Axial force imparted by a conical radiofrequency magneto-plasma thruster

Abstract

Direct thrust measurements of a low pressure (∼0.133 Pa) conical radiofrequency (rf at 13.56 MHz) argon plasma source show a total axial force of about 5 mN for an effective rf power of 650 W and a maximum magnetic field of 0.018 T, of which a measured value of 2.5 mN is imparted by the magnetic nozzle. A simplified model of thrust including contributions from the electron pressure and from the magnetic fieldpressure is developed. The magnetic nozzle is modelled as a “physical” nozzle of increasing cross-sectional area.