Inelastic scattering of quasifree electrons on O7+ projectiles.

Absolute doubly differential cross sections (DDCS's) for the resonant inelastic scattering of quasifree target electrons on H-like projectiles have been measured. Electron spectra for 20.25-MeV ${\mathrm{O}}^{7+}$ projectiles on an ${\mathrm{H}}_{2}$ target were measured. The spectra contain a resonant contribution from the 3l3${\mathit{l}}^{\ensuremath{'}}$ doubly excited states of ${\mathrm{O}}^{6+}$, which decay predominantly to the 2l states of the ${\mathrm{O}}^{7+}$ via autoionization, and a nonresonant contribution from the direct excitation of the projectiles to the ${\mathrm{O}}^{7+}$(2l) state by the quasifree target electrons. Close-coupling R-matrix calculations for the inelastic scattering of free electrons on ${\mathrm{O}}^{7+}$ ions were performed. The relation between the electron-ion inelastic scattering calculation and the electron DDCS's for the ion-atom collision was established by using the inelastic scattering model (ISM). We found excellent agreement between the theoretical and measured resonant peak positions and relative peak heights. The calculated absolute double differential cross sections for the resonance processes are also in good agreement with the measured data. The implication is that collisions of highly charged ions on hydrogen can be used to obtain high-resolution, angle- resolved differential inelastic electron-scattering cross section. \textcopyright{} 1996 The American Physical Society.