A method for obtaining a nuclear radiation dose rate based on dynamic response time

Abstract

The application relates to the technical field of nuclear radiation detection, and provides a nuclear radiation dose rate acquisition method based on dynamic response time, which comprises the following steps: (1) determining corresponding maximum response times under different dose rate levels: according to equipment technical indexes, the corresponding maximum response times that the equipment should meet under typical nuclear radiation dose rate levels in a plurality of measurement ranges are determined; (2) determining a discretized 'dose rate-response time' data table: a curve fitting of 'dose rate-response time' is carried out by using a data fitting tool, and a discretized data table is obtained after discretization processing; and (3) acquiring a final dose rate: an initial dose rate is estimated, a dynamic response time is acquired in combination with the discretized data table, and the final dose rate is acquired by using the latest dynamic response time. The method adopts a data fitting method, considers different response time requirements under different dose rate conditions, and can simultaneously consider the measurement accuracy and response time requirements of the equipment.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation detection technology, specifically a method for obtaining nuclear radiation dose rate based on dynamic response time. Background Technology

[0002] Response time is one of the important indicators of nuclear radiation detection instruments. A reasonable response time can provide users with timely and effective measurement data.

[0003] Radioactive decay exhibits random characteristics. During nuclear radiation detection, the counts recorded by radiation monitoring instruments per unit time fluctuate around an average value. The count rate, typically measured over 1 second, is used. To reduce the measurement uncertainty caused by this fluctuation, an average value over a response time period can be employed.

[0004] Currently, a fixed response time is commonly used, which performs well when the dose rate variation range is small. However, when the dose rate variation range is large, the fixed response time cannot reflect the dose rate change in a timely manner, which will introduce certain errors and lags into the measurement results. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned technology and provide a method for obtaining nuclear radiation dose rate based on dynamic response time. This method uses a data fitting method to obtain dynamic response time according to the technical characteristics of different nuclear radiation detection instruments, and can obtain effective data in a timely manner.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows.

[0007] A method for obtaining nuclear radiation dose rate based on dynamic response time includes the following steps:

[0008] (1) Determine the longest response time corresponding to different dose rate levels: Based on the equipment technical specifications, determine the longest response time that the equipment should meet under typical nuclear radiation dose rate levels within several measurement ranges.

[0009] (2) Determine the discretized “dose rate-response time” data table: Use a data fitting tool to perform curve fitting on the “dose rate-response time” and obtain the discretized data table after discretization.

[0010] (3) Obtain the final dose rate: Estimate the initial dose rate, obtain the dynamic response time by combining the discretized data table, and obtain the final dose rate by using the latest dynamic response time.

[0011] This invention provides a method for obtaining nuclear radiation dose rate based on dynamic response time. It employs a data fitting method to consider the different response time requirements under different dose rates, thus simultaneously balancing the measurement accuracy and response time requirements of the equipment. Detailed Implementation

[0012] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, a detailed description is provided below in conjunction with specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0013] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0014] This embodiment provides a method for obtaining nuclear radiation dose rate based on dynamic response time, including the following steps:

[0015] Step 1: Determine the longest response time corresponding to different dose rate levels:

[0016] Based on the equipment's technical specifications, the longest response time that the equipment should meet at typical nuclear radiation dose rate levels within several measurement ranges was determined. Due to the stochastic nature of radioactive decay, the detector count rate generally fluctuates significantly at low dose rates, requiring a longer response time to ensure measurement accuracy. Conversely, at high dose rates, the count rate fluctuates less, necessitating a shorter response time to maximize response speed while maintaining measurement accuracy. The typical dose rate levels and corresponding response times selected in this example are shown in Table 1.

[0017] Table 1. Longest response time for different dose rate levels

[0018] Response time (s) 100 30 10 3

[0019] Step 2, determine the discretized "dose rate-response time" data table:

[0020] Curve fitting: Use data fitting tools to perform curve fitting on "dose rate x - response time y" to obtain the fitting formula: y = f(x).

[0021] A suitable fitting curve can be selected based on the typical node data determined in step 1.

[0022] This embodiment uses a power function for fitting, with the fitting formula: y = 98.952x -0.505 .

[0023] Discretization: Based on the fitting formula, obtain the response time y corresponding to the stepped dose rate x. Round the response time y to the nearest integer. Combine this with the response time determined in step 1 to obtain a discretized "dose rate x - response time y" data table. The accuracy of the dose rate step should be determined based on the actual requirements of the equipment.

[0024] General principles for setting step precision: Based on the fitted curve, the step spacing can be appropriately increased in areas where the response time changes relatively smoothly; and the step spacing can be appropriately decreased in areas where the response time changes more drastically.

[0025] At the dose rate level agreed upon in step 1, the agreed response time is preferred.

[0026] The "dose rate-response time" data table for this embodiment is shown in Table 2.

[0027] Table 2 "Dose Rate - Response Time" Data Table

[0028] Response time (s) 100 70 49 40 35 30 … Dose rate (μGy / h) 40 42 44 46 48 50 … Response time (s) 15 15 15 14 14 14 … Dose rate (μGy / h) 52 54 56 58 60 62 … Response time (s) 13 13 13 13 13 12 … Dose rate (μGy / h) 90 92 94 96 98 100 … Response time (s) 10 10 10 10 10 10 … Dose rate (μGy / h) 102 104 106 108 110 112 … Response time (s) 10 9 9 9 9 9 … Dose rate (μGy / h) 190 192 194 196 198 200 … Response time (s) 7 7 7 7 7 7 … Dose rate (μGy / h) 216 232 248 264 280 296 … Response time (s) 7 6 6 6 6 6 … Dose rate (μGy / h) 920 936 952 968 984 1000 … Response time (s) 3 3 3 3 3 3 …

[0029] Step 3, obtain the final dose rate:

[0030] Estimating the initial dose rate: Select an initial response time of 10 seconds. Calculate the average count rate of nuclear pulses using the latest data acquired within this timeframe, and then use the dose rate conversion formula to obtain the initial dose rate. Example formula:

[0031] Dose rate (μGy / h) = average count rate (c / s) × 0.5((μGy / h) / (c / s)).

[0032] The estimated initial dose rate in this embodiment is shown in Table 3.

[0033] Table 3 Initial Dose Rate Data

[0034]

[0035] Determine the dynamic response time: Use a comparison search method to find the interval in the "dose rate x - response time y" data table where the initial dose rate is located from large to small, and take the response time value corresponding to the smaller dose rate in the interval as the dynamic response time.

[0036] In this embodiment, the initial dose rate is 280 μGy / h, and the dynamic response time is determined to be 6 s by referring to the data in Table 2.

[0037] Obtain the final dose rate: Based on the dynamic response time, recalculate the average count rate and obtain the final dose rate according to the dose rate conversion formula.

[0038] The final dose rate obtained in this embodiment is shown in Table 4.

[0039] Table 4 Initial Dose Rate Data

[0040]

[0041] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0042] The above embodiments illustrate only one implementation of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for obtaining nuclear radiation dose rate based on dynamic response time, characterized in that... The method includes the following steps: (1) Determine the longest response time corresponding to different dose rate levels: Based on the equipment technical specifications, determine the longest response time that the equipment should meet under typical nuclear radiation dose rate levels within several measurement ranges; (2) Determine the discretized "dose rate-response time" data table: Use a data fitting tool to perform curve fitting on "dose rate-response time" to obtain the fitting formula: y = f(x); According to the fitting formula, obtain the response time y corresponding to the step dose rate x, round the response time y to the nearest integer, and combine it with the response time determined in step (1) to obtain the discretized "dose rate x-response time y" data table. The step accuracy of dose rate calculation should be determined according to the actual needs of the equipment. (3) Obtain the final dose rate: Select an initial response time of 10s, obtain the kernel pulse average count rate of the initial response time, and obtain the initial dose rate according to the dose rate conversion formula; combine the discretized data table to query the dynamic response time, and use the latest dynamic response time to obtain the final dose rate.

2. The method for obtaining nuclear radiation dose rate based on dynamic response time according to claim 1, characterized in that... In step (3), determining the dynamic response time specifically involves: using a comparison search method, searching from large to small for the interval in the "dose rate x - response time y" data table where the initial dose rate is located, and taking the response time value corresponding to the smaller dose rate in the interval as the dynamic response time; obtaining the final dose rate specifically involves: calculating the average count rate of the kernel pulses in the dynamic response time, and obtaining the final dose rate according to the dose rate conversion formula.

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