Double-magnetic-mirror structure magnetic plasma electric propulsion jet flow confinement magnetic field configuration

Abstract

The invention provides a double-magnetic-mirror structure magnetic plasma electric propulsion jet flow confinement magnetic field configuration. The device is composed of a primary magnetic mirror water-cooling magnet exciting coil, a water-cooling magnet exciting coil insulation protective shell, a water-cooling coaxial wire tube insulation protective layer, a water-cooling coaxial wire tube water-cooling channel, a water-cooling coaxial wire tube copper wire core, a secondary magnetic mirror pinch magnetic pole array, a high-temperature-resistant permanent magnet magnetic pole and a sputtering-resistant ceramic coating. According to the device, a first-stage axial magnetic mirror structure magnetic field configuration is generated through a first-stage magnetic mirror water-cooling magnet exciting coil, magnetic plasma electric propulsion discharging is restrained, and the plasma vortex acceleration process is induced; a secondary magnetic mirror pinch magnetic pole array is utilized to form a secondary inclined magnetic mirror structure magnetic field configuration with boundary maximum value magnetic field characteristics, the radial and circumferential speeds of plasmas can be converted into axial speeds along magnetic induction lines, plasma electric propulsion jet flow is focused, the radial loss efficiency of the magnetic plasma electric propulsion jet flow is reduced, and the efficiency of the magnetic plasma electric propulsion jet flow is improved. And the overall performance of magnetic plasma electric propulsion is improved.

Description

Technical Field

[0001] The present invention belongs to the field of space plasma propulsion, and particularly relates to a magnetic field configuration for constraining the jet of a magnetic plasma electric propulsion with a double magnetic mirror structure. Background Art

[0002] Space electric propulsion uses electromagnetic fields to generate and accelerate plasma jets to produce thrust. It has a high specific impulse and can improve the payload and lifespan of spacecraft. It is one of the internationally recognized most advanced space propulsion technologies. Magnetic plasma electric propulsion is a high-power electromagnetic coupling acceleration type electric thruster, which has the advantages of both high specific impulse (104 s) and large thrust (hundreds of N). It is one of the ideal power options for the forefront of space propulsion research and tasks such as manned lunar landing and deep space exploration.

[0003] However, traditional magnetic plasma electric propulsion adopts a divergent magnetic nozzle magnetic field configuration with a single magnetic mirror structure. Under this magnetic field configuration, the magnetic field strength presents a central maximum distribution law, which cannot provide effective radial constraint force for the magnetic plasma electric propulsion jet, resulting in the divergence and performance loss of the plasma jet. It even induces unexpected backflow, which is harmful to the magnetic plasma electric propulsion device and the satellite platform. Summary of the Invention

[0004] The purpose of the present invention is to provide a magnetic field configuration for constraining the jet of a magnetic plasma electric propulsion with a double magnetic mirror structure, to provide a solution for improving the plasma confinement efficiency and thrust performance of high-power magnetic plasma electric propulsion, and to provide an advanced space propulsion technology support for future spacecraft platform orbital transfer and deep space exploration activities.

[0005] A magnetic field configuration for constraining the jet of a magnetic plasma electric propulsion with a double magnetic mirror structure provided by the present invention includes a first-stage magnetic mirror water-cooled excitation coil and a second-stage magnetic mirror constriction magnetic pole array.

[0006] The first part: The first-stage magnetic mirror water-cooled excitation coil is provided with a water-cooled excitation coil insulation protection shell, a water-cooled coaxial tube insulation protection layer, a water-cooled coaxial tube water-cooling channel, and a water-cooled coaxial tube copper wire core.

[0007] The water-cooled excitation coil insulation protection shell is a rotating body with a rectangular thin-wall cross-section. The rotation axis is coaxial with the symmetry axis of the magnetic plasma electric propulsion, and the outer surface is coated with a pressure-resistant insulation material.

[0008] The water-cooled coaxial tube copper wire core is a solid wire with a circular cross-section, and is uniformly distributed in the water-cooled excitation coil insulation protection shell in an array along the axial and radial directions respectively, so as to generate a first-stage axial magnetic mirror structure magnetic field configuration for magnetic plasma electric propulsion discharge constraint and plasma primary acceleration.

[0009] The insulating protective shell of the water-cooled excitation coil is a hollow tube with a circular cross-section, coaxially placed with the water-cooled coaxial tube copper wire core, and covered on the outside of the water-cooled coaxial tube copper wire core.

[0010] The gap between the insulating protective shell of the water-cooled excitation coil and the water-cooled coaxial tube copper wire core is the water-cooling channel of the water-cooled coaxial tube, so that distilled water can flow through to cool the water-cooled coaxial tube copper wire core.

[0011] In an alternative embodiment,

[0012] The insulating protective shell of the water-cooled excitation coil is made of aluminum alloy, and its outer surface is covered with a glass fiber insulating layer, and there is a gap between its inner surface and the water-cooled coaxial tube copper wire core array.

[0013] The insulating protective shell of the water-cooled excitation coil is made of PTFE or PEEK material.

[0014] The water-cooled coaxial tube copper wire core array has 5 turns in the axial direction, each group of coils is divided into 6 layers in the radial direction, and the total number of turns of the coils is 30 turns.

[0015] Second part: The secondary magnetic mirror pinch magnetic pole array is provided with a high-temperature resistant permanent magnet pole and a sputtering-resistant ceramic coating.

[0016] The high-temperature resistant permanent magnet pole is an inclined rectangular parallelepiped structure, and is uniformly circumferentially arrayed along the axis of the magnetoplasma electric propulsion.

[0017] The magnetic field direction of the high-temperature resistant permanent magnet pole is perpendicular to the surface of the pole and points to the axis of the magnetoplasma electric propulsion, forming a magnetic field configuration of a secondary inclined magnetic mirror structure with radial inward pinch, and the highest magnetic field strength is formed at the magnetic field boundary to constrain the radial divergence of the magnetoplasma electric propulsion jet.

[0018] The sputtering-resistant ceramic coating is attached to the surface of the high-temperature resistant permanent magnet pole to prevent the magnetoplasma electric propulsion jet from causing sputtering erosion to the high-temperature resistant permanent magnet pole.

[0019] In an alternative embodiment,

[0020] The secondary magnetic mirror pinch magnetic pole array is provided with 6 permanent magnet poles uniformly distributed circumferentially.

[0021] The size of the high-temperature resistant permanent magnet pole is 150mm×120mm×25mm.

[0022] The sputtering-resistant ceramic coating covers 5 surfaces of the high-temperature resistant permanent magnet pole, and there is no sputtering-resistant ceramic coating on the surface facing away from the magnetoplasma electric propulsion jet.

[0023] Combining the above processes, the device can achieve efficient radial constraint of the magnetoplasma electric propulsion jet.

[0024] Advantages of the present invention compared with the prior art:

[0025] 1. The magnetic field configuration of the secondary inclined magnetic mirror structure squeezes the divergent magnetic field of the primary axial magnetic mirror structure to form a magnetic nozzle configuration with a magnetic field having a maximum value at the boundary, introducing a magnetic field radial gradient barrier to provide a better pinch confinement effect for the plasma, so as to improve the efficiency of magnetic plasma electric propulsion.

[0026] 2. The secondary magnetic mirror pinch magnetic pole array is covered with a sputtering-resistant ceramic coating, which can prevent the sputtering erosion of the permanent magnet poles by the high heat flux density magnetic plasma electric propulsion jet. Description of the drawings

[0027] Figure 1 It is a structural composition diagram of a device for generating a magnetic field configuration for constraining a magnetic plasma electric propulsion jet with a double magnetic mirror structure provided by an embodiment of the present invention.

[0028] Figure 2 It is a structural diagram of a primary magnetic mirror water-cooled excitation coil in a magnetic field configuration for constraining a magnetic plasma electric propulsion jet with a double magnetic mirror structure provided by an embodiment of the present invention.

[0029] Figure 3 It is a structural diagram of a secondary magnetic mirror pinch magnetic pole in a magnetic field configuration for constraining a magnetic plasma electric propulsion jet with a double magnetic mirror structure provided by an embodiment of the present invention.

[0030] Figure 4 It is a magnetic field configuration diagram of a traditional single magnetic mirror structure formed by a primary magnetic mirror water-cooled excitation coil in a magnetic field configuration for constraining a magnetic plasma electric propulsion jet with a double magnetic mirror structure provided by an embodiment of the present invention.

[0031] Figure 5 It is a radial distribution curve diagram of the magnetic field strength of a traditional single magnetic mirror structure formed by a primary magnetic mirror water-cooled excitation coil in a magnetic field configuration for constraining a magnetic plasma electric propulsion jet with a double magnetic mirror structure provided by an embodiment of the present invention.

[0032] Figure 6 It is a magnetic field configuration diagram of a double magnetic mirror structure in a magnetic field configuration for constraining a magnetic plasma electric propulsion jet with a double magnetic mirror structure provided by an embodiment of the present invention.

[0033] Figure 7 It is a radial distribution curve diagram of the magnetic field strength of a double magnetic mirror structure in a magnetic field configuration for constraining a magnetic plasma electric propulsion jet with a double magnetic mirror structure provided by an embodiment of the present invention.

[0034] The reference numerals in the figures are explained as follows:

[0035] 1. The first - stage magnetic mirror water - cooled excitation coil 101, the water - cooled excitation coil insulation protection shell 102, the water - cooled coaxial tube insulation protection layer 103, the water - cooled coaxial tube water - cooling channel 104, the copper wire core of the water - cooled coaxial tube; 2. The second - stage magnetic mirror pinch magnetic pole array 201, the high - temperature resistant permanent magnet pole 202, the sputtering - resistant ceramic coating; 3. The magnetoplasma electric propulsion; 4. The magnetoplasma electric propulsion jet Specific implementation manners

[0036] The present invention provides a magnetic field configuration for constraining a magnetoplasma electric propulsion jet with a double - magnetic - mirror structure. The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0037] In the description of the present invention, it should be noted that the terms "right side", "radially inward", "outer side", "tilted", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present invention, rather than indicating or implying that the device or structural member referred to must have a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0038] As Figure 1 shown, the structure - composition diagram of a device for generating a magnetic field configuration for constraining a magnetoplasma electric propulsion jet with a double - magnetic - mirror structure provided in this embodiment includes, in sequence from left to right: the first - stage magnetic mirror water - cooled excitation coil 1, the second - stage magnetic mirror pinch magnetic pole array 2, the magnetoplasma electric propulsion 3, and the magnetoplasma electric propulsion jet 4.

[0039] Among them, the magnetoplasma electric propulsion 3 and the magnetoplasma electric propulsion jet 4 do not fall within the scope of a magnetic field configuration for constraining a magnetoplasma electric propulsion jet with a double - magnetic - mirror structure of the present invention.

[0040] Its specific working steps are as follows:

[0041] Step 1: First, introduce constant - temperature cooling distilled water at 5 °C into the water - cooling channel 103 of the water - cooled coaxial tube to provide heat dissipation ( Figure 1 and Figure 2 ) for the copper wire core 104 of the water - cooled coaxial tube, and ensure that the first - stage magnetic mirror water - cooled excitation coil 1 operates under the temperature condition of low resistance.

[0042] Step 2: Pass a constant current of 100 A through the copper wire core 104 of the water - cooled coaxial tube, thereby generating a classical first - stage axial magnetic mirror structure magnetic field configuration as Figure 4 shown. Under this magnetic field configuration, the magnetic induction lines are divergent. Taking the center point of the first - stage magnetic mirror water - cooled excitation coil 1 as the axial position zero point, the magnetic field intensity data at the axial normalized distance of 0.1 is statistically analyzed. As Figure 5As shown, the magnetic field strength at this position shows a single-peak structure with a central maximum value that is high in the middle and low at the edges along the radial distribution.

[0043] Step 3: On the basis of the single-mirror configuration magnetic field generated by the first-stage mirror water-cooled excitation coil 1, arrange six sets of high-temperature permanent magnet poles 201 with sputtering-resistant ceramic coatings 202 placed obliquely on the right side of the first-stage mirror water-cooled excitation coil 1 ( Figure 3 ), and arrange them in a circumferentially uniform array to form the second-stage mirror pinch pole array 2.

[0044] Step 4: The size of the high-temperature permanent magnet pole 201 is 150mm×120mm×25mm, and the magnetization direction is perpendicular to the 150mm×120mm surface and points radially inward to the axis of symmetry of the second-stage mirror pinch pole array 2. The radially inward magnetic field of the above high-temperature permanent magnet pole 201 is superimposed on the magnetic field configuration of the first-stage axial mirror structure generated by the first-stage mirror water-cooled excitation coil 1 to form a Figure 6 magnetic field configuration diagram of the double-mirror structure as shown. Compared with the Figure 4 single-mirror configuration magnetic field shown, the magnetic field lines on the outer side of this double magnetic field configuration are driven by the inward pinch magnetic field generated by the second-stage mirror pinch pole array 2 and compressed inward, thus forming the magnetic field configuration of the second-stage inclined mirror structure.

[0045] Step 5: Taking the center point of the first-stage mirror water-cooled excitation coil 1 as the zero point of the axial position, count the magnetic field strength data at the axial normalized distance of 0.1. As Figure 6 shown, the magnetic field strength at this position along the radial distribution under the double-mirror structure magnetic field configuration shows an edge maximum magnetic field configuration with a double-peak structure that first increases and then decreases from the middle to the outside.

[0046] Step 6: Under the action of this double-mirror structure magnetic field configuration, the magnetoplasma electric propulsion 3 is first ionized under the action of the first-stage axial mirror structure magnetic field configuration. The plasma is ejected outward under the vortex acceleration of the axial magnetic field to generate a magnetoplasma electric propulsion jet 4. Further, under the radial pinch action of the second-stage inclined mirror structure magnetic field configuration, the radial and circumferential velocities of the plasma are constrained by the second-stage inclined mirror structure magnetic field configuration and converted into the axial velocity along the magnetic induction line, generating a plasma electric propulsion jet focusing effect, thereby greatly reducing the radial loss efficiency of the magnetoplasma electric propulsion jet 4 and improving the overall performance of the magnetoplasma electric propulsion 3.

Claims

1. A dual magnetic mirror structure magnetic plasma electric propulsion jet confinement magnetic field configuration, characterized by: The system consists of a primary magnetic mirror water-cooled excitation coil, a water-cooled excitation coil insulating protective shell, a water-cooled coaxial line tube insulating protective layer, a water-cooled coaxial line tube water-cooling channel, a water-cooled coaxial line tube copper wire core, a secondary magnetic mirror pinch magnetic pole array, high temperature resistant permanent magnet poles, and a sputtering resistant ceramic coating. Among them, the first-stage magnetic mirror water-cooled excitation coil is composed of a multi-turn water-cooled coaxial tube copper wire core, which is used to generate a first-stage axial magnetic mirror structure magnetic field configuration to form the axial magnetic field required for magnetic plasma electric propulsion discharge and induce the plasma vortex acceleration process; the second-stage magnetic mirror pinch magnetic pole array is composed of high-temperature resistant permanent magnet poles with sputtering-resistant ceramic coating, which is used to form a second-stage inclined magnetic mirror structure magnetic field configuration, converting the radial and circumferential velocities of the plasma into axial velocities along the magnetic flux lines, focusing the plasma electric propulsion jet, reducing the radial loss efficiency of the magnetic plasma electric propulsion jet, and improving the overall performance of magnetic plasma electric propulsion.

2. According to claim 1, a double magnetic mirror structure magnetic plasma electric propulsion jet confinement magnetic field configuration is characterized by: An insulating protective layer of the water-cooled coaxial tube is coated on the outside of the copper wire core of the water-cooled coaxial tube, and a water-cooling channel of the water-cooled coaxial tube is formed on the outer surface of the copper wire core of the water-cooled coaxial tube. Different from the traditional internally water-cooled copper wire tube, the structure of the present invention has a shorter circumference, lower copper wire core resistance, and a simple solid copper wire core coil winding process, thereby avoiding thin-wall damage during the bending process of traditional thin-wall wire tubes.

3. According to claim 1, a dual magnetic mirror structure magnetic plasma electric propulsion jet confinement magnetic field configuration is characterized by: The first-stage magnetic mirror water-cooled excitation coil is provided with a water-cooled excitation coil insulating protective shell, and the outer surface is covered with a pressure-resistant insulating material.

4. According to claim 1, a dual magnetic mirror structure magnetic plasma electric propulsion jet confinement magnetic field configuration is characterized by: The secondary magnetic mirror pinch pole array is composed of 6 high-temperature resistant permanent magnet poles uniformly distributed in the circumferential direction, with a specification of 150mm×120mm×25mm. The high-temperature resistant permanent magnet poles are placed at an angle, and the magnetization direction is perpendicular to the 150mm×120mm surface and radially inward to the symmetry axis of the secondary magnetic mirror pinch pole array.

5. The double magnetic mirror structure magnetic plasma electric propulsion jet confinement magnetic field configuration according to claim 1, characterized in that: Except for the surface facing away from the magnetic plasma electric propulsion jet, the remaining five surfaces of the high-temperature resistant permanent magnet poles are coated with sputtering-resistant ceramic coatings to prevent sputtering erosion of the permanent magnet pole surfaces by the magnetic plasma electric propulsion jet.

6. The double magnetic mirror structure magnetic plasma electric propulsion jet confinement magnetic field configuration according to claim 1, characterized in that: The present invention forms a double magnetic mirror structure magnetic field configuration including a primary axial magnetic mirror structure and a secondary inclined magnetic mirror structure, which is different from a traditional single magnetic mirror structure and utilizes a radial magnetic mirror structure to constrain the radial diffusion process of plasma.

7. The double magnetic mirror structure magnetic plasma electric propulsion jet confinement magnetic field configuration according to claim 1, characterized in that: The magnetic field intensity in the dual magnetic mirror structure magnetic field configuration described in the present invention presents a double-peak structure along the radial distribution that first increases and then decreases from the center to the surroundings, with a minimum value at the center and a maximum value at the edge. Different from the traditional single magnetic mirror structure with a central maximum value, the edge maximum value feature of the dual magnetic mirror structure magnetic field configuration can realize the efficient conversion of the circumferential and radial velocities of charged particles into axial velocities, thereby improving the acceleration efficiency of the magnetic plasma electric propulsion jet.

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