Electron impact double ionisation of Ca and Sr

Abstract
Electron impact double ionisation cross sections for Ca and Sr have been calculated in the modified binary encounter model. Contributions of inner-shell ionisation and Auger emission have been included in the calculations. The calculated cross sections are in good agreement with the experimental observations of McFarland (1968) and Okudaira (1970). The probable reasons behind the discrepancies observed between the experiments and the calculated cross sections have been discussed.