DC Electrical Breakdown in a Metal Pin–Water Electrode System

Electrical breakdown between a metal pin and a water-surface electrode is studied in this paper. The physics of discharges in this electrode geometry are still largely unknown, particularly the breakdown mechanism. Images of the sparks are presented, and the different features are discussed. The formation of a Taylor cone prior to breakdown is studied, and no significant polarity dependence is observed. When the water-surface deformation is small, a glow-to-spark transition is observed when the pin is cathode. When the metal pin is anode, a streamer-to-spark-like transition occurs.