The scattering of charged particles from helium and alkali atoms

The second order potentials method of Bransden and Coleman (1972) has been applied to electron impact excitation of lithium, sodium and helium atoms and to proton impact excitation of helium atoms. The calculations for the e-alkalis are presented in the impact parameter approximation in the energy range 10 - 200 ev., and in the partial wave approximation in the energy range 10-50 ev. On comparing between the two results, it is concluded that the impact parameter approximation is reliable for energies larger than 50 ev. The results for the electron and proton scattering from the helium atoms are presented in the energy range 100 - 1000 ev (kev for proton scattering).