Composite target material and manufacturing method and application thereof

Abstract

The invention discloses a composite target material as well as a manufacturing method and application thereof. The composite target material comprises a substrate and a functional layer, the substrate material is a metal simple substance, and the atomic number Z of the metal simple substance in the periodic table of elements is greater than or equal to 40; the functional layer is made of an elementary substance, and the atomic number Z of the elementary substance in the periodic table of elements is less than 10; the functional layer is coated on one side surface of the substrate, and the thickness of the functional layer is smaller than that of the substrate. According to the composite target material, the characteristic X-ray peak is inhibited through the functional layer, and meanwhile, the tough-induced radiation intensity is improved.

Description

Technical Field

[0001] This invention relates to the field of X-ray generating composite target technology, and more specifically, to a composite target, its manufacturing method, and its application. Background Technology

[0002] When an electron beam interacts with a target, it generates characteristic X-rays and bremsstrahlung. The generation of characteristic X-rays originates from the deep interaction between the electron beam and the atoms of the target. When the energy of the incident electron exceeds the binding energy of the inner-shell electrons, the following process occurs: an inner-shell electron is ejected, forming a hole; an outer-shell electron jumps to fill the hole, releasing characteristic X-ray photons. Traditional targets produce strong characteristic X-ray peaks under high pressure, with the total energy of these peaks exceeding 40% of the incident electron beam energy. However, current XAFS instruments can only utilize continuous X-rays generated by bremsstrahlung, but only 32% of the incident electron beam energy can be converted into useful bremsstrahlung X-rays. Therefore, under rated power conditions, it is necessary to increase the bremsstrahlung intensity of the target. Summary of the Invention

[0003] This invention provides a composite target material, its manufacturing method, and its application, solving the problems of high total energy ratio of characteristic X-ray peaks and low bremsstrahlung intensity in existing target materials.

[0004] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0005] A composite target material includes a substrate and a functional layer; the substrate material is a metallic element with an atomic number Z in the periodic table of elements of ≥40; the functional layer material is an elemental substance with an atomic number Z in the periodic table of elements of ≤10; the functional layer is coated on one side of the substrate, and the thickness of the functional layer is less than the thickness of the substrate.

[0006] As a further improvement, the thickness of the functional layer is 1–10 μm.

[0007] As a further improvement, the substrate thickness is 0.5-3 mm.

[0008] As a further improvement, a bonding layer is formed between the functional layer and the substrate, wherein the atomic number of the bonding layer gradually decreases from the functional layer to the substrate in the periodic table.

[0009] As a further improvement, the substrate material is tungsten or molybdenum.

[0010] As a further improvement, the functional layer is made of carbon or beryllium.

[0011] The present invention also provides a method for manufacturing a composite target, which includes the following steps:

[0012] Pretreatment: The substrate is cleaned.

[0013] Coating: A functional layer is deposited on one surface of the cleaned substrate to form the composite target.

[0014] As a further improvement, an acid solution is used for cleaning in the pretreatment step.

[0015] As a further improvement, the composite target material after coating undergoes post-treatment; the post-treatment is vacuum annealing; during the vacuum annealing, the vacuum degree is 10. -6 ~10 -5 Pa; annealing temperature is 900°~1000°.

[0016] The present invention also provides an application of the composite target material, which is used in an X-ray absorption fine structure spectroscopy instrument.

[0017] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0018] (1) The composite target of the present invention includes a substrate and a functional layer. The functional layer is coated on one side of the substrate and the thickness of the functional layer is smaller than that of the substrate. The functional layer suppresses characteristic X-ray peaks and improves bremsstrahlung intensity, so that the bremsstrahlung intensity exceeds 40% of the incident electron beam energy.

[0019] (2) The composite target of the present invention has a functional layer thickness of 1 to 10 μm, which is less than the electron beam penetration depth, ensuring that electrons can penetrate the functional layer, so that the incident electrons mainly interact with the substrate, and at the same time the functional layer effectively absorbs characteristic X-rays.

[0020] (3) The method for manufacturing the composite target of the present invention forms the desired composite target, suppresses characteristic X-ray peaks through a functional layer, and simultaneously improves bremsstrahlung intensity. The functional properties are formed using magnetron sputtering, and the bonding layer is controlled by vacuum annealing.

[0021] (4) The composite target material of the present invention can be used in X-ray absorption fine structure spectroscopy instruments to utilize bremsstrahlung radiation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the composite target structure;

[0023] Figure 2 Comparison of energy dispersive spectroscopy (EDS) spectra of Mo-C composite target and Mo target;

[0024] Figure 3 This is a simulation diagram of the electron beam path.

[0025] Label Explanation:

[0026] 1. Base; 2. Functional layer. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, this application provides a composite target material, including a substrate 1 and a functional layer 2. The substrate 1 is made of a metallic element with an atomic number Z of ≥40 in the periodic table. The functional layer 2 is made of an element with an atomic number Z of <10 in the periodic table. The functional layer 2 is coated on one side of the substrate 1, and the thickness of the functional layer 2 is smaller than the thickness of the substrate 1.

[0029] The metallic element in substrate 1 has an atomic number Z≥40 in the periodic table, meaning it contains more electrons, which can increase the required X-ray intensity.

[0030] The thickness of functional layer 2 is 1 to 10 μm. For example, the thickness of functional layer 2 can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm.

[0031] The thickness of substrate 1 is 0.5-3mm. For example, the thickness of substrate 1 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, or 3.0mm.

[0032] In order to achieve a strong bond between functional layer 2 and substrate 1, a bonding layer is formed between functional layer 2 and substrate 1. At the bonding layer, atoms of functional layer 2 and substrate 1 interpenetrate each other, causing the atomic number of the bonding layer to gradually decrease from functional layer 2 to substrate 1.

[0033] Preferably, the substrate 1 is made of tungsten (W) or molybdenum (Mo).

[0034] Preferably, the functional layer 2 is carbon (C) or beryllium (Be).

[0035] This application also provides a method for manufacturing a composite target, which includes pretreatment and coating steps. The pretreatment involves cleaning the surface of a substrate 1; the coating involves depositing a functional layer 2 on one surface of the cleaned substrate 1 to form the composite target.

[0036] As a further improvement, an acid solution is used for cleaning in the pretreatment step. This acid solution is a strong acid, such as concentrated sulfuric acid, used to clean the oxide layer on the surface of substrate 1.

[0037] As a further improvement, the composite target material after coating undergoes post-treatment. Specifically, the post-treatment is vacuum annealing, which forms a bonding layer between the functional layer 2 and the substrate 1, thereby improving the bonding strength between the functional layer 2 and the substrate 1. More specifically, during vacuum annealing, the vacuum degree is 10. -5 ~10 -6 Pa; annealing temperature is 900°~1000°.

[0038] To further illustrate this application, specific embodiments are provided below for explanation.

[0039] Example 1

[0040] As one specific implementation, a composite target material is provided, wherein the substrate 1 is a 0.5 mm thick molybdenum substrate; the functional layer 2 is a carbon functional layer with a thickness of 10 μm.

[0041] During the fabrication process, in the pretreatment step, substrate 1 is placed in an acid solution to remove the oxide layer on the surface of the molybdenum substrate, thereby removing oxide layer impurities on the surface of substrate 1 and improving the purity of substrate 1.

[0042] In the coating step, magnetron sputtering is used in this embodiment to deposit a carbon coating onto the surface of a molybdenum substrate to form a carbon functional layer with a thickness of 10 μm.

[0043] Magnetron sputtering is a physical vapor deposition (PVD) technique that uses a magnetic field to confine plasma in a vacuum environment to achieve film deposition. This method increases plasma density and deposition rate through magnetic field confinement, resulting in dense, uniform films with strong adhesion.

[0044] It should be noted that in other embodiments, the functional layer can be plated in other ways, such as electroplating, hot pressing, etc.

[0045] To improve the bonding strength between substrate 1 and functional layer 2, and to make substrate 1 and functional layer 2 form a whole, the composite target material after coating undergoes post-processing. Specifically, the post-processing is vacuum annealing. More specifically, during vacuum annealing, the vacuum degree is 10. -6Pa; annealing temperature is 1000°, and after annealing, it is cooled under natural conditions for 24 hours.

[0046] After annealing, a bonding layer is formed between the substrate 1 and the functional layer 2. At the bonding layer, carbon atoms in the functional layer 2 permeate towards the substrate 1, and molybdenum atoms in the substrate 1 permeate towards the functional layer 2. Preferably, the thickness of the bonding layer reaches 0.1-0.5 μm. Specifically, in this embodiment, the thickness of the bonding layer reaches 0.5 μm.

[0047] The composite target material provided in this embodiment has a substrate 1 and a functional layer 2. Through the design of the composite structure of the functional layer and the substrate, the functional layer 2 achieves the absorption of characteristic X-rays, thereby enhancing the bremsstrahlung intensity and reducing the intensity of characteristic X-rays.

[0048] In this scheme, the thickness of the functional layer 2 is 10 μm, which is less than the electron beam penetration depth, ensuring that electrons can penetrate the functional layer, so that the incident electrons mainly interact with the substrate 1, while the functional layer effectively absorbs characteristic X-rays.

[0049] In contrast to existing single-material targets that struggle to balance characteristic X-ray peak suppression and bremsstrahlung efficiency, this solution uses a combination of materials to suppress characteristic X-ray peaks while simultaneously increasing bremsstrahlung intensity. Furthermore, it optimizes the electron beam penetration depth and energy conversion efficiency of the target, making it suitable for various high-voltage applications. This effectively addresses the problems of low bremsstrahlung efficiency, strong characteristic X-rays, and low energy utilization of the target in existing technologies.

[0050] In the experiment, the electron-target interaction was simulated using Geant4 or MCNP, and X-ray energy dispersive spectroscopy test results were provided. The peak-to-valley ratio, total radiation intensity, and other parameters of the target material of the present invention were compared with those of the traditional target material to demonstrate the absorption efficiency of the composite structure for the characteristic peaks. Specifically, the intensity of the Kα peak of Mo was reduced by 30%, and the bremsstrahlung intensity was increased by 50% (tested at 30 kV).

[0051] like Figure 2 As shown in the figure, comparing the X-ray spectra of Mo-C composite targets and single Mo targets reveals a decrease in characteristic peak intensity and an increase in bremsstrahlung intensity.

[0052] Figure 3 As shown, electron beams are used to blast a Mo-C composite target, demonstrating the energy deposition of electrons in the composite layer and the generation of X-rays.

[0053] Example 2

[0054] As one specific implementation, a composite target material is provided, wherein the substrate 1 is a 0.5 mm thick molybdenum substrate; and the functional layer 2 is a carbon functional layer with a thickness of 5 μm.

[0055] During production, the pretreatment steps are the same as in Example 1.

[0056] In the coating step, magnetron sputtering is also used in this embodiment to deposit a carbon coating onto the surface of a molybdenum substrate to form a carbon functional layer with a thickness of 5 μm.

[0057] To improve the bonding strength between substrate 1 and functional layer 2, and to make substrate 1 and functional layer 2 form a whole, the composite target material after coating undergoes post-processing. Specifically, the post-processing is vacuum annealing. More specifically, during vacuum annealing, the vacuum degree is 10. -6 Pa; annealing temperature is 950°, and after annealing, it is cooled under natural conditions for 24 hours.

[0058] After annealing, a bonding layer is formed between the substrate 1 and the functional layer 2. At the bonding layer, carbon atoms in the functional layer 2 permeate towards the substrate 1, and molybdenum atoms in the substrate 1 permeate towards the functional layer 2. Preferably, the thickness of the bonding layer reaches 0.1-0.5 μm. Specifically, in this embodiment, the thickness of the bonding layer reaches 0.3 μm.

[0059] In this design, the thickness of functional layer 2 is 5 μm. In experiments, the electron-target interaction is simulated using Geant4 or MCNP, and X-ray energy dispersive spectroscopy (EDS) results are provided. The peak-to-valley ratio and total radiation intensity are compared between conventional and the target material of this invention to demonstrate the absorption efficiency of the composite structure for characteristic peaks. Specifically, the measured Kα peak intensity of Mo decreased by 20%, while the bremsstrahlung intensity increased by 30% (tested at 30 kV).

[0060] Example 3

[0061] As one specific implementation, a composite target material is provided, wherein the substrate 1 is a 0.5 mm thick molybdenum substrate; and the functional layer 2 is a carbon functional layer with a thickness of 1 μm.

[0062] During production, the pretreatment steps are the same as in Example 1.

[0063] In the coating step, magnetron sputtering is also used in this embodiment to deposit a carbon coating onto the surface of a molybdenum substrate to form a carbon functional layer with a thickness of 1 μm.

[0064] To improve the bonding strength between substrate 1 and functional layer 2, and to make substrate 1 and functional layer 2 form a whole, the composite target material after coating undergoes post-processing. Specifically, the post-processing is vacuum annealing. More specifically, during vacuum annealing, the vacuum degree is 10. -5 Pa; annealing temperature is 900°, and after annealing, it is cooled under natural conditions for 24 hours.

[0065] After annealing, a bonding layer is formed between the substrate 1 and the functional layer 2. At the bonding layer, carbon atoms in the functional layer 2 permeate towards the substrate 1, and molybdenum atoms in the substrate 1 permeate towards the functional layer 2. Preferably, the thickness of the bonding layer reaches 0.1-0.5 μm. Specifically, in this embodiment, the thickness of the bonding layer reaches 0.1 μm.

[0066] In this design, the thickness of functional layer 2 is 1 μm. In experiments, the electron-target interaction is simulated using Geant4 or MCNP, and X-ray energy dispersive spectroscopy (EDS) results are provided. The peak-to-valley ratio and total radiation intensity are compared between conventional and the target material of this invention to demonstrate the absorption efficiency of the composite structure for characteristic peaks. Specifically, the measured Kα peak intensity of Mo decreased by 5%, while the bremsstrahlung intensity increased by 10% (tested at 30 kV).

[0067] Example 4

[0068] In this embodiment, a composite target material is provided, wherein the substrate 1 is a 0.5 mm thick tungsten substrate; and the functional layer 2 is a carbon functional layer with a thickness of 10 μm.

[0069] During production, the pretreatment steps are the same as in Example 1.

[0070] In the coating step, magnetron sputtering is also used in this embodiment to deposit a carbon coating onto the surface of a tungsten substrate, forming a carbon functional layer with a thickness of 10 μm.

[0071] To improve the bonding strength between substrate 1 and functional layer 2, and to make substrate 1 and functional layer 2 form a whole, the composite target material after coating undergoes post-processing. Specifically, the post-processing is vacuum annealing. More specifically, during vacuum annealing, the vacuum degree is 10. -6 Pa; annealing temperature is 1000°, and after annealing, it is cooled under natural conditions for 24 hours.

[0072] After annealing, a bonding layer is formed between the substrate 1 and the functional layer 2. At the bonding layer, carbon atoms in the functional layer 2 permeate towards the substrate 1, and tungsten atoms in the substrate 1 permeate towards the functional layer 2. Preferably, in this embodiment, the thickness of the bonding layer reaches 0.5 μm.

[0073] Similarly, in the experiment, the electron-target interaction was simulated using Geant4 or MCNP, and X-ray energy dispersive spectroscopy test results were provided. The peak-to-valley ratio, total radiation intensity, and other parameters of the traditional target and the target of this invention were compared to demonstrate the absorption efficiency of the composite structure for the characteristic peaks. Specifically, the intensity of the Kα peak of W was reduced by 80%, and the bremsstrahlung intensity was increased by 60% (tested at 30kV).

[0074] Example 5

[0075] In this embodiment, a composite target material is provided, wherein the substrate 1 is a 0.5 mm thick tungsten substrate; and the functional layer 2 is a carbon functional layer with a thickness of 5 μm.

[0076] During production, the pretreatment steps are the same as in Example 1.

[0077] In the coating step, magnetron sputtering is also used in this embodiment to deposit a carbon coating onto the surface of a tungsten substrate to form a carbon functional layer with a thickness of 5 μm.

[0078] To improve the bonding strength between substrate 1 and functional layer 2, and to make substrate 1 and functional layer 2 form a whole, the composite target material after coating undergoes post-processing. Specifically, the post-processing is vacuum annealing. More specifically, during vacuum annealing, the vacuum degree is 10. -6 Pa; annealing temperature is 950°, and after annealing, it is cooled under natural conditions for 24 hours.

[0079] After annealing, a bonding layer is formed between the substrate 1 and the functional layer 2. At the bonding layer, carbon atoms in the functional layer 2 permeate towards the substrate 1, and tungsten atoms in the substrate 1 permeate towards the functional layer 2. Preferably, in this embodiment, the thickness of the bonding layer reaches 0.3 μm.

[0080] Similarly, in the experiment, the electron-target interaction was simulated using Geant4 or MCNP, and X-ray energy dispersive spectroscopy test results were provided. The peak-to-valley ratio, total radiation intensity, and other parameters of the target material of the present invention were compared with those of the traditional target material to demonstrate the absorption efficiency of the composite structure for the characteristic peaks. Specifically, the Kα peak intensity of W was reduced by 55%, and the bremsstrahlung intensity was increased by 38% (tested at 30kV).

[0081] Example 6

[0082] In this embodiment, a composite target material is provided, wherein the substrate 1 is a 0.5 mm thick tungsten substrate; and the functional layer 2 is a carbon functional layer with a thickness of 1 μm.

[0083] During production, the pretreatment steps are the same as in Example 1.

[0084] In the coating step, magnetron sputtering is also used in this embodiment to deposit a carbon coating onto the surface of a tungsten substrate to form a carbon functional layer with a thickness of 1 μm.

[0085] To improve the bonding strength between substrate 1 and functional layer 2, and to make substrate 1 and functional layer 2 form a whole, the composite target material after coating undergoes post-processing. Specifically, the post-processing is vacuum annealing. More specifically, during vacuum annealing, the vacuum degree is 10. -5 Pa; annealing temperature is 900°, and after annealing, it is cooled under natural conditions for 24 hours.

[0086] After annealing, a bonding layer is formed between the substrate 1 and the functional layer 2. At the bonding layer, carbon atoms in the functional layer 2 permeate towards the substrate 1, and tungsten atoms in the substrate 1 permeate towards the functional layer 2. Preferably, in this embodiment, the thickness of the bonding layer reaches 0.1 μm.

[0087] Similarly, in the experiment, the electron-target interaction was simulated using Geant4 or MCNP, and X-ray energy dispersive spectroscopy test results were provided. The peak-to-valley ratio, total radiation intensity, and other parameters of the target material of the present invention were compared with those of the conventional target material to demonstrate the absorption efficiency of the composite structure for the characteristic peaks. Specifically, the Kα peak intensity of W was reduced by 15%, and the bremsstrahlung intensity was increased by 13% (tested at 30kV).

[0088] Comparative Example

[0089] In this comparative example, the target material is only a molybdenum substrate, and it does not have a functional layer.

[0090] In the experiment, when incident electrons were struck by the target material in this comparative example using Geant4 or MCNP simulation, the inner electrons of molybdenum were ejected to form holes, and the outer electrons transitioned to fill the holes, thereby releasing characteristic X-rays.

[0091] The electron binding energy of the K-shell of Mo is 20 keV. Mo targets produce strong characteristic X-ray peaks under high pressure, such as the Kα1 peak at 17.48 keV and Kα2 at 17.37 keV. The intensity of the Kβ line is approximately 15% of that of Kα. Only less than 1% of the electron energy can be converted into X-rays; most electrons are backscattered by the target or lost as heat within the target. Existing bremsstrahlung XAFS instruments, which are X-ray absorption fine structure spectrometers, produce weak signals when using bremsstrahlung on existing single-structure Mo targets.

[0092] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite target material, characterized in that: It includes a substrate (1) and a functional layer (2); the substrate (1) is made of a metallic element, and the atomic number Z of the metallic element in the periodic table is Z≥40; the functional layer (2) is made of an elemental substance, and the atomic number Z of the elemental substance in the periodic table is Z<10; the functional layer (2) is coated on one side of the substrate (1), and the thickness of the functional layer (2) is smaller than the thickness of the substrate (1).

2. The composite target material according to claim 1, characterized in that: The thickness of the functional layer (2) is 1 to 10 μm.

3. The composite target material according to claim 1, characterized in that: The thickness of the substrate (1) is 0.5-3 mm.

4. The composite target material according to claim 2, characterized in that: A bonding layer is formed between the functional layer (2) and the substrate (1), and the atomic number of the bonding layer gradually decreases from the functional layer (2) to the substrate (1) in the periodic table.

5. The composite target material according to any one of claims 1-4, characterized in that: The substrate (1) is made of tungsten or molybdenum.

6. The composite target material according to any one of claims 1-4, characterized in that: The functional layer (2) is carbon or beryllium.

7. A method for manufacturing a composite target, characterized in that: Used to manufacture the composite target material according to any one of claims 1-6; Includes the following steps, Pretreatment: The substrate (1) is surface cleaned; Coating: A functional layer (2) is deposited on one surface of the cleaned substrate (1) to form the composite target.

8. The method for manufacturing composite target material according to claim 7, characterized in that: An acid solution is used for cleaning in the pretreatment step.

9. The method for manufacturing composite target material according to claim 7, characterized in that: The composite target material after coating undergoes post-treatment; the post-treatment is vacuum annealing; during the vacuum annealing, the vacuum degree is 10. -6 ~10 -5 Pa; annealing temperature is 900°~1000°.

10. An application of a composite target material, characterized in that: The composite target material according to any one of claims 1-6 is applied to an X-ray absorption fine structure spectroscopy instrument.

Images