Gas confinement type carbon nanotube field ion thruster

Abstract

The application discloses a gas-restraint type carbon nanotube field ionization thruster, which comprises a first pole plate, a second pole plate, a gas restraint plate, a sealing ring, a first shell and a second shell. The second pole plate is provided with carbon nanotube clusters with gaps generated by chemical vapor deposition and chemical point covering method, and the carbon nanotube clusters have larger tip electric field and higher ionization efficiency than common emitters, but the distribution of the carbon nanotube clusters is relatively sparse. The gas restraint device cooperates with the carbon nanotube clusters of the emitters to ensure that the carbon nanotube clusters have independent ionization spaces, avoids the working medium gas from escaping into the gaps of the carbon nanotube clusters, and thus improves the ionization efficiency. Meanwhile, the gas restraint device can further shield the electric field influence between the carbon nanotube clusters, avoids the mutual interference between different carbon nanotube clusters during propulsion, improves the controllability of the thruster, and further improves the ionization efficiency. The device can reduce the waste of the working medium gas and improve the service life of the thruster.

Description

Technical Field

[0001] This invention relates to the field of aerospace propulsion technology, and more specifically, to a gas-confined carbon nanotube field ionization thruster. Background Technology

[0002] In recent years, with the development of aerospace technology, microsatellites and electric propulsion technology have made significant progress. Currently, both domestically and internationally, great importance is attached to the development and application of microsatellites, and the number of space launches is increasing year by year. Microsatellites have advantages such as small size and weight, low cost, short development cycle, and flexible launch. Furthermore, several microsatellites can form a satellite constellation, and through inter-satellite coordination, they can perform tasks such as communication, remote sensing, and Earth observation. Due to the inherent characteristics and mission requirements of microsatellites, their propulsion systems must meet requirements such as light weight, small size, low power consumption, long lifespan, and precise thrust.

[0003] Traditional propulsion technologies, due to limitations in their operating principles, struggle to simultaneously meet these multiple requirements. As the earliest operational electric propulsion system in orbit, pulsed plasma thrusters possess characteristics such as high specific impulse, low thrust, low power consumption, flexible control, compact size, and precise thrust, meeting the propulsion needs of microsatellites. They are currently widely used in on-orbit missions such as attitude control, position holding, and orbit transfer, representing an important development direction for electric propulsion systems. However, with the continuous development of electric propulsion technology, the structure and manufacturing process of the emitter are also constantly being updated. Currently, the more advanced emitters use chemical vapor deposition (CVD) and grow spaced carbon nanotube clusters by covering reaction sites with perforated thin films, which can significantly increase the field strength and the ionization ratio of the working gas. However, the main ionization region is still concentrated near the carbon nanotube clusters, leaving a large amount of working gas between the clusters unionized, resulting in low thruster efficiency and significant waste of working gas. Summary of the Invention

[0004] This invention provides a gas-confined carbon nanotube field ionization thruster to solve the problem that in the prior art, the ionization region of the carbon nanotube field ionization thruster is concentrated near the carbon nanotube cluster, and a large amount of working gas escapes before it is ionized, resulting in low thruster efficiency and serious waste of working gas.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A gas-confined carbon nanotube field ionization thruster includes a first electrode plate and a gas confinement plate. The first electrode plate has a plurality of grids evenly distributed on it. A first housing is fixedly connected to the bottom of the first electrode plate by a plurality of bolts. The first housing is made of insulating material. The gas confinement plate is clamped at the bottom of the first housing and fixed to the first housing by a plurality of bolts. A second housing is also provided at the bottom of the first housing. The bottom of the second housing has a vent hole. A second electrode plate is disposed between the second housing and the gas confinement plate.

[0007] Preferably, the upper surface of the second electrode plate is covered with a substrate containing catalyst particles, and the substrate is covered with a thin film with uniformly pored holes, in which carbon nanotubes are grown.

[0008] Preferably, the gas confinement plate has a plurality of ventilation holes arranged in the same way as the holes, and the ventilation holes and the holes are coaxially arranged. Each ventilation hole is connected to a connecting cylinder at its top, and the carbon nanotubes are inserted into the connecting cylinder.

[0009] Preferably, a sealing ring is provided between the gas confinement plate and the second electrode plate. The sealing ring is made of insulating material, the upper surface of the sealing ring is in contact with the bottom surface of the gas confinement plate, and the lower surface of the sealing ring is in contact with the top surface of the second electrode plate.

[0010] The principle and beneficial effects of this technical solution:

[0011] (1) Compared with the traditional carbon nanotube field ionization thruster, the ionization thruster disclosed in this invention has a higher working gas utilization rate, thereby improving the specific impulse of the thruster. Since the device is provided with a gas confinement plate between the first and second plates, when the working gas enters the carbon nanotube clusters provided on the second plate through the vent hole provided at the bottom of the second shell, the working gas is located at the bottom of the carbon nanotube clusters, where the electric field strength is low and it will not be ionized. Then, the working gas will continue to approach the tip of the carbon nanotubes under the guidance of the connecting tube provided on the gas confinement plate, thereby ionizing the working gas in a strong electric field. This prevents the working gas from escaping to the part with a lower electric field strength between the first and second plates, thus preventing the working gas from escaping without ionization, thereby improving the utilization rate of the working gas and increasing the ionization efficiency of the thruster.

[0012] (2) The ionization thruster disclosed in this invention can better protect the carbon nanotube clusters, extend the service life of the carbon nanotubes, and prevent physical damage compared with the traditional carbon nanotube field ionization thruster. At the same time, the working gas will impact the nanotube clusters when it approaches them. There is only a small gap between the inner diameter of the connecting cylinder set on the gas constraint plate and the carbon nanotubes. When the carbon nanotubes bend or shift laterally, the connecting cylinder will restrict the movement of the carbon nanotubes, maintain the shape and strength of the carbon nanotubes, and thus extend the working life of the thruster.

[0013] (3) Compared with the traditional carbon nanotube field ionization thruster, the ionization thruster disclosed in this invention has a gas-constrained plate between the first and second plates. Therefore, the connecting tube on the gas-constrained plate can reduce the mutual influence of electric fields between carbon nanotube clusters, thereby increasing the end electric field strength of the carbon nanotube clusters and improving the ionization rate of the working gas. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the assembled structure of the present invention;

[0015] Figure 2 This is a schematic diagram of the disassembled structure of the present invention;

[0016] Figure 3 This is a schematic diagram showing the flow direction of the working gas at the positions of the carbon nanotubes and the connecting cylinder during the operation of this invention;

[0017] The reference numerals in the accompanying drawings include: 1. First electrode plate; 2. First housing; 3. Gas confinement plate; 4. Sealing ring; 5. Second electrode plate; 6. Second housing; 7. Connecting cylinder; 8. Carbon nanotube. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0019] Example:

[0020] like Figure 1 and Figure 2 As shown, the present invention provides a gas-confined carbon nanotube field ionization thruster, including a first electrode plate 1 and a gas confinement plate 3. The first electrode plate 1 has a plurality of grids evenly distributed on it. The bottom end of the first electrode plate 1 is provided with a first housing 2 fixedly connected by a plurality of bolts. The first housing 2 is made of insulating material. The gas confinement plate 3 is clamped at the bottom end of the first housing 2. The gas confinement plate 3 and the first housing 2 are fixed by a plurality of bolts. The bottom end of the first housing 2 is also provided with a second housing 6. The bottom end of the second housing 6 has a vent hole. The second electrode plate 5 is disposed between the second housing 6 and the gas confinement plate 3.

[0021] like Figure 2As shown, the upper surface of the second electrode plate 5 is covered with a substrate containing catalyst particles, and a thin film with uniformly pored holes is covered on the substrate, with carbon nanotubes 8 grown in the holes.

[0022] like Figure 1 As shown, the gas confinement plate has several ventilation holes, which are arranged in the same way as the holes. Each ventilation hole is connected to a connecting cylinder 7 at its top, and carbon nanotubes 8 are inserted inside the connecting cylinder 7.

[0023] like Figure 1 and Figure 2 As shown, a sealing ring 4 is provided between the gas confinement plate 3 and the second electrode plate 5. The sealing ring 4 is made of insulating material. The upper surface of the sealing ring 4 is in contact with the bottom surface of the gas confinement plate 3, and the lower surface of the sealing ring 4 is in contact with the top surface of the second electrode plate 5.

[0024] The sealing ring 4 is used to separate the gas confinement plate 3 and the carbon nanotube 8, while also filling the gaps in the emitter of the carbon nanotube 8 to prevent gas leakage. At the same time, since the sealing ring 4 separates the gas confinement plate 3 and the carbon nanotube 8, the working gas can move from the gaps between them to the bottom of the nanotube cluster, and then gradually move to the top of the nanotube cluster for ionization.

[0025] This device is mainly composed of 6 layers. The components in each layer are stacked on top of each other and connected and fitted together by bolts in threaded holes around the components. The second shell 6 is mainly composed of two layers. The bottom layer of the second shell 6 is an 80mm*80mm square (with rounded corners of 10mm radius) and has cylindrical surfaces of 20mm height around the edges. The upper layer of the second shell 6 is a 140mm*140mm square (with rounded corners of 10mm radius) with a thickness of 8mm. The entire material is stainless steel. The second electrode plate 5 is 2mm thick, and the diameter of the prototype part is 60mm. Carbon nanotubes with a diameter of 10 micrometers, a spacing of 400 micrometers, and a height of 1500 micrometers are machined on the surface for ionizing the working gas. The sealing ring 4 is a 140mm*140mm square (with rounded corners of 10mm radius), 1.5mm thick, and made of insulating rubber. The connecting tube 7 on the gas confinement plate 3 has an inner radius of 20 micrometers and an outer radius of 100 micrometers. The array pattern of the connecting tube 7 is consistent with that of carbon nanotubes. It is 1.5mm thick, 140mm in diameter, and made of polytetrafluoroethylene. The outer part of the first shell 2 is a 140mm*140mm square (with rounded corners of 10mm radius), and the inner part is an 80mm*80mm square (with rounded corners of 10mm radius). The lower part has a 1.5mm thick prototypical groove for inserting the gas confinement plate 3. It is made of polytetrafluoroethylene. The first electrode plate 1 is a 140mm*140mm square (with rounded corners of 10mm radius), 1mm thick, and has 30 rectangular slots with a length of 90mm, a width of 2mm, and a spacing of 1mm. It is made of stainless steel.

[0026] The specific usage and function of this embodiment are as follows:

[0027] First, the first electrode 1 and the second electrode 5 are connected to the circuit respectively, and the working gas is pumped in through the vent hole at the bottom of the base. Then, the working gas enters the cavity inside the second shell 6 and flows into the gap between the gas confinement plate 3 and the second electrode 5 through the gap between the second electrode 5 and the second shell 6. At this time, the working gas only exists at the bottom of the carbon nanotube cluster and will not be ionized. As the gas moves along the inner wall of the connecting cylinder 7 on the gas confinement plate 3, it gradually reaches the top of the carbon nanotube cluster. The strong electric field generated by the tip discharge at the top of the carbon nanotube cluster ionizes the working gas. The ionized working gas will then carry a charge opposite to that of the first electrode 1. At this time, the working gas will move to the outside of the thruster under the attraction of the first electrode 1, thereby generating thrust to drive the spacecraft.

[0028] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A gas-confined carbon nanotube field ionization thruster, characterized in that: The first electrode plate (1) and the gas constraint plate (3) are included. The first electrode plate (1) is evenly provided with several grids. The bottom end of the first electrode plate (1) is provided with a first housing (2) which is fixedly connected by multiple sets of bolts. The first housing (2) is made of insulating material. The gas constraint plate (3) is clamped at the bottom end of the first housing (2). The gas constraint plate (3) is fixed to the first housing (2) by multiple sets of bolts. The bottom end of the first housing (2) is also provided with a second housing (6). The bottom end of the second housing (6) is provided with a vent hole. The second electrode plate (5) is provided between the second housing (6) and the gas constraint plate (3). The upper surface of the second electrode plate (5) is covered with a substrate containing catalyst particles, and the substrate is covered with a thin film with uniformly pored holes, and carbon nanotubes (8) are grown in the holes. The gas confinement plate (3) has several ventilation holes, which are arranged in the same way as the holes. The ventilation holes and the holes are coaxially arranged. Each ventilation hole is connected to a connecting cylinder (7) at its top. The carbon nanotubes (8) are inserted into the connecting cylinder (7). A sealing ring (4) is provided between the gas confinement plate (3) and the second electrode plate (5). The sealing ring (4) is made of insulating material. The upper surface of the sealing ring (4) is in contact with the bottom surface of the gas confinement plate (3), and the lower surface of the sealing ring (4) is in contact with the top surface of the second electrode plate (5).

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