Laboratory study of the bi-leader process from an electrically floating conductor. Part 2: Bi-leader properties

A specific experiment has been designed to study the simultaneous development of two leaders of opposite polarities from a floating electrode suspended in a plane-to-plane gap. In the paper, the physical properties of both discharges are investigated in detail, and a quantitative analysis of inception thresholds, corona charges, leaders velocities, etc. is presented. Special attention has been devoted to the analysis of the mechanisms of the negative discharge, including the specific processes of the 'pilot system' and the 'space leader', already observed in previous experiments in point-to-plane gaps. The coupling mechanism between the positive and the negative discharges have been studied according to the temporal evolution of the floating potential of the conductor. These results will be used for the development and validation of the self-consistent model of the 'bileader' process to obtain numerical simulations of the aircraft lightning stroke.