Radiation detector, silicon photomultiplier array gain correction method, and storage medium

Abstract

The disclosure provides a kind of ray detector, silicon photomultiplier array gain correction method and storage medium, the method is by analog light source emits with the same characteristics of light signal when ray irradiation crystal, obtains parameter set under different environments, and calculates difference matrix, dynamically adjusts the reverse bias of each SiPM, solves the gain consistency problem, temperature and aging influence problem and multi-channel consistency problem.Through these measures, the energy resolution, long-term stability and calibration efficiency of the detector are significantly improved, the reliability of the system is enhanced, and the maintenance requirements are predicted, which significantly improves the overall performance of the gamma ray detector.

Description

Technical Field

[0001] This invention relates to the field of nuclear detection equipment, specifically to a gamma ray detector, a silicon photomultiplier tube array gain correction method, and a storage medium, for realizing the automatic adjustment of the gain of each silicon photomultiplier tube in the silicon photomultiplier tube array, thereby improving the detection accuracy of the gamma ray detector. Background Technology

[0002] Gamma-ray detectors are widely used in nuclear physics detection, medical imaging, and other fields for radiation detection and energy spectrum analysis. Traditional gamma-ray detectors mainly consist of scintillation crystals and photomultiplier tubes (PMTs). With technological advancements, silicon photomultiplier tubes (SIPMs) are gradually replacing traditional PMTs due to their advantages such as high gain, low operating voltage, and insensitivity to magnetic fields. A SIPM array is a detection device composed of multiple individual SIPMs. In practical applications, due to differences in manufacturing processes, temperature variations, and other factors, the gain of each SIPM in the array is inconsistent. This leads to broadening of the detection energy spectrum, a decrease in energy resolution, and consequently, affects detection accuracy.

[0003] Currently, the commonly used calibration method involves calibrating the detector using a radiation source. However, this method poses radiation safety risks and is cumbersome. Furthermore, temperature variations and aging effects can cause gain drift in silicon photomultiplier tubes, requiring periodic recalibration, which is difficult to implement in many applications. Therefore, developing a method that automatically adjusts the gain of individual silicon photomultiplier tubes in a silicon photomultiplier tube array without requiring a radiation source is of great significance for improving the performance and stability of gamma-ray detectors. Summary of the Invention

[0004] The purpose of this invention is to provide a radiation detector and a gain correction method for its silicon photomultiplier tube array. By using a simulated light source to replace the radiation source for calibration, the gain of each silicon photomultiplier tube in the silicon photomultiplier tube array is automatically adjusted, thereby improving the detection accuracy of the radiation detector.

[0005] In a first aspect, the present invention provides an X-ray detector, specifically comprising an analog light source, a crystal, a silicon photomultiplier tube (SIPM) array, a SIPM array driving circuit, a multi-channel signal acquisition circuit, a storage unit, and a SIPM array calibration circuit, characterized in that: The simulated light source is located at the front end of the crystal, and the SIPM array is located at the rear end of the crystal; The simulated light source is used to emit a first light signal, which has the same wavelength, emission attenuation time and amplitude as the second light signal. The crystal is used to emit a second light signal when irradiated by rays; The silicon photomultiplier tube (SIPM) array includes multiple silicon photomultiplier tubes, each of which is used to generate a current pulse based on the first optical signal or the second optical signal. The silicon photomultiplier array driving circuit is used to provide a reverse bias voltage to each of the silicon photomultiplier tubes; The multi-channel signal acquisition circuit is used to acquire the current pulses generated by each of the silicon photomultiplier tubes; The storage unit is used to store the initial scale of each silicon photomultiplier tube and the initial scale of the silicon photomultiplier tube SIPM array; The silicon photomultiplier tube array calibration circuit is used to adjust the gain of each silicon photomultiplier tube according to the first optical signal and the initial scale.

[0006] Secondly, this invention provides a method for gain correction of a silicon photomultiplier tube array: A simulated light source is obtained, which emits light with the same wavelength, emission decay time, and amplitude as when a crystal is irradiated by rays; The first parameter set of the silicon photomultiplier array is obtained under the first environment through the simulated light source; wherein the first parameter set includes the first current signal amplitude of each silicon photomultiplier in the silicon photomultiplier array, the average first current signal amplitude of all silicon photomultiplier, and the first ratio of the first current signal amplitude of each silicon photomultiplier to the average first current signal amplitude. The second parameter set of the silicon photomultiplier tube array is obtained under the second environment through the simulated light source; wherein the second parameter set includes the third current signal amplitude of each silicon photomultiplier tube in the silicon photomultiplier tube array, the average third current signal amplitude of all silicon photomultiplier tubes, the second ratio of the third current signal amplitude of each silicon photomultiplier tube to the average third current signal amplitude, and the first difference matrix. The third parameter set of the silicon photomultiplier array under the third environment is obtained through the simulated light source; wherein the third parameter set includes the fifth current signal amplitude of each silicon photomultiplier in the silicon photomultiplier array, the average fifth current signal amplitude of all silicon photomultiplier, the third ratio of the fifth current signal amplitude of each silicon photomultiplier to the average fifth current signal amplitude, and the second difference matrix. The reverse bias voltage of each silicon photomultiplier tube is adjusted according to the first difference matrix and the second difference matrix.

[0007] Thirdly, the present invention provides a gain correction method for a silicon photomultiplier tube array of a radiation detector, wherein the radiation detector includes an analog light source, a crystal, and a silicon photomultiplier tube (SIPM) array, characterized in that: The simulated light source is located at the front end of the crystal, and the SIPM array is located at the rear end of the crystal; The simulated light source can emit light with the same wavelength, emission decay time, and amplitude as when a crystal is irradiated by rays. The first parameter set of the silicon photomultiplier array is obtained under the first environment through the simulated light source; wherein the first parameter set includes the first current signal amplitude of each silicon photomultiplier in the silicon photomultiplier array, the average first current signal amplitude of all silicon photomultiplier, and the first ratio of the first current signal amplitude of each silicon photomultiplier to the average first current signal amplitude. The second parameter set of the silicon photomultiplier tube array is obtained under the second environment through the simulated light source; wherein the second parameter set includes the third current signal amplitude of each silicon photomultiplier tube in the silicon photomultiplier tube array, the average third current signal amplitude of all silicon photomultiplier tubes, the second ratio of the third current signal amplitude of each silicon photomultiplier tube to the average third current signal amplitude, and the first difference matrix. The third parameter set of the silicon photomultiplier array under the third environment is obtained through the simulated light source; wherein the third parameter set includes the fifth current signal amplitude of each silicon photomultiplier in the silicon photomultiplier array, the average fifth current signal amplitude of all silicon photomultiplier, the third ratio of the fifth current signal amplitude of each silicon photomultiplier to the average fifth current signal amplitude, and the second difference matrix. The reverse bias voltage of each silicon photomultiplier tube is adjusted according to the first difference matrix and the second difference matrix.

[0008] Fourthly, the present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions for causing a computer to execute the above-described silicon photomultiplier tube array gain correction method for a radiation detector.

[0009] The purpose of this invention is to provide a gamma-ray detector and its silicon photomultiplier tube (SIPM) array gain correction method. By using a simulated light source instead of a radioactive source for calibration, the gain of each SIPM in the array is automatically adjusted, thereby improving the detection accuracy of the gamma-ray detector. The technical solution of this invention has the following advantages: It eliminates the need for a radioactive source, using a simulated light source for calibration, improving the safety and convenience of the calibration process and avoiding radiation safety risks; it can automatically adjust the gain of each SIPM in the array, improving energy resolution; through the calculation of parameter sets and difference matrices, it achieves real-time compensation for gain drift caused by temperature changes and aging effects, improving long-term stability and ensuring consistent detector performance under different environmental conditions; the calibration process is fully automated, requiring no manual intervention, significantly reducing maintenance costs and technical barriers; it employs an iterative optimization algorithm to meet the needs of high-precision nuclear detection applications; the system has a self-diagnostic function, capable of identifying and reporting SIPM performance anomalies and providing early warnings of potential faults.

[0010] The above description is merely an overview of the technical solution disclosed herein. In order to better understand the technical means of this disclosure and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the structure of the X-ray detector provided in an embodiment of this disclosure.

[0013] Figure 2 A flowchart illustrating the silicon photomultiplier tube array gain correction method provided in this embodiment of the disclosure.

[0014] Figure 3 A flowchart illustrating a method for acquiring and storing a first parameter set of a silicon photomultiplier array under a specific environment, as provided in an embodiment of this disclosure.

[0015] Figure 4 A flowchart illustrating a method for acquiring and storing the second parameter set of a silicon photomultiplier array under factory conditions, as provided in embodiments of this disclosure.

[0016] Figure 5 A flowchart illustrating the real-time gain adjustment method for silicon photomultiplier tubes provided in this embodiment.

[0017] Figure 6 This is a schematic diagram of the structure of a computer device provided in an embodiment of the present disclosure. Detailed Implementation

[0018] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0019] It should be understood that the following specific examples illustrate the implementation of this disclosure, and those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0020] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0021] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0022] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0023] like Figure 1As shown, the X-ray detector provided by the present invention specifically includes an analog light source 10, a crystal 20, a silicon photomultiplier tube (SIPM) array 30, a silicon photomultiplier tube array driving circuit 40, a multi-channel signal acquisition circuit 50, a storage unit 60, and a silicon photomultiplier tube array calibration circuit 70.

[0024] The simulated light source 10 is located at the front end of the crystal 20 and is used to emit a first optical signal. This first optical signal has the same wavelength, emission decay time, and amplitude as the second optical signal. The main function of the simulated light source 10 is to simulate the optical signal generated when the crystal is irradiated by radiation, so as to calibrate the silicon photomultiplier tube in an environment without a radiation source. The simulated light source needs to precisely match the luminescence characteristics of the crystal, including wavelength, emission decay time, and light intensity, to ensure that the calibration process is consistent with actual radiation detection conditions.

[0025] The crystal 20, located between the analog light source 10 and the SIPM array 30, is used to emit a second optical signal when irradiated by X-rays. The crystal 20 is typically a scintillation crystal such as sodium iodide, barium fluoride, or LYSO. When gamma rays interact with the crystal, they are converted into visible light photons, which are then detected by the SIPM array. The choice of crystal depends on the specific application of the detector, such as energy range and resolution requirements.

[0026] The silicon photomultiplier tube (SIPM) array 30 is located at the rear end of the crystal 20 and includes multiple silicon photomultiplier tubes. Each of the silicon photomultiplier tubes is used to generate a current pulse according to the first optical signal or the second optical signal. The SIPM array typically consists of tens to hundreds of individual silicon photomultiplier tubes, and each SIPM unit is composed of thousands of avalanche photodiode micro-units operating in Geiger mode connected in parallel. When an incident photon triggers the avalanche process, a measurable current pulse is generated.

[0027] The silicon photomultiplier tube array driver circuit 40 provides a reverse bias voltage to each of the silicon photomultiplier tubes (SIPMs). The driver circuit provides a precisely controlled reverse bias voltage for each SIPM, typically within the range of 20-70V, and can be fine-tuned as needed for calibration. Precise control of the bias voltage is crucial for maintaining the gain stability of the SIPMs; a bias voltage change of 0.1V can result in a gain change of more than 5%.

[0028] The multi-channel signal acquisition circuit 50 is used to acquire the current pulses generated by each of the silicon photomultiplier tubes (SIPMs). This circuit typically includes a preamplifier, waveform shaping circuitry, and an analog-to-digital converter (ADC) to convert the weak current signals generated by the SIPMs into processable digital signals. The multi-channel acquisition design allows for the simultaneous reading of signals from multiple SIPMs, improving data acquisition efficiency.

[0029] The storage unit 60 is used to store the initial calibration of each silicon photomultiplier tube and the initial calibration of the silicon photomultiplier tube SIPM array. The storage unit can use non-volatile memory, such as EEPROM or flash memory, to ensure that calibration data is not lost after power failure. The stored parameters include calibration parameters such as current signal amplitude, ratio, and difference matrix measured under various environmental conditions.

[0030] The silicon photomultiplier tube array calibration circuit 70 is used to adjust the gain of each silicon photomultiplier tube according to the first optical signal and the initial scale. The calibration circuit controls the drive circuit to adjust the reverse bias voltage of each SIPM by calculating the difference between the current measurement value and the stored initial scale, thereby achieving precise gain matching.

[0031] The silicon photomultiplier tube array driver circuit 40 uses a dedicated ASIC chip to individually acquire each signal from the SIPM array in the device. This dedicated ASIC chip is a specialized chip with dozens of identical preamplifier circuits, specifically designed to drive the SIPM array, and its output consists of dozens of conditioned core pulse signals. The core advantages of the ASIC chip are its small size, low power consumption, and high consistency—features that general-purpose preamplifier circuits cannot achieve.

[0032] The multi-channel signal acquisition circuit 50 can also be implemented using a dedicated ASIC chip, and the silicon photomultiplier tube array calibration circuit 70 can be implemented using an FPGA chip. Specifically, during normal operation of the device, each SIPM in the SIPM array generates a current signal. These current signals are first received by the ASIC chip, which amplifies and conditions the current signal of each SIPM to generate a conditioned core pulse signal. Subsequently, these core pulse signals are converted into digital signals by an analog-to-digital converter (ADC). The converted digital signal is transmitted to the FPGA chip through a high-speed interface. In the FPGA chip, the digital signals of all channels are summed to generate a composite signal. This composite signal is then sent to the algorithm flow at the back end of the FPGA for further processing, such as energy calculation and event recognition. This process ensures that the device can efficiently process signals from the SIPM array during normal operation. During calibration, each SIPM in the SIPM array also generates a current signal, which is amplified and conditioned by the ASIC chip to generate a core pulse signal. The core pulse signal is converted into a digital signal by an ADC and then connected to the FPGA chip through a high-speed interface. Unlike normal operation, in calibration mode, the FPGA processes the digital signal of each channel individually. The FPGA calculates the gain adjustment for each SIPM based on the first and second difference matrices, and then calculates a new bias adjustment accordingly. The FPGA then provides these new bias adjustments to the SIPM array driver circuit 40, which provides a corresponding reverse bias to each SIPM based on these adjustments. To verify the adjustment effect, the system remeasures the output signal of each SIPM using an analog light source. If the verification result shows that the adjusted signal does not meet the preset accuracy requirements, the FPGA will perform iterative adjustments until the calibration accuracy meets the requirements. This calibration process ensures that the SIPM array maintains its performance under different operating conditions. like Figure 2 As shown, the present invention provides a method for gain correction of a silicon photomultiplier tube array, which specifically includes: Step S1: Obtain a simulated light source under a specific environment. The simulated light source can emit light with the same wavelength, emission decay time, and amplitude as when a crystal is irradiated by rays.

[0033] The simulated light source is specifically implemented as an ultraviolet or blue light-emitting diode (LED). Ultraviolet or blue LEDs are chosen because their emission wavelengths are close to those of most scintillation crystals. For example, the peak emission wavelength of a LYSO crystal is approximately 420 nm, while the emission wavelength range of a blue LED is typically between 430-470 nm. By selecting a suitable LED, the light-emitting characteristics of the crystal can be well simulated.

[0034] In a specific environment, such as an optical integrating sphere or diffuser, the driving current amplitude of the LED is gradually adjusted using an optical integrating sphere or diffuser to obtain the first optical signal. The optical integrating sphere provides a uniform light field, ensuring that each SIPM receives a light signal of the same intensity. The interior of the optical integrating sphere is constructed with a high-reflectivity material (such as a barium sulfate coating, with a reflectivity >98%) to form a spherical cavity. The LED is installed in a small hole on one side of the integrating sphere, and the light is emitted uniformly from the outlet after multiple reflections. Fine adjustment of the driving current is typically achieved through a digitally controlled constant current source, using a 16-bit DAC chip to provide a current within the range of 0-100mA, with a step accuracy of up to 0.01mA and a relative accuracy better than 0.1%. The system monitors the LED temperature and light output in real time using a closed-loop control algorithm, automatically compensating for light intensity changes caused by temperature drift. For simulations of different energy rays, the current value can be automatically adjusted using a preset current-energy correspondence table to achieve energy equivalent simulation within the range of 20keV to 2MeV. A diffuser is a simpler solution, typically made of PTFE (polytetrafluoroethylene) material with a thickness of 2-3 mm, and placed between the LED and the SIPM array. By adjusting the distance between the diffuser and the LED (adjustable from 5-20 mm) and combining it with precise control of the drive current, uniform light intensity distribution and precise adjustment can be achieved, with a diffusion efficiency typically between 85% and 95%.

[0035] Step S2: Using the simulated light source, obtain the first parameter set of the silicon photomultiplier tube array under a specific environment, and store the first parameter set in the memory unit of the X-ray detector. See Appendix for details. Figure 3 As shown: Step S210: In the specific environment, each silicon photomultiplier tube (SIPM) is placed in the combined environment of the simulated light source. The specific environment includes using an optical integrating sphere or adding a diffuser between the simulated light source and the SIPM. The combined environment is used to obtain temperature-voltage curves at different temperatures. This step is performed in a temperature-controlled environment, typically using a temperature chamber or temperature control device. The measurement temperature range is generally -20°C to 50°C to cover the possible operating temperature range of the detector. In practice, the temperature control accuracy is usually maintained within ±0.5°C, with data collected every 5°C, and the system held at each temperature for at least 30 minutes to ensure thermal equilibrium. For example, at 25°C, the optimal operating voltage of a certain SIPM model is 29.5V, while at -10°C it may need to be reduced to 28.2V, and at 40°C it needs to be increased to 30.3V to maintain the same gain. This temperature-voltage curve typically exhibits an approximately linear relationship, with a temperature coefficient of approximately 20-60mV / °C, depending on the SIPM's manufacturing process and model. For the S13360-6050 series SIPM, the temperature coefficient is approximately 54 mV / ℃, while for the S14160-3050 series it is approximately 35 mV / ℃. These data will serve as important references for subsequent automatic adjustments.

[0036] In step S220, the first current signal amplitude of each silicon photomultiplier tube (SIPM) is obtained by connecting a preamplifier and an oscilloscope to each SIPM. The preamplifier typically employs a low-noise design to amplify the weak current signal of the SIPM to a voltage signal that can be accurately measured by the oscilloscope. Specifically, the preamplifier uses a transimpedance amplifier structure with an input impedance <50Ω, an adjustable gain range of 10-100V / A, a bandwidth >100MHz, and a noise level <1pA / √Hz. During the measurement, the LED drive current is kept constant (typically 20mA±0.01mA) to ensure constant light intensity. Thus, the measured signal amplitude difference mainly reflects the gain difference between the SIPMs. For example, under the same conditions, the output amplitude of device SIPM-01 is 25.3mV, while SIPM-02 is 27.1mV and SIPM-03 is 24.8mV, indicating a gain difference of approximately ±5% between these devices.

[0037] Step S230: Calculate the average amplitude of the first current signal of all the silicon photomultiplier tubes (SIPMs) and the first ratio of the amplitude of the first current signal of each SIPM to the average amplitude of the first current signal. The average is calculated by summing the signal amplitudes of all SIPMs and dividing by the number of SIPMs, while the ratio is the amplitude of each SIPM divided by the average. Taking a 16-channel SIPM array as an example, assuming the measured signal amplitudes of the 16 SIPMs are 25.3mV, 27.1mV, 24.8mV, etc., and the calculated average is 26.2mV, then the ratio for SIPM-01 is 25.3 / 26.2 = 0.966, the ratio for SIPM-02 is 27.1 / 26.2 = 1.034, and the ratio for SIPM-03 is 24.8 / 26.2 = 0.947. These ratios reflect the gain deviation of each SIPM relative to the average level, providing a benchmark for subsequent calibration. The system stores these ratios as calibration parameters, which are used to calculate the precise bias adjustment required for each SIPM.

[0038] In step S240, each of the silicon photomultiplier tubes is then combined into a silicon photomultiplier tube SIPM array 30. Under the specific environment, the amplitude of the second current signal of the silicon photomultiplier tube SIPM array 30 is obtained using a preamplifier and an oscilloscope. This step measures the overall response of the entire SIPM array, which, compared to the measurement of a single SIPM, includes the mutual influence and circuit coupling effects between SIPMs. In actual measurements, the outputs of the SIPM array are typically combined using a signal summing circuit before being fed into an amplifier. For example, for the aforementioned 16-channel SIPM array, the average output of a single SIPM is 26.2mV, while the overall array output may be 412mV, slightly less than the theoretical value of 419.2mV (26.2 × 16). This difference mainly comes from signal transmission loss and inter-channel interference. This overall response value serves as an important reference for system calibration, used to verify the overall performance after calibration of a single SIPM.

[0039] In step S250, the average amplitude of the first current signal of all the silicon photomultiplier tubes, the first ratio of the amplitude of the first current signal of each silicon photomultiplier tube to the average amplitude of the first current signal, and the second current signal amplitude are stored in the storage unit 60. These parameters constitute a calibration reference dataset, which will be used as a reference in subsequent use. Data storage is usually achieved by writing to EEPROM or flash memory to ensure long-term data preservation. For example, for a 16-channel SIPM array, the stored data includes: an average value of 26.2mV, the ratios of each channel (SIPM-01: 0.966, SIPM-02: 1.034, SIPM-03: 0.947...), and the overall array output of 412mV. These data are stored in binary format, with each parameter occupying 4 bytes of floating-point number, totaling approximately 100 bytes of storage space. To prevent data loss, the system adopts a dual backup mechanism, storing a complete copy of the data in both the main EEPROM and the backup flash memory, and using CRC checksum to ensure data integrity. The data writing process involves three steps: erasing, writing, and finally verification.

[0040] Step S3: Using the simulated light source, obtain the second parameter set of the silicon photomultiplier tube array under the factory conditions, and store the second parameter set in the memory unit of the X-ray detector. See Appendix for details. Figure 4 As shown: Step S310: Obtain the third current signal amplitude of each silicon photomultiplier tube (SIPM) at the time of its manufacture using the first optical signal. This step is performed before the equipment leaves the factory, recording the response of each SIPM to the simulated light source under standard conditions (typically room temperature 25°C). After the SIPM assembly is coupled, the LED light source is activated and the signal response amplitude of each SIPM is recorded. Since the precise calibration of each SIPM unit has been completed previously, the gain parameter of each SIPM is known. Therefore, the third current signal amplitude of the LED light source at each position of the SIPM array can be calculated by analyzing the signal amplitude differences of SIPMs at different positions. In specific implementation, a precision current source is used to drive the LED, and the current value is set to 30.00±0.01mA to ensure light intensity stability. For example, in a 16-channel SIPM array, the measured amplitudes of the third current signals from SIPM-01 to SIPM-16 are 28.5mV, 30.2mV, 27.9mV, 29.3mV, 31.0mV, 28.7mV, 29.5mV, 30.8mV, 28.3mV, 29.7mV, 30.5mV, 29.1mV, 28.8mV, 30.3mV, 29.0mV, and 28.6mV, respectively. These values ​​will be stored as factory reference values.

[0041] Step S320: Calculate the average amplitude of the third current signal for all the silicon photomultiplier tubes and the third ratio of the amplitude of the third current signal for each silicon photomultiplier tube to the average amplitude of the third current signal. This set of data serves as a long-term benchmark for SIPM. For the example data above, the calculated average amplitude of the third current signal is 29.4 mV. The third ratio for each channel is calculated as follows: SIPM-01 third ratio = 28.5 / 29.4 = 0.969; SIPM-02 third ratio = 30.2 / 29.4 = 1.027; SIPM-03 third ratio = 27.9 / 29.4 = 0.949; and so on, resulting in the complete third ratio sequence: 0.969, 1.027, 0.949, 0.997, 1.054, 0.976, 1.003, 1.048, 0.962, 1.010, 1.037, 0.990, 0.980, 1.031, 0.986, 0.973. These ratios reflect the relative gain differences of each SIPM at the time of manufacture, with a maximum deviation of approximately ±5.4%, which is within the allowable range of the manufacturing process but requires compensation through subsequent calibration.

[0042] Step S330: The amplitude of the fourth current signal of the silicon photomultiplier tube (SIPM) array 30 at the factory is obtained through the first optical signal. This measurement records the overall response of the entire SIPM array at the factory, serving as reference data for long-term use. For the aforementioned 16-channel SIPM array, after all channel signals are combined by the summing circuit, the measured amplitude of the fourth current signal is 462mV, slightly lower than the theoretical value of 470.4mV (29.4×16), with a difference of approximately 1.8%, mainly caused by signal transmission loss and inter-channel interference. This overall response value, together with the individual measurement values ​​of each channel, constitutes a complete factory calibration reference dataset for comparison and adjustment during subsequent real-time calibration.

[0043] Step S340: Obtain the first difference matrix based on the first current signal amplitude, third current signal amplitude, first ratio, third ratio, second current signal amplitude, and fourth current signal amplitude of each of the silicon photomultiplier tubes. The difference matrix is ​​a mathematical model that describes the response variation law of SIPM under different conditions. By comparing the measurement results under different conditions, a relationship model between SIPM gain and factors such as temperature and aging can be established. The first difference matrix shown includes: (1) the normalized difference between the third current signal amplitude and the first current signal amplitude of each SIPM; (2) the normalized difference after considering the temperature factor; (3) the normalized difference after considering the usage time factor; and (4) the comprehensive normalized difference after considering the temperature and usage time factors.

[0044] (1) The normalized difference between the amplitude of the third current signal and the amplitude of the first current signal for each SIPM is calculated using the following formula: Normalized difference = (Amplitude of the third current signal - Amplitude of the first current signal) / Amplitude of the first current signal; For example, for a 16-channel SIPM array, assuming that the amplitude of the first current signal of SIPM1 is 25.3mV and the amplitude of the third current signal is 28.5mV, the amplitude of the first current signal of SIPM2 is 27.1mV and the amplitude of the third current signal is 30.2mV, and the amplitude of the first current signal of SIPM3 is 24.8mV and the amplitude of the third current signal is 27.9mV, then the normalized difference of SIPM1 = (28.5mV - 30.2mV) / Amplitude of the first current signal. 5-25.3) / 25.3=0.127 or 12.7%, the normalized difference of SIPM2=(30.2-27.1) / 27.1=0.114 or 11.4%, the normalized difference of SIPM3=(27.9-24.8) / 24.8=0.125 or 12.5%; (2) the normalized difference after temperature adjustment, the calculation formula is: the normalized difference after temperature adjustment=the basic normalized difference+(current temperature-reference temperature)×temperature coefficient; for example: assuming the reference temperature is 25℃, the current temperature is 30℃, and the temperature coefficient is 0.01 / ℃: the normalized difference after temperature adjustment of SIPM1: 0.127+(30-25.3) / 25.3=0.127 or 12.7%, the normalized difference of SIPM2=(30.2-27.1) / 27.1=0.114 or 11.4%, the normalized difference of SIPM3=(27.9-24.8) / 24.8=0.125 or 12.5%; (2) the normalized difference after temperature adjustment of SIPM1: 0.127+(30-25.3) / 25.3=0.127 or 12.7%, the normalized difference of SIPM2=(30.2-27.1) / 27.1=0.114 or 11.4%, the normalized difference of SIPM3=(27.9-24.8) / 24.8=0.125 or 12.5%; 25)×0.01=0.177 or 17.7%, the temperature-adjusted normalized difference of SIPM2: 0.114+(30) 25)×0.01=0.164 or 16.4%, the temperature-adjusted normalized difference of SIPM3: 0.125+(30) 25)×0.01=0.175 or 17.5%, which means that when the temperature increases by 5°C, an additional 5% compensation is needed to maintain the stable gain of SIPM. (3) Normalized difference after usage time adjustment, calculation formula: Normalized difference after usage time adjustment = Basic normalized difference + Usage time (hours) × Aging coefficient; For example: Assuming the equipment has been used for 500 hours and the aging coefficient is 0.0002 / hour: Normalized difference after usage time adjustment for SIPM1: 0.127 + 500 × 0.0002 = 0.227 or 22.7%, Normalized difference after usage time adjustment for SIPM2: 0.114 + 500 × 0.0002 = 0.214 or 21.4%, Normalized difference after usage time adjustment for SIPM3: 0.125 + 500 × 0.0002 = 0.225 or 22.5%, This shows that after 500 hours of use, the gain of SIPM will decrease by about 10%, which needs to be compensated by increasing the bias voltage. (4) The formula for calculating the normalized difference after comprehensive adjustment is: Normalized difference after comprehensive adjustment = Basic normalized difference + (Current temperature - Reference temperature) × Temperature coefficient + Usage time (hours) × Aging coefficient; For example: Combining the above conditions (temperature 30℃, usage 500 hours): The normalized difference after comprehensive adjustment of SIPM1 is: 0.127 + (30 25)×0.01+500×0.0002=0.277 or 27.7%, the overall adjusted normalized difference of SIPM2: 0.114+(30 25)×0.01+500×0.0002=0.264 or 26.4%, the normalized difference after overall adjustment for SIPM3: 0.125+(30 25)×0.01+500×0.0002=0.275 or 27.5%. These combined adjustment values ​​will be used to calculate the precise bias adjustment required for each SIPM to ensure gain consistency across the entire array. For a typical SIPM, approximately 0.05V bias adjustment is required for every 1% gain change. Therefore, SIPM1 above requires an additional bias of approximately 1.39V (27.7%×0.05V) to compensate for temperature and aging effects.

[0045] Step S350: The factory-measured temperature, temperature coefficient, usage time, aging coefficient, average third current signal amplitude of all silicon photomultiplier tubes, the second ratio of the third current signal amplitude of each silicon photomultiplier tube to the average third current signal amplitude, the fourth current signal amplitude, and the first difference matrix are stored in the storage unit 60. These factory parameters, together with the previously measured parameters, constitute a complete calibration dataset, providing a basis for subsequent real-time calibration. In practical applications, factory parameters are typically measured in a standard laboratory environment at a temperature of 25±1℃ and recorded with 16-bit precision to ensure data accuracy. For example, for a certain model of SIPM array, the factory-recorded temperature coefficient is 0.0053V / ℃, the aging coefficient is 0.00018V / hour, the average third current signal amplitude is 29.4mV, and the fourth current signal amplitude is 462mV.

[0046] Step S4: Using the simulated light source, obtain the third parameter set of the silicon photomultiplier array under the real-time working environment of the silicon photomultiplier array, and calculate the second difference matrix based on the third parameter set.

[0047] Step S5: Adjust the reverse bias voltage of each silicon photomultiplier tube according to the first difference matrix and the second difference matrix.

[0048] Figure 5 The real-time gain adjustment process of a silicon photomultiplier tube is described: Step S410: Obtain the amplitude of the fifth current signal when each of the silicon photomultiplier tubes (SIPMs) is operating using the first optical signal. During the actual operation of the detector, the current response of each SIPM is measured periodically or when an environmental change is detected, using a simulated light source. This measurement can be automatically triggered, for example, when the temperature change exceeds a preset threshold. In specific implementations, the system can be set to automatically perform a calibration measurement every 4 hours, or to immediately trigger a calibration procedure when the temperature change exceeds 3°C. Taking a 16-channel SIPM array as an example, at an operating temperature of 35℃, the amplitudes of the fifth current signal of SIPM-01 to SIPM-16 may be measured as 23.7mV, 25.5mV, 23.1mV, 24.4mV, 26.2mV, 24.0mV, 24.6mV, 25.9mV, 23.5mV, 24.8mV, 25.7mV, 24.2mV, 24.0mV, 25.4mV, 24.1mV, and 23.8mV, respectively. These values ​​are generally about 16-18% lower than the factory values, mainly due to the cumulative effect of temperature rise and usage time.

[0049] Step S420: Calculate the average amplitude of the fifth current signal for all the silicon photomultiplier tubes and the fifth ratio of the fifth current signal amplitude of each silicon photomultiplier tube to the average amplitude of the fifth current signal. This calculation is similar to the previous average and ratio calculations, but uses measurement data under the current operating conditions. For the example above, the average amplitude of the fifth current signal is 24.6mV, and the fifth ratios for each channel are 0.963, 1.037, 0.939, 0.992, 1.065, 0.976, 1.000, 1.053, 0.955, 1.008, 1.045, 0.984, 0.976, 1.033, 0.980, and 0.967, respectively. By comparing these ratios with the third ratio at the factory, it can be found that the gain changes of each channel are not uniform. For example, the ratio of SIPM-02 changed from 1.027 to 1.037, an increase of about 1%, while the ratio of SIPM-03 changed from 0.949 to 0.939, a decrease of about 1%. This uneven change is exactly what needs to be calibrated and compensated.

[0050] Step S430: Obtain the amplitude of the sixth current signal of the silicon photomultiplier tube (SIPM) array 30 during operation using the first optical signal. This step measures the overall response of the entire SIPM array under the current operating condition. For the aforementioned 16-channel SIPM array, the currently measured amplitude of the sixth current signal is 387mV, which is approximately 16.2% lower than the factory-set amplitude of 462mV. It is noteworthy that this reduction is essentially consistent with the average reduction of individual SIPM measurements, indicating that the overall system response changes are synchronized with the changes in each channel. This is an important indicator for the normal operation of the calibration system.

[0051] Step S440: Obtain the second difference matrix based on the first current signal amplitude, fifth current signal amplitude, first ratio, fifth ratio, second current signal amplitude, and sixth current signal amplitude of each silicon photomultiplier tube. The second difference matrix includes the following parameters: (1) the normalized difference between the fifth current signal amplitude and the first current signal amplitude of each SIPM; (2) the normalized difference after considering the temperature factor; (3) the normalized difference after considering the usage time factor; (4) the comprehensive normalized difference after considering the temperature and usage time factors. Taking SIPM-01 as an example, a detailed calculation is performed: (1) Normalized difference = (23.7-25.3) / 25.3 = -0.063 or -6.3%, indicating that the current signal amplitude is reduced by 6.3% compared with the reference condition. (2) Temperature effect calculation: current temperature 35℃, reference temperature 25℃, temperature difference 10℃, temperature coefficient 0.0053V / ℃. Temperature-induced bias adjustment requirement = 10℃ × 0.0053V / ℃ = 0.053V. Assuming the gain-voltage coefficient of SIPM-01 is 5% / V, the gain change caused by temperature = 0.053V × 5% / V = 0.265%; (3) Aging effect calculation: Assuming the equipment has been used for 1000 hours, the aging coefficient is 0.00018V / hour. The bias adjustment requirement caused by aging = 1000 hours × 0.00018V / hour = 0.18V; the gain change caused by aging = 0.18V × 5% / V = 0.9%; (4) Comprehensive normalized difference = -6.3% + 0.265% + 0.9% = -5.135%; This means that the bias voltage of SIPM-01 needs to be increased by about 0.103V (5.135% ÷ 5% / V) to compensate for the gain change under the current working conditions. Similarly, the bias adjustment values ​​for other SIPM channels can be calculated to form a complete second difference matrix.

[0052] Step S450: Adjust the reverse bias voltage of each silicon photomultiplier tube (SIPM) according to the first and second difference matrices. By comparing the two difference matrices, the precise bias voltage adjustment amount required for each SIPM can be calculated to bring its gain back to the optimal matching state. The calculated reverse bias voltage is verified by the amplitudes of the fourth and sixth current signals.

[0053] Step S460: Based on the first and second difference matrices, the silicon photomultiplier tube array driving circuit 40 adjusts the reverse bias voltage of each silicon photomultiplier tube. By comparing the two difference matrices, the precise bias voltage adjustment amount required for each SIPM can be calculated to bring its gain back to the optimal matching state. The calculated reverse bias voltage is verified using the amplitudes of the fourth and seventh current signals.

[0054] The specific adjustment process follows the mathematical model below: For the i-th SIPM, its bias adjustment amount The calculation formula is: in: This represents the normalized difference value of the i-th SIPM in the first difference matrix. This represents the normalized difference value of the i-th SIPM in the second difference matrix. is the gain-voltage coefficient of the i-th SIPM, typically 5% / V. The temperature compensation term is calculated using the following formula: , The current temperature. For reference temperature, This is the temperature coefficient, with a typical value of 0.0053V / ℃. The aging compensation item is calculated using the following formula: , This is the cumulative usage time (in hours). This represents the aging factor, typically 0.00018 V / hour. Specifically, assuming a 16-channel SIPM array, the parameters of SIPM-05 are as follows: Normalized difference in the first difference matrix. Normalized differences in the second difference matrix Gain-voltage coefficient Current temperature =35℃, reference temperature =25℃, cumulative usage time t=1200 hours; calculate bias adjustment amount. This indicates that the bias voltage of SIPM-05 needs to be reduced by 3.808V to compensate for the gain change under the current conditions.

[0055] Verification steps: After adjusting the bias voltage, measure the amplitude of the seventh current signal of the silicon photomultiplier tube (SIPM) array 30 during operation again using a simulated light source, and calculate the ratio to the amplitude of the fourth current signal. Ideally, this ratio should be close to 1.0, with an allowable error range of ±2%. If it exceeds this range, the system will perform iterative adjustments until the preset accuracy requirement is met. The verification process can be represented by the following mathematical model: Where R is the calibration verification ratio, The amplitude of the seventh current signal is measured after adjustment; A4 represents the amplitude of the fourth current signal at the factory setting. The judgment criterion is... If so, the calibration is successful. If so, iterative adjustments are required. The iterative adjustment uses the following formula: , The current bias adjustment is used for the current calibration step; This new bias adjustment is used for iterative adjustments to ensure the calibration accuracy meets the preset requirements. For example, after the initial adjustment, the measured amplitude of the sixth current signal is 458mV, and the ratio of this amplitude to the fourth current signal amplitude of 462mV is 0.991, which is within the allowable range, indicating successful calibration. If we assume that the measured amplitude of the sixth current signal after the initial adjustment is 445mV, then... The deviation is 3.7%, exceeding the allowable range. Iterative adjustments are necessary at this point. For SIPM-05, the new bias adjustment is: After iterative adjustments, the amplitude of the sixth current signal was measured again to be 460mV, with a ratio of 460 / 462 = 0.996 and an error of only 0.4%, meeting the calibration requirements. Practice shows that the required accuracy is usually achieved in 1-2 iterations, with a maximum of 3 iterations. In practical applications, the system also considers safety limits for bias voltage adjustment; for example, the maximum allowable bias voltage change is usually no more than ±5V to prevent SIPM damage. Furthermore, the system monitors dark current changes during adjustment. If the dark current suddenly increases, it may indicate that the SIPM is approaching its breakdown voltage, at which point the adjustment will automatically stop and a warning will be issued. For large SIPM arrays (such as 64 or 128 channels), the system employs a group adjustment strategy, first coarsely adjusting adjacent 2×2 or 4×4 subarrays, and then finely adjusting individual SIPMs. This hierarchical adjustment method reduces calibration time from linear growth (O(n)) to logarithmic growth (O(logn)), significantly improving the calibration efficiency of large systems. After calibration, the system automatically records the current bias value, signal amplitude, and calibration timestamp for each SIPM, serving as a reference for the next calibration. This data is also used to generate SIPM performance trend charts, helping to predict the SIPM's aging rate and future maintenance needs.

[0056] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

[0057] A computer device according to embodiments of the present disclosure includes a memory and a processor. The memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0058] The processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the computer device to perform desired functions. In one embodiment of this disclosure, the processor is used to execute computer-readable instructions stored in the memory, causing the computer device to perform all or part of the steps of the learning outcome prediction method based on learning behavior data mining of the foregoing embodiments of this disclosure.

[0059] Those skilled in the art will understand that, in order to solve the technical problem of how to achieve a good user experience, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included within the protection scope of this disclosure.

[0060] like Figure 6 This is a schematic diagram of a computer device provided for an embodiment of the present disclosure. It illustrates a structural schematic diagram suitable for implementing the computer device in the embodiments of the present disclosure. Figure 6 The computer device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0061] like Figure 6 As shown, a computer device may include a processor (such as a central processing unit, graphics processing unit, etc.), which can perform various appropriate actions and processes based on programs stored in read-only memory (ROM) or programs loaded from storage devices into random access memory (RAM). The RAM also stores various programs and data required for the operation of the computer device. The processor, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0062] Typically, the following devices can be connected to the I / O interface: input devices, such as sensors or visual information acquisition devices; output devices, such as displays; storage devices, such as magnetic tapes or hard drives; and communication devices. Communication devices allow the computer device to communicate wirelessly or wiredly with other devices (such as edge computing devices) to exchange data. Although a computer device with various devices is illustrated, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively.

[0063] In particular, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device, or installed from a ROM. When the computer program is executed by a processor, all or part of the steps of the learning outcome prediction method based on learning behavior data mining according to embodiments of this disclosure are performed.

[0064] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0065] A computer-readable storage medium according to embodiments of the present disclosure stores non-transitory computer-readable instructions. When the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the learning outcome prediction method based on learning behavior data mining according to the foregoing embodiments of the present disclosure are performed.

[0066] The aforementioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0067] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0068] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0069] In this disclosure, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The block diagrams of devices, apparatuses, devices, and systems involved in this disclosure are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as "comprising," "including," "having," etc., are open-ended terms meaning "including but not limited to," and are used interchangeably with them. The terms "or" and "and" as used herein refer to the terms "and / or," and are used interchangeably with them unless the context clearly indicates otherwise. The term "such as" as used herein refers to the phrase "such as but not limited to," and is used interchangeably with it.

[0070] Additionally, as used herein, the "or" used in a list of items beginning with "at least one" indicates a separate list, such that a list of, for example, "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not imply that the described example is preferred or better than other examples.

[0071] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0072] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0073] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0074] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A radiation detector, specifically comprising an analog light source (10), a crystal (20), a silicon photomultiplier tube (SIPM) array (30), a silicon photomultiplier tube array driving circuit (40), a multi-channel signal acquisition circuit (50), a storage unit (60), and a silicon photomultiplier tube array calibration circuit (70), characterized in that: The simulated light source (10) is located at the front end of the crystal (20), and the SIPM array (30) is located at the rear end of the crystal (20); The simulated light source (10) is used to emit a first light signal, which has the same wavelength, light emission attenuation time and amplitude as the second light signal; The crystal (20) is used to emit a second light signal when irradiated by rays; The silicon photomultiplier tube (SIPM) array (30) includes multiple silicon photomultiplier tubes, each of which is used to generate a current pulse according to the first optical signal or the second optical signal; The silicon photomultiplier array driving circuit (40) is used to provide a reverse bias voltage to each of the silicon photomultiplier tubes; The multi-channel signal acquisition circuit (50) is used to acquire the current pulses generated by each of the silicon photomultiplier tubes; The storage unit (60) is used to store the initial scale of each silicon photomultiplier tube and the initial scale of the silicon photomultiplier tube SIPM array; The silicon photomultiplier array calibration circuit (70) is used to adjust the gain of each silicon photomultiplier tube according to the first optical signal and the initial scale; Methods for gain correction of silicon photomultiplier tube arrays include: A simulated light source is obtained, which emits light with the same wavelength, emission decay time, and amplitude as when a crystal is irradiated by rays; The first parameter set of the silicon photomultiplier array is obtained through the simulated light source under the conditions of an optical integrating sphere or a diffuser; wherein the first parameter set includes the first current signal amplitude of each silicon photomultiplier in the silicon photomultiplier array, the average first current signal amplitude of all silicon photomultiplier, and the first ratio of the first current signal amplitude of each silicon photomultiplier to the average first current signal amplitude. The second parameter set of the silicon photomultiplier tube array under factory conditions is obtained through the simulated light source; wherein the second parameter set includes the third current signal amplitude of each silicon photomultiplier tube in the silicon photomultiplier tube array, the average third current signal amplitude of all silicon photomultiplier tubes, the second ratio of the third current signal amplitude of each silicon photomultiplier tube to the average third current signal amplitude, and the first difference matrix. The third parameter set of the silicon photomultiplier tube array under real-time working environment is obtained through the simulated light source; wherein the third parameter set includes the fifth current signal amplitude of each silicon photomultiplier tube in the silicon photomultiplier tube array, the average fifth current signal amplitude of all silicon photomultiplier tubes, the third ratio of the fifth current signal amplitude of each silicon photomultiplier tube to the average fifth current signal amplitude, and the second difference matrix. The reverse bias voltage of each silicon photomultiplier tube (SIPM) is adjusted according to the first difference matrix and the second difference matrix; wherein, the first difference matrix includes: the normalized difference between the third current signal amplitude and the first current signal amplitude of the SIPM, the normalized difference after considering the temperature factor, the normalized difference after considering the usage time factor, and the comprehensive normalized difference after considering the temperature and usage time factors; the second difference matrix includes the normalized difference between the fifth current signal amplitude and the first current signal amplitude of the SIPM, the normalized difference after considering the temperature factor, the normalized difference after considering the usage time factor, and the comprehensive normalized difference after considering the temperature and usage time factors.

2. The radiation detector according to claim 1, characterized in that: The simulated light source is an ultraviolet or blue light-emitting diode. Under specific conditions, the driving current amplitude of the light-emitting diode is gradually adjusted by using an optical integrating sphere or a diffuser to obtain the first optical signal; wherein the specific conditions include using an optical integrating sphere or adding a diffuser between the analog light source and the silicon photomultiplier tube SIPM, and the combined conditions are to obtain the "temperature-voltage" curve at different temperatures.

3. The radiation detector according to claim 2, characterized in that: The storage of the initial scale of each silicon photomultiplier tube and the initial scale of the silicon photomultiplier tube SIPM array further includes: Each of the silicon photomultiplier tubes is placed in the combined environment of the simulated light source; The amplitude of the first current signal of each silicon photomultiplier tube is obtained by connecting a preamplifier and an oscilloscope to each silicon photomultiplier tube; Calculate the average amplitude of the first current signal of all the silicon photomultiplier tubes and the first ratio of the amplitude of the first current signal of each silicon photomultiplier tube to the average amplitude of the first current signal; Each of the silicon photomultiplier tubes is then combined into a silicon photomultiplier tube SIPM array (30), and the second current signal amplitude of the silicon photomultiplier tube SIPM array (30) is obtained through a preamplifier and an oscilloscope under the specific environment; The average amplitude of the first current signal of all the silicon photomultiplier tubes, the first ratio of the first current signal amplitude of each silicon photomultiplier tube to the average amplitude of the first current signal, and the second current signal amplitude are stored in the storage unit (60).

4. The radiation detector according to claim 3, characterized in that: The storage of the initial scale of each silicon photomultiplier tube and the initial scale of the silicon photomultiplier tube SIPM array further includes: The amplitude of the third current signal at the time of manufacture of each silicon photomultiplier tube is obtained through the first optical signal; Calculate the average amplitude of the third current signal for all the silicon photomultiplier tubes and the third ratio of the amplitude of the third current signal for each silicon photomultiplier tube to the average amplitude of the third current signal; Then, the amplitude of the fourth current signal of the silicon photomultiplier tube (SIPM) array (30) at the time of manufacture is obtained through the first optical signal; A first difference matrix is ​​obtained based on the first current signal amplitude, the third current signal amplitude, the first ratio, the third ratio, the second current signal amplitude, and the fourth current signal amplitude of each silicon photomultiplier tube; The average amplitude of the third current signal of all the silicon photomultiplier tubes, the second ratio of the amplitude of the third current signal of each silicon photomultiplier tube to the average amplitude of the third current signal, the amplitude of the fourth current signal, and the first difference matrix are stored in the memory cell (60).

5. The radiation detector according to claim 4, characterized in that: The step of adjusting the gain of each silicon photomultiplier tube according to the first optical signal and the initial scale further includes: The amplitude of the fifth current signal when each silicon photomultiplier tube is working is obtained through the first optical signal; Calculate the average amplitude of the fifth current signal of all the silicon photomultiplier tubes and the third ratio of the amplitude of the fifth current signal of each silicon photomultiplier tube to the average amplitude of the fifth current signal; Then, the amplitude of the sixth current signal when the silicon photomultiplier tube (SIPM) array (30) is in operation is obtained through the first optical signal; A second difference matrix is ​​obtained based on the first current signal amplitude, the fifth current signal amplitude, the first ratio, the third ratio, the second current signal amplitude, and the sixth current signal amplitude of each silicon photomultiplier tube; Based on the first difference matrix and the second difference matrix, the silicon photomultiplier array driving circuit (40) adjusts the reverse bias voltage of each silicon photomultiplier.

6. The X-ray detector according to claim 5, characterized in that: The step of adjusting the reverse bias voltage of each silicon photomultiplier tube by the silicon photomultiplier array driving circuit (40) according to the first difference matrix and the second difference matrix further includes: The bias adjustment amount of the i-th silicon photomultiplier tube The calculation formula is: in: This represents the normalized difference value of the i-th silicon photomultiplier tube in the first difference matrix. This represents the normalized difference value of the i-th silicon photomultiplier tube in the second difference matrix. Let i be the gain-voltage coefficient of the i-th silicon photomultiplier tube. For temperature compensation, This is an aging compensation item.

7. The radiation detector according to claim 6, characterized in that: The calculated reverse bias voltage is verified based on the amplitudes of the fourth and seventh current signals. The verification formula is: R=A7 / A4, where R is the calibration verification ratio, A7 is the amplitude of the seventh current signal measured after adjustment, and A4 is the amplitude of the fourth current signal at the factory. Set a threshold and determine whether the calibration is successful based on the relationship between the calibration verification ratio R and the threshold. If calibration fails, the bias adjustment ΔVi is iteratively adjusted.

8. A gain correction method for a silicon photomultiplier tube array, the method being used in a radiation detector, the radiation detector comprising an analog light source (10), a crystal (20), and a silicon photomultiplier tube (SIPM) array (30), characterized in that: The simulated light source (10) is located at the front end of the crystal (20), and the SIPM array (30) is located at the rear end of the crystal (20); The simulated light source can emit light with the same wavelength, emission decay time, and amplitude as when the crystal (20) is irradiated by rays; The first parameter set of the silicon photomultiplier array is obtained under the first environment through the simulated light source; wherein the first parameter set includes the first current signal amplitude of each silicon photomultiplier in the silicon photomultiplier array, the average first current signal amplitude of all silicon photomultiplier, and the first ratio of the first current signal amplitude of each silicon photomultiplier to the average first current signal amplitude. Using the simulated light source, a second parameter set of the silicon photomultiplier tube array under a second environment is obtained; wherein the second parameter set includes the third current signal amplitude of each silicon photomultiplier tube in the silicon photomultiplier tube array, the average third current signal amplitude of all silicon photomultiplier tubes, a second ratio of the third current signal amplitude of each silicon photomultiplier tube to the average third current signal amplitude, and a first difference matrix; wherein the first difference matrix includes: the normalized difference between the third current signal amplitude and the first current signal amplitude of the silicon photomultiplier tube SIPM, the normalized difference after considering temperature factors, the normalized difference after considering usage time factors, and the comprehensive normalized difference after considering temperature and usage time factors; The third parameter set of the silicon photomultiplier array under the third environment is obtained through the simulated light source; wherein the third parameter set includes the fifth current signal amplitude of each silicon photomultiplier in the silicon photomultiplier array, the average fifth current signal amplitude of all silicon photomultiplier, the third ratio of the fifth current signal amplitude of each silicon photomultiplier to the average fifth current signal amplitude, and the second difference matrix. The reverse bias voltage of each silicon photomultiplier tube (SIPM) is adjusted according to the first difference matrix and the second difference matrix; wherein, the first difference matrix includes: the normalized difference between the third current signal amplitude and the first current signal amplitude of the SIPM, the normalized difference after considering the temperature factor, the normalized difference after considering the usage time factor, and the comprehensive normalized difference after considering the temperature and usage time factors; the second difference matrix includes the normalized difference between the fifth current signal amplitude and the first current signal amplitude of the SIPM, the normalized difference after considering the temperature factor, the normalized difference after considering the usage time factor, and the comprehensive normalized difference after considering the temperature and usage time factors.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing a computer to perform the silicon photomultiplier tube array gain correction method for the X-ray detector of claim 8.

Images