Study of underwater discharge initiated by a high-voltage preliminary pulse produced by a Marx generator

The results of experimental research on the acoustic and electrical characteristics of underwater spark discharges facilitated by a preliminary discharge are presented. The latter was produced through the application of a short duration high-voltage pulse formed by a Marx generator. The application of this pulse lead to the formation of a low-density region in the form of a streamer which transformed to an oscillating vapor cavity. It was shown that this method provided a breakdown of a significantly increased interelectrode gap for the same charging voltage of the main capacitor and allowed the generation of stronger shocks. The temporal development of transient discharges in a long gap and the relationships between the hydrodynamic and electrical parameters of such discharges are reported and analyzed.