SEARCH FOR INELASTIC ELECTRONS SCATTERED OFF IONS IN ENERGETIC ION-ATOM COLLISIONS

The collision of target electrons with ionic projectiles, in highly as ymmetric ion-atom collisions, can be simulated within the impulse appr oximation (IA) by a beam of electrons scattering off the projectile io n, with a collision energy broadened by the momentum distribution (Com pton profile) of the target. This description works particularly well for 180 degrees elastic scattering of target electrons off the ion (Ph ys. Rev. A 41 (1990) 4816 [1]) appearing in the laboratory as the well known binary encounter electron peak. Inelastic processes due to targ et-electron-projectile-electron interactions (e-e) such as e-e excitat ion (Phys. Rev. Lett. 62 (1989) 2261 [2]) and e-e ionization (Phys. Re v. Lett. 63 (1990) 1938; J. Phys. B 24 (1991) 977; Phys. Rev. A 46 (19 92) 1374; Phys. Rev. Lett. 69 (1992) 3033, 72 (1994) 3170, 72 (1994) 3 166 [3-8]) are also well documented. However, for these processes, the target electron undergoing inelastic scattering has never been explic itly identified and measured in ion-atom collisions. A simple theoreti cal Born-IA treatment gives the expected double differential cross sec tions and their angular distributions for H-like ions in collision wit h H-2 targets. The viability of observing these effects in ion-atom co llisions by electron spectroscopy is investigated.