Wall fluxes of reactive oxygen species of an rf atmospheric-pressure plasma and their dependence on sheath dynamics Ding-Xin Liu Aijun Yang Xiao-Hua Wang Ming-Zhe Rong Felipe Iza Michael G. Kong 2134/16405 https://repository.lboro.ac.uk/articles/journal_contribution/Wall_fluxes_of_reactive_oxygen_species_of_an_rf_atmospheric-pressure_plasma_and_their_dependence_on_sheath_dynamics/9572195 A radio-frequency (rf) atmospheric-pressure discharge in He–O2 mixture is studied using a fluid model for its wall fluxes and their dependence on electron and chemical kinetics in the sheath region. It is shown that ground-state O, O+2 and O− are the dominant wall fluxes of neutral species, cations and anions, respectively. Detailed analysis of particle transport shows that wall fluxes are supplied from a boundary layer of 3–300μm immediately next to an electrode, a fraction of the thickness of the sheath region. The width of the boundary layer mirrors the effective excursion distance during lifetime of plasma species, and is a result of much reduced length scale of particle transport at elevated gas pressures. As a result, plasma species supplying their wall fluxes are produced locally within the boundary layer and the chemical composition of the overall wall flux depends critically on spatio-temporal characteristics of electron temperature and density within the sheath. Wall fluxes of cations and ions are found to consist of a train of nanosecond pulses, whereas wall fluxes of neutral species are largely time-invariant. 2014-12-01 14:56:17 untagged Mechanical Engineering not elsewhere classified