CN112434460B - Geant 4-based general security inspection machine ray shielding design method - Google Patents
Geant 4-based general security inspection machine ray shielding design method Download PDFInfo
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Abstract
The invention provides a general security inspection machine ray shielding design method based on Geant4, which comprises the following steps: under the Geant4 platform, a security inspection machine ray shielding project module is created, and a management module, a command control module and the like are created under the module; a particle beam input module and a command execution module which are appointed in the management module are established, the particle beam input module is used for defining the emission angle of the particle beam, the command execution module is used for establishing a grid on the surface of an ideal absorber body to capture the quantity of emitted particles, establishing a grid in the interior of the ideal absorber body to collect the energy deposition of the emitted particles, and executing the command of outputting the quantity of particles and a program in an energy deposition file; creating a particle information input module specified in the command execution module; the management module organizes compiling to generate a shielding simulation executable file; operating a shielding simulation executable file to obtain a ray shielding result required by the command execution module; and adjusting parameters in the radiation system of the simulation security inspection machine according to the radiation shielding result until a result meeting the requirements is obtained.
Description
Technical Field
The invention belongs to the field of ray shielding design, and particularly relates to a general security inspection machine ray shielding design method based on Geant 4.
Background
At present, an X-ray security inspection machine is distinguished by ray transmitting and receiving positions, and comprises three types of radiation bottom view angles, side view angles and top view angles, wherein the three types comprise various channel sizes according to different application scenes and requirements, different transmitting positions and different channel sizes enable the distance between an X-ray machine and a collimator, and the distance between the X-ray machine and a detector box and the width of a shielding box with the collimator are different. In addition, the energy emitted by the X-ray machines of the baggage item security inspection machine and the freight item security inspection machine are different, for example, 100kev,160kev, etc. are the highest energy emitted by the X-ray used by the baggage item security inspection machine, and for example, 200kev,320kev, etc. are the highest energy emitted by the X-ray used by the freight item security inspection machine. The different ray energies of the light machines and the different distances cause the shielding difference of the rays. For the security inspection machine, the radiation shielding material of rays is generally a lead plate, and under the condition of meeting the national standard dosage value, if lead plates with the same thickness are used, the excessive use of the material is necessarily caused. The security inspection machine has similar structures, and if a single ray shielding design is performed for each structure, the design cost must be increased.
The current ray shielding design has a numerical calculation method, a software simulation method, the numerical calculation method respectively calculates from two aspects of absorption and scattering, the emission track of rays is used, the number of the related numerical values is large, and the calculation process is complex. Some software simulation methods are commercial software, which requires professional personnel to perform simulation calculation, and have more accurate numerical values, long design period and high design cost.
Disclosure of Invention
In order to overcome the defects in the prior art, the inventor performs intensive research and provides a general security inspection machine ray shielding design method based on Geant4, a physical process platform is built for physical processes which reach qualified shielding conditions in reality in the Geant4 platform, the ray emission physical process of the security inspection machine is abstracted, for example, the physical process of rays passing through a collimator is abstracted into rays which are emitted by the collimator with a certain thickness from a radiation emission source, particles are emitted by the collimator, and shielding boxes at two sides of the collimator are abstracted into shielding bodies with nonuniform thickness which are continuously arranged; the ray acts on a scatterer in a channel to abstract that a transmitting source is at a certain distance from the scatterer, and two shielding bodies are built at a position perpendicular to the transmitting direction and avoiding a transmitting port; the shielding protection of the rays reaching the shielding box cover after penetrating the detector plate is abstracted as the rays emitting source emits particles from the shielding body with a certain thickness. The method is characterized in that an ideal absorber with grids on the surface and the inside is arranged behind a shielding body to capture photoelectric effect, the particle quantity and energy deposition after Compton effect are achieved, firstly, a plurality of grids are divided to capture particle density comparison, the result is used as a target for the establishment of shielding boundary lines of security inspection machines with different sizes, then the size, the position and the like of the shielding body in the shielding boundary lines are adjusted, the energy deposition in the ideal absorber is compared in grids with the same size after simulation, and if the energy deposition data in the grids with the same size are close, the secondary shielding body size and the position result are finally designed.
The technical scheme provided by the invention is as follows:
geant 4-based general security inspection machine ray shielding design method comprises the following steps:
step 1, building a Geant4 platform;
step 2, under the Geant4 platform, a ray shielding project module of the security inspection machine is created, and under the ray shielding project module, the following modules are created:
the creation management module is used for initializing the detection structure class and the physical process class, loading the particle beam input module, loading the command execution module and carrying out visual management;
creating an initialization module for initializing the emission particles to gamma;
the creation command control module is used for defining a beamOn command and a mesh grid division information process; wherein the beamOn command defines a launch particle event process; the mesh grid division information is used for extracting grid particle emission event information;
a detection structure module is created for simulating a security inspection machine ray system, comprising: the method comprises the steps of forming a collimator in an optical path structure of a simulation security inspection machine by using lead Pb and iron Fe, simulating a shielding body and a channel plate beside the collimator by using lead Pb, simulating a scattering body by using water, creating physical positions of the detector, which are reached by a target point through the collimator in the X-ray particle emission process of the security inspection machine, creating size and position information of the shielding body beside the collimator, creating size and position information of the channel plate, and creating an ideal absorber with the size not smaller than the size of the shielding body and the channel plate behind the shielding body and the channel plate; the ideal absorber is an object which can absorb the energy of all particles with extremely small thickness;
a particle object module is created and used for defining attribute information of the emission particles;
creating a physical process module for defining a physical process based on the impact of X-rays in Geant 4;
creating a physical process cutting module for defining a cutting command of the particles and a cutting mode of the particles;
a particle source information interface module is established and used for initializing emergent particle information and interfaces;
creating a particle emission action module for defining particle energy information emitted each time in the output simulation;
step 3, a particle beam input module and a command execution module which are appointed in the management module are established, wherein the particle beam input module is used for defining the emission angle of a particle beam, the command execution module is used for executing the command of emitting a given quantity of X-ray particles, establishing a grid on the surface of an ideal absorber body to capture the quantity of the X-ray particles, establishing a grid in the interior of the ideal absorber body to collect the energy deposition of the X-ray particles, and executing the command of outputting the quantity of the particles and a program in an energy deposition file;
step 4, creating a particle information input module appointed in the command execution module, wherein the particle information input module is used for defining the properties and the emergent cross section size of X-ray particles emitted by a target point;
step 5, organizing and compiling to generate a shielding simulation executable file through a management module;
step 6, a shielding simulation executable file is operated to obtain a ray shielding result required by the command execution module;
and 7, adjusting parameters in the radiation system of the simulation security inspection machine according to the radiation shielding result until a final result meeting the requirements is obtained.
According to the Geant 4-based general security inspection machine ray shielding design method provided by the invention, the following beneficial effects are achieved:
the general security inspection machine ray shielding design method based on Geant4 provided by the invention has the advantages that the implementation method is relatively simple, the process is clear, simulation parameters are easy to adjust, the position value in a detection structure module (such as a program in an XrayDetector Constract. Cc file), the thickness value of a lead plate, the grid size and the position value in a command execution module (such as a program in a macro. Mac file) and the target information value in a particle information input module (such as a program in a GPS. In file) can be adjusted, so that the scene can be quickly switched, and the fastest shielding result can be obtained.
Drawings
FIG. 1 shows a schematic diagram of the connection of the modules in the Geant4 platform;
fig. 2 shows a scatter plot form visualization result.
Detailed Description
The features and advantages of the present invention will become more apparent and clear from the following detailed description of the invention.
The principle of the invention is that by constructing an abstract security inspection machine process physical platform, the continuous spectrum of an emission source (target point) of the security inspection machine is simplified into a single spectrum, the maximum energy of X-rays is selected as the energy of the single spectrum, and the shielding structure of the security inspection machine is simulated by utilizing lead plates and steel plates which are placed at different positions. On the basis, photoelectric effect, compton effect and the like are generated by simulating the impact of the emission particles on the collimator or the water scattering body through Geant4, an ideal absorber is built behind the shielding body and the channel plate, grids are divided on the surface and the inside of the ideal absorber, the number of particles captured in the grids on the surface is extracted, and the distribution density of the particles in a plurality of areas is intercepted for comparison. After the thickness, the appearance and the position of the shielding body or the channel plate are adjusted in the area with high particle distribution density, the energy deposition in the grids inside the absorber after the shielding body and the channel plate are extracted in a simulation mode again, and the condition that the energy deposition values in a plurality of grids are close to each other is judged to meet the initial shielding design requirement. The particle density calibration of the proper result is obtained by simulating a physical process which reaches a qualified shielding condition in reality.
Based on the principle, the invention provides a general security inspection machine ray shielding design method based on Geant4, which comprises the following steps:
step 1, building a Geant4 platform;
step 2, under the Geant4 platform, creating a security inspection machine ray shielding project module (such as a program in an xray. Sln file), and under the ray shielding project module, creating the following modules, as shown in fig. 1:
creating a management module (such as a program in an Xray. Cc file) for initializing a detection structure class and a physical process class, loading a particle beam input module (ShootAngle. In), loading a command execution module (Macro. Mac) and performing visual management;
creating an initialization module (such as a program in an XrayActionInitialization. Cc file) for initializing the emission particles to gamma;
creating a command control module (such as a program in an Xraycontrol. Cc file) for defining a beamOn command and a mesh grid division information process; wherein the beamOn command defines a launch particle event process; the mesh grid division information is used for extracting grid particle emission event information;
a detection structure module (e.g., a program in an xray detector construction. Cc file) is created for simulating a security inspection machine ray system, comprising: the method comprises the steps of forming a collimator in an optical path structure of a simulation security inspection machine by using materials Pb and Fe, simulating a shielding body and a channel plate beside the collimator by using the material Pb, simulating a scattering body by using material water (water), creating physical positions of the detector, which are transmitted by a target point through the collimator in the X-ray particle transmitting process of the security inspection machine, creating size and position information of the shielding body beside the collimator, creating size and position information of the channel plate, and creating an ideal absorber which is not smaller than the size of the shielding body and the channel plate behind the shielding body and the channel plate; the ideal absorber is an object which can absorb the energy of all particles with extremely small thickness;
creating a particle object module (such as a program in an xrayparticles. Cc file) for defining attribute information of the emission particles;
creating a physical process module (such as a program in the xrayphisiclist. Cc file) for defining a physical process based on the X-ray impingement in Geant 4;
creating a physical process truncation module (such as a program in an XrayphisisListMessager. Cc file) for defining a particle truncation command and a particle truncation mode;
creating a particle source information interface module (such as a program in an XrayPrimaryGenerator action. Cc file) for initializing emergent particle information and interfaces;
creating a particle emission action module (such as a program in an XrayRunAction. Cc file) for defining particle energy information of each emission in the output simulation;
step 3, a particle beam input module (such as a program in a shooter angle file) and a command execution module (such as a program in a shooter angle file) are created, wherein the particle beam input module (such as a program in a shooter angle file) is used for defining the emission angle of a particle beam, the command execution module (such as a program in a shooter angle file) is used for executing the emission of a given number of X-ray particles and establishing a grid on the surface of an ideal absorber to capture the number of X-ray particles, establishing a grid inside the ideal absorber to collect energy deposition of the X-ray particles, and executing the command of outputting the number of particles and the program in the energy deposition file;
step 4, creating a particle information input module (such as a program in a GPS.in file) designated in a command execution module (such as a program in a macro.Mac file) for defining properties (such as information of type, energy and the like) and an emergent section size of X-ray particles emitted by a target;
step 5, organizing and compiling to generate a shielding simulation executable file (such as a program in an Xray. Exe file) through a management module;
step 6, a shielding simulation executable file (such as a program in an Xray. Exe file) is operated to obtain a ray shielding result required by the command execution module;
and 7, adjusting parameters in the radiation system of the simulation security inspection machine according to the radiation shielding result until a final result meeting the requirements is obtained. Parameters in the simulated security inspection machine radiation system include size and position information of the collimator side shields, size and position information of the tunnel plates.
In a preferred embodiment of the present invention, in step 2, the management module (e.g., a program in an xray. Cc file), the initialization module (e.g., a program in an xray activation initiation. Cc file), the command control module (e.g., a program in an xray control. Cc file), the particle object module (e.g., a program in an xray particles. Cc file), the physical process module (e.g., a program in an xray ph list. Cc file), the physical process cut-off module (e.g., a program in an xray ph list. Cc file), the particle source information interface module (e.g., a program in an xray primary generator activity. Cc file), and the particle emission action module (e.g., a program in an xray Ruction. Cc file) are adapted to different shielding requirements of different security machines, without changing changes when performing shielding simulation of the different security machines.
In a preferred embodiment of the present invention, in step 2, X-ray particles of the security inspection machine in the detection structure module (e.g. the program in the xray detector configuration. Cc file) are edited, and the shielding light path model of different security inspection machines can be built by transmitting the X-ray particles from the target spot to the physical position of the detector through the collimator, the size and position information of the shielding body beside the collimator, the size and position information of the channel plate, and the size and position information of the ideal absorber.
The radiation emission angle can be changed by editing and changing parameters in a particle beam input module (such as a program in a ShootAngle. In file).
The parameters in the command execution module (such as the program in the macro. Mac file) can be edited to change the number of X-ray particles, the grid size, the position and the visual result.
The property and the emergent section size of the emitted X-ray particles can be changed by editing and changing parameters in a particle information input module (such as a program in a GPS.in file).
In a preferred embodiment of the invention, in step 6, the radiation shielding results are presented in the form of a list or scatter diagram, in which grid positions and particle distribution density and/or energy deposition information are shown. Preferably, the ray shielding result obtained by the first run shielding simulation executable file is presented in the particle distribution density; after parameters in a radiation system of the simulation security inspection machine are adjusted, a radiation shielding result obtained by running a shielding simulation executable file is presented in energy deposition information.
It is known that the radiation dose after shielding never becomes zero from the theory of attenuation of radiation. Thus, the shielding design of radiation does not consist in determining a thickness of the layer of material that fully absorbs radiation, but rather in trying to find a shield and channel plate thickness where the radiation dose through the shield and channel plate is reduced several times and the dose limit is met. To this end, the present invention provides an X-ray particle escape assessment method to assist in a fast shielding design, i.e. a meshing method, by which the number of particles not absorbed by the shielding or channel plate (particle distribution density) and/or energy deposition is obtained. Generally, when X-ray particles penetrate through a shielding body or a channel plate with the same thickness in a simulation test, the quantity of attenuated photons on the surface of an ideal absorber is firstly extracted to ensure high efficiency and is used as a judgment basis of a first simulation result; and then adopting energy deposition as a judging condition of a subsequent simulation result.
The shielding design of the shielding box with the X-ray with the energy of 160Kev penetrating through the lead plate gap of the collimator with the thickness of 5mm is described in detail: when 160Kev ray particles with the diameter of 6mm penetrate through a collimator lead plate with the thickness of 5mm, small holes with the diameter of 0.5mm on the lead plate are simplified and eliminated, and when rays penetrate through the 5mm lead plate, the photoelectric effect and the effect occurCompton scattering, in which a shielding box lead plate is placed on the side of a collimator along the ray penetration direction, is mainly used for shielding Compton scattering particles, the relation between the scattered photon energy and the angle is as follows, for example, 30-degree scattered photon energy is 97% of incident photon energy, 60-degree scattered photon energy is 87% of incident photon energy, 90-degree scattered photon energy is 77% of incident photon energy, 120-degree scattered photon energy is 66% of incident photon energy, 180-degree scattered photon energy is 63% of incident photon energy, according to the inverse square law of the attenuation of photon energy, point sources are used as sphere centers, the X-ray intensity on each spherical surface with different radius is inversely proportional to the square of the distance, the X-ray intensity is attenuated to be 1/4 of the original distance, when X-ray reaches the collimator lead plate, for example, 30-degree scattered photon energy is 2 times the distance of 90 DEG, the 90-degree scattered photon energy reaches the shielding box lead plate, namely 30-degree scattered photon energy reaches the shielding box lead plate, 60-degree scattered photon energy is about 97/77/4X 90 DEG, in other words, the distance of 90-degree scattered photon energy is about 90-90% of the lead plate is about 90 DEG, and the distance is about 1.15/90% of the lead plate is about 90 DEG, namely, the distance is about 1/4X/90% of the distance is about 90% of the energy, namely about 90% of the lead plate is about 90. Therefore, under the condition of combining the distance and the intensity, the difference between the thickness of the lead plate of the shielding design and the included angle of 30 degrees of each scattered 90-degree photon is embodied, in order to meet the shielding requirement, the difference design is embodied under the condition of not excessively using the lead plate, the photon intensity in the range is simplified to be consistent, the difference between the lead plate and the shielding outside the range is simplified and related to the number of particles, the lead plate difference at the position of 60mm distance of the shielding lead plate from the collimator is preset to be 68mm width for 160Kev ray particles, the formula is 60 x 2/1.732=68 mm, and the first step is through Geant simulation to divide the particle density dividing line obtained by the grid. After the thickness of the shielding lead plate is adjusted for the area in the particle density dividing line based on the above, according to the exponential decay law, i=i 0 *e ( -μ* d) Wherein I 0 For incident X-ray intensity, d is the thickness of the absorbing material, μ is the line attenuation coefficient, I is the intensity of the X-ray transmitted through the thickness d of the material, e is the natural logarithmic base, e=2.718 … … at 16The half-value layer of the lead plate of 0Kev rays is 1mm, the preset thickness of the shielding body and the channel plate is 2mm, scattered photons are attenuated to be 25% of 90-degree scattered photon intensity after passing through the 2mm, the scattered photons can be shielded by referring to the scattered photon intensity in the scattering range of 30 degrees, the shielding body and the channel plate are not designed by comparing the particle density, an ideal absorber is placed behind the shielding body and the channel plate to enable the rays passing through the lead plate to be shielded by different thicknesses, the energy deposition values in the grid division are compared, and when the deposition energy at the grid division position of the ideal absorber at the rear side of the shielding lead plate is close to the grid deposition energy at the position of 30 degrees, the shielding thickness is determined.
Examples
Example 1
Example 1: screening simulation of target to collimator of cargo security check machine 180180D.
A general security inspection machine ray shielding design method based on Geant4 comprises the following specific implementation steps:
1. downloading and setting installation Geant4
2. Download and set installation Microsoft Visual Studio
3. Creating a source file by creating a security inspection machine ray shielding item xray.
1Xray. Cc, content is as follows: initializing a geographic position and a physical process, loading a transmitting angle ShootAngle. In, and loading a visualized file macro. Mac;
2XrayActionInitialization. Cc, content is as follows: initializing emission particles to gamma
G4ParticleDefinition*particle＝particleTable->FindParticle("gamma")；
3.3 Xraycontrol. Cc, the contents are as follows: defining a beam on command and a control process of capturing particles by a mesh grid;
3.4XrayDetectorConstruction. Cc, the contents are as follows: the collimator in the light path structure of the simulation security inspection machine is formed by materials Pb and Fe, the shielding plate is simulated by the material Pb, the particle emission process of the security inspection machine is created by the absorption and scattering process of target spot emission through the collimator, the relative position of the shielding body beside the collimator is created,
a 5mmx320mmx160mm lead plate was defined and simulated as a shield box baffle on one side of the collimator, 50mm from the X direction of the collimator, as follows:
an ideal absorber is defined which is close to the outer side of a lead plate with the thickness of 5mmx320mmx160mm, the external dimension is 1mmx600mmx300mm and is 50mm away from the X direction of the collimator, and the following contents are:
defining the position of the target point, and keeping the position from the collimator by 350mm in the Z direction, wherein the content is as follows:
G4ThreeVector position＝G4ThreeVector(0,0,-35.0*cm)；
3.5XrayParticles. Cc, the contents are as follows: defining emission particles;
3.6XrayPhisicsList. Cc, the contents are as follows: defining a physical process;
3.7 XryphisisLittMessenger. Cc, the contents are as follows: defining a cut-off command and a cut-off mode;
3.8XrayPrimaryGenerator action. Cc, the contents are as follows: defining particle source related information and interfaces;
3.9XrayRunAction. Cc, content is as follows: defining energy information of particles emitted each time in the output simulation;
3.10 creating a file shooangle. In specified in xray. Cc, the contents are as follows: defining an emission angle of 90 ° of the particle source;
Axx 0 90
3.11 creating a file macro. Mac specified in xray. Cc, the function of which is as follows: establishing a grid box mesh_1 with the size of 0.2mm x600mm x300mm, wherein the position is at a position of 54mm on the side surface of a collimator, namely at a position of 1mm on the rear side of a 5mm lead plate in 3.4, the quantity of emitted particles is 100000000, visually outputting the quantity of particles captured by the corresponding grid box mesh_1 after the effect of the collimator to a file mesh1.Out, establishing a grid box mesh_2 with the size of 1mm x600mm x300mm, clinging to a side surface shielding plate of the collimator, outputting energy captured by the corresponding grid box mesh_2 to deposit to the file mesh2.Out, and visually outputting a scatter diagram of the mesh 1;
/score/create/boxMesh boxMesh_1
/score/mesh/boxSize 0.01 15 30cm
/score/mesh/translate/xyz 54 0-15mm
/score/mesh/nBin 1 10 10
/score/quantity/nOfStep mesh1
/score/close
/score/create/boxMesh boxMesh_2
/score/mesh/boxSize 0.05 15 30cm
/score/mesh/translate/xyz 53 0-15mm
/score/mesh/nBin 1 10 10
/score/quantity/GetTotalEnergyDeposit mesh2
/score/close
/score/list
/run/beamOn 100000000
/score/dumpQuantityToFile boxMesh_1mesh1mesh1.out
/score/dumpQuantityToFile boxMesh_2mesh2mesh2.out
/score/drawProjection boxMesh_1mesh1
3.12 creates a file gps.in specified in macro.mac, the function of which is as follows: defining information such as particle type gamma, energy 320Kev, angle 180 degrees and the like emitted by a target point;
/gps/source/intensity 1
/gps/ene/type Mono
/gps/ene/mono 0.32MeV
/gps/particle gamma
/gps/pos/type Volume
/gps/pos/shape Cylinder
/gps/pos/centre 0.0 0.0-11cm
/gps/pos/radius 3mm
/gps/pos/halfz 0.1cm
/gps/ang/type iso
/gps/ang/mintheta 180deg
/gps/ang/maxtheta 180deg
4. compiling and generating collimation shielding exe, and running to obtain a visual result, wherein the visual result is displayed in a scatter diagram form, and the scatter is captured X-ray particles as shown in figure 2.
The invention has been described in detail in connection with the specific embodiments and exemplary examples thereof, but such description is not to be construed as limiting the invention. It will be understood by those skilled in the art that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, and these fall within the scope of the present invention. The scope of the invention is defined by the appended claims.
What is not described in detail in the present specification is a well known technology to those skilled in the art.
Claims (6)
1. The general security inspection machine ray shielding design method based on Geant4 is characterized by comprising the following steps of:
step 1, building a Geant4 platform;
step 2, under the Geant4 platform, a ray shielding project module of the security inspection machine is created, and under the ray shielding project module, the following modules are created:
the creation management module is used for initializing the detection structure class and the physical process class, loading the particle beam input module, loading the command execution module and carrying out visual management; the number of X-ray particles, the grid size, the position and the visual result can be changed by editing and changing parameters in the command execution module;
creating an initialization module for initializing the emission particles to gamma;
the creation command control module is used for defining a beamOn command and a mesh grid division information process; wherein the beamOn command defines a launch particle event process; the mesh grid division information is used for extracting grid particle emission event information;
a detection structure module is created for simulating a security inspection machine ray system, comprising: the method comprises the steps of forming a collimator in an optical path structure of a simulation security inspection machine by lead and iron, simulating a shielding body and a channel plate beside the collimator by lead, simulating a scattering body by water, creating physical positions of detectors, which are transmitted by targets through the collimator in the X-ray particle transmitting process of the security inspection machine, of the shielding body beside the collimator, creating size and position information of the channel plate, and creating an ideal absorber with the size not smaller than the size of the shielding body and the channel plate; the ideal absorber is an object with small thickness capable of absorbing the energy of all particles; editing physical position of X-ray particles of the security inspection machine in the detection structure module, which are emitted by a target spot and reach a detector through a collimator, size and position information of a shielding body beside the collimator, size and position information of a channel plate and size and position information of an ideal absorber, and constructing shielding light path models of different security inspection machines;
a particle object module is created and used for defining attribute information of the emission particles;
creating a physical process module for defining a physical process based on the impact of X-rays in Geant 4;
creating a physical process cutting module for defining a cutting command of the particles and a cutting mode of the particles;
a particle source information interface module is established and used for initializing emergent particle information and interfaces;
creating a particle emission action module for defining particle energy information emitted each time in the output simulation;
step 3, a particle beam input module and a command execution module which are appointed in the management module are established, wherein the particle beam input module is used for defining the emission angle of a particle beam, the command execution module is used for executing the command of emitting a given quantity of X-ray particles, establishing a grid on the surface of an ideal absorber body to capture the quantity of the X-ray particles, establishing a grid in the interior of the ideal absorber body to collect the energy deposition of the X-ray particles, and executing the command of outputting the quantity of the particles and a program in an energy deposition file;
step 4, creating a particle information input module appointed in the command execution module, wherein the particle information input module is used for defining the properties and the emergent cross section size of X-ray particles emitted by a target point;
step 5, organizing and compiling to generate a shielding simulation executable file through a management module;
step 6, a shielding simulation executable file is operated to obtain a ray shielding result required by the command execution module;
and 7, adjusting parameters in the radiation system of the simulation security inspection machine according to the radiation shielding result until a final result meeting the requirements is obtained.
2. The method according to claim 1, wherein in step 2, the radiation emission angle is changed by editing and changing parameters in the particle beam input module.
3. The method according to claim 1, wherein in step 2, the properties and the exit cross-sectional dimensions of the emitted X-ray particles are modified by editing parameters in the particle information input module.
4. The method according to claim 1, wherein in step 6, the radiation shielding result is presented in the form of a list or a scatter diagram in which grid positions and particle distribution density and/or energy deposition information are shown.
5. The design method according to claim 4, wherein the ray shielding result obtained by the first run shielding simulation executable file is presented in a particle distribution density; after parameters in a radiation system of the simulation security inspection machine are adjusted, a radiation shielding result obtained by running a shielding simulation executable file is presented in energy deposition information.
6. The method of claim 1, wherein in step 7, the parameters in the simulated security inspection machine radiation system include collimator side shield size and position information, and channel plate size and position information.
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