2006 Volume 54 Issue 625 Pages 55-62
We designed two electrothermal pulsed plasma thrusters (PPT). A preliminary PPT using a poly-tetrafluoroethylene (PTFE) tube as a propellant showed thrust efficiencies of 10–12% with stored energy of 21.4J at cavity lengths between 14mm and 29mm. High specific impulse and small impulse bit were obtained with short cavity, and low specific impulse and large impulse bit with long cavity. A PPT with a propellant feeding mechanism using two PTFE bars showed impulse bit per joule of 43–48μNs/J, specific impulse of 470–500s and thrust efficiency of 10–12% with stored energy of 4.5–14.6J. Both the PPT and capacitors were mounted on a thrust stand with an 1-m-long arm developed for precise measurement of an impulse bit. With a repetitive 10,000-shot operation, a total impulse of approximately 3.6Ns was obtained, and each PTFE bar of approximately 2mm was supplied.
