Diffuse discharges in SF6 and mixtures of SF6 with H2, formed by nanosecond voltage pulses in non-uniform electric field

Results of experimental study of nanosecond diffuse discharge in SF6 and gas mixtures of SF6 with H2, D2 and C2H6 are presented. The aim of this work is to study parameters of discharge between two extended electrodes with a small radius of curvature in SF6 and SF6 with additives. It was shown that diffuse discharge can be formed in SF6 at elevated pressure between blade electrodes with length of 30 cm. It was also confirmed that in a sharply non-uniform electric field a beam of runaway electrons is generated and that the gap breakdown occurs due to ionisation waves which begin on electrodes with small radius of curvature. Laser action in the infrared spectral region was obtained in SF6–H2 (D2, C2H6) mixtures. The laser output up to 110 mJ was easily achieved which corresponds to ultimate intrinsic efficiency (with respect to deposited energy) of 10%.