Electric Microfield Distributions in Alkali Plasmas with Account of the Ion Structure in a Moderately Coupled Approximation

The electric microfield distributions (EMD) have been calculated at the location of an ion for Alkali plasmas (Li+, Na+, K+, Cs+) using a coupling parameter integration technique originally developed by Ortner et al. for point-like (structureless) ions [1]. EMD are studied in a frame of the Hellmann-Gurskii-Krasko (HGK) pseudopotential model, taking into account the quantum-mechanical effects and the ion shell structure [2]. For determination of the radial distribution function the screened HGK pseudopotential in a moderately coupled approximation, based on a chain of Bogoljubow equations for the equilibrium distribution functions [3], taking into account not only the quantum-mechanical effects, the ion shell structure but screening field effects has been used [4]. The new expressions for the screened HGK potential have been derived. At the derivation the electron-electron corrected Kelbg micropotential instead of earlier applied Deutsch potential has been used. The results obtained for the EMDs in the Hellmann-Gurskii-Krasko moderately coupled approximation for a moderately coupled plasma in a framework of the Ortner model show a considerable improvement of the results obtained in the Debye screening approximation. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim