Anti-sputtering system and method for electric propulsion ignition test

Abstract

The invention relates to the technical field of aerospace, discloses an electric propulsion ignition test anti-sputtering system and method, and solves the problems that an existing vacuum cabin anti-sputtering system is not convenient to disassemble and transport, active cooling is needed in the thruster beam bombardment process, and the thruster ignition test cost is increased. The anti-sputtering system comprises two end socket anti-sputtering targets 1 and a cabin anti-sputtering target 2 which are arranged in a vacuum cabin, the two end socket anti-sputtering targets 1 are arranged on the two sides of the cabin anti-sputtering target 2 in a gapless mode respectively, the bottom of the cabin anti-sputtering target 2 is a plane, the cabin anti-sputtering target 2 is arranged on a guide rail at the top of a butt joint trolley 3, and the butt joint trolley 3 is arranged on the guide rail. The electric thruster anti-sputtering system designed by the invention adopts a modular design, and each module is in butt joint with the vacuum cabin through the pulleys, so that the device provided by the invention is convenient to disassemble, transport and maintain, and the equipment maintenance and transportation cost is reduced.

Description

Technical Field

[0001] The invention relates to an anti-sputtering system and method for an electric propulsion ignition test, and belongs to the technical field of aerospace. Background Art

[0002] The detector is equipped with an electric propulsion subsystem, and it is necessary to carry out an electric propulsion ignition test at the whole-vehicle level on the structural thermal controller. The whole vehicle needs to verify the ability of the electric propulsion system to work normally with the support of the primary power subsystem and the GNC subsystem in a vacuum environment, as well as the impact of the electric propulsion subsystem on other related subsystem products of the whole vehicle during operation.

[0003] During electric propulsion ignition tests of the entire detector stage in vacuum, the high-energy plume particles generated by the electric propulsion and their sputtering products can contaminate the detector and vacuum chamber. Existing vacuum chamber sputtering protection systems mostly use an integrated structure, which is inconvenient to disassemble and transport. Furthermore, the sputtering protection targets within this integrated structure require active cooling to withstand continuous thruster beam bombardment, increasing the cost of thruster ignition tests. Patent publication number CN115556972B discloses an electric propulsion test plume sputtering protection system. The system comprises at least a front beam stop target, a peripheral sputtering shield, and a dark-sector beam stop target. The three components enclose a nearly closed cavity, forming a sandwich with the vacuum chamber. The electric thruster is located within this cavity. The front beam stop target is positioned in front of the electric thruster, while the dark-sector beam stop target is positioned behind it. The cylindrical peripheral sputtering shield is positioned between the front and dark-sector beam stop targets. The invention patent with publication number CN107340139A discloses a sputtering target device for system-level ignition tests of electric propulsion spacecraft. An opening is provided on the top of the shield for receiving plume particles. A main target is provided on the bottom of the shield opposite to the opening. The main target is made of a low sputtering rate material. The shield has a multi-layer guide structure. When sputtering particles pass through it, multiple collisions occur, increasing the probability of their adsorption on the wall. The unadsorbed particles are guided by the guide structure to the non-sensitive surface in the container. The problems with the above two patents are: they need to rely on active cooling devices to deal with thruster beam bombardment, and the time they can withstand thruster beam bombardment is relatively short. Summary of the Invention

[0004] The present invention aims to solve the problem that the existing vacuum chamber sputtering prevention system is not conducive to disassembly and transportation, and requires active cooling during thruster beam bombardment, which increases the cost of thruster ignition testing. Therefore, an electric propulsion ignition test sputtering prevention system and method are proposed.

[0005] The technical solution adopted by the present invention to solve the above problems is: an electric propulsion ignition test anti-sputtering system proposed by the present invention comprises: Two end-cap sputtering targets (1) and a chamber body sputtering target (2) are arranged in a vacuum chamber, and the two end-cap sputtering targets (1) are respectively arranged on both sides of the chamber body sputtering target (2) without any spacing.

[0006] Furthermore, the electric propulsion ignition test anti-sputtering system also includes two sets of parallel support rails for a head anti-sputtering target (1) and a cabin anti-sputtering target (2) arranged in the vacuum chamber. The two sets of rails have different horizontal heights. The cabin anti-sputtering target (2) is arranged on a rail with a higher horizontal height, and the head anti-sputtering target (1) is arranged on a rail with a lower horizontal height. In addition, the two head anti-sputtering targets (1), the cabin anti-sputtering target (2) and the vacuum chamber are coaxially arranged.

[0007] Furthermore, the chamber anti-sputtering target (2) is a two-section structure with the same diameter and inconsistent lengths, wherein the chamber anti-sputtering target close to the interior of the vacuum chamber comprises three circular rings (5), a skeleton (7) and a plurality of graphite plates (6), wherein the top of the circular ring (5) is a plane and the bottom is a plane with a depression, the three circular rings (5) are arranged in parallel at equal intervals, and a plurality of skeletons are arranged at equal intervals between adjacent circular rings (5), the skeleton (7) is detachably fixed to the circular rings by bolts, and the graphite plates (6) are detachably fixed to the skeleton by graphite screws; Another section of the cabin sputtering target comprises three circular rings (5), a skeleton (7) and a plurality of graphite plates (6). The top of the circular ring (5) is a flat surface and the bottom is a flat surface with a depression. The three circular rings (5) are arranged in parallel at equal intervals. A plurality of skeletons are arranged at equal intervals between adjacent circular rings (5). The skeleton (7) is detachably fixed to the circular rings by bolts, and the graphite plates (6) are detachably fixed to the skeleton by graphite screws. A movable bracket with a brake device is provided at the bottom of the two-section cabin sputtering protection target for free movement on the guide rail.

[0008] Furthermore, the head anti-sputtering target (1) is composed of a plurality of anti-sputtering plates and an annular stainless steel frame, wherein the anti-sputtering plates are equidistant and fixed at both ends of the annular stainless steel frame at the same inclination angle as the stainless steel frame, and each anti-sputtering plate is composed of a plurality of graphite plates spliced ​​horizontally, and a movable bracket with a brake device is provided at the bottom of the stainless steel frame for free movement on the guide rail.

[0009] Furthermore, the guide rails for placing the cabin anti-sputtering target (2) and the guide rails of the docking trolley (3) in the vacuum chamber are of the same size, the guide rails of the cabin anti-sputtering target (2) and the guide rails of the docking trolley (3) are seamlessly docked, the bottom of the docking trolley (3) is provided with a load-bearing wheel with a brake, and the guide rails at the bottom of the docking trolley (3) extend forward.

[0010] A method for preventing sputtering during an electric propulsion ignition test, comprising: The thruster is placed in an electric propulsion ignition test anti-sputtering system to carry out an electric propulsion ignition test, and the sputtering products in the electric propulsion ignition test are blocked by graphite plates arranged on a head anti-sputtering target (1) and a cabin anti-sputtering target (2), so as to ensure that the sensitive surface of the vacuum cabin is not affected by the sputtering products.

[0011] The beneficial effects of the present invention are: 1. The electric thruster anti-sputtering system designed in the present invention adopts a modular design. Each module is docked with a vacuum chamber through a pulley. The docking pipe outlet is equipped with a special plug and cap, and the connecting lines are all double-point double-line, which ensures the independence of each module. The device proposed in the present invention is convenient for disassembly, transportation and maintenance between modules, reducing the cost of equipment maintenance and transportation.

[0012] 2. The head anti-sputtering target and the cabin anti-sputtering target in the system proposed in the present invention both adopt an annular, i.e., inclined structure, to reduce the return of sputtering products to sensitive surfaces. At the same time, the head anti-sputtering target and the cabin anti-sputtering target do not require active cooling means and can withstand no less than 360 hours of continuous thruster beam bombardment and no less than 120 hours of 5kW electric thruster bombardment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of an electric propulsion ignition test sputtering prevention system provided by the present invention. In the figure, 1-head sputtering prevention target, 2-cabin body sputtering prevention target, 3-docking trolley, 4-vacuum chamber; Figure 2 Schematic diagram of the anti-sputtering target for a sealed head provided by the present invention, in which: 1-anti-sputtering target for a sealed head; 4-vacuum chamber; 8-rectangular graphite plate; Figure 3 A schematic diagram of the installed anti-sputtering target for a head provided by the present invention, wherein: 8- rectangular graphite plate; Figure 4 and Figure 5 Schematic diagram of the cabin anti-sputtering target provided by the present invention entering and exiting the vacuum cabin, in which 2 is the cabin anti-sputtering target, 3 is the docking trolley, and 4 is the vacuum cabin; Figure 6 Schematic diagram of the chamber anti-sputtering target provided by the present invention, close to the interior of the vacuum chamber, in which 5 is a ring, 6 is a graphite plate, and 7 is a skeleton; Figure 7 Schematic diagram of another section of the cabin sputtering protection target provided by the present invention, in which 5 is a ring, 6 is a graphite plate, and 7 is a skeleton; Figure 8 This is a schematic diagram of the docking trolley transporting the anti-sputtering target in the cabin provided by the present invention. Figure 8 In the middle, 2-cabin anti-sputtering target, 3-docking trolley. DETAILED DESCRIPTION

[0014] Combine Figure 1-8 This embodiment is described as follows. Figure 1 As shown, the structure of the electric propulsion ignition test anti-sputtering system described in this embodiment includes: Two end-capped sputtering targets 1 are respectively arranged without spacing on two circular surfaces of the cylindrical chamber sputtering target 2, as shown in FIG. Figure 2 As shown, the head anti-sputtering target 1 is designed according to the size of the vacuum chamber. After the head anti-sputtering target 1 is combined with the chamber anti-sputtering target 2, the diameter facing the plume direction is 3.2m. The head anti-sputtering target 1 is made of stainless steel and has a movable bracket at the bottom. The movable bracket can move freely on the guide rail in the vacuum chamber. The wheels of the movable bracket are equipped with brakes. The total height of the movable bracket is 145mm, the diameter of the large circle is 120mm, the length of the bracket is 130mm, the width of the bracket is 130mm, the diameter of the small circle is 90mm, the wheel width of the brake wheel is 80mm, the groove depth is 15mm, and the thickness of the bracket is 9mm. There are two 6306 bearing steel bearings built into the mobile bracket. There are four mounting holes on the bracket. The distance between two adjacent mounting holes is 95mm. The diameter of the mounting hole is 13mm, the edge of the large circle is 20mm, and the weight of a single installation is 6.9kg.

[0015] The head anti-sputtering target 1 includes an annular stainless steel frame and several rectangular graphite plates 8. The rectangular graphite plates 8 adopt a shutter-type structure. The anti-sputtering plates are equidistant and fixed at both ends of the annular stainless steel frame at the same inclination angle as the stainless steel frame to eliminate the influence of plume to the greatest extent. Each rectangular graphite plate is fixedly connected to both ends of the stainless steel frame. Each graphite plate is spliced ​​by several 300mm*300mm square graphite plates. The installed head anti-sputtering target 1 is as follows Figure 3 As shown, the rear portion (3.3m) of the graphite device has a graphite louver screen at the bottom. To meet the user's different test position requirements, the bottom graphite screen is movable and angle-adjustable. The overall louver angle can be adjusted by rotating the round steel of the mechanism.

[0016] The cabin anti-sputtering target 2 is made of stainless steel frame, with an inner diameter of 3.2m, a length of 7m and a frame thickness of 80mm. The capacity of the cabin anti-sputtering target 2 is 4.5m×10m. The graphite device in the cabin has an inner diameter of φ3.75m, an outer diameter of φ3.91m and a total length of 6.5m. The device is divided into front and rear parts, the front part is 3.2m long; the rear part is 3.3m long, and the bottom of the rear part is equipped with a graphite louver screen. A trolley is provided outside the cabin for easy transportation. The cabin anti-sputtering target close to the interior of the vacuum cabin is as follows: Figure 6As shown, it includes three rings 5, a skeleton 7, and multiple graphite plates 6. The skeleton 7 has wheels at the bottom and is placed on the track inside the cabin for easy entry and exit. The lower end of the skeleton is stepped to avoid the pedestrian track, and the upper end of the rear part avoids the equipment inside the cabin. The top of the ring 5 is flat, and the bottom is a flat surface with a recess. The three rings 5 ​​are arranged in parallel with equal spacing. Multiple skeletons are set at equal spacing between adjacent rings 5. The skeleton 7 is detachably fixed to the rings with bolts, and the graphite plates 6 are detachably fixed to the skeleton with graphite screws; the other section of the cabin body anti-sputtering target is as shown Figure 7 As shown, it includes three rings 5, a skeleton 7 and multiple graphite plates 6. The bottom of the ring 5 is a plane with a depression. The three rings 5 ​​are arranged in parallel at equal intervals. Multiple skeletons are arranged at equal intervals between adjacent rings 5. The skeleton 7 is detachably fixed to the ring by bolts, and the graphite plate 6 is detachably fixed to the skeleton by graphite screws. The bottom of the two-section cabin anti-sputtering target is provided with a mobile bracket with a brake device for free movement on the guide rail. The ring 5 is made of 80mm square steel and is divided into three rings: front, middle and rear. The cylinder of the graphite plate 6 is 300mm wide and the bottom screen is 200mm wide. In this embodiment, the top of the chamber body sputtering prevention target close to the interior of the vacuum chamber is set to be flat, which is conducive to smooth docking of the chamber body sputtering prevention target and prevents collision with the interior of the vacuum chamber. It is applicable to vacuum chambers of all sizes.

[0017] The specification of graphite plate 6 is 500mm*300mm, with a mobile bracket at the bottom. The trolley is 3.5m long, and its width and height are consistent with the guide rails in the cabin for easy connection and transportation. The cabin body sputtering target 2 enters and exits the vacuum cabin 5 in sections. Figure 4 and Figure 5 shown.

[0018] The docking trolley 3 is welded with stainless steel square tubes, and its height is the same as the guide rail gas cylinder in the cabin. The upper part of the docking trolley 3 is equipped with a guide rail of the same size as that in the vacuum cabin, for seamless docking. The guide rail of the docking trolley extends forward 300mm to facilitate docking with the guide rail in the cabin. The bottom of the docking trolley 3 is equipped with load-bearing wheels, each wheel has a load-bearing capacity of 1000kg, and is equipped with brakes.

[0019] The graphite plates used in the head anti-sputtering target 1 and the cabin anti-sputtering target 2 are both pressed graphite plates. The specifications of the graphite plates used in the head anti-sputtering target 1 are 300mm*300mm, and the specifications of the graphite plates used in the cabin anti-sputtering target 2 are 500mm*300mm. The total area of ​​the graphite plates is about 120 square meters. The cabin anti-sputtering target is transported by a docking trolley. Figure 8 shown.

[0020] During the docking process between the head anti-sputtering target 1 and the cabin anti-sputtering target 2, the docking pipe outlets are equipped with dedicated plugs and caps, and the connecting lines all use double-point double-line. The head anti-sputtering target 1, cabin anti-sputtering target 2, and docking trolley 3 are all equipped with dedicated packaging boxes to facilitate equipment transportation. In the electric propulsion ignition test anti-sputtering system, components that are frequently calibrated and replaced are placed in easily accessible locations to facilitate component replacement and calibration. When installed in the cabin, the graphite plate is concentric with the container, and its bottom is placed on the cabin guide rail via bottom wheels, parallel to the bottom guide rail. The front end of the graphite plate is 3.5 meters away from the container flange surface. The graphite plate is tangentially connected and covered on the cylindrical frame, and is arranged in a louvered manner at the bottom.

[0021] When conducting the electric propulsion ignition test, the total power supply of the electric propulsion ignition test anti-sputtering system is unified into a common 220V interface, marked with a logo and equipped with a switch indicator light. A grounding pile is set outside the electric propulsion ignition test anti-sputtering system, and the power ground is connected to the shell ground. The flow meter is equipped with a separate power switch and indicator light. The communication interface of the electric propulsion ignition test anti-sputtering system is an RS232 connection, which is integrated into an aviation plug. All structures of the electric propulsion ignition test anti-sputtering system are compatible and scalable.

[0022] After completing the above system design, this embodiment also provides a method for preventing sputtering during an electric propulsion ignition test, as follows: Step 1: Set the brake wheel of one of the end-sputtering targets 1 to the brake state, and place the end-sputtering target 1 on the docking trolley 3. Control the docking trolley 3 to move until the docking trolley 3 is completely in contact with the vacuum chamber 4, so that the end-sputtering target 1 enters the vacuum chamber 4. At the same time, set the brake wheel of the end-sputtering target 1 to the moving state, and control the end-sputtering target 1 to move on the guide rail of the vacuum chamber 4 until it reaches the end of the vacuum chamber 4. Step 2: Set the brake wheel of the front part cabin body anti-sputtering target 2 to the brake state, and place the front part cabin body anti-sputtering target 2 on the docking trolley 3, control the docking trolley 3 to move until the docking trolley 3 is completely in contact with the vacuum chamber 4, so that the front part cabin body anti-sputtering target 2 enters the slide rail of the vacuum chamber 4, and at the same time set the brake wheel of the front part cabin body anti-sputtering target 2 to the moving state, control the front part cabin body anti-sputtering target 2 to move on the guide rail of the vacuum chamber 4 until it docks with the head anti-sputtering target 1; Step 3: Replace the front cabin body anti-sputtering target 2 in step 2 with the rear cabin body anti-sputtering target 2, and repeat step 2 until the rear cabin body anti-sputtering target 2 and the front cabin body anti-sputtering target 2 are docked; Step 4: Place the thruster into the vacuum chamber 4, replace the head anti-sputtering target 1 in step 1 with another head anti-sputtering target 1, and repeat step 1 until the other head anti-sputtering target 1 and the rear cabin anti-sputtering target 2 are docked. After the docking is completed, perform the electric propulsion ignition test. The sputtering products in the electric propulsion ignition test are blocked by the graphite plates set on the head anti-sputtering target 1 and the cabin anti-sputtering target 2 to ensure that the sensitive surfaces of the vacuum chamber are not affected by the sputtering products.

[0023] During the electric propulsion ignition experiment, specific tests of various components include: Verification pressure requirement: The pressure-bearing components in the equipment shall undergo a verification pressure test at 1.5 times the corresponding working pressure, and the bursting pressure shall not be less than 2 times the working pressure.

[0024] Overvoltage and overcurrent protection: The system power supply is designed with overvoltage and overcurrent protection measures. The AC input is protected by double fuses, and the switch also uses double cutting of the neutral wire and the live wire.

[0025] Safety protection: The system has sufficient safety design to ensure the safety of users. The easily accessible parts with voltage to ground (AC peak-to-peak or DC) higher than 36V are protected.

[0026] Insulation: Under standard atmospheric conditions, the insulation resistance between the 220V power supply and the housing must be greater than 20MΩ. The entire system must be reliably grounded, with a ground resistance of less than 1Ω. Grounding point: The entire system must be reliably grounded at a single point.

[0027] Cleanliness requirements: Appropriate waste and cleanliness control measures are implemented during the development process. Operators must wear clean, powder-free gloves and pay particular attention to piping interfaces, which should not be touched directly. The entire system undergoes and passes a 120-hour burn-in test. A software interlock function ensures that vacuum accidents will not occur. The system can set an air pressure protection point, which will activate the protection program when the pressure exceeds the protection point (except for intentional exposure to the atmosphere).

[0028] Performance verification: 360 hours of continuous thruster beam bombardment was conducted, and sensitive surfaces were observed to be unaffected by sputtering products.

[0029] The above experimental verification shows that the electric propulsion ignition test anti-sputtering system provided by the present invention can withstand thruster beam bombardment for no less than 360 consecutive hours without the aid of active cooling means. During the test, the system performance was further verified by bombardment of a 5kW electric thruster for no less than 120 hours, and all met the design requirements.

[0030] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An electric propulsion ignition test anti-sputtering system, characterized in that: include: Two end-cap sputtering targets (1) and a chamber body sputtering target (2) are arranged in a vacuum chamber, wherein the two end-cap sputtering targets (1) are arranged on both sides of the chamber body sputtering target (2) without any spacing.

2. The electric propulsion ignition test anti-sputtering system according to claim 1, characterized in that: The electric propulsion ignition test sputtering prevention system further comprises two sets of parallel support rails for a head sputtering prevention target (1) and a cabin body sputtering prevention target (2) arranged in a vacuum chamber. The two sets of rails have different levels. The cabin body sputtering prevention target (2) is arranged on a rail with a higher level, and the head sputtering prevention target (1) is arranged on a rail with a lower level. Furthermore, the two head sputtering prevention targets (1), the cabin body sputtering prevention target (2) and the vacuum chamber are coaxially arranged.

3. The electric propulsion ignition test anti-sputtering system according to claim 1, characterized in that: The chamber body sputtering prevention target (2) is a two-section structure with the same diameter and inconsistent lengths, wherein the chamber body sputtering prevention target close to the interior of the vacuum chamber comprises three circular rings (5), a skeleton (7) and a plurality of graphite plates (6), wherein the top of the circular ring (5) is a plane and the bottom is a plane with a depression, the three circular rings (5) are arranged in parallel at equal intervals, and a plurality of skeletons are arranged at equal intervals between adjacent circular rings (5), the skeleton (7) is detachably fixed to the circular rings by bolts, and the graphite plates (6) are detachably fixed to the skeleton by graphite screws; Another section of the cabin sputtering target comprises three circular rings (5), a skeleton (7) and a plurality of graphite plates (6). The top of the circular ring (5) is a flat surface and the bottom is a flat surface with a depression. The three circular rings (5) are arranged in parallel at equal intervals. A plurality of skeletons are arranged at equal intervals between adjacent circular rings (5). The skeleton (7) is detachably fixed to the circular rings by bolts, and the graphite plates (6) are detachably fixed to the skeleton by graphite screws. A movable bracket with a brake device is provided at the bottom of the two-section cabin sputtering protection target for free movement on the guide rail.

4. The electric propulsion ignition test anti-sputtering system according to claim 1, characterized in that: The head anti-sputtering target (1) is composed of a plurality of anti-sputtering plates and an annular stainless steel frame. The anti-sputtering plates are equidistant and fixed at both ends of the annular stainless steel frame at the same inclination angle as the stainless steel frame. Each anti-sputtering plate is composed of a plurality of graphite plates spliced ​​together horizontally. A movable bracket with a brake device is provided at the bottom of the stainless steel frame for free movement on a guide rail.

5. The electric propulsion ignition test anti-sputtering system according to claim 1, characterized in that: The guide rails for placing the cabin anti-sputtering target (2) and the guide rails of the docking trolley (3) in the vacuum cabin are of the same size, the guide rails of the cabin anti-sputtering target (2) and the guide rails of the docking trolley (3) are seamlessly docked, the bottom of the docking trolley (3) is provided with a load-bearing wheel with a brake, and the guide rails at the bottom of the docking trolley (3) extend forward.

6. A method for preventing sputtering in an electric propulsion ignition test, applied to an electric propulsion ignition test anti-sputtering system according to any one of claims 1 to 5, characterized in that: include: The thruster is placed in an electric propulsion ignition test anti-sputtering system to carry out an electric propulsion ignition test, and the sputtering products in the electric propulsion ignition test are blocked by graphite plates arranged on a head anti-sputtering target (1) and a cabin anti-sputtering target (2), so as to ensure that the sensitive surface of the vacuum cabin is not affected by the sputtering products.

Images