Capture Cross-section Measurement of 241Am(n,γ) at J-PARC/MLF/ANNRI

Abstract The 241 Am(n, γ ) 242 Am cross sections have been measured for neutron energies between 0.01 and 10 eV using the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) installed at the Materials and Life-science experimental Facility (MLF) in J-PARC. ANNRI combines the strongest neutron-pulsed beam and a high energy resolution γ -ray spectrometer, making possible accurate measurements of neutron capture cross sections for highly radioactive samples. From the measured cross section, the Westcott neutron capture factor and strength of the first three resonances in 241 Am are deduced. These results with precision less than 0.5 % are compared with those derived from JENDL-4.0.