The influence of the electric field shape on the gas breakdown under low pressure and small inter-electrode gap conditions

The connection between nonhomogeneities of the electric field and the value of the breakdown voltage [direct current (dc), pulls] in gases (N₂, SF₆) under low pressure and small inter-electrode gap was investigated in this paper. The obtained results show that the values of the breakdown voltages for nonhomogenous fields are considerably higher than the values for homogenous fields. It was also established that there is some disagreement between experimentally and theoretically (numerically) obtained values of the dc breakdown voltages for nonhomogenous fields. These results could be explained by the small distance effect and by the combination of the gas and vacuum breakdown mechanisms.