Electron-impact ionization of the Si atom

Abstract

Electron-impact ionization cross sections are calculated for the ground configuration of the Si atom for application in erosion diagnostics of plasma facing components in magnetically confined fusion experiments. The single ionization cross sections include contributions from outer subshell direct ionization and excitation-autoionization. The dominant direct ionization cross sections are calculated using a non-perturbative time-dependent close-coupling method. A significant reduction in the direct ionization cross section is found when compared to perturbative distorted-wave results. The theoretical cross sections are compared with available crossed-beams measurements.

Multicenter continuum-distorted-wave eikonal-initial-state description of the electron-impact ionization of aligned H2 molecules

“…From a theoretical point of view, we can distinguish the applied methods in two families: numerically intensive and perturbative treatments. While the former are nowadays considered capable to accurately reproduce the reported experimental cross sections at different collision geometries for simple atoms like H and He [14][15][16] and have been lately implemented for more complex atomic targets [17,18], their extension to complex molecular targets is not so straightforward, even when the problem is simplified to a one electron treatment [19]. In contrast, distorted wave methods have proved to lead to acceptable results regarding simple targets like H, He and Ar [20][21][22][23][24][25][26], and can be in principle extended to deal with complex molecular targets at a considerably inferior computational cost.…”