Observation of strong directional out-of-plane scattering in multiple ionising ion-atom collisions

The authors have measured the azimuthal ( phi p) and polar angle ( theta p) scattering distribution of projectiles in coincidence with recoil ions in charge states from 3+ to 8+ for the collision 0.53 MeV u-1 F8++Ne to F6++NeqR++(qR-2) e-. The coincident scattered particle distributions as a function of the azimuthal and polar angles phi p, theta p are obtained for different degrees of ionisation, ranging from one to six electrons ionised. Transverse projectile and recoil momenta have been experimentally determined. For a high degree of ionisation the authors observe strong deviations from two-body nuclear kinematics, i.e. for a given collision the resultant transverse momentum of all electrons emitted into the continuum increases with the number of ejected electrons and has a direction which is mostly not coplanar with the scattering plane.