Theoretical cross sections for H-on-Cs ionic and neutral reactions

Potential-energy curves and coupling matrix elements have been calculated for the CsH and Cs${\mathrm{H}}^{+}$ systems. The potentials and coupling terms were employed in the coupled equations where the nuclear motion is described classically to obtain the energy dependence of the cross sections for energies 0.1-3.0 keV. The cross sections so obtained were: $Q_{+0\mathrm{}}$ for the reaction ${\mathrm{H}}^{+}$ + Cs → H + ${\mathrm{Cs}}^{+}$, $Q_{+m}$ for ${\mathrm{H}}^{+}+\mathrm{Cs}\to \mathrm{H}\mathrm{}\left(2s\right)+{\mathrm{Cs}}^{+}$, $Q_{-0\mathrm{}}$ for ${\mathrm{H}}^{-}$ + ${\mathrm{Cs}}^{+}$ → H + Cs, and $Q_{0-}$ for $\mathrm{H}\mathrm{}\left(1s\right)+\mathrm{Cs}\to {\mathrm{H}}^{-}+{\mathrm{Cs}}^{+}$. The CsH potential-energy curves were also used to estimate the ionization cross sections $Q_{\mathrm{i}\mathrm{o}\mathrm{n}-\mathrm{C}\mathrm{s}}$ for ${\mathrm{H}}^{-}+\mathrm{Cs}\to {\mathrm{H}}^{-}+{\mathrm{Cs}}^{+}+e$ and $Q_{\mathrm{i}\mathrm{o}\mathrm{n}-\mathrm{H}}$ for ${\mathrm{H}}^{-}+\mathrm{Cs}\to \mathrm{H}+\mathrm{Cs}+e$, and to yield an upper-limit cross section $Q_{m-}$ for the reaction $\mathrm{H}\mathrm{}\left(2s\right)+\mathrm{Cs}\to {\mathrm{H}}^{-}+{\mathrm{Cs}}^{+}$. Semiempirical calculations were employed to obtain the deactivation cross section $Q_{\mathrm{mg}}$ for $\mathrm{H}\mathrm{}\left(2s\right)+\mathrm{Cs}\to \mathrm{H}\mathrm{}\left(2p\right)+\mathrm{Cs}$ where the product $\mathrm{H}\mathrm{}\left(2p\right)\mathrm{}$ rapidly radiates to $\mathrm{H}\mathrm{}\left(1s\right)\mathrm{}$. At 0.5 keV the theoretical cross sections obtained were