Investigation of the electrical strength of liquid dielectrics in vacuum under the action of high-voltage nanosecond pulses

The results of an experimental study of the electrical strength of insulators that are coated with a thin liquid-dielectric layer (1?C2 mm) are presented. Studies were performed in a vacuum at a pressure of 10^?4?C10^?5 Torr and a high-voltage pulse duration of ??100 ns on an experimental setup, which is based on a PG-1 high-voltage nanosecond generator with an output voltage of up to 500 kV at a load of up to 40 ??. It was established that a castor or transformer oil coating on an insulator allows an increase in the amplitude of a voltage pulse, which is applied to the insulator, by a factor of at least 1.7 as compared to the clean insulator without its breakdown over the surface in vacuum.