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US 11,231,023 B2Granted
Electrothermal radio frequency thruster and components
AssigneePhase Four, Inc.
InventorMohammed Umair Siddiqui
Life of this patent
Estimating the term…
Abstract
The invention provides an electrothermal RF plasma production system and thruster design, and associated components, that may be used in terrestrial applications and/or miniaturized to the mass, volume, and power budget of Cube Satellites (CubeSats) to meet the propulsion needs of the small satellite (˜5 to ˜500 kg) constellations and larger satellite buses.
Claims22
A plasma production device comprising:
- (a) a plasma production chamber having a cylinder body, a first closed end and a second open end;
- (b) a magnet system comprising one or more magnets configured to establish a magnetic field within the plasma production chamber, the magnetic field comprising magnetic field lines oriented parallel to a central longitudinal axis of the plasma production chamber with a magnetic field strength that is continuously decreasing from the first closed end to the second open end, each magnet of the one or more magnets producing a magnetic field of a same polarity within the plasma production chamber, wherein the one or more magnets comprises at least one radial magnet located proximate the second open end and distal the first closed end and at least one additional magnet located proximate the first closed end and distal the second open end, wherein the second magnet is another of the at least one radial magnets or at least one planar magnet;
- (c) a propellant tank and a flow regulator in communication with the plasma production chamber and configured to deliver a gaseous propellant into the plasma production chamber;
- and
- (d) a radio frequency (RF) antenna comprising a flat spiral region external to the plasma production chamber and disposed on an external surface of the first closed end, electrically coupled to an AC power source, and configured to deliver an RF energy to an interior region of the plasma production chamber to ionize the gaseous propellant and heat generated plasma produced therefrom by inductive heating;
- wherein a radius (RL) of the plasma production chamber is selected from a range between a minimum radius and a maximum radius, the range configured to provide an increased efficiency of the plasma production device,
- wherein the minimum radius is a predetermined average Larmor orbit radius (Pi) of ions of the generated plasma, the minimum radius configured to allow complete orbits of the ions and electrons in the production chamber,
- wherein the maximum radius is two to ten times a predetermined skin depth (Ps) of the RF energy,
- wherein the RF energy ionizes and heats a majority of the gaseous propellant within the cylinder body inductive heating, and
- wherein the plasma production device is electrodeless and produces a primary source of thrust by ambipolar acceleration of the ions exiting the second open end.
7 more elements
A plasma production device comprising:
- (a) a plasma production chamber having a cylinder body, a first closed end and a second open end;
- (b) a magnet system comprising one or more magnets configured to establish a magnetic field within the plasma production chamber, the magnetic field comprising magnetic field lines oriented parallel to a central longitudinal axis of the plasma production chamber each of the one or more magnets producing a magnetic field of a same polarity within the plasma production chamber, wherein the one or more magnets comprises at least one radial magnet located proximate the second open end and distal the first closed end and at least one additional magnet located proximate the first closed end and distal the second open end, wherein the second magnet is another of the at least one radial magnets or at least one planar magnet;
- (c) a propellant tank and a flow regulator in communication with the plasma production chamber and configured to deliver a gaseous propellant into the plasma production chamber;
- and
- (d) a radio frequency (RF) antenna comprising a flat spiral region external to the plasma production chamber and disposed on an external surface of the first closed end, electrically coupled to an AC power source, and configured to deliver an RF energy to an interior region of the plasma production chamber to ionize the gaseous propellant and heat generated plasma produced therefrom by inductive heating;
- wherein a radius (RL) of the production chamber is selected from a range between a minimum radius and a maximum radius, the range configured to provide an increased efficiency of the plasma production device,
- wherein the minimum radius is a predetermined average Larmor orbit radius (Pi) of ions of the generated plasma, the minimum radius configured to allow complete orbits of the ions and electrons in the production chamber,
- wherein the maximum radius is two to ten times a predetermined skin depth (Ps) of the RF energy,
- wherein the RF energy ionizes and heats a majority of the gaseous propellant within the cylinder body by inductive heating, and
- wherein the plasma production device is electrodeless and produces a primary source of thrust by ambipolar acceleration of the ions exiting the second open end.
7 more elements
Dependencies are inferred from the claim text.