SiPM signal readout and multi-layer processing system and method for muon detection system front end

Abstract

The application provides a muon detection system front-end SiPM signal reading and multi-layer processing system, which comprises a main layer subsystem and at least one auxiliary layer subsystem; the main layer subsystem is connected with each auxiliary layer subsystem; the main layer subsystem is used for reading the voltage value of the electric signal converted by a silicon photomultiplier (SiPM) and processing the signal time stamp of the electric signal converted by the SiPM, and sending the voltage value and the signal time stamp to a PC end; the auxiliary layer subsystem is used for reading and processing the missed muon events of the main layer subsystem, generating the signal time stamp and the voltage value of the missed muon events, and sending the signal time stamp and the voltage value to the main layer subsystem. The missed muon events are processed by the auxiliary layer subsystem, and the accuracy of data processing is improved.

Description

Technical Field

[0001] This application relates to the field of information processing, and in particular to a SiPM signal readout and multi-layer processing system and method for a muon detection system front-end. Background Technology

[0002] Cosmic ray muons are secondary ray particles produced by the interaction of high-energy cosmic rays from space with the atmosphere. They are characterized by a wide energy range and strong penetrating power. Using cosmic ray muons as a source, when they penetrate specific large targets, multiple Coulomb scattering or energy loss occurs. By detecting the muons after they interact with the target, non-destructive imaging of the target can be achieved. The development of muon technology has led to the emergence of a large number of diverse muon detectors, providing various feasible technical means for muon detection applications.

[0003] Currently, muon detectors used in geophysical exploration are divided into three types: plastic scintillator detectors, gas detectors, and nuclear emulsion detectors. Among them, plastic scintillator detectors have advantages over other detectors, such as simple manufacturing, short light decay time, high transparency, stable performance, and good radiation resistance.

[0004] The working principle of a plastic scintillator detector is as follows: First, the scintillator absorbs muons and converts them into photons. Second, the photons are collected by an optical fiber embedded within the scintillator. Then, a silicon photomultiplier (SiPM) connected to the end of the fiber converts the received photons into electrical signals. Finally, the data obtained by analyzing the muon signals is used for imaging and other operations. However, SiPMs have characteristics such as temperature variations and noise interference, and their output is in pulse form; the accompanying time and voltage information cannot be directly processed by a PC.

[0005] Therefore, a front-end SiPM readout and processing system is needed to generate timestamps and read out analog signals.

[0006] Current SiPM readout and processing systems mostly suffer from incomplete functionality and low processing efficiency. Furthermore, in existing single-layer processing systems, when reading analog signals after an event is triggered, the system stops triggering the event again, which misses some valid muon events, resulting in inaccurate statistical data.

[0007] In other words, conventional single-layer processing systems cannot effectively generate timestamps and voltage values, nor can they effectively record and process missed muon events. Summary of the Invention

[0008] The purpose of this application is to solve the technical problems that conventional single-layer processing systems cannot effectively generate timestamp and voltage value data, and cannot effectively record and process missed muon events, and to provide a front-end SiPM signal readout and multi-layer processing system for a muon detection system.

[0009] The above-mentioned objective of this application is achieved through the following technical solution: The system includes: a main layer subsystem and at least one auxiliary layer subsystem; The main layer subsystem is connected to each of the auxiliary layer subsystems; The main layer subsystem is used to read the voltage value of the electrical signal converted by the silicon photomultiplier tube (SiPM) and process the timestamp of the signal generated by the electrical signal converted by the SiPM, and send the voltage value and the timestamp to the PC. The auxiliary layer subsystem is used to read and process the muon events missed by the main layer subsystem, generate the signal timestamp and voltage value of the missed muon events, and send the signal timestamp and voltage value to the main layer subsystem.

[0010] Optionally, the main layer subsystem includes: a signal preprocessing module, an identification module, a triggering module, a first timestamp generation module, a first holding module, a first AD conversion module, a data storage module, a control module, and a communication module; The signal preprocessing module processes the input electrical signal converted by the silicon photomultiplier tube (SiPM) and outputs the preprocessed signal to the discrimination module and the first holding module. The identification module identifies the input signal, sets a threshold voltage, and outputs a coincidence signal to the trigger module. The triggering module triggers the input signal, generates a trigger signal, and outputs it to the first timestamp generation module and the control module; The first timestamp generation module receives the timestamp generation instruction from the control module, generates a signal timestamp, and sends the signal timestamp to the data storage module; The first holding module receives the analog signal and performs holding processing; The first AD conversion module receives the analog signal readout instruction sent by the control module, performs AD conversion on the analog signal stored in the first holding module to generate a digital signal, and sends the digital signal to the data storage module; When the control module receives the trigger signal, it sends the analog signal readout instruction to the first AD conversion module and the timestamp generation instruction to the first timestamp generation module. The data storage module sends the data in the data storage module to the PC through the communication module.

[0011] Optionally, the main layer subsystem further includes a temperature compensation module; The temperature module is used to perform temperature compensation on the SiPM, reducing errors caused by gain changes and dark counting.

[0012] Optionally, the auxiliary layer subsystem includes: a second timestamp generation module, a second retention module, and a second AD conversion module; The second timestamp generation module in the auxiliary layer subsystem receives the trigger signal transmitted by the trigger module and the timestamp generation instruction of the control module, generates a signal timestamp, and sends the signal timestamp to the data storage module; The second holding module in the auxiliary layer subsystem is used to receive the analog signal readout command generated by the control module and the analog signal preprocessed by the signal preprocessing module. The second AD conversion module in the auxiliary layer subsystem performs AD conversion on the analog signal transmitted by the second holding module in the auxiliary layer subsystem to generate a digital signal, and sends the digital signal to the data storage module.

[0013] Optionally, the signal preprocessing module includes: a signal amplification submodule and a shaping submodule; The signal amplification submodule amplifies the analog signal through a charge amplifier; The shaping submodule performs shaping processing on the analog signal waveform through a Schmitt trigger.

[0014] Optionally, the identification module is connected to the triggering module through a preset number of logical AND gates.

[0015] A method for SiPM signal readout and multilayer processing at the front end of a muon detection system, the method comprising: The main subsystem acquires the electrical signal converted by the silicon photomultiplier tube (SiPM), processes and reads the electrical signal converted by the SiPM, generates a signal timestamp and voltage value, and sends it to the PC. The auxiliary layer subsystem reads and processes the muon events missed by the main layer subsystem, generates the signal timestamp and voltage value of the missed muon events, and sends the signal timestamp and voltage value to the main layer subsystem.

[0016] Optionally, the main layer subsystem preprocesses missed muon events by identifying the electrical signal converted by the silicon photomultiplier tube (SiPM) through an identification module and sending it to the triggering module. The triggering module responds to and records the missed muon events but does not trigger the main layer subsystem. The triggering module sends a trigger signal to the control module. The control module calls an idle auxiliary layer subsystem to generate a signal timestamp for the missed muon events and read out the voltage value. The signal timestamp and the voltage value are simultaneously sent to the main layer subsystem for data storage and communication.

[0017] The beneficial effects of the technical solution provided in this application are: The system generates a signal timestamp from the preprocessed analog signal and saves it to the data storage module. It also reads the analog signal and saves it to the data storage module. During the analog-to-digital conversion of the read analog signal, the control module calls the auxiliary layer subsystem to process missed muon events and saves the processed muon events to the data storage module. The communication module sends the data from the data storage module to the PC. By modularizing the system's readout and processing functions, it can effectively read and process the time and voltage data attached to the SiPM output signal, while also utilizing the auxiliary layer subsystem in the multi-layer processing system to process missed muon events, resulting in denser and more accurate data information. Attached Figure Description

[0018] The present application will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a block diagram of the multi-layer processing system design for the SiPM signal readout and multi-layer processing system at the front end of the muon detection system in this application embodiment; Figure 2 This is a block diagram of the main subsystem of the front-end SiPM signal readout and multilayer processing system of the muon detection system in this application embodiment; Figure 3 This is a block diagram of the signal preprocessing of the SiPM signal readout and multilayer processing system at the front end of the muon detection system in this application embodiment; Figure 4 This is a schematic diagram of the SiPM signal readout at the front end of the muon detection system and the trigger signal generation of the multilayer processing system in an embodiment of this application; Figure 5 This is a schematic diagram and timing diagram of the single delay chain TDC structure of the SiPM signal readout and multilayer processing system at the front end of the muon detection system in this application embodiment; Figure 6 This is a schematic diagram and timing diagram of the dual delay chain TDC structure of the SiPM signal readout and multilayer processing system at the front end of the muon detection system in this application embodiment; Figure 7 This is a block diagram of the analog signal readout of the SiPM signal readout and the multilayer processing system at the front end of the muon detection system in this application embodiment; Figure 8 This is a flowchart of the auxiliary layer subsystem of the front-end SiPM signal readout and multilayer processing system of the muon detection system in this application embodiment; Figure 9 This is a block diagram of the auxiliary layer subsystem design of the front-end SiPM signal readout and multilayer processing system of the muon detection system in this application embodiment. Detailed Implementation

[0019] 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.

[0020] Embodiments of this application provide a front-end SiPM signal readout and multi-layer processing system for a muon detection system.

[0021] Please see Figure 1 , Figure 1 This is a block diagram of the multi-layer processing system design for the SiPM signal readout and multi-layer processing system at the front end of the muon detection system in this application embodiment, specifically including the following steps: The system includes: a main layer subsystem and at least one auxiliary layer subsystem; The main layer subsystem is connected to each of the auxiliary layer subsystems; The main layer subsystem is used to read the voltage value of the electrical signal converted by the silicon photomultiplier tube (SiPM) and process the timestamp of the signal generated by the electrical signal converted by the SiPM, and send the voltage value and the timestamp to the PC. The auxiliary layer subsystem is used to read and process the muon events missed by the main layer subsystem, generate the signal timestamp and voltage value of the missed muon events, and send the signal timestamp and voltage value to the main layer subsystem.

[0022] Specifically, the process begins with a muon detector receiving muon rays. As the muons pass through an array of neatly arranged scintillators, they ionize the atoms in the scintillators, generating a stream of visible photons along their designed path. The emitted light from the scintillators is collected via optical fiber and guided to a silicon photomultiplier tube (SiPM) at the fiber's end. The SiPM converts the received optical signal into an electrical signal, which is then input to the readout and multilayer processing system. The main layer subsystem of the multilayer processing system is responsible for reading out and processing the SiPM signal, generating a timestamp and reading out the corresponding voltage value. The auxiliary layer subsystem handles muon events missed by the main system, generating timestamps for the missed muon events, reading out the corresponding voltage value, and sending the processed data back to the main layer subsystem.

[0023] The main layer subsystem includes: a signal preprocessing module, an identification module, a triggering module, a first timestamp generation module, a first holding module, a first AD conversion module, a data storage module, a control module, and a communication module; The signal preprocessing module processes the input electrical signal converted by the silicon photomultiplier tube (SiPM) and outputs the preprocessed signal to the discrimination module and the first holding module. The identification module identifies the input signal, sets a threshold voltage, and outputs a coincidence signal to the trigger module. The triggering module triggers the input signal, generates a trigger signal, and outputs it to the first timestamp generation module and the control module; The first timestamp generation module receives the timestamp generation instruction from the control module, generates a signal timestamp, and sends the signal timestamp to the data storage module; The first holding module receives the analog signal and performs holding processing; The first AD conversion module receives the analog signal readout instruction sent by the control module, performs AD conversion on the analog signal stored in the first holding module to generate a digital signal, and sends the digital signal to the data storage module; When the control module receives the trigger signal, it sends the analog signal readout instruction to the first AD conversion module and the timestamp generation instruction to the first timestamp generation module. The data storage module sends the data in the data storage module to the PC through the communication module.

[0024] The main layer subsystem also includes a temperature compensation module; The temperature module is used to perform temperature compensation on the SiPM, reducing errors caused by gain changes and dark counting.

[0025] Please see Figure 2 , Figure 2 This is a block diagram of the main subsystem of the front-end SiPM signal readout and multilayer processing system of the muon detection system in this application embodiment.

[0026] Specifically, the main subsystem simultaneously generates a signal timestamp and reads the analog signal from the preprocessed analog signal. During the AD conversion of the read analog signal, the triggering module does not trigger new muon events; it only records missed muon events and notifies the control module to call the auxiliary subsystem to process them. The signal timestamp and the read analog signal are stored in the data storage module, and the data in the data storage module is sent to the PC for processing via the communication module.

[0027] Specifically, a temperature module is introduced into the main layer subsystem to compensate for the temperature of the SiPM, reducing errors caused by gain variations and dark counts. During SiPM operation, temperature changes cause variations in noise, gain, and dark counts. As the temperature increases, the gain decreases while the reverse bias remains constant. This gain decrease leads to an indistinct and unstable SiPM output signal, making it difficult for the front-end system to process. Dark counts refer to the possibility, in the field of photon detection, that stray light (non-signal light) and electrical noise may be mistaken for valid light signals by a single-photon detector; in this field, such misjudgments are called dark counts.

[0028] As temperature increases, the dark count also increases. An increased dark count leads to significant noise, affecting the accuracy of data reading and processing. Therefore, to obtain a stable SiPM output signal, it is essential to adjust the reverse bias voltage according to temperature or maintain a constant device temperature. Thus, a temperature compensation module is introduced into the signal reading and processing system to control the SiPM temperature, meeting requirements for gain, dark count, and other parameters.

[0029] The SiPM driver circuit board is equipped with a temperature sensor. A temperature compensation module supplies the SiPM with a specific voltage value. If the temperature rises, the breakdown voltage increases, resulting in a smaller overvoltage and consequently a decrease in gain. By using the temperature compensation module to compensate for the bias voltage according to the temperature change, the overvoltage can be kept constant, thus stabilizing the detector's gain and other properties.

[0030] The auxiliary layer subsystem includes: a second timestamp generation module, a second retention module, and a second AD conversion module; The second timestamp generation module in the auxiliary layer subsystem receives the trigger signal transmitted by the trigger module and the timestamp generation instruction of the control module, generates a signal timestamp, and sends the signal timestamp to the data storage module; The second holding module in the auxiliary layer subsystem is used to receive the analog signal readout command generated by the control module and the analog signal preprocessed by the signal preprocessing module. The second AD conversion module in the auxiliary layer subsystem performs AD conversion on the analog signal transmitted by the second holding module in the auxiliary layer subsystem to generate a digital signal, and sends the digital signal to the data storage module.

[0031] Please see Figure 8 , Figure 8 This is a flowchart of the auxiliary layer subsystem of the front-end SiPM signal readout and multilayer processing system of the muon detection system in this application embodiment; Please see Figure 9 , Figure 9 This is a block diagram of the auxiliary layer subsystem design of the front-end SiPM signal readout and multilayer processing system of the muon detection system in this application embodiment; Specifically, in a multi-layered processing system, the top-level system is the main subsystem, responsible for the vast majority of data processing. The rest are auxiliary subsystems, responsible for handling missed muon events. The number of auxiliary subsystems is set according to the actual scenario requirements. Only when the main subsystem's AD conversion module is in the process of analog-to-digital conversion and the triggering module is not accepting triggers will the triggering module send a corresponding command signal to the control module. When the control module receives the corresponding command signal, it calls upon an idle auxiliary subsystem to handle the missed muon events not triggered by the main system's triggering module. When an auxiliary subsystem is handling missed muon events, the control module marks it as in use. Only after the auxiliary subsystem has completely processed the missed muon events and sent a signal timestamp and voltage value to the main subsystem for data storage and communication will the control module mark the auxiliary subsystem as idle, allowing it to be reallocated.

[0032] In addition, when multiple missed muon events occur, the control module sequentially checks each auxiliary layer subsystem and calls the idle auxiliary layer subsystem to process and transfer the recorded missed muon events.

[0033] The signal preprocessing module includes: a signal amplification submodule and a shaping submodule; The signal amplification submodule amplifies the analog signal through a charge amplifier; The shaping submodule performs shaping processing on the analog signal waveform through a Schmitt trigger.

[0034] Please see Figure 3 , Figure 3 This is a block diagram of the signal preprocessing of the SiPM signal readout and multilayer processing system at the front end of the muon detection system in this application embodiment; Specifically, the preprocessing of analog signals includes two parts: amplification and shaping, which are used to optimize the signal-to-noise ratio and obtain a more easily processed and more ideal original signal waveform; The signal amplification utilizes a charge amplifier, which features high gain, low noise, and fast response. Its high gain amplifies weak charge signals to a readable level, low noise ensures signal clarity, and fast response guarantees the circuit's ability to respond to the input signal quickly. The basic principle of a charge amplifier is to convert the charge in the input capacitor into a voltage signal and amplify it to a level sufficient for measurement.

[0035] Schmitt triggers can be used for signal shaping. In SiPM signal readout and processing, signal distortion during transmission is a common problem. When the capacitance on the transmission line is large, both the rising and falling edges of the waveform are significantly delayed during transmission. For example, if the transmission line is long and the impedance at the receiving end is mismatched with the transmission line's impedance, damped oscillations will occur on the rising and falling edges of the waveform.

[0036] The identification module is connected to the triggering module through a preset number of logical AND gates.

[0037] Please see Figure 4 , Figure 4 This is a schematic diagram of the SiPM signal readout at the front end of the muon detection system and the trigger signal generation of the multilayer processing system in an embodiment of this application; Specifically, after preprocessing the raw analog signal from the SiPM, the signals of each channel are identified and thresholds are set. Then, a trigger module is used to generate a trigger signal.

[0038] First, a discriminator is used to set a threshold voltage on the preprocessed signal to eliminate noise and filter out muon events. Because a muon must pass through both the upper and lower layers of the scintillator array to be recorded, the signal passing through the discriminator is combined with AND logic to form a coincident signal for adjacent channels. After the coincident signal is generated, it is sent to the trigger module, which then generates a corresponding muon event and sends it to the control module. The control module then initiates the generation of the signal timestamp and the readout of the analog signal.

[0039] A method for SiPM signal readout and multilayer processing at the front end of a muon detection system, the method comprising: The main subsystem acquires the electrical signal converted by the silicon photomultiplier tube (SiPM), processes and reads the electrical signal converted by the SiPM, generates a signal timestamp and voltage value, and sends it to the PC. The auxiliary layer subsystem reads and processes the muon events missed by the main layer subsystem, generates the signal timestamp and voltage value of the missed muon events, and sends the signal timestamp and voltage value to the main layer subsystem.

[0040] The main layer subsystem preprocesses missed muon events, and the identification module identifies the electrical signal converted by the silicon photomultiplier tube (SiPM) and sends it to the triggering module. The triggering module responds to and records the missed muon events but does not trigger the main layer subsystem. The triggering module sends a trigger signal to the control module. The control module calls an idle auxiliary layer subsystem to generate a signal timestamp for the missed muon events and read out the voltage value. The signal timestamp and the voltage value are simultaneously sent to the main layer subsystem for data storage and communication.

[0041] Please see Figure 5 , Figure 5 This is a schematic diagram and timing diagram of the single delay chain TDC structure of the SiPM signal readout and multilayer processing system at the front end of the muon detection system in this application embodiment; When the timestamp generation module receives a trigger signal, it can use the Time To Digital Converter (TDC) to generate a timestamp. The TDC employs a state-of-the-art dual-delay chain vernier caliper structure to improve the accuracy of the generated timestamp.

[0042] like Figure 5 As shown, Figure (a) is the schematic diagram of a single delay chain TDC structure, and Figure (b) is the timing diagram of a single delay chain TDC operation. First, a reference clock signal is input to the start terminal for calibration of subsequent times. The Vc input is a DLL (delay-locked loop), which can be used to process the start signal. A time delay is introduced, and the delay signals are input to the triggers. At this point, a trigger signal is input at the stop terminal, where ΔT is the time difference we need to measure. Without introducing a delay at the stop terminal, we can see that at the rising edge of the stop signal, the delay signal at the start terminal will have either a 1 or a 0 state. If the start signal is 1 before the rising edge of the stop signal arrives, the trigger output is 1; otherwise, it is 0. Therefore, the boundary where the trigger output switches from 1 to 0 is the time we need to measure. Each trigger output is a thermometer code, which is then converted to Gray code to generate a timestamp.

[0043] Please see Figure 6 , Figure 6 This is a schematic diagram and timing diagram of the dual delay chain TDC structure of the SiPM signal readout and multilayer processing system at the front end of the muon detection system in this application embodiment; However, single delay chain Since the accuracy can only reach the tens of ps level, a DLL is also introduced at the stop end to delay the trigger signal, mimicking the working principle of a vernier caliper. .like Figure 6As shown, (a) is the schematic diagram of the dual delay chain TDC structure, and (b) is the timing diagram of the dual delay chain TDC operation. In this case, the start delay is equivalent to the "coarse ruler" of a vernier caliper, and the stop delay is equivalent to the "fine ruler." Must be smaller than The accuracy is The principle is similar to that of a single delay chain, where the delayed signal at the stop terminal continuously catches up with the signal at the start terminal. Similarly, at a certain moment, the delayed signal at the stop terminal will catch up with the signal at the start terminal, and the trigger output will show a boundary between 1 and 0, at which point the required time can be measured.

[0044] Please see Figure 7 , Figure 7 This is a block diagram of the analog signal readout of the SiPM signal readout and the multilayer processing system at the front end of the muon detection system in this application embodiment; Specifically, analog signal readout includes two parts: a hold signal and analog-to-digital conversion. After preprocessing the raw SiPM signal, the preprocessed signal is held for a certain period. When the trigger module generates a trigger signal, the control module controls the readout of the hold signal, and the analog signal is converted into a digital signal using analog-to-digital conversion, which is then sent to the data storage module. Finally, the data is sent to the PC via the communication module.

[0045] 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 SiPM signal readout and multi-layer processing system for a muon detection system, characterized in that, The system includes: a main layer subsystem and at least one auxiliary layer subsystem; The main layer subsystem is connected to each of the auxiliary layer subsystems; The main layer subsystem includes: a signal preprocessing module, an identification module, a triggering module, a first timestamp generation module, a first holding module, a first AD conversion module, a data storage module, a control module, and a communication module; The signal preprocessing module processes the input electrical signal converted by the silicon photomultiplier tube (SiPM) and outputs the preprocessed signal to the discrimination module and the first holding module. The identification module identifies the input signal, sets a threshold voltage, and outputs a coincidence signal to the trigger module. The triggering module triggers the input signal, generates a trigger signal, and outputs it to the first timestamp generation module and the control module; The first timestamp generation module receives the timestamp generation instruction from the control module, generates a signal timestamp, and sends the signal timestamp to the data storage module; The first holding module receives the analog signal and performs holding processing; The first AD conversion module receives the analog signal readout instruction sent by the control module, performs AD conversion on the analog signal stored in the first holding module to generate a digital signal, and sends the digital signal to the data storage module; When the control module receives the trigger signal, it sends the analog signal readout instruction to the first AD conversion module and the timestamp generation instruction to the first timestamp generation module. The data storage module sends the data in the data storage module to the PC through the communication module; The main layer subsystem also includes a temperature compensation module; The temperature compensation module is used to compensate for the temperature of the SiPM, reducing errors caused by gain changes and dark counting. The auxiliary layer subsystem includes: a second timestamp generation module, a second retention module, and a second AD conversion module; The second timestamp generation module in the auxiliary layer subsystem receives the trigger signal transmitted by the trigger module and the timestamp generation instruction of the control module, generates a signal timestamp, and sends the signal timestamp to the data storage module; The second holding module in the auxiliary layer subsystem is used to receive the analog signal readout command generated by the control module and the analog signal preprocessed by the signal preprocessing module. The second AD conversion module in the auxiliary layer subsystem performs AD conversion on the analog signal transmitted by the second holding module in the auxiliary layer subsystem to generate a digital signal, and sends the digital signal to the data storage module; The signal preprocessing module includes: a signal amplification submodule and a shaping submodule; The signal amplification submodule amplifies the analog signal through a charge amplifier; The shaping submodule uses a Schmitt trigger to shape the analog signal waveform; The identification module is connected to the triggering module through a preset number of logical AND gates; The main layer subsystem is used to read the voltage value of the electrical signal converted by the silicon photomultiplier tube (SiPM) and process the timestamp of the signal generated by the electrical signal converted by the SiPM, and send the voltage value and the timestamp to the PC. The auxiliary layer subsystem is used to read and process the muon events missed by the main layer subsystem, generate the signal timestamp and voltage value of the missed muon events, and send the signal timestamp and voltage value to the main layer subsystem. When the AD conversion module of the main layer subsystem is in the process of analog-to-digital conversion and the triggering module does not accept triggering, the triggering module sends the corresponding command signal to the control module. When the control module receives the corresponding command signal, the control module calls the idle auxiliary layer subsystem to handle the missed muon events that the triggering module has not triggered.

2. A method for SiPM signal readout and multi-layer processing at the front end of a muon detection system, implemented based on the SiPM signal readout and multi-layer processing system at the front end of a muon detection system as described in claim 1, characterized in that, The method includes: The main subsystem acquires the electrical signal converted by the silicon photomultiplier tube (SiPM), processes and reads the electrical signal converted by the SiPM, generates a signal timestamp and voltage value, and sends it to the PC. The auxiliary layer subsystem reads and processes the muon events missed by the main layer subsystem, generates the signal timestamp and voltage value of the missed muon events, and sends the signal timestamp and voltage value to the main layer subsystem.

3. The method for SiPM signal readout and multi-layer processing at the front end of a muon detection system as described in claim 2, characterized in that, include: The main layer subsystem preprocesses missed muon events, and the identification module identifies the electrical signal converted by the silicon photomultiplier tube (SiPM) and sends it to the triggering module. The triggering module responds to and records the missed muon events but does not trigger the main layer subsystem. The triggering module sends a trigger signal to the control module. The control module calls an idle auxiliary layer subsystem to generate a signal timestamp for the missed muon events and read out the voltage value. The signal timestamp and the voltage value are simultaneously sent to the main layer subsystem for data storage and communication.

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