Dynamics of Unstable Direct-Current Discharges Between a Metal Electrode and the Surface of a Conductive Solution

Unstable extended direct-current discharges between a thin copper wire and the surface of a conductive solution have been studied for two polarities of applied voltage. A high-speed video recording of the discharge made it possible to observe in detail secondary breakdowns that occurred both from the anode surface and between individual parts of a curved discharge channel. A peculiar feature of these breakdowns is that the field strength of their onset was approximately 10 times lower compared to the initial breakdown. At the opposite polarity, the discharge pattern was very different. The discharge channel was attracted to the cathode surface with the subsequent formation of a new discharge channel, and no secondary breakdowns were observed.