We report absolute, state-selective cross sections for single-electron
capture by He-like ions (N5+, O6+, F7+, Ne8+) colliding on He which w
ere determined by vuv photon-emission spectroscopy. The impact energy
was varied between 0.05 and 2 keV amu(-1) The experimental data are co
mpared with theoretical predictions based on the classical overbarrier
model, the Landau-Zener model, and existing close-coupling calculatio
ns.