Electron-impact excitation of atoms or ions with the screened Coulomb potential

Abstract

This paper reports the development of a novel distorted wave approach based on the relativistic configuration interaction theory for calculating atomic structures, radiative properties, and collision dynamics of atoms or ions under external confinement. Due to its physical interpretations, the Hulthén potential, valid for many important areas (widely plasma environments) in physics and chemistry, such as atomic physics, solid-state physics, nuclear physics, particle physics, and astrophysics, is used to include the effect of plasma background. The Breit interaction and quantum electromagnetic dynamics effects are perturbatively included in the multi-electron Hamiltonian. Wave functions of bound and continuous states are obtained, which are analyzed by means of the Dirac equations. Interparticle interactions in the scattering matrix element of the system are described by the screened Coulomb interactions. As a test desk, the present approach is applied to the calculation of atomic structures and collision dynamics of an exemplary He-like S14+ ion embedded in a plasma. The energy eigenvalues, transition probabilities, and excitation cross sections are analyzed in detail in terms of the screening parameter. The results of the verification cases are compared to references from the literature, which show a good agreement. The present study not only opens up an opportunity to provide a simple and effective way for understanding the plasma shielding models for many-electron systems but also has important implications for a wide range of applications in astrophysics and laboratory plasma experiments.