Transient-Spark Discharge in $\hbox {N}_{2}/\hbox {CO}_{2}/\hbox {H}_{2} \hbox {O}$ Mixtures at Atmospheric Pressure

Transient spark, which is a novel type of streamer- to-spark transition discharge, was investigated in N₂/CO₂/H₂O mixtures. It has a pulsed character with short (~100 ns) pulses of high current amplitude (~1 A) with repetitive frequencies of some kilohertz, and it generates nonequilibrium plasma. Emissions of N₂ first and second positive systems, CN violet system, NH, and atomic N, O, and C lines were detected. Two distinct discharge modes at low and high frequencies with different properties were found.