Prediction of breakdown in SF6 under impulse conditions

Prediction of fast transient voltage-induced breakdown in quasi-homogeneous field geometries requires compounding the breakdown probability over time, while taking into account the field-dependent probability of electron detachment. In this paper, a breakdown probability model has been developed to predict the impulse breakdown under quasi-uniform fields, as this is the fundamental condition, the knowledge of which facilitates computation of breakdown probability under more complex conditions. The model will facilitate computation of breakdown probability under more complex conditions. It accounts for the effect of the streamer formation length on the critical volume and the probability of initial electron production by electron detachment from negative ions. The proposed model has been verified through comparison with the measured impulse breakdown probabilities. The predicted breakdown probabilities are in good agreement (+/-10%) with those measured.