报告题目： 用多粒子符合成像方法(Reaction Microscope) 研究氩团簇中的ICD过程

　　报告人：任雪光 教授 西安交通大学

　　时间：2017年11月23日09:00

　　地点：近代物理所5号楼911会议室

　　Abstract:

　　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.