| Abstract: | The thermal neutron capture cross sections and the neutron capture resonance integrals of 241Am leading to the production of the isomer 242Am and the ground-state 242gAm were measured radiochemically by the Cd-ratio technique with neutron flux monitors of Co/Al and Au/Al alloy. Highly-purified 241Am targets were irradiated in an aluminum capsule by using JMTR. The neutron fluxes and their epithermal neutron fractions were determined by measuring γ-rays of 60Co and 198Au. The yields of 242mAm and 242gAm were decided by analyzing growth and decay curves of the α-ray activity ratios 242Cm/241Am. The resultant thermal neutron capture cross sections are 85.7 ± 6.3 b and 768 ± 58 b for 242mAm and 242gAm, and the resonance integrals 114±7 b and 1,694±146 b, respectively. The differences between the present results and the evaluated values by Mughabghab are 38–59%. The isomeric ratios, g/(m+g), of 0.90±0.09 for thermal neutrons and 0.94±0.11 for epithermal neutrons are, however, almost consistent with evaluated values. |
