Regular Article – Atomic and Molecular Collisions
Relativistic excitation of Krypton gas atoms by electrons moving through a complex distortion potential
Department of Physics, Kenyatta University, Nairobi, Kenya
Accepted: 5 July 2021
Published online: 17 August 2021
We present relativistic distorted-wave results for the excitation of the lowest resonance states of krypton gas in which the free incident electron is distorted by a complex potential consisting of electrostatic, exchange, polarization and absorption terms. Krypton atom wave functions are constructed in the multi-configuration Dirac Fork approach by modifying the general-purpose relativistic atomic structure code GRASP. We further used the Wentzel–Kramers–Brillouin (WKB) approximation to calculate the free continuum electron wave functions used in computing the differential and integral scattering cross sections, using our program RDWBA1. It is found that the inclusion of the absorption potential has negligible effect on the krypton cross sections results in the energy range from excitation threshold to about 100 eV electron impact energy, thereafter giving slightly lower cross sections as compared to those obtained using a real distortion potential. Present cross section results also indicate that it is the energy dependent polarization potential adopted in this work that plays a major role in improving shapes of cross-sections at low impact energies where available theoretical methods fail to predict accurate results.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021