Electrical and optical DC vacuum emission phenomena from a ceramic-insulated planar electrode configuration

Details are given of an experimental investigation into the DC prebreakdown characteristics of a cylindrical ceramic insulator regime. Current-voltage plots are presented for the radial conduction processes in the surface of the insulator, together with images of the associated optical processes. By employing a third transparent electrode, it is possible to study the effect of an orthogonal field on the radial conduction process. The experimental findings are discussed in terms of electron injection processes from the cathode triple junction and the role played by gas absorbed from the insulator.<
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