一个超锕系新核素^(259)Db的合成与鉴别

Synthesis and Identification of a New Transactinide Nuclide 259Db

本文简要介绍了超重元素研究的意义及历史背景和国际现状,并叙述了中科院近物所首次合成和鉴别了一个超重新核素^(259)Db。实验是利用兰州国家重离子实验室的SFC加速器提供的^(22)Ne束轰击^(241)Am靶产生了^(259)Db。利用转轮收集系统和精心设计安排的探测器系统测量了产物的α衰变谱,根据母-子核的衰变遗传关系明确无误地鉴别了^(259)Db,并测得它的α能量为9.47MeV,半衰期为0.51秒。该项成果使我们跨入了超重核区的大门,为向“超重岛”迈进打下了良好基础。

Important significance, history, background and present status of the investigation for superheavy elements are described briefly. A new superheavy nuclide 259Db has been synthesized at the first time in IMP, China. 259Db nuclide was produced by bombarding 241Am with 22Ne ion beam provided from HIRFL (Heavy Ion Research Facility Lanzhou). The a-decay spectra of the reaction products were measured by means of rotating wheel collection and detection system via meticulous design and ingenious arrangement of detectors. 259Db nuclide was definitely identified according to the genetic relationship between the new nuclide and the known daughter nuclide. The measured a-decay energy for 259Db is 9.47 MeV with a half-life of 0.51 s.This achievement makes us stride into the door of superheavy nuclide region. And it lays a good foundation for us to go toward 'superheavy island'.