Gamma position sensitive detection system based on scintillator array end face imaging

Abstract

The invention discloses a gamma position sensitive detection system based on scintillator array end face imaging, and the system comprises a scintillator array group which is used for generating a first scintillation light signal of a vertical end face and a second scintillation light signal of a horizontal end face through the irradiation of to-be-detected gamma / X rays; the optical fiber image transmission bundle is used for combining the first scintillation light signal and the second scintillation light signal and transmitting the combined signal to an image transmission bundle terminal; the imaging lens is used for imaging the scintillation light signal of the image transmission bundle terminal to the image sensor; and the computer is used for analyzing the light color and intensity information received by the image sensor. According to the invention, the end face light emitting beams in the vertical direction and the horizontal direction of the scintillator array group are combined to one terminal, and the end face light emitting images in the vertical direction and the horizontal direction can be recorded at the same time by only one image sensor, so that the equipment cost is saved; therefore, real-time monitoring of the two-dimensional center position and time and space distribution of the gamma / X ray to be measured can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of pulse radiation detection, and in particular relates to a gamma position sensitive detection system based on scintillator array end face imaging, which is suitable for measuring ultrafast pulse gamma / X-ray time spectra with small beam spot size and spatial alignment requirements. In particular, the detection system has the ability to achieve spatial position resolution below 400μm. Background Art

[0002] The third and fourth generation light sources, such as hard X-ray free electron lasers, synchrotron radiation sources, strong laser-driven Betatron radiation, and inverse Compton scattering gamma-ray sources, have common characteristics such as good directionality, small beam spots, and ultrafast time characteristics. Information such as the position and spatial distribution of ultrafast pulsed γ / X-rays can reflect the working status of the light source system and experimental equipment. By analyzing the position and spatial distribution information of γ / X-rays, it can guide the work of beam alignment and debugging, experimental system position correction, etc. X-ray position sensitive detectors are an indispensable and important component of synchrotron radiation beam lines. The real-time data of beam position and intensity provided by them are an important basis for monitoring the operating status of beam lines. The γ / X-ray beam spot size used in the precise calibration of aerospace gamma detectors, industrial imaging, tomography, etc. is usually in the order of mm and requires high stability. Multiple applications have put forward higher requirements for the position and spatial distribution monitoring of ultrafast pulsed micro-beam γ / X-rays to meet the monitoring needs of light intensity, beam spot position and its motion trajectory.

[0003] The real-time imaging technology can be used to monitor the spatial position and time spectrum of γ / X-rays. At present, the imaging technology of γ / X-rays usually relies on the imaging plate (Imaging Plate / IP), scintillation screen and CCD image sensor. The imaging system based on IP plate must remove the IP plate from the experimental system, and release the light energy of the latent image in the IP plate through laser scanning to obtain image information. This offline imaging cannot obtain image information in real time, and the IP plate needs to use high-intensity light to erase the residual latent image before it can be used again. The number of exposure reuses is also limited, resulting in increased costs. The scintillation imaging detection system uses a scintillation screen to convert γ / X-rays into visible light signals, and then uses an image sensor for imaging detection. In the compact scintillation imaging detection system, the coupling between the scintillation screen and the image sensor (CCD / CMOS) is usually achieved by optical adhesive bonding. The coupling process requirements are high, and the image sensor and the scintillation screen will be exposed to the irradiation environment together. The image sensor has poor radiation resistance. The damage of any CCD / CMOS chip may cause the coupling component to be scrapped, increasing the consumption cost. In addition, the bonding method makes it impossible to freely match different scintillation screens and image sensors, which has many limitations.

[0004] The above series of problems result in the existing technology being unable to meet the urgent demand for high-quality, high-efficiency and high-reliability monitoring of ultrafast pulse γ / X-ray microbeam spots. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a gamma position sensitive detection system based on scintillator array end face imaging to solve the above problems existing in the prior art.

[0006] To achieve the above object, the present invention provides a gamma position sensitive detection system based on scintillator array end face imaging, comprising:

[0007] A scintillator array group, used for generating a first scintillation light signal on a vertical end surface and a second scintillation light signal on a horizontal end surface by irradiating the gamma / X-ray to be detected;

[0008] An optical fiber image transmission bundle, used for combining the first scintillation light signal and the second scintillation light signal into a bundle and transmitting the bundle to an image transmission bundle terminal;

[0009] An imaging lens, used for imaging the scintillation light signal at the end of the image transmission beam to an image sensor;

[0010] The computer is used to analyze the luminous color and intensity information received by the image sensor, and based on the analysis results, to achieve real-time monitoring of the two-dimensional center position and time and space distribution of the gamma / X-ray to be measured.

[0011] Preferably, the scintillator array group includes two identical one-dimensional scintillator arrays vertically stacked on each other.

[0012] Preferably, the one-dimensional scintillator array comprises one or two scintillator crystal materials, wherein in the one-dimensional scintillator array comprising two scintillator crystal materials, only one scintillator crystal at the center position has a material different from that of scintillator crystals at other positions.

[0013] Preferably, the one-dimensional scintillator array further comprises an ESR total reflection film, wherein the ESR total reflection film and the scintillator crystals are arranged alternately.

[0014] Preferably, hard glass is installed on the upper and lower surfaces of the scintillator array group for protection, and a hollow design is left in the central area of ​​the hard glass to enable γ / X-rays to irradiate the central area of ​​the scintillator array group. An aluminum clamp is connected to the non-light-emitting surface of one side of the scintillator array group to support the scintillator array group.

[0015] Preferably, the optical fiber image transmission bundle is a two-in-one type, comprising a first forked end, a second forked end, a transmission optical fiber and an image transmission bundle terminal.

[0016] Preferably, the vertical end face and the horizontal end face of the scintillator array group are respectively connected to the first forked end and the second forked end of the optical fiber imaging bundle, and the other end of the optical fiber imaging bundle is bundled together to form an imaging bundle terminal.

[0017] Preferably, the pixels at the first forked end and the second forked end of the optical fiber imaging bundle are in one-to-one correspondence with the terminal pixels.

[0018] Preferably, it further comprises an electric displacement frame, through which the distance between the optical fiber image transmission bundle terminal and the imaging lens is adjusted to achieve high-quality imaging.

[0019] Preferably, it also comprises a movable clamp, through which the aluminum clamp is clamped to adjust the position of the scintillator array group, so as to irradiate the γ / X-ray to be measured on the scintillator array group.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] The present invention provides a gamma position sensitive detection system based on scintillator array end face imaging. The system emits light from the end faces of the scintillator array group in the vertical and horizontal directions, transmits the light through an optical fiber imaging bundle, and images the light to an image sensor. The system can achieve high-precision resolution of the two-dimensional center position of ultrafast micro-beam gamma rays at a level below 400 μm. The system has the function of collecting the spatial distribution and time spectrum of micro-beam gamma rays through real-time online monitoring, thereby meeting the monitoring requirements for light intensity, beam spot position, and its motion trajectory.

[0022] The system of the present invention uses a two-in-one optical fiber image transmission bundle as an imaging transmission unit, which has the advantages of light weight, softness, flexibility, and flexible operation. The vertical and horizontal end-face light emission of the scintillator array group is combined into one terminal, and only one image sensor is needed to simultaneously record the end-face light emission images in both vertical and horizontal directions, saving equipment costs. In addition, the system has a compact structure and adopts a mechanical coupling method, which can be freely disassembled and assembled for repeated use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 It is a schematic diagram of the structure of a gamma position sensitive detection system according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of a scintillator array group according to an embodiment of the present invention;

[0026] Figure 3It is a schematic diagram of a hard glass sandwich scintillator array group according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of a gamma position sensitive detection system according to an embodiment of the present invention;

[0028] Figure 5 This is a diagram showing the experimental results of the end-face luminescence of the scintillator array group irradiated by gamma rays according to an embodiment of the present invention;

[0029] Figure 6 This is a diagram showing the experimental results of the end-face luminescence of the scintillator array group irradiated by X-rays according to an embodiment of the present invention;

[0030] Among them, 1. scintillator array group; 2. movable clamp; 3. first fork end of optical fiber image transmission bundle; 4. second fork end of optical fiber image transmission bundle; 5. transmission optical fiber of optical fiber image transmission bundle; 6. image transmission bundle terminal; 7. imaging lens; 8. electric displacement frame; 9. image sensor; 10. computer; 11. scintillator crystal; 12. first ESR total reflection film; 13. second ESR total reflection film; 14. γ / X-ray; 15. vertical end face y direction; 16. horizontal end face x direction; 17. aluminum clamp connector; 18. hard glass; 19. gamma spot. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0033] Embodiment 1

[0034] like Figure 1 As shown, this embodiment provides a gamma position sensitive detection system based on scintillator array end face imaging, including:

[0035] Scintillator array group 1, used for generating a first scintillation light signal on a vertical end surface and a second scintillation light signal on a horizontal end surface by irradiating the gamma / X-ray to be detected;

[0036] An optical fiber image transmission bundle 5, used for combining the first flashing light signal and the second flashing light signal and transmitting them to an image transmission bundle terminal 6;

[0037] An imaging lens 7, used for imaging the scintillation light signal at the end of the image transmission beam to an image sensor 9;

[0038] The computer 10 is used to analyze the luminous color and intensity information received by the image sensor, and based on the analysis results, to achieve real-time monitoring of the two-dimensional center position and time and space distribution of the gamma / X-ray to be measured.

[0039] Specifically, the implementation steps of the system include: the gamma / X-ray 14 to be measured is irradiated on the scintillator array group 1, and scintillation light signals are generated in the vertical end surface y direction 15 and the horizontal end surface x direction 16 of the scintillator array group respectively, and the scintillation light signals are transmitted to the image bundle terminal 6 via the optical fiber image bundle connected to the scintillator array group 1, and the scintillation light is imaged by the imaging lens 7, and the imaging lens 7 images the scintillation light of the optical fiber image bundle terminal to the image sensor 9, and the image sensor 9 takes a picture of the imaged scintillation light. The color and intensity information of the image light in the vertical and horizontal directions is analyzed by the computer 10, so as to realize the real-time monitoring of the two-dimensional center position and the time and space distribution of the gamma / X-ray to be measured.

[0040] In addition, the system further comprises a movable fixture 2 , which is used to clamp the aluminum fixture to adjust the position of the scintillator array group 1 , so that the gamma / X-rays 14 to be measured are irradiated on the scintillator array group 1 .

[0041] like Figure 3 As shown, the scintillator array group 1 is formed by two identical one-dimensional scintillator arrays vertically overlapping each other, and hard glass 18 is installed on the upper and lower surfaces of the scintillator array group 1. The central area of ​​the hard glass 18 is hollowed out to enable γ / X-rays to irradiate the central area of ​​the scintillator array group. An aluminum clamp connector 17 is connected to the non-light-emitting surface of one side of the scintillator array group to support the scintillator array group 1.

[0042] Further, the one-dimensional scintillator array comprises one or two scintillator crystal materials, the one-dimensional scintillator array comprising one material adopts LYSO or GAGG crystal, and the one-dimensional scintillator array comprising two materials has only one scintillator crystal at the center position different from the materials at other positions, such as the one-dimensional scintillator array adopts GAGG scintillator crystal at the center position and LYSO scintillator crystal at other positions;

[0043] like Figure 2 As shown, the one-dimensional scintillator array is formed by alternating scintillator crystals 11 and a second ESR total reflection film 13. The pixel size of the one-dimensional scintillator array is less than or equal to 0.4mm*0.4mm, and the pixel length is designed according to the beam spot size. The upper and lower surfaces of the scintillator array are covered with the first ESR total reflection film 12. Only one end face of each array is used as a light-emitting surface, and the other end face is covered with a second ESR total reflection film 13 of a certain thickness and an outer aluminum foil; the two light-emitting surfaces of the scintillator array group 1 are connected to the optical fiber image transmission bundle.

[0044] Furthermore, the optical fiber image transmission bundle is a two-in-one type, including a first forked end 3 , a second forked end 4 , a transmission optical fiber 5 and an image transmission bundle terminal 6 .

[0045] Furthermore, the vertical end face and the horizontal end face of the scintillator array group are respectively connected to the first forked end 3 and the second forked end 4 of the optical fiber imaging bundle, and the other end of the optical fiber imaging bundle is bundled together to form an imaging bundle terminal 6.

[0046] Specifically, the vertical end face y direction 15 and the horizontal end face x direction 16 of the scintillator array group 1 are respectively connected to the first forked end 3 and the second forked end 4 of the optical fiber imaging bundle, and the other ends of the two optical fiber imaging bundles are bundled together to form an optical fiber imaging bundle terminal 6; the lengths of the first forked end 3 and the second forked end 4 of the optical fiber imaging bundle can be designed as needed, and the pixel size of the optical fiber imaging bundle is less than 0.03 mm.

[0047] Furthermore, the pixels of the first bifurcated end 3 of the optical fiber imaging bundle connected to the vertical end face of the scintillator array group 1 and the second bifurcated end 4 of the optical fiber imaging bundle connected to the horizontal end face are in one-to-one correspondence with the pixels of the imaging bundle terminal 6 .

[0048] Furthermore, the system also includes an electric displacement frame, through which the distance between the optical fiber image transmission bundle terminal and the imaging lens is adjusted to achieve high-quality imaging.

[0049] Specifically, the optical fiber image transmission bundle terminal 6 is installed on the electric displacement frame 8, and the imaging lens 7 is installed behind the image transmission bundle terminal 6. The distance between the optical fiber image transmission bundle terminal 6 and the imaging lens 7 can be adjusted by the electric displacement frame 8;

[0050] The imaging lens 7 has a focal length of 400 mm, an F number of 8, a lens thickness of 10 mm, and a curvature radius of -1927.446 mm.

[0051] The image sensor 9 adopts a color high-resolution CCD, with a pixel size of less than or equal to 3.75 μm×3.75 μm, an effective photosensitive area of ​​4.8 mm×3.6 mm, and a luminous spectrum (visible light band) of the scintillator array within the spectral receiving range of the image sensor 9;

[0052] The color and intensity information of the scintillation light image is analyzed by a computer, and the spatial distribution position and time spectrum of the gamma-ray spot can be determined through reverse calculation.

[0053] In this embodiment, the optical signal transmitted by the optical fiber imaging bundle is the accumulated light emission of the scintillation crystal, which can be identified by grayscale value of the image obtained by the image sensor, such as Figure 4The schematic diagram of the γ / X-ray position sensitive detection is shown. According to the one-to-one position relationship between the pixels of the first bifurcated end 3 and the second bifurcated end 4 of the optical fiber image transmission bundle and the terminal pixels, the two-dimensional position of the gamma spot 19 on the scintillator array group 1 is found. The brightest position in the x direction is position ⑥, and the brightest position in the y direction is position ⑥. Therefore, it can be determined that the coordinate (⑥, ⑥) is the center position of the γ / X-ray 14. Since the pixel size of the scintillator array is less than or equal to 400μm, the system can achieve high-precision resolution of the two-dimensional center position below 400μm. At the same time, combined with other luminous positions, the spatial distribution of the γ / X-ray 14 can be determined. By using the image sensor 9 to continuously and quickly take pictures of the scintillation light imaging, and using the computer 10 to analyze the grayscale value and color of the two-dimensional luminous image, the change of the luminous intensity of the scintillator over time and the luminous spectrum can be determined, and the online monitoring of the ultrafast γ / X-ray time spectrum can be achieved.

[0054] Experimental research was carried out using a 1.25 MeV DC gamma ray source (cobalt source), proving the effectiveness of the developed position sensitive detection system. Two types of image sensors 9, black and white and color, were used to image the scintillator array group 1 in the horizontal and vertical directions, respectively. The experimental results are shown in Figure 1. Figure 5 As shown, it can be seen that the entire field of view is illuminated to different degrees, and the color camera can reflect the color of the flickering visible light. Combined with data such as brightness and light attenuator multiples, a relatively sensitive experimental estimation of the system gamma can be achieved.

[0055] Experimental research was carried out using 140keV, 500μA X-rays, and the luminous images obtained in the horizontal X direction and vertical Y direction are as follows Figure 6 shown.

[0056] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A gamma position sensitive detection system based on scintillator array end face imaging, characterized in that: include: A scintillator array group, used for generating a first scintillation light signal on a vertical end surface and a second scintillation light signal on a horizontal end surface by irradiating the gamma / X-ray to be detected; An optical fiber image transmission bundle, used for combining the first flashing light signal and the second flashing light signal into a bundle and transmitting the bundle to an image transmission bundle terminal; An imaging lens, used for imaging the scintillation light signal at the end of the image transmission beam to an image sensor; A computer that analyzes the light color and intensity information received by the image sensor.

2. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 1, characterized in that: The scintillator array group includes two identical one-dimensional scintillator arrays vertically stacked on each other.

3. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 2, characterized in that: The one-dimensional scintillator array comprises one or two scintillator crystal materials, wherein the one-dimensional scintillator array comprising two scintillator crystal materials has only one scintillator crystal at the center position having a different material from that of the scintillator crystals at other positions.

4. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 3, characterized in that: The one-dimensional scintillator array further includes an ESR total reflection film, wherein the ESR total reflection film and the scintillator crystals are arranged alternately.

5. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 1, characterized in that: The upper and lower surfaces of the scintillator array group are protected by hard glass, and a hollow design is left in the central area of ​​the hard glass to enable γ / X-rays to irradiate the central area of ​​the scintillator array group. An aluminum clamp is connected to the non-light-emitting surface of one side of the scintillator array group to support the scintillator array group.

6. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 1, characterized in that: The optical fiber image transmission bundle is a two-in-one type, comprising a first forked end, a second forked end, a transmission optical fiber and an image transmission bundle terminal.

7. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 6, characterized in that: The vertical end face and the horizontal end face of the scintillator array group are respectively connected to the first forked end and the second forked end of the optical fiber imaging bundle, and the other end of the optical fiber imaging bundle is bundled together to form an imaging bundle terminal.

8. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 7, characterized in that: The pixels at the first forked end and the second forked end of the optical fiber imaging bundle are in one-to-one correspondence with the terminal pixels.

9. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 1, characterized in that: It also includes an electric displacement frame, through which the distance between the optical fiber image transmission bundle terminal and the imaging lens is adjusted to achieve high-quality imaging.

10. The gamma position sensitive detection system based on scintillator array end face imaging according to claim 1, characterized in that: It also includes a movable clamp, which is used to clamp the aluminum clamp to adjust the position of the scintillator array group, so that the gamma / X-ray to be measured is irradiated on the scintillator array group.

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