Elastic scattering of low-energy electrons by a uranium atom: reliability of theoretical predictions of based on a model description

摘要

We used the method of phase functions to solve the radial relativistic Dirac equation and nonrelativistic Schroedinger equation. With these solutions, we investigated the elastic scattering of slow electrons by a uranium atom, and obtained numerical values for the total cross section and elastic scattering phases. In order to check the correctness of the results found from the method of phase functions, in all cases we also solved the Dirac and Schroedinger equations by direct numerical integration. Several types of polarization and exchange potentials were used to simulate the scattering process. We conclude that the strong dependence of the cross section for elastic scattering of an electron by uranium on the shape of the effective potential of the latter at small kinetic energies (Ek < 5 eV) makes it impossible to predict the presence or absence of a Ramsauer effect reliably.