Direct Thrust Measurement of an Electron Cyclotron Resonance Plasma Thruster

Abstract

Direct thrust measurements of an electron cyclotron resonance plasma thruster are performed with a thrust balance. The thruster performances are deduced, and the influence of power and mass-flow rate is studied. The measured thrust is around 1 mN for 50 W of microwave power input and $0.1\mathrm{mg}/\mathrm{s}$ of xenon, corresponding to 1000 s of specific impulse and 11% of total efficiency. It is found that the thrust is increased by 25% when the walls of the plasma source are covered with a dielectric layer. Comparisons are made between the direct thrust measurements and the indirect thrust measurements obtained with electrostatic probes in the plasma beam.