Multilayer scintillator probe, detector and method based on scintillating optical fiber

Abstract

The present application provides a multi-layer scintillator probe, detector, and method based on scintillating fiber, belonging to the field of nuclear detection technology. The probe includes a probe body, the probe body including a first scintillating fiber layer, a second scintillator layer, and a third scintillator layer. The second scintillator layer is disposed between the first and third scintillator layers. The first scintillating fiber layer is used to distinguish between gamma particles and beta particles. The second scintillator layer is used to absorb beta particles that pass through the first scintillating fiber layer. The third scintillator layer is used to measure gamma particles. This method can identify beta particles and gamma particles in a β-γ mixed field and accurately measure the energy spectrum of beta particles and gamma particles simultaneously in the β-γ mixed field.

Description

Technical Field

[0001] The present application belongs to the field of nuclear detection technology, and specifically relates to a multi-layer scintillator probe, detector and method based on scintillating optical fiber. Background Art

[0002] Beta and gamma rays often coexist in nuclear industry sites, nuclear science, medical physics, environmental monitoring, and safety inspections. Due to their significant differences in properties and the resulting damage to human tissue, accurately distinguishing and measuring the energy spectra of beta and gamma particles in mixed fields is crucial for radiation protection. Due to the difficulty in distinguishing between beta and gamma particles in mixed fields, existing equipment cannot simultaneously measure both beta and gamma spectra. Furthermore, the mutual influence of the two measurements makes it difficult to accurately measure the energy spectra of beta particles in mixed beta-gamma fields. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present application is to provide a multi-layer scintillator probe, detector and method based on scintillating optical fiber, which can realize the identification of β particles and γ particles in the β-γ mixed field, and realize the simultaneous and accurate measurement of the β particle energy spectrum and the γ particle energy spectrum in the β-γ mixed field.

[0004] In order to solve the above problems, the first aspect of an embodiment of the present application provides a multi-layer scintillator probe based on scintillating optical fiber, including a probe body, wherein the probe body includes a first scintillating optical fiber layer, a second layer of scintillator and a third layer of scintillator, the second layer of scintillator is arranged between the first scintillating optical fiber layer and the third layer of scintillator, the first scintillating optical fiber layer is used to distinguish between γ particles and β particles, the second layer of scintillator is used to absorb β particles passing through the first scintillating optical fiber layer, and the third layer of scintillator is used to measure γ particles.

[0005] Optionally, the first scintillating fiber layer is formed by scintillating fibers arranged in a matrix; the second layer of scintillators is a plastic scintillator; and the third layer of scintillators is a cesium iodide scintillator.

[0006] Optionally, the probe body further includes a polyester film, and the outer surfaces of the second scintillator layer and the third scintillator layer are both wrapped by the polyester film.

[0007] Optionally, the probe further includes a silicon photomultiplier tube, a signal amplifying board and a signal output head. The first scintillating fiber layer, the second layer of scintillator and the third layer of scintillator are arranged in one-to-one correspondence with the silicon photomultiplier tube. One of the silicon photomultiplier tubes is connected to the first scintillating fiber layer, and the other two silicon photomultiplier tubes are connected to the corresponding second layer of scintillator and the third layer of scintillator after passing through the polyester film. The signal amplifying board is connected to the silicon photomultiplier tube, and the signal output head is arranged on the surface of the signal amplifying board facing away from the silicon photomultiplier tube.

[0008] Optionally, the probe further includes a shell, and the probe body, the silicon photomultiplier tube, the signal amplifying board and the signal output head are encapsulated in the shell.

[0009] Optionally, the shell includes a first end plate, a window is formed on the first end plate, and a polyester film sheet is provided inside the window to form an exploration window.

[0010] Optionally, the housing further includes a second end plate, on which a plurality of connectors are provided, and the signal output head is connected to the connectors correspondingly via optical fibers.

[0011] A second aspect of the present application provides a detector comprising any one of the above-mentioned multi-layer scintillator probes based on scintillation optical fibers.

[0012] A third aspect of the present application provides a method for obtaining a beta particle energy spectrum and a gamma particle energy spectrum, which is measured using the detector described above. The method for obtaining a beta particle energy spectrum and a gamma particle energy spectrum comprises:

[0013] respectively collecting scintillation photons generated by the first scintillating fiber layer, the second scintillator layer, and the third scintillator layer, and converting them into electrical signals for output;

[0014] The electrical signal in each layer is divided into two paths. The first path retains the original energy information, and the second path is sent to the logic coincidence unit for identifying beta particles and gamma particles.

[0015] The first electrical signal and the second logical signal processed by the logic coincidence unit are coupled and a detection signal is output, and the output detection signal is classified to identify the beta particle energy spectrum and the gamma particle energy spectrum.

[0016] Optionally, another path is fed into a logic coincidence unit for identifying particle types, including:

[0017] The logic coincidence unit determines the energy deposition of particles in each layer according to the preset threshold;

[0018] When the energy deposition is higher than the preset threshold, a "1" signal is output; when the energy deposition is less than or equal to the preset threshold, a "0" signal is output;

[0019] The logic signals output by the first scintillating fiber layer, the second scintillator layer, and the third scintillator layer are combined to identify "100" and "110" events as beta particles and "001" event as gamma particles.

[0020] By means of the above technical solution, the present invention has at least the following beneficial effects:

[0021] The embodiments of the present application provide a multi-layer scintillator probe, detector and method based on scintillating optical fiber. By sequentially arranging a first scintillating optical fiber layer, a second scintillator layer and a third scintillator layer, wherein the first scintillating optical fiber layer is used to distinguish between gamma particles and beta particles, the second scintillator layer is used to absorb beta particles passing through the first scintillating optical fiber layer, and the third scintillator layer is used to measure gamma particles, the multi-layer scintillator probe, detector and method can realize the identification of beta particles and gamma particles in a β-gamma mixed field, and realize the simultaneous and accurate measurement of the energy spectrum of beta particles and the energy spectrum of gamma particles in the β-gamma mixed field. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the probe body of a multi-layer scintillator probe based on scintillation optical fiber according to an embodiment of the present application;

[0023] Figure 2 This is an axonometric diagram of a multi-layer scintillator probe based on a scintillating optical fiber according to an embodiment of the present application;

[0024] Figure 3 This is a flow chart of a method for obtaining a beta particle energy spectrum and a gamma particle energy spectrum according to an embodiment of the present application;

[0025] Figure 4 This is a diagram of the energy spectrum of an Sr-90 source measured by a detector of a multi-layer scintillator probe based on a scintillation optical fiber according to an embodiment of the present application;

[0026] Figure 5 This is a diagram of the energy spectrum of a Cs-137 source measured by a detector of a multi-layer scintillator probe based on a scintillation fiber according to an embodiment of the present application.

[0027] The reference numerals indicate:

[0028] 1. First scintillating fiber layer; 2. Second scintillator layer; 3. Third scintillator layer; 4. Silicon photomultiplier tube; 5. Signal amplifier board; 6. Signal output head; 7. Mylar film; 8. Housing. DETAILED DESCRIPTION

[0029] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0031] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0032] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0033] See also Figure 1 and Figure 2 As shown, according to an embodiment of the present application, a multi-layer scintillator probe based on scintillating fiber is provided, including a probe body, the probe body including a first scintillating fiber layer 1, a second scintillator layer 2 and a third scintillator layer 3, the second scintillator layer 2 is arranged between the first scintillating fiber layer 1 and the third scintillator layer 3, the first scintillating fiber layer 1 is used to distinguish between γ particles and β particles, the second scintillator layer 2 is used to absorb β particles passing through the first scintillating fiber layer 1, and the third scintillator layer 3 is used to measure γ particles.

[0034] By sequentially arranging a first scintillating fiber layer 1, a second scintillator layer 2, and a third scintillator layer 3, wherein the first scintillating fiber layer 1 is used to discriminate between gamma particles and beta particles, the second scintillator layer 2 is used to absorb beta particles passing through the first scintillating fiber layer, and the third scintillator layer 3 is used to measure gamma particles, it is possible to realize the identification of beta particles and gamma particles in a β-γ mixed field, and to realize the simultaneous and accurate measurement of the energy spectrum of beta particles and the energy spectrum of gamma particles in the β-γ mixed field.

[0035] Among them, the second layer of scintillator 2 is arranged between the first layer of scintillator fiber 1 and the third layer of scintillator 3. That is, the second layer of scintillator 2 includes a top surface and a bottom surface, the first layer of scintillator fiber 1 is arranged on the top surface of the second layer of scintillator 2, and the third layer of scintillator 3 is arranged on the bottom surface of the second layer of scintillator 2. This layered structure can effectively filter and distinguish different types of particles, and realize the simultaneous and accurate measurement of the energy spectrum of β particles and the energy spectrum of γ particles in the β-γ mixed field.

[0036] In specific use, when a particle enters the first scintillating fiber layer 1, the scintillating fiber will emit scintillation light; if the particle still has enough energy after passing through the scintillating light layer 1, it will enter the third layer of scintillator 2, and the second scintillator will also emit scintillation light, which is used to filter out the β particles passing through the first scintillating fiber layer 1. Since the energy of β particles is low, they will usually be completely absorbed by the first scintillating fiber layer 1; if the particle can pass through the first scintillating fiber layer 1 and the second layer of scintillator 2, it will enter the third scintillator layer 3, and the third scintillator will also emit scintillation light. Since the energy of γ particles is high, they can penetrate the first scintillating fiber layer 1 and the third layer of scintillator 2.

[0037] In other embodiments, the first scintillating fiber layer 1 is formed by scintillating fibers arranged in a matrix; the second scintillator layer 2 is a plastic scintillator; and the third scintillator layer 3 is a cesium iodide scintillator.

[0038] The diameter of the scintillating fiber is 0.5 mm, and the side length of the first scintillating fiber layer 1 is 75 mm. The scintillating fibers are tightly arranged in a matrix, which can efficiently collect photons.

[0039] The second scintillator layer 2 has a thickness of 18 mm and a side length of 75 mm.

[0040] The third scintillator layer 3 has a thickness of 25.4 mm and a side length of 75 mm.

[0041] Limiting the thickness of the second and third scintillator layers 2 and 3 effectively increases the probability of particle-scintillator interaction, ensuring that most beta particles and low-energy gamma particles are completely absorbed by the scintillator, thereby improving detection efficiency. Limiting the side lengths of the second and third scintillator layers 2 and 3 provides a larger detection area, enabling simultaneous detection of multiple particles and further enhancing detection efficiency.

[0042] In other embodiments, the probe body further includes a polyester film 7, and the outer surfaces of the second scintillator layer 2 and the third scintillator layer 3 are both wrapped with the polyester film 7. The polyester film acts as an optical reflective layer or light-absorbing barrier layer, optimizing the optical performance of the scintillator. It can reflect visible light emitted from the back of the scintillator, redirecting it back into the scintillator, thereby improving photon collection efficiency.

[0043] In other embodiments, the probe further includes a silicon photomultiplier tube 4, a signal amplifying board 5, and a signal output head 6. The first scintillating fiber layer 1, the second scintillator layer 2, and the third scintillator layer 3 are arranged in a one-to-one correspondence with the silicon photomultiplier tube 4. One silicon photomultiplier tube 4 is connected to the first scintillating fiber layer 1, and the other two silicon photomultiplier tubes 4 are connected to the corresponding second scintillator layer 2 and third scintillator layer 3 after passing through a polyester film 7. The signal amplifying board 5 is connected to the silicon photomultiplier tube 4, and the signal output head 6 is provided on the surface of the signal amplifying board 5 facing away from the silicon photomultiplier tube 4. A silicon photomultiplier tube 4 is arranged corresponding to each layer, which can independently detect and process light signals. This layered detection method can measure the energy deposition of particles in different layers, thereby achieving more accurate particle identification and energy spectrum analysis.

[0044] Among them, the first scintillating fiber layer 1, the second scintillator layer 2 and the third scintillator layer 3 are arranged in a one-to-one correspondence with the silicon photomultiplier tubes 4. One silicon photomultiplier tube 4 is connected to the first scintillating fiber layer 1, and the other two silicon photomultiplier tubes 4 are connected to the corresponding second scintillator layer 2 and third scintillator layer 3 after passing through the polyester film 7. In other words, the probe body has a three-layer structure, and each layer corresponds to a silicon photomultiplier tube 4. Therefore, the number of silicon photomultiplier tubes 4 here is three.

[0045] One of the silicon photomultiplier tubes 4 is connected to the first scintillation fiber layer 1 , and the scintillation fibers arranged in a matrix are twisted together at the output end and connected to the silicon photomultiplier tube 4 for converting the collected scintillation light into an electrical signal.

[0046] The other two silicon photomultiplier tubes 4 are connected to the corresponding second and third scintillator layers 2 and 3 after passing through the polyester film 7. In other words, the polyester film 7 is not provided at the locations where the silicon photomultiplier tubes 4 are mounted on the second and third scintillator layers 2 and 3. The silicon photomultiplier tubes 4 connected to the second scintillator layer 2 collect scintillation photons that pass through the first scintillating fiber layer 1 and convert them into electrical signals. The silicon photomultiplier tubes 4 connected to the third scintillator layer 3 collect scintillation photons that pass through the first and second scintillator layers 1 and convert them into electrical signals.

[0047] In other embodiments, the probe further includes a housing 8, in which the probe body, silicon photomultiplier tube 4, signal amplification board 5, and signal output head 6 are encapsulated. The arrangement of the housing 8 is used to protect the probe body, silicon photomultiplier tube 4, signal amplification board 5, and signal output head 6, thereby extending the service life of each component.

[0048] Among them, Figure 2 As shown, the shell 8 is a stepped cylindrical structure, including a large diameter part and a small diameter part. The probe body, silicon photomultiplier tube 4, signal amplifier board 5 and signal output head 6 are installed in the space formed by the large diameter part. The large diameter part is connected to the small diameter part and is coaxially arranged. The small diameter part can be used as a handheld part.

[0049] Specifically, the housing 8 is made of aluminum.

[0050] In other embodiments, the housing 8 includes a first end plate having a window formed therein. A polyester film sheet is positioned within the window to form a probe window. The probe window is a key part of the probe's radiation reception system, allowing specific radiation to enter the probe's sensitive area for detection. The polyester film sheet positioned within the probe window protects sensitive components within the probe from environmental damage (e.g., moisture, dust, etc.) without impairing radiation penetration.

[0051] The shell 8 includes a first end plate with a window, that is, the large diameter portion of the shell 8 includes the first end plate, which is also the end plate facing away from the small diameter portion.

[0052] The probe body is arranged in the large diameter portion, wherein the first scintillation optical fiber layer 1 of the probe body is arranged facing the probe window.

[0053] Specifically, the thickness of the polyester film sheet is 2 μm.

[0054] In other embodiments, the housing 8 further includes a second end plate, on which a plurality of connectors are provided, and the signal output head 6 is connected to the corresponding connectors via optical fibers.

[0055] The housing 8 further includes a second end plate, that is, the small diameter portion of the housing 8 includes the second end plate, and the second end plate is also the end plate facing away from the large diameter portion.

[0056] In a second aspect, embodiments of the present application provide a detector comprising any of the aforementioned multilayer scintillator probes based on scintillation fibers. Using the probe of the present application, a detector can identify beta particles and gamma particles in a mixed beta-gamma field, and simultaneously accurately measure the energy spectra of both beta particles and gamma particles in the mixed beta-gamma field.

[0057] During specific use: When a particle passes through the window and enters the first scintillating fiber layer, the scintillating fiber will emit scintillation light. The output ends of the scintillating fibers are twisted together and connected to the silicon photomultiplier tube 4, which converts the scintillation photons into electrical signals. If the particle still has enough energy after passing through the first scintillating fiber layer, it will enter the second layer of scintillator. These scintillation photons are collected by the silicon photomultiplier tube 4 connected to the second layer of scintillator 2 and converted into electrical signals. If the particle can pass through the first scintillating fiber layer 1 and the second scintillator layer 2, it will enter the third scintillator layer 3. These scintillation photons are collected by the silicon photomultiplier tube 4 connected to the third layer of scintillator 3 and converted into electrical signals. This layered detection method can measure the energy deposition of particles in different layers, thereby achieving more accurate particle identification and energy spectrum analysis.

[0058] like Figure 3 As shown, a third aspect of the embodiment of the present application provides a method for obtaining a beta particle energy spectrum and a gamma particle energy spectrum, wherein a detector is used for measurement to obtain a beta particle energy spectrum and a gamma particle energy spectrum, comprising the following steps:

[0059] In step S1 , scintillation photons generated by the first scintillating fiber layer 1 , the second scintillator layer 2 , and the third scintillator layer 3 are collected respectively and converted into electrical signals for output.

[0060] After the particles enter through the exploration window, the first scintillating fiber layer 1 efficiently collects scintillation photons through the silicon photomultiplier tube 4 connected to it and converts them into electrical signals for output; the second layer of scintillator 2 is used to collect scintillation photons passing through the first scintillating fiber layer 1 and convert them into electrical signals for output; the third layer of scintillator 3 is used to collect scintillation photons passing through the first scintillating fiber layer 1 and the second layer of scintillator 2 and convert them into electrical signals for output.

[0061] In step S2, the electrical signal in each layer is divided into two paths, the first path retains the original energy information, and the second path is sent to the logic coincidence unit for identifying beta particles and gamma particles.

[0062] The electrical signal in each layer is divided into two paths. The first path retains the original energy information for subsequent analysis of the particle energy spectrum. The second path is sent to the logic coincidence unit for calculation, that is, transmitted to the integrated circuit chip for particle type identification, that is, for identifying beta particles and gamma particles.

[0063] Step S3: couple the first electrical signal and the second logical signal processed by the logic coincidence unit and output a detection signal, and classify the output detection signal to identify the beta particle energy spectrum and the gamma particle energy spectrum.

[0064] The first electrical signal and the second logical signal processed by the logic coincidence unit are coupled and a detection signal is output. That is, the first electrical signal of the first scintillating optical fiber layer 1, the second scintillator layer 2 and the third scintillator layer 3 and the second logical signal of the first scintillating optical fiber layer 1, the second scintillator layer 2 and the third scintillator layer 3 are coupled, and the detection signal is output.

[0065] The output detection signals are classified to identify the beta particle energy spectrum and the gamma particle energy spectrum. That is, the second logic signal processed by the logic coincidence unit is used as the judgment standard to classify the detection signals, identify beta particles and gamma particles, and then form the beta particle energy spectrum and the gamma particle energy spectrum.

[0066] As a refinement and expansion of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process of this embodiment, another method for obtaining the energy spectrum of beta particles and gamma particles is provided, which includes:

[0067] In step S1 , scintillation photons generated by the first scintillating fiber layer 1 , the second scintillator layer 2 , and the third scintillator layer 3 are collected respectively and converted into electrical signals for output.

[0068] After the particles enter through the exploration window, the first scintillating fiber layer 1 efficiently collects scintillation photons through the silicon photomultiplier tube 4 connected to it and converts them into electrical signals for output; the second layer of scintillator 2 is used to collect scintillation photons passing through the first scintillating fiber layer 1 and convert them into electrical signals for output; the third layer of scintillator 3 is used to collect scintillation photons passing through the first scintillating fiber layer 1 and the second layer of scintillator 2 and convert them into electrical signals for output.

[0069] In step S2, the electrical signal in each layer is divided into two paths, the first path retains the original energy information, and the second path is sent to the logic coincidence unit for identifying beta particles and gamma particles.

[0070] The electrical signal in each layer is divided into two paths. The first path retains the original energy information for subsequent analysis of the particle energy spectrum. The second path is sent to the logic coincidence unit for calculation, that is, transmitted to the integrated circuit chip for particle type identification, that is, for identifying beta particles and gamma particles.

[0071] In step S21 , the logic coincidence unit determines the energy deposition of the particles in each layer according to a preset threshold value; the preset threshold value in the method of the present application is 40 KeV.

[0072] When the energy deposition is higher than the preset threshold, a "1" signal is output; when the energy deposition is less than or equal to the preset threshold, a "0" signal is output.

[0073] In step S22 , the logic signals outputted by the first scintillating fiber layer 1 , the second scintillator layer 2 , and the third scintillator layer 3 are combined to identify the “100” and “110” events as β particles and the “001” event as γ particles.

[0074] Step S3: couple the first electrical signal and the second logical signal processed by the logic coincidence unit and output a detection signal, and classify the output detection signal to identify the beta particle energy spectrum and the gamma particle energy spectrum.

[0075] The first electrical signal and the second logical signal processed by the logic coincidence unit are coupled and a detection signal is output. That is, the first electrical signal of the first scintillating optical fiber layer 1, the second scintillator layer 2 and the third scintillator layer 3 and the second logical signal of the first scintillating optical fiber layer 1, the second scintillator layer 2 and the third scintillator layer 3 are coupled, and the detection signal is output.

[0076] The output detection signals are classified to identify the beta particle energy spectrum and the gamma particle energy spectrum. That is, the second logic signal processed by the logic coincidence unit is used as the judgment standard to classify the detection signals, identify beta particles and gamma particles, and then form the beta particle energy spectrum and the gamma particle energy spectrum.

[0077] Example 1

[0078] Figure 4 This is the measured energy spectrum of the probe of this application for an Sr-90 source. By integrating the entire spectrum, the beta particle counts and gamma particle counts measured by this probe can be obtained respectively, where the net count of the beta channel is: 125.88×1357=170819.16; the net count of the gamma channel is: 0.556×1357=754.5; when the measured source is a beta radiation source, the beta false positive rate = gamma channel count ÷ (beta channel count + gamma channel count); thus, the beta false positive rate = 754.5 ÷ (754.5 + 170819.16) ≈ 0.44%.

[0079] Example 2

[0080] Figure 5 This is the measured energy spectrum of the probe of this application for the Cs-137 source. Similarly, the beta particle count and gamma particle count measured by this probe can be obtained respectively by full spectrum integration, where the net count of the beta channel is: 1.224×1331=1629.144; the net count of the gamma channel is: 99.43×1331=132341.33; when the measured source is a gamma radiation source, the gamma false positive rate = beta channel count / (beta channel count + gamma channel count); thus, the gamma false positive rate = 1629.144 ÷ (1629.144 + 132341.33) ≈ 1.22%.

[0081] In summary, the use of this probe can achieve accurate identification of β particles and γ particles in the energy range of 0.05MeV-3.6MeV in the β-γ mixed field, with the misidentification rate of β particles less than 0.5%, and the misidentification rate of γ particles less than 1.5%. In addition, the energy spectrum of β particles and γ particles can be simultaneously output through a single measurement.

[0082] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0083] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application. The above are merely preferred embodiments of the present application. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present application, and such improvements and variations shall also be considered within the scope of protection of the present application.

Claims

1. A multi-layer scintillator probe based on scintillation optical fiber, characterized in that: The probe body comprises a first scintillating fiber layer (1), a second scintillator layer (2) and a third scintillator layer (3), wherein the second scintillator layer (2) is arranged between the first scintillating fiber layer (1) and the third scintillator layer (3), the first scintillating fiber layer (1) is used to distinguish between gamma particles and beta particles, the second scintillator layer (2) is used to absorb beta particles passing through the first scintillating fiber layer (1), and the third scintillator layer (3) is used to measure gamma particles; The probe body further comprises a polyester film (7), and the outer surfaces of the second layer of scintillators (2) and the third layer of scintillators (3) are both wrapped by the polyester film (7); The probe further comprises a silicon photomultiplier tube (4), a signal amplifying board (5) and a signal output head (6); the first scintillating optical fiber layer (1), the second scintillator layer (2) and the third scintillator layer (3) are arranged in a one-to-one correspondence with the silicon photomultiplier tube (4); one of the silicon photomultiplier tubes (4) is connected to the first scintillating optical fiber layer (1); the other two silicon photomultiplier tubes (4) are connected to the corresponding second scintillator layer (2) and the third scintillator layer (3) after passing through the polyester film (7); the signal amplifying board (5) is connected to the silicon photomultiplier tube (4); and the signal output head (6) is arranged on the surface of the signal amplifying board (5) facing away from the silicon photomultiplier tube (4).

2. A multi-layer scintillator probe based on scintillation optical fiber according to claim 1, characterized in that: The first scintillating optical fiber layer (1) is formed by scintillating optical fibers arranged in a matrix; the second layer of scintillators (2) is a plastic scintillator; and the third layer of scintillators (3) is a cesium iodide scintillator.

3. The multi-layer scintillator probe based on scintillation optical fiber according to claim 1, characterized in that: The probe further comprises a shell (8), wherein the probe body, the silicon photomultiplier tube (4), the signal amplifying board (5) and the signal output head (6) are encapsulated in the shell (8).

4. The multi-layer scintillator probe based on scintillation optical fiber according to claim 3, characterized in that: The housing (8) comprises a first end plate, a window is provided on the first end plate, and a polyester film sheet is provided inside the window to form an exploration window.

5. The multi-layer scintillator probe based on scintillation optical fiber according to claim 3, characterized in that: The housing (8) further comprises a second end plate, on which a plurality of connectors are provided, and the signal output head (6) is correspondingly connected to the connectors via optical fibers.

6. A detector, characterized in that: A multi-layer scintillator probe based on scintillation optical fiber comprising the method according to any one of claims 1 to 5.

7. A method for obtaining a beta particle energy spectrum and a gamma particle energy spectrum, characterized in that: The method of obtaining the beta particle energy spectrum and the gamma particle energy spectrum by using the detector of claim 6 for measurement comprises: respectively collecting scintillation photons generated by the first scintillating optical fiber layer (1), the second scintillator layer (2), and the third scintillator layer (3), and converting them into electrical signals for output; The electrical signal in each layer is divided into two paths. The first path retains the original energy information, and the second path is sent to the logic coincidence unit for identifying beta particles and gamma particles. The first electrical signal and the second logical signal processed by the logic coincidence unit are coupled and a detection signal is output, and the output detection signal is classified to identify the beta particle energy spectrum and the gamma particle energy spectrum.

8. The method for obtaining a beta particle energy spectrum and a gamma particle energy spectrum according to claim 7, characterized in that: The other path is fed into the logic coincidence unit to identify the particle type, including: The logic coincidence unit determines the energy deposition of particles in each layer according to the preset threshold; When the energy deposition is higher than the preset threshold, a "1" signal is output; when the energy deposition is less than or equal to the preset threshold, a "0" signal is output; The logic signals output by the first scintillating optical fiber layer (1), the second scintillator layer (2) and the third scintillator layer (3) are combined to identify "100" and "110" events as beta particles and "001" events as gamma particles.

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