Plume sputtering prevention device and ion flux measurement device for electric propulsion test

Abstract

The application discloses a plume anti-sputtering device and an ion flux measuring device for electric propulsion test, and relates to the technical field of aerospace propulsion. The plume anti-sputtering device comprises a deceleration assembly, a vacuum wall anti-sputtering assembly and an ion and sputtering material recycling assembly. The anti-sputtering target can effectively reduce the pollution of sputtering materials generated by the electric propulsion device during the test to the test environment and equipment. The application improves the safety of the plume of the electric propulsion test, reduces the sputtering risk of the internal equipment and protects the vacuum system, and is suitable for electric propulsion tests of various types.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aerospace propulsion technology, in particular to a plume anti-sputtering device and ion flux measuring device for electric propulsion test. BACKGROUND

[0002] In the field of aerospace, electric propulsion technology has higher efficiency and more precise advantages in satellite operation and attitude control. With the electric propulsion system, the satellite can greatly save propellant, thereby laying the foundation for the realization of deep space exploration. Therefore, electric propulsion technology has been widely used in most propulsion tasks of LEO satellites, GEO satellites and deep space spacecraft.

[0003] During the test process of electric propulsion products, high-energy ions (such as xenon ions, krypton ions and other inert gas ions) are generated, which form a plume and are ejected at high speed. These high-energy ion plumes cause sputtering erosion to the vacuum container and other equipment inside it, resulting in peeling of the surface material of the equipment, performance degradation or even damage, thereby increasing the test cost and risk. At present, most beam blocking targets are made of expensive high-purity graphite and other materials, which not only have complex structures, but also have high manufacturing costs. In addition, part of the high-energy ions will still impact other equipment (including electric thrusters, cryogenic pumps, etc.) after being reflected by the sputtering target, affecting the working condition of the equipment and the test effect.

[0004] In addition, during some electric propulsion test processes, it is necessary to measure the ion flux. Since the existing beam splitting and blocking targets are expensive and have complex structures, the ion flux measurement is also troublesome, and the operation is not convenient and the cost is high. SUMMARY

[0005] The purpose of the present application is to provide a plume active anti-sputtering device and ion flux measuring device for electric propulsion test, which achieves the purpose of providing an electric propulsion test plume protection target with compact structure and significant protection effect.

[0006] To achieve the above object, the present application provides a plume anti-sputtering device for electric propulsion test, comprising a vacuum chamber, one end of the vacuum chamber is provided with a thruster, the other end is provided with a sputtering target, a vacuum chamber wall anti-sputtering assembly, a particle deceleration assembly and an ion and sputtering recovery assembly are arranged between the thruster and the sputtering target, wherein the vacuum chamber wall anti-sputtering assembly comprises a toroidal coil, which is located on the tank wall of the vacuum chamber or outside the electric propulsion plume; the particle deceleration assembly comprises a screen grid and a deceleration grid, wherein the screen grid is arranged on the side close to the thruster, and the deceleration grid is arranged on the side close to the ion and sputtering recovery assembly; a circular through hole is formed in the middle of the screen grid, the thruster is embedded in the through hole or is located on the center line of the through hole, a plurality of small holes for particles to pass through are formed in the remaining part of the screen grid, and a plurality of small holes for particles to pass through are also formed on the surface of the deceleration grid; the ion and sputtering recovery assembly comprises a particle guiding target, which is arranged between the deceleration grid and the sputtering target, a plurality of particle guiding channels are uniformly embedded in the particle guiding target, the particle guiding channels are arranged obliquely, are directed to the center of the sputtering target, and the caliber of the side of the particle guiding channels close to the sputtering target is smaller than that of the side away from the sputtering target; a receiving groove is arranged at the bottom of the sputtering target.

[0007] Optionally, the toroidal coil is connected with alternating current, and the plume is bound by a magnetic field.

[0008] Optionally, the angle between the particle guiding channel and the central axis of the particle guiding target is 10°-50°.

[0009] Optionally, a circulating water pipe is arranged on the side of the particle guiding target close to the sputtering target, the circulating water pipe is arranged between two adjacent particle guiding channels, and the circulating water pipe is connected with a circulating water tank.

[0010] Optionally, a circulating water pipe is arranged on the side of the sputtering target away from the particle guiding target, and the circulating water pipe is connected with a circulating water tank.

[0011] Optionally, the density of the through holes in the center of the screen grid and the deceleration grid is high, and the density of the through holes at the edge is low.

[0012] Optionally, the screen grid and the deceleration grid are one or more of a convex grid, a concave grid and a plane grid.

[0013] In another aspect, the present application also provides an ion flux measuring device, ions are emitted by the plume anti-sputtering device according to any one of the technical solutions described above, and the ion flux is measured by using a retarding energy analyzer.

[0014] The application has the following technical effects: the application generates a uniform magnetic field in the axial direction of the vacuum chamber through the annular coil, ions in the electric propulsion plume particles move linearly or spirally along the magnetic field to the deceleration grid, and electrons move reversely to the screen grid or the vacuum chamber wall. The ions cannot move to the vacuum chamber wall under the constraint of the magnetic field, thereby avoiding sputtering etching of the vacuum chamber wall. In addition, when the ions move to the deceleration grid, the ion energy has been reduced under the joint action of the particle guiding target and the deceleration grid, and the ions move along the particle guiding channel and finally collide with the sputtering target. Since the particle guiding channel has unidirectionality, sputtering generated by the sputtering target cannot enter the vacuum chamber, and finally is adsorbed on the outer surface of the particle guiding channel or falls back to the storage groove. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0016] Figure 1 The present application is a structural schematic diagram.

[0017] 1, thruster; 2, vacuum chamber; 3, annular coil; 4, screen grid; 5, deceleration grid; 6, particle guiding target; 7, circulating water pipe; 8, particle guiding channel; 9, sputtering target; 10, storage groove. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0019] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0020] REFERENCE Figure 1 The present embodiment discloses a plume active anti-sputtering target for electric propulsion test, which comprises a vacuum chamber 2. One end of the vacuum chamber 2 is provided with a thruster 1, and the other end is provided with a sputtering target 9. A vacuum chamber wall anti-sputtering assembly, a particle deceleration assembly and an ion and sputtering recovery assembly are arranged between the thruster 1 and the sputtering target 9.

[0021] Specifically, the vacuum wall sputtering prevention assembly comprises an annular coil 3, which is used to apply current to generate a uniform magnetic field in the vacuum chamber 2. The density of the coil can also be adjusted to generate a "magnetic neck" effect in the plume area of the thruster to focus the plume.

[0022] In the embodiment, the particle deceleration assembly comprises a screen grid 4 installed near the thruster 1 and a deceleration grid 5 installed at the end of the plume of the thruster 1.

[0023] In the embodiment, the screen grid 4 is hollow, and the rest of the screen grid 4 is designed with small holes, in which the thruster 1 is embedded or placed at the center line of the holes of the screen grid 4. The surface of the deceleration grid 5 is designed with small holes, and the particle guiding target 6 is embedded with a particle guiding channel 8, which is an irregular conical structure.

[0024] In the embodiment, the screen grid 4, the deceleration grid 5, and the particle guiding target 6 are arranged in sequence, and are all installed in insulation with the vacuum chamber wall. The deceleration grid 5 can be provided with several layers according to the situation.

[0025] In the embodiment, the screen grid 4 and the deceleration grid 5 are both provided with one.

[0026] The screen grid 4 and the deceleration grid 5 are provided with through holes on the surface, and the number and arrangement of the through holes are different according to different transmittance designs. The distribution design of the through holes is not limited to uniform arrangement. The screen grid 4 and the deceleration grid 5 can be designed as convex grids, concave grids, or flat grids.

[0027] The center holes of the screen grid 4 and the deceleration grid 5 have high density, and the edge holes have low density.

[0028] The screen grid 4 and the deceleration grid 5 are generally made of corrosion-resistant refractory metals, and the typical material is molybdenum. They can also be designed as stainless steel, carbon fiber, tantalum, and other metals according to the service life and cost.

[0029] Specifically, the ion and sputtering product recovery assembly is composed of a circulating water pipe 7, a particle guiding channel 8, a sputtering target 9, and a storage groove 10. In use, the ions collide with the sputtering target 9 after passing through the particle guiding target 6, and the ion energy is reduced again through the cooling of circulating water. The sputtering products are attached to the sputtering target 9 or fall back to the storage groove 10.

[0030] In use, the active sputtering prevention target of the plume provided in the embodiment is biased with a power supply between the screen grid 4 and the thruster 1 to collect electrons. The deceleration grid 5 and the particle guiding channel 8 are also biased with a power supply, and the direction of the electric field is opposite to the direction of ion movement, thereby reducing the ion energy. The circulating water also reduces the partial energy of the ions when the ions finally collide with the particle guiding target 6. The ions are guided by the particle guiding channel 8 and finally collide with the sputtering target 9.

[0031] The plume active anti-sputtering target provided by the embodiment mainly aims at spaceflight propulsion ground test and vacuum beam target, etc.

[0032] In the embodiment, the particle guiding target 6, the circulating water pipe 7 and the sputtering target 9 and the circulating water pipe are tightly connected together respectively.

[0033] The particle guiding target 6 in the embodiment is a key component of the test anti-sputtering target, and the particle guiding channel 8 is embedded in the particle guiding target 6. The particle guiding channel 8 can be uniformly distributed in the target surface of the particle guiding target 6 in the circumferential direction. The particle guiding channel 8 has different conical table inclination angles at different particle guiding target 6 radius positions according to different particle guiding requirements. The ion movement trajectory is constrained, and the ions are guided into the sputtering target 9. The particle guiding channel 8 is designed according to different transmittances, and the number and arrangement mode of the channel are different. The channel distribution design implementation mode is not limited to uniform arrangement.

[0034] The plume anti-sputtering device for electric propulsion experiment provided by the embodiment generates a uniform magnetic field in the axial direction of the vacuum chamber 2 through the annular coil 3. The ions in the electric propulsion plume particles move linearly or spirally along the magnetic field to the deceleration grid 5, and the electrons move reversely to the screen grid 4 or the vacuum chamber wall. The ions cannot move to the vacuum chamber wall under the constraint of the magnetic field, thereby avoiding sputtering etching of the vacuum chamber wall. In addition, when the ions move to the deceleration grid 5, the ions have reduced energy under the joint action of the particle guiding target 6 and the deceleration grid 5, and the ions move along the particle guiding channel 8 and finally collide with the sputtering target 9. Since the particle guiding channel 8 has unidirectionality, the sputtering material generated by the sputtering target 9 cannot enter the vacuum chamber 2, and finally is adsorbed on the outer surface of the particle guiding channel 8 or falls back to the storage groove 10. The sputtering material generated by the electric thruster during the test process can effectively reduce the pollution of the test environment and equipment. The application improves the safety of the electric propulsion test plume, reduces the sputtering risk of the internal equipment and protects the vacuum system, and is suitable for electric propulsion tests of various types.

[0035] In addition, the embodiment also provides an ion flux measuring device, which comprises the plume anti-sputtering device for electric propulsion experiment as described in the above embodiment. A retarding energy analyzer is added between the screen grid 4 and the deceleration grid 5 to measure the ion flux. It should be noted that the principle and measurement method of measuring the ion flux through the retarding energy analyzer belong to the conventional technical means in the field, and therefore will not be described here.

[0036] It should be noted that the structure of the application mainly aims at ground test of spaceflight electric propulsion products, and can also be applied to vacuum coating and other experiments involving electron beam and ion beam plume protection or test targets.

[0037] The above described embodiments are only to illustrate the preferred modes of the present application, and are not intended to limit the scope of the present application. Any modification and improvement made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A plume antisputtering device for electric propulsion testing, characterized by: The device comprises a vacuum chamber (2), one end of which is provided with a thruster (1), and the other end is provided with a sputtering target (9), between which a vacuum chamber wall anti-sputtering assembly, a particle deceleration assembly and an ion and sputtering recovery assembly are arranged, wherein the vacuum chamber wall anti-sputtering assembly comprises an annular coil (3) located on the tank wall of the vacuum chamber (2) or outside the electric propulsion plume; The particle deceleration assembly comprises a screen grid (4) and a deceleration grid (5), wherein the screen grid (4) is arranged on the side close to the thruster (1), and the deceleration grid (5) is arranged on the side close to the ion and sputtering recovery assembly; the middle part of the screen grid (4) is provided with a circular through hole, and the thruster (1) is embedded in the through hole or located on the center line of the through hole; the rest of the screen grid (4) is provided with a plurality of small holes for particles to pass through; the surface of the deceleration grid (5) is also provided with a plurality of small holes for particles to pass through; The ion and sputtering recovery assembly comprises a particle guiding target (6) arranged between the deceleration grid (5) and the sputtering target (9), and the particle guiding target (6) is uniformly embedded with a plurality of particle guiding channels (8), which are arranged obliquely and towards the center of the sputtering target (9), and the caliber of the side of the particle guiding channel (8) close to the sputtering target (9) is smaller than that of the side away from the sputtering target (9); The bottom of the sputtering target (9) is provided with a receiving groove (10).

2. The plume mitigation device of claim 1, wherein: The annular coil (3) is connected with alternating current to bind the plume by magnetic field.

3. The plume mitigation device of claim 1, wherein: The angle between the particle guiding channel (8) and the central axis of the particle guiding target (6) is 10°-50°.

4. The plume mitigation device of claim 1, wherein: The side of the particle guiding target (6) close to the sputtering target (9) is provided with a circulating water pipe (7), which is arranged between two adjacent particle guiding channels (8) and is connected with a circulating water tank.

5. The plume mitigation device of claim 1, wherein: The side of the sputtering target (9) away from the particle guiding target (6) is provided with a circulating water pipe (7), which is connected with a circulating water tank.

6. The plume mitigation device of claim 1, wherein: The density of the small holes in the center of the screen grid (4) and the deceleration grid (5) is high, and the density of the small holes at the edge is low.

7. The plume mitigation device of claim 1, wherein: The screen grid (4) and the deceleration grid (5) are one or more of convex grid, concave grid and plane grid.

8. The plume mitigation device of claim 1, wherein: A bias power supply is arranged between the screen grid (4) and the thruster (1) for collecting electrons.

9. The plume mitigation device of claim 1, wherein: A bias power supply is applied between the deceleration grid (5) and the particle guiding channel (8), and the direction of the electric field is opposite to the direction of ion movement.

10. An ion flux measuring device, characterized by, The device comprises the plume anti-sputtering device for electric propulsion test according to any one of claims 1-9, ions are emitted out of the plume anti-sputtering device, and ion flux is measured by using a retarding energy analyzer.

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