Electrical breakdown of nitrogen at high electric fields

A variety of steady-state techniques has been used to investigate experimentally the electrical breakdown of nitrogen at high pressures (up to 1.2×106 Pa) and high electric field strengths (up to 1.2×107 V/m). Measurements were made of sparking potential and of ionisation and field-emission currents for aluminium, stainless-steel and titanium electrodes subjected to a variety of surface treatments and topographically examined using a talysurf. The results suggest that measurements of surface topography or of parameters such as steady-state field emission cannot readily be used to predict the relative performance of materials to be used as the electrodes of an insulating gap at high field strengths.