Study of state-selective single-electron capture in slow Ne ⁷⁺ colliding with He and H ₂ target

Using the cold target recoil-ion momentum spectroscopy, we measured the state-selective single electron capture in collisions of 3.5–6.3 keV u −1 Ne 7+ ions and He and H 2 . The Q -value spectra and angular distributions as a function of the projectile incident energy were obtained. The results show that the single electron capture into n = 4 states is the dominant reaction channel for the Ne 7+ -He system, while the capture into n = 4 and n = 5 states both are dominant processes for the Ne 7+ -H 2 system. The molecular coulombic barrier model and the potential energy curves can qualitatively explain the measured state populations for both systems.