Multistage Zeeman decelerator for molecular-scattering studies
Multistage Zeeman decelerator for molecular-scattering studies
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DOI：
10.1103/physreva.95.043415
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发表时间：
2017-04-19
影响因子：
2.9
通讯作者：
van de Meerakker, Sebastiaan Y. T.
中科院分区：
文献类型：
--
作者：
Cremers, Theo;Chefdeville, Simon;van de Meerakker, Sebastiaan Y. T.
我们提出了多级塞曼减速器的概念，该减速器特别针对分子束散射实验的应用进行了优化。减速器由一系列交替的六极和螺线管组成，有效地分离了减速器的横向聚焦和纵向减速特性。它可以在减速和加速模式下运行，也可以在混合模式下运行，使粒子束能够以恒定速度引导粒子束通过减速器。减速具有相位稳定性，具有较大的六维相空间接受度。分离的聚焦和减速元件导致这种接受度在纵向和横向之间的分配不均匀。这在散射实验中是理想的，通常受益于较大的纵向接受度和较窄的横向分布。我们使用塞曼减速器成功地实现了这一概念，该减速器由25个六极和24个螺线管组成的阵列组成。用亚稳态氦原子束(S-3)表征了减速器在加速、减速和引导模式下的性能。对于初始速度为520m/S的He原子，消除了高达60%的动能。六极由永久磁铁组成，而螺线管是由单个中空的铜毛细管产生的，冷却液通过它。螺线管设计具有优异的热性能，并允许使用容易获得且价格低廉的电子元件来使高电流通过螺线管。这里展示的塞曼减速器在机械上很容易制造，可以用经济实惠的电子设备操作，并且可以以高达10赫兹的重复频率运行。
We present a concept for a multistage Zeeman decelerator that is optimized particularly for applications in molecular beam scattering experiments. The decelerator consists of a series of alternating hexapoles and solenoids, that effectively decouple the transverse focusing and longitudinal deceleration properties of the decelerator. It can be operated in a deceleration and acceleration mode, as well as in a hybrid mode that makes it possible to guide a particle beam through the decelerator at constant speed. The deceleration features phase stability, with a relatively large six-dimensional phase-space acceptance. The separated focusing and deceleration elements result in an unequal partitioning of this acceptance between the longitudinal and transverse directions. This is ideal in scattering experiments, which typically benefit from a large longitudinal acceptance combined with narrow transverse distributions. We demonstrate the successful experimental implementation of this concept using a Zeeman decelerator consisting of an array of 25 hexapoles and 24 solenoids. The performance of the decelerator in acceleration, deceleration, and guiding modes is characterized using beams of metastable helium (S-3) atoms. Up to 60% of the kinetic energy was removed for He atoms that have an initial velocity of 520 m/s. The hexapoles consist of permanent magnets, whereas the solenoids are produced from a single hollow copper capillary through which cooling liquid is passed. The solenoid design allows for excellent thermal properties and enables the use of readily available and cheap electronics components to pulse high currents through the solenoids. The Zeeman decelerator demonstrated here is mechanically easy to build, can be operated with cost-effective electronics, and can run at repetition rates up to 10 Hz.