Impact-parameter dependence of the electron-electron interaction in (Li2+,C5+)+(H2,He) electron loss.

Abstract

We have measured the scattering-angle dependence of electron loss in 1.1-MeV/u ${\mathrm{Li}}^{2+}$+(${\mathrm{H}}_{2}$,He) and 0.88-, 2.0-, and 3.1-MeV/u ${\mathrm{C}}^{5+}$+(${\mathrm{H}}_{2}$,He) collisions and have attempted to extract the impact-parameter dependence of electron loss, as well as to separate the elastic (screening) and inelastic (antiscreening) target-electron contributions to this process. By dividing the experimental electron-loss probability by the (resolution folded) theoretical probability for screening only, we show that a separation can be effected. For ${\mathrm{Li}}^{2+}$+${\mathrm{H}}_{2}$ and ${\mathrm{C}}^{5+}$+${\mathrm{H}}_{2}$ the experimental loss probability is in good agreement with expressions derived from the straight-line and Coulomb trajectory approximation, but with the He target deviations can be seen, especially at lower bombarding energies. This contrasts with integrated cross sections which fit equally well in all cases.