Velocity selection of Rydberg positronium using a curved electrostatic guide
Velocity selection of Rydberg positronium using a curved electrostatic guide
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DOI：
10.1103/physreva.95.053409
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发表时间：
2017-05
影响因子：
2.9
通讯作者：
A. Alonso;B. Cooper;A. Deller;S. Hogan;L. Gurung;D. Cassidy
中科院分区：
文献类型：
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作者：
A. Alonso;B. Cooper;A. Deller;S. Hogan;L. Gurung;D. Cassidy
我们报告了使用弯曲静电四极杆波导通过速度选择产生慢里德伯正电子（Ps）束的实验。通过均匀电场中的双色光激发过程制备了主量子数n=14的Rydberg-Stark态Ps原子。低场寻找斯塔克态是在 0.6 米长的四极杆导向器（包括 45° 弯曲）的入口处产生的，并通过其湮没 γ 辐射在导向器的末端检测到。进入导向器的原子的平均速度（动能）估计为约 180 km s−1 (185 meV)，而被导向原子的平均纵向速度通过飞行时间测量，发现为约 90 km s−1，相当于 45 meV 的动能。测量的输运数据与蒙特卡罗模拟基本一致，蒙特卡罗模拟也用于确定我们描述的布置可用于执行 Ps 原子散射测量的功效。
We report experiments in which a slow Rydberg positronium (Ps) beam was produced by velocity selection using a curved electrostatic quadrupole guide. Ps atoms in Rydberg-Stark states with principal quantum number n = 14 were prepared by a two-color optical excitation process in a uniform electric field. Low-field-seeking Stark states were produced at the entrance of a 0.6-m-long quadrupole guide that includes a 45◦ bend, and were detected at the end of the guide via their annihilation γ radiation. The mean speed (kinetic energy) of atoms entering the guide was estimated to be ≈180 km s−1 (185 meV), whereas the mean longitudinal speed of guided atoms was measured via time of flight and found to be ≈90 km s−1, equivalent to a kinetic energy of 45 meV. The measured transport data are in broad agreement with Monte Carlo simulations, which are also used to establish the efficacy with which the arrangement we describe could be used to perform Ps-atom scattering measurements.