WO2021184573A1

WO2021184573A1 - X-ray anode target having composite structure

Info

Publication number: WO2021184573A1
Application number: PCT/CN2020/098685
Authority: WO
Inventors: 宗方轲; 郭金川; 杨君
Original assignee: 深圳大学
Priority date: 2020-03-18
Filing date: 2020-06-29
Publication date: 2021-09-23
Also published as: CN111243923A

Abstract

Disclosed in embodiments of the present application is an X-ray anode target having a composite structure. The X-ray anode target having the composite structure comprises an anode target body and a covering layer; the anode target body is an integrally-formed cylinder and comprises a top face, a side face, and a bottom face; the top face comprises a plurality of radiating faces and a plurality of connecting faces; the plurality of radiating faces and the plurality of connecting faces are arranged at intervals, and each connecting face provided between every two adjacent radiating faces connects the plurality of radiating faces sequentially; the covering layer comprises at least one of the following: the covering layer is provided on the plurality of connecting faces and is configured to absorb high-energy electrons; the covering layer is provided on the plurality of radiating faces and is configured to interact with the high-energy electrons to form X-rays.

Description

X-ray anode target with composite structure

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office with an application number of 202010190037.0 on March 18, 2020, and the entire content of the application is incorporated into this application by reference.

Technical field

This application relates to X-ray technology, for example, to an X-ray anode target with a composite structure.

Background technique

X-ray grating imaging technology can simultaneously obtain X-ray absorption images, scatter images, and phase contrast images of the target object, and has very important applications in the fields of medicine, life sciences, materials science, and industrial non-destructive detection. An X-ray source with a periodic structure anode can generate X-rays with a periodic structure. This kind of light source plays an important role in X-ray grating imaging systems such as X-ray grating interference imaging and X-ray grating non-interference imaging.

A reflective X-ray tube is usually used as the X-ray source of the X-ray imaging system. The anode target with periodic microstructure is the core of the X-ray source. The surface of the anode target is made with periodic microstructure by mechanical precision machining. Under the bombardment of high-energy electrons, the X-rays generated on the surface of the anode target are radiated, and the X-rays generated at the bottom of the groove are absorbed by the anode target and cannot be radiated. Therefore, the radiated X-rays are periodic Array structure.

However, only part of the high-energy electrons bombarded the surface of the anode target to radiate X-rays, while a large part of the remaining high-energy electrons bombarded the bottom of the anode target groove. This part of the high-energy electrons did not generate effective X-rays. This results in the low light extraction efficiency of the X-ray source and high energy consumption, which is unfavorable to the heat dissipation of the X-ray source, and it is not easy to increase the light output power. In addition, because the X-ray light generated by the X-ray source with this structure is distributed in the optical axis direction, that is, the X-ray generated by each line emitter on the anode target surface and the adjacent line emitter has one X-ray in the propagation direction. The optical path difference, so that the X-rays emitted by each line emitter in the array X-ray source have different optical path distances to the flat panel detection surface, which is not conducive to the extraction of imaging information by the flat panel detector, and also limits the X-ray imaging system The field of view range.

Summary of the invention

The embodiments of the present application provide an X-ray anode target with a composite structure, so as to realize that a common X-ray source can radiate X-rays with high flux, large field of view, and high-quality microstructures.

The embodiment of the present invention provides an X-ray anode target with a composite structure. The X-ray anode target with a composite structure includes an anode target body and a covering layer, wherein the anode target body is an integrally formed cylinder, and the anode The target body includes a top surface, a side surface, and a bottom surface. The top surface includes a plurality of radiating surfaces and a plurality of connecting surfaces. The connecting surface sequentially connects the multiple radiation surfaces; the covering layer includes at least one of the following: the covering layer is arranged on the multiple connecting surfaces and is arranged to absorb high-energy electrons, and the covering layer is arranged on the A plurality of radiation surfaces are arranged to interact with the high-energy electrons to form X-rays.

Description of the drawings

FIG. 1 is a schematic structural diagram of an X-ray anode target with a composite structure provided in Example 1 of the present application;

2 is a schematic top view of the X-ray anode target with a composite structure provided in Example 1 of the present application;

3 is a schematic structural diagram of an X-ray anode target with a composite structure provided in Example 1 of the present application;

4 is a schematic structural diagram of an X-ray anode target with a composite structure provided in Example 1 of the present application.

Detailed ways

The application will be described below with reference to the drawings and embodiments. The drawings only show a part of the structure related to the present application, but not all of the structure.

In addition, the terms "first", "second", etc. may be used herein to describe various directions, actions, steps or elements, etc., but these directions, actions, steps or elements are not limited by these terms. These terms are only used to distinguish a first direction, action, step or element from another direction, action, step or element. For example, the first included angle may be referred to as the second included angle, and similarly, the second included angle may be referred to as the first included angle. Both the first included angle and the second included angle are included angles, but not the same included angle. The terms "first", "second", etc. cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with “first” and “second” may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, "a plurality of" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Example one

As shown in FIG. 1, Embodiment 1 of the present application provides an X-ray anode target 200 with a composite structure. The X-ray anode target 200 includes an anode target body 100 and a cover layer 500.

The anode target body 100 is an integrally formed cylinder. The anode target body 100 includes a top surface 110, a side surface 120, and a bottom surface 130. The top surface 110 includes a plurality of radiating surfaces 111 and a plurality of connecting surfaces 112. The plurality of radiating surfaces 111 and the plurality of connecting surfaces are arranged at intervals, and the connecting surfaces 112 arranged between adjacent radiating surfaces connect the plurality of radiating surfaces 111 in sequence; the covering layer 500 includes at least one of the following: The covering layer is disposed on the plurality of connecting surfaces 112 and configured to absorb high-energy electrons 410, and the covering layer 500 is disposed on the plurality of radiation surfaces 111 and configured to interact with the high-energy electrons 410 to form X For example, the covering layer 500 in FIG. 1 is arranged on the connection surfaces 112 to absorb high-energy electrons 410, even if the high-energy electrons 410 interacting with the radiation surface 111 radiate to the connection surface 112, the connection surface 112 The above material cannot interact with the high-energy electrons 410 to form X-rays, so there is no connection surface 112 that will generate X-rays, thereby affecting the contrast of the radiated microstructure X-rays.

In the embodiments of the present invention, an anode target body and a covering layer are arranged in an X-ray anode target of a composite structure, wherein the anode target body includes a top surface, a side surface and a bottom surface, and the top surface includes a plurality of radiation surfaces and a plurality of connecting surfaces, The multiple radiating surfaces are arranged at intervals, the multiple connecting surfaces connect the radiating surfaces in turn end to end, and the covering layer is arranged on the multiple connecting surfaces for absorbing high-energy electrons and/or the covering layer is arranged The multiple radiation surfaces are used to interact with the high-energy electrons to form X-rays, which solves the problems of low light extraction efficiency and low contrast of the X-ray source, which is not conducive to the extraction of imaging information by the flat panel detector. It realizes the effect that the ordinary X-ray source can radiate X-rays with high flux, large field of view and high-quality microstructures.

In this embodiment, the X-ray anode target 200 can be used in an X-ray source. The X-ray source also includes an electron source 400 for emitting high-energy electrons 410, and the X-ray anode target 200 is used for receiving high-energy electrons 410. The bombardment emits X-rays. As shown in FIG. 2, viewed from the incident direction of the high-energy electrons 410 emitted by the electron source 400, the multiple radiation surfaces 111 of the X-ray anode target 200 form a continuous whole.

Optionally, the first included angle α between the radiation surface 111 and the side surface 120 is between 20 degrees and 70 degrees. The second included angle β between the connecting surface 112 and the bottom surface 130 is greater than 90 degrees. The anode target body 100 is set at a preset position such that the third included angle θ between the incident direction of the high-energy electrons 410 and the bottom surface 130 is less than or equal to the second included angle β.

In an embodiment, the X-rays obtained by the interaction between the high-energy electrons 410 and the X-ray anode target 200 are microstructured X-rays, which may be linear array X-rays with periodic structures, and the X-ray source further includes an X-ray exit window 300 , The linear array X-rays with a periodic structure will be emitted from the X-ray exit window 300. It can be clearly seen from the X-ray exit window 300 that the projection length of each radiation surface 111 along the side surface 120 is the first length S , That is, the length of the X-ray emitted in the X-ray exit window 300 in a period, the projection length of each connecting surface along the side surface is the second length, and the first length S plus the length of each connecting surface 112 along the The second length of the side surface 120 is P, that is, the length of one period, wherein the length of the connecting surface 112 along the side surface 120 is free of X-rays, and the available duty ratio is S/P. According to different requirements, at least one of the first length S or the second length can be adjusted when manufacturing the X-ray anode target 200 to adjust the duty ratio and period of the radiated microstructure X-rays. Optionally, the length of the first length S ranges from 5 to 100 microns. The length range of the second length P is between 10-200 microns.

In an embodiment, as shown in FIG. 3, when the covering layer 500 is disposed on the plurality of connecting surfaces 112, the material of the anode target body 100 is capable of interacting with the high-energy electrons to form X-rays. The target material 520 and the covering layer 500 is a non-target material 510 that can absorb the high-energy electrons; as shown in FIG. 4, when the covering layer 500 is disposed on the plurality of radiation surfaces 111, the anode target The material of the body 100 is the non-target material 510 and the covering layer 500 is the target material 520.

In this embodiment, the target material 520 and the non-target material 510 should be made of good high-temperature-resistant conductors, so that the high-energy electrons 410 after interacting with the X-ray anode target 200 can be conducted away in time, and the X-ray anode target 200 is reduced. The risk of burnout increases the service life. In one embodiment, the target material 520 can be a metal material with a high atomic number to generate X-rays under the bombardment of high-energy electrons 410, and the non-target material 510 can be a metal material or a non-metallic material with a low atomic number to absorb the The high-energy electron 410 does not generate X-rays. Optionally, the target material 520 includes tungsten or molybdenum, and the non-target material 510 includes graphite, diamond or beryllium. The covering layer 500 is coated on the plurality of radiation surfaces 111 and/or the connection surfaces 112 by using magnetron sputtering and high temperature sintering fusion method. Magnetron sputtering (magnetron sputtering) is based on sputtering, using the mutual electromagnetic interaction between the electric field and the magnetic field of the target material itself, and adding a magnetic field near the target, so that the secondary electrons ionize more argon ions. Increase sputtering efficiency. High-temperature sintering and fusion means that at a high temperature not higher than the melting point, there is mutual attraction between molecules or atoms in the solid state. By heating, the particles can obtain enough energy to migrate, so that the powder body can form particle adhesion, generate strength and lead to densification and re-densification. crystallization.

In an alternative embodiment, any material can be selected for the anode target body 100, and the covering layer 500 is arranged on the plurality of connecting surfaces 112 for absorbing high-energy electrons 410, and the covering layer 500 is arranged on the plurality of connecting surfaces 112. The two radiating surfaces 111 are used to interact with the high-energy electrons 410 to form X-rays.

Claims

An X-ray anode target with a composite structure, comprising: an anode target body and a covering layer, wherein:

The anode target body is an integrally formed cylinder. The anode target body includes a top surface, a side surface and a bottom surface. The top surface includes a plurality of radiation surfaces and a plurality of connecting surfaces. Connecting surfaces are arranged at intervals, and connecting surfaces arranged between adjacent radiating surfaces connect the multiple radiating surfaces in sequence;

The covering layer includes at least one of the following: the covering layer is arranged on the plurality of connecting surfaces and arranged to absorb high-energy electrons, and the covering layer is arranged on the plurality of radiation surfaces and arranged to be in contact with the high-energy electrons. Electrons interact to form X-rays.
The X-ray anode target according to claim 1, wherein:

In the case that the covering layer is provided on the plurality of connecting surfaces, the material of the anode target body is a target material that can interact with the high-energy electrons to form X-rays, and the covering layer is an absorbable material. The non-target materials of high-energy electrons;

In the case where the covering layer is provided on the plurality of radiation surfaces, the material of the anode target body is the non-target material and the covering layer is the target material.
The X-ray anode target according to claim 2, wherein the target material includes tungsten or molybdenum, and the non-target material includes graphite, diamond or beryllium.
The X-ray anode target according to claim 1, wherein the covering layer is coated on at least one of the following by using magnetron sputtering and high-temperature sintering fusion method: the plurality of radiation surfaces, the plurality of connection Surface.
The X-ray anode target according to claim 1, wherein the first included angle between the plurality of radiation surfaces and the side surface is between 20 degrees and 70 degrees.
The X-ray anode target according to claim 1, wherein the second included angle between the plurality of connecting surfaces and the bottom surface is greater than 90 degrees.
The X-ray anode target according to claim 6, wherein the anode target body is set at a preset position so that the third angle between the incident direction of the high-energy electrons and the bottom surface is less than or equal to the second angle Horn.
The X-ray anode target according to claim 1, wherein the X-rays are microstructure X-rays, the projection length of each radiating surface along the side surface is the first length, and the projection of each connecting surface along the side surface The length is the second length, and the duty ratio and period of the microstructure X-ray are adjusted by adjusting at least one of the first length or the second length.
8. The X-ray anode target according to claim 8, wherein the length of the first length ranges from 5 microns to 100 microns.
The X-ray anode target according to claim 8, wherein the length of the second length ranges from 10 microns to 200 microns.