^(32)Si半衰期的加速器质谱测量方法研究  

Measurement on the Half-Life of ^(32)Si by AMS at CIAE

作　　者：郑国文[1] 何明[1] 姜山[1] 董克君[1] 李振宇[1] 胡豪[1] 李恒[2] 武绍勇[1] 

机构地区：[1]中国原子能科学研究院,北京102413 [2]广西大学物理科学与工程技术学院,广西南宁530004

出　　处：《质谱学报》2012年第4期241-246,共6页Journal of Chinese Mass Spectrometry Society

基　　金：国家自然科学基金项目(10875176;11175266)资助

摘　　要：32Si是宇宙射线与空气中的Ar通过散裂反应产生的长寿命放射性核素,利用32 Si可以开展广泛的应用研究。然而作为放射性核素关键数据的32Si半衰期数据仍然存在较大的偏差,这在很大程度上阻碍了32Si的应用。本工作利用中国原子能科学研究院的加速器质谱系统开展了32Si半衰期的测量。通过反应堆辐照Mg2P2O7生产32Si并制备出用于加速器质谱测量和活度测量的样品;利用加速器质谱技术进行了32Si/Si绝对比值的测定;通过液闪对样品进行了放射性活度测量,从而实现了32Si半衰期的测定,得到32 Si的半衰期值为(182±16)a。^32 Si is the only long lived radio isotope of silicon which generated in small amount through primary or secondary cosmic-ray induced spallation of Ar in the atmosphere. It has very important applications in many aspects such as the research of global biogeochemical sillion cycle and the application in geochronometry in the range of 100--1000a. However, The precise value of its half-life are discrept and this decreased its applications to a great extent. This work measures the half-life of ^32 Si by AMS at China Institute of Atomic Energy （CIAE）.^ 32Si was generated through radiated Mg2P2O7 and SiO2 sample was prepared according to certain procedure. The sample was divided into two parts,one for AMS measurement and the other for decay rate measurement. Then the absolute ratio of ^32Si/Si was measured by AMS method and its decay rate was measured by liquid scintillation detector. As a result, the half-life af ^32Si is （182±16）a.

关 键 词：32Si 加速器质谱 半衰期 绝对测量 

分 类 号：TL817.4[核科学技术—核技术及应用] O657.63[理学—分析化学]