Abstract

For the 1-kW XeCl laser being developed by NCLR,¹ the efficiency and smoothness of the discharge are very important. Arcing at a repetition rate of 1 kHz would result in rapid electrode erosion. To study the onset of streamers and arcs we investigate the discharge with a 10-ns gated CCD-camera. Observations show that instabilities start as hot spots on the cathode. From these hot spots plumes arise that diffuse into the homogeneous bulk discharge. The cathode layer, the distance from the cathode to the point where the plumes vanish into the homogeneous part, grows exponentially in time. The plumes individually contract, and finally develop into an arc.

© 1994 IEEE