Optimization of RF multipole ion trap geometries
Optimization of RF multipole ion trap geometries
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DOI：
10.1016/j.jms.2016.12.003
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发表时间：
2017-02-01
影响因子：
1.4
通讯作者：
Schlemmer, Stephan
中科院分区：
文献类型：
--
作者：
Fanghaenel, Sven;Asvany, Oskar;Schlemmer, Stephan
射频（rf）陷阱是理想的地方，以储存冷离子的光谱实验。特定的多极结构最适合于不同的应用，但必须进行修改，以允许例如激光束腰与离子云的适当重叠。因此，应形成相应的圈闭场。为了实现这一目标，采用边界元法计算了射频多极阱的高精度电势和由此产生的有效捕获电势。这些计算用于评估缺陷和优化场的几何形状。为此，将复杂场简化为一组小的多极膨胀系数。这些系数的理想值可以通过CAD设计中实际疏水阀尺寸的系统变化来满足。本文讨论了线性四极对位误差的影响、光学开放保罗阱的优化、转向电极（端电极和环电极）对22极离子阱的影响以及微运动对离子阱中最低可达温度的影响。(C) 2016 Elsevier Inc.版权所有。
Radio-frequency (rf) traps are ideal places to store cold ions for spectroscopic experiments. Specific multipole configurations are suited best for different applications but have to be modified to allow e.g. for a proper overlap of a laser beam waist with the ion cloud. Therefore the corresponding trapping fields should be shaped accordingly. To achieve this goal highly accurate electrical potentials of rf multipole traps and the resulting effective trapping potentials are calculated using the boundary element method (BEM). These calculations are used to evaluate imperfections and to optimize the field geometry. For that purpose the complex fields are reduced to a small set of multipole expansion coefficients. Desirable values for these coefficients are met by systematic changes of real trap dimensions from CAD designs. The effect of misalignment of a linear quadrupole, the optimization of an optically open Paul trap, the influence of steering electrodes (end electrode and ring electrode) on a 22-pole ion trap and the effect of the micro motion on the lowest reachable temperatures in such a trap are discussed. (C) 2016 Elsevier Inc. All rights reserved.