Mechanism of electrical breakdown of gases at very low pressure and interelectrode gap values

The electrical breakdown mechanism of gases at very low pressures (from 10/sup -4/ to 10/sup 5/ Pa) and interelectrode gap values (from 0.1 to 1 mm) is considered. Comparing experimental results and theoretical analysis, the boundaries between areas of different breakdown mechanisms are established. The existence of edge breakdown, which was previously erroneously interpreted by the anomalous Paschen´s effect, is explained and proved. The avalanche hypothesis of vacuum breakdown is experimentally proved.