Dielectric barrier discharges revisited: the case for mobile surface charge

We propose a mechanism to explain many features of the multi-filament dielectric barrier discharge: while part of the charge deposited during previous discharge cycles is immobile on the dielectric over time periods of seconds, the larger fraction of the deposited charge must be mobile on time-scales of hundreds of ns. For alumina, we estimate that a sheet resistance of 3 M Omega sq(-1) is consistent with the multi-filament discharge; an increase in conductivity of at least 12 orders of magnitude. The existence of this type of plasma-induced surface conductivity could prove relevant in modeling a wide range of plasma devices, in addition to DBD.