Residual 60Co activity in steel samples exposed to the Hiroshima atomic-bomb neutrons.
Residual 60Co activity in steel samples exposed to the Hiroshima atomic-bomb neutrons.
复制标题
暴露于广岛原子弹中子的钢样品中的残余 60Co 活性。
DOI：
10.1097/00004032-199809000-00006
复制
发表时间：
1998
期刊：
影响因子：
2.2
通讯作者：
T. Imanaka
中科院分区：
文献类型：
--
作者：
K. Shizuma;K. Iwatani;H. Hasai;T. Oka;S. Endo;J. Takada;M. Hoshi;S. Fujita;T. Watanabe;T. Imanaka
通过γ射线能谱法测量了位于倾斜距离1，800 m以内的7个钢样品和在距震中4.5 km处获得的1个对照样品的广岛原子弹中子产生的残留60 Co放射性。用溶剂萃取法除去钢样中主要成分铁离子后，用离子交换法将镍和钴进行化学分离。伽马射线测量用低背景阱型锗探测器进行。导出的比活度60 Co：Co与以前的测量和计算的基础上，目前的剂量测定系统DS86的中子注量。已经表明，测量的和计算的活性之间存在系统的差异。60 Co的计算值与152 Eu和36 Cl活度的计算值与测量值之比一致。
Residual 60Co radioactivity produced by the neutrons from the Hiroshima atomic bomb has been measured by means of gamma-ray spectrometry for seven steel samples located up to 1,800 m slant range and one control sample obtained at 4.5 km from the hypocenter. After removing the main constituent of iron ions from the steel sample by the solvent extraction method, nickel and cobalt were chemically separated by the ion exchange process. Gamma-ray measurements were performed with a low background well-type germanium detector. Derived specific activities 60Co:Co were compared with previous measurements and with the calculation based on the neutron fluence of current dosimetry system DS86. It has been shown that a systematic discrepancy exists between the measured and calculated activity. The calculated-to-measured ratios for 60Co are consistent with those of 152Eu and 36Cl activity.