Streamer propagation over a liquid-solid interface

Abstract

A study of creepage discharges over a glass-transformer oil interface is presented. A needle immersed in the transformer oil is located just above a sheet of transparent insulating material, whose opposite surface is conducting. By applying a step of high voltage, U, a streamer is generated which propagates radially with numerous branches. The mean velocity of radial extension of the figure is constant and its final radius increases linearly with U. The results of measurements of total charge support the picture of an axisymmetric figure, with mean distribution of charge decreasing linearly with the radius. A similar study is performed on a single rectilinear streamer.<>