Excitation in swift heavy ion-atom collisions

This paper presents a short overview of the most recent experimental and theoretical studies of excitation cross sections of light atoms (H or He) and two-electron heavy ions by multicharged ions and neutral atoms respectively. In both cases, at intermediate velocity, the excitation cross sections tend to saturate when the exciting partner charge increases. Nevertheless, experimental results obtained for two-electron heavy ions may not be explained as is the case for the light atoms. Multiple processes involved in Ar16+ collisions have also been extracted and results show that target electrons seem to play an active role; these need to be taken into account in the theoretical treatment of single excitation. (orig.)