Self synchronization of surface discharges in a twin electrodes device

A twin electrode device coupled to the same high voltage power supply is used to study the propagation of surface streamers. These two identical electrodes are separated from the grounded one by a pyrex plate acting as a dielectric barrier. The gas is dry air, at atmospheric pressure. 1 ns time resolved imaging of the discharge propagation is performed to monitor the discharge ignition and propagation. The discharge consists in filaments which propagate on the dielectric as cathode directed streamers. Each filament transfers 1 nC. The propagation velocities vary from 3.4times10⁷ cm/s at the beginning of the propagation to 7times10⁶ cm/s at the end of the propagation. Ignition at one electrode triggers ignition at the other within 2 ns.