Evidence for dominance of longitudinal electron ejection in electron loss process

Electron transfer processes into the projectile's continuum were studied. According to the theoretical models the change of sign of the second expansion coefficient occurring in the series of the double differential cross section causes a drastic change in the shape of the spectrum: the cusp-shaped curve alters and a dip appears at the top of the peak. This predicted effect was established experimentally on 50-150 keV/u He+-He collision system, using coincidence method. (D.G.) 5 refs.; 1 fig