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《科学前沿报告会》 第367期

科学前沿报告会(367)

报告题目

用多粒子符合成像方法(Reaction Microscope, COLTRIMS)研究电子束驱动的氩团簇中的ICD过程

报 告 人

任雪光 教授

西安交通大学理学院

报告地点

物理楼西楼464教室

报告时间

2017年5月9日 (星期二) 14:00-15:30

联 系 人

刘运全(Tel: 62768852)

报告摘要

In the weakly bond systems, e.g. in the Ar dimer, due to the presence of the environment new autoionization channels as known as Interatomic Coulombic Decay (ICD) can be opened. Here internal excess energy is transferred to the neighbor ionizing it and resulting in highly reactive species: low-energy electrons and a pair of energetic ions. Since its first prediction in 1997 by Cederbaum and co-workers, ICD soon led to a strong interest due to its important roles in various mechanisms of radiation biology and chemistry. Another relaxation process named radiative charge transfer (RCT) may occur if one atom is doubly ionized. Here an electron is transferred from a neighbor to the doubly charged Ar2+ ion. The system can relax by emitting a photon. Both the ICD and RCT processes result in two repulsive Ar+ ions. Experiments have shown that the kinetic energy release (KER) spectrum of the Ar+- Ar+ channel has a double peak structure. Calculations have shown that this KER spectrum can be attributed to the decay channel of ICD. Other calculations suggest that RCT may also contribute. In this talk, I present our recent study the ionization of Ar dimer by low-energy electron-impact using the multiple-particle coincidence technique (reaction microscope) in which the kinetic energies of all final state particles (3 electrons + 2 ions) are measured. The measured kinetic energies of final-state electrons and ions allow to determine the energies of the states reached after electron ejection. From these, we clearly discriminate the two interatomic decay channels (ICD and RCT) in the Ar dimer. [1] Z.W.Liu*, X.Hu, S. Lloyd, PRL118.060502(2017). [2] X.Hu*, A.Milne, B. Zhang, H. Fan, Sci.Rep.6,19365(2016). [3] X.Hu*, H. Fan, Sci.Rep.6,34380(2016) [4] X.Hu*, PRA94.012326(2016)

 

报告人简介:1996.09-2000.07,西安交通大学 应用物理系 (本科) 2000.09-2005.07,清华大学物理系(博士) 工作经历 2005.10-2006.09,法国 巴黎第11大学(博士后) 2006.10-2015.12,德国 马普所和技术物理部(博士后、资深科学家) 2016.01,西安交通大学 理学院 (教授)

 

 

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