阅读说明：本技术 一种x射线靶 (X-ray target ) 是由 李艳丽 牛耕 孔祥东 张新月 韩立 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种X射线靶。所述X射线靶包括：X射线毛细管和靶材件；靶材件设置在X射线毛细管的入口端；电子束照射在靶材件上产生X射线,X射线透过靶材件并在X射线毛细管内聚焦,聚焦后的X射线通过X射线毛细管的出口端出射,形成微焦斑X射线。本发明在大束斑电子束的轰击下,可以直接获得微焦斑X射线,结构简单。(The invention discloses an X-ray target. The X-ray target includes: an X-ray capillary tube and a target piece; the target material piece is arranged at the inlet end of the X-ray capillary tube; the electron beam irradiates on the target material piece to generate X rays, the X rays penetrate through the target material piece and are focused in the X ray capillary, and the focused X rays are emitted out through the outlet end of the X ray capillary to form micro focal spot X rays. The invention can directly obtain micro focal spot X-ray under the bombardment of the large beam spot electron beam, and has simple structure.)

1. An X-ray target, comprising:

an X-ray capillary tube and a target piece;

the target material piece is arranged at the inlet end of the X-ray capillary tube;

the electron beam irradiates on the target material piece to generate X rays, the X rays penetrate through the target material piece and are focused in the X ray capillary, and the focused X rays are emitted through the outlet end of the X ray capillary to form micro focal spot X rays.

2. An X-ray target according to claim 1, wherein the target piece is embedded in the inlet end of the X-ray capillary.

3. The X-ray target according to claim 1, wherein the target material piece is fixed to the inlet end of the X-ray capillary by a fixing member.

4. An X-ray target according to claim 1, wherein the X-ray capillary is an X-ray polycapillary; and the outlet end of the X-ray polycapillary emits a plurality of beams of micro focal spot X-rays.

5. An X-ray target according to claim 1, wherein the X-ray capillary is an X-ray monocapillary; a beam current stopper is arranged at the outlet end of the X-ray single capillary; and the size of the beam current stopper is smaller than that of the outlet end of the X-ray single capillary.

6. An X-ray target according to claim 1, wherein the X-ray capillary is an X-ray monocapillary; the thickness of the central portion of the target piece is greater than the thickness of the peripheral portion; x-rays generated by irradiation of the electron beam on the target material piece are transmitted only in a peripheral portion of the target material piece.

7. An X-ray target according to claim 4 or 5, wherein the thickness of the target material piece is 0.5H-0.6H; wherein, H is the penetration depth,u is the acceleration voltage of the incident electron beam, and ρ is the density of the target piece.

8. The X-ray target according to claim 6, wherein the thickness of the intermediate portion of the target material piece is greater than 3H; the thickness of the peripheral portion of the target piece is 0.5H to 0.6H; wherein, H is the penetration depth,u is the acceleration voltage of the incident electron beam, and ρ is the density of the target piece.

9. The X-ray target according to claim 1, wherein the X-ray capillary is a glass capillary with an inner wall coated with a high-density thin film layer or a glass capillary with an inner wall coated with a multilayer film structure; the high-density film layer has a density of more than 8g/cm³A thin film layer of (2).

10. An X-ray target according to claim 1, wherein the material of the target material piece is a metallic material.

Technical Field

The invention relates to the field of X rays, in particular to an X-ray target.

Background

Since 1895, X-rays have been found to be widely used due to their unique properties, such as diffraction of characteristic X-rays, X-ray imaging, X-ray fluorescence, etc., wherein microbeam X-rays are key factors for improving analysis accuracy, imaging resolution, and microbeam monochromatic X-rays are indispensable for X-ray diffraction.

At present, methods for obtaining microbeam X-rays are mainly divided into two types, one is to reduce the beam spot of an incident electron beam as much as possible so as to obtain an emergent X-ray with a small beam spot, the method relates to a complex electron optical system, and comprises an electron gun for emitting the electron beam with the small beam spot, a magnetic lens for focusing the electron beam and the like, and a double condenser lens and the like are usually needed for obtaining the electron beam with the small beam spot; secondly, the X-ray optical element is utilized to focus the divergent X-rays of the large beam spot into micro-focal spot X-rays, the X-ray capillary tube is an important X-ray focusing element, the X-ray source and the X-ray optical element are separated, the X-ray source generates X-rays, the X-rays are focused into the micro-focal spot X-rays under the action of the optical element, and complicated precise mechanical structures and centering operation are involved in the process. Therefore, the current methods for obtaining the microbeam X-ray have complicated optical path structures.

Disclosure of Invention

Based on this, the embodiment of the invention provides an X-ray target to simplify the optical path structure for acquiring micro-beam X-rays.

In order to achieve the purpose, the invention provides the following scheme:

an X-ray target comprising:

an X-ray capillary tube and a target piece;

the target material piece is arranged at the inlet end of the X-ray capillary tube;

the electron beam irradiates on the target material piece to generate X rays, the X rays penetrate through the target material piece and are focused in the X ray capillary, and the focused X rays are emitted through the outlet end of the X ray capillary to form micro focal spot X rays.

Optionally, the target piece is embedded into the inlet end of the X-ray capillary.

Optionally, the target material piece is fixed at the inlet end of the X-ray capillary by a fixing member.

Optionally, the X-ray capillary is an X-ray polycapillary; and the outlet end of the X-ray polycapillary emits a plurality of beams of micro focal spot X-rays.

Optionally, the X-ray capillary is an X-ray monocapillary; a beam current stopper is arranged at the outlet end of the X-ray single capillary; and the size of the beam current stopper is smaller than that of the outlet end of the X-ray single capillary.

Optionally, the X-ray capillary is an X-ray monocapillary; the thickness of the central portion of the target piece is greater than the thickness of the peripheral portion; x-rays generated by irradiation of the electron beam on the target material piece are transmitted only in a peripheral portion of the target material piece.

Optionally, the thickness of the target piece is 0.5H to 0.6H; wherein, H is the penetration depth,u is the acceleration voltage of the incident electron beam, and ρ is the density of the target piece.

Optionally, the thickness of the middle portion of the target piece is greater than 3H; the thickness of the peripheral portion of the target piece is 0.5H to 0.6H; wherein, H is the penetration depth,u is the acceleration voltage of the incident electron beam, and ρ is the density of the target piece.

Optionally, the X-ray capillary is a glass capillary with a high-density thin film layer plated on the inner wall thereof or a glass capillary with a specific multilayer film structure plated on the inner wall thereof.

Optionally, the material of the target piece is a metal material.

Compared with the prior art, the invention has the beneficial effects that:

an embodiment of the present invention provides an X-ray target, including: the X-ray detector comprises an X-ray capillary tube and a target material piece directly arranged at the inlet end of the X-ray capillary tube; the X-ray source (the target material piece) and the X-ray optical element (the X-ray capillary tube) are of an integral structure, other complex structures are not needed between the X-ray source (the target material piece) and the X-ray optical element (the X-ray capillary tube), the X-ray target can directly obtain the micro-focal spot X-ray under the bombardment of a large-beam-spot electron beam, and the structure is simple.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a target-embedded multi-capillary X-ray target according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a target material-attached multi-capillary X-ray target according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a first target-embedded single-capillary X-ray target according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a second target-embedded single-capillary X-ray target according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The existing method for obtaining the micro-beam X-ray has a complicated light path structure, and the design for directly obtaining the micro-focal spot X-ray is not available under the condition of not changing a large-beam-spot electron beam. The invention aims to directly obtain micro focal spot X-rays under the bombardment of a large beam spot electron beam so as to simplify the structure.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The embodiment provides an X-ray target, which comprises: an X-ray capillary tube and a target piece; the target material piece is arranged at the inlet end of the X-ray capillary tube; the electron beam irradiates on the target material piece to generate X rays, the X rays penetrate through the target material piece and are focused in the X ray capillary, and the focused X rays are emitted out through the outlet end of the X ray capillary to form micro focal spot X rays.

In practical application, the type of the X-ray capillary is selected according to the number of the obtained micro-focal spot X-ray beams, the single-beam micro-focal spot X-ray selects the X-ray single capillary, and the multi-beam micro-focal spot X-ray selects the X-ray multi-capillary. According to the energy range requirement of single-beam or multi-beam micro focal spot X-ray, the structural parameters of the capillary are designed, the wide-energy spectrum micro focal spot X-ray can select a glass capillary or a glass capillary with a high-density thin film layer plated on the inner wall, and the monochromatic micro focal spot X-ray can select a glass capillary with a specific multilayer film structure plated on the inner wall.

In one example, as shown in fig. 1, in order to generate a plurality of beams of micro-focal spot X-rays, the X-ray capillary tube employs an X-ray polycapillary tube 1, the X-ray polycapillary tube 1 is composed of a plurality of single capillaries, the polycapillary tubes are generally arranged in a hexagon from inside to outside, and the inner diameter of each capillary tube is generally several to several tens of micrometers; the outlet end of the X-ray polycapillary 1 emits a plurality of micro-focal spot X-rays a. The target material piece 2 is embedded into the inlet end of the X-ray polycapillary tube 1 to form a target material embedded type polycapillary X-ray target, wherein 3 is an electron beam.

In one example, as shown in fig. 2, to generate a plurality of micro-focal spot X-rays, the X-ray capillary employs an X-ray polycapillary 1; the outlet end of the X-ray polycapillary tube 1 emits a plurality of beams of micro-focal spot X-rays. The target material piece 2 is fixed at the inlet end of the X-ray polycapillary 1 by a fixing piece 4 (support structure). For example, the target material piece 2 is bonded to the inlet end face of the X-ray polycapillary tube 1 by the fixture 4, and the fixture 4 may be diamond, aluminum, or the like, to form a target material bonded polycapillary X-ray target.

In one example, in order to generate a single beam of micro-focal spot X-ray, the X-ray capillary adopts an X-ray single capillary, the single capillary is a single capillary with a specific aperture, the inner diameter is generally hundreds of micrometers, and the capillary can be divided into a cone-shaped capillary, a parabolic capillary, an ellipsoidal mirror-shaped capillary and the like according to the inner diameter variation rule; the target material member 2 may be inserted into the inlet end of the X-ray monocapillary tube, or may be fixed to the inlet end of the X-ray monocapillary tube by a fixing member 4 (support structure).

As shown in fig. 3, taking the target-embedded single-capillary X-ray target (the target material 2 is embedded in the inlet end of the X-ray single capillary 5) as an example, the outlet end of the X-ray single capillary 5 is provided with a beam stopper 6 (beamstop); the beam stopper 6 is positioned in the middle of the outlet end of the X-ray single capillary 5, and the size of the beam stopper 6 is smaller than that of the outlet end of the X-ray single capillary 5 so as to block part of focused X-rays and obtain single-beam micro-focal spot X-rays b.

In one example, to generate a single beam of microfocus X-rays, the X-ray capillary is an X-ray monocapillary 5; the thickness of the central portion of the target piece 2 is larger than that of the peripheral portion; the X-rays generated by the irradiation of the electron beam on the target member 2 are transmitted only in the peripheral portion of the target member 2. The target material member 2 may be inserted into the inlet end of the X-ray monocapillary tube 5, or may be fixed to the inlet end of the X-ray monocapillary tube 5 by a fixing member 4 (support structure).

As shown in fig. 4, in the case of the target-embedded single-capillary X-ray target, the thickness of the central portion of the target material 2 is larger than the thickness of the peripheral portion, and X-rays generated by the irradiation of the electron beam on the central portion of the target material 2 do not penetrate into the X-ray single capillary 5, and X-rays generated by the irradiation of the electron beam on the central peripheral portion of the target material 2 penetrate into the X-ray single capillary 5.

In one example, the thickness of the target member 2 is dependent on the acceleration voltage u (kv) of the incident electron beam and the density ρ (g/cm) of the target member 2³) By the formulaThe penetration depth h (nm) of the electron beam in the target member 2 at a specific accelerating voltage is calculated.

In the polycapillary X-ray target shown in fig. 1 and 2, the thickness of the target material 2 is 0.5H to 0.6H.

In one example, for a single capillary type X-ray target as shown in fig. 3, the thickness of the target member 2 is 0.5H to 0.6H.

In the single capillary type X-ray target shown in fig. 4, the thickness of the central portion of the target member 2 is larger than the thickness of the peripheral portion, and the thickness of the central portion of the target member 2 is larger than 3H; the thickness of the peripheral portion of the target member 2 is 0.5H to 0.6H. No X-ray is emitted from the back of the target material at the middle part, and X-rays are emitted from the back of the target material at the peripheral parts and focused by the X-ray single capillary 5 to form a single beam of micro focal spot X-ray.

In one example, since the X-ray capillary is an X-ray element, focusing X-rays by using total reflection of X-rays at the inner surface of the capillary, according to its operation principle, it is also possible to achieve an increase in the energy range of focused X-rays or to obtain monochromatic X-rays by plating a single-layer high-density thin or specific multi-layer film structure on the inner surface of the single capillary.

For example, the X-ray capillary is a glass capillary whose inner wall is coated with a high-density thin film layer having a density 2.2g/cm higher than that of glass³Usually greater than 8g/cm³To obtain wide-spectrum micro-focal spot X-rays. The X-ray capillary tube is arranged into a glass capillary tube with a multi-layer film structure plated on the inner wall, the multi-layer film structure is a specific multi-layer film structure, the specific multi-layer film structure generally consists of films with a period of a double-layer film, the double-layer film comprises a layer of high atomic number film and a layer of low atomic number film, such as Mo/Si and the like, and the total number of layers is usually more than 200 so as to obtain monochromatic micro-focal spot X-rays.

Optionally, the material of the target member 2 is a metal material. Specifically, the material of the target member 2 may be tungsten, molybdenum, lead, copper, or the like. The X-rays are generated by bombarding a metal target piece 2 with a high-energy electron beam.

In the X-ray target of this embodiment, the target member for generating X-rays is disposed at the inlet end of the X-ray capillary, and after the electron beam irradiates the target member, the generated X-rays penetrate the target member and are focused by the X-ray capillary, so as to obtain the micro-focal spot X-rays at the outlet end of the X-ray capillary. The X-ray target has two advantages: firstly, the generated X-ray is directly focused through an X-ray capillary to obtain a micro focal spot X-ray; secondly, by designing and selecting the type of the X-ray capillary, single-beam micro-focal spot X-rays or multiple-beam micro-focal spot X-rays can be directly obtained under the condition of a large-beam-spot electron beam, monochromatic micro-focal spot X-rays can also be directly obtained, the subsequent centering operation of an optical element of the capillary is omitted, and the structure is simple.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.