Increasing the electric strength of vacuum insulation by irradiating the electrodes with a low-energy high-current electron beam

The paper describes how irradiation of the electrode surface with a LEHCEB (low-energy high-current electron beam) affects the prebreakdown current and the electric strength of vacuum insulation. This study is an extension of a study described earlier. Experiments have been performed for 0.1 mm vacuum gaps formed by refractory metal electrodes and for millimeter vacuum gaps with a pulsed voltage of amplitude 250 kV and duration 30 to 100 ns, both in a high oil-free vacuum and in technical-grade oil vacuum. Based on the results obtained, it is stated that the LEHCEB irradiation of electrode surfaces is a promising technique for increasing the electric strength of vacuum insulation over a wide range of voltages and under varied vacuum conditions.