The elastic scattering of fast electrons and positrons by hydrogen and helium atoms

Abstract

A simplification of the second Born approximation due to Massey & Mohr is used to calculate the differential cross-sections for the elastic scattering of fast electrons and fast positrons by hydrogen atoms and helium atoms, the method of Dalitz being applied to evaluate all the relevant integrals. Although the logarithmic singularity which is found in the differential cross-section for zero-angle scattering is shown to be absent in the true second Born approximation the use of the simplification of this approximation is justified at sufficiently high impact energies provided the angle of scattering is not too small. The results of the calculations for incident electrons in helium are compared with the available experimental data.