Hall Effect Thruster Plasma Plume Characterization with Probe Measurements and Self-Similar Fluid Models

Abstract

A characterization of the far-field plasma plume of two Hall effect thrusters was performed by means of a comparison between experimental plasma properties with semianalytical fluid models of the hypersonic plasma plume. A cylindrical Langmuir probe was employed in the experimental investigation of the plumes. Time-averaged measurements of the plasma potential, the electron temperature and density were performed for various operating conditions of the PPS R 100-ML and the PPI thruster. The measured data was then used to fit a simple fluid model that relies on the quasi-selfsimilarity exhibited by hypersonic plasma plumes. Model agrees well with experimental data and the error committed by the selfsimilarity assumption is shown to be small.