Experimental and numerical studies of primary and secondary streamers in a pulsed surface dielectric barrier discharge

摘要

Generation and propagation of the primary and secondary streamers, initiated by a positive pulsed surface dielectric barrier discharge under different pulse amplitude and different dielectric permittivity, are studied via experimental and numerical simulation. Species (positive ions, negative ions and oxygen atoms) generation and distribution in the primary and secondary streamers are discussed. Experimental and numerical results are qualitatively coincident in discharge morphology, voltage-current characteristics and deposited energy. From visual forms of the discharge, both the primary and secondary streamers are initiated from the edge of the high-voltage (HV) electrode and propagate along the dielectric barrier surface. However, the numerical results show that the primary streamer is not completely attached to the dielectric barrier surface, and the distance between the primary streamer head and the surface is the largest, which is about several microns. Moreover, the secondary streamer starts about tens of microns away from the HV electrode edge. Furthermore, when the secondary streamer occurs, the trailing phenomenon of the primary streamer can still be observed, which is sustained by the accumulated positive charge.