Medium-spin states inMo99

Abstract
The structure of Mo99 has been investigated via the Zr96(α,n) reaction at bombarding energies between 10 and 18 MeV. Excitation functions and angular distributions of deexcitation γ rays have been measured to provide information on the spins of levels deduced in γ-γ coincidence measurements carried out at 13 and 16 MeV. Several new medium-spin levels have been evinced from the present measurements and give a clear indication that collective features play an important role in defining the nuclear structure of Mo99 which can be considered as a typical transitional nucleus in the region around A=100.