State‐selective single‐electron capture in 30‐keV N 3+ –He collisions

• Published in: X-ray spectrometry 2020-01, Vol.49 (1), p.85-89
• Main Authors: Xu, Jiawei, Zhu, Xiaolong, Feng, Wentian, Zhao, Dongmei, Huang, Weizhe, Guo, Dalong, Gao, Yong, Zhang, Shaofeng, Shan, Xu, Chen, Xiangjun, Ma, Xinwen
• Format: Article
• Language: English
• ISSN: 0049-8246; 1097-4539
• DOI: 10.1002/xrs.3059

The cold‐target recoil‐ion momentum spectroscopy has been employed to study the single‐electron‐capture processes in collisions of N 3+ ions with He atoms at an impact energy of 30 keV. From the longitudinal momentum spectrum of recoil ions, the different electronic configuration was identified, and the metastable projectile ions were distinguished. For the ground‐state N 3+ (2s 2 1 S) projectile, the single‐electron capture into the N 2+ (2s 2 2p 2 P) state is the dominant reaction channel, whereas for the metastable‐state N 3+ (2s2p 3 P) projectile, the single‐electron capture into the N 2+ (2s2p 2 2 D) state is the main reaction channel. The fraction of the metastable‐state N 3+ (2s2p 3 P) of the incident projectile beam is about 46%. The relative differential cross sections for the capture to different orbitals of N 3+ ions are obtained and are compared with other experiments at low energy and the predictions of the classical over‐the‐barrier model.