重丰中子新同位素——238Th

利用兰州重离子加速器（ＨＩＲＦＬ）提供的６０ＭｅＶ／ｕ的１８Ｏ离子束照射天然铀靶，通过多核子转移反应生成２３８Ｔｈ．用快速放射化学分离技术从铀及其反应产物的混合物中分离出Ｔｈ同位素．使用两台高纯锗（ＨＰＧｅ）探测器测量了样品的γ射线活性，观测到了２３８Ｔｈ的β－衰变子体２３８Ｐａ的γ射线的生长、衰变行为，测定２３８Ｔｈ的半衰期为9.4±2.0min A new nuclide 238Th has been produced via multinucleon transfer reaction by 60 MeV/u 18 O ion irradiation of natural uranium. The produced thorium was radiochemically separated from the mixture of uranium and its reaction products. The activity of thorium was measured by using a HPGe detector and a planar HPGe detector. 238 Th has been identified for the first time by measuring the growth and decay of the γ rays from its daughter nucleus 238 Pa.