Observation and Analysis of Nanosecond Time-resolved r.f. Corona in Air and Comparison with N2

Abstract

The onset ofr.f. corona and the subsequent development of intermittent and continuous breakdown phenomena have been investigated in air in the space between a hyperboloidal needle-point and plane electrode for pressures from 80 to 650 Torr. Detailed records of the spatio-temporal development of the plasma and the complementary nanosecond time-resolved spectral emissions, with high spatial resolution, provide comparisons with corresponding data previously reported for nitrogen. The significant differences in the behaviour of the two gases are identified and attributed to the dominant role of electron attachment processes in the space-charge modified electric fields in air.