An empirical fractal model for corona discharges in salt water.

Abstract

A corona discharge in water and a concomitant acoustic pulse is produced when a high electric field is applied across a pair of electrodes. The corona structure consists of many branching plasma fingers. The acoustic signal is produced by the formation and collapse of a vapor bubble; however, the details of this process are unclear. Furthermore, the relation between the acoustic and fractal stages is unknown. Voltage and current waveforms, obtained previously, are accurately described by a fractal model. High‐speed photographs of discharges have been taken to further investigate the nature of corona discharges and elucidate the relationship between the two stages. From these experiments, an empirical model is under development that incorporates both the fractal and acoustic aspects of corona discharges. The most recent results of this effort will be presented. [Work supported by the Office of Naval Research.]