CN110514446B - Uniform electromagnetic field device for plasma velocity screening instrument - Google Patents

Abstract

The application discloses a uniform electromagnetic field device for a plasma velocity screening instrument, comprising a first ceramic plate, a second ceramic plate, a first magnetic pole plate, a second magnetic pole plate, a first magnetic pole plate gasket, and a second magnetic pole plate Gasket, first electrode plate, second electrode plate, first electrode plate insulating block, second electrode plate insulating block, first electrode plate adapter, second electrode plate adapter, shell. Through the technical scheme of the present invention, reasonable relative position accuracy can be ensured, and installation accuracy and machining performance can be satisfied. A special concave circular electric field structure design is adopted to provide a uniform electric field and magnetic field inside the plasma velocity screening instrument, so that under the narrow and long electric field structure with limited width, the electric field distribution in the central area is relatively uniform, and from the center The electric field strength in the direction of the electrode plate is gradually reduced, and at the same time, a uniform electromagnetic field channel can be provided for the plasma velocity screening device.

Description

A Uniform Electromagnetic Field Device for Plasma Velocity Screening Instrument

technical field

The invention belongs to the field of electric propulsion plasma measurement, and in particular relates to an ion velocity selector for deflecting and velocity screening measurement of ion thruster beam plasma by using a contact measurement method.

Background technique

Electric propulsion is a kind of advanced propulsion method that uses electric energy to directly heat propellant or uses electromagnetic action to ionize and accelerate propellant to obtain propulsion power. It has high specific impulse, thrust and efficiency. It is used in orbit control of large spacecraft and deep space exploration. It has broad application prospects in space missions such as interstellar navigation.

The ion thruster is a kind of electrostatic electric thruster, which has been widely used in the main propulsion system of satellites and deep space probes.

The measurement of relevant parameters of the beam plasma of the ion thruster is of great significance for improving the optimization of the engine design and improving the performance of the engine. The ion velocity selector is one of the basic test methods for measuring the plasma energy distribution. It belongs to the contact measurement method and has the advantages of high measurement accuracy and strong ion screening ability. However, there are higher requirements for the uniformity of the electromagnetic field inside the instrument. At present, there is no velocity selector specially designed for the beam region of the ion thruster. The main reason is that there is a technical bottleneck in the design of the uniform electromagnetic field structure.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned deficiencies in the prior art, the present invention proposes a device capable of generating a uniform electromagnetic field, which is used in a plasma velocity screening instrument to measure the ion energy distribution of the ion thruster plume. For realizing the above-mentioned technical purpose, the concrete technical scheme of the present invention is as follows:

A uniform electromagnetic field device for plasma velocity screening instrument, characterized in that it comprises a first ceramic plate, a second ceramic plate, a first magnetic pole plate, a second magnetic pole plate, a first magnetic pole plate gasket, and a second magnetic pole plate Gasket, first electrode plate, second electrode plate, first electrode plate insulating block, second electrode plate insulating block, first electrode plate adapter, second electrode plate adapter, casing, wherein,

The first ceramic plate and the second ceramic plate are interlocked, and an insulating cavity is formed inside, and the insulating cavity formed inside the first ceramic plate and the second ceramic plate is sequentially arranged from top to bottom The first magnetic pole plate, the first magnetic pole plate spacer, the second magnetic pole plate spacer, the second magnetic pole plate, between the first magnetic pole plate spacer and the second magnetic pole plate spacer The first electrode plate and the second electrode plate are arranged in sequence from left to right therebetween;

Outside the casing, the first electrode plate adapter is connected to the first electrode plate insulating block, the first electrode plate insulating block is connected to the first electrode plate, and the second electrode plate adapter is connected to the the second electrode plate insulating block, the second electrode plate insulating block is connected to the second electrode plate;

The housing is assembled outside the first ceramic plate and the second ceramic plate.

Further, the opposite end of the first electrode plate and the second electrode plate is arc-shaped, and the radius of curvature is 2mm-3mm, and the opposite end of the second electrode plate and the first electrode plate is arc-shaped, The radius of curvature is 2mm-3mm.

Further, the distance between the first magnetic pole plate and the second magnetic pole plate is 8±0.01mm from the center of the insulating cavity formed inside the first ceramic plate and the second ceramic plate. The distance between the edge of the arc segment and the edge of the arc segment of the second electrode plate is 6±0.01mm from the center of the insulating cavity formed inside the first ceramic plate and the second ceramic plate, and the first magnetic pole The area of the magnetic field generated by the plate and the second magnetic pole plate covers the area where the electric field is generated by the first electrode plate and the second electrode plate.

Further, the magnetic field strength between the first magnetic pole plate and the second magnetic pole plate is maintained at 0.26±0.01T, and the distribution is uniform; the electric field distribution between the first electrode plate and the second electrode plate is overall It presents an "X" shape, the electric field strength is maintained at (2.64±0.01)×10 ³ V/m, and the distribution is uniform.

Further, the first ceramic plate and the second ceramic plate are made of boron nitride.

Further, the first magnetic pole plate and the second magnetic pole plate are made of NdFeB material.

Further, the first electrode plate and the second electrode plate are made of austenitic stainless steel.

The beneficial effects of the present invention are:

1. The electrode plate structure with one end of the arc section is adopted, which can generate a uniform electric field and ensure that the ions are screened in the electromagnetic field with high precision and good collimation.

2. The structure of the magnetic field outside and the electric field inside avoids the influence of the magnet itself on the distribution of the electric field.

3. Using a special concave electric field structure design, in the narrow and long electric field structure with limited width, the electric field intensity distribution in the central area is relatively uniform, and the electric field intensity gradually decreases from the center to the periphery of the electrode plate without sudden change.

4. Through a snap-fit non-metallic shell structure, it can not only ensure reasonable relative position accuracy, but also meet relatively easy installation accuracy and machining performance.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below, and the features and advantages of the present invention will be more clearly understood by referring to the drawings. , the accompanying drawings are schematic and should not be construed as any limitation to the present invention. For those of ordinary skill in the art, other drawings can be obtained from these drawings without creative effort. in:

Fig. 1 is a kind of uniform electromagnetic field device structure diagram for plasma velocity screening instrument;

Fig. 2 is a kind of uniform electromagnetic field device structure diagram for plasma velocity screening instrument;

3 is a magnetic field distribution diagram of a uniform electromagnetic field device used for a plasma velocity screening instrument;

Fig. 4 is a kind of electric field distribution diagram of the uniform electromagnetic field device used for plasma velocity screening instrument;

FIG. 5 is a front cross-sectional view of the electric field distribution of a uniform electromagnetic field device used in a plasma velocity screening apparatus.

Description of reference numbers:

1-first ceramic plate; 2-second ceramic plate; 3-first magnetic pole plate; 4-second magnetic pole plate; 5-first magnetic pole plate gasket; 6-second magnetic pole plate gasket; 7-first Electrode plate; 8-second electrode plate; 9-first electrode plate insulating block; 10-second electrode plate insulating block; 11-first electrode plate adapter; 12-second electrode plate adapter; 13-shell.

Detailed ways

In order to understand the above objects, features and advantages of the present invention more clearly, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments may be combined with each other in the case of no conflict.

Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific details disclosed below. Example limitations.

As shown in Figures 1 and 2, a uniform electromagnetic field device for a plasma velocity screening instrument is characterized in that it comprises a first ceramic plate 1, a second ceramic plate 2, a first magnetic pole plate 3, and a second magnetic pole plate 4. The first magnetic pole plate gasket 5, the second magnetic pole plate gasket 6, the first electrode plate 7, the second electrode plate 8, the first electrode plate insulating block 9, the second electrode plate insulating block 10, the first electrode plate The adapter 11 , the second electrode plate adapter 12 , and the casing 13 , wherein the first ceramic plate 1 and the second ceramic plate 2 are interlocked, and an insulating cavity is formed inside. A magnetic pole plate 3, a first magnetic pole plate spacer 5, a second magnetic pole plate spacer 6, and a second magnetic pole plate 4, in order from left to right between the first magnetic pole plate spacer 5 and the second magnetic pole plate spacer 6 A first electrode plate 7 and a second electrode plate 8 are provided; outside the casing 13, the first electrode plate adapter 11 is connected to the first electrode plate insulating block 9, the first electrode plate insulating block 9 is connected to the first electrode plate 7, the second electrode plate The electrode plate adapter 12 is connected to the second electrode plate insulating block 10 , and the second electrode plate insulating block 10 is connected to the second electrode plate 8 ; the casing 13 is assembled outside the first ceramic plate 1 and the second ceramic plate 2 .

The first electrode plate 7 and the second electrode plate 8 extend out of the device through the first electrode plate adapter 11 and the second electrode plate adapter 12 respectively, and are connected with the external power supply circuit, so that the external power supply system can pass through the first electrode plate adapter 11 and the second electrode plate adapter 12 respectively. The electrode plate adapter 11 and the second electrode plate adapter 12 provide a bias voltage of 0-80V to the first electrode plate 7 and the second electrode plate 8 inside, and finally the first electrode plate 7 and the second electrode plate 8 are obtained. In the case of a bias voltage, a uniform magnetic field is formed in the insulating cavity formed inside the first ceramic plate 1 and the second ceramic plate 2 .

The first electrode plate insulating block 9 and the second electrode plate insulating block 10 ensure that the first electrode plate 7, the second electrode plate 8, the first electrode plate adapter 11 and the second electrode plate adapter 12 are insulated from the entire device, and the outer casing is insulated. 13 All components assembled inside the external fixtures of the first ceramic plate 1 and the second ceramic plate 2.

其中，λ_D是德拜长度、ε₀是真空介电常数、k是波尔茨曼常数、T_e是电子温度、e是元电荷量、N_e是电子密度、R是离子回旋半径、m_i是离子质量、v_b是离子切向速度、q_i是离子电荷量、B是磁场强度。该结构能够产生均匀电场，保证离子在电磁场中筛选精度较高，准直性好，能达到电场强度误差小于0.1V/m，电场的均匀性远高于平行板式的电极结构。In some embodiments, the opposite end of the first electrode plate 7 and the second electrode plate 8 is arc-shaped with a radius of curvature of 2 mm-3 mm, and the opposite end of the second electrode plate 8 and the first electrode plate 7 is arc-shaped and has a curvature radius of 2 mm-3 mm. The radius is 2mm-3mm, and the curvature radius of the first electrode plate 7 and the second electrode plate 8 follows the Debye scale calculation formula of electrostatic shielding and the calculation formula of Larmor's radius of gyration:

where λ _D is the Debye length, ε ₀ is the vacuum permittivity, k is the Boltzmann constant, T _e is the electron temperature, _e is the amount of elementary charge, Ne is the electron density, R is the ion radius of gyration, m _i is the ion mass, v _b is the ion tangential velocity, q _i is the ion charge, and B is the magnetic field strength. The structure can generate a uniform electric field, ensure that the ions are screened with high precision in the electromagnetic field, and have good collimation.

In some embodiments, the distance between the first magnetic pole plate 3 and the second magnetic pole plate 4 is 8±0.01 mm from the center of the insulating cavity formed inside the first ceramic plate 1 and the second ceramic plate 2, and the circle of the first electrode plate 7 is 8±0.01 mm. The distance between the edge of the arc segment and the edge of the arc segment of the second electrode plate 8 is 6±0.01mm from the center of the insulating cavity formed inside the first ceramic plate 1 and the second ceramic plate 2. The first magnetic pole plate 3 and the second magnetic pole plate The magnetic field area generated by 4 covers the area where the electric field is generated by the first electrode plate 7 and the second electrode plate 8. This structure with the magnetic field outside and the electric field inside avoids the distribution of the electric field by the first magnetic pole plate 3 and the second magnetic pole plate 4 themselves. Impact.

As shown in FIGS. 3-5 , in some embodiments, the magnetic field strength between the first magnetic pole plate 3 and the second magnetic pole plate 4 is maintained at 0.26±0.01T, and the distribution is uniform; the first electrode plate 7 and the second electrode The electric field distribution between the plates 8 presents an "X" shape as a whole, the electric field strength is maintained at (2.64±0.01)×10 ³ V/m, and the distribution is uniform.

In some embodiments, the first ceramic plate 1 and the second ceramic plate 2 are made of boron nitride, which not only ensures that the machining accuracy reaches the level of 0.01 mm, but also enhances the anti-sputtering effect of the external plasma.

In some embodiments, the first magnetic pole plate 3 and the second magnetic pole plate 4 are made of NdFeB material, which have good permanent magnet performance and long service life, and can provide a uniform magnetic field.

In some embodiments, the first electrode plate 7 and the second electrode plate 8 are made of austenitic stainless steel, which is non-magnetic, which ensures that the electric field formation area between the first electrode plate 7 and the second electrode plate 8 does not occur. be magnetized without affecting the uniformity of the magnetic field.

In the present invention, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless expressly limited otherwise.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. A uniform electromagnetic field device for a plasma speed screening instrument is characterized by comprising a first ceramic plate, a second ceramic plate, a first magnetic pole plate, a second magnetic pole plate, a first magnetic pole plate gasket, a second magnetic pole plate gasket, a first electrode plate, a second electrode plate, a first electrode plate insulating block, a second electrode plate insulating block, a first electrode plate adapter, a second electrode plate adapter and a shell, wherein,

the first ceramic plate and the second ceramic plate are buckled with each other, an insulating cavity is formed inside the first ceramic plate and the second ceramic plate, the first magnetic pole plate gasket, the second magnetic pole plate gasket and the second magnetic pole plate are sequentially arranged in the insulating cavity formed inside the first ceramic plate and the second ceramic plate from top to bottom, and the first electrode plate and the second electrode plate are sequentially arranged between the first magnetic pole plate gasket and the second magnetic pole plate gasket from left to right;

the first electrode plate adapter is connected with the first electrode plate insulating block outside the shell, the first electrode plate insulating block is connected with the first electrode plate, the second electrode plate adapter is connected with the second electrode plate insulating block, and the second electrode plate insulating block is connected with the second electrode plate;

the housing is mounted externally to the first and second ceramic plates.

2. The uniform electromagnetic field device for a plasma velocity screening apparatus according to claim 1, wherein the end of the first electrode plate opposite to the second electrode plate is arc-shaped with a radius of curvature of 2mm to 3mm, and the end of the second electrode plate opposite to the first electrode plate is arc-shaped with a radius of curvature of 2mm to 3 mm.

3. The uniform electromagnetic field device for a plasma velocity screening apparatus according to claim 1 or 2, wherein the distance between the first magnetic pole plate and the second magnetic pole plate and the center of the insulation cavity formed inside the first ceramic plate and the second ceramic plate is 8 ± 0.01mm, the distance between the edge of the arc section of the first electrode plate and the edge of the arc section of the second electrode plate and the center of the insulation cavity formed inside the first ceramic plate and the second ceramic plate is 6 ± 0.01mm, and the magnetic field area generated by the first magnetic pole plate and the second magnetic pole plate covers the electric field area generated by the first electrode plate and the second electrode plate.

4. The uniform electromagnetic field device for the plasma velocity screening instrument according to claim 1 or 2, wherein the magnetic field intensity between the first magnetic pole plate and the second magnetic pole plate is maintained at 0.26 +/-0.01T and is uniformly distributed, the electric field distribution between the first electrode plate and the second electrode plate is integrally in an X shape, and the electric field intensity is maintained at (2.64 +/-0.01) × 10³V/m, evenly distributed.

5. The apparatus of claim 1 or 2, wherein said first ceramic plate and said second ceramic plate are made of boron nitride.

6. The apparatus of claim 1 or 2 wherein said first and second magnetic plates are of neodymium iron boron material.

7. The uniform electromagnetic field device for a plasma velocity screen according to claim 1 or 2, wherein the first electrode plate and the second electrode plate are made of austenitic stainless steel.

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