Application of basic gas research to practical systems

Improved gaseous dielectrics are being designed on the basis of knowledge of fundamental electron--molecule interactions. Within this program are reported breakdown measurements for four binary mixtures (SF/sub 6//N/sub 2/, c-C/sub 4/F/sub 8//N/sub 2/, 2-C/sub 4/F/sub 8//N/sub 2/, and 2-C/sub 4/F/sub 6//N/sub 2/) of various proportions for the practical conditions of cylindrical geometry, surface roughness, contamination by free conducting particles, and electrode material composition. Each of these binary mixtures teams together one gas that primarily de-energizes free electrons and one gas that removes free electrons from the dielectric by electron attachment. Under all conditions the binary mixtures containing SF/sub 6/ were the worst of the four tested, and this is explained in terms of fundamental electron--molecule interaction processes.