A Hall thruster anode assembly

Abstract

The present invention provides a Hall thruster anode assembly, comprising at least a magnetic shield, a gas distribution ring and an anode; the magnetic shield comprises at least an inner ring and an outer ring arranged concentrically, the outer wall of the inner ring being connected to the inner wall of the outer ring via a bottom ring to form an annular cavity with an open top; the gas distribution ring is arranged in the annular cavity to axially divide the cavity into a primary gas buffer cavity and a secondary gas buffer cavity; the anode is arranged in the secondary gas buffer cavity and connected to the upper end face of the gas distribution ring; wherein the bottom ring is provided with a first through hole for connecting a gas supply pipe and the primary gas buffer cavity; the gas distribution ring is provided with a second through hole connecting the primary gas buffer cavity and the anode inner cavity; and the anode is provided with a plurality of inclined holes connecting the anode inner cavity and the secondary gas buffer cavity.

Description

Technical Field

[0001] The present invention relates to the field of space propulsion technology, in particular to an anode assembly of a Hall thruster. Background Art

[0002] Hall thrusters, with their simple structure, high efficiency, and long operating life, are widely used in spacecraft missions such as station maintenance, orbit transfer, attitude control, and interstellar travel. In recent years, with the rapid development of commercial spaceflight, krypton propellant has become widely used. However, krypton has low ionization efficiency and thus low operating efficiency. Furthermore, krypton thrusters suffer from poor discharge stability. In severe cases, large low-frequency oscillations can cause the thruster to shut down, compromising its operational stability. Therefore, optimizing the performance of Hall thrusters is urgently needed. Summary of the Invention

[0003] To solve the above technical problems, the present invention proposes a Hall thruster anode assembly. By rationally optimizing and improving the anode structure, the residence time of the gas working medium in the discharge channel is increased. The conical design of the anode structure gradually increases the cross-sectional area of ​​the discharge channel along the outlet direction, thereby improving the overall performance of the Hall thruster.

[0004] The present invention provides a Hall thruster anode assembly, which at least includes a magnetic shield, a gas distribution ring and an anode; the magnetic shield at least includes an inner ring and an outer ring arranged concentrically, and the outer wall of the inner ring is connected to the inner wall of the outer ring through a bottom ring to form an annular cavity with an open top; the gas distribution ring is arranged in the annular cavity to axially divide the cavity into a primary gas buffer cavity and a secondary gas buffer cavity; the anode is arranged in the secondary gas buffer cavity and is connected to the upper end face of the gas distribution ring; wherein, the bottom ring is provided with a first through hole for connecting the gas supply pipe and the primary gas buffer cavity; the gas distribution ring is provided with a second through hole connecting the primary gas buffer cavity and the anode inner cavity; the anode is provided with a plurality of inclined holes connecting the anode inner cavity and the secondary gas buffer cavity.

[0005] In one embodiment, the cross-section of the anode is a conical structure, and the top thereof adopts an arc transition.

[0006] In one embodiment, the anode includes an inner distribution ring and an outer distribution ring spaced apart on the upper end surface of the gas distribution ring, and an anode top arranged on the top of the inner distribution ring and the outer distribution ring; the lower end surface of the anode top is provided with an extension section; the extension section extends between the inner distribution ring and the outer distribution ring, and forms the anode cavity together with the outer side surface of the inner distribution ring and the inner side surface of the outer distribution ring.

[0007] In one embodiment, the inclined holes include a plurality of first inclined small holes circumferentially evenly distributed on the inner distribution ring, and a plurality of second inclined small holes circumferentially evenly distributed on the outer distribution ring; each of the first inclined small holes circumferentially diverges from the anode inner cavity to the secondary gas buffer cavity; each of the second inclined small holes circumferentially diverges from the anode inner cavity to the secondary gas buffer cavity.

[0008] In one embodiment, the angle between the axis of the first inclined hole and the tangent plane is an acute angle X; the angle between the axis of the second inclined hole and the tangent plane is an acute angle Y; wherein the angle X is equal to the angle Y.

[0009] In one embodiment, the upper end face of the gas distribution ring is provided with an inner ring boss and an outer ring boss of concentric and different diameters; the bottom of the inner distribution ring is provided with a groove matching the inner ring boss, and the bottom of the outer distribution ring is provided with a groove matching the outer ring boss; the second through holes are evenly distributed between the inner ring boss and the outer ring boss along the circumference of the gas distribution ring.

[0010] In one embodiment, the cone angle of the cone structure ranges from 8° to 25°.

[0011] In any of the above embodiments, bosses of equal height are respectively provided on the outer ring of the inner ring and the inner ring of the outer ring close to the bottom ring, and the gas distribution ring is connected to the inner ring and the outer ring through the bosses.

[0012] In one embodiment, the top of the magnetic shield is higher than the top of the anode.

[0013] In one embodiment, the number of the first inclined holes is equal to the number of the second inclined holes.

[0014] The Hall thruster anode assembly of the present invention has at least one of the following beneficial effects:

[0015] 1. The Hall thruster anode assembly of the present invention provides inclined small holes in the inner and outer distribution rings of the anode, so that the gas working medium rotates and flows out along the inclined small holes of the anode, reducing the axial flow velocity of the gas and extending the residence time of the gas in the channel, thereby significantly improving the ionization efficiency of the working medium (especially krypton working medium).

[0016] 2. The anode of the Hall thruster anode assembly of the present invention has a conical structure, so that the cross-sectional area of ​​the discharge channel gradually increases along the outlet direction, which to a certain extent suppresses the thruster's low-frequency discharge oscillation and improves the thruster's discharge stability.

[0017] 3. The anode position of the Hall thruster anode assembly of the present invention is significantly extended downstream of the discharge channel, shortening the length of the ionization acceleration zone, which is more conducive to ion acceleration and improves thruster performance.

[0018] 4. The magnetic shield, discharge channel, anode and gas distribution ring of the Hall thruster anode assembly of the present invention adopt an integrated structural design. The entire discharge channel and the anode are at the same potential. Compared with the traditional structure, this greatly increases the anode surface area, reduces the electron heat deposition per unit area of ​​the anode, lowers the anode temperature, improves the electron acceptance efficiency and the overall working performance of the thruster.

[0019] 5. The anode assembly of the Hall thruster according to the embodiment of the present invention has a simple and lightweight structure, which greatly reduces the weight of the entire thruster.

[0020] Those skilled in the art will recognize additional features and advantages upon reading the detailed description and upon viewing the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 Schematic diagram of the overall structure of the Hall thruster anode assembly according to an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of a cross section of a Hall thruster anode assembly according to an embodiment of the present invention.

[0024] Figure 3 It is a structural schematic diagram of the gas distribution ring and the anode docking portion according to an embodiment of the present invention.

[0025] Figure 4 1 is a schematic cross-sectional view of an aa section of a Hall thruster anode assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purposes, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are used to illustrate the principles of the present invention, and are not configured to limit the present invention. In addition, the structural components in the drawings are not necessarily drawn to scale. For example, the dimensions of some structural components or areas in the drawings may be enlarged for other structural components or areas to facilitate understanding of the embodiments of the present invention.

[0027] The directional words appearing in the following description refer to the directions shown in the drawings and do not limit the specific structure of the embodiments of the present invention. In the description of the present invention, it should be noted that, unless otherwise specified, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0028] In addition, the terms "include", "comprising", "having" or any other variations thereof are intended to cover non-exclusive inclusion, so that a structure or component comprising a series of elements includes not only those elements, but also other mechanical elements not explicitly listed or inherent in the structure or component. In the absence of more limitations, the elements defined by the sentence "comprising..." do not exclude the presence of other identical elements in the article or device comprising the elements.

[0029] Spatially relative terms such as "below," "beneath," "under," "low," "above," "on," "high," and the like are used to facilitate description to explain the positioning of one element relative to a second element, indicating that these terms are intended to encompass different orientations of the device in addition to orientations different from those shown in the figures. In addition, for example, "one element is above / below another element" can mean that the two elements are in direct contact or that there are other elements between the two elements. Furthermore, terms such as "first," "second," and the like are also used to describe various elements, regions, portions, and the like, and should not be considered limiting. Similar terms are used throughout the description to represent similar elements.

[0030] For those skilled in the art, the present invention can be implemented without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention.

[0031] If a Hall thruster uses krypton as a working fluid, its ionization performance is likely to be poor due to its small atomic radius, high ionization energy, fast atomic motion speed, and short residence time in the discharge channel. Furthermore, at the same power, krypton thrusters are generally less efficient than xenon, and the heat loss caused by electron energy deposition is exacerbated, causing the anode temperature to increase. For high-power Hall thrusters, the voltage is higher and the current is greater, and the anode will also face the huge heat load problem caused by the large electron current, which will cause the anode to become red, and in severe cases, it will cause the anode to self-melt. Furthermore, the discharge stability of krypton thrusters is poor. In severe cases, low-frequency oscillations with large amplitudes can cause the thruster to extinguish, affecting the thruster's operating stability.

[0032] The advantage of krypton thrusters lies in their higher specific impulse. However, the anode in traditional structures is located farther from the discharge channel, resulting in a longer ion acceleration zone within the channel. This increases ion energy loss at the wall, reduces thrust, and thus reduces specific impulse. Therefore, to address these issues, the anode structure must be rationally optimized and improved to maximize the performance of the thruster with krypton as the working fluid.

[0033] In view of this, the present invention provides a high-performance Hall thruster anode assembly. Figure 1 and Figure 2 The present invention provides a Hall thruster anode assembly, which at least includes a magnetic shield 1, a gas distribution ring 2 and an anode 3. The magnetic shield 1 is an annular cavity with one end open, and the gas distribution ring 2 is a thin-walled circular ring structure. The gas distribution ring 2 is arranged in the annular cavity of the magnetic shield 1. The magnetic shield 1 at least includes an inner ring 11 and an outer ring 12 arranged concentrically, and the outer wall of the inner ring 11 and the inner wall of the outer ring 12 are connected by a bottom ring 13 to form an annular cavity with an open top. After the gas distribution ring 2 is arranged in the annular cavity of the magnetic shield 1, it is divided into a primary gas buffer cavity A and a secondary gas buffer cavity B (metal discharge channel) along the axial direction. The primary buffer cavity A is located at the lower end face of the gas distribution ring 2, and the secondary buffer cavity B is located at the upper end face of the gas distribution ring 2. The anode 3 is arranged in the secondary gas buffer cavity B and is connected to the upper end face of the gas distribution ring 2.

[0034] In this embodiment, the base ring 13 is provided with a first through-hole for connecting the gas supply pipe 4 with the primary gas buffer chamber A. The gas supply pipe 4 is inserted into the first through-hole and welded securely along its circumference. This provides gas to the anode assembly of the Hall thruster of this embodiment. The gas distribution ring 2 is provided with a second through-hole connecting the primary gas buffer chamber A with the anode cavity C. The anode 3 is provided with multiple inclined holes connecting the anode cavity C with the secondary gas buffer chamber B.

[0035] The Hall thruster anode assembly of this embodiment of the present invention is supplied with working fluid via a gas supply pipe 4. First, the primary gas buffer chamber A buffers and equalizes the incoming flow. This initial equalization of the working fluid enters the inner cavity C of the anode 3 through the second through-hole, then enters the gas buffer chamber B (metal discharge channel) through the inclined hole for secondary buffering before being discharged. Figure 2 The flow path of the working medium is marked. The working medium rotates and flows out along the inclined hole of the anode, which reduces the axial flow velocity of the gas, prolongs the residence time of the gas in the channel, and improves the ionization efficiency of the working medium (especially krypton).

[0036] Given the higher voltage and greater current of high-power Hall thrusters, the anode also faces the enormous heat load caused by the large electron current, which can easily cause the anode to glow red and, in severe cases, cause the anode to melt. Based on this, the magnetic shield, gas distribution ring, anode, and discharge channel of the embodiment of the present invention adopt an integrated design, and the entire discharge channel and the anode are at the same potential. Compared with traditional anode structures, this greatly increases the anode surface area, reduces the anode temperature, increases the electron acceptance efficiency, and improves the overall performance of the Hall thruster. At the same time, the entire structure also undertakes the functions of plasma discharge, gas distribution, and magnetic conductivity. The component structure is simple and lightweight, reducing the weight of the thruster.

[0037] See also Figure 2 In one embodiment, the cross-section of the anode 3 is conical, with a cone angle ranging from 8° to 25°. This conical anode structure allows the cross-sectional area of ​​the discharge channel (secondary buffer cavity) to gradually increase toward the outlet, suppressing low-frequency discharge oscillations in the thruster to a certain extent and improving thruster discharge stability. As a more preferred option, the cone angle of the anode 3 ranges from 8° to 15°. For ease of processing, the top of the anode 3 can adopt a circular arc transition.

[0038] During the operation of the thruster, the anode needs to withstand the energy deposition caused by frequent electron sputtering bombardment. In addition, the anode cannot affect the original magnetic field configuration, so the material of the anode is non-magnetic stainless steel.

[0039] See also Figure 2 and Figure 3 In one embodiment, to facilitate anode processing and forming, the anode 3 includes an inner distribution ring 31 and an outer distribution ring 32 spaced apart from each other on the upper end surface of the gas distribution ring 2, and an anode top 33 disposed on top of the inner and outer distribution rings 31, 32. The lower end surface of the anode top 33 is provided with an extension extending between the inner and outer distribution rings 31, 32. The extension of the anode top 33, the outer side surfaces of the inner and outer distribution rings 31, and the inner side surfaces of the outer distribution rings form an anode cavity C.

[0040] When assembling the anode 3 and the gas distribution ring 2 , the inner distribution ring 31 and the outer distribution ring 32 can be directly welded to the upper end surface of the gas distribution ring 2 .

[0041] Alternatively, concentric inner and outer bosses 21 and 22 of varying diameters can be provided on the upper end surface of the gas distribution ring 2. The bottom of the inner distribution ring 31 is provided with a groove that matches the inner boss 21, and the bottom of the outer distribution ring 32 is provided with a groove that matches the outer boss 22. In this embodiment, the inner boss 21 is secured by welding after being positioned and fixed within the groove of the inner distribution ring 31, and the outer boss 22 is secured by being positioned and fixed within the groove of the outer distribution ring 32. Subsequently, the anode top 33 is placed between the inner and outer anode distribution rings 31 and 32, and positioned using an extension section positioned between the outer rings of the inner and outer distribution rings 31 and 32. Finally, the anode top 33 is circumferentially welded to the inner and outer distribution rings 31 and 32.

[0042] It should be noted that the distance from the inner ring boss 21 to the inner ring 11 is equal to the distance from the outer ring boss 22 to the outer ring 12 .

[0043] The inner ring boss 21 and the outer ring boss 22 are of the same height, and the height is smaller than the thickness of the gas distribution ring 2 , so as to reduce the weight as much as possible without affecting subsequent welding.

[0044] The tapered anode structure in this embodiment allows the cross-sectional area of ​​the discharge channel to gradually increase toward the outlet, suppressing low-frequency discharge oscillations in the thruster to a certain extent and improving thruster discharge stability. The anode position is significantly extended downstream of the discharge channel, shortening the ionization acceleration zone, further facilitating ion acceleration and enhancing thruster performance.

[0045] See also Figure 3 and Figure 4 In the above embodiment, the second through-holes for connecting the primary gas buffer chamber A and the anode cavity C are located between the inner ring boss 21 and the outer ring boss 22. Specifically, the second through-holes are multiple small holes 23 evenly distributed along the circumference of the gas distribution ring 2 between the inner ring boss 21 and the outer ring boss 22. Furthermore, the number of small holes 23 can be 10 or 12.

[0046] See also Figure 4In one embodiment, the inclined holes include a plurality of first inclined holes 311 uniformly distributed circumferentially on the inner distribution ring 31, and a plurality of second inclined holes 321 uniformly distributed circumferentially on the outer distribution ring 32. The number of the first inclined holes 311 is the same as the number of the second inclined holes 321. Each first inclined hole 311 circumferentially diverges from the anode cavity C to the secondary gas buffer cavity B, and each second inclined hole 321 circumferentially diverges from the anode cavity C to the secondary gas buffer cavity B. It should be noted that the rotation direction of the gas working medium after passing through the first inclined hole and the second inclined hole is the same. That is to say, when looking at the thruster anode of this embodiment from a certain angle, if the gas working medium diverging through the first inclined hole rotates counterclockwise along the secondary gas buffer cavity B, the gas working medium diverging through the second inclined hole must also rotate counterclockwise along the secondary gas buffer cavity B.

[0047] Furthermore, the angle between the axis of the first inclined aperture and the tangent plane is an acute angle X, and the angle between the axis of the second inclined aperture and the tangent plane is an acute angle Y. The angle X is equal to the angle Y, and the angles X and Y are in the range of 15° to 40°.

[0048] The gas working medium rotates and flows out through the inclined small holes of the anode of this embodiment, which reduces the axial flow velocity of the gas working medium, prolongs the residence time of the gas working medium in the discharge channel (secondary gas buffer chamber), and improves the ionization efficiency of the working medium (especially krypton working medium).

[0049] The anode of the embodiment of the present invention adopts a structure in which the inner distribution ring and the outer distribution ring are separated, so as to facilitate the processing of inclined small holes on the inner and outer distribution rings.

[0050] See also Figure 3 In any of the above embodiments, in order to facilitate the positioning and installation of the gas distribution ring, bosses T of equal height are provided on the outer ring of the inner ring 11 and the inner ring of the outer ring 12 close to the bottom ring. The gas distribution ring 2 is placed on the side of the two bosses away from the bottom ring, and is axially positioned by the bosses, and then fixedly connected to the inner ring 11 and the outer ring 12 by circumferential welding.

[0051] In the above embodiment, the top of the magnetic shield is higher than the top of the anode. In other words, the top of the anode is 1 to 3 mm below the discharge channel outlet. Extending the anode downstream of the discharge channel shortens the ionization acceleration zone and increases the magnetic field gradient, which is more conducive to ion acceleration and improves thruster performance.

[0052] The above embodiments can be combined with each other and have corresponding technical effects.

[0053] The Hall thruster anode assembly of the present invention rationally optimizes and improves the anode structure, thereby increasing the ionization rate of the gas working fluid (especially krypton working fluid with higher ionization energy), reducing the anode temperature, and improving the thruster performance.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A Hall thruster anode assembly, characterized in that: At least: A magnetic shield, a gas distribution ring, and an anode; the magnetic shield comprises at least an inner ring and an outer ring arranged concentrically, the outer wall of the inner ring being connected to the inner wall of the outer ring via a bottom ring to form an annular cavity with an open top; the gas distribution ring is arranged in the annular cavity to axially divide the cavity into a primary gas buffer cavity and a secondary gas buffer cavity; the anode is arranged in the secondary gas buffer cavity and connected to the upper end face of the gas distribution ring; The bottom ring is provided with a first through hole for connecting the gas supply pipe and the primary gas buffer chamber; the gas distribution ring is provided with a second through hole for connecting the primary gas buffer chamber and the anode inner cavity; the anode is provided with a plurality of inclined holes for connecting the anode inner cavity and the secondary gas buffer chamber; The primary buffer chamber is located at the lower end surface of the gas distribution ring, and the secondary buffer chamber is located at the upper end surface of the gas distribution ring.

2. The Hall thruster anode assembly according to claim 1, characterized in that: The cross-section of the anode is a conical structure, and the top thereof adopts an arc transition.

3. The Hall thruster anode assembly according to claim 2, characterized in that: The anode includes an inner distribution ring and an outer distribution ring spaced apart and arranged on the upper end surface of the gas distribution ring, and an anode top arranged on the top of the inner distribution ring and the outer distribution ring; An extension section is provided on the lower end surface of the anode top; the extension section extends between the inner distribution ring and the outer distribution ring, and forms the anode cavity together with the outer side surface of the inner distribution ring and the inner side surface of the outer distribution ring.

4. The Hall thruster anode assembly according to claim 3, characterized in that: The inclined holes include a plurality of first inclined small holes uniformly distributed circumferentially on the inner distribution ring, and a plurality of second inclined small holes uniformly distributed circumferentially on the outer distribution ring; Each of the first inclined small holes circumferentially diverges from the anode inner cavity to the secondary gas buffer cavity; each of the second inclined small holes circumferentially diverges from the anode inner cavity to the secondary gas buffer cavity.

5. The Hall thruster anode assembly according to claim 4, characterized in that: The angle between the axis of the first inclined small hole and the tangent plane is an acute angle X; the angle between the axis of the second inclined small hole and the tangent plane is an acute angle Y; Here, the angle of X is equal to the angle of Y.

6. The Hall thruster anode assembly according to claim 3, characterized in that: The upper end surface of the gas distribution ring is provided with an inner ring boss and an outer ring boss of concentric and different diameters; the bottom of the inner distribution ring is provided with a groove matching the inner ring boss, and the bottom of the outer distribution ring is provided with a groove matching the outer ring boss; The second through holes are evenly distributed between the inner ring boss and the outer ring boss along the circumference of the gas distribution ring.

7. The Hall thruster anode assembly according to claim 2, characterized in that: The cone angle of the cone structure ranges from 8° to 25°.

8. The Hall thruster anode assembly according to any one of claims 1 to 7, characterized in that: Bosses of equal height are respectively provided on the outer ring of the inner ring and the inner ring of the outer ring close to the bottom ring, and the gas distribution ring is connected to the inner ring and the outer ring through the bosses.

9. The Hall thruster anode assembly according to claim 8, characterized in that: The top of the magnetic shield is higher than the top of the anode.

10. The Hall thruster anode assembly according to claim 5, characterized in that: The number of the first inclined small holes is equal to the number of the second inclined small holes.

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