Corona measurements in exotic media

Corona discharges, breakdowns, and other parameters, such as charge carriers´ mobilities, have been measured in media of well-defined composition. In order to measure these physical parameters, an instrument was developed which allowed that a gas mixture be produced of predetermined composition and pressure under conditions of reasonable purity, in a stainless steel vessel, that provided safety for the user. Corona discharge was produced in a corona generator with a pin-to-plane geometry. The study concentrated on media with low ionic mobility, mostly those known to be electronegative. For calibration purposes, each of the experiments was compared to the well-known corona in pure nitrogen. The measuring chamber environment was supported by auxiliary systems, namely vacuum pumps, cold traps, a gas chromatograph, etc. In the paper, the result of the measurements are described and conclusions made, regarding the behaviour of the complex molecular structure substances used as the corona media. Data are presented on the surface phenomena, which in certain instances play the dominant role in corona behaviour. Methods are described for the determination of the corona medium purity and for the handling of the potentially hazardous discharge by-products