A Plume Comparison of Xenon and Krypton Propellant on a 600 W Hall Thruster

Abstract

Abstract : An experimental study was conducted to compare variations in the plume of a 600 W Hall effect thruster operating on xenon and krypton propellants. Both a guarded Faraday probe and a retarding potential analyzer were used to measure plume properties for various thruster operating conditions. Discharge current data was also measured in the time domain using an oscilloscope and in the frequency domain using a signal analyzer for all tested operating conditions. Operating conditions were chosen to provide a comparison of the effects of radial magnetic field strength for both propellants. For each xenon propellant operating condition, two krypton propellant operating conditions were tested. One condition matched volumetric flow rate and the other condition matched anode power by increasing the anode flow rate. The plume data were analyzed to calculate various components of the energy and propellant utilization efficiencies as defined in Ref. 1. Faraday probe data were used to calculate the divergence and beam current utilization efficiencies. Voltage utilization efficiency was calculated using data from the retarding potential analyzer. Compared with xenon, krypton divergence efficiency is approximately 15-20% lower and its current utilization efficiency is 5-10% lower. Differences between voltage utilization efficiency for xenon and krypton were small. Anode current oscillation magnitude was lower for krypton propellant.