Knowledge of particle interaction with gaseous and dense material: the behaviour of secondary electrons

The behaviour of secondary electrons generated by ionising radiation is described, with emphasis on the basic mechanisms involved in their interactions with matter. Among these mechanisms, electron resonances (i.e. transient negative ions) are found to play a dominant role in energy losses to vibrational and electronic excitations and in molecular dissociation. It is shown, with specific examples, that the magnitude of these processes is dependent on local molecular environment. (author)