Zoom link: https://kaust.zoom.us/j/95191764135

Abstract

Dielectric barrier discharges (DBDs), one of the non-thermal plasma (NTP) sources, have a long history of application in various fields, leaving behind many interesting scientific questions. This dissertation presents a series of experimental studies exploring the fundamental characteristics of DBDs, particularly in the gas reforming processes in DBDs.

In the first chapter, temporally organized micro discharge patterns were observed in CH₄ mixtures diluted with N₂ and Ar, emphasizing the role of metastable species and Penning ionization. BOLSIG+ simulations supported these findings through analysis of electron energy loss. Further investigation in air revealed that discharge intervals and counts were governed by applied voltage conditions such as peak voltage, frequency, and waveform.

The second chapter focused on the spatiotemporal behavior of CH and CH₃ radicals using Photofragmentation-Planar Laser-Induced Fluorescence (PF-PLIF) diagnostics, supported by 0D numerical simulations. The effects of reduced electric field and input energy on radical production and decay were analyzed, highlighting the influence of diluent gas and CH₄ concentration on reforming chemistry.

Finally, the third chapter examined electric field and space charge dynamics using Electric Field-Induced Second Harmonic generation (EFISH) technique. The results revealed how space charges evolve and deposit after micro discharges, modifying the electric field distribution and enabling successive discharges through polarity-driven reinforcement.

Biography

Jin Park obtained his BS and MS degree in Mechanical Engineering at Chungnam National University (South Korea). He joined the Plasma Assisted Combustion Laboratory at CERP in 2020 as a PhD student in Mechanical Engineering in the PSE division. His current research focuses on the fundamental characteristics of dielectric barrier discharge plasma. He is also interested in clean energy, laser diagnostics, and plasma chemistry.