The gamma-ray strength function for gamma energies in the 1-7 MeV region has been measured for 161,162-Dy and 171,172-Yb using the (3-He,alpha gamma) reaction. Various models are tested against the observed gamma-ray strength functions. The best description is based on the Kadmenskii, Markushev and Furman E1 model with constant temperature and the Lorentzian M1 model. A gamma-ray bump observed at E_gamma=3 MeV is interpreted as the so-called pygmy resonance, which has also been observed previously in (n,gamma) experiments. The parameters for this resonance have been determined and compared to the available systematics.
@article{arxiv.nucl-ex/0009018,
title = {Gamma-ray strength function and pygmy resonance in rare earth nuclei},
author = {A. Voinov and M. Guttormsen and E. Melby and J. Rekstad and A. Schiller and S. Siem},
journal= {arXiv preprint arXiv:nucl-ex/0009018},
year = {2009}
}