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dc.contributor.advisorStaack, David
dc.creatorCampbell, Christopher Scott
dc.date.accessioned2023-09-19T19:06:21Z
dc.date.created2023-05
dc.date.issued2023-05-01
dc.date.submittedMay 2023
dc.identifier.urihttps://hdl.handle.net/1969.1/199151
dc.description.abstractNanosecond-pulsed plasma in liquids provide a high-energy environment within which several different non-negligible regimes of physics intersect, requiring new high-speed diagnostics and imaging techniques for better understanding and use in current and future applications. This dissertation highlights four experimental campaigns which investigate nanosecond-pulsed plasmas in liquids using the following imaging techniques: nanosecond optical imaging for time-resolved velocity measurements and shock imaging (using both backlight and shadowgraph), ultrafast phase-contrast X-ray imaging at the Advanced Photon Source (APS) for picosecond-exposure imaging of multiphase behavior during bright optical emission, and time-resolved Raman spectroscopy for investigation of possible plasma-induced phase transition. The first campaign presents the first-known diagnosis using X-ray phase contrast imaging (PCI) of these types of nanosecond-pulsed plasmas in liquids. X-ray PCI is insensitive to plasma optical emission, which facilitates imaging of previously-obscured phenomena and quantitative analysis using an X-ray diffraction model. Results herein indicate that primary plasma streamers are exclusively low-density phenomena, an important contribution to the ongoing debate over which phenomena governs plasma initiation. Additionally, this first set of PCI experiments demonstrates this plasma device as a relatively low-cost, portable, self-healing target for benchmarking next-generation imaging systems. The second and third campaigns build on the progress of the first in pursuit of this application, using a spark discharge target in liquid heptane (first-known PCI imaging of plasma-induced shocks) and in a mineral oil suspension of microparticles (bismuth and tungsten explosion/atomization), respectively, with X-ray diffraction and thermodynamic analysis. The fourth experimental campaign investigates a known mode transition from spherical to branched plasma structures when plasma energy density is increased. We hypothesize that spherical-to-branched transition may coincide with local production of high-pressure solid phases of water such that plasma initiation and propagation may be governed by stress-induced fracture mechanics, since these plasma events have sufficient energy to isentropically reach pressures indicative of Ice VI and VII; this hypothesis is supported by time-resolved Raman spectroscopy results of the plasma region of interest, since the phase transition qualitatively affects vibrational structure.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.subjectnon-equilibrium plasmas
dc.subjectpulsed plasmas
dc.subjectX-ray imaging
dc.subjectphase contrast imaging
dc.subjectRaman spectroscopy
dc.subjectbenchmark imaging target
dc.subjectplasma initiation
dc.subjectplasmas in liquids
dc.subjecthigh-speed imaging
dc.subjectnanosecond pulsed
dc.titleInvestigation of Nanosecond-Pulsed Plasma Initiation Phenomena in Liquids
dc.typeThesis
thesis.degree.departmentMechanical Engineering
thesis.degree.disciplineMechanical Engineering
thesis.degree.grantorTexas A&M University
thesis.degree.nameDoctor of Philosophy
thesis.degree.levelDoctoral
dc.contributor.committeeMemberJackson, Scott
dc.contributor.committeeMemberJarrahbashi, Dorrin
dc.contributor.committeeMemberKulatilaka, Waruna
dc.type.materialtext
dc.date.updated2023-09-19T19:06:22Z
local.embargo.terms2025-05-01
local.embargo.lift2025-05-01
local.etdauthor.orcid0000-0002-7817-433X


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