量子态选择的分子离子解离动力学：阈值光电子-光离子符合成像技术的应用  

Photodissociation dynamics of state-selected molecular ions: Application of threshold photoelectron-photoion coincidence velocity imaging

作　　者：周晓国[1,2] 唐小锋[1,2,3,4] 刘世林[1,2] 盛六四[3,4] 

机构地区：[1]合肥微尺度物质科学国家实验室(筹) [2]中国科学技术大学化学物理系,合肥230026 [3]同步辐射国家实验室 [4]中国科学技术大学,合肥230029

出　　处：《中国科学：化学》2013年第12期1700-1712,共13页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(21073173,21027005,21373194);国家重点基础研究发展规划项目(973项目,2013CB834602,2010CB923300);中国博士后科学基金(2012M511422)资助

摘　　要：阈值光电子-光离子符合速度成像技术通过对光电子和符合的光离子同时进行速度聚焦控制,大幅提高了电子和离子的收集效率和离子平动能分辨率,成为开展气相分子光电离和光电离-解离动力学研究的有效工具.利用该技术,我们精确地测量了分子的电离能、离子出现势等重要参数,并且开展了若干具有量子态或内能选择的离子解离动力学研究,描绘了相关势能面存在浅势阱等重要动力学特征,讨论了不同振动态和电子态的激发对解离机理和产物通道的重要影响.In a recently developed threshold photoelectron-photoion coincidence （TPEPICO） velocity imaging mass spectrometer, electron and ions are collected with a special double velocity mapping electronic field, which significantly improves the collection efficiency and kinetic energy resolution of ions. Thus the TPEPICO velocity imaging becomes a very powerful tool to investigate photoionization and dissociative photoionization of molecules in gas phase. Using this technique, some important parameters, e.g. ionization energy and appearance energy, can be directly measured with high precision. Several investigations on dissociation dynamics of state-selected or energy-selected molecular ions are performed subsequently, and a shallow well is mapped on potential energy surface along dissociation coordinate. Dependence of various vibrational and electronic states on dissociation mechanism and fragmentation channels of ions is discussed as well.

关 键 词：符合 离子速度成像 阈值光电子 光电离 光解离 

分 类 号：O643.1[理学—物理化学]