Cross sections for U238(n,n'γ) and U238(n,2nγ) reactions at incident neutron energies between 5 and 14 MeV

Precision measurements of 238 U(n,n'γ) and 238 U(n,2nγ) partial cross sections have been performed at Triangle Universities Nuclear Laboratory (TUNL) to improve crucial data needed for testing nuclear reaction models in the actinide mass region. A pulsed and monoenergetic neutron beam was used in combination with high-resolution γ-ray spectroscopy to obtain partial cross sections for incident neutron energies between 5 and 14 MeV. γ-ray yields were measured with high-purity germanium clover and planar detectors. Measured partial cross-section data are compared with previous results using white and monoenergetic neutron beams and calculations from the GNASH and TALYS Hauser-Feshbach statistical-model codes. Present experimental results are in fair to good agreement with most of the existing data for the 238 U(n,n'γ) reaction. However, significant discrepancies are observed for the 238 U(n,2ny) reaction.