MUTUAL ELECTRON-ION INTERACTIONS IN ELECTRON-IMPACT IONIZATION OF A CA BEAM

We evaluate the role of electron-ion mutual interactions as a possible source of systematic errors in an experiment of electron impact ioniz ation and excitation of an effusive Ca beam. By monitoring photons res ulting from the impact excitation of a Ca resonant transition, the tra nsmitted electron beam current by a sectored Faraday cup and total ion yields, we extract information about elementary processes responsible for ionization. We show that our diagnosis allows us to monitor the i nfluence of the produced ionization on the elementary processes and on the density profile of the electron beam.