Electron-ion collisions

This discussion concentrates on basic physics aspects of inelastic processes of excitation, ionization, and recombination that occur during electron-ion collisions. Plasma, ion trap, and electron-ion beam experimental approaches are reviewed, and the Electron Beam Ion Source (EBIS), crossed beam arrangement used for multicharged ions at Oak Ridge, the crossed beam arrangement used for multicharged ions at Giessen, and the inclined beams arrangement used at Harvard-Smithsonian are schematicized. Current experimental insights on electron impact excitations of ions, on electron impact ionization of highly charged ions, and on dielectronic recombination are given