Radiative strength functions in Dy163,164

Abstract

The nuclei Dy163,164 have been investigated using the Oslo method on data from the pickup reaction Dy164(He3,αγ)Dy163 and the inelastic scattering Dy164(He3,He3′γ)Dy164, respectively. The radiative strength functions for both nuclei have been extracted, and a small resonance centered around Eγ≈3 MeV is observed in both cases. The parameters of this so-called pygmy M1 resonance (the scissors mode) are compared with previous results on Dy160,161,162 using the Oslo method, and with data on Dy163 measured by the Prague group using the two-step cascade method. In particular, the integrated reduced transition probability B(M1↑) of the pygmy resonance is compared with neighboring dysprosium isotopes. We also observe an enhanced strength in the region above Eγ≈5 MeV in Dy164. Possible origins of this feature are discussed. © 2010 The American Physical Society.