Abstract
The breakdown characteristics in the gap with a thin dielectric sheet in an atmosphric air are investigated, experimentally. The breakdown phenomena are divided into three patterns by the current pulses. The first pattern consists of the primary pulse as a single pulse, the second pattern consist of secondary pulses as the successors of primary pulse, and the third pattern is growing process from the second pattern to the breakdown as a final stage. The flashover voltage of the sheet is irregular even if experimental condition is same. The breakdown voltage in a complex gap consists of air and thin sheet gaps became higher than that of thin sheet gap. These phenomena are analyzed by using an electric field distribution.
