Variable profiles of plasma pulses generated from high-k dielectric barrier discharge

With a specific design of a high-k dielectric barrier discharge, we observed plasma pulses with variable spatial profiles as a consequence of excitation by a high-voltage pulse at different pressures. The dependence of the profile of the generated plasma pulses on the charging voltage and the operating gas (air) pressure is described and the description of their temporal and spatial build-up mechanism is given. We demonstrate that the profile variation of the plasma pulses is caused by the co-existence of dipole switching-based electron emission and field electron emission from triple junctions. Finally, we propose a scheme describing the interaction of these two electron emission mechanisms that leads to the pressure dependence of plasma pulse profile.