阅读说明：本技术 一种基于峰形拟合的逐步逼近刻度γ能谱高能区的方法 (Method for gradually approaching scale gamma energy spectrum high-energy region based on peak shape fitting ) 是由 张迎增 储诚胜 许业文 郭小峰 曾军 向清沛 袁志文 郝樊华 向永春 朱晨 杨圣 于 2020-06-02 设计创作，主要内容包括：本发明公开了一种基于峰形拟合的逐步逼近刻度γ能谱高能区的方法。本方法逐步采用标准γ源与中子活化特征物质产生的γ射线进行刻度,采用简单能谱刻度低能段,之后使用低能段刻度结果估算高能段峰位置,同时采用峰形拟合方法确定峰中心,不断扩展能量刻度范围,逐步逼近感兴趣的高能段,最终获得感兴趣高能段对应的道址区间。与传统一次活化多样品获得复杂的γ能谱后专业人员识别手动刻度方法相比,本发明的方法提供了一套自适应的流程与算法,实现自动化刻度,减少对操作人员的需求,大大扩展了中子活化分析的应用场景。(The invention discloses a method for gradually approaching a scale gamma energy spectrum high-energy region based on peak shape fitting. The method comprises the steps of gradually adopting a standard gamma source and gamma rays generated by neutron activation characteristic substances to scale, adopting a simple energy spectrum to scale a low-energy section, then estimating the peak position of the high-energy section by using the low-energy section scale result, simultaneously adopting a peak shape fitting method to determine the peak center, continuously expanding the energy scale range, gradually approaching the interested high-energy section, and finally obtaining the address section corresponding to the interested high-energy section. Compared with the traditional method for identifying manual scales by professionals after a plurality of samples are activated once to obtain complex gamma energy spectrums, the method provided by the invention provides a set of self-adaptive flow and algorithm, realizes automatic scales, reduces the requirements on operators and greatly expands the application scene of neutron activation analysis.)

1. A method for gradually approximating a gamma energy spectrum high-energy region based on peak shape fitting is characterized by comprising the following steps of:

(a) use of¹³⁷The Cs radioactive source carries out preliminary calibration on the detector;

(b) use of⁶⁰The Co radioactive source scales the detector at a low energy section;

(c) activating a water sample by using a moderated neutron, and expanding the energy scale range to an intermediate energy section;

(d) activating a graphite sample by using slowing neutrons, and expanding the energy scale range to a middle-high energy section;

(e) activating an iron block sample by using a moderation neutron, and expanding the energy scale range to a high-energy section;

(f) and calculating the corresponding address range of the interested high-energy region in the gamma energy spectrum.

2. The method for gradually approximating the high-energy region of a calibration gamma spectrum based on peak shape fitting of claim 1, wherein the step (a) comprises¹³⁷The Cs radioactive source carries out preliminary scale to the detector, specifically is:

(a1) will be provided with¹³⁷The Cs radioactive source moves to the detector, a plurality of channels are started for data collection, and a gamma energy spectrum S is obtained₁To take back¹³⁷A Cs radioactive source;

(a2) search for energy spectrum S₁The highest point of the road C₁With C₁Selecting a width of 2m for the center₁Data of +1, m₁Is a track address C₁The data was fitted using a peak shape fitting formula for the half width of the peak, as follows:

obtaining the functional relationship between the address count N (C) and the address C, wherein a₀、a₁、a₂、a₃Andobtaining a peak fitting center track address as a fitting parameter

(a3) According to¹³⁷Cs 661.7keV characteristic gamma rays, the initial scale relation between the obtained energy E (C) and the track site C is:

E(C)＝f₁C

in the formulaIs the conversion factor of the energy of the track address.

3. The method for gradually approximating the high-energy region of the gamma energy spectrum based on peak shape fitting of claim 1, wherein the step (b) comprises⁶⁰The low-energy scale of the detector is carried out by the Co radioactive source, which specifically comprises the following steps:

(b1) will be provided with⁶⁰The Co radioactive source moves to the detector, starts a plurality of channels for data collection, and obtains a gamma energy spectrum S₂To take back⁶⁰A Co radioactive source;

(b2) in energy spectrum S₂To ChineseAndtaking the width of 2m respectively as the center₂+1、2m₃+1 data, where round represents approximate rounding, m₂And m₃Are respectively provided with⁶⁰Fitting the half widths of the characteristic gamma ray peaks Co1173.2keV and 1332.5keV respectively by using the peak shape fitting formula in the step (a2) to obtain peak fitting central addresses of which are respectively

(b3) For dataFitting according to an energy scale formula by using a least square method, wherein the energy scale formula is

E(C)＝b₀+b₁C+b₂C²

Obtaining the scale parameter b between the low energy section energy and the road address_{1_0}、b_{1_1}、b_{1_2}。

4. The method for gradually approaching the gamma energy spectrum high-energy region on the basis of peak shape fitting is characterized in that in the step (c), moderated neutrons are used for activating a water sample, and the energy scale range is expanded to an intermediate energy section, and the method comprises the following specific steps:

(c1) moving the water sample to the irradiation activation position, starting a neutron generator, starting multiple channels for data collection when the intensity of a neutron source is stable, and obtaining a gamma energy spectrum S₃Turning off the neutron generator and taking back the water sample;

(c2) solving the rounding address C corresponding to the 2223.3keV characteristic gamma ray generated by the neutron activated water according to the energy scale formula obtained by fitting in the step b3₄In the energy spectrum S₃In C₄As a center, take a width of 2m₄Data of +1, m₄Performing peak shape fitting for the half width of the characteristic peak of 2223.3keV by using the peak shape fitting formula in the step (a2) to obtain a 2223.3keV peak fitting center channel site

(c3) For dataFitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{2_0}、b_{2_1}、b_{2_2}。

5. The method for gradually approaching a scale gamma energy spectrum high-energy region based on peak shape fitting as claimed in claim 1, wherein the step (d) uses moderated neutrons to activate the graphite sample, and expands the energy scale range to a middle-high energy section, specifically:

(d1) moving the graphite sample to an irradiation activation part, starting a neutron generator, starting multiple channels for data collection when a neutron source is strong and stable, and obtaining a gamma energy spectrum S₄Turning off the neutron generator and taking back the graphite sample;

(d2) solving the rounding address C corresponding to 3683keV and 4945keV characteristic gamma rays generated by the neutron activated graphite according to the result obtained by fitting in the step (C3)₅、C₆In the energy spectrum S₄In C₅、C₆As a center, take a width of 2m respectively₅+1、2m₆Number of +1According to m₅And m₆Respectively half-width of characteristic peak of 3683keV and 4945keV, using peak shape fitting formula in step (a2) to make peak shape fitting so as to obtain central channel site for 3683keV and 4945keV peak fitting

(d3) For data Fitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{3_0}、b_{3_1}、b_{3_2}。

6. The method for gradually approaching a gamma energy spectrum high-energy region on the basis of peak shape fitting as claimed in claim 1, wherein in the step (e), moderated neutrons are used for activating the iron block sample, and the energy scale range is expanded to a high-energy section, specifically:

(e1) moving the iron block sample to an irradiation activation part, starting a neutron generator, starting multiple channels for data collection when a neutron source is strong and stable, and obtaining a gamma energy spectrum S₅Turning off the neutron generator and taking back the iron block sample;

(e2) solving the rounding address C corresponding to 7120keV and 7631keV characteristic gamma rays generated by neutron activated iron according to the result obtained by fitting in the step (d3)₇、C₈Respectively taking the width as 2m₇+1、2m₈Data of +1, m₇And m₈Respectively half-width of 7120keV and 7631keV characteristic peak, using peak shape fitting formula in step (a2) to make peak shape fitting so as to obtain 7120keV and 7631keV peak fitting central channel site

(e3) For data Fitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{4_0}、b_{4_1}、b_{4_2}。

7. The method for gradually approximating a scale gamma energy spectrum high-energy region based on peak shape fitting as claimed in claim 1, wherein the corresponding address range of the interest high-energy region in the gamma energy spectrum is calculated in step (f), specifically:

selecting high-energy region of interest [ E ] according to the object to be tested_min，E_max]And (E) solving the energy scale formula obtained by fitting in the step (E3)_minAnd E_maxCorresponding whole channel address C_min、C_max，[C_min，C_max]Namely the address interval corresponding to the interested high-energy area.

Technical Field

The invention belongs to the field of nuclear radiation detection, and particularly relates to a method for gradually approaching a scale gamma energy spectrum high-energy region based on peak shape fitting.

Background

The neutron inquiry technology is to utilize the neutron generated by the neutron generator to react with the object to be detected and emit prompt gamma rays, generally to adopt a scintillator gamma spectrometer to record the energy spectrum of the gamma rays, and to analyze the energy spectrum to determine the related information of the object to be detected. Due to the fact that the element components of an article to be detected, an environmental background and the like are complex, more gamma rays are generated by activation, and the mechanism that the gamma rays interact with a detector material to deposit energy is more, the obtained energy spectrum is very complex. Therefore, it is important to find the characteristic peak of the element of interest, especially the characteristic peak unique to high energy, in the complex energy spectrum induced by neutrons.

For an ideal scintillation gamma spectrometer, the light yield is constant and is irrelevant to the energy of incident gamma rays, the total fluorescence quantity is in direct proportion to the deposition energy of the gamma rays, but the energy of a high-energy detector correspondingly deviates from the linear phenomenon to a far extent due to factors such as light transmission attenuation, photomultiplier matching, electronics nonlinearity and the like; meanwhile, the scintillator light yield and electronic parameters are greatly influenced by factors such as temperature and the like, and the scintillator can not be used for a long time in a graduated mode. At present, when a scintillation spectrometer is used for analyzing a neutron activation gamma energy spectrum high-energy section, an experimenter field calibration method is generally adopted to determine a channel address interval of the energy section of interest, and the method needs operators to have professional knowledge and analysis experience of radiation measurement, is high in cost and is difficult to popularize and apply on a large scale.

Disclosure of Invention

The invention aims to provide a method for gradually approaching a scale gamma energy spectrum high-energy region based on peak shape fitting.

In order to achieve the above purpose, the invention provides the following technical scheme:

a method for gradually approximating a gamma energy spectrum high-energy region on the basis of peak shape fitting is characterized by comprising the following steps of:

(a) use of¹³⁷The Cs radioactive source carries out preliminary calibration on the detector;

(b) use of⁶⁰The Co radioactive source scales the detector at a low energy section;

(c) activating a water sample by using a moderated neutron, and expanding the energy scale range to an intermediate energy section;

(d) activating a graphite sample by using slowing neutrons, and expanding the energy scale range to a middle-high energy section;

(e) activating an iron block sample by using a moderation neutron, and expanding the energy scale range to a high-energy section;

(f) and calculating the corresponding address range of the interested high-energy region in the gamma energy spectrum.

Further, the use in step (a)¹³⁷The Cs radioactive source carries out preliminary scale to the detector, specifically is:

(a1) will be provided with¹³⁷The Cs radioactive source moves to the detector, a plurality of channels are started for data collection, and a gamma energy spectrum S is obtained₁To take back¹³⁷A Cs radioactive source;

(a2) search for energy spectrum S₁The highest point of the road C₁With C₁Selecting a width of 2m for the center₁Data of +1, m₁Is a track address C₁The data was fitted using a peak shape fitting formula for the half width of the peak, as follows:

obtaining the functional relationship between the address count N (C) and the address C, wherein a₀、a₁、a₂、a₃And obtaining a peak fitting center address as a fitting parameter

(a3) According to¹³⁷Cs 661.7keV characteristic gamma rays, the initial scale relation between the obtained energy E (C) and the track site C is:

E(C)＝f₁C

in the formulaIs the conversion factor of the energy of the track address.

Further, use in step (b)⁶⁰The low-energy scale of the detector is carried out by the Co radioactive source, which specifically comprises the following steps:

(b1) will be provided with⁶⁰The Co radioactive source moves to the detector, starts a plurality of channels for data collection, and obtains a gamma energy spectrum S₂To take back⁶⁰A Co radioactive source;

(b2) in energy spectrum S₂To ChineseAndtaking the width of 2m respectively as the center₂+1、2m₃+1 data, where round represents approximate rounding, m₂And m₃Are respectively provided with⁶⁰Fitting the half widths of the characteristic gamma ray peaks Co1173.2keV and 1332.5keV respectively by using the peak shape fitting formula in the step (a2) to obtain peak fitting central addresses of which are respectively

(b3) For dataFitting according to an energy scale formula by using a least square method, wherein the energy scale formula is

E(C)＝b₀+b₁C+b₂C²

Obtaining the scale parameter b between the low energy section energy and the road address_{1_0}、b_{1_1}、b_{1_2}。

Further, in the step (c), a moderated neutron is used for activating the water sample, the energy scale range is expanded to an intermediate energy section, and the specific steps are as follows:

(c1) moving the water sample to the irradiation activation position, starting a neutron generator, starting multiple channels for data collection when the intensity of a neutron source is stable, and obtaining a gamma energy spectrum S₃Turning off the neutron generator and taking back the water sample;

(c2) solving the rounding address C corresponding to 2223.3keV characteristic gamma rays generated by the neutron activated water according to the energy scale formula obtained by fitting in the step (b3)₄In the energy spectrum S₃In C₄As a center, take a width of 2m₄Data of +1, m₄Performing peak shape fitting for the half width of the characteristic peak of 2223.3keV by using the peak shape fitting formula in the step (a2) to obtain a 2223.3keV peak fitting center channel site

(c3) For data Use minimumFitting the two multiplications according to the energy scale formula in the step (b3), and updating the scale parameter between the energy and the track address to be b_{2_0}、b_{2_1}、b_{2_2}。

Further, in the step (d), the graphite sample is activated by using slowing neutrons, and the energy scale range is expanded to a middle-high energy section, specifically:

(d1) moving the graphite sample to an irradiation activation part, starting a neutron generator, starting multiple channels for data collection when a neutron source is strong and stable, and obtaining a gamma energy spectrum S₄Turning off the neutron generator and taking back the graphite sample;

(d2) solving the rounding address C corresponding to 3683keV and 4945keV characteristic gamma rays generated by the neutron activated graphite according to the result obtained by fitting in the step (C3)₅、C₆In the energy spectrum S₄In C₅、C₆As a center, take a width of 2m respectively₅+1、2m₆Data of +1, m₅And m₆Respectively half-width of characteristic peak of 3683keV and 4945keV, using peak shape fitting formula in step (a2) to make peak shape fitting so as to obtain central channel site for 3683keV and 4945keV peak fitting

(d3) For data Fitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{3_0}、b_{3_1}、b_{3_2}。

Further, in the step (e), a moderated neutron is used for activating the iron block sample, and the energy scale range is expanded to a high-energy section, specifically:

(e1) moving the iron block sample to the irradiation activation position, and openingA neutron generator for starting multiple channels for data collection when the neutron source is strongly stable to obtain a gamma energy spectrum S₅Turning off the neutron generator and taking back the iron block sample;

(e2) solving the rounding address C corresponding to 7120keV and 7631keV characteristic gamma rays generated by neutron activated iron according to the result obtained by fitting in the step (d3)₇、C₈Respectively taking the width as 2m₇+1、2m₈Data of +1, m₇And m₈Respectively half-width of 7120keV and 7631keV characteristic peak, using peak shape fitting formula in step (a2) to make peak shape fitting so as to obtain 7120keV and 7631keV peak fitting central channel site

(e3) For data Fitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{4_0}、b_{4_1}、b_{4_2}。

Further, calculating the corresponding address range of the high-energy region of interest in the gamma energy spectrum in the step (f), specifically:

selecting high-energy region of interest [ E ] according to the object to be tested_min，E_max]And (E) solving the energy scale formula obtained by fitting in the step (E3)_minAnd E_maxCorresponding whole channel address C_min、C_max，[C_min，C_max]Namely the address interval corresponding to the interested high-energy area.

Compared with the traditional method that multiple samples are activated at one time to obtain a complex gamma energy spectrum, and operators with professional knowledge of radiation measurement are needed to analyze the complex gamma energy spectrum, the method is difficult to popularize and apply on a large scale.

Drawings

FIG. 1 is a diagram of the overall process and scale application range of a method for gradually approximating a scale gamma energy spectrum high-energy region based on peak shape fitting according to the present invention;

FIG. 2 is a Monte Care simulation method for obtaining a gamma energy spectrum high energy region of a successive approximation scale based on peak shape fitting¹³⁷Cs scale detector energy spectrum S₁；

FIG. 3 is a 661.7keV peak shape and fitting result of a method for gradually approximating a scale gamma energy spectrum high energy region based on peak shape fitting of the present invention;

FIG. 4 is a Monte Care simulation method for obtaining a gamma energy spectrum high energy region of a successive approximation scale based on peak shape fitting⁶⁰Cs scale detector energy spectrum S₂；

FIG. 5 is a 1173.2keV peak shape and fitting result of a method for gradually approximating a scale gamma energy spectrum high energy region based on peak shape fitting of the present invention;

FIG. 6 is a method 1332.5keV peak shape and fitting results for a step-by-step approximation scale gamma energy spectrum high energy region based on peak shape fitting of the present invention;

FIG. 7 is a Monte Care simulation method for obtaining detector spectrum S of moderated neutron activated water sample based on the peak shape fitting successive approximation scale gamma energy spectrum high energy region₃；

FIG. 8 is a method 2223.3keV peak shape and fitting result of a step-by-step approximation scale gamma energy spectrum high energy region based on peak shape fitting of the present invention;

FIG. 9 is a diagram of a detector spectrum S when a moderated neutron activated graphite sample is obtained by Monte-Ka simulation, which is a method for gradually approaching a scale gamma energy spectrum high-energy region based on peak shape fitting₃；

FIG. 10 is a 3683keV peak shape and fitting result of a method for gradually approximating a scale gamma energy spectrum high-energy region based on peak shape fitting of the present invention;

FIG. 11 is a method of the present invention for approximating a scaled gamma energy spectrum high energy region step by step based on peak shape fitting 4945keV peak shape and fitting results;

FIG. 12 is a diagram of a detector spectrum S when a sample of a moderated neutron activated iron block is obtained by Monte-Ka simulation, which is a method for gradually approaching a scale gamma energy spectrum high-energy region based on peak shape fitting₄；

FIG. 13 is a 7120keV peak shape and fitting results of a method of the present invention based on peak shape fitting to gradually approximate a scaled gamma energy spectrum high energy region;

FIG. 14 is a method 7631keV peak shape and fitting result of the invention based on peak shape fitting to gradually approximate the scale gamma energy spectrum high energy region.

Detailed Description

With reference to fig. 1, the method for gradually approximating a gamma energy spectrum high energy region based on peak shape fitting according to the embodiment of the present invention is as follows:

(a) use of¹³⁷The Cs radioactive source carries out preliminary calibration on the detector;

(b) use of⁶⁰The Co radioactive source scales the detector at a low energy section;

(c) activating a water sample by using a moderated neutron, and expanding the energy scale range to an intermediate energy section;

(d) activating a graphite sample by using slowing neutrons, and expanding the energy scale range to a middle-high energy section;

(e) activating an iron block sample by using a moderation neutron, and expanding the energy scale range to a high-energy section;

(f) and calculating the corresponding address range of the interested high-energy region in the gamma energy spectrum.

Aiming at neutron activation analysis, all operations depend on a neutron activation analysis platform, the platform comprises a neutron generator and a control module thereof, a sample to be detected is placed in a replacement module, a scintillator detector and an electronics module thereof, and a multi-channel signal acquisition and computer processing module, working parameters are selected before specific operations, and the operation is kept unchanged in the whole method implementation process;

used in step (a)¹³⁷The specific implementation of the primary calibration of the detector by the Cs radioactive source is as follows:

(a1) will be provided with¹³⁷The Cs radioactive source moves to the detectorStarting multiple channels to collect data and obtain gamma energy spectrum S₁To take back¹³⁷A Cs radioactive source;

(a2) search for energy spectrum S₁The highest point of the road C₁With C₁Selecting a width of 2m for the center₁Data of +1, m₁Is a track address C₁The half width of the peak was fitted to the data using a peak shape fitting formula as follows

Obtaining the functional relationship between the address count N (C) and the address C, wherein a₀、a₁、a₂、a₃And obtaining a peak fitting center address as a fitting parameter

(a3) According to¹³⁷Cs 661.7keV characteristic gamma rays to obtain a preliminary scale relationship between energy E (C) and track site C

E(C)＝f₁C

In the formulaThe scale result is suitable for the energy linearity within 0-1000 keV and can be expanded to 2000keV for estimation;

in step (b) using⁶⁰The specific implementation mode of the Co radioactive source for low-energy scale calibration of the detector is as follows:

(b1) will be provided with⁶⁰The Co radioactive source moves to the detector, starts a plurality of channels for data collection, and obtains a gamma energy spectrum S₂To take back⁶⁰A Co radioactive source;

(b2) in energy spectrum S₂To ChineseAndtaking the width of 2m respectively as the center₂+1、2m₃+1 data, where round represents approximate rounding, m₂And m₃Are respectively provided with⁶⁰Fitting the half widths of the characteristic gamma ray peaks Co1173.2keV and 1332.5keV respectively by using the peak shape fitting formula in the step (a2) to obtain peak fitting central addresses of which are respectively

(b3) For dataFitting according to an energy scale formula by using a least square method, wherein the energy scale formula is

E(C)＝b₀+b₁C+b₂C²

Obtaining the scale parameter b between the low energy section energy and the road address_{1_0}、b_{1_1}、b_{1_2}The calibration result is suitable for the energy linearity within 0-2000 keV and can be expanded to 3000keV for estimation;

in the step (c), a water sample is activated by using moderated neutrons, and the specific implementation manner of expanding the energy scale range to the middle energy section is as follows:

(c1) moving the water sample to the irradiation activation position, starting a neutron generator, starting multiple channels for data collection when the intensity of a neutron source is stable, and obtaining a gamma energy spectrum S₃Turning off the neutron generator and taking back the water sample;

(c2) solving the rounding address C corresponding to 2223.keV characteristic gamma rays generated by neutron activated water according to the energy scale formula obtained by fitting in the step (b3)₄In the energy spectrum S₃In C₄As a center, take a width of 2m₄Data of +1, m₄Performing peak shape fitting for the half width of the characteristic peak of 2223.3keV by using the peak shape fitting formula in the step (a2) to obtain a 2223.3keV peak fitting center channel site

(c3) For dataFitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{2_0}、b_{2_1}、b_{2_2}The calibration result is suitable for the inner energy linearity of 0-3000 keV and can be expanded to 4500keV for estimation;

in the step (d), the graphite sample is activated by using the moderated neutrons, and the specific implementation manner of expanding the energy scale range to the middle-high energy section is as follows:

(d1) moving the graphite sample to an irradiation activation part, starting a neutron generator, starting multiple channels for data collection when a neutron source is strong and stable, and obtaining a gamma energy spectrum S₄Turning off the neutron generator and taking back the graphite sample;

(d2) solving the rounding address C corresponding to 3683keV and 4945keV characteristic gamma rays generated by the neutron activated graphite according to the result obtained by fitting in the step (C3)₅、C₆In the energy spectrum S₄In C₅、C₆As a center, take a width of 2m respectively₅+1、2m₆Data of +1, m₅And m₆Respectively half-width of characteristic peak of 3683keV and 4945keV, using peak shape fitting formula in step (a2) to make peak shape fitting so as to obtain central channel site for 3683keV and 4945keV peak fitting

(d3) For data Fitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{3_0}、b_{3_1}、b_{3_2}The scale result is suitable for 0-55Energy linearity in 00keV, which can be extended to 7500keV for estimation;

activating an iron block sample by using a moderated neutron in the step (e), and expanding the energy scale range to a high-energy section as follows:

(e1) moving the iron block sample to an irradiation activation part, starting a neutron generator, starting multiple channels for data collection when a neutron source is strong and stable, and obtaining a gamma energy spectrum S₅Turning off the neutron generator and taking back the iron block sample;

(e2) solving the rounding address C corresponding to 7120keV and 7631keV characteristic gamma rays generated by neutron activated iron according to the result obtained by fitting in the step (d3)₇、C₈Respectively taking the width as 2m₇+1、2m₈Data of +1, m₇And m₈Respectively half-width of 7120keV and 7631keV characteristic peak, using peak shape fitting formula in step (a2) to make peak shape fitting so as to obtain 7120keV and 7631keV peak fitting central channel site

(e3) For data Fitting according to the energy scale formula in the step (b3) by using a least square method, and updating the scale parameter between the energy and the track address to be b_{4_0}、b_{4_1}、b_{4_2}The calibration result is suitable for the energy linearity within 0-8500 keV and can be expanded to 11000keV for estimation;

the specific implementation mode for calculating the corresponding address range of the high-energy region of interest in the gamma energy spectrum in the step (f) is as follows:

selecting high-energy region of interest [ E ] according to the object to be tested_min，E_max]And (E) calculating E from the energy scale formula obtained by fitting in (E3)_minAnd E_maxCorresponding whole channel address C_min、C_max，[C_min，C_max]Namely the interested high-energy region pairThe corresponding address interval.

The present invention is described in further detail below with reference to examples: