Electrodeless plasma thruster

Patent metadata

Field	Value
Publication number	US-2016207642-A1
Application number	US-201414914065-A
Country	US
Kind code	A1
Filing date	Aug 27, 2014
Priority date	Aug 27, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

A plasma propulsion system with no internal electrodes is described. Gas is flowed into an insulated axisymmetric plasma liner. A radio frequency antenna generates an inductive or helicon plasma discharge within the liner. The plasma is accelerated through a converging/diverging magnetic field out of the liner, generating thrust.

First claim

What is claimed is:

1 . A plasma thruster for providing a motive force, said plasma thruster comprising:
a propellant tank containing a propellant; a plasma discharge system being operably coupled to said propellant tank for receiving said propellant and outputting an accelerated plasma; a magnet system outputting magnetic field lines along at least a portion of said plasma discharge system, said magnet system operable to define a converging section, a throat section downstream of said converging section having a flow boundary smaller than a flow boundary of said converging section, and a diverging section downstream of said throat section having a flow boundary larger than said flow boundary of said throat section, said converging section, throat section, and diverging section collectively receiving and accelerating said propellant through said plasma discharge system; and a radio frequency (RF) source outputting an RF field along at least a portion of said plasma discharge system, said RF field ionizing said propellant to a plasma.

2 . The plasma thruster according to claim 1 wherein said magnet system comprises a plurality of permanent magnets.

3 . The plasma thruster according to claim 1 wherein said magnet system comprises at least one electromagnetic coil.

4 . The plasma thruster according to claim 1 wherein said propellant is a gaseous propellant.

5 . The plasma thruster according to claim 1 wherein said propellant is a liquid propellant.

6 . The plasma thruster according to claim 1 wherein said propellant is a solid propellant.

7 . The plasma thruster according to claim 1 wherein said RF source comprises a loop RF source.

8 . The plasma thruster according to claim 1 wherein said RF source comprises a Boswell-type RF source.

9 . The plasma thruster according to claim 1 wherein said RF source comprises a helical half-twist RF source.

10 . The plasma thruster according to claim 1 wherein said diverging section employs a current free double layer (CFDL) acceleration method.

11 . The plasma thruster according to claim 1 wherein said diverging section employs an ambipolar ion acceleration method.

12 . The plasma thruster according to claim 1 wherein said accelerating said propellant occurs in the absence of electrodes.

Assignees

• Univ Michigan

Inventors

• Longmier Benjamin
• Sheehan John Patrick
• Gallimore Alec D

Classifications

• F03H1/0093 Primary

  Electro-thermal plasma thrusters, i.e. thrusters heating the particles in a plasma (resistojets per se B64G1/415) · CPC title

• F03H1/0037

  Electrostatic ion thrusters · CPC title

• F03H1/0018

  Arrangements or adaptations of power supply systems (for cosmonautic vehicles B64G1/42) · CPC title

• B64G1/413

  Ion or plasma engines · CPC title

• B64G1/405 Primary

  Operations & Transport · mapped topic