Positronium Annihilation in Oxygen and Nitrogen Mixture  

作　　者：WANG Juncheng HE Chunqing DAI Yiqun WANG Shaojie 

机构地区：[1]Key Laboratory of Nuclear Solid State Physics of Hubei Province / School of Physics and Technology, Wuhan University

出　　处：《Wuhan University Journal of Natural Sciences》2013年第2期142-146,共5页武汉大学学报（自然科学英文版）

基　　金：Supported by the National Natural Science Foundation of China(10975108and10974149);the Research Fund for the Doctoral Program of Higher Education of China(20090141120069)

摘　　要：Formed in silica aerogels, positronium annihilation in oxygen and nitrogen mixture is studied by a simple and convenient method. The results show that ortho-positronium （o-Ps） lifetime is significantly shortened when some oxygen is introduced into ni- trogen gas and that the o-Ps collisional quenching rate for an oxy- gen molecule is （28.0±0.4） ±ts%amagat（1 amagat 2.69± 1025 m-3）. It is found that the o-Ps annihilation rate in oxygen of latin at room temperature is （25.5±0.5） us-1 and that the effective num- ber of electrons per oxygen molecule available for 27 annihilation of positron in the o-Ps is （34.6±0.4）.Formed in silica aerogels, positronium annihilation in oxygen and nitrogen mixture is studied by a simple and convenient method. The results show that ortho-positronium （o-Ps） lifetime is significantly shortened when some oxygen is introduced into ni- trogen gas and that the o-Ps collisional quenching rate for an oxy- gen molecule is （28.0±0.4） ±ts%amagat（1 amagat 2.69± 1025 m-3）. It is found that the o-Ps annihilation rate in oxygen of latin at room temperature is （25.5±0.5） us-1 and that the effective num- ber of electrons per oxygen molecule available for 27 annihilation of positron in the o-Ps is （34.6±0.4）.

关 键 词：POSITRONIUM positron annihilation QUENCHING silicaaerogel 

分 类 号：O572.322[理学—粒子物理与原子核物理]