Angular distributions for inelastic deuteron scattering from samarium

Abstract

The elastic and inelastic scattering of 12 MeV deuterons from targets of 148Sm, 150Sm, 152Sm and 154Sm has been investigated. Angular distributions for the elastic group and for the more prominent inelastic groups were measured by means of solid state counters. Supplementary information was obtained from high-resolution magnetic spectrograph data. The elastic angular distributions are smooth and without diffraction structure. The absolute cross section at back angles decreases with increasing mass number. This effect can probably be ascribed to differences in the inelastic excitations since the distributions for the sum of elastic and inelastic intensity are almost identical for all the nuclei. The shape of the angular distributions for the collective 2 +, 4 + and, when observed, for the 6 + levels, for each angular momentum is very similar in all the nuclei, although the character of the levels changes from vibrational to pure rotational. The same is true for the distributions of the strongly excited 3 - levels. It is thus indicated that the angular distributions give a simple determination of the multipolarity of the excitation, the tendency being a decrease in forward-backward ratio with increasing multipolarity.