Systematic Investigation of Electron Densities at The Nucleus for Rydberg States of Barium

Abstract

Isotope shifts of even Ba isotopes in transitions to $6sns^{1}S_{0}$ and $6snd^{1,3}D_{2}$ Rydberg states have been used to study systematically the change in electron density at the nucleus. For $n>~11$ the total charge density at the origin approaches that of ${\mathrm{Ba}}^{+}$. Local perturbers strongly effect the electron density, and admixture coefficients can be derived which are in quantitative agreement with those from multichannel quantum defect theory.