(Georgia Institute of Technology, 2020-11-19)
Brown, Nathan P.
Terahertz time-domain spectroscopy (THz-TDS) is a novel plasma diagnostic that has the potential to fill present gaps in electric propulsion (EP) plasma diagnostic capabilities. However, there remain unanswered questions and challenges regarding THz-TDS capability and data interpretation that must be addressed before the diagnostic is readily applied to EP devices. The purpose of this dissertation is to develop and evaluate THz-TDS for EP plasma diagnostics. To that end, this dissertation provides three major contributions: 1) Analysis of the THz-TDS domain of applicability; 2) Development of a novel Bayesian THz-TDS plasma diagnostic analysis framework and subsequent evaluation of THz-TDS uncertainty; and 3) Development and application of THz-TDS to noninvasively probe plasma bounded and optically shielded by Hall thruster wall material.