Electron-capture cross sections from He in collision with bare nuclear ions

Abstract

The unitarized distorted-wave approximation (UDWA) is applied to single-electron-capture processes in the collision of naked ions with a helium atom, $B+\mathrm{He}(1{s}^{2})\ensuremath{\rightarrow}(B+e)+{\mathrm{He}}^{+}(1s)$, where $B={\mathrm{H}}^{+}, {\mathrm{Li}}^{3+}, {\mathrm{Be}}^{4+}, {\mathrm{C}}^{6+}, \mathrm{and} {\mathrm{O}}^{8+}$. We use the independent-electron model, in which the electron is assumed to move in an averaged Coulomb potential field with an effective nuclear charge. The UDWA cross section becomes more reliable as the charge of the incident ion increases, and good agreement with experimental data is obtained down to a few keV/amu for ${\mathrm{O}}^{8+}$+He.