The influence of polarity on DC-induced streamers in n-hexane

It is shown that prebreakdown streamers can be generated and recorded when DC voltages are applied. With the aid of point-to-plane electrodes it is shown that strong polarity effects exist. A disturbance that originates at the anode may take one of two distinctly different forms. The commonly observed point anode event is shown to be supersonic, while its less frequent counterpart is subsonic. The subsonic anode generated streamer closely resembles that observed when using a point cathode. From conduction measurements made in the test cell circuit, it is shown that the inception and growth phase of each type of streamer is associated with a specific phase of a unique conduction current pulse burst