Spins, moments and charge radii of barium isotopes in the range 122–146Ba determined by collinear fast-beam laser spectroscopy☆

Abstract Hyperfine structures and isotope shifts of barium isotopes in the mass range 122–146 have been measured in the atomic transition 6 s 2 1 S 0 →6 s 6 p 1 P 1 (5536 A ) , utilizing collinear fast-beam laser spectroscopy at the ISOLDE facility at CERN. Nuclear spins, magnetic dipole and electric quadrupole moments, and the changes of mean square charge radii have been deduced. They are discussed within the framework of current nuclear models, revealing single-particle structure and nuclear-shape variations on both sides of the N = 82 neutron-shell closure.