Ion-radical reactions relevant to the interstellar medium and outer atmosphere, under cold controlled collisions

冷控碰撞下与星际介质和外层大气相关的离子自由基反应

• 批准号: 2343952
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2343952
• 关键词: Ion; radical; reactions; relevant; interstellar

This project falls within the EPSRC Physical Sciences theme, with particular relevance to the Analytical Science, Chemical Reaction Dynamics and Mechanisms and Cold Atoms and Molecules research areas. The primary objective of this project is to study ion-radical reactions under extreme conditions, by combining a Zeeman decelerator and a cryogenic ion-trap. Ions and radicals are highly reactive species, therefore their reactions are frequently really challenging to study precisely. Indeed, the presence of other competing reaction channels typically complicates (or, in some cases, even prevents) the study of target reactions. By overcoming this challenge, we will be able to obtain reaction rates for many ion-radical reactions relevant to interstellar medium or outer atmosphere, that are yet to be experimentally measured. These data are of great interest for validating theoreticians' models of reactions in such media. In order to achieve this objectives, I will develop and characterise a novel experimental set-up to study ion-radical reactions in gas phase. We already have a source of cold and controlled radical species provided by a Zeeman decelerator and a magnetic guide. This source of cold radicals will not only quantum-state select radical species of interest, but also tune and filter their velocities. We will combine a cryogenic ion-trap to the source of cold radicals. This cryogenic ion trap will be cryogenically cooled to less than 10 K to reduce the black body radiation and therefore to lower the internal temperature of molecular ions. I am in the process of constructing this new cryogenic ion trap. The device is also equipped with a vibration-isolation system and an imaging detection methodwill be combined with mass spectroscopy detection capabilities. To handle a more efficient, compact design of the ion trap, a new optical imaging system has been developed. The resulting instrument will enable us to study reactions between ions and radicals with unprecedented control over the reaction parameters. We will be able to study these reaction systems with exceptional sensitivity, as we can monitor the reactions of single ions. No other instrument combines a cryogenic ion trapping environment with optical access, mass spectrometry detection capabilities, and a source of cold radical reactants.

该项目属于EPSRC物理科学主题，与分析科学，化学反应动力学和机制以及冷原子和分子研究领域特别相关。该项目的主要目的是通过结合Zeeman减速器和低温离子陷阱来研究极端条件下的离子激进反应。离子和自由基是高反应性的物种，因此它们的反应通常确实具有挑战性。实际上，其他竞争反应通道的存在通常会使目标反应的研究复杂（或者在某些情况下甚至阻止）。通过克服这一挑战，我们将能够获得许多与星际培养基或外部大气相关的离子 - 激进反应的反应速率，这些反应尚未实验。这些数据对于验证理论家在此类媒体中的反应模型非常有兴趣。为了实现这一目标，我将开发并表征一种新型的实验设置，以研究气相中的离子激进反应。我们已经有一个由Zeeman减速器和磁导向器提供的冷和受控物种的来源。这种冷自由基的来源不仅将量子态选择感兴趣的自由基物种，而且还会调整和过滤其速度。我们将将一个低温离子陷阱结合到冷自由基的来源。该低温离子陷阱将被冷冻冷却至小于10 K，以减少黑体辐射，从而降低分子离子的内部温度。我正在构建这个新的低温离子陷阱。该设备还配备了振动 - 隔离系统，并且成像检测方法将与质谱检测能力结合使用。为了处理离子陷阱的更高效，紧凑的设计，已经开发了一种新的光学成像系统。所得的仪器将使我们能够研究离子和自由基之间对反应参数进行前所未有的控制的反应。我们将能够以特殊的灵敏度研究这些反应系统，因为我们可以监测单个离子的反应。没有其他仪器将低温离子捕获环境与光学访问，质谱检测能力和冷自由基反应物的来源结合在一起。