Filamentation of a Nanosecond Pulse Corona Discharge in Air–Propane Mixtures at Atmospheric Pressure

The space and time development of a single nanosecond pulsed corona discharge is studied in atmospheric air-propane mixtures with different concentrations of propane up to 8%. Time-resolved imaging of the discharge shows a complete diffuse pattern in pure dry air, which becomes more and more filamentary when propane is added. Filaments are thinner with higher concentrations of propane, and the whole discharge energy increases and gets saturated.