Discharge trees in polyethylene and silicone fluids due to sub-microsecond voltage pulses

The growth of tree-like discharge channels has been observed and reported by many authors. Usually a point-plane electrode system is used to facilitate the growth of the trees and define their origin. The discharge is usually observed as a series of tree extensions resulting from a sequence of impulse voltage applications or resulting from an intermittently raised AC voltage. By this means a stepped tree growth is observed but its interpretation is not easy.