Electron capture and excitation studied by state-resolved KLL Auger measurement in 0.25−2 MeV/u F 7+(1s 21S, 1s2s 3S) + H 2/He collisions

Abstract

State-resolved KLL Auger cross sections were measured for collisions of 0.25−2 MeV/u F 7+(1s 21S, 1s2s 3S) with H 2 and He targets at 0°. The mechanisms for forming the 1s 2/2/' and 2 s2 p 2S+1L Auger states were identified to be single electron capture, 1s → 2p excitation, and nonresonant and resonant transfer excitation (RTE) by the 1s 21S ground or 1s2s 3S metastable states of the incoming projectile ions. The cross sections for the formation of the doubly excited states were extracted and compared with theory. In particular, the 1s2s2p 4P state showed a projectile energy dependence of E P − n ( n = 4.4 ± 0.3 for He and 5.4 ± 0.3 for H 2 targets) in electron capture. The 1s2p 22D state exhibited a strong RTE signature from the ground state. The 2s2p 3P state produced by excitation of the metastable beam component showed a fair agreement with a PWBA calculation.