Performance of Dimethyl Ether Arcjet Thrusters and Its Dependence on Electrode Configurations

This paper discusses an arcjet thruster using dimethyl ether propellant. Dimethyl ether is an ether compound having no toxicity and relatively weak reactivity to materials and is storable in a liquid form without complex temperature management, because it has a vapor pressure of 0.6 MPa at 273 K. In this study, a dimethyl ether arcjet thruster was prototyped and tested to evaluate its performance: specific impulse and thruster efficiency. Flat-type cathodes of 2 and 4 mm in diameter were designed to investigate the influence of cathode diameter and electrode gap on performance. Thrust measurements showed that a dimethyl ether arcjet thruster with a cathode of 2 mm in diameter set at a 2 mm electrode gap yielded the best specific impulse of 400 s and a thruster efficiency of 0.17.