Coding plate imaging detector

Abstract

The invention relates to the technical field of radiation detection, in particular to a coding plate imaging detector which comprises a crystal unit which is of a polyhedral structure, and at least one end face of the crystal unit is of an uneven structure. An opening structure and a closed structure of the coding plate are constructed through the uneven shape of the end face, under the imaging condition, the concave position of the uneven structure does not have sub-pixels correspondingly, the convex position of the uneven structure has sub-pixels correspondingly, whether the sub-pixels arranged on the surface of the uneven structure exist or not correspond to the opening and the closed opening of the coding plate, and an autologous coding plate of the detector is formed. The whole self-coded detector is represented as a three-dimensional sub-pixel array. According to the invention, the three-dimensional position and the deposition energy of the reaction of the rays in the detection medium are obtained through one detector, so that the coding plate imaging detection of the medium and low energy rays can be carried out, the system is simple, and the imaging field of view is expanded. Compton imaging of 360-degree medium-energy and high-energy rays can also be carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of radiation detection, and particularly to an encoded plate imaging detector. Background Art

[0002] In the detection of radioactive substances, the spatial distribution and orientation of directional radioactive substances are the latest and most important requirements at present.

[0003] Conventionally, the pinhole imaging technique is used to locate and image X-ray and gamma-ray radiation sources. It has high positioning accuracy, but limited field of view and low detection efficiency.

[0004] The split encoded plate structure is an imaging device composed of a traditional metal encoded plate and an imaging detector. It mainly uses the straight-line propagation of rays to direct medium and low-energy rays. However, the field of view of encoded plate imaging is limited, usually about 45 degrees, 60 degrees or 80 degrees. Moreover, for rays of different energies, encoded plates of different thicknesses need to be selected, and the operation is complex.

[0005] The newly emerged self-collimation imaging technique uses a three-dimensional mosaic type structure. The first-layer metal encoded plate is replaced with an encoded plate composed of detector materials, so that the encoded plate acts as a detector. The incident paths of rays in different directions in the detector are different, or the pixels of the detector are composed of scintillators of different materials, or different intervals, or different thicknesses, etc., for three-dimensional ray imaging and positioning to achieve encoded plate imaging. For different rays, different ray paths, and detector pixel materials, corresponding matching material intervals or thicknesses are used to construct a split-structured system, which has many electronic channels, a complex system structure, high manufacturing costs, and complex data processing. Based on the problems in the prior art, the present invention provides an encoded plate imaging detector. Summary of the Invention

[0006] The object of the present invention is to provide an encoded plate imaging detector to solve the technical problems of complex device structure and small imaging field of view in the prior art during the encoded imaging operation process.

[0007] The technical solution of the present invention is: an encoded plate imaging detector, including a crystal unit, the crystal unit is a polyhedral structure, and at least one end face is an uneven structure;

[0008] The uneven shape of the end face constructs the open and closed structures of the encoded plate. Under imaging conditions, the concave positions of the uneven structure correspond to no sub-pixels, and the convex positions correspond to sub-pixels. The presence or absence of the sub-pixels arranged on the uneven structure corresponds to the open and closed states of the encoded plate, forming the self-encoded plate of the detector;

[0009] The entire self - encoding detector is represented as a three - dimensional sub - pixel array. Among them, one or several layers form an uneven sub - pixel layer, and the remaining sub - pixel layers are flat planar array detectors. Each sub - pixel can act as an independent detector and can detect and provide ray signals.

[0010] Preferably, along the length direction, the crystal is constructed by combining and arranging multiple crystal strips in an array. A height difference is set on the same end face of the crystal strips to construct the uneven structure. Under imaging conditions, the crystal strips are divided into sub - pixel crystal arrays layer by layer as pixel strips, and the number of divisions of the sub - pixel crystals is such that the height difference of the unevenness is an integer multiple of the thickness of the sub - pixel.

[0011] The X and Y positions when the ray reacts in the detector are determined by the position of the pixel strip in the planar array; the depth position where the ray reacts in the pixel strip is obtained by processing the signal amplitude and time information at both ends of the acquired pixel; the information of each layer of sub - pixel crystals is represented as (X, Y, Z, E), where X, Y, and Z represent the three - dimensional coordinates of the pixel crystal, and E represents the deposited energy of the sub - pixel crystal; the height difference of the uneven pixel ends is determined based on the ray energy to be imaged.

[0012] Preferably, one end face of the crystal unit is set as an uneven structure, and the opposite end face of the uneven structure is set as flat. The length of the flat crystal strip is determined according to the ray energy range to be detected.

[0013] Or, two crystal units with uneven single end faces are placed with their flat ends opposite, and the two end faces of their respective uneven structures face outwards, constructing an imaging system with two uneven single ends.

[0014] Preferably, one crystal unit is of an integral structure, and the two opposite end faces of the crystal unit are respectively set as uneven structures, constructing a double - end self - encoding plate structure.

[0015] Preferably, multiple crystal strips are orthogonally arranged in three - dimensional directions to form an uneven structure with six end faces.

[0016] Preferably, the self - encoding plate formed by the crystal unit is applied to a semiconductor detector. The crystal strips are semiconductor crystal strips. Pixel metal electrodes are evaporated or sputtered on the two end faces of each semiconductor crystal strip. A spacer layer is arranged between adjacent crystal strips. The semiconductor crystal strips are arranged to form an imaging module of a pixel array. The size of the pixel is determined by the ray energy planned to be tested and the spatial resolution of imaging.

[0017] The crystal unit is configured as a single - end imaging system with an uneven structure on the single end face. The uneven structure corresponds to the open and closed structures of the coding plate, and the opposite end face of the uneven structure is set as a flat end face;

[0018] Or, two crystal units with uneven structures on the single end faces, with the flat ends facing each other and the two end faces of their respective uneven structures facing outwards, constructing two single - end uneven imaging systems.

[0019] Preferably, the self - coding plate formed by the crystal unit is applied to a semiconductor detector. The crystal unit as a whole is made of a semiconductor crystal and configured as an integral polyhedron structure;

[0020] For the polyhedron structure, the first side faces opposite to each other are set as planar cathodes, and the second side faces are set as uneven structures, on which pixel metal anode electrodes are evaporated or sputtered;

[0021] Or, two integral crystal units with uneven structures on the single end faces, with the flat ends facing each other and the two end faces of their respective uneven structures facing outwards, constructing two single - end uneven imaging systems.

[0022] Preferably, the self - coding plate formed by one crystal unit is applied to a semiconductor detector. It is made of a semiconductor crystal as a whole and configured as a single - piece hexahedron structure. One end face of the hexahedron structure is set as an uneven structure, on which metal pixel electrodes are provided as anodes, and the opposite end face of the uneven structure is set as a flat end face and provided with metal electrodes as cathodes;

[0023] Among them, four side faces of the hexahedron structure are set as uneven structures, corresponding to the open and closed arrangement rules of the coding plate, and no metal electrodes are evaporated or sputtered on the four side faces.

[0024] Preferably, the self - coding plate formed by the crystal unit is applied to a gas detector. The crystal strip uses a gas detector strip, with the center of the gas detector strip as the anode and the outer shell as the cathode. The coding plate of the gas detector is configured as a coding plate structure with a single - end uneven structure or a double - end uneven structure.

[0025] Preferably, the self - coding plate formed by the crystal unit is applied to a gas detector. The gas is in the same gas chamber, the cathode surface is a planar electrode, and the pixel anode surface is an uneven structure, and the uneven structure corresponds to the arrangement of the open and closed positions of the coding plate.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] The coded-aperture imaging detector uses a detector to obtain the three-dimensional position of the reaction of rays within the detection medium and the deposited energy corresponding to the rays, and performs coded-aperture imaging detection of medium and low-energy rays. The system is simple and the imaging field of view is enlarged. Moreover, through the simple pixel plane array detection system provided by the present invention, Compton imaging of medium and high-energy rays at 360° can also be performed, and there is no need to externally configure a separate detector coded aperture with a small field of view or a coded aperture made of materials such as tungsten or lead. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the drawings and embodiments:

[0029] Figure 1 For Embodiment 1 of the present invention, a detector with a single-end uneven structure is provided;

[0030] Figure 2 When the detector of the present invention is divided into a three-dimensional sub-pixel array, a schematic diagram of a detection system of a pixel plane array is shown;

[0031] Figure 3 For Embodiment 2 of the present invention, a schematic diagram of the structure of a coded-aperture imaging detector with a large field of view formed by combining two single-end concave and convex coded-aperture detectors is shown;

[0032] Figure 4 For Embodiment 3 of the present invention, a schematic diagram of the structure of a double-end self-coded-aperture detector is shown;

[0033] Figure 5 For Embodiment 4 of the present invention, a schematic diagram of the structure of a three-dimensional hexahedral coded aperture formed by interspersed crystal bars is shown;

[0034] Figure 6 For Embodiment 5 of the present invention, when the self-coded-aperture structure is applied to a semiconductor detector, a schematic diagram of the uneven end face of the crystal bar is shown;

[0035] Figure 7 For Embodiment 5 of the present invention, when the self-coded-aperture structure is applied to a semiconductor detector, a schematic diagram of the aligned flat end of the crystal bar is shown;

[0036] Figure 8 For Embodiment 6 of the present invention, when the self-coded-aperture structure is applied to a semiconductor detector, a schematic diagram of the uneven end face of the semiconductor as a whole structure is shown;

[0037] Figure 9 For Embodiment 6 of the present invention, when the self-coded-aperture structure is applied to a semiconductor detector, a schematic diagram of the aligned flat end of the semiconductor crystal as a whole structure is shown;

[0038] Figure 10In the seventh embodiment of the present invention, when the self-encoding plate structure is applied to a semiconductor detector, it is a schematic diagram of two single-ended uneven systems in the form of two semiconductor crystal strips;

[0039] Figure 11 In the seventh embodiment of the present invention, when the self-encoding plate structure is applied to a semiconductor detector, it is a schematic diagram of two single-ended uneven systems with two semiconductor crystals as an overall structure;

[0040] Figure 12 In the eighth embodiment of the present invention, when the self-encoding plate structure is applied to a semiconductor detector, it is a schematic diagram of a five-sided encoding plate large-field imaging module;

[0041] Figure 13 In the ninth embodiment of the present invention, when the self-encoding plate structure is applied to a gas detector, it is a schematic diagram of a single-ended encoding plate imaging module;

[0042] Figure 14 In the ninth embodiment of the present invention, when the self-encoding plate structure is applied to a gas detector, it is a schematic diagram of a double-ended encoding plate imaging module;

[0043] Figure 15 In the tenth embodiment of the present invention, when the self-encoding plate structure is applied to a gas detector, it is a schematic diagram of the encoding plate electrode structure of gas in the same gas chamber;

[0044] Figure 16 It is a comparison view of the imaging fields of the integrated self-encoding plate and the conventional split encoding plate provided by the present invention;

[0045] 1. Crystal strip; 2. Whole crystal; 3. Convex position; 4. Concave position; 5. Electrode cathode; 6. Electrode anode;

[0046] 1a. Crystal strip in the up-down direction; 1b. Crystal strip in the left-right direction; 1c. Crystal strip protruding in the front-back direction; 1d. Crystal strip recessed in the front-back direction. Detailed implementation manners

[0047] The following combines specific embodiments to further elaborate on the content of the present invention:

[0048] As Figure 1 shown, the encoding plate imaging detector includes

[0049] A crystal unit, the crystal unit has a polyhedral structure, and at least one end face has an uneven structure; the uneven shape of the end face constructs the open and closed structures of the encoding plate. Under imaging conditions, the concave position 4 of the uneven structure corresponds to no sub-pixels, and the convex position 3 corresponds to sub-pixels. The presence or absence of sub-pixels arranged on the uneven structure corresponds to the open and closed structures of the encoding plate, forming the self-encoding plate of the self-encoding plate detector (that is, the encoding plate and the ray signal detector are integrated).

[0050] The detector of the entire self-encoding plate is represented as a three-dimensional sub-pixel array. Among them, one or several layers form an uneven sub-pixel layer, and the remaining pixel layers are flat surface array detectors. Each sub-pixel can act as an independent detector and can detect and provide ray signals.

[0051] The three-dimensional shape structures of the self-encoding detectors are different. For the convenience of description, the present invention takes the self-encoding plate with a hexahedron overall contour as the basis for detailed description.

[0052] The self-encoding plate structure provided by this application can be applied to a scintillation crystal detector, and the crystal unit is an imaging system structure or an integrated imaging system structure combined with a crystal bar array.

[0053] Embodiment 1

[0054] Provide a single-end face uneven structure. Refer to the appendix Figure 1 , one end of the basic hexahedron structure is flat, and the other end is uneven. The uneven arrangement corresponds to constructing the open and closed structures of the encoding plate. The pixel bar at the concave position 4 is the open position, and the pixel bar at the convex position 3 is the closed position. The height difference of the uneven pixel ends is determined by the energy of the planned imaging.

[0055] For the convenience of expression, it is set that along the length direction, the crystal bar 1 can be divided into several sub-grid blocks.

[0056] The X and Y positions when the ray reacts in the detector are determined by the position of the pixel bar in the surface array; the depth position when the ray reacts in the crystal bar is obtained by the dual-end signal readout circuit and the subsequent data processing algorithm, and the signal amplitude and time information at both ends of the obtained pixel are processed to obtain; the number of sub-grid block divisions is uncertain, but the number of divisions needs to ensure that the height difference of the unevenness is an integer multiple of the sub-pixel thickness to facilitate determining the reaction position by the dual-end signal amplitude ratio.

[0057] In this way, the entire detector is divided into a three-dimensional sub-pixel array, that is, each layer is a surface array detector arranged with sub-pixels. Refer to the appendix Figure 2As shown in the figure, a schematic diagram of a detection system for a pixel plane array is provided. Among them, each sub-pixel is an independent detector, and the electronics system cooperates with data processing. The ray energy spectrum, energy information, and position information of each sub-pixel are independent.

[0058] Based on a three-dimensional sub-pixel array, the information of each layer of sub-pixel crystals can be expressed as (X, Y, Z, E), where X, Y, and Z represent the three-dimensional coordinates of the pixel crystals, and E represents the deposited energy of the sub-pixel crystals. For one end of the uneven pixel array crystal, it can be seen that there are no sub-pixels at the concave positions, while there are sub-pixels at the convex positions. The presence or absence of such arranged sub-pixels corresponds to the openings and closings of the encoding plate, forming a detector self-encoding plate.

[0059] The unevenness of the self-encoding plate constructed in this way is integrated, that is, the encoding plate is seamlessly connected to the detector for detecting photoelectric absorption behind it, and the imaging field of view of the encoding plate is close to 180 degrees. At the same time, for the Compton scattering imaging and positioning of medium and high-energy rays, the entire system can detect and image the scattering signals. In particular, the uneven sub-pixel layer is also a detector, which can detect and provide ray signals, providing a higher energy spectrum detection efficiency and Compton scattering imaging detection efficiency than encoding plate systems made of materials such as tungsten or lead.

[0060] The detector with the self-encoding plate structure of the present invention uses simple detector crystal bars to form a pixel array. The top of the pixel is uneven, and there is no need to additionally increase a single detector encoding plate or a pure encoding plate part made of materials such as tungsten or lead. Through flexible processing of algorithms, it is possible to simultaneously achieve large-field imaging of low- and medium-energy rays by the encoding plate and Compton imaging and positioning of medium and high-energy rays.

[0061] For the encoding plate imaging detector, the height difference of the uneven pixel ends is determined based on the energy of the rays to be imaged. The length of the flat crystal bars is determined according to the energy range of the rays to be detected, based on the fact that the flat part can block a sufficient number of rays for detection efficiency.

[0062] For example, for the directional detection of 122 kev rays, with a 4 mm thickness of the scintillation crystal, more than 90% of the rays can be blocked by photoelectric absorption. The length difference of the unevenness can be 4 mm, and at the same time, a 4 mm length of the flat crystal bar part is also sufficient.

[0063] If the entire system also needs to perform Compton imaging and positioning detection of medium and high-energy rays, the length part of the flat crystal needs to be thicker, such as several tens of millimeters. At this time, the aspect ratio, light yield, balance of light collection efficiency, price, and preparation situation of the crystal bars also need to be considered before determining the thickness of the length part of the flat crystal.

[0064] Example 2

[0065] Based on Embodiment 1 (physical structure), two single-ended uneven systems are adopted, with the flush ends placed opposite to each other, forming a double-ended uneven imaging system with two uneven end faces facing outwards. Referring to the attached Figure 3 As shown, this system can achieve a 360-degree imaging field of view for the encoding plate, and the two systems independently read signals, enabling imaging detection in a high-radiation environment.

[0066] Embodiment 3

[0067] Based on Embodiment 1 (mainly referring to the physical structure), the pixel crystal strips are fabricated and arranged into a structure with unevenness at both ends, which is equivalent to forming a self-encoding plate structure at both ends. Referring to the attached Figure 4 As shown, in the entire detector, low-energy encoding plate imaging forms a 360-degree panoramic imaging. It should be noted that at this time, the middle part of the crystal strips needs to be considered to ensure that its length is sufficient to collect and block rays.

[0068] Embodiment 4

[0069] Based on the single double-ended self-encoding plate structure provided in Embodiment 3, the pixel crystal strips are in three-dimensional directions. As shown in the attached Figure 5 As shown, there is one set each of crystal strips 1a in the up-down direction, crystal strips 1b in the left-right direction, protruding crystal strips 1c in the front-back direction, and recessed crystal strips 1d in the front-back direction, which are orthogonally arranged to form a three-group cross-arranged array structure; all six end faces are set to have an uneven structure, that is, a self-encoding plate imaging with six end faces is formed, providing a 360-degree encoding plate imaging field of view for medium and low-energy rays.

[0070] The self-encoding plate structure provided in the above embodiments can be applied to all scintillation detectors, such as CsI, NaI, LaBr3, and CeBr3.

[0071] The self-encoding plate structure provided in this application can also be applied to semiconductor detectors. Electrodes are distributed on the surface of the crystal unit. When the crystal unit is set as an array combination of semiconductor crystal strips, a spacer layer is adaptively arranged between the semiconductor crystal strips.

[0072] Embodiment 5

[0073] A semiconductor detector with a self-encoding plate structure is configured to be similar to the structure of scintillator crystal strips (for the physical structure, refer to Embodiment 1). Referring to the attached Figure 6 and the attached Figure 7 As shown, a schematic diagram of applying the self-encoding plate structure in Embodiment 1 to a semiconductor detector is provided, where the attached Figure 6 is a schematic diagram of one end with an uneven structure, the attached Figure 7 is a schematic diagram of the flat end on the opposite side, the attached Figure 6 and the attached Figure 7The crystal bars shown are specifically cadmium zinc telluride crystals, abbreviated as CZT crystals. Pixel metal electrodes are deposited or sputtered on the two end faces of each semiconductor crystal bar. A spacer layer is adaptively arranged between the semiconductor crystal bars. The semiconductor detector consists of semiconductor crystal bars to form an imaging module with a pixel array, and the size of its pixels is determined by the ray energy to be tested and the spatial resolution of the imaging. By adopting a single-end uneven coding plate structure or a double-end uneven coding plate structure, not only can a large-field-of-view coding plate imaging field of view be obtained, but also 360° Compton scattering imaging positioning can be performed.

[0074] Example 6

[0075] On the basis of Example 1, the semiconductor crystal of the semiconductor detector is set as a single whole cuboid or cube. Refer to the appendix Figure 9 As shown, its cathode is a conventional planar electrode (electrode cathode 5).

[0076] The conventional anode pixel array is to deposit or sputter a metal electrode array on a plane, that is, the anode metal electrode array is on a flat plane. For the self-coding plate structure of the semiconductor detector in this embodiment, refer to the appendix Figure 8 ., its pixel anode array is on an uneven surface, and corresponding pixel metal electrodes are deposited or sputtered (refer to electrode anode 6 in the appendix Figure 8 ). The metal electrode in the concave position represents the opening position of the coding plate, and the metal electrode in the convex position represents the closing position of the coding plate. The concave and convex arrangement of the entire electrode is prepared according to the rules of the coding plate.

[0077] The self-coding plate semiconductor detector with such an electrode structure can not only perform large-field-of-view medium and low-energy ray coding plate imaging positioning, but also perform 360° Compton scattering imaging positioning of medium and high-energy rays.

[0078] Example 7

[0079] On the basis of Example 2, it is applied to a semiconductor detector. The crystal bar is a semiconductor crystal bar. For two single-end uneven systems, one end of the cathode planar electrode is oppositely arranged, and the uneven electrode surface faces outward, forming a 360° imaging positioning field of view for medium and low-energy rays. Refer to the appendix Figure 10 Two single-end uneven systems in the form of semiconductor crystal bars are provided (the appendix corresponding to the display in Example 5 Figure 6 or the appendix Figure 7 ), and the appendix Figure 11 provides two single-end uneven systems respectively composed of a single whole semiconductor crystal (the appendix corresponding to the display in Example 6 Figure 8 or the appendix Figure 9 ).

[0080] Example 8

[0081] Based on the physical structure of the self-coded plate provided in Embodiment 6, that is, the single-ended uneven structure 1, with the opposite end face being a planar cathode. In addition to the planar cathode electrode and the coded plate anode electrode, uneven structures are also made on the four sides of the crystal, corresponding to the open and closed arrangement rules of the coded plate. However, on the uneven sides of the four sides (the end face where the electrode anode 6 is located), no metal electrode is evaporated or sputtered. Refer to the appendix Figure 12 As shown, the semiconductor integrated crystal specifically uses cadmium zinc telluride crystal (English name cadmium zinc tellu ri de, CdZnTe, abbreviated as CZT crystal). Due to the data processing method of simultaneously reading signals from the cathode and anode electrodes, the X and Y positions are determined by the positions of the anode pixel electrodes, and the depth position of the ray reaction inside the crystal is determined by the signal amplitudes and times of the cathode and anode. In this way, the ray signals of the entire crystal are divided into pixel plane arrays layer by layer through data processing, that is, a three-dimensional pixel structure. The semiconductor detector with this structure has a 360-degree coded plate imaging and positioning field of view on five faces.

[0082] The self-coded plate imaging and positioning structure of the semiconductor detector constructed in this way can be applied to various semiconductor detectors such as CdZnTe, CdTe, HgI 2, Tl Br, etc., for imaging and positioning detection of X-rays and gamma rays.

[0083] Similarly, the (physical) structure of the self-coded plate can also be applied to gas detectors. The gas detector strip is a metal shell (such as gold, silver, aluminum), acting as the cathode, with an anode electrode wire arranged in the middle, filled with gas inside, and an electrode layer is arranged on the side wall of the shell.

[0084] Embodiment 9

[0085] For a single gas detector strip, the center is the anode and the outer shell is the cathode. Arranged in a similar way to the scintillator crystal strip, correspondingly, crystal strip 1 corresponds to the gas detector strip, forming a single-ended uneven structure as the coded plate, and the uneven end face corresponds to the electrode anode 6 of the gas detector strip. Refer to the appendix Figure 13 , or, an integrated double-ended uneven full-field coded plate structure. Refer to the appendix Figure 14 .

[0086] Embodiment 10

[0087] Another self-coded plate structure of the gas detector. Refer to the appendix Figure 15As shown in the figure, in the same gas chamber, the cathode surface is a planar electrode (a whole planar electrode plate at the bottom), while the pixel anode is an uneven electrode (a block combination structure at the top), arranged corresponding to the open and closed positions of the coding plate. It can not only increase the imaging field of view of the coding plate, but also perform imaging positioning of medium and high energy rays for Compton scattering.

[0088] Combining the above embodiments, one of the prominent advantages of the integrated self-coding plate imaging and Compton imaging detector of the present application is that the imaging field of view can reach 180 degrees. For a dual-end coding plate system or a multi-sided coding plate system, a 360-degree panoramic field of view can be achieved. As shown in the attached Figure 16 figure, a comparison diagram of the imaging field of view of a conventional split coding plate (the left (a) figure in the attached Figure 16 figure) and the imaging field of view of the present application (the right (b) figure in the attached Figure 16 figure) is provided. The closer the distance between the two-layer detectors (the shaded rectangular blocks in the attached Figure 16 figure), the larger the imaging field of view.

[0089] For the self-coding plate structure of the present application, there is no distance between the two side detectors, and they are integrated. The coding plate structure can obtain the maximum field of view. In addition, since there is no distance between the two detectors, it becomes an integrated system, eliminating the need for discrete two-layer detectors. The structure is simpler, occupies less space, has fewer electronic channels in the system, lower costs, and simpler data processing, and can also achieve coding plate imaging and Compton imaging.

[0090] Therefore, for the detector with the self-coding plate structure of the present invention, a pixel array is composed of simple detector crystal strips, and the top of the pixels is uneven. There is no need to additionally add a single detector coding plate or a pure coding plate part made of materials such as tungsten or lead. Through flexible processing of algorithms, it can not only achieve coding plate imaging of medium and low energy rays with a large field of view, but also perform Compton imaging positioning of medium and high energy rays.

[0091] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention. Their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and should not be used to limit the protection scope of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. Encoding plate imaging detector, characterized in that, It includes a crystal unit, which has a polyhedral structure and at least one end face with an uneven structure; The uneven shape of the end face constructs the open and closed structures of the coding plate. Under imaging conditions, the concave positions of the uneven structure correspond to the absence of sub-pixels, and the convex positions correspond to the presence of sub-pixels. The presence or absence of the sub-pixels arranged on the surface of the uneven structure corresponds to the open and closed states of the coding plate, forming the self-coding plate of the detector; The detector of the entire self-coding plate is represented as a three-dimensional sub-pixel array. Among them, one or several layers form the uneven sub-pixel layer, and the remaining sub-pixel layers are flat surface array detectors. Each sub-pixel can act as an independent detector and can detect and provide ray signals.

2. The coded-aperture imaging detector according to claim 1, wherein Along the length direction, the crystal unit is constructed by combining and arranging multiple crystal bars in an array. A height difference is set on the same end face of the crystal bars to construct the uneven structure. Under imaging conditions, the crystal bars are divided into sub-pixel crystal arrays layer by layer as pixel bars, and the number of divisions of the sub-pixel crystals satisfies that the height difference of the unevenness is an integer multiple of the thickness of the sub-pixels; The X and Y positions when the ray reacts in the detector are determined by the positions of the pixel bars in the surface array; the depth position where the ray reacts in the pixel bar is obtained by processing the signal amplitude and time information at both ends of the acquired pixel. The information of each layer of sub-pixel crystals is represented as (X, Y, Z, E), where X, Y, and Z represent the three-dimensional coordinates of the pixel crystal, and E represents the deposited energy of the sub-pixel crystal; the height difference of the uneven pixel ends is determined based on the ray energy to be imaged.

3. The coded-aperture imaging detector according to claim 2, wherein One end face of the crystal unit is set as an uneven structure, and the opposite end face of the uneven structure is set as flat. The length of the flat crystal bars is determined according to the ray energy range to be detected; Or, two crystal units with uneven single end faces are placed with their flat ends facing each other, and the two end faces of their respective uneven structures face outward, constructing two imaging systems with uneven single ends.

4. The coded-aperture imaging detector according to claim 2, wherein One of the crystal units is an integral structure, and the two opposite end faces of the crystal unit are respectively set as uneven structures, constructing a double-end self-coding plate structure.

5. The coded-aperture imaging detector according to claim 2, wherein Multiple crystal bars are orthogonally arranged in three-dimensional directions to form an uneven structure with six end faces.

6. The coded-aperture imaging detector according to claim 3, wherein The self-coding plate formed by the crystal unit is applied to a semiconductor detector. The crystal bars are semiconductor crystal bars. Pixel metal electrodes are evaporated or sputtered on the two end faces of each semiconductor crystal bar. A spacer layer is provided between adjacent crystal bars. The semiconductor crystal bars are arranged to form an imaging module of a pixel array. The size of the pixel is determined by the ray energy planned to be tested and the spatial resolution of the imaging; The crystal unit is constructed into a single-end imaging system with one end face set as an uneven structure. The uneven structure corresponds to the open and closed structures of the coding plate, and the opposite end face of the uneven structure is set as a flat end face; Or, two crystal units with uneven single end faces are placed with their flat ends facing each other, and the two end faces of their respective uneven structures face outward, constructing two imaging systems with uneven single ends.

7. The coded-aperture imaging detector according to claim 2, wherein, The self - encoding plate formed by the crystal unit is applied to a semiconductor detector. The crystal unit as a whole is constructed of a semiconductor crystal and is an integral polyhedron structure; The first side surfaces opposite to each other of the polyhedron structure are arranged as planar cathodes, and the second side surfaces are arranged as uneven structures, on which pixel metal anode electrodes are evaporated or sputtered; Alternatively, two integral crystal units with uneven single - end surfaces are placed with their flat ends facing each other, and the two end surfaces of their respective uneven structures face outward, constructing two imaging systems with uneven single - ends.

8. The coded-aperture imaging detector according to claim 7, wherein, The self - encoding plate formed by one crystal unit is applied to a semiconductor detector. It is entirely made of a semiconductor crystal and is constructed as a whole hexahedron structure. One end surface of the hexahedron structure is arranged as an uneven structure, on which a metal pixel electrode is provided as the anode, and the opposite end surface of the uneven structure is arranged as a flat end surface, on which a metal electrode is provided as the cathode; Among them, the four side surfaces of the hexahedron structure are arranged as uneven structures, corresponding to the opening and closing arrangement rules of the encoding plate, and no metal electrodes are evaporated or sputtered on the four side surfaces.

9. The coded-aperture imaging detector according to claim 3 or 4, characterized in that The self - encoding plate of the detector formed by the array is applied to a gas detector. The crystal strip uses a gas detector strip. The center of the gas detector strip is the anode, and the outer shell is the cathode. The encoding plate of the gas detector is constructed as an encoding plate structure with a single - end uneven structure or an encoding plate structure with a double - end uneven structure.

10. The coded-aperture imaging detector according to claim 2, wherein, The self - encoding plate of the detector formed by the array is applied to a gas detector. The gas is in the same gas chamber. The cathode surface is an integral planar electrode, and the pixel anode surface is an uneven structure. The uneven structure corresponds to the arrangement of the opening and closing positions of the encoding plate.

Images