Compton scattering signal detection system based on wavelength shift optical fiber

Abstract

The invention relates to a Compton scattering signal detection system based on a wavelength shift optical fiber, which comprises a packaging shell, a scintillator detector, a signal transmission module and a signal collection module, and is characterized in that the packaging shell comprises a black polycarbonate plate and a black sleeve; the scintillator detector comprises a plastic scintillator, optical glass, a mirror surface aluminum foil and a Teflon coating layer; the signal transmission module comprises a wavelength shift optical fiber, a titanium dioxide reflecting layer, an optical fiber shading sleeve, a light guide and a black rubber sleeve; the signal collection module comprises a photomultiplier and a signal collection card. Compared with the prior art, the Compton scattering signal detection efficiency and precision are improved, signal attenuation and loss are avoided, the system structure is simplified, and the manufacturing and maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of signal detection, and in particular to a Compton scattering signal detection system based on wavelength-shifted optical fiber. Background Art

[0002] Compton scattering refers to the phenomenon that after a high-energy photon (such as a gamma ray) collides with an electron in a substance, the photon transfers part of its energy to the electron, resulting in photon scattering and electron recoil. This process has important applications in nuclear physics, high-energy physics, medical imaging (such as positron emission tomography, PET), and radiation detection. However, how to efficiently and accurately detect Compton scattering signals is a key issue.

[0003] Existing Compton scattering signal detection technology usually uses scintillator materials, which emit visible light or ultraviolet light when hit by high-energy photons. Subsequently, these light signals are transmitted to the photomultiplier tube (PMT) through optical fibers and then converted into electrical signals for processing. For example, Chinese patent CN 116577819 B discloses a multi-head Compton detection method system, which obtains Compton scattering events in a single CZT crystal, and accurately calculates the Compton interaction position and deposited energy by a three-dimensional position algorithm; distributed detection can optimize the detection position of the Compton camera in real time and quickly locate the radiation hotspot position; by receiving the detection data of the multi-head Compton camera, the energy spectrum of the radiation hot zone, the activity contour map of the radiation hot zone, the real-time three-dimensional stereo imaging map and other information are displayed to the user in real time. In the form of distributed detection, the shortcomings of the poor axial resolution and low detection efficiency of the Compton camera are overcome, and high axial resolution real-time full three-dimensional stereo imaging of unknown radiation fields is achieved. However, there are some shortcomings in the prior art:

[0004] 1. Signal attenuation and loss: The optical signal generated by the scintillator is susceptible to attenuation and loss during the transmission process, especially during long-distance transmission, the signal strength is significantly reduced, affecting the detection accuracy.

[0005] 2. Low efficiency of traditional optical fibers: Traditional optical fibers have limitations in transmission efficiency, especially when processing optical signals of different wavelengths, which can easily cause loss and scattering, reducing signal quality.

[0006] 3. System complexity: Existing detection systems are usually complex in structure, require multiple materials and components, and have high manufacturing and maintenance costs. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a Compton scattering signal detection system based on wavelength-shifted optical fiber, thereby improving the efficiency and accuracy of Compton scattering signal detection, solving the signal attenuation and loss problems in the prior art, simplifying the system structure, and reducing manufacturing and maintenance costs.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A Compton scattering signal detection system based on wavelength-shifted optical fiber includes: a packaging shell, a scintillator detector, a signal transmission module and a signal collection module.

[0010] The packaging shell includes a black polycarbonate plate and a black sleeve, wherein the black polycarbonate plate wraps the scintillator detector and the signal transmission module; the black sleeve is used to place the photomultiplier tube in the signal collection module;

[0011] The scintillator detector comprises a plastic scintillator, optical glass, a mirror aluminum foil and a Teflon coating layer, wherein the plastic scintillator is used to receive Compton scattered signals, the mirror aluminum foil wraps the optical glass and the plastic scintillator, and the Teflon coating layer wraps the mirror aluminum foil;

[0012] The signal transmission module comprises a wavelength-shifting optical fiber, a titanium dioxide reflective layer, an optical fiber light-shielding sleeve, a light guide and a black rubber sleeve. The wavelength-shifting optical fiber is inserted into a hole in the optical glass. The optical fiber light-shielding sleeve wraps the portion of the wavelength-shifting optical fiber outside the hole. The black rubber sleeve is sleeved at the end of the bundle to wrap the bundled wavelength-shifting optical fiber.

[0013] The signal collection module includes a photomultiplier tube and a signal collection card, the photomultiplier tube and the signal collection card are connected, the photomultiplier tube is used to receive the optical signal of the wavelength-shifted optical fiber and convert it into an electrical signal for output; the signal collection card is used to collect the electrical signal output by the photomultiplier tube.

[0014] Furthermore, the black polycarbonate plate is an integral body, and a circular hole is provided on its side; the black sleeve is made of polycarbonate and is fixed to the circular hole on the side of the black polycarbonate plate by using black PVC adhesive, and there is no gap between the two.

[0015] Furthermore, the plastic scintillator is bonded to the optical glass by transparent UV glue, and the transparent UV glue is poured into the holes of the optical glass to fix the wavelength-shifting optical fiber.

[0016] Furthermore, the optical glass is made of a low refractive index material to match the refractive index of the plastic scintillator.

[0017] Furthermore, the refractive index of the transparent UV glue matches the refractive index of the optical glass and the plastic scintillator.

[0018] Furthermore, a plurality of holes are opened in the middle of the optical glass along the width direction, and the cross-section of the holes is circular and runs through the entire optical glass.

[0019] Furthermore, the interior of the hole is polished.

[0020] Furthermore, the titanium dioxide reflective layer is coated on the cross section of the wavelength-shifting optical fiber on the side where it is inserted into the hole.

[0021] Furthermore, the wavelength-shifting optical fiber adopts a single-cladding structure.

[0022] Furthermore, the light guide is made of white PC material, a circular hole is opened in the middle of the light guide, the wavelength-shifted optical fiber with bundled shading treatment is placed in the hole, ensuring that the end face of the wavelength-shifted optical fiber is flush with the end face of the light guide, and transparent UV glue is filled into the hole to fix the wavelength-shifted optical fiber with bundled shading treatment.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention applies wavelength-shifted optical fiber to the detection of Compton scattered signals. The wavelength-shifted optical fiber can maintain high transmission efficiency, high efficiency and low loss characteristics over a long distance, significantly improve the transmission efficiency of optical signals, reduce signal attenuation, and improve the detection sensitivity and accuracy of the detection system for Compton scattered signals.

[0025] 2. The detector system of the present invention adopts a fully encapsulated design, making it an independent, easy-to-install and easy-to-use system, overcoming the deficiency that there are no commercial Compton scatter detectors on the market. The fully encapsulated design not only provides reliable protection, but also simplifies the integration and application of the system.

[0026] 3. The present invention can solve the problem of incomplete photographing of objects due to changes in the field of view at different detection distances by replacing packaging modules of different sizes, thereby increasing the flexibility and scope of application of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of the Compton scattering signal detection system based on wavelength-shifted optical fiber proposed in the present invention.

[0028] Legend: 1. Black polycarbonate plate; 2. Black sleeve; 3. Mirror aluminum foil; 4. Optical glass; 5. Transparent UV glue; 6. Plastic scintillator; 7. Titanium dioxide reflective layer; 8. Wavelength-shifting optical fiber; 9. Optical fiber shading sleeve; 10. Black rubber sleeve; 11. Light guide; 12. Photomultiplier tube; 13. Signal acquisition card. DETAILED DESCRIPTION

[0029] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0030] This embodiment provides a Compton scattering signal detection system based on wavelength-shifted optical fiber, and its structural schematic diagram is shown in FIG. Figure 1 As shown, it includes: a packaging shell, a scintillator detector, a signal transmission module and a signal collection module.

[0031] The packaging shell is composed of a black polycarbonate plate 1 and a black sleeve 2. The shell provides solid protection to prevent external light from interfering with the operation of the detector. The black polycarbonate plate 1 completely wraps the scintillator detector and the signal transmission module. The black sleeve 2 is used to place the photomultiplier tube 12 in the signal collection module. The black polycarbonate plate 1 and the black sleeve 2 are bonded with black PVC glue. The inside of the shell is designed with a special partition and support structure to fix and protect the scintillator detector, wavelength-shifting optical fiber 8 and the signal collection module.

[0032] The scintillator detector includes a plastic scintillator 6, an optical glass 4, a mirror aluminum foil 3, a Teflon coating layer, and a transparent UV glue 5. The plastic scintillator 6 is used to receive Compton scattered signals. The mirror aluminum foil 3 completely wraps the optical glass 4 and the plastic scintillator 6 to reflect the visible light of the two and prevent visible light leakage. The Teflon coating layer is used to wrap the mirror aluminum foil 3 to prevent visible light from the external environment from entering the detector and the optical glass 4. The optical glass 4 covers the surface of the plastic scintillator 6 to improve the transmission efficiency of the optical signal. The transparent UV glue 5 tightly couples the plastic scintillator 6 and the optical glass 4 to ensure the effective transmission of the optical signal.

[0033] In this embodiment, a plastic scintillator with a size of 40cm×20cm×4cm is used, which emits ultraviolet light or blue light when hit by high-energy photons generated by Compton scattering. The refractive index of the plastic scintillator is 1.58, and the optical glass is selected from a low-refractive index material with a refractive index of 1.58, which matches the plastic scintillator. The size of the optical glass is 40cm×20cm×2cm. A hole is opened in the middle of the optical glass along the width direction. Its cross-section is circular and runs through the entire optical glass. The inside of the hole is polished. The refractive index of the transparent UV glue 5 is 1.58, which is used to bond the plastic scintillator and the optical glass. The above three materials have the same refractive index, which minimizes the transmission loss of photons between different media.

[0034] The signal transmission module includes a wavelength-shifting optical fiber 8, a titanium dioxide reflective layer 7, an optical fiber shading sleeve 9, a light guide 11, a black rubber sleeve 10 and a transparent UV glue 5. The wavelength-shifting optical fiber 8 adopts a single-cladding structure, with a cladding refractive index of 1.59 and a core refractive index of 1.49. The wavelength-shifting optical fiber 8 is inserted into a hole in the optical glass 4 and then fixed with transparent UV glue 5. All wavelength-shifting optical fibers 8 are bundled into a bundle at the end for easy handling; the titanium dioxide reflective layer 7 is applied to the cross section of the optical fiber inserted into the hole to increase the reflectivity of photons reaching the optical fiber cross section; the optical fiber shading sleeve 9 is used to shade the wavelength-shifting optical fiber 8. The optical fiber exposed to the environment is sheathed with the optical fiber shading sleeve 9 and heated The air gun heats the sleeve to shrink and fix it on the optical fiber; the black rubber sleeve 10 is made of 1mm thick black rubber material, which is soft and opaque, and wraps the wavelength-shifted optical fiber after the bundle is assembled; the light guide 11 is made of white PC material, and a circular hole is opened in the middle of the light guide 11. The wavelength-shifted optical fiber 8 with bundled light-shielding treatment is placed in the hole to ensure that the end face of the wavelength-shifted optical fiber 8 is flush with the end face of the light guide 11, and then the transparent UV glue 5 is filled into the hole to fix it. The light guide 11 is used to further guide and concentrate the optical signal to improve the signal transmission efficiency. Then the signal of the wavelength-shifted optical fiber 8 is collected by the signal collection module.

[0035] In this embodiment, the wavelength shifting optical fiber 8 is a Y-11 type single-clad optical fiber with a total length of 1m, a core diameter of 0.48mm, a cladding thickness of 0.2mm, and a total diameter of 0.5mm. The optical fiber is inserted into the hole opened on the optical glass 4, and the ultraviolet light or blue light generated by the scintillator 6 can be converted into green light and transmitted to the photomultiplier tube 12.

[0036] The signal collection module includes a photomultiplier tube 12 and a signal acquisition card 13. The photomultiplier tube 12 is used to receive the signal of the wavelength-shifted optical fiber 8 and convert the obtained optical signal into an electrical signal for output; the signal acquisition card 13 is used to collect the electrical signal of the photomultiplier tube 12. The photomultiplier tube 12 has high sensitivity and can detect weak optical signals. It is installed at both ends of the wavelength-shifted optical fiber 8 to receive the transmitted optical signal and convert it into an electrical signal. The signal acquisition card 13 is connected to the photomultiplier tube 12 to process, amplify and filter the electrical signal, and finally output the detection signal. The signal acquisition card 13 can perform efficient data acquisition and processing to ensure the accuracy and stability of the signal.

[0037] The detector system in this embodiment adopts a fully encapsulated design, making it an independent molding system that is easy to install and use.

[0038] The specific steps of using the signal detection system proposed in this embodiment to detect the Compton scattering signal are as follows:

[0039] 1. System preparation:

[0040] Ensure that all components of the detection system are intact, including the package housing, scintillator detector, signal transmission module, and signal collection module. Check and confirm that the system's power connection is normal and the signal transmission and collection components are intact.

[0041] 2. Installation and Setup

[0042] Mount the package housing at the desired sensing location, ensuring it is secure and properly aligned with the target area.

[0043] 3. Signal collection module connection

[0044] The signal acquisition card 13 is connected to the photomultiplier tube 12 to ensure that the electrical signal can be received and processed by the signal acquisition card 13 .

[0045] 4. System Calibration

[0046] Turn on the power, start the detection system, and perform preliminary calibration. Use a known light source or a standard ray source to test the system's response. Adjust the position and angle of each part of the system to ensure that the detector's response sensitivity to the target area is optimal.

[0047] 5. Start detection

[0048] After ensuring that all connections and settings are correct, start the detection task. High-energy photons collide with electrons in the plastic scintillator 6 to generate optical signals. The plastic scintillator 6 converts these optical signals into ultraviolet light or blue light, which is transmitted to the wavelength-shifted optical fiber 8 through the optical glass 4. The wavelength-shifted optical fiber 8 converts these optical signals into green light and transmits them to the photomultiplier tube 12 through the titanium dioxide reflective coating 7 and the light guide 11. The photomultiplier tube 12 converts the optical signal into an electrical signal, which is processed and converted by the signal acquisition card 13, and the data on the signal acquisition card 13 is monitored in real time to ensure the signal quality and accuracy during the detection process. The final output electrical signal is used to further analyze the system.

[0049] 6. Data Analysis

[0050] After the collection is completed, the data in the signal acquisition card 13 is exported to a computer or a data processing system for analysis. Special software is used to process and analyze the detection signal to obtain the required detection results.

[0051] 7. System maintenance

[0052] Turn off the system power and check whether each component is damaged or abnormal. Perform necessary cleaning and maintenance to ensure long-term stable operation of the system.

[0053] Regularly calibrate and check the system to ensure that its detection performance and sensitivity remain at optimal levels.

[0054] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A Compton scattering signal detection system based on wavelength-shifted optical fiber, characterized in that: It includes: packaging shell, scintillator detector, signal transmission module and signal collection module. The packaging shell comprises a black polycarbonate plate (1) and a black sleeve (2), wherein the black polycarbonate plate (1) encloses the scintillator detector and the signal transmission module; and the black sleeve (2) is used to place the photomultiplier tube (12) in the signal collection module; The scintillator detector comprises a plastic scintillator (6), optical glass (4), a mirror aluminum foil (3) and a Teflon coating layer, wherein the plastic scintillator (6) is used to receive Compton scattered signals, the mirror aluminum foil (3) wraps the optical glass (4) and the plastic scintillator (6), and the Teflon coating layer wraps the mirror aluminum foil (3); The signal transmission module comprises a wavelength-shifting optical fiber (8), a titanium dioxide reflective layer (7), an optical fiber light-shielding sleeve (9), a light guide (11) and a black rubber sleeve (10); the wavelength-shifting optical fiber (8) is inserted into a hole in the optical glass (4); the optical fiber light-shielding sleeve (9) wraps the portion of the wavelength-shifting optical fiber (8) outside the hole; and the black rubber sleeve (10) is sleeved at the end of the bundle to wrap the bundled wavelength-shifting optical fiber (8); The signal collection module comprises a photomultiplier tube (12) and a signal collection card (13), wherein the photomultiplier tube (12) and the signal collection card (13) are connected to each other, the photomultiplier tube (12) is used to receive the optical signal of the wavelength-shifted optical fiber (8) and convert it into an electrical signal for output; and the signal collection card (13) is used to collect the electrical signal output by the photomultiplier tube (12).

2. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 1, characterized in that: The black polycarbonate plate (1) is a whole, and a circular hole is provided on its side; the black sleeve (2) is made of polycarbonate and is fixed to the circular hole on the side of the black polycarbonate plate (1) by using black PVC glue, and there is no gap between the two.

3. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 1, characterized in that: The plastic scintillator (6) and the optical glass (4) are bonded together by means of a transparent UV glue (5), and the transparent UV glue (5) is poured into the hole of the optical glass (4) to fix the wavelength shifting optical fiber (8).

4. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 3, characterized in that: The optical glass (4) is made of a low refractive index material, which matches the refractive index of the plastic scintillator (6).

5. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 4, characterized in that: The refractive index of the transparent UV glue (5) matches the refractive index of the optical glass (4) and the plastic scintillator (6).

6. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 1, characterized in that: A plurality of holes are provided in the middle of the optical glass (4) along the width direction; the holes have a circular cross section and penetrate the entire optical glass (4).

7. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 6, characterized in that: The interior of the hole is polished.

8. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 6, characterized in that: The titanium dioxide reflective layer (7) is applied to the cross section of the wavelength shifting optical fiber (8) on the side where it is inserted into the hole.

9. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 1, characterized in that: The wavelength-shifting optical fiber (8) adopts a single-cladding structure.

10. The Compton scattering signal detection system based on wavelength-shifted optical fiber according to claim 1, characterized in that: The light guide (11) is made of white PC material, a circular hole is opened in the middle of the light guide (11), the wavelength shifting optical fiber (8) that has been subjected to bundled light-shielding treatment is placed in the hole, ensuring that the end face of the wavelength shifting optical fiber (8) is flush with the end face of the light guide (11), and transparent UV glue (5) is filled into the hole to fix the wavelength shifting optical fiber (8) that has been subjected to bundled light-shielding treatment.

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