External reflection target, radiation source device and X-ray focus size adjusting method

Abstract

The invention provides an external reflection target, a radiation source device and an X-ray focus size adjusting method. The external reflection target comprises a target body; the target sheet is positioned on the surface of one side, facing the electron emission source, of the target body; the connecting assembly is used for connecting the target body and the electron emission source; the connecting assembly comprises a connecting plate and a connecting flange, and the connecting plate is fixedly connected with the electron emission source and is arranged perpendicular to the incident direction of electron beams; the target body is arranged on the connecting flange and is connected with the connecting plate through the connecting flange; the connecting plate comprises a mounting groove, the connecting flange comprises a connecting surface which is adjustably matched with the mounting groove, and the connecting surface is embedded in the mounting groove so as to adjust the included angle theta between the target sheet and the connecting plate, so that X-rays with different focus sizes can be flexibly obtained, and the inherent limit of a micro-focus beam in the design of an accelerating tube is successfully made up; the micro-focus design can be realized without the help of four-grade iron, the equipment cost and the size are greatly reduced, and the method has outstanding economical efficiency and practicability.

Description

Technical Field

[0001] This invention relates to the field of X-ray source technology. More specifically, it relates to an external reflective target, a radiation source device, and a method for adjusting the size of the X-ray focal spot. Background Technology

[0002] X-ray sources have wide applications in industrial inspection, scientific instruments, medical imaging, and treatment. In an X-ray source, an electron beam bombards a target material to generate X-rays.

[0003] Most existing X-ray source devices use a linear target design, with the accelerating tube directly connected to the target assembly via welding. The electron beam generated by the accelerating tube is output as an X-ray beam perpendicular to the target. This type of X-ray source device can only output an electron beam or X-ray in the same horizontal direction as the accelerating tube. Therefore, the workpiece to be inspected can only be inspected if it is placed in the same horizontal direction as the X-ray beam. An angular deviation in placement will result in the workpiece not being inspected or being inspected incompletely. At the same time, the X-ray source can only produce a focal spot of one size, which limits the types and number of workpieces that can be inspected and the inspection accuracy. If other sizes of X-ray beams (smaller focal spots) are desired, the X-ray source must be replaced, which will incur additional operating costs.

[0004] Currently, the industry generally uses external quadrupole iron or focusing coils to obtain smaller focal points. Although this method can obtain smaller focal points, it is characterized by large size and heavy weight, which does not meet the market's demand for miniaturization. Summary of the Invention

[0005] In view of the above problems, one object of the present invention is to provide an external reflective target.

[0006] One object of the present invention is to provide a radiation source device with an adjustable focal size.

[0007] One object of the present invention is to provide a method for adjusting the X-ray focal spot size based on the above-mentioned X-ray source device.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: According to one aspect of the present invention, an external reflective target is provided, comprising: Target; The target sheet located on the surface of the target body facing the electron emission source; and A connecting component for connecting the target and the electron emission source; The connecting assembly includes a connecting plate and a connecting flange. The connecting plate is fixedly connected to the electron emission source and is arranged perpendicular to the electron beam incident direction. The target is disposed on the connecting flange and connected to the connecting plate via the connecting flange; The connecting plate includes a mounting groove, and the connecting flange includes a connecting surface that is adjustable to the mounting groove. The connecting surface is embedded in the mounting groove to adjust the included angle θ between the target plate and the connecting plate.

[0009] Alternatively, the mounting groove can be an arc-shaped groove, and the connecting surface can be an arc-shaped surface that corresponds to and mates with the arc-shaped groove. The arc-shaped surface is embedded in the arc-shaped groove, and the connecting flange can rotate relative to the connecting plate around the center of the arc-shaped groove to adjust the included angle θ between the target plate and the connecting plate.

[0010] Alternatively, the target sheet is bombarded by an electron beam and outputs X-rays perpendicular to the incident direction of the electron beam. The angle between the X-ray output direction and the target sheet is equal to the angle θ between the target sheet and the connecting plate, and the value of θ is in the range of 0° < θ < 90°.

[0011] In addition, an alternative option is that when the included angle θ between the target and the connecting plate is in the range of 0° < θ < 45°, the focal size of the emitted X-rays is smaller than the cross-sectional size of the incident electron beam. When the included angle θ between the target and the connecting plate is 45°, the focal size of the emitted X-rays is equal to the cross-sectional size of the incident electron beam. When the included angle θ between the target and the connecting plate is in the range of 45° < θ < 90°, the focal size of the emitted X-rays is larger than the cross-sectional size of the incident electron beam.

[0012] Alternatively, when the included angle θ between the target and the connecting plate is 0°, the target body has a beam channel coaxially arranged with the target. The beam channel is a cylindrical through hole that penetrates the target body along the axial direction, and its axis coincides with the incident direction of the electron beam. The target sheet is bombarded by an electron beam, and X-rays are output through the beam channel that coincide with the incident direction of the electron beam.

[0013] In addition, an optional solution is that the external reflective target also includes a water inlet pipe, a water outlet pipe, and a cover plate located on the side of the target body away from the target plate. The surface of the target body facing away from the target piece is recessed along the axial direction towards the target piece to form an annular water groove. The annular water groove and the target piece are coaxially arranged, and the cover plate is sealed at the annular water groove. The target includes an inlet port and an outlet port that are respectively connected to an annular water tank. The inlet pipe is connected to the annular water tank through the inlet port, and the outlet pipe is connected to the annular water tank through the outlet port.

[0014] Alternatively, the mounting groove may have a recessed structure formed on its surface, and the recessed structure may be filled with solder.

[0015] According to one aspect of the present invention, a radiation source device is provided, comprising: an electron emission source, a water channel flange disposed radially outside the electron emission source, and an external reflective target; The water circuit flange includes a water cooling circulation section and a connecting section located above the water cooling circulation section, wherein the connecting plate and the connecting section are fixed together.

[0016] Alternatively, the electron emission source may include an accelerating tube and a titanium window assembly, wherein the accelerating tube and the titanium window assembly are coaxially arranged. The water passage flange is fitted on the radial outer side of the acceleration pipe.

[0017] According to one aspect of the present invention, a method for adjusting the focal size of an X-ray source is provided, comprising adjusting the focal size of an emitted X-ray using a X-ray source device, including: The focal size of the X-rays emitted by the X-ray source device is adjusted by adjusting the included angle θ between the target and the connecting plate. The cross-sectional dimensions of the electron beam emitted by the electron emission source are a×b, where a is the transverse dimension and b is the longitudinal dimension. When the electron beam hits the target, its projection size on the target is a×(b / cosθ), where a is the horizontal dimension and b / cosθ is the vertical dimension. The focal size of the emitted X-rays is a × (b * tanθ).

[0018] The beneficial effects of this invention are as follows: To address the technical problems existing in the prior art, this invention provides an external reflective target, a radiation source device, and a method for adjusting the X-ray focal spot size. By designing an adjustable fit between the mounting groove of the connecting plate and the connecting flange, the installation angle of the external reflective target is adjustable. While ensuring stable output of electron beams and X-rays along the accelerating tube direction, the invention allows for flexible acquisition of X-rays with different focal spot sizes by conveniently changing the installation angle θ of the external reflective target or replacing it with an external reflective target with a different angle θ. This successfully overcomes the inherent limitations of micro-focal beams in accelerating tube design, achieving micro-focal design without the need for quaternary iron, significantly reducing equipment cost and size, and demonstrating outstanding economy and practicality.

[0019] Meanwhile, this design enhances the flexibility of workpiece placement during actual testing, reduces workpiece adjustment time, significantly improves testing efficiency, and lowers overall testing costs. The adjustable fit between the connecting plate and connecting flange, along with the groove structure filled with solder, allows for stable angle adjustment during welding to ensure the required θ angle. The combination of the inlet pipe, annular water tank, cover plate, and outlet pipe forms a ring water circuit structure for the external reflector target, efficiently dissipating heat and extending equipment lifespan. Furthermore, it is not limited by the accelerator tube's application band and can be adapted to all bands of X-ray sources by matching the outer diameter, demonstrating strong versatility and a wide range of applications. Attached Figure Description

[0020] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0021] Figure 1 A schematic diagram of the structure of the external reflective target provided in an embodiment of the present invention is shown.

[0022] Figure 2 This is a front view of the external reflective target provided in an embodiment of the present invention.

[0023] Figure 3 A cross-sectional view of the external reflective target provided in an embodiment of the present invention is shown.

[0024] Figure 4 Show Figure 3 Enlarged view of section I in the middle.

[0025] Figure 5 This diagram illustrates the principle of adjusting the focal size of the external reflective target provided in an embodiment of the present invention.

[0026] Figure 6 This diagram illustrates the X-ray beam output effect when the X-ray output direction coincides with the electron beam incident direction.

[0027] Figure 7 This diagram shows the structure of the X-ray source device when the X-ray output direction coincides with the electron beam incident direction.

[0028] Figure 8 Show Figure 6 The corresponding sectional view.

[0029] Figure 9 A schematic diagram of the internal structure of the target provided in an embodiment of the present invention is shown.

[0030] Figure 10 A schematic diagram of the structure of the radiation source device provided in an embodiment of the present invention is shown.

[0031] Figure 11 This is a front view of the radiation source device provided in an embodiment of the present invention.

[0032] Figure 12 A schematic diagram of the structure of the water flange provided in an embodiment of the present invention is shown. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0034] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or a connection through an intermediate medium or gap; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] In this invention, unless otherwise expressly specified and limited, the first feature "above" or "below" the second feature may include direct contact between the first and second features, or contact between the first and second features not in direct contact but through another feature between them.

[0036] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0037] To address the technical problems existing in the prior art, embodiments of the present invention provide an external reflective target, combined with Figure 1-9 As shown, the reflective target includes a target body 1, a target piece 2, and a connecting assembly.

[0038] Target plate 2 is located on the surface of target 1 facing the electron emission source. Target plate 2 is the core functional component of the reflective target, directly determining the X-ray generation efficiency, wavelength characteristics, output direction, and output stability. It is the key carrier for realizing the energy conversion of the electron beam to X-rays and directional reflection. Target plate 2 is generally made of high atomic number metal materials, such as those containing gold, tungsten, copper, or their alloys.

[0039] The connecting assembly is used to connect the target 1 and the electron emission source. The connecting assembly includes a connecting plate 3 and a connecting flange 4. The connecting plate 3 is fixedly connected to the electron emission source and is set perpendicular to the electron beam incident direction.

[0040] The target 1 is located on the connecting flange 4 and is connected to the connecting plate 3 via the connecting flange 4.

[0041] The connecting plate 3 includes a mounting groove 31, and the connecting flange 4 includes a connecting surface 41 that is adjustablely fitted with the mounting groove 31. The connecting surface 41 is embedded in the mounting groove 31, and the angle θ between the target plate 2 and the connecting plate 3 can be adjusted by rotating the connecting surface 41 within the mounting groove 31, thereby adjusting the size of the X-ray focal spot.

[0042] In a specific embodiment, such as Figure 2-4 As shown, the mounting groove 31 is an arc-shaped groove, and the connecting surface 41 is an arc-shaped surface that corresponds to and mates with the arc-shaped groove. The arc-shaped surface is embedded in the arc-shaped groove, and the connecting flange 4 can rotate relative to the connecting plate 3 around the circle of the arc-shaped groove to adjust the included angle θ between the target piece 2 and the connecting plate 3.

[0043] In a specific embodiment, such as Figure 5 As shown, the target 2 is bombarded by an electron beam and outputs X-rays perpendicular to the incident direction of the electron beam. The angle between the X-ray output direction and the target 2 is equal to the angle θ between the target 2 and the connecting plate 3, where the value of θ is in the range of 0° < θ < 90°.

[0044] In this embodiment, as Figure 5 As shown, the cross-section of the electron beam (e.g.) Figure 5 The cross-section of the electron beam spot (the projection of the electron beam onto the plane perpendicular to the incident direction of the electron beam) is generally elliptical in shape. Here, the cross-sectional dimensions of the electron beam are denoted as a×b, where a is the transverse dimension and b is the longitudinal dimension. When the electron beam hits the target 2, as... Figure 5 The beam spot shape formed on the target surface of target 2 is seen from direction A perpendicular to target 2. The size of this beam spot is a×b / cosθ, where a is the lateral dimension and b / cosθ is the longitudinal dimension. When the electron beam bombards target 2, it is deflected by the target surface and outputs X-rays perpendicular to the incident direction of the electron beam. The focal size of the X-ray is a'×b'=a×(b / cosθ)*sinθ=a×(b*tanθ), where the lateral dimension a' is a and the longitudinal dimension b' is b*tanθ. It can be seen that the longitudinal dimension of the output X-ray focal size changes compared to the incident electron beam beam size due to the presence of the θ angle. The relationship between the longitudinal dimension b' of the X-ray focal size and the longitudinal dimension b of the incident electron beam beam cross-section is b'=b*tanθ, which, according to the law of the tangent function, shows a monotonically increasing trend in the interval between -π / 2 and π / 2.

[0045] In this embodiment, when the angle θ between the target plate 2 and the connecting plate 3 is in the range of 0° < θ < 45°, the focal size of the emitted X-rays is smaller than the cross-sectional size of the incident electron beam. An external reflecting target can be used to obtain a focal point with a smaller cross-sectional size than the incident electron beam, thereby improving the imaging resolution in industrial non-destructive testing. When the angle θ between the target plate 2 and the connecting plate 3 is in the range of 45° < θ < 90°, the focal size of the emitted X-rays is larger than the cross-sectional size of the incident electron beam. An external reflecting target can be used to obtain a focal point with a larger lateral dimension than the incident electron beam, which can be applied in industrial irradiation accelerators to increase the irradiation range of the irradiated object. When the angle θ between the target plate 2 and the connecting plate 3 is 90°, the focal size of the emitted X-rays is equal to the cross-sectional size of the incident electron beam.

[0046] In summary, by changing the connection angle between the connecting flange 4 and the connecting plate 3, the angle θ between the target plate 2 and the connecting plate 3 can be adjusted, thereby regulating the X-ray focal spot size and thus achieving the purpose of adjusting the focal spot size of the accelerating tube. The smaller the value of θ, the smaller the obtained focal spot size, thus compensating for the limitations of the micro-focal beam design in the accelerating tube, achieving micro-focal output at a lower cost and smaller size without the aid of quaternary iron. Simultaneously, the external target provided in this embodiment can also increase the cross-sectional size of the electron beam, improving the efficiency of irradiation treatment of industrial wastewater, medical waste, and food. The specific value of θ can be determined based on the a×b dimension obtained from the accelerating tube beam material design and the desired beam spot size a'×b'. In application, external reflective targets with different θ values ​​can be developed simultaneously, thereby achieving the output of different beam spot sizes in the same accelerating tube during beam exit.

[0047] In another specific example, such as Figure 6-8 As shown, when the included angle θ between the target plate 2 and the connecting plate 3 is 0°, a beam channel 11 coaxially arranged with the target plate 2 is provided on the target body 1. The beam channel 11 is a cylindrical through-hole that penetrates the target body 1 along the axial direction, and its axis coincides with the incident direction of the electron beam. In this embodiment, the target plate 2 is bombarded by the electron beam and outputs X-rays that coincide with the incident direction of the electron beam through the beam channel 11, so that the accelerating tube can realize the function of outputting an X-ray beam along the beam direction of the accelerating tube. The beam channel 11 is set to ensure the output of the X-ray beam.

[0048] In this embodiment, when the X-ray emission direction coincides with the electron beam incident direction, the thickness of the connecting plate 3 is greater than the thickness of the connecting plate when the X-ray emission direction is perpendicular to the electron beam incident direction, so as to avoid interference between the external reflective target and the electron emission source.

[0049] In one specific embodiment, the external reflective target also includes a water inlet pipe 5, a water outlet pipe 6, and a cover plate 7 located on the side of the target body 1 facing away from the target plate 2. When the X-ray emission direction needs to coincide with the electron beam incident direction, a beam channel also needs to be provided on the cover plate 7.

[0050] In this embodiment, as Figure 9 As shown, an annular water groove 12 is formed by a recess on the side of the target body 1 facing away from the target piece 2 along the axial direction. The annular water groove 12 and the target piece 2 are coaxially arranged. The cover plate 7 is placed over the annular water groove 12 to seal the annular water groove 12 and form an annular pipeline.

[0051] The target body 1 also includes an inlet port 13 and an outlet port 14 that are respectively connected to the annular water tank 12. The inlet pipe 5 is connected to the annular water tank 12 through the inlet port 13, and the outlet pipe 6 is connected to the annular water tank 12 through the outlet port 14. The inlet pipe 5, the annular water tank 12, the cover plate 7 and the outlet pipe 6 are combined to form the annular water circuit structure of the external reflector target. Cooling water flows out from the inlet pipe 5 through the annular water tank 12 and out through the outlet pipe 6, which ensures the heat dissipation of the external reflector target and ensures the service life of the external reflector target.

[0052] In one specific embodiment, the diameter of the target 2 can be limited according to the range of the angle θ, so as to ensure that the electron beam flow at the contact position with the reflective target is always within the circumference of the target 2 during the change of the angle θ.

[0053] In a specific embodiment, such as Figure 4 As shown, the mounting groove 31 is an arc-shaped groove with a groove structure 32 formed on its surface. The recessed structure 32 is formed radially along the mounting groove 31 and is filled with solder, so that the mounting groove 31 can be connected and fixed with the connecting surface 4.

[0054] One embodiment of the present invention provides a radiation source device, combined with Figure 10-12 As shown, the radiation source device includes an electron emission source, a water channel flange 8 disposed radially outside the electron emission source, and an external reflective target provided in the above embodiment.

[0055] In this embodiment, the water circuit flange 8 includes a water cooling circulation section 81 and a connecting section 82 located above the water cooling circulation section 81. The connecting plate 3 and the connecting section 82 are fixed together to realize the connection between the external reflective target and the electron emission source.

[0056] Specifically, bolt holes 821 are provided on the connecting part 82, and mounting holes are provided on the connecting plate 3 accordingly. By connecting the bolt holes 821 and the mounting holes with bolts, the connecting plate 3 can be installed and fixed on the water flange 8.

[0057] In one specific embodiment, the electron emission source includes an accelerating tube 91 and a titanium window assembly 92, which are coaxially arranged. Figure 11 Only the two-cavity chain structure of the accelerating tube 91 is shown. As for the electron gun, coupler, and isolation layer, since the X-ray source device provided in this embodiment of the invention does not directly involve the connection relationship with these structural parts, they are not shown.

[0058] In this embodiment, the accelerating tube 91 generates an electron beam, and the titanium window structure 92 protects the vacuum environment of the accelerating tube and outputs electron lines along the beam flow direction of the accelerating tube. The output electron lines bombard the target plate 2 at the external reflective target and cause trajectory deflection.

[0059] In this embodiment, a through hole 811 is provided at the center of the water cooling circulation section 81 of the water flange 8. The water flange 8 is fitted onto the radial outer side of the accelerator tube 91 through the through hole 811. The radius of the through hole 811 is designed to match the outer diameter of the accelerator tube of the corresponding waveband.

[0060] An embodiment of the present invention provides a method for adjusting the focal size of X-rays. The method uses the X-ray source device provided in the above embodiment to adjust the focal size of the emitted X-rays. The method specifically includes: adjusting the focal size of the X-rays emitted by the X-ray source device by adjusting the included angle θ between the target plate 2 and the connecting plate 3.

[0061] In one specific embodiment, the target 2 is bombarded by an electron beam and outputs X-rays perpendicular to the incident direction of the electron beam. The angle between the X-ray output direction and the target 2 is equal to the angle θ between the target 2 and the connecting plate 3, wherein the value of θ is in the range of 0° < θ < 90°.

[0062] In this embodiment, as Figure 5 As shown, the cross-section of the electron beam (e.g.) Figure 5 The cross-section of the electron beam spot (the projection of the electron beam onto the plane perpendicular to the incident direction of the electron beam) is generally elliptical in shape. Here, the cross-sectional dimensions of the electron beam are denoted as a×b, where a is the transverse dimension and b is the longitudinal dimension. When the electron beam hits the target 2, as... Figure 5The beam spot shape formed on the target surface of target 2 is seen from direction A perpendicular to target 2. The size of this beam spot is a×b / cosθ, where a is the lateral dimension and b / cosθ is the longitudinal dimension. When the electron beam bombards target 2, it is deflected by the target surface and outputs X-rays perpendicular to the incident direction of the electron beam. The focal size of the X-ray is a'×b'=a×(b / cosθ)*sinθ=a×(b*tanθ), where the lateral dimension a' is a and the longitudinal dimension b' is b*tanθ. It can be seen that the longitudinal dimension of the output X-ray focal size changes compared to the incident electron beam beam size due to the presence of the θ angle. The relationship between the longitudinal dimension b' of the X-ray focal size and the longitudinal dimension b of the incident electron beam beam cross-section is b'=b*tanθ, which, according to the law of the tangent function, shows a monotonically increasing trend in the interval between -π / 2 and π / 2.

[0063] In this embodiment, when the angle θ between the target plate 2 and the connecting plate 3 is in the range of 0° < θ < 45°, the focal size of the emitted X-rays is smaller than the cross-sectional size of the incident electron beam. An external reflecting target can be used to obtain a focal point with a smaller cross-sectional size than the incident electron beam, thereby improving the imaging resolution in industrial non-destructive testing. When the angle θ between the target plate 2 and the connecting plate 3 is in the range of 45° < θ < 90°, the focal size of the emitted X-rays is larger than the cross-sectional size of the incident electron beam. An external reflecting target can be used to obtain a focal point with a larger lateral dimension than the incident electron beam, which can be applied in industrial irradiation accelerators to increase the irradiation range of the irradiated object. When the angle θ between the target plate 2 and the connecting plate 3 is 90°, the focal size of the emitted X-rays is equal to the cross-sectional size of the incident electron beam.

[0064] In summary, by changing the connection angle between the connecting flange 4 and the connecting plate 3, the angle θ between the target plate 2 and the connecting plate 3 can be adjusted, thereby regulating the X-ray focal spot size and thus achieving the purpose of adjusting the focal spot size of the accelerating tube. The smaller the value of θ, the smaller the obtained focal spot size, thus compensating for the limitations of the micro-focal beam design in the accelerating tube, achieving micro-focal output at a lower cost and smaller size without the aid of quaternary iron. Simultaneously, the external target provided in this embodiment can also increase the cross-sectional size of the electron beam, improving the efficiency of irradiation treatment of industrial wastewater, medical waste, and food. The specific value of θ can be determined based on the a×b dimension obtained from the accelerating tube beam material design and the desired beam spot size a'×b'. In application, external reflective targets with different θ values ​​can be developed simultaneously, thereby achieving the output of different beam spot sizes in the same accelerating tube during beam exit.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. An external reflective target, characterized in that, include: Target; A target sheet located on the surface of the target body facing the electron emission source; as well as A connecting component for connecting the target and the electron emission source; The connecting assembly includes a connecting plate and a connecting flange. The connecting plate is fixedly connected to the electron emission source and is arranged perpendicular to the electron beam incident direction. The target is disposed on the connecting flange and connected to the connecting plate via the connecting flange; The connecting plate includes a mounting groove, and the connecting flange includes a connecting surface that is adjustable to the mounting groove. The connecting surface is embedded in the mounting groove to adjust the included angle θ between the target plate and the connecting plate.

2. The external reflective target according to claim 1, characterized in that, The mounting groove is an arc-shaped groove, and the connecting surface is an arc-shaped surface that corresponds to and matches the arc-shaped groove. The arc-shaped surface is embedded in the arc-shaped groove, and the connecting flange can rotate relative to the connecting plate around the center of the arc-shaped groove to adjust the included angle θ between the target plate and the connecting plate.

3. The external reflective target according to claim 1, characterized in that, The target is bombarded by an electron beam and outputs X-rays perpendicular to the incident direction of the electron beam. The angle between the X-ray output direction and the target is equal to the angle θ between the target and the connecting plate, and the value of θ is in the range of 0° < θ < 90°.

4. The external reflective target according to claim 3, characterized in that, When the included angle θ between the target and the connecting plate is in the range of 0° < θ < 45°, the focal size of the emitted X-rays is smaller than the cross-sectional size of the incident electron beam. When the included angle θ between the target and the connecting plate is 45°, the focal size of the emitted X-rays is equal to the cross-sectional size of the incident electron beam. When the included angle θ between the target and the connecting plate is in the range of 45° < θ < 90°, the focal size of the emitted X-rays is larger than the cross-sectional size of the incident electron beam.

5. The external reflective target according to claim 1, characterized in that, When the included angle θ between the target and the connecting plate is 0°, the target body has a beam channel coaxially arranged with the target. The beam channel is a cylindrical through hole that penetrates the target body along the axial direction, and its axis coincides with the incident direction of the electron beam. The target sheet is bombarded by an electron beam, and X-rays are output through the beam channel that coincide with the incident direction of the electron beam.

6. The external reflective target according to claim 1, characterized in that, The external reflective target also includes an inlet pipe, an outlet pipe, and a cover plate located on the side of the target body away from the target plate. The surface of the target body facing away from the target piece is recessed along the axial direction towards the target piece to form an annular water groove. The annular water groove and the target piece are coaxially arranged, and the cover plate is sealed at the annular water groove. The target includes an inlet port and an outlet port that are respectively connected to an annular water tank. The inlet pipe is connected to the annular water tank through the inlet port, and the outlet pipe is connected to the annular water tank through the outlet port.

7. The external reflective target according to claim 1, characterized in that, The mounting groove has a recessed structure on its surface, and the recessed structure is filled with solder.

8. A radiation source device, characterized in that, include: An electron emission source, a water channel flange fitted radially outside the electron emission source, and an external reflective target as described in any one of claims 1-7; The water circuit flange includes a water cooling circulation section and a connecting section located above the water cooling circulation section, wherein the connecting plate and the connecting section are fixed together.

9. The radiation source device according to claim 8, characterized in that, The electron emission source includes an accelerating tube and a titanium window assembly, which are coaxially arranged. The water passage flange is fitted on the radial outer side of the acceleration pipe.

10. A method for adjusting the focal size of an X-ray source, comprising adjusting the focal size of the emitted X-rays using the X-ray source device as described in claim 8, characterized in that... include: The focal size of the X-rays emitted by the X-ray source device is adjusted by adjusting the included angle θ between the target and the connecting plate. The cross-sectional dimensions of the electron beam emitted by the electron emission source are a×b, where a is the transverse dimension and b is the longitudinal dimension. When the electron beam hits the target, its projection size on the target is a×(b / cosθ), where a is the horizontal dimension and b / cosθ is the vertical dimension. The focal size of the emitted X-rays is a × (b * tanθ).

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