报告题目：Highly Charged Atomic Ions in Collisions with Electrons 

　　报告人： Prof. Dr. Stefan Schippers 

　　Justus-Liebig-University Giessen 

　　Institute of Experimental Physics I 

　　Atomic and Molecular Physics 

　　时间： 2017年8月30日 15:30  

　　地点：  近代物理所5号楼911会议室 

　　Abstract: 

　　Recent progress in experimental studies of electron-ion collisions using(stored) ion beams will be reviewed. This field of research is motivated twofold. First, electron-impact ionization of ions and electron-ion recombination are important atomic collision processes in plasmas governing the charge state distributions of the atomic species contained therein. 

　　Recently, attention has been given to tungsten ions because of their prominent role in nuclear fusion plasmas. A particular challenge for theory is the complex electronic structure of these many-electron systems, particularly, if they have an open 4f atomic subshell. Benchmarking by experiment lead to considerable advances in the theoretical understanding of electron-ion recombination of such complex atomic systems. Second, ionization and recombination resonances provide access to the atomic structure of highly charged ions. Electron-ion collision spectroscopy exploits this aspect of electron-ion collisions. This method of atomic spectroscopy is competitive with or sometimes even ahead of optical methods.  

　　Electron-ion collision spectroscopy of few-electron highly charged ions has been used for measuring atomic lifetimes, transition energies, and nuclear properties. Finally, I will point out perspectives for future studies with cooled and state-prepared ions at upcoming storage-ring facilities.