Data-Driven Estimation of Background Pressure Effect on Thrust in Hall Effect Thrusters

Previous studies showed a correlation between the measurement (e.g., thrust and discharge current) of Hall Effect Thrusters (HET) and the background pressure in testing facilities. Generally, as the background pressure decreases, the thrust generated by the HET also decreases. However, since the experimental conditions within these testing facilities cannot perfectly replicate the conditions in space, we typically rely on extrapolating the facility data to a zero-background pressure to estimate the thruster performance in space. In contrast to current approaches that directly extrapolate experimental thrust values obtained from testing facilities, this research focuses on examining the time-dependent electron mobility. A zero-dimensional (0D) global plasma model of a HET discharge plasma is used to estimate the electron mobility over time at different background pressures. The average value, oscillation amplitude, and frequency of the electron mobility are then extrapolated to zero pressure. This extrapolation allows for the estimation of the thrust and discharge current oscillations under in-space vacuum conditions.