Differential cross sections ͑DCSs͒ for elastic scattering of electrons from pyrimidine ͑C 4 H 4 N 2 ͒ are presented for incident energies from 50 to 300 eV. The measurements were performed using a cross beam technique, for scattering angles from 20°to 110°. The relative DCSs were measured as a function of both the angle and incident energy and the absolute DCSs were determined using the relative flow method. The calculations of electron interaction cross sections are based on a corrected form of the independent-atom method, known as the screen corrected additivity rule procedure and using an improved quasifree absorption model. Calculated results agree very well with the experiment.

The experimental and theoretical studies of elastic electron scattering by calcium atom have been made. The experimental investigation was carried out using a crossed electron-atom beam technique. The measurements were performed at electron-impact energies (E0) of 10, 20, 40, 60 and 100 eV and for a range of scattering angles (θ) from 10° up to 150°. The absolute differential cross sections (DCSs) have been obtained from the elastic-to-inelastic (the resonant 41P0 state) intensity ratio at θ = 10° at each E0. Calculations have been performed in the optical potential approximation for the same E0 and θ between 0° and 180°. Results for DCSs and integrated (integral, momentum transfer and viscosity) cross sections are presented and compared with those predicted by existing calculations.

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The position of the critical minimum in elastic electron–krypton scattering at intermediate electron energies was investigated. Differential cross sections (DCSs) were measured as a function of both incident electron energy (100–260 eV) and scattering angle (30–110°), in small steps around the critical minimum. The energy dependence of the angular positions of DCS minima were determined. Also, the positions of minima in energy-dependent DCSs were obtained at several fixed scattering angles close to the critical value. The position of the critical minimum was determined to be at 187.9 ± 0.5 eV and 83.0° ± 0.2°. However, the strong dependence of critical energy on small changes of critical angle was found. The obtained results are compared with the most recent theoretical calculations.

Differential ͑DCS͒, integral ͑Q I ͒, momentum transfer ͑Q M ͒, and viscosity ͑Q V ͒ cross sections are obtained both experimentally and theoretically for elastic electron scattering by lead atoms in the energy range from 10 to 100 eV. The experiment is performed using an electron spectrometer with crossed electron and atom-beam arrangement. The relative DCS measurements are placed on an absolute scale using measured elastic-to-inelastic intensity ratios and the absolute DCS of the 6p7s 3 P 1 state ͓S. Milisavljević, M. S. Rabasović, D. Šević, V. Pejčev, D. M. Filipović, L. Phys. Rev. A 76, 022714 ͑2007͔͒ at a scattering angle of 10°for incident energies of 40, 60, 80, and 100 eV and at 30°for 10 and 20 eV. Corresponding theoretical results are obtained from a relativistic approach based on solving the Dirac equation using Hartree-Fock and Dirac-Fock wave functions to calculate cross sections at all the energies measured. Comparisons between the present experiment and theory, as well as comparisons with other available results, have been made.