Population distribution subsequent to charge exchange of 29.85 keV Ni+ on sodium vapor

Abstract The population of low-energy metastable states in Ni I subsequent to charge-exchange reactions and cascade decay was studied for 29.85 keV Ni ions impinging on a sodium vapor. The charge-exchange cross sections were calculated using a semi-classic time-dependent perturbation theory and redistribution of the population via rapid spontaneous decays was simulated. Collinear laser spectroscopy experiments were performed on four emission lines in Ni I to determine populations in low-energy metastable states: 3 d 9 4 s 3 D 3 (204.787 cm − 1 ), 3 d 9 4 s 3 D 2 (879.816 cm − 1 ), 3 d 9 4 s 3 D 1 (1713.087 cm − 1 ) and 3 d 9 4 s 1 D 2 (3409.937 cm − 1 ). Fair agreement was obtained between the simulation and experimental results. The low-energy metastable states were preferentially populated after the cascade decay in contrast to weak populations in near-resonant high-energy states in Ni I.