Static field anode corona characteristics in sulphur hexafluoride

This paper reports the results of an experimental investigation of the static field anode corona characteristics in SF6over a wide range of gas pressures and field non-uniformities. In addition to the experimental study the theoretical streamer onset voltages of the various test gap geometry-pressure configurations were calculated and these are compared with the experimentally determined breakdown voltages and onset levels of the various stages of prebreakdown current activity. Also discussed is a method of estimating the minimum gas. pressure at which breakdown occurs in the absence of positive DC corona in a non-uniform field.