The Effects of Corona on the EMP Response of Insulated Cables Lying on the Surface of the Earth

In this paper, a method of including the effects of corona on the transient response of insulated cables is presented. The corona is treated as a plasma sheath which exists outside the insulation, and the sheath´s conductivity is determined from a dynamic solution to a set of air chemistry equations. Results are presented for a surface cable in a nuclear source region, a cable illumined by high altitute EMP, and for a cable in free space above a lossless ground plane. In the two former cases, the effects of corona appear to be negligible. For the last case, corona can have a noticeable effect on the response.