X-ray flying spot scanning device of back scattering imaging detector

Abstract

The utility model discloses an X-ray flying spot scanning device of a back scattering imaging detector, and particularly relates to the technical field of security and industrial detection, which comprises a base, an X-ray source used for emitting X-rays is arranged at the top of the base, a light shielding plate made of tungsten alloy light shielding materials is arranged at the top of the base, a light-transmitting square block is arranged on the light shielding plate, and the light-transmitting square block is connected with the X-ray source. A sliding rail is fixedly arranged at the top end of the base, a sliding table is arranged at the top of the base and slidably connected with the top end of the base through the sliding rail, the shading plate is detachably arranged at the top end of the sliding table, and a motor used for driving the sliding table to reciprocate left and right is arranged at one end of the sliding rail. According to the utility model, a chopper wheel in the prior art is replaced by the shading plate and the light-transmitting square block, so that the structure is simpler and smaller in design, and the whole system is better in maintenance compared with a chopper wheel structure in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical fields of security and industrial detection, and particularly relates to an X-ray flying spot scanning device for a backscatter imaging detector. Background Art

[0002] The interaction between X-rays and matter mainly includes: photoelectric effect, coherent scattering, Compton scattering, and electron pair effect, etc. X-ray backscatter imaging is based on the Compton scattering principle, and the detection of matter is realized by detecting the Compton scattering signal of incident X-rays on the matter. Substances with low atomic number and low density (such as drugs and explosives mainly composed of C, H, O, N) have a large Compton scattering cross-section and strong scattering signals, while metals have a small scattering cross-section and weak scattering signals. Therefore, the type of matter can be judged based on the difference in the intensity of the matter scattering signal.

[0003] The existing flying spot X-ray implementation methods of backscatter imaging detectors on the market are all realized by driving a chopper wheel with a motor. The specific working principle is as follows: The conical beam generated by the X-ray tube is collimated into a fan-shaped beam through a pre-collimation slit, and then irradiated on the high-speed rotating chopper wheel. Several radially distributed slits are opened on the chopper wheel, and the area outside the slits is shielded with high atomic number materials to ensure that the part outside the chopper wheel slits cannot transmit X-rays. During the high-speed rotation of the chopper wheel, there is only one slit intersecting with the pre-collimation slit at the same moment. Therefore, when the fan-shaped X-ray passes through the chopper wheel, a thin X-ray beam can be formed and perform a one-dimensional high-speed line scan in the vertical direction. At the same time, the other dimension scan is generated by the relative movement between the object to be inspected and the device. The detector and the X-ray tube are both located on the same side of the object to be inspected. When the detector receives the backscatter signal generated by the object to be inspected, the optical signal is converted into an electrical signal, and the algorithm is used to reconstruct the time-sequential electrical signal into a two-dimensional backscatter image of the object to be inspected.

[0004] In the prior art, the chopper wheel flying spot device requires precise motor drive and control systems to ensure the periodic generation of the X-ray beam, which increases the manufacturing cost and maintenance difficulty of the device. At the same time, since the chopper wheel needs to be placed on the X-ray source side, plus the drive motor of the chopper wheel, the volume is often large in structural design and is not conducive to miniaturization;

[0005] In addition, due to the chopper wheel method, the flying spot is realized by the intersection point of two slits. Since the area formed by the intersection of the two slits at different angles of the rays is different, the slits on the chopper wheel cannot be made of equal width and need to be made into a slit triangular structure, which has extremely high requirements for design and processing and often requires high costs. Summary of the Utility Model

[0006] The purpose of the present utility model is to provide an X-ray flying spot scanning device for a backscatter imaging detector. By using a light-shielding plate and a light-transmitting square to replace the chopper wheel in the prior art, the structure is relatively simple and compact in design, and the entire system is easier to maintain compared to the chopper wheel structure in the prior art.

[0007] To achieve the above purpose, the present utility model provides the following technical solutions: An X-ray flying spot scanning device for a backscatter imaging detector, including a base. On the top of the base, there is an X-ray source for emitting X-rays. On the top of the base, there is a light-shielding plate made of tungsten alloy light-shielding material. The light-shielding plate is provided with a light-transmitting square. The light-shielding plate can also be made of other materials with high atomic numbers, such as lead, tungsten, etc.

[0008] The size of the light-shielding plate has certain requirements. If the slit on the microfocus source is the same width as the light-transmitting square, then the length of the light-shielding plate should be at least twice the length of the slit minus the length of the light-transmitting square, and the width of the light-shielding plate should be at least greater than the width of the light-transmitting square, so as to play a role of complete shielding except for the light-transmitting square at the extreme positions on both sides.

[0009] A slide rail is fixedly provided at the top end of the base. A slide table is provided on the top of the base. The slide table is slidably connected to the top end of the base through the slide rail. The light-shielding plate is detachably provided at the top end of the slide table. One end of the slide rail is provided with a motor for driving the slide table to reciprocate left and right. The motor can drive the slide table to move and then drive the light-shielding plate to move quickly.

[0010] Further, the motor is fixedly provided at the top end of the base. One end of the output shaft of the motor is fixedly provided with a reciprocating lead screw. The reciprocating lead screw penetrates through the slide table and is movably connected to the slide table through a ball screw nut pair. The motor drives the reciprocating lead screw to rotate and drives the slide table to reciprocate left and right.

[0011] Further, a fixing component for fixing the X-ray source is provided on the front side of the light-shielding plate. The fixing component includes a lower support table fixedly provided at the top end of the base. An upper fixing table is provided at the top end of the lower support table through bolts. The X-ray source is clamped between the lower support table and the upper fixing table to fix the X-ray source, and the X-ray source can also be disassembled and replaced for maintenance.

[0012] In the above technical solutions, the technical effects and advantages provided by the present utility model are as follows:

[0013] 1. By using a light-shielding plate and a light-transmitting square to replace the chopper wheel in the prior art, the structure is relatively simple and compact in design, and the entire system is easier to maintain compared to the chopper wheel structure in the prior art;

[0014] 2. By moving the light-transmitting squares on the light-shielding plate along the slit direction of the X-ray source, the obtained X-ray flying spots are more uniform. This design greatly reduces the manufacturing requirements for the light-shielding plate and makes the manufacturing and processing more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present utility model. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0016] Figure 1 is the front view structure diagram of the present utility model;

[0017] Figure 2 is the rear view structure diagram of the present utility model;

[0018] Figure 3 is the structure diagram of the fixing component and the X-ray source of the present utility model;

[0019] Figure 4 is the structure diagram of the light-shielding plate of the present utility model;

[0020] Figure 5 is the structure diagram of the sliding table, slide rail and motor of the present utility model.

[0021] Description of the reference numerals:

[0022] 1. Base; 2. Fixing component; 201. Lower support platform; 202. Upper fixing platform; 3. X-ray source; 4. Slide rail; 5. Sliding table; 6. Motor; 7. Light-shielding plate; 8. Light-transmitting square. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to enable those skilled in the art to better understand the technical solutions of the present utility model, the following will further introduce the present utility model in detail in conjunction with the drawings.

[0024] The present utility model provides an X-ray flying spot scanning device for a backscatter imaging detector as shown in Figures 1-5 , which includes a base 1. An X-ray source 3 for emitting X-rays is provided at the top of the base 1. A light-shielding plate 7 made of tungsten alloy light-shielding material is provided at the top of the base 1. The light-shielding plate 7 is provided with light-transmitting squares 8. The light-shielding plate 7 can also use other materials with high atomic numbers, such as lead, tungsten, etc.

[0025] The size of the light-shielding plate 7 has certain requirements. If the slit on the micro-focus source and the light-transmitting square 8 are of the same width, then the length of the light-shielding plate 7 should be at least twice the length of the slit minus the length of the light-transmitting square 8, and the width of the light-shielding plate 7 should be at least greater than the width of the light-transmitting square 8, so as to play the role of completely shielding except for the light-transmitting square 8 at the extreme positions on both sides.

[0026] A slide rail 4 is fixedly arranged at the top end of the base 1. A slide table 5 is arranged on the top of the base 1. The slide table 5 is slidably connected to the top end of the base 1 through the slide rail 4. The light-shielding plate 7 is detachably arranged at the top end of the slide table 5. One end of the slide rail 4 is provided with a motor 6 for driving the slide table 5 to reciprocate left and right. The motor 6 can drive the slide table 5 to move and then drive the light-shielding plate 7 to move quickly.

[0027] First, preheat the X-ray source 3 to make it ready and reach the working state. Then turn on the motor 6. After the motor 6 is turned on, the slide table 5 can reciprocate quickly left and right along the slide rail 4 at the top end of the base 1. While the slide table 5 is moving, it drives the light-shielding plate 7 and the light-transmitting square 8 on the light-shielding plate 7 to reciprocate quickly left and right. Then turn on the X-ray source 3. Under the continuous exposure of the continuous X-ray source 3, there will be a light beam passing through the light-transmitting square 8, which irradiates the object to be measured and generates Compton scattering, and then an image of the pixel size of the light-transmitting square 8 is obtained. By continuously scanning this row, the entire row of pixels is stitched together into a row, and then imaging is performed by moving vertically from the outside. This structure is relatively simple and compact in design, and the entire system is easier to maintain compared with the chopping wheel structure in the prior art. The light-transmitting square 8 on the light-shielding plate 7 moves along the slit direction of the X-ray source 3, and the obtained X-ray flying spots are more uniform. This design scheme greatly reduces the manufacturing and processing requirements for the light-shielding plate 7, and the manufacturing and processing are more convenient.

[0028] The movement of the light-shielding plate 7 is driven by the rotation of the motor 6. As Figure 5 shown, the motor 6 is fixedly arranged at the top end of the base 1. One end of the output shaft of the motor 6 is fixedly provided with a reciprocating lead screw. The reciprocating lead screw passes through the slide table 5 and is movably connected to the slide table 5 through a ball screw pair. The motor 6 drives the reciprocating lead screw to rotate and drives the slide table 5 to reciprocate left and right.

[0029] During use, turn on the motor 6. The motor 6 drives the reciprocating lead screw to rotate at a high speed. The slide table 5 is connected to the top end of the base 1 through the slide rail 4. Therefore, the slide table 5 does not rotate with the reciprocating lead screw, but moves quickly back and forth left and right under its drive, thereby driving the light-shielding plate 7 and the light-transmitting square 8.

[0030] During use, the position of the X-ray source 3 needs to be fixed. As Figure 1 、 3As shown, a fixing component 2 for fixing the X-ray source 3 is provided on the front side of the light-shielding plate 7. The fixing component 2 includes a lower support platform 201 fixedly arranged at the top end of the base 1. An upper fixing platform 202 is provided at the top end of the lower support platform 201 through bolts. The X-ray source 3 is clamped between the lower support platform 201 and the upper fixing platform 202, thereby fixing the X-ray source 3, and the X-ray source 3 can also be disassembled and replaced for maintenance.

[0031] During use, the X-ray source 3 emits X-rays. The X-ray source 3 is fixed at the rear side of the light-shielding plate 7 through the fixing component 2. The fixing component 2 is composed of two detachable parts, namely the lower support platform 201 and the upper fixing platform 202. The X-ray source 3 is clamped between the two, and the lower support platform 201 is fixed at the top end of the base 1, thereby fixing the position of the X-ray source 3. The X-ray source 3 can also be disassembled from the fixing component 2 for easy maintenance or replacement.

[0032] Only some exemplary embodiments of the present invention are described above by way of illustration. Undoubtedly, for those of ordinary skill in the art, without departing from the spirit and scope of the present invention, the described embodiments can be modified in various different ways. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the protection scope of the claims of the present invention.

Claims

1. An X-ray flying spot scanning device for a backscatter imaging detector, comprising a base (1), and an X-ray source (3) for emitting X-rays is provided at the top of the base (1), characterized in that: The top of the base (1) is provided with a light-shielding plate (7) made of tungsten alloy light-shielding material, and a light-transmitting square (8) is provided on the light-shielding plate (7); The top end of the base (1) is fixedly provided with a slide rail (4), the top of the base (1) is provided with a slide table (5), the slide table (5) is slidably connected to the top end of the base (1) through the slide rail (4), the light-shielding plate (7) is detachably arranged at the top end of the slide table (5), and one end of the slide rail (4) is provided with a motor (6) for driving the slide table (5) to reciprocate left and right.

2. The X-ray flying spot scanning device of a backscatter imaging detector according to claim 1, characterized in that: The motor (6) is fixedly arranged at the top end of the base (1), and a reciprocating lead screw is fixedly arranged at one end of the output shaft of the motor (6). The reciprocating lead screw penetrates through the slide table (5) and is movably connected to the slide table (5) through a ball screw pair.

3. The X-ray flying spot scanning device of a backscatter imaging detector according to claim 1, characterized in that: A fixing assembly (2) for fixing the X-ray source (3) is arranged on the front side of the light-shielding plate (7). The fixing assembly (2) includes a lower support platform (201) fixedly arranged at the top end of the base (1), an upper fixing platform (202) is provided at the top end of the lower support platform (201) through bolts, and the X-ray source (3) is clamped between the lower support platform (201) and the upper fixing platform (202).

4. The X-ray flying spot scanning device of a backscatter imaging detector according to claim 1, characterized in that: If the slit on the micro-focus source is of the same width as the light-transmitting square (8), the length of the light-shielding plate (7) is greater than twice the length of the slit minus the length of the light-transmitting square (8), and the width of the light-shielding plate (7) is greater than the width of the light-transmitting square (8).

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