H0+H2 and H0+O2 collisions at low kilo-electron-volt energies.

Abstract

Small-angle ${\mathrm{H}}^{0}$+${\mathrm{H}}_{2}$ and ${\mathrm{H}}^{0}$+${\mathrm{O}}_{2}$ collisions are studied at energies of 1.0, 2.0, and 3.0 keV. Time-of-flight techniques are used to identify the dominant direct scattering (\ensuremath{\rightarrow}${\mathrm{H}}^{0}$) processes. The stripping (\ensuremath{\rightarrow}${\mathrm{H}}^{+}$) and electron capture (\ensuremath{\rightarrow}${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$) channels are identified by electrostatic energy analysis. The probabilities and reduced differential cross sections for the dominant processes are determined as a function of \ensuremath{\tau} (=E\ensuremath{\theta}), the reduced scattering angle. This is found to be a useful variable for plotting the probabilities and reduced cross sections for the processes studied, since the results at the different energies generally lie on common curves. The electronically inelastic processes are found to dominate the collision for \ensuremath{\tau}>0.2 keV deg in H+${\mathrm{H}}_{2}$ and \ensuremath{\tau}>0.3 keV deg in H+${\mathrm{O}}_{2}$. The stripping process in ${\mathrm{H}}_{2}$ primarily results in ${\mathrm{H}}^{+}$+${\mathrm{H}}_{2}$(X)+${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ while the ${\mathrm{H}}^{+}$+${\mathrm{O}}_{2}^{\mathrm{\ensuremath{-}}}$ channel is found to dominate the small-angle stripping in ${\mathrm{O}}_{2}$. \textcopyright{} 1996 The American Physical Society.