Prebreakdown light emission, density change streamer and current pulses in liquid nitrogen

The relationships between the three prebreakdown phenomena, light emission, density change streamer and current pulses, in liquid nitrogen were investigated. A needle-plane electrode system, consisting of a tungsten needle of tip radius 1.0 μm and a stainless steel plane, was used throughout the experiments. The prebreakdown phenomena were observed under impulse voltage conditions of both positive and negative polarities. Firstly, the density change streamer and the prebreakdown current pulses were observed simultaneously. Then, the light emission and the current pulses were observed under the same experimental conditions. The results of the two individual experiments were compared and their relationship considered