Design and characterization of a velocity-map imaging apparatus for low-energy photo-ion spectroscopy using magneto-optically trapped atoms

Feng Fang; Wenchang Zhou; Yufan Li; Dongbin Qian; Changjie Luo; Dongmei Zhao; Xinwen Ma; Jie Yang

doi:10.1063/5.0033595

Design and characterization of a velocity-map imaging apparatus for low-energy photo-ion spectroscopy using magneto-optically trapped atoms

Rev Sci Instrum. 2021 Apr 1;92(4):043103. doi: 10.1063/5.0033595.

Authors

Feng Fang¹, Wenchang Zhou¹, Yufan Li², Dongbin Qian¹, Changjie Luo¹, Dongmei Zhao¹, Xinwen Ma¹, Jie Yang¹

Affiliations

¹ Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
² School of Physics and Electrical Engineering, Anyang Normal University, Anyang 455000, China.

PMID: 34243435
DOI: 10.1063/5.0033595

Abstract

We present a velocity-map imaging (VMI) apparatus coupled with a magneto-optical trap (MOT) of ⁸⁷Rb atoms designed for low-energy photo-ion spectroscopy. The VMI-electrode geometry uses a three-electrode configuration, and the focusing electric field is optimized based on systematic simulations of relatively low-energy ions. To calibrate the apparatus, we use resonant two-color two-photon ionization of rubidium atoms as Doppler-selected ions. This VMI system provides an accuracy of 0.15 m/s and a resolution of 7.5 m/s for photoions with speeds below 100 m/s. Finally, details of the design, construction, and testing of the VMI-MOT system are presented.