Electric field breakdown at micrometre separations in various media

The DC breakdown characteristics of micrometre gaps between highly polished electrodes were extensively investigated in air, vacuum and SF ₆. At large separation, the behaviour of electrodes has been widely studied and is reasonably well understood. However, some fundamental problems have not been properly addressed such as maximum safe operating voltages and critical dimensions required at small separations between different types of materials. Specimens for examination at electrode separations from 500 nm to 25 μm have been made with different electrode configurations, such as flat to flat, flat to point and point to point. All the tests were made in air, at differing pressures and finally using SF₆