新重丰中子核^(237)Th的合成和鉴别

The Synthesis and Identification of New Neutron-Rich Heavy Nuclide ^(237)Th

用14MeV中子照射(NH_4)_2U_2O_7粉末,通过^(238)U(n,2p)^(237)Th反应产生了新的重丰中子同位素^(237)Th,并用放射化学方法分离了它。借助于跟踪其子体^(237)pa的γ射线的时间序列谱首次鉴别了这个新活性。利用递次衰变分析程序得到了^(237)Th的半衰期为5.0±0.9min。另外,发现了一条能量为35.1±003keV T_(1/2)=5.0±1.1min的新γ射线并指定它为^(237)Th衰变。

New neutron-rich heavy isotope ^(237)Th was produced in the ^(238)U(n, 2p)^(237)Th reaction by 14 MeV neutron irradiation of (NH_4)_2O_2O_7 powder and separated by radiochemical methods. The new activity was first identified by following the time sequence spectra of the γ-rays of its daughter ^(237)Pa. A radioactive series decay analyzing program was applied resulting in the halflife of 5.0±0.9min for ^(237)Th. In addition, a new 35.1±0.3 keV γ-ray with T_(1/2)=5.0±1.1 min was found and assigned to ^(237)Th.