Influence of Previous Positive Streamers on Streamer Propagation and Breakdown in a Positive Point-to-Plane Gap

Abstract

The influence of a positive streamer upon its successor in a sequence of streamers is experimentally studied in a 3.17‐cm positive point‐to‐plane gap using room air at room temperature. Streamers are triggered either by natural processes or by voltage perturbations (pulses) superimposed on the steady gap voltage. Despite the fact that a streamer has an inhibiting effect on the triggering of a later streamer, if another streamer is successfully triggered within a few tenths of a millisecond of the earlier streamer, using gap voltages of 16–25 kV, the later streamer will follow the same path and propagate faster than if the time interval between streamers was longer. Observations are made of the buildup and speed of primary and secondary streamers in sequences culminating in breakdown, and the filamentary spark breakdown of the gap is shown to have different current and light characteristics as a function of time from a streamer. A qualitative model of the streamer buildup mechanism involving metastable atoms or molecules is presented.