A trapezoidal scintillating fiber optic probe and a quasi-distributed radiation detector based on the probe

Abstract

The present invention relates to a trapezoidal scintillation fiber probe and a quasi-distributed radiation detector based on the probe, belonging to the field of radiation sensing and detection. The probe comprises n structural elements fused sequentially, each structural element comprising an inorganic scintillation fiber, the upstream and downstream ends of which are respectively combined with an inorganic transmission fiber A, and the combining region is respectively fused with an inorganic transmission fiber B. In accordance with the combining direction, the inorganic transmission fiber B at the upstream and downstream ends of each structural element is fused with the inorganic transmission fiber A of the next structural element. The inorganic scintillation fiber and the inorganic transmission fiber of the present invention are arranged in a trapezoidal shape, responsible for radioactivity detection and light transmission, respectively, effectively solving the problems of large scintillation fiber loss, low light yield, and inability to achieve long-distance real-time monitoring. Furthermore, two photomultiplier tubes are located at the proximal end, effectively solving the problem of inability to achieve position resolution of particles over a large range due to the need to install photomultiplier tubes at both the proximal and distal ends of the scintillation fiber.

Description

Technical Field

[0001] The invention relates to a trapezoidal scintillation optical fiber probe and a quasi-distributed radiation detector based on the probe, belonging to the technical field of radiation sensing detection. Background Art

[0002] Scintillator detectors are primarily composed of a scintillator, a photomultiplier tube (PMT), and an electrical signal processing circuit. Scintillator is an energy-converting, luminescent material with the characteristic of scintillation luminescence. It can emit light in the ultraviolet or visible region when exposed to various ionizing radiations, such as X-rays, gamma rays, and high-energy particles such as thermal neutrons, alpha rays, and beta rays. Scintillator detectors offer advantages such as high radiation detection efficiency, high radiation hardness, short response time, and high energy resolution. They can effectively measure ionizing radiation doses and have been applied in fields such as security scanning, medical imaging, environmental monitoring, and high-energy physics. However, the scintillator in a scintillator detector is relatively large, resulting in low spatial resolution. The photoelectric processing unit is usually combined with the scintillator, allowing only "point" detection. Long-term exposure of electronic components to strong ionizing radiation environments can easily damage them, making real-time monitoring impossible.

[0003] A scintillation fiber detector primarily consists of a scintillation fiber, a photomultiplier tube, and an electrical signal processing circuit. A scintillation fiber is a combination of a scintillator and an optical fiber, possessing both the scintillation properties of a scintillator and the advantages of an optical fiber. This means it simultaneously performs the functions of radioactivity detection and optical transmission waveguide. A scintillation fiber detector uses the radiation-sensitive material scintillator as its fiber core. While radiating light, it provides a directional optical waveguide for the scintillation photons, transmitting the photons to the backend for photoelectric detection. This eliminates the need for electronic components within the radiation zone, thus achieving the separation of radiation sensing elements from electronic components. Compared to traditional bulk scintillator detectors, scintillation fiber detectors offer the advantages of bulk scintillator detectors, such as high detection efficiency and high irradiation hardness, along with the advantages of optical fiber sensors, such as electromagnetic interference resistance, fast response speed, and integrated sensing. However, current scintillation fiber detectors use a single optical fiber or fiber bundle as a probe, which has high transmission loss and low light yield, making it difficult to achieve position resolution of particles over a large area and long-distance real-time monitoring. Summary of the Invention

[0004] The present invention aims to address the problems of high transmission loss, low light yield, and difficulty in achieving position resolution of particles over a wide area and remote real-time monitoring in existing detection systems for radioactivity detection and analysis. The present invention proposes a trapezoidal scintillation fiber probe and a quasi-distributed radiation detector based on this probe. The radiation detector utilizes a specially designed trapezoidal scintillation fiber probe composed of inorganic scintillation fiber and inorganic transmission fiber. These fibers are arranged in a trapezoidal pattern, responsible for radioactivity detection and light transmission, respectively. This effectively addresses the high transmission loss, low light yield, and inability to achieve remote real-time monitoring of existing scintillation fiber probes. This trapezoidal scintillation fiber probe locates both photomultiplier tubes (PMTs) required for position resolution measurement at the proximal end, effectively resolving the problem of current PMT radiation detectors being unable to achieve position resolution of particles over a wide area when measuring position information, due to the need for PMTs at both the proximal and distal ends of the scintillation fiber.

[0005] The present invention adopts the following technical solutions:

[0006] A trapezoidal scintillation fiber optic probe comprises n structural primitives fused together in sequence, where n is a natural number greater than or equal to 2;

[0007] Each structural unit includes an inorganic scintillating fiber, the uplink end and the downlink end of the inorganic scintillating fiber are respectively combined with an inorganic transmission fiber A, the inorganic transmission fiber A serves as the uplink input end and the downlink input end, and the combining area is fused with an inorganic transmission fiber B, which serves as the uplink output end and the downlink output end, respectively;

[0008] According to the direction of beam combining, the inorganic transmission fiber B at the upstream and downstream ends of each structural element is fused with the inorganic transmission fiber A of the next structural element, and the inorganic transmission fiber B of the last structural element serves as the output port of the probe.

[0009] Preferably, the end of the inorganic transmission fiber A of the first structural unit is coated with a silver high-reflection coating, preferably with a thickness of 20 to 60 nanometers. The trapezoidal scintillation fiber probe is coated with a high-reflection coating at the distal end, effectively suppressing extraneous light from the environment from being transmitted to the photomultiplier tube, thereby effectively reducing the dark noise level of the detector.

[0010] Preferably, the outer diameter of the inorganic scintillating optical fiber is 125 to 500 microns and the inner diameter is 10 to 105 microns;

[0011] The outer diameters of the inorganic transmission optical fiber A and the inorganic transmission optical fiber B are both 125 to 500 microns, and the inner diameters are both 10 to 105 microns. They use inorganic transmission optical fibers with low loss in the luminous band of inorganic scintillating optical fibers.

[0012] Preferably, the length of the inorganic scintillation optical fiber can be changed according to the needs of the detection environment. Under the condition that the spacing between the inorganic scintillation optical fibers is certain, the longer the inorganic scintillation optical fiber, the larger the area of the longitudinal detection area distributed along the direction of the inorganic scintillation optical fiber, that is, the larger the positioning range of the detector, but the worse the sensitivity of the detector.

[0013] Preferably, the number of trapezoidal scintillating fiber structural elements (n) in the trapezoidal scintillating fiber probe can be adjusted according to the detection environment. A greater number of trapezoidal scintillating fiber structural elements results in a longer detection range, but due to splicing losses, the intensity of the far-end light reaching the photomultiplier tube also decreases. The distance between the elements can also be adjusted according to the detection environment. A greater distance reduces splicing losses, but also reduces position resolution.

[0014] A method for manufacturing the above-mentioned trapezoidal scintillation fiber optic probe comprises the following steps:

[0015] 1) The adding end of the inorganic scintillating fiber is combined with the inorganic transmission fiber A using the taper technology, and the inorganic transmission fiber B is fused after the combining area using a fiber fusion splicer as the adding output end.

[0016] 2) The inorganic scintillating fiber's downlink end is combined with the inorganic transmission fiber A using a tapered technique. A fiber fusion splicer is used to fuse the inorganic transmission fiber B after the combining area as the downlink output end. The structural element of the trapezoidal scintillating fiber probe is completed.

[0017] 3) Repeat steps 1) and 2) to prepare n structural units;

[0018] 4) The n structural elements in step 3) are sequentially fused together in the direction of beam combining, with the uplink output end of the n structural elements being connected to the uplink input end of the next structural element, and with the downlink output end being connected to the uplink input end of the next structural element. The inorganic transmission fiber B of the last structural element is used as the output port of the probe, and the trapezoidal scintillation fiber probe is completed.

[0019] Preferably, in steps 1) and 2), the length of the beam combining area is preferably 30 to 60 mm.

[0020] Preferably, the portion between the uplink end of the inorganic scintillating optical fiber and the inorganic transmission optical fiber A, and the portion between the downlink end of the inorganic scintillating optical fiber and the inorganic transmission optical fiber A are tapered by a twisting method.

[0021] A quasi-distributed radiation detector includes the above-mentioned trapezoidal scintillation fiber optic probe, wherein the upstream output port of the trapezoidal scintillation fiber optic probe is sequentially connected to a first photomultiplier tube (PMT1), a first phase detector (CFD1), a time-to-amplitude converter (TAC), and a multi-channel analyzer (MCA), and the downstream output port of the trapezoidal scintillation fiber optic probe is sequentially connected to a second photomultiplier tube (PMT2), a second phase detector (CFD2), a delay device (DLA), the time-to-amplitude converter, and the multi-channel analyzer.

[0022] The distal upper and lower input ports of the trapezoidal scintillation fiber probe are coated with a highly reflective coating, while the proximal upper and lower output ports are not. The output light is directly coupled into a photomultiplier tube (PMT). The signal processing section consists of two paths: the upper path, which transmits the signal through the first photomultiplier tube (PMT1) and the first phase detector (CFD1) to a time-to-amplitude converter (TAC). The lower path, which transmits the signal through the second photomultiplier tube (PMT2), the second phase detector (CFD2), and the delay element (DLA), reaches the time-to-amplitude converter (TAC). The TAC measures the time interval Δt between the arrival of the two signals and generates analog output pulses proportional to this time interval. These analog output pulses are then transmitted to a multi-channel analyzer (MCA) for analysis. The location of the radiation source can be calculated using the time-of-flight method, and the radiation dose can be estimated based on the pulse frequency.

[0023] Preferably, the first photomultiplier tube (PMT1) and the second photomultiplier tube (PMT2) have the same parameters such as sensitivity, current gain, photoelectric characteristics, anode characteristics, dark current, etc., and their optimal detection range is the luminescence band of the inorganic scintillating fiber.

[0024] In the present invention, the data processing unit after the photomultiplier tube is not limited to a phase detector, a time-to-amplitude converter, or a multi-channel analyzer, and may also be other data processing units.

[0025] A method for operating the quasi-distributed radiation detector is as follows: after high-energy particles emitted by a radiation source are absorbed by an inorganic scintillating fiber, physical processes such as the photoelectric effect, Compton scattering, and electron pair effect occur in the inorganic scintillating fiber, causing electrons in the inorganic scintillating fiber to absorb the high-energy particles and become excited-state electrons. The unstable excited-state electrons release energy and return to the ground state, generating a light signal.

[0026] Because the inorganic scintillating fiber functions as an optical transmission waveguide, the optical signal generated by the radiation source is transmitted along the inorganic scintillating fiber. In the quasi-distributed radiation detector, the optical signal generated by the radiation source is divided into optical signal A and optical signal B, and transmitted simultaneously along the upper and lower paths. In the upper path, optical signal A passes through the inorganic scintillating fiber and the inorganic transmission fiber B to reach the first photomultiplier tube (PMT1), converting optical signal A into electrical signal A. Electrical signal A then reaches the first phase detector (CFD1) for phase discrimination, and finally reaches the time-to-amplitude converter (TAC).

[0027] At the same time, the optical signal B in the lower channel reaches the second photomultiplier tube (PMT2) through the inorganic scintillation fiber and the inorganic transmission fiber B, realizing the conversion of optical signal B into electrical signal B. Then, electrical signal B reaches the second phase detector (PMT2) to realize phase identification of electrical signal B. Then electrical signal B reaches the delay device (DLA) to realize time delay of electrical signal B. Finally, electrical signal B reaches the time amplitude converter (TAC). The time amplitude converter measures the time interval Δt between the arrival of the two signals, namely electrical signal A and electrical signal B, and generates an analog output pulse proportional to the time interval Δt. The analog output pulse is transmitted to the multi-channel analyzer (MCA) for analysis. Finally, the position of the radiation source is calculated according to the time-of-flight method, and the size of the radiation source dose is determined according to the pulse frequency.

[0028] Where the present invention is not exhaustive, please refer to the prior art.

[0029] The beneficial effects of the present invention are:

[0030] 1) The quasi-distributed radiation detector based on a trapezoidal scintillation fiber structure of the present invention uses a specially designed trapezoidal scintillation fiber structure as a probe. The probe is composed of an inorganic scintillation fiber and an inorganic transmission fiber. The inorganic scintillation fiber and the inorganic transmission fiber are arranged in a "trapezoidal" shape, responsible for radioactivity detection and light transmission, respectively. This allows light generated by a remote radiation source to be transmitted to a photomultiplier tube via the low-loss inorganic transmission fiber, effectively solving the current problem of inability to achieve long-distance real-time monitoring due to the high loss and low light yield of the scintillation fiber.

[0031] 2) The present invention's quasi-distributed radiation detector based on a trapezoidal scintillation fiber structure utilizes a specially designed trapezoidal scintillation fiber structure as a probe. The inorganic scintillation fibers are spaced longitudinally apart. Light generated by the radiation source in the inorganic scintillation fiber is split into two paths, one above and one below, through inorganic transmission fibers to reach two photomultiplier tubes at the proximal end. Time-of-flight analysis is then used to determine particle position information. This specially designed trapezoidal scintillation fiber probe positions both photomultiplier tubes (PMTs) at the proximal end, effectively resolving the problem of current PMTs, which require PMTs at both the proximal and distal ends of the scintillation fiber, that prevents position resolution over a wide range.

[0032] 3) The quasi-distributed radiation detector based on the trapezoidal scintillating fiber structure of the present invention is coated with a high-reflection film at the far end of the fiber probe, which effectively suppresses irrelevant light in the environment from being transmitted to the photomultiplier tube, effectively reducing the dark noise level of the detector.

[0033] 4) The quasi-distributed radiation detector based on a trapezoidal scintillating fiber structure of the present invention is equipped with a time delay element (DLA) in the signal processing section, so that the position information of the radiation source near the second photomultiplier tube (PMT2) can be effectively obtained. This effectively solves the problem that the light pulses generated by the radiation source near the second photomultiplier tube (PMT2) generate negative phase difference data in the time-to-amplitude converter (TAC), which makes it impossible for the multi-channel analyzer (MAC) to perform information analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of a trapezoidal scintillation fiber optic probe according to the present invention;

[0035] Figure 2 Schematic diagram of the welding process of two structural elements in the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of combining the inorganic scintillating fiber and the inorganic transmission fiber A / B using the tapered technology in the present invention;

[0037] Figure 4 is a schematic structural diagram of the quasi-distributed radiation detector of the present invention;

[0038] In the figure, 1-inorganic scintillating fiber, 2-inorganic transmission fiber A, 3-beam combining region, 4-inorganic transmission fiber B, 5-high reflection film, 6-first photomultiplier tube, 7-first phase detector, 8-time-amplitude converter, 9-multi-channel analyzer, 10-second photomultiplier tube, 11-second phase detector, 12-delay device. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, they will be described in detail below with reference to the accompanying drawings and specific embodiments, but are not limited thereto. Matters not fully described in the present invention shall be based on conventional techniques in the art.

[0040] Example 1:

[0041] A trapezoidal scintillation fiber optic probe, such as Figure 1-3 As shown, it includes n structural elements welded together in sequence, where n is a natural number greater than or equal to 2;

[0042] Each structural unit includes an inorganic scintillating fiber 1, the add end and the drop end of the inorganic scintillating fiber 1 are respectively combined with an inorganic transmission fiber A 2, and the inorganic transmission fiber A 2 serves as the add input end and the drop input end respectively. The combining area 3 is fused with an inorganic transmission fiber B 4, which serves as the add output end and the drop output end respectively.

[0043] According to the direction of beam combining, the inorganic transmission fiber B4 at the uplink and downlink ends of each structural element are fused with the inorganic transmission fiber A2 of the next structural element, and the inorganic transmission fiber B4 of the last structural element serves as the output port of the probe.

[0044] Example 2:

[0045] A trapezoidal scintillation fiber probe has the same structure as that shown in Example 1, except that the end of the inorganic transmission fiber A in the first structural unit is coated with a silver high-reflection coating 5. Specifically, both the distal upper and lower input ports of the trapezoidal scintillation fiber probe are coated with a high-reflection coating, while the proximal upper and lower output ports are not. The output light is directly coupled into a photomultiplier tube (PMT). In this embodiment, the thickness of the high-reflection coating 5 is 45 nanometers. The distal high-reflection coating of this trapezoidal scintillation fiber probe effectively suppresses extraneous light from reaching the PMT, effectively reducing the detector's dark noise level.

[0046] The outer diameter of the inorganic scintillating optical fiber 1 is 125 to 500 microns, and the inner diameter is 10 to 105 microns;

[0047] The outer diameters of the inorganic transmission optical fiber A2 and the inorganic transmission optical fiber B4 are both 125 to 500 microns, and the inner diameters are both 10 to 105 microns. They use inorganic transmission optical fibers with low loss in the luminous band of inorganic scintillating optical fibers.

[0048] Example 3:

[0049] A method for manufacturing a trapezoidal scintillation optical fiber probe comprises the following steps:

[0050] 1) Optical fiber selection: Ce:YAG crystal-derived optical fiber was selected as the scintillating optical fiber, with an outer diameter of 125 μm and an inner diameter of 30 μm. Ultraviolet quartz optical fiber with low transmission loss near a wavelength of 500 nm was selected as the transmission optical fiber, with an outer diameter of 125 μm and an inner diameter of 40 μm.

[0051] The inorganic scintillating fiber 1 is combined with the inorganic transmission fiber A 2 by using the tapering technology. The length of the combining area 3 is preferably 30 to 60 mm. The inorganic transmission fiber B 4 is fused after the combining area 3 by using a fiber fusion splicer as the adding output end.

[0052] 2) Using the same method as in step 1), the drop end of the inorganic scintillating fiber 1 is combined with the inorganic transmission fiber A 2 using a tapered technique. A fiber fusion splicer is then used to fusion-splice the inorganic transmission fiber B 4 after the combining region 3 as the drop output end. The structural element of the trapezoidal scintillating fiber probe is thus fabricated. In this embodiment, the length of the scintillating fiber in the structural element is 5 meters.

[0053] 3) Repeat steps 1) and 2) to prepare n structural units;

[0054] 4) The n structural primitives in step 3) are welded in sequence along the direction of the beam combination, with the uplink output end of the n structural primitives being welded to the uplink input end of the next structural primitive, and with the downlink output end being welded to the uplink input end of the next structural primitive (e.g. Figure 2 As shown, the left uplink inorganic transmission fiber B4 is fused with the right uplink inorganic transmission fiber A2, and the left downlink inorganic transmission fiber B4 is fused with the right downlink inorganic transmission fiber A2). The inorganic transmission fiber B of the last structural unit is used as the output port of the probe. The trapezoidal scintillation fiber probe is completed. The n structural units are fused together to form the following: Figure 1 The trapezoidal scintillation fiber probe shown has a spacing of 5 meters between adjacent scintillation fibers.

[0055] Example 4:

[0056] A method for manufacturing a trapezoidal scintillation fiber probe is as shown in Example 3, except that in steps 1) and 2), a twisting method is used to tapered the area between the upstream end of the inorganic scintillation fiber 1 and the inorganic transmission fiber A2, and between the downstream end of the inorganic scintillation fiber 1 and the inorganic transmission fiber A2.

[0057] Example 5:

[0058] A quasi-distributed radiation detector, such as Figure 4As shown, it includes the above-mentioned trapezoidal scintillation fiber optic probe, the output port of the upper end of the trapezoidal scintillation fiber optic probe is connected in sequence to the first photomultiplier tube (PMT1) 6, the first phase detector (CFD1) 7, the time-to-amplitude converter (TAC) 8 and the multi-channel analyzer (MCA) 9, and the output port of the lower end of the trapezoidal scintillation fiber optic probe is connected in sequence to the second photomultiplier tube (PMT2) 10, the second phase detector (CFD2) 11, the delay device (DLA) 12, the time-to-amplitude converter 8 and the multi-channel analyzer 9.

[0059] Example 6:

[0060] A quasi-distributed radiation detector operates in a manner such that after high-energy particles emitted by a radiation source are absorbed by an inorganic scintillating optical fiber 1, physical processes such as the photoelectric effect, Compton scattering, and electron pair effect occur in the inorganic scintillating optical fiber 1, causing electrons in the inorganic scintillating optical fiber to absorb the high-energy particles and become excited-state electrons. The unstable excited-state electrons release energy and return to the ground state, generating a light signal.

[0061] Since the inorganic scintillating fiber functions as an optical transmission waveguide, the optical signal generated by the radiation source excitation will be transmitted along the inorganic scintillating fiber 1. The optical signal generated by the radiation source excitation in the quasi-distributed radiation detector is divided into an optical signal A and an optical signal B, and is transmitted simultaneously along the upper and lower paths respectively. In the upper path, the optical signal A reaches the first photomultiplier tube 6 via the inorganic scintillating fiber 1 and the inorganic transmission fiber B 4, realizing the conversion of the optical signal A into the electrical signal A. Subsequently, the electrical signal A reaches the first phase detector 7 to realize the phase identification of the electrical signal A. Finally, the electrical signal A reaches the time-to-amplitude converter 8.

[0062] At the same time, the lower optical signal B reaches the second photomultiplier tube 10 via the inorganic scintillation fiber 1 and the inorganic transmission fiber B4, realizing the conversion of the optical signal B into the electrical signal B. Subsequently, the electrical signal B reaches the second phase detector 11 to realize the phase identification of the electrical signal B. Then the electrical signal B reaches the delay device 12 to realize the time delay of the electrical signal B. Finally, the electrical signal B reaches the time-amplitude converter 8. The time-amplitude converter 8 measures the time interval Δt between the arrival of the two signals, namely the electrical signal A and the electrical signal B, and generates an analog output pulse proportional to the time interval Δt. The analog output pulse is transmitted to the multi-channel analyzer 9 for analysis. Finally, the position of the radiation source is calculated according to the time-of-flight method, and the size of the radiation source dose is determined according to the pulse frequency.

[0063] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A trapezoidal scintillation fiber optic probe, characterized in that: It includes n structural elements welded together in sequence, where n is a natural number greater than or equal to 2; Each structural unit includes an inorganic scintillating fiber, the uplink end and the downlink end of the inorganic scintillating fiber are respectively combined with an inorganic transmission fiber A, the inorganic transmission fiber A serves as the uplink input end and the downlink input end, and the combining area is fused with an inorganic transmission fiber B, which serves as the uplink output end and the downlink output end, respectively; According to the direction of beam combining, the inorganic transmission fiber B at the upstream and downstream ends of each structural element is fused with the inorganic transmission fiber A of the next structural element, and the inorganic transmission fiber B of the last structural element serves as the output port of the probe; The end of the inorganic transmission optical fiber A of the first structural element is coated with a high-reflection film made of silver, and the thickness of the high-reflection film is 20 to 60 nanometers.

2. The trapezoidal scintillation fiber probe according to claim 1, characterized in that: The inorganic scintillating optical fiber has an outer diameter of 125 to 500 microns and an inner diameter of 10 to 105 microns; The outer diameters of the inorganic transmission optical fiber A and the inorganic transmission optical fiber B are both 125 to 500 microns, and the inner diameters are both 10 to 105 microns.

3. A method for manufacturing the trapezoidal scintillation fiber probe according to claim 1, characterized in that: The following steps are involved: 1) The inorganic scintillating fiber's add-in end is combined with the inorganic transmission fiber A using the taper technology, and the inorganic transmission fiber B is fused after the combining area using a fiber fusion splicer as the add-in output end; 2) The inorganic scintillating fiber's downlink end is combined with the inorganic transmission fiber A using a tapered technique. A fiber fusion splicer is used to fuse the inorganic transmission fiber B after the combining area as the downlink output end. The structural element of the trapezoidal scintillating fiber probe is completed. 3) Repeat steps 1) and 2) to prepare n structural units; 4) The n structural elements in step 3) are sequentially fused together in the direction of beam combining, with the upstream output end of the n structural elements being connected to the upstream input end of the next structural element, and with the downstream output end being connected to the downstream input end of the next structural element. The inorganic transmission fiber B of the last structural element is used as the output port of the probe, and the trapezoidal scintillation fiber probe is completed.

4. The method for manufacturing a trapezoidal scintillation fiber probe according to claim 3, wherein: In steps 1) and 2), the length of the beam combining area is 30 to 60 mm.

5. The method for manufacturing a trapezoidal scintillation fiber probe according to claim 3, wherein: The uplink end of the inorganic scintillating optical fiber and the inorganic transmission optical fiber A, as well as the downlink end of the inorganic scintillating optical fiber and the inorganic transmission optical fiber A are both tapered using a twisting method.

6. A quasi-distributed radiation detector, characterized in that: The invention comprises the trapezoidal scintillation fiber optic probe according to claim 1, wherein the output port at the upstream end of the trapezoidal scintillation fiber optic probe is connected in sequence to a first photomultiplier tube, a first phase detector, a time-amplitude converter and a multi-channel analyzer, and the output port at the downstream end of the trapezoidal scintillation fiber optic probe is connected in sequence to a second photomultiplier tube, a second phase detector, a delay device, the time-amplitude converter and the multi-channel analyzer.

7. An operating method of the quasi-distributed radiation detector according to claim 6, characterized in that: After the high-energy particles emitted by the radiation source are absorbed by the inorganic scintillating fiber, a physical process occurs in the inorganic scintillating fiber, causing the electrons in the inorganic scintillating fiber to absorb the high-energy particles and become excited electrons. The unstable excited electrons release energy and return to the ground state, generating light signals. The optical signal generated by the radiation source will be transmitted along the inorganic scintillation fiber. The optical signal generated by the radiation source in the quasi-distributed radiation detector is divided into optical signal A and optical signal B, and transmitted simultaneously along the upper and lower paths respectively. In the upper path, optical signal A reaches the first photomultiplier tube via the inorganic scintillation fiber and the inorganic transmission fiber B, realizing the conversion of optical signal A into electrical signal A. Subsequently, electrical signal A reaches the first phase detector to realize phase identification of electrical signal A, and finally electrical signal A reaches the time-amplitude converter. At the same time, the optical signal B in the lower path reaches the second photomultiplier tube through the inorganic scintillation fiber and the inorganic transmission fiber B, realizing the conversion of optical signal B into electrical signal B. Then the electrical signal B reaches the second phase detector to realize phase identification of the electrical signal B. Then the electrical signal B reaches the delay device to realize time delay of the electrical signal B. Finally, the electrical signal B reaches the time-amplitude converter. The time-amplitude converter measures the time interval Δt between the arrival of the two signals, namely the electrical signal A and the electrical signal B, and generates an analog output pulse proportional to the time interval Δt. The analog output pulse is transmitted to the multi-channel analyzer for analysis. Finally, the position of the radiation source is calculated according to the time-of-flight method, and the size of the radiation source dose is judged according to the pulse frequency.

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