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

摘要

Propagation of an ionization front in the beam channel was observed after plasma was generated using a 170 GHz 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 75 kW cm~(-2). The momentum coupling coefficient C_m, a ratio of the propulsive impulse to the input energy, was measured using conical and cylindrical thruster models. A C_m value greater than 350 N MW~(-1) was recorded when the ionization front propagated with supersonic velocity.