Electron Capture to the Continuum at Asymptotically High Velocities

The velocity distrubutions of electrons ejected from gaseous He targets into the forward direction by 15-18 au velocity bare O, Ne and Ar nuclei are measured. The shape of the resulting ECC (electron capture to the continuum) cusps is studied in detail by three fitting methods and compared to theory. The results favor theoretical treatments which include higher-order ejected electron partial waves to describe the observed asymmetry.