The Laboratory Study on the Corona Sheath Current in the Lightning Return Stroke

Abstract

The leader and return stroke channels are represented by co-axial cylindrical electrodes with a short circuit. When negative DC voltage over an onset corona voltage is applied to an inner electrode, negative space charges caused by corona discharges from the inner electrode are formed between electrodes. As the inner electrode is grounded by a chopping gap, many impulsive discharges occurred around the inner electrode for over 100μs. The number of the dischargesincreases in keeping with the applied voltage. The corona sheath current flowed to the ground is calculated from light intensity changes obtained here. This current waveform is very similar to that calculated by the Lin-Uman-Standler return stroke model.