Breakdown of t-decalin and cyclohexane for positive needle/plane electrodes

Breakdown voltages of t-decalin and cyclohexane were measured at various gas pressures for a positive point. The breakdown voltage of argon-dissolved t-decalin was 1.2 to 1.3 times as high as that of ammonia-dissolved t-decalin, i.e. the ammonia molecules could reduce the breakdown voltage of t-decalin. Ammonia peaks were observed at ~550 nm. This indicated that ammonia ions were produced near the point tip and recombined with injected electrons from the tip. Positive carrier mobility was estimated according to DC current vs voltage curves, ~10 ^-2 cm²/Vs for the argon dissolved t-decalin, and 10^-4 cm²/Vs for the ammonia. In cyclohexane, the breakdown voltage ratio was 1.05 to 1.1. The breakdown velocity was estimated according to the time lag to breakdown and ranged from 50 to 120 m/s