Prebreakdown imaging in DC stressed n-hexane

Sequential image recording obtained with the use of a high-sped framing camera was used to study the consequences of the DC stressing of n-hexane. It is observed that partial discharges, or conduction current pulses, produced by DC stressing are intimately related to the generation of prebreakdown streamers. The DC-induced events have characteristics that are similar to those produced by impulse voltages. In contrast to the impulse case, the absence of a displacement current for DC conditions allows the conduction current activity to be examined in detail. A demarcation is shown between streamer growth during the current wavefront and decay in the wavetail. The stepped nature of the current wavefront appears not to be related to the event profile, although it may be associated with the underlying discharge process