阅读说明：本技术 一种用于bnct仿真水模内部的热中子通量三维分布测量系统 (Thermal neutron flux three-dimensional distribution measuring system used inside BNCT simulation water model ) 是由 周斌 梁天骄 陈俊阳 唐彬 陈少佳 王修库 童剑飞 胡志良 傅世年 于 2021-08-03 设计创作，主要内容包括：本发明主要涉及硼中子俘获治疗技术领域,尤指一种用于BNCT仿真水模内部的热中子通量三维分布测量系统；一种用于BNCT仿真水模内部的热中子通量三维分布测量系统,所述的测量系统主要包括三轴扫描台、仿真水模、中子探测器和远程控制器,中子探测器连接在三轴扫描台上其探测端采用锂玻璃闪烁体。三轴扫描台可带动锂玻璃闪烁体伸入仿真水模内部并实现移动扫描,实时测量仿真水模中的热中子通量；本发明一方面用于验证BNCT装置的整体设计可靠性,另外,本发明还适用于BNCT质量控制与质量保证(QA/QC),可为开展精准治疗提供有利保障。(The invention mainly relates to the technical field of boron neutron capture treatment, in particular to a thermal neutron flux three-dimensional distribution measuring system used in a BNCT simulation water model; the utility model provides a three-dimensional distribution measurement system of thermal neutron flux for inside BNCT emulation water mould, measurement system mainly include triaxial scanning platform, emulation water mould, neutron detector and remote control ware, the detection end adopts the lithium glass scintillator on the triaxial scanning platform is connected to the neutron detector. The three-axis scanning table can drive the lithium glass scintillator to extend into the simulated water model and realize mobile scanning, and the thermal neutron flux in the simulated water model is measured in real time; the invention is used for verifying the reliability of the overall design of the BNCT device, is also suitable for BNCT quality control and quality assurance (QA/QC) and can provide favorable guarantee for developing accurate treatment.)

1. A three-dimensional distribution measurement system of thermal neutron flux for BNCT simulation inside water model is characterized in that: the measuring system mainly comprises a triaxial scanning table, a simulation water model, a neutron detector and a remote controller, wherein the neutron detector is connected to the triaxial scanning table, a detection end of the neutron detector is provided with a lithium glass scintillator, and the triaxial scanning table can drive the neutron detector to move.

2. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, wherein: under the drive of the triaxial scanning platform, the lithium glass scintillator of the neutron detector can extend into the simulated water model to realize mobile scanning, and the thermal neutron flux in the simulated water model is measured in real time.

3. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, wherein: the neutron detector consists of a lithium glass scintillator, optical fibers, a silicon photomultiplier, an electronics system and data acquisition and analysis software.

4. The system according to claim 3, wherein said system is used for measuring three-dimensional distribution of thermal neutron flux inside BNCT simulation water model, and is characterized in that: and the lithium glass scintillator is coated with an optical coupling agent and then is connected with the optical fiber.

5. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, 2, 3 or 4, wherein: the rear end of the lithium glass scintillator is coupled with an optical fiber, and the scintillating light is transmitted to the outside of the simulated water model through the optical fiber for optical signal processing.

6. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 4, wherein: after the lithium glass scintillator is coupled with the optical fiber, a layer of optical reflection material is coated on the periphery of the lithium glass scintillator, and then black organic glue is adopted for coating.

7. The system according to claim 3, wherein said system is used for measuring three-dimensional distribution of thermal neutron flux inside BNCT simulation water model, and is characterized in that: the silicon photomultiplier is used as a photoelectric converter.

8. The system according to claim 3, wherein said system is used for measuring three-dimensional distribution of thermal neutron flux inside BNCT simulation water model, and is characterized in that: the electronic system is internally integrated with modules such as a charge sensitive preamplifier, a pulse linear amplifier, an amplitude comparison discriminator, a mode electric converter and the like.

9. The system according to claim 8, wherein said system is used for measuring three-dimensional distribution of thermal neutron flux inside BNCT simulation water model, and comprises: the analog-to-digital converter converts the analog signal into a digital signal for transmitting to data acquisition and analysis software for data processing.

10. The system according to claim 3, wherein said system is used for measuring three-dimensional distribution of thermal neutron flux inside BNCT simulation water model, and is characterized in that: the data acquisition and analysis software is used for carrying out acquisition management, issuing configuration and analysis processing on working parameters converted into digital signals by the electronic system.

11. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, 2, 3 or 4, wherein: in the lithium glass scintillator⁶The Li abundance is 5-10%.

12. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, 2, 3 or 4, wherein: and the lithium glass scintillator is cut into particles with the size less than or equal to 4 cubic millimeters.

13. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, wherein: the three-axis scanning platform on be provided with the workstation, be provided with emulation water mould on the workstation, neutron detector is connected through scanning connecting rod and three-axis scanning platform and is installed in the top of emulation water mould.

14. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, wherein: the remote controller is connected with the three-axis scanning table through a control system.

15. The system according to claim 14, wherein said system is used for measuring three-dimensional distribution of thermal neutron flux inside a BNCT simulation water model, and comprises: the remote controller is a computer or a mobile phone.

16. The system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model according to claim 1, wherein: the triaxial moving mechanism of the triaxial scanning table is driven by a stepping motor, the stepping motor drives the triaxial moving mechanism to move in three directions of an X, Y, Z shaft, and the triaxial moving mechanism controls the scanning connecting rod to move so as to drive the neutron detector to adjust and move.

17. When the system for measuring the three-dimensional distribution of the thermal neutron flux inside the BNCT simulation water model is used for analog measurement and analysis, as claimed in claim 1, the system is characterized in that: the method mainly comprises the following steps:

s1, moving the neutron detector above the simulation water mold by the three-axis scanning platform, and placing the lithium glass scintillator at the detection end in the simulation water mold;

s2, BNCT generates neutrons to be incident into the simulation water mold, and the neutrons are moderated to be mixed with the neutrons in the lithium glass scintillator⁶Li generates a capture reaction to generate flare light;

s3, transmitting the scintillation light to a silicon photomultiplier outside the simulated water model by the optical fiber to perform photoelectric signal conversion;

s4, outputting the electric signal of the silicon photomultiplier to an electronic system for filtering, shaping, processing and amplifying;

s5, converting the analog signal into a digital signal by the electronic system, and processing the digital signal by data acquisition and analysis software;

s6; the data acquisition and analysis software is used for carrying out acquisition management, issuing configuration and analysis processing on working parameters converted into digital signals by the electronic system;

s7, the movement of the triaxial scanning table in the axial direction of XYZ is controlled through the remote controller, the movement of the neutron detector is driven, the neutron detector can move in the simulation water model to scan and measure the thermal neutron flux, and real-time visual display is realized.

Technical Field

The invention mainly relates to the technical field of boron neutron capture treatment, in particular to a thermal neutron flux three-dimensional distribution measuring system used in a BNCT simulation water model.

Background

At present, the energy of the neutron beam for treating Boron Neutron Capture Therapy (BNCT) device mainly covers 0.5eV-10keV, and after the neutron beam is incident to a human body, the epithermal neutrons interact with atomic nuclei such as C, H, O in superficial tissues to be converted into thermal neutrons which are then captured by boron-10 atoms with high enrichment degree in tumor cells, charged particles are released, and the tumor cells are killed. The thermal neutron flux represents the quotient of the number of thermal neutrons entering a sphere centered at a certain point in space, in any direction, at a given point location in time, divided by the maximum cross-sectional area of the sphere, in n/cm 2/s. When BNCT tumor treatment is carried out, the BNCT treatment planning system can accurately calculate treatment time by combining information such as distribution condition of thermal neutron flux in a human body phantom or a simulated water phantom, the position of a target area, boron-containing concentration and the like, protect normal tissue cells to the maximum extent and give enough radiation dose to the target area, thereby achieving the optimal treatment effect.

Based on this, in practical application, there is a need for a scanning measurement system for measuring and studying three-dimensional spatial distribution of thermal neutron flux in a simulated water model on a BNCT apparatus, and the current BNCT experimental measurement technology mainly focuses on two aspects: the concentration value and distribution of boron atoms in organisms are mainly concerned, and a plurality of patents and documents are focused on the problem for technical development, wherein medical instruments such as PET, CT and the like are mainly adopted for measurement research; there are also a few reports recording the use of scintillator array coupled fiber to detect the gamma rays with characteristic energy released by the interaction between boron atoms and neutrons in the organism to be treated, and deducing the boron concentration and distribution in the organism; and (3) adopting a solid track detector to carry out small-range area imaging on alpha and 7Li particles released by the reaction of neutrons and boron atoms so as to obtain the related technology of boron concentration and distribution thereof. In the second aspect, the technology development is mainly performed for BNCT quality control and quality assurance (QA/QC). Before the BNCT treatment is routinely performed, it is usually necessary to perform a strict and highly accurate measurement on the quality of the neutron beam output by the BNCT apparatus, so as to ensure that the actually generated neutrons of the BNCT apparatus are highly consistent with the neutron source items used by the treatment planning system. However, the QA/QC related technology for BNCT is not reported in patent at present, and only a lot of scientific papers discuss it. Research shows that the papers mainly research two aspects, one is that the neutron parameters are directly measured at the position of a BNCT beam leading-out hole, and the main measurement objects are neutron energy spectrum, flux and the like at the position of an outlet. However, as mentioned above, the neutrons generated by BNCT are mostly epithermal neutron beams with energy covering 0.5eV-10keV, and the direct measurement of neutron energy spectrum in this energy interval by the existing neutron detection technology has a great difficulty, and the error introduced by the measurement is generally large. In practice, a material with a large hydrogen content ratio, such as polyethylene and water, is used to slow the epithermal neutrons output by the device into thermal neutrons with relatively lower energy, and then the thermal neutron flux is measured by using the existing and mature thermal neutron detection technology, and then the epithermal neutron energy spectrum is obtained by using an inversion algorithm. However, the indirect measurement process usually needs to use a priori simulation information, and the measurement accuracy is very limited, so that it is difficult to properly meet the rigid requirement of high-accuracy measurement at present by directly developing QA/QC technical means at the extraction hole. In the second aspect, the QA/QC related measurement requirements are met by directly measuring the thermal neutron flux distribution in the human body simulation water model. Because the content of water in organisms is extremely high (the specific gravity of water in brain tissues exceeds 80 percent), when the interaction of the BNCT output beam and the organisms is researched, a water model with the size similar to the head shape of a human body is used for replacing internationally. Therefore, the characteristic BNCT device beam quality can be converted into the distribution of the measured neutron beams after the neutron beams enter the simulated water model for showing. As water is a good neutron moderating medium, the epithermal neutrons generated by the BNCT device are radiated into the water model and can be moderated into thermal neutrons, and the flux distribution in the simulated water model is measured by a relatively mature thermal neutron measurement technology, so that the quality of the BNCT neutron beam current can be accurately evaluated to a great extent. Most of the prior documents adopt off-line measurement methods (such as a gold wire activation method for measuring depth distribution and a copper foil activation method for measuring two-dimensional distribution), and the methods cannot display flux distribution in a simulated water mold on line in real time.

In summary, there is no technical means for measuring the three-dimensional distribution of thermal neutron flux in the simulated water model in real time in any current technology, patent or paper report.

Disclosure of Invention

In order to fill the technical blank of measuring the thermal neutron flux three-dimensional distribution in the simulated water model in real time, the invention aims to provide a thermal neutron flux three-dimensional distribution measuring system used in a BNCT simulated water model, which is used for measuring the thermal neutron flux three-dimensional distribution caused by the fact that a treatment beam output by a boron neutron capture treatment device is incident on a human body simulated water model in an online real-time manner.

The technical scheme adopted by the invention is as follows: the utility model provides a three-dimensional distribution measurement system of thermal neutron flux for BNCT emulation water mould is inside, measurement system mainly include triaxial scanning platform, emulation water mould, neutron detector and remote control ware, the neutron detector is connected its detection end adoption lithium glass scintillator on the triaxial scanning platform, the triaxial scanning platform can drive the neutron detector and remove.

Under the drive of the triaxial scanning platform, the lithium glass scintillator of the neutron detector can extend into the simulated water model to realize mobile scanning, and the thermal neutron flux in the simulated water model is measured in real time.

The neutron detector consists of a lithium glass scintillator, optical fibers, a silicon photomultiplier, an electronics system and data acquisition and analysis software.

And the lithium glass scintillator is coated with an optical coupling agent and then is connected with the optical fiber.

The rear end of the lithium glass scintillator is coupled with an optical fiber, and the scintillating light is transmitted to the outside of the simulated water model through the optical fiber for optical signal processing.

After the lithium glass scintillator is coupled with the optical fiber, a layer of optical reflection material is coated on the periphery of the lithium glass scintillator, and then black organic glue is adopted for coating.

The silicon photomultiplier is used as a photoelectric converter.

The electronic system is internally integrated with modules such as a charge sensitive preamplifier, a pulse linear amplifier, an amplitude comparison discriminator, a mode electric converter and the like.

The analog-to-digital converter converts the analog signal into a digital signal for transmitting to data acquisition and analysis software for data processing.

The data acquisition and analysis software is used for carrying out acquisition management, issuing configuration and analysis processing on working parameters converted into digital signals by the electronic system.

In the lithium glass scintillator⁶The Li abundance is 5-10%.

The lithium glass scintillator is cut into particles with the volume less than or equal to 4 cubic millimeters.

The three-axis scanning platform on be provided with the workstation, be provided with emulation water mould on the workstation, neutron detector is connected through scanning connecting rod and three-axis scanning platform and is installed in the top of emulation water mould.

The remote controller is connected with the three-axis scanning table through a control system.

The remote controller is a computer or a mobile phone.

The triaxial moving mechanism of the triaxial scanning table is driven by a stepping motor, the stepping motor drives the triaxial moving mechanism to move in three directions of an X, Y, Z shaft, and the triaxial moving mechanism controls the scanning connecting rod to move so as to drive the neutron detector to adjust and move.

When a thermal neutron flux three-dimensional distribution measuring system used in a BNCT simulation water model is used for analog measurement and analysis, the method mainly comprises the following steps:

s1, moving the neutron detector above the simulation water mold by the three-axis scanning platform, and placing the lithium glass scintillator at the detection end in the simulation water mold;

s2, BNCT generates neutrons to be incident into the simulation water mold, and the neutrons are moderated to be mixed with the neutrons in the lithium glass scintillator⁶Li generates a capture reaction to generate flare light;

s3, transmitting the scintillation light to a silicon photomultiplier outside the simulated water model by the optical fiber to perform photoelectric signal conversion;

s4, outputting the electric signal of the silicon photomultiplier to an electronic system for filtering, shaping, processing and amplifying;

s5, converting the analog signal into a digital signal by the electronic system, and processing the digital signal by data acquisition and analysis software;

s6; the data acquisition and analysis software is used for carrying out acquisition management, issuing configuration and analysis processing on working parameters converted into digital signals by the electronic system;

s7, the movement of the triaxial scanning table in the axial direction of XYZ is controlled through the remote controller, the movement of the neutron detector is driven, the neutron detector can move in the simulation water model to scan and measure the thermal neutron flux, and real-time visual display is realized.

The invention has the beneficial effects that: the invention provides a thermal neutron flux three-dimensional distribution measuring system used in a BNCT simulation water model, which is a thermal neutron flux three-dimensional distribution measuring system specially used for BNCT beam incident into the simulation water model, has the advantages of real-time display, high precision, high spatial resolution, low cost, convenience, rapidness, time saving and labor saving, can be applied to the daily QA/QC practice of a BNCT device, is used for verifying the integral design reliability of the BNCT device on one hand, and is also suitable for BNCT quality control and quality assurance (QA/QC) and can provide favorable guarantee for developing accurate treatment.

Drawings

Fig. 1 is a schematic diagram of the layout structure of the present invention.

FIG. 2 is a schematic view of a neutron detector according to the present invention.

FIG. 3 is a schematic diagram of the working logic of the neutron detector in the simulated water model.

Reference is made to the accompanying drawings in which: the method comprises the following steps of 1-a three-axis scanning table, 11-a servo motor, 12-a scanning connecting rod, 2-a simulation water model, 3-a neutron detector, 31-a lithium glass scintillator, 32-a reflecting material, 33-an optical coupling agent, 34-organic glue, 35-an optical fiber, 36-a silicon photomultiplier, a 4-electronics system and 5-data acquisition and analysis software.

Detailed Description

The utility model provides a three-dimensional distribution measurement system of thermal neutron flux for BNCT emulation water model 2 is inside, measurement system mainly include triaxial scanning platform 1, emulation water model 2, neutron detector 3 and remote control ware, neutron detector 3 is connected on triaxial scanning platform 1 and is set up in emulation water model 2 top, the detection end of neutron detector 3 adopts lithium glass scintillator 31, lithium glass scintillator 31 adopt⁶Li; the lithium glass scintillator 31 is cut into particles having a size of less than or equal to 2mm by 1 mm; the three-axis scanning table 1 can drive the lithium glass scintillator 31 to extend into the simulated water model 2 and realize mobile scanning, and the thermal neutron flux in the simulated water model 2 is measured in real time.

The neutron detector 3 consists of a lithium glass scintillator 31, an optical fiber 35, a silicon photomultiplier 36(SiPM), an electronics system 4 and data acquisition and analysis software 5; the lithium glass scintillator 31 is coated with the optical couplant 33 and then connected with the optical fiber 35, more specifically, the rear end of the lithium glass scintillator 31 is coupled with the optical fiber 35, and the scintillating light is transmitted to the outside of the simulated water model 2 through the optical fiber 35 for optical signal processing; meanwhile, after the lithium glass scintillator 31 is coupled with the optical fiber 35, a layer of optical reflection material 32 is coated on the periphery of the lithium glass scintillator, and then the lithium glass scintillator is coated with black organic glue 34.

The silicon photomultiplier 36 is used as a photoelectric converter; the electronic system 4 is internally integrated with modules such as a charge sensitive preamplifier, a pulse linear amplifier, an amplitude comparison discriminator, a mode electric converter and the like; the analog-to-digital converter converts the analog signal into a digital signal for transmitting to the data acquisition and analysis software 5 for data processing; the data acquisition and analysis software 5 performs acquisition management, distribution configuration and analysis processing on the working parameters converted into digital signals by the electronic system 4.

As the neutron flux output by the BNCT device is higher, the neutron flux can reach 1E +09n/cm²At the level of/s, to avoid large errors due to pulse pile-up, the lithium glass neutron detector 3 employed in the present invention, on the one hand, needs to reduce the overall size of the lithium glass scintillator 31 in the measurement system as much as possible, so that the lithium glass scintillator 31 is cut into particles with a size of 2mm 1mm or less, thus reducing the amount of thermal neutron converting material [ in ] thereof⁶Li atom]The total number of atoms, thereby reducing the thermal neutron detection efficiency of the scintillator, and in addition, the small-size design can also bring more ideal effect for realizing better spatial resolution of the measuring device, and can further reduce the sensitivity to gamma rays; on the other hand, it is also necessary to select a natural abundance⁶Li[7.5％]The glass scintillator further reduces the detection efficiency and ensures that the neutron detector 3 is in a normal pulse working mode; in the present invention, the lithium glass scintillator 31 is purchased from the lithium glass manufactured by the Scintacor company and having the model number GS1, the mass percentage of lithium is 2.4%, the wavelength of scintillation light is 395nm, and in order to meet the use requirement, the lithium glass scintillator 31 is cut into small particles with the size of less than or equal to 2mm 1mm, and is connected with the optical fiber 35 after being coated with a small amount of optical coupling agent 33.

The remote controller is connected with the three-axis scanning table 1 through a control system; the remote controller is a computer or a mobile phone; the three-axis scanning table 1 is provided with a workbench, the workbench is provided with a simulation water model 2, and the neutron detector 3 is connected with the three-axis scanning table 1 through a scanning connecting rod 12 and is arranged above the simulation water model 2; the three-axis moving mechanism of the three-axis scanning table 1 is driven by a stepping motor 11, the stepping motor 11 drives the three-axis moving mechanism to move in three directions of an X, Y, Z axis, and the three-axis moving mechanism controls a scanning connecting rod 12 to move so as to drive the neutron detector 3 to adjust and move; when a thermal neutron flux three-dimensional distribution measuring system used in a BNCT simulation water model 2 is adopted for analog measurement and analysis, the method mainly comprises the following steps:

s1, placing the whole triaxial scanning table 1 in an irradiation room, connecting the whole triaxial scanning table 1 with a remote controller outside the irradiation room through a network cable, controlling a moving mechanism on the triaxial scanning table 1 through the remote controller, moving the neutron detector 3 to the position above the simulated water model 2, and placing the lithium glass scintillator 31 at the detection end in the simulated water model 2;

s2, BNCT generates neutrons which are incident into the simulated water model 2 and are moderated with the neutrons in the lithium glass scintillator 31⁶Li is subjected to a capture reaction; neutrons generated by BNCT enter the simulated water model 2, are gradually moderated and are mixed with the neutrons in the lithium glass scintillator 31⁶Li is subjected to trapping reaction, charged particles are released by the reaction to excite substances in the scintillator to enable the substance to emit scintillation light, and the scintillator is arranged inside the simulated water model 2, so that the optical fiber 35 is coupled to the rear end of the scintillator to avoid short circuit caused by contact of a photoelectric device and water and performance reduction caused by irradiation effect of a high-intensity neutron beam flow excited light-emitting device.

S3, transmitting the scintillation light to the silicon photomultiplier 36 outside the simulated water model 2 through the optical fiber 35 for optical signal processing; the fiber 35 is followed by a photoelectric conversion device, in the present invention a silicon photomultiplier 36, to convert the scintillation light signal to a weak electrical signal.

S4, the silicon photomultiplier 36 outputs the processed optical signal to the electronic system 4 for filtering, shaping, processing and amplifying; conventional photomultiplier tubes tend to have large end window areas requiring the deployment of a high voltage power supply of about 1kV, and in the present invention, the cross-sectional area of the small-sized scintillator-coupled optical fiber 35 is small, thus abandoning the conventional photomultiplier tube approach. In contrast, the silicon photomultiplier 36[ SiPM ] has the advantages of compact structure, small volume, large gain, low operating voltage, fast time response, etc., and it is selected as a photoelectric converter device in the present invention, which successfully reduces the overall size of the measurement system, thereby improving portability.

S5, the electronic system 4 converts the analog signal into a digital signal, and the digital signal is processed by the data acquisition and analysis software 5; the electronic system 4 is internally integrated with modules such as a charge sensitive preamplifier, a pulse linear amplifier, an amplitude comparison discriminator, an analog-to-digital converter (ADC) and the like, wherein the preamplifier is used for pre-amplifying an electric signal and realizing impedance matching and conversion, the charge sensitive preamplifier has better voltage amplitude stability, and the pulse linear amplifier is used for further amplifying the electric signal and shaping a small amount of accumulated signals formed by the preamplifier; the amplitude comparison discriminator eliminates the noise signal and the gamma signal through the discrimination and comparison of the amplitude of the electric signal; the analog to digital converter converts the analog signal to a digital signal for subsequent processing by data acquisition and analysis software 5.

S6; the data acquisition and analysis software 5 performs acquisition management, issuing configuration and analysis processing on the working parameters converted into digital signals by the electronic system 4; the data acquisition and analysis software 5 is mainly used for providing matched software for the electronic system 4, and the functions of the data acquisition and analysis software include management and issuing configuration of working parameters (such as threshold values, working modes, operation control and the like) of the electronic system 4, and receiving, caching, unpacking, analysis and reconstruction, storage, online real-time neutron flux display and the like of neutron case data uploaded by the electronic system 4.

S7, the movement of the triaxial scanning table 1 in the XYZ axial direction is controlled through a remote controller to drive the neutron detector 3 to move, so that the neutron detector 3 can move in the simulated water model 2 to scan and measure the thermal neutron flux, and real-time visual display is realized; the brother specifically is through the axial removal in XYZ of the moving mechanism of remote control ware control triaxial scanning platform 1 to drive the removal of neutron detector 3, and realize debugging the position of neutron detector 3 through the position of debugging triaxial scanning platform 1, make the lithium glass scintillation 31 of neutron detector 3 detection end can stretch into emulation water mould 2, realize the mobile scanning, in fact through the neutron detector 3 system that lithium glass scintillation 31, optic fibre 35, silicon photomultiplier 36, electronics system 4 and data acquisition analysis software 5 constitute can realize measuring in real time the hot neutron flux in emulation water mould 2, and realize real-time visual display.

The moving mechanism in the triaxial scanning table 1 is driven by a stepping motor 11 and is connected with a remote controller through a network cable to realize remote control, the remote controller can be a computer or a mobile terminal such as a mobile phone and the like and is placed outside an irradiation room, an operator can remotely control the moving mechanism in the triaxial scanning table 1 in the irradiation room through the remote controller outside the irradiation room under the condition that equipment normally operates, the movement of a scanning connecting rod 12 in the triaxial scanning table 1 is driven to drive a neutron detector 3 to move, the movement stroke of the triaxial scanning table 1 is greater than 200mm, and the movement control precision is superior to 0.1 mm.

When the system is used for carrying out analog measurement and analysis on the thermal neutron flux three-dimensional distribution measurement system, the neutron detector 3 detector of the small-size lithium glass scintillator 31 is arranged in the simulated water model 2, the rear end of the simulated water model is connected with the optical fiber 35 to transmit a scintillation light signal of the lithium glass scintillator 31, and a weak point signal obtained after photoelectric conversion of SiPM is processed by the electronic system 4 and then is transmitted to a computer outside an irradiation chamber through a network cable to be displayed. Meanwhile, the neutron detector 3 is connected with the scanning connecting rod 12 of the triaxial scanning platform 1, and the motion of the triaxial scanning platform 1 is controlled through a remote computer, so that the scanning connecting rod 12 also moves simultaneously to drive the motion of the neutron detector 3, and the real-time three-dimensional measurement and display of the thermal neutron flux inside the simulation water model 2 are realized in the mode.

In the specific implementation of the present invention, the lithium glass scintillator 31 selected in the embodiment has a small size, and is coated with the black organic glue 34 after being coupled with the optical fiber 35 and coated with the optical reflective material 32 on the periphery, so that on one hand, the noise count caused by the transmission of visible light into the optical fiber 35 and to the SiPM is avoided, and at the same time, the water-blocking effect is achieved. The scintillator and optical fiber 35 coupling body is soaked in the water mould and driven by the scanning connecting rod 12 to move. The scintillator of the neutron detector 3 was purchased from lithium glass manufactured by Scintacor, model GS1, the mass percentage of lithium was 2.4%, and the wavelength of scintillation light was 395 nm. To meet the requirements of use, the lithium glass scintillator 31 is cut into small particles with a size of 2mm by 1mm, and is connected to the optical fiber 35 by coating a small amount of optical coupling agent 33. Optical fiber 35 was purchased from Mitsubishi corporation as model MH4002-500, with an optical fiber 35 core diameter of 980 microns, a cladding diameter of 1000 microns, an NA value of 0.3(650nm), and a bandwidth of-3 dB. The length of the optical fiber 35 is selected to be 200cm, so that electronic equipment at the rear end is far away from a radiation source, and the electronic equipment is prevented from being damaged by BNCT high-flux neutron beam. The photoelectric device SiPM is produced by Sensl company and has the model of MicroFC30035, the photon detection efficiency is 28 percent, and the gain is 2.8E + 5A/W. The three-dimensional scanning table drives the coupling body of the lithium glass scintillator 31 and the optical fiber 35 to perform scanning movement in the water film, the three-axis movement stroke is larger than 200mm, the movement control precision is superior to 0.1mm, the driven stepping motor 11 is a 57 series stepping motor 11, the operation speed can be selected, and the selectable speed range is 10-70 mm/s.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, and those skilled in the art may make modifications and variations within the spirit of the present invention, and all modifications, equivalents and modifications of the above embodiments according to the technical spirit of the present invention are within the scope of the present invention.