182, 184, 186W(α, α') Reactions at Eα = 24 MeV

Abstract

Angular distributions of 24 MeV α-particles elastically and inelastically scattered from 182, 184, 186W have been measured for the angular range θ lab = 40°–140°. Coupled-channels analyses of the data for the ground-state rotational bands which assume a symmetric-rotor model lead to the conclusion that, for each nucleus, the β 2 and β 4 deformation parameters for the Coulomb and the nuclear potentials are quite different ; these differences are not accounted for by the geometrical scaling method of Hendrie but are, in most cases, accounted for by the multipole-moment method of Mackintosh. A rigid asymmetric-rotor model is found to provide a good description of the data for excitation of the second 2 + state in 186W. A second-order rotational-vibrational model provides a good description of the excitation of the 3 − state in 184W and suggests that transitions other than the direct excitation (0 + → 3 −) play an important role in the description of the data; this interpretation, however, fails to clearly distinguish between K = 0 and K = 2 models for the 3 − state.