Date of Award
2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Space Science
Committee Chair
Gary P. Zank
Committee Member
Yogesh K. Vohra
Committee Member
Jakobus Le Roux
Committee Member
Jun Chieh (Jerry) Wang
Committee Member
Lingling Zhao
Committee Member
Shane Aaron Catledge
Research Advisor
Vladimir Kolobov
Subject(s)
Atmospheric pressure, Dielectrics, Plasma astrophysics
Abstract
This dissertation investigates the self-pulsing of Dielectric Barrier Discharges (DBDs) at low driving frequencies, in particular, (a) the dependence of current on the product pd of gas pressure p and the gas gap length d, (b) the effects of lossy dielectrics (in resistive discharges) and large dielectric permittivity (in ferroelectrics) on current dynamics, (c) the transition from Townsend to a dynamic Capacitively Coupled Plasma (CCP) discharge with changing pd values, and (d) the transition from Townsend to a high-frequency CCP regime with increasing the driving frequency. A one-dimensional fluid model of Argon plasma is coupled to an equivalent RC circuit for lossy dielectrics. Our results show multiple current pulses per AC period in Townsend and CCP discharge modes which are explained by uncoupled electron-ion transport in the absence of quasineutrality and surface charge deposition at dielectric interfaces. The number of current pulses decreases with an increasing applied frequency when the Townsend discharge transforms into the CCP discharge. The resistive barrier discharge with lossy dielectrics exhibits Townsend and glow modes for the same pd value (7.6 Torr cm) for higher and lower resistances, respectively. Finally, we show that ferroelectric materials can amplify discharge current in DBDs. Similarities between current pulsing in DBD, Trichel pulses in corona discharges, and subnormal oscillations in DC discharges are discussed.
Recommended Citation
Thagunna, Shanti K., "Simulation of atmospheric pressure dielectric barrier discharges at low driving frequencies" (2024). Dissertations. 416.
https://louis.uah.edu/uah-dissertations/416