Dielectronic recombination rates for the Fe ions

Abstract

The empirical rate formula for dielectronic recombination is improved by incorporating existing theoretical data for different ions in various degrees of ionization. The formula is then used to generate a complete set of rate coefficients for the Fe isonuclear sequence. Both the Δ n t≠0 and Δ n t=0 excitation modes are treated separately in the low-density zero-field limit. Explicit data are not available in the regions of N=5–8 and N⩾13, where N is the number of electrons in the ion before capture. A smooth variation of rates in N is predicted for N≳11, but some shell-structure dependence is present around N=2 and N=10.