以交叉分子束及时间切片离子速度成像法研究产物成对相关讯息(英文)

Product Pair-correlation by Crossed Molecular Beam and Time-sliced Ion Velocity Imaging Methods

研发了一种新颖的实验方法 ,用以在交叉分子束条件下测量双分子反应产物的成对相关 (paircorrela tion)讯息 .作为尝试 ,首先选取了F +CD4/CHD3 /CH4反应体系 .结合时间切片离子速度成像与交叉分子束技术 ,可直接测得产物态分辨且成对相关的角分布 .已研究了产物成对相关的几个方面 ,阐释了碰撞能效应 .测量表明 ,产物角分布对HF/DF产物振动态有极强的相关性 ,同时对甲基产物的振动态也有不可忽视的相关性 .在低碰撞能时 ,在F +CH4多原子反应中 ,首度发现了反应动态共振的证据 .

A novel experimental technique has been developed to measure the attributes of product pair correlation of bimolecular reactions under the crossed molecular beam condition. The first system that we picked is F+CD 4/CHD 3/CH 4 reactions. By combining a crossed molecular beam method with a time-sliced ion velocity imaging technique, the product state-resolved pair-correlated differential cross sections were revealed directly from the measurements. Several facets of the product pair correlation have been explored. The dependence on the collisional energy has been elucidated. The pair-correlated angular distributions show strong dependences on the HF/DF vibrational quantum numbers, and weaker yet not negligible dependences on the methyl radical vibrational quantum numbers. For the F+CH 4 reaction at collisional energies close to the reaction threshold, the first experimental evidences of a reactive resonance in a polyatomic reaction were discovered. The product pair-correlated information helps us to unravel the complexity of polyatomic reactions and offers the important link between A+BC type of reactions and more general polyatomic reactions.