四氟化碳分子电离解离过程中的异构化动力学

采用离子动量成像谱仪研究了能量为1.0 ke V的电子束碰撞条件下CF₄分子的解离动力学.实验上，对解离离子的三维动量进行了成像测量，通过离子飞行时间关联谱识别了CF₄²⁺异构化生成F₂⁺分子的两个通道:F₂⁺+CF₂⁺与CF⁺+F₂⁺+F，得到了两个通道的离子动能及动能释放分布.对于其中的三体解离通道，我们进一步采用Dalitz图与Newton图等三体动力学分析方法对解离碎片的动量关联进行了分析.该通道以两个带电离子的背对背出射为主，中性的F原子作为旁观者只得到极小的反冲动量.

Isomerization Dynamics in Dissociative Ionization of Carbon Tetrafluoride

The dissociation dynamics of CF4 molecules by electron collisions with impact energy of 1.0 keV was studied by using an ion momentum imaging spectrometer. In the experiment, the three-dimensional momentum vectors of the fragment ions were measured and two isomerization channels for F2+ formation from CF42+, i.e. F2+ + CF2+ and CF+ + F2+ + F, were identified by ion time-of-flight correlation map. The kinetic energy and kinetic energy release distributions of the two channels were obtained. For the three-body dissociation channel, we analyzed the momentum correlation of the dissociated fragments using the three-body dynamics analysis schemes such as the Dalitz diagram and Newton diagram. The channel is dominated by the back-to-back emission of two charged ions, and the neutral F atom acts as a spectator which only gets a very small recoil momentum.