Collective excitations in shape-transitional nuclei: investigations of 196Pt, 198Pt, and 200Hg by the (n,n'γ)

The (n,n'γ) reaction has been employed to study the level schemes of low-lying, low-spin states of the transitional nuclei 196Pt, 198Pt, and 200Hg. Multigram isotopically enriched samples of these isotopes were bombarded with neutrons of energies up to 3.5 MeV, and excitation functions and angular distributions were measured for promptly emitted γ rays. Results from this investigation have permitted the placement of excited states and the assignment of spins and parities to many of these levels. Clarifications of spin-parity assignments for many previously known levels have been made. Relative transition probabilities were also deduced. Experimentally observed energies and decay modes of various states have been compared with the results from different model calculations