High-counting-rate neutron sensitive scintillator probe, neutron detector and preparation method

Abstract

The invention discloses a neutron sensitive scintillator probe with a high counting rate, a neutron detector and a preparation method, and relates to the technical field of neutron detectors. The neutron sensitive scintillator probe is different from a traditional layered or array structure, a neutron sensitive material and a scintillation luminescent material which are uniformly mixed are adopted as a probe main body, the neutron sensitive material and incident neutrons are subjected to nuclear reaction to generate secondary charged particles, the secondary charged particles are energy-deposited in the scintillation luminescent material, and the neutron sensitive material and the scintillation luminescent material are separated from each other. The scintillation luminescent material is excited to emit scintillation light, so that the signal transmission time is reduced, the counting rate of the detector is improved, and the detector has the advantages of strong anti-interference capability and small size.

Description

Technical Field

[0001] The present application relates to the technical field of neutron detectors, and in particular to a high-counting-rate neutron-sensitive scintillator probe, a neutron detector, and a preparation method thereof. Background Art

[0002] Neutron detection has a wide range of applications in nuclear physics experiments, nuclear radiation detection, non-destructive testing, photon imaging, material research and other fields. Currently commonly used neutron detectors, such as 3 He proportional counter tubes, fission ionization chambers, scintillator detectors, etc. Traditional scintillator detection probes usually use physically separated neutron conversion layers and scintillator layers. The layered structure results in a large size and volume, making it difficult to adapt to micro-detection scenarios; charged particles need to cross the interface to enter the scintillator, resulting in energy loss, and multiple reflections at the interface will extend the photon transmission path, causing the signal rise time to increase, limiting the upper limit of the count rate; the separated or array structure is susceptible to magnetic field disturbances, and high electromagnetic shielding requirements are required. This results in traditional probes being unable to achieve effective detection in some special detection scenarios with high count rates and narrow spaces. Summary of the Invention

[0003] The present application provides a high-counting-rate neutron-sensitive scintillator probe, a neutron detector, and a preparation method to solve the problems of existing neutron detectors, such as large size, high electromagnetic shielding requirements, and low upper limit of counting rate.

[0004] This application is implemented through the following technical solutions: In a first aspect of the present application, a high-count-rate neutron-sensitive scintillator probe is provided, wherein the neutron-sensitive scintillator probe comprises a uniformly mixed neutron-sensitive material and a scintillation luminescent material; The neutron-sensitive material is used to generate secondary charged particles by undergoing nuclear reactions with incident neutrons; The scintillation luminescent material is used to emit scintillation light under the excitation of the secondary charged particles.

[0005] The probe body includes a uniform mixture of neutron-sensitive material and scintillation luminescent material. Therefore, when a neutron is incident on the probe, the neutron-sensitive material undergoes a nuclear reaction with the incident neutron to generate secondary charged particles. The energy of the secondary charged particles is deposited in the scintillation luminescent material, which excites the scintillation luminescent material to emit scintillation light. Because the neutron-sensitive material and the scintillation luminescent material are uniformly mixed, the secondary charged particles can directly deposit energy in the scintillation material, reducing the time for signal transmission and improving the response speed. The increase in response speed can reduce the processing time of a single event, thereby allowing more events to be processed in a shorter time and improving the detector's counting rate. The uniform mixing makes the neutron-sensitive material and the scintillation luminescent material have strong interaction capabilities, thereby having strong anti-interference capabilities during signal transmission and reducing the need for electromagnetic shielding. At the same time, the probe is made of a uniform mixture of neutron-sensitive material and scintillation luminescent material into an integrated structure. Compared with traditional separated structures or array structures, it has a smaller volume, which is conducive to the detection of some narrow space scenes.

[0006] In some embodiments, the neutron sensitive material comprises Isotopes or Isotope compounds.

[0007] In some embodiments, the light rise time and light fall time of the scintillation luminescent material are both in the order of nanometers.

[0008] In some embodiments, the scintillating luminescent material is .

[0009] In some embodiments, the mass ratio of the slow neutron sensitive material to the scintillation luminescent material is 1:1.

[0010] In a second aspect of the present application, a high counting rate neutron detector is provided, comprising: The neutron-sensitive scintillator probe according to any one of the first aspects of the present application; an optical fiber transmission line, wherein the incident end face of the optical fiber transmission line is coupled to the neutron-sensitive scintillator probe, and the output end face of the optical fiber transmission line is coupled to the signal input end of the photoelectric conversion device, and is used to transmit the scintillation light signal emitted by the neutron-sensitive scintillator probe to the photoelectric conversion device; The photoelectric conversion device is used to convert the flashing light signal into an electrical pulse signal and output the signal through the signal output terminal of the photoelectric conversion device.

[0011] By combining a scintillator probe with an optical fiber, which contains a uniform mixture of neutron-sensitive and scintillation-luminescent materials, the probe converts incident neutrons into a scintillation light signal with a pulse width on the order of nanometers. Combined with the efficient transmission efficiency of the optical fiber, this further improves the detector's count rate, enabling effective neutron detection in the high-count-rate range. Furthermore, the optical fiber, typically with a diameter of 1 mm, combined with the compact scintillator probe, can meet the detection requirements of confined spaces.

[0012] In some embodiments, the coupling portion between the photoelectric conversion device and the output end face of the optical fiber transmission line is filled with optical silicone grease.

[0013] In some embodiments, the photoelectric conversion device is a photomultiplier tube, and the output end face of the optical fiber transmission line is coupled to the photocathode portion of the photomultiplier tube.

[0014] In some embodiments, the neutron detector further includes a metal protective cover, and the photoelectric conversion device is disposed in the metal protective cover for light shielding and electromagnetic shielding.

[0015] In some embodiments, the neutron-sensitive scintillator probe further has a metal protective shell, which is arranged on the outer contour surface between the neutron incident surface and the scintillation light output surface of the neutron-sensitive scintillator probe; wherein, the neutron incident surface is used to receive incident neutrons, and the scintillation light output surface is coupled with the incident end face of the optical fiber transmission line to output a scintillation light signal to the incident end face of the optical fiber transmission line.

[0016] A third aspect of the present application provides a method for preparing a neutron-sensitive scintillator probe, comprising: S1, mixing a neutron-sensitive material and a scintillation luminescent material according to a preset ratio to obtain a mixture; S2, adding an organic volatile solvent to the mixture to obtain a uniform mixed solution; S3, pouring the uniform mixed liquid into a mold and solidifying it into a shape to obtain a neutron-sensitive scintillator probe.

[0017] In some embodiments, the method for preparing a neutron-sensitive scintillator probe further comprises: S4, adding a metal protective shell to the first outer contour surface of the neutron-sensitive scintillator probe to obtain a preformed neutron-sensitive scintillator probe; the first outer contour surface is the remaining outer surface of the outer surface of the neutron-sensitive scintillator probe excluding the neutron incident surface and the scintillation light output surface.

[0018] A fourth aspect of the present application provides a method for preparing a neutron detector, comprising: Preparation of neutron-sensitive scintillator probe materials: S11, mixing the slow neutron sensitive material and the scintillation luminescent material according to a preset ratio to obtain a uniform mixture; S12, adding an organic volatile solvent to the uniform mixture to obtain a uniform mixed liquid; Preparation of neutron-sensitive scintillator probe: S13, polishing and grinding both ends of the optical fiber transmission line; S14, spraying the uniform mixed liquid multiple times to a predetermined thickness at one end of the optical fiber transmission line using a spraying process, and obtaining a neutron-sensitive scintillator probe coupled to the one end of the optical fiber transmission line after solidification; Preparation of neutron detectors: S15, coupling the other end of the optical fiber transmission line to the signal input end of the photoelectric conversion device through an optical coupling material; S16, adding a metal protective shell to the first outer contour surface of the neutron-sensitive scintillator probe, where the first outer contour surface is the remaining outer surface of the outer surface of the neutron-sensitive scintillator probe excluding the neutron incident surface and the scintillation light output surface; adding a metal protective cover to the outside of the photoelectric conversion device to obtain a neutron detector.

[0019] Compared with the prior art, this application has the following advantages and beneficial effects: 1. In the probe, the neutron-sensitive material and the scintillation luminescent material are evenly mixed. The secondary charged particles directly deposit energy in the scintillation material, which reduces the signal transmission time and improves the response speed, thereby allowing more events to be processed in a shorter time and increasing the count rate; 2. The use of slow neutron sensitive materials with large reaction cross-sections makes it easier to capture neutrons, improves reaction efficiency, thereby enhancing detection sensitivity and reducing the possibility of missed detection; 3. Using scintillation luminescent materials with nanometer-scale rise and fall times, incident neutrons are converted into nanometer-scale scintillation light signal outputs, further improving the counting rate; 4. The neutron-sensitive material and the scintillation luminescent material are uniformly mixed in a mass ratio of 1:1, which ensures both sufficient neutron capture and effective energy conversion and light emission, achieving the best balance in the interaction between the two materials; 5. The uniform mixing makes the interaction between the neutron-sensitive material and the scintillation luminescent material strong, so the anti-interference ability during signal transmission is strong and the demand for electromagnetic shielding is reduced.

[0020] 6. The probe is made by uniformly mixing neutron-sensitive materials and scintillation luminescent materials into an integrated form, which has a smaller volume. When combined with an optical fiber with a diameter of about 1mm, it can achieve efficient signal conversion and transmission while facilitating application in narrow spaces. 7. The preparation process of neutron-sensitive scintillator probes and detectors is simple and does not rely on complex equipment. The neutron-sensitive scintillator probes can be directly coupled with optical fiber transmission lines through a spraying process, or they can be prepared separately, which improves the integration of the equipment. The separate probes can be applied to more scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings: Figure 1 Schematic diagram of the structure of a high-count-rate neutron-sensitive scintillator probe provided in an embodiment of the present application; Figure 2 1 is a schematic structural diagram of a high counting rate neutron detector provided in an embodiment of the present application; Figure 3 This is a flow chart of a method for preparing a high-count-rate neutron-sensitive scintillator probe provided in an embodiment of the present application; Figure 4 This is a flow chart of a method for preparing a high-counting-rate neutron detector provided in an embodiment of the present application; Figure 5 This is a typical pulse waveform output by the neutron detector provided in the embodiment of the present application.

[0022] The following are the descriptions of the reference numerals: 10- neutron-sensitive scintillator probe, 11- neutron-sensitive material, 12- scintillation luminescent material, 20- optical fiber transmission line, 30- photoelectric conversion device. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of this application more clear, the present application is further described in detail below in conjunction with examples and drawings. The schematic implementation methods of this application and their descriptions are only used to explain this application and are not intended to limit this application.

[0024] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to other steps or units inherent in the device.

[0025] The terms used in the various embodiments of the present application are only used for the purpose of describing specific embodiments and are not intended to limit the various embodiments of the present application. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. Unless otherwise specified, all terms used herein (including technical terms and scientific terms) have the same meaning as those commonly understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning, unless clearly defined in the various embodiments of the present application.

[0026] The drawings of the present invention are for illustrative purposes only and are schematic diagrams rather than actual drawings, and should not be construed as limiting the present invention. In order to better illustrate the embodiments of the present invention, certain components of the drawings may be omitted, enlarged, or reduced in size, and do not represent the dimensions of actual products. The same or similar reference numerals in the drawings correspond to the same or similar components. It is understandable to those skilled in the art that certain well-known structures and their descriptions may be omitted in the drawings.

[0027] The embodiments of the present application provide a neutron-sensitive scintillator probe with a high counting rate, a neutron detector, and a preparation method, which are suitable for neutron measurement in high counting rate detection scenarios and have the advantages of miniaturization and strong anti-interference ability.

[0028] A first embodiment of the present application provides a high-counting-rate neutron-sensitive scintillator probe. Figure 1 The figure shows a schematic structural diagram of a high-count-rate neutron-sensitive scintillator probe 10 according to the present embodiment. Unlike conventional layered or array structures, the probe according to the present embodiment is an integrally formed structure. The neutron-sensitive scintillator probe 10 includes a uniformly mixed neutron-sensitive material 11 and a scintillation-luminescent material 12. Specifically, the probe body is formed by a uniform mixture of the neutron-sensitive material and the scintillation-luminescent material. During preparation, the slow neutron-sensitive material and the scintillation-luminescent material can be uniformly mixed using an organic volatile solvent. After the solvent in the mixture evaporates, a probe of a predetermined shape is formed. In the probe, the neutron-sensitive material undergoes a nuclear reaction with incident neutrons to generate secondary charged particles. The energy of the secondary charged particles is deposited in the scintillation-luminescent material, which excites the scintillation-luminescent material to emit scintillation light.

[0029] Because the neutron-sensitive material and the scintillation luminescent material are evenly mixed, the secondary charged particles can directly deposit energy in the scintillation material, reducing the signal transmission time and improving the response speed. The improved response speed can reduce the processing time of a single event, thereby allowing more events to be processed in a shorter time and improving the counting rate.

[0030] Because the intensity of a probe's electromagnetic radiation is positively correlated with the area of ​​its conductor loop, conventional detectors are bulky. Consequently, the equivalent electromagnetic loop formed by internal high-voltage electrodes and signal transmission paths is large, making it susceptible to interference from external electromagnetic fields. Furthermore, the electromagnetic noise generated by the detector itself is also stronger, necessitating strict electromagnetic shielding requirements. However, the probe in this embodiment is a highly integrated, uniform blend of neutron-sensitive and scintillating luminescent materials. Compared to conventional probe structures, it is more compact and achieves effective electromagnetic shielding through the outer metal shielding layer.

[0031] In some embodiments, the neutron sensitive material comprises or This embodiment adopts slow neutron sensitive materials of isotopes. or Nuclei with large reaction cross sections are more likely to capture neutrons, which improves reaction efficiency, thereby enhancing detection sensitivity and reducing the possibility of missed detection. Boron carbide ( )powder, Lithium fluoride ( ) nanoparticles.

[0032] In some embodiments, the scintillating luminescent material is a material whose light rise time and light fall time are both in the nanometer (nm) range, such as gallium-doped zinc oxide. It converts incident neutrons into scintillation light signal output with a pulse width at the nanometer level. By collecting and processing the scintillation light signal, effective detection of neutrons in the high count rate range can be achieved.

[0033] In some embodiments, the mass ratio of the neutron-sensitive material to the scintillation luminescent material is 1:1. A uniform mixing ratio of 1:1 ensures both sufficient neutron capture and energy conversion and light emission efficiencies, achieving an optimal balance in the interaction between the two materials.

[0034] In some embodiments, the neutron-sensitive scintillator probe 10 of this embodiment further comprises a metal protective shell. This metal protective shell is disposed on the outer contour surface between the neutron incident surface and the scintillation light output surface of the neutron-sensitive scintillator probe 10. Specifically, the metal protective shell is disposed on all outer surfaces other than the neutron incident surface and the scintillation light output surface. The neutron incident surface is the surface for receiving incident neutrons, while the scintillation light output surface is the surface for connecting to an optical signal receiving device, i.e., the scintillation light output surface outputs scintillation light signals to the optical signal receiving device. In the probe structure, the neutron incident surface and the scintillation light output surface are opposing surfaces.

[0035] The embodiment of the second aspect of the present application provides a high counting rate neutron detector, such as Figure 2Figure 2 shows a schematic diagram of the structure of a neutron detector, which consists of a neutron-sensitive scintillator probe 10, an optical fiber transmission line 20, and a photoelectric conversion device 30. The incident end face of the optical fiber transmission line 20 is coupled to the neutron-sensitive scintillator probe 10 to receive the flash signal emitted by the scintillation light output surface of the neutron-sensitive scintillator probe 10. The output end face of the optical fiber transmission line 20 is coupled to the signal input end of the photoelectric conversion device 30, thereby transmitting the scintillation light signal emitted by the neutron-sensitive scintillator probe 10 to the photoelectric conversion device 30 via the optical fiber. The photoelectric conversion device 30 receives the optical signal and converts it into an electrical pulse signal, which is then output to the back-end equipment for processing through the signal output port.

[0036] The neutron-sensitive scintillator probe 10 is made of the material uniformly mixed with the neutron-sensitive material 11 and the scintillation luminescent material 12 according to the first aspect of the present application.

[0037] This neutron detector combines a neutron-sensitive scintillator probe with an optical fiber. The probe contains a uniform mixture of neutron-sensitive and scintillation-luminescent materials. By collecting and processing the scintillation light signals through the optical fiber, it effectively detects neutrons in the high-count-rate range. The specific operating principle is that incident neutrons react with the neutron-sensitive material to generate secondary charged particles. These charged particles excite the scintillation-luminescent material to emit scintillation light. This scintillation light is then transmitted via the optical fiber to a photoelectric conversion device, where it is converted into a current pulse signal, ultimately achieving effective neutron detection.

[0038] In the neutron sensitive scintillator detector, the scintillation luminescent material with the light rise time and light fall time both in the nanometer range is selected, and the scintillation light pulse width is controlled in the nanometer range, which can make the upper limit of the detector count rate reach .

[0039] The neutron detector implemented in this embodiment converts neutron rays into scintillation light signals that are easy to collect and process. The detector is small in size, has strong resistance to environmental interference, and has a high upper limit on counting rate. It can be used to effectively detect neutron signals in high neutron fluence rate environments, enriching the means of neutron detection and having important significance for the application of neutron technology.

[0040] Among them, the main material of the neutron-sensitive scintillator probe adopts a uniform mixture of atomic nuclei with a large reaction cross-section and scintillation luminescent materials with a luminescence rise time / fall time at the nanometer level, which converts the incident neutrons into scintillation light signal output with a pulse width at the nanometer level, and combines it with the efficient transmission efficiency of optical fiber to further improve the counting rate.

[0041] In some embodiments, the connection between the photoelectric conversion device 30 and the output end face of the optical fiber transmission line 20 is filled with optical silicone grease. The optical silicone grease couples the photoelectric conversion device to the optical fiber end face, improves optical coupling efficiency, reduces reflection loss, and provides mechanical stability and a sealed environment for the connection.

[0042] Furthermore, the neutron detector further includes a metal protective cover, and the photoelectric conversion device 30 is arranged in the metal protective cover to achieve light shielding and electromagnetic shielding.

[0043] Furthermore, before the optical fiber transmission line 20 is coupled with the neutron-sensitive scintillator probe 10 and the photoelectric conversion device 30 , the two coupling end faces of the optical fiber transmission line 20 are polished to have a surface roughness of less than 10 μm.

[0044] In some embodiments, the photoelectric conversion device 30 is a photomultiplier tube, the output end face of the optical fiber transmission line 20 is coupled to the photocathode portion of the photomultiplier tube, and the coupling portion is filled with optical silicone grease.

[0045] Furthermore, the photomultiplier tube is arranged in a metal protective sleeve, such as a stainless steel sleeve, to achieve light shielding and electromagnetic shielding.

[0046] In some embodiments, the neutron-sensitive scintillator probe 10 further includes a metal protective shell disposed on the outer contour surface between the neutron incident surface and the scintillation light output surface of the neutron-sensitive scintillator probe body. The neutron incident surface is configured to receive incident neutrons, while the scintillation light output surface couples with the incident end face of the optical fiber transmission line 20 and outputs a scintillation light signal to the incident end face of the optical fiber transmission line 20 via the scintillation light output surface.

[0047] The embodiment of the third aspect of the present application provides a method for preparing a neutron-sensitive scintillator probe with a high counting rate, that is, the method for preparing the neutron-sensitive scintillator probe 10 with a high counting rate of the first aspect of the present application, such as Figure 3 The figure shows a schematic diagram of the preparation process of a neutron-sensitive scintillator probe, which includes the following steps.

[0048] S1, mixing a neutron sensitive material and a scintillation luminescent material according to a preset ratio to obtain a mixture.

[0049] S2, adding an organic volatile solvent to the mixture to obtain a uniform mixed solution.

[0050] S3, pouring the uniform mixed liquid into a mold and solidifying it into a shape to obtain a neutron-sensitive scintillator probe.

[0051] In one embodiment, the neutron sensitive material is a slow neutron sensitive material with a large reaction cross section, such as 、 The scintillation luminescent material uses materials with light rise time and light fall time both in the nanometer (nm) range, such as gallium-doped zinc oxide Mixed. For example, and Mixed or and Mixed preparation. The organic volatile solvent can be acetone, ethanol, isopropanol, toluene, tetrahydrofuran (THF), N-methylpyrrolidone (NMP), etc.

[0052] In one embodiment, the neutron-sensitive scintillator probe is cylindrical in shape, with preferred dimensions of 0.25 mm in thickness and 1 mm in diameter. A mold of corresponding dimensions is prepared in advance before manufacturing the neutron-sensitive scintillator probe.

[0053] In one embodiment, the neutron sensitive material and the scintillation luminescent material are mixed in a mass ratio of 1:1, and the light yield of the scintillation luminescent material is set to 10,000 photons / MeV.

[0054] In one embodiment, the method for preparing a neutron-sensitive scintillator probe further includes S4: attaching a metal protective shell to a first outer contour surface of the neutron-sensitive scintillator probe to obtain a preformed neutron-sensitive scintillator probe. The first outer contour surface is the remaining outer surface of the neutron-sensitive scintillator probe excluding the neutron incident surface and the scintillation light output surface.

[0055] The fourth embodiment of the present application provides a method for preparing a neutron detector with a high counting rate, see Figure 4 The flowchart shown includes the following steps (1) to (3).

[0056] (1) Preparation of neutron-sensitive scintillator probe materials.

[0057] S11, mixing the neutron sensitive material and the scintillation luminescent material according to a preset ratio to obtain a mixture; S12, adding an organic volatile solvent to the mixture to obtain a uniform mixed liquid (probe material).

[0058] (2) Preparation of neutron-sensitive scintillator probes.

[0059] S13, polishing and grinding both ends of the optical fiber transmission line; S14, spraying the mixed liquid uniformly on one end of the optical fiber transmission line multiple times to a predetermined thickness using a spraying process, and obtaining a neutron-sensitive scintillator probe coupled to the one end of the optical fiber transmission line after solidification.

[0060] (3) Preparation of neutron detector.

[0061] S15, coupling the other end of the optical fiber transmission line to the signal input end of the photoelectric conversion device through an optical coupling material; S16, adding a metal protective shell to the first outer contour surface of the neutron-sensitive scintillator probe, where the first outer contour surface is the remaining outer surface of the neutron-sensitive scintillator probe excluding the neutron incident surface and the scintillation light output surface; and adding a metal protective cover to the outside of the photoelectric conversion device to obtain a neutron detector.

[0062] The specific steps, materials, mixing ratios, etc. for preparing the neutron-sensitive scintillator probe material in step (1) may be the same as steps S1-S2 for preparing the neutron-sensitive scintillator probe in the third aspect.

[0063] The spray coating process uses a spray gun to perform multiple spraying and curing steps. The organic volatile solvent evaporates quickly after spraying, ultimately achieving a probe with a fine and compact structure, uniform composition, and high light yield. The probe diameter is the same as the cross-sectional diameter of the optical fiber, typically 1mm, so the detector can detect neutrons in confined spaces.

[0064] An embodiment of a fifth aspect of the present application provides a method for preparing a neutron detector with a high counting rate, comprising the following steps: S10, preparing a neutron-sensitive scintillator probe according to the method of steps S1-S3 above; S20, polishing and grinding both ends of the optical fiber transmission line, coupling one end of the optical fiber transmission line to a neutron-sensitive scintillator probe, and coupling the other end of the optical fiber transmission line to a signal input end of a photoelectric conversion device through an optical coupling material to obtain a neutron detector.

[0065] The coupling methods between the end face of the optical fiber transmission line and the neutron-sensitive scintillator probe include, but are not limited to, optical adhesive, mechanical, or fusion coupling. By independently preparing and molding the neutron-sensitive scintillator probe, the probe of this application can be combined with other equipment and systems for application in different fields.

[0066] In one embodiment, the neutron-sensitive scintillator probe is prepared in step S10 according to the method of steps S1 to S4.

[0067] This application uses the Monte Carlo tool FLUKA to study the parameter design of the above neutron detector and explore the influence of the material parameters and geometric structure of the detector on the neutron detection performance. First, FLUKA is used to establish the following Figure 2 The neutron detector model shown in the figure has a scintillator probe coating thickness of 0.25 mm, an optical fiber length of 20 m, and a diameter of 1 mm. The neutron sensitive material of the scintillator probe is selected , scintillating luminescent materials are selected , the mass ratio of the neutron sensitive material and the scintillation luminescent material is set to 1:1, and the light yield of the scintillation luminescent material is set to 10,000 photons / MeV.

[0068] The experiment counted the number of output scintillation photons for each neutron incident event at the end face of an ordinary optical fiber. Statistical analysis was performed for neutron incident events and gamma-ray incident events respectively. The experimental process and results are as follows.

[0069] (1) The incident neutron energy is set to 0.0265 eV. Neutrons enter the scintillator probe and, after undergoing various physical processes, emit scintillation photons from the fiber end face. A total of 100,000 slow neutron incident events are simulated. The number of scintillation photons collected for each slow neutron incident is counted, and the average number of scintillation photons output per neutron incident is found to be 2,000. The calculation results show that the neutron detection efficiency of the detector is approximately 10%.

[0070] (2) The gamma ray energy was set to 1 MeV, and 100,000 gamma ray incident events were simulated. The number of scintillation photons collected for each gamma ray incident was counted, and the average number of scintillation photons output caused by each neutron incident was 100.

[0071] The results show that both neutron and gamma ray incidents can cause the detector to emit scintillation photons. The number of scintillation photons induced by neutron incidents is significantly higher than that caused by gamma ray incidents, making it possible to clearly distinguish between gamma ray incident events and neutron incident events.

[0072] The typical pulse waveform output by the neutron detector is as follows: Figure 5 As shown, the pulse half-width is about 6ns, that is, the maximum counting rate of the detector is .

[0073] In addition, the scintillator fiber neutron probe test was carried out. The test process and results are as follows: The scintillator probe was placed in a In the neutron field, the pulse count rate after background deduction is 133 / s, and the corresponding neutron detection efficiency is 8.5%, which is close to the theoretical simulation result (10%).

[0074] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above description is only the specific implementation methods of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A high-count-rate neutron-sensitive scintillator probe, characterized in that: The neutron-sensitive scintillator probe (10) includes a uniformly mixed neutron-sensitive material (11) and a scintillation luminescent material (12); The neutron-sensitive material (11) is used to generate secondary charged particles by undergoing nuclear reactions with incident neutrons; The scintillation luminescent material (12) is used to emit scintillation light under the excitation of the secondary charged particles.

2. The high counting rate neutron sensitive scintillator probe according to claim 1, characterized in that: The neutron sensitive material (11) comprises Isotopes or Isotope compounds.

3. The high counting rate neutron sensitive scintillator probe according to claim 1, characterized in that: The light rise time and light fall time of the scintillation luminescent material (12) are both in the nanometer range.

4. The high counting rate neutron sensitive scintillator probe according to claim 3, characterized in that: The scintillation luminescent material (12) is .

5. The neutron-sensitive scintillator probe according to any one of claims 1 to 4, characterized in that: The mass ratio of the neutron sensitive material (11) to the scintillation luminescent material (12) is 1:

1.

6. A high count rate neutron detector, characterized in that: include: The neutron-sensitive scintillator probe (10) according to any one of claims 1 to 5; An optical fiber transmission line (20), wherein an incident end face of the optical fiber transmission line (20) is coupled to the neutron-sensitive scintillator probe (10), and an output end face of the optical fiber transmission line (20) is coupled to a signal input end of a photoelectric conversion device (30), and is used to transmit a scintillation light signal emitted by the neutron-sensitive scintillator probe (10) to the photoelectric conversion device (30); The photoelectric conversion device (30) is used to convert the flashing light signal into an electrical pulse signal, and output the signal through a signal output terminal of the photoelectric conversion device (30).

7. The high counting rate neutron detector according to claim 6, characterized in that: The coupling portion between the photoelectric conversion device (30) and the output end face of the optical fiber transmission line (20) is filled with optical silicone grease.

8. The high counting rate neutron detector according to any one of claims 6 to 7, characterized in that: The photoelectric conversion device (30) is a photomultiplier tube, and the output end face of the optical fiber transmission line (20) is coupled to the photocathode portion of the photomultiplier tube.

9. The high counting rate neutron detector according to claim 8, characterized in that: The neutron detector further comprises a metal protective sleeve, and the photoelectric conversion device (20) is arranged in the metal protective sleeve for light shielding and electromagnetic shielding.

10. The high counting rate neutron detector according to claim 6, characterized in that: The neutron-sensitive scintillator probe (10) further comprises a metal protective shell, which is arranged on an outer contour surface between a neutron incident surface and a scintillation light output surface of the neutron-sensitive scintillator probe (10); wherein the neutron incident surface is used to receive incident neutrons, and the scintillation light output surface is coupled to the incident end surface of the optical fiber transmission line (20) and is used to output a scintillation light signal to the incident end surface of the optical fiber transmission line (20).

11. A method for preparing a neutron-sensitive scintillator probe, characterized in that: include: S1, mixing a neutron-sensitive material and a scintillation luminescent material according to a preset ratio to obtain a mixture; S2, adding an organic volatile solvent to the uniform mixture to obtain a uniform mixed solution; S3, pouring the uniform mixed liquid into a mold and solidifying it into a shape to obtain a neutron-sensitive scintillator probe.

12. The method for preparing a neutron-sensitive scintillator probe according to claim 11, characterized in that: Also includes: S4, adding a metal protective shell to the first outer contour surface of the neutron-sensitive scintillator probe to obtain a preformed neutron-sensitive scintillator probe; the first outer contour surface is the remaining outer surface of the outer surface of the neutron-sensitive scintillator probe excluding the neutron incident surface and the scintillation light output surface.

13. A method for preparing a neutron detector, characterized in that: include: Preparation of neutron-sensitive scintillator probe materials: S11, mixing the neutron sensitive material and the scintillation luminescent material according to a preset ratio to obtain a mixture; S12, adding an organic volatile solvent to the mixture to obtain a uniform mixed solution; Preparation of neutron-sensitive scintillator probe: S13, polishing and grinding both ends of the optical fiber transmission line; S14, spraying the uniform mixed liquid multiple times to a predetermined thickness at one end of the optical fiber transmission line using a spraying process, and obtaining a neutron-sensitive scintillator probe coupled to the one end of the optical fiber transmission line after solidification; Preparation of neutron detectors: S15, coupling the other end of the optical fiber transmission line to the signal input end of the photoelectric conversion device through an optical coupling material; S16, adding a metal protective shell to the first outer contour surface of the neutron-sensitive scintillator probe, where the first outer contour surface is the remaining outer surface of the outer surface of the neutron-sensitive scintillator probe excluding the neutron incident surface and the scintillation light output surface; adding a metal protective cover to the outside of the photoelectric conversion device to obtain a neutron detector.

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