Thermal-neutron capture cross section and resonance integral of americium-241

The thermal-neutron capture cross section (sigma(0,g)) and the resonance integral (I-0,I-g) leading to the ground state of Am-242 were measured by an activation method for neutron capture by Am-241. A method with gadolinium, which was similar to the cadmium difference method, was used to measure the cross section sigma(0,g) with attention to resonances of Am-241. Americium chloride samples containing Am-241 radioisotope were irradiated for 68 It in the long-irradiation plug of the Kyoto University Research Reactor, KUR. Wires of Co/Al and Au/Al alloys were used as monitors to determine thermal-neutron fluxes and epithermal Westcott's indexes at the irradiation positions. An a-ray spectrometer was used to measure the activity ratios of Cm-242 to Am-241. On the basis of Westcott's convention, the sigma(0,g) and I-0,I-g values were determined as 628 +/- 22b and 3.5 +/- 0.3 kb, respectively.