Visualization of a Spark Discharge Driven by a High-Voltage Pulse With Sub-ns Rise-Time at Atmospheric Pressure.

A spark discharge generated by a 5-ns high-voltage pulse of 21 kV with a rise-time of 200 ps in a 1-mm gap between half-sphere steel electrodes was investigated in N2–O2 gas mixtures at atmospheric pressure. We compared short exposure and long exposure ICCD images of the discharge, as well as single shot images and accumulated images. At high repetition rates more discharge channels form due to higher background ionization. The influence of the O2 concentration between 0.1 and 10 vol% O2 in N2 is insignificant. [ABSTRACT FROM PUBLISHER]