Field enhancement factor dependence on electric field and implications on microscale gas breakdown: Theory and experimental interpretation

In this letter, we obtain a better understanding of effective field enhancement factors (beta(eff)) in the context of microscale gas breakdown with specific emphasis on its dependence on applied electric field. The theoretical dependence of beta(eff) on electric field for various hemi-ellipsoidal asperities indicates that the value of beta(eff) decreases with increasing electric field. The interpretation of experimental data using a typical one-dimensional modified Paschen law indicates a qualitatively similar electric field dependence even though the data could not be completely explained using a single effective asperity size. The values of beta(eff) extracted from seven independent experimental datasets for microscale breakdown of argon and air are shown to be consistent and an empirical dependence on electric field is determined. Copyright (C) EPLA, 2015