Temporal Growth of Suppressed Corona Streamers in Atmospheric Air

Abstract

Suppressed positive streamers are produced in a short (3 cm) positive‐point‐to‐plane gap in air by the discharge of the small anode capacitance. A study is made of the growth of current at the cathode plane, and the growth of luminosity at various positions in the gap with one or two photomultipliers and with a camera. The results are compared with some photographs obtained with an image converter. From a comparison of current and photomultiplier output it is shown that sharp peaks in the current are the result of the arrival of streamer tips at the cathode. The method has allowed measurement of streamer tip velocity at various positions in the gap. It has not proved possible to detect directly any return strokes produced when the streamers reach the cathode, but the subsequent growth of the discharge indicates that they are active in much the same way as previously shown for long (25 cm) gaps.