A magnetic field design structure for improving the performance of a hall thruster

Abstract

The application relates to the technical field of Hall thrusters, in particular to a magnetic field design structure for improving the performance of a Hall thruster, which comprises a magnetic core, a discharge channel, an excitation coil and an excitation power supply, wherein: the magnetic core is composed of pure electrical iron and has a "H" shaped structure in cross section; the excitation coil is wound by insulated wires and is wound on the pure electrical iron, and comprises an inner excitation coil and an outer excitation coil, the inner excitation coil and the outer excitation coil are coaxial in structure; the discharge channel is arranged between the inner excitation coil and the outer excitation coil; and the excitation power supply is arranged in multiple groups and is connected with the inner excitation coil and the outer excitation coil respectively. In the application, the excitation coil in the traditional Hall thruster is divided into multiple independent excitation coils, the vector characteristics of the magnetic field are utilized, and the current size or direction in each excitation coil is independently regulated, so that the regulation of the magnetic field distribution in the plume area can be realized without changing the magnetic field configuration in the discharge channel of the thruster and the maximum magnetic field intensity at the outlet of the thruster.

Description

Technical Field

[0001] This application relates to the field of Hall thruster technology, and more specifically, to a magnetic field design structure for improving the performance of Hall thrusters. Background Technology

[0002] Hall thrusters, as an electrostatic electric propulsion technology based on the principle of electron closed-loop drift, have the advantages of simple structure, high thrust-to-power ratio and high thrust density compared with grid ion thrusters. At present, Hall thrusters have been widely used in satellite communication, low-Earth orbit Internet constellations and other fields.

[0003] During the operation of the Hall thruster, a portion of the primary electrons emitted by the hollow cathode outside the discharge channel enter the discharge channel. Under the constraint of the magnetic field, a local high-density electron accumulation region is formed at the location of the strongest magnetic field in the discharge channel. Due to the local concentration of electrons, the spatial potential of the electron accumulation region drops sharply, forming a large axial electric field. The neutral gas entering the discharge channel from the gas distribution ring ionizes and collides with the primary electrons constrained by the magnetic field to form ions. The ionized ions are accelerated out of the discharge channel under the action of the axial electric field and neutralize with the electrons emitted by the hollow cathode that have not entered the discharge channel to form a neutral beam, thereby generating thrust.

[0004] Based on the aforementioned working principle of Hall thrusters, researchers both domestically and internationally have conducted extensive research to improve their performance. This includes optimizing the distribution of the gas distribution ring's outlet holes and their exhaust angle to improve the uniformity of the neutral gas within the discharge channel, increase the ionization rate of the neutral gas, and enhance the utilization rate of the neutral gas working fluid; optimizing the topology of the magnetic field in the discharge channel (changing the axial magnetic field gradient, controlling the position of the magnetic null point, etc.) to improve the magnetic field's ability to confine primary electrons, prolong the residence time of primary electrons in the discharge channel, and increase the collision probability of primary electrons with the neutral gas, thereby increasing the plasma density; or improving the thruster's efficiency by reducing the plume divergence angle to suppress discharge oscillations in the Hall thruster. However, almost all of these methods for improving Hall thruster performance involve controlling the magnetic field within the Hall thruster's discharge channel, or through parameter optimization design, or even the use of external additional circuits. While improving thruster performance, these methods inevitably alter the physical processes within the thruster's discharge channel or require additional input power. Summary of the Invention

[0005] This application provides a magnetic field design structure to improve the performance of a Hall thruster. Without changing the magnetic field characteristics within the thruster's discharge channel, the magnetic field in the thruster's plume region is altered to influence the beam dynamics, thereby improving the thruster's performance.

[0006] To achieve the above objectives, this application provides a magnetic field design structure for improving the performance of a Hall thruster, including a magnetic core, a discharge channel, an excitation coil, and an excitation power supply. The magnetic core is composed of electrical pure iron with an "I"-shaped cross-section. The excitation coil is made of insulated wire wound around the electrical pure iron, including an inner excitation coil and an outer excitation coil, which are coaxial. The discharge channel is located between the inner and outer excitation coils. Multiple excitation power supplies are provided, each connected to both the inner and outer excitation coils.

[0007] Furthermore, multiple sets of internal excitation coils are provided, and the multiple sets of internal excitation coils are sequentially fitted onto one side of the magnetic core near the inner wall of the discharge channel from top to bottom. Each set of internal excitation coils is connected to an independent excitation power supply.

[0008] Furthermore, multiple sets of external excitation coils are provided, and the multiple sets of external excitation coils are sequentially fitted onto one side of the magnetic core near the outer wall of the discharge channel from top to bottom. Each set of external excitation coils is connected to an independent excitation power supply.

[0009] Furthermore, each set of internal excitation coils and each set of external excitation coils are set up accordingly, and the internal excitation coils and external excitation coils are symmetrical in structure.

[0010] Furthermore, copper gaskets with a thickness of ≥1mm are provided between two adjacent sets of excitation coils.

[0011] Furthermore, the discharge channel has a "U" shaped structure and is made of sputter-resistant ceramic.

[0012] Furthermore, when performing magnetic field control, by adjusting each group of independent excitation power supplies, the magnitude or direction of the excitation current in the independent internal or external excitation coils connected to them can be individually adjusted, thereby achieving overall control of the magnetic field distribution.

[0013] The magnetic field design structure provided by this invention for improving the performance of a Hall thruster has the following beneficial effects:

[0014] This application divides the excitation coil in a traditional Hall thruster into multiple independent excitation coils. By utilizing the vector characteristics of the magnetic field, the magnetic field distribution in the plume region can be controlled by independently adjusting the magnitude or direction of the current in each excitation coil without changing the magnetic field configuration in the thruster discharge channel or the maximum magnetic field strength at the thruster outlet. The structure is simple and easy to operate. No additional input power is required to improve the performance of the Hall thruster. It does not change the magnetic circuit structure of the traditional Hall thruster, does not affect the physical processes in the Hall thruster discharge channel, and does not exacerbate the sputtering corrosion of the wall material by high-energy ions while improving the thruster performance. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings:

[0016] Figure 1 This is a schematic diagram of a magnetic field design structure for improving the performance of a Hall thruster according to an embodiment of this application;

[0017] In the diagram: 1-Magnetic core, 2-Internal excitation coil, 3-External excitation coil, 4-Excitation power supply, 5-Discharge channel, 6-Copper pad. Detailed Implementation

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

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] In addition, the term "multiple" should mean two or more.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 As shown, this application provides a magnetic field design structure for improving the performance of a Hall thruster, including a magnetic core 1, a discharge channel 5, an excitation coil, and an excitation power supply 4. The magnetic core 1 is composed of electrical pure iron with an "I"-shaped cross-section. The excitation coil is made of insulated wire wound around the electrical pure iron, including an inner excitation coil 2 and an outer excitation coil 3, which are coaxial. The discharge channel 5 is located between the inner excitation coil 2 and the outer excitation coil 3. Multiple sets of excitation power supplies 4 are provided, each connected to the inner excitation coil 2 and the outer excitation coil 3.

[0025] Specifically, the magnetic field design structure for improving the performance of Hall thrusters provided in this application divides the excitation coil in a traditional Hall thruster into multiple independent excitation coils. By utilizing the vector characteristics of the magnetic field and independently adjusting the magnitude or direction of the current in each excitation coil, the magnetic field distribution in the plume region can be controlled without changing the magnetic field configuration in the thruster discharge channel 5 and the maximum magnetic field strength at the thruster outlet, thereby achieving the goal of improving thruster performance. The magnetic core 1 is mainly located on both sides of the discharge channel 5. It is composed of electrical pure iron (DT4C) with excellent magnetic permeability, primarily to increase the confinement of the magnetic field and ensure that the magnetic lines of force are distributed along the shape of the magnetic circuit of the core 1, preventing them from spreading to areas other than the outlet of the discharge channel 5. The cross-section of the core 1 preferably adopts an "I"-shaped structure to prevent the excitation coil wound on the core 1 from slipping off at both ends. The excitation coil is mainly made of insulated wire wound on the "I"-shaped electrical pure iron. The insulated wire wound on the core 1 is generally in even layers, ensuring that the insulated wire enters and exits from the same end of the electrical pure iron. The excitation coil is mainly used to generate the magnetic field of the Hall thruster, including internal excitation. Coil 2 and external excitation coil 3, as well as internal excitation coil 2 and external excitation coil 3, are coaxial. They work together to generate the magnetic field required for the Hall thruster to operate. Discharge channel 5 is located between internal excitation coil 2 and external excitation coil 3. Excitation power supply 4 is connected to the excitation coil and is mainly used to control the magnitude and direction of the current in the excitation coil connected to it. The two ends of the wires constituting a single excitation coil are connected to the positive and negative poles of excitation power supply 4, respectively. The magnitude of the excitation current can be adjusted by adjusting the magnitude of the current in excitation power supply 4. Changing the connection sequence of the insulated wires to the positive and negative poles of the power supply can change the direction of the current in the excitation coil, thereby changing the magnetic poles of the excitation coil and thus controlling the overall magnetic field distribution.

[0026] Furthermore, multiple sets of internal excitation coils 2 are arranged, with each set nested sequentially from top to bottom on one side of the magnetic core 1 near the inner wall of the discharge channel 5. Each set of internal excitation coils 2 is connected to an independent excitation power supply 4. The internal excitation coils 2 are arranged in multiple sets according to the actual length of the magnetic core 1. Each set of internal excitation coils 2 is an independent excitation coil group, meaning each set is connected to a separate excitation power supply 4. This separate excitation power supply 4 allows for individual adjustment of the current magnitude or direction within the set of internal excitation coils 2, thereby enabling individual adjustment of the magnetic field strength or direction generated by the set of internal excitation coils 2.

[0027] Furthermore, multiple sets of external excitation coils 3 are provided, and these sets are sequentially mounted on the magnetic core 1 near the outer wall of the discharge channel 5 from top to bottom. Each set of external excitation coils 3 is connected to an independent excitation power supply 4. Similarly, multiple sets of external excitation coils 3 are provided according to the actual length of the magnetic core 1, and these sets are sequentially mounted on the magnetic core 1 near the outer wall of the discharge channel 5 from top to bottom. Each set of external excitation coils 3 is an independent excitation coil group, meaning that each set of external excitation coils 3 is connected to a separate excitation power supply 4. This separate excitation power supply 4 allows for individual adjustment of the current magnitude or direction in the set of external excitation coils 3, thereby enabling individual adjustment of the magnetic field strength or direction generated by the set of external excitation coils 3.

[0028] Furthermore, each set of internal excitation coils 2 and each set of external excitation coils 3 are correspondingly arranged, and the internal excitation coils 2 and external excitation coils 3 are generally symmetrical in structure. The internal excitation coils 2 and external excitation coils 3 are arranged in pairs, such as... Figure 1 As shown, a set of internal excitation coils 2 is correspondingly provided with a set of external excitation coils 3. In addition, except for the internal and external excitation coils 3 located at the bottom of the magnetic core 1, the lengths of the other paired internal excitation coils 2 and external excitation coils 3 are consistent. This is mainly to reduce the number of parts of different sizes to be processed and to reduce the difficulty of thrust coil conversion.

[0029] Furthermore, a copper gasket 6 is provided between two adjacent sets of excitation coils, and the thickness of the copper gasket 6 is ≥1mm. Whether it is the inner excitation coil 2 or the outer excitation coil 3, a copper gasket 6 is provided between two adjacent sets of excitation coils. The copper gasket 6 has good thermal conductivity, is non-magnetic, and preferably has a thickness of ≥1mm. The copper gasket 6 separates the two adjacent sets of excitation coils to prevent mutual interference between the excitation coils.

[0030] Furthermore, the discharge channel 5 has a "U"-shaped structure and is made of sputter-resistant ceramic. In this embodiment, the discharge channel 5 of the Hall thruster is preferably a sputter-resistant ceramic discharge channel 5 with a "U"-shaped structure.

[0031] Furthermore, when performing magnetic field control, by adjusting each group of independent excitation power supply 4, the magnitude or direction of the excitation current in the independent internal excitation coil 2 or independent external excitation coil 3 connected to it can be individually adjusted, thereby achieving overall control of the magnetic field distribution. In this embodiment, the magnetic field is generated based on the superposition principle of magnetic field vector characteristics. Multiple independent excitation coils generate a multi-degree-of-freedom adjustable magnetic field. Specifically, according to the required magnetic field distribution, the independent excitation power supply 4 corresponding to each group of excitation coils is adjusted, allowing for individual adjustment of the current magnitude or direction of each group. Based on the vector superposition characteristics of the magnetic field, overall adjustment of the magnetic field distribution can be achieved. Furthermore, the number of independent excitation coils can be increased during the adjustment process to achieve multi-degree-of-freedom adjustment of the magnetic field. When using this embodiment for magnetic field control, it is not necessary to increase the thruster's input power or maximum magnetic field strength, nor to change the magnetic field topology within the discharge channel 5. No new magnetic circuit structure needs to be designed. Simply dividing the excitation coils in a traditional Hall thruster into multiple independent excitation coils and utilizing the vector characteristics of the magnetic field, by independently adjusting the current magnitude or direction in each excitation coil, the magnetic field distribution can be controlled without altering the magnetic field configuration within the thruster's discharge channel 5 or the maximum magnetic field strength at the thruster's outlet.

[0032] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A magnetic field design structure to improve the performance of a Hall Thruster, characterized in that, It includes a magnetic core, a discharge channel, an excitation coil, and an excitation power supply, among which: The magnetic core is made of electrical pure iron and has an "I" shaped cross-section. The excitation coil is made of insulated wire wound around electrical pure iron, and includes an inner excitation coil and an outer excitation coil, which are coaxial. The discharge channel is disposed between the inner excitation coil and the outer excitation coil; The excitation power supply is provided in multiple sets, which are respectively connected to the inner excitation coil and the outer excitation coil; The internal excitation coil is provided in multiple sets, and the multiple sets of internal excitation coils are sequentially sleeved on one side of the magnetic core near the inner wall of the discharge channel from top to bottom. Each set of internal excitation coils is connected to an independent excitation power supply. The external excitation coil is provided in multiple sets, and the multiple sets of external excitation coils are sequentially fitted onto the magnetic core on one side of the outer wall of the discharge channel from top to bottom. Each set of external excitation coils is connected to an independent excitation power supply. When performing magnetic field control, by adjusting each group of independent excitation power supplies, the magnitude or direction of the excitation current in the independent internal or external excitation coils connected to them can be individually adjusted, thereby achieving overall control of the magnetic field distribution.

2. The magnetic field design structure for boosting the performance of a Hall thrustor according to claim 1, characterized in that, Each set of internal excitation coils and each set of external excitation coils are set up in a corresponding manner, and the internal excitation coils and external excitation coils are symmetrical in structure.

3. The magnetic field design structure for boosting the performance of a Hall thrustor according to claim 2, characterized in that, A copper pad is provided between two adjacent sets of excitation coils, and the thickness of the copper pad is ≥1mm.

4. The magnetic field design structure for boosting the performance of a Hall thrustor according to claim 1, wherein The discharge channel has a "U" shaped structure and is made of sputter-resistant ceramic.

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