Coulomb excitation of 232Th vibrational states

High-spin states, and in particular the octupole vibrational state, of 232Th have been studied. The 0.1 mm thick 232Th targets were irradiated by the 370 and 450 MeV Kr ions. The scheme of levels and the moment of inertia dependence on the rotational frequency for the 232Th ground-state and octupole band. The moments of inertia of the ground and octupole bands of 232Th and 238U are compared. An attempt is made to interpret the ground state band energies by means of the boson hamiltonian including the sixth order terms. A good agreement is found with the experiment up to 1=14+, the discrepancy then sharply increasing with the increase of spin. The energy of the 232Th and 238U octupole bands is also indicated. The conclusion is made that the tendency takes place for 238U to al gn the angular moment of the octupole band relative to the rotating core moment. To understand the energies of the 232Th octupole band, the rotational-vibrational and coriolis interactions are to be accounted for in a much smaller degree than for 238U