Dependency of Performance on Repetitive Frequency for Coaxial Pulsed Plasma Thrusters

Abstract

T his paper deals with the dependenc y of performance on repetitive fir i ng frequency for the coaxial type pulsed plasma thruster (PPT). PPTs produce small impulse bits (impulsive thrust) and have simple structure s thank s to the use of solid polytetrafluoroethylene propellant and throttling capabilities with adjusting repetitive firing frequency. Variable thrust using repetitive firing frequency is compatible with digital control and necessitates no variable voltage regulated power supply. However, there have been a few studies on the influence of repetitive firing frequency on performance. Hence, in this study, a 5 J coaxial type PPT was designed to evaluate the dependenc y in the frequency range from 1 to 7 Hz. Thrust measurement showed that higher repetitive firing frequency increased specific impulse, thrust to power ratio, and thruster efficiency but reduced total impulse due to the decreased number of shots until the end of life.