Changes of charge radii and hyperfine interactions of the Dy isotopes

A continuous wave dye laser and a thermal atomic beam were used to measure the optical isotope shifts and hyperfine splittings for the 5547 Å, 5639 Å, 5652 Å, 5974 Å, and the 5989 Å transition of the seven stable isotopes of dysprosium. The hyperfine splitting of the odd-$A$ isotopes has been analyzed using the formalism of Sanders and Beck and the hyperfine anomaly has been extracted. Comparison with calculations using Nilsson wave functions is presented. The isotope shift measurements have been analyzed with published electronic and muonic x-ray isotope shifts to yield $\delta 〈r^2〉$ values and some estimates of the specific mass shift constant.