Intense electron emission from carbon fiber cathodes

We studied the emission properties of carbon fiber cathodes. These cathodes were made either of a single carbon fiber or of carbon fabric, or of an ar ray of carbon fiber bundles. It was found that an intense emission of elect rons occurs from a plasma which is formed on the carbon fiber surface as a result of a flashover process. In addition, the time delay in the appearanc e of the electron emission with respect to the start of the accelerating vo ltage pulse was, found to depend strongly on the voltage growth rate. A sim ple model of the plasma formation is suggested.