A method and system for real-time monitoring of radiation dose throughout the At-211 production process.

Abstract

This invention relates to the field of radiation monitoring technology and discloses a method and system for real-time monitoring of radiation dose throughout the At-211 production process. The method includes: simultaneously acquiring gamma ray dose rate and neutron dose rate in real time at at least three fixed spatial points at 0 degrees, 90 degrees, and 180 degrees from the proton beam axis outside the bombardment cavity of the proton beam bombardment target; simultaneously acquiring the proton beam intensity in real time during the proton beam transmission process; generating dose monitoring instructions that can determine whether the radiation dose is abnormal or normal through multi-step collaborative analysis, accurately reflecting the internal and external radiation situation and potential abnormal risks, effectively avoiding the influence of signal lag or distortion from external radiation detectors, and thus accurately capturing changes in radiation dose within the bombardment cavity caused by instantaneous fluctuations in proton beam intensity, ensuring the health and safety of radiation during the bombardment process and the entire At-211 production process.

Description

Technical Field

[0001] This invention relates to the field of radiation monitoring technology, specifically to a method and system for real-time monitoring of radiation dose throughout the At-211 production process. Background Technology

[0002] Currently, in the At-211 production process, radiation dose monitoring is mainly carried out at fixed locations in key processes such as At-211 target bombardment, product separation, purification, and packaging. Radiation dose detectors are deployed at these locations to collect the dose of different rays at each location in real time, thereby achieving real-time monitoring of radiation dose in the At-211 production process.

[0003] However, the above-mentioned radiation dose monitoring method still has the following defects: During the At-211 target material bombardment reaction stage, which is the stage with the highest and most drastic radiation dose fluctuation in At-211 production, the radiation is strongly attenuated and scattered when it penetrates the cavity structure. At this time, the signal of the external radiation dose detector is severely lagging and distorted, which means that the radiation dose detector can only monitor the overall radiation dose of the outer periphery of the bombardment cavity, but it cannot accurately capture the changes in radiation dose inside the bombardment cavity caused by the instantaneous fluctuation of beam intensity during the bombardment process. Therefore, it is impossible to determine whether the radiation dose is abnormal, which affects the real-time monitoring effect of radiation dose during the bombardment stage. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method and system for real-time monitoring of radiation dose throughout the At-211 production process, thus solving the aforementioned problems.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A method for real-time monitoring of radiation dose throughout the At-211 production process includes:

[0007] Step S1: At least three fixed spatial points at 0 degrees, 90 degrees and 180 degrees from the proton beam axis, outside the bombardment cavity of the proton beam bombarding the target, the gamma ray dose rate and neutron dose rate are synchronously and in real time acquired. At the same time, the proton beam intensity is acquired in real time during the transmission of the proton beam.

[0008] Step S2: After preprocessing the gamma ray dose rate, neutron dose rate and proton beam intensity, respectively, the analysis is performed to generate a cavity radiation state index that represents the overall radiation state of the cavity periphery under the current bombardment state.

[0009] Step S3: Perform a joint calculation on the cavity radiation situation index and the pre-processed proton beam intensity to obtain the internal radiation risk value representing the potential abnormal risk of the radiation dose field inside the current bombardment cavity.

[0010] Step S4: Based on the internal radiation risk value and the pre-processed proton beam intensity, analyze the degree of drastic change in the current internal and external radiation fields, and generate a dynamic risk threshold.

[0011] Step S5: Compare the internal radiation risk value with the dynamic risk threshold to generate a dose monitoring instruction.

[0012] Furthermore, the gamma-ray dose rate, neutron dose rate, and proton beam intensity are preprocessed and analyzed to generate a cavity radiation state index representing the overall radiation state of the cavity periphery under the current bombardment state, including:

[0013] The gamma-ray dose rate and neutron dose rate at three fixed spatial points are calculated respectively, and the gamma-ray dose dispersion factor and neutron dose dispersion factor are generated.

[0014] For the gamma-ray dose rate and neutron dose rate at the 0-degree point, the synchronicity between the two and the proton beam intensity is analyzed to generate the gamma-beam synchronization coefficient and the neutron-beam synchronization coefficient.

[0015] Furthermore, after preprocessing the gamma-ray dose rate, neutron dose rate, and proton beam intensity, analysis is performed to generate a cavity radiation state index representing the overall radiation state of the cavity periphery under the current bombardment state. This also includes:

[0016] Based on the gamma-ray dose rate and neutron dose rate at three fixed spatial points, the trend of radiation recombination growth is calculated, and a mixed radiation change vector representing the degree of drastic change in total radiation intensity is obtained.

[0017] The gamma dose dispersion factor, neutron dose dispersion factor, gamma-beam synchronization coefficient, neutron-beam synchronization coefficient and mixed radiation variation vector are fused to generate a cavity radiation state index that represents the overall radiation state of the cavity periphery under the current bombardment state.

[0018] Furthermore, the cavity radiation situation index and the pre-processed proton beam intensity are calculated together to obtain the internal radiation risk value representing the potential anomaly risk of the current bombardment cavity's internal radiation dose field, including:

[0019] Radiation-beam adaptation analysis was performed on the cavity radiation state index and the pre-processed proton beam intensity to generate radiation-beam adaptation factor;

[0020] Based on the radiation-beam adaptation factor, the transient fluctuation law of internal radiation dose with proton beam intensity is analyzed, and transient radiation gradient value is generated.

[0021] Based on the transient radiation gradient value and the proton beam intensity, the gradient enhancement ratio and beam enhancement ratio are calculated to obtain the radiation peak hazard value, which represents the strength of the peak risk.

[0022] Furthermore, the cavity radiation situation index and the pre-processed proton beam intensity are calculated together to obtain an internal radiation risk value representing the potential anomaly risk of the current bombardment of the cavity's internal radiation dose field, which also includes:

[0023] By jointly calculating the transient radiation gradient value and the radiation peak potential value, an internal radiation risk value representing the potential abnormal risk of the radiation dose field inside the current bombardment cavity is obtained.

[0024] Furthermore, based on the internal radiation risk value and the pre-processed proton beam intensity, the degree of drastic change in the current internal and external radiation fields is analyzed to generate dynamic risk thresholds, including:

[0025] Based on the internal radiation risk value and the pre-processed proton beam intensity, the synchronous characteristics of their changes are analyzed, and the radiation-beam correlation coefficient is generated.

[0026] Based on the radiation-beam correlation coefficient, the degree of change of the current internal and external radiation fields with the proton beam intensity is analyzed, and a radiation variability value representing the degree of drastic change of the internal and external radiation fields is generated.

[0027] Furthermore, based on the internal radiation risk value and the pre-processed proton beam intensity, the degree of drastic change in the current internal and external radiation fields is analyzed to generate a dynamic risk threshold, which also includes:

[0028] Based on the radiation variability value, the threshold calibration amplitude is calculated to obtain the threshold dynamic calibration factor;

[0029] By integrating radiation variability values ​​with threshold dynamic calibration factors, dynamic risk thresholds are generated.

[0030] Furthermore, the internal radiation risk value is compared with the dynamic risk threshold to generate dose monitoring instructions, including:

[0031] The internal radiation risk value and the dynamic risk threshold are compared and analyzed in a coordinated manner to calculate the degree of deviation between the two and generate a radiation risk deviation value.

[0032] Furthermore, by comparing the internal radiation risk value with the dynamic risk threshold to generate dose monitoring instructions, it also includes:

[0033] Based on the radiation risk deviation value, determine the current radiation dose status and generate dose monitoring instructions.

[0034] Furthermore, a real-time radiation dose monitoring system for the entire At-211 production process, applied to the aforementioned monitoring method, includes:

[0035] The data acquisition unit is used to synchronously and in real time acquire the gamma ray dose rate and neutron dose rate at at least three fixed spatial points at 0 degrees, 90 degrees and 180 degrees from the proton beam axis, outside the bombardment cavity of the proton beam bombarding the target material, and simultaneously acquire the proton beam intensity in real time during the proton beam transmission process.

[0036] The radiation dose analysis unit is used to analyze the gamma ray dose rate, neutron dose rate and proton beam intensity after preprocessing, and generate a cavity radiation state index that represents the overall radiation state of the cavity periphery under the current bombardment state.

[0037] The radiation risk analysis unit is used to jointly calculate the cavity radiation situation index and the pre-processed proton beam intensity to obtain the internal radiation risk value, which represents the potential abnormal risk of the radiation dose field inside the current bombardment cavity.

[0038] The radiation change analysis unit is used to analyze the degree of change in the current internal and external radiation fields based on the internal radiation risk value and the pre-processed proton beam intensity, and to generate dynamic risk thresholds.

[0039] The radiation dose monitoring unit is used to compare the internal radiation risk value with the dynamic risk threshold and generate dose monitoring instructions.

[0040] In summary, the present invention has the following main beneficial effects:

[0041] By analyzing parameters such as gamma dose dispersion factor, neutron dose dispersion factor, and gamma-beam synchronization coefficient, and integrating hybrid radiation change vector and radiation-beam adaptation factor, dynamic risk thresholds and radiation risk deviation values ​​are generated. Finally, dose monitoring commands are generated. This solution achieves real-time monitoring throughout the entire process, accurately reflects the internal and external radiation situation and risks, avoids the influence of external signal distortion, and can precisely capture radiation changes in the cavity caused by beam fluctuations. This improves the timeliness and accuracy of radiation anomaly judgment and ensures the safety of radiation monitoring during the At-211 production bombardment process and throughout the entire process. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating the method for real-time monitoring of radiation dose throughout the At-211 production process according to the present invention.

[0043] Figure 2 This is a schematic diagram of the real-time radiation dose monitoring system for the entire At-211 production process according to the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] refer to Figure 1 and Figure 2 A method for real-time monitoring of radiation dose throughout the At-211 production process, including:

[0046] Step S1: At least three fixed spatial points at 0 degrees, 90 degrees and 180 degrees from the proton beam axis, outside the bombardment cavity of the proton beam bombardment target, the gamma ray dose rate and neutron dose rate are synchronously and in real time acquired. At the same time, the proton beam intensity is acquired in real time during the proton beam transmission process. Among them, outside the bombardment cavity of the proton beam bombardment target, the center point of the flange at the end of the beam transmission tube is taken as the origin of the coordinate system, and the extension direction of the geometric center line of the beam tube is taken as the 0-degree reference axis. This reference axis is the proton beam axis.

[0047] Step S2: After preprocessing the gamma ray dose rate, neutron dose rate and proton beam intensity, respectively, the analysis is performed to generate a cavity radiation state index that represents the overall radiation state of the cavity periphery under the current bombardment state.

[0048] Step S3: Perform a joint calculation on the cavity radiation situation index and the pre-processed proton beam intensity to obtain the internal radiation risk value representing the potential abnormal risk of the radiation dose field inside the current bombardment cavity.

[0049] Step S4: Based on the internal radiation risk value and the pre-processed proton beam intensity, analyze the degree of drastic change in the current internal and external radiation fields, and generate a dynamic risk threshold.

[0050] Step S5: Compare the internal radiation risk value with the dynamic risk threshold to generate a dose monitoring instruction.

[0051] In one embodiment, the gamma-ray dose rate, neutron dose rate, and proton beam intensity are preprocessed and analyzed to generate a cavity radiation state index representing the overall radiation state of the cavity periphery under the current bombardment state, including:

[0052] The gamma-ray dose rate and neutron dose rate at three fixed spatial locations are calculated separately to generate gamma-ray dose dispersion factors and neutron dose dispersion factors. Specifically, for the gamma-ray dose rate at the three fixed spatial locations, the mean of the three gamma-ray dose rates is calculated as a reference. The absolute difference between the gamma-ray dose rate at each fixed location and the reference is calculated. The directional weights of 0 degrees, 90 degrees, and 180 degrees are set to 1, 1.2, and 0.8, respectively. This weight setting can reflect the inherent asymmetry that may exist in the radiation field along the beam axis. The absolute difference at the corresponding locations is multiplied by the corresponding weight and then summed to obtain the gamma deviation sum. The gamma deviation sum is then divided by the arithmetic mean of the gamma-ray dose rate, and the calculation result is normalized to the 0-1 interval to obtain the gamma-ray dose dispersion factor. The gamma-ray dose dispersion factor is mainly used to determine whether there is an abnormal distribution of gamma radiation.

[0053] For the neutron dose rate at three fixed spatial locations, the maximum value is used as the maximum value benchmark. The relative ratio deviation of the neutron dose rate at each location from the maximum value benchmark is calculated. The directional weights for 0 degrees, 90 degrees, and 180 degrees are set to 1.1, 1, and 0.9, respectively, to adapt to the characteristics of neutron flux distribution. The relative ratio deviation corresponding to each location is multiplied by the corresponding directional weight and then summed. After normalizing the calculation results to the 0-1 interval, the total neutron deviation is obtained. The geometric mean of the three neutron dose rates is calculated. The total neutron deviation is multiplied by the square root of the geometric mean and then divided by the maximum value benchmark. The calculation results are normalized to the 0-1 interval to obtain the neutron dose dispersion factor. This factor is mainly used to determine whether there is an abnormal distribution of neutron rays and can comprehensively check the validity of external neutron dose data.

[0054] For the gamma-ray dose rate and neutron dose rate at the 0-degree point, the synchronicity between the two and the proton beam intensity is analyzed to generate the gamma-beam synchronization coefficient and the neutron-beam synchronization coefficient. Specifically, this involves continuously sampling the gamma-ray dose rate and proton beam intensity at the 0-degree point within a fixed time window of 5 seconds to form two sequences; calculating the rate of change between adjacent sampling points in the two sequences to obtain the gamma dose rate change sequence and the beam intensity rate of change sequence.

[0055] Using the beam intensity change rate sequence as a baseline, the gamma dose rate change rate sequence is time-shifted and matched. The offset starts from 0 milliseconds and gradually increases to 100 milliseconds in steps of 10 milliseconds, generating a total of 11 offsets. For each offset, such as a delay of 30 milliseconds, the gamma sequence is shifted backward by 3 sampling points. Since the sampling interval is 10 milliseconds, it is misaligned with the beam sequence on the time axis. After alignment, only the data points of the two sequences within the completely overlapping time period are taken to form a pair of temporary sequences of equal length.

[0056] For each pair of temporary sequences, compare the signs of the rate of change values ​​of the two temporary sequences at the same time. If both are positive or both are negative, they are recorded as having the same sign. The number of data points with the same sign is divided by the total number of such aligned data points to obtain the sign-matching ratio.

[0057] For data points with consistent signs, the gamma rate of change and beam rate of change for each point are normalized to the 0-1 interval. Then, the ratio of the absolute value of the gamma rate of change to the absolute value of the beam rate of change for each point is calculated. Within this time window, all ratios are combined into a dataset, and the 25th and 75th quantiles of the dataset are used as dynamic reasonable range boundaries. For example, if the ratio falls within the reasonable range boundaries, it is considered that the amplitude is matched. The number of points falling within the reasonable range boundaries is divided by the number of points with consistent signs to obtain the amplitude covariance ratio.

[0058] Multiplying the sign consistency ratio by a fixed weight of 0.6 and the amplitude covariance ratio by a fixed weight of 0.4 yields the synchronization matching degree at that offset. After traversing all 11 offsets, 11 synchronization matching degree values ​​are obtained. The maximum value is selected as the gamma-beam synchronization coefficient. The gamma-beam synchronization coefficient is mainly used to reflect the synchronization between the change in gamma ray dose rate and the change in proton beam intensity.

[0059] Among them, the sign consistency ratio directly reflects the fundamental directional relationship between the gamma radiation response and the beam change, and is the core and stable criterion for synchronicity, so its weight is 0.6; while the amplitude covariance ratio reflects the proportional relationship of the response intensity, but its fluctuation is relatively large, so it is given a slightly lower weight of 0.4.

[0060] Within a fixed time window of 30 seconds, the neutron dose rate and proton beam intensity were acquired and sequenced. The two sequences were then smoothed by applying three moving average filters with different widths, set to 1 second, 5 seconds and 10 seconds respectively, to obtain smoothed sequences at short, medium and long time scales.

[0061] For each scale, the first-order difference of the smoothed sequence is calculated to generate the corresponding difference sequence. At each independent time scale, the cross-correlation coefficients of the neutron difference sequence and the beam difference sequence are progressively calculated under different delays within a time delay range of 0 to 500 milliseconds by sliding the time delay between them. For each scale, the value at which the cross-correlation coefficient reaches its highest point during the entire time delay scan is found, i.e., the peak cross-correlation coefficient, and the time delay value corresponding to the peak value is recorded.

[0062] The peak cross-correlation coefficients obtained from the three scales are fused. During fusion, the corresponding peak cross-correlation coefficients are weighted according to the time delay values ​​recorded at each scale. The weight is set to a baseline value of 1 when the time delay value is 100 milliseconds, and the weight decreases by 0.3 for every 100 milliseconds increase in time delay value, with a minimum weight value of 0.1. The neutron-beam synchronization coefficient is obtained by adding the three weighted peak cross-correlation coefficients and dividing by the sum of the three weights. The neutron-beam synchronization coefficient is mainly used to reflect the synchronicity between changes in neutron dose rate and changes in beam intensity. Its purpose is to supplement the judgment of the correlation between external neutron dose data and beam fluctuations, and to avoid missed detection of intracavity neutron dose changes due to neutron signal lag or distortion.

[0063] In one embodiment, the gamma-ray dose rate, neutron dose rate, and proton beam intensity are preprocessed and analyzed to generate a cavity radiation state index representing the overall radiation state of the cavity periphery under the current bombardment state. This also includes:

[0064] Based on the gamma-ray dose rate and neutron dose rate at three fixed spatial locations, the trend of radiation recombination growth is calculated to obtain a mixed radiation change vector representing the degree of drastic change in total radiation intensity. Specifically, this involves: simultaneously acquiring gamma and neutron dose rate sampling data 100 times per second at the three spatial locations within a two-second time window; for each location, calculating the difference between adjacent sampling points in the gamma dose rate sequence to obtain the gamma change sequence; simultaneously calculating the adjacent differences in the neutron dose rate sequence to obtain the neutron change sequence; and calculating the product of these two change sequences point by point: multiplying the gamma change value and the neutron change value at the same moment; if the gamma change and neutron change are both positive or both negative at that moment, multiplying the product by a positive one; if one is positive and the other is negative, multiplying the product by a negative one, finally obtaining the instantaneous co-occurrence value at that location.

[0065] Sum all instantaneous coordination values ​​of the point within a two-second window to obtain the original coordination strength of the point; calculate the sum of the absolute values ​​of the original coordination strengths of the three points, and divide the original coordination strength of each point by this sum of absolute values ​​to obtain three dynamic spatial weights.

[0066] Multiply the original coordinated intensity of the point by the corresponding dynamic spatial weight to obtain the final intensity value of each point; thus, the final intensity values ​​of three fixed points can be obtained, representing the degree of coordinated change in gamma and neutron radiation intensity in the directions of 0 degrees, 90 degrees and 180 degrees respectively. After normalizing the final intensity value of each point to the 0-1 interval, it is used as a component and combined into a mixed radiation change vector representing the degree of change in total radiation intensity.

[0067] The gamma dose dispersion factor, neutron dose dispersion factor, gamma-beam synchronization coefficient, neutron-beam synchronization coefficient and mixed radiation change vector are fused to generate a cavity radiation state index that represents the comprehensive radiation state of the cavity periphery under the current bombardment state. Specifically, this includes: calculating the square root of the sum of squares of the three components in the mixed radiation change vector to obtain the mixed change index.

[0068] For the five parameters—gamma dose dispersion factor, neutron dose dispersion factor, gamma-beam synchronization coefficient, neutron-beam synchronization coefficient, and mixing variation index—calculate their percentiles in the historical data over the past sixty seconds.

[0069] Historical data is collected once per second. There are 60 historical values ​​for each parameter. For each parameter, the current value is compared with the historical value. The number of historical values ​​that are less than the current value is counted. The number is divided by 60 to obtain the current percentile of the parameter.

[0070] Add the five percentiles together, divide by 5, and normalize the result to the 0-1 range to obtain the cavity radiation state index, which represents the overall radiation state of the cavity periphery under the current bombardment state.

[0071] By preprocessing the gamma-ray dose rate, neutron dose rate, and proton beam intensity, respectively, and calculating the gamma dose dispersion factor and neutron dose dispersion factor at three fixed spatial points, it is possible to accurately determine whether there are abnormal distributions of gamma and neutron radiation. At the same time, the synchronicity between radiation dose and beam intensity can be captured by the gamma-beam synchronization coefficient and the neutron-beam synchronization coefficient. Combined with the mixed radiation change vector, the intensity of radiation synergistic change is reflected, and finally, the cavity radiation situation index is generated, which realizes the accurate quantification of the comprehensive radiation situation around the bombardment cavity and improves the accuracy of real-time monitoring of radiation dose during the bombardment phase.

[0072] In one embodiment, the cavity radiation situation index and the pre-processed proton beam intensity are calculated together to obtain an internal radiation risk value representing the potential anomaly risk of the current bombardment cavity's internal radiation dose field, including:

[0073] Radiation-beam adaptation analysis was performed on the cavity radiation state index and the preprocessed proton beam intensity to generate a radiation-beam adaptation factor. Specifically, the cavity radiation state index sequence and the proton beam intensity sequence were acquired simultaneously within a time window of 10 seconds. The beam intensity sequence was preprocessed, and the relative rate of change of each data point relative to the initial value within the window was calculated, thereby converting it into a dimensionless beam relative intensity sequence.

[0074] Calculate the first derivative sequences of the cavity radiation state index sequence and the beam relative intensity sequence within the window to obtain two derivative sequences; count the proportion of data points with opposite signs (one positive and one negative) in the two derivative sequences to the total number of points in the window, which is the trend sign mismatch rate;

[0075] For all data points with the same sign, the ratio of the absolute value of the derivative of the cavity radiation situation index to the absolute value of the derivative of the beam relative intensity is calculated, and the standard deviation of these ratios is calculated to obtain the trend amplitude imbalance. The trend sign mismatch rate is directly added to the trend amplitude imbalance, and the calculation result is normalized to the 0-1 interval to obtain the radiation-beam adaptation factor. The larger the radiation-beam adaptation factor, the worse the real-time adaptation between the external radiation situation and the beam driving force, and the higher the internal risk.

[0076] Based on the radiation-beam adaptation factor, the transient fluctuation law of internal radiation dose with proton beam intensity is analyzed, and transient radiation gradient values ​​are generated. Specifically, within a time window of 20 seconds, the radiation-beam adaptation factor sequence and the proton beam intensity sequence are acquired simultaneously. For the proton beam intensity sequence, all local maxima and local minima are identified, and these extreme points are connected in chronological order to form a broken line sequence describing significant beam changes.

[0077] Set a set of candidate delay times from 0 milliseconds to 1000 milliseconds with a step size of 100 milliseconds. For each candidate delay time, shift the radiation-beam adaptation factor sequence backward by the corresponding number of data points so that it is misaligned with the piecewise linear sequence in time. In the interval where the time axes of the two overlap, identify the local extreme points of the radiation-beam adaptation factor sequence.

[0078] For each local maximum and local minimum point of the beam variation piecewise linear curve, the extreme points with the closest time in the time-aligned radiation-beam adaptation factor sequence are found and paired. For all successfully paired extreme point pairs, the absolute value of the time difference between the two extreme points in the pair is calculated, and the ratio of the values ​​of the two extreme points in the pair is also calculated.

[0079] Calculate the arithmetic mean of the absolute values ​​of the time differences of all extreme point pairs, calculate the standard deviation of the numerical ratio of all extreme point pairs, and multiply the arithmetic mean by the standard deviation to obtain the morphological difference degree under the current candidate delay time. After traversing all candidate delay times, find the delay time that minimizes the morphological difference degree, which is the optimal response delay. Normalize the reciprocal of the morphological difference degree under the optimal response delay to the 0-1 interval, which is the transient radiation gradient value representing the degree of transient distribution difference of the internal radiation dose field as the proton beam intensity changes.

[0080] Based on the transient radiation gradient value and the proton beam intensity, the gradient enhancement ratio and beam enhancement ratio are calculated to obtain the radiation peak risk value, which represents the strength of the peak risk. Specifically, for each proton beam intensity in the proton beam intensity sequence, when it exceeds 103% of the median of its own value in the past ten seconds, it is marked as the starting point of the rising edge of concern. Until the proton beam intensity does not exceed 103% of the median of its own value in the past ten seconds, it is marked as the falling point. The entire period from the starting point to the falling point is regarded as a beam disturbance event.

[0081] For each beam disturbance event, the transient radiation gradient values ​​synchronously acquired during the beam disturbance event period are extracted to form a subsequence. The average value of the subsequence from the midpoint of the event to the fallback point is calculated and divided by the average value from the starting point to the midpoint of the event to obtain the gradient enhancement ratio. At the same time, the ratio of the peak value of the proton beam intensity in the beam disturbance event to the proton beam intensity at the starting point of the event is calculated to obtain the beam enhancement ratio.

[0082] For all beam disturbance events in the past five minutes, select the beam disturbance event with the largest beam enhancement ratio, and directly multiply its gradient enhancement ratio by the beam enhancement ratio to obtain the individual vulnerability level of the beam disturbance event.

[0083] The radiation peak hazard value, which represents the strength of the peak risk, is obtained by adding the individual hazard level of the latest beam disturbance event before the current moment to the maximum individual hazard level of all events in the past five minutes and dividing by 2.

[0084] In one embodiment, the cavity radiation situation index and the pre-processed proton beam intensity are calculated together to obtain an internal radiation risk value representing the potential anomaly risk of the current bombardment cavity's internal radiation dose field, which further includes:

[0085] The transient radiation gradient value and the radiation peak hazard value are calculated together to obtain the internal radiation risk value representing the potential abnormal risk of the radiation dose field inside the current bombardment cavity. Specifically, this includes: obtaining the transient radiation gradient value and radiation peak hazard value of the current moment and the previous four consecutive sampling points to form two short sequences of length five, with a sampling interval of 100 milliseconds; calculating the Pearson correlation coefficient of these two short sequences on the first difference, and using the absolute value of the Pearson correlation coefficient as the instantaneous coupling coefficient.

[0086] Multiply the transient radiation gradient value at the current moment by the radiation peak hazard value as the numerator, then subtract the radiation peak hazard value from the transient radiation gradient value at the current moment, and add 1 to the absolute value of the result as the denominator. Divide the numerator by the denominator to obtain the self-excitation intensity.

[0087] Multiplying the instantaneous coupling coefficient by the self-excitation intensity yields the internal radiation risk value, which represents the potential anomaly risk of the radiation dose field inside the current bombardment cavity.

[0088] By capturing the synchronicity between radiation and beam using gamma-beam synchronization coefficients and neutron-beam synchronization coefficients, and combining the mixed radiation change vector to reflect the intensity of coordinated radiation changes, a cavity radiation situation index is generated. Then, the internal radiation risk value is calculated by co-calculating the radiation-beam adaptation factor, transient radiation gradient value, and radiation peak hazard value. This accurately reflects the potential abnormal risks of internal radiation, effectively avoids the influence of external signal distortion, and achieves high-precision monitoring of the internal and external radiation situation of the cavity, thus improving the accuracy of radiation anomaly judgment during the bombardment phase.

[0089] In one embodiment, based on the internal radiation risk value and the pre-processed proton beam intensity, the degree of drastic change in the current internal and external radiation fields is analyzed to generate a dynamic risk threshold, including:

[0090] Based on the internal radiation risk value and the preprocessed proton beam intensity, the synchronization characteristics of their changes are analyzed to generate a radiation-beam correlation coefficient. Specifically, this involves: synchronously acquiring the internal radiation risk value sequence and the preprocessed proton beam intensity sequence within a three-second time window, and calculating the instantaneous rate of change sequences for both sequences; dividing the absolute value of the rate of change of each instantaneous rate of change sequence into three equal groups: the smallest third is classified as the low-energy group, the middle third as the medium-energy group, and the largest third as the high-energy group; calculating the sum of the absolute values ​​of the rates of change of the two instantaneous rate of change sequences in the low, medium, and high-energy groups, then calculating the absolute value of the relative difference between the sums of the two instantaneous rate of change sequences in the corresponding energy groups, calculating the arithmetic mean of the absolute values ​​of the relative differences among the three energy groups, and then subtracting the arithmetic mean from 1 to obtain the matching degree of the energy distribution change.

[0091] Within the same three-second window, all local extreme points of the internal radiation risk value sequence and the proton beam intensity sequence are identified respectively. For each extreme point of the proton beam intensity sequence, among the extreme points of the internal radiation risk value sequence, points with an absolute time difference of less than 100 milliseconds and the same direction of change are selected for pairing. The number of successfully paired extreme points is divided by the total number of extreme points of the proton beam intensity sequence to obtain the critical phase synchronization rate.

[0092] Within the aforementioned three-second window, the number of times the instantaneous change direction of the internal radiation risk value is the same as the instantaneous change direction of the proton beam intensity is counted at all sampling moments. This number is divided by the total number of sampling moments within the window to obtain the trend direction consistency rate. The instantaneous change direction is determined by the numerical difference between adjacent sampling points. The instantaneous changes of the two internal radiation risk value sequences and the proton beam intensity sequence are calculated separately. If both are greater than 0 or both are less than 0, the instantaneous change direction is determined to be the same at that moment. The radiation-beam correlation coefficient is obtained by multiplying the change energy distribution matching degree, the critical phase synchronization rate, and the trend direction consistency rate. The radiation-beam correlation coefficient is mainly used to reflect the degree of correlation between the internal radiation risk value and the proton beam intensity.

[0093] Based on the radiation-beam correlation coefficient, the degree of change of the current internal and external radiation fields with the proton beam intensity is analyzed, and a radiation variability value representing the degree of drastic change of the internal and external radiation fields is generated. Specifically, this includes: within the most recent three-second window, collecting the radiation-beam correlation coefficients and their corresponding proton beam intensities at all synchronous monitoring points, finding the global minimum and global maximum values ​​of the proton beam intensity within this window, and taking the range from the global minimum to the global maximum value as the intensity range; uniformly dividing the intensity range into ten consecutive equal-width intervals, counting the number of radiation-beam correlation coefficients falling into each intensity interval, and then calculating the coefficient of variation of the radiation-beam correlation coefficients in these ten intensity intervals to obtain the interval distribution dispersion.

[0094] For each intensity interval containing at least one data point, the range of all radiation-beam correlation coefficient values ​​within that intensity interval is calculated. Then, the arithmetic mean of all these ranges is calculated to obtain the fluctuation range within the interval. Multiplying the interval distribution dispersion by the fluctuation range within the interval yields the radiation variability value, which represents the degree of drastic change in the internal and external radiation fields.

[0095] In one embodiment, based on the internal radiation risk value and the pre-processed proton beam intensity, the degree of drastic change in the current internal and external radiation fields is analyzed to generate a dynamic risk threshold, which further includes:

[0096] Based on the radiation variability value, the threshold calibration amplitude is calculated to obtain the threshold dynamic calibration factor. Specifically, this includes: monitoring the radiation variability value in real time with a fixed sampling period of 50 milliseconds; when the value is found to be monotonically increasing or monotonically decreasing within three consecutive sampling periods, this is defined as an effective monotonically changing segment; recording the start and end values ​​of the effective monotonically changing segment, and calculating the absolute value of the difference between the two as the unilateral change amplitude of the effective monotonically changing segment.

[0097] Within the most recent two-second time window, find all effective monotonic variation segments and calculate the unilateral variation amplitude, then take the maximum value and the arithmetic mean; subtract the arithmetic mean of all the radiative variability values ​​within the two-second window from the current radiative variability value, and then divide by the standard deviation of all the radiative variability values ​​within the two-second window to obtain the threshold calibration amplitude.

[0098] Multiply the calculated threshold calibration amplitude by the maximum value of the unilateral change amplitude, divide by the arithmetic mean of the unilateral change amplitude, and normalize the calculation result to the 0-1 range to obtain the threshold dynamic calibration factor. The threshold dynamic calibration factor is mainly used to calibrate the adjustment amplitude of the dynamic threshold according to the changing trend of the radiation variability, so as to accurately adapt to the instantaneous changes of the radiation field.

[0099] Integrating the radiation variability value with the threshold dynamic calibration factor to generate a dynamic risk threshold, specifically including: directly multiplying the current radiation variability value with the threshold dynamic calibration factor to obtain the original fused value;

[0100] Calculate the arithmetic mean of the radiation variability value and the threshold dynamic calibration factor; at the same time, calculate the quotient of the radiation variability value divided by the threshold dynamic calibration factor. If the quotient is negative or zero, take its absolute value and add 1 to obtain the correction value.

[0101] Multiply the arithmetic mean by the natural logarithm of the correction value to obtain the dynamic adjustment weight; then multiply the original fusion value by the dynamic adjustment weight to obtain the dynamic risk threshold.

[0102] By integrating radiation-beam correlation coefficient, radiation variability value, and threshold dynamic calibration factor to generate dynamic risk threshold, it can accurately reflect the degree of drastic change in internal and external radiation fields, realize dynamic calibration of risk threshold, effectively avoid the influence of external signal distortion, facilitate timely capture of radiation changes in the cavity caused by beam fluctuations, improve the timeliness and accuracy of radiation anomaly judgment, and achieve high-precision monitoring of radiation status during bombardment.

[0103] In one embodiment, the internal radiation risk value is compared with a dynamic risk threshold to generate a dose monitoring instruction, including:

[0104] The internal radiation risk value and the dynamic risk threshold are compared and analyzed in a coordinated manner to calculate the degree of deviation between the two and generate a radiation risk deviation value. Specifically, the internal radiation risk value is subtracted from the current dynamic risk threshold and then divided by the current dynamic risk threshold to obtain the instantaneous relative difference percentage.

[0105] Within a 50-millisecond analysis segment, the instantaneous rate of change of the internal radiation risk value and the dynamic risk threshold are calculated separately. The instantaneous relative slope is obtained by dividing the instantaneous rate of change of the internal radiation risk value by the instantaneous rate of change of the dynamic risk threshold.

[0106] Retrieve all instantaneous relative slopes calculated in the past 5 seconds and take their 75th percentile as the historical relative slope benchmark; multiply the absolute value of the current instantaneous relative difference percentage by the current instantaneous relative slope, and then divide by the historical relative slope benchmark to obtain the radiation risk deviation value. The radiation risk deviation value is used to reflect the degree of deviation between the internal radiation risk value and the dynamic risk threshold.

[0107] In one embodiment, comparing the internal radiation risk value with a dynamic risk threshold to generate a dose monitoring command further includes:

[0108] Based on the radiation risk deviation value, determine the current radiation dose status and generate a dose monitoring instruction, which specifically includes: acquiring all radiation risk deviation values ​​within the most recent 30-second time window and calculating the arithmetic mean and standard deviation of all radiation risk deviation values;

[0109] The upper boundary of dynamic risk is calculated as the arithmetic mean plus three times the standard deviation. If the current radiation risk deviation value is greater than the upper boundary of dynamic risk, a first dose monitoring instruction is generated, indicating that the radiation dose is abnormal; otherwise, a second dose monitoring instruction is generated, indicating that the radiation dose is normal.

[0110] By comparing the internal radiation risk value with the dynamic risk threshold, the radiation risk deviation value and the upper boundary of the dynamic risk are calculated, and finally the first dose monitoring command and the second dose monitoring command are generated. This can inversely map the degree of risk deviation, clarify the normal and abnormal states of radiation dose, effectively avoid the influence of external signal distortion, capture the radiation changes in the cavity caused by beam fluctuations, improve the accuracy of radiation anomaly judgment, and realize the monitoring of radiation status during the bombardment phase.

[0111] In one embodiment, a real-time radiation dose monitoring system for the entire At-211 production process is applied to the aforementioned monitoring method, including:

[0112] The data acquisition unit is used to synchronously and in real time acquire the gamma ray dose rate and neutron dose rate at at least three fixed spatial points at 0 degrees, 90 degrees and 180 degrees from the proton beam axis, outside the bombardment cavity of the proton beam bombarding the target material, and simultaneously acquire the proton beam intensity in real time during the proton beam transmission process.

[0113] The radiation dose analysis unit is used to analyze the gamma ray dose rate, neutron dose rate and proton beam intensity after preprocessing, and generate a cavity radiation state index that represents the overall radiation state of the cavity periphery under the current bombardment state.

[0114] The radiation risk analysis unit is used to jointly calculate the cavity radiation situation index and the pre-processed proton beam intensity to obtain the internal radiation risk value, which represents the potential abnormal risk of the radiation dose field inside the current bombardment cavity.

[0115] The radiation change analysis unit is used to analyze the degree of change in the current internal and external radiation fields based on the internal radiation risk value and the pre-processed proton beam intensity, and to generate dynamic risk thresholds.

[0116] The radiation dose monitoring unit is used to compare the internal radiation risk value with the dynamic risk threshold and generate dose monitoring instructions.

[0117] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for real-time monitoring of the total radiation dose in the production process of At-211, characterized in that, include: Step S1: At least three fixed spatial points at 0 degrees, 90 degrees and 180 degrees from the proton beam axis, outside the bombardment cavity of the proton beam bombarding the target, the gamma ray dose rate and neutron dose rate are synchronously and in real time acquired. At the same time, the proton beam intensity is acquired in real time during the transmission of the proton beam. Step S2 involves preprocessing and analyzing the gamma-ray dose rate, neutron dose rate, and proton beam intensity to generate a cavity radiation state index that represents the overall radiation state of the cavity periphery under the current bombardment state. This includes calculating the gamma-ray dose rate and neutron dose rate at three fixed spatial points and generating the gamma dose dispersion factor and neutron dose dispersion factor. For the gamma-ray dose rate and neutron dose rate at the 0-degree point, the synchronicity between the two and the proton beam intensity is analyzed, and the gamma-beam synchronization coefficient and neutron-beam synchronization coefficient are generated. Based on the gamma-ray dose rate and neutron dose rate at three fixed spatial points, the trend of radiation recombination growth is calculated, and a mixed radiation change vector representing the degree of drastic change in total radiation intensity is obtained. The gamma dose dispersion factor, neutron dose dispersion factor, gamma-beam synchronization coefficient, neutron-beam synchronization coefficient and mixed radiation change vector are fused to generate a cavity radiation situation index that represents the comprehensive radiation situation of the cavity periphery under the current bombardment state. Step S3: Perform a joint calculation on the cavity radiation situation index and the pre-processed proton beam intensity to obtain the internal radiation risk value representing the potential abnormal risk of the radiation dose field inside the current bombardment cavity. Step S4: Based on the internal radiation risk value and the pre-processed proton beam intensity, analyze the degree of drastic change in the current internal and external radiation fields, and generate a dynamic risk threshold. Step S5: Compare the internal radiation risk value with the dynamic risk threshold to generate a dose monitoring instruction.

2. The real-time whole-body radiation dose monitoring method for At-211 production process according to claim 1, characterized in that, By jointly calculating the cavity radiation situation index and the pre-processed proton beam intensity, an internal radiation risk value representing the potential anomaly risk of the current bombardment cavity's internal radiation dose field is obtained, including: Radiation-beam adaptation analysis was performed on the cavity radiation state index and the pre-processed proton beam intensity to generate radiation-beam adaptation factor; Based on the radiation-beam adaptation factor, the transient fluctuation law of internal radiation dose with proton beam intensity is analyzed, and transient radiation gradient value is generated. Based on the transient radiation gradient value and the proton beam intensity, the gradient enhancement ratio and beam enhancement ratio are calculated to obtain the radiation peak hazard value, which represents the strength of the peak risk.

3. The real-time whole-body radiation dose monitoring method for At-211 production process according to claim 2, wherein, The cavity radiation situation index and the pre-processed proton beam intensity are calculated together to obtain the internal radiation risk value, which represents the potential anomaly risk of the radiation dose field inside the current bombardment cavity. This also includes: By jointly calculating the transient radiation gradient value and the radiation peak potential value, an internal radiation risk value representing the potential abnormal risk of the radiation dose field inside the current bombardment cavity is obtained.

4. The method for real-time monitoring of radiation dose throughout the At-211 production process according to claim 3, characterized in that, Based on the internal radiation risk value and the pre-processed proton beam intensity, the drastic changes in the current internal and external radiation fields are analyzed to generate dynamic risk thresholds, including: Based on the internal radiation risk value and the pre-processed proton beam intensity, the synchronous characteristics of their changes are analyzed, and the radiation-beam correlation coefficient is generated. Based on the radiation-beam correlation coefficient, the degree of change of the current internal and external radiation fields with the proton beam intensity is analyzed, and a radiation variability value representing the degree of drastic change of the internal and external radiation fields is generated.

5. The method for real-time monitoring of radiation dose throughout the At-211 production process according to claim 4, characterized in that, Based on the internal radiation risk value and the pre-processed proton beam intensity, the drastic changes in the current internal and external radiation fields are analyzed to generate dynamic risk thresholds, which also include: Based on the radiation variability value, the threshold calibration amplitude is calculated to obtain the threshold dynamic calibration factor; By integrating radiation variability values ​​with threshold dynamic calibration factors, dynamic risk thresholds are generated.

6. The method for real-time monitoring of radiation dose throughout the At-211 production process according to claim 5, characterized in that, The internal radiation risk value is compared with the dynamic risk threshold to generate dose monitoring instructions, including: The internal radiation risk value and the dynamic risk threshold are compared and analyzed in a coordinated manner to calculate the degree of deviation between the two and generate a radiation risk deviation value.

7. The method for real-time monitoring of radiation dose throughout the At-211 production process according to claim 6, characterized in that, The system compares internal radiation risk values ​​with dynamic risk thresholds to generate dose monitoring instructions, and also includes: Based on the radiation risk deviation value, determine the current radiation dose status and generate dose monitoring instructions.

8. A real-time radiation dose monitoring system for the entire At-211 production process, applied in the monitoring method as described in any one of claims 2-7, characterized in that, include: The data acquisition unit is used to synchronously and in real time acquire the gamma ray dose rate and neutron dose rate at at least three fixed spatial points at 0 degrees, 90 degrees and 180 degrees from the proton beam axis, outside the bombardment cavity of the proton beam bombarding the target material, and simultaneously acquire the proton beam intensity in real time during the proton beam transmission process. The radiation dose analysis unit is used to analyze the gamma ray dose rate, neutron dose rate and proton beam intensity after preprocessing, and generate a cavity radiation state index that represents the overall radiation state of the cavity periphery under the current bombardment state. The radiation risk analysis unit is used to jointly calculate the cavity radiation situation index and the pre-processed proton beam intensity to obtain the internal radiation risk value, which represents the potential abnormal risk of the radiation dose field inside the current bombardment cavity. The radiation change analysis unit is used to analyze the degree of change in the current internal and external radiation fields based on the internal radiation risk value and the pre-processed proton beam intensity, and to generate dynamic risk thresholds. The radiation dose monitoring unit is used to compare the internal radiation risk value with the dynamic risk threshold and generate dose monitoring instructions.

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