Merged-beams measurements of electron-capture cross sections forO5++H at electron-volt energies

Absolute total cross-section measurements are presented for electron capture in ${\mathrm{O}}^{5+}$+H(D) collisions over the energy range 0.9–800 eV/amu. These are the first experimental data to be reported using a new multicharged-ion–atom merged-beams apparatus developed at Oak Ridge National Laboratory. The experimental method and the cross-section measurements are described in detail. At energies below 2 eV/amu, the data show a cross-section enhancement which may be attributed to the ion-induced dipole attraction between the reactants. Agreement with recent unpublished quantum-mechanical calculations ranges from fair at the lower energies to excellent at the higher energies.