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.