2026-06-16 中国科学院（CAS）
＜関連情報＞
- https://english.cas.cn/newsroom/research-news/202606/t20260617_1170118.shtml
- https://iopscience.iop.org/article/10.3847/1538-4365/ae690d
6.43–42.86 keVのu −1 14N6とHeの衝突における状態選択的電荷交換 State-selective Charge Exchange in the 6.43–42.86 keV u−1 14N6 Collision with He
R. T. Zhang, X. B. Zhu, L. Liu, C. J. Zhang, Y. Zhou, G. Y. Liang, L. Gu, S. Mitrani, K. Hansen, B. R. Lamichhane,…
The Astrophysical Journal supplement Series Published: 2026 June 8
DOI:10.3847/1538-4365/ae690d
Abstract
The charge-exchange (CX) reaction between highly charged ions from coronal mass ejections and neutrals in Earth’s magnetosphere provides key diagnostics for understanding the dynamics of the Sun–Earth space environment. However, the accuracy of current astrophysical laboratory modeling is affected by the limited availability of reliable state-selective CX cross sections. Here, using a high-resolution cold-target recoil-ion momentum spectroscopy apparatus, we present experimental measurements of state-selective single CX and double CX between 14N6+ ions and He atoms in the collision energy range from 6.43 to 42.86 keV u−1. For the single CX, we obtain the principal quantum number n-resolved fractions for electron transfer from He atoms to the n = 3, 4, 5, and ≥6 levels of 14N5+ ions. The semiclassical two-center atomic-orbital close-coupling calculations show good agreement with the experimentally obtained fractions for these state-selective electron capture processes. For double CX processes, we find that autoionizing double-electron capture populating doubly excited states of 14N4+ (1s2ℓnℓ) with n = 2, 3, 4, 1s2ℓnℓ (n ≥ 5), and 1s3ℓnℓ (n ≥ 4) dominates over true double-electron capture populating doubly excited states of 1s2ℓ3ℓ, 1s2ℓ4ℓ, and 1s2ℓnℓ (n ≥ 5) levels of 14N4+ ions. The results provide experimental benchmarks for theoretical calculations, which are useful for quantifying the abundances of N5+ and N6+ ions in coronal mass ejection events.
