Method for Increasing Quality of the Cathode Surface of a Vacuum Gap

摘要

A method for controlled processing of the cathode surface in vacuum has been developed. The control is effected in a steady-state regime by monitoring the amplification factor of the electric-field strength at cathode microinhomogeneities. High-voltage pulses of nanosecond durations with amplitudes ensuring a breakdown delay time equal to the duration of the applied pulse, t{sub}d - t{sub}p, are used to affect the surface. This method allows the surface quality to be substantially improved after application of a minimum number of pulses. The application of five pulses at t{sub}p = 10 ns with amplitudes ensuring the condition t{sub}d = t{sub}p to stainless-steel electrodes results in a decrease in the field-amplification factor by a factor exceeding 5 (from 136 to 26) and in an increase in the emission area by more than four orders of magnitude (from 4.6×10{sup}(-19) to 10{sup}(-14) m{sup}2).