A metal halide perovskite-based neutron multiplicity measurement device and method

Abstract

The application discloses a kind of metal halogen perovskite-based neutron multiplicity measuring device and method, the device includes: shell, the shell is used to install and protect other components of the measuring device;Radiation detection module is arranged in the shell, and the radiation detection module is mainly composed of perovskite material and photomultiplier tube etc.;Shielding unit is arranged in the shell and located at the side and bottom of the perovskite scintillator, for reducing gamma-ray background;And, readout electronics module is arranged in the shell, and the readout electronics module is used to read the electrical signal generated by the photomultiplier tube and convert it into digital signal output.The application can realize the effective discrimination of neutron and gamma, so as to accurately deduct the influence of gamma-ray background, improve the sensitivity of fast neutron measurement.

Description

Technical Field

[0001] This invention belongs to the field of nuclear material property measurement technology, specifically relating to a neutron multiplicity measurement device and method based on metal halide perovskite. Background Technology

[0002] Traditional multiplex counting techniques for slow / thermal neutrons require a slowing process, resulting in a discrete counting time distribution and significant uncertainty. Fast neutron multiplex analysis, developed from the classic NMC (Neutron Multiplicity Counter) method, does not require a polymer slowing process, overcoming the shortcomings of slow / thermal neutron multiplex measurements and effectively preserving neutron energy and timing information. This holds promise for playing a crucial role in measuring nuclear material properties in fields such as nuclear safety. However, the influence of gamma-ray background in fast neutron detection is difficult to accurately subtract. Summary of the Invention

[0003] To address the problem of limited measurement sensitivity caused by the difficulty in accurately subtracting the gamma-ray background in existing fast neutron detection methods, this invention proposes a neutron multiplicity measurement device and method based on metal halide perovskite. This invention combines metal halide perovskite materials and readout electronics analysis methods to achieve effective discrimination between neutrons and gamma rays, thereby improving the sensitivity and structural strength of fast neutron detection.

[0004] This invention is achieved through the following technical solution:

[0005] A neutron multiplicity measurement device based on metal halide perovskite, the neutron multiplicity measurement device comprising:

[0006] A housing for mounting and protecting other components of the measuring device;

[0007] The radiation detection module is disposed within the housing and consists of a perovskite scintillator, an optical reflective film, and a photomultiplier tube. The perovskite scintillator is used to convert neutron signals emitted by the radiation source into optical signals. The optical reflective film is disposed on the surface of the perovskite scintillator except for the light-emitting surface. The photomultiplier tube is disposed on the top light-emitting surface of the perovskite scintillator and is used to convert the optical signals generated by the perovskite scintillator into electrical signals.

[0008] The shielding unit, located inside the housing and on the side and bottom of the perovskite scintillator, is used to reduce the gamma background.

[0009] In addition, a readout electronics module is disposed within the housing, the readout electronics module being used to read the electrical signal generated by the photomultiplier tube and convert it into a digital signal for output.

[0010] In some embodiments, the photomultiplier tube is coupled to the light-emitting surface of the perovskite scintillator via optical silicone grease.

[0011] In some embodiments, the perovskite scintillator is made of a metal halide material, PEA2PbBr4.

[0012] The perovskite scintillator is a cuboid.

[0013] In some embodiments, the optical reflective film is made of aluminum film and has a thickness of 10 μm.

[0014] In some embodiments, the housing includes an upper cover, an upper steel shell, a lower steel shell, and a rear cover;

[0015] Both the upper and lower steel shells are shell structures with open end faces;

[0016] The end face opening of the upper steel shell matches the upper cover, and the end face opening of the lower steel shell matches the rear cover.

[0017] The upper steel shell and the lower steel shell are assembled into a whole by the first shock-absorbing pad and the mounting thread;

[0018] The upper cover and the upper steel shell are assembled and fixed by the second shock-absorbing pad and the first fastener;

[0019] The rear cover, the lower steel shell, and the shielding unit located on the bottom surface of the perovskite scintillator are assembled and fixed by a third shock-absorbing pad and a second fastener.

[0020] In some embodiments, the housing is made of 06Cr18Ni11Ti material.

[0021] In some embodiments, the shielding unit is made of Pb-Sb10-Sn2 material and the thickness of the shielding unit is 5 mm.

[0022] In some embodiments, the neutron multiplicity measurement device further includes:

[0023] An electrical output component, located on the top of the housing, is used to connect to an external power supply and output measurement signals.

[0024] In some embodiments, the readout electronics module includes:

[0025] A readout circuit is used to read the pulse signal generated by the photomultiplier tube;

[0026] A pre-amplifier low-noise amplifier circuit is used to perform noise reduction and amplification processing on the pulse signal;

[0027] A signal conditioning circuit, which is used to condition the signal after noise reduction and amplification;

[0028] And a back-end digitization module, which is used to convert the conditioned signal into a digital signal and output it.

[0029] On the other hand, the present invention also proposes a neutron multiplicity measurement method based on metal halide perovskites, the neutron multiplicity measurement method comprising:

[0030] Control the radiation source to emit neutron signals;

[0031] The neutron signal is detected using the neutron multiplicity measurement device described in any of the above embodiments;

[0032] The signals detected by the neutron multiplicity measurement device are collected and processed by the digital acquisition and processing unit and then uploaded to the industrial control computer.

[0033] The time correlation analysis and multiplicity solution of the pulse neutron sequence are performed using a solution algorithm loaded in an industrial control computer.

[0034] The present invention proposes a neutron multiplicity measurement device and method based on metal halide perovskite. It uses perovskite material and photomultiplier tube as radiation detection module, and sets up a shielding unit to reduce gamma-ray background. Combined with readout electronics module, it can effectively distinguish between neutrons and gamma rays, thereby accurately subtracting the influence of gamma-ray background and improving the sensitivity of fast neutron measurement.

[0035] The present invention proposes a neutron multiplicity measurement device and method based on metal halide perovskite. It also enhances the reliability and environmental adaptability of the measurement device by setting shock-absorbing pads inside the shell, which is particularly beneficial for field source finding, mineral exploration and other operations.

[0036] The present invention proposes a neutron multiplicity measurement device and method based on metal halide perovskite, which can realize the quality diagnosis of special nuclear materials in the test item under the premise of knowing the external dimensions and structural composition of the test item. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 This is a schematic diagram of the measuring device structure according to an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the radiation detection module composition according to an embodiment of the present invention;

[0040] Figure 3 This is a block diagram illustrating the composition principle of the readout electronics module in an embodiment of the present invention.

[0041] Figure 4 This is a block diagram illustrating the principle of the measurement system according to an embodiment of the present invention;

[0042] Figure 5 This is a flowchart of the solution algorithm according to an embodiment of the present invention.

[0043] Figure reference numerals and corresponding component names:

[0044] 1-Rear cover, 2-First shielding unit, 3-Lower steel shell, 4-Third shock-absorbing pad, 5-Second shielding unit, 6-Optical reflective film, 7-Perovskite scintillator, 8-Photomultiplier tube, 9-Readout electronics module, 10-Upper steel shell, 11-First shock-absorbing pad, 12-Second shock-absorbing pad, 13-Top cover, 14-Third fastener, 15-First fastener, 16-Second fastener. Detailed Implementation

[0045] In the following, the terms “comprising” or “may include” as used in various embodiments of the invention indicate the presence of an inventive function, operation, or element, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in various embodiments of the invention, the terms “comprising,” “having,” and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or adding one or more combinations of the foregoing.

[0046] In various embodiments of the invention, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0047] The expressions used in the various embodiments of the present invention (such as "first," "second," etc.) may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used for the purpose of distinguishing one element from other elements. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, a first element may be referred to as a second element without departing from the scope of the various embodiments of the present invention, and similarly, a second element may also be referred to as a first element.

[0048] It should be noted that if a description is made of "connecting" one component to another, then the first component can be directly connected to the second component, and a third component can be "connected" between the first and second components. Conversely, when a component is "directly connected" to another component, it can be understood that there is no third component between the first and second components.

[0049] The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the invention pertain. The terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of the invention.

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention.

[0051] Example:

[0052] This embodiment proposes a neutron multiplicity measurement device based on metal halide perovskite. The proposed neutron multiplicity measurement device uses perovskite material and photomultiplier tubes as radiation detection modules, and sets up a shielding unit to reduce the gamma-ray background. Combined with the readout electronics module, it can effectively distinguish between neutrons and gamma rays, thereby accurately subtracting the influence of gamma-ray background and improving the sensitivity of fast neutron detection.

[0053] like Figure 1 As shown, the neutron multiplicity measurement device proposed in this embodiment includes:

[0054] The housing is used to mount and protect the entire measuring device; optionally, the housing may be made of stainless steel.

[0055] A radiation detection module housed within a stainless steel casing comprises a perovskite scintillator 7, an optical reflective film 6, and a photomultiplier tube 8. The perovskite scintillator 7 detects neutron signals emitted by a radiation source (converting neutron signals into optical signals). The optical reflective film 6 is disposed on the surface of the perovskite scintillator 7 (i.e., all surfaces other than the light-emitting surface). The optical reflective film 6 reduces light leakage from the non-light-emitting surfaces of the perovskite scintillator 7, thereby efficiently collecting the optical signals emitted by the perovskite scintillator 7. The photomultiplier tube 8 is disposed above the light-emitting surface of the perovskite scintillator 7 and converts the optical signals emitted by the perovskite scintillator 7 into electrical signals. Optionally, the photomultiplier tube 8 is coupled to the upper surface of the perovskite scintillator 7 via optical silicone grease, such as... Figure 2 As shown. Specifically, the perovskite scintillator 7 is made of metal halide PEA2PbBr4 material and has a cuboid shape. The optical reflective film 6 is made of aluminum film with a thickness of 10 μm, and the optical reflective film 6 has good adhesion to the surface of the perovskite scintillator. Optionally, the photomultiplier tube 8 used in this embodiment can be a high-gain SiPM (photomultiplier tube) operating in a low-voltage state.

[0056] The shielding unit, located inside the stainless steel housing and on the sides and bottom of the perovskite scintillator, is used to reduce the gamma background.

[0057] Additionally, a readout electronics module 9 is housed within a stainless steel casing. This readout electronics module 9 processes the electrical signals generated by the radiation detection module. Optionally, the readout electronics module 9 is assembled and secured to the perovskite scintillator 7 via a brass base and a third fastener 14.

[0058] The measurement principle of the neutron multiplicity measurement device proposed in this embodiment is as follows: An external radiation source, such as a pulsed neutron generator, emits a neutron signal to irradiate the test object. The nuclear material inside the test object induces fission to generate a neutron beam. After absorbing photons, the luminescent center of the perovskite scintillator 7 generates scintillation light through energy transfer and electron transition processes. The light signal is collected by a photomultiplier tube and generates a corresponding electrical signal. Finally, the readout electronics module reads out the electrical signal, processes it, and outputs it. Thus, the pulsed neutron sequence time correlation analysis and multiplicity solution are performed by the solution algorithm built into the industrial control computer. Under the premise of knowing the external dimensions and structural composition of the test object, the quality diagnosis of the core material of the test object can be realized.

[0059] Optionally, the stainless steel housing in this embodiment further includes: an upper cover 13, an upper steel shell 10, a lower steel shell 3, and a rear cover 1. The upper steel shell 10 and the lower steel shell 3 are shell structures with open end faces. The end face opening of the upper steel shell 10 matches the upper cover 13, and the end face opening of the lower steel shell 3 matches the rear cover 1. It should be noted that "matching" means that the upper cover 13 can at least completely close the end face opening of the upper steel shell 10, and the rear cover 1 can at least completely close the end face opening of the lower steel shell 10. The upper steel shell 10 and the lower steel shell 3 are assembled as a whole using a first shock-absorbing pad 11 and mounting threads. The upper cover 13 and the upper steel shell 10 are assembled and fixed using a second shock-absorbing pad 12 and a first fastener 15. Preferably, the stainless steel housing can be made of materials such as 06Cr18Ni11Ti.

[0060] Optionally, the neutron multiplicity measuring device in this embodiment further includes a first shielding unit 2, which is disposed between the bottom surface of the perovskite scintillator 7 and the rear cover 1 of the stainless steel shell. The first shielding unit 2, the rear cover 1 of the stainless steel shell and the lower steel shell 3 are assembled and fixed by a second fastener 16 and a third shock-absorbing pad 4.

[0061] Optionally, the fasteners used in this embodiment (first fastener 15, second fastener 16, and third fastener 14, etc.) can be threaded fasteners such as screws and bolts. The vibration damping pads used in this embodiment refer to any component with vibration damping function, such as the ZN13 series. By setting vibration damping pads inside the stainless steel housing, this embodiment helps to enhance the reliability and environmental adaptability of the measuring device.

[0062] Optionally, the neutron multiplicity measuring device in this embodiment further includes a second shielding unit 5, which is disposed between the side of the perovskite scintillator 7 and the side of the stainless steel housing, and the second shielding unit 5 is not directly connected to the stainless steel housing.

[0063] Optionally, the shielding units (first shielding unit 2 and second shielding unit 5) used in this embodiment are components made of materials capable of localized radiation shielding, such as Pb-Sb10-Sn2, with a thickness of 5 to 10 millimeters. These components effectively shield gamma rays and are not easily deformed. This embodiment reduces the gamma ray background and improves detection sensitivity by setting shielding units on the bottom and sides of the perovskite scintillator 7.

[0064] Optionally, the neutron multiplicity measurement device in this embodiment further includes:

[0065] An electrical output component, located on the top of the stainless steel housing, is used to connect to an external power supply and output measurement signals. Specifically, the electrical output component may include one J30J type power input interface and seven SMA type signal output interfaces; the specific arrangement and configuration of the interfaces can be determined according to the actual situation.

[0066] Optionally, the readout electronics module 9 mainly includes: a SiPM readout circuit (i.e., a photomultiplier tube readout circuit), a pre-amplifier low-noise amplifier circuit, a signal conditioning circuit, and a back-end digitization module, such as... Figure 3 As shown. The power supply voltage range of the readout electronics module is +15 V to +36 V, and the bias voltage required for the SiPM readout circuit is +28 V to +32 V. The SiPM readout circuit reads the pulse signal generated by the photomultiplier tube 8 and transmits it to the pre-amplifier low-noise amplifier circuit for noise reduction and amplification. The signal processed by the pre-amplifier low-noise amplifier circuit is then transmitted to the signal conditioning circuit for signal conditioning before being transmitted to the back-end digitization module for neutron multiplicity calculation. Optionally, the signal conditioning circuit mainly includes a programmable amplifier, the amplification factor of which is determined by the back-end digitization module. Furthermore, both the pre-amplifier low-noise amplifier circuit and the signal conditioning circuit employ DC-DC voltage conversion and LDO voltage regulation technology. The back-end digitization module can be implemented using programmable devices, such as FPGAs, to convert analog electrical signals into digital electrical signals for acquisition and neutron multiplicity calculation by the host computer. It should be noted that each module unit of the readout electronics module 9 can be implemented using existing components and / or modules, therefore, further details are omitted here.

[0067] This embodiment also proposes a neutron multiplicity measurement system based on metal halide perovskites, such as... Figure 4 As shown, the neutron multiplicity measurement system includes a radiation source, an industrial control computer, a digital acquisition and processing unit, and the aforementioned neutron multiplicity measurement device.

[0068] The radiation source, under the control of the industrial control computer, emits neutron signals to irradiate the test object. The core material of the test object is induced to undergo fission to generate a neutron beam. The neutron beam is input into the perovskite scintillator inside the stainless steel shell. The center of the luminous character of the perovskite scintillator emits luminous flashes after absorbing photons. The photomultiplier tube converts the optical signal into an electrical signal. The readout electronics module reads out the electrical signal and processes it into a digital signal. The digital signal is acquired and processed by the digital acquisition and processing unit and uploaded to the industrial control computer through the data transmission unit for pulse neutron sequence time correlation analysis and multiplicity solution.

[0069] The process for pulsed neutron sequence time correlation analysis and multiplicity solution is as follows: Figure 5As shown in the figure, the solution process is mainly divided into two parts: the theoretical simulation represented by the gray box area in the upper part and the actual detection data acquisition and processing represented by the white box area in the lower part. The solution principle is to infer the actual material mass properties based on the actual detected neutron distribution. However, this inference process often has multiple solutions, and the uncertainty is large if only the actual detection data is relied upon for inference. Therefore, in order to reduce the uncertainty and effectively avoid the non-uniqueness of the solution, this embodiment also adopts theoretical simulation. Therefore, the solution process specifically includes: using prior knowledge and simulation tools to obtain the counted neutron distribution and theoretical factorial distance; based on the actual detected neutron distribution, which includes the sample emission neutron distribution (i.e., source term distribution) and the background random neutron distribution (i.e., background distribution), the corresponding statistical information belongs to the foreground count distribution, while the statistical information corresponding to the simple background signal belongs to the background count distribution. Therefore, the source term distribution obtained by inverse calculation can be obtained by subtracting the background count distribution from the foreground count distribution. It should be noted that in the specific application process, this subtraction is achieved by constructing statistics and estimating parameters using test data to obtain the source term distribution, thereby obtaining the count distribution and measured factorial distance of the inverse calculation process; finally, based on the theoretical factorial distance and measured factorial distance, supplemented by the calibration curve (or calibration coefficient) of the actual detection system, a closed equation can be constructed based on the number of unknowns and factorial distance information, and the material mass can be finally obtained.

[0070] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0071] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0072] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0073] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0074] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A neutron multiplicity measurement device based on metal halide perovskite, characterized in that, The neutron multiplicity measurement device includes: A housing for mounting and protecting other components of the measuring device; The radiation detection module is disposed within the housing and consists of a perovskite scintillator, an optical reflective film, and a photomultiplier tube. The perovskite scintillator is used to convert neutron signals emitted by the radiation source into optical signals. The optical reflective film is disposed on the surface of the perovskite scintillator except for the light-emitting surface. The photomultiplier tube is disposed on the top light-emitting surface of the perovskite scintillator and is used to convert the optical signals generated by the perovskite scintillator into electrical signals. The shielding unit, located inside the housing and on the side and bottom of the perovskite scintillator, is used to reduce the gamma background. Furthermore, a readout electronics module is disposed within the housing. This module reads the electrical signal generated by the photomultiplier tube and converts it into a digital signal for output. The digital signal is acquired and processed by a digital acquisition and processing unit and uploaded to an industrial control computer for pulsed neutron sequence time correlation analysis and multiplicity solving. This includes: using prior knowledge and simulation tools to solve for the counted neutron distribution and theoretical factorial distance; obtaining the counted neutron distribution and measured factorial distance based on the actually detected sample emission neutron distribution and background random neutron distribution; and constructing a closed equation based on the theoretical factorial distance and measured factorial distance, combined with the calibration curve, and according to the number of unknowns and factorial distance information, to solve for the material mass.

2. The neutron multiplicity measurement device based on metal halide perovskite according to claim 1, characterized in that, The photomultiplier tube is coupled to the light-emitting surface of the perovskite scintillator via optical silicone grease.

3. The neutron multiplicity measurement device based on metal halide perovskite according to claim 1, characterized in that, The perovskite scintillator is made of metal halide PEA2PbBr4 material; The perovskite scintillator is a cuboid.

4. The neutron multiplicity measurement device based on metal halide perovskite according to claim 1, characterized in that, The optical reflective film is made of aluminum film and has a thickness of 10 μm.

5. A neutron multiplicity measurement device based on metal halide perovskite according to any one of claims 1-4, characterized in that, The housing includes an upper cover, an upper steel shell, a lower steel shell, and a rear cover; Both the upper and lower steel shells are shell structures with open end faces; The end face opening of the upper steel shell matches the upper cover, and the end face opening of the lower steel shell matches the rear cover. The upper steel shell and the lower steel shell are assembled into a whole by the first shock-absorbing pad and the mounting thread; The upper cover and the upper steel shell are assembled and fixed by the second shock-absorbing pad and the first fastener; The rear cover, the lower steel shell, and the shielding unit located on the bottom surface of the perovskite scintillator are assembled and fixed by a third shock-absorbing pad and a second fastener.

6. The neutron multiplicity measurement device based on metal halide perovskite according to claim 5, characterized in that, The shell is made of 06Cr18Ni11Ti material.

7. A neutron multiplicity measurement device based on metal halide perovskite according to any one of claims 1-4, characterized in that, The shielding unit is made of Pb-Sb10-Sn2 material and has a thickness of 5mm.

8. The neutron multiplicity measurement device based on metal halide perovskite according to claim 5, characterized in that, The neutron multiplicity measurement device also includes: An electrical output component, located on the top of the housing, is used to connect to an external power supply and output measurement signals.

9. A neutron multiplicity measurement device based on metal halide perovskite according to claim 5, characterized in that, The electronics module includes: A readout circuit is used to read the pulse signal generated by the photomultiplier tube; A pre-amplifier low-noise amplifier circuit is used to perform noise reduction and amplification processing on the pulse signal; A signal conditioning circuit, which is used to condition the signal after noise reduction and amplification; And a back-end digitization module, which is used to convert the conditioned signal into a digital signal and output it.

10. A method for measuring neutron multiplicity based on metal halide perovskites, characterized in that, The neutron multiplicity measurement method includes: Control the radiation source to emit neutron signals; The neutron signal is detected by the neutron multiplicity measurement device according to any one of claims 1-9; The signals detected by the neutron multiplicity measurement device are collected and processed by the digital acquisition and processing unit and then uploaded to the industrial control computer. The time correlation analysis and multiplicity solution of the pulse neutron sequence are performed using a solution algorithm loaded in an industrial control computer.

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