Segmented wall-less hall thruster

Patent metadata

Field	Value
Publication number	US-12049878-B2
Application number	US-202217896651-A
Country	US
Kind code	B2
Filing date	Aug 26, 2022
Priority date	Aug 26, 2021
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

Disclosed is a miniaturized plasma propulsion device with minimized surface area of the thruster walls exposed to the plasma and, as a result, reduced plasma-surface interactions including a set of segmented electrodes to facilitate the following improvements compared to relevant existing technologies: 1) control of the plasma flow including focusing of the plasma plume 2) increase of the thrust 2) reduction of inefficiencies associated with the electron cross field current, and 3) mitigation of low frequency oscillations. The electrodes affect all these actions when a DC or modulated voltage is applied to one or all of them with the same or different amplitudes, with the same or different frequencies or phases which are all optimized to realize the best performance through changes in the acceleration and/or ionization regions. In addition, the applied voltage to the main electrodes may also be modulated.

First claim

What is claimed is:

1. A segmented wall-less Hall thruster having an axial axis;
the segmented wall-less Hall thruster comprising:
an anode configured to function as a gas distributor;
a cathode; and
an insulator and an additional electrode that each circumscribe the axial axis and are concentric with the anode about axial axis, wherein the insulator has a first surface, the first surface having a first surface radially inner portion and a first surface radially outer portion separated radially from each other by a recess therebetween, the recess extending into the first surface in an axially upstream direction, wherein the first surface, the first surface radially inner portion, the first surface radially outer portion and the recess each circumscribe the axial axis and are concentric with the anode about the axial axis;
wherein the anode is inserted into the recess so that a portion of the anode is axially upstream of the first surface, wherein a downstream-most surface of the anode is coplanar with or protrudes axially downstream of the first surface,
wherein the additional electrode is separated from the anode radially by the first surface radially inner portion or the first surface radially outer portion,
wherein the anode and the additional electrode are configured to be held at different electrical potentials,
wherein the segmented wall-less Hall thruster generates ions during operation so as to provide thrust,
wherein a power supply applies a voltage to the additional electrode such that the additional electrode focuses the ions and increase the thrust while reducing power consumption thereby increasing an operating efficiency of the segmented wall-less Hall thruster.

2. The segmented wall-less Hall Thruster of claim 1 , having a magnetic core.

3. The segmented wall-less Hall thruster according to claim 1 , wherein the magnetic core comprises low carbon steel.

4. The segmented wall-less Hall thruster according to claim 2 , wherein the magnetic core comprises a permanent magnet.

5. The segmented wall-less Hall thruster according to claim 4 , wherein the permanent magnet comprises samarium cobalt and/or neodymium.

6. The segmented wall-less Hall thruster according to claim 2 , wherein the magnetic core comprises an electromagnetic coil.

7. The segmented wall-less Hall thruster according to claim 1 , wherein the anode comprises a high temperature non-magnetic material.

8. The segmented wall-less Hall thruster according to claim 7 , wherein the high temperature non-magnetic material comprises stainless steel, molybdenum, and/or tungsten.

9. The segmented wall-less Hall thruster according to claim 1 , wherein the additional electrode comprises a high temperature non-magnetic material.

10. The segmented wall-less Hall thruster according to claim 9 , wherein the high temperature non-magnetic material comprises stainless steel, molybdenum, and/or tungsten.

11. The segmented wall-less Hall thruster according to claim 4 , wherein the permanent magnet is separated from the second surface by a gap, the insulator comprising a second surface opposite the first surface, and the second surface faces the permanent magnet.

12. The segmented wall-less Hall thruster according to claim 4 , wherein the insulator comprising a second surface opposite the first surface and the permanent magnet is in contact with the second surface.

13. The segmented wall-less Hall thruster according to claim 1 , wherein the insulator is a ceramic.

14. The segmented wall-less Hall thruster according to claim 13 , wherein the ceramic is a boron nitride ceramic.

15. The segmented wall-less Hall thruster according to claim 1 , wherein the cathode comprises one of a thermionic hollow cathode or a thermionic filament.

16. The segmented wall-less Hall thruster according to claim 1 , wherein the power supply is configured to apply voltage to the cathode, and at least one of the anode and the additional electrode.

17. The segmented wall-less Hall thruster according to claim 16 , wherein the power supply is configured to apply a DC or modulated voltage to the additional electrode to change an acceleration region and/or ionization region of the segmented wall-less Hall thruster.

18. The segmented wall-less Hall thruster according to claim 16 , wherein the power supply is coupled to at least one processor, the at least one processor configured to control an acceleration and suppress spoke instability of the segmented wall-less Hall thruster by controlling a frequency and/or an amplitude of a voltage provided by the power supply to at least one of the anode and the additional electrode and/or the cathode.

19. The segmented wall-less Hall thruster according to claim 1 , wherein the anode is disposed in a location configured to produce a higher radial magnetic field than a magnetic field near the additional electrode.

20. The segmented wall-less Hall thruster according to claim 1 , wherein the additional electrode is disposed in a location configured to produce a higher axial magnetic field than a magnetic field near the anode.

21. The segmented wall-less Hall thruster according to claim 1 , further comprising a magnetic core and a single central permanent magnet disposed within the magnetic core.

Assignees

• Univ Princeton

Inventors

• Simmonds Jacob
• Raitses Yevgeny

Classifications

• F03H1/0075

  with an annular channel; Hall-effect thrusters with closed electron drift · CPC title

• F03H1/0068 Primary

  with a central channel, e.g. end-Hall type · CPC title