A two-dimensional array detector for neutron and photon spatial distribution measurements

Abstract

This invention relates to the field of nuclear radiation detection technology and discloses a two-dimensional array detector for measuring the spatial distribution of neutrons and photons. The detector body includes a detector body comprising a detection unit layer, a light guide layer, and a readout layer. The detection unit layer, light guide layer, and readout layer are vertically stacked sequentially from top to bottom to form a three-layer modular integrated structure. The layers are precisely mechanically aligned and optically coupled without air gaps. The light guide layer is composed of an array of multiple optical fibers. The detection unit layer is composed of an array of multiple detection units, with each detection unit corresponding to one optical fiber. This invention offers advantages such as modularity, high spatial resolution, and real-time signal processing. It can be applied to the measurement of the spatial distribution of neutrons and photons in the field of boron neutron capture therapy, meeting the practical needs of online real-time measurement of the spatial distribution of the neutron-photon mixed radiation field and accurate verification of the treatment irradiation field dose in boron neutron capture therapy.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation detection technology, and more specifically to a two-dimensional array detector for measuring the spatial distribution of neutrons and photons. Background Technology

[0002] In the implementation and verification of boron neutron capture therapy, due to the presence of a mixed radiation field of neutrons and photons, both types of radiation contribute to the final therapeutic dose to the patient. Therefore, it is necessary to accurately measure the spatial distribution of neutrons and photons separately, which places extremely high demands on the spatial resolution, neutron-photon resolution, response speed, and anti-interference capability of the detector.

[0003] Among existing detection technologies, common detectors used for the spatial distribution of photons include LiCAF scintillation detectors (Eu:LiCaAlF6), diamond detectors, activated foils, boron-coated ionization chambers, dual ionization chambers, fission ionization chambers, BF3 proportional counters, thermoluminescent detectors, and EBT films.

[0004] Among these methods, activated foil, thermoluminescent detectors, and EBT film are offline processing methods, which are complex, cumbersome, and time-consuming. Boron-coated ionization chambers, fission ionization chambers, and BF3 proportional counters are bulky and have poor spatial resolution. Dual ionization chambers can be used to measure the spatial distribution of medium photon dose, but most dual ionization chambers are of the gas flow type, which is cumbersome to operate and has poor spatial resolution. LiCAF scintillation detectors and diamond detectors have small probe sizes and good spatial resolution, making them the preferred detectors for online measurement of medium photon spatial distribution.

[0005] As nuclear radiation detection technology iterates towards modularization, digitalization, and high precision, the pain points of traditional detection technologies are becoming increasingly apparent: offline measurement processes are complex, cumbersome, and time-consuming; detectors are large in size and have poor spatial resolution; and most detectors lack photon resolution capabilities. Summary of the Invention

[0006] This invention provides a two-dimensional array detector for measuring the spatial distribution of neutrons and photons, which can effectively solve the technical defects of existing equipment such as offline detection lag, poor spatial resolution, difficulty in distinguishing mixed field signals, large measurement error and weak anti-interference ability.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0008] A two-dimensional array detector for measuring the spatial distribution of neutrons and photons includes: a detector body; the detector body includes a detection unit layer, an optical guide layer and a readout layer, wherein the detection unit layer, the optical guide layer and the readout layer are vertically stacked in a top-to-bottom order to form a three-layer modular integrated structure, wherein the layers are precisely mechanically aligned and optically coupled without air gaps;

[0009] The optical guide layer is composed of an array of multiple optical fibers;

[0010] The detection unit layer is composed of an array of multiple detection units, each detection unit corresponding to one optical fiber; each detection unit includes: a substrate, fixed directly above the corresponding optical fiber; a Li-6 micro scintillator, fixed directly above the substrate; and an encapsulation layer, fixed directly above and outside the Li-6 micro scintillator.

[0011] In the detection unit layer, multiple Li-6 micro scintillators are arranged in a regular matrix to form a 600×600 pixel detection array, corresponding to an effective detection area of ​​60cm×60cm. The size of a single Li-6 micro scintillator is matched with the array spacing, enabling a single pixel to have millimeter-level spatial resolution. The Li-6 micro scintillators are configured to synchronously respond to incident neutrons and photons and generate scintillating light signals.

[0012] In the optical guide layer, each optical fiber corresponds to a pixel, and the incident end face of the optical fiber and the light-emitting surface of the corresponding Li-6 micro scintillator are coupled point-to-point without air gap.

[0013] The readout layer is configured with a multi-channel digital front-end electronics system, which integrates a silicon photomultiplier tube array. Each channel of the silicon photomultiplier tube array is coupled to the output end of one of the optical fibers to complete the conversion of optical signals to electrical pulse signals and full-channel parallel synchronous readout and real-time digital sampling, so as to obtain full digital pulse information containing pulse shape characteristics and pulse amplitude characteristics.

[0014] The multi-channel digital front-end electronics system also integrates a pulse shape discrimination module and a pulse amplitude discrimination module. The pulse amplitude discrimination module sets multiple thresholds based on the difference in pulse amplitude distribution of neutron-photon signals to perform primary discrimination of pulse signals. The pulse shape discrimination module performs secondary coincidence selection of the signals after primary discrimination based on the difference in the decay time constant of the scintillation pulses generated by neutron and photon signals in the Li-6 micro scintillator. The neutron-photon pulse shape discrimination module and the pulse amplitude discrimination module work together online to distinguish between neutron signals and photon signals, so as to synchronously and independently acquire the two-dimensional spatial distribution count data of neutrons and photons respectively.

[0015] Furthermore, the substrate of the detection unit layer is made of an optically transparent low-gamma-response organic polymer material and serves as the carrier substrate for the entire detection array. All Li-6 micro scintillators are regularly positioned and fixed at preset array points on the upper surface of the substrate. The encapsulation layer fully covers the sidewalls and non-light-emitting areas of the upper surface of the corresponding Li-6 micro scintillators. Each Li-6 micro scintillator is isolated and protected by an independent encapsulation layer. The substrate is used to reduce the interference noise of its own substrate on the photon detection signal, and the encapsulation layer is used to avoid optical crosstalk between adjacent detection units and mechanical displacement deviation caused by long-term use.

[0016] Furthermore, the Li-6 micro scintillator is made of Eu:LiCaAlF6 inorganic scintillator crystal material, and the external dimensions of a single Li-6 micro scintillator are set to 1mm×1mm×0.5mm, with the array pixel spacing uniformly set to 1mm. The light-emitting surface of the Li-6 micro scintillator facing the optical fiber is optically polished and coated with an anti-reflection film. Through size matching and optical surface treatment, the millimeter-level spatial resolution of the detector body is stably guaranteed, and the coupling efficiency of the scintillator light signal output is improved simultaneously.

[0017] Furthermore, the optical fibers of the optical guide layer are all made of high-density silica optical fiber, with a single fiber outer diameter of <1.0mm. All optical fiber arrays adopt an integrated molding structure of potting and curing. The overall size of the cured optical fiber array is completely matched with the effective detection area of ​​the detection unit layer. Long-term operation can effectively avoid structural defects such as misalignment, detachment, and loosening, ensuring the stability of optical signal transmission. The overall optical signal collection efficiency of the optical guide layer is not less than 85%, and it can stably realize low-loss directional transmission of scintillation optical signals between the detection unit layer and the readout layer.

[0018] Furthermore, the multi-channel digital front-end electronics system of the readout layer incorporates a signal conditioning unit, a high-speed ADC sampling unit, and a main control processing unit. The signal conditioning unit interfaces with the output of the silicon photomultiplier tube array and is used to amplify, shape, reduce noise, and perform baseline correction preprocessing on the raw electrical pulse signal after photoelectric conversion. The high-speed ADC sampling unit is used to synchronously acquire complete pulse amplitude data and waveform feature data. The main control processing unit is used to perform real-time pulse parameter extraction, detection data buffering, high-speed data transmission, and overall control of the entire detector body.

[0019] Furthermore, both the pulse shape discrimination module and the pulse amplitude discrimination module adopt a hardware-embedded integrated design and are built into the multi-channel digital front-end electronics system; the total signal processing delay of the pulse shape discrimination module and the pulse amplitude discrimination module working together is ≤1μs, the pulse response speed of the detector body is ≤100ns, the dual discrimination modules perform real-time hardware calculation and processing throughout the process, and are equipped with real-time readout and display functions in software, which is suitable for uninterrupted real-time online measurement of neutron and photon mixed fields.

[0020] Furthermore, the detector body is equipped with a dedicated two-dimensional spatial distribution reconstruction algorithm program for neutrons and photons. The reconstruction algorithm program is pre-installed in the host computer readout software of the detector body. The reconstruction algorithm program has built-in full-process data preprocessing logic for pixel coordinate accurate mapping, dead pixel correction, channel crosstalk correction, gain normalization calibration and temperature drift dynamic correction, which can independently and accurately reconstruct the two-dimensional spatial distribution map of neutrons and the two-dimensional spatial distribution map of photons.

[0021] Furthermore, the spatial distribution reconstruction algorithm supports pseudo-color rendering of detection data, automatic plotting of dose lines in the radiation field, and visualization display of multimodal fusion of neutron and photon dual radiation fields. The measurement data output by the algorithm reconstruction can be directly connected to the treatment control system, providing core data support for accurate dose monitoring during boron neutron capture therapy.

[0022] Furthermore, the overall dimensions of the detector body are set at 62cm×62cm×5cm. The whole machine adopts a fully modular and detachable assembly structure. The detection unit layer, optical guide layer, and readout layer can all be independently disassembled, inspected, replaced, and maintained. The detector body has strong resistance to electromagnetic interference, radiation, and aging, and is suitable for long-term continuous and stable operation in the complex and strong radiation working environment of boron neutron capture therapy.

[0023] Furthermore, the detector body is suitable for online real-time measurement of the spatial distribution of neutron-photon mixed radiation field and accurate verification of treatment irradiation field dose in boron neutron capture therapy scenarios.

[0024] The above-described solution of the present invention has at least the following beneficial effects:

[0025] Compared to traditional neutron and photon detection devices, this invention effectively addresses the shortcomings of existing devices in terms of hardware structure, signal processing, data reconstruction, and operational condition adaptation. These shortcomings include lagging offline detection, poor spatial resolution, difficulty in distinguishing mixed field signals, large measurement errors, and weak anti-interference capabilities. By adopting a three-layer vertically stacked modular integrated structure consisting of a detection unit layer, an optical guide layer, and a readout layer, it overcomes the defects of traditional split devices, such as loose structure, complex maintenance, and susceptibility to mechanical displacement and signal crosstalk. The overall structure is stable and easy to disassemble and repair. Through a 600×600 high-density Li-6 micro scintillator pixel array, it achieves millimeter-level ultra-high spatial resolution while covering a large effective detection area of ​​60cm×60cm, accurately capturing subtle differences in local dose distribution in the radiation field and solving the problem of insufficient measurement accuracy of traditional detectors. The device integrates hardware-embedded pulse shape discrimination and pulse amplitude discrimination dual-level joint recognition technology, relying on quantized discrimination thresholds to perform two-level selection of neutron and photon signals, effectively suppressing mixed radiation fields. Despite signal interference, the device independently and accurately outputs two-dimensional spatial distribution counting data of two types of radiation without requiring secondary offline software processing. Equipped with built-in multiple error correction logic and a dedicated reconstruction algorithm, it corrects measurement errors caused by hardware deviations, pixel crosstalk, and temperature drift, accurately reconstructing two-dimensional radiation distribution maps of neutrons and photons and supporting multimodal visualization. The measurement data can be directly connected to the treatment control system. The device features fast pulse response and low signal processing latency, enabling continuous real-time online monitoring of the radiation field, avoiding the drawbacks of offline detection data lag. Furthermore, the device exhibits excellent resistance to electromagnetic interference and radiation aging, making it suitable for long-term stable operation under complex and intense radiation conditions. The detector itself boasts modularity, high spatial resolution, and real-time signal processing capabilities, making it applicable to neutron and photon spatial distribution measurement scenarios in boron neutron capture therapy. It meets the practical needs of online real-time measurement of the spatial distribution of mixed neutron-photon radiation fields and accurate verification of treatment field doses in clinical boron neutron capture therapy, effectively improving treatment accuracy and clinical safety. Attached Figure Description

[0026] Figure 1 A schematic diagram of the overall three-layer modular design of a two-dimensional array detector for measuring the spatial distribution of neutrons and photons, provided for an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the detection unit structure of a two-dimensional array detector for measuring the spatial distribution of neutrons and photons, provided as an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] In the figure: 1. Detector layer; 11. Substrate; 12. Li-6 micro scintillator; 13. Encapsulation layer; 2. Optical guide layer; 21. Optical fiber; 3. Readout layer. Detailed Implementation

[0030] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0031] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a two-dimensional array detector for measuring the spatial distribution of neutrons and photons, comprising: a detector body; the detector body includes a detection unit layer 1, an optical guide layer 2, and a readout layer 3, wherein the detection unit layer 1, the optical guide layer 2, and the readout layer 3 are stacked vertically in a top-to-bottom order to form a three-layer modular integrated structure, wherein the layers are precisely mechanically aligned and optically coupled without air gaps.

[0032] The light guide layer 2 is composed of an array of multiple optical fibers 21; the detection unit layer 1 is composed of an array of multiple detection units, each detection unit corresponding to one optical fiber 21; each detection unit includes: a substrate 11, fixed directly above the corresponding optical fiber 21; a Li-6 micro scintillator 12, fixed directly above the substrate 11; and an encapsulation layer 13, fixed directly above and outside the Li-6 micro scintillator 12.

[0033] In the detection unit layer 1, multiple Li-6 micro scintillators 12 are arranged in a regular matrix to form a 600×600 pixel detection array, corresponding to an effective detection area of ​​60cm×60cm. The size of a single Li-6 micro scintillator 12 is matched with the array spacing, so that a single pixel has millimeter-level spatial resolution. The Li-6 micro scintillators 12 are configured to synchronously respond to incident neutrons and photons and generate scintillating light signals.

[0034] In the light guide layer 2, each optical fiber 21 corresponds to a pixel, and point-to-point optical coupling without air gap is implemented between the incident end face of the optical fiber 21 and the light emitting surface of the corresponding Li-6 micro scintillator 12.

[0035] The readout layer 3 is configured with a multi-channel digital front-end electronics system, which integrates a silicon photomultiplier tube array. Each channel of the silicon photomultiplier tube array is coupled to the output end of an optical fiber 21 to complete the conversion of optical signals to electrical pulse signals and the parallel synchronous readout and real-time digital sampling of all channels to obtain full digital pulse information containing pulse shape characteristics and pulse amplitude characteristics.

[0036] The multi-channel digital front-end electronics system also integrates a pulse shape discrimination module and a pulse amplitude discrimination module. The pulse amplitude discrimination module sets multiple thresholds based on the difference in pulse amplitude distribution between neutron and photon signals to perform primary discrimination of the pulse signals. The pulse shape discrimination module performs secondary coincidence selection of the signals after primary discrimination based on the difference in the decay time constant of the scintillation pulses generated by the neutron-photon signals in the Li-6 micro scintillator 12. The pulse shape discrimination module and the pulse amplitude discrimination module work together online to distinguish between neutron and photon signals, so as to synchronously and independently acquire the two-dimensional spatial distribution count data of neutrons and photons respectively.

[0037] Specifically, neutrons and photons in the neutron-gamma mixed radiation field are incident from different directions onto the surface of the detector unit layer 1, penetrate the encapsulation layer 13, and enter the interior of the Li-6 micro scintillator 12. The Li-6 atomic nuclei in the Li-6 micro scintillator 12 undergo nuclear reactions with the neutrons, producing charged particles that deposit energy in the crystal. Photons, on the other hand, deposit energy in the crystal through Compton scattering or the photoelectric effect. Both types of particles excite the scintillator crystal to emit scintillation fluorescence. The scintillation fluorescence exits downwards from the light-emitting surface of the Li-6 micro scintillator 12, couples into the interior of the corresponding optical fiber 21 through the incident end face in the optical guide layer 2, and propagates longitudinally along the optical fiber 21 to the readout layer 3. Each channel of the silicon photomultiplier tube array in the readout layer 3 synchronously receives the optical signal output from the corresponding optical fiber 21, converts the optical signal into an electrical pulse signal, and the multi-channel digital front-end electronics system performs parallel synchronous readout and real-time digital sampling across all channels, forming fully digital pulse information containing pulse shape and amplitude characteristics. The pulse amplitude discrimination module sets multiple thresholds based on the differences in pulse amplitude distribution between neutron and photon signals to perform primary discrimination of pulse signals. The pulse shape discrimination module performs secondary coincidence selection on the signals after primary discrimination based on the differences in the decay time constants of scintillation pulses generated by neutron and photon signals in the Li-6 micro scintillator, filtering out residual signals that match the characteristics of photon amplitude distribution, and finally outputs neutron two-dimensional spatial distribution count data and photon two-dimensional spatial distribution count data synchronously and independently.

[0038] In another preferred embodiment of the present invention, the substrate 11 of the detection unit layer 1 is made of an optically transparent low-gamma-response organic polymer material and serves as the carrier substrate for the entire detection array. All Li-6 micro scintillators 12 are regularly positioned and fixed at preset array points on the upper surface of the substrate 11. The encapsulation layer 13 fully covers the sidewalls and non-light-emitting areas of the upper surface of the corresponding Li-6 micro scintillators 12. Each Li-6 micro scintillator 12 is isolated and protected by an independent encapsulation layer 13. The substrate 11 is used to reduce the interference noise of its own substrate on the photon detection signal, and the encapsulation layer 13 is used to avoid optical crosstalk between adjacent detection units and mechanical displacement deviation caused by long-term use.

[0039] The Li-6 micro scintillator 12 is made of Eu:LiCaAlF6 inorganic scintillator crystal material. The dimensions of a single Li-6 micro scintillator 12 are set to 1mm×1mm×0.5mm, and the pixel spacing of the array is uniformly set to 1mm. The light-emitting surface of the Li-6 micro scintillator 12 facing the optical fiber 21 is optically polished and coated with an anti-reflection film. Through size matching and optical surface treatment, the millimeter-level spatial resolution of the detector body is stably guaranteed, and the coupling efficiency of the scintillator light signal output is improved simultaneously.

[0040] Specifically, in the fabrication process of the detector unit layer 1, a low-gamma-response organic polymer material is first processed into a substrate 11 with a regular array of 600×600 dots, with a center-to-center spacing of 1 mm between each dot. Li-6 micro-scintillators 12, after optical polishing and antireflection coating, are then placed one by one into the corresponding array dots on the upper surface of the substrate 11. A precision mounting process ensures that the light-emitting surface of each Li-6 micro-scintillator 12 faces the incident end face of the corresponding optical fiber 21 below the substrate 11. After each Li-6 micro-scintillator 12 is fixed, an encapsulation layer 13 is coated on the sidewalls and non-light-emitting areas of the upper surface. After curing, the encapsulation layer 13 forms an independent optical isolation barrier. The low gamma response characteristics of the substrate 11 mean that almost no additional scintillation signal is generated when photons are incident on the substrate 11 material itself. The isolation structure of the encapsulation layer 13 prevents the scintillation fluorescence emitted by the adjacent Li-6 micro scintillators 12 from lateral crosstalk into the incident end face of the adjacent optical fiber 21, while firmly locking each Li-6 micro scintillator 12 in a preset position on the substrate 11, so that no micron-level displacement occurs under long-term irradiation.

[0041] In another preferred embodiment of the present invention, the optical fibers of the optical guide layer are all made of high-density silica optical fiber, with a single fiber outer diameter of <1.0mm. All optical fiber arrays adopt an integrated molding structure of potting and curing. The overall size of the cured optical fiber array is completely matched with the effective detection area of ​​the detection unit layer. Long-term operation can effectively avoid structural defects such as misalignment, detachment, and loosening, and ensure the stability of optical signal transmission. The overall optical signal collection efficiency of the optical guide layer is not less than 85%, and the low-loss directional transmission of scintillation optical signal between the detection unit layer and the readout layer is stably realized.

[0042] Specifically, the point-to-point optical coupling between the incident end face of the high-density silica fiber 21 and the emitting surface of the Li-6 micro scintillator 12 ensures that almost all of the scintillation fluorescence emitted from the crystal enters the numerical aperture angle range of the fiber. The fiber 21, with a core diameter of 0.8mm to 1.0mm, achieves both flexible arrangement and mechanical strength while completely covering the 1mm × 1mm scintillator emitting surface. An integrated potting and curing process fixes 360,000 fibers 21 within the array coordinate system, with each fiber 21's spatial position precisely aligned with its corresponding detection unit. The curing material fills the gaps between the fibers 21, forming a rigid overall structure that eliminates micro-displacements caused by vibration or thermal expansion and contraction. The optical signal is transmitted within the fiber 21 via total internal reflection, keeping transmission loss at a low level, ultimately stabilizing the overall collection efficiency of the light guide layer 2 at over 85%.

[0043] In another preferred embodiment of the present invention, the multi-channel digital front-end electronics system of readout layer 3 has a built-in signal conditioning unit, a high-speed ADC sampling unit, and a main control processing unit. The signal conditioning unit is connected to the output terminal of the silicon photomultiplier tube array and is used to amplify, shape, reduce noise, and perform baseline correction preprocessing on the original electrical pulse signal after photoelectric conversion. The high-speed ADC sampling unit is used to synchronously acquire pulse full amplitude data and waveform feature data. The main control processing unit is used to complete pulse parameter extraction, detection data buffering, high-speed data transmission, and overall control of the entire detector body in real time.

[0044] Specifically, the raw electrical pulse signal output from the corresponding channel of the silicon photomultiplier tube array for each radiation event in the mixed neutron and photon radiation field first enters the signal conditioning unit for pre-amplification and pulse shaping. This enhances the weak single-photon pulse to a voltage amplitude range suitable for sampling, while suppressing high-frequency noise components and correcting baseline drift. The shaped pulse signal is then sent to the high-speed ADC sampling unit, where analog-to-digital conversion is performed throughout the pulse's rising edge, flat-top, and falling edge at a sufficiently high sampling rate, completely recording the pulse amplitude peak and decay time curves. The main control processing unit extracts the arrival time, area integral, peak amplitude, and decay constant parameters of each pulse from the sampled data stream, packages these parameters into a buffer, and transmits them to the host computer via a high-speed data interface according to a preset timing sequence. Simultaneously, it receives control commands from the host computer to dynamically adjust the sampling parameters and discrimination thresholds.

[0045] In another preferred embodiment of the present invention, both the pulse shape discrimination module and the pulse amplitude discrimination module adopt a hardware-embedded integrated design and are built into the multi-channel digital front-end electronics system; the total signal processing delay of the pulse shape discrimination module and the pulse amplitude discrimination module working together is ≤1μs, the overall pulse response speed of the detector body is ≤100ns, the dual discrimination modules perform real-time hardware calculation and processing throughout the process, and are equipped with the real-time readout display function of the software, which is suitable for uninterrupted real-time online measurement of neutron and photon mixed fields.

[0046] Specifically, after the pulse shape discrimination module outputs the classification results, the pulse amplitude discrimination module further performs multi-threshold conformance selection on the signal amplitude to eliminate misclassification events caused by detector noise or edge effects. The pulse shape discrimination module performs real-time decay time constant calculation at the hardware logic level. Utilizing the difference between the longer scintillation decay time of neutron signals and the shorter decay time of photon signals in Eu:LiCaAlF6 crystals, it compares the decay constant of each pulse with a preset discrimination curve to complete the initial classification of neutrons and photons. The hardware-embedded design allows the discrimination operation to be executed in parallel in a pipelined manner within the FPGA or dedicated integrated circuit, without relying on host computer software. The time delay from the pulse arriving at the discrimination module input to the output discrimination result does not exceed 1 μs, and the total response time of the detector from radiation incidence to the generation of an effective discrimination signal does not exceed 100 ns.

[0047] In another preferred embodiment of the present invention, the detector body is equipped with a dedicated two-dimensional spatial distribution reconstruction algorithm program for neutrons and photons. The reconstruction algorithm program is pre-installed in the host computer readout software of the detector body. The reconstruction algorithm program has built-in full-process data preprocessing logic for pixel coordinate accurate mapping, dead pixel correction, channel crosstalk correction, gain normalization calibration and temperature drift dynamic correction, which can independently and accurately reconstruct the two-dimensional spatial distribution map of neutrons and the two-dimensional spatial distribution map of photons.

[0048] The spatial distribution reconstruction algorithm supports pseudo-color rendering of detection data, automatic plotting of dose lines in the radiation field, and visualization of multi-modal fusion of neutron and photon dual radiation fields. The measurement data output by the algorithm reconstruction can be directly connected to the treatment control system, providing core data support for accurate dose monitoring during boron neutron capture therapy.

[0049] Specifically, the host computer readout software receives the filtered count data from readout layer 3. The reconstruction algorithm first indexes the physical coordinate mapping table according to the pixel channel number in the data packet, and fills the neutron count and photon count into the two-dimensional matrix of the corresponding pixel position. The dead pixel correction module detects low-count or zero-count pixels with abnormal responses in the matrix and fills them with the count values ​​of adjacent normal pixels. The channel crosstalk correction module subtracts the count component contributed by leakage from adjacent channels from the original count of each pixel based on the crosstalk coefficient matrix measured during the calibration phase. The gain normalization calibration module incorporates the sensitivity non-uniformity of each pixel caused by the difference in scintillator luminous efficiency and fiber coupling efficiency into the correction factor to unify the equivalent count response of each pixel. The temperature drift dynamic correction module compensates for and corrects the drift of scintillator light output caused by temperature changes based on the real-time reading of the temperature sensor built into the detector body. After data correction is completed, the algorithm applies pseudo-color mapping to the neutron two-dimensional matrix and the photon two-dimensional matrix respectively to generate neutron spatial distribution maps and photon spatial distribution maps. At the same time, the dose profile is calculated and superimposed on the same view. The overlapping area of ​​neutron distribution and photon distribution is rendered with different color channels. The measurement data is output to the boron neutron capture therapy control system through a standardized interface protocol.

[0050] In another preferred embodiment of the present invention, the overall dimensions of the detector body are set to 62cm×62cm×5cm. The whole machine adopts a fully modular and detachable assembly structure. The detection unit layer 1, the light guide layer 2, and the readout layer 3 can all be independently disassembled, inspected, replaced, and maintained. The detector body has strong anti-electromagnetic interference, anti-radiation, and anti-aging capabilities, and is suitable for long-term continuous and stable operation in the complex and strong radiation working environment of boron neutron capture therapy.

[0051] Specifically, the 62cm×62cm×5cm dimensions accommodate a 60cm×60cm effective detection area while providing a structural support framework for the detection unit layer 1, the optical guide layer 2, and the readout layer 3. The mechanical connections between the three modules employ a detachable assembly method using a combination of precision positioning pins and fastening screws. After disassembling the detection unit layer 1, the incident end face of the optical fiber 21 in the optical guide layer 2 can be directly cleaned or damaged optical fiber 21 can be replaced. After disassembling the readout layer 3, the silicon photomultiplier tube array module or the front-end electronics board can be directly replaced. The detector body shell is made of a metal material with low neutron field disturbance and low neutron activation, and is designed as a sealed structure. This reduces external electromagnetic interference and minimizes the generation of activated gamma rays, thereby ensuring the accuracy and reliability of the detector body's measurement results. The detector body materials undergo irradiation aging screening, and the performance degradation of the scintillation crystal, optical fiber, and electronic components under long-term neutron and photon irradiation is controlled within acceptable limits.

[0052] In another preferred embodiment of the present invention, the detector body is suitable for online real-time measurement of the spatial distribution of neutron-photon mixed radiation field in boron neutron capture therapy, accurate verification of treatment irradiation field dose, and dynamic monitoring of radiation safety throughout the treatment process.

[0053] Specifically, during boron neutron capture therapy, the neutron beam generated by the accelerator is slowed and shaped before irradiating the patient's treatment site, with photons also present in the treatment field. The detector body is placed at the beam exit position of the treatment head, with detector unit layer 1 facing the beam direction, to measure the neutron flux distribution and photon flux distribution at various points on the treatment plane in real time. In the treatment field dose verification stage, the reconstructed two-dimensional spatial distribution maps of neutrons and photons are compared with the dose distribution data preset by the treatment planning system for deviation analysis.

[0054] This embodiment provides a two-dimensional array detector for measuring the spatial distribution of neutrons and photons in mixed fields. The detector body is composed of a detection unit layer 1, an optical guide layer 2, and a readout layer 3, stacked vertically from top to bottom to form a three-layer modular integrated structure. The three-layer modular integrated structure employs precise mechanical alignment between layers, with no air gaps in the optical coupling, ensuring both light transmission efficiency and mechanical stability. The overall dimensions of the detector body are 62cm × 62cm × 5cm, with an effective detection area covering 60cm × 60cm, suitable for online measurement requirements of commonly used irradiation fields in boron neutron capture therapy. The detector body adopts a fully modular and detachable assembly structure; the detection unit layer 1, optical guide layer 2, and readout layer 3 can all be independently disassembled, inspected, and replaced for maintenance. The entire unit possesses resistance to electromagnetic interference and radiation aging.

[0055] The detection unit layer 1 is composed of multiple detection unit arrays. Each detection unit includes a substrate 11, a Li-6 micro scintillator 12, and an encapsulation layer 13. The substrate 11 is fixed directly above the corresponding optical fiber 21, the Li-6 micro scintillator 12 is fixed directly above the substrate 11, and the encapsulation layer 13 is fixed directly above the Li-6 micro scintillator 12. The substrate 11 is made of an optically transparent low-gamma-response organic polymer material and serves as the carrier substrate for the entire detection array. All Li-6 micro scintillators 12 are regularly positioned and fixed in the array points pre-set on the upper surface of the substrate 11.

[0056] The Li-6 micro scintillator 12 is prepared using Eu:LiCaAlF6, an inorganic scintillator crystal material doped with Li-6, wherein the abundance of Li-6 is 95% and the doping concentration of Eu active ions is <0.1%. The doping ratio can accurately match the differential attenuation characteristics of neutron and photon pulses, providing basic physical property support for the subsequent accurate identification of dual modules. The external dimensions of a single Li-6 micro scintillator 12 are set to 1mm×1mm×0.5mm, arranged in a regular matrix of 600×600, with a corresponding pixel spacing of 1mm, forming a detection array with a total of 360,000 pixels, corresponding to an effective detection area of ​​60cm×60cm, and each pixel has millimeter-level spatial resolution.

[0057] The Li-6 miniature scintillator 12 is configured to synchronously respond to incident neutrons and photons, generating a scintillating light signal upon stimulation. The light-emitting surface of the Li-6 miniature scintillator 12 facing the fiber 21 is optically polished and coated with an anti-reflection film to improve the output coupling efficiency of the scintillating light signal. The encapsulation layer 13 fully covers the non-light-emitting areas of the sidewalls and upper surface of the corresponding Li-6 miniature scintillator 12. Each Li-6 miniature scintillator 12 is isolated and protected by an independent encapsulation layer 13, avoiding optical crosstalk between adjacent detection units and mechanical displacement deviations caused by long-term use. The entire array is cured to further ensure structural stability.

[0058] The optical guide layer 2 is composed of an array of multiple optical fibers 21, made of high-density silica optical fiber. Each optical fiber 21 corresponds to one pixel, and the core diameter of the optical fiber 21 is controlled within the range of 0.8mm to 1.0mm. The incident end face of the optical fiber 21 is optically coupled point-to-point without air gap to the light-emitting surface of the corresponding Li-6 micro scintillator 12, and the emitting end face of the optical fiber 21 is connected to the readout layer 3. The entire optical fiber 21 array adopts a potting and curing integrated molding structure. The overall size of the cured optical fiber 21 array is completely matched with the effective detection area of ​​the detection unit layer 1, and there are no misalignments or structural defects during long-term operation. The overall optical signal collection efficiency of the optical guide layer 2 is not less than 85%, and it stably realizes low-loss directional transmission of scintillator optical signals between the detection unit layer 1 and the readout layer 3.

[0059] The readout layer 3 is equipped with a multi-channel digital front-end electronics system, integrating a silicon photomultiplier tube array, a signal conditioning unit, a high-speed ADC sampling unit, and a main control processing unit. Each channel of the silicon photomultiplier tube array is coupled to the output end of an optical fiber 21 to complete the conversion of the scintillation light signal into an electrical pulse signal. The signal conditioning unit is electrically connected to the output end of the silicon photomultiplier tube array to amplify, shape, reduce noise, and perform baseline correction preprocessing on the raw electrical pulse signal after photoelectric conversion. The high-speed ADC sampling unit synchronously acquires complete pulse amplitude data and waveform feature data of the conditioned pulse signal to obtain fully digital pulse information containing pulse shape and amplitude features. The main control processing unit completes pulse parameter extraction, probe data buffering, high-speed data transmission, and overall system control. The readout layer 3 supports 360,000 channels of fully parallel synchronous readout without channel crosstalk, meeting the high-speed measurement requirements of large-area arrays.

[0060] The detector body integrates a pulse amplitude discrimination module and a pulse shape discrimination module, both of which adopt a hardware-embedded integrated design and are built into the multi-channel digital front-end electronics system of readout layer 3. The pulse amplitude discrimination module sets multiple thresholds based on the difference in pulse amplitude distribution between neutron and photon signals. The specific configuration of the thresholds and selection logic is as follows: three levels of amplitude thresholds are set: low threshold 50mV, medium threshold 300mV, and high threshold 800mV. The secondary conformity selection rules are as follows: for signals determined by the first-level discrimination to be neutrons, pulse amplitudes within the range of 300mV to 800mV (inclusive) are considered valid neutron signals, and signals outside this range are directly rejected; for signals determined by the first-level discrimination to be photons, pulse amplitudes within the range of 50mV to 300mV are considered valid photon signals, and signals outside this range are rejected as noise false triggering signals. The pulse shape discrimination module performs secondary discrimination based on the difference in the decay time constants of scintillation pulses generated by neutron and photon signals in the Li-6 micro scintillator 12. The front-end electronics system calculates the pulse decay time in real time to complete the distinction. The quantization discrimination parameters are explicitly configured as follows: the decay time constant of neutron signal scintillation pulses ranges from 800ns to 1200ns, and the decay time constant of photon signal scintillation pulses ranges from 150ns to 300ns. The hardware embedded program has a built-in discrimination threshold uniformly set at 450ns. A pulse decay time constant ≥ 450ns is determined to be a neutron signal, and a pulse decay time constant < 450ns is determined to be a preliminary photon signal. The pulse shape discrimination module and the pulse amplitude discrimination module work together online to distinguish between neutron and photon signals, synchronously and independently acquiring the two-dimensional spatial distribution count information of neutrons and photons respectively. The total signal processing delay of the two discrimination modules working together does not exceed 1μs, and the overall pulse response speed of the detector body does not exceed 100ns. The entire process is performed online in real time, adapting to uninterrupted real-time online measurement conditions of neutron-gamma mixed fields.

[0061] The detector itself is equipped with a dedicated two-dimensional spatial distribution reconstruction algorithm for neutrons and photons, pre-installed within the accompanying host computer readout software. The reconstruction algorithm incorporates a complete data preprocessing logic, including precise pixel coordinate mapping, dead pixel correction, channel crosstalk correction, gain normalization calibration, and temperature drift dynamic correction. All calibration steps are configured with quantization calibration methods, fixed correction coefficients, and compensation calculation formulas, allowing for direct algorithm compilation and data processing reproduction. Specific quantization calibration configurations are as follows:

[0062] First, dead pixel correction: All pixel response counts are detected in advance through global uniform irradiation calibration. Pixels with counts lower than 10% of the global average count are defined as dead pixels. Data filling is completed by interpolation compensation using the mean of the effective pixel counts in the eight neighboring areas. The correction compensation fixed coefficient is 0.99.

[0063] Second, channel crosstalk correction is performed using a standard single-point source pixel-by-pixel scanning calibration method. The crosstalk contribution ratio of adjacent pixels is measured and a 600×600 dedicated channel crosstalk coefficient matrix is ​​generated. The crosstalk correction calculation formula is as follows: ,in For single-adjacent crosstalk coefficients, the value range of all crosstalk coefficients is uniformly controlled between 0.002 and 0.01; The effective radiation count for a single pixel after crosstalk correction; is the uncorrected raw measured radiation count for a single pixel; i is the index of the eight neighboring pixels of the pixel, ranging from 1 to 8; Let be the single-neighbor crosstalk coefficient of the i-th adjacent pixel; The original radiation count of the i-th adjacent pixel;

[0064] Thirdly, gain normalization calibration is performed. Using the center pixel of the detector's entire domain as the reference pixel, the response gain ratio of each pixel to the reference pixel is calculated pixel-by-pixel as a normalization correction factor. The single-pixel count correction formula is as follows: The gain correction factor is controlled within the range of 0.95 to 1.05; Radiation counts after gain normalization calibration for a single pixel; The raw, measured radiation count for a single pixel without gain calibration; This is the gain normalization correction factor for a single pixel relative to the reference pixel;

[0065] Fourthly, temperature drift dynamic correction: The built-in temperature sensor collects the detector's operating temperature in real time. The temperature reference calibration value is set to 25℃, and the temperature drift compensation calculation formula is as follows: Among them, the temperature compensation coefficient The value is fixed at 0.0008 / ℃ to compensate for the measurement deviation caused by temperature fluctuations in the scintillator's light output; This is the final radiation count for a single pixel after temperature drift compensation; For pixel radiance counts that have undergone gain normalization calibration; The real-time operating temperature is collected by the temperature sensor built into the detector.

[0066] Based on the identified synchronously acquired data and the full-process quantization correction, the algorithm fills the counting information into a 600×600 two-dimensional matrix according to the pixel physical coordinates, and independently reconstructs the two-dimensional spatial distribution maps of neutrons and photons, achieving accurate synchronous reconstruction of the spatial distribution of neutrons and photons. The spatial distribution reconstruction algorithm supports pseudo-color rendering, automatic drawing of dose lines in the radiation field, and visualization display of multimodal fusion of neutron and photon dual radiation fields.

[0067] The complete working process of the detector is as follows: A mixed radiation field of neutrons and photons is incident on the detector unit layer 1, and the Li-6 micro scintillator 12 is stimulated to generate scintillation fluorescence, which corresponds to the energy deposition of the radiation particles; the optical signal is transmitted at low loss to the readout layer 3 through the high-density optical fiber 21 array in the optical guide layer 2; the silicon photomultiplier tube array in the readout layer 3 completes photoelectric conversion; the signal conditioning unit amplifies, shapes, reduces noise, and corrects the baseline of the electrical pulse signal; the high-speed ADC sampling unit performs synchronous analog-to-digital conversion on the pulse and acquires the full digital pulse information; the pulse shape inside the front-end electronics system... The discrimination module and pulse amplitude discrimination module rely on preset quantization thresholds and selection rules to perform two-level joint discrimination in real time, accurately distinguishing neutron signals from photon signals online, and counting the effective counts according to pixel channel coordinates. The processed data is uploaded to the host computer through a high-speed interface. The host computer reads the spatial distribution reconstruction algorithm program embedded in the software, calls various quantization correction coefficients and compensation formulas, performs two-dimensional distribution reconstruction after completing full-dimensional data preprocessing, and completes the drawing and multi-modal fusion display of the spatial distribution maps of neutrons and photons in real time, and simultaneously completes data storage and measurement result output.

[0068] The key performance indicators of the detector in this embodiment are: effective detection area of ​​60cm×60cm, pixel array size of 600×600, spatial resolution not exceeding 1mm, online discrimination capability between neutrons and gamma rays, support for full-channel multi-channel synchronous parallel readout, pulse response speed not exceeding 100ns, signal processing delay not exceeding 1μs, and operating mode of online real-time measurement. The detector body is suitable for online real-time measurement of the spatial distribution of neutron-photon mixed radiation field in boron neutron capture therapy scenarios, accurate verification of treatment irradiation field dose, and dynamic monitoring of radiation safety throughout the treatment process.

[0069] The detector body adopts a three-layer vertically stacked modular integrated structure consisting of a detection unit layer 1, an optical guide layer 2, and a readout layer 3. This overcomes the shortcomings of traditional split devices, such as loose structure, complex operation and maintenance, and susceptibility to mechanical displacement and signal crosstalk. The overall structure is stable and easy to disassemble and repair. Through a 600×600 high-density Li-6 micro scintillator pixel array, it achieves millimeter-level ultra-high spatial resolution while covering a large effective detection area of ​​60cm×60cm, accurately capturing subtle differences in local dose distribution in the radiation field and solving the problem of insufficient measurement accuracy in traditional detector bodies. The device integrates hardware-embedded pulse shape discrimination and pulse amplitude discrimination dual-level joint recognition technology, relying on quantized discrimination thresholds to distinguish neutrons and... The photon signal undergoes two-stage selection to effectively suppress mutual interference between mixed radiation field signals, and independently and accurately outputs two-dimensional spatial distribution count data of the two types of rays without the need for secondary offline software processing. It is equipped with built-in multiple error correction logic and a dedicated reconstruction algorithm to offset measurement errors caused by hardware deviations, pixel crosstalk, and temperature drift, accurately reconstructing the two-dimensional radiation distribution spectrum of neutrons and photons and supporting multimodal visualization. The measurement data can be directly connected to the treatment control system. The whole machine has fast pulse response and low signal processing latency, enabling uninterrupted real-time online monitoring of the radiation field, avoiding the drawbacks of offline detection data lag. The equipment also has excellent resistance to electromagnetic interference and radiation aging, making it suitable for long-term stable operation under complex and strong radiation conditions.

[0070] Two-dimensional array detectors have the advantages of modularity, good spatial resolution, and real-time signal processing. They can be applied to the field of boron neutron capture therapy to measure the spatial distribution of neutrons and photons. They can meet the actual needs of online real-time measurement of the spatial distribution of neutron-photon mixed radiation field and accurate verification of treatment field dose in boron neutron capture therapy, effectively improving treatment accuracy and clinical safety.

[0071] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons, characterized in that, include: The detector body includes a detection unit layer, a light guide layer, and a readout layer. The detection unit layer, light guide layer, and readout layer are stacked vertically from top to bottom to form a three-layer modular integrated structure. The layers are precisely mechanically aligned and optically coupled without air gaps. The optical guide layer is composed of an array of multiple optical fibers; The detection unit layer is composed of an array of multiple detection units, each detection unit corresponding to one optical fiber; each detection unit includes: a substrate, fixed directly above the corresponding optical fiber; a Li-6 micro scintillator, fixed directly above the substrate; and an encapsulation layer, fixed directly above and outside the Li-6 micro scintillator. In the detection unit layer, multiple Li-6 micro scintillators are arranged in a regular matrix to form a 600×600 pixel detection array, corresponding to an effective detection area of ​​60cm×60cm. The size of a single Li-6 micro scintillator is matched with the array spacing, enabling a single pixel to have millimeter-level spatial resolution. The Li-6 micro scintillators are configured to synchronously respond to incident neutrons and photons and generate scintillating light signals. In the optical guide layer, each optical fiber corresponds to a pixel, and the incident end face of the optical fiber and the light-emitting surface of the corresponding Li-6 micro scintillator are coupled point-to-point without air gap. The readout layer is configured with a multi-channel digital front-end electronics system, which integrates a silicon photomultiplier tube array. Each channel of the silicon photomultiplier tube array is coupled to the output end of one of the optical fibers to complete the conversion of optical signals to electrical pulse signals and full-channel parallel synchronous readout and real-time digital sampling, so as to obtain full digital pulse information containing pulse shape characteristics and pulse amplitude characteristics. The multi-channel digital front-end electronics system also integrates a pulse shape discrimination module and a pulse amplitude discrimination module. The pulse amplitude discrimination module sets multiple thresholds based on the difference in pulse amplitude distribution between neutron and photon signals to perform primary discrimination of the pulse signals. The pulse shape discrimination module performs secondary coincidence selection of the signals after primary discrimination based on the difference in the decay time constant of the scintillation pulses generated by neutron and photon signals in the Li-6 micro scintillator. The pulse shape discrimination module and the pulse amplitude discrimination module work together online to distinguish between neutron and photon signals, so as to synchronously and independently acquire the two-dimensional spatial distribution count data of neutrons and photons respectively.

2. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 1, characterized in that, The substrate of the detection unit layer is made of an optically transparent low-gamma-response organic polymer material and serves as the carrier substrate for the entire detection array. All Li-6 micro scintillators are regularly positioned and fixed at preset array points on the upper surface of the substrate. The encapsulation layer fully covers the sidewalls and non-light-emitting areas of the upper surface of the corresponding Li-6 micro scintillators. Each Li-6 micro scintillator is isolated and protected by an independent encapsulation layer. The substrate is used to reduce the interference noise of its own substrate on the photon detection signal, and the encapsulation layer is used to avoid optical crosstalk between adjacent detection units and mechanical displacement deviation caused by long-term use.

3. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 2, characterized in that, The Li-6 micro scintillator is made of Eu:LiCaAlF6 inorganic scintillator crystal material. The size of a single Li-6 micro scintillator is set to 1mm×1mm×0.5mm, and the pixel spacing of the array is uniformly set to 1mm. The light-emitting surface of the Li-6 micro scintillator facing the optical fiber is optically polished and coated with an anti-reflection film. Through size matching and optical surface treatment, the millimeter-level spatial resolution of the detector body is stably guaranteed, and the coupling efficiency of the scintillator light signal output is improved simultaneously.

4. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 1, characterized in that, The optical fibers in the optical guide layer are all made of high-density silica optical fiber, with a single fiber outer diameter of <1.0mm. All optical fiber arrays adopt an integrated molding structure of potting and curing. The overall size of the cured optical fiber array is completely matched with the effective detection area of ​​the detection unit layer. Long-term operation can effectively avoid structural defects such as misalignment, detachment, and loosening, ensuring the stability of optical signal transmission. The overall optical signal collection efficiency of the optical guide layer is not less than 85%, and it can stably realize low-loss directional transmission of scintillation optical signals between the detection unit layer and the readout layer.

5. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 1, characterized in that, The multi-channel digital front-end electronics system of the readout layer has a built-in signal conditioning unit, a high-speed ADC sampling unit, and a main control processing unit. The signal conditioning unit is connected to the output of the silicon photomultiplier tube array and is used to amplify, shape, reduce noise, and perform baseline correction preprocessing on the original electrical pulse signal after photoelectric conversion. The high-speed ADC sampling unit is used to synchronously acquire pulse full amplitude data and waveform feature data. The main control processing unit is used to complete pulse parameter extraction, detection data caching, high-speed data transmission, and overall control of the entire detector body in real time.

6. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 1, characterized in that, Both the pulse shape discrimination module and the pulse amplitude discrimination module adopt a hardware-embedded integrated design and are built into the multi-channel digital front-end electronics system. The total signal processing delay of the pulse shape discrimination module and the pulse amplitude discrimination module working together is ≤1μs, the pulse response speed of the detector body is ≤100ns, the dual discrimination modules perform real-time hardware calculation and processing throughout the process, and are equipped with real-time readout and display functions in software, which is suitable for uninterrupted real-time online measurement of neutron and photon mixed fields.

7. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 1, characterized in that, The detector body is equipped with a dedicated two-dimensional spatial distribution reconstruction algorithm program for neutrons and photons. The reconstruction algorithm program is pre-installed in the host computer readout software of the detector body. The reconstruction algorithm program has built-in full-process data preprocessing logic for pixel coordinate accurate mapping, dead pixel correction, channel crosstalk correction, gain normalization calibration and temperature drift dynamic correction, which can independently and accurately reconstruct the two-dimensional spatial distribution map of neutrons and the two-dimensional spatial distribution map of photons.

8. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 7, characterized in that, The spatial distribution reconstruction algorithm supports pseudo-color rendering of detection data, automatic plotting of dose lines in the radiation field, and visualization of multimodal fusion of neutron and photon dual radiation fields. The measurement data output by the algorithm reconstruction can be directly connected to the treatment control system, providing core data support for accurate dose monitoring and quantitative control of treatment efficacy in the boron neutron capture therapy process.

9. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 7, characterized in that, The overall dimensions of the detector body are 62cm×62cm×5cm. The whole machine adopts a fully modular structure, and the detection unit layer, optical guide layer and readout layer can be independently disassembled, inspected and replaced. The detector body has strong resistance to electromagnetic interference, radiation and aging, and is suitable for long-term continuous and stable operation in the complex and strong radiation working environment of boron neutron capture therapy.

10. A two-dimensional array detector for measuring the spatial distribution of neutrons and photons according to claim 9, characterized in that, The detector body is suitable for online real-time measurement of the spatial distribution of neutron-photon mixed radiation field and accurate verification of treatment irradiation field dose in boron neutron capture therapy scenarios.

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