Abstract
The neutron-deficient isotopes have been studied using collinear fast atom beam laser spectroscopy with mass-separated beams of 7× to 4× atoms per second. By laser excitation of the 535 nm atomic transitions of atoms in the beam, the 67s and 66p hyperfine structures were measured, as were the isotope shifts of the 535 nm transitions. From these, the magnetic dipole moments, spectroscopic quadrupole moments, and isotopic changes in mean-square charge radii were deduced. A large isomer shift in was observed, implying a larger deformation in the isomer than in the ground state. The ,191,193 isotopes have deformations that increase as the mass decreases. A deformed shell model calculation indicates that this increase in deformation can account for the drop in energy of the bandhead in these isotopes. An increase in neutron pairing correlations, having opposite and compensating effects on the rotational moment of inertia, maintains the spacing of the levels in the strong-coupled band. Results for differ from previously published values, but are consistent with the ,192 data.
- Received 27 April 1987
DOI:https://doi.org/10.1103/PhysRevC.36.2560
©1987 American Physical Society