Partial-wave analysis of n+Am241 reaction cross sections in the resonance region

International audience; Cross sections for neutron-induced reactions of Am241 in the resonance region have been evaluated. Results of time-of-flight cross section experiments carried out at the GELINA, LANSCE, ORELA and Saclay facilities have been combined with optical model calculations to derive consistent cross sections from the thermal energy region up to the continuum region. Resolved resonance parameters were derived from a resonance shape analysis of transmissions, capture yields, and fission yields in the energy region up to 150 eV using the refit code. From a statistical analysis of these parameters, a neutron strength function (104S0=1.01±0.12), mean level spacing (D0=0.60±0.01 eV) and average radiation width (⟨Γγ0⟩=43.3±1.1 meV) for s-wave resonances were obtained. Neutron strength functions for higher partial waves (l>0) together with channel and effective scattering radii were deduced from calculations based on a complex mean-field optical model potential, applying an equivalent hard-sphere scattering radius approximation.