Transition of branched positive streamer to non-branched positive streamer with increase of discharge-repetition rate

This paper presents that the transition mechanism of branched positive streamer to non-branched positive streamer with increase of discharge repetition rate. The time change of gas temperature distribution between the electrodes after occurrence of non-branched positive streamer was visualized by means of laser schlieren method. As a result, residual localized gas heating along the streamer channel was confirmed. From this, it can be considered that a guide effect of streamer by residual plasma including localized gas heating contributes to the formation of non-branched positive streamer. In fact, a streamer head preferentially propagated high temperature region (high E/N region) without branching and a non-branched positive streamer was formed.