Hybrid and particle-in-cell models of a stationary plasma thruster

Stationary Plasma Thrusters (SPTs) are ion sources used for satellite propulsion. They operate at low gas density and the electrons are confined by a magnetic field perpendicular to the discharge axis. Experimental observations and recent simulations (hybrid models) based on a simple description of electron transport have shown that SPTs are subject to strong current oscillations due to ionization instabilities. In this paper we present comparisons between the predictions of the simple hybrid model and those from a more detailed PIC-MCC (particle-in-cell Monte Carlo collisions) simulations. The good qualitative agreement between hybrid and PIC models confirms the interpretation of the low-frequency oscillations deduced from our previous work.