Magnetically-conformed, variable area discharge chamber for hall thruster, and method

A Hall thruster comprising:

• An annular discharge chamber, having a first, closed end and an open second end, including an ionization zone, a transition region, and an acceleration zone, each having a cross sectional area, whereby the cross sectional area of the ionization zone is less than the cross sectional area of the transition region and the cross sectional area of the transition region is less than the cross sectional area of the acceleration zone;
• an anode located within and adjacent to the first end of the discharge chamber, and adjacent to the ionization zone;
• a cathode located so as to provide a potential difference in the discharge chamber, creating an electric field;
• and
• a magnetic circuit capable of forming a local magnetic field having a curvature within the transition region whereby the transition region conforms to the curvature of the local magnetic field.

A Hall thruster comprising:

• An annular discharge chamber having a first, closed end and a second, open end of the discharge chamber, having an ionization zone, a transition region, and an acceleration zone therein, wherein a cross sectional area of the ionization zone is less than a cross sectional area of the transition region and a cross sectional area of the transition region is less than a cross sectional area of the acceleration zone;
• an anode, within and adjacent to the first end of the discharge chamber, and a cathode located so as to provide potential difference in the discharge chamber so as to create an electric field;
• and
• a magnetic circuit capable of forming a magnetic field in the discharge chamber such that a portion of the discharge chamber is arranged to conform to a portion of the magnetic field.

A method of operating a Hall thruster with a high thrust-to-power ratio at relatively low discharge voltages comprising:

• Providing an annular discharge chamber having a first, closed end and a second, open end including an ionization zone, a transition region, and an acceleration zone, whereby the discharge chamber is wider through the acceleration zone and narrower through the ionization zone;
• forming a magnetic field within the discharge chamber having a converging plasma lens configuration whereby the transition region conforms to a curvature of a local magnetic field;
• introducing a propellant into the narrower ionization zone of the discharge chamber;
• introducing electrons into the acceleration zone of the discharge chamber;
• and
• applying a potential difference between an anode, located within and adjacent to the first end of the discharge chamber, and a cathode to produce an electric field in the discharge chamber.