Enhanced radiative strength in the quasicontinuum of 117Sn.

The radiative strength function of {sup 117}Sn has been measured up to the neutron separation energy using the ({sup 3}He, {sup 3}He{sup '}{gamma}) reaction. An increase in the slope of the strength function around E{sub {gamma}}=4.5 MeV indicates the onset of a resonancelike structure, giving a significant enhancement of the radiative strength function compared to standard models in the energy region 4.5{<=}E{sub {gamma}}{<=}8.0 MeV. For the first time, the functional form of this resonancelike structure has been measured in an odd tin nucleus below neutron threshold in the quasicontinuum region.