A pulsed gamma ray beam energy selective imaging device

Abstract

The present application relates to a kind of pulse gamma ray beam energy selection imaging device.The technical problem that the present pulse gamma ray beam imaging energy resolution is lower, and it is difficult to realize the gamma ray imaging of specific energy point is solved.The device of the present application includes gamma ray source, radiation conversion target, electronic energy selection system and optical imaging system;Radiation conversion target is arranged on the exit path of gamma ray source;Electronic energy selection system includes angle limiter, first di-magnet, energy limiter and second di-magnet;Angle limiter is arranged at the entrance of first di-magnet;The position of radiation conversion target and energy limiter is mirror image symmetry with the radial midplane of first di-magnet as symmetry surface;First di-magnet and second di-magnet are rotationally symmetric with the radial center line of energy limiter as axis;Compton scattering electron beam is sequentially through angle limiter, first di-magnet, energy limiter and second di-magnet, then enters optical imaging system and is imaged.

Description

Technical Field

[0001] This invention relates to an energy-selective imaging device for radiation detection and imaging, specifically to a pulsed gamma-ray beam energy-selective imaging device. Background Technology

[0002] Pulsed gamma-ray beam imaging is one of the key measurement techniques for studying the performance of devices such as inertial confinement fusion. Pulsed gamma-ray beam imaging can intuitively obtain the spatial distribution of the fusion combustion zone, and the measurement results have important reference value for evaluating the success or failure of fusion ignition.

[0003] Existing pulsed gamma-ray beam imaging methods are mainly based on pinhole imaging and scintillation detection principles. It's difficult to distinguish gamma-ray images of different energies, even though these images reflect different physical processes. For example, in the DT fusion reaction, the spatial distribution of 4.44 MeV gamma rays generated by the inelastic scattering of fusion neutrons with carbon in the ablation layer can be used to diagnose the state of the ablation layer. Gamma rays of specific energies imply specific reaction types. Quasi-monoenergy imaging of pulsed gamma-ray beams can yield image information with clearer physical meaning. Therefore, developing pulsed gamma-ray beam energy-selective imaging technology is of great significance for performance research of devices such as inertial confinement fusion reactors.

[0004] To address the characteristics of pulsed gamma-ray beam imaging, researchers in Chinese patent CN114757105A employed a combination of three arrayed scintillators and two attenuators to achieve three-band gamma imaging. This method can obtain gamma-ray images of three energy bands in a single measurement, exhibiting high spatial resolution and detection efficiency. However, its drawback lies in insufficient energy resolution, making it impossible to achieve energy-selective imaging of gamma rays at specific energy points according to application requirements. This affects the accurate evaluation of the performance of devices such as inertial confinement fusion and limits further research and application of this technology. Therefore, it is essential to develop new methods to achieve pulsed gamma-ray beam energy-selective imaging with adjustable target energy and high energy resolution. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem that existing pulsed gamma-ray beam imaging has low energy resolution and is difficult to achieve gamma-ray imaging at specific energy points as needed, and to provide a pulsed gamma-ray beam energy selective imaging device.

[0006] The technical solution of this invention is:

[0007] A pulsed gamma-ray beam energy-selective imaging device, characterized in that it includes a gamma-ray source, a radiation conversion target, an electronic energy selection system, and an optical imaging system;

[0008] The gamma-ray source is used to generate pulsed gamma-ray beams with energy distribution;

[0009] The radiation conversion target is positioned in the path of the pulsed gamma-ray beam from the gamma-ray source to convert the pulsed gamma-ray beam into a Compton scattered electron beam.

[0010] The electronic energy selection system includes an angle limiter, a first dipole magnet, an energy limiter, and a second dipole magnet arranged sequentially along the emission path of the Compton scattered electron beam.

[0011] The angle limiter is set on the exit path of the Compton scattered electron beam and located at the entrance of the first diode magnet, so as to allow the Compton scattered electron beam that meets the emission angle requirements to pass through and enter the first diode magnet.

[0012] The positions of the radiation conversion target and the energy limiter are mirror-symmetrically arranged with the radial midpoint of the first dipole magnet as the plane of symmetry.

[0013] The energy limiter is positioned between the first and second dipole magnets and at the midpoint, and is used to allow Compton scattered electrons that meet the energy requirements to pass through.

[0014] The first and second diode magnets are arranged in a rotationally symmetrical manner with the radial center line of the energy limiter as the axis; the first and second diode magnets are used to control the trajectory of Compton scattered electrons through the magnetic field, so that the Compton scattered electrons enter from the first diode magnet and exit from the second diode magnet.

[0015] The optical imaging system is positioned along the exit path of the Compton scattered electron beam emitted from the second dipole magnet, and is used to image the Compton scattered electron beam emitted from the second dipole magnet.

[0016] Furthermore, both the first and second dipole magnets have an arc-shaped structure and the same structural parameters.

[0017] The transmission matrix of the Compton-scattered electron beam within the first and second dipole magnets is a sixth-order matrix A, and the sixth-order matrix A satisfies the following condition:

[0018] , , ,

[0019] Among them, A in the sixth-order matrix A 11 A 22 A 33 A 44 These represent the elements in the first row and first column, the second row and second column, the third row and third column, and the fourth row and fourth column, respectively.

[0020] The magnetic field strength B of the first and second dipole magnets satisfies the following formula:

[0021]

[0022] Represents the central energy of a beam of charged particles;

[0023] Represents the speed of light;

[0024] Represents the amount of charge carried by a single charged particle;

[0025] E0 represents the rest energy of a single charged particle;

[0026] R represents the radius of the circle containing the arc of the diode magnet.

[0027] Furthermore, the optical imaging system includes an electro-optic conversion screen located on the path of the Compton scattered electron beam emitted from the second dipole magnet, and a reflector and a camera arranged sequentially along the light path emitted from the electro-optic conversion screen;

[0028] The positions of the electro-optic conversion screen and the energy limiter are mirror-symmetrically arranged with the radial midpoint of the second dipole magnet as the plane of symmetry.

[0029] The positions of the electro-optic conversion screen and the radiation conversion target are arranged in a rotationally symmetrical manner with the radial center line of the energy limiter as the axis.

[0030] The Compton scattered electron beam emitted from the second dipole magnet is converted into visible light by an electro-optic conversion screen, and the visible light is reflected by a mirror into the camera for imaging.

[0031] Furthermore, the electro-optic conversion screen material is YAG;

[0032] The radiation conversion target material is selected from beryllium or aluminum.

[0033] Furthermore, the deflection radius R of the first and second diode magnets is 500 mm, the deflection angle θ is 50 degrees, and the edge angle α is 14.8 degrees.

[0034] Wherein, the deflection angle θ is the central angle of the circle containing the arc of the dipole magnet, the deflection radius R is the radius of the circle containing the arc of the dipole magnet, and the edge angle α is the angle between the diameter of the intersection point of the central axis of the dipole magnet and the two end faces and the corresponding end face.

[0035] The distance between the radiation conversion target and the inlet of the first diode magnet is 1.2 meters, the distance between the outlet of the first diode magnet and the inlet of the second diode magnet is 2.4 meters, and the distance between the outlet of the second diode magnet and the electro-optic conversion screen is 1.2 meters.

[0036] The radiation conversion target is made of beryllium and has a thickness of 0.3 mm.

[0037] The beneficial effects of this invention are:

[0038] This invention discloses a pulsed gamma-ray beam energy-selective imaging device. It converts a pulsed gamma-ray beam into a Compton-scattered electron beam using a radiation conversion target. Energy selection of the pulsed gamma-ray beam is achieved through angle and energy limiters. Furthermore, the trajectory of the Compton-scattered electron beam is controlled by two secondary magnets, enabling achromatic, point-to-point imaging of the Compton-scattered electron beam. This allows for the selection of specific energies from a continuously distributed gamma-ray beam for clear imaging. This invention provides a guarantee for the accurate evaluation of the performance of devices such as inertial confinement fusion and provides a sound physical foundation for further research and application of this technology.

[0039] This invention discloses a pulsed gamma-ray beam energy selective imaging device. By adjusting the structural parameters and magnetic induction intensity of a diode magnet, quasi-monoenergetic images of gamma rays with different energies can be obtained. This enables energy selective imaging of gamma rays with different target energies to meet specific application requirements, thereby obtaining image information reflecting different physical processes and providing richer information for the accurate evaluation of the performance of devices such as inertial confinement fusion.

[0040] This invention discloses a pulsed gamma-ray beam energy-selective imaging device, wherein the parameters R, θ, α, and entrance distance of the diode magnet conform to a sixth-order matrix A and satisfy the following conditions: , , , Furthermore, the matching results are superior, resulting in clear image imaging.

[0041] This invention provides an energy-selective imaging device for pulsed gamma rays. By using an energy limiter, the energy dispersion of electrons reaching the detection surface can be limited, thereby achieving high energy resolution. Compared with the prior art, the device of this invention has higher energy resolution, and a single measurement can obtain a quasi-monoenergetic pulsed gamma ray beam image with high energy resolution. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of an embodiment of the pulsed gamma-ray beam energy selective imaging device of the present invention;

[0043] Figure 2 This is a schematic diagram of the structure of a diode magnet in an embodiment of a pulsed gamma-ray beam energy selective imaging device of the present invention;

[0044] Figure 3The following is a simulation result of pulsed gamma-ray energy selective imaging implemented by an embodiment of the pulsed gamma-ray beam energy selective imaging device of the present invention: (a) is the original image, (b) is the high-energy gamma-ray image obtained by the camera, and (c) is the low-energy gamma-ray image obtained by the camera.

[0045] Figure reference numerals: 1-Radiation conversion target; 2-Electron energy selection system; 201-First dipole magnet; 202-Second dipole magnet; 203-Angle limiter; 204-Energy limiter; 3-Optical imaging system; 301-Electro-optical conversion screen; 302-Reflector; 303-Camera; 401-Pulsed gamma-ray beam; 402-Compton scattered electron beam; 403-Electron beam with energy near the central energy; 404-Electron beam with energy greater than the central energy; 405-Electron beam with energy less than the central energy; 406-Visible light; 407-Reference particle trajectory with energy at the central energy. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] This invention provides a pulsed gamma-ray beam energy-selective imaging device, such as... Figure 1 As shown, it includes a gamma-ray source, a radiation conversion target 1, an electron energy selection system 2, and an optical imaging system 3. The gamma-ray source is used to generate pulsed gamma-ray beams with energy distribution;

[0048] Radiation conversion target 1 is placed in the path of the pulsed gamma-ray beam from the gamma-ray source to convert the pulsed gamma-ray beam into a Compton scattered electron beam. Radiation conversion target 1 is a low-Z millimeter target, and the material is a low-Z substance such as beryllium or aluminum.

[0049] The electron energy selection system 2 includes an angle limiter 203, a first dipole magnet 201, an energy limiter 204, and a second dipole magnet 202, arranged sequentially along the emission path of the Compton scattered electron beam. The angle limiter 203 is positioned at the entrance of the first dipole magnet 201 on the emission path of the Compton scattered electron beam, and is used to limit the angle of the electron beam, allowing the Compton scattered electron beam that meets the emission angle requirements to pass through. The radiation conversion target 1 and the energy limiter 204 are positioned in a mirror-symmetric manner with respect to the radial midpoint of the first diode magnet 201. The energy limiter 204 is located between the first diode magnet 201 and the second diode magnet 202, at the midpoint, to allow Compton-scattered electrons meeting the energy requirements to pass through. The first diode magnet 201 and the second diode magnet 202 are rotationally symmetric about the radial centerline of the energy limiter 204. The first diode magnet 201 and the second diode magnet 202 are used to control the trajectory of the Compton-scattered electrons through a magnetic field, causing the Compton-scattered electrons to enter from the first diode magnet 201 and exit from the second diode magnet 202. The reference particle trajectory 407 with the energy of the center energy is shown in the figure. Figure 2 As shown, the optical imaging system 3 is positioned in the path of the Compton scattered electron beam emitted from the second dipole magnet 202, and is used to image the Compton scattered electron beam emitted from the second dipole magnet 202.

[0050] The optical imaging system 3 includes an electro-optic conversion screen 301 located on the path of the Compton-scattered electron beam emitted from the second dipole magnet 202, and a reflector 302 and a camera 303 arranged sequentially along the light path emitted from the electro-optic conversion screen 301. The electro-optic conversion screen 301 is used to convert the electron beam 403 with energy near the central energy into visible light 406 that can be captured by the camera. The material of the electro-optic conversion screen 301 is YAG. The reflector 302 is used to reflect the visible light 406 emitted from the electro-optic conversion screen 301. The reflector 302 is placed at a 45-degree angle to the emission direction of the visible light 406 emitted from the surface of the electro-optic conversion screen 301. The camera 303 is used to capture the visible light 406 reflected by the reflector 302 to form an image. The positions of the electro-optic conversion screen 301 and the energy limiter 204 are mirror-symmetrical about the radial midline of the second dipole magnet 202; the positions of the electro-optic conversion screen 301 and the radiation conversion target 1 are rotationally symmetrical about the radial centerline of the energy limiter 204; the Compton scattered electron beam emitted from the second dipole magnet 202 is converted into visible light by the electro-optic conversion screen 301 (i.e., at the image plane), and the visible light is reflected by the mirror 302 and enters the camera 303 for imaging.

[0051] In this invention, both the first dipole magnet 201 and the second dipole magnet 202 are arc-shaped structures with identical structural parameters. The transmission matrix of the Compton-scattered electron beam within the first dipole magnet 201 and the second dipole magnet 202 is a sixth-order matrix A, and the sixth-order matrix A satisfies the following condition:

[0052] , , ,

[0053] Among them, A in the sixth-order matrix A 11 A 22 A 33 A 44 Let represent the elements in the first row and first column, the second row and second column, the third row and third column, and the fourth row and fourth column, respectively. The magnetic field strength B of the first dipole magnet 201 and the second dipole magnet 202 satisfies the following formula:

[0054]

[0055] Represents the central energy of a beam of charged particles;

[0056] Represents the speed of light;

[0057] Represents the amount of charge carried by a single charged particle;

[0058] E0 represents the rest energy of a single charged particle;

[0059] R represents the radius of the circle containing the arc of the diode magnet.

[0060] The working principle of the device of the present invention is as follows: The pulsed gamma-ray beam 401 interacts with the radiation conversion target 1 to generate a Compton scattered electron beam 402. The Compton scattered electron beam 402 emitted from the radiation conversion target 1 carries the energy and image information of the incident gamma-ray beam into the electron energy selection system 2. The Compton scattered electron beam 402 emitted from the radiation conversion target 1 first enters the angle limiter 203. When passing through the angle limiter 203, electrons with smaller emission angles can pass through, while electrons with larger emission angles will be blocked by the angle limiter 203 and cannot continue to be transported. Thus, the angle limiter 203 can be used to limit the emission angle of the electron beam. After the Compton scattered electron beam 402 is emitted from the angle limiter 203, it passes through the first diode magnet 201, the energy limiter 204, and the second diode magnet 202 in sequence. The electron energy selection system 2 utilizes the magnetic fields provided by the centrally symmetrically placed first and second dipole magnets 201 and 202 to control the trajectory of the electron beam and form achromatic, point-to-point imaging at the image plane. After passing through the first dipole magnet 201, the electron beam 403 with energy near the central energy is focused at the center of the energy limiter 204. The electrons passing through the energy limiter 204 continue to be transported and pass through the second dipole magnet 202. Under the action of the magnetic field provided by the second dipole magnet 202, the focused electrons are redispersed and imaged at the image plane by the optical imaging system 3. The electron image at the image plane corresponds to the image of the Compton scattered electrons emitted from the rear surface of the radiation conversion target 1. Furthermore, the magnetic fields provided by the first and second dipole magnets 201 and 202 can control the trajectory of the electron beam and eliminate chromatic aberration caused by the electron energy deviating from the central energy at the image plane, thereby forming achromatic, point-to-point imaging at the image plane. After the electron beam 403 with energy near the central energy is formed into achromatic, point-to-point imaging at the electro-optic conversion screen 301, the electro-optic conversion screen 301 converts the electron beam 403 with energy near the central energy into visible light 406. The visible light 406 is reflected by the reflector 302 and finally captured by the camera 303 to form an image.

[0061] The gamma-ray beam energy selective imaging device of the present invention uses a radiation conversion target 1 to convert a pulsed gamma-ray beam 401 into a Compton scattered electron beam 402. The Compton scattered electron beam 402 emitted from the radiation conversion target 1 carries the energy and image information of the pulsed gamma-ray beam 401 and enters the electron energy selection system 2. The electron energy selection system 2 uses an angle limiter 203 to limit the angle of the electron beam. Electrons with smaller emission angles can pass through, while electrons with larger emission angles will be blocked by the angle limiter 203 and cannot continue to be transported. Thus, the angle limiter 203 can be used to limit the emission angle of the electron beam. The trajectory of the electron beam is controlled by the magnetic fields provided by the first and second dipole magnets 201 and 202. The magnetic fields provided by the first and second dipole magnets 201 and 202 include the dipole magnetic field distributed within the magnets and the edge magnetic field distributed at the magnet entrance and exit. When the electron beam moves in the magnetic field provided by the dipole magnets, it will encounter the Lorentz force. Under the action of the Lorentz force, the trajectory of the electron beam will be deflected and focused. The size of the deflection radius is related to the electron energy. The higher the electron energy, the larger the deflection radius, and the lower the electron energy, the smaller the deflection radius. By setting the shape and magnetic induction intensity of the first and second dipole magnets 201 and 202, the electron beam 403 with energy near the center energy is focused at the center position of the energy limiter 204 after passing the first dipole magnet 201. The focusing positions of the electron beam 404 with energy greater than the center energy and the electron beam 405 with energy less than the center energy are far away from the center position of the energy limiter 204. Energy selection of the electron beam is achieved using energy limiter 204. Electron beam 403 with energy near the central energy point exits from the first dipole magnet 201 and is focused at the center of energy limiter 204, thus passing through energy limiter 204 and continuing its transport. Electron beams 404 with energy greater than the central energy and electron beams 405 with energy less than the central energy are blocked by energy limiter 204 and cannot continue their transport. Thus, energy limiter 204 can limit the energy of the electron beam. The remaining electrons passing through energy limiter 204 achieve achromatic, point-to-point imaging at the image plane, i.e., the electro-optic conversion screen 301. Optical imaging system 3 acquires the electron image at electro-optic conversion screen 301. The image acquired by optical imaging system 3 can obtain a quasi-monoenergetic image of the incident gamma rays at a specific energy point, thereby realizing gamma-ray beam energy-selective imaging.

[0062] In order to make the electron beam 403 with energy near the center energy point focus at the center of the energy limiter 204 after being emitted from the first dipole magnet 201, and form achromatic, point-to-point imaging at the electro-optic conversion screen 301, it is necessary to set the structure parameters of the dipole magnet so that the magnetic field meets the requirements. Figure 2 This is a schematic diagram of the structure of the two diode magnets in an embodiment of the present invention. The two diode magnets have the same structure and parameters, as shown below. Figure 2As shown, the key structural parameters mainly include: the deflection radius R of the diode magnet, the deflection angle θ of the diode magnet, and the edge angle α of the diode magnet; where the deflection angle θ is the central angle of the circle containing the arc of the diode magnet, the deflection radius R is the radius of the circle containing the arc of the diode magnet, and the edge angle α is the angle between the diameter of the intersection point of the central axis of the diode magnet and the two end faces and the corresponding end face. There are multiple sets of diode magnet structural parameters that meet the requirements of the device of this invention. This embodiment adopts one set of preferred structural parameters: the deflection radius R of the diode magnet = 500 mm, the deflection angle θ of the diode magnet = 50 degrees, and the edge angle α of the diode magnet = 14.8 degrees. Under this set of diode magnet structural parameters, the material of the radiation conversion target 1 is beryllium with a thickness of 0.3 mm. The distance between the radiation conversion target 1 and the inlet of the first diode magnet 201 is 1.2 meters. The distance between the outlet of the first diode magnet 201 and the inlet of the second diode magnet 202 is 2.4 meters. The distance between the outlet of the second diode magnet 202 and the electro-optical conversion screen 301 is 1.2 meters. The electro-optical conversion screen is made of YAG.

[0063] To visually demonstrate the advantages of this invention, Monte Carlo simulation software was used to model the entire system. The structures of each component of the system were set according to the above parameters, and the entire operation process of the device was simulated. The results are as follows. Figure 3 As shown. Figure 3 (a) is an image of the pulsed gamma-ray beam 401 at the position of the radiation conversion target 1, i.e. the original image. The image size is 100mm×100mm. In the image, the letter "H" represents high-energy gamma rays with an energy of 1.33MeV, and the letter "L" represents low-energy gamma rays with an energy of 1.17MeV. Figure 3 (b) and Figure 3 (c) An image of the electron beam 403 with energy near the center energy, obtained by the optical imaging system, at the image plane, where... Figure 3 (b) is a quasi-monoenergetic image of a high-energy pulsed gamma ray with a target energy of 1.33 MeV. Figure 3 (c) is a quasi-monoenergetic image of a low-energy pulsed gamma ray with a target energy of 1.17 MeV.

[0064] Figure 3 The results show that, according to the preferred parameter settings of this embodiment, the device can select gamma rays of a specific energy from gamma ray beams of different energies for imaging; the target energy is adjustable, and energy-selective imaging can be performed on gamma rays of different target energies according to application requirements, thereby obtaining image information reflecting different physical processes; the energy resolution is high, and the device can resolve at least two energies of gamma rays, 1.33 MeV and 1.17 MeV, and obtain quasi-monoenergetic pulsed gamma ray beam images with high energy resolution in a single measurement.

[0065] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. The present invention can be modified and varied in various ways. Any modifications, equivalent substitutions, improvements, etc., made based on the design principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pulsed gamma-ray beam energy-selective imaging device, characterized in that: It includes a gamma-ray source, a radiation conversion target (1), an electronic energy selection system (2), and an optical imaging system (3); The gamma-ray source is used to generate pulsed gamma-ray beams with energy distribution; The radiation conversion target (1) is set in the pulsed gamma-ray beam exit path of the gamma-ray source and is used to convert the pulsed gamma-ray beam into a Compton scattered electron beam. The electronic energy selection system (2) includes an angle limiter (203), a first dipole magnet (201), an energy limiter (204), and a second dipole magnet (202) arranged sequentially along the exit path of the Compton scattered electron beam. The angle limiter (203) is set on the exit path of the Compton scattered electron beam and located at the entrance of the first dipole magnet (201) to allow the Compton scattered electron beam that meets the emission angle requirements to pass through and enter the first dipole magnet (201); The positions of the radiation conversion target (1) and the energy limiter (204) are mirror-symmetrically arranged with the radial midpoint of the first dipole magnet (201) as the symmetry plane; The energy limiter (204) is disposed between the first diode magnet (201) and the second diode magnet (202) and located at the midpoint, for allowing Compton scattered electrons that meet the energy requirements to pass through; The first diode magnet (201) and the second diode magnet (202) are arranged in rotational symmetry about the radial center line of the energy limiter (204); the first diode magnet (201) and the second diode magnet (202) are used to control the trajectory of Compton scattered electrons through the magnetic field, so that the Compton scattered electrons enter from the first diode magnet (201) and exit from the second diode magnet (202); The optical imaging system (3) is set on the exit path of the Compton scattered electron beam emitted from the second dipole magnet (202) and is used to image the Compton scattered electron beam emitted from the second dipole magnet (202). The optical imaging system (3) includes an electro-optic conversion screen (301) located on the path of the Compton scattered electron beam emitted from the second dipole magnet (202), and a reflector (302) and a camera (303) arranged sequentially along the light path emitted from the electro-optic conversion screen (301). The positions of the electro-optic conversion screen (301) and the energy limiter (204) are mirror-symmetrically arranged with the radial midpoint of the second dipole magnet (202) as the symmetry plane; The positions of the electro-optic conversion screen (301) and the radiation conversion target (1) are arranged in a rotationally symmetrical manner with the radial center line of the energy limiter (204) as the axis; The Compton scattered electron beam emitted from the second dipole magnet (202) is converted into visible light by the electro-optic conversion screen (301), and the visible light is reflected by the mirror (302) and enters the camera (303) for imaging.

2. The pulsed gamma-ray beam energy-selective imaging device according to claim 1, characterized in that: Both the first diode magnet (201) and the second diode magnet (202) have an arc-shaped structure and the same structural parameters; The transmission matrix of the Compton-scattered electron beam within the first and second dipole magnets (201) is a sixth-order matrix A, and the sixth-order matrix A satisfies the following condition: 、 、 、 ； Among them, A in the sixth-order matrix A 11 A 22 A 33 A 44 These represent the elements in the first row and first column, the second row and second column, the third row and third column, and the fourth row and fourth column, respectively. The magnetic field strength B of the first diode magnet (201) and the second diode magnet (202) satisfies the following formula: ； Represents the central energy of a beam of charged particles; Represents the speed of light; Represents the amount of charge carried by a single charged particle; E0 represents the rest energy of a single charged particle; R represents the radius of the circle containing the arc of the diode magnet.

3. The pulsed gamma-ray beam energy-selective imaging device according to claim 2, characterized in that: The electro-optic conversion screen (301) is made of YAG material; The material of the radiation conversion target (1) is beryllium or aluminum.

4. The pulsed gamma-ray beam energy-selective imaging device according to claim 3, characterized in that: The first diode magnet (201) and the second diode magnet (202) have a deflection radius R of 500 mm, a deflection angle θ of 50 degrees, and an edge angle α of 14.8 degrees. Wherein, the deflection angle θ is the central angle of the circle containing the arc of the dipole magnet, the deflection radius R is the radius of the circle containing the arc of the dipole magnet, and the edge angle α is the angle between the diameter of the intersection point of the central axis of the dipole magnet and the two end faces and the corresponding end face. The distance between the radiation conversion target (1) and the entrance of the first dipole magnet (201) is 1.2 meters, the distance between the exit of the first dipole magnet (201) and the entrance of the second dipole magnet (202) is 2.4 meters, and the distance between the exit of the second dipole magnet (202) and the electro-optic conversion screen (301) is 1.2 meters. The radiation conversion target (1) is made of beryllium and has a thickness of 0.3 mm.

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