Experimental check of the high-frequency behavior of the electrons in molecular and atomic gas plasmas

Abstract

The high-frequency behavior of the electron component in collision-dominated nitrogen plasmas of dc glow discharges, acted upon by an additional microwave field, has been studied on an adequate kinetic basis for field frequencies exceeding the characteristic frequency for energy dissipation in electron collisions with nitrogen molecules. In particular, the phase delay of the electron current density with respect to the driving microwave field has been calculated. To check the validity of the results obtained by the electron kinetic approach, the phase delay has been experimentally determined adapting an appropriate microwave resonator method to the dc plasma. The comparison of the theoretically and experimentally determined phase delay of the ac electron current in the nitrogen plasma leads to a good agreement in the entire range of high-field frequencies and confirms the conclusions on the high-frequency behavior of the electrons deduced from the electron kinetic approach. Using previous results for a neon plasma, the remarkable impact of the atomic data of the collision processes in different gases on the high-frequency behavior of the electron component in these gas plasmas is additionally evaluated.