SiPM scintillator detector

Abstract

This invention provides a SiPM-type scintillator detector, comprising a signal detection module, a signal amplification and processing module, and a signal coincidence output module connected in sequence. The signal detection module includes a scintillator crystal and a SiPM array, the SiPM array comprising a first subarray and a second subarray. The signal amplification and processing module is used to sum and amplify each first electrical signal output from the first subarray to obtain a first amplified signal, and also to sum and amplify each second electrical signal output from the second subarray to obtain a second amplified signal. The signal coincidence output module is used to determine an output signal based on the first amplified signal and / or the second amplified signal when the first amplified signal and the second amplified signal satisfy a coincidence condition during the detection process. This invention can effectively reduce leakage current and dark noise in the output signal of the SiPM-type scintillator detector, ensuring the effectiveness of the output signal, thereby improving the sensitivity of the SiPM-type scintillator detector.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation detection equipment technology, and in particular to a SiPM type scintillator detector. Background Technology

[0002] Compared with traditional photomultiplier tubes, silicon photomultiplier tubes (SiPMs) have advantages such as low operating voltage, small size, high gain, high quantum efficiency, and high integration, and are widely used in the field of detection equipment.

[0003] Detectors used for space astronomical observations typically employ SiPM-type scintillator detectors, which use a crystal scintillator combined with a SiPM array for readout. However, during the on-orbit operation of SiPM-type scintillator detectors carried on satellites, charged particles in the space environment can cause radiation damage to the semiconductor photoelectric conversion devices (SiPMs), leading to increased leakage current and dark noise, thus compromising the sensitivity of the SiPM-type scintillator detector. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a SiPM type scintillator detector.

[0005] This invention provides a SiPM type scintillator detector, comprising: a signal detection module, a signal amplification and processing module, and a signal coincidence output module connected in sequence;

[0006] The signal detection module includes a scintillation crystal and a SiPM array, wherein the SiPM array includes a first subarray and a second subarray.

[0007] The signal amplification and processing module is used to sum and amplify each of the first electrical signals output by the first subarray to obtain a first amplified signal, and is also used to sum and amplify each of the second electrical signals output by the second subarray to obtain a second amplified signal;

[0008] The signal coincidence output module is used to determine an output signal based on the first amplified signal and / or the second amplified signal when it is determined that the first amplified signal and the second amplified signal meet the coincidence condition during the detection process.

[0009] According to the SiPM type scintillator detector provided by the present invention, the signal coincidence output module is specifically used for:

[0010] Based on the comparison result between the signal value of the first amplified signal and the preset value, the first overthreshold time corresponding to the first amplified signal is determined, and based on the comparison result between the signal value of the second amplified signal and the preset value, the second overthreshold time corresponding to the second amplified signal is determined.

[0011] If both the first threshold crossing time and the second threshold crossing time exist, the threshold crossing time difference between the first amplified signal and the second amplified signal is determined based on the first threshold crossing time and the second threshold crossing time.

[0012] Based on the comparison result between the overthreshold time difference and the preset coincidence time window, it is determined whether the first amplified signal and the second amplified signal meet the coincidence condition.

[0013] According to the SiPM type scintillator detector provided by the present invention, the signal coincidence output module is further used for:

[0014] If the first threshold time and / or the second threshold time do not exist, it is determined that the first amplified signal and the second amplified signal do not meet the condition.

[0015] The SiPM-type scintillator detector provided by the present invention further includes a time window construction module, the time window module being used for:

[0016] During the test, multiple first amplified signals output by the signal amplification and processing module and multiple second amplified signals corresponding to the multiple first amplified signals are acquired within a preset time period.

[0017] Determine the overthreshold time difference between each of the first amplified signals and the corresponding second amplified signal, and use it as the test time difference;

[0018] The conformity time window is determined based on the distribution of the test time differences.

[0019] According to the SiPM type scintillator detector provided by the present invention, the signal coincidence output module is specifically used for:

[0020] Obtain the distance between the amplitude of the first amplified signal and the amplitude of the second amplified signal, and use it as the target distance;

[0021] Based on the comparison result between the target distance and the distance threshold, it is determined whether the first amplified signal and the second amplified signal meet the compliance condition; wherein, the distance threshold is obtained based on the average of the amplitude of the first amplified signal and the amplitude of the second amplified signal.

[0022] According to the SiPM type scintillator detector provided by the present invention, the signal coincidence output module is further used for:

[0023] When it is determined, based on the first amplified signal and the second amplified signal, that the first amplified signal and the second amplified signal do not meet the condition, the first amplified signal and the second amplified signal are discarded.

[0024] According to the SiPM scintillator detector provided by the present invention, the signal amplification and processing module includes a first amplification and processing module and a second amplification and processing module.

[0025] The first amplification processing module includes N (N≥1) stages of first summing amplification circuits, used to perform group summing amplification processing on each of the first electrical signals;

[0026] And / or,

[0027] The second amplification processing module includes M (M≥1) stages of second summing amplification circuits, used to perform grouped summing amplification processing on each of the second electrical signals.

[0028] According to the SiPM scintillator detector provided by the present invention, the output terminal of the first summing amplifier circuit of the Nth stage is connected to the signal coincidence output module through a first differential circuit. The first differential circuit is used to perform differential processing on the first amplified signal output by the first summing amplifier circuit of the Nth stage.

[0029] And / or,

[0030] The output of the second summing amplifier circuit of the Mth stage is connected to the signal coincidence output module through a second differential circuit. The second differential circuit is used to perform differential processing on the second amplified signal output by the second summing amplifier circuit of the Mth stage.

[0031] According to the SiPM-type scintillator detector provided by the present invention, the first subarray includes a plurality of first SiPM units, the second subarray includes a plurality of second SiPM units, and the first SiPM units and the second SiPM units are alternately arranged in a first direction and / or a second direction.

[0032] The SiPM scintillator detector provided by the present invention further includes a first voltage source, a second voltage source, a voltage adjustment module, and a temperature acquisition module, wherein the first voltage source is a fixed voltage source and the second voltage source is an adjustable voltage source;

[0033] The anode of each first SiPM unit and the anode of each second SiPM unit are connected to the first voltage source, and the cathode of each first SiPM unit and the cathode of each second SiPM unit are connected to the second voltage source.

[0034] The temperature acquisition module is used to acquire the current ambient temperature;

[0035] The voltage regulation module is used to determine the target output voltage of the second voltage source based on the current ambient temperature, and to control the second voltage source to perform voltage regulation based on the target output voltage.

[0036] The SiPM scintillator detector provided by this invention includes a signal detection module, a signal amplification and processing module, and a signal coincidence output module connected in sequence. The signal detection module includes a scintillator crystal and a SiPM array. The SiPM array includes a first subarray and a second subarray. The signal amplification and processing module sums and amplifies each first electrical signal output from the first subarray to obtain a first amplified signal, and sums and amplifies each second electrical signal output from the second subarray to obtain a second amplified signal. During the detection process, the signal coincidence output module determines the output signal based on the first amplified signal and the second amplified signal, and when the first amplified signal and the second amplified signal meet the coincidence condition, it determines the output signal based on the first amplified signal and / or the second amplified signal. This effectively reduces leakage current and dark noise in the output signal of the SiPM scintillator detector, ensures the effectiveness of the output signal, and thus improves the sensitivity of the SiPM scintillator detector. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of the SiPM type scintillator detector provided by the present invention;

[0039] Figure 2 This is a schematic diagram of the waveforms of the first amplified signal and the second amplified signal provided by the present invention satisfying the conditions;

[0040] Figure 3 This is a waveform diagram showing that the first amplified signal and the second amplified signal provided by the present invention do not meet the conditions.

[0041] Figure 4 This is a distribution diagram of multiple test time differences provided by the present invention;

[0042] Figure 5 This is a connection diagram of the SiPM array, signal amplification and processing module, and signal coincidence output module provided by the present invention;

[0043] Figure 6This is a schematic diagram of the distribution of SiPM cells in the SiPM array provided by the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0045] The following is combined Figures 1-6 This invention describes a SiPM-type scintillator detector. This SiPM-type scintillator detector can be carried by satellites for space astronomical observations, such as gamma-ray detection. Figure 1 As shown, the SiPM-type scintillator detector of the present invention includes at least: a signal detection module 101, a signal amplification and processing module 102, and a signal coincidence output module 103 connected in sequence;

[0046] The signal detection module 101 includes a scintillation crystal and a SiPM array, wherein the SiPM array includes a first subarray and a second subarray.

[0047] The signal amplification and processing module 102 is used to perform summation and amplification processing on each of the first electrical signals output by the first subarray to obtain a first amplified signal, and is also used to perform summation and amplification processing on each of the second electrical signals output by the second subarray to obtain a second amplified signal;

[0048] The signal coincidence output module 103 is used to determine an output signal based on the first amplified signal and / or the second amplified signal when it is determined that the first amplified signal and the second amplified signal meet the coincidence condition during the detection process.

[0049] In this embodiment, the signal detection module 101 is used to detect target rays, such as gamma rays. The signal detection module 101 is constructed based on a scintillation crystal and a SiPM array. The scintillation crystal is used to excite scintillation light under the action of the target ray, and the SiPM array is used to receive the scintillation light excited by the scintillation crystal and convert the scintillation light into an electrical signal before outputting it to the signal amplification and processing module 102.

[0050] As an optional implementation, the signal detection module 101 may include a beryllium window, a scintillation crystal, a quartz window, and a SiPM array arranged sequentially from top to bottom. A crystal cell, such as an aluminum-magnesium alloy crystal cell, may be disposed around the scintillation crystal. When a target ray is present in the environment where the SiPM scintillator detector is located, the target ray enters through the beryllium window and acts on the scintillation crystal. The scintillation light excited by the scintillation crystal passes through the quartz window and is received by the SiPM array. The SiPM array converts the scintillation light into an electrical signal and outputs it to the signal amplification and processing module 102.

[0051] The scintillation crystal can be made of sodium iodide, which has high light yield, high density, and short light decay time. Understandably, the larger the size of the scintillation crystal, the higher the sensitivity of the scintillator detector. As an optional implementation, the sodium iodide crystal can have a diameter of 101 mm and a thickness of 10 mm.

[0052] A SiPM array can include multiple SiPM units, each of which can include multiple avalanche photodiodes (APDs) operating in Geiger mode. Each APD is a pixel, and upon receiving a photon, it outputs a charge pulse signal. The sum of the charges output by all APDs is proportional to the total number of photons detected by that SiPM unit. The number of SiPM units in the SiPM array can be determined based on the size of the scintillation crystal. For example, if the diameter of the scintillation crystal is 101 mm, the number of SiPM units can be 100, and the size of each SiPM unit can be 6 mm × 6 mm.

[0053] Multiple SiPM units in a SiPM array can be divided into two groups to form a first subarray and a second subarray. The SiPM units in the first subarray can serve as first SiPM units, and the SiPM units in the second subarray can serve as second SiPM units. The number of first SiPM units can be equal to the number of second SiPM units, thus effectively ensuring the consistency of the first amplified signal and the second amplified signal when the target ray is incident. Each first SiPM unit in the first subarray outputs a first electrical signal to the signal amplification and processing module 102, and each second SiPM unit in the second subarray outputs a second electrical signal to the signal amplification and processing module 102.

[0054] The signal amplification and processing module 102 is used to sum and amplify each of the first electrical signals output by the first subarray to obtain a first amplified signal. At the same time, the signal amplification and processing module 102 is also used to sum and amplify each of the second electrical signals output by the second subarray to obtain a second amplified signal.

[0055] During the detection process, the signal coincidence output module 103 can determine whether the first amplified signal and the second amplified signal meet the coincidence condition based on the first amplified signal and the second amplified signal. For example, it can determine whether the amplitude of the first amplified signal matches the amplitude of the second amplified signal. If they match, the coincidence condition is met; otherwise, it is not met. It can also determine whether the threshold crossing time of the first amplified signal matches the threshold crossing time of the second amplified signal. If they match, the coincidence condition is met; otherwise, it is not met.

[0056] If the first amplified signal and the second amplified signal meet the conditions, the output signal of the SiPM scintillator detector is determined based on the first amplified signal and / or the second amplified signal. For example, a preset amplified signal in the first amplified signal and the second amplified signal can be used as the output signal. Alternatively, the threshold crossing time of the first amplified signal and the second amplified signal can be determined, and the amplified signal with the earlier threshold crossing time in the first amplified signal and the second amplified signal can be used as the output signal.

[0057] After determining the output signal, it can be sent to a signal receiving device for analysis and processing of the detection results. Considering that the scintillation light excited by the scintillation crystal can be simultaneously received by the first and second sub-arrays, the signal is output only when the first and second amplified signals meet certain conditions. This effectively reduces leakage current and dark noise in the output signal of the SiPM scintillator detector, ensuring the effectiveness of the output signal and thus improving the sensitivity of the SiPM scintillator detector.

[0058] This embodiment of the SiPM scintillator detector includes a signal detection module 101, a signal amplification and processing module 102, and a signal coincidence output module 103 connected in sequence. The signal detection module 101 includes a scintillator crystal and a SiPM array. The SiPM array includes a first subarray and a second subarray. The signal amplification and processing module 102 performs summation and amplification processing on each first electrical signal output from the first subarray to obtain a first amplified signal, and performs summation and amplification processing on each second electrical signal output from the second subarray to obtain a second amplified signal. During the detection process, the signal coincidence output module 103 determines the output signal based on the first amplified signal and the second amplified signal when the first amplified signal and the second amplified signal meet the coincidence condition. This effectively reduces the leakage current and dark noise in the output signal of the SiPM scintillator detector, ensures the effectiveness of the output signal, and improves the sensitivity of the SiPM scintillator detector.

[0059] In an exemplary embodiment, the signal coincidence output module 103 is specifically used for:

[0060] Based on the comparison result between the signal value of the first amplified signal and the preset value, the first overthreshold time corresponding to the first amplified signal is determined, and based on the comparison result between the signal value of the second amplified signal and the preset value, the second overthreshold time corresponding to the second amplified signal is determined.

[0061] If both the first threshold crossing time and the second threshold crossing time exist, the threshold crossing time difference between the first amplified signal and the second amplified signal is determined based on the first threshold crossing time and the second threshold crossing time.

[0062] Based on the comparison result between the overthreshold time difference and the preset coincidence time window, it is determined whether the first amplified signal and the second amplified signal meet the coincidence condition.

[0063] In this embodiment, the signal values ​​of the first amplified signal at each moment during its rise can be compared with preset values, and the moment when the signal value of the first amplified signal reaches the preset value is taken as the first threshold crossing moment corresponding to the first amplified signal. The preset value can be set according to accuracy requirements.

[0064] Simultaneously, the signal value of the second amplified signal at each moment during its rise can be compared with the preset value, and the moment when the signal value of the second amplified signal reaches the preset value can be taken as the second overthreshold moment corresponding to the second amplified signal.

[0065] It is understandable that if the signal value of the first amplified signal is less than the preset value at each moment during the rise of the signal, it is determined that the first threshold moment does not exist; if the signal value of the second amplified signal is less than the preset value at each moment during the rise of the signal, it is determined that the second threshold moment does not exist.

[0066] If both the first and second threshold crossing times exist, the absolute value of the difference between the first and second threshold crossing times can be obtained and used as the threshold crossing time difference between the first and second amplified signals. The threshold crossing time difference is then compared with a preset compliance time window. Based on the comparison result between the threshold crossing time difference and the preset compliance time window, it is determined whether the first and second amplified signals meet the compliance conditions.

[0067] The coincidence time window is used to characterize the upper limit of the cross-threshold time difference between the first amplified signal and the second amplified signal. The coincidence time window can be predetermined and stored in the signal coincidence output module 103 so that it can be called in real time during the detection process. For example, the coincidence time window can be 100 nanoseconds, that is, it means that the value range of the cross-threshold time difference is 0 to 100 nanoseconds.

[0068] In practice, if the overthreshold time difference meets the value range corresponding to the time window, it indicates that the first overthreshold time corresponding to the first amplified signal matches the second overthreshold time corresponding to the second amplified signal, and the first and second amplified signals are determined to meet the compliance condition. If the overthreshold time difference does not meet the value range corresponding to the time window, it indicates that the first overthreshold time corresponding to the first amplified signal does not match the second overthreshold time corresponding to the second amplified signal, and the first and second amplified signals are determined to not meet the compliance condition. This effectively ensures the reliability of the determination result of whether the first and second amplified signals meet the compliance condition, and further improves the effectiveness of the output signal.

[0069] The following is passed Figure 2 and Figure 3 Examples are provided to illustrate the situations where the conditions are met and those where the conditions are not met. Figure 2 The time difference between the first threshold time corresponding to the first amplified signal and the second threshold time corresponding to the second amplified signal satisfies the value range corresponding to the time window, indicating that the first amplified signal and the second amplified signal meet the condition. Figure 3 In this context, the second overthreshold moment corresponding to the second amplified signal does not exist, indicating that the first and second amplified signals do not meet the condition. Figure 2 and Figure 3 In the diagram, the horizontal axis represents time, with the smallest unit being 1 microsecond, and the vertical axis represents the signal value, with the smallest unit being 20 millivolts.

[0070] The effect of determining the output signal based on the first amplified signal and / or the second amplified signal when the first amplified signal and the second amplified signal meet the conditions based on the time window can be described by equation (1):

[0071] n=2τ·n1·n2 (1)

[0072] In the formula, n is the count rate of the output signal, n1 is the count rate of the first amplified signal, n2 is the count rate of the second amplified signal, and τ is the coincidence time window, where the count rate is the number of signals transmitted per second. When the coincidence time window is 100 nanoseconds, both n1 and n2 are 10. 5 At a count rate of 1000 counts per second, the count rate of the output signal of the SiPM scintillator detector can be reduced to 2 × 10⁻⁶. 3 The count rate is reduced by 1000 counts per second, which effectively reduces the leakage current and dark noise count rate in the output signal of the SiPM scintillator detector, thereby improving the sensitivity of the SiPM scintillator detector.

[0073] In an exemplary embodiment, the signal coincidence output module 103 is further configured to:

[0074] If the first threshold time and / or the second threshold time do not exist, it is determined that the first amplified signal and the second amplified signal do not meet the condition.

[0075] In this embodiment, if the first threshold time and / or the second threshold time do not exist, it indicates that at least one of the first amplified signal and the second amplified signal is a leakage current signal or a dark noise signal. It can be directly determined that the first amplified signal and the second amplified signal do not meet the compliance condition, thereby further improving the reliability of the determination result of whether the first amplified signal and the second amplified signal meet the compliance condition.

[0076] In an exemplary embodiment, a time window construction module is also included, the time window construction module being used to:

[0077] During the test, multiple first amplified signals output by the signal amplification and processing module 102 within a preset time period and multiple second amplified signals corresponding to the multiple first amplified signals are acquired.

[0078] Determine the overthreshold time difference between each of the first amplified signals and the corresponding second amplified signal, and use it as the test time difference;

[0079] The conformity time window is determined based on the distribution of the test time differences.

[0080] This embodiment also includes a time window construction module, which is used to construct a time window that conforms to the test data. For example, a target ray can be emitted from a preset radiation source. After the signal detection module 101 in the SiPM scintillator detector receives the target ray, it outputs a first amplified signal and a second amplified signal to the time window construction module through the signal amplification and processing module 102. The time window construction module then constructs a time window based on each of the first and second amplified signals.

[0081] In practice, a function selection device, such as a button or a touch screen, can be set on the SiPM type scintillator detector to select the detection function and the test function. When the detection function is selected, the output signal is determined and output by the signal coincidence output module 103. When the test function is selected, the coincidence time window is constructed by the time window construction module.

[0082] In the process of constructing a time window that conforms to the time window, the time window construction module can obtain multiple first amplified signals output by the signal amplification and processing module 102 within a preset time period and multiple second amplified signals that correspond one-to-one with the multiple first amplified signals, and determine the threshold time difference between each first amplified signal and the corresponding second amplified signal as the test time difference, thereby obtaining multiple test time differences.

[0083] During implementation, the distribution of multiple test time differences can be obtained. For example, the distribution of multiple test time differences can be represented by a line graph or bar chart. The distribution of multiple test time differences can be as follows: Figure 4 As shown, Figure 4 In the diagram, the horizontal axis represents the test time difference, and the vertical axis represents the number of first amplified signals. In determining the conformance time window based on the distribution of multiple test time differences, a target interval for a preset time difference can be determined based on a preset proportion, and the conformance time window can be determined based on this target interval. As an optional implementation, the absolute values ​​of the lower and upper limits of the target interval can be obtained, and the larger of these two values ​​can be used as the conformance time window. This effectively reduces the risk of losing valid signals while minimizing leakage current and dark noise during signal conformation through the conformance time window.

[0084] In an exemplary embodiment, the signal coincidence output module 103 is specifically used for:

[0085] Obtain the distance between the amplitude of the first amplified signal and the amplitude of the second amplified signal, and use it as the target distance;

[0086] Based on the comparison result between the target distance and the distance threshold, it is determined whether the first amplified signal and the second amplified signal meet the compliance condition; wherein, the distance threshold is obtained based on the average of the amplitude of the first amplified signal and the amplitude of the second amplified signal.

[0087] In this embodiment, the amplitude of the first amplified signal and the amplitude of the second amplified signal can be averaged to obtain the average value of the amplitude of the first amplified signal and the amplitude of the second amplified signal, that is, the average amplitude. The product of the preset proportional coefficient and the average amplitude is used as the distance threshold. For example, 30% of the average amplitude can be used as the distance threshold.

[0088] In practice, the absolute value of the difference between the amplitude of the first amplified signal and the amplitude of the second amplified signal can be obtained as the distance between the amplitude of the first amplified signal and the amplitude of the second amplified signal, i.e., the target distance. The target distance is then compared with a distance threshold to determine whether the first amplified signal and the second amplified signal meet the conditions based on the comparison result.

[0089] For example, if the target distance is less than or equal to the distance threshold, it indicates that the amplitude of the first amplified signal matches the amplitude of the second amplified signal, and it is determined that the first amplified signal and the second amplified signal meet the compliance condition; if the target distance is greater than the distance threshold, it indicates that the amplitude of the first amplified signal does not match the amplitude of the second amplified signal, and it is determined that the first amplified signal and the second amplified signal do not meet the compliance condition. This effectively ensures the reliability of the determination result of whether the first amplified signal and the second amplified signal meet the compliance condition, and further improves the effectiveness of the output signal.

[0090] In an exemplary embodiment, the signal coincidence output module 103 is further configured to:

[0091] When it is determined, based on the first amplified signal and the second amplified signal, that the first amplified signal and the second amplified signal do not meet the condition, the first amplified signal and the second amplified signal are discarded.

[0092] In this embodiment, the signal coincidence output module 103 is also used to treat the first amplified signal and the second amplified signal as noise signals and discard them when the first amplified signal and the second amplified signal do not meet the coincidence condition. This can effectively reduce the leakage current and the count rate of dark noise in the signal output by the SiPM scintillator detector, thereby improving the sensitivity of the SiPM scintillator detector.

[0093] Understandably, leakage current and dark noise count rate can also be reduced by decreasing the density of SiPM cells in the SiPM array and / or by reducing the operating voltage of the SiPM cells. Additionally, leakage current and dark noise count rate can also be reduced by lowering the operating temperature of the SiPM scintillator detector.

[0094] In an exemplary embodiment, the signal amplification processing module 102 includes a first amplification processing module and a second amplification processing module;

[0095] The first amplification processing module includes N (N≥1) stages of first summing amplification circuits, used to perform group summing amplification processing on each of the first electrical signals;

[0096] And / or,

[0097] The second amplification processing module includes M (M≥1) stages of second summing amplification circuits, used to perform grouped summing amplification processing on each of the second electrical signals.

[0098] In this embodiment, the signal amplification processing module 102 may include a first amplification processing module and a second amplification processing module. The input terminal of the first amplification processing module is connected to the first subarray, and the output terminal of the first amplification processing module is connected to the signal coincidence output module 103, for performing group summation amplification processing on each of the first electrical signals output by the first subarray. The input terminal of the second amplification processing module is connected to the second subarray, and the output terminal of the second amplification processing module is connected to the signal coincidence output module 103, for performing group summation amplification processing on each of the second electrical signals output by the second subarray.

[0099] In implementation, all first SiPM units in the first subarray can be grouped according to the number of stages of the first summing amplifier circuit. The number of stages of the first summing amplifier circuit is the same as the grouping stage of the first SiPM units, so that the signals output by each group of first SiPM units can be summed and amplified by the first amplification processing module. Multiple first SiPM units in the smallest group are connected in parallel, and the signal output by the smallest group is the sum of the first electrical signals output by each first SiPM unit in that smallest group. That is, the signals output by multiple smallest group units are summed and amplified by the first-stage first summing amplifier circuit. When N > 1, the nth (1 < n ≤ N)th stage first summing amplifier circuit is used to sum and amplify the signals output by each of the (n-1)th stage first summing amplifier circuits. It can be understood that when N = 1, the number of first summing amplifier circuits is 1, thus effectively reducing the required number of first summing amplifier circuits while ensuring the reliability of summing and amplifying the first electrical signals, thereby reducing the complexity of the structure.

[0100] Simultaneously, all second SiPM units in the second subarray can be grouped according to the number of stages of the second summing amplifier circuit. The number of stages of the second summing amplifier circuit is the same as the grouping stage of the second SiPM units, so that the signals output by each group of second SiPM units can be summed and amplified by the second amplification processing module. Multiple second SiPM units in the smallest group unit are connected in parallel, and the signal output by the smallest group unit is the sum of the second electrical signals output by each second SiPM unit in that smallest group unit. That is, the signals output by multiple smallest group units are summed and amplified by the first-stage second summing amplifier circuit. When M > 1, the m-th (1 < m ≤ M)-th stage second summing amplifier circuit is used to sum and amplify the signals output by each second summing amplifier circuit in the (m-1)-th stage. It can be understood that when M = 1, the number of second summing amplifier circuits is 1, thus effectively reducing the number of second summing amplifier circuits while ensuring the reliability of summing and amplifying the second electrical signals, thereby reducing the complexity of the structure.

[0101] As an optional implementation, N=M=2, the connection diagram of the SiPM array, signal amplification and processing module 102 and signal convergence output module 103 is shown below. Figure 5 As shown. All first SiPM units 501 in the first subarray are divided into two first SiPM groups. Each first SiPM group is further divided into four first SiPM subgroups 502, and each first SiPM group is connected to a corresponding first-stage first summing amplifier circuit 503. Each first SiPM group and its corresponding first-stage first summing amplifier circuit 503 are considered as a first detection amplifier circuit 504. Each first SiPM subgroup 502 may include 6-7 first SiPM units 501. The first SiPM units 501 in the first SiPM subgroup 502 are connected in parallel, and the anode of each first SiPM unit 501 is connected to a first voltage source through a first filter circuit. Figure 5 (Not shown in the image), the cathode of each first SiPM unit 501 and the second voltage source ( Figure 5 (Not shown in the diagram) The output of the first SiPM subgroup 502 is connected to the first-stage first summing amplifier circuit 503 via a first signal coupling circuit. The first filter circuit includes a first capacitor C1 and a first resistor R1, and the first signal coupling circuit includes a second capacitor C2 and a second resistor R2. The first-stage first summing amplifier circuit 503 includes a first operational amplifier U1. The inverting input of the first operational amplifier U1 is connected to four parallel first branches. Each of the four first branches has a first amplification resistor Ra1, a second amplification resistor Ra2, a third amplification resistor Ra3, and a fourth amplification resistor Ra4. The other ends of the four first branches are connected to the outputs of the four first SiPM subgroups 502 respectively. The inverting input of the first operational amplifier U1 is also connected to its output via a first feedback resistor Rf1 and a first phase compensation capacitor Cf1, with the first feedback resistor Rf1 and the first phase compensation capacitor Cf1 connected in parallel. The non-inverting input terminal of the first operational amplifier U1 is grounded through the first protection resistor Rb1, and the output terminal of the first operational amplifier U1 is also connected to the input terminal of the second-stage first summing amplifier circuit 505. The structure of the second-stage first summing amplifier circuit 505 can be referred to the first-stage first summing amplifier circuit 503, and will not be described in detail here.

[0102] Simultaneously, all the second SiPM units 506 in the second subarray are divided into two second SiPM groups. Each second SiPM group is further divided into four second SiPM subgroups 507, and each second SiPM group is connected to a corresponding first-stage second summing amplifier circuit 508. Each second SiPM group and its corresponding first-stage second summing amplifier circuit 508 are considered as a second detection amplifier circuit 509. Each second SiPM subgroup 507 may include 6-7 second SiPM units 506. The second SiPM units 506 in the second SiPM subgroup 507 are connected in parallel, and the anode of each second SiPM unit 506 is connected to a first voltage source through a second filter circuit. Figure 5 (Not shown in the image) is connected, and the cathode of each second SiPM unit 506 is connected to the second voltage source ( Figure 5 (Not shown in the diagram) The output of the second SiPM subgroup 507 is connected to the first-stage second summing amplifier circuit 508 via a second signal coupling circuit. The second filter circuit includes a third capacitor C3 and a third resistor R3, and the second signal coupling circuit includes a fourth capacitor C4 and a fourth resistor R4. The first-stage second summing amplifier circuit 508 includes a second operational amplifier U2. The inverting input of the second operational amplifier U2 is connected to four parallel second branches. Each of the four second branches has a fifth amplifying resistor Ra5, a sixth amplifying resistor Ra6, a seventh amplifying resistor Ra7, and an eighth amplifying resistor Ra8. The other ends of the four second branches are connected to the outputs of the four second SiPM subgroups 507 respectively. The inverting input of the second operational amplifier U2 is also connected to its output via a second feedback resistor Rf2 and a second phase compensation capacitor Cf2. The second feedback resistor Rf2 and the second phase compensation capacitor Cf2 are connected in parallel. The non-inverting input terminal of the second operational amplifier U2 is grounded through the second protection resistor Rb2, and the output terminal of the second operational amplifier U2 is also connected to the input terminal of the second-stage second summing amplifier circuit 510. The structure of the second-stage second summing amplifier circuit 510 can be referred to the first-stage second summing amplifier circuit 508, and will not be described in detail here.

[0103] In addition, the output terminals of the second-stage first summing amplifier circuit 505 and the second-stage second summing amplifier circuit 510 are both connected to the signal coincidence output module 103. The second-stage first summing amplifier circuit 505 outputs a first amplified signal to the signal coincidence output module 103, and the second-stage second summing amplifier circuit 510 outputs a second amplified signal to the signal coincidence output module 103. When the first amplified signal and the second amplified signal meet the coincidence condition, the signal coincidence output module 103 generates an output signal and performs data downlink, transmitting the output signal to the signal receiving device so that the detection result can be analyzed and processed by the signal receiving device.

[0104] As another optional implementation, the signal amplification processing module 102 may include a plurality of first signal amplification devices connected one-to-one with a plurality of first SiPM units, a plurality of second signal amplification devices connected one-to-one with a plurality of second SiPM units, a first summing device, and a second summing device. The input terminal of the first summing device is connected to the output terminal of each of the first signal amplification devices, and the output terminal of the first summing device is connected to the signal convergence output module 103. The input terminal of the second summing device is connected to the output terminal of each of the second signal amplification devices, and the output terminal of the second summing device is connected to the signal convergence output module 103. This allows the first electrical signal output by the corresponding first SiPM unit to be amplified by the first signal amplification device, the second electrical signal output by the corresponding second SiPM unit to be amplified by the second signal amplification device, and the results of the amplification of each first electrical signal to be summed by the first summing device to obtain a first amplified signal. The results of the amplification of each second electrical signal to be summed by the second summing device are then used to obtain a second amplified signal, thereby effectively improving the reliability of the signal amplification processing results.

[0105] In an exemplary embodiment, the output terminal of the Nth stage first summing amplifier circuit is connected to the signal convergence output module 103 through a first differential circuit. The first differential circuit is used to perform differential processing on the first amplified signal output by the Nth stage first summing amplifier circuit.

[0106] And / or,

[0107] The output of the second summing amplifier circuit of the Mth stage is connected to the signal convergence output module 103 through a second differential circuit. The second differential circuit is used to perform differential processing on the second amplified signal output by the second summing amplifier circuit of the Mth stage.

[0108] In this embodiment, the first differential circuit is used to perform differential processing on the first amplified signal output by the Nth stage first summing amplifier circuit, thereby effectively reducing signal interference, ensuring the reliability of the first amplified signal output to the signal conformal output module 103, and thus improving the sensitivity of the SiPM type scintillator detector.

[0109] The second differential circuit is used to perform differential processing on the second amplified signal output from the Mth stage second summing amplifier circuit, thereby effectively reducing signal interference, ensuring the reliability of the second amplified signal output to the signal conformal output module 103, and thus improving the sensitivity of the SiPM type scintillator detector.

[0110] The first differential circuit and the second differential circuit can be implemented using differential amplifiers.

[0111] In an exemplary embodiment, the first subarray includes a plurality of first SiPM units, and the second subarray includes a plurality of second SiPM units, wherein the first SiPM units and the second SiPM units are alternately arranged in a first direction and / or a second direction.

[0112] In this embodiment, the multiple SiPM units in the SiPM array can be divided into two parts: multiple first SiPM units corresponding to the first subarray and multiple second SiPM units corresponding to the second subarray.

[0113] The first direction and the second direction are the arrangement directions of each SiPM unit in the SiPM array, respectively. For example, the first direction and the second direction can be the horizontal axis direction and the vertical axis direction, respectively.

[0114] In implementation, the first SiPM unit and the second SiPM unit can be alternately arranged in the first direction and / or the second direction, so that the scintillation light excited by the scintillation crystal can be uniformly received by the first subarray and the second subarray, ensuring the consistency of the timing and intensity of the optical signals received by the first subarray and the second subarray, thereby effectively reducing the risk of valid signals being misjudged as not meeting the conditions and discarded. Figure 6 This example illustrates the distribution of SiPM cells in a SiPM array. Figure 6 The black square in the middle represents the first SiPM unit 501, and the white square represents the second SiPM unit 506.

[0115] In an exemplary embodiment, the system further includes a first voltage source, a second voltage source, a voltage regulation module, and a temperature acquisition module, wherein the first voltage source is a fixed voltage source and the second voltage source is an adjustable voltage source.

[0116] The anode of each first SiPM unit and the anode of each second SiPM unit are connected to the first voltage source, and the cathode of each first SiPM unit and the cathode of each second SiPM unit are connected to the second voltage source.

[0117] The temperature acquisition module is used to acquire the current ambient temperature;

[0118] The voltage regulation module is used to determine the target output voltage of the second voltage source based on the current ambient temperature, and to control the second voltage source to perform voltage regulation based on the target output voltage.

[0119] In this embodiment, each first SiPM unit and each second SiPM unit are connected in parallel. Simultaneously, the anodes of each first SiPM unit and each second SiPM unit are connected to a first voltage source, and the cathodes of each first SiPM unit and each second SiPM unit are connected to a second voltage source. This allows the first and second voltage sources to provide operating voltage to each SiPM unit in the SiPM array. The first voltage source is a fixed voltage source; for example, its output voltage can be fixed at 26.2 volts. The second voltage source is an adjustable voltage source; for example, its output voltage can be adjusted from 0 to 2 volts.

[0120] The temperature acquisition module can collect the current ambient temperature in real time. The current ambient temperature is the temperature of the environment in which the SiPM scintillator detector is located at the current moment, that is, the current operating temperature of the SiPM scintillator detector.

[0121] The voltage regulation module can be connected to both the second voltage source and the temperature acquisition module. It determines the target output voltage of the second voltage source based on the current ambient temperature and controls the second voltage source to regulate its voltage based on this target output voltage. For example, the voltage regulation module can determine the output voltage of the second voltage source corresponding to the current ambient temperature, based on the current ambient temperature and a preset correspondence between the ambient temperature and the output voltage of the second voltage source. This output voltage serves as the target output voltage, enabling real-time adjustment of the power supply voltage to the SiPM array according to the ambient temperature of the SiPM scintillator detector. This effectively reduces the impact of ambient temperature on the operating performance of the SiPM scintillator detector and further improves its sensitivity.

[0122] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0123] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A scintillator detector of SiPM type, characterized in that, include: The signal detection module, signal amplification and processing module, and signal coincidence output module are connected in sequence. The signal detection module includes a scintillation crystal and a SiPM array, wherein the SiPM array includes a first subarray and a second subarray. The signal amplification and processing module is used to sum and amplify each of the first electrical signals output by the first subarray to obtain a first amplified signal, and is also used to sum and amplify each of the second electrical signals output by the second subarray to obtain a second amplified signal; The signal coincidence output module is used to determine an output signal based on the first amplified signal and / or the second amplified signal when it is determined that the first amplified signal and the second amplified signal meet the coincidence condition during the detection process. The signal conformance output module is specifically used to: obtain the distance between the amplitude of the first amplified signal and the amplitude of the second amplified signal, and use it as a target distance; determine whether the first amplified signal and the second amplified signal meet the conformance condition based on the comparison result of the target distance and the distance threshold; wherein, the distance threshold is obtained based on the average of the amplitudes of the first amplified signal and the second amplified signal.

2. The scintillator detector of SiPM type according to claim 1, characterized in that, The signal output module is specifically used for: Based on the comparison result between the signal value of the first amplified signal and the preset value, the first overthreshold time corresponding to the first amplified signal is determined, and based on the comparison result between the signal value of the second amplified signal and the preset value, the second overthreshold time corresponding to the second amplified signal is determined. If both the first threshold crossing time and the second threshold crossing time exist, the threshold crossing time difference between the first amplified signal and the second amplified signal is determined based on the first threshold crossing time and the second threshold crossing time. Based on the comparison result between the overthreshold time difference and the preset coincidence time window, it is determined whether the first amplified signal and the second amplified signal meet the coincidence condition.

3. The scintillator detector of SiPM type according to claim 2, characterized in that, The signal coincidence output module is also used for: If the first threshold time and / or the second threshold time do not exist, it is determined that the first amplified signal and the second amplified signal do not meet the condition.

4. The scintillator detector of SiPM type according to claim 2, characterized in that, It also includes a time window construction module, which is used for: During the test, multiple first amplified signals output by the signal amplification and processing module and multiple second amplified signals corresponding to the multiple first amplified signals are acquired within a preset time period. Determine the overthreshold time difference between each of the first amplified signals and the corresponding second amplified signal, and use it as the test time difference; The conformity time window is determined based on the distribution of the test time differences.

5. Scintillator detector of SiPM type according to any one of claims 1 to 4, characterized in that The signal coincidence output module is also used for: When it is determined, based on the first amplified signal and the second amplified signal, that the first amplified signal and the second amplified signal do not meet the condition, the first amplified signal and the second amplified signal are discarded.

6. Scintillator detector of SiPM type according to any of claims 1 to 4, characterized in that The signal amplification and processing module includes a first amplification and processing module and a second amplification and processing module; The first amplification processing module includes N (N≥1) stages of first summing amplification circuits, used to perform group summing amplification processing on each of the first electrical signals; And / or, The second amplification processing module includes M (M≥1) stages of second summing amplifier circuits, used to perform grouped summing amplification processing on each of the second electrical signals.

7. The scintillator detector of SiPM type according to claim 6, characterized in that, The output of the first summing amplifier circuit of the Nth stage is connected to the signal coincidence output module through a first differential circuit. The first differential circuit is used to perform differential processing on the first amplified signal output by the first summing amplifier circuit of the Nth stage. And / or, The output of the second summing amplifier circuit of the Mth stage is connected to the signal coincidence output module through a second differential circuit. The second differential circuit is used to perform differential processing on the second amplified signal output by the second summing amplifier circuit of the Mth stage.

8. The SiPM type scintillator detector according to any one of claims 1 to 4, characterized in that, The first subarray includes a plurality of first SiPM units, and the second subarray includes a plurality of second SiPM units, wherein the first SiPM units and the second SiPM units are alternately arranged in a first direction and / or a second direction.

9. The scintillator detector of SiPM type according to claim 8, characterized in that, It also includes a first voltage source, a second voltage source, a voltage regulation module, and a temperature acquisition module. The first voltage source is a fixed voltage source, and the second voltage source is an adjustable voltage source. The anode of each first SiPM unit and the anode of each second SiPM unit are connected to the first voltage source, and the cathode of each first SiPM unit and the cathode of each second SiPM unit are connected to the second voltage source. The temperature acquisition module is used to acquire the current ambient temperature; The voltage regulation module is used to determine the target output voltage of the second voltage source based on the current ambient temperature, and to control the second voltage source to perform voltage regulation based on the target output voltage.

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