CN105003409A - Cathode center layout of Hall thruster - Google Patents

Abstract

The invention discloses a cathode center layout of a Hall thruster. The invention can improve the plasma uniformity in the discharge channel, reduce the coupling voltage between the cathode and the discharge chamber, reduce the loss energy of plume neutralization, and finally effectively improve the efficiency of the thruster. In the present invention, firstly, a cylindrical cavity that runs through the inner winding post and the inner pole piece is opened along the center axis of the Hall thruster in the inner winding post and the inner pole shoe in the existing Hall thruster structure; then the Hall thruster is adjusted to The coil ampere-turns on the inner winding post and the outer winding post of the Hall thruster until the magnetic field required to meet the discharge chamber channel of the Hall thruster is obtained, and the magnetic field of the inner winding post is in a non-saturated state; finally, the cylindrical The main body structure of the cathode is placed in the cavity of the inner winding post; and a ceramic sleeve is installed between the cathode and the cavity of the inner winding post.

Description

Cathode Center Layout of a Hall Thruster

technical field

The invention relates to the fields of aerospace technology and low-temperature plasma technology, in particular to a cathode center layout of a Hall thruster.

Background technique

The cathode is an important part of the Hall thruster. The electrons emitted by the cathode have two main functions. Some of the electrons enter the channel of the Hall thruster and are used to ionize the working fluid; the other part of the electrons recombine with the beam ions in the plume. , to ensure electrical neutrality in the plume region. A large number of experiments have shown that due to the coupling effect of the cathode and thruster discharge process, the installation position and angle of the cathode have a great influence on the discharge plasma characteristics, thrust macroscopic performance and beam neutralization characteristics of the Hall thruster.

In the Hall thruster structure of the prior art, the cathode is arranged outside the discharge chamber, as shown in FIG. 1 and FIG. 2 . The main problems are as follows: (1) Since the cathode is arranged outside the discharge chamber, the electrons emitted by the cathode cannot enter the discharge channel evenly, and the coupling voltage between the cathode and the discharge chamber is high, which affects the overall efficiency of the thruster; (2) due to The position of the cathode deviates from the central axis of the discharge chamber, and the beam neutralization effect is not ideal, which brings certain difficulties to the satellite space plume protection.

Aiming at the problem of the asymmetry of the electrons emitted by the cathode relative to the discharge channel and the beam current, a solution to the structure of the Hall thruster with a symmetrical layout of the cathode is proposed.

Contents of the invention

In view of this, the present invention provides a central layout of the cathode of the Hall thruster, which can improve the uniformity of the plasma in the discharge channel, reduce the coupling voltage between the cathode and the discharge chamber, reduce the loss of energy in plume neutralization, and finally Effectively improve the efficiency of the thruster.

The cathode center layout of the Hall thruster of the present invention, the Hall thruster includes an inner pole shoe, an inner winding post, a discharge channel, an outer pole shoe, an outer winding post, a magnetic permeation base and a cathode, and the cathode consists of Cylindrical cathode main body structure and supporting components,

Step 1: Open a cylindrical cavity through the inner winding post and the inner pole piece along the central axis of the Hall thruster in the inner winding post and the inner pole piece of the Hall thruster, wherein the diameter of the cavity is the same as The outer diameter of the cathode body structure of the Hall thruster matches;

Step 2, adjust the ampere-turns of the coils on the inner winding post and the outer winding post of the Hall thruster until the magnetic field required by the discharge chamber channel of the Hall thruster is obtained, and the magnetic field of the inner winding post is in a non-saturated state ;

Step 3, placing the cylindrical cathode body structure in the cavity of the inner winding post; and installing a ceramic sleeve between the cathode and the cavity of the inner winding post.

Beneficial effect:

The Hall thruster of the present invention can increase the coupling effect of the cathode and the thruster, thereby reducing the coupling voltage of the cathode, increasing the effective voltage (acceleration voltage) of the anode of the thruster, and finally significantly improving the efficiency of the Hall thruster; The neutralization uniformity of beam ions has a certain positive effect on the protection of satellite electric propulsion plume.

Description of drawings

Fig. 1 is a schematic cross-sectional structure diagram of a Hall thruster in the prior art.

Fig. 2 is a schematic top view structure diagram of a Hall thruster in the prior art.

Fig. 3 is a schematic structural diagram of the magnetic circuit of the Hall thruster of the present invention.

Fig. 4 is a schematic cross-sectional structure diagram of the Hall thruster of the present invention.

Fig. 5 is a schematic top view structure diagram of the Hall thruster of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and examples.

The invention provides a cathode center layout of a Hall thruster. The structure of the existing Hall thruster is shown in Figure 1, including the inner pole piece, the inner winding post, the discharge channel, the outer pole piece, the outer winding post, the permeable base and the cathode, wherein the cathode consists of a cylindrical cathode body Structure and supporting parts, the invention arranges the cathode at the center of the Hall thruster to achieve a symmetrical layout of the cathode structure, the cathode emits electrons that can enter the discharge channel evenly, and at the same time emits the original electrons at the center of the beam to achieve beam ion neutralization more uniformly . The specific structure is shown in Figure 3 to Figure 5, which specifically includes the following steps:

Step 1, in the magnetic circuit structure of the Hall thruster, open a cylindrical cavity structure through the inner winding post and the inner pole shoe along the central axis of the Hall thruster, wherein the hollow The diameter of the cavity structure matches the outer diameter of the cathode body structure;

Step 2, adjust the ampere-turns of the coils on the inner winding post and the outer winding post until the magnetic field required by the discharge chamber channel of the Hall thruster is obtained, and the magnetic field of the inner winding post is in a non-saturated state. Among them, the main indicators that the discharge channel magnetic field needs to meet are as follows: 1) The discharge channel is mainly a radial magnetic field, and the magnetic field is symmetrical about the center of the discharge channel; 2) The magnetic field near the anode is approximately zero; 3) The magnetic field strength from the anode to the exit direction Gradually increases, with a maximum (>160Gs) at the exit.

Step 3, removing the supporting part of the cathode, retaining only the cylindrical structure of its main body, placing the cathode in the cavity part of the inner winding post; and installing a ceramic sleeve between the cathode and the cavity part of the inner winding post, The electrical insulation between the cathode and the inner winding post is realized.

The invention realizes a cathode center layout scheme of the Hall thruster through the change of the local structure. Its magnetic circuit structure is shown in Figure 3, mainly including: magnetic base, outer winding post, inner winding post, outer pole piece, inner pole piece and magnetic shield. Since the cathode is placed at the geometric center of the thruster, the electrons from the cathode have the same probability to enter the discharge channel, which will benefit the plasma uniformity in the discharge channel, reduce the coupling voltage between the cathode and the thruster, and thus increase the Hall thruster. The effective voltage of the anode (acceleration voltage) finally makes the efficiency of the thruster significantly improved. At the same time, under the Hall thruster structure with a symmetrical layout of the cathode, the emitted electrons can more effectively neutralize the beam ions, reducing the loss of energy in plume neutralization.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (1)

1. A cathode center layout of a Hall thruster, said Hall thruster comprising an inner pole shoe, an inner winding post, a discharge channel, an outer pole shoe, an outer winding post, a magnetic permeation base and a cathode, said cathode It consists of a cylindrical cathode body structure and a supporting part, and is characterized in that it includes the following steps: Step 1: Open a cylindrical cavity through the inner winding post and the inner pole piece along the central axis of the Hall thruster in the inner winding post and the inner pole piece of the Hall thruster, wherein the diameter of the cavity is the same as The outer diameter of the cathode body structure of the Hall thruster matches; Step 2, adjust the ampere-turns of the coils on the inner winding post and the outer winding post of the Hall thruster until the magnetic field required by the discharge chamber channel of the Hall thruster is obtained, and the magnetic field of the inner winding post is in a non-saturated state ; Step 3, placing the cylindrical cathode body structure in the cavity of the inner winding post; and installing a ceramic sleeve between the cathode and the cavity of the inner winding post.