Determination of (n,γ) cross sections in the rare-earth region using the surrogate ratio method

The surrogate ratio method was used to convert experimentally determined relative γ-decay probabilities for excited 171Yb and 161Dy nuclei, populated using (3He, 3He') and (3He, α) reactions, into neutron-induced γ-decay cross sections in an equivalent neutron energy range of 165-465 keV. The relative γ-decay probabilities were measured using the CACTUS array at the Oslo Cyclotron Laboratory and were found to agree with the ratio of neutron-induced γ-decay cross sections for the same compound nuclei over the range of excitation energies measured. No significant entrance-channel effects on the extracted (n,γ) cross sections were observed. The cross sections obtained using the surrogate ratio method were compared to directly measured neutron-capture cross sections and found to agree within the total estimated uncertainty over the range of equivalent neutron energies measured