The identification of low energy K and Ca + autoionizing levels observed in electron impact experiments

The ejected electron spectra of K and Ca vapours following electron impact excitation of the 3p-subshell have been compared with Hartree–Fock calculations. Most K ɪ and Ca ɪɪ 3p 5 3d 4s levels have been identified, albeit tentatively in many cases. A detailed analysis of low energy K ɪ lines is presented, including some minor changes to earlier assignments of photo-absorption lines. A good general description of the low energy ejected electron spectrum of Ca has also been achieved, almost exclusively in terms of autoionization of Ca ɪɪ levels.