Statistical Model of Dielectronic Recombination of Heavy Ions in Plasmas

Calculation of the total dielectronic recombination (DR) rates was done in the frame of a statistical model of atoms. The model is based on the idea of collective excitations of atomic electrons with the local plasma frequency, which depends on atomic electrons density distribution. The electron density is described in a frame of the Thomas-Fermi model of atoms. Simple scaling laws for temperature T-e and nuclear charge Z dependences follow from the statistical model of DR. Results of the statistical model were compared with other numerical data following detailed level-by-level computations for different multielectron ions. The specific attention is paid to Ni-like ion sequences of different chemical elements in order to check the Z-dependence of DR rates. A comparison with numerical data of Flexible Atomic Code (FAC) is presented for tungsten ions. The reasonable correspondence between the statistical model and the detailed numerical data is demonstrated. The application of the statistical model provides very simple and fast calculations of the DR rates useful in modern plasma modelling. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim