Collisions of highly charged ions with isolated water molecules: Orientation and alignment effects

Studies on low energy ion molecule collisions are an area of much contemporary interest. The kinetics and dynamics of molecules interacting with slow highly charged ions provide an interesting test bench for theoretical many-body calculations, as well as provide information for processes in many natural as well as man-made plasma environments. We have studied the multiple ionization and resultant Coulomb explosion induced dissociation of isolated water molecules on impact of Xe9+ ions with 450 keV total energy and present here the angular distribution of recoil fragment momentum vectors with respect to the incoming projectile direction. From these measurements, made in multi-particle coincidence mode, we note that there is a strong forward-backward asymmetry in the D+ and Oq+ fragments, indicating strong alignment and orientation effects.