Electric Charging in Dielectric Barrier Discharges with Asymmetric Gamma‐Coefficients

A dielectric barrier discharge with different electrode surfaces is investigated and the dynamic evolution of surface charge on the dielectric surface is measured optically. It is found that the amount of surface charge after the positive and the negative half‐cycle are not equal, i.e. a bias charge emerges. To understand this phenomenon, the transfered charge per half‐cycle is estimated from the Paschen curve and the shape of the driving voltage waveform. It turns out that the charge bias is necessary to compensate for the asymmetry of the discharge conditions due to the different surfaces and hence is required for a balanced charge transfer in the steady state (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)