PIC model of an air-breathing low power Hall thruster

This work represents a first attempt to include the complex variety of electron-molecule collisional processes in a full kinetic PIC model of low power Hall thrusters, with particular emphasis on air species propellants for the air-breathing Hall thruster concept. Results show that N2 and O2 rotational and vibrational excitations have a minor role in comparison to dissociation as additional electron energy loss mechanisms. The dissociation leads to very fast atoms that either cross the channel axially or hit the walls, with very small chance of ionization. By using the standard SPT20 size (channel length and cross sectional area), molecular oxygen shows performances slightly worse than Xe, while molecular nitrogen is a very inefficient propellant. Further studies necessitate to investigate the role of vibrational kinetics and metastable electronic states for stepwise ionization.