Collisions of excited states and ionized media

Abstract

The importance of the field is underlined. Essentially two classes of collisions are considered: bound-bound and bound-free transitions. In the first category, emphasis is put on transfer of excitation. Methods and results are reported, it is shown that electronic energy is more easily transferred during the collision of high excited states than of low excited stated. Explanation for this behaviour is given. The second category deals with ionization processes. Good agreement is obtained between theory and experiment for Penning and associative ionization processes. Different experimental methods used are described, they have contributed to deduce important data concerning probability of transition and potential curves. The last part is devoted to the collision of two excited states (metastables). The results obtained with the help of an afterglow technique seem to clear the way to various measurements concerning excited state chemistry.