DIFFRACTION STRUCTURES IN BINARY ENCOUNTER ELECTRON-SPECTRA - A DOMINANT FEATURE FOR PROJECTILES ABOVE CL AND A TOOL TO STUDY THE IONIZATION MECHANISM

The energy and angular distributions of electrons produced in collisio ns of about 0.3 MeV/u ions on H-2 have been measured over a broad rang e of projectiles (Cl, Cu and I) and observation angles (theta(L)) of 0 degrees to 70 degrees with respect to the beam direction. A double pe ak structure is observed in the binary encounter electron (BEe) region for projectiles heavier than Cl. This structure can be understood in the impulse approximation as elastic scattering of quasi free target e lectrons in the screened projectile potential. The angular distributio n of BEe production is investigated for different projectiles, and the violation of a q(2)-scaling is observed not only for 0 degrees but fo r the whole angular range covered.