Magnetic focusing of low-power Hall thruster with a center-mounted hollow cathode

Magnetic focusing with xenon propellant has been verified in orbit from medium-to high-power Hall thrusters but has yet to be achieved in low-power Hall thrusters. A magnetically focused Hall thruster was designed to solve the common issue of large plume divergence angle in low-power Hall thrusters, which realizes the plasma lens magnetic field topography with permanent magnet excitation on the wide channel and adopts the center-mounted cathode layout. Experimental results indicate that the HEP-300CHC thruster exhibits an optimal magnetic focusing mode when operated at 288W with plume divergence half-angle approximately 11.7 degrees. The magnetic focusing range is relatively narrow, concentrated within discharge voltage between 210V and 230V, and anode flowrate between 18sccm and 20sccm.The anode efficiency is higher than 40% at the nominal power, and the maximum anode efficiency reach 52% at the discharge power of 300W. This study provides a reference basis for ion beam control of low-power Hall thrusters.