Breakdown electric field calculations of hot SF6 for high voltage circuit breaker applications

The critical reduced electric field strengths of hot SF6 corresponding to the dielectric recovery phase of a high voltage circuit breaker are calculated for a large temperature range (300 - 3000 K). Calculations are based on a multi-term Boltzmann equation solution using, in comparison to the literature works, improved cross section sets for the interactions of electrons with various SF6 dissociated products. The obtained critical electric fields show a reasonable agreement with the available data. These results are then used in hydrodynamics simulations which correctly predicts the circuit breaker behaviors observed in the case of a successful breaking test as well as in a failed one.