A method for evaluating environmental background interference for marine gamma-ray spectroscopy

Abstract

The present application provides a kind of environmental background interference evaluation method for marine gamma energy spectrum analysis, first in current sea area acquisition gamma energy spectrum data, the characteristic peak of natural radioactive nuclide K is located and Gaussian fitting is carried out;Subsequently, the original data accumulation in peak area is calculated, and the background straight line is constructed with the left and right boundary points, the random point number in the region surrounded by Gaussian fitting curve and background straight line is counted, and the region cumulative sum of signal value in the region is calculated according to the region cumulative sum of signal value in the region.The difference between original cumulative sum and region cumulative sum is finally taken as the environmental background interference evaluation value of current sea area.The present application takes the stable natural nuclide K peak in seawater as the reference standard to obtain the actual background evaluation of current sea area, which provides a key background correction basis for subsequent accurate monitoring of marine artificial radioactive nuclide, and the method of the present application is not limited by cumulative time, which effectively improves the reliability, accuracy and anti-interference of on-site analysis.

Description

Technical Field

[0001] This invention belongs to the field of seawater detection technology, specifically, it relates to an environmental background interference assessment method for marine gamma spectral analysis. Background Technology

[0002] In the detection of radioactive materials in the ocean, gamma spectroscopy measurement and analysis are commonly used techniques. Specific radionuclides will form characteristic peaks in corresponding energy ranges. By identifying and analyzing these peaks, qualitative and quantitative monitoring of radioactive materials in seawater can be achieved.

[0003] However, in actual marine field testing, due to the complex and variable environment, the measurement signals are often interfered with by various factors, leading to instability in the energy spectrum. This is mainly manifested as irregular drift of characteristic peak positions, random changes in amplitude, and the presence of numerous spurious peaks caused by interference. These factors make it extremely difficult to accurately and quickly extract the true radionuclide signals from the complex energy spectrum.

[0004] Currently, most domestic methods for monitoring marine radioactivity are based on the assumption of signal stationarity or time invariance. While these methods are applicable under controlled laboratory conditions, in the real and variable marine environment, interference from hydrology, geology, biological activity, and instrument status leads to significant time-varying and non-stationar characteristics in the measured signals, resulting in a decline in the accuracy and reliability of traditional methods. Accurate estimation of environmental background interference is a key factor in improving the efficiency of marine radioactivity measurements. Summary of the Invention

[0005] The purpose of this invention is to provide an environmental background interference assessment method for marine gamma spectroscopy analysis, which can adapt to complex marine environments and extract environmental background interference of radionuclides in real time and accurately, so as to improve the efficiency and accuracy of radionuclide calculation.

[0006] The present invention is implemented using the following technical solutions:

[0007] A method for assessing environmental background disturbances in marine gamma spectroscopy analysis is proposed, including:

[0008] Data was collected in the current sea area to find the peak of the naturally occurring radioactive nuclide K, and Gaussian fitting was performed on it.

[0009] Calculate the cumulative sum of all signal values ​​within the left and right boundaries of the peak;

[0010] Establish the baseline line using the two points corresponding to the left and right boundaries of the peak;

[0011] The target region is defined by the left boundary, right boundary, maximum value, and minimum value of the peak. N random points are obtained by traversing the target region. The count is incremented by 1 when the random point is within the range enclosed by the baseline line and the Gaussian fitted curve.

[0012] Calculate the regional cumulative sum of signal values ​​within the target defined area based on the counting results;

[0013] The environmental background disturbance in the current sea area is obtained by the difference between the cumulative sum and the regional cumulative sum.

[0014] Compared with existing technologies, the advantages and positive effects of this invention are as follows: The environmental background interference assessment method for marine gamma spectral analysis proposed in this invention first collects gamma spectral data in the current sea area, locates the characteristic peak of the natural radionuclide K, and performs Gaussian fitting. Then, it calculates the cumulative sum of the original data within the peak region, constructs a background line using the left and right boundary points of the peak, and counts the number of random points falling within the area enclosed by the Gaussian fitting curve and the background line. Based on this, the regional cumulative sum of the signal values ​​in that region is calculated. Finally, the difference between the original cumulative sum and the regional cumulative sum is used as the environmental background interference assessment value for the current sea area. This invention uses the stable natural radionuclide K peak in seawater as a reference standard to obtain the actual background assessment of the current sea area, providing a crucial background correction basis for the subsequent accurate monitoring of artificial marine radionuclides. Furthermore, the method of this invention is not limited by the accumulation time, effectively improving the reliability, accuracy, and anti-interference capability of on-site analysis.

[0015] Other features and advantages of the present invention will become clearer after reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. Attached Figure Description

[0016] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions are used to explain the invention but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without creative effort. Figure 1

[0017] Figure 1 This is a schematic diagram of the environmental background interference assessment method for marine gamma spectral analysis proposed in this invention.

[0018] Figure 2 This is the original energy spectrum curve of the current sea area obtained in an embodiment of the present invention;

[0019] Figure 3 for Figure 2 A magnified schematic of the peak portion of the natural radionuclide K in the energy spectrum curve shown.

[0020] Figure 4To Figure 3 The comparison curves after Gaussian fitting of the energy spectrum curves shown are shown.

[0021] Figure 5 This is an example of a target-defined region in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0024] This invention aims to propose an environmental background interference assessment method for on-site monitoring of radionuclides in the ocean. It utilizes the characteristic peak of K, a naturally occurring radionuclide commonly found in seawater, as a reference standard, and analyzes the difference between the measured and theoretical signals of its peak to dynamically assess the background interference level in the current marine environment. This background interference level can then be used as a correction factor to improve the reliability and accuracy of quantitative analysis of other radionuclides in the same spectrum, reducing the risk of misjudgment caused by complex background conditions.

[0025] Specifically, such as Figure 1 As shown, it includes the following steps:

[0026] S1: Collect data in the current sea area, find the peak of the natural radionuclide K, and perform Gaussian fitting on it.

[0027] In this embodiment, the energy spectrum data curves of all channels are as follows: Figure 2 As shown, the data curve has 1024 channels, and the signal value of each channel corresponds to the number of gamma-ray events detected within a set cumulative time period. Figure 3 As shown, the peak range of the natural radionuclide K is 770-850. The specific peak finding method can be achieved using existing technology and is not limited to the part of this invention.

[0028] like Figure 4 As shown, Gaussian fitting was performed on the data curve within the peak channel range of the natural radionuclide K. The data under the Gaussian fitted curve is the data generated by the natural radionuclide K and accumulated within the accumulation period, rather than the interference data caused by other factors such as changes in the marine environment.

[0029] The Gaussian fitting function is:

[0030] ;

[0031] in, The signal value of the peak. The channel value of the peak. To fit the squared values ​​of half the height and width at half maximum, These are the channel values ​​for the fitted curve. For the fitted curve channel The corresponding signal value.

[0032] In this embodiment, the coefficients of the Gaussian fitting function are:

[0033] : 1016.726558, : 807.126069, : 287.603514, fwhm (half-width, half-height): 22.546913; Gaussian fit left boundary : 770; Gaussian fit right boundary :850.

[0034] S2: Calculate the cumulative sum of all signal values ​​within the left and right boundaries of the peak.

[0035] In this embodiment, the signal value of the peak is calculated based on the Gaussian fitting function. 287.603514, left boundary of the peak The right boundary of the peak is 770. The signal value at the left boundary is 850. 74.136912, signal value at the right boundary 47.164872, minimum value 47.164872, this minimum value is the minimum value of the left boundary signal and the right boundary signal.

[0036] Signal values ​​of all channels of the peak , ... , The cumulative sum is denoted as S. Signal value. It is calculated based on the Gaussian fitting function obtained from S2.

[0037] S3: Establish the baseline line using the two points corresponding to the left and right boundaries of the peak.

[0038] The established straight line is as follows Figure 5 As shown, the slope of the base line ;intercept .

[0039] S4: Using the left boundary, right boundary, maximum value, and minimum value of the peak as the target bounding region, traverse the target bounding region to obtain N random points. When a random point is within the range enclosed by the base line and the Gaussian fitted curve, increment the count by 1.

[0040] like Figure 5 As shown, within the area defined by the red box, N=1,000,000 random points are generated randomly. , , When a random point falls within the range defined by the Gaussian fitted curve of the peak and the baseline line, the count sum is incremented by 1; otherwise, the sum value remains unchanged.

[0041] S5: Calculate the regional cumulative sum of signal values ​​within the target defined area based on the counting results.

[0042] The regional cumulative rate of signal values ​​within the target defined area is The cumulative sum of the region is .

[0043] S6: The environmental background disturbance of the current sea area is obtained by the difference between the cumulative sum and the regional cumulative sum.

[0044] The current environmental background disturbance in the sea area is ;in This is the cumulative sum obtained in step S2.

[0045] The present invention utilizes the characteristic peak of K, a stable and ubiquitous natural radionuclide in seawater, as a reference benchmark. By analyzing the deviation between the measured signal and the ideal signal of natural radionuclide K, the background interference level in the current marine environment is dynamically assessed. The assessed background interference can then be used as a quality factor or correction parameter to improve the accuracy and reliability of the analysis of other radionuclides in the same spectrum, and reduce the risk of misjudgment caused by complex background interference.

[0046] It should be noted that the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for assessing environmental background disturbances in marine gamma-ray spectroscopy analysis, characterized in that, include: Data was collected in the current sea area to find the peak of the naturally occurring radioactive nuclide K, and Gaussian fitting was performed on it. Calculate the cumulative sum of all signal values ​​within the left and right boundaries of the peak; Establish the baseline line using the two points corresponding to the left and right boundaries of the peak; The target region is defined by the left boundary, right boundary, maximum value, and minimum value of the peak. N random points are obtained by traversing the target region. The count is incremented by 1 when the random point is within the range enclosed by the baseline line and the Gaussian fitted curve. Calculate the regional cumulative sum of signal values ​​within the target defined area based on the counting results; The environmental background disturbance in the current sea area is obtained by the difference between the cumulative sum and the regional cumulative sum.

Images