Excitation cross sections and polarization of impact radiation inBe+-Mg+—He-Ne high-energy collisions: A comparison of model potential calculations

Cross sections and polarization of impact radiation have been calculated for the excitation of ${\mathrm{Be}}^{+}\mathrm{}\left(2s\right)\mathrm{}$ and ${\mathrm{Mg}}^{+}\mathrm{}\left(3s\right)\mathrm{}$ ions in collisions with ground-state He and Ne atom targets in the energy range $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=0.5-100\mathrm{}$ keV. Each ion-atom pair has been treated as a quasi-one-electron three-particle system consisting of the valence electron of the ion, the closed-shell ion core, and the closed-shell rare-gas atom. The interactions among these three have been represented by model potentials. Charge transfer and excitation of the rare-gas target atoms are neglected. We have obtained three- and seven-state (in the case of ${\mathrm{Mg}}^{+}$) close-coupling solutions to the impact-parameter equations, assuming a rectilinear trajectory for the motion of the two heavy particles. Comparisons are made of theoretical predictions based on two Bottcher-type model potentials ($V_{B1\mathrm{}}$ and $V_{B2\mathrm{}}$) and the simple Hartree-Fock frozen-core potential ($V_{\mathrm{HF}}$) for the electron-rare-gas interaction. The predictions based on $V_{\mathrm{HF}}$ agree better with experimental results than do those based on $V_{B1\mathrm{}}$ or $V_{B2\mathrm{}}$, especially in the case of ${\mathrm{Be}}^{+}$-${\mathrm{Mg}}^{+}$-He collisions.