A plastic scintillator coincidence detection method and system

Abstract

The application relates to the technical field of plastic scintillator, in particular to a plastic scintillator anticoincidence detection method and system, which comprises the following steps: obtaining a scintillator array electric pulse signal, identifying a continuous trigger state, analyzing a trigger sequence in combination with a detector spatial coordinate, comparing a central and peripheral trigger time interval, and analyzing the central and peripheral trigger time relationship. In the application, a continuous time sequence is constructed by reading a trigger time and a detector number, and abnormal trigger signals are screened out in combination with a pulse amplitude, so that the detection data maintains stable trigger characteristics; by analyzing adjacent trigger intervals, a particle trigger path is formed according to the analysis of the spatial coordinate of the array detector and the trigger sequence of adjacent positions; and the central trigger event chain is identified according to the relationship between the central trigger time and the peripheral trigger time interval, so that the anticoincidence event judgment is established on the basis of time correlation and spatial path cooperative analysis, random trigger interference is reduced, and the particle event recognition stability is improved.

Description

Technical Field

[0001] This invention relates to the field of plastic scintillator technology, and in particular to a method and system for detecting plastic scintillators in anti-coincidence mode. Background Technology

[0002] The field of plastic scintillator technology mainly involves a technical system for detecting and measuring nuclear radiation or high-energy particles using organic polymer materials as scintillation media. This field typically includes core components such as plastic matrix materials, luminescent dopants, optical signal generation structures, and photoelectric conversion devices. The basic principle is that when gamma rays, beta particles, or cosmic rays enter the plastic scintillator material, they generate excitation within the material and release visible light. This scintillating light is then received by a photomultiplier tube and converted into an electrical pulse signal to achieve the detection and recording of radiated particles. This technology is widely used in nuclear physics experiments, radiation monitoring, and particle detection equipment. One traditional method of plastic scintillator anti-coincidence detection involves setting up a central plastic scintillator detector and peripheral plastic scintillator detectors in the radiation detection device. The central and peripheral scintillators are connected to photomultiplier tubes to form photoelectric conversion channels. When a particle is incident, the scintillator generates an optical signal and converts it into an electrical pulse. A time discrimination circuit synchronizes the pulses from the central and peripheral detectors, recording only the events where the central detector generates a pulse but the peripheral detector does not, thus completing the anti-coincidence detection.

[0003] Traditional plastic scintillator anti-coincidence detection structures rely on the instantaneous correspondence between the central and peripheral detection signals within a time window to complete the counting and judgment. The judgment is based on a single trigger signal, lacking a holistic analysis of the continuous relationship and spatial variation characteristics between multiple trigger signals. When high-energy particles generate continuous triggering or scattering phenomena in the array structure, the multiple trigger signals generated by each detector are often processed independently, making it difficult to form a complete event correlation. This makes it difficult to accurately reflect the particle motion process. At the same time, random noise signals in complex radiation environments may be close to the effective trigger within the time window, thereby increasing the chance of accidental judgment. For example, when multiple trigger signals appear consecutively in a short period of time, there is a lack of correlation analysis, which can easily cause fluctuations in the counting results, thus affecting the stability of the detection data and the reliability of the event judgment. Summary of the Invention

[0004] To address the technical problems existing in the prior art, embodiments of the present invention provide a method for detecting anti-coincidence of a plastic scintillator;

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for detecting anti-coincidence in a plastic scintillator, comprising the following steps:

[0006] S1: Obtain the plastic scintillator detector array and connect it to the photomultiplier tube to output electrical pulse signals. Read the trigger time, detector number and pulse amplitude value, remove electrical pulse signals below the trigger voltage, and obtain the scintillator trigger time sequence.

[0007] S2: Based on the scintillator trigger time sequence, read the trigger time and detector number, analyze the adjacent trigger time intervals and identify the continuous trigger sequence by referring to the particle propagation time range, and obtain the particle trigger event chain;

[0008] S3: Based on the particle triggering event chain, obtain the event chain number and detector number, call the plastic scintillator array detector spatial coordinate table to read the spatial position, analyze the changes in the direction of adjacent spatial positions according to the spatial position corresponding to the triggering time sequence, and obtain the particle spatial triggering path;

[0009] S4: Based on the particle space triggering path, read the event chain number and triggering time, obtain the triggering time of the plastic scintillator detector array, compare the central triggering time with the peripheral triggering time interval, and obtain the central triggering event chain set;

[0010] S5: Based on the central trigger event chain set, read the event chain number and trigger time, analyze the relationship between the central trigger time and the peripheral trigger time, and obtain the anti-coincidence detection event.

[0011] As a further aspect of the present invention, the scintillator triggering time sequence includes a detector trigger identifier, a triggering time marker, a pulse amplitude record, a time sequence index, and a detector number mapping; the particle triggering event chain includes an event chain number, an event chain time interval, a continuous triggering correlation, a particle triggering duration segment, and an event chain detector combination; the particle space triggering path includes a path number, a path space coordinate sequence, a path direction vector, a path continuity identifier, and a path detector distribution; the central triggering event chain set includes a central detector trigger identifier, a peripheral detector triggering correlation, a triggering time comparison segment, a central triggering event number, and a peripheral correlation judgment relationship; and the anti-coincidence detection event includes an anti-coincidence event number, a central triggering record, a peripheral triggering exclusion identifier, an event path correspondence, and an anti-coincidence event type identifier.

[0012] As a further aspect of the present invention, the electrical pulse signal below the trigger voltage refers to a signal whose amplitude of the electrical pulse output by the photomultiplier tube is lower than the set trigger threshold and is determined to be invalid and rejected.

[0013] The reference particle propagation time range refers to a preset time interval set according to the propagation speed of particles in the detector array.

[0014] As a further aspect of the present invention, the continuous trigger sequence refers to a time-continuous trigger recording sequence composed of trigger signals generated sequentially by multiple detectors within the particle propagation time range;

[0015] The peripheral trigger time interval refers to the time range during which the peripheral plastic scintillator detector generates a trigger signal.

[0016] As a further aspect of the present invention, the specific steps of S1 are as follows:

[0017] S101: Acquire the electrical pulse signal output by the photomultiplier tube connected to the plastic scintillator detector array, collect the electrical pulse trigger time, detector number and pulse amplitude value, compare the pulse amplitude value with the photomultiplier tube trigger voltage, and discard electrical pulse signals lower than the trigger voltage to obtain electrical pulse trigger sequence data;

[0018] S102: Based on the electrical pulse trigger sequence data, read the trigger time and detector number, analyze the adjacent trigger time intervals and make a judgment with reference to the particle propagation time range, classify the trigger times with time intervals within the particle propagation time range into the same particle trigger activity sequence, and simultaneously map the corresponding detector number relationship to obtain particle trigger activity sequence data.

[0019] S103: Based on the particle-triggered activity sequence data, extract the trigger time and detector number, perform time sequence division on the trigger time and synchronously associate the correspondence between the trigger time and detector number to obtain the scintillator trigger time sequence.

[0020] As a further aspect of the present invention, the specific steps of S2 are as follows:

[0021] S201: Based on the scintillator trigger time sequence, retrieve the trigger time and detector number, extract the comparison time interval between adjacent trigger times, compare the time interval value with the particle propagation time range, classify the trigger times within the particle propagation time range into the same trigger activity sequence, and associate the corresponding detector number to obtain the particle trigger time association sequence.

[0022] S202: Based on the particle triggering time association sequence, extract the triggering time and detector number, determine the continuity of the continuous triggering time sequence, aggregate the continuous triggering times, and associate the triggering activity group with the mapping relationship between the triggering time and the detector number to obtain the triggering activity association group;

[0023] S203: Based on the trigger activity association group, extract the trigger time and detector number, divide the trigger time sequence within the same trigger activity group, while maintaining the correspondence between the trigger time and detector number, and convert the trigger activity group into an independent event chain structure to obtain the particle trigger event chain.

[0024] As a further aspect of the present invention, the specific steps of S3 are as follows:

[0025] S301: Based on the particle-triggered event chain, retrieve the event chain number and detector number, call the plastic scintillator array detector spatial coordinate table, extract the corresponding spatial position coordinates, match the detector number sequence coordinates within the same event chain, and obtain the detector spatial position sequence.

[0026] S302: Based on the spatial position sequence of the detector, extract the spatial position coordinates and the trigger time sequence, determine the spatial direction change of adjacent spatial position coordinates, and at the same time retrieve the corresponding spatial position change direction according to the trigger time sequence to obtain the spatial direction change sequence;

[0027] S303: Based on the spatial direction change sequence, extract the direction change result and event chain number, identify the spatial position coordinate path with continuous and consistent direction and associate it with the trigger time sequence and detector number sequence, and match the identified path structure with the event chain number to obtain the particle space trigger path.

[0028] As a further aspect of the present invention, the specific steps of S4 are as follows:

[0029] S401: Based on the particle space triggering path, obtain the triggering time sequence of the anti-coincidence plastic scintillator detector array and the triggering time sequence of the center detector, retrieve the triggering time sequence corresponding to the event chain number, and align the triggering time sequence of the anti-coincidence plastic scintillator detector array according to the event chain number to obtain the peripheral triggering time sequence;

[0030] S402: Based on the peripheral trigger time sequence, extract the trigger time data, and at the same time retrieve the central detector trigger time sequence, determine the time interval relationship between the peripheral trigger time sequence and the central detector trigger time sequence, and obtain the event chain number of the time data with the corresponding trigger relationship in the time interval to obtain the peripheral trigger association sequence;

[0031] S403: Based on the peripheral trigger association sequence, extract the event chain number and the central detector trigger time sequence, identify the corresponding trigger time of the peripheral trigger association sequence and the trigger time of the central detector, and obtain the central trigger event chain set.

[0032] As a further aspect of the present invention, the specific steps of S5 are as follows:

[0033] S501: Based on the central trigger event chain set, retrieve the event chain number and trigger time sequence, and extract the detector number and path number. Aggregate and identify the trigger time sequence corresponding to the event chain number to trigger the activity, and match the central detector trigger time sequence with the detector number sequence to obtain the central trigger activity sequence.

[0034] S502: Based on the central triggering activity sequence, extract the event chain number and triggering time sequence, retrieve the triggering time sequence of the peripheral detector and compare the triggering activities, determine the correspondence between the triggering time of the central triggering activity sequence and the triggering time of the peripheral detector, and obtain the independent central triggering sequence;

[0035] S503: Based on the independent center trigger sequence, extract the event chain number, trigger time sequence, detector number sequence and path number sequence, identify the corresponding event chain number and path number, and at the same time associate and determine the trigger time sequence and detector number sequence to obtain the anti-coincidence detection event.

[0036] A plastic scintillator anti-coincidence detection system includes:

[0037] The pulse acquisition module acquires the electrical pulse signals output by the plastic scintillator detector array and the photomultiplier tube, reads the electrical pulse trigger time, detector number and pulse amplitude value, compares the pulse amplitude value with the photomultiplier tube trigger voltage and removes electrical pulse signals lower than the trigger voltage to obtain the scintillator trigger time sequence;

[0038] The event chain identification module reads the trigger time and detector number based on the scintillator trigger time sequence, judges the time interval between adjacent trigger times, identifies continuous trigger sequences by referring to the particle propagation time range, divides the continuous trigger sequences according to the trigger time, and obtains the particle trigger event chain.

[0039] Based on the particle triggering event chain, the path recognition module reads the event chain number and the detector number, calls the spatial coordinate table of the plastic scintillator detector array to obtain the spatial position of the detector, analyzes the changes in the direction of adjacent spatial positions, and obtains the particle spatial triggering path.

[0040] Based on the particle space triggering path, the peripheral determination module reads the event chain number and triggering time, obtains the triggering time generated by the anti-coincidence plastic scintillator detector array, compares the triggering time of the center detector with the triggering time interval of the peripheral detectors, and obtains the central triggering event chain set.

[0041] The anti-coincidence determination module reads the event chain number and trigger time based on the central trigger event chain set, analyzes the triggering relationship between the trigger time of the central detector and the trigger time of the peripheral detector, and obtains the anti-coincidence detection event.

[0042] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0043] In this invention, a continuous time series is constructed by reading the trigger time and detector number, and abnormal trigger signals are filtered out by combining pulse amplitude, so that the detection data maintains stable trigger characteristics. By analyzing the adjacent trigger intervals, and then analyzing the changes in the direction of adjacent positions based on the spatial coordinates of the array detectors and the trigger sequence, a particle trigger path is formed. The central trigger event chain is identified by the relationship between the central trigger time and the peripheral trigger time intervals, so that the determination of anti-coincidence events is based on the collaborative analysis of time correlation and spatial path, reducing random trigger interference and improving the stability of particle event recognition. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the steps of the present invention;

[0046] Figure 2 This is a detailed schematic diagram of S1 of the present invention;

[0047] Figure 3 This is a detailed schematic diagram of S2 of the present invention;

[0048] Figure 4 This is a detailed schematic diagram of S3 of the present invention;

[0049] Figure 5 This is a detailed schematic diagram of S4 of the present invention;

[0050] Figure 6 This is a detailed schematic diagram of S5 of the present invention;

[0051] Figure 7 This is a system module diagram of the present invention. Detailed Implementation

[0052] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0053] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0054] Please see Figure 1 This invention provides a method for detecting anti-coincidence in a plastic scintillator, comprising the following steps:

[0055] S1: Obtain the plastic scintillator detector array, connect the photomultiplier tube to output the electrical pulse signal, read the corresponding trigger time, detector number and pulse amplitude value of the electrical pulse, compare the pulse amplitude value with the photomultiplier tube trigger voltage, remove electrical pulse signals below the trigger voltage range, divide the electrical pulse signal into time series according to the trigger time, associate the correspondence between the trigger time and the detector number to obtain the scintillator trigger time series;

[0056] S2: Based on the scintillator trigger time sequence, read the trigger time and detector number, analyze the adjacent trigger time interval and identify the same particle triggering activity by referring to the particle propagation time range, divide the consecutive trigger times into the same event chain, and synchronously retain the corresponding detector number information to obtain the particle triggering event chain;

[0057] S3: Based on the particle-triggered event chain, obtain the event chain number and detector number, call the plastic scintillator array detector spatial coordinate table to obtain the detector spatial position, analyze the spatial position and spatial direction corresponding to the triggering time sequence inside the event chain, identify the continuously appearing spatial paths and assign path numbers to obtain the particle spatial triggering path.

[0058] S4: Based on the particle space triggering path, read the event chain number and triggering time, obtain the triggering time generated by the anti-coincidence plastic scintillator detector array, compare the triggering relationship between the time intervals of the triggering times, identify the correlation between the triggering time of the peripheral detector and the triggering time of the central detector, and obtain the central triggering event chain set.

[0059] S5: Based on the central trigger event chain set, read the event chain number, analyze the relationship between the event chain number, trigger time, detector number and path number, identify the event chain where the central detector triggering activity is not accompanied by the peripheral detector triggering activity, and obtain the anti-coincidence detection event.

[0060] The scintillator trigger time series includes detector trigger identifier, trigger time marker, pulse amplitude record, time series index, and detector number mapping. The particle trigger event chain includes event chain number, event chain time interval, continuous trigger correlation, particle trigger duration segment, and event chain detector combination. The particle space trigger path includes path number, path space coordinate sequence, path direction vector, path continuity identifier, and path detector distribution. The central trigger event chain set includes central detector trigger identifier, peripheral detector trigger correlation, trigger time comparison segment, central trigger event number, and peripheral correlation judgment relationship. The anti-coincidence detection event includes anti-coincidence event number, central trigger record, peripheral trigger exclusion identifier, event path correspondence, and anti-coincidence event type identifier.

[0061] Please see Figure 2 The specific steps of S1 are as follows:

[0062] S101: Acquire the electrical pulse signal output by the photomultiplier tube connected to the plastic scintillator detector array, collect the electrical pulse trigger time, detector number and pulse amplitude value, compare the pulse amplitude value with the photomultiplier tube trigger voltage, and discard electrical pulse signals lower than the trigger voltage to obtain electrical pulse trigger sequence data;

[0063] First, the electrical pulse signals output by 64 plastic scintillator detector units distributed in the test space are acquired. Each detector unit converts captured photons into weak voltage pulses through a photomultiplier tube coupled to its end. The data acquisition hardware captures all 64 output channels in real time with a sampling period of 10 nanoseconds. A high-speed analog-to-digital converter circuit records the trigger time of each electrical pulse, the corresponding detector number, and the pulse amplitude representing the amount of charge deposition. To filter out randomly generated thermal noise and background radiation signals from the complex background environment, a trigger voltage reference value is preset. The process of setting this reference value is based on statistical analysis of the single-photoelectron peak distribution of the photomultiplier tubes in a passive environment. The noise voltage waveform is acquired using an oscilloscope, and the standard deviation of its voltage distribution is calculated. The logic for setting the trigger voltage reference value is: add four times the voltage standard deviation to the mean of the noise voltage fluctuation. For example, if the measured mean open-circuit voltage of a batch of photomultiplier tubes is 1.2 mV and the voltage standard deviation is 2.8 mV, then the calculated trigger voltage reference value is 12.4 mV. During execution, the amplitude value of each acquired electrical pulse signal is compared with 12.4 millivolts one by one. If the amplitude value of the pulse from detector number 5 is 45.0 millivolts, which is greater than 12.4 millivolts, it is retained; if the amplitude value of the pulse from detector number 12 is 8.5 millivolts, it is determined to be electronic noise and is discarded. Subsequently, all valid signals that pass the screening are sorted in ascending order according to their trigger time, and the trigger time, detector number, and pulse amplitude value are encapsulated into structured data to obtain electrical pulse trigger sequence data.

[0064] S102: Based on the electrical pulse trigger sequence data, read the trigger time and detector number, analyze the adjacent trigger time intervals and make a judgment with reference to the particle propagation time range, classify the trigger times with time intervals within the particle propagation time range into the same particle trigger activity sequence, and at the same time map the corresponding detector number relationship to obtain the particle trigger activity sequence data;

[0065] First, the trigger time and detector number of each pulse contained within the sequence are read. To identify whether the same particle penetrates the detector array, a time difference calculation is performed on two temporally adjacent electrical pulse signals in the sequence to calculate the time interval between adjacent triggers. At this point, a preset particle propagation time range is invoked. This time range limits the reasonable time span between consecutive trigger signals of the same particle in the detector array. The lower limit is estimated based on the shortest geometric distance the particle travels through adjacent scintillator elements and the expected propagation velocity of the particle in the detection medium. The upper limit is estimated based on the time required for the particle to travel across the maximum geometric span of the detector array at a lower expected velocity, thus forming the time interval used to determine consecutive trigger relationships. Considering the geometry of the plastic scintillator detector array and the typical velocity range of particles in this type of detection experiment, the particle propagation time range is set between 0.5 nanoseconds and 40.0 nanoseconds. In actual execution, the time point of the first valid trigger record (12560.5 nanoseconds) and the time point of the second record (12565.8 nanoseconds) are extracted. The calculated time interval is 5.3 nanoseconds. Since 5.3 nanoseconds falls within the range of 0.5 nanoseconds to 40.0 nanoseconds, these two triggers are determined to be consecutive triggering activities of the same particle. If a subsequent trigger interval of 55.0 nanoseconds is extracted, exceeding the aforementioned time range, it is determined to be two independent particle incidents. By performing a full-element traversal of the entire sequence, trigger time points with time intervals within the particle propagation time range are grouped into the same particle triggering activity sequence, and the logical relationship of the corresponding detector number is synchronously mapped to obtain the particle triggering activity sequence data.

[0066] S103: Based on particle-triggered activity sequence data, extract the trigger time and detector number, perform time sequence division on the trigger time and synchronously associate the correspondence between the trigger time and detector number to obtain the scintillator trigger time sequence;

[0067] First, the trigger time and detector number are extracted to perform fine-grained time series division of the entire dynamic triggering process. This division operation adopts an equally spaced segmentation mechanism, cutting the continuous activity process into several tiny time units, with a step size of 5 nanoseconds. This step size value is obtained by balancing the average rise time of the detector output pulse with the timing resolution of the electronic system, aiming to ensure that each time unit has a clear and unique position. During the division process, each segmented time interval is synchronously associated with the detector number that generates the response within it, establishing a dynamic mapping between the time axis and spatial position. For example, for a particle penetration process with a total duration of 15 nanoseconds, it is divided into three time segments: 0 to 5 nanoseconds, 5 to 10 nanoseconds, and 10 to 15 nanoseconds. If detector number 5 responds at 2.1 nanoseconds, detector number 28 responds at 7.4 nanoseconds, and detector number 42 responds at 12.6 nanoseconds, then a logical correspondence is established between the first time segment and detector number 5, the second time segment and detector number 28, and the third time segment and detector number 42, resulting in the scintillator triggering time sequence.

[0068] Please see Figure 3 The specific steps of S2 are as follows:

[0069] S201: Based on the scintillator trigger time sequence, retrieve the trigger time and detector number, extract the comparison time interval between adjacent trigger times, compare the time interval value with the particle propagation time range, classify the trigger times within the particle propagation time range into the same trigger activity sequence, and associate the corresponding detector number to obtain the particle trigger time association sequence.

[0070] First, the recorded trigger times and detector numbers are retrieved. The trigger times of any two adjacent nodes in the sequence are extracted and subtracted to obtain the comparison time interval. To further eliminate sub-nanosecond interference caused by multiple scattering and the long delay response of extremely low-energy particles, a converged particle propagation time range is introduced, set to 1.5 nanoseconds to 25.0 nanoseconds. During execution, the time values ​​of adjacent nodes are extracted. For example, if the trigger time of the previous node is 100.2 nanoseconds and the trigger time of the next node is 110.5 nanoseconds, the difference between the two yields a comparison time interval of 10.3 nanoseconds. It is determined that 10.3 nanoseconds falls within the preset range of 1.5 nanoseconds to 25.0 nanoseconds, confirming the continuity of these two nodes in terms of physical evolution logic. Therefore, trigger times within this range are grouped into the same trigger activity sequence. Subsequently, the selected trigger times are structurally associated with the corresponding detector numbers to ensure that each timestamp accurately points to a physical detection unit, resulting in a particle trigger time association sequence.

[0071] S202: Based on the particle trigger time correlation sequence, extract the trigger time and detector number, determine the continuity of the continuous trigger time sequence, aggregate the continuous trigger times, and associate the trigger activity group with the mapping relationship between the trigger time and the detector number to obtain the trigger activity correlation group;

[0072] First, the trigger time and detector number are extracted, and the continuity determination logic for the continuous trigger time sequence is executed. This determination identifies the integrity of the particle trajectory by detecting whether the time jump at each step in the sequence meets the stationarity requirement. A continuity criterion value is set to 35.0 nanoseconds, based on the average interaction interval of particles in the detection medium and the maximum dead time of the detector readout system. During execution, the span between adjacent trigger points in the sequence is calculated one by one. If the time span between two points is found to be 12.0 nanoseconds, which is less than the criterion value of 35.0 nanoseconds, the physical continuity is considered good; if the span exceeds 35.0 nanoseconds, the physical process is determined to be interrupted. Through this logic, the continuous trigger times are aggregated, and the trigger activities are grouped according to the complete penetration stage of the particle. A mapping matrix between the trigger time and detector number is associated with each group of trigger activities to obtain the trigger activity association group.

[0073] S203: Based on the trigger activity association grouping, extract the trigger time and detector number, divide the trigger time sequence within the same trigger activity group, and maintain the correspondence between the trigger time and detector number. Convert the trigger activity grouping into an independent event chain structure to obtain the particle trigger event chain.

[0074] First, the trigger time and detector number contained within each group are extracted, and a structured transformation is performed on the trigger time sequences within the same triggering activity group. This process involves topologically sorting the trigger times in ascending order and maintaining a strong mapping between each time node and the detector number. The originally flat grouped data is transformed into a linked data structure with independent indices and node pointers. Each linked list node stores the current detector number, the precise trigger time value, and a memory address pointing to the next response node in the sequence. For example, the group data numbered 101 is transformed into an event chain containing three nodes. The first node stores the time 12560.5 nanoseconds and the number 5, and its pointer points to the second node storing the time 12565.8 nanoseconds and the number 28. This transformation ensures that the causality of particle motion is solidified in the data structure, thereby converting the triggering activity groups into an independent event chain structure, resulting in a particle trigger event chain.

[0075] Please see Figure 4 The specific steps of S3 are as follows:

[0076] S301: Based on the particle-triggered event chain, retrieve the event chain number and detector number, call the plastic scintillator array detector spatial coordinate table, extract the corresponding spatial position coordinates, match the detector number sequence coordinates within the same event chain, and obtain the detector spatial position sequence.

[0077] First, the event chain number and detector number are retrieved, and the spatial coordinate table of the plastic scintillator array detectors stored in non-volatile memory is accessed. This table precisely records the three-dimensional coordinates (X, Y, Z) of the geometric centers of all 64 detector units in the array in the laboratory coordinate system, with coordinate values ​​in millimeters. Based on the chronological sequence of detector numbers in the event chain, the corresponding three-dimensional spatial coordinates are matched one by one. For example, when event chain 101 includes detector numbers 5, 28, and 42, the coordinate table is consulted to find that the center coordinates of detector number 5 are (100.5, 100.5, 50.0), the center coordinates of detector number 28 are (200.0, 200.0, 150.0), and the center coordinates of detector number 42 are (300.5, 300.5, 250.0). These coordinates are extracted sequentially and arranged according to the trigger time to construct a set of geometric points reflecting the particle trajectory, thus obtaining the detector spatial position sequence.

[0078] S302: Based on the detector's spatial position sequence, extract the spatial position coordinates and trigger time sequence, determine the spatial direction change of adjacent spatial position coordinates, and simultaneously retrieve the corresponding spatial position change direction according to the trigger time sequence to obtain the spatial direction change sequence;

[0079] First, based on the detector's spatial position sequence, spatial position coordinates and corresponding trigger time sequences are extracted. To quantify the directional evolution and possible scattering behavior of particles during penetration, the displacement vector between adjacent spatial position coordinate points is calculated. By calculating the differences between two adjacent coordinate points along the horizontal, vertical, and longitudinal axes, the direction vector of that path segment is determined. Subsequently, the change direction of the corresponding spatial position is retrieved according to the trigger time sequence, and the smoothness of the direction is evaluated by calculating the cosine value of the angle between two adjacent direction vectors. For example, if the calculated cosine value of the direction angle between the first and second path segments is 0.998, it indicates that the direction has hardly changed; if the cosine value decreases significantly, the specific spatial direction offset is recorded, resulting in a spatial direction change sequence.

[0080] S303: Based on the spatial direction change sequence, extract the direction change result and event chain number, identify the spatial position coordinate path with continuous and consistent direction and associate it with the trigger time sequence and detector number sequence, and match the identified path structure with the event chain number to obtain the particle space trigger path;

[0081] First, the direction change results and event chain numbers are extracted, and a path recognition algorithm is executed. In the sequence, spatial coordinate paths with continuous and consistent directions are identified. The recognition criterion is set as follows: the cosine of the angle between adjacent direction vectors must be continuously greater than 0.966 (i.e., the angle is less than 15 degrees). The coordinate subsequences that meet this consistency condition are extracted and synchronously associated with the corresponding trigger time sequence and detector number sequence. For example, if all angles in the direction change sequence of an event chain are within 3 degrees when penetrating the entire array, the complete geometric structure is identified as a valid path, assigned a path number, and bound to the original event chain number. Non-linear noise points caused by random overlap are removed, resulting in the particle space trigger path.

[0082] Please see Figure 5 The specific steps of S4 are as follows:

[0083] S401: Based on the particle space triggering path, obtain the triggering time sequence of the anti-coincidence plastic scintillator detector array and the triggering time sequence of the center detector, retrieve the triggering time sequence corresponding to the event chain number, align the triggering time sequence of the anti-coincidence plastic scintillator detector array according to the event chain number, and obtain the peripheral triggering time sequence.

[0084] First, based on the particle space triggering path, the triggering time series of the anti-coincidence plastic scintillator detector array and the triggering time series of the central detector are obtained. The core triggering time series corresponding to the event chain number is retrieved as the reference time for that event. To determine whether the external shielding layer has captured the entry signal of the same particle, all triggering records of the anti-coincidence array are aligned along the time axis according to the event chain number. A synchronization time window with a width of 80 nanoseconds is set during the alignment process. By calculating the difference between the triggering time of the peripheral anti-coincidence detector and the triggering time of the first node in the event chain, if this difference falls within a range of ±40 nanoseconds, the peripheral signal is considered to be synchronized with the internal event in time. Through this time alignment operation, all peripheral response data within the synchronization window are extracted to obtain the peripheral triggering time series.

[0085] S402: Based on the peripheral trigger time series, extract the trigger time data, and at the same time retrieve the central detector trigger time series. Determine the time interval relationship between the peripheral trigger time series and the central detector trigger time series. If there is a time data event chain number with a corresponding trigger relationship in the time interval, obtain the peripheral trigger association sequence.

[0086] First, based on the peripheral trigger time series, trigger time data is extracted, and the trigger time series generated by the central detector is retrieved. The time interval relationship between the peripheral trigger time series and the central detector trigger time series is determined to identify the coincidence response logic of the internal and external detectors. A correlation overlap threshold of 50 nanoseconds is set, and the absolute value of the time difference between the peripheral trigger time and any trigger time point of the central detector is calculated. If this absolute value is less than 50 nanoseconds, a correlation trigger relationship is determined for that time interval, indicating that the event may be a background particle penetrating from the outside, and the corresponding event chain number is marked. For example, if the peripheral recording time is 12500 nanoseconds and the central recording time is 12520 nanoseconds, the difference of 20 nanoseconds is less than 50 nanoseconds, indicating a correlation, and the peripheral trigger correlation sequence is obtained.

[0087] S403: Based on the peripheral trigger association sequence, extract the event chain number and the central detector trigger time sequence, identify the corresponding trigger time of the peripheral trigger association sequence and the trigger time of the central detector, and obtain the central trigger event chain set;

[0088] First, based on the peripheral triggering correlation sequence, the event chain numbers and the triggering time sequence of the central detector are extracted. To accurately isolate responses caused by external particles from the candidate events, the triggering times corresponding to the peripheral triggering correlation sequences and the triggering times of the central detector are correlated. By performing a logical intersection operation, specific event chains that produce synchronous responses at both the inner and outer layers are selected. For example, when database correlation reveals that event number 101 meets the requirements for both peripheral and central responses, this event chain and its related spatiotemporal parameters are included in the central event set. Through this step, events with synchronous characteristics are summarized to obtain the central triggering event chain set.

[0089] Please see Figure 6 The specific steps of S5 are as follows:

[0090] S501: Based on the central trigger event chain set, retrieve the event chain number and trigger time sequence, extract the detector number and path number, aggregate and identify the trigger activities corresponding to the event chain number and trigger time sequence, and match the central detector trigger time sequence with the detector number sequence to obtain the central trigger activity sequence;

[0091] First, based on the central triggering event chain set, the event chain number and triggering time sequence are retrieved, and the detector number and path number are extracted simultaneously. Aggregation and identification logic is executed to integrate all distributed triggering activities belonging to the same physical penetration event. A one-to-one physical correspondence is established between the triggering time sequence of the central detector and the specific detector number sequence, creating a strong correlation between the number of each detector unit and its response's nanosecond-level timestamp and spatial coordinates. For example, the responses of detectors numbered 30, 31, and 32 within a specific time window in the central region are aggregated into a complete detection trajectory, ensuring that the particle energy deposition path is logically complete and continuous, thus obtaining the central triggering activity sequence.

[0092] S502: Based on the central triggering activity sequence, extract the event chain number and triggering time sequence, retrieve the triggering time sequence of the peripheral detectors and compare the triggering activities, determine the correspondence between the triggering time of the central triggering activity sequence and the triggering time of the peripheral detectors, and obtain the independent central triggering sequence;

[0093] First, based on the central triggering activity sequence, the event chain number and trigger time sequence are extracted. The original trigger time sequences of the peripheral detectors within the corresponding time period are retrieved and a consistency comparison is performed. To confirm whether the central triggering activity occurred independently, it is determined whether there is a time overlap between the triggering time of the central triggering activity sequence and the triggering time of the peripheral detectors. An independence discrimination interval of 300 nanoseconds before and after the start time of the central triggering activity is set. If there are no signal records from the peripheral detectors within 300 nanoseconds before and after the start time of the central triggering activity, the event is determined to be an independent trigger. For example, if the central activity starts at 8000.0 nanoseconds, and the most recent peripheral trigger is found to be at 7500.0 nanoseconds, the interval of 500 nanoseconds is greater than 300 nanoseconds, thus it is determined to be an independent event, and an independent central triggering sequence is obtained.

[0094] S503: Based on the independent center trigger sequence, extract the event chain number, trigger time sequence, detector number sequence and path number sequence, identify the corresponding event chain number and path number, and at the same time associate and determine the trigger time sequence and detector number sequence to obtain the anti-coincidence detection event;

[0095] First, the event chain number, trigger time sequence, detector number sequence, and path number sequence are extracted. A final comprehensive judgment process is executed, identifying the logical matching relationship between the event chain number and the path number to ensure that the reconstructed spatial trajectory conforms to the linear extrapolation law. Simultaneously, the temporal causal chain of the trigger time sequence and the detector number sequence is correlated to verify whether the particle's velocity between detectors is within the physically expected range. After confirming that all data items conform to the physical characteristics of independent center triggering, all parameters are finally encapsulated, eliminating all background noise associated with the surrounding anti-coincidence system, resulting in the anti-coincidence detection event.

[0096] Please see Figure 7 A plastic scintillator anti-coincidence detection system, comprising:

[0097] The pulse acquisition module acquires the electrical pulse signals output by the plastic scintillator detector array and the photomultiplier tube, reads the electrical pulse trigger time, detector number and pulse amplitude value, compares the pulse amplitude value with the photomultiplier tube trigger voltage and removes electrical pulse signals lower than the trigger voltage to obtain the scintillator trigger time sequence;

[0098] The event chain identification module is based on the scintillator trigger time sequence. It reads the trigger time and detector number, judges the time interval between adjacent trigger times, and identifies continuous trigger sequences by referring to the particle propagation time range. It divides the continuous trigger sequences according to the trigger time to obtain the particle trigger event chain.

[0099] The path recognition module is based on the particle triggering event chain. It reads the event chain number and the detector number, calls the spatial coordinate table of the plastic scintillator detector array to obtain the spatial position of the detector, analyzes the changes in the direction of adjacent spatial positions, and obtains the particle spatial triggering path.

[0100] The peripheral determination module reads the event chain number and trigger time based on the particle space trigger path, obtains the trigger time generated by the anti-coincidence plastic scintillator detector array, compares the trigger time of the center detector with the trigger time interval of the peripheral detector, and obtains the set of center trigger event chains.

[0101] The anti-coincidence determination module reads the event chain number and trigger time based on the central trigger event chain set, analyzes the triggering relationship between the trigger time of the central detector and the trigger time of the peripheral detector, and obtains the anti-coincidence detection event.

[0102] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for detecting anti-coincidence in a plastic scintillator, characterized in that, Includes the following steps: S1: Obtain the plastic scintillator detector array and connect it to the photomultiplier tube to output electrical pulse signals. Read the trigger time, detector number and pulse amplitude value, remove electrical pulse signals below the trigger voltage, and obtain the scintillator trigger time sequence. S2: Based on the scintillator trigger time sequence, read the trigger time and detector number, analyze the adjacent trigger time intervals and identify continuous trigger sequences by referring to the particle propagation time range to obtain the particle trigger event chain; S3: Based on the particle triggering event chain, obtain the event chain number and detector number, call the plastic scintillator array detector spatial coordinate table to read the spatial position, analyze the changes in the direction of adjacent spatial positions according to the spatial position corresponding to the triggering time sequence, and obtain the particle spatial triggering path; S4: Based on the particle space triggering path, read the event chain number and triggering time, obtain the triggering time of the plastic scintillator detector array, compare the central triggering time with the peripheral triggering time interval, and obtain the central triggering event chain set; S5: Based on the central triggering event chain set, read the event chain number and trigger time, analyze the relationship between the central trigger time and the peripheral trigger time, and obtain the anti-coincidence detection event; The specific steps for S3 are as follows: S301: Based on the particle-triggered event chain, retrieve the event chain number and detector number, call the plastic scintillator array detector spatial coordinate table, extract the corresponding spatial position coordinates, match the detector number sequence coordinates within the same event chain, and obtain the detector spatial position sequence. S302: Based on the spatial position sequence of the detector, extract the spatial position coordinates and the trigger time sequence, determine the spatial direction change of adjacent spatial position coordinates, and at the same time retrieve the corresponding spatial position change direction according to the trigger time sequence to obtain the spatial direction change sequence; S303: Based on the spatial direction change sequence, extract the direction change result and event chain number, identify the spatial position coordinate path with continuous and consistent direction and associate it with the trigger time sequence and detector number sequence, and match the identified path structure with the event chain number to obtain the particle space trigger path; The specific steps of S4 are as follows: S401: Based on the particle space triggering path, obtain the triggering time sequence of the anti-coincidence plastic scintillator detector array and the triggering time sequence of the center detector, retrieve the triggering time sequence corresponding to the event chain number, and align the triggering time sequence of the anti-coincidence plastic scintillator detector array according to the event chain number to obtain the peripheral triggering time sequence; S402: Based on the peripheral trigger time sequence, extract the trigger time data, and at the same time retrieve the central detector trigger time sequence, determine the time interval relationship between the peripheral trigger time sequence and the central detector trigger time sequence, and obtain the event chain number of the time data associated with the trigger relationship in the corresponding time interval to obtain the peripheral trigger associated sequence; S403: Based on the peripheral trigger association sequence, extract the event chain number and the central detector trigger time sequence, and identify the corresponding trigger time of the peripheral trigger association sequence and the trigger time of the central detector to obtain the central trigger event chain set; The specific steps of S5 are as follows: S501: Based on the central trigger event chain set, retrieve the event chain number and trigger time sequence, and extract the detector number and path number. Aggregate and identify the trigger time sequence corresponding to the event chain number to trigger the activity, and match the central detector trigger time sequence with the detector number sequence to obtain the central trigger activity sequence. S502: Based on the central triggering activity sequence, extract the event chain number and triggering time sequence, retrieve the triggering time sequence of the peripheral detector and compare the triggering activities, determine the correspondence between the triggering time of the central triggering activity sequence and the triggering time of the peripheral detector, and obtain the independent central triggering sequence; S503: Based on the independent center trigger sequence, extract the event chain number, trigger time sequence, detector number sequence and path number sequence, identify the corresponding event chain number and path number, and at the same time associate and determine the trigger time sequence and detector number sequence to obtain the anti-coincidence detection event.

2. The plastic scintillator anti-coincidence detection method according to claim 1, characterized in that, The scintillator trigger time sequence includes detector trigger identifier, trigger time marker, pulse amplitude record, time sequence index, and detector number mapping. The particle trigger event chain includes event chain number, event chain time interval, continuous triggering correlation, particle triggering duration segment, and event chain detector combination. The particle space trigger path includes path number, path space coordinate sequence, path direction vector, path continuity identifier, and path detector distribution. The central trigger event chain set includes central detector trigger identifier, peripheral detector triggering correlation, trigger time comparison segment, central trigger event number, and peripheral correlation judgment relationship. The anti-coincidence detection event includes anti-coincidence event number, central trigger record, peripheral trigger exclusion identifier, event path correspondence, and anti-coincidence event type identifier.

3. The plastic scintillator anti-coincidence detection method according to claim 1, characterized in that, The electrical pulse signal below the trigger voltage refers to the signal whose amplitude of the electrical pulse output by the photomultiplier tube is lower than the set trigger threshold and is judged to be invalid and rejected. The reference particle propagation time range refers to a preset time interval set according to the propagation speed of particles in the detector array.

4. The plastic scintillator anti-coincidence detection method according to claim 1, characterized in that, The continuous trigger sequence refers to a time-continuous trigger recording sequence composed of trigger signals generated sequentially by multiple detectors within the particle propagation time range; The peripheral trigger time interval refers to the time range during which the peripheral plastic scintillator detector generates a trigger signal.

5. The plastic scintillator anti-coincidence detection method according to claim 1, characterized in that, The specific steps of S1 are as follows: S101: Acquire the electrical pulse signal output by the photomultiplier tube connected to the plastic scintillator detector array, collect the electrical pulse trigger time, detector number and pulse amplitude value, compare the pulse amplitude value with the photomultiplier tube trigger voltage, and discard electrical pulse signals lower than the trigger voltage to obtain electrical pulse trigger sequence data; S102: Based on the electrical pulse trigger sequence data, read the trigger time and detector number, analyze the adjacent trigger time intervals and make a judgment with reference to the particle propagation time range, classify the trigger times with time intervals within the particle propagation time range into the same particle trigger activity sequence, and simultaneously map the corresponding detector number relationship to obtain particle trigger activity sequence data. S103: Based on the particle-triggered activity sequence data, extract the trigger time and detector number, perform time sequence division on the trigger time and synchronously associate the correspondence between the trigger time and detector number to obtain the scintillator trigger time sequence.

6. The plastic scintillator anti-coincidence detection method according to claim 1, characterized in that, The specific steps of S2 are as follows: S201: Based on the scintillator trigger time sequence, retrieve the trigger time and detector number, extract the comparison time interval between adjacent trigger times, compare the time interval value with the particle propagation time range, classify the trigger times within the particle propagation time range into the same trigger activity sequence, and associate the corresponding detector number to obtain the particle trigger time association sequence. S202: Based on the particle triggering time association sequence, extract the triggering time and detector number, determine the continuity of the continuous triggering time sequence, aggregate the continuous triggering times, and associate the triggering activity group with the mapping relationship between the triggering time and the detector number to obtain the triggering activity association group; S203: Based on the trigger activity association group, extract the trigger time and detector number, divide the trigger time sequence within the same trigger activity group, while maintaining the correspondence between the trigger time and detector number, and convert the trigger activity group into an independent event chain structure to obtain the particle trigger event chain.

7. A plastic scintillator anti-coincidence detection system, characterized in that, The system is used to implement the plastic scintillator anti-coincidence detection method according to any one of claims 1-6, the system comprising: The pulse acquisition module acquires the electrical pulse signals output by the plastic scintillator detector array and the photomultiplier tube, reads the electrical pulse trigger time, detector number and pulse amplitude value, compares the pulse amplitude value with the photomultiplier tube trigger voltage and removes electrical pulse signals lower than the trigger voltage to obtain the scintillator trigger time sequence; The event chain identification module reads the trigger time and detector number based on the scintillator trigger time sequence, judges the time interval between adjacent trigger times, identifies continuous trigger sequences by referring to the particle propagation time range, divides the continuous trigger sequences according to the trigger time, and obtains the particle trigger event chain. The path recognition module, based on the particle triggering event chain, reads the event chain number and detector number, calls the spatial coordinate table of the plastic scintillator detector array to obtain the spatial position of the detector, analyzes the changes in the direction of adjacent spatial positions, and obtains the particle spatial triggering path; including: Based on the particle-triggered event chain, the event chain number and detector number are retrieved, the spatial coordinate table of the plastic scintillator array detector is called, the corresponding spatial position coordinates are extracted, and the detector number sequence coordinates within the same event chain are matched to obtain the detector spatial position sequence. Based on the detector's spatial position sequence, the spatial position coordinates and trigger time sequence are extracted, the spatial direction changes of adjacent spatial position coordinates are determined, and the corresponding spatial position change direction is retrieved according to the trigger time sequence to obtain the spatial direction change sequence. Based on the spatial direction change sequence, the direction change results and event chain numbers are extracted, the spatial position coordinate paths with continuous and consistent directions are identified and associated with the trigger time sequence and detector number sequence, and the identified path structure is matched with the event chain number to obtain the particle space trigger path. The peripheral determination module, based on the particle space trigger path, reads the event chain number and trigger time, obtains the trigger time generated by the anti-coincidence plastic scintillator detector array, compares the trigger time of the central detector with the trigger time interval of the peripheral detectors, and obtains the central trigger event chain set; including: Based on the particle space triggering path, the triggering time sequence of the anti-coincidence plastic scintillator detector array and the triggering time sequence of the central detector are obtained. The triggering time sequence corresponding to the event chain number is retrieved. The triggering time sequence of the anti-coincidence plastic scintillator detector array is aligned with the event chain number to obtain the peripheral triggering time sequence. Based on the peripheral trigger time series, trigger time data is extracted, and the trigger time series of the central detector is retrieved. The time interval relationship between the peripheral trigger time series and the trigger time series of the central detector is determined. The event chain number of the time data with the corresponding trigger relationship in the time interval is obtained to obtain the peripheral trigger association sequence. Based on the peripheral trigger association sequence, the event chain number and the central detector trigger time sequence are extracted, and the trigger time corresponding to the peripheral trigger association sequence is identified with the trigger time of the central detector to obtain the central trigger event chain set. The anti-coincidence determination module reads the event chain number and trigger time based on the central trigger event chain set, analyzes the triggering relationship between the central detector trigger time and the peripheral detector trigger time, and obtains the anti-coincidence detection event; including: Based on the central trigger event chain set, the event chain number and trigger time sequence are retrieved, and the detector number and path number are extracted. The trigger activities corresponding to the event chain number are aggregated and identified. The central detector trigger time sequence is matched with the detector number sequence to obtain the central trigger activity sequence. Based on the central triggering activity sequence, the event chain number and triggering time sequence are extracted, the triggering time sequence of the peripheral detectors is retrieved and the triggering activities are compared, the correspondence between the triggering time of the central triggering activity sequence and the triggering time of the peripheral detectors is determined, and an independent central triggering sequence is obtained. Based on the independent center trigger sequence, the event chain number, trigger time sequence, detector number sequence and path number sequence are extracted, the corresponding event chain number and path number are identified, and the trigger time sequence and detector number sequence are correlated and determined to obtain the anti-coincidence detection event.

Images