Plasma Processes in Inert-Gas Thrusters

Abstract

A model has been developed to describe electron diffusion across a magnetic field that is driven by both density and potential gradients, with Bohm diffusion used to predict the diffusion rate. This model has applications to conduction across magnetic fields inside a discharge chamber, as well as through a magnetic baffle region used to isolate a hollow cathode from the main chamber. Doubly charged ions constitute a significant lifetime limiter for inert-gas ion thrusters. From an existing model for double ion production, correlations have been developed that may be used without experimental data to predict double ion densities for the design of new, and especially larger ion thrusters.