A new global model with two electron groups for weakly ionized argon discharges at low pressure

Abstract

A new global model is developed for weakly ionized argon discharges at low pressure with a non-Maxwellian electron energy distribution. This model adopts the ‘two-electron group approximation’, as done in reference (Vriens L 1973 J. Appl. Phys. 44 3980; Ligthart F A S and Keijser R A J 1980 J. Appl. Phys. 51 5295; Kudryavtsev A A and Tsendin L D 2002 Tech. Phys. Lett. 28 841), but the effective temperatures for both groups of electrons, the energy boundary between them in energy space and the total volume-averaged electron density are all obtained in a self-consistent manner. By treating low- and high-energy electrons as two different species and involving particle and energy balance equations for both of them, the model-predicted electron distributions agree well with the measured ones under a wide range of discharge conditions. A detailed comparison between the results from the model presented in this work and those from the previous models is also made, along with the discussion of the reasons that cause the differences.