Effect of electron temperature anisotropy on plasma-wall interaction in Hall thruster

Abstract

To further reveal the physical mechanism of the saturated electron temperature which is about 50-60 eV in the discharge channel of Hall thruster, the effect of electron temperature anisotropy (ETA) on plasma-wall interaction in Hall thruster is studied by using a 2D3V particle-in-cell sheath dynamic model. Some important physical parameters such as electron-wall collision frequency, electron energy deposition at wall and the cooling effect of near-wall sheath on channel electron are calculated. Numerical results indicate that the influence of ETA on plasma-wall interaction is neglectable when electron temperature is low. However, when Te>24 eV, the ETA can significantly reduce electron-wall collision frequency, thereby reducing the electron energy deposition at wall and weakening the cooling effect of near-wall sheath on channel electron. It suggests that the anisotropy of electron temperature tends to increase the saturated electron temperature in the discharge channel of Hall thruster through remarkably weakening the interaction between channel electron and wall.