Characterisation of volume and surface dielectric barrier discharges in N2_2–O2_2 mixtures using optical emission spectroscopy

A volume and a twin surface dielectric barrier discharge (VDBD and SDBD) are generated in different nitrogen–oxygen mixtures at atmospheric pressure by applying damped sinusoidal voltage waveforms with oscillation periods in the microsecond time scale. Both electrode configurations are located inside vacuum vessels and operated in a controlled atmosphere to exclude the influence of surrounding air. The discharges are characterised with different spatial and temporal resolution by applying absolutely calibrated optical emission spectroscopy in conjunction with numerical simulations and current–voltage measurements. Plasma parameters, namely the electron density and the reduced electric field, and the dissipated power are found to depend strongly on the oxygen content in the working gas mixture. Different spatial and temporal distributions of plasma parameters and dissipated power are explained by surface and residual volume charges for different O$_2$ admixtures due to their effects on the electron recombination rate. Thus, the oxygen admixture is found to strongly influence the breakdown process and plasma conditions of a VDBD and a SDBD