Ignitor Plug Operation in a Pulsed Plasma Thruster

Abstract

Results are presented of a 1-mlb pulsed plasma thruster ignition system study. An ignitor plug, producing a plasma stream is used to ignite this type of electric thruster. Parameters investigated during these tests were ignitor plug deposition, erosion, optimum plug electrical coupling to the thruster cathode, and the manner in which the ignitor plug arc is initiated. The results of these tests indicate that inductive rather than resistive coupling of the ignitor plug to the thruster cathode and the use of a high-current, short-pulse-length plug trigger circuit offer significant increases in ignitor plug lifetime.