Extending the performance limit of xenon cylindrical Hall thrusters through krypton admixtures

Abstract This study investigates the performance enhancement of a cylindrical Hall thruster through ion-focusing induced by Xe and Kr mixture discharges. The thruster operated at a fixed anode flow rate for both Xe and Xe–Kr mixture gases, with the anode voltage varying from 250 to 450 V and the anode power from 350 to 700 W. Results indicate that for anode voltages higher than 375 V, the performance of the Xe–Kr mixture discharge with 46% Xe surpasses that of the pure Xe discharge. At an anode voltage of 400 V, the 46% Xe discharge demonstrates improvements in thrust (20.3 mN vs 18.6 mN), anode specific impulse (2455 s vs 2263 s), and anode efficiency (40.2% vs 33.8%). Using laser-induced fluorescence diagnostics, an upstream shift in the ion velocity profile is observed, indicating a corresponding shift in the acceleration region within the discharge cavity. This upstream shift of the acceleration structure is related to ion-focusing, which narrows the plume angle and enhances the thrust compared with the pure Xe discharge.