Dulitz Katrin, Motsch Michael, Vanhaecke Nicolas, Softley Timothy P
Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland.
J Chem Phys. 2014 Mar 14;140(10):104201. doi: 10.1063/1.4866906.
Zeeman deceleration is an experimental technique in which inhomogeneous, time-dependent magnetic fields generated inside an array of solenoid coils are used to manipulate the velocity of a supersonic beam. A 12-stage Zeeman decelerator has been built and characterized using hydrogen atoms as a test system. The instrument has several original features including the possibility to replace each deceleration coil individually. In this article, we give a detailed description of the experimental setup, and illustrate its performance. We demonstrate that the overall acceptance in a Zeeman decelerator can be significantly increased with only minor changes to the setup itself. This is achieved by applying a rather low, anti-parallel magnetic field in one of the solenoid coils that forms a temporally varying quadrupole field, and improves particle confinement in the transverse direction. The results are reproduced by three-dimensional numerical particle trajectory simulations thus allowing for a rigorous analysis of the experimental data. The findings suggest the use of a modified coil configuration to improve transverse focusing during the deceleration process.
塞曼减速是一种实验技术，其中利用螺线管线圈阵列内部产生的非均匀、随时间变化的磁场来操纵超声速束流的速度。已经构建了一台12级塞曼减速器，并以氢原子作为测试系统对其进行了表征。该仪器具有几个独特的特点，包括可以单独更换每个减速线圈。在本文中，我们详细描述了实验装置，并展示了其性能。我们证明，只需对装置本身进行微小改动，塞曼减速器的整体接受度就能显著提高。这是通过在构成随时间变化的四极场的一个螺线管线圈中施加相当低的反平行磁场来实现的，从而改善了粒子在横向的限制。通过三维数值粒子轨迹模拟再现了结果，从而能够对实验数据进行严格分析。研究结果表明，可以使用改进的线圈配置来改善减速过程中的横向聚焦。
