241Am: a difficult actinide for (n,γ) cross section measurement

Many attempts have been made in the past to determine accurate cross section data for neutron capture in 241Am, however, the reported data for thermal neutron energies scatter by more than 25% around 680 b. The situation is complicated as the product of the capture reaction is twofold: 241Am (n,ɣ)242gAm,242mAm. The production ratio for ground- and metastable state is uncertain but also 241Am exhibits a very low first resonance at about 0.3 eV and this might influence the 1/v behaviour at thermal energy, 0.025 eV. In our experiments, we are using cold neutrons at the PGAA facilities of the Budapest and Garching Research Reactors, hence, we assume to be independent of the perturbations from possible non-1/v behaviour