Deviation of the binary encounter electron energy from simple conservation laws in ion-atom and in ion-solid collisions

Abstract We have measured electron energy spectra from fast (0.4–2.0 MeV/u) light projectiles (H + , He + , H + 2 , H + 3 , H 0 ) impinging on gaseous (He, Ar and Kr) and solid (C, Cu, Au, 600 A) targets under observation angles of 0° ⩽ Θ ⩽ 50° and Θ = 110°, 120°, 180°. Major interest was directed upon the position of the binary encounter and electron loss peaks, which are commonly assumed to follow simple kinematics. However, our measurements confirm recent results which show that the peaks are significantly shifted towards lower energies. For comparison we calculated double differential electron emission cross sections with different theoretical approaches.