4月27日学术报告：Low-energy stereodynamics of ion-forming reactions

　　报告题目：Low-energy stereodynamics of ion-forming reactions

　　报告人：邹俊文博士，瑞士洛桑联邦理工学院（EPFL）

　　报告时间：2021年4月27日（周二）上午10:00

　　报告地点：溢智厅

　　报告摘要：

　　In this talk, an experimental study of low-temperature stereodynamics in the reactive scattering of Ne(³P₂) + X collisions (X = Ar, Kr, Xe, CO and N₂) will be presented. The steric effect of Ne(³P₂) in these reactions is observed experimentally using a controllable magnetic field. The observations are interpreted using classical and quantum models. This study provides state-selected stereodynamics over a wide range of collision energies from 1000 K down to sub-Kelvin energies using a combination of the merged beam technique and external field manipulation.

　　The key parameter to characterize the steric effect in these reactions is the branching between different possible reaction channels as a function of magnetic field direction. These branching ratios are obtained for individual states that differ only in Ω, the projection of the neon total angular momentum vector on the inter-particle axis, by using a Monte-Carlo fitting algorithm to fit an analytical expression for the relative importance of the different, state and process-specific, reaction channels to the experimental data. From the comparison of these experimental data, several interesting dynamical phenomena are found, including the reorientation effect and predissociation in atom-molecule collisions, which provides a new way to understand the reaction dynamics at low temperatures.

　　Finally, we use a combination of an electrostatic hexapole and (2+1) resonance-enhanced multiphoton ionization to produce and characterize an oriented ammonia sample (ND₃) using a controllable electric field, which provides a method to study stereodynamics of Ne(³P₂) with oriented polar molecules.

　　报告人简介：

　　邹俊文博士在2015年及2021年分别从德国慕尼黑大学 (Ludwig Maximilian University of Munich) 和瑞士洛桑联邦理工学院 (école Polytechnique Fédérale de Lausanne)获得硕士和博士学位。其研究课题分别是阿秒尺度上的带相位标记的电子动力学和离子形成反应中的低能立体动力学。邹俊文博士的主要研究方向在低温立体动力学。邹俊文博士在国际期刊发表了6篇论文，其中包括Nature Chemistry, Physical Review Letters, The Journal of Chemical Physics等高引杂志。同时他参加了2次国际会议，其中在iCOMET 2019做大会报告。

　　近五年发表主要文章：

　　[1] Zou J., Osterwalder A. Investigation of the low-energy stereodynamics in the Ne (³P₂) + N₂, CO reactions. J. Chem. Phys., 2020, 153(10): 104306.

　　[2] Zou J., Gordon S. D. S., Osterwalder A. Sub-Kelvin Stereodynamics of the Ne (³P₂) + N₂ Reaction. Phys. Rev. Lett., 2019, 123(13): 133401.

　　[3] Gordon S. D. S., Omiste J. J., Zou J., et al. Quantum-state-controlled channel branching in cold Ne ( ³P₂ ) + Ar chemi-ionization. Nat. Chem., 2018, 10(12): 1190 -1195.

　　[4] Zou J., Gordon S. D. S., Tanteri S., et al. Stereodynamics of Ne (³P₂) reacting with Ar, Kr, Xe, and N₂. J. Chem. Phys., 2018, 148(16): 164310.

　　[5] Gordon S. D. S., Zou J., Tanteri S., et al. Energy Dependent Stereodynamics of the Ne (³P₂) + Ar Reaction. Phys. Rev. Lett., 2017, 119(5): 053001.