Isotope shifts and hyperfine structure of the BaI $6s^2{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}-6s6p{}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}$ transitions ($\lambda =553.6\mathrm{}\mathrm{nm}$) in neutron deficient Ba nuclides ($N<\mathrm{}82\mathrm{}$) have been investigated by observing the resonance fluorescense in a well collimated atomic beam with a high resolution tunable CW dye laser. The experiments aimed at information on nuclear charge radii and on nuclear moments. Results are presented for the radioactive isotopes and isomers ${}_{}{}^{133}{}_{}{}^{}\mathrm{Ba}_{}^g{}_{}{}^{}$, ${}_{}{}^{133}{}_{}{}^{}\mathrm{Ba}_{}^m{}_{}{}^{}$, ${}_{}{}^{131}{}_{}{}^{}\mathrm{Ba}$, ${}_{}{}^{128}{}_{}{}^{}\mathrm{Ba}$, in addition to remeasurements of all stable Ba nuclides. The extracted values of $\delta 〈r^2〉$, the observed odd-even staggering and the nuclear moments are discussed in the light of other theoretical and experimental nuclear structure studies of the region $50\le (Z, N)\le 82$.

NUCLEAR STRUCTURE isotope shifts and hyperfine structure ${}_{}{}^{133}{}_{}{}^{}\mathrm{Ba}_{}^g{}_{}{}^{}$, ${}_{}{}^{133}{}_{}{}^{}\mathrm{Ba}_{}^m{}_{}{}^{}$, ${}_{}{}^{131}{}_{}{}^{}\mathrm{Ba}$, ${}_{}{}^{128}{}_{}{}^{}\mathrm{Ba}$, measured by laser spectroscopy, deduced $\delta 〈{\mathcal{r}}^2〉$ and nuclear moments.

• Received 21 June 1978

DOI:https://doi.org/10.1103/PhysRevC.18.2369