ELECTRON-ATOM COLLISIONS IN EIKONAL APPROXIMATION

Abstract

The work reported in the thesis contains the results of the author's attempt to study the scattering of intermediate and high energy electrons by simple atomic and ionic targets. The eikonal approximation has been used as the main tool in this investigation. The first chapter of the thesis gives a brief review of quantal and semi-classical scattering theories. Chapter 2 deals with the study of elastic and inelastic scattering, of electrons by helium atom based on the Glauber eikonal series (GES). In GES the Glauber scattering amplitude is expanded in the reciprocal powers of kit the wave number of the incident electron, for fixed momentum transfer. For the intermediate and high incident energies, where ki is large, it is expected that only first few terms of GES will give a good representat-ion of the conventional Glauber scattering amplitude. We have obtained the first three terms of GES in closed form, both for elastic and inelastic scattering of electrons from helium. It is found that the inclusion of only the first three terms in GES method gives a good representation of the Glauber-elastic differential cross section, whereas it does not yield a good representation for the inelastic transition (11S-21s). It is seen that in the case of inelastic scattering the third term, 1f31, is greater than the second term of the series, If21, and consequently the expansion does not converge.