Self-Sustaining Partial Discharges in Argon at the Dielectric Surface

The inception voltage of the surface discharges produced by alternating voltage was measured and mathematically analyzed. The specimen thickness, the dielectric material, and ambient argon pressure were varied. A new definition of the inception voltage is proposed. Analysis is based on the simplified equivalent circuit model, Paschen low, and properties of carriers injected-evaporated from the surface of dielectrics. The results are fairly well interpreted and qualitatively described in terms of the modified Paschen low.