Observation analysis of arc plasma channel developing and expansion behavior in single arc discharging

Arc plasma channel developing and expansion behavior was investigated based on experimental observation and theory analysis in this research. Images of arc plasma channel of a single arc discharging were recorded in definite time steps using a high-speed camera. Observing results indicated that the arc plasma channel developing can be divided into three subsequent stages, ignition, expansion and stabilization. Moreover, the diameter and length of arc plasma channel were studied to make a better understanding of expansion evolution in arc discharging process. In order to analyse the mechanism of arc plasma expansion behavior, the discharge waveforms and the erosion of needle electrode were researched. At last, an empirical formulation of plasma diameter in arc discharging process was deduced based on the observation results and previous researches. (C) 2018 The Authors. Published by Elsevier B.V.