Kαtransition probabilities for fluorinelike ions from neon to gold:Ab initiorelativistic coupled-cluster calculations

Abstract

We have applied the relativistic Fock-space coupled-cluster theory to calculate $K\ensuremath{\alpha}$ transition properties of F-like ions for a number of elements throughout the periodic table. A state-specific form of the coupled-cluster method for electron detachment has been used to calculate the $K\ensuremath{\alpha}$ energies and line strengths. The computed energies are used to determine the transition probabilities for more than 30 elements to study the $Z$ dependencies for $Z=10--79$. This application of a variant of coupled-cluster theories to study the $K\ensuremath{\alpha}$ transitions should be the most accurate determination of these transition probabilities to date. The most important finding in this paper is the crossover of $K{\ensuremath{\alpha}}_{1}$ and $K{\ensuremath{\alpha}}_{2}$ at high $Z$. In general, for lighter ions, $K{\ensuremath{\alpha}}_{2}$ is higher in magnitude than $K{\ensuremath{\alpha}}_{1}$, but at $Z=41--42$ they are switched. In addition, the results demonstrate the variation with $Z$ of the $K{\ensuremath{\alpha}}_{2}$ $A$ values along the Periodic Table. The astrophysical significance in the analysis of $K\ensuremath{\alpha}$ lines, important in x-ray astronomy, is pointed out.