BREAKDOWN OF TERT-DECALIN AND CYCLOHEXANE FOR POSITIVE NEEDLE PLANE ELECTRODES

Breakdown voltages of t-decalin and cyclohexane were measured at various gas pressures for positive point. Breakdown voltage of argon-dissolved t-decalin was 1.2 to 1.3x as high as that of the ammonia-dissolved one; i.e. the ammonia molecules could reduce the breakdown voltage of t-decalin. Back discharge light was detected at the tail of the voltage pulse for the case of no breakdown. Ammonia peaks were observed approximately 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 by de current vs. voltage curves, approximately 10(-2) cm2/Vs for the argon dissolved t-decalin and 10(-4) cm2/Vs for the ammonia one. In cyclohexane, the breakdown voltage ratio was 1.05 to 1.1. The breakdown velocity was estimated by the time lag to breakdown and ranged from 50 to 120 m/s. The velocity depended on the applied voltage and correspond to the other results.