Influence of the percentage share of electronegative gas in the mixture with noble gas on the free-electron gas spectrum and recovery time

This paper discusses the validity of applied theoretical methods by which ionization coefficients were derived, assuming the Maxwellian shape of the free-electron gas spectrum in the electronegative SF6 and noble gas mixtures. It has been shown that dc breakdown voltage values calculated in such way are in a good agreement with correspondingly obtained experimental results. The predicted model has been explained by the fact that electronegative gas affects more the low-energy part of free-electron gas spectrum than the high-energy part. Since high-energy electrons have higher probability to initiate the breakdown the Paschen curve obtained under assumption of Maxwellian shape of free-electron gas spectrum does not change significantly. In addition to these observed microscopic characteristics, the influence of the gas insulation recovery time on the macroscopic characteristics was determined by adding the SF6 gas to noble gases.