New muon event recognition method and device for plastic scintillating muon camera imaging detector
By preprocessing and analyzing muon signals, they are divided into special and regular muon events. By combining the muon track visualization model to identify special cases, the problem of low muon receiver in existing muon event identification methods is solved, and higher identification accuracy and detector performance are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA UNIV OF GEOSCIENCES (WUHAN)
- Filing Date
- 2023-09-11
- Publication Date
- 2026-06-02
AI Technical Summary
Existing muon event recognition methods can only identify one muon event when multiple muons pass through the detector simultaneously, resulting in low muon reception, high probability of misjudgment and false screening, and reduced detector performance.
Muon signals are acquired and preprocessed to generate muon data. This data is then analyzed and categorized into special and regular muon events, which are then examined to determine valid events. These valid events are stored in a data buffer and then output to a host computer for imaging. A muon track visualization model is used to identify special cases, such as incident at specific angles and simultaneous incident of multiple muons.
It improved the accuracy of muon event identification and detector precision, reduced the probability of false positives and false negatives, saved detection time, and improved muon reception.
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Figure CN117289329B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of muon recognition, and in particular to a novel method and device for muon event recognition using a plastic scintillator muon imaging detector. Background Technology
[0002] Muons are highly penetrating particles, and due to this property, muon detection technology has been applied in many fields, with muon imaging being a key technology. There are two main muon imaging methods: photographic imaging and tomographic imaging. The former images based on the flux changes caused by the ionization loss of muons within an object, while the latter images based on the track deflection caused by multiple Coulomb scattering of muons within an object. Tomographic imaging is often used for 3D density imaging, while photographic imaging is often used for detecting and imaging large-scale objects. This application primarily focuses on photographic imaging, and three types of muon detectors are used for muon imaging: gas detectors, nuclear emulsion detectors, and plastic scintillator detectors. Compared to other detectors, plastic scintillator detectors have advantages such as simple structure, flexible shape, low power consumption, and real-time monitoring capabilities.
[0003] For plastic scintillator muon detectors, the detector's muon receptivity is a key performance indicator. Receptivity encompasses two aspects: the number of muons that can be received and the number of muons that can be utilized. The former mainly depends on the area of the detection plane, while the latter includes the identification and utilization of muon events. The ability to identify more effective muon events has a significant impact on the overall performance of the detector.
[0004] Currently, the muon event identification methods adapted to the current muon detector structure include: the two-end OR method, the channel number identification method, and the layer-by-layer scanning method. Among these, the most widely used method is the two-end OR method: that is, the output value of each channel in the detector is ORed to generate a trigger signal, and the muon event is identified based on the value of the trigger signal. This method has fast determination speed, low hardware requirements, and clear determination logic.
[0005] However, in certain special cases, such as when multiple muons pass by the detector simultaneously, this method can only identify one muon event. Other methods may also experience false screening and misjudgment in other special cases, leading to a decrease in the accuracy of muon event identification, a reduction in the detector's muon receptivity, and a longer detection time. Summary of the Invention
[0006] The purpose of this application is to solve the technical problem of low muon reception in conventional muon event recognition technology, and to provide a novel muon event recognition method and device using a plastic scintillator muon imaging detector.
[0007] The above-mentioned objective of this application is achieved through the following technical solution:
[0008] S1: Acquire the muon signal, preprocess the muon signal, and generate muon data;
[0009] S2: Analyze the muon data and divide it into special muon events and regular muon events; examine the special muon events and the regular muon events respectively to determine the valid muon events;
[0010] S3: Store the valid muon events in the data buffer. When the number of stored muon events is greater than a preset threshold, output all muon events in the data buffer to the host computer for imaging.
[0011] Optionally, step S1 includes:
[0012] S11: Perform signal shaping and scintillator channel encoding on the muon signal input from the front end to generate a timestamp of the muon hitting each scintillator;
[0013] S12: Convert the muon signal into muon data through analog-to-digital conversion, and then send the muon data to the motherboard.
[0014] Optionally, step S2 includes:
[0015] S21: Perform scintillator cross-section modeling on the muon data to construct a visual model of muon tracks;
[0016] set up Let the length of the right-angled side of the scintillator be . The interior angle of the scintillator, Let n be the incident angle of the muon; as the muon passes the detector, it forms a pair of similar triangles between two adjacent scintillators, n is the distance the muon travels in the upper scintillator, and N is the distance the muon travels in the lower scintillator. L represents the base lengths of two similar triangles, and x represents the distance between the position of the muon strike on the common side of the two scintillators and the vertex of the scintillator. and The energy deposited inside the scintillator after the muon passes through it;
[0017] S22: Extract the valid information of the muon data, the valid information including: the distance the muon moves in the scintillator, the incident point of the muon hitting the scintillator, and the exit point of the muon hitting the scintillator;
[0018] S23: Map the incident point and the exit point to the muon track visualization model;
[0019] S24: Scan the muon data from the inside out and make a judgment;
[0020] Using the voltage data stored in the storage space, the movement distances n and N of the muon inside the scintillator are calculated; the similarity formula of triangles is used to deduce... x The value;
[0021] (1)
[0022] The ratio of the movement distance n to N is expressed as the ratio of the energy deposited inside the scintillator, i.e.:
[0023] (2)
[0024] The energy deposition ratio is calculated using the voltage data stored in the storage space;
[0025] The average energy loss of a particle per unit path is described by the Bethe-Bloth formula, as follows:
[0026] (3)
[0027] In the formula, K is a constant, z=1 is the unit charge of the incident muon, c and z represent the electron mass and the speed of light, respectively; Z and A represent the atomic number and mass number of the matter through which the muon passes, respectively. Let I be the maximum kinetic energy that a muon can transfer to one electron when colliding with an atom, and let I be the average excitation energy of the atoms it passes through. As a correction factor for the mass density effect, and These are the relativistic velocity and relativistic factor of the incident muon, respectively;
[0028] The muon energy is calculated using formula (3). The maximum average distance that can be penetrated at that time, when the object being measured is a multi-layered mixed material, the mass and thickness are calculated by formula (4);
[0029] (4)
[0030] (5)
[0031] In the formula, X is the mass thickness, i.e., the path of the muon, ρ is the average density of the muons passing through the object, and E is the energy lost by the muons. The function representing the distance traveled. A function representing energy loss;
[0032] If the movement distance of the muon data is equal to a special value, then the muon event corresponding to the muon data is regarded as a special muon event; the special value includes: the movement distance of the muon data is equal to the length of the height of the scintillator, the movement distance of the muon data is equal to the length of the right-angled side of the scintillator, and multiple muon events are incident at the same time;
[0033] If the movement distance of the muon data is not equal to the special value, then the muon event corresponding to the muon data is regarded as a regular muon event;
[0034] S25: The special muon events are analyzed using a muon track visualization model. Special muon events incident at special angles and special muon events incident at the same time by multiple muons are all identified as valid muon events.
[0035] S26: Check the number and location of the regular muon events. If the checks pass, the regular muon events are determined to be valid muon events.
[0036] A novel muon event recognition system for a plastic scintillator muon photographic imaging detector, comprising: a preprocessing module, an analysis module, and a transmission module;
[0037] The preprocessing module performs the following: shaping of the input signal from the front end, scintillator channel encoding, generation of timestamps for muons hitting each scintillator, and conversion of analog signals into digital signals for transmission to the motherboard.
[0038] The analysis module includes a determination module and a FIFO module. The determination module is used for extracting muon event information and identifying muon events. The FIFO module is used to cache the generated muon events to coordinate the timing of data input and data output.
[0039] The sending module determines the number of muon events and outputs all muon events in the data buffer to the host computer for imaging.
[0040] A storage device stores instructions and data for implementing a novel muon event recognition method for a plastic scintillator muon imaging detector.
[0041] A novel muon event recognition device for a plastic scintillator muon imaging detector includes: a processor and a storage device; the processor loads and executes instructions and data in the storage device to implement a novel muon event recognition method for a plastic scintillator muon imaging detector.
[0042] The beneficial effects of the technical solution provided in this application are:
[0043] 1. The muon signal is preprocessed to generate muon data. Based on the muon data, muon events are divided into special muon events and regular muon events. Both special and regular muon events are then examined to determine valid muon events. These valid muon events are then output to the host computer for imaging. This muon event identification method improves the detector's receiver accuracy. Compared to traditional identification methods, it reduces the probability of false positives and false negatives in muon event identification.
[0044] 2. Under normal circumstances, identification is performed by combining the scintillator channel number and timestamp. In special cases, the established muon track visualization model can identify muon events that cannot be identified by traditional methods, such as those incident at special angles or multiple muons incident simultaneously. By establishing the muon track visualization model and using an inside-out scanning method, the aim is to ensure that, based on the existing accuracy of muon event identification, special muon events can be identified, such as muons incident along the right-angle side or perpendicular bisector of the scintillator, multiple muons incident simultaneously, and muons incident along the edge. This improves the accuracy of muon event identification and the overall detection precision of the detector, while saving detection time. Attached Figure Description
[0045] The present application will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:
[0046] Figure 1 This is a step diagram of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0047] Figure 2 This is a schematic diagram of the internal logic of the preprocessing module of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0048] Figure 3 This is a schematic diagram of the motherboard internal logic of the novel muon event recognition method of the plastic flash muon photographic imaging detector in the embodiments of this application;
[0049] Figure 4 This is a schematic diagram of the scintillator channel cross-section of the novel muon event recognition method of the plastic scintillator muon photographic imaging detector in the embodiments of this application;
[0050] Figure 5 This is a visualization model of the muon track of the novel muon event recognition method of the plastic scintillator muon photographic imaging detector in the embodiments of this application;
[0051] Figure 6 This is a schematic diagram of the detector structure of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0052] Figure 7This is a muon event recognition logic diagram of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0053] Figure 8 This is a schematic diagram of the conventional case of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0054] Figure 9 This is a schematic diagram illustrating a special case of the novel muon event recognition method for the plastic scintillator muon imaging detector in the embodiments of this application;
[0055] Figure 10 This is a schematic diagram of a muon incident marker at a special angle in the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0056] Figure 11 This is a schematic diagram of multiple muon incident time markers in the novel muon event recognition method of the plastic scintillator muon photographic imaging detector in the embodiments of this application;
[0057] Figure 12 This is a schematic diagram of the hardware device working in the embodiments of this application. Detailed Implementation
[0058] To provide a clearer understanding of the technical features, objectives, and effects of this application, the specific embodiments of this application will now be described in detail with reference to the accompanying drawings.
[0059] The embodiments of this application provide a novel muon event recognition method and device for a plastic scintillator muon imaging detector.
[0060] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating the steps of a novel muon event recognition method for a plastic scintillator muon imaging detector according to an embodiment of this application, specifically including the following steps:
[0061] S1: Acquire the muon signal, preprocess the muon signal, and generate muon data;
[0062] Specifically, before identifying a muon event, data related to muons needs to be collected by a detector. After a muon passes through a scintillator, photons are generated inside the scintillator. The photons are converted into electrical signals by a photoelectric sensor (such as a photomultiplier tube or a silicon photomultiplier tube). The converted electrical signals carry information about the muon event. The electrical signals from the front end contain noise interference and need to be filtered. The subsequent data analysis process also requires converting analog signals into digital signals and encoding the signal channels, which means that the converted electrical signals need to be preprocessed.
[0063] S2: Analyze the muon data and divide it into special muon events and regular muon events; examine the special muon events and the regular muon events respectively to determine the valid muon events;
[0064] Specifically, by performing scintillator cross-section modeling on the data processed at the front end, information about muon events contained in the signal is extracted, and then the information is judged to determine whether it belongs to a valid muon event.
[0065] S3: Store the valid muon events in the data buffer. When the number of stored muon events is greater than a preset threshold, output all muon events in the data buffer to the host computer for imaging.
[0066] Specifically, muon data is analyzed and utilized to identify valid muon data, i.e., valid muon events. For a detector with a detection plane size of one square meter, it can receive about 10,000 muons per hour. Without considering real-time imaging, there is enough time to process and identify the acquired signals.
[0067] Figure 2 This is a schematic diagram of the internal logic of the preprocessing module of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application.
[0068] Step S1 includes:
[0069] S11: Perform signal shaping and scintillator channel encoding on the muon signal input from the front end to generate a timestamp of the muon hitting each scintillator;
[0070] S12: Convert the muon signal into muon data through analog-to-digital conversion, and then send the muon data to the motherboard.
[0071] Specifically, by preprocessing the data transmitted by the SiPM (Silicon photomultiplier) in the detection plane, the accuracy of muon event identification can be improved and interference inside the muon detector can be eliminated.
[0072] Figure 4 This is a schematic diagram of the scintillator channel cross-section of the novel muon event recognition method of the plastic scintillator muon photographic imaging detector in the embodiments of this application;
[0073] refer to Figure 5 , Figure 5 This is a visualization model of the muon track of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application.
[0074] refer to Figure 6 , Figure 6This is a schematic diagram of the detector structure of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application.
[0075] Step S2 includes:
[0076] S21: Perform scintillator cross-section modeling on the muon data to construct a visual model of muon tracks;
[0077] set up Let the length of the right-angled side of the scintillator be . The interior angle of the scintillator, Let n be the incident angle of the muon; as the muon passes the detector, it forms a pair of similar triangles between two adjacent scintillators, n is the distance the muon travels in the upper scintillator, and N is the distance the muon travels in the lower scintillator. L represents the base lengths of two similar triangles, and x represents the distance between the position of the muon strike on the common side of the two scintillators and the vertex of the scintillator. and The energy deposited inside the scintillator after the muon passes through it;
[0078] S22: Extract the valid information of the muon data, the valid information including: the distance the muon moves in the scintillator, the incident point of the muon hitting the scintillator, and the exit point of the muon hitting the scintillator;
[0079] S23: Map the incident point and the exit point to the muon track visualization model;
[0080] S24: Scan the muon data from the inside out and make a judgment;
[0081] Using the voltage data stored in the storage space, the movement distances n and N of the muon inside the scintillator are calculated; the similarity formula of triangles is used to deduce... x The value;
[0082] (1)
[0083] The ratio of the movement distance n to N is expressed as the ratio of the energy deposited inside the scintillator, i.e.:
[0084] (2)
[0085] The energy deposition ratio is calculated using the voltage data stored in the storage space;
[0086] The average energy loss of a particle per unit path is described by the Bethe-Bloth formula, as follows:
[0087] (3)
[0088] In the formula, K is a constant, z=1 is the unit charge of the incident muon, c and z represent the electron mass and the speed of light, respectively; Z and A represent the atomic number and mass number of the matter through which the muon passes, respectively. Let I be the maximum kinetic energy that a muon can transfer to one electron when colliding with an atom, and let I be the average excitation energy of the atoms it passes through. As a correction factor for the mass density effect, and These are the relativistic velocity and relativistic factor of the incident muon, respectively;
[0089] The muon energy is calculated using formula (3). The maximum average distance that can be penetrated at that time, when the object being measured is a multi-layered mixed material, the mass and thickness are calculated by formula (4);
[0090] (4)
[0091] (5)
[0092] In the formula, X is the mass thickness, i.e., the path of the muon, ρ is the average density of the muons passing through the object, and E is the energy lost by the muons. The function representing the distance traveled. A function representing energy loss;
[0093] If the movement distance of the muon data is equal to a special value, then the muon event corresponding to the muon data is regarded as a special muon event; the special value includes: the movement distance of the muon data is equal to the length of the height of the scintillator, the movement distance of the muon data is equal to the length of the right-angled side of the scintillator, and multiple muon events are incident at the same time;
[0094] If the movement distance of the muon data is not equal to the special value, then the muon event corresponding to the muon data is regarded as a regular muon event;
[0095] S25: The special muon events are analyzed using a muon track visualization model. Special muon events incident at special angles and special muon events incident at the same time by multiple muons are all identified as valid muon events.
[0096] S26: Check the number and location of the regular muon events. If the checks pass, the regular muon events are determined to be valid muon events.
[0097] Specifically, the modeling process in this application is performed on a PC. A suitable region size and number are selected to represent the cross-section of a scintillator channel. The total number of regions required is calculated based on the detector's geometric parameters, and each region is numbered. When special muon events need to be analyzed on the PC, the incident and exit points of the muons on the scintillator are calculated using formulas and algorithms, and the corresponding regions are marked. Figure 5 As shown, since the track of a muon is basically a straight line, the track of a muon can be determined based on the incident point and the exit point. After further analysis, the analysis results are transmitted to the motherboard to complete the identification of the muon event.
[0098] Due to the detector's special structure, the motherboard must also have four storage spaces for storing muon data, each representing a layer of the detection plane. Each storage space can store 16 sets of data representing 16 scintillators in each layer of the detection plane.
[0099] Specifically, after signal preprocessing, most of the intrinsic noise in the detectors can be filtered out, and the remaining signals all satisfy the output signal characteristics of SiPM after a muon strikes the scintillator. The motherboard further judges the remaining signals: determining the number of channel signals and whether the particle tracks represented by the signals satisfy the conditions for a muon event.
[0100] The set of muon data transmitted in the preprocessing module includes the channel number. Based on the channel number, the motherboard stores the voltage value and timestamp of the channel output into the position of the plastic scintillator representing that number in the storage space representing each layer.
[0101] By analyzing the voltage data stored in the memory, the distance the muon traveled within the scintillator can be calculated. Figure 4 n and N in the equation.
[0102] When the calculated distance of motion in the muon is equal to the height of the plastic scintillator or the length of the right-angled side, the muon event can be directly regarded as a special case, and it can be tentatively classified as incident along the right-angled side or incident along the perpendicular bisector for subsequent identification.
[0103] Figure 7 This is a muon event recognition logic diagram of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0104] Figure 8 This is a schematic diagram of the conventional case of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0105] Figure 9 This is a schematic diagram illustrating a special case of the novel muon event recognition method for the plastic scintillator muon imaging detector in the embodiments of this application;
[0106] Figure 10This is a schematic diagram of a muon incident marker at a special angle in the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application;
[0107] Figure 11 This is a schematic diagram of multiple muon incident time markers in the novel muon event recognition method of the plastic scintillator muon photographic imaging detector in the embodiments of this application;
[0108] Specifically, the process of muon event identification mainly involves: scanning the data in each layer of storage space to categorize muon events into regular and special cases, such as... Figure 7 As shown. In this invention, the process of identifying muon events adopts an overall inside-out scanning method, as follows: Figure 6 In the detection plane shown, layers 2 and 3 are inner layers, and layers 1 and 4 are outer layers. A valid muon event (i.e. a muon event that can be used in the subsequent imaging process) must pass through the 4-layer detection plane.
[0109] Figure 7 This indicates that muon events are divided into normal cases and special cases. Both cases require specific conditions to be recognized as valid muon events.
[0110] Normal scenario: The normal scenario refers to the case where the muon is incident at a normal angle. In this case, the muon will pass through the detector's four detection planes and 6-8 scintillators (such as...). Figure 8 As shown in the diagram, when a muon passes through the inner layer, it will inevitably pass through two adjacent scintillators. The energy deposited in the scintillators is processed by the SiPM and the data preprocessing section and converted into 6-8 sets of voltage value data, which are stored in the memory space within the motherboard. The location of each set of data represents the location of the scintillator that generated that set of data. These data must meet the following conditions:
[0111] 1) Data in the inner layer must have two corresponding scintillators that are adjacent to each other.
[0112] 2) When there are two data points in the outer layer, the scintillators corresponding to these two data points must be adjacent. When there is only one data point, the scintillator corresponding to that data point must be located at opposite ends of the detection plane.
[0113] Therefore, when identifying muon events under normal circumstances, a valid muon event can be identified as long as the amount of data in the storage space meets the conditions and the position of the scintillator corresponding to the data meets the conditions.
[0114] Special cases: Special cases include muons incident along the perpendicular bisector of the scintillator or along a right-angled side of the scintillator, and multiple muon events incident simultaneously. Using other muon event identification methods, the former would be identified as a non-muon event, while the latter would be treated as a single muon event. Figure 9 As shown.
[0115] Specifically, this application handles the cases of multiple muons incident simultaneously and those incident at special angles separately, but both require the use of the previously established muon track visualization model. In the step of extracting muon event information, the path length of the muon in the scintillator is calculated, and the special case of incident at a special angle is preliminarily determined. Then, according to formulas (1) and (2), the parameter sizes of each part of the two similar triangles in the remaining layers of the scintillator are calculated. The incident and exit points of the muons in each plane are marked according to the area size set when establishing the muon track visualization model, such as... Figure 10 As shown, the incident angle of a muon is a constant when incident along the perpendicular bisector and along the right-angled side. This value is also reflected in the region numbering; for example, the difference between the size of the incident region and the exit region is also a constant. Whether a data set represents a special muon event can be identified by checking if the size of the region marked in each layer meets the conditions.
[0116] When multiple muons are incident simultaneously, after the above process, each layer of markings will have multiple incident and exit points (e.g., Figure 11 As shown in the figure, based on the obtained muon motion distance, it is determined which two incident points and exit points belong to the same muon track. Finally, based on the tracks of the four-layer plane, it can be identified whether there are multiple muon events incident at the same time.
[0117] A novel muon event recognition system for a plastic scintillator muon photographic imaging detector, comprising: a preprocessing module, an analysis module, and a transmission module;
[0118] Preprocessing module: Shapes the input signal from the front end, encodes the scintillator channel, generates the timestamp of the muon hitting each scintillator, and converts the analog signal into a digital signal and transmits it to the motherboard.
[0119] Analysis module: includes a decision module and a FIFO module. The decision module is used for extracting muon event information and identifying muon events, while the FIFO module is used to cache the generated muon events to coordinate the timing of data input and data output.
[0120] Sending module: Determines the number of muon events and outputs all muon events from the data buffer to the host computer for imaging.
[0121] Specifically, the muon event identification method proposed in this invention classifies muon events into regular muon events and special muon events by using an inside-out scanning method based on the inherent characteristics of muons passing through the detection plane.
[0122] Under normal circumstances, identification is performed by combining the scintillator channel number and timestamp, which reduces the probability of misjudgment and misscreening of muon events compared to traditional identification methods.
[0123] In special cases, by establishing a visual model of muon tracks, it is possible to identify muon events that cannot be identified by traditional methods, such as those incident at specific angles or multiple muons incident simultaneously. This method of muon event identification improves the detector's receiver reception.
[0124] refer to Figure 3 , Figure 3 This is a schematic diagram of the internal logic of the motherboard of the novel muon event recognition method of the plastic scintillator muon imaging detector in the embodiments of this application, as shown below:
[0125] Specifically, the valid muon event identification part of this application is performed on the motherboard, which includes an FPGA chip and an ARM chip (used for communication with the host computer). The internal logic of the motherboard is as follows: Figure 3 As shown, the identification process of valid muon events is primarily handled by the FPGA chip on the motherboard, with the PC playing a secondary role. The PC is mainly responsible for analyzing specific muon events and transmitting the analysis results to the motherboard. The FPGA is internally divided into a decision module and a FIFO module. The decision module also includes a muon flag output. When the decision result is a valid muon event, the FPGA sets the flag to "1" if it is valid and to "0" if it is not. The FIFO determines whether to store this set of data based on the value of this flag. The FIFO is a data buffer on the motherboard. Since muon imaging requires tens of thousands or even millions of muon events, the purpose of the data buffer is to prevent format and bit width mismatches during data input and serial communication, and to coordinate the timing of data input and transmission.
[0126] Please see Figure 12 , Figure 12 This is a schematic diagram of the hardware device in an embodiment of this application. The hardware device specifically includes: a novel muon event recognition device 401 for a plastic flash muon photographic imaging detector, a processor 402, and a storage device 403.
[0127] A novel muon event recognition device 401 for a plastic scintillator muon imaging detector: The novel muon event recognition device 401 for a plastic scintillator muon imaging detector implements a novel muon event recognition method for a plastic scintillator muon imaging detector.
[0128] Processor 402: Processor 402 loads and executes instructions and data in storage device 403 to implement a novel muon event recognition method for a plastic scintillator muon imaging detector.
[0129] Storage device 403: Storage device 403 stores instructions and data; storage device 403 is used to implement a novel muon event recognition method for a plastic scintillator muon imaging detector.
[0130] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A novel muon event recognition method for a plastic scintillator muon photographic imaging detector, characterized in that, The method includes the following steps: S1: Acquire the muon signal, preprocess the muon signal, and generate muon data; S2: Analyze the muon data and divide it into special muon events and regular muon events; The special muon events and the regular muon events are examined separately to determine the valid muon events; Step S2 includes: S21: Perform scintillator cross-section modeling on the muon data to construct a visual model of muon tracks; set up Let the length of the right-angled side of the scintillator be . The interior angle of the scintillator, Let n be the incident angle of the muon; as the muon passes the detector, it forms a pair of similar triangles between two adjacent scintillators, n is the distance the muon travels in the upper scintillator, and N is the distance the muon travels in the lower scintillator. L represents the base lengths of two similar triangles, and x represents the distance between the position of the muon strike on the common side of the two scintillators and the vertex of the scintillator. and The energy deposited inside the scintillator after the muon passes through it; S22: Extract the valid information of the muon data, the valid information including: the distance the muon moves in the scintillator, the incident point of the muon hitting the scintillator, and the exit point of the muon hitting the scintillator; S23: Map the incident point and the exit point to the muon track visualization model; S24: Scan the muon data from the inside out and make a judgment; Using the voltage data stored in the storage space, the movement distances n and N of the muon inside the scintillator are calculated; the similarity formula of triangles is used to deduce... x The value; (1) The ratio of the movement distance n to N is expressed as the ratio of the energy deposited inside the scintillator, i.e.: (2) The energy deposition ratio is calculated using the voltage data stored in the storage space; The average energy loss of a particle per unit path is described by the Bethe-Bloth formula, as follows: (3) In the formula, K is a constant, z=1 is the unit charge of the incident muon, c and z represent the electron mass and the speed of light, respectively; Z and A represent the atomic number and mass number of the matter through which the muon passes, respectively. Let I be the maximum kinetic energy that a muon can transfer to one electron when colliding with an atom, and let I be the average excitation energy of the atoms it passes through. As a correction factor for the mass density effect, and These are the relativistic velocity and relativistic factor of the incident muon, respectively; The muon energy is calculated using formula (3). The maximum average distance that can be penetrated at that time, when the object being measured is a multi-layered mixed material, the mass and thickness are calculated by formula (4); (4) (5) In the formula, X is the mass thickness, i.e., the path of the muon, ρ is the average density of the muons passing through the object, and E is the energy lost by the muons. The function representing the distance traveled. A function representing energy loss; If the movement distance of the muon data is equal to a special value, then the muon event corresponding to the muon data is regarded as a special muon event; the special value includes: the movement distance of the muon data is equal to the length of the height of the scintillator, the movement distance of the muon data is equal to the length of the right-angled side of the scintillator, and multiple muon events are incident at the same time; If the movement distance of the muon data is not equal to the special value, then the muon event corresponding to the muon data is regarded as a regular muon event; S25: The special muon events are analyzed using a muon track visualization model. Special muon events incident at special angles and special muon events incident at the same time by multiple muons are all identified as valid muon events. S26: Check the number and location of the regular muon events. If the checks pass, the regular muon events are determined to be valid muon events. S3: Store the valid muon events in the data buffer. When the number of stored muon events is greater than a preset threshold, output all muon events in the data buffer to the host computer for imaging.
2. The novel muon event recognition method for a plastic scintillator muon imaging detector as described in claim 1, characterized in that, Step S1 includes: S11: Perform signal shaping and scintillator channel encoding on the muon signal input from the front end to generate a timestamp of the muon hitting each scintillator; S12: Convert the muon signal into muon data through analog-to-digital conversion, and then send the muon data to the motherboard.
3. A novel muon event recognition system for a plastic scintillator muon imaging detector, used to implement the novel muon event recognition method for a plastic scintillator muon imaging detector as described in any one of claims 1-2, characterized in that, The system includes: a preprocessing module, an analysis module, and a sending module; The preprocessing module performs the following: shaping of the input signal from the front end, scintillator channel encoding, generation of timestamps for muons hitting each scintillator, and conversion of analog signals into digital signals and transmission to the motherboard. The analysis module includes a determination module and a FIFO module. The determination module is used for extracting muon event information and identifying muon events. The FIFO module is used to cache the generated muon events to coordinate the timing of data input and data output. The sending module determines the number of muon events and outputs all muon events from the data buffer to the host computer for imaging.
4. A storage device, characterized in that: The storage device stores instructions and data to implement the novel muon event recognition method of any one of the plastic scintillator muon imaging detectors according to claims 1 to 2.
5. A novel muon event recognition device for a plastic scintillator muon photographic imaging detector, characterized in that: include: Processor and storage device; the processor loads and executes instructions and data in the storage device to implement a novel muon event recognition method for any one of the plastic scintillator muon imaging detectors of claims 1 to 2.