Effect of Collisional De-Excitations on the Alignment of the 2p53s 3P1 Level of Neon-like Germanium Ion

Abstract

The alignment of the 2p53s 3P1 level of neon-like germanium ion excited by impact with an unpolarized electron beam has been theoretically studied. For high electron-beam densities, 1019–1021 cm-3, we have calculated the relative populations of the 2p53s 3P1 MJ = 0 and |MJ| = 1 magnetic sublevels allowing for direct collisional excitation from the 2p6 1S0 ground level as well as collisional de-excitations from the 2p53p 1S0, 1D2 levels. The collision strengths for the transitions between magnetic sublevels were obtained in intermediate coupling using the University-College-London distorted-wave code. The calculations were carried out for impact electron energies from 155 to 750 Ry. It is shown that the collisional de-excitation effects result in a strong decrease of the degree of alignment and can even lead to a change of sign. The reported results might have useful applications in the modeling and diagnostics of hot and dense plasmas in which beams of energetic electrons are generated.