SPIN, MOMENTS, AND MEAN-SQUARE NUCLEAR-CHARGE RADIUS OF SR-77

The neutron deficient 77Sr nucleus was studied by fast ion beam collinear laser spectroscopy with a detection scheme based on optical pumping, state selective neutralization, and atom counting. From the measured hyperfine splitting and isotope shift of the Sr II transition 5s S-2(1/2) --> 5p P-2(3/2) the nuclear spin I = 5/2, the nuclear moments mu = -0.348(4)mu(N), Q(s) = 1.40(11) b, and the change in mean square charge radius delta[r2]88,77 = 0.248(12) fm2 were deduced. These ground-state properties indicate a large prolate deformation of epsilon-2 congruent-to 0.4 and allow a comparison with calculations performed in the particle-plus-deformed-core model, assigning a [422]5/2 Nilsson configuration to the ground state of 77Sr.