Identification and characterization of the dielectronic process in the formation of two K-shell vacancies in atomic Li by fast electron impact
Résumé
Electron correlation effects in the production of two K-shell vacancies in lithium are investigated by bombarding atomic Li with 5-keV electrons. High-resolution Auger electron spectra show that discrete doubly vacant K-shell states are predominantly formed from ionization plus excitation, giving rise to the 2sns 1,3S and 2snp 1,3P states of Li+. For these fast electron projectiles, the shake-up and dielectronic manifestations of the electron-electron interaction are shown to be the only mechanisms for creating the observed hollow states. The formation of the 2snp 1,3P states is found to be mediated only by the dielectronic process, permitting this aspect of the electron-electron interaction to be separately identified and its contribution characterized.