Plasmachemical Processing of Field Emission Cathodes Made of Carbon Fibers Bundles

A new method of processing field emission cathodes made of carbon fiber bundle is presented. It is the etching of carbon fibers bundle cathode by corona discharge on air. The influence of the plasmachemical processing on the emission characteristics of the field emission cathodes, was examined. Results show that for cathodes processed by corona discharge, carbon fiber bundle is subject less to the abrupt reorganization of its structure (redistribution of fibers in a bundle). Also, the value of local fluctuation of anode voltage had been significantly decreased. The field emission parameters of cathodes, namely: the emitting surface area and the form-factor of the cathode, have been obtained from analysis of the current-voltage characteristics. The form-factor of the cathode after the processing by corona discharge has been decreased while the emitting surface area of the cathode after the etching process has been increased. The plasmachemical processing by corona discharge promoted for more uniform distribution of field emission electrons on the surface of the cathode