Plasma generation using high-power millimeter-wave beam and its application for thrust generation

Abstract

Propagation of an ionization front in the beam channel was observed after plasma was generated using a 170GHz millimeter-wave beam in the atmosphere. The propagation velocity of the ionization front was found to be supersonic when the millimeter-wave power density was greater than 75kWcm−2. The momentum coupling coefficient Cm, a ratio of the propulsive impulse to the input energy, was measured using conical and cylindrical thruster models. A Cm value greater than 350NMW−1 was recorded when the ionization front propagated with supersonic velocity.