Elastic scattering of electrons and positrons by complex atoms at intermediate energies

The elastic scattering of fast electrons and positrons by complex atoms is analyzed by using the basic ideas of the eikonal-Born series method within the framework of the optical-model formalism. This approach allows us to derive from first principles a local second-order pseudopotential which in addition to the static interaction also accounts for polarization, absorption, and exchange effects. A full wave treatment of this pseudopotential is then performed. Our ab initio optical-model theory is illustrated by a detailed analysis of the elastic scattering of electrons and positrons by helium and neon atoms for incident energies ranging from 100 to 700 eV. Our theoretical values for electron-helium and electron-neon differential cross sections are in excellent agreement with recent absolute experimental data. © 1977 The American Physical Society.SCOPUS: ar.j