Numerical prediction of the saturation limit of atmospheric pressure AC dielectric barrier discharges

In this paper the evolution of species densities up to the saturation limit in pulsed dielectric barrier discharges in atmospheric air plasma is predicted. The saturation limit itself is presented in the form of an exponential equation and is validated by computer modeling of continuity equations and atmospheric reactions coupled with appropriate dielectric dependent boundary conditions. Microdischarge streamer times are treated independently and a profile of the species generation due to all microdischarges within the plasma is presented. Quasi-neutrality is assumed for calculations and a theoretical maximum value for species densities in such a plasma is additionally outlined. Results show a good agreement between simulated and calculated values and serve to illustrate the onset of saturation in atmospheric pressure plasmas in general. Practical conditions of voltage, gap distance and frequency are incorporated so as to make the model as realistic as possible.