A method for quickly obtaining a natural nuclide unit spectrum

Abstract

The application provides a kind of fast acquisition natural nuclide unit spectrum calculation method, utilizes gamma spectrometer to carry out measurement on the radioactivity calibration model of known K, U, Th and background content, obtains the gamma spectrum of K model, U model, Th model and background model of gamma spectrometer, deducts the background spectrum on K model, U model, Th model, constructs matrix, establishes the function relationship between content and count, quickly obtains the count of K, U, Th in each channel with unit content, obtains K, U, Th and other natural radioactive nuclide unit spectrum.The fast acquisition natural nuclide unit spectrum calculation method provided by the application has the relationship between K, U, Th content and count, establishes matrix for calculation, can quickly obtain K, U, Th unit spectrum, the unit spectrum obtained can be used for the correction of atmospheric radon in aviation monitoring process, and K, U, Th and other natural radioactivity content can be calculated quickly, has the advantages of convenience.

Description

Technical Field

[0001] This invention relates to the field of natural radionuclides, and in particular to a computational method for rapidly obtaining the unit spectrum of natural radionuclides. Background Technology

[0002] Traditional airborne gamma spectroscopy data processing methods mainly rely on the IAEA-recommended "standard three-window method," also known as... 40 K, 238 U、 232 The windowed data processing method for Th has been widely used in uranium exploration and aerial monitoring for geological mapping. With the application of airborne gamma spectroscopy in radiation environment assessment and nuclear accident emergency monitoring, and the development of UAV airborne gamma spectroscopy technology, data processing methods have evolved from the single three-window method to spectral data processing methods. The airborne gamma full-spectrum analysis method, or "full-spectrum method" (FSA), is a data processing method based on full-spectrum data. It utilizes all spectral data from airborne gamma spectroscopy measurements to directly correct for aircraft and instrument background, cosmic radiation background, and aerial survey altitude. Atmospheric radon is treated as a variable and calculated together with the potassium, uranium, and thorium content of ground-based radiation sources and the concentration or activity of other nuclear contaminants (artificial nuclides). This method effectively solves the problem of significant uncertainty introduced by atmospheric radon correction in windowed data processing. Extensive research has been conducted on the principles and applications of this method. In airborne gamma spectroscopy measurements targeting naturally occurring radionuclides, the measurement sources include: cosmic rays, aircraft and instrument background radiation, atmospheric radon, and naturally occurring radionuclides on the Earth's surface. 40 K, 238 U、 232 Th). A crucial step in data processing is acquiring... 40 K, 238 U、 232 The spectral data of Th unit content (unit spectrum) is obtained by converting the unit spectrum at different altitudes based on the attenuation coefficient of different characteristic energy levels during dynamic test flight to obtain the atmospheric radon calibration spectrum, which facilitates atmospheric radon correction. Secondly, after subtracting the background of the instrument and the instrument itself, as well as the influence of atmospheric radon, a matrix relationship between the content and each count is established, which can realize the surface... 40 K, 238 U、 232 Quantitative analysis of Th natural radionuclides.

[0003] In summary, rapidly obtaining the unit spectrum of natural radionuclides, as a crucial step in the "full-spectrum method," can be used for atmospheric radon correction. This effectively reduces the significant problems introduced by atmospheric radon correction in the "three-window method," thereby achieving surface... 40 K, 238 U、 232Quantitative analysis of naturally occurring radioactive nuclides (Th) is of great significance.

[0004] Therefore, it is necessary to provide a computational method for rapidly obtaining the spectrum of natural nuclide units to solve the above-mentioned technical problems. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a method for quickly obtaining the unit spectrum of K, U, and Th by establishing a matrix based on the relationship between K, U, and Th content and count. The obtained unit spectrum can be used for correction of atmospheric radon during aviation monitoring. At the same time, it can quickly calculate the content of natural radioactivity such as K, U, and Th. This method is convenient and fast for obtaining the unit spectrum of natural nuclides.

[0006] To solve the above-mentioned technical problems, the present invention provides a calculation method for rapidly obtaining the spectrum of natural nuclide units, comprising the following steps:

[0007] S1: On the airborne radiometric background calibration model, use an airborne gamma spectrometer system to measure for 15 minutes to obtain data including cosmic rays, atmospheric radon, and naturally occurring radionuclides from the background model. 40 K, 238 U、 232 γ-ray spectral data of Th;

[0008] S2: Place the airborne gamma spectrometer system on the potassium model, uranium model, and thorium model respectively for 10 minutes to obtain the corresponding gamma energy spectrum;

[0009] S3: The energy spectrum data measured by the background model obtained in S1 is used as the background spectrum data of the airborne gamma spectrometer and the surrounding environment.

[0010] S4: Subtract the background spectral data from the γ-ray energy spectra of the potassium model, uranium model, and thorium model obtained in S2 to obtain the potassium model, thorium model, and uranium model after subtracting cosmic rays and atmospheric radon. 40 K, 238 U、 232 Th mixed energy spectrum data;

[0011] S5: Based on the K, U, and Th values ​​in the potassium, uranium, thorium models and background model of the airborne radiometric measurement calibration model, calculate the values ​​of K, U, and Th in the potassium, uranium, and thorium models after subtracting the values ​​from the background model. 40 K, 238 U、 232 After Th content 40 K, 238 U、 232 Th content;

[0012] S6: Establish natural radionuclides using the calculation results from S4 and S5. 40 K,238 U、 232 The relationship between Th content and counts for each track is established, and a functional relationship between counts and content is formed as follows;

[0013] N = Ac

[0014]

[0015] Among them: NK n,1 For the nth channel count of the potassium model; NU n,2 For the nth channel count in the uranium model; NTh n,3 For the nth channel count of the thorium model; AK n,1 For the nth channel of the 40K unit spectrum; AU n,1 For the nth channel of the 238U unit spectrum; ATh n,3 For the nth channel of the 232Thh unit spectrum; cK K cK represents the K content in the potassium model. U The content of U in the potassium model; cK Th The content of Th in the potassium model; cU K The K content in the uranium model; cU U The content of 238U in the uranium model; cU Th cTh represents the Th content in the uranium model; K The content of 40K in the thorium model; cTh U The content of 238U in the thorium model; cTh Th This represents the content of 232Th in the thorium model.

[0016] S7: Based on the matrix established in S6, calculate the inverse matrix of S3, thus calculating... 40 K, 238 U、 232 The unit spectrum of Th.

[0017] Preferably, the contents of K, U, and Th in the airborne radioactivity measurement calibration model are known.

[0018] Preferably, the gamma spectrometer measures a total count of characteristic peaks greater than 10,000 on the potassium model, uranium model, and thorium model, a measurement time greater than 10 minutes on the mixed model, and a measurement time greater than 15 minutes on the background model.

[0019] Preferably, the γ-ray spectrum needs to be saturated during the measurement process.

[0020] Preferably, in S1, the background calibration model for airborne radiometric measurements is free of artificial radionuclides.

[0021] Compared with related technologies, the calculation method for rapidly obtaining natural nuclide unit spectra provided by this invention has the following beneficial effects:

[0022] This invention provides a method for rapidly obtaining the spectra of natural nuclide units, utilizing a gamma spectrometer in known... 40 K, 238 U、 232 Measurements of Th content were performed on a radiometric calibration model. Gamma spectra were obtained from the K-model, U-model, Th-model, and background model. After subtracting the background spectrum from the background model, each count in the gamma spectra obtained from the K-model, U-model, and Th-model was contributed by different energies of the K, U, and Th series. A matrix was constructed to establish a functional relationship between content and counts, allowing for rapid acquisition of the gamma spectrum per unit content. 40 K, 238 U、 232 The count of Th in each channel is used to obtain the unit spectrum of natural radioactive nuclides such as K, U, and Th. Attached Figure Description

[0023] Figure 1 A flowchart illustrating the calculation method for rapidly obtaining natural nuclide unit spectra provided by this invention;

[0024] Figure 2 The spectral diagrams obtained from each model in the calculation method for rapidly obtaining the spectrum of natural nuclide units provided by this invention;

[0025] Figure 3 The γ-ray spectra of the potassium model, uranium model, and thorium model after background subtraction in the calculation method for rapidly obtaining the spectra of natural nuclide units provided by this invention;

[0026] Figure 4 The natural radioactive potassium-series, uranium-series, and thorium-series unit spectral lines obtained after calculation in the calculation method for rapidly obtaining natural nuclide unit spectra provided by this invention;

[0027] Figure 5 This invention provides a method for rapidly obtaining the spectra of natural nuclide units. The comparison diagram shows the γ-ray spectral lines obtained using the actual measured mixed model and those obtained using the γ-ray spectral lines of the potassium series, uranium series, and thorium series units. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Please refer to the following: Figure 1-5 ,in, Figure 1 A flowchart illustrating the calculation method for rapidly obtaining natural nuclide unit spectra provided by this invention; Figure 2The spectral lines obtained from each model in the calculation method for rapidly obtaining the spectrum of natural nuclide units provided by the present invention are as follows: AP-B is the γ spectral line on the background model, AP-K is the γ spectral line on the potassium model, AP-U is the γ spectral line on the uranium model, and AP-TH is the γ spectral line on the thorium model. Figure 3 The calculation method for rapidly obtaining the spectrum of natural nuclide units provided by this invention includes the γ-ray spectral diagrams of the potassium model, uranium model, and thorium model after background subtraction, where NET-K is the γ-ray spectral line after background subtraction on the potassium model, NET-U is the γ-ray spectral line after background subtraction on the uranium model, and NET-TH is the γ-ray spectral line after background subtraction on the thorium model. Figure 4 The natural radioactive potassium-series, uranium-series, and thorium-series unit spectral lines obtained after calculation in the calculation method for rapidly obtaining natural nuclide unit spectra provided by this invention; Figure 5 The calculation method for rapidly obtaining the spectrum of natural nuclide units provided by this invention is shown in the comparison diagram of the γ-ray spectral lines obtained by the actual measured mixture model and the γ-ray spectral lines obtained by the potassium series, uranium series and thorium series unit spectra. M-1 is the γ-ray spectral line measured by an airborne γ-ray spectrometer on the mixture model, and M-2 is the γ-ray spectral line obtained by the mixture model content and the potassium series, uranium series and thorium series unit spectra.

[0030] The calculation method for rapidly obtaining natural nuclide unit spectra provided by this invention includes the following steps:

[0031] a. On an airborne radiometric background calibration model, which contains no artificial radionuclides, measurements were taken for 15 minutes using an airborne gamma spectrometer system to obtain data including cosmic rays, atmospheric radon, and naturally occurring radionuclides from the background model. 40 K, 238 U、 232 γ-ray spectral data of Th;

[0032] b. Use an airborne gamma spectrometer system to measure the corresponding gamma energy spectra for 10 minutes in the potassium model, uranium model, and thorium model respectively;

[0033] c. The energy spectrum data measured by the background model obtained in step a are used as the background spectrum data of the airborne gamma spectrometer and the surrounding environment;

[0034] d. Subtract the background spectral data from the γ-ray energy spectra of the potassium, uranium, and thorium models obtained in step b to obtain the potassium, thorium, and uranium models after subtracting cosmic rays and atmospheric radon. 40 K, 238 U、 232 Th mixed energy spectrum data;

[0035] e. Based on the K, U, and Th values ​​in the potassium model, uranium model, thorium model, and background model of the airborne radiometric measurement calibration model, calculate the values ​​of K, U, and Th in the potassium model, uranium model, and thorium model minus the background model. 40 K,238 U、 232 After Th content 40 K, 238 U、 232 Th content;

[0036] f. Establish natural radionuclides using the calculation results of d and e. 40 K, 238 U、 232 The relationship between Th content and counts for each track is established, and a functional relationship between counts and content is formed as follows;

[0037] N = Ac

[0038]

[0039] Among them: NK n,1 For the nth channel count of the potassium model; NU n,2 For the nth channel count in the uranium model; NTh n,3 For the nth channel count of the thorium model; AK n,1 For the nth channel of the 40K unit spectrum; AU n,1 For the nth channel of the 238U unit spectrum; ATh n,3 For the nth channel of the 232Thh unit spectrum; cK K cK represents the K content in the potassium model. U The content of U in the potassium model; cK Th The content of Th in the potassium model; cU K The K content in the uranium model; cU U The content of 238U in the uranium model; cU Th cTh represents the Th content in the uranium model; K The content of 40K in the thorium model; cTh U The content of 238U in the thorium model; cTh Th This represents the content of 232Th in the thorium model.

[0040] g. Based on the matrix established in step f, calculate the inverse matrix of c, and thus calculate the... 40 K, 238 U、 232 The unit spectrum of Th.

[0041] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A computational method for rapidly obtaining the spectrum of natural nuclide units, characterized in that, Includes the following steps: S1: On the airborne radiometric background calibration model, use an airborne gamma spectrometer system to measure for 15 minutes to obtain data including cosmic rays, atmospheric radon, and naturally occurring radionuclides from the background model. 40 K, 238 U、 232 γ-ray spectral data of Th; S2: Place the airborne gamma spectrometer system on the potassium model, uranium model, and thorium model respectively for 10 minutes to obtain the corresponding gamma energy spectrum; S3: The energy spectrum data measured by the background model obtained in S1 is used as the background spectrum data of the airborne gamma spectrometer and the surrounding environment. S4: Subtract the background spectral data from the γ-ray energy spectra of the potassium model, uranium model, and thorium model obtained in S2 to obtain the potassium model, thorium model, and uranium model after subtracting cosmic rays and atmospheric radon. 40 K, 238 U、 232 Th mixed energy spectrum data; S5: Based on the K, U, and Th values ​​in the potassium, uranium, thorium models and background model of the airborne radiometric measurement calibration model, calculate the values ​​of K, U, and Th in the potassium, uranium, and thorium models after subtracting the values ​​from the background model. 40 K, 238 U、 232 After Th content 40 K, 238 U、 232 Th content; S6: Establish natural radionuclides using the calculation results from S4 and S5. 40 K, 238 U、 232 The relationship between Th content and counts for each track is established, and a functional relationship between counts and content is formed as follows; N = Ac Among them: NK n,1 For the nth channel count of the potassium model; NU n,2 For the nth channel count in the uranium model; NTh n,3 For the nth channel count of the thorium model; AK n,1 This is the count for the nth channel of the 40K unit spectrum; AU n,1 For the nth channel of the 238U unit spectrum; ATh n,3 For the nth channel of the 232Thh unit spectrum; cK K cK represents the K content in the potassium model. U The content of U in the potassium model; cK Th The content of Th in the potassium model; cU K The K content in the uranium model; cU U The content of 238U in the uranium model; cU Th cTh represents the Th content in the uranium model; K The content of 40K in the thorium model; cTh U The content of 238U in the thorium model; cTh Th The content of 232Th in the thorium model; S7: Based on the matrix established in S6, calculate the inverse matrix of S3, thus calculating... 40 K, 238 U、 232 The unit spectrum of Th.

2. The calculation method for rapidly obtaining natural nuclide unit spectra according to claim 1, characterized in that, The contents of K, U, and Th in the calibration model for airborne radioactivity measurement are known.

3. The calculation method for rapidly obtaining the spectrum of natural nuclide units according to claim 1, characterized in that, The gamma spectrometer measured a total count of characteristic peaks greater than 10,000 on the potassium model, uranium model, and thorium model, a measurement time greater than 10 minutes on the mixed model, and a measurement time greater than 15 minutes on the background model.

4. The calculation method for rapidly obtaining the spectrum of natural nuclide units according to claim 1, characterized in that, The γ-ray spectrum requires saturation measurement during the measurement process.

5. The calculation method for rapidly obtaining the spectrum of natural nuclide units according to claim 1, characterized in that, In S1, the background calibration model for airborne radiometric measurements is used, wherein the model does not contain artificial radionuclides.

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