Date of Award
Doctor of Philosophy (PhD)
Charles I. Sukenik
R. Jeffery Balla
Non-intrusive ﬂow diagnostics are essential for studying the physics of hypersonic ﬂow wake regions. To advance the development of next generation hypersonic vehicles and to improve computational ﬂuid dynamics techniques in the hypersonic regime, NASA needs a suitable non-intrusive diagnostic technique to measure velocity, density, and temperature. We will present our work on developing a seedless, non-intrusive diagnostic technique using excited state argon atoms, prepared via multi-photon excitation. In this dissertation, we report results on the ﬁrst phase of this hypersonic wake measurement project. In particular, we have redesigned and characterized the performance of a high energy, nanosecond pulsed Ti:Sapphire laser. Using this laser, we have studied in argon, a three-photon excitation that yields a long-lived metastable state via radiative decay. Our measurements were conducted over a range of pressures both with and without a krypton buﬀer gas. We compare our measured results to detailed calculations of the excitation pathway and describe the physical processes that govern the excitation and decay processes. Finally, we provide a roadmap for the next phase of the project.
Mills, Jack L.. "Investigation of Multi-Photon Excitation in Argon with Applications in Hypersonic Flow Diagnostics" (2016). Doctor of Philosophy (PhD), dissertation, Physics, Old Dominion University, https://digitalcommons.odu.edu/physics_etds/5