Thomas R D, Schmidt H T, Andler G, Björkhage M, Blom M, Brännholm L, Bäckström E, Danared H, Das S, Haag N, Halldén P, Hellberg F, Holm A I S, Johansson H A B, Källberg A, Källersjö G, Larsson M, Leontein S, Liljeby L, Löfgren P, Malm B, Mannervik S, Masuda M, Misra D, Orbán A, Paál A, Reinhed P, Rensfelt K-G, Rosén S, Schmidt K, Seitz F, Simonsson A, Weimer J, Zettergren H, Cederquist H
Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden.
Rev Sci Instrum. 2011 Jun;82(6):065112. doi: 10.1063/1.3602928.
We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.
我们描述了瑞典斯德哥尔摩大学正在建造的一种新型存储设备的设计，该设备使用纯静电聚焦和偏转元件，在这种设备中，相反电荷的离子束在极高真空低温条件下被限制在单独的“环”中，并在一个公共直线段上合并。这种双静电离子环实验的构造独特地允许在低且明确的内部温度和质心碰撞能量分别低至约10 K和10 meV的条件下研究阳离子和阴离子之间的相互作用。位置敏感多击中探测器系统已经过广泛测试，并被证明可在低温环境中工作，这些系统将用于测量例如电子转移过程中反应产物之间的相关性。使用纯静电离子存储设备相对于磁性设备具有许多技术优势，但最相关的优势有：静电元件更紧凑且更易于构建；磁性设备中令人担忧的剩磁、磁滞和涡流不再相关；控制离子轨道所需的电场不仅比相应的磁场更容易产生和控制，而且对可存储离子的质量也没有上限限制。这些技术差异对基础实验研究的新领域是一个福音，不仅在原子和分子物理学中，而且在这些领域与化学和生物学的边界中。例如，对与内部低温分子离子相互作用的研究对于天体物理学应用将特别有用，而对溶剂化离子簇的研究将与高层大气物理学和生物学相关。
