Avalanche mechanism of vacuum breakdown

Justification of the hypothesis of the avalanche mechanism of vacuum breakdown is examined. For this purpose, values of dc and impulse breakdown voltage have been measured under well-defined laboratory conditions, in the pressure range from 10−6 mbar to 1 bar, and for inter-electrode distances from 0.1 to 1 mm. Variable parameters of the experiment included the type of residual gas and the material of the electrodes in the system used for forming a homogeneous electric field. Statistical analysis of experimental results and their comparison with the predictions of a theoretical model attest that the avalanche mechanism of breakdown does come about in low vacuums.