Cosmic ray muon imaging system and method

Abstract

The invention relates to the technical field of imaging systems, and discloses a cosmic ray muon imaging system and a cosmic ray muon imaging method. The detector is arranged on the supporting structure through a driving motor, is driven by the supporting structure to rotate and is used for responding to and reading the muon signal; the readout electronics system is respectively connected with the detector and the driving motor and is used for collecting and processing muon signals read out by the detector and communicating with back-end equipment in real time; and the driving motor is arranged on the supporting structure and is used for driving the readout electronics system and the detector to rotate. According to the invention, impact events of cosmic ray muons at different angles can be recorded.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging systems, and in particular to a cosmic ray muon imaging system and method. Background Art

[0002] At present, muon detectors are mainly divided into scintillator detectors, gas detectors, etc. They are used for multi-angle and all-round detection of cosmic rays and their derivative phenomena. Changes in the spatial distribution of muons in the environment are usually caused by drastic changes in the environment, and because the propagation speed of muons is faster than changes in the physical environment, monitoring the spatial distribution of muons can achieve monitoring of environmental changes. Therefore, how to record the impact events of cosmic ray muons at different angles has become a technical problem that needs to be solved urgently. Summary of the invention

[0003] In view of the above problems, an object of the present invention is to provide a cosmic ray muon imaging system and method, which can record cosmic ray muon impact events at different angles.

[0004] To achieve the above object, the present invention adopts the following technical solution: a cosmic ray muon imaging system, comprising: Support structure; The detector is arranged on the support structure through a driving motor and driven to rotate by the support structure to respond to and read out the muon signal; The readout electronics system is connected to the detector and the drive motor, and is used to collect and process the muon signals read out by the detector and communicate with the back-end equipment in real time; The drive motor is arranged on the support structure and is used for driving the readout electronics system and the detector to rotate.

[0005] Furthermore, it also includes a protective sleeve; the protective sleeve adopts a cylindrical structure, and both ends thereof are open; The drive motor, readout electronics system and detector are arranged in a protective sleeve; The protective sleeve is arranged on the supporting structure, and the position angle of the protective sleeve is adjusted to a desired angle through the supporting structure.

[0006] Further, the support structure includes a stainless steel bracket, a support plate and rollers; The two sides of the stainless steel bracket adopt a triangular structure, and a support plate is arranged in the upper part of the triangular structure on each side, and the driving motor and the protective sleeve are installed on the stainless steel bracket through the support plate; A roller is respectively arranged at the four top corners of the bottom of the stainless steel bracket.

[0007] Furthermore, the support structure also includes screws with adjustable angles; the support plate is connected to the drive motor and the protective sleeve via screws with adjustable angles; The position angles of the protection sleeve and the drive motor are adjusted by an angle-adjustable screw.

[0008] Furthermore, fixing plates are respectively provided on both sides of the protective sleeve, and the drive motor is fixed in the protective sleeve through the fixing plates on both sides; the fixing plates are connected to the support plates through screws with adjustable angles.

[0009] Further, the detector includes a first strip-shaped plastic scintillator, a second strip-shaped plastic scintillator and a silicon photomultiplier tube; The length of the first strip-shaped plastic scintillator is greater than that of the second strip-shaped plastic scintillator, and the second strip-shaped plastic scintillator is arranged inside the first strip-shaped plastic scintillator to form a pair of scintillators with a gap therebetween; A pair of scintillators are respectively arranged on both sides of the readout electronics system, and the two pairs of scintillators are symmetrically arranged with the readout electronics system as a symmetry center; The front ends of the first strip plastic scintillator and the second strip plastic scintillator are coupled with silicon photomultiplier tubes, which convert the light signal generated by the cosmic muon hitting the scintillator detected by the scintillator into an electrical signal and transmit it to the readout electronics system via a radio frequency connecting line.

[0010] Further, the readout electronics system includes a circuit board, and a SiPM and a detector circuit, a GNSS circuit, a posture sensor circuit, a WIFI communication circuit, a PWM high-voltage control circuit, an FPGA, an analog modulation circuit, and a high-speed comparator circuit arranged on the circuit board; The FPGA controls the PWM high-voltage control circuit to generate the bias voltage of the SiPM, and inputs it into the SiPM and the detector circuit. The SiPM and the detector circuit receive the muon distribution electrical signal transmitted to them through the silicon photomultiplier tube in the detector, and the SiPM and the detector circuit output a charge pulse signal, which is fed into the analog modulation circuit for IV conversion, filtering and shaping processing; the processed voltage signal is transmitted to the high-speed comparator circuit, compared with the preset voltage threshold, and the comparison result is output, and the comparison result is fed back to the FPGA; the GNSS circuit is used to detect the absolute time information of each muon detected by the detector and transmit it to the FPGA; the attitude sensor circuit is used to detect the spatial angle information of each muon detected by the detector and transmit it to the FPGA; the FPGA processes the received signal and packages it and sends it to the WIFI communication circuit, and communicates with the back-end equipment through the WIFI communication circuit.

[0011] Furthermore, the readout electronics system also includes an electronics fixing bracket; the circuit board is connected to the electronics fixing bracket through a copper seat, and a pair of scintillators are fixedly arranged on both sides of the electronics fixing bracket. The bottom center position of the electronics fixing bracket is connected to the output shaft of the driving motor through a brush, and the driving motor drives the electronics fixing bracket and the circuit board to rotate, thereby driving the two pairs of scintillators to rotate to change the angle of the scintillators.

[0012] Furthermore, the FPGA can output the ignition count of each plastic scintillator per second and the spatial angle and absolute time information of each muon impact event. After the set position test, the muon flux calculation and the muon incident zenith angle count distribution calculation are performed through the test and analysis of the ignition data and the information analysis of each muon impact event. The muon impact count is corrected by the accidental coincidence count of muons to obtain the distribution relationship of the muon incident zenith angle at the set position, the relationship between the muon impact event and time, and the angle flux change data with the angle.

[0013] A cosmic ray muon imaging method is implemented based on the above-mentioned cosmic ray muon imaging system, which includes: numbering each plastic scintillator, adjusting the position of the protection sleeve by an angle-adjustable screw according to the use requirements, and then adjusting the spatial angle of the detector and the readout electronics system by a driving motor; the energy generated when the muon passes through is detected by two pairs of plastic scintillators and converted into a photon signal, and the SiPM converts the photon signal into an electrical signal, which is transmitted to the SiPM and the detector circuit; FPGA controls the PWM high-voltage circuit to generate a bias voltage of the SiPM and inputs it into the SiPM, and after the detector circuit receives the light signal generated by the muon passing through the scintillator, the SiPM converts and outputs a charge pulse signal, and the charge pulse signal is fed to the analog modulation circuit for IV conversion, filtering and shaping processing; The processed voltage signal is transmitted to the high-speed comparator circuit, compared with the preset voltage threshold, and the comparison result is output, which is fed back to the FPGA; at the same time, the absolute time information and spatial angle information of each muon obtained by the GNSS circuit and the attitude sensor circuit are transmitted to the FPGA; the FPGA uses the set triggering method to trigger plastic scintillators with different numbers, and outputs the ignition count and triggering status of each plastic scintillator. Through the testing and analysis of the ignition count and triggering status data, the muon flux is calculated and corrected, and the flux of cosmic ray muons at a given position and the data of the cosmic ray muon incident zenith angle distribution are obtained; by analyzing the collected data, the distribution of muons in the measured environment is monitored in real time. When changes in the muon distribution are detected, possible environmental change events can be predicted.

[0014] The present invention adopts the above technical solution, which has the following advantages: 1. Compared with other detectors, the plastic scintillator detector used in the present invention has a higher light yield and can effectively convert the energy generated by the passage of high-energy particles into photon signals; it can respond quickly and emit photons within nanoseconds, so that the detector has a high time resolution; it can be easily processed into various shapes and sizes to meet different detection needs; it is relatively low-cost, and its materials and related manufacturing process costs are low.

[0015] 2. Compared with other photoelectric conversion devices, the present invention adopts silicon photomultiplier tube readout method, which has high gain characteristics and can effectively amplify weak light signals. Its high photon detection efficiency enables more photons to be detected, thereby improving the signal strength and signal-to-noise ratio; it has the advantage of low operating voltage. For example, photomultiplier tubes (PMTs) usually require an operating voltage of more than one thousand volts, while silicon photomultiplier tubes have a lower operating voltage, usually in the range of tens of volts, which simplifies power supply design and use; it has the advantages of miniaturization and integration. SiPM is small in size and light in weight, and is easy to integrate into the detector system, which is particularly suitable for applications requiring space and weight restrictions; it has higher mechanical stability and durability. SiPM is made of solid-state semiconductor materials and does not have fragile vacuum tubes and high-voltage components. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall structure of a cosmic ray muon imaging system in an embodiment of the present invention; Figure 2 It is a schematic diagram of the structure of the detector and readout electronics in an embodiment of the present invention; Figure 3 is a schematic diagram of the readout electronics principle in an embodiment of the present invention; Figure 4 is a schematic diagram of detector position coding in an embodiment of the present invention; Figure 5 Schematic diagram of the structure and dimensions of the plastic flash in an embodiment of the present invention; Reference numerals: 1-readout electronics system; 2-drive motor; 3-protective sleeve; 4-stainless steel bracket; 5-support plate; 6-roller; 7-angle-adjustable screw; 8-fixing plate; 9-first strip plastic scintillator; 10-second strip plastic scintillator; 11-silicon photomultiplier tube; 12-circuit board; 13-brush; 14-electronic fixing bracket. DETAILED DESCRIPTION

[0017] Cosmic rays are high-energy particle streams from deep in the universe, mainly composed of protons, heavy nuclei and electrons. When these high-energy particles interact with the Earth's atmosphere, a series of secondary particles are produced. Cosmic ray muons are mainly produced by the decay of pions produced by the reaction of high-energy protons in interstellar space with the Earth's atmosphere. Among the charged particles in cosmic rays, muons are the most numerous particles that reach the sea level. Factors such as the Earth's latitude, solar activity cycle, and temperature have a certain impact on the muon flux. Muons are very similar to electrons, but their mass is about 207 times that of electrons and their lifetime is about 2.2 microseconds, but they can propagate through the universe at an astonishing speed.

[0018] According to research, muons have strong penetrating power and can pass through materials that are hundreds of meters to kilometers thick. By studying muons, we can reveal deeper mysteries of the universe, thereby promoting human understanding of the origin and evolution of the universe. In high-energy physics experiments, muons are also used to study the properties and interactions of particles, opening a new window for understanding the microscopic world. The main applications of muons are: 1) Particle physics research. Muons can be used to study the interactions and physical processes of elementary particles in high-energy physics. They can be used to measure the energy spectrum of cosmic rays, detect particle annihilation and reaction products, etc.; 2) Nuclear industry. Muons can be used for non-destructive testing of nuclear fuel storage containers. By measuring the scattering and absorption of muons in storage containers, it can help evaluate the integrity and safety of storage containers; 3) Underground detection. Muons are used to detect underground structures and geological features. By measuring the absorption and scattering of muons by underground materials, information about underground structures, such as rock formations, caves or mineral deposits, can be obtained; 4) Nuclear fusion. Muons can be used to study the behavior and properties of plasma in nuclear fusion reactions. By measuring the energy spectrum and angular distribution of muons, the temperature, density and flow information of plasma can be revealed, which helps to optimize and control nuclear fusion experiments.

[0019] In order to realize the recording of cosmic ray muon impact events at different angles, the flux of cosmic ray muons at a given position and the data of the cosmic ray muon incident zenith angle distribution are obtained through impact events at different angles. Through these data analysis, the distribution of muons in the measured environment is monitored in real time. When changes in the muon distribution are monitored, possible environmental change events can be predicted. The present invention provides a cosmic ray muon imaging system and method, which has the characteristics of high efficiency, simplicity, and real-time.

[0020] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] In one embodiment of the present invention, a cosmic ray muon imaging system is provided. In this embodiment, Figure 1 As shown, the system includes: A supporting structure, used for supporting the entire imaging system; The detector is arranged on the support structure through the driving motor 2, and is driven by the support structure to rotate with high precision, so as to respond and read out the muon signal efficiently and quickly; The readout electronics system 1 is connected to the detector and the drive motor 2 respectively, and is used to collect and process the muon signal read out by the detector, and communicate with the back-end equipment in real time; The driving motor 2 is arranged on the supporting structure and is used to drive the readout electronics system 1 and the detector to rotate.

[0023] When in use, the detector and the readout electronics system 1 are driven by the drive motor 2 and the supporting structure to rotate and change the angle, so that the detector can respond efficiently and quickly to read the muon signals at different angles, and the muon signals are collected and processed by the readout electronics system 1. The processed muon signals are transmitted to the back-end equipment via the readout electronics system 1 to realize the recording of cosmic ray muon impact events at different angles.

[0024] In a preferred embodiment, the cosmic ray muon imaging system further includes a protective sleeve 3 for fixing and protecting the detector and the readout electronic system. The protective sleeve 3 is a cylindrical structure with both ends open. The drive motor 2, the readout electronics system 1 and the detector are arranged in the protective sleeve 3; the protective sleeve 3 is arranged on a support structure, and the position angle of the protective sleeve 3 can be adjusted to a desired angle through the support structure, for example, the protective sleeve 3 can be adjusted to be placed horizontally with both ends open on the horizontal line, or the protective sleeve 3 can be adjusted to be placed vertically with both ends open on the vertical line.

[0025] In a preferred embodiment, the support structure includes a stainless steel bracket 4, a support plate 5 and a roller 6. The two sides of the stainless steel bracket 4 adopt a triangular structure, and a support plate 5 is provided in the upper part of the triangular structure on each side, and the drive motor 2 and the protective sleeve 3 are installed on the stainless steel bracket 4 through the support plate 5. A roller 6 is provided at each of the four top corners at the bottom of the stainless steel bracket 4 to facilitate the movement of the entire imaging system. When in use, the stainless steel bracket 4 can ensure the stability and accuracy of the imaging system during operation.

[0026] In this embodiment, the support structure further includes an angle-adjustable screw 7. The support plate 5 is fixedly connected to the drive motor 2 and the protective sleeve 3 by the angle-adjustable screw 5. The position angle of the protective sleeve 3 and the drive motor 2 can be adjusted by the angle-adjustable screw 5.

[0027] In this embodiment, fixing plates 8 are respectively provided on both sides of the protective sleeve 3, and the drive motor 2 is fixed in the protective sleeve 3 through the fixing plates 8 on both sides. At the same time, the fixing plates 8 are connected to the support plate 5 through screws 5 with adjustable angles.

[0028] In a preferred embodiment, Figure 2 As shown, the detector includes a first strip-shaped plastic scintillator (W) 9, a second strip-shaped plastic scintillator (N) 10 and a silicon photomultiplier (SiPM) 11. The length of the first strip-shaped plastic scintillator 9 is greater than the length of the second strip-shaped plastic scintillator 10, and the second strip-shaped plastic scintillator 10 is arranged on the inner side of the first strip-shaped plastic scintillator 9 to form a pair of scintillators, with a gap between the two. A pair of scintillators is arranged on both sides of the readout electronics system (that is, the second strip-shaped plastic scintillator 10 is adjacent to the readout electronics system), and the two pairs of scintillators are symmetrically arranged with the readout electronics system as the symmetry center. The front ends of the first strip-shaped plastic scintillator 9 and the second strip-shaped plastic scintillator 10 are coupled with a silicon photomultiplier 11, and the light signal generated by the cosmic muon hitting the scintillator detected by the scintillator is converted into an electrical signal through the silicon photomultiplier 11, and transmitted to the readout electronics system via a radio frequency connection line.

[0029] In this embodiment, in each pair of scintillators, the gap distance between the first strip-shaped plastic scintillator 9 and the second strip-shaped plastic scintillator 10 is preferably 204 mm.

[0030] Preferably, Figure 5 As shown, the sizes of the first strip-shaped plastic scintillator 9 and the second strip-shaped plastic scintillator 10 are 400 mm (length)×40 mm (width)×10 mm (thickness) and 300 mm (length)×25 mm (width)×10 mm (thickness), respectively.

[0031] In a preferred embodiment, Figure 2 , Figure 3 As shown, the readout electronics system 1 includes a circuit board 12 and an electronics fixing bracket 14, as well as a SiPM and a detector circuit, a GNSS circuit, a posture sensor circuit, a WIFI communication circuit, a PWM high-voltage control circuit, an FPGA, an analog modulation circuit, a high-speed comparator circuit and peripheral circuits arranged on the circuit board 12; it is used for data acquisition and signal processing, and provides necessary data support for subsequent data analysis and image reconstruction.

[0032] The circuit board 12 is connected to the electronic fixing bracket 14 through a copper seat. A pair of scintillators are fixedly arranged on both sides of the electronic fixing bracket 14. The bottom center of the electronic fixing bracket 14 is connected to the output shaft of the driving motor 2 through a brush 13. The driving motor 2 drives the electronic fixing bracket 14 and the circuit board 12 to rotate, thereby driving the two pairs of scintillators to rotate to change the angle of the scintillators. In this embodiment, the output shaft of the driving motor 2 is used as the symmetry axis. The driving motor 2 can realize that the two pairs of scintillators rotate around the symmetry axis at an adjustable rotation rate of 0.5 cycles / s to 10 cycles / s, so as to monitor the distribution of cosmic ray muons at different angles in real time.

[0033] In this embodiment, the scintillator is fixed on both sides of the electronics fixing bracket 14 by bolts.

[0034] In this embodiment, the FPGA controls the PWM high-voltage control circuit to generate the bias voltage of the SiPM and the SiPM 11 in the detector circuit, and inputs it to the SiPM. The detector circuit receives the muon distribution electrical signal transmitted to it by the silicon photomultiplier in the detector, and the SiPM and the detector circuit output the charge pulse signal, which is fed to the analog modulation circuit for IV conversion, filtering and shaping processing; the processed voltage signal is transmitted to the high-speed comparator circuit, compared with the preset voltage threshold, and the comparison result is output, and the comparison result is fed back to the FPGA. The GNSS circuit is used to detect the absolute time information of each muon detected by the detector and transmit it to the FPGA; the attitude sensor circuit is used to detect the spatial angle information of each muon detected by the detector and transmit it to the FPGA. The FPGA processes the received signal and packages it to the WIFI communication circuit, and communicates with the back-end device through the WIFI communication circuit.

[0035] like Figure 4 As shown, the present invention uses four plastic scintillators: two first strip-shaped plastic scintillators W1 and W2, and two second strip-shaped plastic scintillators N1 and N2. The triggering modes are classified into five categories, as shown in Table 1.

[0036]

[0037] Among them, Y means ignition, N means no signal, and X means don't care. For each muon hit event, record the type of triggering.

[0038]

[0039]

[0040]

[0041]

[0042]

[0043] In the formula, and The detection efficiency of plastic flash W1 and W2 is calculated using the count values ​​of different trigger numbers during the entire test time. For a better test system, the detection efficiency should be above 90%. is the flux, calculated by dividing the trigger number T4 by the product of the detection efficiencies of the plastic flashes W1 and W2. For the accidental coincidence count value, is the length of time each muon hits the record in the FPGA, and is the average ignition count per second of plastic flash W1 and W2, The role of is to correct the real trigger count. In the test, the real hit count is the integral of the muon hit count during the test time minus the integral of the accidental coincidence count value during the test time.

[0044] Therefore, the ignition count of each plastic scintillator per second and the spatial angle and absolute time information of each muon hit event are output in the FPGA. After the set position test, the muon flux calculation and the muon incident zenith angle count distribution calculation are performed by testing and analyzing the ignition count and trigger situation data, as well as the information analysis of each muon hit event. The muon hit count is corrected by the accidental coincidence count of the muon, and the distribution relationship of the muon incident zenith angle at the set position, the distribution relationship of the muon hit event over time, and the angle flux change data with the spatial angle are obtained, thereby completing the imaging of the muon (including the distribution relationship of the muon incident zenith angle at the set position, the distribution relationship of the muon hit event over time, and the angle flux change data with the spatial angle, etc.). For the results of the fixed position, the present invention can compare them with the data of subsequent tests to monitor environmental changes.

[0045] In summary, the imaging system of the present invention can realize the imaging of cosmic ray muons efficiently, simply and in real time.

[0046] In one embodiment of the invention, a cosmic ray muon imaging method is provided, which is implemented based on the cosmic ray muon imaging system in the above embodiments. In this embodiment, the imaging method includes the following steps: 1) Number each plastic scintillator, adjust the position of the protective sleeve 3 by the angle-adjustable screw 5 according to the use requirements, and then adjust the spatial angle of the detector and the readout electronics system 1 by the drive motor 2; 2) The energy generated by the muon passing through the two pairs of plastic scintillators is converted into a photon signal, and the SiPM11 converts the photon signal into an electrical signal and transmits it to the SiPM and detector circuit; 3) FPGA controls the PWM high-voltage circuit to generate the bias voltage of SiPM 11 and inputs it into SiPM. After the detector circuit receives the light signal generated by the muon passing through the scintillator, SiPM converts and outputs the charge pulse signal. The charge pulse signal is fed into the analog modulation circuit for IV conversion, filtering and shaping. 4) The processed voltage signal is transmitted to the high-speed comparator circuit, compared with the preset voltage threshold, and the comparison result is output, which is fed back to the FPGA; at the same time, the absolute time information and spatial angle information of each muon obtained by the GNSS circuit and the attitude sensor circuit are transmitted to the FPGA; 5) FPGA uses the set triggering mode to trigger plastic scintillators with different numbers, outputs the ignition count and triggering status of each plastic scintillator, and calculates and corrects the muon flux through testing and analyzing the ignition count and triggering status data, and obtains the cosmic ray muon flux at a given position and the cosmic ray muon incident zenith angle distribution data; 6) By analyzing the collected data, the distribution of muons in the measured environment can be monitored in real time. When changes in the muon distribution are detected, possible environmental change events can be predicted.

[0047] The method provided in this embodiment is implemented based on the above-mentioned system embodiments. Please refer to the above-mentioned embodiments for the specific process and detailed contents, which will not be repeated here.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cosmic ray muon imaging system, characterized in that: include: Support structure; The detector is arranged on the support structure through a driving motor and driven to rotate by the support structure to respond to and read out the muon signal; The readout electronics system is connected to the detector and the drive motor, and is used to collect and process the muon signals read out by the detector and communicate with the back-end equipment in real time; The drive motor is arranged on the support structure and is used for driving the readout electronics system and the detector to rotate.

2. The cosmic ray muon imaging system according to claim 1, characterized in that: The protective sleeve is provided. The protective sleeve adopts a cylindrical structure, and both ends thereof are open. The drive motor, readout electronics system and detector are arranged in a protective sleeve; The protective sleeve is arranged on the supporting structure, and the position angle of the protective sleeve is adjusted to a desired angle through the supporting structure.

3. The cosmic ray muon imaging system according to claim 1, characterized in that: The supporting structure includes stainless steel brackets, support plates and rollers; The two sides of the stainless steel bracket adopt a triangular structure, and a support plate is arranged in the upper part of the triangular structure on each side, and the driving motor and the protective sleeve are installed on the stainless steel bracket through the support plate; A roller is respectively arranged at the four top corners of the bottom of the stainless steel bracket.

4. The cosmic ray muon imaging system according to claim 3, characterized in that: The support structure also includes screws with adjustable angles; the support plate is connected to the drive motor and the protective sleeve via screws with adjustable angles; The position angles of the protection sleeve and the drive motor are adjusted by an angle-adjustable screw.

5. The cosmic ray muon imaging system according to claim 4, characterized in that: Fixed plates are respectively arranged on both sides of the protective sleeve, and the drive motor is fixed in the protective sleeve through the fixed plates on both sides; the fixed plates are connected to the support plates through screws with adjustable angles.

6. The cosmic ray muon imaging system according to claim 1, characterized in that: The detector includes a first strip-shaped plastic scintillator, a second strip-shaped plastic scintillator and a silicon photomultiplier tube; The length of the first strip-shaped plastic scintillator is greater than that of the second strip-shaped plastic scintillator, and the second strip-shaped plastic scintillator is arranged inside the first strip-shaped plastic scintillator to form a pair of scintillators with a gap therebetween; A pair of scintillators are respectively arranged on both sides of the readout electronics system, and the two pairs of scintillators are symmetrically arranged with the readout electronics system as a symmetry center; The front ends of the first strip plastic scintillator and the second strip plastic scintillator are coupled with silicon photomultiplier tubes, which convert the light signal generated by the cosmic muon hitting the scintillator detected by the scintillator into an electrical signal and transmit it to the readout electronics system via a radio frequency connecting line.

7. The cosmic ray muon imaging system according to claim 1, characterized in that: The readout electronics system includes a circuit board, and a SiPM and a detector circuit, a GNSS circuit, a posture sensor circuit, a WIFI communication circuit, a PWM high-voltage control circuit, an FPGA, an analog modulation circuit, and a high-speed comparator circuit arranged on the circuit board; The FPGA controls the PWM high-voltage control circuit to generate the bias voltage of the SiPM, and inputs it into the SiPM and the detector circuit. The SiPM and the detector circuit receive the muon distribution electrical signal transmitted to them by the silicon photomultiplier tube in the detector, and the SiPM and the detector circuit output a charge pulse signal, which is fed into the analog modulation circuit for IV conversion, filtering and shaping processing; the processed voltage signal is transmitted to the high-speed comparator circuit, compared with the preset voltage threshold, and the comparison result is output, and the comparison result is fed back to the FPGA; the GNSS circuit is used to detect the absolute time information of each muon detected by the detector and transmit it to the FPGA; The attitude sensor circuit is used to detect the spatial angle information of each muon detected by the detector and transmit it to the FPGA; the FPGA processes the received signal, packages it and sends it to the WIFI communication circuit, and communicates with the back-end device through the WIFI communication circuit.

8. The cosmic ray muon imaging system according to claim 7, characterized in that: The readout electronics system also includes an electronics fixing bracket; the circuit board is connected to the electronics fixing bracket through a copper seat, a pair of scintillators are fixedly arranged on both sides of the electronics fixing bracket, and the bottom center position of the electronics fixing bracket is connected to the output shaft of the driving motor through a brush. The driving motor drives the electronics fixing bracket and the circuit board to rotate, thereby driving the two pairs of scintillators to rotate to change the angle of the scintillators.

9. The cosmic ray muon imaging system according to claim 7, characterized in that: The FPGA can output the ignition count of each plastic scintillator per second and the spatial angle and absolute time information of each muon impact event. After the set position test, the muon flux calculation and the muon incident zenith angle count distribution calculation are performed through the test and analysis of the ignition data and the information analysis of each muon impact event. The muon impact count is corrected by the accidental coincidence count of muons to obtain the distribution relationship of the muon incident zenith angle at the set position, the relationship between the muon impact event and time, and the angle flux change data with angle.

10. A cosmic ray muon imaging method, implemented based on the cosmic ray muon imaging system according to any one of claims 1 to 9, characterized in that: include: Each plastic scintillator is numbered, and the position of the protective sleeve is adjusted by the angle-adjustable screw according to the usage requirements, and the driving motor adjusts the spatial angle of the detector and the readout electronics system; The energy generated by the passage of muons detected by two pairs of plastic scintillators is converted into photon signals, and the SiPM converts the photon signals into electrical signals, which are transmitted to the SiPM and detector circuits; FPGA controls the PWM high-voltage circuit to generate the bias voltage of SiPM and input it into SiPM. After the detector circuit receives the light signal generated by the muon passing through the scintillator, SiPM converts and outputs the charge pulse signal. The charge pulse signal is fed into the analog modulation circuit for IV conversion, filtering and shaping. The processed voltage signal is transmitted to the high-speed comparator circuit, compared with the preset voltage threshold, and the comparison result is output, and the comparison result is fed back to the FPGA; at the same time, the absolute time information and spatial angle information of each muon obtained by the GNSS circuit and the attitude sensor circuit are transmitted to the FPGA; FPGA uses the set triggering mode to trigger plastic scintillators with different numbers, outputs the ignition count and triggering status of each plastic scintillator, and calculates and corrects the muon flux through testing and analyzing the ignition count and triggering status data, and obtains the cosmic ray muon flux at a given position and the cosmic ray muon incident zenith angle distribution data; By analyzing the collected data and monitoring the distribution of muons in the measured environment in real time, when changes in the muon distribution are detected, possible environmental change events can be predicted.

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