Cathode erosion in the negative corona discharge

A negative corona discharge is investigated in a Trichel pulse and a pulseless mode in the point-to-plane electrode configuration. Cathodes made of copper, graphite, tungsten, aluminum and silver are used. Stable, unstable, and stochastic regimes of Trichel pulses are found. The formation of erosion craters with typical size 40-100 nm is found on the cathode surface. This process is explained in terms of electro-explosive mechanism. The partial redeposition of erosion products is found for copper and silver in nanocrystalline form on the cathode surface.