Li(2p <- 2s) excitation by impact of slow ions

We present a systematic experimental and theoretical study of Li(2p <- 2s) excitation by impact of slow (ν ≤ 1 au) singly and multiply charged ions. In particular, the scaling behaviour of excitation cross sections σLi1 with projectile ion charge state q is investigated. Due to the dominance of competing electron capture channels at low impact energies E, the excitation cross sections deviate significantly from a commonly applied σ/q=f(E/q) cross section scaling relation. (author)