Experimental Characterization of a Double-Stage Hall Effect Thruster

Abstract

Double-Stage (DS) Hall-Effect Thruster (HET) is capable in principle of significantly enlarging the operating range of conventional HET, by separating the propellant ionization and acceleration processes in two different thruster regions. By far several different DSHET prototypes have been developed and tested worldwide, but convincing results neither on the concept effectiveness nor on the thruster configuration have been achieved yet. In this scenario Laben and Alta are involved in a ESA-awarded activity for developing and testing a DS-HET, whose main characteristics are the magnetic design, capable of generating a second peak in the ionization stage and the presence of an active Intermediate Electrode (IE). Preliminary experimental results of the on-going test activity are presented in this paper. At this stage, the investigation has mainly concentrated on IE performance, in terms of electron emission. The thruster has also been operated in single stage mode up to 1.9 kW, with both the conventional one-peak and two-peak magnetic field configuration. In the last case 60% of thrust efficiency has been measured for a particular combination of magnetic field peak values in the ionization and acceleration stages.