Pulsed Inductive Thruster (PIT) Clamped Discharge Evaluation

摘要

The Pulsed Inductive Thruster (PIT) produces the plasma current inductively rather than by an electrode discharge. This research program has addressed the conditions necessary for early plasma breakdown and rapid formation of a diamagnetic current sheet. While fairly good efficiency has been achieved with a ringing discharge, attempts to improve performance with a clamped discharge have not been successful. This report presents an analysis of plasma probe measurements of magnetic and electric fields and current sheet density for both ringing and clamped discharge operation, together with development of a numerical model of the current sheet formation which agreed well with the probe data. The cause of poor current sheet formation in the clamped mode has been identified as excessive parasitic inductance. A necessary condition for complete ionization, as well as efficient acceleration, is that the circuit parasitic inductance be very small relative to the stroke inductance of the thruster coil. Pulsed inductive thruster, Electric propulsion, Plasma breakdown. (mjm)