Optimization of the Ferroelectric Plasma Thruster for Microspacecraft Propulsion

Summary form given only. The ferroelectric plasma thruster (FEPT) is a microthruster for use in microspacecraft propulsion. The FEPT parameters are optimized under the constraints of maximum efficiency and low mass. The use of a ferroelectric dielectric allows for plasma to be produced with a low applied rf voltage. Depending on the polarity, the applied voltage electrostatically accelerates ions or electrons out of the plasma. Based on ion current and energy measurements as well as emission and mass spectroscopy, thruster characteristics include thrust of ~60 muN, specific impulse of 1400 s, and impulse bits of 92 pN-s. Ferroelectric plasma sources typically utilize ferroelectric switching to lower the applied electric field required to produce plasma. High-permittivity dielectrics increase the triple-point field enhancement which also potentially reduces the required applied field to form plasma. Our research has shown a strong effect of the piezoelectric properties of the dielectric in creating plasma. We present these effects and their influence on thruster performance. In addition to the piezoelectric effect listed above, we will present progress on reducing thruster mass. Also, steps taken to increase thruster efficiency will be detailed. The measured thrust for the prototype will be presented and compared to past calculations. Finally, future designs and performance projections will be made.