^(239)Pa的鉴别及其特性  

Identification and Characteristic of ^(239)Pa

作　　者：袁双贵[1] 丁华杰[1] 徐岩冰[1] 杨维凡[1] 

机构地区：[1]中国科学院近代物理研究所,甘肃兰州730000

出　　处：《原子能科学技术》2008年第B09期1-3,共3页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(10575118);中国科学院资助项目

摘　　要：利用60 MeV/u18O离子束轰击天然铀靶,经多核子转移反应生成重丰中子核素239Pa。用放射化学方法从被照射的靶中分离出镤。借助于239Pa和它的子体239U的γ射线观测和分析,鉴别了239Pa,测得239Pa的半衰期为(106±30)min。长寿命同位素,如232Th和238U,可给出一个测定核合成持续时间的可能性,而中等寿命同位素,如235U,则可给出有关产生函数时间历史的信息。总地说来,通过232Th/238U2、35U/238U或244Pu/238U的比率,用公式NA(Δ)/NB(Δ)=(PA/PB)f(λA,λB,S0,λR,Δ)便可推导出宇宙年龄。由239Pa的衰变途径,可简单叙述239Pa的异常长的半衰期对于宇宙年龄估计的影响。Abstract. A nuclide ^239 Pa was produced via a multinucleon transfer reaction by 60 MeV/u 180 ions bombardment of natural uranium. Protactinium was radiochemically separated from the irradiated targets. ^239 Pa has been identified by using observation and analysis of γ-rays of ^239 Pa and ^239U as a daughter nucleus of ^239 Pa. The half-life of 239 Pa was determined to be （106±30） rain. Long lived isotopes like ^232Th and ^238U give a possibility of determining the duration of nucleosynthesis whereas intermediate lived nuclei like ^235U can give information about the time history of the production function. Generally the universe age is deduced through the ratios of the ^232Th/^238 U, ^235U/^238U or ^244pu/^238 U with formular NA（△）/Ng（△） = （PA/PB）f（λA ,λB ,So ,λR ,△）. The influence of the novel long half-life of ^239 Pa on the universe age estimate is simply mentioned by ^^239 Pa decay path.

关 键 词：鉴别 ^239Pa 宇宙年龄 

分 类 号：O571.324[理学—粒子物理与原子核物理]