Low-Weight Fixed Ceramic Capacitor Impedance Matching System for an Electrothermal Plasma Microthruster

摘要

OVER the past few years, there has been increasing interest in the development of small-size radiofrequency (rf) plasma sources for a variety of applications: portable sources for biological applications, process uniformity using hexagonal close packing of plasma sources, material milling with nonmetallic focused ion beam sources, and plasma thruster development for space use. There are a number of rf-driven thrusters currently being developed that span a large rf power range, i.e., over tens of kW in the VASIMR plasma rocket and only a few tens of W in the Pocket Rocket electrothermal microthruster or in the dielectric capillary rf thruster. Although theuseofrf power has some advantages (lower breakdown potential, higher plasma coupling efficiency, wider range of plasma parameters), its implementation on a spacecraft poses a number of challenges (electromagnetic radiation control, thermal control, weight/volume/power restrictions). Still, remarkable success was achieved with the rf inductive ion gridded thruster Rf Ion Thruster (RTF) flown on the Artemis mission.