Radiochemical Determination of Neutron Capture Cross Sections of 241Am
Radiochemical Determination of Neutron Capture Cross Sections of 241Am
复制标题
241Am 中子俘获截面的放射化学测定
DOI：
10.3327/jnst.34.613
复制
发表时间：
1997
影响因子：
1.2
通讯作者：
N. Kohno
中科院分区：
文献类型：
--
作者：
N. Shinohara;Y. Hatsukawa;K. Hata;N. Kohno
用Co/Al和Au/Al合金中子通量监测仪，用Cd比技术放射化学测量了~(241)Am的热中子俘获截面和中子俘获共振积分，得到了~(241)Am产生同分异构体~(242)Am和基态~(242)GAm的结果。用JMTR将高纯度的~(241)Am靶照射在铝胶囊中。通过测量~(60)Co和~(198)Au的γ射线，确定了中子通量及其超热中子分数。通过分析α-射线活度比242 cm/241Am的生长和衰变曲线，确定了242mAm和242gAm的产率计算得到的242mAm和242gAm的热中子俘获截面分别为85.7±6.3b和768±58b，共振积分分别为114±7b和1694±146b。目前的结果与Mughabghab的评估值之间的差异为38%-59%。热中子的g/(m+g)为0.90±0.09，超热中子的g/(m+g)为0.94±0.11。
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 v...