Micro-focus X-ray tube anode target rod and micro-focus X-ray tube

Abstract

According to the micro-focus X-ray tube anode target rod and the micro-focus X-ray tube, the anode target rod comprises the metal target rod seat, the diamond rod, the metal target rod head and the spring, the axial thermal expansion amount of the target rod can be reduced, the focus drift phenomenon is further reduced, the focus offset correction difficulty of a system algorithm is reduced, and the service life of the system is prolonged. The reconstruction image quality and the spatial resolution can be improved; the springs can relieve the situation that the target rod base and the target rod head pull welding seams at the two ends of the diamond rod during thermal expansion, and structural failure caused by breakage of the welding seams at the two ends of the diamond rod is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of X-ray tube technology, and relates to a microfocus X-ray tube anode target rod and a microfocus X-ray tube. Background Technology

[0002] Micro-CT uses micron and submicron X-ray sources as the core components for achieving high-resolution imaging. Microfocus X-ray tubes have the characteristics of high spatial resolution and high-precision non-destructive testing, and have been widely used in micro-CT systems.

[0003] Typically, the anode target rod of a microfocus X-ray tube is a one-piece oxygen-free copper rod, and its structure is as follows: Figure 1 As shown, when the electron beam bombards the X-ray focal point of the target surface, localized high temperatures are generated. This heat is conducted into the anode target rod. Due to the increased temperature, and based on the thermal expansion properties of the material, the anode target rod will experience a certain axial displacement. Figure 2 As shown, the axial expansion of the anode target rod will change the position of the X-ray focus. Since the trajectory of the electron beam remains unchanged, the image point will shift, which in turn will lead to a decrease in the quality and spatial resolution of the reconstructed image.

[0004] Therefore, how to provide a microfocus X-ray tube anode target rod and a microfocus X-ray tube to improve the quality of reconstructed images and spatial resolution has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a microfocus X-ray tube anode target rod and a microfocus X-ray tube to solve the problem of reduced image quality and spatial resolution caused by anode target rod focus shift in the prior art.

[0006] To achieve the above and other related objectives, this utility model provides a microfocus X-ray tube anode target rod, comprising:

[0007] A target rod holder has a first end face and a second end face that are disposed opposite to each other. A first mounting hole is provided in the target rod holder, and the first mounting hole extends from the second end face of the target rod holder into the interior of the target rod holder.

[0008] A diamond rod includes a first end, a middle part, and a second end that are disposed opposite to each other. The first end of the diamond rod is located in the first mounting hole, and the first end of the diamond rod is fixedly connected to the bottom surface of the first mounting hole.

[0009] The target rod head has a first end face and a second end face that are disposed opposite to each other. A second mounting hole is provided in the target rod head. The second mounting hole extends from the first end face of the target rod head into the interior of the target rod head. The second end face of the target rod head is provided with an anode target surface. The second end of the diamond rod is located in the second mounting hole, and the second end of the diamond rod is fixedly connected to the bottom surface of the second mounting hole.

[0010] A spring is located on the periphery of the middle part of the diamond rod. One end of the spring is fixedly connected to the second end face of the target rod seat, and the other end of the spring is fixedly connected to the first end face of the target rod head. The spring is in a non-stretched state, and the target rod seat is electrically connected to the target rod head through the spring.

[0011] Optionally, in the direction from the target rod holder to the target rod head, the axis of the target rod holder, the axis of the diamond rod, and the axis of the target rod head are on the same straight line.

[0012] Optionally, the second end face of the target rod head is a bevel, and the shortest distance between the second end face of the target rod head and the diamond rod is 3 to 7 mm.

[0013] Optionally, the surface of the target holder is provided with a stepped support surface.

[0014] Optionally, the first end of the diamond rod is welded to the bottom surface of the first mounting hole, and the second end of the diamond rod is welded to the bottom surface of the second mounting hole.

[0015] Optionally, the spring and the second end face of the target rod seat are welded and fixed, and the spring and the first end face of the target rod head are welded and fixed.

[0016] Optionally, the diamond rod is cylindrical, the spring is cylindrical, and the spring is arranged in a ring around the middle part of the diamond rod.

[0017] Optionally, the spring is a wave spring.

[0018] Optionally, the anode target surface is a tungsten layer.

[0019] This utility model also provides a microfocus X-ray tube, which includes the microfocus X-ray tube anode target rod described in any of the above claims.

[0020] As described above, in the microfocus X-ray tube anode target rod and microfocus X-ray tube of this invention, the anode target rod includes a metal target rod seat, a diamond rod, a metal target rod head, and a spring. This reduces the axial thermal expansion of the target rod, thereby reducing focus drift and lowering the difficulty of the system algorithm in correcting focus shift, which helps improve the quality of reconstructed images and spatial resolution. Furthermore, the spring can alleviate the tension on the welds at both ends of the diamond rod when the target rod seat and target rod head are thermally expanded, preventing the welds at both ends of the diamond rod from breaking and causing structural failure. Attached Figure Description

[0021] Figure 1 The diagram shown is of an integrated anode target rod.

[0022] Figure 2 This is a schematic diagram showing the focus shift after the thermal expansion of the anode target.

[0023] Figure 3 The image shown is a cross-sectional view of the anode target rod of the microfocus X-ray tube in an embodiment of this utility model.

[0024] Figure 4 The image shown is a perspective view of the anode target rod of the microfocus X-ray tube in an embodiment of this utility model.

[0025] Component designation explanation

[0026] 1 Target holder

[0027] 100 support surface

[0028] 2 Diamond rod

[0029] 3. Target head

[0030] 300 Anode Target

[0031] 4 springs Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model 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 this utility model.

[0033] Please see Figure 3 and Figure 4It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show the components related to this utility model and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] This invention provides a microfocus X-ray tube anode target rod. Please refer to [link / reference]. Figure 3 and Figure 4 The microfocus X-ray tube anode target rod includes a target rod seat 1, a diamond rod 2, a target rod head 3, and a spring 4. The target rod seat 1 has a first end face and a second end face arranged opposite to each other. A first mounting hole is provided in the target rod seat 1, extending from the second end face of the target rod seat 1 into the interior of the target rod seat 1. The diamond rod 2 includes a first end, a middle part, and a second end face arranged opposite to each other. The first end face of the diamond rod 2 is located in the first mounting hole, and the first end face of the diamond rod 2 is fixedly connected to the bottom surface of the first mounting hole. The target rod head 3 has a first end face and a second end face arranged opposite to each other. A second mounting hole is provided in the target rod head 3, which extends from the first end face of the target rod head 3 into the interior of the target rod head 3. The second end face of the target rod head 3 is provided with an anode target surface 300. The second end of the diamond rod 2 is located in the second mounting hole, and the second end of the diamond rod 2 is fixedly connected to the bottom surface of the second mounting hole. The spring 4 is located on the periphery of the middle part of the diamond rod 2. One end of the spring 4 is fixedly connected to the second end face of the target rod seat 1, and the other end of the spring 4 is fixedly connected to the first end face of the target rod head 3. The target rod seat 1 is electrically connected to the target rod head 3 through the spring 4.

[0035] As an example, the target rod holder 1 has a cylindrical body, and a stepped support surface 100 is provided on the surface of the target rod holder 1. The support surface 100 is distributed on the periphery of the target rod holder 1. The stepped support surface 100 is used to weld and fix the anode target rod and the anode mounting seat of the X-ray tube, and improves the structural stability of the anode target rod.

[0036] As an example, the body of the target head 3 is cylindrical, and the second end face of the target head 3 is a slope, that is, the angle between the second end face of the target head 3 and the axis of the target head 3 is not 90°.

[0037] As an example, the diamond rod 2 is cylindrical, and the axis of the target rod seat 1, the axis of the diamond rod 2, and the axis of the target rod head 3 are on the same straight line in the direction from the target rod seat 1 to the target rod head 3, so that heat can be evenly conducted along the anode target rod and vibration and stress concentration can be reduced, thus extending the service life of the X-ray tube.

[0038] As an example, the spring 4 is cylindrical and is arranged around the middle part of the diamond rod 2.

[0039] As an example, the target rod holder 1 and the target rod head 3 are made of metal. In this embodiment, the target rod holder 1 and the target rod head 3 are made of oxygen-free copper; the spring 4 is made of oxygen-free copper.

[0040] As an example, the first end of the diamond rod 2 is welded and fixed to the bottom surface of the first mounting hole, and the second end of the diamond rod 2 is welded and fixed to the bottom surface of the second mounting hole; the spring 4 is welded and fixed to the second end surface of the target rod seat 1, and the spring 4 is welded and fixed to the first end surface of the target rod head 3.

[0041] As an example, the shortest distance L between the second end face of the target rod head 3 and the diamond rod 2 is 3-7 mm. When the electron beam bombards the anode target surface 300, heat will be transferred inward through the target rod head 3 to the diamond rod 2 and then to the target rod seat 1. Since the thermal expansion coefficients of the target rod seat 1 and the target rod head 3 are greater than those of the diamond rod 2, the target rod seat 1 and the target rod head 3 will pull on the welds at both ends of the diamond rod 2. By setting the spring 4, the pulling on the welds at both ends of the diamond rod 2 when the target rod seat 1 and the target rod head 3 are thermally expanded is relieved, thus avoiding the welds at both ends of the diamond rod 2 from breaking and causing structural failure.

[0042] As an example, the free length of the spring 4 is L0. After the spring 4 is welded and fixed to the target rod seat 1 and the target rod head 3 respectively, the length of the spring 4 is L1. The ratio between L0 and L1 is in the range of 0.7 to 1.3, and can be selected according to the requirements.

[0043] As an example, in this embodiment, the spring 4 is a wave spring, which, compared to a traditional helical spring, can provide precise elastic force and uniform load distribution.

[0044] As an example, the length of the diamond rod 2 is 25-75 mm, and the length of the diamond rod 2 assembled in the target rod holder 1 is 15-35 mm. In the area where the diamond rod 2 is assembled in the target rod holder 1, the outer diameter Φ0 of the target rod holder 1 and the original anode target rod ( Figure 1The outer diameters of the corresponding positions of the integrated anode target rod shown are the same. The diamond rod Φ1 is (0.1~0.7)×Φ0, the outer diameter of the spring 4 is Φ0, and the inner diameter of the spring 4 is greater than Φ1.

[0045] As an example, the anode target surface 300 is a tungsten surface, and high-melting-point tungsten is welded to the side of the target rod head 3 away from the diamond rod 2. The area where the tungsten is welded is the anode target surface 300, that is, the electron beam bombards the tungsten to generate X-rays; the target rod head 3 is electrically connected to the target rod seat 1 through the spring 4, and the remaining electrons are guided away through the anode target rod.

[0046] As an example, with Figure 1 The integrated oxygen-free copper anode target shown is a comparative example. Its highest temperature under stable conditions is 286°C, and the axial expansion length at the focal point is 217.3 μm. In this embodiment, the anode target includes a metal target holder, a diamond rod, a metal target head, and a spring. Its highest temperature under stable conditions is 233°C, and the axial expansion length at the focal point is 36.9 μm, with the axial thermal expansion reduced by 83%.

[0047] As an example, during imaging, by marking the focus and eliminating the focus drift caused by thermal deformation of the X-ray source or micro-CT system in the imaging algorithm, the micro-focus X-ray tube anode target rod of this invention can reduce the axial thermal expansion of the target rod, thereby reducing the focus drift phenomenon, reducing the difficulty of the system algorithm to correct the focus offset, and helping to improve the quality and spatial resolution of the reconstructed image.

[0048] This embodiment also provides a microfocus X-ray tube, which includes the microfocus X-ray tube anode target rod described above.

[0049] In summary, the anode target rod of the microfocus X-ray tube of this invention, comprising a metal target rod base, a diamond rod, a metal target rod head, and a spring, reduces the axial thermal expansion of the target rod, thereby reducing focus drift and simplifying the system algorithm's correction of focus shift, thus improving the quality and spatial resolution of the reconstructed image. Furthermore, the spring alleviates the strain on the welds at both ends of the diamond rod caused by thermal expansion of the target rod base and head, preventing weld breakage and structural failure. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and possesses high industrial applicability.

[0050] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A microfocus X-ray tube anode target rod, characterized in that, include: A target rod holder has a first end face and a second end face that are disposed opposite to each other. A first mounting hole is provided in the target rod holder, and the first mounting hole extends from the second end face of the target rod holder into the interior of the target rod holder. A diamond rod includes a first end, a middle part, and a second end that are disposed opposite to each other. The first end of the diamond rod is located in the first mounting hole, and the first end of the diamond rod is fixedly connected to the bottom surface of the first mounting hole. The target rod head has a first end face and a second end face that are disposed opposite to each other. A second mounting hole is provided in the target rod head. The second mounting hole extends from the first end face of the target rod head into the interior of the target rod head. The second end face of the target rod head is provided with an anode target surface. The second end of the diamond rod is located in the second mounting hole, and the second end of the diamond rod is fixedly connected to the bottom surface of the second mounting hole. A spring is located on the periphery of the middle part of the diamond rod. One end of the spring is fixedly connected to the second end face of the target rod seat, and the other end of the spring is fixedly connected to the first end face of the target rod head. The target rod seat is electrically connected to the target rod head through the spring.

2. The microfocus X-ray tube anode target rod according to claim 1, characterized in that: In the direction from the target rod holder to the target rod head, the axis of the target rod holder, the axis of the diamond rod, and the axis of the target rod head are on the same straight line.

3. The microfocus X-ray tube anode target rod according to claim 2, characterized in that: The second end face of the target rod head is a bevel, and the shortest distance between the second end face of the target rod head and the diamond rod is 3~7mm.

4. The microfocus X-ray tube anode target rod according to claim 1, characterized in that: The surface of the target holder is provided with a stepped support surface.

5. The microfocus X-ray tube anode target rod according to claim 1, characterized in that: The first end of the diamond rod is welded and fixed to the bottom surface of the first mounting hole, and the second end of the diamond rod is welded and fixed to the bottom surface of the second mounting hole.

6. The microfocus X-ray tube anode target rod according to claim 1, characterized in that: The spring and the second end face of the target rod seat are welded and fixed, and the spring and the first end face of the target rod head are welded and fixed.

7. The microfocus X-ray tube anode target rod according to claim 1, characterized in that: The diamond rod is cylindrical, the spring is cylindrical, and the spring is arranged in a ring around the middle part of the diamond rod.

8. The microfocus X-ray tube anode target rod according to claim 7, characterized in that: The spring is a wave spring.

9. The microfocus X-ray tube anode target rod according to claim 1, characterized in that: The anode target surface is a tungsten layer.

10. A microfocus X-ray tube, characterized in that: The microfocus X-ray tube includes the microfocus X-ray tube anode target rod according to any one of claims 1-9.

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