The Radius of the Visible Ionization Layer for Positive and Negative Coronas

An experimental analysis of the size of the visible ionization layer of a dc corona discharge is presented for both positive and negative polarities in a coaxial cylinder geometry. The analysis of the steady-state corona layer is based on wire size ranges from 0.58-0.17 mm. The resulting graphs provide a reasonable estimate of the radius of the corona layer for corona currents from inception to near sparkover. Such knowledge may prove useful in the future analysis of the ionization layer and the power loss due to corona.