Multiple-ionisation cross sections for highly stripped ions colliding with He, Ne and Ar

The classical-trajectory Monte Carlo method has been used to calculate the multiple-ionisation cross sections for 1 MeV amu -1 collisions of highly stripped ions in charge states q=2-20 with He, Ne and Ar targets. An independent-electron model was used to represent the rare-gas targets. For the highest charge state studied (q=20), the cross section for removing all the outer-shell electrons from Ne or Ar is approximately 2*10 -16 cm 2 , whereas the cross section for removing both electrons from He is approximately 1*10 -15 cm 2 . The calculated values are consistent with experimental observations of the cross section for the total number of electrons ejected from the target.