CROSS-CORRELATION SPECTROSCOPY STUDY OF THE BREAKDOWN MECHANISM IN ATMOSPHERIC PRESSURE AIR TRANSIENT SPARK DISCHARGE

A streamer-to-spark transition in a self-pulsing transient spark (TS) discharge of positive polarity in air was investigated using cross-correlation spectroscopy. The entire temporal evolution of the TS, including the primary streamer, the secondary streamer, and the transition to spark was recorded at several wavelengths of spectral bands or lines corresponding to the second positive system of N-2 (337.1 nm), the first negative system of N-2(+) (391.4 nm), and to atomic oxygen (777.1 nm) and nitrogen (746 nm). The obtained results contribute to a deeper understanding of the breakdown mechanism in air at high repetition frequencies.