Subbarrier fusion of 16O+147,149Sm.

Abstract

Fusion cross sections have been measured for $^{16}$O${+}^{147}$,149Sm at bombarding energies in the range 61 MeV \ensuremath{\le}${E}_{\mathrm{lab}{(}^{16}\mathrm{O})\mathit{\ensuremath{\le}}75}$ MeV by off-line observation of x rays emitted in the radioactive decay of Yb isotopes and their daughters. The fusion excitation functions are similar to those of the adjacent even Sm isotopes. It appears, therefore, that the odd valence neutrons do not have any unusual influence on the subbarrier enhancement of ${\ensuremath{\sigma}}_{\mathrm{fus}}$ in these systems. The x-n distributions of the evaporation residues were also determined. The nuclear deformation parameters ${\ensuremath{\beta}}_{2}$ deduced for the odd and even Sm isotopes using Wong's model establish a smooth systematic behavior of ${\ensuremath{\beta}}_{2}$ with target collectivity. Fusion cross sections for $^{16}\mathrm{O}$ with all the stable Sm isotopes are tabulated.