CN113009545A - Computing method for net counting of seawater radionuclides - Google Patents

Abstract

The invention belongs to the technical field of seawater detection, and relates to a calculation method for net counting of seawater radionuclides. The method comprises the following steps: (1) establishing a Gaussian fitting function for the peak of the found radionuclide; (2) calculating the signal value Y of the peak_maxSignal value Y of left and right boundaries_l、Y_r(ii) a (3) Establishing a background data linear function according to two points corresponding to the left and right boundaries; (4) traversing n times to obtain a random point (X, y), wherein X belongs to the (X)_l～X_r)，y∈(Y_min～Y_max)，Y_minIs Y_l、Y_rThe smaller of these; (5) counting the count sum of the points (x, y) falling in the range enclosed by the background data straight line and the Gaussian fitting curve; (6) net count of marine radionuclide (X)_r‑X_l)×(Y_max‑Y_min) And/n. The method for calculating net count of radionuclides in seawater provided by the invention is not subject to accumulationThe limit of the length of the chamber is not limited by the interference of the marine environment, and the net count of the radioactive nuclide in the seawater can be quickly and accurately calculated.

Description

Computing method for net counting of seawater radionuclides

Technical Field

The invention belongs to the technical field of seawater detection, and relates to a calculation method for net counting of seawater radionuclides.

Background

In the comprehensive measurement process of the ocean radioactive substances, if corresponding radioactive substances exist, corresponding peaks appear in corresponding energy intervals. The existing method for monitoring the radioactive environment of seawater is generally based on the premise that the detection signal corresponding to the radioactive substance to be detected in seawater is stable or unchanged, and is not suitable for complex marine environment.

However, the actual ocean field detection environment is complex and variable, and the interference factors are many. In the actual operation process, the interference of the change of the marine environment on the measurement of marine substances is found, and the phenomenon is that the amplitude of a detected voltage signal can change irregularly, so that the real net counting rate corresponding to the radioactive nuclide in the seawater is difficult to judge quickly and accurately. Usually, during the radionuclide detection process, a lot of peak fluctuations occur, and there are also error peaks caused by interference data. For the above reasons, existing methods for calculating the net count rate of marine radionuclides do not have on-site real-time detection.

Disclosure of Invention

In order to solve the technical problems, the invention provides a calculation method for net counting of the radionuclides in the seawater, so as to achieve the purpose of improving the efficiency and accuracy of calculating the radionuclides.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for calculating net count of radionuclides in seawater comprises the following steps:

(1) establishing a Gaussian fitting function for the peak of the found radionuclide;

(2) calculating the signal value Y of the peak_maxSignal value Y of left and right boundaries_l、Y_r；

(3) Establishing a background data linear function according to two points corresponding to the left and right boundaries;

(4) traversing n times to obtain a random point (X, y), wherein X belongs to the (X)_l～X_r)，y∈(Y_min～Y_max)，Y_minIs Y_l、Y_rThe smaller of these;

(5) counting the count sum of the points (x, y) falling in the range enclosed by the background data straight line and the Gaussian fitting curve;

(6) net count of marine radionuclide (X)_r-X_l)×(Y_max-Y_min)/n。

Further preferably, in step (1), the gaussian fitting function is:

wherein, Y_maxIs the signal value of the peak, X_maxIs the channel value of the peak, S/2 is the square value of the fitted full width at half maximum, X_iAs channel values of the fitted curve, Y_iFor fitting a curve channel value X_iThe corresponding signal value.

Further preferably, in the step (3), the background data straight-line function is: y ═ k × x + b, wherein,

b＝Y_l-k*X_l。

further preferably, for point (X, y), another X_iX, if Y < Y < Y_iIf yes, sum is sum + 1.

The method for calculating the net counting of the radionuclides in the seawater is not limited by the length of the accumulation time and the interference of the marine environment, and can quickly and accurately calculate the net counting of the radionuclides in the seawater.

Drawings

FIG. 1 is a flow chart of a method for calculating net counts of seawater radionuclides in accordance with the present invention;

FIG. 2 is a raw energy spectrum plot;

FIG. 3 is a plot of the spectral data of the partial amplification of the radionuclide peak in FIG. 2;

FIG. 4 is a plot of spectral data after a Gaussian fit;

FIG. 5 is a Gaussian-fit curve, a background data line, and a maximum random number curve, where a is the Gaussian-fit curve, b is the background data line, and c is the maximum random number curve.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

The invention provides a method for calculating net counting of seawater radionuclides, which comprises the following specific processes as shown in figure 1:

s101, establishing a Gaussian fitting function for the peak of the found radionuclide.

In the present embodiment, the spectral data curve of all channels is as shown in fig. 2, and the data curve has 1024 channels. The data of the section showing the peak is enlarged as shown in fig. 3, and the channel interval for finding the peak of the radionuclide is 770-850 according to the peak finding method, as shown in fig. 4, in this embodiment, for the purpose of a truly stable counting rate, the gaussian fitting is performed on the data curve in this range, so as to obtain a true data value, and the data value is due to the generation of the radionuclide and is completed in the accumulation period, but not due to the interference data generated by other factors such as the marine environmental change.

The gaussian fit function is:

wherein, Y_maxIs the signal value of the peak, X_maxIs the channel of the peak, S/2 is the square of half the fitted full width at half maximum, X_iAs channel values of the fitted curve, Y_iFor fitting a curve channel value X_iThe corresponding signal value.

In this embodiment, the parameters fitted according to the gaussian fitting function are as follows:

S：1016.726558；

X_max：807.126069；

Y_max：287.603514；

fwhm：22.546913

X_l：700；

X_r：850。

s102, according to a Gaussian fitting function, calculating left and right boundary signal values and a minimum value as follows:

Y_l：74.136912

Y_r：47.164872

Y_min：47.164872。

s103, establishing a background data linear function by using two points corresponding to the left and right boundaries.

The straight line established is shown as b in figure 5,

b＝Y_l-k·X_l＝75.136912-(-0.3371505)×770＝334.742797。

Y＝k·x+b＝-0.3371505x+334.742797。

s104, traversing for enough times, for example 1000000 times, obtaining a random point (x, y), x is within the range of 700-850, y is within the range of 47.164872-287.603514,

in the present embodiment, as shown in c in fig. 5, a random point (x, y) within the range of the box area is traversed.

And S105, counting sum +1 if the point (x, y) falls between the curve a after Gaussian fitting and the background data straight line b, otherwise, keeping the count sum unchanged.

In this embodiment, for random point (X, y), another X_i＝x：

(1) Substituting a Gaussian fitting function:

calculating to obtain Y_i；

(2) Substituting a background data linear function: calculating Y as k x + b;

if Y is less than Y_i(ii) a Then the point is the point that falls between the gaussian fitted curve and the background data line.

S106, net counting of marine radionuclide (X)_r-X_l)×(Y_max-Y_min)/n。

In this example, the net count is sum (850 × (770) × (287.603514-47.164872)/1000000.

The net count is the area of the radionuclide peak after background data subtraction, i.e., the percentage of the area enclosed by the fitted curve and the background data line to the total area, multiplied by the total area.

Since the method of calculating the content of the substance in the seawater using the spectrum data is already a known technique, the embodiment will not be described here.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Of course, the above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, many modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (4)

1. A method for calculating net count of radionuclides in seawater is characterized by comprising the following steps:

(1) establishing a Gaussian fitting function for the peak of the found radionuclide;

(2) calculating the signal value Y of the peak_maxSignal value Y of left and right boundaries_l、Y_r；

(3) Establishing a background data linear function according to two points corresponding to the left and right boundaries;

(4) traversing n times to obtain a random point (X, y), wherein X belongs to the (X)_l～X_r)，y∈(Y_min～Y_max)，Y_minIs Y_l、Y_rThe smaller of these;

(5) counting the count sum of the points (x, y) falling in the range enclosed by the background data straight line and the Gaussian fitting curve;

(6) net count of marine radionuclide (X)_r-X_l)×(Y_max-Y_min)/n。

2. The method of claim 1, wherein in step (1), the Gaussian fitting function is:

wherein, Y_maxIs the signal value of the peak, X_maxIs the channel value of the peak, S/2 is the square value of the fitted full width at half maximum, X_iAs channel values of the fitted curve, Y_iFor fitting a curve channel value X_iThe corresponding signal value.

3. The method of claim 2, wherein in step (3), the background data linear function is: y ═ k × x + b, wherein,

b＝Y_l-k*X_l。

4. the method of claim 3, wherein for point (X, y), another X is calculated_iX, if Y < Y < Y_iIf yes, sum is sum + 1.

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