ELECTRON-ENERGY DISTRIBUTION-FUNCTIONS IN WEAKLY IONIZED ARGON

In this paper we present measurements of the electron energy distribution functions (EEDF) for electrons in argon discharges at moderate and high E/N values (E being the electric field and N the gas density), for homogeneous electric fields and a low-current diffuse glow regime. Results were obtained for electric field to gas density ratios (E/N from 500 Td to 50 kTd (1 Td = 10(-21) V m2). A multigridded energy analyser with a retarding grid potential was used to measure distribution functions of electrons sampled through an aperture in the anode. Experimental data are used to make a comparison with the two-term Boltzmann calculations for E/N < 1 kTd, and the single-beam model predictions, normally used to model electron kinetics at high values of E/N.