Abstract
We have measured deexcitation gamma rays in the neutron-rich nuclei of U-240, Pu-246, and Cm-250 produced by the (O-18, O-16) two-neutron transfer reactions, in coincidence with the O-16 particles using Si Delta E-E detectors. The gamma rays in these nuclei were identified by selecting the kinetic energies of O-16 particles, which correspond to the excitation energies in the residual nuclei below the neutron separation energies. The ground-state bands of U-240, Pu-246, and Cm-250 were established up to 12(+) stop states and the K-pi = 0(-) octupole band of U-240 was established up to 9(-) states. The systematics of the moments of inertia of the ground-state bands for actinide nuclei shows that the deformed subshell closure at N = 152 is sustained for Cm-96 isotopes and that it disappears for Pu-94 isotopes.