【摘要】 原子阱痕量分析是一种基于激光的新方法,能够对数微升氪气中丰度低至10^-14的⁸⁵Kr和⁸¹Kr原子进行计数测量.介绍了在合肥建成的痕量放射性氪同位素测量系统,包括ATTA装置、水中溶解气提取和氪气分离提纯的样品处理设备.利用该系统对国内多处大气中⁸⁵Kr浓度的测量结果为1.3¹.6 Bq/m³,与文献中北半球大气本底值相吻合.对华南和华北的几个浅层和深层地下水样品进行了⁸⁵Kr和⁸¹Kr测年,示范了该系统的应用.更多还原

【Abstract】 Because of their unique chemical and physical properties,long-lived rare krypton radioisotopes,⁸⁵Kr and ⁸¹Kr,are ideal tracers for environmental samples,including air,groundwater and ice.Atom trap trace analysis（ATTA） is a new laser-based method for counting both⁸⁵Kr and ⁸¹Kr atoms with the abundance as low as 10^-14 with micro-liters（STP） krypton gas.The entire system for rare radio-krypton measurement built at Hefei is presented,including the atom trap trace analysis instrument and sampling apparatus of gas extraction from water and krypton purification.Atmospheric ⁸⁵Kr concentrations at different places in China were measured,showing a range of 1.3-1.6 Bq/m³,consistent with the northern hemispheric baseline.As a demonstration of the system,some shallow and deep groundwater samples in north and south China were sampled and dated.更多还原