JP4592815B2 - Radiation analyzer - Google Patents

Description

  The present invention relates to a radiation analysis apparatus that performs radiation analysis of an apparatus that needs to ensure reliability with respect to radiation.

  Conventionally, a Monte Carlo calculation code using the Monte Carlo method is used to analyze how much the generated radiation is attenuated and diffused by the shield to reach the target device.

  When performing a radiation analysis using a Monte Carlo calculation code, input data describing the boundary conditions of the radiation analysis system such as the shape and layout of the shield is required. When preparing the input data, generally, the input data of the Monte Carlo calculation code is not created from the beginning, but the shielding object is first designed by a computer aided design (CAD, hereinafter simply referred to as CAD). Then, a file in STEP format or IGES format, which is an intermediate format of CAD, is output and the shape and layout of the designed shielding object are transferred to the Monte Carlo calculation code. Then, the Monte Carlo calculation code divides the surface including the free surface of the shielding object in the received three-dimensional CAD data into planes, describes the divided planes by plane equations, and reconstructs them for Monte Carlo calculation. The Monte Carlo calculation code executes the Monte Carlo calculation using the reconstructed data as input data for radiation analysis. The above method is hereinafter simply referred to as a conventional method.

  Regarding the Monte Carlo method, Patent Document 1 introduces a method of simulating the diffusion behavior of radionuclides diffused in the atmosphere by the Monte Carlo method and determining the dose of radiation reaching the ground surface.

  In the method for calculating the background count rate proposed in Patent Document 2, the shape of the shielding object is measured using a three-dimensional shape measuring apparatus, and the obtained three-dimensional shape is reconstructed into an input file used for a Monte Carlo calculation code. And running a Monte Carlo calculation. However, if CAD data used when designing and manufacturing a shielding object can be used, it is more convenient and high analysis accuracy can be expected. Patent Document 3 introduces a method of calculating the radiation exposure dose when an operator works in the radiation management region with high accuracy using layout graphic data of the arrangement of each structure in the radiation management region.

JP 2005-249667 A Japanese Patent Laid-Open No. 2005-140566 JP-A-4-357488

  However, when a highly accurate analysis is performed using the above-described conventional method, a very long calculation time is required. The following two factors can be cited as the cause.

  The first reason is that the Monte Carlo calculation code itself is a time-consuming calculation method for calculating each particle that simulates radiation. The analysis accuracy improves as the number of particles increases, but the calculation time also increases.

  As the second cause, first, the Monte Carlo calculation code divides the free-form surface of the object described in the transferred CAD intermediate file into planes. At this time, if plane division is performed so as to maintain the same level of accuracy as described in the transferred file, the number of planes increases, and a large number of plane equations are used. When the Monte Carlo particle transport calculation is executed here, the number of processes for obtaining the intersection of the surface defined by the surface equation and the track of each particle increases. This is the second cause of an increase in calculation time.

  In this way, in the conventional method, when the Monte Carlo calculation code converts the received CAD intermediate file for calculation, a large number of plane divisions are taken and many particles are defined while ensuring the accuracy of the shape. When calculation is performed, high-accuracy radiation analysis can be performed, but it takes a lot of calculation time. Therefore, in order to perform radiation analysis in a realistic calculation time for an object having a complicated shape, the number of particles handled is reduced, or the complicated shape is approximately expressed by a simple shape such as a cylinder or a cube. It has been unavoidable to increase the calculation time at the expense of analysis accuracy.

  However, in the field where industrial products are developed, both high analysis accuracy and high calculation speed are required. For this reason, it has been a challenge to develop a radiation analyzer that achieves both high analysis accuracy and high calculation speed.

  The present invention has been made in view of the above, and an object of the present invention is to provide a radiation analysis apparatus that achieves both high analysis accuracy and high calculation speed.

  In order to solve the above-described problems and achieve the object, the radiation analysis apparatus according to the present invention is a three-dimensional CAD in which the shape and positional relationship of the shielding object of the radiation analysis system is described and the radiation analysis point is designated by the user. From the data, the material of the shield through which the radiation passes, the shielding thickness that is the range of the radiation in the shield, and the distance between the shields are obtained using the straight line creation function and the interference component extraction function provided in the CAD kernel. When the information extraction unit to be extracted, the material of the shielding object, the shielding thickness, the distance from the shielding object to the desired position, and the energy spectrum of incident radiation incident on the shielding object are specified, the energy of the radiation at the desired position An object radiation correlation database giving the spectrum, the extracted shielding material, shielding thickness and distance, and the energy spectrum of the incident radiation. The object radiation correlation database is searched using the search key as the search key, and the calculation of the acquired radiation energy spectrum as the incident radiation energy spectrum of the adjacent shielding object is sequentially performed, and the radiation energy reaching the radiation analysis point is sequentially performed. A radiation analysis unit for calculating a spectrum.

  According to the present invention, 3D CAD data having a detailed shape and configuration for product design / manufacturing can be obtained without creating simplified 3D CAD data for analysis and converting it into an intermediate format such as STEP or IGES. It can be diverted, information can be extracted from the three-dimensional CAD, and analysis can be performed by calling the previous calculation results stored as a database without performing time-consuming calculation by the Monte Carlo method. Therefore, it is possible to provide a radiation analysis apparatus that achieves both high analysis accuracy and high calculation speed.

FIG. 1 is a flowchart for explaining a comparison between an analysis method of a radiation analysis apparatus according to an embodiment of the present invention and a conventional method. FIG. 2 is a configuration diagram of the radiation analysis apparatus 1. FIG. 3 is a diagram illustrating the information extracted by the information extraction unit 3. FIG. 4 is a flowchart for explaining the operation of the radiation analysis apparatus 1. FIG. 5 is a flowchart for explaining the operation of the information extraction unit 3. FIG. 6 is a flowchart for explaining the operation of the radiation analysis unit 8 in the first and second embodiments. FIG. 7 is a flowchart for explaining the operation of the radiation analysis unit 8 according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radiation analyzer 2 Input part 3 Information extraction part 4 Half straight line preparation part 5 Shielding object intersection information calculation part 6 Material database 7 Radiation analysis information output part 8 Radiation analysis part 9 Object radiation correlation database 10 Storage area 11 Display output part 20 Half line 21 Radiation analysis point 22-25 Shield

  FIG. 1 is a diagram for explaining a comparison between a process from creation of an analysis model to an analysis of a radiation analysis apparatus according to an embodiment of the present invention and a process of a conventional method. The advantages of the system of this embodiment over the conventional system will be described with reference to FIG. In the present embodiment, a point where radiation analysis is performed is referred to as a radiation analysis point, and an object through which radiation passes before reaching the radiation analysis point is referred to as a shield.

  In FIG. 1, first, regarding the shape creation / layout of the shielding object, in the conventional method, in addition to the three-dimensional CAD data used for designing / manufacturing the shielding object, CAD data with a simplified configuration is created (step S1). The simplification of the shape performed at this stage improves the calculation speed for radiation analysis, but the analysis accuracy decreases. In contrast, the present embodiment uses the three-dimensional CAD data for designing and manufacturing the shielding object as it is (step S2). Therefore, according to the apparatus of the embodiment of the present invention, high analysis accuracy is maintained, and the labor for creating analysis three-dimensional CAD data can be saved.

  Next, in the conventional method, in order to pass the shielding object shape / layout information to the analysis software, it is output in a CAD intermediate format (STEP, IGES format, etc.) (step S3). In the apparatus of the present embodiment, the shielding thickness, which is the thickness of the shielding object viewed from the radiation analysis point, the distance between the shielding objects, and the material information of the shielding object are extracted (step S5). In the operation of step S5, each information can be extracted at high speed by using the basic function provided in the kernel of the three-dimensional CAD. Up to this point, the three-dimensional CAD software is executed in the conventional method and the apparatus according to the present embodiment.

  Next, in the conventional method, the analysis software converts the CAD intermediate format data output in step S3 into an input format for execution of the analysis analyzed by the Monte Carlo method, and describes the positional relationship between the shielding object and the radiation analysis points. The input file is reconstructed (step S4). Then, the process proceeds to step S6, and the Monte Carlo calculation is executed using the input file created in step S4. Here, in the Monte Carlo calculation, since all the behaviors of radiation are calculated, a lot of calculation time is required. Since the shape of the shield is simplified and described in step S1, the number of plane divisions used for the data after the reconstruction in step S4 can be reduced, and as a result, the calculation time in step S6 can be shortened. Can do. However, the accuracy of the analysis is reduced as a compensation for shortening the calculation time.

  In the present embodiment, Monte Carlo calculation is performed in advance on the shielding object using the material, shielding thickness, incident radiation information, and the distance between the shielding object and the measurement point as variables. A material radiation correlation database has been constructed in which the relationship with information is made into a database. The radiation analysis software refers to the substance radiation interaction database using the material of the shielding object, the shielding thickness, the distance between the shielding objects, and the information of the incident radiation extracted in step S5 as search keys, and at the radiation analysis point. Deriving radiation information.

  As described above, when the radiation analysis apparatus according to the present embodiment extracts input information for radiation analysis from the shape of the shielding object described by the three-dimensional CAD, a complex shape is approximated by a simple shape as in the conventional method. Therefore, high analysis accuracy is maintained. Furthermore, since the radiation information at the radiation analysis point is calculated by referring to the object radiation interaction database that stores the result of the Monte Carlo calculation performed on the shielding object in advance, it is not necessary to perform the Monte Carlo calculation at the time of analysis. Thereby, the calculation speed is improved as compared with the conventional method. Therefore, according to the radiation analysis apparatus of the embodiment of the present invention, it is possible to perform radiation analysis that achieves both high analysis accuracy and high calculation speed.

  Hereinafter, the present embodiment will be described more specifically. In addition, this invention is not limited by these description.

Embodiment 1.
First, the configuration and function of the radiation analysis apparatus according to the first embodiment of the present invention will be described. FIG. 2 is a diagram illustrating the configuration of the radiation analysis apparatus according to the first embodiment.

  In FIG. 2, the radiation analysis apparatus 1 according to the first exemplary embodiment includes an input unit 2, an information extraction unit 3, a radiation analysis unit 8, an object radiation correlation database 9, a storage area 10, and a display output unit 11. The information extraction unit 3 includes a half straight line creation unit 4, a shield intersection information calculation unit 5, a material database 6, and a radiation analysis information output unit 7.

  The input unit 2 is an input device such as a mouse or a keyboard, and is used for design work of three-dimensional CAD data of a shielding object, input of radiation analysis points, and operation of the radiation analysis apparatus 1.

  The information extraction unit 3 extracts data necessary for radiation analysis from the three-dimensional CAD data in which the shielding object and the radiation analysis points are described, and outputs the data to a radiation analysis information file. First, the half straight line creation unit 4 creates half straight lines starting from the radiation analysis point in all directions while changing the horizontal angle and the vertical angle for each predetermined step angle, and assigns a straight line ID to each. Output to analysis information file. This file is held in the storage area 10.

  The shielding object intersection information calculation unit 5 calls the half line from the radiation analysis information file, extracts the intersection of the half line and the shielding object, and the material of the shielding object, and sequentially outputs them to the radiation analysis information file. The extraction operation here uses a straight line creation function and an interference component extraction function, which are basic functions of a CAD kernel, which is good at such work.

  The material database 6 is a database in which information for associating materials and material IDs is accumulated, and is stored in the storage area 10.

  The radiation analysis information output unit 7 calls the straight line ID, the intersection information, and the material information described in the radiation analysis information file stored in the storage area 10, and each half line is farthest from the radiation analysis point. In order from the shield, the shielding thickness, which is the range of passing through the half-line shield, and the distance between the escape coordinates from the shield and the entry coordinates to the adjacent shield, and the material database 6 are calculated. The material ID corresponding to the material information of each shielding object is given by reference, and the straight line ID, vertical angle, horizontal angle, shielding thickness, distance, and material ID are output to the radiation analysis information file.

  Here, the shielding object farthest from the radiation analysis point is named shielding object 1, shielding object 2,..., Shielding object i,. FIG. 3 is a diagram for explaining a naming method. In FIG. 3, a certain straight line 20 reaches the radiation analysis point 21. In the meantime, the shield located in the place farthest from the radiation analysis point 21 shown in 22, the shield 2 shown in 1, 23, the shield i shown in 24, and the shield located in the place closest to the radiation analysis point 21 shown in 25. n is passed. Furthermore, the shielding thickness of the shielding object i is named Ti, the distance between the shielding object i and the shielding object i + 1 is named Li, and the material ID of the material of the shielding object i is named Mi. However, n is a positive integer and i is a positive integer satisfying 1 ≦ i ≦ n. Ln is the distance between the shield n and the radiation analysis point. That is, the radiation analysis information output unit 7 outputs the vertical angle, horizontal angle, T1 to Tn, M1 to Mn, and L1 to Ln of the half line to the radiation analysis information file for all the straight lines of the straight line ID. .

  Furthermore, the radiation analysis information output unit 7 divides 4π by the number of half lines created to obtain a solid angle ω0 (unit: steradian) of the space represented by one half line, and the radiation analysis information described above. The information is output to an information file and stored in the storage area 10.

  The radiation analysis unit 8 performs radiation analysis. The object radiation correlation database 9 performs a Monte Carlo particle transport calculation in advance for a simple shaped shield, and for the shield, a unit solid that is a function of the shield thickness T and material M, the distance L, and the energy of the incident radiation. When the flux dφ (E) / dω per corner is designated, the flux dφ ′ (E) / dω per unit solid angle of radiation at a position away from the shield by the distance L is given.

  The radiation analysis unit 8 includes Ti, Li, and Mi related to the half line of each straight line ID described in the information file for radiation analysis, and the flux dφi (E) / dω per unit solid angle of the radiation incident on the shielding object i. And the object radiation correlation database 10 as a search key, and the operation of obtaining the flux dφi + 1 (E) / dω per unit solid angle of the radiation reaching the shield i + 1 is performed. This operation is sequentially repeated with i = i + 1 to obtain dφn + 1 (E) / dω. dφn + 1 (E) / dω is a radiation flux per unit solid angle at a radiation analysis point in a divided space represented by a half line of each straight line ID. As dφ1 (E) / dω, a value input by the user as an initial value is used. When dφn + 1 (E) / dω is obtained for the half lines of all the straight lines ID, all the half lines dφn + 1 (E) / dω are multiplied by ω0, and the total value of the radiation flux φALL at the radiation analysis point is obtained. (E). φALL (E) is output to the radiation analysis information file, stored in the storage area 10, and displayed on the display output unit 11.

  The storage area 10 includes, for example, an input unit 2, a half line creation unit 4, a shielding object intersection information calculation unit 5, a material database 6, a radiation analysis information output unit 7, a radiation analysis unit 8, and an object radiation correlation database realized by the CPU. 9 and a ROM for storing each program for controlling the operation of the display output unit 11, a three-dimensional CAD data prepared by the user, and a RAM for storing the calculation results of the above-described units.

  The display output unit 11 is a part that outputs the result in a form that can be confirmed by the user, such as a monitor or a printer. The user operates the input unit 2 while looking at the display output unit.

  Next, the operation of the radiation analysis apparatus according to Embodiment 1 will be described.

  FIG. 4 is a flowchart for explaining the operation of the radiation analysis apparatus according to the first embodiment. In FIG. 4, when the radiation analysis work is started, first, the user uses the input unit 2 to design 3D CAD data describing the shielding object (step S101). Here, the detailed shape of each part (here, the shielding object) defined as a result of the normal design work and the arrangement in the three-dimensional space can be used as they are. Next, the user uses the input unit 2 to input a radiation analysis point, which is a location desired to be analyzed, into the three-dimensional CAD data (step S102). The three-dimensional CAD data created in this way is stored in the storage area 10.

  Next, the information extraction unit 3 reads the three-dimensional CAD data and starts extracting analysis information for radiation analysis (step S103). Details of the processing flow in step S103 will be described with reference to FIG. FIG. 5 is a flowchart for explaining processing for extracting information for analysis in the information extraction unit 3.

  In FIG. 5, first, in step S201, the half line creation unit 4 creates a half line starting from the radiation analysis point using the CAD line creation function, assigns a straight line ID to the created half line, and generates radiation. Output to analysis information file. Further, the half line creation unit 4 creates a new half line by shifting the horizontal angle or the vertical angle of the half line created in step S201, or both by a predetermined step angle, and creates a straight line on the newly created half line. An ID is assigned and output to the radiation analysis information file (step S202). Next, when the half straight line creation unit 4 determines whether a half straight line has been created uniformly in all directions (step S203) and determines that a half straight line has been created uniformly in all directions (step S203, Yes), step S204 is performed. Migrate to When the half line creation unit 4 determines that half lines are not created evenly in all directions, the process proceeds to step S202.

  In step S204, the shielding object intersection information calculation unit 5 calls a half line of a predetermined straight line ID from the radiation analysis information file. Next, the shielding object intersection information calculation unit 5 calculates all the intersection coordinates of the called half line and the shielding object, and at the same time, using the interference component extraction function of CAD, the material of all the shielding objects through which the half line passes is also obtained. Extract (step S205). Next, the radiation analysis information output unit 7 refers to the material database and associates the material extracted in step S205 with the material ID Mi (database 206). In step S207, the radiation analysis information output unit 7 calculates the shielding thickness Ti and the distance Li between the shielding objects from the intersection information between the shielding object and the half line (step S207).

  Next, the radiation analysis information output unit 7 outputs the calculated T1 to Tn, M1 to Mn, and L1 to Ln together with the straight line ID, horizontal angle, and vertical angle of the half line to the radiation analysis information file. (Step S208). Then, the radiation analysis information output unit 7 determines whether or not the processing in steps S205 to S208 has been completed for all half lines (step S209), and determines that the processing has been completed (step S209, Yes). ), The process proceeds to step S211. When it determines with having not completed (step S209, No), it transfers to step S210. In step S210, the shielding object intersection information calculation unit 5 calls a half line of another ID that has not yet completed the processing of steps S205 to S208, and proceeds to step S205.

  In step S211, the radiation analysis information output unit 7 divides 4π by the number of half lines created by the half line creation unit 4, and calculates the solid angle ω0 (unit: steradian) of the space represented by each half line. To do. Next, the radiation analysis information output unit 7 outputs the value of ω0 to the radiation analysis information file (step S212). Next, the operation of the information extraction unit 3 is finished, and the process proceeds to step S104 in FIG.

  In step S <b> 104 in FIG. 4, the radiation analysis unit 8 executes radiation analysis using information output to the radiation analysis information file. Here, the details of the processing flow in step S104 will be described with reference to FIG. FIG. 6 is a flowchart for explaining the operation in which the radiation analysis unit 8 performs the radiation analysis.

  In FIG. 6, when radiation analysis is started, the radiation analysis unit 8 determines from the radiation analysis information file the horizontal angle, vertical angle, T1 to Tn, M1 to Mn, and L1 to the half line of the predetermined straight line ID. Ln is read (step S301). Next, the user inputs the flux dφ1 (E) / dω per unit solid angle of the radiation incident on the shield 1 (step S302). Next, the radiation analysis unit 8 sets i = 1 (step S303), refers to the object radiation correlation database 9 using Ti, Mi, Li, and dφi (E) / dω as search keys (step S304) and is called. The obtained value dφ ′ (E) / dω is taken as dφi + 1 (E) / dω (step S305). Next, the radiation analysis unit 8 determines whether i = n is true (step S306). If it is determined that i = n is true (step S306, Yes), the process proceeds to step S308. When it is not determined that i = n is true (No in Step S306), the process proceeds to Step S307, and the radiation analysis unit 8 adds 1 to i, and then proceeds to Step S305. dφn + 1 (E) / dω obtained when i = n is true is the radiation flux per unit solid angle at the radiation analysis point of the radiation incident from the space represented by the straight line ID.

  In step S308, the radiation analysis unit 8 outputs dφn + 1 (E) / dω to the radiation analysis information file. Next, the radiation analysis unit 8 determines whether or not the processing in steps S302 to S308 has been performed for all the half lines (step S309), and determines that the processing has been performed for all the half lines (step S309, Yes), the process proceeds to step S311, and when it is determined that the processing has not been performed for all the half lines (No in step S309), the process proceeds to step S310. In step S310, the radiation analysis unit 8 reads half-line information that has not been subjected to the processing in steps S302 to S308 from the radiation analysis information file, and proceeds to step S302. In step S311, the calculation of dφn + 1 (E) / dω has been completed for all the straight lines of the straight line IDs, so all the obtained dφn + 1 (E) / dω are multiplied by ω0 and summed, and φALL (E) Is calculated. φALL (E) is the radiation flux at the radiation analysis point. Then, φALL (E) is output to the radiation analysis information file. And the radiation analysis by the radiation analysis part 8 is complete | finished, and it transfers to step S105 in FIG. 4 (step S313).

  In FIG. 4, φALL (E) described in the radiation analysis information file stored in the storage area 10 is read, and the value of φALL (E) is displayed on the display output unit 11. And the operation | movement by the radiation analyzer 1 is complete | finished.

  As described above, when the radiation analysis apparatus according to the first embodiment extracts input information for radiation analysis from the shape of the shield described by the three-dimensional CAD, a complex shape is approximated by a simple shape as in the conventional method. Therefore, high analysis accuracy is maintained. Furthermore, since the radiation information at the radiation analysis point is calculated by referring to the object radiation interaction database that stores the result of the Monte Carlo calculation performed on the shielding object in advance, it is not necessary to perform the Monte Carlo calculation at the time of analysis. Thereby, the calculation speed is improved as compared with the conventional method. Therefore, the radiation analysis apparatus according to the first embodiment of the present invention can perform radiation analysis that achieves both high analysis accuracy and high calculation speed.

Embodiment 2.
Next, a radiation analysis apparatus according to the second embodiment will be described. The radiation analysis apparatus according to the second embodiment uses the density ratio between the material of the shielding object and the predetermined material, and converts the shielding thickness into the predetermined material equivalent shielding thickness, so that the radiation analysis according to the first embodiment is performed. The time for constructing the object radiation correlation database 9 of the apparatus and the resources of the storage area 10 used by the object radiation correlation database 9 are reduced.

  The configuration of the radiation analysis apparatus according to the second embodiment is the same as that of the radiation analysis apparatus according to the first embodiment. Here, functions and operations of parts different from those of the radiation analysis apparatus according to the first embodiment will be described. 4 to 6 are used as diagrams used in this description.

  The material database 6 is a database that associates a material with a density ratio between the material and a predetermined material. The radiation analysis information output unit 7 calculates the shielding thickness, the material, and the distance, and then calculates the material database described above. Referring to the density ratio between the above-mentioned material and the predetermined material, the above-described shielding thickness is converted into a predetermined material-converted shielding thickness in step S207, and the straight line ID, vertical angle, horizontal angle, and predetermined material are stored in the radiation analysis information file. The converted shielding thickness Ts and the distance L are output in step S208.

  Further, the object radiation correlation database 9 specifies the distance L from the shielding object when the predetermined material equivalent shielding thickness Ts, the distance L, and the flux dφ (E) / dω per unit solid angle of the incident radiation are designated for the shielding object. A flux dφ ′ (E) / dω per unit solid angle of radiation at a position separated by a distance is given. In step S304, the radiation analysis unit 8 refers to the object radiation correlation database 9 using Tsi, Li, and dφi (E) / dω as a search key, and uses the called value dφ ′ (E) / dω to perform the step. In S305, dφi + 1 (E) / dω is set.

  Other functions and operations are the same as those of the radiation analysis apparatus according to the first embodiment.

  As described above, the radiation analyzing apparatus according to the second embodiment is configured such that the shielding thickness, which is one of analysis information used in the radiation analyzing apparatus according to the first embodiment, is a predetermined material equivalent shielding thickness that is a shielding thickness of a predetermined material. Therefore, after deriving the predetermined material equivalent shielding thickness, material information other than the predetermined material is not required. As a result, the object radiation correlation database 9 only needs to hold data of only a predetermined material with respect to the material, so that the calculation time for constructing the object radiation correlation database 9 by performing the Monte Carlo calculation in advance is significantly reduced, and the object radiation correlation. This provides an effect of saving resources of the storage area 10 used by the database 9.

  By the way, in the radiation analysis apparatus according to the first and second embodiments, the user inputs dφ1 (E) / dω in step S302. However, a file in which dφ1 (E) / dω is previously collected for all half lines is prepared. It may be prepared and read by the radiation analysis unit 8. In addition, the energy function flux is used as radiation information. Alternatively, any one of the energy function fluence, the wavelength or wave number function flux, or the wavelength or wave number function fluence may be used. Good. Further, the dose at the radiation analysis point may be calculated from the radiation flux at the radiation analysis point.

Embodiment 3.
A radiation analysis apparatus according to the third embodiment will be described. The configuration of the radiation analysis apparatus according to the third embodiment is the same as that of the first embodiment. Here, functions and operations of parts different from those of the radiation analysis apparatus according to the first embodiment will be described.

  When the shielding thickness Ti, the material Mi, and the distance Li are specified for the shielding object, the object radiation correlation database 9 indicates the dose dDi / dω per unit solid angle of the radiation incident on the shielding object and the distance L from the shielding object. An attenuation amount Δ (dDi / dω) that is a difference between doses dDi + 1 / dω per unit solid angle of radiation at a distant position is given.

The radiation analysis unit 8 refers to the object radiation correlation database 9 using Ti, Mi, and Li as search keys, and accumulates the called values of attenuation Δ (dDi / dω) in the range of i = 1 to n. ΣΔ (dDi / dω), which is the total attenuation of the dose per unit solid angle of the radiation that passes through the shielding objects 1 to n and reaches the radiation analysis point, is obtained. Then, the value obtained by subtracting the above-mentioned ΣΔ (dDi / dω) from dD1 / dω input by the user is multiplied by ω 0, and the obtained value is integrated over the whole half-line, thereby calculating the dose D _ALL at the radiation analysis point. obtain.

  Next, the operation of the radiation analysis apparatus according to the third exemplary embodiment will be described. The operation of the radiation analysis apparatus according to the third embodiment is different from that of the first embodiment only in the radiation analysis processing in step S104 in FIG. Here, a part of the operation different from that of the first embodiment will be described. FIG. 7 is a flowchart for explaining the operation of the radiation analysis unit 8 of the radiation analysis apparatus according to the third embodiment.

  In FIG. 7, when the radiation analysis is started, the radiation analysis unit 8 reads the horizontal angle, the vertical angle, T1 to Tn, M1 to Mn, and L1 to the half line of the predetermined straight line ID from the radiation analysis information file. Ln is read (step S401). Next, the user inputs a dose dD1 / dω per unit solid angle of radiation incident on the shield 1 (step S402). Next, the radiation analysis unit 8 sets i = 1 (step S403), refers to the object radiation correlation database 9 using Ti, Mi, Li, and dDi / dω as search keys (step S404), and Δ (dDi / dω ) Is obtained (step S405). Next, the radiation analysis unit 8 determines whether i = n is true (step S406). If it is determined that i = n is true (step S406, Yes), the process proceeds to step S408. If it is not determined that i = n is true (No in step S406), the process proceeds to step S407, and the radiation analysis unit 8 adds 1 to i, and the process proceeds to step S405.

In step S <b> 408, the radiation analysis unit 8 outputs the value of dD1 / dω−ΣΔ (dDi / dω) to the storage area 10. Next, the radiation analysis unit 8 determines whether or not the processing in steps S402 to S408 has been performed for all the half lines (step S409), and determines that the processing has been performed for all the half lines (step S409, Yes), the process proceeds to step S411, and when it is determined that the processing has not been performed for all the half lines (No in step S409), the process proceeds to step S410. In step S410, the radiation analysis unit 8 reads half-line information from the radiation analysis information file that has not been subjected to the processing in steps S402 to S408 yet, and proceeds to step S402. In step S411, since the calculation of dD1 / dω−ΣΔ (dDi / dω) has been completed for all the straight lines of the straight line ID, ω0 is added to all the obtained dD1 / dω−ΣΔ (dDi / dω). Multiply and add up to calculate D _ALL . D _ALL is the radiation dose at the radiation analysis point. Then, D _ALL is output to the radiation analysis information file. And the radiation analysis by the radiation analysis part 8 is complete | finished, and it transfers to step S105 in FIG. In step S <b> 105 in FIG. 4, the D _ALL described in the radiation analysis information file is output to the display output unit 11.

  As described above, in the radiation analysis apparatus according to the third embodiment, when the shielding thickness, material, and distance are designated in the substance radiation correlation database, the attenuation amount of the radiation dose before and after passing through the shielding object is given. Since the amount of attenuation can be calculated simply by adding together the dose lost through the shielding object 1 to the shielding object n and reaching the radiation analysis point, the radiation amount is higher than that of the radiation analysis apparatus according to the first and second embodiments. This provides an effect that the operation of the analysis unit 8 is simplified.

  As described above, the radiation analysis apparatus according to the present invention is useful for radiation analysis, and is particularly suitable for radiation analysis of an apparatus that needs to ensure reliability with respect to radiation.

Claims (8)

From the three-dimensional CAD data in which the shape and positional relationship of the shield in the radiation analysis system is described and the radiation analysis point is designated by the user, the material of the shield through which the radiation passes and the range of the radiation in the shield An information extraction unit that extracts a certain shielding thickness and a distance between shielding objects using a straight line creation function and an interference component extraction function provided in the CAD kernel;
Given the material of the shield, the thickness of the shield, the distance from the shield to the desired location, and the energy spectrum of the incident radiation incident on the shield, an object radiation correlation database that gives the energy spectrum of the radiation at the desired location When,
The object radiation correlation database is searched using the extracted shielding material, shielding thickness and distance, and the energy spectrum of the incident radiation as search keys, and the incident radiation of the adjacent shielding is obtained with the acquired energy spectrum of the radiation. A radiation analysis unit that sequentially calculates the energy spectrum and calculates the energy spectrum of the radiation that reaches the radiation analysis point;
A radiation analysis apparatus comprising: The information extraction unit includes:
The whole space is divided for each predetermined solid angle starting from the radiation analysis point, and a half line passing through the center of the space divided from the radiation analysis point is created in each of the divided spaces. Extract the material of the shield through which the half line passes, and the intersection of the half line and the shield, the shielding thickness that is the range through which each half line passes through each shield, and between the shields The distance and the distance between the shield and the radiation analysis point closest to the radiation analysis point are calculated from the intersection, and the material, the shielding thickness and the distance are used as radiation analysis information,
The object radiation correlation database is:
Given the shielding material, shielding thickness, the distance from the shielding to the desired position, and the energy spectrum per unit solid angle of incident radiation incident on the shielding, the unit solid angle of radiation at the desired position Give the energy spectrum of
The radiation analysis unit
With respect to the shielding object included in each of the divided spaces, the energy spectrum per unit solid angle of incident radiation and the material, shielding thickness, and distance of the shielding object read from the radiation analysis information are used as search keys. With reference to the object radiation correlation database, the calculation is performed with the energy spectrum per unit solid angle of the acquired radiation as the energy spectrum per unit solid angle of incident radiation incident on the adjacent shielding object or the radiation analysis point. An energy spectrum per unit solid angle of incident radiation for each half line at the radiation analysis point is calculated by sequentially performing from the shield farthest from the analysis point to the radiation analysis point, and at the radiation analysis point Unit solid angle per half line The value obtained by multiplying the predetermined solid angle to the energy spectrum of the incident radiation or by integrating the entire semi-straight line segments to calculate the energy spectrum of the radiation in the radiation analysis points,
The radiation analysis apparatus according to claim 1, wherein: From the three-dimensional CAD data in which the shape and positional relationship of the shield in the radiation analysis system is described and the radiation analysis point is designated by the user, the material of the shield through which the radiation passes and the range of the radiation in the shield A certain shielding thickness and a distance between shielding objects are extracted using a straight line creation function and an interference component extraction function provided in the CAD kernel, and the extracted using a density ratio of a predetermined material and the extracted material. An information extraction unit for calculating a predetermined material equivalent shielding thickness from the shielding thickness;
For a shield of a predetermined material, when a predetermined material equivalent shield thickness, a distance from the shield to a desired position, and an energy spectrum of incident radiation incident on the shield are specified, an energy spectrum of the radiation at the desired position is obtained. A given object radiation correlation database;
Referring to the object radiation correlation database using the extracted / calculated predetermined material equivalent shielding thickness and distance and the energy spectrum of incident radiation as a search key, and incident on an adjacent shielding object with the acquired energy spectrum of radiation A radiation analysis unit that sequentially performs an operation to obtain an energy spectrum of radiation and calculates an energy spectrum of radiation that reaches the radiation analysis point;
A radiation analysis apparatus comprising: The information extraction unit includes:
The whole space is divided for each predetermined solid angle starting from the radiation analysis point, and a half line passing through the center of the space divided from the radiation analysis point is created in each of the divided spaces. The material of the shield through which the half line passes and the intersection of the half line and the shield are extracted, the shielding thickness that is the range through which each half line passes through each shield, and the distance between each shield, and The distance between the shielding object closest to the radiation analysis point and the radiation analysis point is calculated from the intersection point, and the density ratio between the material and the predetermined material is used to calculate the predetermined material conversion shielding from the shielding thickness. Calculate the thickness and use the predetermined material shielding thickness and the distance as information for radiation analysis,
The object radiation correlation database is:
When a predetermined material equivalent shielding thickness, a distance from the shielding to a desired position, and an energy spectrum per unit solid angle of incident radiation incident on the shielding are specified for the shielding of the predetermined material, Gives the energy spectrum of radiation per unit solid angle,
The radiation analysis unit
The object radiation correlation database is read using the predetermined material equivalent shielding thickness and the distance from the radiation analysis information, and using the read predetermined material equivalent shielding thickness and distance and the energy spectrum per unit solid angle of the incident radiation as a search key. Searching and calculating the energy spectrum per unit solid angle of incident radiation incident on the shielding object adjacent to the radiation analysis point or the radiation analysis point with the energy spectrum per unit solid angle of the acquired radiation, An energy spectrum per unit solid angle of incident radiation for each half line at the radiation analysis point is calculated by sequentially performing from the outermost shield to the radiation analysis point in order, and incident for each half line at the radiation analysis point. Radiation unit solid angle To by integrating a value obtained by multiplying the predetermined solid angle to the energy spectrum in the total ray amount calculating an energy spectrum of the radiation in the radiation analysis points,
The radiation analysis apparatus according to claim 3, wherein: From the three-dimensional CAD data in which the shape and positional relationship of the shield in the radiation analysis system is described and the radiation analysis point is designated by the user, the material of the shield through which the radiation passes and the range of the radiation in the shield An information extraction unit that extracts a certain shielding thickness and a distance between shielding objects using a straight line creation function and an interference component extraction function provided in the CAD kernel;
When the shielding material, shielding thickness, and distance from the shielding to the desired position are specified, the attenuation amount, which is the difference between the radiation dose to the desired position and the radiation dose incident on the shielding, is determined. A given object radiation correlation database;
The object radiation correlation database is searched using the extracted material, shield thickness, and distance as search keys to acquire attenuation, and the acquired attenuation is integrated for the shield passing up to the radiation analysis point. A radiation analysis unit that calculates the dose at the radiation analysis point, and the amount of attenuation of the radiation that passes through all shields with the value and reaches the radiation analysis point;
A radiation analysis apparatus comprising: The information extraction unit includes:
On the three-dimensional CAD data describing the shape and positional relationship of the shield in the radiation analysis system, the whole space is divided into predetermined solid angles starting from the radiation analysis point specified by the user, and the radiation analysis point is the starting point. A half line passing through the center of the divided space is created in each of the divided spaces, the material of the shield through which each half line passes, and the intersection of the half line and the shield are extracted, and each shield Shielding thickness that is the range through which each half line passes through an object, the distance between the shielding objects, and the distance between the shielding object and the radiation analysis point closest to the radiation analysis point Calculated from the material, the shielding thickness and the distance as information for radiation analysis,
The object radiation correlation database is:
When the shielding material, shielding thickness, and distance from the shielding to the desired position are specified, the radiation dose per unit solid angle to the desired position and the unit solid angle of the radiation incident on the shielding Giving the amount of attenuation that is the difference from the dose per unit,
The radiation analysis unit
For all the shields included in each of the divided spaces, material, shield thickness, and distance are read from the radiation analysis information, and the object radiation correlation is used by using the read material, shield thickness, and distance as a search key. Attenuation is obtained by searching a database, the acquired attenuation is accumulated for the shielding from the outermost shielding to the radiation analysis point, and the accumulated attenuation is located farthest from the radiation analysis point. Subtracting from the radiation incident dose per unit solid angle to the shield at the radiation analysis point to calculate the dose per unit solid angle per half line at the radiation analysis point, and per unit solid angle per half line at the radiation analysis point The dose at the radiation analysis point is calculated by multiplying the dose obtained by multiplying the predetermined solid angle by the total half-line. To,
The radiation analysis apparatus according to claim 5, wherein: The shape and positional relationship of the shield of the radiation analysis system described in the three-dimensional CAD data are as follows:
Using the three-dimensional CAD data of the shape and configuration described for design or manufacture related to the shielding as it is,
The radiation analysis apparatus according to any one of claims 1 to 6, wherein the radiation analysis apparatus is characterized in that:   The radiation analysis apparatus according to claim 1, wherein the radiation analysis unit calculates a radiation dose at the radiation analysis point from an energy spectrum of the radiation at the radiation analysis point.

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