Theory of positronium formation with surface electrons for realistic band structures

Abstract

The energy and angular distributions of positroniums (Ps) formed at surfaces are calculated numerically using the integro-differential equation which appears in the dynamical theory of Ps formation based on the semiclassical trajectory approximation. The wide-band approximation, which is well known in the theory of neutralization of surface-scattered ions, is not adequate for the Ps formation. Strong deviation from the Born approximation is pointed out in the case of narrow-band electrons.