Method for calculating radiation dose rate based on pulse counting

Abstract

The invention discloses a method for calculating a radiation dose rate based on pulse counting, which is used for filtering the influence of a large pulse generated under the condition of jitter or other interference in a dose rate calculation process on dose rate jitter calculation, and can effectively reduce the dose rate jitter caused by the interference. Meanwhile, pulse increase or decrease caused by normal rapid increase or decrease of radiation is responded in time, dose rate output is rapidly calculated, that is, when the radiation is rapidly increased or decreased, the dose rate change time is shortened, and therefore the current dose rate level is displayed more timely and stably; through the method provided by the invention, the calculation of the dose rate can effectively filter abnormal pulses and reduce fluctuations, and meanwhile, when the radiation intensity changes quickly, quick response can be realized, the timeliness of dose rate calculation can be improved, the stability and accuracy of dose rate output can be ensured, and reliable data support can be provided for safe operation in a nuclear radiation environment.

Description

Technical Field

[0001] The invention belongs to the technical field of radiation measurement, and in particular relates to a method for calculating radiation dose rate based on pulse counting. Background Art

[0002] In areas where nuclear radiation may occur or has occurred, in order to ensure the safety of workers in the area, it is necessary to detect the intensity of nuclear radiation in real time so as to adjust the work content and requirements in time according to the changes in the intensity of nuclear radiation. At present, the common scheme for detecting the intensity of nuclear radiation is to use a counter tube to convert the light signal generated by radiation into an electrical signal pulse, and then use a processor electrically connected to the counter tube to collect the pulses and count the number of pulses generated per second, and finally use the number of pulses generated per second (Counts Per Second, abbreviated as cps) to calculate the corresponding dose rate.

[0003] The existing counter tubes not only have the characteristics of large fluctuations, but are also easily disturbed by factors such as jitter during actual use, resulting in fluctuations, which causes the counter tubes to occasionally produce large pulses during the photoelectric conversion process, and the corresponding number of pulses is abnormal; if the radiation dose rate is directly calculated using the statistically obtained cps, it will cause the dose rate to fluctuate greatly, making it difficult to better characterize the radiation intensity of the current environment. Therefore, at present, the cps over a period of time is generally used to calculate the average, and then the dose rate is calculated using the average. In this way, although the dose rate will appear to be relatively stable, the timeliness is poor, and it is difficult to timely reflect the changes in the current radiation intensity. Therefore, in view of the problem that the dose rate obtained by the existing method of calculating the radiation dose rate is difficult to have good stability and timeliness at the same time, it is necessary to improve the method of calculating the radiation dose rate so that the dose rate can clearly and timely reflect the changes in the current radiation intensity. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for calculating radiation dose rate based on pulse counting, so as to solve the problem that the dose rate obtained by the existing method is difficult to have good stability and timeliness at the same time, so as to achieve the effect that the dose rate can clearly and timely reflect the current changes in radiation intensity.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A method for calculating radiation dose rate based on pulse counting, comprising: Data processing: continuously collect cps and store the corresponding values ​​in sequence into an array with queue characteristics. The number of elements in the array is n; Judgment parameters: Take x consecutive values ​​in the array to find the mean and standard deviation, the initial value of x is k, and the judgment interval is constructed based on the mean E and standard deviation δ; Data filtering: If the n-1th value in the array is outside the judgment interval, and the nth value is within the judgment interval, the n-1th value is judged as an abnormal value and filtered out; Dynamic adjustment: If the n-1th value and the nth value in the array are both greater than the maximum value of the judgment interval or both less than the minimum value of the judgment interval, the value k of x is updated to m, m<k; each time a new value is stored in the array, the judgment interval is rebuilt based on the x after the previous update; if the n-1th value and the nth value in the subsequent array are still greater than the maximum value of the judgment interval or both less than the minimum value of the judgment interval, the value of x is maintained at m, and if the n-1th value and the nth value in the subsequent array fall back into the judgment interval, the value m of x is updated to p, p>m and increases gradually to k; Result output: Each time a new value is stored in the array, the real-time average is calculated based on the updated x, and the dose rate is calculated and output using the real-time average.

[0006] Furthermore, the queue characteristic means that after collecting n values ​​and filling the array, when a new value is to be stored, all the values ​​in the array are scrolled forward, the value at the first position of the array is removed, and the new value is stored in the array and occupies the end of the array.

[0007] Furthermore, in the judgment parameter, the x consecutive values ​​before the n-1th value in the array are taken to calculate the mean E and the standard deviation δ, and k is taken to be n-2.

[0008] Furthermore, in the judgment parameter, the judgment interval is E±3δ, E represents the mean, and δ represents the standard deviation.

[0009] Furthermore, in the dynamic adjustment, as p increases gradually to k, p increases by 1 each time.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The method for calculating radiation dose rate based on pulse counting of the present invention can filter the influence of large pulses generated by jitter or other interference in the process of calculating dose rate on the calculated dose rate jump, can effectively reduce the dose rate jump caused by interference, and at the same time promptly respond to the increase or decrease of pulses caused by the rapid increase or decrease of normal radiation, and quickly calculate the dose rate output, that is, when the radiation increases and decreases rapidly, the time of dose rate change is shortened, so as to display the current dose rate level more timely and stably; through the method of the present invention, the calculation of dose rate can effectively filter abnormal pulses and reduce fluctuations, and at the same time, when the radiation intensity changes rapidly, it can respond quickly, improve the timeliness of dose rate calculation, ensure the stability and accuracy of dose rate output, and provide reliable data support for safe operation in nuclear radiation environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1The schematic diagram of the mechanism of the method for calculating radiation dose rate based on pulse counting described in the embodiment is shown. DETAILED DESCRIPTION

[0012] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0013] Example: See also Figure 1 The method for calculating radiation dose rate based on pulse counting described in this embodiment includes a data processing mechanism, a parameter judgment mechanism, a data filtering mechanism, a dynamic adjustment mechanism and a result output mechanism.

[0014] The data processing mechanism is: continuously collect cps and store the corresponding values ​​in sequence in an array with queue characteristics, and the number of elements in the array is n; the queue characteristic means that after collecting n values ​​and filling the array, when a new value is to be stored, all the values ​​in the array are scrolled forward, the value at the first position of the array is removed, and the new value is stored in the array and occupies the end of the array.

[0015] Judgment parameters: take x consecutive values ​​in the array to calculate the mean and standard deviation, the initial value of x is k, and construct a judgment interval based on the mean E and the standard deviation δ; in this embodiment, the judgment parameters are specifically: take x consecutive values ​​before the n-1th value in the array to calculate the mean E and the standard deviation δ, k is n-2, and the judgment interval is constructed as E±3δ, E represents the mean, and δ represents the standard deviation.

[0016] Data filtering: If the n-1th value in the array is outside the judgment interval and the nth value is within the judgment interval, the n-1th value is judged as an abnormal value and filtered out.

[0017] Dynamic adjustment: If the n-1th value and the nth value in the array are both greater than the maximum value of the judgment interval or both are less than the minimum value of the judgment interval, the value k of x is updated to m, m<k; each time a new value is stored in the array, the judgment interval is reconstructed based on the x after the previous update; if the n-1th value and the nth value in the subsequent array are still greater than the maximum value of the judgment interval or both are less than the minimum value of the judgment interval, the value of x is maintained at m, if the n-1th value and the nth value in the subsequent array fall back into the judgment interval, the value m of x is updated to p, p>m and gradually increases to k. In this embodiment, p is increased by 1 each time.

[0018] Result output: Each time a new value is stored in the array, the real-time average is calculated based on the updated x, and the dose rate is calculated and output using the real-time average.

[0019] Specifically, an array with an element count of n and queue characteristics is used to store the values corresponding to the number of pulses per second (cps) collected continuously. The array is represented as D[d1, …, d n-1 , d n . Then, when the (n + 1)-th value is obtained, the first value d1 of the array is removed, and the remaining values in the array are rolled forward. Then, the (n + 1)-th value is stored in the array as the new d n ; It is generally considered that the statistical count of radioactive values follows a normal distribution. Using E to represent the mean value of the values corresponding to a certain number of cps, and δ to represent the corresponding standard deviation, the probability that the value corresponding to cps is within the interval E ± 3δ is 99.7%, and the probability outside the interval E ± 3δ is 0.3%. The probability of being outside the interval E ± 3δ twice in a row is only 0.09‱; Based on this, first use the first n - 2 values in the array D[d1, …, d n-1 , d n to calculate the mean value E and the standard deviation δ. Since at least 5 values are required to calculate the standard deviation, n can be at least 7. In this implementation, n is taken as 120. Even after the detection device using this method is placed in the radiation environment for 2 minutes, it can stably and quickly reflect the change in radiation intensity; When the value corresponding to d n-1 is outside the interval E ± 3δ, that is, when the value corresponding to d n-1 is greater than E + 3δ or less than E - 3δ, this value is not processed temporarily. If the value corresponding to d n is within the interval E ± 3δ, then it is considered that the value corresponding to d n-1 is a large pulse from an anomaly. At this time, d n-1 is filtered, that is, the value affected by the fluctuation of the counter tube is removed; If the value corresponding to d n-1 is greater than E + 3δ (or less than E - 3δ), and at the same time the value corresponding to d n is also greater than E + 3δ (or less than E - 3δ), then it is considered that the radiation intensity is increasing (when greater than E + 3δ) or decreasing (when less than E - 3δ). At this time, the number of values used to calculate the mean is reduced from n - 2 to the latest m (m < n - 2); in this way, the mean calculated with fewer values can more quickly reflect the jump of the mean, and using this mean to calculate the dose rate can more quickly reflect the change in the current radiation intensity; If the subsequent values ​​continue to be greater than E+3δ or less than E-3δ, the most recent m values ​​are continuously used to calculate the mean and standard deviation; if the subsequent values ​​fall within the interval E±3δ again, the number of averages is increased by 1 from m each time until it increases to n-2; wherein, the larger n is and the smaller m is, the greater the climbing slope of the dose rate corresponding curve is, reflecting the faster the change in radiation intensity, n and m can be adjusted according to actual conditions. In this embodiment, m is 5, which takes into account both the sensitivity when the radiation changes and the stability of the dose rate.

[0020] The method for calculating radiation dose rate based on pulse counting of the present invention can filter the influence of large pulses generated by jitter or other interference in the process of calculating dose rate on the calculated dose rate jump, and can effectively reduce the dose rate jump caused by interference. At the same time, it can promptly respond to the increase or decrease of pulses caused by the rapid increase or decrease of normal radiation, and quickly calculate the dose rate output, that is, when the radiation increases and decreases rapidly, it shortens the time of dose rate change, so as to display the current dose rate level more timely and stably; therefore, the present invention can effectively solve the problem that the dose rate obtained by the existing method is difficult to have good stability and timeliness at the same time, and achieve the effect that the dose rate can clearly and timely reflect the change of the current radiation intensity; Through the method of the present invention, the calculation of dose rate can effectively filter abnormal pulses and reduce fluctuations. At the same time, when the radiation intensity changes rapidly, it can respond quickly, improve the timeliness of dose rate calculation, ensure the stability and accuracy of dose rate output, and provide reliable data support for safe operations in nuclear radiation environments.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A method for calculating radiation dose rate based on pulse counting, characterized in that: include: Data processing: continuously collect cps and store the corresponding values ​​in sequence into an array with queue characteristics. The number of elements in the array is n; Judgment parameters: Take x consecutive values ​​in the array to find the mean and standard deviation, the initial value of x is k, and the judgment interval is constructed based on the mean E and standard deviation δ; Data filtering: If the n-1th value in the array is outside the judgment interval, and the nth value is within the judgment interval, the n-1th value is judged as an abnormal value and filtered out; Dynamic adjustment: If the n-1th value and the nth value in the array are both greater than the maximum value of the judgment interval or both less than the minimum value of the judgment interval, the value k of x is updated to m, m<k; each time a new value is stored in the array, the judgment interval is rebuilt based on the x after the previous update; if the n-1th value and the nth value in the subsequent array are still greater than the maximum value of the judgment interval or both less than the minimum value of the judgment interval, the value of x is maintained at m, and if the n-1th value and the nth value in the subsequent array fall back into the judgment interval, the value m of x is updated to p, p>m and increases gradually to k; Result output: Each time a new value is stored in the array, the real-time average is calculated based on the updated x, and the dose rate is calculated and output using the real-time average.

2. The method for calculating radiation dose rate based on pulse counting according to claim 1, characterized in that: The queue characteristic means that after collecting n values ​​and filling the array, when a new value is to be stored, all the values ​​in the array are scrolled forward, the value at the first position of the array is removed, and the new value is stored in the array and occupies the end of the array.

3. The method for calculating radiation dose rate based on pulse counting according to claim 1, characterized in that: In the judgment parameter, take the x consecutive values ​​before the n-1th value in the array to calculate the mean E and standard deviation δ, and k is n-2.

4. The method for calculating radiation dose rate based on pulse counting according to claim 1, characterized in that: In the judgment parameters, the judgment interval is E±3δ, E represents the mean, and δ represents the standard deviation.

5. The method for calculating radiation dose rate based on pulse counting according to claim 1, characterized in that: During dynamic adjustment, p increases by 1 each time as it increases to k.

Images