Model of the plasma discharge in a Hall thruster with heat conduction

Abstract

The inclusion of heat conduction into a one-dimensional, macroscopic model of the plasma inside a Hall thruster and in the near plume is found to smooth the temperature profile of previous solutions with a nonconductive model. The spatial structure still consists of reverse-flow, ionization, and acceleration regions. Conductive energy flow, being of the same order of convective flow, has significant effects on the rear part of the channel where it can make impossible the establishment of a steady anode sheath. As a result, there is an upper bound on the plasma reverse flow for the existence of stationary solutions. The analysis of inertial effects on the electron dynamics concludes that the main contribution is the azimuthal electron motion, which can produce extra collisionality, mainly in the near plume. The different contributions to the effective axial diffusion of electrons and the ion temperature are evaluated. A parametric investigation yields the basic scaling laws of the thruster stationary performance.