Sparking potentials in fluorocarbon vapours

Uniform-field electric-strength measurements on a range of fluorocarbon vapours are reported. The fully fluorinated compounds were examined over a temperature range of ¿40°C to temperatures just below the respective boiling points and for gap spacings in the range 1.5¿5 mm. The electric strengths and breakdown distributions are interpreted in terms of the ionisation and attachment processes taking place. The utilisation of the exceptionally good dielectric properties of these materials when operated as evaporative coolants/insulants is discussed.