Fs. Joras et al., ELECTRON-EMISSION FROM BINARY COLLISIONS WITH Z(PROJECTILE)LESS-THAN-OR-EQUAL-TO-Z(TARGET), Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 124(2-3), 1997, pp. 327-330
We have measured doubly differential cross sections for electron emiss
ion in ion-atom collisions. In one set of experiments, 0.5 MeV/u He2projectiles impinged on the target atoms He, Ne, Ar, Kr and Xe and mol
ecules N-2 and O-2; in another set, H+ (energy ranging from 2.0 to 6.0
MeV) and 0.75 MeV/u Nq+ (q = 2-7) collided with Ar targets. In both c
ases, emitted electrons were observed under 0 degrees. Major interest
was directed upon the position of the Binary Encounter Peak, which is
commonly assumed to follow a simple kinematic model. Surprisingly the
peak is significantly shifted towards lower energies. For comparison w
e calculated spectra with the Plane Wave Born Approximation and the Pl
ane Wave Approximation. These do not show in general good agreement wi
th our experimental data, presenting large discrepancies not only in a
bsolute values but also in the behaviour with the target atomic number
.