Dielectronic recombination data for dynamic finite-density plasmas

IX. The fluorine isoelectronic sequence

¹ Department of Physics, Western Michigan University, Kalamazoo, Michigan, 49008-5252, USA e-mail: [gorczyca;korista]@physics.wmich.edu
² Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
³ Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027-6601, USA e-mail: savin@astro.columbia.edu

Received: 30 June 2005
Accepted: 27 July 2005

Abstract

Partial and total dielectronic recombination (DR) rate coefficients for fluorine-like ions forming neon-like systems have been calculated as part of the assembly of a final-state level-resolved DR database necessary for the modelling of dynamic finite-density plasmas (Badnell et al. 2003). Calculations have been performed for DR of both ground and metastable initial states for Ne⁺ to Zn²¹⁺, as well as for Kr²⁷⁺, Mo³³⁺, and Xe⁴⁵⁺. Results for a selection of ions are presented and discussed. We find that low-temperature DR, via core excitations involving no change in the principal quantum number of the core electron, does not scale smoothly with nuclear charge Z due to resonances straddling the ionization limit of the recombined system, thereby making explicit calculations for each ion necessary. Most of the earlier calculations neglected contributions from the fine-structure excitation which has been shown to be very important for low-temperature DR coefficients. The DR data are suitable for modelling of solar and cosmic plasmas under conditions of collisional ionization equilibrium, photoionization equilibrium, and non-equilibrium ionization.