Hollow cathode track environment gas atmosphere life assessment experiment system

Abstract

The invention relates to the technical field of spacecraft propulsion, in particular to a hollow cathode orbit environment gas atmosphere life assessment experiment system which comprises a vacuum chamber, an experiment box, a hollow cathode, an oxygen cylinder, an atomic oxygen generation device, a mixed gas cylinder and a xenon cylinder, and the experiment box is fixed in the vacuum chamber; the hollow cathode is fixed in the experiment box; the atomic oxygen generating device is arranged at the top in the vacuum cabin; the oxygen cylinder is connected with the atomic oxygen generating device through a gas pipeline; the mixed gas cylinder is arranged on one side outside the vacuum cabin and is communicated with the experiment box; and the xenon gas cylinder is arranged at the bottom end outside the vacuum cabin and is communicated with the experiment box. By arranging the vacuum gauge near the hollow cathode, the partial pressure of each component of the gas atmosphere where the hollow cathode is located can be accurately measured, and the atomic oxygen partial pressure, the nitrogen partial pressure and the oxygen partial pressure of the gas atmosphere where the hollow cathode is located can be adjusted.

Description

Technical Field

[0001] This application relates to the field of spacecraft propulsion technology, and more specifically, to a hollow cathode orbital environment gas atmosphere lifetime assessment experimental system. Background Technology

[0002] Air-breathing electric propulsion systems use solar cells for energy and utilize the rarefied nitrogen, oxygen, and oxygen atoms in the ultra-low Earth orbit (ULE) environment as a working propellant. The ionization and accelerated ejection of these propellants generate thrust, which serves as the power source for maintaining the orbit of ULE spacecraft. This allows spacecraft to remain and maneuver in ULE with less or no propellant, solving the problem that current technologies cannot enable long-term spacecraft ambush and maneuver in ULE. It is a highly promising cutting-edge aerospace propulsion technology. Air-breathing electric propulsion systems can be widely applied to spacecraft platforms such as high-resolution Earth observation satellites, Earth gravity field measurement satellites, and ultra-high-speed communication satellites.

[0003] The most important factor influencing the feasibility of an air-breathing electric propulsion system is the efficiency of the type of electric propulsion used. Currently, ion thrusters based on electron bombardment ionization using ambient gas as the working propellant are the most efficient. However, ion thrusters have hollow cathodes. During space operations, the working propellant in the thruster's discharge chamber is the orbital ambient gas. Only a small portion of this gas is ionized; most remains in a neutral particle state. While the hollow cathode uses Xe gas as its working propellant, being located within the discharge chamber, it is subject to atomic oxygen corrosion, accelerating its failure.

[0004] Currently, the technology for generating large electron flows in a small volume using electrodeless cathodes such as microwave and radio frequency cathodes is relatively immature. For space experiments verifying air-breathing electric propulsion technology, long system lifespan is not a requirement; therefore, hollow cathodes can still be used in ion thrusters for space experiments verifying air-breathing electric propulsion technology. Lifetime testing of hollow cathodes in orbital gas atmospheres can reveal changes in their performance over time, providing a reference for space experiments verifying air-breathing electric propulsion technology. In the future, when electrodeless cathode technology matures, replacing the hollow cathode of the ion thruster with a microwave or radio frequency cathode capable of long-term operation in the gas atmosphere of the space orbital environment can solve the problem of thruster failure due to cathode failure. Summary of the Invention

[0005] This application provides a hollow cathode orbital environment gas atmosphere life test system, which can simulate the space working environment conditions of air-breathing electric propulsion devices on the ground, examine the performance of air-breathing electric propulsion devices, and help optimize air-breathing electric propulsion systems.

[0006] To achieve the above objectives, this application provides a hollow cathode orbital environment gas atmosphere lifetime testing experimental system, including a vacuum chamber, an experimental chamber, a hollow cathode, an oxygen cylinder, an atomic oxygen generator, a mixed gas cylinder, and a xenon cylinder. The experimental chamber is fixed inside the vacuum chamber, with an atomic oxygen flux opening at the top, a first pipeline perforation on the side wall, and a second pipeline perforation at the bottom. The hollow cathode is fixed inside the experimental chamber. The atomic oxygen generator is located at the top inside the vacuum chamber and is connected to the experimental chamber through the atomic oxygen flux opening. The oxygen cylinder is connected to the atomic oxygen generator through a gas pipeline. The mixed gas cylinder is located on one side outside the vacuum chamber and is connected to the experimental chamber through a gas pipeline passing through a first chamber flange and the first pipeline perforation. The xenon cylinder is located at the bottom outside the vacuum chamber and is connected to the experimental chamber through a gas pipeline passing through a second chamber flange and the second pipeline perforation.

[0007] Furthermore, a resistance vacuum gauge and a first ionization vacuum gauge are installed at the top of the vacuum chamber.

[0008] Furthermore, a second ionization vacuum gauge is installed inside the experimental chamber, and the second ionization vacuum gauge is positioned close to the hollow cathode.

[0009] Furthermore, a first flow meter is installed on the gas pipeline connected to the oxygen cylinder; a second flow meter is installed on the gas pipeline connected to the mixed gas cylinder; and a third flow meter is installed on the gas pipeline connected to the xenon cylinder.

[0010] Furthermore, the vacuum chamber is equipped with a vacuum pumping device, which includes a mechanical pump and a molecular pump.

[0011] Furthermore, ventilation holes are also provided on the side wall of the experimental chamber.

[0012] The hollow cathode orbital environment gas atmosphere lifetime testing system provided in this application has the following beneficial effects: This application allows for the accurate measurement of the partial pressures of various components in the gas atmosphere surrounding the hollow cathode by arranging a vacuum gauge near the hollow cathode. Furthermore, it enables the adjustment of the partial pressures of atomic oxygen, nitrogen, and oxygen in the gas atmosphere surrounding the hollow cathode, accurately creating the gas atmosphere conditions required for the hollow cathode when an air-breathing electric propulsion system operates at a certain altitude in space. This allows for the examination of the hollow cathode's performance changes over time. Simultaneously, by setting up an experimental chamber, atomic oxygen can be localized within a certain range, reducing damage to equipment inside the vacuum chamber. Attached Figure Description

[0013] 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.

[0014] In the attached diagram: Figure 1 This is a schematic diagram of the hollow cathode orbital environment gas atmosphere life test system provided in the embodiments of this application; Figure 2 This is a schematic diagram of the experimental box provided according to an embodiment of this application; In the diagram: 1-Vacuum chamber, 11-First penetration flange, 12-Second penetration flange, 2-Experimental chamber, 21-Atomic oxygen flux opening, 22-First pipeline perforation, 23-Second pipeline perforation, 24-Second ionization vacuum gauge, 25-Vent hole, 3-Hollow cathode, 4-Oxygen cylinder, 41-First flow meter, 5-Atomic oxygen generator, 6-Mixed gas cylinder, 61-Second flow meter, 7-Xenon cylinder, 71-Third flow meter, 8-Resistance vacuum gauge, 9-First ionization vacuum gauge. Detailed Implementation

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] In addition, the term "multiple" should mean two or more.

[0020] 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.

[0021] like Figure 1-2 As shown, this application provides a hollow cathode orbital environment gas atmosphere life assessment experimental system, including a vacuum chamber 1, an experimental chamber 2, a hollow cathode 3, an oxygen cylinder 4, an atomic oxygen generator 5, a mixed gas cylinder 6, and a xenon cylinder 7. The experimental chamber 2 is fixed inside the vacuum chamber 1, with an atomic oxygen flux opening 21 at the top, a first pipeline perforation 22 on the side wall, and a second pipeline perforation 23 at the bottom. The hollow cathode 3 is fixed inside the experimental chamber 2. The atomic oxygen generator 5 is located at the top inside the vacuum chamber 1 and is connected to the experimental chamber 2 through the atomic oxygen flux opening 21. The oxygen cylinder 4 is connected to the atomic oxygen generator 5 through a gas pipeline. The mixed gas cylinder 6 is located on one side outside the vacuum chamber 1 and is connected to the experimental chamber 2 through a gas pipeline that passes sequentially through a first chamber flange 11 and a first pipeline perforation 22. The xenon cylinder 7 is located at the bottom outside the vacuum chamber 1 and is connected to the experimental chamber 2 through a gas pipeline that passes sequentially through a second chamber flange 12 and a second pipeline perforation 23.

[0022] Specifically, the hollow cathode orbital environment gas atmosphere life assessment experimental system provided in this application embodiment can accurately create the gas atmosphere conditions of the hollow cathode 3 when the air-breathing electric propulsion system operates at a certain altitude in space. This system allows for the examination of the performance changes of the hollow cathode 3 over time, thus providing an important reference for the space experimental verification scheme of the air-breathing electric propulsion system. During operation, the vacuum chamber 1 is evacuated to the same vacuum level as a certain orbital altitude in space. A mixture of atomic oxygen, nitrogen, and oxygen is introduced into the vacuum chamber 1. When the partial pressures of atomic oxygen, nitrogen, and oxygen near the hollow cathode 3 are the same as those in the discharge chamber when the electric thruster is operating, the hollow cathode 3 is activated for life assessment.

[0023] Furthermore, a resistance vacuum gauge 8 and a first ionization vacuum gauge 9 are installed at the top of the interior of the vacuum chamber 1. Both the resistance vacuum gauge 8 and the first ionization vacuum gauge 9 are used to measure the vacuum level inside the vacuum chamber 1.

[0024] Furthermore, a second ionization vacuum gauge 24 is installed inside the experimental chamber 2, positioned close to the hollow cathode 3. The second ionization vacuum gauge 24 is used to accurately measure the gas pressure near the hollow cathode 3, thereby facilitating the adjustment of the partial pressure of different gas atmosphere components.

[0025] Furthermore, a first flow meter 41 is installed on the gas pipeline connected to the oxygen cylinder 4; a second flow meter 61 is installed on the gas pipeline connected to the mixed gas cylinder 6; and a third flow meter 71 is installed on the gas pipeline connected to the xenon cylinder 7.

[0026] Specifically, by setting up experimental chamber 2, atomic oxygen can be relatively localized within experimental chamber 2, reducing the damage of atomic oxygen to the equipment inside vacuum chamber 1. The mass flow rate of oxygen can be adjusted by the first flow meter 41, thereby adjusting the atomic oxygen flux produced by atomic oxygen generator 5, thus achieving the adjustment of the partial pressure of atomic oxygen generated near hollow cathode 3; the mass flow rate of the mixed gas can be adjusted by the second flow meter 61, thereby adjusting the partial pressure of nitrogen and oxygen generated near hollow cathode 3; and the mass flow rate of xenon can be adjusted by the third flow meter 71.

[0027] Furthermore, vacuum chamber 1 is equipped with a vacuum pumping device, which includes a mechanical pump and a molecular pump. Vacuum chamber 1 is used to provide the vacuum environment required for the experiment. During vacuuming, the mechanical pump is first used to evacuate vacuum chamber 1 to 10... -4 The pressure is on the order of Pa, and then a molecular pump is used to evacuate the air to the ambient gas pressure corresponding to a certain orbital altitude in space.

[0028] Furthermore, ventilation holes 25 are provided on the side wall of the experimental chamber 2. Ventilation holes 25 are used for the entry and exit of gas, enabling gas exchange with the interior of the vacuum chamber 1.

[0029] Specifically, when the hollow cathode orbital environment gas atmosphere life assessment experimental system provided in this application is working, it first uses a mechanical pump to evacuate the vacuum chamber 1 to P0 (10 -4(On the order of Pa), measured by a resistance vacuum gauge 8, the vacuum chamber 1 is evacuated to P1 using a molecular pump, corresponding to the ambient gas pressure at a certain orbital altitude in space, and measured by a first ionization vacuum gauge 9; then the atomic oxygen generator 5 is activated to inject atomic oxygen into the vacuum chamber 1, the oxygen mass flow rate is adjusted by a first flow meter 41, and the degree of ionization of the oxygen is adjusted by adjusting the microwave power of the atomic oxygen generator 5, thereby adjusting the partial pressure of the atomic oxygen injected into the vacuum chamber 1, so that the reading of the second ionization vacuum gauge 24 near the hollow cathode 3 is P2; next, the mass flow rate of the mixed gas is adjusted by adjusting the second flow meter 61, so that the reading of the second ionization vacuum gauge 24 near the hollow cathode 3 is P5, where P5 is the sum of the nitrogen partial pressure P3 and the oxygen partial pressure P4 (where the pressure ratio of nitrogen to oxygen is the pressure ratio of nitrogen to oxygen when the hollow cathode 3 is working, and the mixed gas is prepared according to the corresponding ratio). At this time, the gas atmosphere in which the hollow cathode 3 is located is the same gas atmosphere in which the hollow cathode 3 is located during the space operation of the air-breathing electric propulsion system; finally, xenon gas (Xe) is introduced into the hollow cathode 3, and the mass flow rate of Xe is adjusted by the third flow meter 71 to start the operation of the hollow cathode 3 and begin the environmental gas atmosphere life test experiment of the hollow cathode 3.

[0030] 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 hollow cathode track environmental gas atmosphere life test system, characterized in that, The device comprises a vacuum chamber, an experiment box, a hollow cathode, an oxygen gas cylinder, an atomic oxygen generator, a mixed gas cylinder and a xenon gas cylinder. The experiment box is fixed inside the vacuum chamber, and is provided with an atomic oxygen flux opening at the top, a first pipeline perforation on the side wall and a second pipeline perforation at the bottom. The hollow cathode is fixed inside the experiment box. The atomic oxygen generator is arranged at the top inside the vacuum chamber and is communicated with the experiment box through the atomic oxygen flux opening. The oxygen gas cylinder is connected with the atomic oxygen generator through a gas pipeline. The mixed gas cylinder is arranged outside the vacuum chamber on one side, and is communicated with the experiment box through a gas pipeline in sequence through a first chamber-penetrating flange and a first pipeline perforation. The xenon gas cylinder is arranged outside the vacuum chamber at the bottom end, and is communicated with the experiment box through a gas pipeline in sequence through a second chamber-penetrating flange and a second pipeline perforation.

2. The hollow cathode track environment gas atmosphere life test system according to claim 1, characterized in that, The top end inside the vacuum chamber is provided with an electric resistance vacuum gauge and a first ionization vacuum gauge.

3. The hollow cathode track environment gas atmosphere life test system according to claim 2, characterized in that, The inside of the experiment box is provided with a second ionization vacuum gauge, and the second ionization vacuum gauge is arranged close to the hollow cathode.

4. The hollow cathode track environment gas atmosphere life test system according to claim 3, characterized in that, A first flow meter is arranged on the gas pipeline connected with the oxygen gas cylinder, a second flow meter is arranged on the gas pipeline connected with the mixed gas cylinder, and a third flow meter is arranged on the gas pipeline connected with the xenon gas cylinder.

5. The hollow cathode track environment gas atmosphere life test system of claim 2, wherein, The vacuum chamber is provided with a vacuumizing device, and the vacuumizing device comprises a mechanical pump and a molecular pump.

6. The hollow cathode track environment gas atmosphere life test system according to claim 5, characterized in that, The side wall of the experiment box is further provided with a vent hole.

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