Classical binary-encounter calculations of ionization by heavy charged projectiles

Classical binary-encounter calculations have been performed for the K-shell ionization cross section of Al and Ni target atoms by ¹₁H, ⁴₂He and ⁷₃Li projectiles. The binding-energy correction due to the interaction of the projectile with target K electrons has been incorporated along with the correction due to Coulomb repulsion. It is found that the simple BEA theory can account for the experimentally observed deviation of the cross section from a Z²₁ dependence.