Detectors for measuring radiation and their sensitivity calibration methods

Abstract

This invention provides a detector for measuring radiation and a method for calibrating its sensitivity. By measuring the plateau characteristic curves of each sub-detector, the method can accurately obtain the gain state of the sub-detectors in the combined detector due to voltage division. By changing the state of the combined detector, a multivariate linear equation concerning the mutual shielding effect parameters of the sub-detectors can be obtained. Combined with the obtained gain state parameters caused by detector voltage division, the gain caused by the mutual shielding effect on the sub-detectors can be accurately obtained. This decouples the gain caused by detector voltage division from the gain caused by the mutual shielding effect of the sub-detectors, enabling quantitative determination of the impact of voltage division offset and shielding effect on the performance of the combined detector, thereby significantly improving the sensitivity and other performance characteristics of the combined detector.

Description

Technical Field

[0001] This invention relates to the field of radiation detector technology. Background Technology

[0002] Typically, radiation detectors are used outside the reactor to monitor reactor power in real time during reactor startup, power operation, shutdown, and design basis accident conditions. These detectors output real-time power level and power change rate signals for reactor protection, playing a crucial role in safe reactor operation. During initial startup and other similar conditions, the ambient radiation field is extremely weak, requiring significantly improved detector sensitivity for effective monitoring.

[0003] In the field of radiation detection, multiple detectors are often combined into arrays to construct combined detectors for measurement, thereby improving detection range and sensitivity. However, due to various factors such as radiation shielding and blocking effects between individual detectors, as well as voltage deviations caused by applying voltage to multiple detectors using parallel voltage divider branches, the sensitivity of a combined detector is not simply the sum of the individual detectors. To achieve a high level of sensitivity, the combined detector system needs to be calibrated and adjusted to minimize these influencing factors.

[0004] Patent document CN104820233A discloses a scintillator array structure and a neutron detector using the scintillator array structure. The document describes the structure and operating mode of the neutron detector, but does not explain the calibration method.

[0005] Patent document CN202210182456.9 discloses a calibration method and system for a photodetector array, which calibrates the performance of the photodetector array and obtains the response matrix of the sub-detectors. However, the object is a photodetector, and the calibration is performed by sunlight. There is no self-shielding effect or voltage division effect between the detectors.

[0006] As mentioned above, in existing technologies, the combined detector is treated as a whole, and the overall output of the entire detector is examined. The overall effect of multiple performance parameters of the combined detector is analyzed. However, the performance parameters of the individual sub-detectors in the detector array are not analyzed in detail, and the potential of the detector cannot be fully explored. Moreover, if the detector performance is found to be unsatisfactory after calibration, the detector needs to be redesigned, such as modifying the number of detectors, layout, and other parameters. This process is time-consuming, costly, and inefficient. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a detector for measuring radiation and a method for calibrating its sensitivity, which can eliminate the influence of voltage division and shielding effects on detector performance and achieve higher detection performance.

[0008] The first aspect of this invention provides a sensitivity calibration method for a detector used to measure radiation. The detector includes multiple sub-detectors, each sub-detector having a predetermined setting position. The calibration method includes the following steps:

[0009] Step S1: In the radiation field, each sub-detector is set up individually at its predetermined position. The plateau voltage range U(i, min) to U(i, max) of the plateau curve of each sub-detector is measured, as well as the signal value N(i, rec) corresponding to the optimal operating voltage U(i, rec) of each sub-detector. Here, i = 1, 2, 3, ... M, and M is the number of sub-detectors.

[0010] Step S2: Place all sub-detectors in their predetermined positions, apply voltage to the detectors, measure the operating voltage U(i, com) of each sub-detector, and adjust the detector voltage so that the operating voltage U(i, com) of each sub-detector is within its plateau voltage range U(i, min) to U(i, max), and obtain the voltage state S0(i) of each sub-detector. Here, S0(i) = N(i, com) / N(i, rec) × 100%, where N(i, com) is the signal value measured by the i-th sub-detector under the operating voltage U(i, com).

[0011] Step S3: In the radiation field, measure the sum of the output signals N0(com) of all sub-detectors of the detector. N0(com) satisfies the following relationship:

[0012] N0(com)=a1·N(1,com)+a2·N(2,com)+……+a M ·N(M, com)

[0013] =a1·S0(1)·N(1, rec)+a2·S0(2)·N(2, rec)+……+a M ·S0(M)·N(M,rec)

[0014] in,

[0015] a i This indicates the effect of the mutual shielding effect between sub-detectors on the signal output of the sub-detectors;

[0016] Step S4: Change the detector state P times to obtain P different detector states j, j = 1, 2, 3...P. Under each detector state j, execute steps S2 and S3 to measure the voltage state S of each sub-detector. j (i), j = 1, 2, 3…P, and the sum of the output signals of all sub-detectors N j (com), based on the P measurement results, a is calculated.i .

[0017] Preferably, in step S4, P = M-1, and in (M-1) measurements, the sum N of the output signals of all sub-detectors is obtained each time. j (com),

[0018] N j (com) satisfies the following relation:

[0019] N j (com)=a1·N(1,com)+a2·N(2,com)+……+a M ·N(M, com)

[0020] =a1·S j (1)·N(1,rec)+a2·S j (2)·N(2,rec)+……+a M ·S j (M)·N(M, rec)

[0021] The obtained N0(com), N1(com), ... N j Combining the equations from (com), we obtain the following equation:

[0022]

[0023] Solving the equation, we get a i .

[0024] Preferably, in step S1, the plateau curve is normalized, with the voltage V applied to each sub-detector as the abscissa and the ratio N(i,V) / N(i,rec)×100% corresponding to the signal value N(i,rec) of the optimal operating voltage U(i,rec) of the sub-detector as the ordinate, to obtain the plateau curve of the percentage signal output of each sub-detector.

[0025] Preferably, in step S4, when the state of the detector is changed, the predetermined setting position of each sub-detector and the radiation field remain unchanged.

[0026] Preferably, using the obtained S0(i) and a i This improves the performance of the detector.

[0027] A second aspect of the present invention provides a detector for measuring radiation, which is calibrated using the calibration method provided in the first aspect of the present invention.

[0028] According to the detector and calibration method of the present invention, by measuring the plateau characteristic curves of each sub-detector, the gain state of the sub-detectors caused by voltage division in the combined detector can be accurately obtained. By changing the state of the combined detector, a multivariate linear equation concerning the mutual shielding effect parameters of the sub-detectors can be obtained. Combined with the obtained gain state parameters caused by detector voltage division, the gain caused by mutual shielding effect on the sub-detectors can be accurately obtained, thereby decoupling the gain caused by detector voltage division and the gain caused by mutual shielding effect of sub-detectors. This allows for the quantitative determination of the impact of voltage division offset and shielding effect on the performance of the combined detector, thereby greatly improving the sensitivity and other performance characteristics of the combined detector. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly described below.

[0030] Figure 1 This is a schematic diagram of a detector located within a radiation field according to a specific embodiment of the present invention;

[0031] Figure 2 This is a flowchart illustrating a detector calibration method according to a specific embodiment of the present invention;

[0032] Figure 3 This is a flowchart illustrating the measurement sub-detector plateau characteristic curve of a specific embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of a sub-detector installed at a predetermined position in a specific embodiment of the present invention;

[0034] Figure 5 This is the plateau characteristic curve of a sub-detector in a specific embodiment of the present invention;

[0035] Figure 6 This is a normalized plateau curve according to a specific embodiment of the present invention;

[0036] Figure 7 This is a plateau curve representing the percentage of the operating voltage within its plateau voltage range, according to a specific embodiment of the present invention. Detailed Implementation

[0037] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0038] Figure 1 This is a schematic diagram of a detector 100 located in a radiation field according to a specific embodiment of the present invention.

[0039] like Figure 1As shown, detector 100 is a detector array (also called a combined detector) consisting of multiple sub-detectors 1. Each sub-detector 1 is mounted on a specially designed support frame 2 (which can also be called a "test fixture" 2 when testing the detector). During detection and testing, the spatial position of each sub-detector 1 is fixed.

[0040] Detector 100 is located in the radiation field 3 and detects radiation. In this embodiment, as an example, neutron source 4 generates radiation field 3, and detector 100 is a neutron detector.

[0041] The number of sub-detectors 1 in detector 100 can be determined based on factors such as measurement requirements. Figure 1 In the middle, detector 100 contains 10 sub-detectors 1.

[0042] Before conducting formal measurements, detector 100 needs to be calibrated to ensure it is in optimal working condition. When measuring extremely weak radiation fields, detector 100 should have sufficiently high detection sensitivity; therefore, it is necessary to calibrate detector 100 to maximize its sensitivity.

[0043] Figure 2 This is a flowchart of a calibration method for a detector 100 according to a specific embodiment of the present invention.

[0044] like Figure 2 As shown, the calibration method of the detector 100 in this embodiment includes the following steps.

[0045] Step S1: Sequentially set each sub-detector 1 individually at its predetermined installation position on the test fixture 2. In the radiation field 3, measure the plateau characteristic curve of each sub-detector 1 individually to determine the plateau voltage range of the plateau curve of each sub-detector 1, as well as the signal value measured by each sub-detector 1 under the optimal operating voltage recommended by the detector manufacturer.

[0046] Step S2: Set all sub-detectors 1 at their predetermined installation positions on the test fixture 2 to form a combined detector 100 (detector array). Apply voltage to the combined detector 100 and measure the actual operating voltage of each sub-detector 1. If the operating voltage of a sub-detector 1 is not within the plateau voltage range of its plateau curve, adjust the voltage of the combined detector 100 so that the operating voltage of each sub-detector 1 is within its plateau voltage range. Determine the voltage deviation state of each sub-detector 1 based on the actual operating voltage of each sub-detector 1 and the signal value at that voltage, the optimal operating voltage and the signal value at that voltage.

[0047] Step S3: In the radiation field 3, the total output signal of the combined detector 100 is measured. The output signal satisfies a certain relationship with the output signals of each sub-detector 1, the voltage deviation state parameter, and the mutual shielding effect parameter of the sub-detectors.

[0048] Step S4: Change the state of the combined detector 100 to obtain different detector states. Under different detector states, execute steps S2 and S3 to measure the total output signal of the combined detector 100 and the voltage deviation state parameters of each sub-detector 1.

[0049] This process is repeated multiple times to obtain multiple measurement results. Based on these multiple measurement results, parameters characterizing the mutual shielding effect of the sub-detectors are calculated.

[0050] The detector calibration method of this embodiment is described in detail below.

[0051] First, let's explain step S1.

[0052] Figure 3 This is a flowchart illustrating the characteristic curve of the measurement sub-detector 1 ping (approximately 1 square meter) according to a specific embodiment of the present invention.

[0053] like Figure 3 As shown, step S1 specifically includes the following steps.

[0054] Step S11: Place a sub-detector 1 on the test fixture 2 at the predetermined setting position 21 of the sub-detector.

[0055] Figure 4 This is a schematic diagram of a sub-detector 1 installed at a predetermined setting position 21 in a specific embodiment of the present invention.

[0056] One sub-detector 1 is installed at a predetermined position 21 on the test fixture 2, and no sub-detectors are installed at the other positions of the test fixture 2. Assume that the number of sub-detectors is M, and the sub-detector 1 is numbered from 1 to M. Figure 4 In the test fixture 2, the sub-detector 1 is the second one from the top (i=2), and the power supply of the sub-detector 1 is connected to make the sub-detector 1 work. Then the shield of the neutron source 4 is removed, so that the sub-detector 1 is in the radiation field 3.

[0057] Step S12: Adjust the voltage V of the sub-detector 1 (i=2) and record the signal value N(i,V) output by the sub-detector 1 (i=2) under different voltages V, and plot the plateau characteristic curve of the signal value changing with the voltage V of the sub-detector 1 (i=2).

[0058] Figure 5 The image shows the plateau characteristic curve of sub-detector 1 in a specific embodiment of the present invention.

[0059] Figure 5 In the diagram, the horizontal axis represents the voltage V applied to sub-detector 1 (i=2), and the vertical axis represents the signal value N(i,V) measured by sub-detector 1 (i=2) under voltage V. Figure 5 In this context, the type of signal value N(i,V) is exemplified by the count rate cps (counts per second).

[0060] Figure 5 In the middle, the signal value under voltage U(i,min) is N(i,min), and the signal value under voltage U(i,max) is N(i,max). The changes are not significant, showing a slowly changing region. This region is called the "plateau region" of the sub-detector 1. U(i,min) is the minimum voltage value of the plateau region, and U(i,max) is the maximum voltage value of the plateau region.

[0061] Figure 5 In this context, U(i,rec) represents the optimal operating voltage for sub-detector 1 (i=2), which is usually the recommended operating voltage value provided by the detector manufacturer, but can also be determined by the detector user through measurement. The signal value at voltage U(i,rec) is N(i,rec).

[0062] Step S13, will Figure 5 The plateau curve in the middle is normalized.

[0063] Figure 6 This is a normalized plateau curve according to a specific embodiment of the present invention.

[0064] about Figure 5 The plateau curve is obtained by dividing the signal value N(i,V) at each voltage V by the signal value N(i,rec) at the optimal operating voltage U(i,rec). Figure 6 The normalized plateau curve in the figure. That is, Figure 6 The vertical axis represents the ratio of the signal value N(i, V) at voltage V to the signal value N(i, rec) at the optimal operating voltage U(i, rec), which is N(i, V) / N(i, rec) × 100%. Therefore... Figure 6 The normalized plateau curve is also called the percentage signal output plateau curve. Figure 6 In the diagram, when the operating voltage U(i, com) of sub-detector 1 is at its optimal operating voltage U(i, rec), the value on the ordinate is 100%. When the operating voltage U(i, com) of sub-detector 1 deviates from the optimal operating voltage U(i, rec), the value on the ordinate deviates from 100%. Therefore, Figure 6 The percentage signal output plateau curve characterizes the effect of the change in the operating voltage U(i,com) of sub-detector 1 relative to the optimal operating voltage on the signal value of sub-detector 1.

[0065] Step S14: Replace sub-detector 1 by placing another sub-detector 1 at the predetermined installation position 21 on the test fixture 2. Do not place sub-detectors 1 at other positions on the test fixture 2. Repeat steps S11 to S13 to obtain the plateau curve of the other sub-detector 1.

[0066] This process is repeated so that the sub-detector number i takes values ​​from 1 to M. Steps S11 to S13 are executed M times in total. This yields the plateau voltage range U(i, min) to U(i, max) of the plateau curves for all M sub-detectors 1, the signal value N(i, rec) at the optimal operating voltage U(i, rec) for each sub-detector, and the percentage signal output plateau curve for each sub-detector 1.

[0067] Step 2 is explained in detail below.

[0068] As described above, in step S2, all sub-detectors 1 are set at their predetermined positions 21 on the test fixture 2 to form a combined detector 100 (detector array). A voltage is applied to the combined detector 100, and the actual operating voltage U(i, com) of each sub-detector 1 is measured using a voltage testing device. If the actual operating voltage U(i, com) of a sub-detector 1 is not within its plateau voltage range U(i, min) to U(i, max), the voltage of the combined detector 100 is adjusted so that the operating voltage U(i, com) of each sub-detector 1 is within its plateau voltage range U(i, min) to U(i, max), and the operating voltage U(i, com) of all sub-detectors 1 at this time is recorded, i = 1, 2, 3...M.

[0069] use Figure 6 The normalized percentage signal output plateau curve of sub-detector 1, when the horizontal axis value is the actual operating voltage U(i, com) of sub-detector 1, the vertical axis value of the point on the percentage signal output plateau curve is N(i, com) / N(i, rec)×100%. This value N(i, com) / N(i, rec)×100% reflects the influence of the change in the actual operating voltage U(i, com) of sub-detector 1 relative to the optimal operating voltage on the signal value of sub-detector 1. Here, it is denoted as the voltage state S0(i) of sub-detector 1, that is,

[0070] S0(i)=N(i,com) / N(i,rec)×100%,

[0071] N(i, com) is the signal value measured by the i-th sub-detector under the operating voltage U(i, com). The voltage state S0(i) represents the effect of the change in the operating voltage of the sub-detector 1 on its signal output. Its subscript "0" indicates the current state of detector 100, that is, the state in which all sub-detectors 1 are subjected to voltage (detector state 0).

[0072] Using the above method, the voltage state S0(i) of all sub-detectors 1 is obtained, i = 1, 2, 3...M.

[0073] Figure 7 This invention demonstrates how the voltage state S0(i) of the sub-detector 1 is determined using a percentage signal output plateau curve in a specific embodiment.

[0074] like Figure 7 As shown, when the horizontal axis value is the actual operating voltage U(i, com) of the sub-detector 1, the vertical axis value of the point on the percentage signal output plateau curve is N(i, com) / N(i, rec)×100%, thus obtaining the voltage state S0(i) of the sub-detector 1.

[0075] Step 3 is explained in detail below.

[0076] After obtaining the voltage state S0(i) of all sub-detectors 1 in detector state 0, proceed to step S3.

[0077] In step S3, the radiation field 3 of the neutron source 4 is measured using the combined detector 100, and the total output signal NO(com) of the combined detector 100 is recorded. The total output signal NO(com) of the combined detector 100 is related to step S1 and the data obtained from step S1. Figure 5 The output signals N(1,com), ..., N(i,com), ..., N(M,com) of each individual sub-detector 1 under the voltage U(i,com) determined by the plateau curve satisfy the following relationship.

[0078] N0(com)=a1·N(1,com)+a2·N(2,com)+……+a M ·N(M, com)

[0079] =a1·S0(1)·N(1, rec)+a2·S0(2)·N(2, rec)+……+a M ·S0(M)·N(M,rec) (1)

[0080] In equation (1),

[0081] a iThis describes the impact of the mutual shielding effect between sub-detectors 1 on the signal output of sub-detector 1. In the combined detector 100, other sub-detectors B exist around one sub-detector A. The surrounding sub-detectors B interact with neutrons, thus altering the neutron radiation field measured by sub-detector A. The mutual shielding effect (or self-shielding effect) of the sub-detectors is an interference factor that degrades the performance of detector 100. To improve detector sensitivity, it is necessary to determine the quantitative value of the sub-detector shielding effect to provide a basis for reducing the shielding effect.

[0082] S0(1)~S0(M) are the voltage state parameters of the first to Mth sub-detectors 1 obtained in step S2 under detector state 0, respectively.

[0083] As shown in equation (1), the total output signal N0(com) of the combined detector 100 is not the sum of the individual output signals N(1,com), ..., N(i,com), ..., N(M,com) of each sub-detector 1, but is affected by the mutual shielding effect between the sub-detectors 1 on the signal output of the sub-detectors 1, using parameter a i This indicates the impact.

[0084] In equation (1), a i S0(i)·N(i,rec) is the signal value N(i,rec) of the i-th sub-detector 1 at the optimal operating voltage U(i,rec) multiplied by the mutual shielding effect parameter a of the sub-detectors 1. i Then multiply by the voltage state parameter S0(i) of sub-detector 1 to obtain the contribution of the output signal of sub-detector 1 to the total output signal of the combined detector 100. The output signals a of all sub-detectors 1 are then multiplied. i S0(i) and N(i,rec) are added together to obtain the sum of the output signals of all sub-detectors 1 in detector state 0, N0(com), which is the total output signal of the combined detector 100.

[0085] In equation (1), only parameter a i Unknown, all other coefficients are known.

[0086] Step 4 is explained in detail below.

[0087] In step S4, without changing the installation position of each sub-detector 1, the position of the neutron source 4, and the state of the radiation field 3, the operating parameters of detector 100 are changed so that the state of detector 100 is different from detector state 0, which is recorded as detector state 1.

[0088] In detector state 1, step S2 is executed again to obtain the voltage states S1(i) of all sub-detectors 1, i = 1, 2, 3…M. Then, step S3 is executed again to measure the total output signal N1(com) of the group and detector 100 in detector state 1. N1(com) satisfies the following relationship:

[0089] N1(com)=a1·N(1, com)+a2·N(2, com)+……+a M ·N(M, com)

[0090] =a1·S1(1)·N(1, rec)+a2·S1(2)·N(2, rec)+……+a M ·S1(M)·N(M,rec) (2)

[0091] In equation (2),

[0092] a i This indicates the effect of the mutual shielding effect between sub-detectors 1 on the signal output of sub-detector 1. When the state of detector 100 is changed, since the installation position of sub-detector 1 and the state of the radiation field 3 do not change, therefore a i No change.

[0093] S1(1)~S1(M) are the voltage states of each sub-detector 1 in detector state 1.

[0094] Thus, the total output signal N1(com) of detector 100 in detector state 1 is obtained.

[0095] By changing the state of detector 100 multiple times, for example, P times, P different detector states j, j = 1, 2, 3...P are obtained. Depending on the actual needs, the number of cycles P can be equal to, less than, or greater than the number of sub-detectors M.

[0096] In each detector state j, steps S2 and S3 are executed to measure the voltage state S of each sub-detector 1. j (i), j = 1, 2, 3…P, and the total output signal N of detector 100 j (com), N j (com) satisfies the following relation:

[0097] N j (com)=a1·N(1,com)+a2·N(2,com)+……+a M ·N(M, com)

[0098] =a1·S j(1)·N(1,rec)+a2·S j (2)·N(2,rec)+……+a M ·S j (M)·N(M, rec) (3)

[0099] As an example, the number of cycles is P = M-1, that is, the state of detector 100 is changed M-1 times. Combined with detector state 0, a total of M different detector states are obtained, thus obtaining M relational expressions (3). Since S j Given (i) and N(i, com), we can obtain the M a's based on the M relations. i The value of is used to obtain the shielding effect parameter 'a' for each sub-detector 1. i The value of is the effect of the mutual shielding effect on the signal output of sub-detector 1. Specifically, it is as follows.

[0100] The obtained equations (1), (2), (3), etc., have M N0(com), N1(com), ..., N j Combining the relational expressions, we obtain the following equation:

[0101]

[0102] Equation (4) is a system of M linear equations. Solving equation (4) yields a. i .

[0103] As described above, through steps S2 to S4, the influence of the voltage state of sub-detector 1 on the output signal of each sub-detector 1, S0(i), and the influence of the mutual shielding effect between sub-detectors 1 on the output signal of each sub-detector 1, a, can be obtained. i This enables precise calibration.

[0104] Using the obtained S0(i) and a i This can correct the output signal of detector 100, improve the detector's sensitivity and other detection performance, and allow for improvements to the detector design in subsequent designs based on the measurement results.

[0105] The present invention also provides a detector 100 for measuring radiation, which is calibrated using the above-described calibration method, and can achieve high sensitivity and good detection performance.

[0106] In the calibration method of this invention, the plateau characteristic curves of each sub-detector 1 are measured to accurately obtain the change in signal output of sub-detector 1 due to voltage division in the combined detector 100. By changing the state of the combined detector 100, the mutual shielding effect parameter α of the sub-detectors 1 is obtained. i The multivariate linear equation can be used to accurately obtain the parameter a.i This decouples the effects of voltage division by detector 100 from the mutual shielding effects of sub-detectors 1, enabling quantitative determination of the impact of voltage division offset and shielding effects on the performance of the combined detector 100, thereby significantly improving the detection performance, such as sensitivity, of the combined detector 1. Simultaneously, it allows for the acquisition of the characteristics of each sub-detector 1, providing a more comprehensive understanding of its operational status.

[0107] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A sensitivity calibration method for a detector used to measure radiation, the detector comprising a plurality of sub-detectors, each sub-detector having a predetermined setting position, the method characterized by comprising the following steps: Step S1: In the radiation field, each of the sub-detectors is individually set at its predetermined location, and the plateau voltage range of the plateau curve of each sub-detector is measured. And the optimal operating voltage for each sub-detector. Corresponding signal value ,here i =1,2,3,…M, where M is the number of sub-detectors; Step S2: Place all the sub-detectors in their predetermined positions, apply voltage to the detectors, and measure the operating voltage of each sub-detector. And adjust the voltage of the detector so that the operating voltage of each sub-detector is... Within its plateau voltage range The voltage states of each sub-detector are obtained. ,here, = , For the first i Individual detectors at operating voltage The measured signal value; Step S3: In the radiation field, measure the sum of the output signals of all sub-detectors of the detector. , The following relationship must be satisfied: in, This indicates the effect of the mutual shielding effect between sub-detectors on the signal output of the sub-detectors; Step S4: Without changing the installation positions of each sub-detector, the position of the neutron source, or the state of the radiation field, change the state of the detector P times to obtain P different detector states j. In each detector state j, steps S2 and S3 are performed to measure the voltage state of each sub-detector. , The sum of the output signals of all sub-detectors Based on P measurement results, the following calculations are obtained: ; In step S4, P=M-1, In (M-1) measurements, the sum of the output signals of all sub-detectors is obtained each time. , The following relationship must be satisfied: Get , , ... Combining these equations, we obtain the following equation: Solving the equation, we get ; Changing the state of the detector means changing the operating parameters of the detector.

2. The sensitivity calibration method for a detector used to measure radiation according to claim 1, characterized in that, In step S1, the plateau curve is normalized, with the voltage V applied to each sub-detector as the abscissa and the signal value corresponding to voltage V as the ordinate. With the optimal operating voltage of this sub-detector Corresponding signal value ratio Using the vertical axis as the ordinate, we obtain the plateau curve representing the percentage signal output of each sub-detector.

3. The sensitivity calibration method for a detector used to measure radiation according to claim 1 or 2, characterized in that, Utilize and This improves the performance of the detector.

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