Momentum imaging spectroscopy of fragment ions produced in highly charged ion - molecule collisions controlled by the heat of formation

这项研究最重要的目的是发展一种实验技术，以确定高电荷态离子与分子碰撞中中间态和随后的碎裂过程之间的关联。为了研究离子与分子之间的电子转移引起的碎裂过程，有必要确定分子在碰撞后立即产生的中间态。然而，由于到目前为止只选择了入射离子的电荷态变化，所以还没有得到关于中间态的信息。在这项研究中，我们开发了一台HEW光谱装置，它不仅可以测量碎片离子的电荷状态变化，而且可以测量与碎片离子的三维动量图像相符合的动能变化。这项研究还包括开发一种不需要任何冷却系统就能产生高电荷离子的紧凑型离子源。在该项目的第一阶段(2000年)，…开发了一种紧凑型多电荷离子源更多，并发表了一篇相关的论文。该离子源体积很小(长40 cm，直径20 cm)，功耗很低(4W)。利用一对NdFeB永磁体和异形磁轭，成功地从离子源引出了Ne^&lt；10+>、Ar^&lt；18+和Kr^&lt；29+。我们参加了一些会议，并发表了会议记录。利用该分析仪不仅可以测量碎片离子的电荷状态变化，而且可以测量与碎片离子的SD动量像符合的动能变化。这种装置使得在电子转移碰撞后立即分配入射离子和目标分子的电子态成为可能。首次确定了Ar^&lt；q+&gt；(q=3，8，9，11和12)与N_2，CH_4和CF_4分子碰撞中分子的电子态。此外，还从结果中获得了一些关于分子取向和碎裂不对称性的信息。较少

The most important purpose of this research is developing of an experimental technique to identify the correlation between an intermediate state and following fragmentation processes in collisions between highly charged ion and molecule. In order to investigate fragmentation processes induced by electron transfer between ion and molecule, it is necessary to specify an intermediate state of molecule produced just after the collision. No information about the intermediate state, however, had been obtained because only charge-state change of incident ion had been selected until now. In this research, we developed a hew spectroscopic device which is able to measure not only charge-state change but also kinetic energy change in coincidence with 3D-momentum image of fragment ions. This research also includes development of a compact ion source producing highly charged ions without any cooling system.In the first term of this project (2000), a compact multiply-charged ion source was developed … More , and a related paper was published. The size of the ion source is very small (40 cm long and 20 cm diameter) and the power consumption is very low (4 W). Extraction of Ne^<10+>, Ar^<18+>, and Kr^<29+> was succeeded from the ion source by using a pair of NdFeB permanent magnets and special shaped yokes.In the last term of this project (2001), the SD-momentum imaging analyzer was developed. We participated in some conferences and published the proceedings. It is possible to measure not only charge-state change but also kinetic energy change in coincidence with SD-momentum image of fragment ions by using this analyzer. This device makes it possible to assign both electronic states of incident ion and target molecule just after the electron transfer collision. It was possible to specify the electronic states of molecules in collisions between Ar^<q+> (q=3, 8, 9, 11, and 12) and N_2, CH_4, and CF_4 molecules for the first time. In addition, some information on molecular orientation and asymmetry of fragmentation were obtained from the results. Less