Ultra-high-speed photographic observations of discharge development along the ice surface

This paper reports results of a laboratory investigation on the impulse breakdown process on an ice surface. The experiments were performed using two metallic hemispherical capped rods of 12 mm diameter were half submerged in ice. The distance between the electrodes was 7 mm. A high-speed streak camera was used to record the development of the surface breakdown when a lightning surge was applied. In addition to a decrease in impulse breakdown voltage with an increase in surface conductivity, the analysis of the photographic observations showed a significant decrease in the time to breakdown