First observation of low-energy {\gamma}-ray enhancement in the   rare-earth region
  The {\gamma}-ray strength function and level density in the quasi-continuum of 151,153Sm have been measured using BGO shielded Ge clover detectors of the STARLiTeR system. The Compton shields allow for an extraction of the {\gamma} strength down to unprecedentedly low {\gamma} energies of about 500 keV. For the first time an enhanced low- energy {\gamma}-ray strength has been observed in the rare-earth region. In addition, for the first time both the upbend and the well known scissors resonance have been observed simultaneously for the same nucleus. Hauser-Feshbach calculations show that this strength enhancement at low {\gamma} energies could have an impact of 2-3 orders of magnitude on the (n,{\gamma}) reaction rates for the r-process nucleosynthesis. 
A. Simon, M. Guttormsen, A.C. Larsen, C.W. Beausang, P. Humby, J.T.   Burke, R.J. Casperson, R.O. Hughes, T.J. Ross, J.M. Al...
nucl-ex