Isotope Shift and Nuclear Charge Radii of Barium Isotopes

Abstract

Relativistic coupled-cluster calculations of hyperfine structure and field isotope shift constants for the 6s and 6p states in Ba+ have been performed. Comparison with experimental hyperfine structures shows agreement within a few per cent and we assign a similar uncertainty to the electronic factor for the field shift: F6s→6p3/2=−4.20(13) GHz fm-2. This value, which is about 18% smaller than semi-empirical estimates used in earlier works, has been used to extract revised values for the changes δ(r2) in nuclear charge radii using optical isotope shifts for 12214SBa and muonic results for the stable isotopes134−138Ba. Also the factor B/Q, relating the observed quadmpole hyperfine structure to the nuclear quadmpole moment, was calculated, giving B/Q = 374 (4) MHz b−1. © 1992 IOP Publishing Ltd.