Nathan Brown
(Advisors: Prof. Mitchell Walker and Prof. Adam Steinberg]

will defend a doctoral thesis entitled,

Development and Evaluation of Terahertz Time-Domain Spectroscopy for Electric Propulsion Plasma Diagnostics

On

Monday, November 9th at 9 a.m.
https://bluejeans.com/1111838738

Abstract
Electric propulsion utilizes plasma to provide propel satellites and space exploration vehicles. Due to limitations in available plasma diagnostics, open questions regarding the physics of electric propulsion (EP) thruster operation remain unanswered. Terahertz time-domain spectroscopy (THz-TDS) is a novel plasma diagnostic that has the potential to fill present gaps in 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) Assessment 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 obscured by Hall thruster wall material.

Committee

• Prof. Mitchell Walker – School of Aerospace Engineering (advisor)
• Prof. Adam Steinberg – School of Aerospace Engineering (advisor)
• Prof. Wenting Sun – School of Aerospace Engineering
• Prof. Lukas Graber – School of Electrical and Computer Engineering
• Prof. Jason Deibel – School of Physics, Wright State University