The Influence of Kraft Papers and Mica Insertion on the Insulator Leakage Current of Coaxial Electrodes

The insertion of mica barrier between coaxial electrodes results in a larger reduction of leakage current than the use of kraft paper insertion. The reduction is influenced by the barrier position and the testing voltage level. When using the kraft paper, there is a certain voltage level beyond which the characteristic of leakage current as a function of barrier position is relatively the image of that under the voltage level. At this level, the leakage current is almost the same wherever the barrier position. The use of mica insertion tends to shift the symmetry axis of the characteristic curves, meaning higher leakage current level.