An acid-proof scintillation fiber probe

Abstract

The application relates to an acid-proof scintillation fiber detector which comprises a detector shell, a plane cover plate arranged in the detector shell, a photoelectric detector arranged at the top of the plane cover plate, a detector electronic unit connected with the photoelectric detector, a fiber collimation coupling body connected with one end of the photoelectric detector, a detector bottom frame arranged at the bottom of the plane cover plate, a light shielding film arranged in the detector bottom frame, a scintillator arranged at the top of the detector bottom frame, a fiber fixing frame arranged at the top of the scintillator, a plurality of scintillation fibers arranged in a U-shaped mode on the fiber fixing frame, the end portions of the scintillation fibers penetrating through the plane cover plate and being connected with the fiber collimation coupling body, a light guide arranged at the top of the fiber fixing frame, a light reflection layer arranged at the top of the light guide, and the top surface of the light reflection layer being connected with the bottom surface of the plane cover plate. The detector can work in a strong oxidizing acid environment for a long time, and can avoid the problem of the detector size being too long in a single direction while meeting the requirements of the detection efficiency and the detection sensitive area.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nuclear radiation monitoring, and particularly relates to an acid-proof scintillation optical fiber detector. BACKGROUND

[0002] The scintillation optical fiber detector is a kind of nuclear radiation scintillator detector, and the main difference from the traditional scintillator detector is that the scintillation optical fiber detector arranges the scintillation optical fiber on one side of the scintillator as a light transmission medium, and transmits the scintillation light generated by the scintillator to the photoelectric detector. The scintillation optical fiber detector can be matched with different scintillators and probes according to different use scenarios to detect alpha, beta, gamma and neutron rays.

[0003] The existing scintillation optical fiber detector is mainly used for surface contamination detection of hands and feet, whole body, etc. or conventional environmental radiation detection. However, in some scenarios, such as spent fuel reprocessing and some laboratory measurements, these scenarios may have strong oxidizing acid properties, and the measured objects include not only solid waste but also strong oxidizing acid radioactive liquid. When detecting in a strong oxidizing acid environment, the strong oxidizing acid gas or liquid will corrode the light reflection layer, causing light leakage and corrosion of the optical fiber and other materials, resulting in a decrease in detection efficiency. After a period of time, the detector cannot achieve the task of normal detection. Secondly, the scintillation optical fiber detector currently mainly uses photomultiplier tubes and Si PM as photoelectric detectors. The detector using the photomultiplier tube has a large volume and is limited by the arrangement of the optical fiber, resulting in a single direction length of the detector being too long. Although the detector using Si PM has a small volume, the detection efficiency is not high. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides an acid-proof scintillation optical fiber detector which uses a series of acid-resistant materials and structural sealing designs, can work in a strong oxidizing acid environment for a long time, and can avoid the problem of the single direction length of the detector being too long while meeting the detection efficiency and detection sensitive area standards.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0006] An acid-proof scintillation optical fiber detector, comprising a detector shell, a planar cover plate is arranged in the detector shell, a photoelectric detector is arranged on the top of the planar cover plate, a detector electronic unit connected with the photoelectric detector, and a fiber collimation coupling body is connected to one end of the photoelectric detector;

[0007] A detector bottom frame is arranged on the bottom of the planar cover plate, a light shielding film is arranged in the detector bottom frame, a scintillator is arranged on the top of the detector bottom frame, a fiber fixing frame is arranged on the top of the scintillator, a plurality of scintillation optical fibers are arranged on the fiber fixing frame in a U-shaped and equidistant manner, and the end of the scintillation optical fiber passes through the planar cover plate and is connected to the fiber collimation coupling body.

[0008] The top of the optical fiber fixing frame is provided with a light guide, and the top of the light guide is provided with a light reflection layer, and the top surface of the light reflection layer is connected with the bottom surface of the plane cover plate.

[0009] Preferably, the detector shell is provided with a detector waterproof power supply connector and a detector waterproof communication connector on the side, and the detector waterproof power supply connector and the detector waterproof communication connector are connected with the detector electronic unit.

[0010] Preferably, the detector shell and the plane cover plate are made of 316 stainless steel material, and the bottom of the detector bottom frame is longitudinally provided with two rib strips, and the rib strips divide the scintillation fiber detector into three detection sensitive areas.

[0011] Preferably, the waterproof power supply connector and the detector waterproof communication connector are provided with a sealing ring and a sealing glue at the joint with the detector shell.

[0012] Preferably, the light shielding film is made of polished titanium foil, and the reflectivity of the polished titanium foil to the wavelength of 400nm-700nm is greater than or equal to 70%.

[0013] Preferably, the scintillation fiber is a plastic wave shifting fiber.

[0014] Preferably, the optical fiber fixing frame is made of acrylic material, and a plurality of optical fiber positioning holes for penetrating the scintillation fiber are arranged at equal intervals at both ends of the optical fiber fixing frame, and the two ends of the scintillation fiber are respectively penetrated into the adjacent two optical fiber positioning holes at one end of the optical fiber fixing frame and penetrated out of the corresponding two optical fiber positioning holes at the other end of the optical fiber fixing frame.

[0015] Preferably, the scintillator is a ZnS plastic scintillator, and the peak value of the light emitting wavelength of the ZnS plastic scintillator is 423nm.

[0016] Preferably, the light reflection layer is made of an aluminum-plated film, and the light reflectivity of the aluminum-plated film in the wavelength range of 400nm-500nm is greater than or equal to 90%.

[0017] Preferably, the top of the detector shell is provided with a handle.

[0018] The technical effects and advantages of the present application are as follows:

[0019] 1. The acid-proof scintillation fiber detector provided by the present application adopts the combined structure of the plane cover plate, the photodetector, the detector electronic unit, the optical fiber collimation coupling body, the detector bottom frame, the light shielding film, the optical fiber fixing frame, the scintillation fiber, the scintillator, the light guide and the light reflection layer in the detector shell, which not only enables the detector to work in a strong oxidizing acid environment for a long time, but also avoids the problem of excessive length of the detector size in the electric direction while meeting the detection efficiency and detection sensitive area.

[0020] Specifically shown as:

[0021] 1、The probe shell adopts 316 stainless steel material, and the waterproof power supply joint, the probe waterproof communication joint and the joint between the probe bottom frame and the probe shell are all provided with sealing pads and sealing structure glue, so that the whole probe device has good sealing performance and acid corrosion resistance;

[0022] 2、The light shielding film adopts a 5μm thick pure titanium foil which is completely different from the conventional probe often used aluminum-plated polyester film, which has excellent acid resistance (especially nitric acid as representative of oxidizing acid) and better wear resistance while meeting the basic requirements of light shielding, maintaining a relatively thin thickness and high light reflectivity.

[0023] 3、The scintillation fiber adopts a wave-shifting fiber, which is particularly suitable for lateral large-area light collection when multiple fibers are arranged. Based on fully considering the characteristics of the light transmission efficiency of the wave-shifting fiber being lost with the increase of distance and being lost with the decrease of bending radius, the fiber arrangement structure and the photomultiplier tube arrangement structure adopted by the probe not only retain the photomultiplier tube with high detection efficiency, but also solve the problem of the length of the probe size being too long in a single direction caused by the photomultiplier tube as much as possible. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 is the overall explosion structure schematic diagram of the probe of the present application;

[0025] Fig. 2 is the explosion structure schematic diagram of the internal structure of the probe of the present application.

[0026] The drawings show that: 1, the probe shell; 2, the plane cover plate; 3, the probe bottom frame; 4, the light shielding film; 5, the scintillation fiber; 6, the fiber fixing frame; 7, the scintillator; 8, the light guide; 9, the light reflection layer; 10, the photoelectric detector; 11, the probe waterproof

[0027] power supply joint; 12, the probe electronic unit; 13, the fiber collimation coupling body; 14, the probe waterproof communication joint. DETAILED DESCRIPTION

[0028] The following embodiments given in combination with the drawings will further illustrate the present application.

[0029] Referring to Figs. 1-2 the drawing, an acid-proof scintillation fiber probe includes a probe shell 1, the probe shell 1 is provided with a plane cover plate 2, the plane cover plate 2 is provided with a photoelectric detector 10 at the top, and a probe electronic unit 12 connected with the photoelectric detector 10, one end of the photoelectric detector 10 is connected with a fiber collimation coupling body 13.

[0030] The bottom of the flat cover plate 2 is provided with a detector bottom frame 3, the detector bottom frame 3 is provided with a light shielding film 4, the top of the detector bottom frame 3 is provided with a scintillator 7, the scintillator 7 is a plastic scintillator, the top of the scintillator 7 is provided with a fiber fixing frame 6, a plurality of scintillation fibers 5 are arranged on the fiber fixing frame 6 in a U-shaped and equidistant manner, the end of the scintillation fiber 5 is connected with a fiber collimation coupling body 13 through the flat cover plate 2, the top of the fiber fixing frame 6 is provided with a light guide 8, the top of the light guide 8 is provided with a light reflection layer 9, the top surface of the light reflection layer 9 is connected with the bottom surface of the flat cover plate 2.

[0031] In the embodiment, the side of the detector shell 1 is respectively provided with a detector waterproof power supply connector 11 and a detector waterproof communication connector 14, the power supply voltage of the detector waterproof power supply connector 11 is 12V, the detector waterproof communication connector 14 is an RS485 communication interface, a sealing ring and sealing glue are arranged at the joint of the detector waterproof power supply connector 11 and the detector waterproof communication connector 14 and the detector shell 1 to realize high sealing of the inside of the shell, finally, the detector waterproof power supply connector 11 and the detector waterproof communication connector 14 are connected with the detector electronic unit 12.

[0032] In the embodiment, the detector shell 1 and the flat cover plate 2 are both made of 316 stainless steel, thereby providing acid resistance of the detector.

[0033] In the embodiment, two longitudinal rib strips are arranged at the bottom of the detector bottom frame 3, the rib strips divide the scintillation fiber detector into three detection sensitive areas, the width of the two rib strips is 5mm.

[0034] In the embodiment, the light shielding film 4 is made of polished titanium foil, the thickness of the titanium foil is 5μm, the metal titanium has excellent oxidation resistance and acid resistance, especially excellent corrosion resistance to nitric acid which often exists in the field of nuclear detection, when the acid gas / liquid contacts the light shielding film 4, the light shielding film 4 can block the acid gas / liquid for a long time without being corroded and penetrated, the light shielding film 4 also has good light reflection ability, the light reflection rate of the light shielding film 4 to the wavelength of 400nm-700nm is ≥70%, the light shielding film 4 can reflect the scintillation light emitted by the plastic scintillator 7, thereby further improving the efficiency of the detector.

[0035] In the embodiment, the scintillation fiber 5 is a plastic wave shifting fiber, the fiber has high absorption rate to the light emitted from the side of the fiber and the plastic scintillator 7, and can change the wavelength of the emitted light, so that the emitted light is more suitable for being detected by the photodetector 10.

[0036] In this embodiment, the optical fiber fixing frame 6 is made of acrylic material, and a plurality of optical fiber positioning holes for penetrating the scintillating optical fiber 5 are arranged at equal intervals at both ends of the optical fiber fixing frame 6. The two ends of the scintillating optical fiber 5 are respectively penetrated into two adjacent optical fiber positioning holes at one end of the optical fiber fixing frame 6 and are respectively penetrated out of two corresponding optical fiber positioning holes at the other end of the optical fiber fixing frame 6. The ends of all the scintillating optical fibers 5 are gathered into a bundle at the outlet, and then enter the optical fiber collimation coupling body 13 after being bent with a proper bending radius, and contact the photodetector 10 and transmit light into the photodetector 10.

[0037] In this embodiment, the scintillator 7 is a ZnS plastic scintillator, which can respond to α / β rays at the same time, and the light emission wavelength peak is 423 nm.

[0038] In this embodiment, the light reflection layer 9 is made of an aluminized film, which is mainly used for reflecting the scintillating light emitted by the plastic scintillator 7, and the light reflectivity in the wavelength range of 400 nm to 500 nm is greater than or equal to 90%, covering the light emission wavelength peak of the plastic scintillator 7.

[0039] In this embodiment, the photodetector 10 is a photomultiplier tube, which is mainly used for receiving the light conducted by the scintillating optical fiber 5.

[0040] In this embodiment, the detector electronics unit 12 is a conventional detector circuit, and the main function is to collect and process the electrical signals emitted by the photodetector 10, which will not be described in detail here.

[0041] In this embodiment, the detector housing 1 is provided with a handle 15 at the top, which is used for conveniently moving the detection device.

[0042] In use, the detector is powered and communicated through the detector waterproof power supply connector 11 and the detector waterproof communication connector 14 on the detector shell 1, and the detector starts to detect at this time. When there is radiation, the radiation first passes through the light shielding film 4, then irradiates the scintillator 7, which is a 1mm ZnS plastic scintillator and is fixed by the light guide 8 and the high-transmittance optical glue. The scintillator 7 emits scintillation light after being irradiated by the rays. Most of the scintillation light is absorbed by the scintillation fiber 5, which is a 1mm plastic wave-shifting fiber. The spacing between the fibers is 1cm. A part of the light that is not absorbed by the scintillation fiber 5 is reflected by the light shielding film 4 and the light reflection layer 9, and has a certain probability of being absorbed by the scintillation fiber 5 again. The light absorbed by the scintillation fiber 5 is conducted into the photodetector 10 along the optical path through the fiber collimation coupling body 13, which is a plastic cylindrical structure containing 20 holes with an aperture of 1.1mm. The fiber collimation coupling body 13 is in close contact with the end window surface of the photodetector 10 through the fixing structure, and is filled with optical silicone as the coupling material. When the photodetector 10 receives the light signal, it will convert the light signal into an electrical signal and transmit it into the detector electronics unit 12. The detector electronics unit 12 collects and processes the electrical signal, and finally completes the detection.

[0043] The above only describes the preferred embodiments of the present application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept, and these modifications and improvements are within the scope of the present application.

Claims

1. An acid quenched scintillating fiber probe, characterized by: The application relates to a detector shell (1) which is internally provided with a plane cover plate (2), the top of the plane cover plate (2) is provided with a photoelectric detector (10), and the photoelectric detector (10) is connected with a detector electronic unit (12); one end of the photoelectric detector (10) is connected with a fiber collimation coupling body (13). The bottom of the plane cover plate (2) is provided with a detector bottom frame (3), the detector bottom frame (3) is internally provided with a light shielding film (4), the top of the detector bottom frame (3) is provided with a scintillator (7), the top of the scintillator (7) is provided with a fiber fixing frame (6), a plurality of scintillating optical fibers (5) are arranged on the fiber fixing frame (6) in a U-shaped and equidistant mode, and the end of the scintillating optical fiber (5) penetrates through the plane cover plate (2) and is connected with the fiber collimation coupling body (13). The top of the fiber fixing frame (6) is provided with a light guide (8), the top of the light guide (8) is provided with a light reflection layer (9), and the top surface of the light reflection layer (9) is connected with the bottom surface of the plane cover plate (2).

2. An acid proof scintillating fiber probe according to claim 1, characterized in that: The side of the detector shell (1) is respectively provided with a detector waterproof power supply connector (11) and a detector waterproof communication connector (14), and the detector waterproof power supply connector (11) and the detector waterproof communication connector (14) are connected with the detector electronic unit (12).

3. An acid proof scintillating fiber probe according to claim 2, characterized in that: The detector shell (1) and the plane cover plate (2) are made of 316 stainless steel material, two longitudinal rib strips are arranged on the bottom of the detector bottom frame (3) in a spaced mode, and the rib strips divide the scintillating optical fiber detector into three detection sensitive areas.

4. An acid proof scintillating fiber probe according to claim 2, characterized in that: The joint between the waterproof power supply connector (11) and the detector waterproof communication connector (14) and the detector shell (1) is provided with a sealing ring and a sealing glue.

5. The acid proof scintillating fiber probe of claim 1, wherein: The light shielding film (4) is made of a polished titanium foil, and the reflectivity of the light shielding film (4) to light with a wavelength of 400nm-700nm is greater than or equal to 70%.

6. An acid proof scintillating fiber probe according to claim 1, characterized in that: The scintillating optical fiber (5) is a plastic wave moving optical fiber.

7. An acid proof scintillating fiber probe according to claim 6, characterized in that: The fiber fixing frame (6) is made of acrylic material, a plurality of fiber positioning holes for penetrating the scintillating optical fiber (5) are arranged on the two ends of the fiber fixing frame (6) in an equidistant mode, and the two ends of the scintillating optical fiber (5) penetrate into the adjacent two fiber positioning holes on one end of the fiber fixing frame (6) and penetrate out of the corresponding two fiber positioning holes on the other end of the fiber fixing frame (6).

8. The acid quenched scintillating fiber probe of claim 1, wherein: The scintillator (7) is a ZnS plastic scintillator, and the light emitting wavelength peak value of the scintillator (7) is 423nm.

9. The acid quenched scintillating fiber probe of claim 1, wherein: The light reflection layer (9) is made of an aluminum-plated film, and the light reflection rate of the light reflection layer (9) to light with a wavelength of 400nm-500nm is greater than or equal to 90%.

10. The acid quenched scintillating fiber probe of claim 1, wherein: The top of the detector shell (1) is provided with a handle (15).

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