CORONA STABILIZATION IN SF6/N2 MIXTURES UNDER IMPULSE CONDITIONS

ABSTRACT The use of optical multichannel analysis is described to quantify the establishment of corona in a positive point/plane electrode gap for 50/50 SF 6 /N 2 gas mixtures. The system permits spatial and temporal resolution of the emitted light and, in conjunction with other measurements, provides evidence on the mechanism of corona stabilization for a range of pressures and step voltages up to breakdown. On the basis of the optical results a tentative model is advanced based on the establishment of a collaborative streamer cloud from which individual streamers emanate. Aspects of this work call into question the true interpretation of the critical pressure.