Laboratory investigations of pulsed RF plasmas relevant to CW arc pluming at high-power aerials. Part 1: Critical breakdown under pulsed RF conditions

The mechanisms responsible for the development of electrical discharges at high-power aerial arrays under RF conditions have been investigated in the laboratory using pulsed discharge techniques. Both uniform and nonuniform electric field conditions have been studied, the former to investigate the influence of such parameters as humidity and environmental conditions, the latter to establish more precisely the role of sharp points and the consequent localised distortion of electric fields. The dramatic effects observed under actual operating conditions could be explained in terms of the influence of small protuberances at the corona shields, and highlights the possibly important environmental consequence of large insect populations in the vicinity of such aerial arrays.