Radiochemical Determination of Neutron Capture Cross Sections of ^<241>Am
The thermal neutron capture cross sections and the neutron capture resonance integrals of <SUP>241</SUP>Am leading to the production of the isomer <SUP>242m</SUP>Am and the ground-state <SUP>242g</SUP>Am were measured radiochemically by the Cd-ratio technique with neutron flux monitors of Co/Al and Au/Al alloy. Highly-purified <SUP>241</SUP>Am 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 <SUP>60</SUP>Co and <SUP>198</SUP>Au. The yields of <SUP>242m</SUP>Am and <SUP>242g</SUP>Am were decided by analyzing growth and decay curves of the α-ray activity ratios <SUP>242</SUP>Cm/<SUP>241</SUP>Am. The resultant thermal neutron capture cross sections are 85.7±6.3b and 768±58b for <SUP>242m</SUP>Am and <SUP>242g</SUP>Am, and the resonance integrals 114±7b and 1, 694±146b, 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.
- Journal of nuclear science and technology
Journal of nuclear science and technology 34(7), 613-621, 1997-07-25
Atomic Energy Society of Japan