Radiative strength functions in 93-98Mo -: art. no. 044307

Radiative strength functions (RSFs) in Mo93-98 have been extracted using the (He-3,alpha gamma) and (He-3,He-3'gamma) reactions. The RSFs are U shaped as function of gamma energy with a minimum at around E-gamma=3 MeV. The minimum values increase with neutron number because of the increase in the low-energy tail of the giant electric dipole resonance with nuclear deformation. The unexpected strong increase in strength below E-gamma=3 MeV, here called soft pole, is established for all Mo93-98 isotopes. The soft pole is present at all initial excitation energies in the 5-8-MeV region.