A portable neutron gamma detection system based on nail crystal

Abstract

The application belongs to the field of nuclear radiation detection system, and provides a portable neutron gamma detection system based on NaIL crystal, which comprises a detection device, a tablet computer, a support, and a handle, the support and the handle are installed on the detection device through a plurality of groups of fastening bolts and spring washers, the tablet computer is fixed on the support through buckles, and the detection device comprises a shell, a polyethylene moderator, a NaIL crystal, a photomultiplier tube, a front-end electronic part, a rear-end electronic part, and a wireless communication antenna. The application has simple structure, is easy to hold and use or carry in a backpack, only uses one detection element, greatly simplifies the structure of the detection device, only needs to consider the processing of one-way signal for the front-end electronic part and the rear-end electronic part, significantly reduces the equipment cost and design difficulty, and significantly improves the reliability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of nuclear radiation detection system, and particularly relates to a portable neutron gamma detection system based on NaIL crystal. BACKGROUND

[0002] Measurement of neutron and gamma ray has wide demand in the fields of radiation protection, radioactive source management, nuclear emergency, industrial application, environmental protection, security and anti-terrorism. In traditional nuclear radiation detection system, neutron detector (based on helium 3 proportional tube or semiconductor detection element) and gamma detector (based on ionization chamber or Geiger-Muller counter tube, plastic scintillator, crystal scintillator, semiconductor, etc.) are needed to measure and distinguish the two kinds of rays, and pulse signal amplification circuit is configured for the two kinds of detectors respectively, and the design of digital signal processing circuit is also more complex, and the cost of equipment is higher. At the same time, it is difficult to reduce the volume and weight of the equipment, which leads to great difficulty in designing portable instruments. With the development of new detection elements and pulse waveform distinguishing technology, the neutron and gamma ray detection technology using only one kind of detection element has made significant progress, but there is no mature portable instrument product and related patent. SUMMARY

[0003] The purpose of the application is to overcome the problems of traditional nuclear radiation detection system in realizing measurement and distinguishing of neutron and gamma ray, such as complex structure, high cost, great difficulty in designing portable instruments, etc., and a portable neutron gamma detection system based on NaIL crystal is proposed, which can greatly reduce the complexity of system structure, material cost and design difficulty.

[0004] To achieve the above purpose, the technical scheme adopted by the application is: a portable neutron gamma detection system based on NaIL crystal, comprising a detection device, a tablet computer, a support, and a handle, the support and the handle are installed on the detection device through a plurality of fastening bolts and spring washers, and the tablet computer is fixed on the support through buckles.

[0005] The detection device is composed of a shell, a polyethylene moderator, a NaIL crystal, a photomultiplier tube, a photomultiplier tube seat and a front-end electronics part, a back-end electronics part, a battery compartment and a lithium battery pack, and a wireless communication antenna, the polyethylene moderator is installed on the shell through a plurality of fastening bolts and spring washers, the NaIL crystal, the photomultiplier tube, the photomultiplier tube seat and the front-end electronics part are packaged as a whole, the NaIL crystal is completely inserted into the polyethylene moderator, the photomultiplier tube seat and the front-end electronics part are installed on the shell through a plurality of fastening bolts and spring washers, the back-end electronics part, the battery compartment and the lithium battery pack are installed on the shell through a plurality of fastening bolts and spring washers, the wireless communication antenna and the waterproof aviation connector are installed on the shell through a nut, a spring washer and a sealing ring, the photomultiplier tube seat and the front-end electronics part are connected to the back-end electronics part through a connector and a shielded cable, the back-end electronics part is connected to the battery compartment and the lithium battery pack through a connector and a wire, and the back-end electronics part is connected to the wireless communication antenna through a connector and a shielded cable.

[0006] In the above technical solution, the NaIL crystal is used as a detection element, and the waveform discrimination and ray discrimination functions are realized based on the different light emission characteristics of neutrons and gamma rays in the crystal.

[0007] In the above technical solution, polyethylene is used as a neutron moderator material, and the thickness of the moderator is 5-7 cm, so that a high neutron moderation efficiency can be achieved while ensuring a small device size and easy use.

[0008] In the above technical solution, the front-end electronics part only uses one current-sensitive preamplifier circuit, and the back-end electronics part only uses one digital sampling circuit, so that the device cost and design difficulty are significantly reduced, and the reliability is significantly improved.

[0009] In the above technical solution, the NaIL crystal, the photomultiplier tube, the photomultiplier tube seat and the front-end electronics part are packaged as a whole, and a rubber sleeve is used for vibration reduction.

[0010] In the above technical solution, the detection device is connected to the adapter using a waterproof aviation connector, which further improves the environmental adaptability of the device, and the back-end electronics part is connected to the waterproof aviation connector through a connector and a shielded cable.

[0011] In the above technical solution, the detection device and the tablet computer are connected through WIFI and Bluetooth wireless communication, which reduces the number of connection lines and other accessories and is more convenient to use.

[0012] The tablet computer is provided with a touch display screen, a speaker, various I / O interfaces, various function buttons, a large-capacity polymer lithium ion battery, an adapter (tablet), WIFI, Bluetooth, 4G communication function and GPS module, Beidou module, and required software is pre-installed, and the following functions can be realized by calling tablet computer resources: drawing PSD-energy spectrum, neutron and gamma ray discrimination, calculating and displaying neutron count rate, gamma ray count rate, gamma ray energy spectrum, gamma dose rate and other information, drawing dose rate distribution graph, distinguishing radioactive source type and position, sound and light alarm and the like, and the development difficulty and production cost of the equipment are reduced.

[0013] When carried by using a backpack, the detection device, the tablet computer, the adapter and the like are placed on the foam material fixing position, and then the whole is placed in the backpack. At this time, the tablet computer can also be used alone by hand, and is used for observing measurement results and sound and light alarm information.

[0014] Compared with the prior art, the portable neutron gamma detection system based on the NaIL crystal has the following beneficial effects:

[0015] 1. Only one detection element is used, and the structure of the detection device is greatly simplified. The NaIL crystal is a kind of inorganic crystal scintillator with a relatively mature growth process and a relatively large growth volume, and a higher response to neutrons and gamma rays can be obtained at the same time compared with other detection elements.

[0016] 2. The front-end electronics part and the back-end electronics part only need to consider the processing of 1-way signal, and the cost and design difficulty of the equipment using two kinds of detection elements are significantly reduced, and the reliability is significantly improved.

[0017] 3. A commercially available tablet computer is used, and the difficulty and cost of equipment development and system integration are reduced.

[0018] 4. Wireless communication is used between the detection device and the tablet computer, the number of connecting lines and other accessories is reduced, and use is more convenient.

[0019] 5. The maximum size of the detection device of the detection system is ≯φ200mm*450mm, and the maximum weight is ≯6kg; the maximum weight of the whole system is ≯8kg; it is easy to use by hand or carry by backpack, and after simple modification, it is also suitable for unmanned aerial vehicles, robot cars, robot dogs and other carriers, and the adaptation field of the equipment is greatly widened. DETAILED DESCRIPTION

[0020] Figure 1 It is a schematic diagram of the detection system of the application (handheld front view).

[0021] Figure 2 It is a schematic diagram of the handheld side of the detection system of the application.

[0022] Figure 3 As Figure 1 A-A cross-sectional view.

[0023] Figure 4 As As

[0024] Wherein: 1. detection device, 2. tablet computer, 3. support, 4. handle, 5. wireless communication antenna, 6. waterproof aviation connector, 7. adapter (tablet), 8. foam material, 9. backpack, 10. adapter (detection device), 11. polyethylene moderator, 12. rubber sleeve, 13. NaIL crystal, 14. photomultiplier tube, 15. photomultiplier tube base and front-end electronics part, 16. back-end electronics part, 17. battery compartment and lithium battery pack, 18. shell. DETAILED DESCRIPTION

[0025] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited to the specific implementation disclosed below.

[0026] It should be noted that when an element is referred to as being "mounted on" another element, it can be directly on the other element or there can be a middle element.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0028] As Figure 1 , Figure 2 As shown in the drawings, the embodiment of the present application provides a portable neutron gamma detection system based on NaIL crystal, which comprises a detection device 1 and a tablet computer 2, and can be additionally equipped with a support 3, a handle 4, a backpack 9, an adapter (tablet) 7, an adapter (detection device) 10 and other accessories.

[0029] As Figure 3As shown, the detection device is composed of a shell 18, a polyethylene moderator 11, a NaIL crystal 13, a photomultiplier tube 14, a photomultiplier tube base and front-end electronics part 15, a rubber sleeve 12, a back-end electronics part 16, a battery compartment and lithium battery pack 17, a wireless communication antenna 5, a waterproof aviation connector 6, and the like.

[0030] The shell 18 of the detection device 1 is made of aluminum alloy material, which has good mechanical properties, waterproof performance, electromagnetic shielding performance, and is relatively light in weight. The polyethylene moderator 11 has a thickness of 5 cm or 7 cm, which can slow down the neutrons with high energy into thermal neutrons. In addition to the elastic and inelastic scattering interactions, part of the thermal neutrons can be absorbed in the NaIL crystal 13 to deposit energy and make it emit light. 6 Li(n,α) 3 H reaction to produce alpha particles and tritium nuclei and deposit 2.051 MeV and 2.735 MeV energy to make it emit light. Gamma rays in the NaIL crystal 13 deposit energy through photoelectric effect, Compton effect and electron pair effect to make it emit light. 6 Li(n,α) 3 The decay time of the alpha particles and tritium nuclei produced by the Li(n,α) H reaction in the NaIL crystal 13 and the decay time of the light emitted by other processes are obviously different.

[0031] The voltage division module in the photomultiplier tube base and front-end electronics part 15 provides working high voltage for the photomultiplier tube 14, which can convert optical signals into electrical signals. The preamplifier current sensitive amplification module in the photomultiplier tube base and front-end electronics part 15 further amplifies the electrical signals, and the obtained pulse waveform is related to the light emission decay time of the scintillator.

[0032] The back-end electronics part 16 provides working voltage for the photomultiplier tube base and front-end electronics part 15 through the connector and shielded cable, and obtains the electrical signals processed by the front-end electronics part. The back-end electronics part 16 can realize functions such as digital sampling of electrical signals, PSD value calculation, energy calibration, data storage, etc., and connects with the tablet computer 2 through the wireless communication antenna 5 and sends data to the tablet computer 2.

[0033] The battery compartment and lithium battery pack 17 are connected with the back-end electronics part 16 through the connector and wire, and provide working power supply. The waterproof aviation connector is connected with the back-end electronics part 16 through the connector and shielded cable, which can charge the detection device when the adapter (detection device) 10 is used, and the detection device supports battery-free adapter power supply operation.

[0034] The tablet computer 2 (with the necessary software pre-installed) plots a PSD-energy spectrum based on the PSD and energy values, enabling the identification of neutrons and gamma rays. The tablet computer 2 calculates and displays information such as neutron count rate, gamma ray count rate, gamma ray energy spectrum, and gamma dose rate. Based on the gamma dose rate and GPS information, the tablet computer 2 plots a dose rate distribution map, identifies the type and location of radiation sources, and provides audible and visual alarm functions.

[0035] The adapter (tablet) 7 is connected to the tablet computer 2 and charges the tablet computer 2. The tablet computer 2 supports operation without a battery adapter.

[0036] like Figure 4 As shown, when carrying the device in a backpack, the detection device 1, tablet computer 2, adapter, etc., are placed on the fixed position of the foam material 8, and then the entire device is placed in the backpack 9. The tablet computer can also be used individually by hand to observe measurement results and receive audible and visual alarm information.

[0037] The above provides a detailed description of a portable neutron-gamma detection system based on NaIL crystals provided by this patent. Specific examples have been used to illustrate the principles and implementation methods of this patent. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of this patent. Furthermore, those skilled in the art will recognize that modifications may be made to the specific implementation methods and application scope based on the ideas of this patent. Therefore, the content of this specification is only an embodiment of the present invention and does not limit the patent scope of this invention. Any equivalent structural or procedural transformations made using the content of this specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this invention and should not be construed as a limitation of this patent.

[0038] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A portable neutron-gamma detection system based on NaIL crystals, characterized in that: The system includes a detection device, a tablet computer, a stand, and a handle. The stand and handle are mounted on the detection device using multiple sets of fastening bolts and spring washers. The tablet computer is fixed to the stand using clips. The detection device consists of a housing, a polyethylene moderator, a NaIL crystal, a photomultiplier tube, a photomultiplier tube socket, front-end electronics, rear-end electronics, a battery compartment and lithium battery pack, and a wireless communication antenna. The polyethylene moderator is mounted on the housing using multiple sets of fastening bolts and spring washers. The NaIL crystal, photomultiplier tube, photomultiplier tube socket, and front-end electronics are encapsulated as a single unit, with the NaIL crystal completely inserted into the polyethylene moderator. The NaIL crystal is used as the detection element, and waveforms are realized based on the different luminescence characteristics of neutrons and gamma rays within the crystal. The photomultiplier tube socket and front-end electronics are mounted on the housing via multiple sets of fastening bolts and spring washers. The rear-end electronics, battery compartment, and lithium battery pack are also mounted on the housing via multiple sets of fastening bolts and spring washers. The wireless communication antenna and waterproof aviation connector are mounted on the housing via nuts, spring washers, and sealing rings. The photomultiplier tube socket and front-end electronics are connected to the rear-end electronics via connectors and shielded cables. The rear-end electronics are connected to the battery compartment and lithium battery pack via connectors and wires. The rear-end electronics are also connected to the wireless communication antenna via connectors and shielded cables. The front-end electronics uses only one current-sensitive preamplifier circuit, and the rear-end electronics uses only one digital sampling circuit.

2. The portable neutron-gamma detection system based on NaIL crystal according to claim 1, characterized in that: Polyethylene is used as the neutron moderator material, and the thickness of the moderator is 5 to 7 centimeters.

3. The portable neutron-gamma detection system based on NaIL crystal according to claim 1, characterized in that: The NaIL crystal, photomultiplier tube, photomultiplier tube socket, and front-end electronics are packaged as a whole and encased in a rubber sleeve for vibration damping.

4. The portable neutron-gamma detection system based on NaIL crystal according to claim 1, characterized in that: The detection device uses a waterproof aviation connector to connect with the adapter, which improves the environmental adaptability of the equipment. The back-end electronics are connected to the waterproof aviation connector through connectors and shielded cables.

5. The portable neutron-gamma detection system based on NaIL crystal according to claim 1, characterized in that: The detection device and the tablet computer communicate wirelessly via WIFI and Bluetooth.

6. The portable neutron-gamma detection system based on NaIL crystal according to claim 1, characterized in that: The tablet computer features a touchscreen display, speaker, multiple I / O interfaces, multiple function buttons, a high-capacity polymer lithium-ion battery, and an adapter. It also has WIFI, Bluetooth, 4G communication functions, a GPS module, and a Beidou module. The necessary software is pre-installed to perform the following functions: drawing PSD-energy spectrum, identifying neutrons and gamma rays, calculating and displaying neutron count rate, gamma ray count rate, gamma ray energy spectrum, and gamma dose rate information, drawing dose rate distribution map, identifying the type and location of radiation sources, and providing audible and visual alarms.

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