Discharge development in SF6-N2 mixtures under fast oscillating impulse conditions

For different gas mixtures (5%SF₆/95%N₂; 10%SF₆/90%N₂ 30%SF₆/70%N2) and pressures (0.1 MPa; 0.3 MPa) the discharge development in coaxial electrode configuration with a needle protrusion, fixed on the inner conductor, was investigated. The configuration was stressed by applying monofrequent voltage pulses (2.5 MHz<f<10 MHz) of positive polarity concerning the needle. V-t characteristics (voltage-time) for these frequencies and pressure ranges are presented. The discharge development is investigated by current and voltage measurements with high time resolution. The performance of SF₆-N₂ gas mixtures is discribed by a factor of merit due to the comparision with pure SF₆ and N₂