Impulse breakdown of positive rod-plane gaps in hydrogen and hydrogen-SF6mixtures

The paper describes an investigation of impulse breakdown phenomena in hydrogen and hydrogen/SF6mixtures for positive rod-plane gaps at pressures up to 3 bar and spacings up to 0.25m. It is shown that mixtures with an SF6content of less than 1% by volue can have breakdown voltages more than twice those for hydrogen and that the breakdown voltage-pressure characteristics in mixtures are similar in shape to those reported for pure SF6in that there is a pressure region where the breakdown voltage falls as pressure is increased. The results are discussed with reference to observations of the effect of SF6on the prebreakdown corona activity.