239Pu and 241Am (n, 2n) cross-section measurements near En= 14 MeV

We measured the (n, 2n) cross sections for neutron energies from 13.7 to 15.1 MeV on 239Pu and 241Am by α- and γ-spectroscopy measurements of the post–irradiation 238Pu/239Pu and 240Am/241Am ratios relative to the (n, 2n) cross sections of 196Au and other calibration reactions. Statistical errors on the measurements were not more than a few percent. Cross–section values ranged from 228 to 214 millibarns for the reaction on 239Pu and from 260 to 222 millibarns for the 241Am reaction for neutron energies from 13.7 to 15.1 MeV.