Long life ion thruster capable of outputting a wide range of thrust

Abstract

This application relates to the field of aerospace technology, specifically to a long-life ion thruster capable of outputting a wide range of thrust. The thruster includes a shell, an ionization module, an extraction and acceleration module, a gas supply module, and an insulation module. The ionization module is located inside the shell; the extraction and acceleration module is located at the working propellant outlet of the ionization module; the gas supply module is connected to the gas inlet of the ionization module; and the insulation module is connected in series in the gas path of the gas supply module. The ionization module, extraction and acceleration module, gas supply module, and insulation module are integrated into a single unit via the shell and internal support components. This application employs a graphite-contact hollow cathode and widens its emission current range, enabling the thruster to adapt to large fluctuations in input power and providing a wide range of thrust output capability. A sputtering deposition anti-detachment structure is provided on the inner surface of the discharge chamber, effectively suppressing internal contamination and short-circuit risks caused by sputtering product detachment, significantly extending the thruster's service life.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and more specifically, to a long-life ion thruster capable of outputting a wide range of thrust. Background Technology

[0002] Ion thrusters, as an advanced electric propulsion device, possess outstanding advantages such as high specific impulse, high efficiency, and long lifespan, making them an important choice for spacecraft attitude control, orbital transfer, and main propulsion missions in deep space exploration. With the continuous development of space exploration missions, especially the fluctuations in solar power caused by changes in the spacecraft's distance from the sun in deep space exploration missions, ion thrusters must possess a wide range of thrust adjustment capabilities to adapt to changes in input power. Simultaneously, the ever-increasing speed increment requirements also place higher demands on the thruster's operational lifespan, requiring the thruster to operate stably for extended periods to generate sufficient total impulse.

[0003] Existing ion thrusters typically consist of a hollow cathode, a discharge chamber, a grid assembly, a gas supply system, and an insulating structure. Their typical operation involves the hollow cathode emitting electrons into the discharge chamber, ionizing the working gas to generate plasma, and the grid assembly extracting and accelerating the ions to generate thrust. In existing technologies, researchers have attempted to improve thruster performance by optimizing the cathode structure and modifying the grid material. For example, some designs use scandium cathodes to increase the emission current density, or molybdenum grids to enhance sputtering resistance; other designs improve discharge uniformity by increasing the discharge chamber volume or optimizing the magnetic field configuration.

[0004] However, the aforementioned existing technologies still have significant drawbacks. First, the emission current range of conventional hollow cathodes is narrow, making it difficult to simultaneously meet the discharge requirements of both low and high thrust conditions under wide power input, thus limiting the thrust adjustment range of the thruster. Second, the discharge chamber is subjected to long-term ion sputtering, and sputtered deposits are prone to detachment and particulate contamination, which can lead to internal short circuits or discharge instability in severe cases, limiting the thruster's lifespan. Furthermore, it is difficult to guarantee extremely small spacing tolerances during the fabrication and assembly of traditional gates; uneven gate spacing can lead to a decline in the performance of the ion optics system and an increased risk of accelerated voltage breakdown. Finally, the insulation structure in the gas supply pipeline exhibits unstable insulation performance under wide flow rate variations, and increased leakage current affects the thruster's efficiency and reliability. In summary, existing ion thrusters cannot simultaneously meet the dual requirements of wide-range thrust output and long-life operation. Summary of the Invention

[0005] This application provides a long-life ion thruster capable of outputting a wide range of thrust, which can address the needs of spacecraft power variations and large velocity increments. It can also be applied to spacecraft attitude and orbit control missions with diverse thrust requirements, improving the flexibility, efficiency, and accuracy of attitude or orbit control.

[0006] To achieve the above objectives, this application provides a long-life ion thruster capable of outputting a wide range of thrust, comprising a housing, an ionization module, an extraction and acceleration module, a gas supply module, and an insulation module. The ionization module is disposed inside the housing and is used to ionize the working gas to generate plasma. The extraction and acceleration module is disposed at the working gas outlet of the ionization module and is used to extract ions from the plasma and accelerate them out to generate thrust. The gas supply module is connected to the gas inlet of the ionization module and is used to supply the working gas to the ionization module. The insulation module is connected in series in the gas path of the gas supply module to maintain electrical insulation between the gas supply module and the ionization module. The ionization module, extraction and acceleration module, gas supply module, and insulation module are integrated into a single unit through the housing and internal support components, jointly achieving wide-range thrust output and long-life operation.

[0007] Furthermore, the ionization module includes a discharge chamber and a hollow cathode, wherein: the inner surface of the discharge chamber has a sputtering deposition anti-detachment structure; the hollow cathode is a graphite contact electrode hollow cathode, and its contact electrode material is sputter-resistant high-purity graphite.

[0008] Furthermore, the hollow cathode includes a first cathode and a second cathode, wherein: the first cathode serves as the cathode of the discharge chamber, and its emission current range is: the minimum self-sustaining emission current is less than 1A lower than the discharge current corresponding to the minimum thrust output of the ion thruster, and the maximum emission current is more than 2A higher than the discharge current corresponding to the maximum thrust output of the ion thruster; the second cathode serves as the cathode of the neutralizer, and its emission current range is: the minimum self-sustaining emission current is less than 0.1A lower than the beam current corresponding to the minimum thrust output of the ion thruster, and the maximum emission current is more than 0.5A higher than the beam current corresponding to the maximum thrust output of the ion thruster.

[0009] Furthermore, the ratio of the average to the maximum ion density at the discharge chamber outlet is ≥0.75; the discharge loss is ≤200W / A when the ion thruster outputs maximum thrust and ≤300W / A when it outputs minimum thrust.

[0010] Furthermore, the acceleration module is a graphite gate, which includes at least two stacked gate sheets.

[0011] Furthermore, the difference between the maximum and minimum spacing between two adjacent gate plates in the entire gate aperture area is <0.05mm; the gate aperture alignment is <0.05mm.

[0012] Furthermore, the insulation module is a gas-electric insulator located between the high-potential and low-potential sections of the gas supply module pipeline. Within the range of the highest operating voltage difference and the working fluid flow rate corresponding to all output thrusts, its leakage current is <20μA.

[0013] Furthermore, the internal support components are ceramic insulated support components.

[0014] This application provides a long-life ion thruster capable of outputting a wide range of thrust, which has the following advantages: This application employs a graphite contact electrode hollow cathode and widens its emission current range, enabling the thruster to adapt to large fluctuations in input power and possess a wide range of thrust output capabilities. The inner surface of the discharge chamber is equipped with a sputtering deposition anti-detachment structure, which effectively suppresses internal contamination and short-circuit risks caused by sputtering product peeling, significantly extending the thruster's service life. By improving the gate processing and assembly precision, optimizing discharge uniformity, and improving gas supply insulation performance, the thruster's operational stability and efficiency under a wide range of operating conditions are comprehensively improved, meeting the dual requirements of power adaptability and large total stroke for deep space exploration missions. 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: Figure 1 This is a schematic diagram of the structure of a long-life ion thruster capable of outputting a wide range of thrust, provided according to an embodiment of this application. In the figure: 1-first cathode, 2-discharge chamber, 3-graphite grid, 4-gas circuit electrical insulator, 5-outer shell, 6-gas supply module, 7-internal support assembly, 8-second cathode. Detailed Implementation

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] In addition, the term "multiple" should mean two or more.

[0021] 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.

[0022] like Figure 1 As shown, this application provides a long-life ion thruster capable of outputting a wide range of thrust, including a housing 5, an ionization module, an extraction and acceleration module, a gas supply module 6, and an insulation module. The ionization module is located inside the housing 5 and is used to ionize the working gas to generate plasma. The extraction and acceleration module is located at the working gas outlet of the ionization module and is used to extract ions from the plasma and accelerate them out to generate thrust. The gas supply module 6 is connected to the gas inlet of the ionization module and is used to supply the working gas to the ionization module. The insulation module is connected in series in the gas path of the gas supply module 6 to maintain electrical insulation between the gas supply module 6 and the ionization module. The ionization module, extraction and acceleration module, gas supply module 6, and insulation module are integrated into one unit through the housing 5 and internal support components 7, jointly achieving wide-range thrust output and long-life operation.

[0023] Specifically, the long-life ion thruster with a wide thrust range provided in this application embodiment has a thrust range of 10~120mN, a lifespan of over 30,000 hours, and a total impulse of over 9MN·s. The ionization module, extraction acceleration module, gas supply module 6, and insulation module are integrated into one unit via a housing 5 and internal support components 7. The ionization module is used to ionize the working gas to generate plasma; the extraction acceleration module is used to extract ions from the plasma and accelerate them out to generate thrust; the gas supply module 6 is used to supply the working gas to the ionization module; and the insulation module is used to maintain electrical insulation between the gas supply module 6 and the ionization module.

[0024] Furthermore, the ionization module includes a discharge chamber 2 and a hollow cathode, wherein: the inner surface of the discharge chamber 2 has a sputtering deposition anti-detachment structure; the hollow cathode is a graphite contact electrode hollow cathode, and its contact electrode material is sputter-resistant high-purity graphite.

[0025] Specifically, the inner surface of discharge chamber 2 adopts a textured structure to prevent sputtered deposits from detaching. This ensures that the sputtered deposits adhere firmly to the wall surface, preventing them from peeling off into fragments. This guarantees a clean working environment within discharge chamber 2, thereby maintaining plasma stability and avoiding secondary failures caused by peeling. Consequently, the lifespan of discharge chamber 2 and the entire thruster is significantly extended. The hollow cathode is made of high-purity graphite, which experiences extremely slow wear under long-term ion bombardment and can maintain its original geometry for a long time. Under high-temperature thermal stress, it can reduce mechanical structural damage caused by thermal deformation. At the same time, it has good thermal conductivity and radiative heat dissipation capabilities, enabling rapid heat dissipation from the cathode emission area.

[0026] Furthermore, the hollow cathode includes a first cathode 1 and a second cathode 8, wherein: the first cathode 1 serves as the cathode of the discharge chamber 2, and its emission current range is: the minimum self-sustaining emission current is less than 1A lower than the discharge current corresponding to the minimum thrust output of the ion thruster, and the maximum emission current is more than 2A higher than the discharge current corresponding to the maximum thrust output of the ion thruster; the second cathode 8 serves as the cathode of the neutralizer, and its emission current range is: the minimum self-sustaining emission current is less than 0.1A lower than the beam current corresponding to the minimum thrust output of the ion thruster, and the maximum emission current is more than 0.5A higher than the beam current corresponding to the maximum thrust output of the ion thruster.

[0027] Specifically, in the embodiments of this application, the first cathode 1, which serves as the discharge cathode of the discharge chamber 2, preferably has an emission current range greater than 12A, a minimum self-sustaining emission current preferably 1.9A lower than the discharge current corresponding to the minimum thrust output of the ion thruster, and a maximum emission current preferably 5A higher than the discharge current corresponding to the maximum thrust output of the ion thruster; the second cathode 8, which serves as the neutralizer, preferably has an emission current range of 5A, a minimum self-sustaining emission current preferably 0.2A lower than the beam current corresponding to the minimum thrust output of the ion thruster, and a maximum emission current preferably 2.7A higher than the beam current corresponding to the maximum thrust output of the ion thruster.

[0028] More specifically, by widening the range of the hollow cathode emission current, it ensures that the cathode is always above the self-sustaining discharge shutdown limit within a wide range; it ensures that the cathode has a margin when operating at high current and does not operate in the emission limit region, thereby delaying cathode wear and ensuring full-condition coverage and stable operation.

[0029] Furthermore, the ratio of the average to the maximum ion density at the outlet of discharge chamber 2 is ≥0.75, ensuring the long lifespan and thermal uniformity of the grid and the wall of discharge chamber 2; the discharge loss is ≤200W / A when the ion thruster outputs maximum thrust, ensuring that the energy is not overloaded at full power; the discharge loss is ≤300W / A when outputting minimum thrust, ensuring that the flame does not shut down at low power.

[0030] Furthermore, the acceleration module is a graphite gate 3, which includes at least two stacked gate sheets, preferably a screen gate and an acceleration gate, to form an electrostatic field to accelerate ions and reduce beam divergence.

[0031] Furthermore, the difference between the maximum and minimum spacing between two adjacent gate plates in the entire gate aperture area is <0.05mm, preferably 0.04mm, to prevent local breakdown; the gate aperture alignment is <0.05mm, preferably 0.03mm, to ensure the smooth passage of the ion beam and prevent the gate from being directly bombarded and lost.

[0032] Furthermore, the insulation module is a gas-circuit electrical insulator 4, located between the high-potential and low-potential sections of the gas supply module 6 pipeline. Its leakage current is <20μA across the highest operating voltage difference and the working fluid flow rate range corresponding to all output thrusts. The gas-circuit electrical insulator 4 possesses electrical insulation capabilities across all flow rates, and its leakage current is less than 3μA at the highest operating voltage of 1290V and at all flow rates corresponding to the output thrust of the ion thruster.

[0033] Furthermore, the internal support component 7 is a ceramic insulated support component, which ensures that the position of each module remains unchanged under vibration and thermal environments, provides insulation without leakage under a wide range of operating conditions, resists plasma erosion, and guarantees a long service life.

[0034] 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 long-life ion thruster capable of outputting a wide range of thrust, characterized in that, It includes a casing, an ionization module, an extraction and acceleration module, a gas supply module, and an insulation module, wherein: The ionization module is located inside the outer casing and is used to ionize the working gas to generate plasma. The extraction acceleration module is located at the working fluid outlet end of the ionization module and is used to extract ions from the plasma and accelerate them out to generate thrust. The gas supply module is connected to the gas inlet of the ionization module and is used to supply working gas to the ionization module; The insulation module is connected in series in the gas path of the gas supply module to maintain the electrical insulation between the gas supply module and the ionization module; The ionization module, the extraction acceleration module, the gas supply module, and the insulation module are integrated into one unit through the outer shell and internal support components, which together achieve a wide range of thrust output and long service life.

2. The long-life ion thruster capable of outputting a wide range of thrust according to claim 1, characterized in that, The ionization module includes a discharge chamber and a hollow cathode, wherein: The inner surface of the discharge chamber has a sputtering deposition anti-detachment structure; The hollow cathode is a graphite contact hollow cathode, and its contact material is sputter-resistant high-purity graphite.

3. The long-life ion thruster capable of outputting a wide range of thrust according to claim 2, characterized in that, The hollow cathode includes a first cathode and a second cathode, wherein: The first cathode serves as the cathode of the discharge chamber, and its emission current range is as follows: the minimum self-sustaining emission current is less than 1A lower than the discharge current corresponding to the minimum thrust output by the ion thruster, and the maximum emission current is more than 2A higher than the discharge current corresponding to the maximum thrust output by the ion thruster. The second cathode serves as the cathode of the neutralizer, and its emission current range is as follows: the minimum self-sustaining emission current is less than 0.1A lower than the beam current corresponding to the minimum thrust output of the ion thruster, and the maximum emission current is more than 0.5A higher than the beam current corresponding to the maximum thrust output of the ion thruster.

4. The long-life ion thruster capable of outputting a wide range of thrust according to claim 3, characterized in that, The ratio of the average to the maximum ion density at the outlet of the discharge chamber is ≥0.75; the discharge loss is ≤200W / A when the ion thruster outputs the maximum thrust and ≤300W / A when it outputs the minimum thrust.

5. The long-life ion thruster capable of outputting a wide range of thrust according to claim 4, characterized in that, The extraction acceleration module is a graphite gate, which includes at least two stacked gate sheets.

6. The long-life ion thruster capable of outputting a wide range of thrust according to claim 5, characterized in that, The difference between the maximum and minimum spacing between two adjacent gate plates in the entire gate aperture area is <0.05mm; the gate aperture alignment is <0.05mm.

7. The long-life ion thruster capable of outputting a wide range of thrust according to claim 6, characterized in that, The insulation module is a gas-electric insulator located between the high-potential and low-potential sections of the gas supply module pipeline. Within the range of the highest operating voltage difference and the working fluid flow rate corresponding to all output thrusts, its leakage current is <20μA.

8. The long-life ion thruster capable of outputting a wide range of thrust according to claim 7, characterized in that, The internal support component is a ceramic insulating support component.

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