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

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