Initiation of Electrical Discharge in Water Using a Thin-Layer Conductor

The results of experimental study of pressure waves produced during electrical discharges in water initiated with a thin-layer copper conductor in the form of a nylon thread coated with a thin copper layer are presented. The experiments are performed in two different modes that provide discharges of shorter and longer periods. Use of the thread with a thin copper layer is a promising approach to initiating electrical discharges in water because it allows the shorter prebreakdown stage, lower prebreakdown energy losses, spatially more stable discharges, and improved effectiveness of discharge impact. The amplitude of pressure waves produced during short electrical discharges is comparable to that observed when using a thin solid copper conductor for initiation, with the amplitude of generated pressure wave growing exponentially with the wire length: more than a twofold increase in the amplitude is observed as the wire length increases from 20 to 50 mm. Similarly, it is shown that the thread with thin copper layer has a good stability under the conditions prevailing during electrical discharges in water.