Magnetic arch plasma expansion\in a cluster of two ECR plasma sources

Abstract

The feasibility of a novel 'magnetic arch' topology for controllecd contactless plasma beam acceleration is experimentally demonstrated using a pair of coaxial electron cyclotron resonance sources with opposing magnetic polarities, such that their respective magnetic nozzles connect to form a closed-line configuration. Retarding potential analyser measurements are taken for a single source and the two sources with same and opposing polarities, as well as no applied magnetic field, showing that the magnetic arch yields higher maximum ion current and lower plume divergence angle than other configurations, albeit the mean ion energy is lower, in agreement with existing models. This validation paves the way to clustering magnetic-nozzle-based plasma thrusters for space propulsion.