Laser spectroscopy studies of intruder states inBi193,195,197

Abstract

In-source laser spectroscopy experiments on bismuth isotopes using the 306.77-nm atomic transition have been carried out at the Investigation of Radioactive Isotopes on Synchrocyclotron facility of the Petersburg Nuclear Physics Institute. New data for the isotope shifts and hyperfine structures of $^{193,195,197}\mathrm{Bi}^{\mathrm{g},\mathrm{m}}$ isotopes and isomers have been obtained. A large isomer shift between $I=1/{2}^{+}$ (intruder) and $I=9/{2}^{\ensuremath{-}}$ (normal) states has been found. The charge radii of the $^{193,195,197}\mathrm{Bi}$ ground states follow the trend found previously for isotonic (spherical) lead nuclei. The larger radii for the $1/{2}^{+}$ isomers suggest a larger deformation of these isomers compared to the ground state and support the shape coexistence interpretation of the previously obtained experimental data. Magnetic moments of Bi intruder isomers depart from the trend of the magnetic moments of the $1/{2}^{+}$ thallium ground states at $Nl114$.