A multi-mode Compton imaging detection device and its application

Abstract

This invention provides a multi-mode Compton imaging detection device and its application, comprising: a housing and a radiation source, a scattering detector, an absorption detector, a visible light imaging unit, a signal processing unit, a central control board, a power supply assembly, and a display screen disposed within the housing; two scattering detector arrays are formed by multiple scattering detector arrays; two absorption detector arrays are formed by multiple absorption detector arrays; the visible light imaging unit is disposed on one side of the scattering detectors; the signal processing unit is connected to both the scattering and absorption detectors; the central control board is connected to the signal processing unit and the visible light imaging unit; the power supply assembly provides power to other components; and the display screen is connected to the central control board. This detection device is used for the identification and location detection of organic contraband and radionuclides. The detection device of this invention can achieve multiple modes of detection, is easy to operate, highly portable, has low overall investment cost, and saves resources.

Description

Technical Field

[0001] This invention belongs to the field of radiation imaging inspection technology, and in particular relates to a multi-mode Compton imaging inspection device and its application. Background Technology

[0002] Currently, the international methods for detecting trace amounts of drugs and explosives mainly employ ion mobility spectrometry, mass spectrometry, and their combined techniques. For detecting small and large quantities of drugs and explosives, radiation imaging techniques are primarily relied upon. Because drugs and explosives are composed of low atomic number elements (C, H, N, O, P, etc.), have low material density but high electron density, they have poor absorption of radiation but strong Compton scattering. Compton backscattering imaging technology can brighten and display organic contraband such as drugs and explosives. Furthermore, the flexible layout of backscattering detectors makes backscattering imaging technology highly suitable for imaging and detecting drugs or explosives and other organic contraband in concealed or well-sealed locations, leading to its widespread adoption by customs and border control.

[0003] For the identification and detection of radionuclides or substances, an energy spectrometer is usually used to measure the energy spectrum of the target substance, and then the obtained characteristic energy spectrum is preprocessed, peak-finding and matched to determine the nuclide type.

[0004] For the localization of radionuclides, there are three main effective techniques: pinhole imaging, coded aperture imaging, and Compton scattering imaging. Since Compton scattering imaging does not require a collimator to limit the field of view, it is superior to the other two techniques in terms of portability and imaging angle range. Therefore, the imaging radionuclide localization technique based on Compton forward scattering has been widely adopted.

[0005] In the existing technology, there are no reports on portable detection devices and related devices that can simultaneously identify and locate organic contraband such as drugs and explosives, as well as radionuclides. The existing technology uses Compton backscatter imaging to detect organic items such as drugs and explosives, uses energy dispersive spectrometers to identify radionuclides, and uses Compton forward scattering to locate radionuclides, which easily leads to high overall investment costs and waste of resources for detection equipment.

[0006] On the other hand, the principle of the mainstream flying-spot scanning technology in Compton scattering imaging is to add a rotating disk with slits evenly spaced around the front of the fan-shaped beam exit of the X-ray machine. As the disk rotates, the slits intersect with the fan-shaped beam exit, forming periodic gaps from top to bottom or from left to right, thus creating a pencil-shaped or flying-spot-shaped X-ray beam. Although this solution is mature, it has the following drawbacks: ① During flying-spot scanning imaging, most of the X-rays are shielded by the collimator and chopper mechanism, resulting in extremely low X-ray utilization and low signal-to-noise ratio and poor resolution in the obtained images; ② To improve image resolution and signal-to-noise ratio, the exposure time usually needs to be extended, but the flying-spot scanning speed is limited by the chopper's rotation speed, making it difficult to meet the needs of high-throughput detection applications; ③ The mechanical mechanism that generates the flying spots is complex, large, and cumbersome, which is not only prone to failure but also hinders the miniaturization of the equipment.

[0007] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a multi-mode Compton imaging detection device and its application, to solve the problems of the lack of portable detection equipment that can both detect organic contraband and identify and locate radionuclides in the prior art, and the high total investment cost of detection equipment, resulting in resource waste. It also solves the problems of low X-ray utilization, low signal-to-noise ratio and low resolution of the obtained images in the prior art, and the complex, bulky and poor portability of the mechanical mechanism that generates flying points during Compton scattering imaging.

[0009] To achieve the above and other related objectives, the present invention provides a multi-mode Compton imaging detection device, the detection device comprising: a housing and an X-ray source, a scattering detector, an absorption detector, a visible light imaging unit, a signal processing unit, a central control board, a power supply assembly, and a display screen disposed within the housing;

[0010] The system comprises: a radiation source for generating a radiation beam; multiple scattering detectors arranged in an array to form two scattering detector arrays; multiple absorption detectors corresponding to multiple scattering detectors arranged in an array to form two absorption detector arrays; a visible light imaging unit located on one side of the scattering detectors for capturing images of the object under test; a signal processing unit connected to both the scattering and absorption detectors for processing the received signals; a central control board connected to the signal processing unit and the visible light imaging unit for data processing and image reconstruction of the received signals; a power supply unit providing power to the radiation source, scattering detectors, absorption detectors, visible light imaging unit, signal processing unit, central control board, and display screen; and a display screen connected to the central control board for displaying the image reconstructed by the central control board.

[0011] Preferably, the radiation source is a Spindt linear array radiation source, which is located between the two scattering detector arrays and is arranged parallel to the longitudinal direction of the scattering detector arrays.

[0012] Preferably, the Spindt linear array X-ray source includes a substrate and a plurality of electron emitters, which are arranged in an array on the substrate and electrically connected to a X-ray controller. The X-ray controller controls the electron emitters to periodically emit and shut down, and the plurality of electron emitters take turns generating flying point X-ray beams. The flying point X-ray beams interact with the object under test to produce scattered photons.

[0013] Preferably, the scattering detector comprises a first scintillation crystal, a first light cone, and a first photoelectric conversion device that are sequentially coupled together.

[0014] The absorption detector includes a second scintillation crystal, a second light cone, and a second photoelectric conversion device that are coupled together in sequence.

[0015] Preferably, both the first scintillation crystal and the second scintillation crystal are provided with a shielding layer and a reflective layer around their perimeter;

[0016] Both the first and second light cones are coated with a mirror-reflective layer, which is used for lossless transmission of optical signals.

[0017] The first photoelectric conversion device and the second photoelectric conversion device are both one or a combination of photomultiplier tubes, photodiodes, avalanche photodiodes, and silicon photomultiplier tubes.

[0018] Preferably, the signal processing unit includes a signal amplification circuit, an A / D converter, a threshold comparison circuit, a counting circuit, and an amplitude analyzer, which are connected in sequence.

[0019] Preferably, the power supply assembly includes a power supply battery and a power controller. The power controller is connected to the power supply battery, and the power supply battery controls the circuit switching of the X-ray source, scattering detector, absorption detector, visible light imaging unit, signal processing unit, control board, and display screen through the power control controller.

[0020] Preferably, both the scattering detector and the absorption detector are semiconductor detectors.

[0021] Preferably, the detection device further includes a storage unit connected to the central control board for storing the final detection results.

[0022] The present invention also provides an application of the Compton imaging detection device employing the above-mentioned multi-mode, wherein the detection device is used for imaging detection of organic contraband, and for the identification and localization detection of radionuclides.

[0023] As described above, the multi-mode Compton imaging detection device and its application of the present invention have the following beneficial effects:

[0024] The detection device of this invention includes both a scattering detector and an absorption detector. The scattering detector is used to achieve imaging detection of organic contraband and identification of radionuclides. The scattering detector and the absorption detector can also be used simultaneously to locate radionuclides. A single detection device can achieve multiple detection modes, making the detection equipment easy to operate and portable. When applied to the imaging detection of organic contraband and the identification and location detection of radionuclides, the overall investment cost of the detection device is low and resources are saved.

[0025] The detection device in this invention uses a Spindt linear array X-ray source to replace the fan-beam light source and the flying point X-ray generation mechanism of the chopper wheel in the prior art. Since the scanning control of the Spindt linear array X-ray source is flexible and faster than mechanical scanning, it effectively improves the scattering imaging speed and X-ray utilization, reduces shielding difficulty and the cumulative absorbed dose of operators, and can greatly reduce the complexity of the entire detection device, improve the portability of the device, and at the same time obtain high signal-to-noise ratio and high resolution of the image. Attached Figure Description

[0026] Figure 1 The diagram shown is a partial structural schematic of the multi-mode Compton imaging detection device in a specific embodiment of the present invention.

[0027] Figure 2The diagram shown is a schematic representation of the planar structure of the scattering detector in a specific embodiment of the present invention.

[0028] Figure 3 The diagram shown is a three-dimensional structural schematic of the absorption detector in a specific embodiment of the present invention.

[0029] Figure 4 The diagram shown is a structural schematic of the Spindt linear array X-ray source in a specific embodiment of the present invention.

[0030] Figure 5 The diagram shown is a schematic representation of the structure of the Spindt linear array X-ray source generating a flying point X-ray beam in a specific embodiment of the present invention.

[0031] Figure 6 Displayed as Figure 5 Cross-sectional view along direction AA.

[0032] Figure 7 The diagram shown illustrates the working principle of the multi-mode Compton imaging detection device for locating radionuclides in a specific embodiment of the present invention.

[0033] Figure 8 The diagram shown is a structural schematic of a multi-mode Compton imaging detection device in a specific embodiment of the present invention.

[0034] Component designation explanation

[0035] 100 Spindt linear array X-ray source

[0036] 101 substrate

[0037] 102 Electron emitters

[0038] 1021 Flying Spot Ray Beam

[0039] 200 Scattering Detectors

[0040] 201 First Scintillation Crystal

[0041] 202 First Light Cone

[0042] 203 First photoelectric conversion device

[0043] 300 Absorption Detector

[0044] 301 Second Scintillation Crystal

[0045] 302 Second Light Cone

[0046] 303 Second photoelectric conversion device

[0047] 400 visible light imaging units

[0048] 500 signal processing units

[0049] 600 Central Control Panel

[0050] 700 power supply unit

[0051] 800 display screen

[0052] 900 storage units Detailed Implementation

[0053] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0054] Please see Figures 1 to 8 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0055] The detection device of this invention includes both a scattering detector and an absorption detector. The scattering detector enables imaging detection of organic contraband and identification of radionuclides. Both detectors can also be used simultaneously to locate radionuclides. A single detection device can perform multiple detection modes, making it easy to operate and highly portable. When applied to imaging detection of organic contraband and identification and location detection of radionuclides, the overall investment cost of the detection device is low, saving resources. The detection device of this invention uses a Spindt linear array X-ray source instead of the existing fan-beam source and chopper wheel flying-point X-ray generation mechanism. Because the Spindt linear array X-ray source offers flexible scanning control and is faster than mechanical scanning, it effectively improves the scattering imaging speed and X-ray utilization rate, reduces shielding difficulty and the cumulative absorbed dose to operators, and significantly reduces the complexity of the entire detection device, improving its portability. Simultaneously, it obtains images with high signal-to-noise ratio and high resolution.

[0056] The present invention provides a multi-mode Compton imaging detection device, which includes: a housing and an X-ray source, a scattering detector 200, an absorption detector 300, a visible light imaging unit 400, a signal processing unit 500, a central control board 600, a power supply assembly 700 and a display screen disposed within the housing.

[0057] The system includes a radiation source for generating a radiation beam; multiple scattering detectors 200 are arranged in an array to form two arrays; multiple absorption detectors 300 are also arranged in an array, each corresponding to one of the multiple scattering detectors 200, forming two arrays; a visible light imaging unit 400 is located on one side of the scattering detectors 200 and is used to capture images of the object under test; a signal processing unit 500 is connected to both the scattering detectors 200 and the absorption detectors 300 and is used to process the received signals; a central control board 600 is connected to the signal processing unit 500 and the visible light imaging unit 400 and is used to perform data processing and image reconstruction on the received signals; a power supply unit 700 provides power to the radiation source, scattering detectors 200, absorption detectors 300, visible light imaging unit 400, signal processing unit 500, central control board 600, and display screen; the display screen is connected to the central control board 600 and is used to display the image reconstructed by the central control board 600.

[0058] Specifically, the signal processed by the signal processing unit 500 is transmitted to the central controller. The central controller performs data processing and image reconstruction on the received signal. The visible light imaging unit 400 is mainly used to capture images of the object under test and transmit the captured image information to the central controller. It can play an auxiliary role in the data processing and image reconstruction of the object under test. In this embodiment, the visible light imaging unit 400 includes a camera and a flash, and is mainly used to capture images. The visible light imaging unit 400 may also include other components, which are not excessively limited here.

[0059] Specifically, the scattering detector 200 is used to realize energy spectrum detection, dose rate detection, and backscattering imaging; the absorption detector 300 is located behind the scattering detector 200 to absorb the energy of the γ photons scattered by the scattering detector 200 and detect the position of the scattered γ photons. The position of the radiation source is reconstructed and determined by combining the positions of the γ photons received by the scattering detector 200 and the γ photons received by the absorption detector 300.

[0060] As an example, the X-ray source is a Spindt linear array X-ray source 100, which is located between two arrays of scattering detectors 200 and is arranged parallel to the longitudinal direction of the arrays of scattering detectors 200.

[0061] As an example, the Spindt linear array X-ray source 100 includes a substrate 101 and a plurality of electron emitters 102. The plurality of electron emitters 102 are arranged in an array on the substrate 101 and are electrically connected to a X-ray controller. The X-ray controller controls the electron emitters 102 to periodically emit and turn off. The plurality of electron emitters 102 take turns generating a flying point X-ray beam 1021. The flying point X-ray beam 1021 interacts with the object under test to produce scattered photons.

[0062] Specifically, the electron emitter 102 supplies electrons using photoelectric emission, field emission, or secondary emission. The power supply to the Spindt linear array X-ray source 100 is turned on, and the X-ray controller controls the electron emitter 102 to periodically start and stop one by one from top to bottom or from left to right. The electron emitter 102 alternately generates a cone-shaped flying-spot X-ray beam 1021. When the cone-shaped flying-spot X-ray beam 1021 is transmitted to the surface of the object under test, it undergoes Compton backscattering with the electrons in the object. The scattered photons are received by the backscatter detectors 200 located on both sides of the Spindt linear array X-ray source 100 and converted into voltage signals through photoelectric conversion. In this embodiment, the generated flying-spot X-ray beam 1021 provides flexible scanning control of the object under test. Compared with the mainstream flying-spot scanning technology of Compton scattering imaging in the prior art, the scanning speed in this embodiment is faster, which can effectively improve the backscatter imaging speed, reduce shielding difficulty, and decrease the cumulative absorbed dose for operators.

[0063] As an example, the scattering detector 200 includes a first scintillation crystal 201, a first light cone 202, and a first photoelectric conversion device 203 that are coupled together in sequence; the absorption detector 300 includes a second scintillation crystal 301, a second light cone 302, and a second photoelectric conversion device 303 that are coupled together in sequence.

[0064] Specifically, a scintillator is a type of material that emits light after absorbing high-energy particles or rays, and is typically processed into a scintillator crystal in applications. The first scintillator crystal 201 in the scattering detector 200 receives scattered photons and converts them into visible light. After multiple reflections by the first light cone 202, the visible light is transmitted to the first photoelectric conversion device 203, which converts the optical signal into a voltage signal. (See [reference]). Figure 5 As shown, the first scintillation crystal 201 is located at the foremost point, and the first light cone 202 is coupled between the first scintillation crystal 201 and the first photoelectric conversion device 203; see reference Figure 6As shown, the second light cone 302 in the absorption detector 300 is coupled between the second scintillation crystal 301 and the second light cone 302; in this embodiment, the first scintillation crystal 201 is relatively small in density and thickness, such as a 2-5 mm thick GOS (gadolinium oxysulfide) film, CsI (cesium iodide) crystal, CZT (cadmium zinc telluride) crystal, etc.; the second scintillation crystal 301 is relatively large in density and thickness, such as a 1-2 cm thick CsI (cesium iodide), GOS (gadolinium oxysulfide), GAGG (gadolinium aluminum gallium garnet), CZT (cadmium zinc telluride) crystal, etc.

[0065] When the detection device of the present invention is used for radionuclide localization, the gamma rays with energy E0 released from the decay of the radionuclide first enter the scattering detector 200 and produce Compton scattering in the scattering detector 200, resulting in energy deposition E1. The scattered photons exit through the scattering detector 200 and produce photoelectric effect in the absorption detector 300, and the photon energy is completely absorbed by the detector.

[0066] As an example, the first scintillation crystal 201 and the second scintillation crystal 301 are both provided with a shielding layer and a reflective layer around their perimeter; the interior of the first light cone 202 and the second light cone 302 is coated with a mirror reflective layer, which is used for lossless transmission of optical signals; the first photoelectric conversion device 203 and the second photoelectric conversion device 303 are both one or a combination of photomultiplier tubes, photodiodes, avalanche photodiodes, and silicon photomultiplier tubes.

[0067] Specifically, the shielding layer is used to shield visible light and radiation, thereby improving the utilization rate of radiation and reducing the harm to operators from radiation. The reflective layer reflects any leakage radiation back to the reaction area, improving the utilization rate of radiation. However, in this embodiment, there are no excessive restrictions on the materials used for the shielding layer and the reflective layer.

[0068] As an example, the signal processing unit 500 includes a signal amplification circuit, an A / D converter, a threshold comparison circuit, a counting circuit, and an amplitude analyzer connected in sequence.

[0069] Specifically, the signal amplification circuit amplifies weak signals; in this embodiment, it further amplifies voltage signals. The A / D converter is an electronic component that converts analog signals into digital signals; in this embodiment, it converts amplified voltage signals into digital signals. Threshold comparison includes adaptive Steind unbiased risk estimation thresholds, average threshold methods, or minimax threshold methods. The counting circuit consists of basic counting units and some control gates. The amplitude analyzer is an instrument that measures the amplitude distribution of electrical pulse signals. It classifies pulse signals according to their amplitude and records the number of signals in each category. It is often used to analyze the output signals of X-ray detectors and measure the energy spectrum of X-rays. The specific structure of each component in the signal processing unit 500 is not overly restricted here; it only needs to meet practical requirements.

[0070] As an example, the power supply assembly 700 includes a power supply battery and a power controller. The power controller is connected to the power supply battery, and the power supply battery controls the circuit switching of the X-ray source, the scattering detector 200, the absorption detector 300, the visible light imaging unit 400, the signal processing unit 500, the control board, and the display screen through the power controller.

[0071] Specifically, the power controller controls the on / off state of different components' circuits. When performing radionuclide identification, energy spectrum detection, or radioactive dose detection, only one or more of the scattering detectors 200, signal processing units 500, control boards, and displays can be powered on. When performing radionuclide localization, all circuits except for the radiation source and visible light imaging unit 400 need to be connected. When detecting organic contraband, the circuits related to the absorption detector 300 are disconnected, and other circuits are connected.

[0072] As an example, both the scattering detector 200 and the absorption detector 300 are semiconductor detectors.

[0073] Specifically, a semiconductor detector is a radiation detector that uses semiconductor materials as the detection medium. The most common semiconductor materials are germanium and silicon. Its basic principle is that charged particles generate electron-hole pairs in the sensitive volume of the semiconductor detector. The electron-hole pairs drift under the action of an external electric field and output a signal. In this embodiment, the semiconductor detector is a CZT (cadmium zinc telluride) or GAGG (gadolinium aluminum gallium garnet) semiconductor detector.

[0074] As an example, the detection device further includes a storage unit 900, which is connected to the central control board 600 and is used to store the final detection results.

[0075] To better understand the multi-mode Compton imaging detection device in this invention, this invention also provides an application of the multi-mode Compton imaging detection device, which is used for imaging detection of organic contraband, and for the identification and localization detection of radionuclides, as described in the following embodiments.

[0076] Example 1

[0077] This embodiment provides a multi-mode Compton imaging detection device for the identification of radionuclides and radiation dose detection. The specific detection method includes the following steps:

[0078] a1. Circuit for the power controller to control the power supply assembly 700 to turn on one or more of the scattering detectors 200, the signal processing unit 500, the control board and the display screen.

[0079] a2. The first scintillation crystal 201 on the scattering detector 200 is excited and de-excited under the action of the characteristic γ-rays released by the decay of radionuclides, and then produces fluorescence or phosphorescence. The fluorescence or phosphorescence is transmitted to the first photoelectric conversion device 203 after multiple reflections by the first light cone 202, which converts the light signal into a voltage signal.

[0080] a3. The voltage signal is transmitted to the signal processing unit 500, where it is further amplified, converted by A / D, compared by a threshold, counted by a counting circuit, and analyzed by an amplitude analyzer to form a spectrum.

[0081] a4. The generated spectrum is transmitted to the central control board 600. The spectral peaks in the spectrum are matched and compared with the spectral peaks of the nuclides in the database using a peak matching algorithm. The resulting image is reconstructed and displayed on the screen as the characteristic energy spectrum of the tested radionuclide, the nuclide matching result, and the dose information.

[0082] Example 2

[0083] This embodiment also provides a multi-mode Compton imaging detection device for the localization and detection of radionuclides, and the specific detection method includes the following steps:

[0084] b1. The circuit of the power controller controlling the power supply assembly 700 to turn on the scattering detector 200 and the absorption detector 300, as well as the circuit of turning on the visible light imaging unit 400, the signal processing unit 500, the control board and the display screen.

[0085] b2. The probe of the visible light imaging unit 400 and the scattering detector 200 are aligned with the suspected orientation of the radionuclide to be tested. The visible light imaging unit 400 takes pictures of the orientation of the radionuclide to be tested. The γ-rays with energy E0 released by the decay of the radionuclide first enter the scattering detector 200 and produce Compton scattering in the scattering detector 200. The photons that produce Compton scattering produce energy deposition E1 on the scattering detector 200, and the scattering position is (x1, y1, z1). After the first scintillation crystal 201 is excited and de-excited, it produces fluorescence or phosphorescence. The fluorescence is converted into a first electrical signal by the first light cone 202 and the first photoelectric conversion device 203. The first electrical signal is processed by the signal processing unit 500 and the information of the incident position range of the ray is recorded.

[0086] b3. After the Compton-scattered photons are emitted from the scattering detector 200, they generate a photoelectric effect in the absorption detector 300. The photon energy is completely absorbed by the absorption detector 300. During the absorption process, the electrons outside the nucleus of the second scintillation crystal 301 are excited. After the electrons de-excite, fluorescence is generated. The fluorescence is converted into a second electrical signal by the second light cone 302 and the second photoelectric conversion device 303. The second electrical signal is processed by the signal processing unit 500 and the incident position range information of the ray is recorded. Among them, the energy deposited in the absorption detector 300 of the γ-ray is E0-E1, and the absorption position is (x2, y2, z2).

[0087] According to the Compton imaging principle, the emission position of the gamma rays can be determined at a point on the surface of a cone. The vertex of this cone is located on the scattering detector 200, with coordinates (x1, y1, z1). The axis of the cone lies on the straight line between the scattering point (x1, y1, z1) and the absorption point (x2, y2, z2), where: In the formula m e c 2 Let be the rest mass of the electron.

[0088] This embodiment can determine the location range of radioactive nuclides. By conducting multiple tests and statistical calculations of the intersection points of multiple cones, combined with the images captured by the visible light imaging unit 400, the specific location of the radiation source can be determined, thus realizing the localization and detection of radioactive nuclides.

[0089] Example 3

[0090] This embodiment also provides a multi-mode Compton imaging detection device for the detection of organic contraband, and the specific detection method includes the following steps:

[0091] c1. The power controller controls the power supply component 700 to turn on the circuits of the Spindt linear array X-ray source 100, the two scattering detectors 200 array, the signal processing unit 500, the control board and the display screen, and to turn off the circuit of the absorption detector 300.

[0092] c2. The array of backscatter detectors 200 is aimed at the object under test. The radiation controller controls the electron emitters 102 to start and stop periodically from top to bottom or from left to right. Multiple electron emitters 102 take turns generating conical flying point radiation beams 1021. The conical flying point radiation beams 1021 interact with the object under test, and the radiation that produces Compton backscattering is received by the backscatter detector array 200 located on both sides of the Spindt linear array radiation source 100, forming a voltage signal.

[0093] c3. After the voltage signal is transmitted to the signal processing unit 500 for processing, the electron density distribution image of the measured point can be obtained, and then transmitted to the central control board 600.

[0094] c4. Move the detection device left and right or up and down at a constant speed to obtain electron density images of multiple test points. The central control board 600 reconstructs and stitches the multi-point electron density images to obtain the electron density image of the entire test object.

[0095] In summary, the detection device of this invention includes both a scattering detector and an absorption detector. The scattering detector enables imaging detection of organic contraband and identification of radionuclides. Both the scattering and absorption detectors can also be used to locate radionuclides. A single detection device can perform multiple detection modes, making it easy to operate and highly portable. When applied to imaging detection of organic contraband and identification and location detection of radionuclides, the overall investment cost of the detection device is low, saving resources. The detection device of this invention uses a Spindt linear array X-ray source instead of the fan-beam source and chopper wheel flying-point X-ray generation mechanism in existing technologies. Because the scanning control of the Spindt linear array X-ray source is flexible and faster than mechanical scanning, it effectively improves the scattering imaging speed and X-ray utilization rate, reduces shielding difficulty and the cumulative absorbed dose to operators, and significantly reduces the complexity of the entire detection device, improving its portability. Simultaneously, it obtains images with high signal-to-noise ratio and high resolution. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value.

[0096] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A multi-mode Compton imaging detection device, characterized in that, The detection device includes: a housing and an X-ray source, a scattering detector, an absorption detector, a visible light imaging unit, a signal processing unit, a central control board, a power supply assembly, and a display screen disposed within the housing; The system comprises: a radiation source for generating a radiation beam; multiple scattering detectors arranged in an array to form two scattering detector arrays; multiple absorption detectors corresponding to multiple scattering detectors, also arranged in an array to form two absorption detector arrays; a visible light imaging unit located on one side of the scattering detectors for capturing images of the object under test; a signal processing unit connected to both the scattering and absorption detectors for processing the received signals; a central control board connected to the signal processing unit and the visible light imaging unit for data processing and image reconstruction of the received signals; a power supply unit providing power to the radiation source, scattering detectors, absorption detectors, visible light imaging unit, signal processing unit, central control board, and display screen; and a display screen connected to the central control board for displaying the image reconstructed by the central control board. The radiation source is a Spindt linear array radiation source, which is located between the two scattering detector arrays and is arranged parallel to the longitudinal direction of the scattering detector arrays. The Spindt linear array X-ray source includes a substrate and multiple electron emitters. The multiple electron emitters are arranged in an array on the substrate and are electrically connected to a X-ray controller. The X-ray controller controls the electron emitters to periodically emit and shut down. The multiple electron emitters take turns generating flying point X-ray beams, and the flying point X-ray beams interact with the object under test to produce scattered photons.

2. The multi-mode Compton imaging detection device according to claim 1, characterized in that: The scattering detector includes a first scintillation crystal, a first light cone, and a first photoelectric conversion device that are sequentially coupled together. The absorption detector includes a second scintillation crystal, a second light cone, and a second photoelectric conversion device that are coupled together in sequence.

3. The multi-mode Compton imaging detection device according to claim 2, characterized in that: Both the first scintillation crystal and the second scintillation crystal are surrounded by a shielding layer and a reflective layer. Both the first and second light cones are coated with a mirror-reflective layer, which is used for lossless transmission of optical signals. The first photoelectric conversion device and the second photoelectric conversion device are both one or a combination of photomultiplier tubes, photodiodes, avalanche photodiodes, and silicon photomultiplier tubes.

4. The multi-mode Compton imaging detection device according to claim 1, characterized in that: The signal processing unit includes a signal amplification circuit, an A / D converter, a threshold comparison circuit, a counting circuit, and an amplitude analyzer, which are connected in sequence.

5. The multi-mode Compton imaging detection device according to claim 1, characterized in that: The power supply assembly includes a power supply battery and a power controller. The power controller is connected to the power supply battery, and the power supply battery controls the circuit switching of the X-ray source, scattering detector, absorption detector, visible light imaging unit, signal processing unit, control board, and display screen through the power control controller.

6. The multi-mode Compton imaging detection device according to claim 1, characterized in that: Both the scattering detector and the absorption detector are semiconductor detectors.

7. The multi-mode Compton imaging detection device according to claim 1, characterized in that: The detection device further includes a storage unit connected to the central control board for storing the final detection results.

8. An application of the multi-mode Compton imaging detection device as described in any one of claims 1 to 7, characterized in that: The detection device is used for imaging detection of organic contraband, as well as for the identification and localization of radionuclides.

Images