Method and apparatus for improving efficiency of a hall effect thruster

A method of improving thrust efficiency in a Hall effect thruster, the method comprising:

• providing a thruster body comprising a discharge chamber, wherein the discharge chamber has a first opening therein, the first opening lying within a first plane, and an axis centrally located relative to the first opening and perpendicular to the first plane;
• providing a cathode having a second opening at a first end thereof, the cathode being disposed at a radial position, relative to the axis, outside of the first opening;
• situating the cathode at a radial position relative to the axis, away from the first opening;
• providing an outer pole piece comprising a magnetic plate, the outer pole piece being adjacent to the discharge chamber and extending radially outward, relative to the axis;
• disposing at least one magnet adjacent to, and in magnetic communication with, the outer pole piece, such that the outer pole piece extends radially outward beyond the at least one magnet, the at least one magnet projecting a footprint in a direction parallel to the axis onto the outer pole piece, a magnetic field being formed adjacent to the anode and the outer pole piece, the magnetic field having a separatrix surface therein;
• and
• disposing the second opening adjacent to the separatrix surface.

A method of designing a plasma thruster with improved thrust efficiency, the method comprising:

• providing a thruster body comprising a discharge chamber, wherein the discharge chamber has a first opening therein, the first opening lying within a first plane, and an axis centrally located relative to the first opening and perpendicular to the first plane;
• providing a cathode having a second opening at a first end thereof, the cathode being disposed at a radial position, relative to the axis, outside of the first opening;
• providing an outer pole piece comprising a magnetic plate, the outer pole piece being adjacent to the first plane and extending radially outward, relative to the axis;
• disposing at least one electromagnet adjacent to, and in magnetic communication with, the outer pole piece, a magnetic field being formed adjacent to the thruster body and the outer pole piece, the magnetic field having a separatrix surface therein;
• and
• altering the magnetic field such that the separatrix surface is moved outward in a radial direction relative to the axis toward the second opening.