Oscillator strengths and lifetimes calculated by the Dirac-Fock method for the levels of ions of the cesium isoelectronic sequence

Oscillator strengths f are calculated by the Dirac-Fock method for the resonance transitions of the first ten members of the cesium isoelectronic sequence. The change in the values of f along the isoelectronic sequence is considered. The corresponding transition probabilities and lifetimes τ of some excited levels are also calculated. The dependence of values of τ on the charge of an ion is approximated by an analytic expression. It is established that the lifetime of the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$6P_{1/2}^ \circ$$\end{document} levels decreases along the isoelectronic sequence as τ ∼ zef−β, where zef is the ion core charge and β = 3.21. The calculated values of f and τ are compared with the experimental data.