EFFECT OF CATHODE SURFACE-PROPERTIES ON GLOW-TO-ARC TRANSITION IN A SHORT POSITIVE CORONA GAP IN AMBIENT AIR

Measurements were made of current growth waveforms corresponding to th e glow-to-are transition in a 1 cm positive point-to-plane gap in cond itions similar to those in pulsed corona devices used for flue gas cle aning. The glow-to-arc transition was significantly accelerated using a freshly polished unconditioned cathode surface. A duration of glow-t o-arc transition as short as 25 ns was observed using a graphite-coate d cathode. A possible explanation in terms of the cathode sheath break -ups is presented.