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 exam ine the transient development of corona discharges in a 1 cm hyperboloid (5 0 mu m tip radius) point-plane gap in air at a frequency of 40MHz. The inve stigation revealed the formation of streamers in the positive part of the v oltage cycle during the transient stage. These are suppressed in the steady state due to the formation of negative ions, while a cathode fall region i s fully established. The effects of attachment, secondary emission and diff usion are also examined, both in the transient and steady states.