Cross sections for ionization-excitation, double excitation, excitation and ionization of helium by charged particle impact

The most comprehensive study of extreme ultraviolet(EUV) and electron emission cross sections for one and two electron processes in Helium induced by negative and positive charged particle impact is presented. The study of such two electron transitions is of fundamental importance to the understanding of few body dynamics, and He is the simplest test case for the investigation of electron correlation effects in few body Coulomb systems. The technique of high resolution EUV radiation and electron spectroscopy has been applied to elucidate the many electron processes in ionization - excitation, double excitation, excitation and ionization of He. Specifically, the measurement of absolute EUV photon and electron emission cross sections may allow the authors to develop a more comprehensive formulation of few-body atomic processes. Some important applications in which those few electron transitions can occur are plasma dynamics, fusion energy research and astrophysical processes