WO2022052892A1 - 背散射检查系统 - Google Patents

背散射检查系统 Download PDF

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Publication number
WO2022052892A1
WO2022052892A1 PCT/CN2021/116726 CN2021116726W WO2022052892A1 WO 2022052892 A1 WO2022052892 A1 WO 2022052892A1 CN 2021116726 W CN2021116726 W CN 2021116726W WO 2022052892 A1 WO2022052892 A1 WO 2022052892A1
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Prior art keywords
gap
detector
detectors
pencil beam
shielding
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PCT/CN2021/116726
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English (en)
French (fr)
Inventor
陈志强
李元景
唐晓
吴万龙
唐乐
桑斌
孙秀平
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同方威视技术股份有限公司
清华大学
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Publication of WO2022052892A1 publication Critical patent/WO2022052892A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
    • G01N23/203—Measuring back scattering
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
    • G01N23/20008—Constructional details of analysers, e.g. characterised by X-ray source, detector or optical system; Accessories therefor; Preparing specimens therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V5/00—Prospecting or detecting by the use of nuclear radiation, e.g. of natural or induced radioactivity
    • G01V5/222—
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/05—Investigating materials by wave or particle radiation by diffraction, scatter or reflection
    • G01N2223/053—Investigating materials by wave or particle radiation by diffraction, scatter or reflection back scatter
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/10—Different kinds of radiation or particles
    • G01N2223/101—Different kinds of radiation or particles electromagnetic radiation
    • G01N2223/1016—X-ray

Definitions

  • the present invention relates to the field of X-ray inspection, in particular to a backscatter inspection system.
  • X-ray backscatter imaging technology has been widely used in the field of safety inspection of human body, goods and vehicles due to its advantages of low radiation dose, good safety and sensitivity to lightweight materials.
  • X-ray backscatter imaging technology obtains material images within a certain depth on the surface of the object by detecting the intensity of X-ray scattering by different materials.
  • the backscatter inspection system includes an X-ray source and a detector, wherein the X-rays emitted by the X-ray source are formed by a pencil beam forming device to form a pencil beam, and the surface of the object to be inspected is scanned point by point; the detector receives the scattering signal of the object to form the surface of the object depth image.
  • the backscatter inspection systems described above place conflicting demands on the width of the gap between the detectors.
  • the gap between the detectors needs to be as narrow as possible to reduce the distance between the detector and the irradiation point on the surface of the object, so as to obtain a stronger scattering signal.
  • the X-ray source and the pencil beam forming device are located behind the detector, when the pencil beam passes through the narrow detector gap, its own scattering will cause interference signals to the detector and affect the imaging quality.
  • the scattering of X-rays as they pass through the front panel of a backscatter inspection system can also cause interfering signals to the detector.
  • One aspect of the present invention provides a backscatter inspection system, comprising: an X-ray source for generating X-rays; a pencil beam forming device for modulating the X-rays generated by the X-ray source into an X-ray pencil beam; two detectors a detector for receiving X-rays backscattered after the modulated X-ray pencil beam irradiates the object to be inspected, two detectors are spaced apart to form a gap, the detector includes a receiving surface for facing the object to be inspected; and a shield Means, located adjacent to the gap between the two detectors and/or the receiving surface of the detectors, for reducing the effect on the detectors of scattering caused by the X-ray pencil beam before it reaches the object to be inspected.
  • the shielding device includes two slot shielding parts disposed in the gap between the two detectors and forming a gap, wherein the gap between the two slot shielding parts is aligned with the pencil beam forming device such that The modulated X-ray pencil beam is able to pass through the gap between the two slot shielding portions.
  • the backscatter inspection system further includes a front panel, which is disposed in front of the receiving surface of the detector, and is used for blocking external foreign objects from contacting the detector.
  • the shielding device includes two front-side shielding portions disposed between the front panel and the receiving surface of the detector and covering a portion of the receiving surface of the detector near the gap, the two front-side shielding portions being spaced apart Opened to form a gap, the gap between the two front side shield parts is aligned with the pencil beam forming means so that the modulated X-ray pencil beam can pass through the gap between the two front side shield parts.
  • the first slit shield portion and the first front side shield portion are integrally formed, and the second slit shield portion and the second front side shield portion are integrally formed.
  • the first slit shielding portion, the first front side shielding portion, the second slit shielding portion, and the second front side shielding portion are integrally formed.
  • the backscatter inspection system further includes a housing in which the X-ray source, the pencil beam forming device, the two detectors and the shielding device are arranged.
  • the backscatter inspection system further includes a controller for generating a backscattered X-ray image according to the backscattered X-rays received by the detector.
  • the backscatter inspection system further includes a display for displaying the backscatter X-ray image generated by the controller.
  • the backscatter inspection system includes a shielding device, which can reduce the influence of the scattering caused by the X-ray pencil beam before reaching the object to be inspected on the detector, that is, reduce the interference scattering caused by the backscatter inspection system inside the detector. Impact. Therefore, the backscatter inspection system including the shielding device can effectively reduce the influence of internal interference scattering on the scanning imaging, and improve the quality of the backscatter image, such as image contrast.
  • FIG. 1 is a schematic diagram of a backscatter inspection system according to an embodiment of the present invention.
  • FIG. 2 is a schematic diagram of a pencil bundle forming apparatus according to an embodiment of the present invention.
  • FIG. 3 is a schematic diagram of a backscatter inspection system including a shielding device according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of a shielding device according to an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of a backscatter inspection system including a shielding device according to an embodiment of the present invention.
  • FIG. 6 is a schematic diagram of a shielding device according to an embodiment of the present invention.
  • the backscatter inspection device can perform scanning inspection on objects, such as vehicles, building walls, or other objects that need to identify the internal structure and the safety of the internal objects.
  • Backscatter inspection devices according to embodiments of the present invention are particularly suitable as portable backscatter inspection devices.
  • the backscatter inspection system 10 may include a housing 11 , an X-ray source 12 , a pencil beam forming device 13 , a detector 14 , a controller 15 and a display 16 .
  • the X-ray source 12 , the pencil beam forming device 13 and the detector 14 may be arranged inside the housing 11 .
  • Figure 1 shows the housing 11 in partial cross-section for ease of showing the components within the housing 11 .
  • the backscatter inspection system can perform scanning inspection towards the object to be inspected 20 .
  • One side of the housing 11 is used to face the object 20 to be inspected.
  • the X-ray source 12 is used to generate X-rays.
  • the pencil beam forming device 13 is used to modulate the X-rays generated by the X-ray source 12 into an X-ray pencil beam.
  • the detector 14 is configured to receive X-rays backscattered from the object to be inspected 20 after the X-ray pencil beam modulated by the pencil beam forming device 13 is irradiated to the object to be inspected 20 .
  • the controller 15 is configured to generate a backscattered X-ray image according to the backscattered X-ray received by the detector 14 .
  • the controller 15 may be disposed inside the casing 11 as shown in FIG. 1 , eg, disposed on the side of the casing 11 away from the detector 14 , or may be disposed outside the casing 11 .
  • the controller 15 is communicatively connected to the X-ray source 12, the detector 14, etc., eg, by wired communication or wireless communication.
  • the display 16 is used to display the backscattered X-ray image generated by the controller 15 .
  • the display 16 is communicatively connected to the controller 15, such as by wired or wireless communication.
  • the display 16 may be disposed external to the housing 11 , such as separately from the housing 11 as shown in FIG. 1 , or the display 16 may be attached to the housing 11 .
  • the X-ray source 12 is located at the rear of the backscatter inspection system
  • the detector 14 is located at the front
  • the pencil beam forming device 13 is located between the X-ray source 12 and the detector 14 .
  • front and “front” refer to the side of the backscatter inspection system facing the object to be inspected 20
  • rear and “rear” refer to the side of the backscatter inspection system that is remote from the object to be inspected 20 .
  • the backscatter inspection system includes two detectors 14 .
  • the two detectors 14 are arranged spaced apart such that a gap is formed between the two detectors 14 .
  • Each detector 14 includes a front surface for facing the object to be inspected 20 and a side surface facing the other detector at the slit.
  • the front surface serves as the receiving surface of the detector 14 for receiving backscattered X-rays.
  • the X-ray source 12 emits X-rays (eg, wide-angle X-rays); the pencil beam forming device 13 modulates the X-rays emitted by the X-ray source 12 into high-speed rotating X-rays Ray pencil beam; X-ray pencil beam passes through the gap between the two detectors 14 and finally irradiates on the object 20 to be inspected.
  • the pencil beam forming device modulates the pencil beam so that its projection moves at high speed in a straight line, whereby the object 20 to be inspected can be scanned in one dimension.
  • the backscatter inspection system can also move in a direction perpendicular to the one-dimensional scanning direction, so that the backscatter inspection system scans through a certain area, that is, the object to be inspected 20 is scanned two-dimensionally. scanning.
  • the detector 14 may receive X-rays backscattered from the object to be inspected 20 during the scanning process and generate backscattered signals, and the controller 15 may acquire the backscattered signals from the detector 14 and generate X-ray backscattered images, such as those with a certain depth. 2D image.
  • the display 16 may display the generated X-ray backscattered image.
  • the outer surface of the backscatter inspection system is in contact with the surface of the object 20 to be inspected.
  • the pencil beam forming device 13 may take various forms, such as a rotary modulation device such as a disc type, a wheel type, and a column type. The following description will be given by taking the disk chopper device as an example.
  • FIG. 2 is a schematic diagram of a pencil bundle forming apparatus according to an embodiment of the present invention.
  • the pencil beam forming device 13 may include a shielding plate 31 , a chopper disk 32 and a shielding plate 33 .
  • the wide angle X-rays first reach the slitted shielding plate 31 and pass through the slits to form a fan beam, then reach the rotating chopper disk 32 and form a reciprocating X-ray pencil beam.
  • a shielding plate 33 with a slit can be placed on the exit side of the chopper disk 32.
  • the shielding plates 31, 33 and the chopper disk 32 are made of a metal material having a high atomic number, such as lead, tin, iron, tungsten, or alloys thereof.
  • the shielding plates 31, 33 and the chopper disc 32 need to have a certain thickness to have a sufficient shielding effect on rays other than the desired X-ray pencil beam.
  • the shielding plates 31 and 33 and the chopper disk 32 are parallel to each other and maintain a fixed distance, so that the chopper disk 32 can maintain stable high-speed rotation.
  • the pencil beam forming device 13 can realize the forming of the X-ray pencil beam and has an effective shielding effect, but it is still unavoidable that certain scattered X-rays exist on the exit side of the pencil beam forming device 13 .
  • the X-ray pencil beam modulated by the pencil beam forming device 13 passes through the gap between the two detectors 14 and finally irradiates the surface of the object 20 to be inspected.
  • the X-ray pencil beam will penetrate a certain depth of the object 20 to be inspected and interact with the object 20 to be inspected. Some of the X-rays are backscattered and reach the front surface of detector 14 . With the scanning movement of the backscatter inspection system, the X-ray pencil beam moves on the surface of the object to be inspected 20 .
  • the front surface of the detector 14 needs to cover the backscattered X-ray of sufficient intensity.
  • the surface needs to have a sufficient area to receive backscattered X-rays.
  • the detector 14 may be configured as a polyhedron having a cavity capable of reflecting the optical signal, ie the detector 14 has a certain thickness.
  • the backscatter inspection system may further include a front panel 17 placed in front of the detector 14 for blocking foreign objects from contacting the detector 14 .
  • the front panel 17 can be used to block external dust, water vapor, foreign matter, etc. from entering the gap between the detectors 14 or scratching the surface of the detector 14 .
  • the backscatter inspection system includes the front panel 17 , the X-ray pencil beam passing through the gap between the two detectors 14 also needs to penetrate the front panel 17 before reaching the object to be inspected 20 .
  • the front panel 17 is generally made of a lighter material to reduce radiation attenuation, such as acrylic, plastic, carbon fiber, and the like. These materials attenuate X-rays less, but scatter more X-rays as they pass through.
  • the X-ray pencil beam may generate scattering from other surfaces before reaching the surface of the object to be inspected 20, which may be detected by the detector 14 as interfering scattering and thus affect the accuracy of the backscatter inspection .
  • the X-ray pencil beam passes through the gap between the two detectors 14, scattered X-rays leaking from the pencil beam forming device 13 may reach the side surfaces of the two detectors 14 at the gap.
  • the scattered X-rays caused by the front panel 17 may also reach the surface of the detector 14 as interference scattering. Both of the above-mentioned scatters can be interfering scatters for the detector 14 .
  • the backscatter inspection system 10 may further include a shielding device.
  • the structure of the shielding device and the backscatter inspection system including the shielding device will be described below with reference to the accompanying drawings.
  • 3 is a schematic diagram of a backscatter inspection system including a shielding device according to some embodiments of the present invention.
  • FIG. 4 is a schematic diagram of the shielding device shown in FIG. 3 .
  • 5 is a schematic diagram of a backscatter inspection system including a shielding device according to some embodiments of the present invention.
  • FIG. 6 is a schematic diagram of the shielding device shown in FIG. 5 .
  • shielding means 18 may be provided adjacent to the gap between the two detectors 14 and/or at the front surface of the detector 14 to reduce the occurrence of X-ray pencil beams before they reach the object to be inspected. The effect of scattering on detector 14 .
  • the shielding device 18 may include a slit shielding portion 81 and a front side shielding portion 82 .
  • the gap shielding portion 81 serves to shield interference scattering in the gap between the two detectors 14 .
  • the front side shielding portion 82 serves to shield the interfering scatter near the slit on the front surface of the detector 14 .
  • the shielding device 18 may include two slit shielding portions 81 and two front side shielding portions 82 .
  • the shielding device 18 is divided into two shielding units, each shielding unit including a slit shielding portion 81 and a front side shielding portion 82 .
  • One slot unit is used for one detector 14 and the other slot unit is used for the other detector 14 .
  • the two gap shielding portions 81 are spaced apart to form a gap, and the gap is aligned with the pencil beam forming means of the backscatter inspection system to enable the X-ray pencil beam to pass through the gap.
  • the two front-side shielding portions 82 are spaced apart to form a gap, and the gap is aligned with the pencil beam forming device so that the X-ray pencil beam can pass through the gap.
  • the two slit shielding parts 81 and the two front side shielding parts 82 may be integrally formed.
  • the shielding device 18 may be integrally formed in a flat barrel shape with both ends open.
  • the two slit shielding portions 81 may be attached to the side surfaces of the two detectors 14, respectively, and the two front shielding portions 82 may be attached to the two detectors 14 at the junctions of the side surfaces and the front surface of the detectors 14, respectively. on the front surface.
  • the two slit shielding portions 81 may be connected by side plates on both lateral sides thereof.
  • the two slit shielding parts 81 and the two side plates may form an opening on the X-ray entrance side and an opening on the X-ray exit side.
  • the X-ray pencil beam may enter from the opening on the X-ray entrance side, pass through the gap between the slit shielding portions 81, and exit from the opening on the X-ray exit side.
  • the X-ray pencil beam will sweep through a fan-shaped space with a certain thickness.
  • the gaps between the gap shielding parts 81 allow the fan-shaped space having a certain thickness swept by the X-ray pencil beam to pass therethrough.
  • the slot shielding portion 81 may have a generally fan-shaped shape.
  • the area of the slit shielding portion 81 is large enough to cover the fan-shaped area swept by the X-ray pencil beam entering the slit.
  • the two side plates can be closed on both lateral sides of the slit shielding portion 81 , so as to more effectively block the interference scattering leaked from the pencil beam forming device 13 and/or the interference scattering from the front panel 17 from reaching the two detectors 14 located in the slits. side surface.
  • the shielding device 18 may include two independent shielding units, ie, the two slot shielding portions 81 for the two detectors 14 are separated from each other, And the front side shield portions 82 for the two detectors 14, respectively, are also separated from each other.
  • the slit shield portion 81 and the front side shield portion 82 for one detector 14 may be integrally formed, and the slit shield portion 81 and the front side shield portion 82 for the other detector 14 may be integrally formed form.
  • the two slit shielding portions 81 may be attached to the side surfaces of the two detectors 14, respectively, and the two front shielding portions 82 may be attached to the two detectors 14 at the junctions of the side surfaces and the front surface of the detectors 14, respectively. on the front surface.
  • the gaps between the gap shielding parts 81 allow the fan-shaped space having a certain thickness swept by the X-ray pencil beam to pass therethrough.
  • the area of the slit shielding portion 81 is large enough to cover the fan-shaped area swept by the X-ray pencil beam entering the slit.
  • the area of the two slit shielding portions 81 may cover the side surfaces of the two detectors 14 , so that interference scattering leaking from the pencil beam forming device 13 and/or interference from the front panel 17 may be more favorably blocked. The scattering reaches the side surfaces of the two detectors 14 at the slit.
  • the front side shielding portion 82 of the shielding device 18 is mainly used for shielding the interference scattering that occurs when the X-ray pencil beam reaches and penetrates the front panel 17 . This part of the interference scattering will reach the position of the detector 14 closest to the position where the X-ray pencil beam reaches the front panel 17 , that is, the junction of the side surface and the front surface of the detector 14 .
  • the front side shield portion 82 of the shielding device 18 may be positioned to cover the edge of the front surface of the detector 14 proximate the side surface.
  • the area or width of the front side shielding portion 82 (the distance extending from the junction of the side and front surfaces of the detector 14 ) may be determined depending on, for example, the material of the front panel 17 and the strength of interfering scattering.
  • the thickness of the slit shielding portion 81 and/or the front side shielding portion 82 of the shielding device 18 can be determined according to the shielding effect to be achieved and the materials used.
  • the shielding device 18 can be fixed on the housing 11 or on other specially designed brackets.
  • the shielding device 18 may be made of a metal material with a high atomic number, such as lead, tin, iron, tungsten, or alloys thereof. In some embodiments, in order to reduce the weight of the shielding device 18 and the backscatter inspection system, the shielding device 18 may be made of a low atomic number metal material, such as aluminum, copper, or alloys thereof.
  • the shielding device 18 includes the slit shielding portion 81 and the front-side shielding portion 82 in two parts.
  • the present invention is not limited to this.
  • the shielding device 18 may include only the front side shielding portion 82 without the slit shielding portion 81 between the two detectors 14 .
  • the shielding device 18 may only include the gap shielding portion 81 between the two detectors 14, but not the front-side shielding portion 82.
  • the slit shielding portion 81 and the front-side shielding portion 82 of each shielding unit described above are integrally formed.
  • the present invention is not limited to this.
  • the slit shielding portion 81 and the front-side shielding portion 82 of each shielding unit may also be formed separately and installed separately.
  • the backscatter inspection system includes a shielding device, which can reduce the influence of the scattering caused by the X-ray pencil beam before reaching the object to be inspected on the detector, that is, reduce the interference scattering caused by the backscatter inspection system inside the detector. Impact. Therefore, the backscatter inspection system including the shielding device can effectively reduce the influence of internal interference scattering on the scanning imaging, and improve the quality of the backscatter image, such as image contrast.

Abstract

本发明涉及背散射检查系统。公开了一种背散射检查系统，包括：X射线源，用于生成X射线；笔束形成装置，用于将X射线源生成的X射线调制成X射线笔束；两个探测器，用于接收在调制的X射线笔束照射到待检查物体后背散射的X射线，两个探测器间隔开布置以形成缝隙，探测器包括用于朝向待检查物体的接收面；和屏蔽装置，位于邻近两个探测器之间的缝隙和/或探测器的接收面处，用于降低在X射线笔束到达待检查物体之前引起的散射对探测器的影响。

Description

背散射检查系统 技术领域
本发明涉及X射线检查领域，特别是涉及背散射检查系统。
背景技术
X射线背散射成像技术因其辐射量剂量低、安全性好和对轻质材料敏感等优点，已被广泛应用于人体、货物和车辆的安全检查领域。X射线背散射成像技术通过探测不同物质对X射线散射的强弱，得到物体表面一定深度以内的物质图像。背散射检查系统包括X射线源和探测器，其中X射线源发出的X射线经过笔束形成装置形成笔束，在待检查物体表面进行逐点扫描；探测器接收物体的散射信号，形成物体表面深度图像。
对于物体表面受到X射线照射后散射出的X射线，其强度与到物体表面照射点的距离成平方反比关系。因此，希望探测器的位置能够尽可能地接近物体表面照射点。目前的背散射检查系统通常包括位于前端的两个探测器，X射线源和笔束形成装置位于探测器后方。X射线笔束穿过两个探测器之间的缝隙并不断移动，对目标物体进行扫描检查。
上述背散射检查系统对探测器之间缝隙的宽度提出了矛盾需求。一方面，需要探测器之间的缝隙尽量窄，以减小探测器与物体表面的照射点之间的距离，以得到更强的散射信号。另一方面，由于X射线源和笔束形成装置位于探测器后方，笔束穿过狭窄的探测器缝隙时，其自身的散射会对探测器造成干扰信号，影响成像质量。此外，X射线穿过背散射检查系统的前面板时造成的散射也会对探测器造成干扰信号。
为此，需要一种能够降低内部散射干扰的背散射检查系统。
发明内容
本发明的一个目的是提供一种能够降低内部散射干扰的背散射检查系 统。本发明的另一目的是提供一种能够提高成像质量的背散射检查系统。
本发明的一方面提供一种背散射检查系统，包括：X射线源，用于生成X射线；笔束形成装置，用于将X射线源生成的X射线调制成X射线笔束；两个探测器，用于接收在调制的X射线笔束照射到待检查物体后背散射的X射线，两个探测器间隔开布置以形成缝隙，探测器包括用于朝向待检查物体的接收面；和屏蔽装置，位于邻近两个探测器之间的缝隙和/或探测器的接收面处，用于降低在X射线笔束到达待检查物体之前引起的散射对探测器的影响。
根据本发明的实施例，屏蔽装置包括两个缝隙屏蔽部分，其设置在两个探测器之间的缝隙中并且形成间隙，其中两个缝隙屏蔽部分之间的间隙对准笔束形成装置以使得调制的X射线笔束能够穿过两个缝隙屏蔽部分之间的间隙。
根据本发明的实施例，背散射检查系统还包括前面板，其设置在探测器的接收面前方，用于阻挡外界异物接触到探测器。
根据本发明的实施例，屏蔽装置包括两个前侧屏蔽部分，其设置在前面板与探测器的接收面之间并且覆盖探测器的接收面的靠近缝隙的一部分，两个前侧屏蔽部分间隔开以形成间隙，两个前侧屏蔽部分之间的间隙对准笔束形成装置以使得调制的X射线笔束能够穿过两个前侧屏蔽部分之间的间隙。
根据本发明的实施例，第一缝隙屏蔽部分和第一前侧屏蔽部分是一体地形成的，并且第二缝隙屏蔽部分和第二前侧屏蔽部分是一体地形成的。
根据本发明的实施例，第一缝隙屏蔽部分、第一前侧屏蔽部分、第二缝隙屏蔽部分和第二前侧屏蔽部分是一体地形成的。
根据本发明的实施例，背散射检查系统还包括外壳，X射线源、笔束形成装置、两个探测器和屏蔽装置设置在外壳内。
根据本发明的实施例，背散射检查系统还包括控制器，用于根据探测器接收的背散射X射线，生成背散射X射线图像。
根据本发明的实施例，背散射检查系统还包括显示器，用于显示控制器所生成的背散射X射线图像。
根据本发明的实施例，背散射检查系统包括屏蔽装置，可以降低在X射线笔束到达待检查物体之前引起的散射对探测器的影响，即降低背散射检查系统内部引起的干扰散射对探测器的影响。因此，包括屏蔽装置的背散射检查系统可以有效降低内部干扰散射对扫描成像的影响，提高背散射图像的质量，例如图像对比度等。
附图说明
图1是根据本发明的实施例的背散射检查系统的示意图。
图2是根据本发明的实施例的笔束形成装置的示意图。
图3是根据本发明的实施例的包括屏蔽装置的背散射检查系统的示意图。
图4是根据本发明的实施例的屏蔽装置的示意图。
图5是根据本发明的实施例的包括屏蔽装置的背散射检查系统的示意图。
图6是根据本发明的实施例的屏蔽装置的示意图。
具体实施方式
下文中，参照附图描述本发明的实施例。下面的详细描述和附图用于示例性地说明本发明的原理，本发明不限于所描述的优选实施例，本发明的范围由权利要求书限定。现参考示例性的实施方式详细描述本发明，一些实施例图示在附图中。以下描述参考附图进行，除非另有表示，否则在不同附图中的相同附图标记代表相同或类似的元件。以下示例性实施方式中描述的方案不代表本发明的所有方案。相反，这些方案仅是所附权利要求中涉及的本发明的各个方面的系统和方法的示例。
根据本发明的实施例的背散射检查装置可以对物体，例如车辆、建筑物墙面、或其他需要对内部结构和内部物品安全性进行鉴别的物体，进行扫描检查。根据本发明的实施例的背散射检查装置特别适合作为便携式背散射检查装置。
图1是根据本发明的某些实施例的背散射检查系统的示意图。如图1 所示，背散射检查系统10可以包括外壳11、X射线源12、笔束形成装置13、探测器14、控制器15和显示器16。X射线源12、笔束形成装置13和探测器14可以设置在外壳11的内部。应当注意，为便于显示外壳11内的部件，图1以局部剖视的方式示出外壳11。背散射检查系统可以对朝向待检查物体20进行扫描检查。外壳11的一侧用于朝向待检查物体20。
X射线源12用于生成X射线。笔束形成装置13用于将X射线源12生成的X射线调制成X射线笔束。探测器14用于接收在经笔束形成装置13调制的X射线笔束照射到待检查物体20后，从待检查物体20背散射的X射线。
控制器15用于根据探测器14接收的背散射X射线，生成背散射X射线图像。控制器15可以如图1所示设置在外壳11的内部，例如设置在外壳11内远离探测器14的一侧，或者可以设置在外壳11的外部。控制器15与X射线源12、探测器14等通信连接，例如通过有线通信或无线通信。
显示器16用于显示控制器15所生成的背散射X射线图像。显示器16与控制器15通信连接，例如通过有线通信或无线通信。在一些实施例中，显示器16可以设置在外壳11的外部，例如如图1所示与外壳11分开设置，或者显示器16可以连接到外壳11上。
在背散射检查系统中，X射线源12位于背散射检查系统的后部，探测器14位于前部，笔束形成装置13位于X射线源12和探测器14之间。在本文中，“前部”和“前”表示背散射检查系统的朝向待检查物体20的一侧，“后部”和“后”表示背散射检查系统的远离待检查物体20的一侧。
根据本发明的实施例，背散射检查系统包括两个探测器14。两个探测器14间隔开布置，从而在两个探测器14之间形成缝隙。每个探测器14包括用于朝向待检查物体20的前表面和在缝隙处朝向另一探测器的侧表面。前表面作为探测器14的用于接收背散射X射线的接收面。
在背散射检查系统对待检查物体20进行扫描检查时，X射线源12发出X射线(例如大张角X射线)；笔束形成装置13将X射线源12发出 的X射线调制成高速旋转的X射线笔束；X射线笔束穿过两个探测器14之间的缝隙并最终照射在待检查物体20上。在一些实施例中，笔束形成装置将笔束调制成其投影沿直线高速运动，由此可以对待检查物体20进行一维扫描。此外，在对待检查物体20进行一维扫描时，背散射检查系统还可以沿与一维扫描方向垂直的方向移动，使背散射检查系统扫描经过一定面积的范围，即对待检查物体20进行二维扫描。探测器14可以在扫描过程中接收从待检查物体20背散射的X射线并且生成背散射信号，控制器15可以从探测器14获取背散射信号并且生成X射线背散射图像，例如具有一定深度的二维图像。之后，显示器16可以显示生成的X射线背散射图像。在扫描过程中，背散射检查系统的外表面贴合待检查物体20的表面。
笔束形成装置13可以采用各种形式，例如盘式、轮式、柱式等旋转调制装置。下面以盘式斩波装置为例进行描述。图2是根据本发明的实施例的笔束形成装置的示意图。如图2所示，笔束形成装置13可以包括屏蔽板31、斩波盘32和屏蔽板33。在操作过程中，大张角X射线首先到达带有狭缝的屏蔽板31并且穿过狭缝形成扇形束，然后到达旋转的斩波盘32并且形成往复运动的X射线笔束。在斩波盘32的出射侧可以放置带有狭缝的屏蔽板33。通常，屏蔽板31、33和斩波盘32由具有高原子序数的金属材料制成，如铅、锡、铁、钨或其合金等。屏蔽板31、33和斩波盘32需要具有一定的厚度，以对所需X射线笔束之外的射线具有足够的屏蔽作用。屏蔽板31、33和斩波盘32之间相互平行并保持固定的距离，使得斩波盘32能够保持稳定的高速旋转。笔束形成装置13能够实现X射线笔束的形成并具有有效的屏蔽作用，但是在笔束形成装置13的出射侧，仍难以避免地存在一定的散射X射线。
经过笔束形成装置13调制的X射线笔束穿过两个探测器14之间的缝隙，并最终照射到待检查物体20的表面。X射线笔束将穿透待检查物体20的一定深度，与待检查物体20发生相互作用。部分X射线被背散射回来，并到达探测器14的前表面。随着背散射检查系统的扫描移动，X射线笔束在待检查物体20的表面移动。由于照射到待检查物体20上的X射线 笔束具有一定的移动范围，并且探测器14的前表面的接收范围需要覆盖来自该移动范围的足够强度的背散射X射线，因此探测器14的前表面需要具有足有的面积以接收背散射X射线。在一些实施例中，为了收集该面积内的足够强度的背散射X射线，探测器14可以构造成具有空腔的能够反射光信号的多面体，即探测器14具有一定的厚度。
根据本发明的某些实施例，背散射检查系统还可以包括放置在探测器14的前方的前面板17，用于阻挡外界异物接触到探测器14。前面板17可以用于阻挡外界的灰尘、水汽、异物等进入探测器14之间的缝隙或划伤探测器14的表面。在背散射检查系统包括前面板17时，穿过两个探测器14之间的缝隙的X射线笔束在到达待检查物体20之前还需要穿透前面板17。前面板17一般由较轻的材料制成以降低对射线的衰减，例如亚克力、塑料、碳纤维等。这些材料对X射线的衰减较小，但是在X射线穿过时的散射较大。
在背散射检查系统10中，X射线笔束在到达待检查物体20的表面之前可能产生从其他表面的散射，这些散射可能作为干扰散射被探测器14检测到并因此影响背散射检查的准确性。例如，在X射线笔束穿过两个探测器14之间的缝隙时，从笔束形成装置13泄露的散射X射线可能会到达两个探测器14的位于缝隙处的侧表面。此外，在X射线笔束穿透前面板17时，前面板17造成的散射X射线也可能作为干扰散射到达探测器14的表面。上述两种散射都会成为对探测器14的干扰散射。
根据本发明的实施例，为降低干扰散射对探测器14的影响，背散射检查系统10还可以包括屏蔽装置。下面参考附图描述屏蔽装置和包括屏蔽装置的背散射检查系统的结构。图3是根据本发明的某些实施例的包括屏蔽装置的背散射检查系统的示意图。图4是图3中所示的屏蔽装置的示意图。图5是根据本发明的某些实施例的包括屏蔽装置的背散射检查系统的示意图。图6是图5中所示的屏蔽装置的示意图。应当注意，为便于说明和避免模糊重点，图3和图5中仅以局部剖视的方式示出外壳11，并且未示出背散射检查系统10的X射线源12、笔束形成装置13、控制器15和显示器16。这些未示出的部件的描述参见上文所述，这里不再赘述。
如图3和图5所示，屏蔽装置18可以设置在邻近两个探测器14之间的缝隙和/或探测器14的前表面处，以降低在X射线笔束到达待检查物体之前引起的散射对探测器14的影响。
在示例性实施例中，如图4和图6所示，屏蔽装置18可以包括缝隙屏蔽部分81和前侧屏蔽部分82。缝隙屏蔽部分81用于在两个探测器14之间的缝隙中屏蔽干扰散射。前侧屏蔽部分82用于在探测器14的前表面的靠近缝隙处屏蔽干扰散射。
在示例性实施例中，屏蔽装置18可以包括两个缝隙屏蔽部分81和两个前侧屏蔽部分82。由此，屏蔽装置18分成两个屏蔽单元，每个屏蔽单元包括一个缝隙屏蔽部分81和一个前侧屏蔽部分82。一个缝隙单元用于一个探测器14，另一缝隙单元用于另一探测器14。两个缝隙屏蔽部分81间隔开布置以形成间隙，并且该间隙对准背散射检查系统的笔束形成装置以使得X射线笔束能够穿过该间隙。此外，两个前侧屏蔽部分82间隔开布置以形成间隙，并且该间隙对准笔束形成装置以使得X射线笔束能够穿过该间隙。
根据本发明的某些实施例，如图4所示，两个缝隙屏蔽部分81和两个前侧屏蔽部分82可以一体地形成。例如，屏蔽装置18可以整体形成为两端开口的扁桶状。两个缝隙屏蔽部分81可以分别贴在两个探测器14的侧表面上，并且两个前侧屏蔽部分82可以分别在探测器14的侧表面和前表面的连接处贴在两个探测器14的前表面上。两个缝隙屏蔽部分81在其横向两侧可以通过侧板连接。两个缝隙屏蔽部分81和两个侧板可以形成位于X射线进入侧的开口和位于X射线出射侧的开口。X射线笔束可以从X射线进入侧的开口进入，穿过缝隙屏蔽部分81之间的间隙并从X射线出射侧的开口离开。X射线笔束将扫过具有一定厚度的扇形空间。缝隙屏蔽部分81之间的间隙使得X射线笔束扫过的具有一定厚度的扇形空间能够从中通过。在一些实施例中，缝隙屏蔽部分81可以具有大致扇形形状。缝隙屏蔽部分81的面积足够大，以覆盖进入到缝隙中的X射线笔束所扫过的扇形面积。两个侧板可以在缝隙屏蔽部分81的横向两侧封闭，从而更有利于阻挡从笔束形成装置13泄露的干扰散射和/或来自前面板17 的干扰散射到达两个探测器14的位于缝隙处的侧表面。
根据本发明的某些实施例，如图5和图6所示，屏蔽装置18可以包括两个独立的屏蔽单元，即，分别用于两个探测器14的两个缝隙屏蔽部分81彼此分开，并且分别用于两个探测器14的前侧屏蔽部分82也彼此分开。在一些实施例中，用于一个探测器14的缝隙屏蔽部分81和前侧屏蔽部分82可以一体地形成，并且用于另一探测器14的缝隙屏蔽部分81和前侧屏蔽部分82可以一体地形成。两个缝隙屏蔽部分81可以分别贴在两个探测器14的侧表面上，并且两个前侧屏蔽部分82可以分别在探测器14的侧表面和前表面的连接处贴在两个探测器14的前表面上。缝隙屏蔽部分81之间的间隙使得X射线笔束扫过的具有一定厚度的扇形空间能够从中通过。缝隙屏蔽部分81的面积足够大，以覆盖进入到缝隙中的X射线笔束所扫过的扇形面积。在一些实施例中，两片缝隙屏蔽部分81的面积可以覆盖两个探测器14的侧表面，从而可以更有利地阻挡从笔束形成装置13泄露的干扰散射和/或来自前面板17的干扰散射到达两个探测器14的位于缝隙处的侧表面。
屏蔽装置18的前侧屏蔽部分82主要用于屏蔽X射线笔束到达并穿透前面板17时发生的干扰散射。这部分干扰散射会到达探测器14的最接近X射线笔束到达前面板17的位置，也就是探测器14的侧表面和前表面的连接处。屏蔽装置18的前侧屏蔽部分82可以设置成覆盖探测器14的前表面的靠近侧表面的边缘。前侧屏蔽部分82的面积或宽度(从探测器14的侧表面和前表面的交界处延伸的距离)可以根据例如前面板17的材料和干扰散射的强度等确定。屏蔽装置18的缝隙屏蔽部分81和/或前侧屏蔽部分82的厚度可以根据需要达到的屏蔽效果和使用的材料来确定。屏蔽装置18可以固定在外壳11上或其他专门设计的支架上。
在一些实施例中，为了达到更好的屏蔽效果，屏蔽装置18可以由高原子序数的金属材料制成，如铅、锡、铁、钨或其合金等。在一些实施例中，为了降低屏蔽装置18以及背散射检查系统的重量，屏蔽装置18可以由低原子序数的金属材料制成，如铝、铜或其合金等。
上文描述屏蔽装置18包括缝隙屏蔽部分81和前侧屏蔽部分82两部 分。但是，本发明不限于此。例如，在来自前面板17的干扰散射较强情况下，屏蔽装置18可以只包括前侧屏蔽部分82，而没有位于两个探测器14之间的缝隙屏蔽部分81。在来自前面板17的干扰散射较弱情况下，屏蔽装置18可以只包括位于两个探测器14之间的缝隙屏蔽部分81，而没有前侧屏蔽部分82。
上文描述每个屏蔽单元的缝隙屏蔽部分81和前侧屏蔽部分82一体地形成。但是，本发明不限于此。根据本发明的某些实施例，每个屏蔽单元的缝隙屏蔽部分81和前侧屏蔽部分82也可以分开形成并且分别安装。
根据本发明的实施例，背散射检查系统包括屏蔽装置，可以降低在X射线笔束到达待检查物体之前引起的散射对探测器的影响，即降低背散射检查系统内部引起的干扰散射对探测器的影响。因此，包括屏蔽装置的背散射检查系统可以有效降低内部干扰散射对扫描成像的影响，提高背散射图像的质量，例如图像对比度等。
尽管已经参考示例性实施例描述了本发明，但是应理解，本发明并不限于上述实施例的构造和方法。相反，本发明意在覆盖各种修改例和等同配置。另外，尽管在各种示例性结合体和构造中示出了所公开发明的各种元件和方法步骤，但是包括更多、更少的元件或方法的其它组合也落在本发明的范围之内。

Claims (10)

  1. 一种背散射检查系统，包括：
    X射线源，用于生成X射线；
    笔束形成装置，用于将所述X射线源生成的X射线调制成X射线笔束；
    两个探测器，用于接收在调制的X射线笔束照射到待检查物体后背散射的X射线，所述两个探测器间隔开布置以形成缝隙，所述探测器包括用于朝向所述待检查物体的接收面；和
    屏蔽装置，位于邻近所述两个探测器之间的所述缝隙和/或所述探测器的所述接收面处，用于降低在X射线笔束到达所述待检查物体之前引起的散射对所述探测器的影响。
  2. 根据权利要求1所述的背散射检查系统，其中，所述屏蔽装置包括分别用于所述两个探测器的两个缝隙屏蔽部分，其设置在所述两个探测器之间的所述缝隙中并且形成间隙，其中所述两个缝隙屏蔽部分之间的间隙对准所述笔束形成装置以使得调制的X射线笔束能够穿过所述两个缝隙屏蔽部分之间的间隙。
  3. 根据权利要求2所述的背散射检查系统，还包括前面板，其设置在所述探测器的接收面前方，用于阻挡外界异物接触到所述探测器。
  4. 根据权利要求3所述的背散射检查系统，其中，所述屏蔽装置包括分别用于所述两个探测器的两个前侧屏蔽部分，其设置在所述前面板与所述探测器的所述接收面之间并且覆盖所述探测器的所述接收面的靠近所述缝隙的一部分，所述两个前侧屏蔽部分间隔开以形成间隙，所述两个前侧屏蔽部分之间的间隙对准所述笔束形成装置以使得调制的X射线笔束能够穿过所述两个前侧屏蔽部分之间的间隙。
  5. 根据权利要求4所述的背散射检查系统，其中，用于一个探测器的缝隙屏蔽部分和前侧屏蔽部分是一体地形成的，并且用于另一探测器的缝隙屏蔽部分和前侧屏蔽部分是一体地形成的。
  6. 根据权利要求5所述的背散射检查系统，其中，分别用于所述两个 探测器的所述两个缝隙屏蔽部分和所述两个前侧屏蔽部分是一体地形成的。
  7. 根据权利要求1所述的背散射检查系统，还包括前面板，其设置在所述探测器的所述接收面前方，用于阻挡外界异物接触到所述探测器，
    其中，所述屏蔽装置包括两个前侧屏蔽部分，其设置在所述前面板与所述探测器的所述接收面之间并且覆盖所述探测器的所述接收面的靠近所述缝隙的一部分，所述两个前侧屏蔽部分间隔开以形成间隙，所述两个前侧屏蔽部分之间的间隙对准所述笔束形成装置以使得调制的X射线笔束能够穿过所述两个前侧屏蔽部分之间的间隙。
  8. 根据权利要求1至7中任一项所述的背散射检查系统，还包括外壳，所述X射线源、所述笔束形成装置、所述两个探测器和所述屏蔽装置设置在所述外壳内。
  9. 根据权利要求8所述的背散射检查系统，还包括控制器，用于根据所述探测器接收的背散射X射线，生成背散射X射线图像。
  10. 根据权利要求8所述的背散射检查系统，还包括显示器，用于显示所述控制器所生成的背散射X射线图像。
PCT/CN2021/116726 2020-09-11 2021-09-06 背散射检查系统 WO2022052892A1 (zh)

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