Investigation of heating mode transition in a dielectric barrier discharge at atmospheric pressure using a particle-incell simulation

Summary form only given. Recently, atmospheric pressure micro plasmas attract lots of interests for the useful applications such as surface modification and bio-medical treatment. Among many plasma devices, a dielectric barrier discharge (DBD) is conventionally used for the simplest device which can sustain glow discharge with a short gap length. However, experimental diagnostics of micro DBDs are limited for spatio-temporal analysis of the discharge. In this study, a particle-in-cell Monte Carlo collision (PIC-MCC) simulation was adopted to compare the discharge characteristics of a planar micro DBD with a driving frequency from 13.56 MHz to 162.72 MHz with different heating modes, the alpha and the gamma mode. In a gamma mode where the secondary electron emission plays an important role in sheath heating, the electron energy distribution function (EEDF) shows two-temperature profiles. The variation of frequency results in the change in the electron density through the relationship between the ion transit time and the driving period. On the other hand, ohmic heating is more dominant in alpha mode. It is possible to categorize the efficient operation range of DBDs for its applications by controlling the interactions between plasmas and neutral gas for the generation of preferable radicals. Finally, the variation of ion fluxes at the dielectric surface induces heating mode transition of atmospheric dielectric barrier discharges.