COMPARATIVE-STUDY OF ELASTIC-SCATTERING OF LOW-ENERGY ELECTRONS, POSITRONS AND PROTONS IN SOLIDS

The differential cross section (DCS) and total cross section (TCS) for elastic scattering of 0.1 eV-1 keV electrons, positrons and protons by atoms bound in solids (Z = 3-82) are calculated using the partial wave expansion technique. The DCS for low-energy positrons decreases in the forward direction due to the cancellation of the electrostatic interaction by the polarization of the atom. This cancellation effect for positrons results in a much smaller TCS than that for electrons at low energy, whereas, at high energy, they are close to each other due to dominant electrostatic interaction. The DCS for protons shows a strong forward scattering. This results in a TCS much greater than that for positrons, whereas, for large angles, the DCS is equal to that of positrons (except for very low energy).