Radio frequency plasma T-shaped magnetic micro-thruster with pre-ionization function

Abstract

The application designs a radio frequency plasma T-shaped magnetic micro-thruster with pre-ionization function, which is provided with a gas supply module, a pre-ionization module, an ionization module and a plasma extraction module in sequence along the direction of working gas entering; the pre-ionization module is provided with a porous partition plate with transmittance meeting the requirements of gas pressure on both sides, ignition and maintenance, the glass discharge chamber is divided into two areas by the porous partition plate, and a yttrium iridium filament is added near the working gas inlet for pre-ionizing the working gas; the plasma extraction module comprises a T-shaped permanent magnet spliced by two ring-shaped high-temperature-resistant samarium-cobalt permanent magnets with different sizes, the permanent magnet near the discharge chamber has a larger size, the permanent magnet far from the discharge chamber has a smaller size, and the two permanent magnets form a T-shaped permanent magnet structure; the application proposes a pre-ionization auxiliary ignition method, and solves the problems of low efficiency and low ionization rate of the existing thruster at low power.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aerospace propulsion technology, in particular to a radio frequency plasma T-shaped magnetic jet micro-thruster device with pre-ionization function. BACKGROUND

[0002] Electric propulsion technology injects electric energy into propellant working medium in the form of discharge ionization, accelerates the working medium to be ejected from the thruster in the form of heating expansion, electromagnetic acceleration, etc. Compared with the conventional chemical propulsion method, electric propulsion technology has the advantages of high specific impulse and long service life. Electric propulsion technology can greatly improve the effective payload ratio and reduce transportation costs, and is particularly suitable for various space missions.

[0003] Radio frequency plasma thrusters are one of the directions with great potential in the field of electric propulsion technology. Due to its advantages such as no-grid design, long service life and simple structure, it is expected to have more extensive application requirements in future space missions, especially in micro-satellite missions.

[0004] One of the difficulties in designing a radio frequency plasma thruster for a micro-satellite is that the thruster operates at low power, which causes the ionization rate to drop sharply, making it difficult to adapt to the micro-thrust requirements of small satellites. Due to the small size of micro-satellites, which are only the size of a shoebox and weigh only about 10 kilograms, the area of solar panels used is very limited, which determines the low power of micro-satellites. Since the thruster is installed on the micro-satellite and the micro-satellite provides power to the thruster, the thruster used for micro-satellites is also a low-power thruster. The low-power thruster causes the free electrons generated after the working gas enters the discharge chamber to be relatively few, which makes the ionization rate relatively poor, making it difficult to adapt to the micro-thrust requirements of small satellites.

[0005] The second difficulty in designing a radio frequency plasma thruster for a micro-satellite is that the thruster operates at low power, which causes the acceleration efficiency to drop sharply, making it difficult to adapt to the micro-thrust requirements of small satellites. Most existing high-power radio frequency plasma thrusters are placed on the outer periphery of the left side of the plasma discharge chamber, which is located between the inlet and the Laval nozzle on the outer surface of the discharge chamber. Due to the placement on the outer periphery of the left side of the discharge chamber and the circular shape of the magnetic nozzle, the acceleration effect of the magnetic nozzle is not particularly significant. When the thruster changes from high power to low power, the acceleration efficiency drops sharply, making it difficult to adapt to the micro-thrust requirements of small satellites. SUMMARY

[0006] The present application proposes a radio frequency plasma T-shaped magnetic jet micro-thruster with pre-ionization function to solve the problem of radio frequency plasma thrusters operating at low power, ionization rate and acceleration efficiency dropping sharply, and being difficult to adapt to the micro-thrust requirements of small satellites.

[0007] The application discloses a T-shaped magnetic plasma micro-thruster with a pre-ionization function.

[0008] A radio frequency plasma T-shaped magnetic micro-thruster with a pre-ionization function, which is provided with a gas supply module, a pre-ionization module, an ionization module and a plasma extraction module in sequence along the direction of working gas entering; the pre-ionization module is provided with a porous partition (5) with a transmittance meeting the requirements of gas pressure on both sides, ignition and maintenance; the porous partition (5) divides a glass discharge chamber (4) into two areas, and a yttrium iridium filament (6) is added near the gas inlet for pre-ionizing the working gas; the ionization module couples radio frequency energy into the plasma through a radio frequency coil (2) to form a radio frequency plasma self-sustaining discharge; the discharge chamber (4) is composed of a cylindrical section and a Laval nozzle section, and the outlet end is a Laval nozzle for greatly increasing the internal gas pressure of the discharge chamber and improving the ionization rate; the plasma extraction module includes a T-shaped permanent magnet (3) which is spliced by two annular high-temperature-resistant samarium-cobalt permanent magnets with different sizes; the permanent magnet near the cylindrical section of the discharge chamber has a larger size, and the permanent magnet far from the cylindrical section of the discharge chamber has a smaller size, and the two permanent magnets form a T-shaped permanent magnet structure.

[0009] Further, the optimal transmittance of the porous partition (5) is about 20%.

[0010] Further, the optimal transmittance includes that 8 holes are uniformly distributed on the outer periphery, and the ratio of the hole diameter to the plate diameter of the porous partition (5) is 1 / 6.

[0011] Further, the size of the pre-ionization area needs to meet the following three requirements: the electron density in the area can generate electrons, the power of the yttrium iridium filament (6) cannot be too low or too high, and the voltage of the pre-ionization area is higher than that of the radio frequency coil area; when the yttrium iridium filament (6) is 50w, the axial installation position of the porous partition (5) is at one fifth of the cylindrical section of the discharge chamber near the inlet side of the discharge chamber; the cylindrical section of the discharge chamber is the part from the inlet of the discharge chamber to the front of the Laval nozzle of the discharge chamber.

[0012] Further, the positions of the multiple holes of the porous partition (5) on the radius of the plate are larger than the position of the yttrium iridium filament (6) on the radius of the plate, so as to reduce the direct erosion of the backflow plasma on the yttrium iridium filament (6).

[0013] Further, the T-shaped permanent magnet is arranged at the beam port of the thruster, and is better coupled with the radio frequency coil (2) to improve the plasma beam extraction efficiency and reduce the ignition difficulty.

[0014] Further, the glass discharge chamber (4) beam port aperture is 1 / 3 of the discharge chamber cylindrical section.

[0015] Further, the ratio of the outer diameter of the T-shaped permanent magnet (3) near the discharge chamber cylindrical section and the outer diameter of the permanent magnet away from the discharge chamber cylindrical section is 1.5, and the inner diameters of the two are the same; the ratio of the thickness of the permanent magnet near the discharge chamber cylindrical section and the permanent magnet away from the discharge chamber cylindrical section is 1.5.

[0016] Further, the outer diameter of the permanent magnet near the discharge chamber cylindrical section is 50mm; the inner diameter of the permanent magnet (3) near the discharge chamber cylindrical section and away from the discharge chamber cylindrical section is 30mm.

[0017] Advantages and effects of the present application

[0018] 1. Compared with other radio frequency plasma thrusters, the structure is simple, does not need a cathode and a complex magnetic field structure, is easy to miniaturize, reduces the difficulty of thruster manufacturing, reduces cost, and improves the reliability of the thruster.

[0019] 2. A pre-ionization auxiliary ignition method is proposed, which uses a pre-ionization module composed of a porous partition plate and a yttrium iridium oxide filament, wherein the porous partition plate is made of alumina ceramic and uniformly punched 8 times on the outer periphery, and the hole diameter is 1 / 6 of the plate diameter. The porous partition plate can not only increase the gas pressure at the pre-ionization module, but also prevent the subsequent plasma in the discharge chamber from flowing back and corroding the yttrium iridium oxide filament 6. The working process is to first pre-ionize the working gas through the pre-ionization module, and then fully ionize it with a radio frequency source, which reduces the total power consumption to below 100 watts, improves the ignition efficiency and success rate, and can be applied to microsatellite orbit maintenance, super-low orbit gas electric propulsion, Mars exploration, carbon dioxide in-situ resource utilization, etc., and is more targeted. The existing thruster has low efficiency and low ionization rate at low power, and is difficult to maintain.

[0020] 3. A T-shaped permanent magnet configuration is designed and placed at the beam port of the discharge chamber, where the plasma is converged and constrained, further improving the plasma density and ionization rate, and then accelerated and ejected in the expansion section; the unique design of the position and configuration of the permanent magnet is composed of two annular permanent magnets, wherein the outer diameter of the larger permanent magnet is 50mm, the inner diameter is 30mm, and the thickness is 10mm. The inner diameters of the two are the same, the outer diameter ratio is 1.5, and the thickness ratio is 1.5. It can better couple with the throat size of the discharge chamber, improve the density in the discharge chamber, and thus improve the ionization rate, and the magnetic field generated at the same time is beneficial to the constraint and acceleration of the plasma.

[0021] 4. The discharge chamber structure is unique, replacing the traditional cylindrical discharge chamber, using a specially designed discharge chamber, the outlet end of which is a Laval nozzle, and the beam port size is coupled with the magnetic field generated by the T-shaped permanent magnet, and the aperture is 1 / 3 of the discharge chamber cylindrical section. This structure can greatly improve the internal gas pressure of the discharge chamber and improve the ionization rate.

[0022] 5、The radio frequency coil adopts copper wire winding, the diameter is 2mm, and the coil structure is simple, light and convenient to install. The radio frequency frequency point is 5.2MHz, and the radio frequency power is 50W, which can greatly reduce the power consumption required by the thruster and be applied to microsatellites and other tasks with relatively limited energy.

[0023] 6、The present application has unique magnetic field design and structure optimization, which shows obvious advantages in microsatellite formation maintenance and deep space probe orbit correction scenes, and effectively overcomes the defects of high power requirement and configuration redundancy of traditional propulsion systems. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Working principle diagram of the radio frequency plasma T-shaped magnetic jet micro-thruster with pre-ionization function;

[0025] Figure 2 Front view of the porous septum;

[0026] In the figure: 1: radio frequency plasma T-shaped magnetic jet micro-thruster;2: radio frequency coil;3: T-shaped permanent magnet;4: discharge chamber;5: porous septum;6: yttrium iridium oxide filament; DETAILED DESCRIPTION

[0027] I、The innovation point of the present application

[0028] 1. Pre-ionization module: The glass discharge chamber is divided into two areas by the porous septum, and a section of yttrium iridium oxide filament is added near the air inlet to pre-ionize the working gas. The pre-ionized electrons enter the area of the radio frequency coil 2 for further ionization, which can greatly improve the success rate of ignition and improve energy utilization. At the same time, the porous septum 5 can prevent the backflow of plasma in the discharge chamber from eroding the yttrium iridium oxide filament in the pre-ionization area, thereby improving the service life of the micro-thruster.

[0029] 2. T-shaped permanent magnet magnetic nozzle: The T-shaped permanent magnet configuration is used to build an axial magnetic field to form a natural magnetic mirror in the glass discharge chamber 4 to achieve effective acceleration of the plasma.

[0030] 3. The structure of the discharge chamber is unique, replacing the traditional cylindrical discharge chamber. A specially designed discharge chamber is used, and the outlet end is a Laval nozzle. The coupling between the nozzle size and the magnetic field generated by the T-shaped permanent magnet is 1 / 3 of the diameter of the cylindrical section of the discharge chamber. This structure can greatly improve the internal gas pressure of the discharge chamber and improve the ionization rate.

[0031] 4、Compared with the conventional radio frequency plasma thruster, the present application has the advantages of simple structure, unique permanent magnet configuration design, long service life, low power consumption, easy ignition, and application potential in long-term orbit maintenance tasks of microsatellites.

[0032] Second, the design principle of the pre-ionization module

[0033] 1. Design principle of the pre-ionization module

[0034] First, the method of pre-ionization auxiliary ignition is proposed, which uses a pre-ionization module composed of a porous partition plate 5 and a yttrium iridium oxide filament 6. The porous partition plate is made of alumina ceramic and uniformly punched at the outer periphery. The ratio of the hole diameter to the plate diameter is 1 / 6. The porous partition plate can not only increase the gas pressure at the pre-ionization module, but also prevent the backflow of plasma in the subsequent discharge chamber from corroding the yttrium iridium oxide filament 6. The working process is to first pre-ionize the working gas through the pre-ionization module, and then fully ionize it with a radio frequency source, which reduces the total power consumption to below 100 watts, improves the ignition efficiency and success rate, and can be applied to microsatellite orbit maintenance, super-low orbit gas electric propulsion, Mars exploration, carbon dioxide in-situ resource utilization, etc. The existing thrusters have low efficiency and low ionization rate at low power, making it difficult to maintain.

[0035] Second, the porous partition plate 5 uses the space of the original discharge chamber 4 to increase the number of collisions of electrons without additional space, thereby achieving full ionization and adapting to the small size of microsatellites.

[0036] Third, the design of the pre-ionization area is the result of the combination of three aspects, namely the design of the transmittance and the size of the pre-ionization area, and the design of the position of the porous radius. These three aspects are complementary to each other. The transmittance design (number of holes, diameter) ensures the voltage requirements on both sides, but if the pre-ionization area is designed too large, the voltage of the pre-ionization area will decrease, and if the pre-ionization area is designed too small, the voltage of the pre-ionization area will increase, thereby affecting the effect of the transmittance design. Similarly, when the size of the pre-ionization area meets the requirements of electron density and low power of the filament, if the transmittance cannot guarantee the gas pressure requirements on both sides, the electrons generated by the pre-ionization area will not be transmitted to the radio frequency coil of the discharge chamber on the right side, so that the electrons cannot be fully ionized by the radio frequency coil. When the holes of the porous partition plate 5 are arranged at a position smaller than the radius of the filament on the plate, the backflow will hit the filament, which will be damaged over time. The filament damage will cause the ionization rate to drop sharply, and at this time, the design of the transmittance and the size of the area cannot function due to the damage of the filament. Therefore, the design of the pre-ionization area is the organic combination of the three aspects.

[0037] 2. Design of the plasma extraction module

[0038] First, the design of the size of the T-shaped magnetic nozzle. The design of the T-shaped magnetic nozzle (or stepped nozzle) is to make the front magnetic field strong (far from the outlet), the rear magnetic field weak (close to the outlet), the magnetic field with relatively large diameter and thickness is relatively strong, and the magnetic field with relatively small diameter and thickness is relatively weak. The design of the strong front magnetic field is to constrain the beam in the area of about five-thirds of the axis of the Laval nozzle, that is, to increase the ion density in this interval, which is conducive to the ejection of accelerated ions; the purpose of designing the weak rear magnetic field is to weaken the constraint of the magnetic field on the beam near the outlet of the Laval nozzle. Because the magnetic field line is closed from N to S, the magnetic field at the outlet of the nozzle is closed. If the magnetic field is too strong, it will reflect the ions to the satellite along the magnetic field line. Therefore, the radial size and thickness of the permanent magnet at the outlet of the Laval nozzle must be relatively small to release the constraint of the magnetic field on the ions.

[0039] Second, the design of the position of the T-shaped magnetic nozzle. The key point of the design of the T-shaped magnetic nozzle is the change of the position of the magnetic nozzle and the innovation of the position. The prior art arranges the magnetic nozzle at the left side of the discharge chamber, that is, at the outer periphery of the cylindrical section on the left side of the Laval nozzle of the discharge chamber. The reason why the magnetic nozzle cannot be arranged at the position of the Laval nozzle of the present application is that the prior art does not reform the shape of the permanent magnet, which is a circular ring (not a large circular ring and a small circular ring in the present application). If the prior art arranges the circular ring at the position of the Laval nozzle at the outlet of the discharge chamber, the closed magnetic field line at the outlet will constrain the emission of ions. Therefore, the prior art arranges the permanent magnet ring at a position far from the outlet, that is, at the position of the cylindrical section of the discharge chamber. The present application designs the T-shaped magnet with two permanent magnets with different sizes and thicknesses to solve the problem of the emission of ions constrained by the magnetic field line of the permanent magnet at the outlet. Specifically, the position of the T-shaped magnetic nozzle is improved from the position far from the Laval nozzle to the position surrounding the outer periphery of the Laval nozzle and the same axial position of the Laval nozzle. In the area of five-thirds of the Laval nozzle, the permanent magnet and the Laval nozzle superimpose to produce convergent constraint on the plasma. In the area of two-thirds of the Laval nozzle, the radial size and thickness of the permanent magnet are reduced to weaken the magnetic field, and the weakening of the magnetic field weakens the constraint of the magnetic field line on the ions. In summary, after the position of the T-shaped magnetic nozzle is moved, the constraint of the Laval nozzle on the ions is stronger in most areas, and in a small part of the area near the outlet of the Laval nozzle, the problem of the constraint of the magnetic field line on the ions is solved by weakening the magnetic field.

[0040] In summary, after the thruster works normally, the magnetic nozzle system with T-shaped permanent magnet as the core accelerates and leads out the plasma to generate the plasma beam. The T-shaped permanent magnet is spliced by two annular high-temperature-resistant samarium-cobalt permanent magnets with different sizes. The permanent magnet close to the discharge chamber has a larger size, and the permanent magnet far from the discharge chamber has a smaller size. The two permanent magnets form a T-shaped permanent magnet structure, and the core function is to form a more significant convergent-divergent magnetic field than the permanent magnet with the same size to constrain and accelerate the plasma. For example, the outer diameter of the larger permanent magnet can be set as 50 mm, the inner diameter can be set as 30 mm, and the thickness can be set as 10 mm. The inner diameters of the two permanent magnets are the same, the ratio of the outer diameters is 1.5, and the ratio of the thicknesses is 1.5. The convergent-divergent magnetic field generated by the T-shaped permanent magnet first generates a beam waist effect on the plasma to improve the plasma density, and then accelerates and leads out to generate the plasma beam and the thrust. In addition, the T-shaped permanent magnet is arranged at the beam port of the thruster, which is better coupled with the radio frequency coil, can improve the plasma beam leading-out efficiency, and reduce the ignition difficulty.

[0041] Based on the above principle, as shown in Figure 1 , Figure 2 The present application designs a radio frequency plasma T-shaped magnetic nozzle micro-thruster with a pre-ionization function. The thruster is sequentially provided with a gas supply module, a pre-ionization module, an ionization module and a plasma leading-out module along the direction of the working gas entering. The pre-ionization module is provided with a porous partition plate 5 with a transmittance that meets the requirements of the gas pressure on both sides, facilitates ignition and maintenance. The porous partition plate 5 divides the glass discharge chamber 4 into two areas, and a section of yttrium iridium filament 6 is added near the working gas inlet to pre-ionize the working gas. The ionization module couples the radio frequency energy into the plasma through the radio frequency coil 2 to form a radio frequency plasma self-sustaining discharge. The discharge chamber 4 is composed of a cylindrical section of the discharge chamber and a Laval nozzle section of the discharge chamber, and the outlet end is a Laval nozzle, which can greatly improve the internal gas pressure of the discharge chamber and improve the ionization rate. The plasma leading-out module includes a T-shaped permanent magnet 3 spliced by two annular high-temperature-resistant samarium-cobalt permanent magnets with different sizes. The permanent magnet close to the cylindrical section of the discharge chamber has a larger size, and the permanent magnet far from the cylindrical section of the discharge chamber has a smaller size, and the two form a T-shaped permanent magnet structure.

[0042] The optimal transmittance of the porous partition plate (5) that meets the requirements of the gas pressure on both sides and facilitates ignition and maintenance is about 20%.

[0043] As shown in Figure 2 , the optimal transmittance includes that 8 holes are uniformly distributed on the outer periphery, and the ratio of the hole diameter to the plate diameter of the porous partition plate (5) is 1 / 6.

[0044] Further, the size of the pre-ionization region should consider the electron density, the power of the yttrium-iridium oxide filament 6, and the voltage of the pre-ionization region, which should be greater than the voltage of the radio frequency coil region; when the yttrium-iridium oxide filament 6 is 50w, the axial installation position of the porous partition 5 is at one-fifth of the discharge chamber cylindrical segment close to the inlet side of the discharge chamber.

[0045] Further, the position of the plurality of holes of the porous partition 5 on the radius of the plate is greater than the position of the yttrium-iridium oxide filament 6 on the radius of the plate, so as to reduce the direct erosion of the backflow plasma to the yttrium-iridium oxide filament 6.

[0046] Further, the T-shaped permanent magnet is arranged at the beam port of the thruster, and is better coupled with the radio frequency coil 2, so as to improve the plasma beam current extraction efficiency and reduce the ignition difficulty.

[0047] Further, the beam port aperture of the glass discharge chamber 4 is 1 / 3 of the discharge chamber cylindrical segment.

[0048] Further, the ratio of the outer diameter of the permanent magnet close to the discharge chamber cylindrical segment to the outer diameter of the permanent magnet away from the discharge chamber cylindrical segment is 1.5, and the inner diameters of the two are the same; the ratio of the thickness of the permanent magnet close to the discharge chamber cylindrical segment to the thickness of the permanent magnet away from the discharge chamber cylindrical segment is 1.5.

[0049] Further, the outer diameter of the permanent magnet close to the discharge chamber cylindrical segment is 50mm; the inner diameters of the permanent magnets 3 close to and away from the discharge chamber cylindrical segment are 30mm.

[0050] Embodiment one

[0051] The thruster installation steps of the present application are as follows: (1) fixing the thruster body on a micro-newton level thrust measurement platform and performing symmetrical counterweighting; (2) connecting the working medium supply system: using a metal sealed interface to connect the thruster gas inlet pipe with the vacuum cabin gas supply system; (3) establishing radio frequency energy transmission: through the vacuum cabin flange, the radio frequency interface is connected with the cabin external radio frequency source for impedance matching; (4) integrating the pre-ionization system: through the multi-electrode feedthrough structure of the vacuum cabin flange, the yttrium-iridium oxide filament 6 is connected to the adjustable direct current power supply loop.

[0052] After the closed vacuum cabin is started, the high vacuum system is started, and the background vacuum degree in the cabin is maintained at the order of 1*10-4Pa through the molecular pump group;

[0053] The ignition timing is executed: (1) the yttrium iridium filament 6 is heated by the direct current power supply, and pre-ionization of the working gas is realized; (2) 50W radio frequency power is fed into the discharge chamber 4 by the radio frequency source, and the working gas is excited to form a steady-state plasma; (3) the discharge parameters are monitored and maintained stable in real time by the LabVIEW control system; (4) the yttrium iridium filament 6 is closed, and only the radio frequency energy is relied on for plasma maintenance.

[0054] The application can be installed on a micro-nano satellite, and only needs to be connected with an air path and a radio frequency source to work stably, and is applied to space tasks such as micro-nano satellite orbit keeping, orbit changing and deep space exploration orbit correction.

[0055] It should be emphasized that the above specific embodiments are only an explanation of the application, and are not a limitation of the application, and those skilled in the art can make modifications to the above embodiments without creative contribution after reading the specification, but as long as it is within the scope of the claims of the application, it is protected by the patent law.

Claims

1. A radio frequency plasma T-shaped magnetic microrocket thruster with pre-ionization function, the thruster is sequentially provided with a gas supply module, a pre-ionization module, an ionization module and a plasma extraction module along the direction of the working gas entering; characterized in that: The pre-ionization module is provided with a porous partition plate (5) which meets the requirements of both sides of the gas pressure and facilitates ignition and maintenance, and separates the glass discharge chamber (4) into two areas, and a section of yttrium iridium filament (6) is added near the working gas inlet for pre-ionization of the working gas; the ionization module couples RF energy into the plasma through the RF coil (2) to form RF plasma self-sustaining discharge; the discharge chamber (4) is composed of a cylindrical section of the discharge chamber and a Laval nozzle section of the discharge chamber, and the outlet end is a Laval nozzle to greatly increase the internal gas pressure of the discharge chamber and improve the ionization rate; the plasma extraction module includes a T-shaped permanent magnet (3) spliced by two ring-shaped high-temperature-resistant samarium-cobalt permanent magnets with different sizes, the permanent magnet near the cylindrical section of the discharge chamber has a larger size, and the permanent magnet away from the cylindrical section of the discharge chamber has a smaller size, and the two form a T-shaped permanent magnet structure.

2. The RF plasma T-magnet penietron with pre-ionization function according to claim 1, characterized in that: The optimal transmittance of the porous partition plate (5) which meets the requirements of both sides of the gas pressure and facilitates ignition and maintenance is about 20%.

3. The RF plasma T-magnet penietron with pre-ionization according to claim 2, characterized in that: The optimal transmittance includes that 8 holes are uniformly distributed on the outer periphery, and the ratio of the hole diameter to the plate diameter of the porous partition plate (5) is 1 / 6.

4. The RF plasma T-magnet penietron with pre-ionization according to claim 2, characterized in that: The size of the pre-ionization area needs to consider the electron density in the area, the power of the yttrium iridium filament (6) cannot be too low or too high, and the voltage of the pre-ionization area needs to be higher than that of the RF coil area; when the yttrium iridium filament (6) is 50w, the axial installation position of the porous partition plate (5) is at one fifth of the cylindrical section of the discharge chamber near the inlet side of the discharge chamber; the cylindrical section of the discharge chamber is the part from the inlet of the discharge chamber to the front of the Laval nozzle of the discharge chamber.

5. The RF plasma T-magnetic penietron thruster with pre-ionization function according to claim 2, characterized in that: The positions of the multiple holes of the porous partition plate (5) on the radius of the plate are larger than the position of the yttrium iridium filament (6) on the radius of the plate, so as to reduce the direct erosion of the backflow plasma on the yttrium iridium filament 6.

6. The RF plasma T-magnetic penietron thruster with pre-ionization function according to claim 4, characterized in that: The T-shaped permanent magnet is arranged at the thrust engine beam port, and is better coupled with the RF coil (2) to improve the plasma beam extraction efficiency and reduce the ignition difficulty.

7. The RF plasma T-magnetic penietron thruster with pre-ionization function according to claim 1, characterized in that: The beam port diameter of the glass discharge chamber (4) is 1 / 3 of the cylindrical section of the discharge chamber.

8. The RF plasma T-magnetic penietron thruster with pre-ionization function according to claim 1, characterized in that: The ratio of the outer diameter of the permanent magnet near the cylindrical section of the discharge chamber to the outer diameter of the permanent magnet away from the cylindrical section of the discharge chamber is 1.5, and the inner diameters of the two are the same; the ratio of the thickness of the permanent magnet near the cylindrical section of the discharge chamber to the thickness of the permanent magnet away from the cylindrical section of the discharge chamber is 1.

5.

9. The RF plasma T-magnetic penietron thruster with pre-ionization function according to claim 4, characterized in that: The outer diameter of the permanent magnet near the cylindrical section of the discharge chamber is 50mm; the inner diameter of the permanent magnet (3) near the cylindrical section of the discharge chamber and away from the cylindrical section of the discharge chamber is 30mm.

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