Electron transfer processes in collisions of relativistic ions with atoms

The main processes occurring to a relativistic ion colliding with an atom are the radiative and the non-radiative electron capture into the vacant states of the ion and the stripping (ionization) of electrons from the ion. A brief review of these processes is given separately for the heavy and for the light ions. The results of recent experiments at the RCNP Osaka on the electron capture to He++ projectiles and the stripping of electron from He+ ions are presented. The astrophysical relevance of this information is discussed. (author)