Breakdown characteristics of CO/sub 2/ containing 0.125% of SF/sub 6/

AC breakdown strengths of CO/sub 2/, SF/sub 6/ and a mixture of CO/sub 2/+SF/sub 6/ containing 0.125% of SF/sub 6/ in nonuniform field were experimentally studied. The electrode gap spacing and the relative gas pressure were varied within the range of 5-25 mm and of 100-500 kPa respectively. The experimental results have shown that the addition of SF/sub 6/ to CO/sub 2/ causes a significant increase of the AC breakdown voltage with respect to CO/sub 2/. Even at about pressures of 300 kPa and 25 mm gap spacing breakdown voltage of mixture were obtained 15% higher than that of pure SF/sub 6/ and 54% higher than that of pure CO/sub 2/.