Contribution of ions in radio frequency properties of atmospheric pressure microgaps

In this paper, the contribution of ions in RF permittivity and electrical conductivity of atmospheric pressure micro- and sub-microgaps in both pre-breakdown and post-breakdown regimes is investigated. It is shown that ions are ignorable in post-breakdown conditions, while their role becomes significant in pre-breakdown mode especially for gaps on the right side of Paschen's curve. Also, it is demonstrated that the contribution of ions in RF properties increases by decreasing the operating frequency in comparison with ion-neutral collision frequency.