Electron transport and electron energy dissipation in Hall thruster discharges

Summary form only given. Due to their high thrust efficiencies and low propellant consumption, coaxial, cross-field (E x B) plasma accelerators (also called Hall thrusters) are gaining popularity as orbit-maintenance devices on commercial, scientific, and military satellites. Stanford University has constructed several laboratory Hall thruster models for investigation of the physical mechanisms, which control electron transport and electron energy dissipation. These types of plasmas are magnetized, and the mechanism for cross-field (B-field) electron transport is poorly understood. A variety of diagnostics have been developed and applied to this type of plasma These include time-resolved optical emission laser-induced fluorescence, direct thrust measurements, and electrostatic probe techniques to characterize the mean fluctuations in the plasma properties within the acceleration region of the discharge. The disturbances have both "coherent" and stochastic components, the later of which ranges from the tens of kHz to MHz range, and are consistent with a Bohm-type mechanism of cross-field transport. In this paper, we present a study of some of these interesting discharge phenomenon, their variations with changes in operating conditions, and the impact that they may have in applications in satellite propulsion.