A pen-shaped ray beam generating mechanism

Abstract

The application provides a pen-shaped ray beam generating mechanism, which comprises a ray source, a front collimator and a chopping assembly, the front collimator is provided with a front slit extending along a first direction, the chopping assembly comprises a shielding unit and a moving unit, the moving unit is located in the shielding unit, the shielding unit is filled with a liquid which prevents the ray beam from penetrating, and a ray lead-out valve in the moving unit can reciprocate along the first direction, so that a sheet-shaped ray beam passing through the front slit passes through the ray lead-out valve to form a pen-shaped ray beam, thereby scanning. In the pen-shaped ray beam generating mechanism provided by the application, the shape and size of the flying spot depend on the ray lead-out valve, the shape and size of the flying spot can be adjusted by replacing the ray lead-out valve, and the operation is simple; in addition, the pen-shaped ray beam generating mechanism provided by the application is simple in structure, compact and light in quality, and is beneficial to the small size and light weight of the back scattering imaging instrument.

Description

Technical Field

[0001] This invention belongs to the field of radiation imaging detection technology, specifically, it relates to a pencil-shaped ray beam generating mechanism. Background Technology

[0002] X-ray backscattering imager is a non-destructive testing instrument based on the Compton scattering principle. Unlike transmission imaging, where the X-ray source and detector need to be placed on opposite sides of the object being imaged, the X-ray source and detector of the backscattering imager are on the same side of the object being imaged. This allows for a compact and highly flexible overall structure. In addition, backscattering imaging is more sensitive to items with low atomic numbers, giving it certain advantages in the detection of drugs and explosives.

[0003] The pencil beam generation mechanism is the core structure of a backscatter imager. Its main function is to generate a continuously scanning pencil beam of X-rays in one dimension, serving as collimator and chopper. Typically, this part consists of a collimator and a chopper. The collimator is fixed in place, and the chopper rotates at high speed to chop the X-rays, thus generating a line-by-line scanning pencil beam. Existing pencil beam generation mechanisms suffer from drawbacks such as large size and heavy weight, which are unfavorable to the miniaturization and lightweight requirements of backscatter imagers. Furthermore, adjusting the size and shape of the flying points requires re-machining the collimator and chopper wheel, which is difficult and inconvenient to operate. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the present invention provides a pencil-shaped X-ray beam generating mechanism, including a X-ray source, a pre-collimator, and a chopper assembly. The pre-collimator has a pre-slit extending along a first direction. The chopper assembly includes a shielding unit and a moving unit, with the moving unit located within the shielding unit. The shielding unit is filled with a liquid to prevent the X-ray beam from passing through. The X-ray outlet valve in the moving unit can reciprocate along the first direction, allowing the thin sheet-like X-ray beam passing through the pre-slit to pass through the X-ray outlet valve to form a pencil-shaped X-ray beam for scanning. In the pencil-shaped X-ray beam generating mechanism provided by the present invention, the shape and size of the flying point depend on the X-ray outlet valve. The shape and size of the flying point can be adjusted by replacing the X-ray outlet valve, making operation simple. In addition, the pencil-shaped X-ray beam generating mechanism provided by the present invention has a simple, compact, and lightweight structure, which is beneficial to the miniaturization and lightweight requirements of backscattered imagers.

[0005] To achieve the above and other related objectives, the present invention provides a pencil-shaped ray beam generating mechanism, comprising:

[0006] A radiation source, used to generate a radiation beam;

[0007] A pre-collimator is disposed at the front end of the radiation source. The pre-collimator has a pre-slit extending along a first direction. The radiation beam generated by the radiation source passes through the pre-slit to form a sheet-like radiation beam.

[0008] A chopper assembly is disposed on the side of the pre-collimator away from the X-ray source and is arranged parallel to the pre-collimator. The chopper assembly includes a shielding unit and a moving unit, with the moving unit located within the shielding unit.

[0009] The shielding unit is a shielding wall structure, and the shielding unit is filled with a liquid to prevent the radiation beam from passing through;

[0010] The moving unit includes a radiation extraction valve and a driving device. The driving device is used to drive the radiation extraction valve to reciprocate along the first direction, and the thin-sheet radiation beam passes through the radiation extraction valve to form a pencil-shaped radiation beam.

[0011] Optionally, the moving unit further includes a limiting guide groove for limiting the moving direction of the ray outlet valve.

[0012] Optionally, the driving device includes:

[0013] Two fixing members are located at both ends of the moving unit along the first direction;

[0014] A limiting spring is used to connect the ray outlet valve to the fixing component;

[0015] The control unit is used to control the extension and retraction of the limit spring along the first direction, thereby driving the ray outlet valve to reciprocate along the first direction.

[0016] Optionally, the surface of the limiting spring is coated with a polytetrafluoroethylene film or a polyimide film.

[0017] Optionally, the radiation discharge valve has a hollow structure.

[0018] Optionally, the radiation extraction valve is cylindrical, and the axis of the radiation extraction valve is perpendicular to the plane where the shielding unit is located.

[0019] Optionally, the liquid used to fill the shielding unit includes one of tungstic acid, amalgam, and heavy liquid.

[0020] Optionally, along the thickness direction of the shielding unit, the length of the radiation outlet valve is less than or equal to the thickness of the shielding unit, and the difference between the two is less than or equal to 0.1 mm.

[0021] The pencil-shaped ray beam generating mechanism provided by the present invention has at least the following beneficial effects:

[0022] 1. Compact structure and light weight. The size of the chopper assembly is slightly larger than the size of the front slit, which can achieve the effect of shielding and extracting the pencil beam; while the existing technology requires a large chopper, which increases the size and weight of the equipment.

[0023] 2. The shape and size of the flying point are easy to adjust. The shape and size of the flying point depend on the X-ray outlet valve. Simply replacing the X-ray outlet valve can adjust the shape and size of the flying point, making the operation simple. In contrast, existing technologies require re-machining of the collimator and chopper, which is more difficult.

[0024] 3. Simple radiation protection structure. The pencil-shaped ray beam generating mechanism provided by this invention has a more reasonable radiation protection form, which can complete radiation protection simply by being close to the light source outlet; while the existing pencil-shaped ray beam generating mechanism is prone to lateral radiation leakage, and requires an additional outer shell to shield the radiation leakage, resulting in a complex structure. Attached Figure Description

[0025] Figure 1 The diagram shown is a schematic representation of the pencil-shaped ray beam generating mechanism provided in the embodiment.

[0026] Figure 2 The diagram shown is a structural schematic of the chopper assembly provided in the embodiment.

[0027] Component designation explanation

[0028] 10 X-ray sources

[0029] 20 Pre-collimator

[0030] 30 Chopper Components

[0031] 31 Shielding Unit

[0032] 32 moving units

[0033] 321 X-ray discharge valve

[0034] 322 Limiting Guide Groove

[0035] 3231 First fastener

[0036] 3232 Second fastener

[0037] 3241 First Limit Spring

[0038] 3242 Second limit spring

[0039] 325 power supply

[0040] 326 Controller

[0041] 327 First Conductor

[0042] 328 Second Conductor

[0043] 329 Third Conductor Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0045] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the actual number, shape and size of the components, the shape, quantity, positional relationship and proportion of each component can be arbitrarily changed under the premise of realizing the technical solution of this invention, and the layout of the components may also be more complex.

[0046] Example

[0047] This embodiment provides a pencil-shaped ray beam generating mechanism, such as Figure 1 As shown, it includes a radiation source 10, a pre-collimator 20, and a chopper assembly 30.

[0048] As an example, the X-ray source 10 is used to generate an X-ray beam, and the X-ray source 10 is communicatively connected to an X-ray source controller (not shown in the figure). In this embodiment, the X-ray source controller is used to control the X-ray source 10 to generate an X-ray beam, and can also control the X-ray source 10 to adjust parameters such as the intensity and exit angle of the X-ray beam. The specific structure and model of the X-ray source controller are not excessively limited here.

[0049] like Figure 1 As shown, the pre-collimator 20 is disposed at the front end of the X-ray source 10, and the pre-collimator 20 has a feature along the first direction ( Figure 1 A pre-collimator (not shown in the figure) extends along the Z-axis direction, through which the X-ray beam generated by the X-ray source 10 passes to form a sheet-like X-ray beam. In this embodiment, the pre-collimator 20 can be a W metal pre-collimator, a Pb metal pre-collimator, or a Cu metal pre-collimator.

[0050] like Figure 1 As shown, the chopper assembly 30 is positioned on the side of the pre-collimator 20 away from the X-ray source 10, and is arranged parallel to the pre-collimator 20. Figure 2 As shown, the chopper assembly 30 includes a shielding unit 31 and a moving unit 32, with the moving unit 32 located within the shielding unit 31.

[0051] As an example, the shielding unit 31 is a shielding wall structure, and the shielding unit 31 is filled with a liquid that can prevent the radiation beam from passing through without hindering the movement of the moving unit 32 within the shielding unit 31. In this embodiment, the filling liquid can be one of tungstic acid, amalgam, or heavy liquid.

[0052] like Figure 2 As shown, the moving unit 32 includes a radiation discharge valve 321, a drive device, and a limiting guide groove 322.

[0053] As an example, the radiation discharge valve 321 can move along a first direction under the drive of the drive device ( Figure 2 The ray outlet valve 321 reciprocates along the Z-axis direction, and the thin sheet-like ray beam can pass through the ray outlet valve 321 to form a pencil-shaped ray beam. When the ray outlet valve 321 reciprocates along the first direction, the ray outlet valve 321 intersects the front slit in the front collimator 20, always forming a pencil-shaped ray beam with a defined area and shape, used to form a flying point for backscattered imaging scanning. In this embodiment, the ray outlet valve 321 has a hollow structure to allow the thin sheet-like ray beam to pass through, and it is made of a material that can prevent corrosion by the aforementioned filling liquid.

[0054] In this embodiment, the X-ray extraction valve 321 is cylindrical, and its axis is perpendicular to the plane where the shielding unit 31 is located. That is, the thin sheet-like X-ray beam exits through the end face of the X-ray extraction valve 321. In other optional embodiments, the X-ray extraction valve 321 can also be circular, conical, or other shapes. Traditional pencil-shaped X-ray beam generating mechanisms require re-machining of the collimator and chopper wheel to adjust the flying point size, while in this embodiment, the flying point size can be adjusted simply by replacing the X-ray extraction valve 321. In addition, the flying point shape can be controlled by replacing the X-ray extraction valve 321 with different shapes, making the operation simple.

[0055] As an example, along the thickness direction of the shielding unit 31 ( Figure 2 (As shown in the Y-axis direction), the length of the X-ray outlet valve 321 is less than or equal to the thickness of the shielding unit 31, and the difference between the two is less than or equal to 0.1 mm, so as to prevent the X-ray outlet valve 321 from rubbing against the shielding unit 31 when it is reciprocating.

[0056] like Figure 2 As shown, the limiting guide groove 322 is along the first direction ( Figure 2 Extending in the Z-axis direction (as shown), it is used to limit the movement direction of the ray outlet valve 321.

[0057] like Figure 2 As shown, the drive device includes a fixing component, a limit spring, and a control unit.

[0058] As an example, the fastener includes a first fastener 3231 and a second fastener 3232, along a first direction ( Figure 2The two ends of the moving unit 32 are respectively located in the Z-axis direction shown. The first fixing member 3231 is located above the ray outlet valve 321, and the second fixing member 3232 is located below the ray outlet valve 321.

[0059] As an example, the limiting spring includes a first limiting spring 3241 and a second limiting spring 3242, wherein the first limiting spring 3241 is used to connect the radiation outlet valve 321 to the first fixing member 3231, and the second limiting spring 3242 is used to connect the radiation outlet valve 321 to the second fixing member 3232. In this embodiment, the surface of the limiting spring is coated with a polytetrafluoroethylene film or a polyimide film to avoid corrosion by the filling liquid.

[0060] As an example, the control unit includes a power supply 325, a controller 326, a first wire 327, a second wire 328, and a third wire 329. The first wire 327 connects the power supply 325 and the end of the second limiting spring 3242 near the radiation outlet valve 321; the second wire 328 connects the power supply 325 and the end of the second limiting spring 3242 away from the radiation outlet valve 321; the third wire 329 connects the power supply 325 and the end of the first limiting spring 3241 away from the radiation outlet valve 321; and the controller 326 controls the connection or disconnection of the first wire 327, the second wire 328, and the third wire 329. In this embodiment, the control unit controls the limiting spring along a first direction (…). Figure 2 The Z-axis direction (as shown) extends and retracts, thereby driving the ray outlet valve 321 along the first direction ( Figure 2 The X-ray outlet valve 321 reciprocates along the Z-axis direction (as shown). Specifically, when the first wire 327 and the second wire 328 are connected to form a passage, the second limiting spring 3242 is compressed, causing the X-ray outlet valve 321 to move closer to the second fixing member 3232; when the first wire 327 and the third wire 329 are connected to form a passage, the first limiting spring 3241 is compressed, causing the X-ray outlet valve 321 to move closer to the first fixing member 3231; the controller 326 controls the above wires to alternately connect or disconnect according to a preset setting, so that the X-ray outlet valve 321 can move along the first direction (Z-axis direction). Figure 2 The X-ray beam reciprocates along the Z-axis (as shown), thereby achieving periodic pencil beam X-ray scanning.

[0061] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A pencil-shaped ray beam generating mechanism, characterized in that, include: A radiation source, used to generate a radiation beam; A pre-collimator is disposed at the front end of the radiation source. The pre-collimator has a pre-slit extending along a first direction. The radiation beam generated by the radiation source passes through the pre-slit to form a sheet-like radiation beam. A chopper assembly is disposed on the side of the pre-collimator away from the X-ray source and is arranged parallel to the pre-collimator. The chopper assembly includes a shielding unit and a moving unit, with the moving unit located within the shielding unit. The shielding unit is a shielding wall structure, and the shielding unit is filled with a liquid to prevent the radiation beam from passing through; The moving unit includes a radiation outlet valve and a driving device. The driving device is used to drive the radiation outlet valve to reciprocate along the first direction, and the thin sheet-like radiation beam passes through the radiation outlet valve to form a pencil-shaped radiation beam. The moving unit also includes a limiting guide groove for limiting the moving direction of the ray outlet valve; The driving device includes: Two fixing members are located at both ends of the moving unit along the first direction; A limiting spring is used to connect the ray outlet valve to the fixing component; The control unit is used to control the extension and retraction of the limit spring along the first direction, thereby driving the ray outlet valve to reciprocate along the first direction.

2. The pencil-shaped ray beam generating mechanism according to claim 1, characterized in that, The surface of the limiting spring is coated with a polytetrafluoroethylene film or a polyimide film.

3. The pencil-shaped ray beam generating mechanism according to claim 1, characterized in that, The radiation discharge valve has a hollow structure.

4. The pencil-shaped ray beam generating mechanism according to claim 3, characterized in that, The radiation extraction valve is cylindrical, and its axis is perpendicular to the plane containing the shielding unit.

5. The pencil-shaped ray beam generating mechanism according to claim 1, characterized in that, The liquid used to fill the shielding unit includes one of tungstic acid, amalgam, and heavy liquid.

6. The pencil-shaped ray beam generating mechanism according to claim 1, characterized in that, Along the thickness direction of the shielding unit, the length of the radiation outlet valve is less than or equal to the thickness of the shielding unit, and the difference between the two is less than or equal to 0.1 mm.

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