NONSTATIONARY THEORY OF WAVE-PACKET POTENTIAL SCATTERING

Potential scattering of free-electron wave packets is considered in th e framework of the nonstationary quantum-mechanical theory. To charact erize the efficiency of this process, the average angle of scattering is calculated in the lowest (first and second) orders of perturbation theory in the potential. In the approximation of a well-localized, nar row, and nonspreading wave packet, the first-order term is shown to ag ree with the classical angle of scattering, linear in the potential. T his term is shown to vanish at a very large size of the initial wave p acket (much larger than the size of a target). An analogy between the potential scattering of wave packets and electron-light ponderomotive scattering is discussed. [S1050-2947(98)01608-4]