Multi-section grid low-divergence beam assembly of miniature direct-current ion thruster

Abstract

The invention, which belongs to the technical field of the ion thruster, provides a multi-segment grid electrode low-divergence beam assembly of a miniature direct-current ion thruster, comprising an outer acceleration grid electrode, an inner acceleration grid electrode and an insulating ring, the insulating ring is provided with a connecting hole, and the outer acceleration grid electrode is connected with the inner acceleration grid electrode. The outer acceleration grid and the inner acceleration grid are both provided with first connecting holes and second connecting holes corresponding to the connecting holes, the outer diameter of the insulating ring is the same as the inner diameter of the outer acceleration grid, and the inner diameter of the insulating ring is the same as the outer diameter of the inner acceleration grid. And the outer acceleration grid electrode is connected with the inner acceleration grid electrode through the insulating ring. By the adoption of the multi-section grid low-divergence beam assembly of the miniature direct-current ion thruster, the plume divergence angle can be restrained, and the performance of the thruster is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ion thrusters, in particular to a multi-segment grid low-divergence beam component of a miniature DC ion thruster. Background Art

[0002] In the field of spacecraft electric propulsion systems, ion thrusters, as a highly efficient and long-life propulsion device, are widely used in missions such as satellite orbit adjustment, attitude control, and deep space exploration. Ion thrusters ionize a working gas to form a plasma and accelerate the ions under the action of an electric field to generate thrust. To meet the mission requirements of low thrust and low power, the miniaturization of ion thrusters has become one of their current major development directions and has broad application prospects. Miniature DC ion thrusters generate plasma by ionizing a working gas through electron bombardment. Their core performance indicators mainly include thrust, specific impulse, and efficiency. Efficiency is directly related to the energy efficiency of the thruster and the economic efficiency of mission execution.

[0003] During the operation of a micro-DC ion thruster, the plume divergence angle is one of the key parameters for measuring its performance. The plume divergence angle is defined as the angle between the local beam velocity direction at the radial position containing 95% of the total ion flux and the thruster axis. It directly reflects the collimation of the ion beam. Under the same power conditions, a smaller plume divergence angle means a more concentrated ion beam and higher thruster energy conversion efficiency, thereby more effectively utilizing limited energy resources and improving overall spacecraft performance.

[0004] However, conventional ion thrusters have limitations in suppressing plume divergence. Due to design flaws in the grid assembly, ions are easily affected by the self-consistent electromagnetic field when they are accelerated in the electric field between the grids. This generates a transverse velocity component, which in turn widens the plume divergence. This not only reduces thruster efficiency but can also damage delicate spacecraft components, hindering mission success. Summary of the Invention

[0005] The object of the present invention is to provide a multi-segment grid low-divergence beam assembly for a miniature DC ion thruster, which can suppress the plume divergence angle and improve the thruster performance.

[0006] To achieve the above objectives, the present invention provides a multi-segment grid low-divergence beam assembly for a miniature DC ion thruster, comprising an outer accelerating grid, an inner accelerating grid, and an insulating ring. The insulating ring is provided with a connection hole. Both the outer accelerating grid and the inner accelerating grid are provided with a first connection hole and a second connection hole corresponding to the connection hole. The outer diameter of the insulating ring is the same as the inner diameter of the outer accelerating grid, and the inner diameter of the insulating ring is the same as the outer diameter of the inner accelerating grid. The outer accelerating grid is connected to the inner accelerating grid via the insulating ring.

[0007] Preferably, the outer accelerating grid is an annular plate structure, first through holes with a hexagonal structure are distributed on the outer accelerating grid, and positioning holes are opened on the outer side of the outer accelerating grid, and the positioning holes are arranged outside the first through holes.

[0008] Preferably, the inner accelerating grid is a circular plate structure, and second through holes with a hexagonal structure are distributed on the inner accelerating grid.

[0009] Preferably, the central axes of the insulating ring, the inner accelerating grid and the outer accelerating grid coincide with each other.

[0010] Preferably, the outer accelerating gate is connected to a DC negative bias voltage, and the inner accelerating gate is connected to a DC negative bias voltage.

[0011] Preferably, the outer acceleration gate is made of metal material or carbon material.

[0012] Preferably, the inner acceleration gate is made of metal material or carbon material.

[0013] Preferably, the insulating ring is made of insulating material.

[0014] Therefore, the present invention adopts the above-mentioned micro DC ion thruster multi-segment grid low divergence beam component, and the technical effects are as follows: 1. Reduce the plume divergence angle: By dividing the acceleration grid into two sections, inner and outer, and independently controlling them, and applying a lower negative pressure to the outer acceleration grid and a higher negative pressure to the inner acceleration grid, a spatially differentiated electric field distribution is formed, thereby effectively reducing the plume divergence angle.

[0015] 2. Improve thruster performance: Optimizing the plume divergence angle directly improves thruster performance, including key indicators such as thrust, specific impulse, and efficiency.

[0016] 3. Optimize ion beam control: The hexagonal through-hole design and the coaxiality of the grid assembly ensure uniform acceleration and collimation of the ion beam when passing through the grid assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an overall schematic diagram of the multi-segment grid assembly of the present invention; Figure 2 This is a front view of the multi-segment grid assembly of the present invention; Figure 3 This is a rear view of the multi-segment grid assembly of the present invention; Figure 4 It is a side cross-sectional view of the multi-segment grid assembly of the present invention.

[0018] Reference numerals 1. Outer accelerating gate; 2. Insulating ring; 3. Inner accelerating gate; 4. Connecting hole; 5. First connecting hole; 6. Second connecting hole; 7. First through hole; 8. Positioning hole; 9. Second through hole. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0020] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0021] Example 1 like Figures 1-4 As shown, the present invention provides a multi-segment grid low-divergence beam assembly for a miniature DC ion thruster, comprising an outer accelerating grid 1, an inner accelerating grid 3, and an insulating ring 2. The outer accelerating grid 1 is an annular plate structure made of metal or carbon material, exhibiting excellent electrical conductivity and high-temperature resistance. Multiple circular first through-holes 7 of equal diameter are distributed on the surface of the outer accelerating grid 1. These first through-holes 7 are arranged in a hexagonal pattern to ensure uniform acceleration of the ion beam. The outer accelerating grid 1 is connected to a negative DC bias voltage, such as -150V, for initial acceleration of the ion beam.

[0022] The inner accelerating grid 3 is a circular plate structure, also made of metal or carbon. Its surface is covered with multiple circular second through-holes 9 of the same diameter. These second through-holes 9 correspond to the first through-holes 7 of the outer accelerating grid 1 and are arranged in a hexagonal pattern. The inner accelerating grid 3 is connected to a negative DC bias voltage, but at a higher value than the outer accelerating grid 1, such as -250V. This voltage is used to further accelerate the ion beam and create a spatially differentiated electric field distribution, suppressing the transverse velocity component and reducing the plume divergence angle.

[0023] The insulating ring 2 is an annular plate with an outer diameter identical to the inner diameter of the outer accelerating grid 1 and an inner diameter identical to the outer diameter of the inner accelerating grid 3. It is installed between the outer and inner accelerating grids 1 and 3 to provide electrical isolation and mechanical fixation. Made of ceramic or high-performance insulating plastic, the insulating plate offers excellent electrical insulation and mechanical strength. It ensures electrical isolation between the outer and inner accelerating grids 1 and 3, while also providing mechanical support and maintaining the coaxiality of the grid assembly.

[0024] This component can achieve a multi-ring expansion structure, including nested third accelerating grids connected by an additional insulating ring 2, forming a multi-level voltage control unit. This provides more precise voltage control capabilities, further optimizes the beam divergence angle, and meets the needs of more complex space missions.

[0025] The outer accelerating grid 1 is provided with a positioning hole 8, located outside the first through-hole 7. The outer accelerating grid 1 is connected to the screen grid and discharge chamber through the positioning hole 8, ensuring the accurate positioning of the grid assembly in the thruster. The insulating ring 2 is provided with a connection hole 4. Both the outer accelerating grid 1 and the inner accelerating grid 3 are provided with a first connection hole 5 and a second connection hole 6 corresponding to the connection hole 4. The insulating ring 2 is installed between the outer accelerating grid 1 and the inner accelerating grid 3, and the connection hole 4 is used to achieve mechanical fixation and ensure electrical isolation. The inner accelerating grid 3 is coaxially mounted with the insulating ring 2 and the outer accelerating grid 1, ensuring that the through-hole axes coincide, allowing the ion beam to pass smoothly.

[0026] When a micro-DC ion thruster is operating, the working gas is ionized into ions and electrons within the discharge chamber, forming a plasma. The ions are accelerated in the electric field between the gates. By applying a relatively low negative pressure to the outer accelerating gate 1 and a relatively high negative pressure to the inner accelerating gate 3, segmented voltage regulation is achieved, forming a spatially differentiated electric field distribution, effectively suppressing the transverse velocity component of the ion beam and reducing the plume divergence angle. The addition of a multi-ring extension structure further provides multi-level voltage regulation capabilities, optimizing the beam divergence angle and meeting the needs of higher-precision beam control. The reduction in the plume divergence angle makes the ion beam more concentrated, improving the thruster's energy conversion efficiency. At the same power, the thruster can generate greater effective thrust, extending the service life of the spacecraft or improving mission execution capabilities.

[0027] Therefore, the present invention adopts the above-mentioned multi-segment grid low-divergence beam assembly of the miniature DC ion thruster. Through the segmented voltage control strategy, a lower negative voltage is applied to the outer accelerating grid and a higher negative voltage is applied to the inner accelerating grid, forming a spatially differentiated electric field distribution, suppressing the transverse velocity component of the ion beam, reducing the plume divergence angle, and improving the thruster efficiency.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A multi-segment grid low-divergence beam assembly for a micro DC ion thruster, characterized in that: The invention comprises an outer accelerating grid, an inner accelerating grid and an insulating ring, wherein the insulating ring is provided with a connecting hole, and the outer accelerating grid and the inner accelerating grid are both provided with a first connecting hole and a second connecting hole corresponding to the connecting hole. The outer diameter of the insulating ring is the same as the inner diameter of the outer accelerating grid, and the inner diameter of the insulating ring is the same as the outer diameter of the inner accelerating grid. The outer accelerating grid is connected to the inner accelerating grid via the insulating ring.

2. The multi-segment grid low divergence beam assembly of a miniature DC ion thruster according to claim 1, characterized in that: The outer accelerating grid is an annular plate structure. First through holes with a hexagonal structure are distributed on the outer accelerating grid. Positioning holes are opened on the outer side of the outer accelerating grid. The positioning holes are arranged on the outer side of the first through holes.

3. The multi-segment grid low-divergence beam assembly of a miniature DC ion thruster according to claim 1, characterized in that: The inner accelerating grid is a circular plate structure, and second through holes with a hexagonal structure are distributed on the inner accelerating grid.

4. The multi-segment grid low-divergence beam assembly of a miniature DC ion thruster according to claim 1, characterized in that: The central axes of the insulating ring, the inner accelerating grid and the outer accelerating grid coincide with each other.

5. The multi-segment grid low-divergence beam assembly of a miniature DC ion thruster according to claim 1, characterized in that: The outer accelerating grid is connected to a DC negative bias voltage, and the inner accelerating grid is connected to a DC negative bias voltage.

6. The multi-segment grid low-divergence beam assembly of a miniature DC ion thruster according to claim 1, characterized in that: The external accelerating grid is made of metal material or carbon material.

7. The multi-segment grid low-divergence beam assembly of a miniature DC ion thruster according to claim 1, characterized in that: The inner accelerating grid is made of metal material or carbon material.

8. The multi-segment grid low-divergence beam assembly for a miniature DC ion thruster according to claim 1, characterized in that: The insulating ring is made of insulating material.

Images