Simulation of the coronal development in air at radio frequency: the effects of attachment, secondary emission and diffusion

The finite-element flux-corrected transport (FE-FCT) method is used to examine the transient development of corona discharges in a 1 cm hyperboloid (50 μm tip radius) point-plane gap in air at a frequency of 40 MHz. The investigation revealed the formation of streamers in the positive part of the voltage cycle during the transient stage. These are suppressed in the steady state due to the formation of negative ions, while a cathode fall region is fully established. The effects of attachment, secondary emission and diffusion are also examined, both in the transient and steady states