Branching Behavior of Continuous Leaders in Positive Laboratory Long Air Discharges

Abstract:
An essential inquiry in long air discharge pertains to why the discharge channel generates extensive branches. Here we have studied the extensive optical measurements of continuous leader channel branching. An exploration into branching behaviours shows a tendency for positive leaders to bifurcate or trifurcate, with a preference for bifurcation. The findings notably reveal a decrease in branching frequency as the channel approaches the ground electrode. Moreover, over 80% of branching events occurred within a ±30deg angle range in front of the high-voltage electrode before breakdown. Statistical analysis of 280 bifurcations identifies three distinct branching types, with Type I being the most common and Type II the least frequent. Type II exhibits the narrowest branching angle range and lowest average, while in Type I branching, the deflection angle distributions of the left and right branches are essentially similar. Finally, the variation noticed in the partial velocity of the primary leader is notably affected by the development of sub-branches.