Back scattering imaging detection device

Abstract

The invention relates to a back scattering imaging detection device. The device comprises a radioactive source used for generating gamma rays; irradiating the surface of the to-be-measured object with the gamma rays to form Compton scattering gamma rays; the first detection unit is used for acquiring imaging position information; the second detection unit is used for acquiring imaging energy information; the signal processing unit is used for receiving the imaging position information and the imaging energy information; and the image reconstruction unit is electrically connected with the signal processing unit and is used for carrying out data processing and image reconstruction on the received information. According to the invention, the Na-22 radioactive source is used as a light source to generate gamma rays, so that the thickness of a detectable sample is increased; the device is convenient to use, the position, pose and other information of the device are easy to record or grasp, inconvenience caused by long-time continuous use of the detection device is reduced, the detection units with the same or different resolution precision can be replaced according to needs, and the device has the advantages of miniaturization, good portability and high detection precision and can be used under various complex working conditions.

Description

Technical Field

[0001] The invention relates to the technical field of radiation dosage and imaging, in particular to a backscatter imaging detection device. Background Art

[0002] Most existing backscatter imaging devices use coded aperture imaging: first, several holes are punched on the plate, the rays are positioned through the holes at different positions, and then imaging is performed based on the light intensity at each hole after the rays are irradiated. This method requires relative motion between the object to be measured and the coded hole, and also requires scanning.

[0003] Backscatter imaging devices can be further divided into two categories: handheld and desktop.

[0004] The existing handheld backscatter imaging device uses an X-ray tube as the light source, which can only generate X-rays. The energy of X-rays is much smaller than that of gamma rays (X-ray energy <70keV). Therefore, the detection depth of metal by the existing handheld backscatter imaging device is less than 5mm.

[0005] The existing desktop backscatter imaging device uses an accelerator as a light source to generate gamma rays. However, due to the use of an accelerator, the existing desktop backscatter imaging device is large in size and very expensive.

[0006] In a nuclear power plant, if it is necessary to detect non-detachable metal pipes, the existing handheld backscatter imaging device cannot complete the detection because the metal detection depth is less than 5mm. In addition, it is difficult to locate the handheld backscatter imaging device, and it is not convenient to record or grasp the position, posture and other information of the device during detection. It is difficult for users to hold it for a long time. The existing desktop backscatter imaging device cannot complete the detection at the required position due to its large size. Large-scale industrial CT has high requirements on space and other conditions. It is difficult to provide the space required for equipment installation when detecting non-detachable metal pipes.

[0007] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0008] In view of the defects existing in the prior art, the purpose of the present invention is to provide a backscatter imaging detection device, which adopts a Na-22 radiation source as a light source to generate gamma rays, thereby increasing the detectable sample thickness; the device is easy to use and easy to record or grasp the position, posture and other information of the device, thereby reducing the inconvenience of continuous use of the detection device for a long time, and the detection units with the same or different resolution accuracy can be replaced as needed. The device has the advantages of miniaturization, good portability and high detection accuracy, and can meet the use of various complex working conditions.

[0009] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0010] A backscatter imaging detection device, characterized in that it comprises:

[0011] A first chamber 100, wherein a radiation source 101 is disposed in the first chamber 100, wherein the radiation source 101 is used to generate gamma rays 102; the gamma rays 102 include a first direct gamma ray 1021 and a second direct gamma ray 1022 generated at the same time;

[0012] A second chamber 200 , in which a first detection unit 201 is disposed, the first detection unit 201 being used to acquire a first direct gamma ray 1021 entering the second chamber 200 and directly coming from the radiation source 101 ;

[0013] The position acquisition unit 600 is electrically connected to the first detection unit 201 and acquires position information corresponding to the first direct gamma ray 1021 from the first detection unit 201;

[0014] The second direct gamma ray 1022 directly from the radiation source 101 irradiates the surface of the object 401 to be measured, and after the Compton effect occurs with the object 401 to be measured, the second direct gamma ray 1022 is backscattered to form Compton scattered gamma ray 1023;

[0015] A third chamber 300, in which a second detection unit 301 is disposed, and the second detection unit 301 is used to obtain Compton scattered gamma rays 1023 entering the third chamber 300 and coming from the object to be detected 401;

[0016] The energy acquisition unit 700 is electrically connected to the second detection unit 301 and acquires energy information corresponding to the Compton scattered gamma ray 1023 from the second detection unit 301;

[0017] The radiation shielding plate 501 is disposed between the radiation source 101 and the object to be measured 401. The radiation shielding plate 501 has a first state and a second state by reciprocating movement. When in the first state, the radiation shielding plate 501 is located within the path of the second direct gamma ray 1022 irradiating the object to be measured 401. When in the second state, the radiation shielding plate 501 is located outside the path of the second direct gamma ray 1022 irradiating the object to be measured 401.

[0018] The signal processing unit 800 is electrically connected to the position acquisition unit 600 and the energy acquisition unit 700, respectively, and is used to process the position information and the energy information;

[0019] The image reconstruction unit 900 is electrically connected to the signal processing unit 800 and is used to perform data processing and image reconstruction on the received information. The image reconstruction unit 900 includes a display module 901, and the display module 901 presents the reconstructed image in a wired or wireless manner.

[0020] On the basis of the above technical solution, the radiation source 101 is a Na22 radiation source for generating 511keV gamma rays.

[0021] On the basis of the above technical solution, the radiation source 101 is provided with a matching collimator 103 , which faces the first detection unit 201 and is used to define the range of the first linear gamma ray 1021 . The gamma photons generated by the radiation source 101 form the first linear gamma ray 1021 after passing through the collimator 103 .

[0022] On the basis of the above technical solution, the first direct gamma ray 1021 and the second direct gamma ray 1022 generated at the same time have opposite directions.

[0023] On the basis of the above technical solution, a first driving device 104 is provided in the first chamber 100 for controlling the radiation source 101 to move sequentially between at least two predetermined positions.

[0024] On the basis of the above technical solution, the first detection unit 201 comprises a rectangular bottom plate, and a first sensor is covered on the side facing the radiation source 101, and the first sensor is configured to receive gamma rays and convert them into electrical pulse signals;

[0025] There are multiple first sensors, which are evenly arranged at equal intervals on one side of the bottom plate facing the radiation source 101;

[0026] The first sensor is a scintillator detector or a CZT gamma detector.

[0027] On the basis of the above technical solution, a second driving device 202 is provided in the second chamber 200 for adjusting the distance between the first detection unit 201 and the radiation source 101 to a set value;

[0028] The set values ​​include at least one detection position set value and one replacement position set value;

[0029] The detection position setting value is used to receive gamma rays and convert them into electrical pulse signals when the first detection unit 201 moves to the detection position;

[0030] The replacement position setting value is used to replace the first detection unit 201 with the same or different resolution accuracy as needed when the first detection unit 201 moves to the replacement position.

[0031] On the basis of the above technical solution, the second detection unit 301 is in an annular shape as a whole, and is composed of four fan-shaped detection submodules 302. The inner circular area 303 of the second detection unit 301 forms a cavity, and the cavity is used for the second direct gamma ray 1022 to pass through and irradiate the surface of the object 401 to be detected;

[0032] Each sector detection submodule 302 is at least one second sensor;

[0033] The second sensor is a scintillator detector or a CZT gamma detector.

[0034] On the basis of the above technical solution, a distance measuring mechanism 302 is provided on the outer surface of the wall of the third chamber 300 , and the distance measuring mechanism 302 faces the object to be measured 401 , and is used to obtain the distance between the backscatter imaging detection device and the object to be measured 401 .

[0035] On the basis of the above technical solution, a shielding cover is provided along the outer envelope of the detection device, and any one, part or all of the following are provided in conjunction: a handheld part, a positioning movement mechanism, a ruler mechanism, and a laser ruler;

[0036] A hand-held part, at least one in number, used to hold the detection device and manually adjust the position and distance between the detection device and the object to be detected 401;

[0037] The positioning and moving mechanism is provided with a roller and / or a clamping unit and / or a suspension unit. The roller contacts the object to be measured 401 to make the detection device move linearly along the roller direction and the distance remains unchanged; the clamping unit contacts the object to be measured 401 and clamps the detection device on the object to be measured 401; the suspension unit contacts the object to be measured 401 and suspends the detection device below the object to be measured 401;

[0038] A scale mechanism, used to obtain the relative position of the detection device on the object to be detected 401;

[0039] The laser ruler is used to project horizontal markings and / or vertical markings to assist in determining the spatial position of the detection device.

[0040] The backscatter imaging detection device described in the present invention has the following beneficial effects:

[0041] 1. The embodiment of the present invention adopts backscattered direct radiation imaging;

[0042] A Na-22 radioactive source is used as a light source to generate gamma rays. Through the gamma rays, the gamma rays and the detected object undergo a Compton effect, and the photons are scattered and emitted in the back direction, which can achieve imaging of metal pipes with a thickness of up to 10 mm.

[0043] 2. The device is easy to use and easy to record or grasp the location, posture and other information of the device;

[0044] Based on the miniaturization and good portability of the device, the embodiments of the present invention can add auxiliary components such as positioning movement mechanism, scale mechanism, laser scale as needed, which improves the usability of the device, facilitates the grasping and recording of the position, posture and other information of the device, helps to improve the detection accuracy, is more convenient to use, and can adapt to various complex working conditions. For example:

[0045] In a nuclear power plant, for non-detachable metal pipes, the device described in the embodiment of the present invention can be used to image the damage on the inner wall of the metal pipe in real time; the damage on the inner wall of the metal pipe is no greater than 10 mm.

[0046] In military units, the device described in the embodiment of the present invention can be used to image the metal inner wall of a weapon in real time.

[0047] In dangerous areas in the wild, metal objects in the soil can be imaged, such as landmines. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention has the following accompanying drawings:

[0049] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation of the present invention.

[0050] Figure 1 A structural block diagram of the first embodiment of the detection device of the present invention.

[0051] Figure 2 A structural block diagram of the second embodiment of the detection device of the present invention.

[0052] Figure 3 A structural block diagram of the third embodiment of the detection device of the present invention.

[0053] Figure 4 A structural block diagram of a fourth embodiment of the detection device of the present invention.

[0054] Figure 5 Schematic diagram of the structure of the second detection unit.

[0055] Figure 6 A structural block diagram of a sixth embodiment of the detection device of the present invention.

[0056] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below in conjunction with the accompanying drawings. The detailed description is an explanation made in conjunction with the exemplary embodiments of the present invention, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0058] like Figure 1 As shown, the present invention provides a backscatter imaging detection device, comprising:

[0059] A first chamber 100, wherein a radiation source 101 is disposed in the first chamber 100, wherein the radiation source 101 is used to generate gamma rays 102; the gamma rays 102 include a first direct gamma ray 1021 and a second direct gamma ray 1022 generated at the same time;

[0060] Exemplarily, the radiation source 101 is a point source for generating 511keV gamma rays, for example, a Na22 radiation source; the radiation source 101 uses an organic membrane shell to seal the radioactive isotope, and the radiation source 101 generates positrons e + , positron e + With the negative electrons e in the medium - Positron-electron pairs are flooded and converted into two gamma photons with an energy of 511 keV, namely the first direct gamma ray 1021 and the second direct gamma ray 1022;

[0061] It can be understood that two gamma photons with energy of 511 keV fly towards each other at 180° in the mass center system, so the first direct gamma ray 1021 and the second direct gamma ray 1022 generated at the same time are in opposite directions;

[0062] A second chamber 200 , in which a first detection unit 201 is disposed, the first detection unit 201 being used to acquire a first direct gamma ray 1021 entering the second chamber 200 and directly coming from the radiation source 101 ;

[0063] The position acquisition unit 600 is electrically connected to the first detection unit 201 and acquires position information corresponding to the first direct gamma ray 1021 from the first detection unit 201, that is, imaging position information;

[0064] Exemplarily, the second chamber 200 is connected to the first chamber 100; the first direct gamma ray 1021 directly from the radiation source 101 enters the second chamber 200 from the first chamber 100 and is received by the first detection unit 201, and the position acquisition unit 600 acquires position information from the first direct gamma ray 1021, and the position information reflects the detection position of the object 401 to be detected;

[0065] The second direct gamma ray 1022 directly from the radiation source 101 irradiates the surface of the object 401 to be measured, and after the Compton effect occurs with the object 401 to be measured, the second direct gamma ray 1022 is backscattered to form Compton scattered gamma ray 1023;

[0066] A third chamber 300, in which a second detection unit 301 is disposed, and the second detection unit 301 is used to obtain Compton scattered gamma rays 1023 entering the third chamber 300 and coming from the object to be detected 401;

[0067] The energy acquisition unit 700 is electrically connected to the second detection unit 301 and acquires energy information corresponding to the Compton scattered gamma ray 1023 from the second detection unit 301, that is, imaging energy information;

[0068] Exemplarily, the third chamber 300 is connected to the first chamber 100; the second direct gamma ray 1022 directly from the radiation source 101 irradiates the surface of the object to be tested 401, and the generated Compton scattered gamma ray 1023 enters the third chamber 300 and is received by the second detection unit 301. The energy acquisition unit 700 obtains energy information from the Compton scattered gamma ray 1023. The energy information reflects the detection depth of the object to be tested 401. The thickness of the object to be tested 401 can be determined according to the detection depth. The thinning of the thickness reflects the location of the defect in the object to be tested 401, and the defect location is usually the internal damage location.

[0069] The radiation shielding plate 501 is disposed between the radiation source 101 and the object to be measured 401. The radiation shielding plate 501 has a first state and a second state by reciprocating movement. When in the first state, the radiation shielding plate 501 is located within the path of the second direct gamma ray 1022 irradiating the object to be measured 401. When in the second state, the radiation shielding plate 501 is located outside the path of the second direct gamma ray 1022 irradiating the object to be measured 401.

[0070] It can be understood that, if the ray shielding plate 501 is located within the path of the second direct gamma ray 1022 irradiating the object to be measured 401, the ray shielding plate 501 blocks the second direct gamma ray 1022, and the second direct gamma ray 1022 cannot irradiate the object to be measured 401; if the ray shielding plate 501 is located outside the path of the second direct gamma ray 1022 irradiating the object to be measured 401, the ray shielding plate 501 cannot block the second direct gamma ray 1022, and the second direct gamma ray 1022 can irradiate the object to be measured 401; when the backscatter imaging detection device is held for detection, the ray shielding plate 501 should be placed in the second state by reciprocating movement; when no detection is performed, the ray shielding plate 501 should be placed in the first state by reciprocating movement;

[0071] The signal processing unit 800 is electrically connected to the position acquisition unit 600 and the energy acquisition unit 700, respectively, and is used to process the position information and the energy information;

[0072] The image reconstruction unit 900 is electrically connected to the signal processing unit 800 and is used to perform data processing and image reconstruction on the received information. The image reconstruction unit 900 includes a display module 901, and the display module 901 presents the reconstructed image in a wired or wireless manner.

[0073] It can be understood that the embodiment of the present invention collects paired gamma photons, determines the detection position of the object to be tested 401 through the first detection unit 201, determines the detection depth of the object to be tested 401 through the second detection unit 301, and binds the detection position and the detection depth into an information pair. Through statistical analysis, the internal material distribution of the object to be tested 401 can be imaged, and the internal material distribution corresponds to the internal damage of the object to be tested 401.

[0074] Based on the above technical solution, Figure 2 As shown, the radiation source 101 is provided with a matching collimator 103 , which faces the first detection unit 201 and is used to define the range of the first straight gamma ray 1021 . The gamma photons generated by the radiation source 101 form the first straight gamma ray 1021 after passing through the collimator 103 .

[0075] As one of the optional implementation schemes, only one collimator 103 is provided, which has one tapered hole covered with lead.

[0076] As one of the optional implementation schemes, the collimator 103 is installed on the radiation source 101, and the two can move synchronously.

[0077] Based on the above technical solution, Figure 3As shown, a first driving device 104 is disposed in the first chamber 100 for controlling the radiation source 101 to move sequentially between at least two predetermined positions.

[0078] As one of the optional implementation schemes, through the first driving device 104, the present invention can adjust the radiation source 101 at at least two different positions, so that the gamma ray 102 detects the same position or different positions of the object to be detected 401; detecting the same position can improve the detection accuracy, and detecting different positions can improve the detection efficiency.

[0079] As one of the optional implementation schemes, the predetermined positions are any two or more of the following positions:

[0080] The default detection position is a fixed position preset by the backscatter imaging detection device for imaging detection;

[0081] The default calibration position is used to calibrate the default position of the backscatter imaging detection device; accordingly, the backscatter imaging detection device is provided with a standard object to be tested for calibration, and by imaging and detecting the standard object to be tested, it can be determined whether the backscatter imaging detection device meets the requirements of accuracy and the like;

[0082] The second detection position is a fixed default distance from the default detection position; the default distance is a preset value;

[0083] The distributed detection positions are based on the default detection position, a fixed default spacing as the moving distance, and the key points in the preset moving trajectory as the target. The finally determined detection positions are the distributed detection positions, and the number of distributed detection positions is at least one; for example: based on the default detection position, a fixed default spacing as the moving distance, the preset moving trajectory is a rectangle, and the four vertices of the rectangle are the key points, and the key points are used as the target, and the default detection position and three distributed detection positions are finally determined, corresponding to the four vertices of the rectangle respectively; for another example: based on the default detection position, a fixed default spacing as the moving distance, and the preset moving trajectory It is a rectangle, and the four vertices of the rectangle are key points, the midpoints of the four sides of the rectangle are also key points, and the key points are taken as the target to finally determine the default detection position and seven distributed detection positions, which correspond to the four vertices of the rectangle and the midpoints of the four sides respectively; for another example: taking the default detection position as the reference, a fixed default spacing as the moving distance, the preset moving trajectory is a circle, and four key points are taken on the circular trajectory in equal parts, and taking the key points as the target to finally determine the default detection position and four distributed detection positions, the default detection position corresponds to the center of the circle, the fixed default spacing corresponds to the radius, and a total of four distributed detection positions are obtained at the four equally divided positions on the circular trajectory.

[0084] It is understandable that the preset movement trajectory can be a line segment (straight line, arc, broken line, etc.) or a geometric figure (circle, polygon, etc.), and is not specifically limited.

[0085] On the basis of the above technical solution, the first detection unit 201 comprises a rectangular bottom plate, and a first sensor is covered on the side facing the radiation source 101, and the first sensor is configured to receive gamma rays and convert them into electrical pulse signals;

[0086] There are multiple first sensors, which are evenly arranged at equal intervals on a side of the bottom plate facing the radiation source 101;

[0087] The first sensor is a scintillator detector or a CZT gamma detector.

[0088] As one of the optional implementation schemes, the overall thickness of the first detection unit 201 is 2 mm, the first sensor is configured as a pixel-type CZT gamma detector, a single pixel size is 5 mm*5 mm, a pitch is 2 mm, and the number of pixels is 20*20=400.

[0089] It is understandable that the size, spacing, and number of pixels of a single pixel can be selected according to different required resolution accuracies.

[0090] Based on the above technical solution, Figure 4 As shown, a second driving device 202 is provided in the second chamber 200 for adjusting the distance between the first detection unit 201 and the radiation source 101 to a set value;

[0091] The set values ​​include at least one detection position set value and one replacement position set value;

[0092] The detection position setting value is used to receive gamma rays and convert them into electrical pulse signals when the first detection unit 201 moves to the detection position;

[0093] The replacement position setting value is used to replace the first detection unit 201 with the same or different resolution accuracy as needed when the first detection unit 201 moves to the replacement position.

[0094] Exemplarily, an inspection door is provided on the wall of the second chamber 200, and the replacement position corresponding to the replacement position setting value is opposite to and adjacent to the inspection door. When the first detection unit 201 with the same or different resolution accuracy needs to be replaced, the inspection door can be opened to disassemble and assemble the first detection unit 201.

[0095] It can be understood that adjusting the distance between the first detection unit 201 and the radiation source 101 to a set value can ensure the consistency of each detection, which is conducive to reducing errors and improving detection accuracy.

[0096] Based on the above technical solution, Figure 5As shown, the second detection unit 301 is in an annular shape as a whole, and is composed of four fan-shaped detection submodules 302. The inner circular area 303 of the second detection unit 301 forms a cavity, and the cavity is used for the second direct gamma ray 1022 to pass through and irradiate the surface of the object to be detected 401;

[0097] Each sector detection submodule 302 is at least one second sensor;

[0098] The second sensor is a scintillator detector or a CZT gamma detector.

[0099] As one of the optional embodiments, the second sensor is configured as a sodium iodide crystal detector (NaI(Tl) detector), and the fan-shaped detection submodule 302 has a thickness of 20 mm, an inner diameter of 80 mm, and an outer diameter of 200 mm.

[0100] Based on the above technical solution, Figure 6 As shown, a distance measuring mechanism 302 is provided on the outer surface of the wall of the third chamber 300 , and the distance measuring mechanism 302 faces the object to be measured 401 , and is used to obtain the distance between the backscatter imaging detection device and the object to be measured 401 .

[0101] As one of the optional implementation schemes, the distance measuring mechanism 302 is a detachable laser distance meter.

[0102] On the basis of the above technical solution, a shielding cover is provided along the outer envelope of the detection device, and any one, part or all of the following are provided in conjunction with the detection device: a handheld part, a positioning movement mechanism, a ruler mechanism, and a laser ruler; the outer envelope can be understood as the outer surface of the product;

[0103] A hand-held part, at least one in number, for holding the detection device and manually adjusting the position and distance between the detection device and the object to be detected 401; as one of the optional implementation schemes, the hand-held part can be a handle, or a grip, or a groove adapted to the shape of a finger and suitable for holding; the hand-held part can be integrally formed with the shielding cover, or can be a detachable hand-held part;

[0104] The positioning and moving mechanism is provided with a roller and / or a clamping unit and / or a suspension unit. The roller contacts the object to be measured 401 to make the detection device move linearly along the roller direction and the distance remains unchanged; the clamping unit contacts the object to be measured 401 and clamps the detection device on the object to be measured 401; the suspension unit contacts the object to be measured 401 and suspends the detection device under the object to be measured 401; through the positioning and moving mechanism, on the one hand, the backscatter imaging detection device can be moved regularly along the surface of the object to be measured 401, so as to improve the imaging accuracy; on the other hand, it can reduce the force of the user holding the backscatter imaging detection device for a long time, providing more convenient use;

[0105] A ruler mechanism is used to obtain the relative position of the detection device on the object to be measured 401; the position of the detection device on the object to be measured 401 can be accurately measured by the ruler mechanism, for example: a ruler positioning hole is provided, and by inserting a ruler of a fixed length into the ruler positioning hole, the relative position of the detection device on the object to be measured 401 can be determined by the ruler of the fixed length;

[0106] The laser ruler is used to project horizontal and / or vertical markings to assist in determining the spatial position of the detection device. Through the laser ruler, a visual marking can be directly projected to assist in confirming the position of the XYZ axes, thereby assisting in determining the spatial position of the detection device.

[0107] As one of the optional implementation schemes, a plurality of mounting rails are provided on the shielding cover, and the handheld part, the positioning movement mechanism, the ruler mechanism, and the laser ruler are all slidably assembled on the mounting rails, or slidably removed from the mounting rails.

[0108] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0109] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by those skilled in the art based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.

Claims

1. A backscatter imaging detection device, characterized in that: include: A first chamber (100), wherein a radiation source (101) is disposed in the first chamber (100), wherein the radiation source (101) is used to generate gamma rays (102); the gamma rays (102) include a first direct gamma ray (1021) and a second direct gamma ray (1022) generated at the same time; A second chamber (200), wherein a first detection unit (201) is arranged in the second chamber (200), and the first detection unit (201) is used to obtain a first direct gamma ray (1021) that enters the second chamber (200) and directly comes from the radiation source (101); A position acquisition unit (600) is electrically connected to the first detection unit (201) and acquires position information corresponding to the first direct gamma ray (1021) from the first detection unit (201); A second direct gamma ray (1022) directly from the radiation source (101) irradiates the surface of the object to be measured (401), and after a Compton effect occurs with the object to be measured (401), backscatters to form Compton scattered gamma rays (1023); A third chamber (300), wherein a second detection unit (301) is arranged in the third chamber (300), and the second detection unit (301) is used to obtain Compton scattered gamma rays (1023) from the object to be detected (401) that enter the third chamber (300); An energy acquisition unit (700) is electrically connected to the second detection unit (301) and acquires energy information corresponding to the Compton scattered gamma ray (1023) from the second detection unit (301); A radiation shielding plate (501) is disposed between a radiation source (101) and an object to be measured (401), and the radiation shielding plate (501) has a first state and a second state by reciprocating movement. When in the first state, the radiation shielding plate (501) is located within a path of the second direct gamma ray (1022) irradiating the object to be measured (401), and when in the second state, the radiation shielding plate (501) is located outside the path of the second direct gamma ray (1022) irradiating the object to be measured (401); A signal processing unit (800) is electrically connected to the position acquisition unit (600) and the energy acquisition unit (700) respectively, and is used to process the position information and the energy information; The image reconstruction unit (900) is electrically connected to the signal processing unit (800) and is used to perform data processing and image reconstruction on the received information. The image reconstruction unit (900) includes a display module (901), and the display module (901) presents the reconstructed image in a wired or wireless manner.

2. A backscatter imaging detection device as claimed in claim 1, characterized in that: The radiation source (101) is a Na22 radiation source for generating 511keV gamma rays.

3. A backscatter imaging detection device as claimed in claim 1, characterized in that: The radiation source (101) is provided with a matching collimator (103), which faces the first detection unit (201) and is used to define the range of the first straight gamma ray (1021). The gamma photons generated by the radiation source (101) form the first straight gamma ray (1021) after passing through the collimator (103).

4. A backscatter imaging detection device as claimed in claim 1, characterized in that: The first direct gamma ray (1021) and the second direct gamma ray (1022) generated at the same time have opposite directions.

5. The backscatter imaging detection device according to claim 1, characterized in that: A first driving device (104) is arranged in the first chamber (100) for controlling the radiation source (101) to move sequentially between at least two predetermined positions.

6. The backscatter imaging detection device according to claim 1, characterized in that: The first detection unit (201) comprises a rectangular bottom plate, and a first sensor is covered on a side facing the radiation source (101), wherein the first sensor is configured to receive gamma rays and convert them into electrical pulse signals; There are a plurality of first sensors, which are evenly arranged at equal intervals on a side of the bottom plate facing the radiation source (101); The first sensor is a scintillator detector or a CZT gamma detector.

7. The backscatter imaging detection device according to claim 1, characterized in that: A second driving device (202) is provided in the second chamber (200) for adjusting the distance between the first detection unit (201) and the radiation source (101) to a set value; The set values ​​include at least one detection position set value and one replacement position set value; The detection position setting value is used for receiving gamma rays and converting them into electrical pulse signals when the first detection unit (201) moves to the detection position; The replacement position setting value is used to replace the first detection unit (201) with the same or different resolution accuracy as needed when the first detection unit (201) moves to the replacement position.

8. The backscatter imaging detection device according to claim 1, characterized in that: The second detection unit (301) is in an annular shape as a whole and is composed of four fan-shaped detection submodules (302); an inner circular area (303) of the second detection unit (301) forms a cavity, and the cavity is used for the second direct gamma ray (1022) to pass through and irradiate the surface of the object to be detected (401); Each sector detection submodule (302) is at least one second sensor; The second sensor is a scintillator detector or a CZT gamma detector.

9. The backscatter imaging detection device according to claim 1, characterized in that: A distance measuring mechanism (302) is provided on the outer surface of the wall of the third chamber (300), and the distance measuring mechanism (302) faces the object to be measured (401) and is used to obtain the distance between the backscatter imaging detection device and the object to be measured (401).

10. The backscatter imaging detection device according to claim 1, characterized in that: A shielding cover is provided along the outer envelope of the detection device, and is equipped with any one, part or all of the following: a handheld portion, a positioning movement mechanism, a ruler mechanism, and a laser ruler; A hand-held part, at least one in number, used for holding the detection device and manually adjusting the position and distance between the detection device and the object to be detected (401); The positioning movement mechanism is provided with a roller and / or a clamping unit and / or a suspension unit, wherein the roller contacts the object to be measured (401) to make the detection device move linearly along the roller direction and the distance remains unchanged; the clamping unit contacts the object to be measured (401) and clamps the detection device on the object to be measured (401); the suspension unit contacts the object to be measured (401) and suspends the detection device below the object to be measured (401); A scale mechanism, used to obtain the relative position of the detection device on the object to be detected (401); The laser ruler is used to project horizontal markings and / or vertical markings to assist in determining the spatial position of the detection device.

Images