Differential cross sections for the elastic scattering of electrons by helium atoms

Abstract

The differential cross sections for the elastic scattering of 100-500 eV electrons by helium atoms are calculated in the plane wave approximation. The interaction potential consists of the first order static potential and the second order adiabatic and non-adiabatic polarization potentials. An alternative derivation of the asymptotic value of the non-adiabatic potential is presented and the second order scattering amplitude is compared with the second Born amplitude. In the calculation of differential cross sections the effect of exchange is included by employing the Ochkur approximation and terms up to only third order in the interaction energy are retained. The cross sections are within 15% of the experimental values. Similar agreement is obtained with more sophisticated calculations.