Interior and Near-Wall Ion Velocity Distribution Functions in the H6 Hall Thruster

Abstract

This paper presents the results of a two-axis laser-induced fluorescence velocimetry study of singly charged xenon in the interior and near the channel walls of the H6 Hall thruster. The thruster has a nominal operating discharge power of 6 kW and has been operated for before testing. It is operated under seven conditions spanning discharge voltages of 150–600 V and anode mass flow rates of . The mean velocity of the near-wall ion populations varies from 0.5 to with an angle of incidence relative to the wall surface that varies from 30 to 80 deg. In general, the mean velocity and angle of incidence are strongly correlated with the discharge voltage and weakly correlated with the anode mass flow rate. There is strong correlation between the axial locations where high energy (greater than a few tens of electron volts) ions exist and where erosion is discernible in the channel profile. This evidence supports the notion that erosion is negligible below a certain energy threshold. Potential application of this velocimetry technique for qualitative analysis of Hall thruster channel wall lifetime is also discussed.