Elastic scattering of slow electrons by calcium atoms into an angular range depending on the collision energy

The use of trochoidal and hypocycloidal spectrometers that are applied in modern experimental techniques for studying processes of electron scattering by atoms, ions, and surfaces is considered in some detail. The angular range of the collection of scattered electrons is determined by the operation mode of the spectrometer and depends on the collision energy. To analyze the structure of the measured energy dependence S(E), an analytical formalism reflecting both resonance and nonresonance features of low-energy scattering was used. A theoretical analysis of elastic scattering of slow (to 2 eV) electrons by Ca atoms permitted the interpretation of the observed structure of S(E) as a manifestation of the D-2 shape resonance. A comparison of the theoretical values of the S(E) function with the total and differential scattering cross sections was performed. (C) 2001 MAIK "Nauka/Interperiodica".