Pre-chamber annular gas feed for ion thruster discharge chamber

Abstract

The application provides a front ring gas supply device for an ion thruster discharge chamber, comprising a gas supply ring groove and a gas supply ring cover, the gas supply ring groove and the gas supply ring cover cooperate to form a cavity, the cavity comprises a first cavity and a second cavity, a plurality of through holes are arranged on the gas supply ring cover, the first cavity and the second cavity are communicated through the through holes, the first cavity is communicated with a gas supply pipeline, and the second cavity is communicated with a discharge chamber cavity. By adopting the two-stage cavity buffer gas supply mode, the distribution of the working gas in the ion thruster discharge chamber is more uniform, the spatial uniformity of the plasma density in the ion thruster is improved, and then the flatness of the extracted ion beam is improved, which is beneficial to prolonging the service life of the ion thruster; by adopting the oblique gas injection mode, the axial velocity of the gas is reduced, the residence time of the working gas in the ion thruster discharge chamber is prolonged, and the working gas utilization rate of the ion thruster is improved.

Description

Technical Field

[0001] This invention relates to the field of electric propulsion technology, and more specifically, to a pre-annular gas supply device for the discharge chamber of an ion thruster. Background Technology

[0002] The gas supply system of the ion thruster discharge chamber injects propellant gas into the discharge chamber, ionizing the gas to generate plasma. Ions in the plasma are accelerated and ejected to generate thrust. The speed and uniformity of gas injection affect the ionization efficiency within the ion thruster discharge chamber and the thruster's lifespan, thus significantly influencing the performance of the ion thruster.

[0003] In ion thrusters, single-point axial gas supply is common, where neutral gas is injected from the bottom of the discharge chamber towards the grid through a single gas supply port. This injection method results in two problems: firstly, a large axial velocity component of the gas, with some gas quickly reaching the grid and leaking through its openings; and secondly, uneven gas injection. The gas is not ionized and is ejected directly from the ion thruster as neutral atoms at low velocity, leading to a decrease in thrust and specific impulse. Uneven gas distribution results in uneven plasma density within the discharge chamber, causing significant differences in beam focusing at different grid locations, potentially exacerbating grid erosion and reducing the ion thruster's lifespan. Therefore, reducing the propellant gas injection velocity and improving gas injection uniformity are crucial for improving ion thruster performance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a pre-annular gas supply device for the discharge chamber of an ion thruster.

[0005] According to the present invention, a pre-annular gas supply device for an ion thruster discharge chamber includes: a gas supply ring groove and a gas supply ring cover, wherein the gas supply ring groove and the gas supply ring cover cooperate to form a cavity, the cavity including a primary cavity and a secondary cavity, the gas supply ring cover being provided with a plurality of through holes, the primary cavity and the secondary cavity being connected through the through holes, the primary cavity being connected to a gas supply pipeline, and the secondary cavity being connected to the discharge chamber cavity.

[0006] Preferably, the air supply ring groove is a U-shaped cross-section body of revolution with a step formed at its opening, and the air supply ring cover is a T-shaped cross-section body of revolution, including a T-shaped cross-section horizontal plate and a T-shaped cross-section vertical edge. The edge of the T-shaped cross-section horizontal plate forms a step that matches the air supply ring groove, and the T-shaped cross-section horizontal plate seals the opening of the U-shaped cross-section of the air supply ring groove to form the cavity.

[0007] Preferably, the end of the vertical side of the T-shaped section away from the horizontal plate of the T-shaped section is tightly fitted with the bottom of the U-shaped section of the air supply ring groove. The vertical side of the T-shaped section divides the closed cavity into the primary cavity and the secondary cavity, and the primary cavity is located outside the secondary cavity.

[0008] Preferably, the vertical edge of the T-shaped section is uniformly provided with a plurality of through holes along the circumference, the number of through holes being between 24 and 36, and the diameter of the through holes being 1 mm.

[0009] Preferably, a radial air pipe is provided on the outer wall of the air supply ring groove, and the radial air pipe is connected to the bottom of the primary cavity.

[0010] Preferably, the radial air tube is connected to the adapter air tube via a right-angle connector, and the adapter air tube is connected to the air supply line.

[0011] Preferably, the inner wall and bottom of the secondary cavity are connected to form a 45-degree conical surface. Multiple small holes are evenly opened along the circumference of the conical surface. The secondary cavity is connected to the discharge chamber through the small holes. The number of small holes is between 24 and 36, and the diameter of the small holes is 0.3 mm.

[0012] Preferably, the outer diameter of the gas supply ring groove is equal to the outer diameter of the discharge chamber, and the inner diameter of the gas supply ring groove is 13mm smaller than the outer diameter.

[0013] Preferably, the gas supply ring groove, the gas supply ring cover, the right-angle pipe, and the adapter pipe are all made of titanium alloy. The gas supply ring groove, the gas supply ring cover, the right-angle pipe, and the adapter pipe are welded together to form a whole and placed at the front end of the discharge chamber.

[0014] Preferably, the axial length of the cavity is 1 / 10 to 1 / 20 of the axial length of the discharge chamber.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention employs a two-stage cavity buffer gas supply method, resulting in a more uniform distribution of the working gas within the ion thruster discharge chamber. This improves the spatial uniformity of plasma density within the ion thruster, thereby enhancing the straightness of the extracted ion beam and extending the ion thruster's lifespan. By using an oblique jet injection method to reduce the axial velocity of the gas, after entering the discharge chamber, the gas initially moves towards the bottom of the chamber. After rebounding from the chamber wall, it has a certain probability of moving towards the ion thruster's grid region, extending the residence time of the working gas within the discharge chamber and improving the working gas utilization rate. The gas supply device is designed with a ring structure, which can be integrated into the ion thruster discharge chamber structure and scaled down according to the appropriate thruster size. Attached Figure Description

[0017] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0018] Figure 1 This is a schematic diagram illustrating the structure of the pre-annular gas supply device used in the discharge chamber of an ion thruster, which is the main feature of this invention.

[0019] Figure 2 This is a cross-sectional schematic diagram of the pre-annular gas supply device used in the discharge chamber of an ion thruster, which is the main feature of this invention.

[0020] Figure 3 This is a schematic diagram illustrating the main gas flow direction of the present invention;

[0021] Figure 4 This is a schematic diagram illustrating the structure of the ion thruster, which is the main feature of this invention.

[0022] As shown in the figure:

[0023] 1. Air supply ring groove; 2. Air supply ring cover; 3. Right angle pipe.

[0024] 4-way trachea Detailed Implementation

[0025] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0026] like Figure 1-4 As shown, a pre-annular gas supply device for the discharge chamber of an ion thruster according to the present invention includes: a gas supply ring groove 1 and a gas supply ring cover 2. The gas supply ring groove 1 and the gas supply ring cover 2 cooperate to form a cavity, which includes a primary cavity and a secondary cavity. The gas supply ring cover 2 is provided with a plurality of through holes. The primary cavity and the secondary cavity are connected through the through holes. The primary cavity is connected to the gas supply pipeline, and the secondary cavity is connected to the discharge chamber cavity.

[0027] Currently, in ion thruster technology, most thrusters are supplied with gas through a direct-flow gas distributor. This can easily lead to uneven distribution of the working gas in the discharge chamber or excessive axial velocity of the working gas, causing it to leak rapidly from the thruster grid hole. This results in uneven plasma distribution in the thruster and a decrease in the utilization rate of the working gas.

[0028] This application introduces neutral gas output from the thruster into the primary chamber of the device via a gas supply pipeline. After buffering, the gas enters the secondary chamber through evenly distributed small holes on the partition between the primary and secondary chambers. Then, it is ejected obliquely downwards along the inner edge of the bottom of the gas supply ring groove 1, evenly distributed in the circumferential direction. The two-stage chambers buffer the injected gas twice, improving the pressure uniformity within the secondary chamber. The oblique holes at the bottom of the ring groove convert the forward axial movement of the gas into an oblique backward movement, increasing the gas's residence time in the ion thruster.

[0029] The air supply ring groove 1 is a U-shaped body of revolution with a step at its opening. The air supply ring cover 2 is a T-shaped body of revolution, including a T-shaped horizontal plate and a T-shaped vertical edge. The edge of the T-shaped horizontal plate has a step that matches the air supply ring groove 1. The T-shaped horizontal plate seals the opening of the U-shaped section of the air supply ring groove 1 to form a cavity. The end of the T-shaped vertical edge away from the T-shaped horizontal plate is tightly fitted against the bottom of the U-shaped section of the air supply ring groove 1. The T-shaped vertical edge divides the closed cavity into a primary cavity and a secondary cavity, with the primary cavity located outside the secondary cavity.

[0030] The T-shaped cross-section has multiple through holes evenly distributed along its circumference on its vertical edge. The number of through holes ranges from 24 to 36, and the diameter of each through hole is 1 mm. The number and diameter of the vent holes between the primary and secondary chambers are adjusted according to the flow rate of the neutral gas output from the thruster.

[0031] A radial air pipe is provided on the outer wall of the air supply ring groove 1, and the radial air pipe is connected to the bottom of the primary cavity. The radial air pipe is connected to the adapter air pipe 4 through the right-angle connector 3, and the adapter air pipe 4 is connected to the air supply pipeline.

[0032] The inner wall and bottom of the secondary cavity form a 45-degree conical surface. Multiple downward-sloping holes are evenly distributed along the circumference of this conical surface. The secondary cavity connects to the discharge chamber through these holes. The number of holes ranges from 24 to 36, and the diameter of each hole is 0.3 mm. The number, diameter, and position of the downward-sloping holes in the gas supply ring groove 1 can be adjusted according to the gas flow rate and the size of the ion thruster discharge chamber. The position of the hole axis relative to the gas supply ring groove axis can be adjusted from 0° to 90° as needed.

[0033] The outer diameter of the gas supply ring groove 1 is equal to the outer diameter of the discharge chamber, and the inner diameter of the gas supply ring groove 1 is 13 mm smaller than the outer diameter. The axial length of the cavity is 1 / 10 to 1 / 20 of the axial length of the discharge chamber. The axial length of the cavity is determined according to the working performance parameters of the thruster, and the range of the axial length is 1 / 10 to 1 / 20 of the axial length of the discharge chamber of the ion thruster in which the gas supply ring is placed.

[0034] The gas supply ring groove 1, gas supply ring cover 2, right-angle pipe 3, and adapter pipe 4 are all made of TC4 M titanium alloy. They are welded together to form a single unit and placed at the front end of the discharge chamber. Preferably, the gas supply ring groove 1 and gas supply ring cover 2 are welded together using vacuum electron beam welding, and the gas supply ring groove 1, right-angle pipe 3, and adapter pipe 4 are connected using argon arc welding.

[0035] This application is assembled as a whole by welding and placed at the front end of the discharge chamber. The gas supply ring cover 2 divides the gas supply ring groove 1 into two-stage cavities. The cavity connected to the right-angle tube 3 is the primary cavity, and the other cavity is the secondary cavity. The two cavities are connected by small holes. The gas supply ring groove 1 has downward-sloping small holes. The neutral gas output from the thruster enters the primary cavity of the device through the gas supply pipeline. After being buffered, it enters the secondary cavity through the small holes evenly distributed on the partition between the primary and secondary cavities, and then is ejected along the bottom inner edge of the gas supply ring groove 1 and the downward-sloping small holes evenly distributed in the circumferential direction. The two-stage cavities buffer the injected gas twice, improving the pressure uniformity in the secondary cavity. The downward-sloping small holes at the bottom of the ring groove convert the forward axial movement of the gas into a backward-sloping movement, increasing the residence time of the gas in the ion thruster.

[0036] This application employs a two-stage cavity buffer gas supply method, which makes the distribution of the working gas in the discharge chamber of the ion thruster more uniform, improves the spatial uniformity of plasma density within the ion thruster, and thus improves the straightness of the extracted ion beam, which is beneficial to extending the life of the ion thruster. By reducing the axial velocity of the gas through oblique jetting, the gas initially moves towards the bottom of the discharge chamber after entering the chamber, and only after rebounding from the chamber wall does it have a certain possibility of moving towards the grid region of the ion thruster. This prolongs the residence time of the working gas in the discharge chamber of the ion thruster and improves the working gas utilization rate of the ion thruster. The gas supply device is designed with a ring structure, which can be integrated into the structure of the ion thruster discharge chamber and can be scaled down according to the size of the suitable thruster.

[0037] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0038] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A pre-annular gas feed for a discharge chamber of an ion thruster, characterized in that include: Gas supply ring groove (1) and gas supply ring cover (2) are provided. The gas supply ring groove (1) and the gas supply ring cover (2) cooperate to form a cavity. The cavity includes a primary cavity and a secondary cavity. The gas supply ring cover (2) is provided with multiple through holes. The primary cavity and the secondary cavity are connected through the through holes. The primary cavity is connected to the gas supply pipeline. The secondary cavity is connected to the discharge chamber cavity. The air supply ring groove (1) is a U-shaped cross-section of a rotating body with a step at its opening. The air supply ring cover (2) is a T-shaped cross-section of a rotating body, including a T-shaped cross-section horizontal plate and a T-shaped cross-section vertical edge. The edge of the T-shaped cross-section horizontal plate has a step that matches the air supply ring groove (1). The T-shaped cross-section horizontal plate seals the opening of the U-shaped cross-section of the air supply ring groove (1) to form the cavity.

2. A front-facing annular gas feed for a discharge chamber of an ion thruster as defined in claim 1, characterized in that The end of the vertical side of the T-shaped section away from the horizontal plate of the T-shaped section is tightly fitted with the bottom of the U-shaped section of the air supply ring groove (1). The vertical side of the T-shaped section divides the closed cavity into the primary cavity and the secondary cavity. The primary cavity is located outside the secondary cavity.

3. The front-facing ring gas feed for a discharge chamber of an ion thruster of claim 1, wherein, The T-shaped cross-section has multiple through holes evenly arranged along its vertical edge in the circumferential direction. The number of through holes is between 24 and 36, and the diameter of each through hole is 1 mm.

4. A front-facing annular gas feed for a discharge chamber of an ion thruster as defined in claim 2, characterized in that A radial air pipe is provided on the outer wall of the air supply ring groove (1), and the radial air pipe is connected to the bottom of the primary cavity.

5. A front face ring gas feed for a discharge chamber of an ion thruster as defined in claim 4, characterized in that The radial air tube is connected to the transfer air tube (4) through a right-angle tube (3), and the transfer air tube (4) is connected to the air supply line.

6. The front-facing ring gas feed for a discharge chamber of an ion thruster of claim 2, wherein, The inner wall and bottom of the secondary cavity are connected by a 45-degree conical surface. Multiple small holes are evenly distributed along the circumference of the conical surface. The secondary cavity is connected to the discharge chamber through the small holes. The number of small holes is between 24 and 36, and the diameter of the small holes is 0.3 mm.

7. The front-facing ring gas feed for a discharge chamber of an ion thruster of claim 1, wherein, The outer diameter of the gas supply ring groove (1) is equal to the outer diameter of the discharge chamber, and the inner diameter of the gas supply ring groove (1) is 13 mm smaller than the outer diameter.

8. The front-facing ring gas feed for a discharge chamber of an ion thruster of claim 5, wherein, The gas supply ring groove (1), the gas supply ring cover (2), the right-angle tube (3) and the connecting gas pipe (4) are all made of titanium alloy. The gas supply ring groove (1), the gas supply ring cover (2), the right-angle tube (3) and the connecting gas pipe (4) are welded together to form a whole and placed at the front end of the discharge chamber.

9. A front face ring gas feed for a discharge chamber of an ion thruster as defined in claim 8, characterized in that The axial length of the cavity is 1 / 10 to 1 / 20 of the axial length of the discharge chamber.

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