Gamma detector activation analysis method and PGNAA detection system

Abstract

The invention relates to the technical field of gamma-ray spectrum analysis, particularly provides a gamma-ray detector activation analysis method and a PGNAA detection system, and aims to solve the problems that gamma rays obtained by detection of an existing gamma-ray detector comprise rays generated by decay of crystals after activation in a neutron field; therefore, the component detection result of the to-be-detected sample is not accurate. In order to achieve the purpose, the activation analysis method for the gamma detector comprises the steps that a to-be-detected sample is irradiated through a neutron source; repeatedly collecting a plurality of groups of gamma-ray energy spectrums of the sample to be detected by using a gamma-ray detector; constructing an energy spectrum signal matrix based on the gamma-ray energy spectrum of the to-be-detected sample, wherein the energy spectrum signal matrix is a mixed signal composed of instant gamma rays generated by neutron activation of the to-be-detected sample, environmental background gamma rays and interference signals generated by crystal activation in a gamma detector; and obtaining the effective instant gamma ray based on the energy spectrum signal matrix. The self-interference influence of the detector is effectively reduced, and the target element content evaluation precision of the to-be-detected object is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gamma spectrum analysis, and specifically provides a gamma detector activation analysis method and a PGNAA detection system. Background Art

[0002] The mining, smelting, and finishing of rare metals, nonferrous metals, and other strategic materials urgently require accurate, real-time, online measurement of their raw material composition to provide critical process data. Prompt gamma-ray neutron activation analysis (PGNAA) offers simultaneous multi-element analysis, short analysis times, and volumetric measurement capabilities, fully meeting the real-time, online material analysis needs of traditional industrial and mining enterprises like cement, coal, and metallurgy.

[0003] Gamma detectors are the most commonly used detectors in neutron activation analysis systems. During the detection process, the crystals in the detector mainly respond to gamma rays. However, when the neutron source in the activation analysis system is strong, the crystals in the detector will be activated and produce corresponding activation products. The activation products will produce continuous beta rays and gamma rays during the decay process, which will cause great interference and influence on the detection results, and directly affect the accuracy of component detection. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings, the present application is proposed to provide a solution, or at least a partial solution, to the technical problem that gamma rays detected by existing gamma detectors include those generated by crystals activated and then decaying in a neutron field, thereby leading to inaccurate composition detection results of the sample being tested. This application provides a gamma detector activation analysis method and a PGNAA detection system.

[0005] In a first aspect, the present application provides a gamma detector activation analysis method, the method comprising:

[0006] irradiating the sample to be tested using a neutron source;

[0007] repeatedly collecting multiple sets of gamma energy spectra of the sample to be tested using a gamma detector;

[0008] constructing an energy spectrum signal matrix based on the multiple sets of gamma energy spectra of the sample to be tested, wherein the energy spectrum signal matrix is a mixed signal composed of prompt gamma rays generated by neutron activation of the sample to be tested, environmental background gamma rays, and interference signals generated by crystal activation in the gamma detector;

[0009] Effective prompt gamma rays are acquired based on the energy spectrum signal matrix.

[0010] In a specific embodiment of the present application, repeatedly collecting multiple sets of gamma energy spectra of the sample to be tested using a gamma detector includes: collecting multiple sets of gamma energy spectra of the sample to be tested at equal time intervals using a gamma detector.

[0011] In a specific embodiment of the present application, constructing the energy spectrum signal matrix based on the gamma energy spectrum of the samples to be tested includes: constructing the energy spectrum signal matrix according to a preset channel address based on the gamma energy spectrum of each group of samples to be tested.

[0012] In a specific embodiment of the present application, the gamma detector is a scintillator detector.

[0013] In a specific embodiment of the present application, when the scintillator detector is a NaI detector, the interference signal generated by the crystal activation in the gamma detector includes and Gamma rays produced by decay;

[0014] The energy spectrum signal matrix satisfies the following relationship:

[0015] Among them, S is the energy spectrum signal matrix, A is the sample to be tested and the environmental background count, B and C are and The interference count weights, M1 and M2 are respectively and The coefficient matrix related to the activity of nuclides.

[0016] In a specific embodiment of the present application, the step of obtaining effective prompt gamma rays based on the energy spectrum signal matrix includes:

[0017] Vectorizing the energy spectrum signal matrix;

[0018] Solving the vectorized energy spectrum signal matrix;

[0019] The effective prompt gamma ray is extracted from the energy spectrum signal matrix according to the solution result.

[0020] In a specific embodiment of the present application, vectorizing the energy spectrum signal matrix includes: vectorizing the energy spectrum signal matrix using a Kronecker product, and the vectorized energy spectrum signal matrix is expressed as:

[0021] Among them, vec represents vectorization, I 306 is the 306×306 identity matrix, represents the Kronecker product; and / or

[0022] The solving the vectorized energy spectrum signal matrix includes: solving the vectorized energy spectrum signal matrix using a least squares method.

[0023] In a specific embodiment of the present application, the neutron source is an isotope neutron source or an accelerator neutron source.

[0024] In a specific embodiment of the present application, the method further includes: evaluating the content of the target element in the sample to be tested based on the effective prompt gamma ray.

[0025] In a second aspect, a PGNAA detection system is provided, wherein the PGNAA detection system is used to perform the aforementioned gamma detector activation analysis method.

[0026] The above one or more technical solutions of this application have at least one or more of the following Beneficial effects:

[0027] The gamma detector activation analysis method in the present application includes: irradiating the sample to be tested with a neutron source; repeatedly collecting gamma energy spectra of multiple groups of samples to be tested with a gamma detector; constructing an energy spectrum signal matrix based on the multiple groups of gamma energy spectra of the sample to be tested, the energy spectrum signal matrix is a mixed signal composed of prompt gamma rays generated by neutron activation of the sample to be tested, environmental background gamma rays and interference signals generated by crystal activation in the gamma detector; obtaining effective prompt gamma rays based on the energy spectrum signal matrix. The neutron source is responsible for providing a neutron beam for irradiating the sample to be tested, thereby inducing a neutron activation reaction of specific elements in the sample to be tested to produce prompt gamma rays. The gamma detector is responsible for collecting gamma energy spectrum data of multiple groups of samples to be tested, which includes a mixture of prompt gamma rays generated in the sample, background gamma rays in the environment and interference signals generated by the crystal inside the gamma detector after being irradiated by the neutron source. By constructing an energy spectrum signal matrix, these complex data can be integrated to effectively distinguish and extract the main prompt gamma ray signals. This provides a reliable means for non-destructive analysis of sample composition. By accurately identifying and quantifying prompt gamma-ray signals, the impact of detector interference is effectively reduced, improving the accuracy and reliability of activation analysis. This also helps improve the accuracy of detecting the presence and content of specific elements in the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The disclosure of this application will be more easily understood with reference to the accompanying drawings. Those skilled in the art will readily appreciate that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Furthermore, similar numbers in the figures represent similar components, where:

[0029] Figure 1 This is a schematic diagram of the counting of the same group of NaCl solution samples using a NaI gamma detector;

[0030] Figure 2 It is a schematic diagram of the main process of the gamma detector activation analysis method in one embodiment of the present application. DETAILED DESCRIPTION

[0031] Some embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application.

[0032] In the description of this application, "module" and "processor" may include hardware, software, or a combination of both. A module may include hardware circuitry, various suitable sensors, communication ports, and memory. It may also include software components, such as program code, or a combination of software and hardware. A processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor, or any other suitable processor. A processor has data and / or signal processing capabilities. A processor may be implemented in software, hardware, or a combination of both. Non-transitory computer-readable storage media include any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" refers to all possible combinations of A and B, such as only A, only B, or both A and B. The terms "at least one of A or B" or "at least one of A and B" have similar meanings to "A and / or B" and may include only A, only B, or both A and B. The singular forms "a" and "the" may also include the plural forms.

[0033] Conventional gamma detectors currently detect gamma rays, including those produced by the activation and subsequent decay of crystals in a neutron field. This can lead to inaccurate compositional analysis results for samples under test. For example, sodium iodide (NaI) gamma detectors are the most commonly used detectors in neutron activation analysis systems. During detection, NaI crystals primarily respond to gamma rays. However, when the neutron source intensity in the activation analysis system is strong, exceeding 1e10 n / s, the Na and I elements in the crystals of the NaI detectors are activated by the system's thermal neutrons to produce Na24 and I128 activation products. These Na24 and I128 decay into continuous beta and gamma rays, which significantly interfere with and affect the detection results, directly impacting the accuracy of compositional analysis.

[0034] In the PGNAA detection based on the NaI gamma detector, the crystal of the NaI detector will undergo an activation reaction under the thermal neutron field, as follows:

[0035] Na23+n→Na24; I 127+n→I 128

[0036] The decay equations for Na24 and I 128 are:

[0037] Among them, the β and γ rays in the decay process will directly trigger the gamma detector to generate signal counts, causing interference to the actual effective signal. The half-life is about 15 hours (14.956 hours), The half-life is about 25 minutes (24.99 minutes), The decay of contributes the main part, so in the continuous measurement (20 minutes) group, The content of iodine continues to increase (and the increase is getting lower and lower).

[0038] However, due to the different time during the detection process, the contribution ratio of NaI activation to the total signal varies. Figure 1 It can be used as a schematic diagram of the counting of the same group of (sodium chloride) solution samples using a NaI gamma detector. Figure 1 It can be seen that with the increase of irradiation time, for the same sample to be tested, there are obvious counting differences in the range of 600keV to 2MeV.

[0039] To this end, the present application proposes a gamma detector activation analysis method and a PGNAA detection system.

[0040] Before explaining the execution process of this application, the principle of this application is first explained.

[0041] In general, it is believed that the contribution of NaI crystal activation to the gamma detector signal is proportional to the content of the products of the activated nuclides Na and I. The activity of NaI crystal changes with time as follows: A Na-I =N Na-I *σ Na-I *Φ*[1-exp(-λ Na-I *t)]

[0042] Among them, A Na-I is the activity of Na24 or I 128, N Na-I is the nucleon density of Na24 or I 128, σ Na-I is the thermal neutron microscopic cross section of Na24 or I128, Φ is the thermal neutron flux density of NaI crystal, λ Na-I is the decay constant of Na24 or I 128, and t is the irradiation time.

[0043] In the time interval [t1, t2], the signal b obtained by the NaI detector is i It can be composed of the following three parts:

[0044] Among them, a g(t) is the count rate of prompt gamma rays, a 24Na (t) Yes The decay count rate, a 128I (t) Yes Decay count rate.

[0045] and The decay counting rate is proportional to their activity at the corresponding moment. Generally speaking, the decay law of radioactive nuclides activity conforms to the exponential function characteristics, that is,

[0046] Finally, the expression of the change of NaI activation interference signal count over time shows an exponential relationship. Assuming that two consecutive measurement segments are [t1, t2] and [t2, t3], then

[0047] When the neutron source is turned on in the [t1, t2] period

[0048] When [t1, t2] the neutron source is turned off

[0049] Among them, k1 and k2 are coefficients to be determined, λ 24Na yes The decay constant is about 7.7243×10 -4 min -1 ,λ 128I yes The decay constant is about 0.02774min -1 .

[0050] because The content of is proportional to the interference signal counts it contributes. In order to separate the interference signal part from each set of counting results, the difference between the two sets of counting results is calculated:

[0051] in, Indicates the total signal detected by the NaI detector during the interval between the measurement time points t2 and t1, a g (t) represents the signal of the sample and surrounding environment entering the detector due to the gamma rays induced by PGNAA.

[0052] When PGNAA is used for detection, the neutron source is always in a stable state. When the sample and other environmental background counts are measured at the same time, the counting results of the two contributions should be the same. The intervals between the detection experiments of each group are consistent, that is, t3-t2=t2-t1

[0053] Then there is

[0054] Thus there is

[0055] Where C1 and C2 are data associated with the decay constants of the relevant nuclides.

[0056] Based on the above analysis, it can be seen that by collecting multiple sets of data in the same time period, the interference signal can be separated from the mixed signal.

[0057] Next, the specific implementation of this application is described in detail.

[0058] See attached Figure 2 , Figure 2 It is a flow chart of the main steps of a gamma detector activation analysis method according to one embodiment of the present application.

[0059] like Figure 2 As shown, the gamma detector activation analysis method in the embodiment of the present application mainly includes the following steps S10 to S40.

[0060] Step S10: irradiating the sample to be tested with a neutron source.

[0061] A neutron source is a device or substance that produces neutrons, which are used to initiate nuclear reactions (such as neutron capture and fission). Neutron sources can be either isotope neutron sources or accelerator neutron sources. An example of an isotope neutron source is cf-252 (californium-252), which primarily releases neutrons through spontaneous fission. Accelerator neutron sources primarily generate neutrons by bombarding a target material (such as a Be target) with a particle accelerator.

[0062] Specifically, a neutron source is used to irradiate the sample to be tested, causing the atomic nuclei in the sample to be tested to absorb neutrons and generate radioactive isotopes, which then release prompt gamma rays.

[0063] Step S20: repeatedly collecting multiple sets of gamma energy spectra of the sample to be tested using a gamma detector.

[0064] A gamma detector is a device used to detect gamma rays by converting the energy of gamma rays into electrical signals for measurement. For example, gamma detectors can include scintillator detectors, semiconductor detectors, and gas detectors.

[0065] In a specific embodiment of the present application, repeatedly collecting multiple sets of gamma energy spectra of the sample to be tested using a gamma detector includes: collecting multiple sets of gamma energy spectra of the sample to be tested at equal time intervals using a gamma detector.

[0066] The gamma detector in this embodiment may be a scintillator detector, such as a Na I detector.

[0067] Specifically, a gamma detector can be used to collect multiple sets of gamma spectra of the sample to be tested at equal time intervals. For example, the gamma spectra of the sample to be tested can be collected at fixed intervals, such as every 10 seconds, 1 minute, or longer, to obtain multiple sets of gamma spectra of the sample to be tested.

[0068] Step S30: constructing an energy spectrum signal matrix based on the gamma energy spectrum of the sample to be tested, wherein the energy spectrum signal matrix is a mixed signal composed of prompt gamma rays generated by neutron activation of the sample to be tested, environmental background gamma rays and interference signals generated by crystal activation in the gamma detector.

[0069] In a specific embodiment of the present application, constructing the energy spectrum signal matrix based on the gamma energy spectrum of the samples to be tested includes: constructing the energy spectrum signal matrix according to a preset channel address based on the gamma energy spectrum of each group of samples to be tested.

[0070] The channel address refers to the channel address of the multi-channel analyzer, which is a component of the detector. The preset channel address range is 110 to 415.

[0071] The energy spectrum signal matrix is a two-dimensional matrix that arranges multiple gamma spectra into time series and energy channels. It is used for mathematical modeling and signal separation. The rows of the two-dimensional matrix represent the channel locations of the acquired signals, and the columns of the two-dimensional matrix represent the time period of the measured signals.

[0072] In a specific embodiment of the present application, when the scintillator detector is a NaI detector, the interference signal generated by the crystal activation in the gamma detector includes and Gamma rays produced by decay;

[0073] The energy spectrum signal matrix satisfies the following relationship:

[0074] Among them, S is the energy spectrum signal matrix, A is the sample to be tested and the environmental background count, B and C are and The interference count weights, M1 and M2 are respectively and The coefficient matrix related to the activity of nuclides.

[0075] According to the relationship satisfied by the energy spectrum signal matrix, A1 T It can be the prompt gamma rays generated by neutron activation of the sample to be tested and the environmental background gamma rays, and is the interference signal generated by the crystal activation in the gamma detector, where in the Na I detector, It can be a gamma detector The interference signal generated by activation, It can be a gamma detector Interference signals generated by activation.

[0076] Specifically, the interference region of NaI activation on PGNAA detection is mainly between 600keV and 2MeV, and the channel addresses of the detector multi-channel analyzer are 110 to 415.

[0077] For example, taking the measurement of multiple gamma spectra of 7 groups of samples to be tested as an example, the count of the measurement results of group i (i = 1, 2, 3, ..., 7) in channel j (j = 110, 111, ..., 415) is: S(j, i) = A(j) + B(j) N 24Na (t i )+C(j)N 128I (t i ).

[0078] Among them, S(j,i) is the total count, A(j) is the count contributed by the sample to be tested and the background environment, B(j)N 24Na (t i )yes Interference counts caused by decay, C(j)N 128I (t i )yes The interference counts caused by decay, the counts of the decay part are proportional to the content of the corresponding element.

[0079] pair(j,i)=A(j)+B(j)N 24Na (t i )+C(j)N 128I (t i ) can be transformed into the following matrix form:

[0080] Among them, S is a 306×7 known matrix (corresponding to the 110th to 415th channels of the existing 7 sets of measurement spectra); A is a 306*1 matrix, representing the counts contributed by the sample and background in these channels; 1 T is a 1×7 all-1 vector; B is a 306*1 matrix, constant 1×7 matrix, represent Interference count caused by decay; C is a 306*1 matrix, constant 1×7 matrix, represent Interference counts caused by decay.

[0081] By constructing an energy spectrum signal matrix, it is beneficial to achieve effective correction of the signal collected by the NaI detector, solve the problem of NaI activation interfering with PGNAA detection, and avoid the time and material costs brought about by increasing shielding, changing physics and other methods in existing methods.

[0082] Step S40: Acquire effective prompt gamma rays based on the energy spectrum signal matrix.

[0083] Specifically, the above step S40 can be implemented through the following steps S401 to S403.

[0084] Step S401: vectorize the energy spectrum signal matrix.

[0085] In a specific embodiment of the present application, vectorizing the energy spectrum signal matrix includes: vectorizing the energy spectrum signal matrix using the property of the Kronecker product, wherein the energy spectrum signal matrix after vectorization is expressed as:

[0086] Among them, vec represents vectorization, I 306 is the 306×306 identity matrix, represents the Kronecker product.

[0087] Step S402: solving the quantized energy spectrum signal matrix.

[0088] Specifically, the vectorized energy spectrum signal matrix is a series of overdetermined equations, which can be solved using the least squares method. The basic idea is to consider an overdetermined equation ax = b, consider the residual term r = ax - b, and find the x value that minimizes the Euclidean norm of r. Therefore, solving the vectorized energy spectrum signal matrix can be expressed as a least squares problem:

[0089] By solving the above equations, we can obtain the coefficients A, B, and C in the energy spectrum signal matrix.

[0090] Step S403: extracting effective prompt gamma rays from the energy spectrum signal matrix according to the solution result.

[0091] Specifically, after solving the coefficient A in the energy spectrum signal matrix, the effective prompt gamma ray can be obtained. The effective prompt gamma ray refers to the prompt gamma ray generated by the neutron activation of the sample to be tested and the environmental background gamma ray (that is, A1 in the energy spectrum signal matrix). T ).

[0092] By obtaining effective prompt gamma rays based on the energy spectrum signal matrix, correction processing is carried out on all signals received by the NaI detector, eliminating the interference signals caused by the activation of Na24 and I 128, and retaining the prompt gamma characteristic signals induced by the sample during the detection process, thereby improving the accuracy and reliability of neutron composition detection.

[0093] Based on the above steps S10-S40, the sample to be tested is first irradiated with a neutron source; a gamma detector is used to repeatedly collect gamma energy spectra of multiple groups of samples to be tested; an energy spectrum signal matrix is constructed based on the multiple gamma energy spectra of the samples to be tested. The energy spectrum signal matrix is a mixed signal composed of prompt gamma rays generated by neutron activation of the sample to be tested, background gamma rays in the environment, and interference signals generated by crystal activation in the gamma detector; and effective prompt gamma rays are obtained based on the energy spectrum signal matrix. The neutron source is responsible for providing a neutron beam for irradiating the sample to be tested, thereby inducing neutron activation reactions of specific elements in the sample to be tested, generating prompt gamma rays. The gamma detector is responsible for collecting gamma energy spectrum data of multiple groups of samples to be tested. This data includes a mixture of prompt gamma rays generated in the sample, background gamma rays in the environment, and interference signals generated by the crystal inside the gamma detector after being irradiated by the neutron source. By constructing the energy spectrum signal matrix, this complex data can be integrated to effectively distinguish and extract the main prompt gamma ray signals. This provides a reliable means for non-destructive analysis of sample composition. By accurately identifying and quantifying prompt gamma-ray signals, the impact of detector interference is effectively reduced, improving the accuracy and reliability of activation analysis. This also helps improve the accuracy of detecting the presence and content of specific elements in the sample.

[0094] In another embodiment of the present application, the method further comprises: evaluating the content of the target element in the sample to be tested based on the effective prompt gamma ray.

[0095] Specifically, the content of the target element in the sample to be tested can be further evaluated based on the effective prompt gamma ray. The evaluation of the content of the target element in the sample to be tested based on the effective prompt gamma ray belongs to the quantitative analysis method of the PGNAA system and will not be described here.

[0096] The NaI detector activation analysis method applied to PGNAA detection in the present application realizes the effective correction of the NaI detector acquisition signal, solves the problem of interference of NaI activation on PGNAA detection, avoids the time and material costs brought about by increasing shielding, changing physics and other methods in the existing methods, and improves the assessment accuracy of the target element content in the sample to be tested.

[0097] It should be pointed out that although the various steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effect of the present application, different steps do not have to be performed in such an order. They can be performed simultaneously (in parallel) or in other orders. These changes are within the scope of protection of the present application.

[0098] Furthermore, the present application also provides a PGNAA detection system, which is used to perform the aforementioned gamma detector activation analysis method.

[0099] Thus far, the technical solutions of the present application have been described in conjunction with the specific embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A gamma detector activation analysis method, characterized in that: The method comprises: irradiating the sample to be tested using a neutron source; repeatedly collecting multiple sets of gamma energy spectra of the sample to be tested using a gamma detector; constructing an energy spectrum signal matrix based on the multiple sets of gamma energy spectra of the sample to be tested, wherein the energy spectrum signal matrix is a mixed signal composed of prompt gamma rays generated by neutron activation of the sample to be tested, environmental background gamma rays, and interference signals generated by crystal activation in the gamma detector; Effective prompt gamma rays are acquired based on the energy spectrum signal matrix.

2. The gamma detector activation analysis method according to claim 1, characterized in that: The repeatedly collecting multiple groups of gamma energy spectra of the sample to be tested by using a gamma detector includes: collecting multiple groups of gamma energy spectra of the sample to be tested at equal time intervals by using a gamma detector.

3. The gamma detector activation analysis method according to claim 1, characterized in that: The constructing of the energy spectrum signal matrix based on the gamma energy spectrum of the samples to be tested includes: constructing the energy spectrum signal matrix according to a preset channel address based on the gamma energy spectrum of each group of samples to be tested.

4. The gamma detector activation analysis method according to claim 3, characterized in that: The gamma detector is a scintillator detector.

5. The gamma detector activation analysis method according to claim 4, characterized in that: When the scintillator detector is a NaI detector, the interference signal generated by the crystal activation in the gamma detector includes and Gamma rays produced by decay; The energy spectrum signal matrix satisfies the following relationship: Among them, S is the energy spectrum signal matrix, A is the sample to be tested and the environmental background count, B and C are and The interference count weights, M1 and M2 are respectively and The coefficient matrix related to the activity of nuclides.

6. The gamma detector activation analysis method according to claim 1, characterized in that: The obtaining of effective prompt gamma rays based on the energy spectrum signal matrix includes: Vectorizing the energy spectrum signal matrix; Solving the vectorized energy spectrum signal matrix; The effective prompt gamma ray is extracted from the energy spectrum signal matrix according to the solution result.

7. The gamma detector activation analysis method according to claim 6, characterized in that: The vectorizing the energy spectrum signal matrix includes: vectorizing the energy spectrum signal matrix using a Kronecker product, wherein the vectorized energy spectrum signal matrix is expressed as: Among them, vec represents vectorization, I 306 is the 306×306 identity matrix, represents the Kronecker product; and / or The solving the vectorized energy spectrum signal matrix includes: solving the vectorized energy spectrum signal matrix using a least squares method.

8. The gamma detector activation analysis method according to claim 1, characterized in that: The neutron source is an isotope neutron source or an accelerator neutron source.

9. The gamma detector activation analysis method according to claim 1, characterized in that: The method further includes: evaluating the content of a target element in the sample to be tested based on the effective prompt gamma ray.

10. A PGNAA detection system, characterized in that: The PGNAA detection system is used to perform the gamma detector activation analysis method according to any one of claims 1 to 9.

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