Annular Hall Thruster with High Anode Efficiency

Abstract

We introduce an annular Hall thruster with a convex magnetic field structure inside a discharge channel by utilizing an internal magnetic circuit rather than a trim coil. The convex magnetic field exhibited a strong component parallel to channel walls except a few millimeters of channel exit. The discharge demonstrated that discharge current was maintained constantly by increasing the anode voltage up to 500 V. Without the magnetic field tailoring, the discharge current increased continuously with the anode voltage, and as a result, a reasonable power efficiency was not obtained. On the other hand, our optimized magnetic field condition exhibited an outstanding operation result: 53.1% anode efficiency, 22 mN thrust, and 2275 s specific impulse at approximately 460 W anode power.