Dynamic PSD threshold value correction method, device and equipment suitable for digital pulse waveform discrimination

Abstract

The invention provides a dynamic PSD threshold value correction method, device and equipment suitable for digital pulse waveform discrimination, and relates to the technical field of nuclear radiation detection.The method comprises the steps that a current PSD-energy two-dimensional spectrum is obtained through a nuclear radiation detecting instrument, counts in a target energy range in the current PSD-energy two-dimensional spectrum are removed, and the current PSD-energy two-dimensional spectrum is obtained; converting into a one-dimensional PSD spectrum by using a preset formula; determining the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum, determining a PSD threshold value, and resetting the target PSD value range according to the PSD threshold value; and obtaining the target PSD-energy two-dimensional spectrum again, carrying out statistics on the discrimination target ray counting value and the total counting value, and determining a main target ray counting value according to a difference value between the total counting value and the discrimination target ray counting value so as to determine a main target ray counting rate and a discrimination target ray counting rate. By regularly and automatically analyzing the PSD-energy two-dimensional spectrum and dynamically adjusting the PSD threshold value, different particles can be more accurately discriminated, and the particle detection accuracy and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear radiation detection, and in particular, to a dynamic PSD threshold correction method, device and equipment suitable for digital pulse waveform discrimination. Background Art

[0002] In the field of nuclear radiation detection, digital pulse shape discrimination (PSD) technology is a commonly used particle discrimination method. Different particles have different luminescence time constants when generating luminescence phenomena in a scintillator, resulting in different waveforms of the electrical signals output by a photomultiplier tube. By amplifying the electrical signal through a current-sensitive preamplifier circuit and using a digital multi-channel analyzer (MCA) to obtain digital pulse waveform data, particles can be further discriminated through PSD algorithms, such as the charge comparison method, the rise time method, the frequency domain analysis method, and the intelligent analysis method, etc. Taking the charge comparison method as an example, this method calculates the total charge Q of the pulse, the fast component charge Qf and the slow component charge Qs, and defines the PSD value as Qf / Q or Qs / Q for particle discrimination. For example, when using a NaIL crystal to realize neutron and γ-ray discrimination, the pulse signal generated by neutrons has a smaller time constant than that of γ-rays. Therefore, the particle type can be determined by comparing the magnitude of Qf / Q with a specific PSD threshold.

[0003] However, there is a significant problem with traditional PSD technology: the luminescence efficiency and luminescence time constant of the scintillator are directly affected by the ambient temperature, resulting in shifts in the energy spectrum and PSD spectrum measured at different temperatures. When the PSD threshold is a fixed value, temperature changes can lead to discrimination errors, thereby affecting the discrimination effect and detection efficiency of particle detection. For example, at different temperatures, both the position of the background PSD peak and the central PSD value of the AmBe source will change significantly. To solve the above problems, existing technologies usually adopt a PSD threshold correction method based on temperature measurement. This method requires dynamically setting the PSD threshold according to the working ambient temperature of the detection instrument. The specific process includes steps such as conducting an energy calibration test, setting the energy calibration coefficient, measuring the two-dimensional spectrum of energy-PSD values, changing the working ambient temperature and measuring, and determining the correspondence between the PSD threshold and temperature. However, this method has the following deficiencies: First, each radiation detection instrument needs to be individually tested before leaving the factory to determine the correspondence between the working ambient temperature and the PSD threshold, which places extremely high requirements on the consistency of components such as the scintillator, photomultiplier tube, and preamplifier circuit; Second, considering that it takes several hours for the equipment to reach the thermal equilibrium state after the working ambient temperature is adjusted, and as many working ambient temperature points as possible are required to accurately represent the correspondence, the duration of the factory test will increase significantly, not meeting the requirements of large-scale production; and the long-term temperature test may have a negative impact on the paint, circuits, etc. of the equipment, increasing the risk of equipment damage; Third, the temperature sensors, scintillators, photomultiplier tubes, preamplifier circuits, etc. have inconsistent sensitivities to temperature changes, and the reading changes of the temperature sensors do not fully match the performance changes of the rest of the parts, which may lead to inaccurate PSD threshold correction; Finally, after long-term use, the performance of each component of the nuclear radiation detection instrument may change, resulting in the inconsistency between the correspondence between the working ambient temperature and the PSD threshold determined at the factory and the real-time state of the equipment, thereby affecting the correction accuracy of the PSD threshold.

[0004] Currently, there is no technical solution that can solve the above technical problems, and there is no dynamic PSD threshold correction method, device, and equipment applicable to digital pulse waveform discrimination. Summary of the Invention

[0005] The present invention provides a dynamic PSD threshold correction method, device, and equipment applicable to digital pulse waveform discrimination, which can achieve dynamic correction of the PSD threshold in a more efficient and accurate manner, improving the accuracy and reliability of nuclear radiation detection.

[0006] In a first aspect, the present invention provides a dynamic PSD threshold correction method applicable to digital pulse waveform discrimination, including:

[0007] Use a nuclear radiation detection instrument to obtain the current two-dimensional PSD-energy spectrum, count the working duration of the nuclear radiation detection instrument, and every preset PSD threshold correction period, eliminate the counts within the target energy range in the current two-dimensional PSD-energy spectrum, and convert them into a one-dimensional PSD spectrum using a preset formula;

[0008] Determine the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum, and determine the PSD threshold according to the sum value of the position of the maximum peak and the full width at half maximum, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold;

[0009] Use the nuclear radiation detection instrument again to obtain the target two-dimensional PSD-energy spectrum, count the discrimination target ray count and the total count within the target energy range and the target PSD value range in the target two-dimensional PSD-energy spectrum, and determine the main target ray count according to the difference between the total count and the discrimination target ray count, so as to determine the main target ray counting rate and the discrimination target ray counting rate.

[0010] According to the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention, before using the nuclear radiation detection instrument to obtain the current two-dimensional PSD-energy spectrum, the method further includes:

[0011] Define the main target ray, the discrimination target ray and the preset PSD threshold correction period of the nuclear radiation detection instrument;

[0012] Set the energy calibration coefficient according to the energy calibration test of the nuclear radiation detection instrument;

[0013] Determine the target energy range and the target PSD value range of the discrimination target ray according to the measurement of the two-dimensional energy-PSD value spectrum of the nuclear radiation detection instrument.

[0014] According to the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention, the main target ray is a γ ray, the discrimination target ray is a neutron, and the preset PSD threshold correction period is 600 seconds;

[0015] The target energy range is from 3.0 MeV to 3.5 MeV, and the target PSD value range is from 0.63 to 0.73;

[0016] The main target ray counting rate is the γ ray counting rate, and the discrimination target ray counting rate is the neutron counting rate.

[0017] According to the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention, after using the nuclear radiation detection instrument to obtain the current two-dimensional PSD-energy spectrum, the method further includes:

[0018] When the working duration of the nuclear radiation detection instrument is less than or equal to the preset PSD threshold correction period, count the discrimination target ray count value and the total count value in the target energy range and the target PSD value range in the current PSD-energy two-dimensional spectrum, and determine the main target ray count value according to the total count value and the discrimination target ray count value, so as to determine the main target ray count rate and the discrimination target ray count rate.

[0019] According to the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention, the conversion into a one-dimensional PSD spectrum by using a preset formula includes:

[0020]

[0021] where psd is the PSD value; E is the energy value; n(psd, E) is the count value at a certain place in the PSD-energy two-dimensional spectrum with a unit PSD value and a unit energy value, E ThrH is the upper limit of the target energy of the discrimination target ray, E ThrL is the lower limit of the target energy of the discrimination target ray, E H is the upper limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument, E L is the lower limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument, and n(psd, E)dpsd is the count value at a certain PSD value in the one-dimensional PSD spectrum.

[0022] According to the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention, the determination of the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum includes:

[0023] Traverse the one-dimensional PSD spectrum to find all local maximum points. The local maximum point is a point where the value of any point is greater than the values on the left and right sides of the point. Determine all candidate peaks according to all local maximum points, and determine the candidate peak with the largest count value as the maximum peak. The position of the maximum peak is the PSD value corresponding to the abscissa of the maximum peak;

[0024] Find the points where the count first drops below the half-height value on the rising edge and the falling edge of the maximum peak, denoted as the left half-height position and the right half-height position, and determine the full width at half maximum according to the left half-height position and the right half-height position. The half-height value is the corresponding value of half of the position of the maximum peak.

[0025] According to the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention, the counting of the discrimination target ray count value and the total count value in the target PSD-energy two-dimensional spectrum within the target energy range and the target PSD value range includes:

[0026] According to the upper limit of the target energy for discriminating the target ray, the lower limit of the target energy for discriminating the target ray, and the target PSD value range, count the number of discriminated target rays in the target PSD-energy two-dimensional spectrum;

[0027] According to the upper limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument and the lower limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument, count the total number of values in the target PSD-energy two-dimensional spectrum.

[0028] According to the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention, after determining the number of main target rays, the method further includes:

[0029] Obtain the current measurement duration;

[0030] According to the quotient of the number of discriminated target rays and the current measurement duration, determine the counting rate of the discriminated target rays;

[0031] According to the quotient of the number of main target rays and the current measurement duration, determine the counting rate of the main target rays.

[0032] In a second aspect, a dynamic PSD threshold correction device applicable to digital pulse waveform discrimination is provided, including:

[0033] An acquisition unit, which is used to obtain the current PSD-energy two-dimensional spectrum by using a nuclear radiation detection instrument, count the working duration of the nuclear radiation detection instrument, and every preset PSD threshold correction period, eliminate the counts within the target energy range in the current PSD-energy two-dimensional spectrum, and convert them into a one-dimensional PSD spectrum by using a preset formula;

[0034] A determination unit, which is used to determine the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum, and determine the PSD threshold according to the sum of the position of the maximum peak and the full width at half maximum, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold;

[0035] A statistics unit, which is used to obtain the target PSD-energy two-dimensional spectrum again by using the nuclear radiation detection instrument, count the number of discriminated target rays and the total number of values within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum, and determine the number of main target rays according to the difference between the total number of values and the number of discriminated target rays, so as to determine the counting rate of the main target rays and the counting rate of the discriminated target rays.

[0036] In a third aspect, an electronic device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination is implemented.

[0037] Compared with the correction method based on temperature measurement, the dynamic PSD threshold correction method provided by the present invention significantly reduces the test steps required before the device leaves the factory, thereby reducing the production and calibration costs and meeting the requirements of mass production; by avoiding long-term temperature tests, the negative impacts that the tests may cause to the device performance are effectively reduced, such as damage to components like paint and circuits.

[0038] The dynamic PSD threshold correction method provided by the present invention is more accurate than the correction method based on temperature measurement because it not only takes into account the changes in the ambient temperature but also dynamically adjusts the PSD threshold by real-time analyzing the PSD-energy two-dimensional spectrum, thus more accurately reflecting the actual performance of the nuclear radiation detection instrument; it avoids the need for regular temperature tests during the device use to re-establish the "temperature-PSD threshold" relationship, improving the usability and maintenance efficiency of the device; the dynamic PSD threshold correction can respond in a timely manner to the overall performance changes of the nuclear radiation detection instrument, rather than just the changes in the ambient temperature, so the reliability of the device is better; by real-time analyzing the PSD-energy two-dimensional spectrum and dynamically adjusting the PSD threshold, the method of the present application can more accurately discriminate different particles, improving the accuracy and efficiency of particle detection. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 It is a schematic diagram of the charge comparison method in the prior art;

[0041] Figure 2 It is one of the schematic diagrams of PSD tests in the prior art;

[0042] Figure 3 It is another schematic diagram of PSD tests in the prior art;

[0043] Figure 4 It is a third schematic diagram of PSD tests in the prior art;

[0044] Figure 5 It is a schematic diagram of the process before the nuclear radiation detector leaves the factory in the prior art;

[0045] Figure 6 is a schematic flow diagram during the use of a nuclear radiation detector instrument in the prior art;

[0046] Figure 7 is a schematic flow diagram of a dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the present invention;

[0047] Figure 8 is a schematic flow diagram before the nuclear radiation detector instrument provided by the present invention leaves the factory;

[0048] Figure 9 is a schematic flow diagram during the use of the nuclear radiation detector instrument provided by the present invention;

[0049] Figure 10 is a schematic structural diagram of a dynamic PSD threshold correction device applicable to digital pulse waveform discrimination provided by the present invention;

[0050] Figure 11 is a schematic structural diagram of an electronic device provided by the present invention. Detailed Embodiments

[0051] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0052] Digital pulse waveform discrimination technology is often used to discriminate different particles when a nuclear radiation detection instrument measures radiation. For example, when using a plastic scintillator to measure alpha rays and beta rays, this technology is used to discriminate alpha rays and beta rays; when using a crystal scintillator to measure neutrons and gamma rays, this technology is used to discriminate neutrons and gamma rays. Its main working principle is that different particles, such as electrons, alpha particles, protons, etc., cause different luminescence time constants in the scintillator, so the electrical signals output by the photomultiplier tube have different waveforms. After amplifying this electrical signal using a current-sensitive preamplifier circuit, it is input to a digital multi-channel analyzer to obtain digital pulse waveform data. PSD discrimination algorithms include charge comparison method, rise time method, frequency domain analysis method, intelligent analysis method, etc. As Figure 1 shown, taking the charge comparison method as an example:

[0053] Define Q as the total charge of the pulse, Qf as the charge of the fast component, and Qs as the charge of the slow component. The Qf / Q, Qs / Q, and Qf / Qs of different particles will all show differences. Define the PSD value as follows:

[0054]

[0055] The charge comparison method discriminates particles according to the difference in PSD values. Taking the discrimination of neutrons and γ-rays using a NaIL crystal as an example, the pulse signal generated by neutrons has a smaller time constant than that of γ-rays. Therefore, if Qf / Q is greater than a certain specific PSD threshold, it can be determined as a neutron; if Qf / Q is less than this PSD threshold, it can be determined as a γ-ray.

[0056] However, the luminescence efficiency and luminescence time constant of the scintillator are directly affected by the ambient temperature. Therefore, the energy spectrum and PSD spectrum measured at different temperatures will shift with temperature changes. When the PSD threshold is a fixed value, temperature changes will cause discrimination errors, affecting the particle detection and discrimination effect and detection efficiency.

[0057] As Figure 2 shown, after maintaining for several hours at 25 °C, the position of the background PSD peak is 484 channels (i.e., 0.59), the PSD value at the center of the AmBe source is approximately 548 channels (i.e., 0.67), and the position of the full-energy peak of K-40 is 300 channels.

[0058] As Figure 3 shown, after maintaining for several hours at -20 °C, the position of the background PSD peak is 345 channels (i.e., 0.42), the PSD value at the center of the AmBe source is approximately 384 channels (i.e., 0.47), and the position of the full-energy peak of K-40 is 300 channels.

[0059] As Figure 4 shown, after maintaining for several hours at 50 °C, the position of the background PSD peak is 526 channels (i.e., 0.64), the PSD value at the center of the AmBe source is approximately 610 channels (i.e., 0.74), and the position of the full-energy peak of K-40 is 300 channels.

[0060] To avoid the above problems, generally, the PSD threshold needs to be dynamically set according to the working ambient temperature of the detection instrument. Taking the discrimination of neutrons and γ-rays using a nuclear radiation detection instrument based on a NaIL crystal as an example, steps 1-7 are the steps required before the equipment leaves the factory, and the remaining steps are automatically implemented during the use of the equipment without manual operation, which can be referred to Figure 5 . And the schematic flow diagram during the use of the nuclear radiation detection instrument in the subsequent prior art can be referred to Figure 6 .

[0061] Specifically, the main work process is as follows:

[0062] 1. Define the main target rays, discrimination target rays, etc. of the nuclear radiation detection instrument.

[0063] 2. Conduct an energy calibration test on the nuclear radiation detection instrument and set the energy calibration coefficient.

[0064] 3. Measure the two-dimensional spectrum of energy-PSD values using a nuclear radiation detection instrument and a radiation source that generates the target rays to be discriminated, and clarify the target energy range of the target rays to be discriminated.

[0065] 4. Change the working environmental temperature of the nuclear radiation detection instrument and maintain it for several hours to bring the entire device to a thermal equilibrium state.

[0066] 5. Measure the environmental temperature and the two-dimensional spectrum of energy-PSD values (using a radiation source that generates the target rays to be discriminated) with the nuclear radiation detection instrument.

[0067] 6. Determine the PSD threshold at this working environmental temperature and establish the corresponding relationship between the working environmental temperature and the PSD threshold.

[0068] 7. Judge whether the temperature test covers the working environmental temperature range. If so, end the temperature characteristic test; if not, return to step 4.

[0069] 8. Use the nuclear radiation detection instrument to measure and obtain the two-dimensional spectrum P1 of PSD-energy and the temperature measurement value T.

[0070] 9. Determine the PSD threshold according to the temperature measurement value T.

[0071] 10. Count the number N2 of the target rays to be discriminated within the target energy range and the target PSD value range in the two-dimensional spectrum P1 of PSD-energy. The calculation formula is as follows:

[0072]

[0073] where n(psd,E) is the count value per unit psd and per unit E in the two-dimensional spectrum of PSD-energy; psd Thr is the PSD threshold; E ThrH and E ThrL are the upper and lower limits of the target energy of the target rays to be discriminated, respectively.

[0074] 11. Count the total number N in the two-dimensional spectrum P1 of PSD-energy. The calculation formula is as follows

[0075]

[0076] where E H and E L are the upper and lower limits of the energy for energy spectrum measurement by the nuclear radiation detection instrument, respectively.

[0077] 12. Calculate the count N1 of the main target rays, and the formula is as follows:

[0078] N1 = N - N2

[0079] 13. Complete subsequent counting rate and dose rate calculations, energy spectrum and PSD value spectrum statistics, energy spectrum-PSD two-dimensional spectrum, energy spectrum, PSD spectrum display and other tasks.

[0080] However, the design ideas in the prior art have the following problems:

[0081] 1. Due to the consistency issues of scintillators, multiplier tubes, preamplifier circuits, temperature sensors, charge integration window selection, etc. used in nuclear radiation detection instruments, each radiation detection instrument needs to be tested separately before leaving the factory to determine the corresponding relationship between the working environment temperature and the PSD threshold.

[0082] 2. The above work of determining the correspondence between the working environment temperature and the PSD threshold takes into account that it takes several hours for the equipment to reach a thermal equilibrium state after the working environment temperature is adjusted, and as many working environment temperature points as possible are required to accurately represent the correspondence. Therefore, the factory test time will be significantly increased, which does not meet the needs of large-scale production.

[0083] 3. Temperature characteristic test is destructive to a certain extent. Long-term test may have a certain negative impact on the paint, circuit, etc. of the equipment.

[0084] 4. The sensitivity of temperature sensors, scintillators, photomultiplier tubes, preamplifier circuits, etc. to temperature changes is not consistent. The reading changes of the temperature sensor cannot completely match the performance changes of the rest of the parts, which may lead to inaccurate correction of the PSD threshold based on the temperature sensor reading changes during the use of the equipment.

[0085] 5. After long-term use, the performance of the temperature sensor, scintillator, photomultiplier tube, preamplifier circuit, etc. of the nuclear radiation detection instrument may change, resulting in the correspondence between the working environment temperature and the PSD threshold determined at the factory being inconsistent with the real-time status of the equipment, resulting in inaccurate correction of the PSD threshold based on changes in the temperature sensor reading.

[0086] In order to solve the above technical problems, the present application proposes a dynamic PSD threshold correction method, device and equipment suitable for digital pulse waveform identification. Figure 7 The present invention provides a flow chart of a dynamic PSD threshold correction method for digital pulse waveform identification, wherein the dynamic PSD threshold correction method for digital pulse waveform identification comprises:

[0087] Step 101, using a nuclear radiation detection instrument to obtain a current PSD-energy two-dimensional spectrum, counting the working time of the nuclear radiation detection instrument, presetting a PSD threshold correction cycle at intervals, removing counts within a target energy range in the current PSD-energy two-dimensional spectrum, and converting it into a one-dimensional PSD spectrum using a preset formula;

[0088] Step 102: Determine the position of the maximum peak and the full width at half maximum (FWHM) in the one-dimensional PSD spectrum, and determine the PSD threshold according to the sum value of the position of the maximum peak and the FWHM, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold;

[0089] Step 103: Use the nuclear radiation detection instrument again to obtain the target PSD-energy two-dimensional spectrum, count the discrimination target ray count and the total count in the target PSD-energy two-dimensional spectrum within the target energy range and the target PSD value range, and determine the main target ray count according to the difference between the total count and the discrimination target ray count, so as to determine the main target ray count rate and the discrimination target ray count rate.

[0090] In step 101, a nuclear radiation detection instrument is used to perform radiation measurement and collect the current PSD-energy two-dimensional spectrum data. This step involves using a photomultiplier tube, a preamplifier circuit, and a digital multi-channel analyzer (MCA) to capture and record the pulse waveform and energy information of the radiation signal, and checking whether the working duration of the nuclear radiation detection instrument is greater than a preset PSD threshold correction period. This period can be set according to actual application requirements and device performance, such as 500 s, 600 s, or 700 s. Those skilled in the art understand that this application uses the example of using a NaI(Tl) crystal for n / γ discrimination to describe the technical solution. In fact, when using other materials (such as plastic scintillator, CLYC crystal) and discriminating other particles (such as α-ray / β-ray discrimination), the method described in this application can also be used. At this time, the main target ray, the discrimination target ray, the discrimination target ray energy range, the discrimination target ray PSD value range, etc. will also be different values, including the set PSD threshold correction period being 600 s, which can also be set to 60 s or 6000 s in other embodiments according to different application scenarios.

[0091] Optionally, count the working duration of the nuclear radiation detection instrument. Every time the preset PSD threshold correction period elapses, assuming the preset PSD threshold correction period is 10 minutes, after the working duration of the nuclear radiation detection instrument is greater than 10 minutes, correction is required, that is, in this application, correction is performed every 10 minutes.

[0092] If the working duration meets the conditions, the counts within the target energy range in the current PSD-energy two-dimensional spectrum are excluded. This step is to avoid the influence of the counts of target rays (such as neutrons) on the subsequent PSD spectrum analysis. The PSD-energy two-dimensional spectrum after excluding the counts is converted into a one-dimensional PSD spectrum using a preset formula. This formula may involve integration or summation operations on the energy dimension to obtain a one-dimensional distribution related only to the PSD values. Optionally, the present invention can also use machine learning algorithms to intelligently identify and exclude the counts within the target energy range to improve the accuracy and efficiency of preprocessing. In addition to the PSD-energy two-dimensional spectrum, information from other dimensions (such as time, position, etc.) can be considered for comprehensive analysis to improve the accuracy of spectrum conversion.

[0093] Optionally, before obtaining the current PSD-energy two-dimensional spectrum using the nuclear radiation detection instrument, the method further includes:

[0094] Defining the main target rays, discrimination target rays, and preset PSD threshold correction period of the nuclear radiation detection instrument;

[0095] Setting the energy scale coefficient according to the energy scale test of the nuclear radiation detection instrument;

[0096] Determining the target energy range and target PSD value range for discriminating the target rays according to the measurement of the energy-PSD value two-dimensional spectrum of the nuclear radiation detection instrument.

[0097] Optionally, according to the actual application scenario, determine the ray types that need to be mainly concerned about, and determine other ray types that need to be discriminated from the main target rays. Set a suitable PSD threshold correction period according to the stability of the device and application requirements. This period determines how often the device automatically corrects the PSD threshold to ensure the accuracy of discrimination. Optionally, dynamically adjust the PSD threshold correction period according to the real-time working state or environmental conditions of the device. For example, when the working temperature of the device changes greatly, the correction period can be shortened.

[0098] Optionally, use a radioactive source with a known energy to perform an energy scale test on the nuclear radiation detection instrument and record the response values at different energies. According to the results of the energy scale test, calculate the energy scale coefficient for converting the response value of the detection instrument into the actual energy value. This coefficient is usually a linear or non-linear function for calibrating the energy response of the detection instrument. For a detection instrument with a large energy response range, a multi-segment scale method can be adopted to scale different energy segments separately to improve the calibration accuracy.

[0099] Optionally, a nuclear radiation detection instrument is used to measure a radiation source containing the target ray to be discriminated, and a two-dimensional energy-PSD value spectrum is obtained. The two-dimensional energy-PSD value spectrum shows the PSD value distribution at different energies. According to the results of the two-dimensional spectrum, the main energy distribution range of the target ray to be discriminated is determined. The main energy distribution range is usually determined by analyzing the peak, width, and shape of the spectrum. Similarly, according to the results of the two-dimensional spectrum, the PSD value range corresponding to the target ray to be discriminated is determined, and the PSD value range is used to judge the particle type during subsequent particle discrimination.

[0100] In an optional embodiment, the main target ray is a gamma ray, the target ray to be discriminated is a neutron, and the preset PSD threshold correction period is 600 seconds;

[0101] The target energy range is 3.0 MeV to 3.5 MeV, and the target PSD value range is 0.63 to 0.73;

[0102] The main target ray count rate is the gamma ray count rate, and the target ray to be discriminated count rate is the neutron count rate.

[0103] Optionally, after obtaining the current PSD-energy two-dimensional spectrum by using the nuclear radiation detection instrument, the method further includes:

[0104] When the working duration of the nuclear radiation detection instrument is less than or equal to the preset PSD threshold correction period, the count value of the target ray to be discriminated and the total count value within the target energy range and the target PSD value range in the current PSD-energy two-dimensional spectrum are statistically analyzed. According to the total count value and the count value of the target ray to be discriminated, the count value of the main target ray is determined to determine the main target ray count rate and the target ray to be discriminated count rate.

[0105] In this optional embodiment, a supplementary processing step for a dynamic PSD threshold correction method when the working duration of the nuclear radiation detection instrument is less than or equal to the preset PSD threshold correction period is provided. It ensures that even when the PSD threshold correction period is not reached, the currently acquired two-dimensional PSD-energy spectrum can be effectively analyzed to statistically discriminate the count values of the target rays and the main target rays, and further calculate their counting rates. Specifically, first, the system checks whether the working duration of the nuclear radiation detection instrument is less than or equal to the preset PSD threshold correction period, which is the key condition for determining whether to perform subsequent statistical steps. When the working duration condition is met, the system filters out the data points located within the target energy range and the target PSD value range from the currently acquired two-dimensional PSD-energy spectrum. These data points correspond to the counts of the discriminated target rays. The system counts the number of these filtered data points, that is, the count value of the discriminated target rays. At the same time, the system also counts the total number of data points in the entire two-dimensional PSD-energy spectrum, that is, the total count value. This total count value represents the total number of all detected rays. Based on the total count value and the count value of the discriminated target rays, the system determines the count value of the main target rays by calculating their difference. This is because the total count value includes all detected rays, while the count value of the discriminated target rays represents a part of specific types of rays. Finally, the system calculates the counting rates of the discriminated target rays and the main target rays respectively according to the count value of the discriminated target rays, the count value of the main target rays, and the current measurement duration. The counting rate is the number of rays detected per unit time and is an important indicator for evaluating the ray intensity.

[0106] Optionally, the conversion into a one-dimensional PSD spectrum using the preset formula includes:

[0107]

[0108] where psd is the PSD value; E is the energy value; n(psd, E) is the count value at a certain position in the two-dimensional PSD-energy spectrum with a unit PSD value and a unit energy value, E ThrH is the upper limit of the target energy of the discriminated target rays, E ThrL is the lower limit of the target energy of the discriminated target rays, E H is the upper limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument, E L is the lower limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument, and n(psd, E)dpsd is the count value at a certain PSD value in the one-dimensional PSD spectrum.

[0109] In step 102, search for the maximum peak in the one-dimensional PSD spectrum, and record its PSD peak position K and full width at half maximum (FWHM). This step can be achieved by traversing the spectral data and finding local maxima. Calculate a new PSD threshold based on the PSD peak position K and FWHM, which is specifically calculated according to application requirements and device characteristics. Reset the target PSD value range of the nuclear radiation detection instrument according to the calculated PSD threshold to ensure the accuracy of subsequent particle discrimination.

[0110] Optionally, determining the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum includes:

[0111] Traverse the one-dimensional PSD spectrum to find all local maximum points. A local maximum point is a point whose value is greater than the values on its left and right sides. Determine all candidate peaks based on all local maximum points, and identify the candidate peak with the largest count value as the maximum peak. The position of the maximum peak is the PSD value corresponding to the abscissa of the maximum peak;

[0112] Find the points where the count first drops below the half-height value at the rising edge and falling edge of the maximum peak, denoted as the left half-height position and the right half-height position. Determine the full width at half maximum based on the left half-height position and the right half-height position. The half-height value is the corresponding value of half of the position of the maximum peak.

[0113] Optionally, starting from the starting point of the one-dimensional PSD spectrum, traverse each data point in sequence until reaching the end of the spectrum. For each data point, compare its value with the values of the adjacent left and right data points. If the value of this data point is greater than the values of its left and right data points, then this point is regarded as a local maximum point. Record the positions and corresponding PSD values of all found local maximum points. Consider each local maximum point and the data points within a certain range adjacent to it as a candidate peak. This range can be determined according to actual application requirements and the characteristics of the spectral data. For each candidate peak, calculate the sum of the PSD values of all the data points it contains as the count value of this candidate peak. Compare the count values of all candidate peaks, and identify the candidate peak with the largest count value as the maximum peak.

[0114] Furthermore, calculate the half-height value based on the PSD value at the position of the maximum peak. The half-height value is usually defined as half of the PSD value of the maximum peak. Starting from the left side of the maximum peak, search to the right until finding the first point with a PSD value lower than the half-height value, denoted as the left half-height position. Similarly, starting from the right side of the maximum peak, search to the left until finding the first point with a PSD value lower than the half-height value, denoted as the right half-height position. When searching for the left and right half-height positions, strategies such as linear search and binary search can be adopted to improve efficiency. Subtract the abscissa of the left half-height position from the abscissa of the right half-height position, and the resulting value is the full width at half maximum.

[0115] In step 103, a nuclear radiation detection instrument is used to perform radiation measurement again to obtain target PSD-energy two-dimensional spectrum data. This step is similar to the data acquisition in step 101, but the purpose is to perform particle discrimination using the newly set PSD threshold, and to count the discrimination target ray count values and the total count values in the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum. It involves traversing the spectrum data and screening and counting using the preset energy and PSD value ranges, determining the main target ray count value based on the difference between the total count value and the discrimination target ray count value, and further calculating the main target ray counting rate and the discrimination target ray counting rate. The present invention aims at the ultimate goal of particle discrimination and is used to evaluate the relative content or intensity of different particles.

[0116] Optionally, the counting of the discrimination target ray count values and the total count values in the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum includes:

[0117] According to the upper limit of the target energy of the discrimination target ray, the lower limit of the target energy of the discrimination target ray, and the target PSD value range, count the discrimination target ray count values in the target PSD-energy two-dimensional spectrum;

[0118] According to the upper limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument and the lower limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument, count the total count values in the target PSD-energy two-dimensional spectrum.

[0119] Optionally, it is necessary to clarify the upper limit and the lower limit of the target energy of the discrimination target ray. These two values are determined according to the actual application requirements and the device characteristics and are used to define the energy interval that needs to be concerned about. Similarly, it is also necessary to determine the target PSD value range. This range corresponds to the characteristics of the discrimination target ray in the PSD dimension. Traverse each data point in the target PSD-energy two-dimensional spectrum, and count the data points that meet the conditions. The total number obtained is the discrimination target ray count value. Similarly, clarify the upper limit and the lower limit of the energy range for energy spectrum measurement by the nuclear radiation detection instrument. These two values define the entire energy interval that the device can detect. Traverse each data point in the target PSD-energy two-dimensional spectrum, and count the data points that meet the conditions. The total number obtained is the total count value. This value represents the total number of all rays detected within the entire energy spectrum measurement range.

[0120] Optionally, after determining the main target ray count value, the method further includes:

[0121] Obtain the current measurement duration;

[0122] Determine the discrimination target ray count rate according to the quotient of the discrimination target ray count value and the current measurement duration;

[0123] Determine the main target ray count rate according to the quotient of the main target ray count value and the current measurement duration.

[0124] Optionally, when the nuclear radiation detection instrument starts to work, start a timer or record an initial timestamp. During the detection process, continuously record or update the current timestamp. When calculating the count rate, read the current timestamp and subtract it from the initial timestamp to obtain the current measurement duration. The discrimination target ray count rate refers to the number of discrimination target rays detected per unit time. Divide the statistically obtained discrimination target ray count value by the current measurement duration to obtain the discrimination target ray count rate. Similarly, the main target ray count rate refers to the number of main target rays detected per unit time. Divide the previously determined main target ray count value by the current measurement duration to obtain the main target ray count rate.

[0125] Figure 8 It is a schematic flow diagram before the nuclear radiation detection instrument provided by the present invention leaves the factory, Figure 9 It is a schematic flow diagram during the use of the nuclear radiation detection instrument provided by the present invention. Taking the use of a nuclear radiation detection instrument based on a NaIL crystal to realize neutron and γ-ray discrimination as an example, the specific implementation manner is described. Among them, steps 1-3 are the steps required before the equipment leaves the factory, and the remaining steps are automatically implemented during the use of the equipment without manual operation:

[0126] 1. Define the main target ray, discrimination target ray, and PSD threshold correction period of the nuclear radiation detection instrument. For example, define γ-ray as the main target ray, neutron as the discrimination target ray, and the PSD threshold correction period as 600 s. At this time, the equipment needs to correct the PSD threshold every 600 s of operation.

[0127] 2. Conduct an energy calibration test on the nuclear radiation detection instrument and set the energy calibration coefficient.

[0128] 3. Conduct a two-dimensional spectrum measurement of energy-PSD value of the nuclear radiation detection instrument to clarify the target energy range and target PSD value range of the discrimination target ray. For example, use an AmBe source and measure the two-dimensional spectrum of energy-PSD value. Through the test results, clarify and set the target energy range of the discrimination target ray to be 3.0 MeV to 3.5 MeV, and the PSD threshold to be 0.63. That is, only particles with energy in

[0129] the range of 3.0 MeV to 3.5 MeV and PSD value greater than 0.63 will be identified as neutrons.

[0130] 4. Measure using a nuclear radiation detection instrument to obtain the two-dimensional PSD-energy spectrum P1, and determine whether PSD threshold correction is required based on the device operating time and PSD threshold correction period. If not, proceed to step 8; if so, proceed to the next step.

[0131] 5. Eliminate the counts within the target energy range in the two-dimensional PSD-energy spectrum P1 and convert it into a one-dimensional PSD spectrum P2.

[0132] 6. Find the maximum peak in the one-dimensional PSD spectrum P2, and record the PSD peak position K and the full width at half maximum FWHM.

[0133] 7. Calculate and reset the PSD threshold according to the PSD peak position K and the full width at half maximum FWHM. For example, the PSD threshold can be calculated according to the following formula:

[0134] psd Thr = K + FWHM

[0135] 8. Statistically discriminate the target ray count N2.

[0136] 9. Statistically count the total count N.

[0137] 10. Calculate the count N1 of the main target ray.

[0138] 11. Complete subsequent work such as count rate calculation. For example, the neutron count rate C n The calculation formula is:

[0139] C n = N2 / t

[0140] The calculation formula for the γ count rate is:

[0141] C γ = N1 / t

[0142] where t is the measurement time.

[0143] The dynamic PSD threshold correction method provided by the present invention significantly reduces the test steps required before the device leaves the factory compared with the correction method based on temperature measurement, thereby reducing the production and calibration costs and meeting the requirements of mass production; by avoiding long-term temperature tests, it effectively reduces the negative impacts that the tests may cause to the device performance, such as damage to components such as paint and circuits;

[0144] The dynamic PSD threshold correction method provided by the present invention is more accurate than the correction method based on temperature measurement. Because it not only considers the change of ambient temperature, but also dynamically adjusts the PSD threshold by real-time analyzing the PSD-energy two-dimensional spectrum, thus more accurately reflecting the actual performance of the nuclear radiation detection instrument; it avoids the need for regular temperature tests during the use of the equipment to re-establish the "temperature-PSD threshold" relationship, improving the usability and maintenance efficiency of the equipment; the dynamic PSD threshold correction can respond in a timely manner to the overall performance change of the nuclear radiation detection instrument, rather than just the change of ambient temperature, so the reliability of the equipment is better; by real-time analyzing the PSD-energy two-dimensional spectrum and dynamically adjusting the PSD threshold, the method of the present application can more accurately distinguish different particles, improving the accuracy and efficiency of particle detection.

[0145] Figure 10 FIG. 4 is a structural schematic diagram of a dynamic PSD threshold correction device applicable to digital pulse waveform discrimination provided by the present invention. The dynamic PSD threshold correction device applicable to digital pulse waveform discrimination includes an acquisition unit 1. The acquisition unit 1 is used to obtain the current PSD-energy two-dimensional spectrum by using a nuclear radiation detection instrument, count the working duration of the nuclear radiation detection instrument, and every preset PSD threshold correction period, eliminate the counts within the target energy range in the current PSD-energy two-dimensional spectrum, and convert them into a one-dimensional PSD spectrum by using a preset formula. The working principle of the acquisition unit 1 can refer to the foregoing step 101 and will not be elaborated here.

[0146] The dynamic PSD threshold correction device applicable to digital pulse waveform discrimination further includes a determination unit 2. The determination unit 2 is used to determine the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum, and determine the PSD threshold according to the sum value of the position of the maximum peak and the full width at half maximum, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold. The working principle of the determination unit 2 can refer to the foregoing step 102 and will not be elaborated here.

[0147] The dynamic PSD threshold correction device applicable to digital pulse waveform discrimination further includes a statistics unit 3. The statistics unit 3 is used to obtain the target PSD-energy two-dimensional spectrum again by using the nuclear radiation detection instrument, count the discrimination target ray count value and the total count value within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum, and determine the main target ray count value according to the difference between the total count value and the discrimination target ray count value, so as to determine the main target ray count rate and the discrimination target ray count rate. The working principle of the statistics unit 3 can refer to the foregoing step 103 and will not be elaborated here.

[0148] The dynamic PSD threshold correction method provided by the present invention significantly reduces the test steps required before the device leaves the factory compared with the correction method based on temperature measurement, thereby reducing the production and calibration costs and meeting the requirements of mass production; by avoiding long-term temperature tests, it effectively reduces the negative impacts that the tests may cause to the device performance, such as damage to components such as paint and circuits.

[0149] The dynamic PSD threshold correction method provided by the present invention is more accurate than the correction method based on temperature measurement because it not only considers the change of the ambient temperature, but also dynamically adjusts the PSD threshold by real-time analyzing the PSD-energy two-dimensional spectrum, thereby more accurately reflecting the actual performance of the nuclear radiation detection instrument; it avoids the need for regular temperature tests during the device use to re-establish the "temperature-PSD threshold" relationship, improving the usability and maintenance efficiency of the device; the dynamic PSD threshold correction can respond in a timely manner to the overall performance change of the nuclear radiation detection instrument, rather than just the change of the ambient temperature, so the reliability of the device is better; by real-time analyzing the PSD-energy two-dimensional spectrum and dynamically adjusting the PSD threshold, the method of the present application can more accurately distinguish different particles, improving the accuracy and efficiency of particle detection.

[0150] Figure 11 It is a schematic structural diagram of the electronic device provided by the present invention. As Figure 11 shown, the electronic device may include: a processor 110, a communications interface 120, a memory 130, and a communication bus 140. Among them, the processor 110, the communications interface 120, and the memory 130 complete the communication with each other through the communication bus 140. The processor 110 can call the logical instructions in the memory 130 to execute the dynamic PSD threshold correction method applicable to digital pulse waveform discrimination. The method includes: using the nuclear radiation detection instrument to obtain the current PSD-energy two-dimensional spectrum, counting the working duration of the nuclear radiation detection instrument, and every preset PSD threshold correction period, eliminating the counts within the target energy range in the current PSD-energy two-dimensional spectrum and converting them into a one-dimensional PSD spectrum using a preset formula; determining the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum, and determining the PSD threshold according to the sum value of the position of the maximum peak and the full width at half maximum, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold; using the nuclear radiation detection instrument again to obtain the target PSD-energy two-dimensional spectrum, counting the discrimination target ray count value and the total count value within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum, and determining the main target ray count value according to the difference between the total count value and the discrimination target ray count value, so as to determine the main target ray count rate and the discrimination target ray count rate.

[0151] In addition, the logical instructions in the above-mentioned memory 130 can be implemented in the form of software functional units and stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, external hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0152] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the above-mentioned various methods. The method includes: obtaining a current PSD-energy two-dimensional spectrum using a nuclear radiation detection instrument, counting the working duration of the nuclear radiation detection instrument, and every time a preset PSD threshold correction period elapses, excluding the counts within the target energy range in the current PSD-energy two-dimensional spectrum and converting them into a one-dimensional PSD spectrum using a preset formula; determining the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum, and determining the PSD threshold according to the sum value of the position of the maximum peak and the full width at half maximum, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold; obtaining a target PSD-energy two-dimensional spectrum again using the nuclear radiation detection instrument, counting the discrimination target ray count value and the total count value within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum, and determining the main target ray count value according to the difference between the total count value and the discrimination target ray count value, so as to determine the main target ray counting rate and the discrimination target ray counting rate.

[0153] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements a dynamic PSD threshold correction method applicable to digital pulse waveform discrimination provided by the above-mentioned various methods. The method includes: obtaining a current PSD-energy two-dimensional spectrum by using a nuclear radiation detection instrument, counting the working duration of the nuclear radiation detection instrument, and every time a preset PSD threshold correction period elapses, eliminating the counts within the target energy range in the current PSD-energy two-dimensional spectrum, and converting them into a one-dimensional PSD spectrum by using a preset formula; determining the position of the maximum peak and the full width at half maximum in the one-dimensional PSD spectrum, and determining the PSD threshold according to the sum value of the position of the maximum peak and the full width at half maximum, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold; obtaining a target PSD-energy two-dimensional spectrum again by using the nuclear radiation detection instrument, counting the discrimination target ray count value and the total count value within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum, and determining the main target ray count value according to the difference between the total count value and the discrimination target ray count value, so as to determine the main target ray count rate and the discrimination target ray count rate.

[0154] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative labor.

[0155] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. The 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 for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dynamic PSD threshold correction method suitable for digital pulse waveform identification, characterized in that: include: Using a nuclear radiation detection instrument to obtain a current PSD-energy two-dimensional spectrum, counting the working time of the nuclear radiation detection instrument, presetting a PSD threshold correction cycle at intervals, eliminating counts within a target energy range in the current PSD-energy two-dimensional spectrum, and converting it into a one-dimensional PSD spectrum using a preset formula; Determine the maximum peak position and half-height width in the one-dimensional PSD spectrum, determine a PSD threshold value according to the sum of the maximum peak position and half-height width, and reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold value; The nuclear radiation detection instrument is used again to obtain the target PSD-energy two-dimensional spectrum, and the identification target ray count values ​​and the total value within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum are counted. The main target ray count value is determined according to the difference between the total value and the identification target ray count value to determine the main target ray count rate and the identification target ray count rate.

2. The dynamic PSD threshold correction method for digital pulse waveform identification according to claim 1 is characterized in that: Before using the nuclear radiation detection instrument to obtain the current PSD-energy two-dimensional spectrum, the method further includes: Defining the main target rays, identification target rays and preset PSD threshold correction period of the nuclear radiation detection instrument; According to the energy calibration test of the nuclear radiation detection instrument, an energy calibration coefficient is set; According to the energy-PSD value two-dimensional spectrum measurement of the nuclear radiation detection instrument, the target energy range and the target PSD value range for identifying the target ray are determined.

3. The dynamic PSD threshold correction method for digital pulse waveform identification according to claim 2 is characterized in that: The main target ray is a gamma ray, the identification target ray is a neutron, and the preset PSD threshold correction period is 600 seconds; The target energy range is 3.0 MeV to 3.5 MeV, and the target PSD value range is 0.63 to 0.73; The main target ray counting rate is a gamma ray counting rate, and the identification target ray counting rate is a neutron counting rate.

4. The dynamic PSD threshold correction method for digital pulse waveform identification according to claim 1, characterized in that: After obtaining the current PSD-energy two-dimensional spectrum by using the nuclear radiation detection instrument, the method further includes: When the working time of the nuclear radiation detection instrument is less than or equal to the preset PSD threshold correction period, the discrimination target ray count value and the total value within the target energy range and the target PSD value range in the current PSD-energy two-dimensional spectrum are counted, and the main target ray count value is determined according to the total value and the discrimination target ray count value to determine the main target ray count rate and the discrimination target ray count rate.

5. The dynamic PSD threshold correction method for digital pulse waveform identification according to claim 1, characterized in that: The conversion into a one-dimensional PSD spectrum using a preset formula includes: Where psd is the PSD value; E is the energy value; n(psd,E) is the count value of the unit PSD value and unit energy value at a certain point in the PSD-energy two-dimensional spectrum, and E ThrH is the upper limit of target energy for identifying target rays, E ThrL is the lower limit of target energy for identifying target rays, E H The upper limit of the energy range for energy spectrum measurement of nuclear radiation detection instruments, E L It is the lower limit of the energy range of energy spectrum measurement for nuclear radiation detection instruments. n(psd,E)dpsd is the count value at a certain PSD value in the one-dimensional PSD spectrum.

6. The dynamic PSD threshold correction method for digital pulse waveform identification according to claim 1, characterized in that: Determining the position of the maximum peak and the half-height width in the one-dimensional PSD spectrum includes: Traversing the one-dimensional PSD spectrum, finding all local maximum points, the local maximum point being a point where the value of any point is greater than the value on the left and right of the point, determining all candidate peaks according to all local maximum points, determining the candidate peak with the largest count value as the maximum peak, and the position of the maximum peak being the PSD value corresponding to the abscissa of the maximum peak; Find the points where the count is lower than the half-height value for the first time on the rising edge and the falling edge of the maximum peak, respectively, and record them as the left half-height position and the right half-height position. Determine the half-height width based on the left half-height position and the right half-height position. The half-height value is the corresponding value of half of the position of the maximum peak.

7. The dynamic PSD threshold correction method for digital pulse waveform identification according to claim 1, characterized in that: The counting of the target ray count values ​​and the total value within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum includes: According to the target energy upper limit of the target ray, the target energy lower limit of the target ray, and the target PSD value range, counting the target ray count values ​​in the target PSD-energy two-dimensional spectrum; According to the upper limit of the energy range of the energy spectrum measurement performed by the nuclear radiation detection instrument and the lower limit of the energy range of the energy spectrum measurement performed by the nuclear radiation detection instrument, the total value in the target PSD-energy two-dimensional spectrum is counted.

8. The dynamic PSD threshold correction method for digital pulse waveform identification according to claim 1, characterized in that: After determining the primary target ray count value, the method further includes: Get the current measurement duration; Determining a target identification ray counting rate according to a quotient of the target identification ray counting value and the current measurement duration; The main target ray count rate is determined according to a quotient of the main target ray count value and the current measurement duration.

9. A dynamic PSD threshold correction device suitable for digital pulse waveform identification, characterized in that: include: An acquisition unit, the acquisition unit is used to acquire a current PSD-energy two-dimensional spectrum using a nuclear radiation detection instrument, count the working time of the nuclear radiation detection instrument, preset a PSD threshold correction cycle at intervals, remove counts within a target energy range in the current PSD-energy two-dimensional spectrum, and convert it into a one-dimensional PSD spectrum using a preset formula; A determination unit, the determination unit is used to determine the maximum peak position and half-height width in the one-dimensional PSD spectrum, determine a PSD threshold value according to the sum of the maximum peak position and the half-height width, so as to reset the target PSD value range of the nuclear radiation detection instrument according to the PSD threshold value; A statistical unit is used to use the nuclear radiation detection instrument again to obtain a target PSD-energy two-dimensional spectrum, count the identification target ray count values ​​and the total value within the target energy range and the target PSD value range in the target PSD-energy two-dimensional spectrum, determine the main target ray count value according to the difference between the total value and the identification target ray count value, and determine the main target ray count rate and the identification target ray count rate.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the dynamic PSD threshold correction method suitable for digital pulse waveform identification as described in any one of claims 1 to 8 is implemented.

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