Space instant gamma radiation detection device and monitoring method

Abstract

The embodiment of the invention provides a space instant gamma radiation detection device and monitoring method, and relates to the technical field of gamma radiation monitoring, the device comprises a device body and a signal acquisition and processing system; the device body comprises a shell, and a scintillator array assembly and an anti-coincidence scintillator assembly which are fixed in the shell; the center of the anticoincidence scintillator assembly is provided with a cuboid groove, and the scintillator array assembly is located in the cuboid groove. Wherein the scintillator array assembly and the anticoincidence scintillator assembly are both connected with the signal acquisition and processing system. According to the technical scheme, the problem of instant gamma radiation time spectrum measurement in a space complex radiation background environment is solved, the signal-to-noise ratio and the time performance of gamma radiation time spectrum measurement are improved on the basis of ensuring lightweight design, and the accumulation probability is reduced while the sensitivity upper limit is expanded.

Description

Technical Field

[0001] This application relates to the technical field of gamma radiation monitoring. Specifically, it relates to a spatial prompt gamma radiation detection device and a monitoring method. Background Art

[0002] Spatial prompt gamma radiation has multiple sources, including gamma-ray bursts, solar flares, atmospheric lightning, and gamma flashes formed by events such as ground nuclear explosions. It has characteristics such as strong randomness, short duration, high instantaneous count, and non-reproducibility. For example, gamma-ray bursts may originate from physical processes such as supernova explosions and neutron star mergers, and are related to frontier physics issues such as thermonuclear fusion and gravitational waves. There are various conjectures about the instantaneous radiation mechanism of gamma-ray bursts, but there is still no conclusion yet. Therefore, it is particularly important to timely capture spatial prompt gamma radiation events and accurately measure their arrival times for locating the prompt radiation sources and further analyzing their generation sources and mechanisms.

[0003] In spatial prompt pulse radiation measurement, signal-to-noise ratio, sensitivity, time characteristics, and lightweight are the key technical indicators of the detection device. In the prior art, spatial prompt gamma radiation detection mainly focuses on extraterrestrial gamma flashes as the target. For example, the GRID-02 detection payload developed by the TianGe project initiated by Tsinghua University is used for continuous on-orbit observation and analysis of gamma-ray bursts, solar activities, pulsars, etc. The design of large-size and multi-channel GAGG:Ce crystals can ensure detection sensitivity, but its dead time is close to 20 μs. Another example is the gamma-ray detector (GRD) developed by the Gamma-ray burst High Energy EM Counterpart All-sky Monitor (GECAM) project of the Chinese Academy of Sciences, which adopts a technical route of using relatively large-size LaBr3∶Ce scintillation crystals and digital full-acquisition multi-channel amplitude analysis, but its dead time is still about 4 μs.

[0004] In addition, for the pulse radiation rise time formed by ground gamma flash events transmitted to low-earth orbit satellites, it may be much lower than that of extraterrestrial astronomical gamma pulse radiation, and its intensity range may span multiple orders of magnitude. Ground gamma flash events will be affected by electron and proton backgrounds at the orbital satellite and false triggers caused by extraterrestrial gamma flash events such as gamma-ray bursts. Therefore, the monitoring payload needs higher sensitivity to timely capture events; it needs shorter dead time redundancy to adapt to high-intensity dynamic range particle counting and reduce the stacking probability; it needs higher detection signal-to-noise ratio to reduce false triggers and distinguish its azimuth source, and improve reliability. Generally speaking, how to further improve its dead time and signal-to-noise ratio performance, and ensure good sensitivity and lightweight to meet the requirements of ground gamma flash event detection tasks is an urgent problem to be solved in current research. Summary of the Invention

[0005] Embodiments of the present application provide a space prompt gamma radiation detection device and a monitoring method to meet the technical requirements such as rapid and reliable triggering of space gamma prompt pulse radiation and azimuth source resolution, and to achieve time spectrum and energy spectrum measurements of gamma-ray bursts, solar flares, atmospheric lightning, and ground gamma flash events.

[0006] Other features and advantages of the present application will become apparent from the following detailed description, or will be learned in part through the practice of the present application.

[0007] According to the first aspect of the embodiments of the present application, a space prompt gamma radiation detection device is provided, including:

[0008] A device body and a signal acquisition and processing system;

[0009] The device body includes: a housing, and a scintillator array assembly and an anti-coincidence scintillator assembly fixed in the housing;

[0010] A rectangular parallelepiped groove is provided at the center of the anti-coincidence scintillator assembly, and the scintillator array assembly is located in the rectangular parallelepiped groove;

[0011] Among them, the scintillator array assembly and the anti-coincidence scintillator assembly are both connected to the signal acquisition and processing system to transmit the analog signal output by the scintillator array assembly and the output signal of the anti-coincidence scintillator assembly to the signal acquisition and processing system.

[0012] In some embodiments of the present application, based on the foregoing solution, the scintillator array assembly includes: a LYSO crystal array, a LYSO crystal SiPM, and a LYSO crystal assembly bottom plate;

[0013] Among them, the LYSO crystal SiPM is arranged on the LYSO crystal assembly bottom plate;

[0014] The LYSO crystal array includes a plurality of LYSO crystals, and the plurality of LYSO crystals are arranged in an array;

[0015] Each LYSO crystal is individually coupled to the LYSO crystal SiPM;

[0016] Each LYSO crystal is also connected to the LYSO crystal assembly bottom plate, and the LYSO crystal assembly bottom plate is connected to the signal acquisition and processing system.

[0017] In some embodiments of the present application, based on the foregoing solution, the anti-coincidence scintillator assembly includes: a BGO crystal assembly bottom plate, a BGO crystal SiPM, and a BGO crystal;

[0018] The BGO crystal SiPM is arranged on the BGO crystal assembly bottom plate;

[0019] The BGO crystal is coupled with the BGO crystal SiPM;

[0020] A rectangular parallelepiped groove is formed in the BGO crystal, and the four side walls of the rectangular parallelepiped groove are thinner than the bottom surface;

[0021] The BGO crystal is connected to the bottom plate of the BGO crystal assembly, and the bottom plate of the BGO crystal assembly is connected to the signal acquisition and processing system.

[0022] In some embodiments of the present application, based on the foregoing solution, the outer shell is of a double-layer structure, the material of the inner layer structure is polyethylene, the material of the outer layer structure is AL, and the space between the inner layer structure and the outer layer structure is evacuated.

[0023] According to the second aspect of the embodiments of the present application, a method for monitoring spatial prompt gamma radiation is provided, including:

[0024] Performing FIR low-pass filtering on the collected original signal;

[0025] Setting a trigger threshold, and distinguishing valid nuclear pulses and noise in the filtered signal based on the trigger threshold;

[0026] If the discrimination result is a valid nuclear pulse, record the sampling points before and after the trigger threshold trigger point, and perform linear spline interpolation and linear fitting;

[0027] Obtain the zero-crossing moment of the fitting curve of the sampling points to obtain the particle arrival time;

[0028] Measure the deposited energy of the incident particles based on the valid nuclear pulses, and preliminarily screen the target particles through an energy threshold;

[0029] Perform anticoincidence according to the particle arrival time and the deposited energy of the incident particles;

[0030] Based on the particle arrival time after anticoincidence, perform coincidence counting according to the time resolution requirement to obtain a time spectrum.

[0031] In some embodiments of the present application, based on the foregoing solution, the performing FIR low-pass filtering on the collected original signal includes:

[0032] Collect the original signal by using a signal acquisition and processing system, and the original signal includes: nuclear pulse signals, noise signals, and mixed signals of the two;

[0033] Perform FIR low-pass filtering on the original signal based on formula (1);

[0034]

[0035] Wherein: x(n) is the input signal, h(h) is the FIR filter coefficient, y(n) is the signal after filtering, N represents the number of taps of the FIR filter, and N-1 is the filter order.

[0036] In some embodiments of the present application, based on the foregoing solution, setting the trigger threshold and distinguishing valid nuclear pulses and noise in the filtered signal based on the trigger threshold includes:

[0037] Obtaining the zero-crossing duration of the valid nuclear pulse signal according to experiments as the trigger threshold t e ;

[0038] Comparing the duration t of the filtered signal with the trigger threshold t e If t < t e *k, it indicates that the filtered signal is a noise signal, otherwise it is a valid signal, where k < 1 and k is an empirical parameter obtained through experiments.

[0039] In some embodiments of the present application, based on the foregoing solution, measuring the deposited energy of incident particles based on valid nuclear pulses and preliminarily screening target particles through an energy threshold includes:

[0040] Performing trapezoidal shaping, pile-up rejection, amplitude extraction, and energy calibration processing on the valid nuclear pulses to obtain the deposited energy of incident particles;

[0041] Calculating the energy threshold through Monte Carlo simulation;

[0042] Comparing the deposited energy of the incident particles with the energy threshold to screen out target particles with qualified energy.

[0043] In some embodiments of the present application, based on the foregoing solution, performing anti-coincidence according to the particle arrival time and the deposited energy of incident particles includes:

[0044] Dividing the particle arrival time into the particle arrival time t1 of the scintillator array component and the particle arrival time t2 of the anti-coincidence scintillator component;

[0045] Setting a time window T0;

[0046] Based on the comparison of time t1, time t2, and time window T0, if t2 - t1 < T0 and the deposited energy of the incident particles when the particle is in the anti-coincidence scintillator component is less than the deposited energy when the particle is in the scintillator array component, it indicates that the particle is a qualified particle and no rejection process is performed, otherwise, a rejection process is performed.

[0047] In some embodiments of the present application, based on the foregoing solution, the time spectrum is obtained by performing coincidence counting according to the time resolution requirement based on the arrival time of the particles after anti-coincidence, including:

[0048] The arrival times of the particles of the scintillator array assembly and the arrival times of the particles of the anti-coincidence scintillator assembly are respectively summarized into two groups;

[0049] The counting rates within the unit time resolution of the two groups of times are counted, and the time spectrum is output. Among them, the x-axis of the time spectrum is time, and the y-axis is the counting rate.

[0050] The technical solution of the present application has the following beneficial effects:

[0051] 1. Improve the signal-to-noise ratio and event trigger credibility: For the problems that the electron and proton background interference at the space orbit makes it difficult to distinguish the extraterrestrial and ground gamma flash events and leads to false triggers, etc.; the present application proposes a technical solution of composite shell physical shielding - anti-coincidence crystal - high and low energy thresholds, which effectively improves the signal-to-noise ratio of target particle detection and trigger credibility, which is an effect that cannot be achieved by the traditional single crystal technical solution.

[0052] 2. Fast event resolution: The present application forms an array with multiple small-sized LYSO crystals, which can effectively reduce the size and junction capacitance of the coupled SiPM, and ensure good time resolution ability of the output waveform. And the zero-crossing point of the waveform is obtained by sampling point fitting, breaking through the time resolution limitation caused by the sampling gap, which is an effect that cannot be achieved by the traditional fixed threshold timing.

[0053] 3. High sensitivity and low pile-up probability: During the long-term on-orbit monitoring process of the detector, the dynamic range of the intensity of space gamma flash events is large, and may span multiple orders of magnitude. If the sensitivity is increased, the output counting rate will be further increased, which will inevitably increase the pile-up probability and cause the detector to saturate. The present application forms an array with multiple small-sized LYSO crystals, reducing the detection sensitivity of each channel but ensuring the overall sensitivity, thereby simultaneously meeting the counting requirements of high sensitivity and low pile-up probability, which is an effect that cannot be achieved by the traditional single large-sized crystal technical solution.

[0054] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The drawings here are incorporated into the specification and constitute a part of this specification, showing the embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings:

[0056] Figure 1 Shows a schematic structural diagram of a space prompt gamma radiation detection device according to an embodiment of the present application;

[0057] Figure 2 Shows a schematic flow diagram of a space prompt gamma radiation detection method according to an embodiment of the present application.

[0058] Description of reference numerals

[0059] 1 - Top cover, 2 - Middle cylinder, 3 - Bottom cover, 4 - BGO crystal assembly bottom plate, 5 - BGO crystal SiPM, 6 - BGO crystal, 7 - LYSO crystal array, 8 - LYSO crystal SiPM, 9 - LYSO crystal assembly bottom plate, 10 - Circuit board of the signal acquisition and processing system. Detailed implementation manners

[0060] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art.

[0061] In addition, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. can be employed. In other instances, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of this application.

[0062] The flowcharts shown in the accompanying drawings are merely illustrative and not necessarily include all the content and operations / steps, nor are they necessarily executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to the actual situation.

[0063] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0064] The following will describe in detail some embodiments of the present application in conjunction with the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0065] In view of the deficiencies of the current space gamma prompt pulse radiation detection device in terms of signal-to-noise ratio, time resolution, sensitivity, etc., the embodiments of the present application provide a space prompt gamma radiation detection device, which specifically includes:

[0066] A device body and a signal acquisition and processing system;

[0067] The device body includes: a housing, and a scintillator array assembly and an anticoincidence scintillator assembly fixed in the housing;

[0068] A rectangular parallelepiped groove is provided in the center of the anticoincidence scintillator assembly, and the scintillator array assembly is located in the rectangular parallelepiped groove;

[0069] Wherein, the scintillator array assembly and the anticoincidence scintillator assembly are both connected to the signal acquisition and processing system to transmit the analog signal output by the scintillator array assembly and the output signal of the anticoincidence scintillator assembly to the signal acquisition and processing system.

[0070] In some feasible embodiments, based on the foregoing solution, the scintillator array assembly includes: a LYSO crystal array, a LYSO crystal SiPM, and a LYSO crystal assembly bottom plate;

[0071] Wherein, the LYSO crystal SiPM is arranged on the LYSO crystal assembly bottom plate;

[0072] The LYSO crystal array includes a plurality of LYSO crystals, and the plurality of LYSO crystals are arranged in an array;

[0073] Each LYSO crystal is separately coupled to the LYSO crystal SiPM;

[0074] Each LYSO crystal is also connected to the LYSO crystal assembly bottom plate, and the LYSO crystal assembly bottom plate is connected to the signal acquisition and processing system.

[0075] In some feasible embodiments, based on the foregoing solution, the anticoincidence scintillator assembly includes: a BGO crystal assembly bottom plate, a BGO crystal SiPM, and a BGO crystal;

[0076] The BGO crystal SiPM is arranged on the BGO crystal assembly bottom plate;

[0077] The BGO crystal is coupled to the BGO crystal SiPM;

[0078] The cuboid groove is formed in the BGO crystal, and the four side walls of the cuboid groove are thinner than the bottom surface;

[0079] The BGO crystal is connected to the bottom plate of the BGO crystal component, and the bottom plate of the BGO crystal component is connected to the signal acquisition and processing system.

[0080] In some feasible embodiments, based on the foregoing solution, the outer shell is a double-layer structure, the material of the inner layer structure is polyethylene, the material of the outer layer structure is AL, and the space between the inner layer structure and the outer layer structure is evacuated.

[0081] Exemplarily, referring to Figure 1 shows a schematic structural diagram of a spatial prompt gamma radiation detection device.

[0082] As Figure 1 shown, the device includes a device body and a signal acquisition and processing system. The device body includes a housing fixedly connected in sequence by a top cover 1, a middle cylinder 2, and a bottom cover 3, a scintillator array assembly and an anti-coincidence scintillator assembly fixed inside the housing.

[0083] Among them, the housing is a double-layer structure of inner and outer layers, with a vacuum between the inner and outer layers. The material of the outer layer is AL (aluminum), and the material of the inner layer is polyethylene.

[0084] The scintillator array assembly includes a LYSO crystal array 7, a LYSO crystal SiPM 8, and a LYSO crystal component bottom plate 9. The LYSO crystal array 7 is coupled to the LYSO crystal SiPM 8. The LYSO crystal SiPM 8 is disposed on the LYSO crystal component bottom plate 9. The LYSO crystal array 7 is also connected to the LYSO crystal component bottom plate 9. The LYSO crystal component bottom plate 9 is connected to the circuit board 10 of the signal acquisition and processing system. The signal generated by the LYSO crystal array 7 is first transmitted to the LYSO crystal component bottom plate 9, and then transmitted from the LYSO crystal component bottom plate 9 to the circuit board 10 of the signal acquisition and processing system.

[0085] Among them, the LYSO crystal array 7 includes a plurality of LYSO scintillation crystals coupled to the LYSO crystal SiPM 8. Each LYSO scintillation crystal has a cuboid structure and integrates an independent preamplifier and a SiPM power supply to achieve separate output of signals. The plurality of LYSO scintillation crystals are arranged in an array form by splicing to form a cuboid-structured LYSO crystal array 7. The gaps between each channel in the LYSO crystal array 7 are filled with vacuum.

[0086] It should be noted that each LYSO scintillation crystal is connected to the LYSO crystal component bottom plate 9, and the LYSO scintillation crystal and the LYSO crystal component bottom plate 9 can be connected by a coaxial cable or a board-to-board connector.

[0087] It should be noted that the bottom plate 9 of the LYSO crystal assembly can be connected to the circuit board 10 of the signal acquisition and processing system using a coaxial cable.

[0088] The anticoincidence scintillator assembly includes a BGO crystal assembly bottom plate 4, a BGO crystal SiPM 5, and a BGO crystal 6. The BGO crystal SiPM 5 is disposed on the BGO crystal assembly bottom plate 4. The BGO crystal 6 is coupled with the BGO crystal SiPM 5 and is also connected to the BGO crystal assembly bottom plate 4. The BGO crystal assembly bottom plate 4 is connected to the circuit board 10 of the signal acquisition and processing system. The signal generated by the BGO crystal 6 is first transmitted to the BGO crystal assembly bottom plate 4 and then transmitted from the BGO crystal assembly bottom plate 4 to the circuit board 10 of the signal acquisition and processing system.

[0089] It should be noted that the BGO crystal 6 can be connected to the BGO crystal assembly bottom plate 4 using a coaxial cable or a board-to-board connector. The BGO crystal assembly bottom plate 4 can be connected to the circuit board 10 of the signal acquisition and processing system using a coaxial cable.

[0090] Among them, the BGO crystal 6 is provided with a rectangular parallelepiped groove for placing the scintillator array assembly. The rectangular parallelepiped groove has five sensitive surfaces of "front, back, left, right, and bottom". The four wall surfaces of the "front, back, left, and right" of the rectangular parallelepiped groove are thinner than the "bottom" surface of the rectangular parallelepiped groove. Specifically, the thickness of the "front, back, left, and right" sensitive surfaces is less than or equal to 10 mm, and the thickness of the "bottom" sensitive surface is greater than or equal to 25.4 mm. The thicker "bottom" surface crystal is used for monitoring extra-terrestrial high-energy gamma flash events and shielding the electron and proton backgrounds incident on the "bottom" surface.

[0091] The BGO crystal 6 is externally wrapped with a reflective layer and integrated with a preamplifier and an SiPM power supply to uniformly output a single-channel signal.

[0092] Based on the same inventive concept, an embodiment of the present application also provides a method for monitoring spatial prompt gamma radiation, including steps S100 to step S700.

[0093] Exemplarily, referring to Figure 2 , a flowchart showing a method for monitoring spatial prompt gamma radiation provided by an embodiment of the present application is shown.

[0094] Referring to Figure 2 , in step S100, the acquired original signal is subjected to FIR low-pass filtering.

[0095] In some feasible embodiments, based on the foregoing solution, the step of subjecting the acquired original signal to FIR low-pass filtering includes:

[0096] The original signal is acquired using a signal acquisition and processing system. The original signal includes: nuclear pulse signals, noise signals, and mixed signals of the two.

[0097] Perform FIR low-pass filtering on the original signal based on formula (1);

[0098]

[0099] Where: x(n) is the input signal, h(k) is the FIR filter coefficient, y(n) is the signal after filtering, N represents the number of taps of the FIR filter, and N-1 is the filter order.

[0100] Continue to refer to Figure 2 , step S200, set the trigger threshold, and distinguish the effective nuclear pulses and noise in the filtered signal based on the trigger threshold.

[0101] In some feasible embodiments, based on the foregoing solution, the setting of the trigger threshold and the distinguishing of the effective nuclear pulses and noise in the filtered signal based on the trigger threshold include:

[0102] Obtain the zero-crossing duration of the effective nuclear pulse signal through experiments as the trigger threshold t e ;

[0103] Compare the duration t of the filtered signal with the trigger threshold t e for comparison. If t < t e *k, it indicates that the filtered signal is a noise signal, otherwise it is a valid signal, where k < 1 and k is an empirical parameter obtained through experiments.

[0104] Continue to refer to Figure 2 , step S300, if the discrimination result is an effective nuclear pulse, record the sampling points before and after the trigger threshold trigger point, and perform linear spline interpolation and linear fitting.

[0105] Continue to refer to Figure 2 , step S400, obtain the zero-crossing moment of the sampling point fitting curve to obtain the particle arrival time.

[0106] Continue to refer to Figure 2 , step S500, measure the deposited energy of the incident particle based on the effective nuclear pulse, and preliminarily screen the target particles through the energy threshold.

[0107] It can be understood that this step can eliminate the influence of space electrons, protons, and non-ground gamma-ray sources.

[0108] In some feasible embodiments, based on the foregoing solution, the measuring of the deposited energy of the incident particle based on the effective nuclear pulse and the preliminary screening of the target particles through the energy threshold include:

[0109] The effective nuclear pulses are subjected to trapezoidal shaping, pile-up rejection, amplitude extraction and energy calibration to obtain the incident particle deposition energy.

[0110] The energy threshold is calculated by Monte Carlo simulation;

[0111] Based on the comparison between the incident particle deposition energy and the energy threshold, target particles with qualified energy are screened out.

[0112] For example, the qualification condition is that the energy is greater than or equal to the energy threshold. If the incident particle deposition energy is less than the energy threshold, it indicates that the particle is unqualified and is rejected.

[0113] It can be understood that the objects filtered out by setting the energy threshold are mainly energy deposition formed by low-energy electrons and high-energy protons.

[0114] Exemplarily, the specific process of obtaining the energy threshold through Monte Carlo simulation is as follows:

[0115] The energy spectrum of the space electron and proton background and the gamma source term to be measured in the LYSO scintillation crystal at the satellite orbit is calculated by Monte Carlo simulation as the energy threshold.

[0116] In the experiment, by setting multiple groups of high and low energy thresholds, the ratio of gamma counts to electron and proton background counts was calculated to obtain the energy threshold with the optimal signal-to-noise ratio.

[0117] Continue to refer Figure 2 , step S600, anti-conformity is performed according to the particle arrival time and the incident particle deposition energy.

[0118] It can be understood that this step is used to remove the influence of space electrons, protons and non-terrestrial gamma-ray sources.

[0119] In some feasible embodiments, based on the above scheme, anti-coincidence according to the particle arrival time and the incident particle deposition energy includes:

[0120] The particle arrival time is divided into the particle arrival time t1 of the scintillator array component and the particle arrival time t2 of the anti-coincidence scintillator component;

[0121] Set the time window T0;

[0122] Based on the comparison between time t1, time t2 and time window T0, if t2-t1 <T0,且粒子在反符合闪烁体组件时的入射粒子沉积能量小于在闪烁体阵列组件时的入射粒子沉积能量,则表明该粒子为合格粒子,不进行剔除处理,否则,进行剔除处理。

[0123] Continue to refer Figure 2, step S700, based on the arrival times of the particles after anticoincidence, perform coincidence counting according to the time resolution requirement to obtain a time spectrum.

[0124] In some feasible embodiments, based on the foregoing solution, the step of performing coincidence counting according to the time resolution requirement based on the arrival times of the particles after anticoincidence to obtain a time spectrum includes:

[0125] Summarize the arrival times of the particles of the scintillator array component and the arrival times of the particles of the anticoincidence scintillator component into two groups respectively;

[0126] Count the counting rates within the unit time resolution of the two groups of times and output to obtain a time spectrum, where the x-axis of the time spectrum is time and the y-axis is the counting rate.

[0127] After considering the specification and practicing the disclosed embodiments herein, those skilled in the art will readily conceive of other embodiments of the present application. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include known common knowledge or conventional technical means in the technical field not disclosed in the present application. It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A spatial prompt gamma radiation detection device, characterized in that Comprising: The device body and the signal acquisition and processing system; The device body includes: a housing, and a scintillator array assembly and an anticoincidence scintillator assembly fixed within the housing; A rectangular parallelepiped groove is provided at the center of the anticoincidence scintillator assembly, and the scintillator array assembly is located within the rectangular parallelepiped groove; Wherein, both the scintillator array assembly and the anticoincidence scintillator assembly are connected to the signal acquisition and processing system to transmit the analog signal output by the scintillator array assembly and the output signal of the anticoincidence scintillation assembly to the signal acquisition and processing system.

2. The device according to claim 1, characterized in that, The scintillator array assembly includes: a LYSO crystal array, a LYSO crystal SiPM, and a LYSO crystal assembly bottom plate; Wherein, the LYSO crystal SiPM is disposed on the LYSO crystal assembly bottom plate; The LYSO crystal array includes a plurality of LYSO crystals, and the plurality of LYSO crystals are arranged in an array; Each LYSO crystal is individually coupled to the LYSO crystal SiPM; Each LYSO crystal is further connected to the LYSO crystal assembly bottom plate, and the LYSO crystal assembly bottom plate is connected to the signal acquisition and processing system.

3. The device according to claim 1, characterized in that, The anticoincidence scintillator assembly includes: a BGO crystal assembly bottom plate, a BGO crystal SiPM, and a BGO crystal; The BGO crystal SiPM is disposed on the BGO crystal assembly bottom plate; The BGO crystal is coupled to the BGO crystal SiPM; The rectangular parallelepiped groove is formed on the BGO crystal, and the four side walls of the rectangular parallelepiped groove are thinner than the bottom surface; The BGO crystal is connected to the BGO crystal assembly bottom plate, and the BGO crystal assembly bottom plate is connected to the signal acquisition and processing system.

4. The device according to claim 1, characterized in that, The housing is of a double-layer structure, the material of the inner layer structure is polyethylene, the material of the outer layer structure is AL, and the space between the inner layer structure and the outer layer structure is evacuated.

5. A method for monitoring spatial prompt gamma radiation, characterized in that, Comprising: Performing FIR low-pass filtering on the acquired original signal; Setting a trigger threshold, and distinguishing the effective nuclear pulses and noise in the filtered signal based on the trigger threshold; If the discrimination result is an effective nuclear pulse, record the sampling points before and after the trigger threshold trigger point, and perform linear spline interpolation and linear fitting; Obtain the zero-crossing moment of the sampling point fitting curve to obtain the particle arrival time; Measure the deposited energy of the incident particle based on the effective nuclear pulse, and preliminarily screen the target particle through an energy threshold; Perform anticoincidence according to the particle arrival time and the deposited energy of the incident particle; Based on the particle arrival time after anticoincidence, perform coincidence counting according to the time resolution requirement to obtain a time spectrum.

6. The method according to claim 5, wherein The performing FIR low-pass filtering on the acquired original signal includes: Collecting the original signal by using the signal acquisition and processing system, and the original signal includes: nuclear pulse signals, noise signals, and mixed signals of the two; Performing FIR low-pass filtering on the original signal based on formula (1); Where: x(n) is the input signal, h(k) is the FIR filter coefficient, y(n) is the filtered signal, N represents the number of taps of the FIR filter, and N-1 is the filter order.

7. The method according to claim 5, characterized in that Setting the trigger threshold and differentiating valid nuclear pulses from noise in the filtered signal, including: The zero-crossing duration of the effective nuclear pulse signal obtained from the experiment is used as the trigger threshold t e ; Compare the duration t of the filtered signal with the trigger threshold t e If t < t e *k, it indicates that the filtered signal is a noise signal; otherwise, it is a valid signal. Here, k < 1 and k is an empirical parameter obtained from experiments.

8. The method according to claim 5, characterized in that Measuring the deposited energy of incident particles based on the valid nuclear pulses and preliminarily screening target particles through an energy threshold, including: Performing trapezoidal shaping, pile-up rejection, amplitude extraction, and energy calibration on the valid nuclear pulses to obtain the deposited energy of incident particles; Calculating the energy threshold through Monte Carlo simulation; Comparing the deposited energy of the incident particles with the energy threshold and screening out target particles with qualified energy.

9. The method according to claim 5, characterized in that, Performing anticoincidence based on the arrival time of particles and the deposited energy of incident particles, including: Dividing the arrival time of particles into the arrival time t1 of particles at the scintillator array assembly and the arrival time t2 of particles at the anticoincidence scintillator assembly; Setting a time window T0; Based on the comparison of time t1, time t2, and time window T0, if t2 - t1 < T0 and the deposited energy of the incident particles when the particles are at the anticoincidence scintillator assembly is less than the deposited energy of the incident particles when the particles are at the scintillator array assembly, it indicates that the particle is a qualified particle and no rejection process is performed; otherwise, a rejection process is performed.

10. The method according to claim 9, wherein Based on the arrival time of particles after anticoincidence, performing coincidence counting statistics according to the time resolution requirement to obtain a time spectrum, including: Respectively aggregating the arrival time of particles at the scintillator array assembly and the arrival time of particles at the anticoincidence scintillator assembly into two groups; Counting the counting rates within the unit time resolution of the two groups of times and outputting to obtain a time spectrum, where the x-axis of the time spectrum is time and the y-axis is the counting rate.

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