Performance characterization of the micro-Cathode Arc Thruster and propulsion system for space applications

Abstract

This paper describes a further development and characterization of vacuum arc thruster with external magnetic field. The velocity of ions moving from the micro-Cathode Arc Thrusters ( CAT) cathode spots was measured using a set of grid probes along the path of the plasma plume expansion. The goal was to get the ion drift velocity and determine how much, if any, change of ion drift velocity occurs in the expanded plasma propagation path. It was found the ion drift velocity was increased when magnetic field increased (from 0 up to 200mT). The average ion velocity (cathode material is Ti) increases by factor of 2-3 up to about (3-4) 10 m s 1 with magnetic field strength 200mT applied. Rotation of cathode spot as a result of an applied magnetic field is demonstrated by using Langmuir probes inserted inside the source channel azimuthally. Ion current distribution outside the thruster channel was measured using a set of special assemble of concentric circles plan probe alone the plasma propagation path. It is shown that plasma generated at the cathode spot is guided along the magnetic field line.