Propellant losses because of participate emission in a pulsed plasma thruster

Abstract

Propellant inefficiency material in particulate form is characterized in a laboratory pulsed plasma thruster (PPT) operating at 1 Hz with a 20-J discharge energy (20 W). Exhaust deposits are collected and analyzed using a combination of a scanning electron microscope with energy dispersive x-ray analysis and microscopic imaging. Teflon® particulates are observed with characteristic diameters ranging from over 100 μm down to less than 1 μm. Estimates show that the particulate emission consumes 40 ± 3% of total propellant mass while contributing less than 1% to the total thrust. If PPT modifications can be developed that eliminate this propellant loss mechanism, without affecting the PPT thrust, the potential exists to increase PPT efficiency by a factor of 1.7.