Near-wall plasma properties and EEDF measurements of a 6-kW Hall thruster
In preparation for in-depth internal wall measurements for erosion and electron mobility studies, a flush-mounted Langmuir probe and emissive probe were used to characterize the near-wall region near the exit plane of a 6-kW Hall thruster. Various plasma properties and electron energy distribution functions were measured at discharge voltages of 150 and 300 V, and anode mass flow rates of 10, 20, and 30 mg/s, as well as at 600 V and 10 mg/s. It was found that this region is characterized by a significantly lower number density and plasma potential than expected, while the electron temperature is relatively consistent with previous internal measurements. The electron energy distribution function was found to be highly non-Maxwellian, possibly due to filtering out of low-energy particles by large radial potential gradients. Incident ion power deposition and implications of the structure of the distribution function are discussed. © 2009 by the American Institute of Aeronautics and Astronautics, Inc.
