in the aerosol filter stage is filterable before being dispensed to the ambient, wherein the iodine filter stage is arranged within the containment vessel. When operating nuclear power plants an accident, like e.g. a coolant accident, can have an effect that sufficient heat output from the reactor core cannot be provided anymore. Lack of cooling can lead to overheating the reactor pressure vessel, also designated as reactor which can cause an evaporation of the cooling water from the primary cycle of the reactor and to a destruction of concrete in the reactor foundation. This generates large amounts of steam and non-condensing gases which lead to a pressure buildup in the containment vessel which encloses the reactor and the components of the primary cycle pressure tight. It is known in the art that a pressurized-water reactor with a failure pressure of the containment vessel that is between 2.5 and 9 bar depending on its configuration reaches this failure pressure after 2-5 days when a core melt down has occurred. The atmosphere of the containment vessel then includes only fractions of the amount of radioactive aerosols originally generated by the core melt down due to decay processes occurring without additional external measures. As a consequence of the accident in Chernobyl in the Soviet Union in 1986 all nuclear power plants in Germany were equipped with venting filters in order to prevent uncontrolled release of this radio activity through a sudden failure of the containment vessel and in order to further reduce the amount of released radioactivity. After the reactor accident in Fukushima in Japan in 2011 a retrofit of containment vessels of nuclear power plants with venting filters was commenced in Japan and also in other countries. In particular for extreme conditions in the containment vessel prevailing after a core melt down, thus gas temperatures of up to 250° C. and pressures up to 9 bar a filter system was developed by the Kernforschungszentrum Karlsruhe, the so called dry filter method which helps to reduce environmental impacts through radioactive aerosols and gaseous radioactive iodine or organic iodine compounds by orders of magnitude. The dry filter method is a completely passive system, typically including: metal fleece filters of the aerosol filter for retaining airborne radioactive aerosols, and specially doted molecular sieve absorbents for chemical absorption of gaseous radioactive iodine and its organic compounds. During a core melt down the pressurized gas vapor mix of the containment vessel is only conducted into the venting chimney after passing a highly effective accident filter. The pressure relief prevents a failure of the containment vessel due to excessive pressure. The filter system protects the environment from airborne radioactive aerosols and iodine compounds. DE 10 2011 056 889 B3 discloses an aerosol filter device for use in a pressure relief device of a nuclear power plant which aerosol filter device is characterized by increased heat transfer. DE 38 15 850 A1 describes a method for a pressure relief of a nuclear power plant in which the relief flow is initially dehumidified by a metal fleece filter and aerosols are filtered and the relief gas flow is then expansion dried before the dried relief gas flow is brought into direct contact with the molecular sieve for iodine absorption filtering. The method known from DE 38 15 850 A1 addresses the problem that an accident provides high pressure and high humidity due to the water vapor, wherein the water vapor makes iodine absorption filtering with a molecular sieve impossible due to an agglomeration of water molecules in the molecular sieve (inhibition). Only a dried relief flow can be effectively routed through a molecular sieve. Due to the high pressure that is provided in the containment vessel when an accident occurs (between 2 and 9 bar) drying the relief flow is typically performed by a throttle that is connected upstream of the iodine filter (also designated as pressure reduction orifice or expansion valve) only outside the containment vessel wherein the volume however is multiplied. Drying the relief gas flow outside the containment vessel has the following disadvantages: On the one hand side multiplying the volume of the relief flow for drying requires filter devices that are sized accordingly and on the other hand side filtering the relief flow including radioactive aerosols and also gaseous radioactive iodine and its organic compounds is performed outside of the containment vessel, thus outside of a controlled area. This necessitates additional shielding measures for securing personnel and environment against radioactivity, in particular against radioactive isotopes of iodine and its organic compounds. Furthermore due to a high temperature difference between the relief flow and the filter device outside of the containment vessel there is a risk of condensation in the filter device wherein in particular radioactive residual condensate remains in the filter device which is arranged outside of the containment vessel. According to an embodiment it is provided in DE 38 15 850 A1 or DE 38 06 872 A1 that the iodine filter stage is also arranged within the containment vessel in addition to the aerosol filter stage so that a majority of the disadvantages recited supra is overcome. In order to provide a sufficient degree of separation a throttle for pressure reduction is provided between the aerosol filter stage and iodine filter stage for pressure reduction, thus for expansion, so that a dew point spread is reached that is sufficiently large in order to secure the iodine sorption mechanism. However, in order to assure that there is a pressure differential between the iodine filter stage and the atmosphere outside of the containment vessel, it is mandatory for a pressure relief that another throttle is arranged in flow direction after the iodine filter stage, wherein the throttle provides a certain amount of pressure in the iodine filter stage. This second throttle has to be adaptable to the individually provided pressure conditions and requires a control unit. It is furthermore required that the housing of the iodine filter stage is configured very stable in order to be able to stand up to the pressure differential between the outer portion of the iodine filter stage, thus within the containment vessel and the inner portion of the iodine filter stage in case of an accident. Thus, it is an object of the present invention to improve a nuclear power plant of the type described supra so that the recited disadvantages are overcome. The object is achieved in that the aerosol filter stage and the iodine filter stage are connected with one another so that transferring the gas volume flow starting from the aerosol filter stage into the iodine filter stage is essentially performed on the same pressure level. The limitation “essentially the same” pressure level comes from the fact that certain pressure loses can be occur based on the system, like e.g. natural pressure loses over the length of the tubular conduit. According to the instant application a possible pressure deviation between the aerosol filter stage and the iodine filter stage is only below 200 mbar. According to the invention expansion drying upstream of the iodine filter stage is omitted, this means there is no expansion valve between the aerosol filter stage and the iodine filter stage. For this reason furthermore an additional controllable throttle for maintaining a particular minimum pressure which is typically arranged in flow direction of the gas volume flow behind the iodine filter stage can be omitted. According to the invention generally no expansion valve is arranged in the entire pressure relief conduit. Consequently the iodine filter stage operates in a high pressure range in case of an accident, this means that approximately the same pressure is provided in the iodine filter stage that is provided in the containment vessel. It is self evident that starting from an interior of the containment vessel and flowing through the aerosol filter stage and the iodine filter stage, connecting tubular conduits and the pressure relief conduit a certain pressure drop is provided which facilitates exhausting the gas volume flow into the ambient. Before the relief flow is dispensed to the ambient it can be conducted from the pressure relief conduit into a smoke stack or initially into an air exhaust channel which in turn leads into a smoke stack. Alternatively the pressure relief conduit can also lead directly into the ambient. Due to the fact that the iodine filter stage according to the present invention is used in the high pressure range the long term prejudice in the art is overcome that an adsorbent used in the iodine filter stage only works reliably when a dew point spread is provided, this means when the gas volume flow to be filtered is dried by expansion. In this respect there was a rule that the degree of precipitation increases when the dew point spread also increases. Tests performed by the applicant, however, have surprisingly shown that also a dew point spread of approximately 0 K facilitates a sufficient degree of precipitation with the adsorbents that are currently in use. It has rather become evident that the adsorbent also functions correctly under high humidity or under dew point conditions (there is condensation) so that an expansion of the relief flow between the aerosol filter stage and the iodine filter stage can be omitted. Omitting an expansion valve upstream of the iodine filter stage viewed in flow direction of the gas volume flow to be filtered has the following advantages. The iodine filter stage is used in analogy to the aerosol filter stage at a prevailing pressure over atmosphere of up to 10 bar which has the consequence that contrary to the conventionally used iodine filter stages a small gas volume flow is fed which is almost proportional to the pressure. Due to the significantly lower gas volume flow to be filtered the iodine filter stage can be configured significantly smaller which becomes relevant in particular in view of the space constraints within the containment vessel. Thus, also flexibility is obtained with respect to a possible installation location and much better handling properties for installing the iodine filter stage. Another advantage is that a sufficient pressure drop is always provided which is mandatory for the passive venting system. Also with respect to the tubular conduits conducting the gas volume flow the lower gas volume flow is advantageous since the conduits can accordingly have lower tube diameters. This means in turn that freedom is gained for routing the conduits because they require significantly less installation space. It is also guaranteed by omitting expansion drying in front of the iodine filter stage that even for tubular conduits with a length of several hundred meters and a pressure drop associated therewith a sufficient pressure drop for conveying the gas volume flow remains in the pressure relief conduit. Thus, this is an absolutely passive filter system and no additional energy is required. Due to the fact that the same pressure is provided in the aerosol filter stage and also in the iodine filter stage as in the containment vessel the filter housings can be configured according to a simple standard with respect to their strength. A variant for configuring a connection between the aerosol filter stage and the iodine filter stage can be provided as a tubular conduit which leads from the aerosol filter stage to the iodine filter stage. Thus, the tubular conduit includes in particular no devices for throttling the gas volume flow like for example an expansion valve. Another alternative for connecting the aerosol filter stage and the iodine filter stage can be provided according to an embodiment of the invention in that the aerosol filter stage and the iodine filter stage are arranged within the same filter housing so that a combined aerosol-iodine filter unit is provided. Thus, the two filter stages can be combined into a compact unit. This removes the requirement to connect the aerosol filter stage by accordingly tight and strong conduits with a separately configured iodine filter stage. However, space in the containment vessel can be so limited that a separate configuration of the two filter stages is preferred. With respect to a compact configuration of the combined aerosol-iodine filter unit and a continuous and even flow through it can be advantageous when an outlet cross section of the aerosol filter stage corresponds to an inlet cross section of the iodine filter stage. Due to the small space requirement for the iodine filter stage when the aerosol filter stage and the iodine filter stage are arranged within the same filter housing so that a combined aerosol-iodine filter unit is provided a depth in flow direction of the combined aerosol-iodine filter unit can be between 1,400 mm and 2,000 mm and a height that typically extends vertically of the combined aerosol-iodine filter unit can be between 2500 and 2900 mm. A combined aerosol-iodine filter stage is characterized by a compact configuration and is in particular installable well and in a flexible manner within the space constraints of a nuclear power plant. Conventional combined aerosol-iodine filter stages which are only known outside of the containment vessel have a depth in flow direction of 9 m at a filter width of approximately 1.50 m and a height of approximately 3.70 m or more. A particularly advantageous embodiment of the nuclear power plant according to the invention provides that the iodine filter stage chemically adsorbs iodine and/or at least an organic iodine compound, in particular iodomethane wherein the adsorbable iodine and/or the at least one organic iodine compound can be radio-active. Thus, it is furthermore advantageous when the iodine filter stage includes a zeolith material as an adsorbent, wherein the zeolith is advantageously hydrophobic. For a hydrophobic zeolith material an organic crystalline tectosilicate can be used which has three dimensional grid structures made from SiO4 and AlO4 tetrahedrons. Zeoliths are characterized by their open structure, wherein SiO4 and AlO4 encloses large cavities which are connected with one another by channels (pores) with a uniform precisely defined diameter. The zeolite material can be doted with silver so that the iodine to be precipitated is chemically adsorbed by the silver (chemical sorption) which is bonded in the zeolite structure. In order to prevent possible catalytic reactions caused by media including H2 an advantageously configured zeolite material can have respective chemical properties (inhibitor). The described zeolite material is characterized by its extremely hydrophobic properties and temperature resistance so that this zeolite material facilitates applications in a steam saturated atmosphere that can be provided in a containment vessel. With respect to retrofitting existing power plants it is particularly advantageous when the aerosol filter stage, the iodine filter stage and/or the combined aerosol-iodine filter unit is assembled from at least two modules that are connectable with one another fluid tight since preexisting locks typically only have intentionally small dimensions. It is thus most useful when individual filters that are provided with an enveloping partial housing are provided at least at one side with a circumferential flange through which adjoining partial housings can be connected. It is appreciated that a filter stage or a filter unit can be assembled from three, four, five or more modules in particular when the filter stage includes plural filters connected in series. Independently from a separate or combined configuration of the filter stages it has proven very advantageous when an outlet surface of an aerosol filter stage has a distance from an inlet surface of an iodine filter stage which is smaller than 260 mm, advantageously smaller than 250 mm further advantageously smaller than 240 mm. It is particularly advantageous that heat captured in the aerosol filter stage heats the adjacent iodine filter stage and thus has a drying effect. This influences a degree of precipitation of the iodine filter stage in a positive manner. Accordingly a heater for the iodine filter stage can be omitted which is particularly desirable for a passive and thus non failure prone system. As stated supra dimensions of the iodine filter stage can be drastically reduced based on the arrangement of the iodine filter stage stipulated according to the invention. It is even possible to provide an iodine filter stage in which a bed depth of the adsorbent is less than 80 mm, advantageously less than 60 mm, further advantageously less than 50 mm. Furthermore the invention also relates to a method for providing pressure relief to a containment vessel of a nuclear power plant in which a gas volume flow is initially run through an aerosol filter stage and subsequently through an iodine filter stage before the filtered gas volume flow is passed into the ambient through a pressure relief conduit, wherein the aerosol filter stage and also the iodine filter stage are arranged within a containment vessel including a reactor pressure vessel. According to the invention the gas volume flow is transferred from the aerosol filter stage into the iodine filter stage so that the nuclear power plant has the advantages described supra. According to an advantageous embodiment of the method that is provided that the gas volume flow is conducted from the aerosol filter stage directly into the iodine filter stage so that the iodine filter stage is continuously dried by heat generated in the aerosol filter stage. As stated supra this improves the degree of precipitation of the adsorbent. The term “directly” shall be interpreted according to the patent claim so that the aerosol filter stage and the iodine filter stage are flowed through closely adjacent to one another, this means that a tubular conduit arranged there between is configured very short. Advantageously it is provided that an outlet cross section of the aerosol filter stage and an inlet cross section of the iodine filter stage are arranged within a common housing and a tubular conduit between the two stages can be omitted. A distance between the aerosol filter stage and the iodine filter stage should be advantageously between 240 mm and 260 mm in order to provide optimum heat transfer. FIG. 1 depicts a schematic view of a nuclear power plant 1 according to the invention including a containment vessel 2 in which a reactor pressure vessel 3 is arranged for receiving a fissionable nuclear fuel that is not illustrated in the drawing figure. In view of a possible accident where a pressure build up in the containment vessel 2 requires pressure relief an aerosol pre filter stage 5, an aerosol filter stage 6 and an iodine filter stage 7 are arranged in the containment vessel 2 for filtering a gas volume flow (arrow 4) coming out of the nuclear power plant 1 wherein the filter stages are connected in series. The three filter stages 5, 6, 7 can be arranged at separate locations and can be connected with one another through respective conduits that are not illustrated in the drawing figure but they can also be combined to form a compact filter unit. By the same token only two of the three filter stages can be combined to form a unit. Starting from the iodine filter stage 7 a pressure relief conduit 8 leads through a pass through opening 9 in the containment vessel 2 and through an addition 10 of the nuclear power plant 1 into a smoke stack 11 through which the filtered relief flow which is indicated by an arrow 12 is released into the environment. The pressure relief conduit 8 thus leads out of the entire safety area of the nuclear power plant 1 and terminates in the smoke stack 11. Alternatively an additional air relief channel can be arranged at a transition between the pressure relief conduit 8 and the smoke stack 11 so that the relief flow is conducted starting from the pressure relief conduit through the air relief channel into the smoke stack. Furthermore alternatively the smoke stack 11 and also the air relief channel can be omitted so that the pressure relief conduit terminates in the ambient. FIG. 2 illustrates an advantageous embodiment for the aerosol filter stage 6 of the nuclear power plant 1 according to the invention in a view where the aerosol filter stage 6 is configured as a unit that is separate from the iodine filter stage 7. The aerosol filter stage 6 has an almost square housing with a rectangular cross section wherein the housing 14 is supported by 6 supports 15, on a base 16. The aerosol filter stage 6 has a mirror symmetrical configuration so that a gas volume flow that is to be filtered which is indicated in the figures with arrows 17 respectively flows from two opposite sides respectively from above and from below into the aerosol filter stage 6 and exits the aerosol filter stage 6 through an outlet 19 arranged on a center axis 18 of the aerosol filter stage 6 at a top side of the housing 14, wherein the volume flow exiting the aerosol filter stage 6 is indicated by another arrow 20. In FIG. 3 which illustrates a horizontal sectional view of the the aerosol filter stage 6 according to FIG. 2 it is evident that ten filter elements 21a, 21b, 21c, 21d, 21e, 21f, 21g, 21h, 22a, 22b are arranged in the housing 14 in parallel and at a distance from one another, wherein the filter elements are respectively circumferentially supported in a sealing manner at circumferentially arranged consoles of the housing 14 so that they respectively close the cross section of the housing 14. A precise support of the filter elements 21, 22 at the consoles 23 can be performed in a conventional and known manner which does not need to be described in more detail. The filter elements 21, 22 have a sickle shaped cross section so that they have lower thickness along the consoles 23, whereas they are configured thicker in a center. In the center of the housing 14, this means between the fifth and the sixth filter element 22a, b there is a clean gas collector 24 which extends approximately over a width B of approximately 400 mm and a height H of approximately 2700 mm to approximately 2900 mm of the housing 14 and which is provided on the top side with the outlet 19. The two inlet cross sections of the aerosol filter stage 6 are respectively provided with a pre chamber 25 into which the gas volume flow to be filtered (arrow 17 points into the drawing plane) can flow on both sides from above and also from below. This way it is prevented that open flames in the interior cavity of the safety container 2 reach into the aerosol filter stage 6. Downstream of the pre chamber 25 in flow direction support elements 26 configured as C-profiles are arranged that extend over the height of the housing 14, from which C-profiles the volume flow to be filtered can only flow through open top sides and bottom sides of the C-profiles and through gaps between the C-profiles and the housing 14 into the filter elements 21, 22. Accordingly the gas volume flow flows from the safety container 2 initially into the pre chamber 25 then through openings into the support elements 26 and eventually through the filter elements 21, 22 into the clean gas collector 24. Since the aerosol filter stage 6 is configured mirror symmetrical the gas volume flow to be filtered (arrow 17) passes five filter elements 21a, 21b, 21c, 21d, 22a or 22b 21e, 21f, 21g, 21h before it reaches the clean gas collector 24. The first four filter elements 21 in flow direction are configured as pre filters, whereas the filter elements 22 that are oriented towards the clean gas collector 24 are respectively operated as main filters. In flow direction of the volume flow there is a row of tubular elements 27 with a circular cross section in front of each filter element 21, 22 wherein the tubular elements extend vertically and penetrate the housing 14 in an upper and in a lower lateral surface 28 so that the inner space of the tubular elements is in contact with ambient air. When the aerosol filter stage 6 is operated heat that is generated in the aerosol filter stage 6 also heats ambient air in the tubular elements 27 which creates natural convection which is used for cooling the aerosol filter stage 6. FIG. 4 illustrates a view of the iodine filter stage 7 of the nuclear power plant 1 according to the invention illustrated in FIG. 1, wherein the iodine filter stage 7 has a cuboid housing 28 similar to the aerosol filter stage 6 of FIG. 2 and is attached by four supports 29 at a base 30. Three connection spouts 31 are arranged at a top side of the housing 28 wherein the volume flow to be filtered flows into the iodine filter stage 7 through the three connection spouts. Due to the fact that the iodine filter stage 7 is configured as a separate unit the volume flow exiting the aerosol filter stage 6 is conducted into the iodine filter stage 7 through respective conduits that are not illustrated in the figures and which connect with the connecting spouts 31 of the iodine filter stage 7. The filtered volume flow exits the iodine filter stage 7 through two rectangular outlet openings 32 at which pressure relief conduits are connected which are not illustrated in the drawing figure. In the embodiment the iodine filter stage 7 includes four beds 33 which are filled with poured iodine sorption material, wherein the beds 33 are respectively filled through filling openings 34 arranged at a top side of the beds 33, wherein the filling openings extends over the entire width B1 of the iodine filter stage 7. The filling openings 34 have a circumferential flange on which a cover plate 35 is arranged in a sealing manner with respective bolts 36. From FIG. 5 which illustrates a horizontal sectional view through the iodine filter stage 7 of FIG. 4 it is evident that the beds 33 for the iodine sorption material are assembled from sheet metal plates wherein lateral sheet metal plates 37 that extend perpendicular to a main flow through direction (arrow 39) are configured as perforated plates, so that the gas volume flow to be filtered which is indicated by arrows 38 can pass through the iodine sorption material. The entire hole pattern of the perforated sheet metal plates is thus adapted to the sieve line of the iodine sorption material so that the smallest elements cannot pass through the holes of the lateral plates 37. The bed depth T according to the embodiment of the iodine filter stage 7 illustrated herein is 40 mm with a flow through surface of approximately 2 m2. However, also other dimensions are feasible. It is evident that the gas volume flow to be filtered which has an orientation corresponding to the arrows 38 after its entry into the iodine filter stage 7 is initially deflected by approximately 90° after its entry through the connection spouts 31 into the iodine filter stage 7 so that it passes the iodine filter material and is then deflected by approximately 90° again so that it exits the iodine filter stage 7 through the outlet openings 32. Though the main flow through direction of the gas volume flow through the iodine filter stage 7 which is indicated by the arrow 39 is perpendicular to the flow direction upon induction of the gas volume flow (arrow 38), however an actual pattern of the gas volume flow will be established which is approximately S shaped according to the line 40. In analogy to the aerosol filter stage 6 of FIG. 2 also the iodine filter stage 7 has tubular elements 27 for cooling the iodine filter stage 7 during operations. The tubular elements 27 are respectively arranged in flow through direction (line 40) upstream of the beds and distributed over the width B1. FIG. 6 illustrates a horizontal sectional view through a combined aerosol and iodine filter unit 41 in which an iodine filter stage 7′ is arranged between the aerosol filter stage 6′ and the clean gas collector 24. Though FIG. 6 only illustrates an aerosol filter stage 6′ with only five filter elements 21, 22 at which the iodine filter stage 7′ and the clean gas collector 24 are connected, it is also feasible to arrange another iodine filter stage 7 and another aerosol filter stage 6 at another side of the clean gas collector 24 so that a mirror symmetrical configuration is provided in analogy to the aerosol filter stage 6 according to FIG. 3, wherein the mirror symmetrical configuration includes ten filter elements, two iodine filter stages and 1 clean gas collector. It is certainly feasible to select a different number of filter elements or iodine filter stages as a function of individual requirements of the nuclear power plant 1. The basic configuration of the aerosol filter stage 6′ coincides with the configuration of the aerosol filter stage 6 according to FIG. 3 with a pre chamber 25, support elements 26, tubular elements 27 and filter stages 21, 22. A row of tubular elements is also arranged for cooling purposes between the main filter 22 of the aerosol filter stage 6′ according to FIG. 6 and the iodine filter stage 7′. The housing 14′ of the aerosol filter stage 6′ includes an elbow 42 on a side oriented towards the iodine filter stage 7′ at both longitudinal sides, wherein a respective U-shaped folded piece of sheet metal 43 is arranged at the elbow 42 wherein the iodine filter stage 7′ is attached at the piece of sheet metal 43 wherein the iodine filter stage 7′ is essentially provided from two perforated sheet metal plates 44 arranged at the sheet metal plates 43 and poured iodine sorption material arranged there between. The connections are respectively provided gas tight so that the gas volume flow to be filtered or the filtered gas volume flow can only flow into the clean gas connector 24 so that it can exit the nuclear power plant 1 in a controlled manner through the pressure relief conduit 8 connected at the clean gas collector 24. The combined aerosol-iodine filter unit 41 has a joint filter housing 50 so that it can be transported and set up as a unit. It is furthermore evident that the aerosol-iodine filter unit 41 is assembled from eight modules 47, 48, wherein all modules 47 in addition to the edge modules 48 are provided with a circumferential flange 49 on both sides. The edge modules 48 are only provided with a circumferential flange 49 on a side oriented towards a module 47. Due to the modular configuration the illustrated combined aerosol-iodine filter unit 41 is suitable in particular for retrofitting a nuclear power plant since the modules 47, 48 have small dimensions and can thus be introduced into the containment vessel through exiting locks in the nuclear power plant. An outlet surface 51 of the gas volume flow from the main filter 22 corresponds in FIG. 6 substantially to an inlet surface 52 into the iodine filter stage 7′. In the vertical sectional view of the combined aerosol-iodine filter unit 41 which is illustrated in FIG. 7 it is apparent that the iodine filter stage 7′ protrudes at its top side beyond the aerosol filter stage 6′, wherein the iodine filter stage 7′ has a fill in opening 34′ with a circumferential flange at its top side wherein filling the bed 33′ is performed through the fill in opening. After filling the bed 33 the fill in opening 34′ is closed tight with a cover plate 35′. Furthermore FIG. 7 illustrates a connection spout 46 at the clean gas connector 24 wherein the non illustrated pressure relief conduit 8 connects to the clean gas connector. The combined aerosol-iodine filter unit illustrated in FIGS. 6 and 7 has a length l of approximately 1500 mm and a height h of approximately 2700 mm and a width b of approximately 1500 mm. The height of the inlet surface 52 into the iodine filter stage is greater than the outlet surface 51 of the gas volume flow from the main filter 22. A distance a between the outlet surface 51 and the inlet surface 52 is approximately 250 mm in FIG. 7. 1 nuclear power plant 2 containment vessel 3 reactor vessel 4 arrow (gas volume flow to be filtered) 5 aerosol pre filter stage 6, 6′ aerosol filter stage 7, 7′ iodine filter stage 8 pressure relief conduit 9 pass through opening 10 addition 11 smoke stack 12 arrow 14, 14′ housing 15 support 16 base 17 arrow 18 center axis 19 outlet 20 arrow 21 filter element 22 filter element 23 console 24 clean gas collector 25 pre chamber 26 support elements 27 tubular element 28, 28′ housing 29 support 30 base 31 connection spout 32 outlet openings 33, 33′ bed 34, 34′ fill in openings 35, 35′ cover plate 36 bolt 37 side plate 38 arrow 39 arrow 40 line 41 aerosol-iodine filter unit 42 elbow 43 sheet metal plate 44 perforated plate 45 poured material 46 connection spout 47 module 48 edge module 49 flange 50 common filter housing 51 outlet surface 52 inlet surface B width H height 1, width iodine filter stage T bed depth l length h height b width a distance
043354661	claims	1. A method of substantially instantaneously measuring the axial gross gamma activity profile of a irradiated fuel assembly, said method comprising: using a multielement detector requiring no collimator and requiring no scanning, said detector comprising a plurality of spaced apart substantially identical individual current-measuring (as opposed to pulse-measuring) detectors to measure substantially instantaneously a profile of gross gamma activity as a function of axial position along said fuel assembly. measuring substantially instantaneously the axial gross gamma activity profile of said particular fuel assembly according to the method of claim 1 both (a) at some initial time t.sub.o, so as to obtain an initial axial gross gamma activity profile, and then (b) at some later time t.sub.1, so as to obtain a final axial gross gamma activity profile; and then comparing said initial axial gross gamma activity profile with said final axial gross gamma activity profile so as to determine whether any significant differences in said profiles exist. (a) substantially instantaneously measuring the gross gamma activity profile of a fuel assembly according to the method of claim 1, wherein said gross gamma activity profile is measured with said multielement detector located out-of-core and after a cooling time which is at least about 9 months; (b) normalizing said gross gamma activity profile obtained in step (a) so as to obtain a normalized gross gamma activity profile having a peak value which is equal to 1.0; and (c) using a previously determined calibration curve of a burnup monitor and using one measurement of the burnup monitor by a gamma spectrometer to convert the normalized profile to the true burnup profile. (1) integrating said normalized gross gamma activity profile so as to obtain an integrated value G; (2) measuring the intensity I, of a particular gamma ray of a burnup monitor with a germanium detector at one axial position along said fuel assembly and determining therefrom the corresponding intensity I.sub.o at the center of said fuel assembly; (3) multiplying I.sub.o .times.G so as to obtain a monitor-calibrated total intensity I.sub.T ; and (4) locating I.sub.T on a previously obtained calibration curve of total intensity of said particular gamma ray of said monitor vs. declared burnup, so as to obtain a value of burnup corresponding to I.sub.T. (a) integrating said profile of gross gamma activity as a function of axial position along said fuel assembly so as to obtain an integrated detector response, R, for said cooling time T.sub.1 ; (b) locating T.sub.1 on a previously experimentally determined graph of (R/declared burnup) vs. cooling time, so as to obtain a corresponding value of burnup. 2. A method according to claim 1, wherein said current-measuring detectors are selected from the group of detectors consisting of gamma-measuring ionization chambers and gamma-measuring proportional chambers. 3. A method according to claim 2, wherein said object is a spent fuel assembly. 4. A method according to claim 3, wherein said individual current-measuring detectors are ionization chambers, wherein said ionization chambers are located along a straight line and are all spaced an equal distance apart, and wherein the distance between the two outermost individual detectors is equal to the length of said fuel assembly. 5. A method of determining whether a particular fuel assembly has been tampered with, said method requiring less than 10 seconds of total measurement time and comprising: 6. A method according to claim 5 wherein (t.sub.1 -t.sub.o) is less than about 2 months and wherein the cooling time is less than 9 months. 7. A method of determining burnup of an object, said method requiring less than 10 minutes of total measurement time, said method comprising: 8. A method according to claim 7 wherein said burnup monitor is Cs-137. 9. A method according to claim 8, wherein said fuel assembly has a burnup within the range from about 0 to about 40,000 MWD/MTU. 10. A method according to claim 9, wherein said fuel assembly is selected from the group consisting of BWR, PWR, and MTR fuel assemblies. 11. A method according to claim 7 or claim 10 wherein said cooling time is about 9 months and wherein step 7(c) consists of the following steps: 12. A method of determining burnup to within 10% of the declared burnup of a particular object having a known cooling time T.sub.1, using a multielement ionization chamber detector as a stand-alone device, said method comprising the method according to claim 1 and including also the following steps: 13. A method according to claim 12 wherein T.sub.1 is greater than about 9 months. 14. An apparatus requiring no collimator and no scanning and being suitable for substantially instantaneously measuring the axial gross gamma activity profile of a irradiated fuel assembly, said apparatus comprising a plurality of variably spaced apart substantially identical individual current-measuring (as opposed to pulse-measuring) detectors selected from the group of detectors consisting of gamma-measuring ionization chambers and gamma-measuring proportional chambers operable in cooperation with an electronics system which converts the multiple detector signals into an observable profile. 15. An apparatus according to claim 14, wherein said individual detectors are located along a straight line, are spaced apart equidistantly, and wherein said individual detectors occupy a total length equal to or greater than the length of an object being measured. 16. An apparatus according to claim 15, wherein said detectors are adjustably mounted on a base and wherein said individual detectors occupy a total length equal to the length of an object being measured.
	description	This is a continuing application, under 35 U.S.C. § 120, of copending international application No. PCT/EP2003/010103, filed Sep. 11, 2003, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German patent application No. 102 46 252.6, filed Oct. 2, 2002; the prior applications are herewith incorporated by reference in their entirety. 1. Field of the Invention The invention relates to a process for the treatment of a gas stream, in which the gas stream is passed over a catalytic adsorber module to oxidize entrained impurities. It further relates to a gas treatment system suitable for carrying out the process. 2. Summary of the Invention It is accordingly an object of the invention to provide a method for treating a flow of gas and a gas treatment system that overcome the above-mentioned disadvantages of the prior art devices and methods of this general type. In the operation of a nuclear plant, in particular a nuclear power station, a customary design objective is the best possible avoidance of corrosion damage on important components, especially in the primary region of the respective plant, for example on graphite internals, fuel assemblies or other components in the pressure vessel of the reactor. This is because substantial avoidance of corrosion damage on these components should increase the life or operating time and keep down the maintenance and repair requirement associated with the alleviation of corrosion damage in the primary region of the nuclear plant, which is sometimes considerable. For this reason, the use of helium may be specified as a working or cooling medium in a nuclear plant, in particular in the primary circuit of a high-temperature reactor. This is because helium is chemically inert, so that, for example, corrosion phenomena caused by the cooling gas on the components specified does not have to be reckoned with when helium is used as the cooling gas for these components. However, impurities such as carbon monoxide (CO), molecular hydrogen (H2), methane (CH4), molecular oxygen (O2), tritium, water (H2O), carbon dioxide (CO2) and/or dust particles can get into the helium used as the primary coolant or cooling gas during operation of the nuclear plant, in particular during operation of a high-temperature reactor. The impurities can in turn lead to undesirable corrosion phenomena on the components specified. To keep these effects small and, in particular, below prescribed limits which are considered to be still permissible, limitation of the concentration of such impurities in the cooling gas stream by use of a gas purification plant or a gas treatment system may be specified. During operation of such a gas purification system, a substream of from about 50 kg/h to 300 kg/h is usually taken from the helium cooling circuit and first passed through a dust filter. The gas stream to be purified is subsequently heated to a temperature of about 250° C. and fed to a catalytic adsorber module. The catalytic adsorber module serves first to catalyze the transformation processes provided and second as a type of buffer for the temporary storage of oxygen required in these processes. In the catalytic adsorber module, which usually contains a Cu—CuO mixture as catalytically active adsorber component, oxidation of the hydrogen and carbon monoxide entrained as impurities in the gas stream to be purified to water (H2O) and carbon dioxide (CO2) occurs under the specified, suitably selected operating temperature. The oxygen required for this is taken from the CuO of the catalytically active adsorber material, so that a continuous increase in the proportion of Cu at the expense of the CuO occurs as a result of the reaction. The gas stream to be purified, which has now been freed of molecular hydrogen and carbon monoxide, is then usually cooled, with the entrained water and carbon dioxide being separated out in molecular sieves. A low-temperature adsorption in which predominantly methane, molecular oxygen and association products are removed by adsorption from the gas stream to be purified is then usually carried out. After the removal of the impurities is complete, the now purified gas stream is returned to the helium cooling circuit. However, such a gas treatment system is comparatively complicated, especially in respect of the number and installation of the components required. In addition, the use of the catalytic adsorber module of the type mentioned results in that regeneration by treatment with oxygen is necessary after the CuO in the catalytic adsorber module has been “consumed”, i.e. after virtually all the CuO has been converted into Cu, so that the respective module is not available for purification of the gas stream during this time. For this reason, two or more similar sub-lines are usually connected in parallel in such a gas treatment system, which increases the outlay for apparatus even further. It is therefore an object of the invention to provide a process for the treatment of a gas stream of the above-mentioned type by which reliable purification of the gas stream is made possible using comparatively simple apparatus. Furthermore, a gas treatment system, which is particularly suitable for carrying out the process is to be provided. According to the invention, this object is achieved in respect of the process by passing the gas stream over a first catalytic adsorber module in a first purification stage for the oxidation of entrained impurities and mixing molecular or atomic oxygen into the gas stream, with the gas stream which has been admixed with the mixed-in oxygen being passed over an oxidation catalyst in a second purification stage and the gas stream leaving the oxidation catalyst being passed over a second catalytic adsorber module in a third purification stage for the reduction of excess oxygen. The invention starts out from the idea that the outlay in terms of apparatus and operation for reliable purification of the gas stream using catalytic adsorber modules can be kept particularly low by, in particular, keeping the total number of components required small. The concept of gas treatment should therefore be directed at substantial avoidance of redundancies in the components used. To accordingly keep the number of sub-lines having the same effect which are connected in parallel particularly small or to be able to configure the gas treatment system as a single line in terms of the gas flow, the concept for the treatment of the gas stream should be directed at continuous operation of the respective catalytic adsorber module. This can be achieved by the use of two catalytic adsorber modules connected in series in the direction of gas flow, of which one is used in a conventional manner for the oxidation of the entrained impurities in the treatment of the gas stream and is reduced as a result, while the other catalytic adsorber module is used for the reduction of oxygen and is oxidized as a result. When one of the adsorber modules is completely “exhausted”, i.e. the respective constituent is completely oxidized or reduced, in such a configuration, continued operation of the gas treatment system is made possible by simple reversal of the gas flow through the catalytic adsorber modules. To make the combined use of the catalytic adsorber modules for oxidation and reduction, respectively, possible, the gas stream is subjected to a further purification stage, which is required in any case, in an oxidation catalyst between the catalytic adsorber modules. The additional oxygen required for this purpose is mixed into the gas stream at a suitable point upstream of the oxidation catalyst, with excess oxygen being available in the second, downstream catalytic adsorber module for oxidation and thus regeneration of the latter. A Cu—CuO mixture is advantageously used as the catalytic adsorber material both in the first catalytic adsorber module and in the second catalytic adsorber module. In the first catalytic adsorber module viewed in the direction of gas flow, which is provided for oxidation of impurities entrained in the gas stream, the CuO in the adsorber material is converted into Cu with liberation of the oxygen required for oxidation. In contrast, in the second catalytic adsorber module viewed in the direction of gas flow, in which the excess oxygen now present in the gas stream is removed by adsorption, the Cu in the catalytic adsorber material is converted into CuO. As the time of operation of the treatment of the gas stream increases, the proportion of Cu in the first, upstream catalytic adsorber module increases and the proportion of CuO in the catalytic adsorber material present there decreases, while, conversely, the proportion of Cu in the second, downstream catalytic adsorber module decreases and the proportion of CuO in the catalytic adsorber material present there increases. If one of the catalytic adsorber modules is found to be “exhausted”, i.e. the respective catalytic adsorber material present has been completely converted into Cu or CuO, the gas flow through the catalytic adsorber modules can be switched over, so that the CuO-enriched catalytic adsorber module is now used as first catalytic adsorber module for the oxidation of impurities entrained in the gas stream and the Cu-enriched catalytic adsorber module is used as second catalytic adsorber module for the reduction of excess oxygen. Oxygen is advantageously mixed in in such an amount that sufficient excess oxygen is always present in the second, downstream catalytic adsorber module to oxidize the catalytically active adsorber material present there. For this purpose, it is advantageous to determine an index for the proportion of entrained impurities in the gas stream before the gas stream enters the first catalytic adsorber module, by which the amount of oxygen to be mixed into the gas stream settles. To ensure efficient utilization of both the first catalytic adsorber module and also the second catalytic adsorber module, the amount of oxygen mixed in is advantageously set so that there is a deficiency of oxygen based on the total impurities entrained in the gas stream and thus at least part of the oxidation of the impurities occurs in the first catalytic adsorber module and so that there is an oxygen excess based on the reaction of further impurities intended to occur in the oxidation catalyst, so that excess oxygen is available in the second catalytic adsorber module for regeneration of the catalytic adsorber material present there. The oxidation catalyst is preferably used for the treatment of impurities such as methane or tritium. To ensure a particularly high conversion and thus particularly careful removal of such impurities from the gas stream, the temperature of the gas stream is advantageously set to from about 400° C. to 450° C. before it enters the oxidation catalyst, so that, when sufficient oxygen has been made available, particularly substantial conversion of the impurities mentioned into water and carbon dioxide can occur. A particularly resource-conserving and thus economical mode of operation can be achieved in a particularly advantageous embodiment by the gas stream being preheated by recuperative heat exchange with the gas stream leaving the oxidation catalyst before the first gas stream enters the oxidation catalyst. The heat contained in the gas stream leaving the oxidation catalyst is at least partly utilized for preheating the gas stream entering the oxidation catalyst, so that supplementary heating, for example electric supplementary heating, may still be necessary for setting the final desired entry temperature in the gas stream. Particularly when using a Cu—CuO mixture as the catalytically active adsorber material in the first catalytic adsorber module, this is preferably used for the oxidation of hydrogen and carbon monoxide entrained in the gas stream. To ensure a particularly favorable reaction rate and a particularly favorable degree of reaction in the oxidation of these to water and carbon dioxide with targeted utilization of the catalytic properties of Cu, a temperature of about 250° C. is advantageously set for the gas stream before it enters the first catalytic adsorber module. Here too, a particularly resource-conserving and thus economical mode of operation can be achieved in a further advantageous embodiment by the gas stream being preheated by recuperative heat exchange with the gas stream leaving the second catalytic adsorber module before the first gas stream enters the first catalytic adsorber module. Thus, in this advantageous embodiment, the heat content of the total gas stream leaving the second catalytic adsorber module and thus the gas purification system is utilized for the partial preheating of the gas stream flowing into the gas purification system. In a particularly advantageous embodiment, the process is used in the operation of a nuclear power plant for the treatment of a substream of a helium cooling gas stream. Here, the substream of the helium cooling gas stream is preferably freed of entrained impurities such as carbon monoxide, molecular hydrogen, methane, molecular oxygen, tritium, water and/or carbon dioxide. The conversion of molecular hydrogen and carbon monoxide into water and carbon dioxide is preferably effected in the first catalytic adsorber element. When a sufficient amount of oxygen is mixed in in good time, methane and/or tritium are then likewise converted into carbon dioxide and/or water in the oxidation catalyst. The excess oxygen, which then still remains in the gas stream is subsequently used for enrichment of the second catalytic adsorber module and thus removed from the gas stream again. Removal of the water and carbon dioxide still present in the gas stream can subsequently be effected in a conventional way, and can, if appropriate, be supplemented by removal of dust particles or noble gas activities. The helium gas substream, which has been purified in this way is subsequently returned to the actual helium cooling circuit. In this application in particular, the process can be utilized in a particularly advantageous way to make continuous treatment of a gas stream possible while using comparatively few components. Since the first catalytic adsorber module viewed in the flow direction of the gas stream is reduced in the treatment of the gas stream but the second catalytic adsorber module viewed in the flow direction of the gas stream is oxidized, CuO is continuously converted into Cu in the first catalytic adsorber module and Cu is continuously converted into CuO in the second catalytic adsorber module. As soon as it has been established that one of the catalytic adsorber modules is completely “exhausted”, i.e. the Cu or the CuO has been converted completely into the other component of the mixture, the order in which the catalytic adsorber modules are connected in the flow path of the gas stream can be switched around. After switching has been carried out, the second catalytic adsorber module which has hitherto been utilized for removal of oxygen from the gas stream is thus utilized further as newly connected first catalytic adsorber module, with the oxygen incorporated in this adsorber module now being given off again to the gas stream in the treatment of the relevant impurities in the gas stream. The first catalytic adsorber module which has hitherto been used for the oxidation of hydrogen or carbon monoxide in the gas stream is, after switching over, utilized as newly connected second catalytic adsorber module, with the CuO present in the catalytically active adsorber material being regenerated by uptake of the excess oxygen from the gas stream. To achieve timely and particularly appropriate implementation of the switch-over, an index for the proportion of possibly entrained oxygen is advantageously determined for the gas stream leaving the second catalytic adsorber module. After a prescribed limit for this index has been exceeded, it is concluded that the Cu in the second catalytic adsorber module has been completely reacted, so that the positions of the first and second catalytic adsorber elements in the flow path of the gas stream are exchanged. With regard to the gas treatment system, the object indicated is achieved by at least two catalytic adsorber modules, which are connected in series in the direction of a gas stream and between which an oxidation catalyst is located. To aid the intended conversion of the respective impurities in the oxidation catalyst to a particular degree, the oxidation catalyst is advantageously preceded in the gas flow direction by a feed unit for molecular or atomic oxygen (test, see above). In a particularly advantageous embodiment, the introduction or mixing-in of the oxygen into the gas stream is carried out in the amount required and thus as a function of the impurities entrained in the gas stream. To make this possible, a control parameter transducer assigned to the feed unit is advantageously connected on the inlet side to a sensor for the proportion of entrained impurities in the gas stream located upstream of the first, upstream catalytic adsorber module. The gas treatment system is advantageously equipped for use in the treatment of a substream from a helium primary cooling circuit of a nuclear plant. For the removal of typical impurities such as molecular hydrogen or carbon monoxide from a helium gas stream in particular, first the catalytic properties and second the suitability for storage of oxygen of a Cu—CuO mixture are particularly advantageous. The catalytic adsorber modules of the gas treatment system therefore advantageously each contain a Cu—CuO mixture as catalytic adsorber material. To make it possible to set particularly advantageous and appropriate operating parameters, in particular a suitable operating temperature in the oxidation catalyst, the oxidation catalyst is advantageously preceded in the gas flow direction by an intermediate heating system. This can be operated in a particularly resource-conserving and thus economical manner when it is configured for the recovery of heat from the gas stream leaving the oxidation catalyst. To achieve this, the intermediate heating system advantageously contains a recuperative heat exchanger, which is connected on the primary side into an outflow line for the gas stream from the oxidation catalyst and on the secondary side into an inflow line for the gas stream to the oxidation catalyst. To make it possible for a desired entry temperature of the gas stream into the oxidation catalyst to be set appropriately in a flexible mode of operation, the recuperative heat exchanger is supplemented in a further advantageous embodiment by a heating element, advantageously an electric heater. In an analogous manner, the gas treatment system is also configured for the setting of a particularly favorable operating temperature in the first, upstream catalytic adsorber module. For this purpose, it is advantageously preceded by a heating system. The heating system, too, can be operated in a particular resource-conserving and thus economical manner by being advantageously configured for the recovery of heat from the gas stream leaving the gas treatment system. To achieve this, the heating system contains, in a further advantageous embodiment, a recuperative heat exchanger, which is connected on the primary side into an outflow line for the gas stream from the second catalytic adsorber module and on the secondary side into an inflow line for the gas stream into the first catalytic adsorber module. In a particularly advantageous embodiment, the gas treatment system is configured for a continuous mode of operation in which the first, upstream catalytic adsorber module is reduced during operation and the second, downstream catalytic adsorber module is oxidized. To make continuous operation possible even after complete reaction of the active materials in these reactions, the gas treatment system is advantageously configured for switching of the catalytic adsorber modules in respect of their connection in the flow path of the gas stream when necessary. For this purpose, the catalytic adsorber modules are advantageously provided with a joint switching system for directing the flow of the gas stream. A particularly compact construction of the gas treatment system can be achieved in a particularly advantageous embodiment by its components, i.e. in particular the catalytic adsorber modules and the oxidation catalyst but also, if applicable, the heating systems with their heat exchangers and/or the feed unit for oxygen, being disposed in an integrated configuration in a common pressure vessel. Here, all components mentioned can be surrounded by a common pressurized enclosure which ensures maintenance of the pressure of the total system. The individual components located in the high-pressure enclosure can, as a result of the decoupling of the maintenance of the pressure from the structural configuration of the individual components, have comparatively thin walls and be designed for low mechanical stresses. This first allows a material-saving and thus economical construction and second, owing to the then comparatively small thermal masses, comparatively rapid heating and cooling of individual components and rapid and flexible matching of the reaction temperatures required for the gas stream to be purified. In particular, a thin-walled configuration of the active components makes it possible for a comparatively high temperature to be set quickly and reliably in the respective reaction zones, so that a comparatively high conversion in the individual reactions can be achieved even in the short term. In addition, the integration of the recuperative heat exchanger into the common pressurized enclosure also allows effective cooling of the outflowing gas stream before it reaches downstream purification components, for example molecular sieves, with effective heating of the inflowing gas stream being ensured at the same time. The recuperative heat exchanger located upstream of the oxidation catalyst likewise makes it possible to achieve effective cooling of the gas stream leaving the oxidation catalyst, so that overheating of the second catalytic adsorber module located downstream of this can be reliably avoided. The gas treatment system is advantageously connected to the helium cooling gas circuit of a nuclear plant. The advantages achieved by the invention are, in particular, that the connection of an oxidation catalyst in series between a first catalytic adsorber module and a second catalytic adsorber module makes targeted treatment of various impurities in the respective gas stream possible, with the first, upstream catalytic adsorber module being able to be used for oxidation purposes in the treatment of the gas stream and its oxygen-carrying component thus being increasingly consumed but the second, downstream catalytic adsorber module being at the same time able to be used in converse operation to remove excess oxygen from the gas stream, thus regenerating its oxygen-carrying component. The normal operation of a catalytic adsorber module and the regeneration of a catalytic adsorber module are thus effected at the same time and thus in one process operation. Even after “consumption” of the oxygen-carrying component has occurred in the first, upstream catalytic adsorber module, the gas treatment system can be utilized further without an appreciable interruption to operation after the positions of the catalytic adsorber modules in the flow path of the gas stream have simply been switched over so that the previously regenerated adsorber module is now used as first, upstream catalytic adsorber module for the oxidation of impurities in the gas stream and the “exhausted” catalytic adsorber module is now regenerated at the same time. As a result of the continuous operation of the gas treatment system, in which interruptions to operation for specific regeneration of individual adsorber modules are no longer necessary, made possible in this way, redundancies or multi-stream configurations of such systems can be dispensed with or at least reduced. In addition, the integration of the active components into a common pressurized enclosure achieves a particularly compact and thus space-saving construction in which particularly simple and rapid process operation is additionally made possible as a result of the decoupling of maintenance of the pressure from the thermally stressed structural components. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a method for treating a flow of gas and a gas treatment system, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. In all the figures of the drawing, sub-features and integral parts that correspond to one another bear the same reference symbol in each case. Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a gas treatment system 1. The gas treatment system 1 is provided for the treatment of a gas stream G, namely a substream from a helium primary cooling circuit of a nuclear plant, which is not shown in more detail. For this purpose, the gas treatment system 1 is connected via a gas feed line 2 and a gas discharge line 4 to the helium primary cooling circuit, which is not shown in more detail, of the nuclear plant. The gas treatment system 1 is provided for the targeted removal of impurities, for example hydrogen, carbon monoxide, methane or tritium, which are possibly entrained in the helium of the gas stream G. The removal of hydrogen and carbon monoxide is to be effected by oxidation to water and carbon dioxide, respectively, which are in each case removed and retained in molecular sieves, which are not shown in more detail, installed in the gas discharge line 4. To convert hydrogen and carbon monoxide into water and carbon dioxide, respectively, the gas purification system contains a number of catalytic adsorber modules 6. A Cu—CuO mixture is present as the catalytic adsorber material in each catalytic adsorber module 6. When using the catalytic adsorber material, its property as a catalyst to aid the desired conversion of hydrogen into water and of carbon monoxide into carbon dioxide is utilized. Second, the ability of the catalytic adsorber material to temporarily store oxygen, which is liberated into the gas stream for the oxidation of hydrogen or carbon monoxide when required, i.e. in the desired reaction, is also utilized. In a catalytic adsorber module 6 operated in this operating mode, i.e. for the oxidation of hydrogen or carbon monoxide, the proportion of CuO in the catalytic adsorber material is decreased while the proportion of Cu is increased. In addition, the gas treatment system 1 has an oxidation catalyst 8 for the specific conversion of methane or tritium into carbon dioxide and/or water. The gas stream G enters the oxidation catalyst 8, which contains a suitably structured noble metal honeycomb, preferably one containing platinum and/or palladium, as the catalytically active component, via an inflow line 10. On the outlet side, the oxidation catalyst 8 is connected to an outflow line 12 for the gas stream G. To make the desired reaction for removing the impurities methane or tritium in the oxidation catalyst 8 possible, a feed line 13 for oxygen is installed in the inflow line 10 upstream of the oxidation catalyst 8. The illustrative embodiment provides for molecular oxygen to be fed in, but it would also be possible to provide other suitable selected oxygen carriers. To avoid multiple redundancies and to keep the total number of components required small, the gas treatment system is configured for continuous operation. Continuous operability is provided even for the case when the CuO in the catalytic adsorber module 6 used for the oxidation of the specified impurities in the gas stream G has been completely or virtually completely consumed. To make continued operation of the gas treatment system 1 possible in this case, too, without interruption for a regeneration phase for the catalytic adsorber module 6 being necessary, the gas treatment system 1 has a plurality of, in the illustrative embodiment two, similarly configured catalytic adsorber modules 6. The catalytic adsorber modules 6 are connected in series in the gas flow direction via the inflow line 10 and the outflow line 12, with the oxidation catalyst 8 being located, viewed in the gas flow direction, between the catalytic adsorber modules 6. To connect the catalytic adsorber modules 6 and the oxidation catalyst 8 to one another in terms of gas flow, the catalytic adsorber modules 6 are provided with a joint switching system 14 which includes a first switching unit 16 located at the end of the catalytic adsorber modules 6 and a second switching unit 18 located at the other end of the catalytic adsorber modules 6. The switching units 16, 18 are, as indicated by the double arrow 20, connected in an interactive way so that appropriate synchronous switching of the flow path through the catalytic adsorber module 6 is made possible. The switching system 14 is configured so that the positioning of the two catalytic adsorber modules 6 in respect of the series arrangement in the gas flow direction of the first catalytic adsorber module 6, the oxidation catalyst 8 and the second catalytic adsorber module 6 can be exchanged. As can be seen for a first switching position in FIG. 1, the catalytic adsorber module 6 shown as lower module in FIG. 1 is connected at the inlet end to the gas feed line 2 and at the outlet end to the oxidation catalyst 8 via the inflow line 10. In contrast, in this switching position, the catalytic adsorber module 6 shown at the top in FIG. 1 is connected at the inlet end to the oxidation catalyst 8 via the outflow line 12 and at the outlet end to the outflow line 4. In the switching position shown in FIG. 1, the lower catalytic adsorber module 6 as the first catalytic adsorber module 6, the oxidation catalyst 8 and the upper catalytic adsorber module 6 as the second catalytic adsorber module 6 are thus disposed in series in the gas flow direction. After the series connection has been switched over by the switching system 14, an alternative switching position represented in FIG. 1 by the switching elements shown in broken lines in the switching units 16, 18 can be obtained. In the second switching position, the catalytic adsorber module 6 shown at the top is now connected as the first catalytic adsorber module 6 upstream of the oxidation catalyst 8 by the inflow line 10, while, in the second switching position, the lower catalytic adsorber module 6 is connected as the second catalytic adsorber module 6 downstream of the oxidation catalyst 8 by the outflow line 12. The catalytic adsorber module 6, which is connected as the first catalytic adsorber module 6 upstream of the oxidation catalyst 8 in the respective switching position serves to oxidize hydrogen or carbon monoxide entrained in the gas stream G. Here, the CuO in the respective catalytic adsorber module 6 gives off oxygen into the gas stream G to make the oxidation possible. To make a reaction temperature in the gas stream G, which is particularly favorable for this reaction possible with comparatively low operating costs and in a resource-conserving manner, a recuperative heat exchanger 22 whose primary or heating side is connected into the offgas line 4 is disposed in the feed line 2. The recuperative heat exchanger 22 thus makes heat transfer from the gas stream G leaving the gas treatment system 1 to the gas stream G flowing into the gas treatment system 1 possible, so that particularly resource-conserving preheating of the inflowing gas stream G is achieved. To make it possible to set particularly favorable operating parameters, in particular an operating temperature of about 250° C., which is particularly favorable for the desired reaction, the recuperative heat exchanger 22 is supplemented by an electrically operated heater 24, which together with the recuperative heat exchanger 22 forms a heating system 26 for the gas treatment system 1. The heating power of the electrically operable heater 24 is controlled via a central control unit 28 which provides suitable control parameters for the electric heater 24 on the basis of a multiplicity of operating parameters determined at suitable positions in the gas stream G, as represented by the arrows 30. After the hydrogen or carbon monoxide impurities in the gas stream G have been converted in the first, upstream catalytic adsorber module 6, the gas stream G is passed on to the oxidation catalyst 8. There, in the illustrative embodiment, entrained methane or tritium is converted. To make this possible, a suitably selected amount of oxygen is mixed into the gas stream G via the feed line or unit 13. The feed rate for the oxygen is set by the central control unit 28 on the basis of an index determined by a sensor 32 for the proportion of impurities entrained in the gas stream G. To ensure reliable removal of the specified impurities from the gas stream G in the oxidation catalyst 8, provision is made for the setting of a temperature level, which is particularly suitable for achieving this at the point at which the gas stream G enters the oxidation catalyst 8. For this purpose, an intermediate heating system 34 is installed upstream of the oxidation catalyst 8. The intermediate heating system 34 contains a recuperative heat exchanger 36, which is connected on the primary side into the outflow line 12 and on the secondary side into the inflow line 10. The recuperative heat exchanger 36 thus makes heat transfer from the gas stream G leaving the oxidation catalyst 8 to the gas stream G flowing into the oxidation catalyst 8 possible in a resource-conserving way in the manner of a heat recovery facility. To enable final setting of an entry temperature of the gas stream G of from about 400° C. to 450° C. which is particularly favorable for the reaction in the oxidation catalyst 8, the recuperative heat exchanger 36 is supplemented by an electric heater 38 whose heating power is likewise controlled via the central control unit 28. To promote the oxidation dreaction of the specified impurities occurring in the oxidation catalyst 8 further, provision is made for particularly intimate mixing of the oxygen fed in via the feed line or unit 13 with the gas stream G before the latter enters the oxidation catalyst 8. For this purpose, a suitable mixer 40, for example a static mixer, is installed upstream of the oxidation catalyst 8. After the oxidation of the specified impurities by reaction with the oxygen fed in has occurred in the oxidation catalyst 8, the gas stream G flowing out from the oxidation catalyst 8 still contains a small amount of excess oxygen. To remove the excess oxygen, the gas stream G is conveyed via the second, downstream catalytic adsorber module 6 before being discharged. Here, the excess oxygen entrained in the gas stream is incorporated in the catalytic adsorber material present there. In particular, the proportion of CuO in the catalytic adsorber material present in the second, downstream catalytic adsorber module 6 is increased by incorporation of oxygen, with the proportion of Cu in the adsorber material being reduced. As a result of the incorporation of the excess oxygen, the CuO of the catalytic adsorber module 6 is regenerated in normal operation of the gas treatment system 1, so that the catalytic adsorber module 6 is once again available for use as the first, upstream catalytic adsorber module 6 after a sufficient period of operation. To obtain a particularly compact and thus space-saving and material-saving construction, the significant components of the gas treatment system 1 are integrated into a structural unit 42, which is shown in longitudinal section in FIG. 2 and in cross section in FIG. 3. The structural unit 42 has, in particular, a pressure-rated, essentially cylindrical outer housing 44, which encloses all the components mentioned. The outer housing 44 is configured to withstand the full pressure encountered, so that the components disposed within it can have comparatively thin walls and do not have to be configured to withstand separate mechanical stress. The oxidation catalyst 8 is located in the central region of the outer housing 44, and the mixer 40 is positioned immediately above it. The feed unit 13 for the oxygen is disposed in the manner of an annular injection unit above the mixer 40. In the illustrative embodiment, the recuperative heat exchanger 36, supplemented by the electric heater 38, is located below the oxidation catalyst 8. The recuperative heat exchanger 36 is advantageously configured as a shell-and-tube heat exchanger. The heating power of the heater 38 can be regulated. The precise configuration of the heating rods in each of these components can of course be varied and chosen according to requirements. The positioning of the recuperative heat exchanger 36 and the oxidation catalyst 8 in the central region of the structural unit 42 ensures that only comparatively small heat losses occur, so that a particularly favorable degree of conversion can be achieved even at only low heating power. The two catalytic adsorber elements 6 in the illustrative embodiment are located in the outer region within the outer housing 44. With regard to the dimensions of the Cu/CuO reaction beds located therein, a ratio of reaction bed height to reaction bed length of about L/d≡4 . . . 8 is adhered to. Compensators, which are not shown in more detail are provided to compensate for thermal expansion. To control the process conditions appropriately, temperature sensors 46 and suitably positioned sampling elements 48 to make analysis of the impurities entrained in the gas stream G possible are disposed in the catalytic adsorber elements 6. The sensors provided for analysis are suitably configured for the analysis of the impurities. In particular, they can be gas chromatographs, mass spectrometers and/or sensors operating according to the principle of heat dissolution or thermal conductivity. The configuration of the gas treatment system 1 as an integrated unit 42 achieves structural decoupling of the thermally stressed components from the pressure-stressed outer housing 44. The decoupling first allows the outer housing to be constructed using commercially available materials with a low materials consumption and with particularly high operating lives being ensured, and second makes it possible for the thermally stressed components to have comparatively thin walls. The operation of the gas treatment system 1 is configured, in particular, so that the second catalytic adsorber element 6 located in the downstream position as a function of the respective switching position of the switching system 14 is regenerated for future use by appropriate exposure to excess oxygen. Accordingly, the introduction of the oxygen in the feed unit 13 is set so that there is still sufficient excess oxygen available for incorporation into the respective downstream catalytic adsorber module 6 even after the gas stream G has passed through the oxidation catalyst 8. The oxygen is, in particular, fed in in such an amount that an excess of oxygen, based on the methane impurity determined in the gas stream G, prevails in the oxidation catalyst 8, so that remaining excess oxygen can be passed onto the downstream catalytic adsorber module 6. However, the amount of oxygen fed in is also set so that there is a deficiency of oxygen based on the total impurities determined in the gas stream G. This ensures that the amount of oxygen released from the catalytic adsorber material of the first, upstream catalytic adsorber module 6 in the oxidation of water or carbon monoxide in the adsorber module is greater than the amount of oxygen which is taken up again in the second, downstream catalytic adsorber module 6. The reduction reaction in the Cu—CuO mixture of the first, upstream catalytic adsorber module 6 therefore proceeds more quickly than the oxidation reaction in the Cu—CuO mixture of the second, downstream catalytic adsorber module 6. Accordingly, should “consumption” of the oxygen in the first, upstream catalytic adsorber module 6 be found, for example in the case of breakthrough of hydrogen or carbon monoxide, an excess of oxygen based on the total impurities determined is set by adjusting the feed rate for the oxygen in the feed unit 13, so that reliable conversion of the remaining impurities in the oxidation catalyst 8 is ensured. As soon as a sufficiently high incorporation of oxygen in the second, downstream catalytic adsorber module 6 is then established, the order in which the catalytic adsorber modules 6 are connected relative to the oxidation catalyst 8 can be switched over in the manner described.
	claims	1. A nuclear fuel rod for a fast reactor, comprising:tubular fuel materials comprising a hollow portion formed therein;a tubular inner pipe inserted into the hollow portion of the tubular fuel materials to prevent collapse of the tubular fuel materials due to combustion of nuclear fuel;a tubular cladding pipe which surrounds the tubular fuel materials; anda liquid metal charged in a gap between the tubular fuel materials and the tubular cladding pipe, whereinthe tubular inner pipe comprises a collecting space formed therein to collect fission products which are generated due to combustion of the nuclear fuel,wherein the tubular cladding pipe is formed from stainless steel,wherein the tubular inner pipe is formed from molybdenum (Mo), tungsten (W), niobium (Nb), or tantalum (Ta). 2. The nuclear fuel rod of claim 1, wherein the tubular fuel materials comprises at least one element selected from a group consisting of uranium (U), plutonium (Pu), zirconium (Zr), americium (Am), neptunium (Np), and curium (Cm). 3. The nuclear fuel rod of claim 1, wherein a cross section fraction occupied by the tubular fuel materials takes up 50% to 90% of the total cross section of the fuel rod. 4. The nuclear fuel rod of claim 1, wherein an outer circumference of the tubular inner pipe and an inner circumference of the tubular fuel materials contact each other, so that the tubular inner pipe supports the tubular fuel materials. 5. The nuclear fuel rod of claim 1, wherein the liquid metal is sodium. 6. The nuclear fuel rod of claim 1, wherein the tubular fuel materials are formed by casting metal fuel materials. 7. The nuclear fuel rod of claim 1, wherein the tubular fuel materials are formed by Vibro-packing metal fuel particles.
053348478	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ionizing radiation shields. More particularly, the present invention relates to a shielding composition for attenuating gamma rays and absorbing neutrons. 2. Discussion of Background In working with high-level radioactive materials, such as spent nuclear fuels, nuclear waste and industrial radiation sources, the use of thick shielding, remote manipulation, or both is necessary to minimize radiation exposure to human operators. Lead has often been used for gamma ray shielding because it is dense, easily worked and relatively inexpensive. Also, a lead shield can often be smaller than a comparable radiation shield made of virtually any other material so it takes up less space and is more portable. However, lead is a toxic metal that is slowly attacked and corroded by air, water and soil acids. Also, water-soluble lead compounds, such as lead carbonate, tend to persist in the environment for long periods of time and are highly toxic to humans and other forms of life. Lead tends to accumulate in the body, similar to other heavy-metal poisons, and continues producing toxic effects for many years after exposure. Therefore, it is desirable to eliminate lead from many of its present uses, including radiation shielding, and to find substitutes for lead. Depleted uranium (chiefly uranium-238) is well known for use in absorbing gamma radiation. For example, Takeshima et al, in U.S. Pat. No. 5,015,863, discloses the use of depleted uranium particles for radiation shielding. Also, Barnhart et al, in U.S. Pat. No. 4,868,400, discloses the use of depleted uranium rods or small balls as radiation shielding in an iron cask for shipping and storing spent nuclear fuel. However, U-238 is radioactive, with a half-life of about 4.5 billion years, and undergoes about 12,000 disintegrations per gram per second. Uranium, in addition to being radioactive, is readily corroded. Also, its soluble salts are quite toxic. However, uranium is not as likely as lead to accumulate in the body. Because of its radioactivity, its tendency to corrode or other factors, uranium is usually accompanied by an overcoating of a non-radioactive, highly absorbent material, such as lead. In U.S. Pat. No. Re. 29,876, Reese discloses a depleted uranium container, with a corrosion-free coating of stainless steel, for transporting radioactive materials. Takeshima, in U.S. Pat. No. 5,015,863, uses depleted uranium particles coated with a metal of high thermal conductivity, such as aluminum, copper, silver, magnesium, or the like. As for shielding neutrons, cadmium is the material most known for such use. Other neutron-absorbing materials exist, but do not absorb neutrons as well as cadmium and also have disadvantages that discourage their use. For example, hydrogen, the most common neutron absorber, is readily available and non-toxic, but hydrogen has a relatively small absorption cross-section, or probability of a nucleus absorbing a neutron. Also, lithium and boron, which are relatively better neutron absorbers, are both chemical poisons and are difficult to handle in the metallic state. Cadmium-113 absorbs thermal (low energy) neutrons extremely well but, like uranium, is a radioactive material with a very long half-life. Also, cadmium is very toxic to humans, with effects on the central nervous system similar to those of mercury. Because of the undesirable features of cadmium as a neutron absorber, gadolinium is sometimes substituted. Gadolinium is a rare-earth metal existing in seven natural isotopes. Only one of these isotopes is slightly radioactive, and it makes up only 0.2% of the total metal. Natural gadolinium averages only about one gadolinium-152 disintegration per gram in each ten minutes, and thus is considered to be non-radioactive for most purposes. Gadolinium is used primarily in controlling the chain reaction in nuclear energy production. Gadolinium is also known as a shielding material, especially in storing radioactive materials, as is disclosed by Takeshima et al in U.S. Pat. No. 5,015,863 and Barnhart et al in U.S. Pat. No. 4,868,400. Both gadolinium-155 and gadolinium-157 have much higher neutron absorption cross-sections than cadmium (three times and twelve times that of cadmium-113, respectively). Moreover, each of these isotopes makes up a higher percentage of gadolinium metal than does the isotope cadmium-113 in cadmium. Therefore, a neutron absorber made substantially of gadolinium does not have to be as pure as one made of cadmium to absorb thermal neutrons as effectively. In nature, gadolinium occurs mixed with other rare-earth metals, but can be separated by well known techniques such as ion-exchange and the like. Gadolinium is malleable, ductile, and available in a number of forms, including sheets, foil and wire. Gadolinium is stable in dry air, but is attacked by acids and moist air. Thus, gadolinium requires varying degrees of protection for certain applications. Despite the availability of radiation shield materials such as depleted uranium, which absorbs gamma rays, and gadolinium, which absorbs neutrons, there remains a need for more effective radiation shielding. SUMMARY OF THE INVENTION According to its major aspects and broadly stated, the present invention is a composition for radiation shielding. In particular, it is a radiation shield with a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheeting of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably formed into a container for storing radioactive materials. The container is formed by pre-forming uranium into a vessel, adding gadolinium sheeting to the vessel if neutron absorption is needed, and casting bismuth around the pre-formed uranium/gadolinium vessel. The resulting container is a structurally-sound, corrosion-resistant metallic block having strong radiation-attenuating properties, yet has a non-toxic, non-radioactive surface. A major feature of the present invention is the use of bismuth as a coating for a uranium shield. In addition to absorbing gamma rays, the bismuth coating protects the shield from corrosion. In a container for transportation of radioactive materials from a facility, a corrosion-free surface is important not only for a long-lived container but also for making the requisite measurements of contamination that might have gotten on the exterior surface of the container before such a container can depart the facility. If the container is to be used for permanent disposal of the radioactive material, corrosion resistance is essential to prevent loss of container integrity before radioactive decay is complete. Another feature of the present invention is the interaction between bismuth and both uranium and gadolinium. Bismuth, when molten, spreads evenly over both uranium and gadolinium without dissolving significant amounts of either material. Upon cooling, the bismuth adheres strongly to the material, forming a high-melting, intermetallic compound. This feature provides a high-integrity coating that will not be removed easily, even under extreme conditions. Other features and advantages of the present invention will be apparent to those skilled in the art from a careful reading of the Detailed Description of a Preferred Embodiment presented below and accompanied by the drawings.
	abstract	A securing device is installable on an outer circumferential surface of a nuclear reactor core shroud and in contact with an inner circumferential surface of a pressure vessel. The securing device includes a base configured for contacting the outer circumferential surface of the nuclear reactor core shroud. The securing device also includes a radial extender including an actuator, a stationary support section fixed to the base and a movable contact section. The radial extender is configured such that the movable contact section is movable along the stationary support section by the actuator to force the movable contact section radially into the inner circumferential surface of the pressure vessel.
	claims	1. A method comprising:releasing a stream of target material droplets toward a target region, the droplets in the stream traveling along a trajectory from a target material supply system to the target region;producing a spatially-extended target distribution by directing a first pulse of light along a direction of propagation toward a first target material droplet while the first droplet is between the target material supply apparatus and the target region, the impact of the first pulse of light on the first target material droplet increasing a cross-sectional diameter of the first target material droplet in a plane that faces the direction of propagation and decreasing a thickness of the first target material droplet along a direction that is parallel to the direction of propagation;positioning an optic to establish a beam path that intersects the target location;coupling a gain medium to the beam path; andproducing an amplified light beam that interacts with the spatially-extended target distribution to produce plasma that generates extreme ultraviolet (EUV) light by scattering photons emitted from the gain medium off of the spatially-extended target distribution, at least some of the scattered photons placed on the beam path to produce the amplified light beam. 2. The method of claim 1, wherein the EUV light is generated without providing external photons to the beam path. 3. The method of claim 1, wherein the stream comprises a plurality of target material droplets, each separated from one another along the trajectory, and separate spatially-extended target distributions are produced from more than one of the droplets in the stream. 4. The method of claim 1, wherein the first pulse of light has a wavelength of 1.06 μm. 5. The method of claim 1, wherein a cross-sectional diameter of the spatially-extended target distribution in the plane that is transverse to the direction of propagation is 3 to 4 times larger than the cross-sectional diameter of the first target material droplet. 6. The method of claim 1, wherein the spatially-extended target distribution is produced a time period after the first light pulse impacts the first target material droplet. 7. The method of claim 1, wherein the first pulse of light has a duration of 10 ns. 8. The method of claim 1, wherein the amplified light beam has a foot-to-foot duration of 400-500 ns. 9. The method of claim 1, wherein the amplified light beam comprises light having a wavelength of 10.6 μm. 10. The method of claim 1, wherein the amplified light beam has light having a wavelength that is about ten times the wavelength of the first pulse of light. 11. The method of claim 1, further comprising sensing that a first target material droplet in the stream of droplets is between the target material supply system and the target region. 12. The method of claim 1, wherein the spatially-extended target distribution is in the form of a disk. 13. The method of claim 12, wherein the disk comprises a disk of molten metal. 14. The method of claim 1, wherein the amplified light beam interacts with the spatially-extended target distribution to generate extreme ultraviolet (EUV) light without any coherent radiation being produced. 15. The method of claim 1, wherein the optic is positioned at a side of the gain medium opposite to the target location to reflect light back on the beam path. 16. An extreme ultraviolet light source comprising:an optic positioned to provide light to a beam path;a target supply system that generates a stream of target material droplets along a trajectory from the target supply system to a target location that intersects the beam path;a light source positioned to irradiate a target material droplet in the stream of target material droplets at a location that is between the target supply system and the target location, the light source emitting light of an energy sufficient to physically deform a target material droplet into a spatially-extended target distribution;a gain medium positioned on the beam path between the target location and the optic; anda spatially-extended target distribution positionable to at least partially coincide with the target location to define an optical cavity along the beam path and between the spatially-extended target distribution and the optic, whereinthe spatially-extended target distribution and the target material droplets comprise a material that emits EUV light in a plasma state. 17. The light source of claim 16, wherein the target material comprises tin, and the target material droplets comprise droplets of molten tin. 18. The light source of claim 16, wherein the spatially-extended target distribution has a cross-sectional diameter in a plane that is perpendicular to direction of propagation of an amplified light beam that is produced by the optical cavity, and the cross-sectional diameter of the spatially-extended target distribution is 3-4 times larger than a cross-sectional diameter of the target material droplet.
056028881	abstract	A method for mitigating crack growth on the surface of stainless steel or other alloy components in a water-cooled nuclear reactor wherein a solution or suspension of a compound containing a noble metal is injected into the coolant water while the reactor is not generating nuclear heat, e.g., during shutdown or recirculation pump heatup. During shutdown, the reactor coolant water reaches temperatures as low as 120.degree. F., in contrast to the water temperature of 550.degree. F. during normal operation. During pump heatup, the water temperature reaches 400.degree.-450.degree. F. At these reduced temperatures, the rate of thermal decomposition of the injected noble metal compound is reduced. However, radiation-induced decomposition also occurs inside the reactor. In particular, the noble metal compound can be decomposed by the gamma radiation emanating from the nuclear fuel core of the reactor. The noble metal compound decomposes under reactor thermal and radiation conditions to release ions/atoms of the noble metal which incorporate in or deposit on the oxide film formed on the stainless steel and other alloy components. As a result, the electrochemical potential of the metal surface is maintained at a level below the critical potential in the presence of low levels of hydrogen to protect against intergranular stress corrosion cracking.
06294858&	abstract	Microminiature thermionic converts (MTCs) having high energy-conversion efficiencies and variable operating temperatures. Methods of manufacturing those converters using semiconductor integrated circuit fabrication and micromachine manufacturing techniques are also disclosed. The MTCs of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. Existing prior art thermionic converter technology has energy conversion efficiencies ranging from 5-15%. The MTCs of the present invention have maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.
	claims	1. A method of constructing a nuclear reactor module, the method comprising:providing a first formwork defining a chamber in which is mounted a nuclear reactor comprising a nuclear reactor pressure vessel configured to contain nuclear fuel when in use;providing a second formwork defining a containment structure configured to contain an internal pressure generated by an escape of coolant from a reactor coolant circuit, the first formwork being housed within the second formwork;filling one or more voids within the first formwork with concrete through at least one concrete supply pipe that extends from outside of the second formwork, through the second formwork, and through a wall of the first formwork so as to open into the one or more voids of the first formwork;forming the containment structure by filling one or more voids within the second formwork with concrete; andventing the one or more voids within the first formwork through one or more vent pipes, thereby forming a concrete support structure for the nuclear reactor,wherein the filling of the one or more voids within the second formwork occurs after the filling of the one or more voids within the first formwork. 2. The method of constructing a nuclear reactor module according to claim 1,further comprising removing at least one removable support that is configured to support at least some of the nuclear reactor during transportation. 3. The method of constructing a nuclear reactor module according to claim 1, further comprising removing at least one removable brace that is configured to support at least some of the first formwork during transportation. 4. The method of constructing a nuclear reactor module according to claim 1, further comprising:detaching the at least one concrete supply pipe after the first formwork has been filled with concrete, andremoving the at least one concrete supply pipe from the containment second formwork. 5. The method of constructing a nuclear reactor module according to claim 1,wherein the first formwork comprises at least one arrangement comprising: (i) a structural void, (ii) an expansion void disposed above the structural void, and (iii) a structural support plate disposed between the structural void and the expansion void and having at least one hole therein, andwherein the method further comprises filling the structural void with concrete to a level above the structural support plate such that the structural void is filled with structural concrete that can support a load applied to the structural support plate.
	abstract	An electron beam irradiation apparatus has an electron accelerator for accelerating electrons emitted from an electron beam source to irradiate a target, and a power supply for supplying power of direct current having a high voltage to the electron accelerator. The power supply comprises an inverter device for transforming a commercial AC power output into an AC power output of a variable voltage, a DC power supply for stepping up a voltage of the AC power output of the inverter device, rectifying the stepped up voltage to a high DC voltage, and applying the high DC voltage to the electron accelerator, and a feedback control circuit for controlling the power output of the inverter device by detecting the high DC voltage and a current.
041815726	summary	BACKGROUND OF THE INVENTION This invention relates to closure heads for nuclear reactors and more particularly to closure heads for nuclear reactors having a sealing and lubricating system. In nuclear reactor designs well known in the art, a reactor vessel with fuel assemblies disposed therein and having an inlet and an outlet for circulation of a coolant in heat transfer relationship with the fuel assemblies, is sealed by a closure head located on top of the reactor vessel. In certain designs, the closure head comprises one or more rotatable plugs. These rotatable plugs which may be of varying sizes disposed eccentrically within each other, serve at least two purposes. One purpose is, of course, to seal the reactor internals inside the reactor vessel. Another purpose is to support refueling machines. The rotation of the rotatable plugs positions the refueling machines in appropriate relationship to the fuel assemblies in the reactor vessel to facilitate the refueling process. Since the rotatable plugs must be able to rotate relative to each other, the plugs are mounted so as to define an annulus between them. The annulus, while allowing the rotation of the plugs, also establishes a path for the release of radioactive particles located in the reactor vessel. Accordingly, seals are provided at various locations across the annulus to prevent this release of radioactive particles. The seals also function to prevent oxygen in the atmosphere outside the reactor vessel from passing through the annulus to the reactor coolant, which in a liquid metal fast breeder reactor may be liquid sodium, because contact of liquid sodium with oxygen may result in the formation of impurities in the liquid sodium. To further prevent oxygen leakage into the reactor vessel, a cover gas is provided that fills the space from the top of the reactor coolant pool to the bottom of the closure head and up the annulus to the seals across the annulus. One type of closure head seal well known to those skilled in the art is a liquid dip seal. In a liquid dip seal, the annulus between the closure head plugs is contoured so that a trough is formed by the annulus itself. A liquid such as liquid sodium is placed in the trough thereby dividing the annulus into two sections, one above the liquid and one below thereby forming a dip seal. The cover gas, inside the reactor, containing radioactive particles, then extends from the top of the reactor coolant pool up through the annulus to the liquid sodium in the dip seal. The liquid dip seal under normal conditions provides an effective seal against cover gas migration out of the annulus and against oxygen migration into the reactor vessel while allowing the rotatable closure head plugs to rotate relative to each other. However, it is generally considered advisable to utilize another type of seal in conjunction with the dip seal in order to prevent contact between the liquid metal and air. Another type of closure head seal well known in the art is the inflatable seal wherein single or multiple inflatable seals in series are placed across the annulus. During reactor refueling, the inflatable seals are slightly deflated to allow better rotation on the rotatable closure head plugs while during reactor operation the seals are inflated to increase their sealing capability. Examples of these types of seals may be found in U.S. Pat. No. 3,514,115 to S. Gallo, issued May 26, 1970 and in U.S. Pat. No. 3,819,479 to R. Jacquelin, issued June 25, 1974. Still another seal well known in the art is a type of labyrinth seal in which a piece of metal is bolted to one of the closure head plugs so as to extend across the annulus between the plugs to within close proximity to the other plugs. The purpose of this seal is to effectively lower the leak path area to thus limit leakage. Of course, since the piece of metal does not contact both rotatable components it does not provide an effective seal. In addition, the other commonly known types of seals such as O-rings, bellows, etc., while possibly being effective under certain conditions, do not allow for effective rotation of the closure head plugs. SUMMARY OF THE INVENTION A closure head for a nuclear reactor comprising a stationary outer ring integral with the reactor vessel with a first rotatable plug disposed within the stationary outer ring and defining an annulus therebetween. A bearing is disposed in the annulus and attached to the stationary outer ring and the first rotatable plug for rotatably supporting the first rotatable plug from the stationary outer ring. A sealing system is disposed in the annulus and around the bearing for sealing the annulus against in leakage of oxygen and out-leakage of radioactive contaminants from within the reactor vessel. The sealing system comprises a tubular seal element disposed in the annulus and capable of contacting both the stationary outer ring and the first rotatable component under the actuation of load springs. In addition, the sealing system comprises a mechanism for pumping a lubricating fluid around the bearing, through the annulus, and around the tubular seal element thereby compressing the load springs and allowing the passage through the annulus of the lubricating fluid. The lubricating fluid in conjunction with the tubular seal element provides a seal across the annulus.

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