ELASTIC-SCATTERING OF ELECTRONS AND POSITRONS BY BOUND GALLIUM AND ARSENIC ATOMS

Elastic differential and total cross sections for positrons, from 5 eV to 10 keV, and for electrons, from 50 eV to 10 keV, scattered by bound gallium and arsenic atoms have been calculated using the method of partial waves. The optical potential consists of a static potential, a Buckingham-type polarization potential, and the Mittleman-Watson exchange potential (for electrons). Low-order partial wave phase shifts are computed by numerical integration of the radial part of the Schrodinger equation. For higher orders, a closed analytic expression is obtained in the first Born approximation for the phase shifts. The calculated total cross sections are parametrized in terms of the screened Rutherford cross section to be used in Monte Carlo transport codes.