Fragmentation of H2O Molecules by slow multiply charged Ions

We used the method of fragment ion spectroscopy to study ion-induced fragmentation of water molecules. An overview of our results for the energy and angular distribution of ionic fragments following the interaction with keV ions, ranging from 5 keV He2+ to 2 and 90 keV Ne9+, is presented. Specific attention is paid to the strong dependence on the projectile charge state and energy. The interpretation of the experimental results is guided by a classical trajectory simulation based on a Coulomb explosion model. In particular, the model elucidates the forward-backward asymmetry of the energy and intensity of the H+ fragments. The integrated cross-sections over all fragmentation channels, determined on the absolute scale, compare well with the cross-sections derived using the classical over-barrier model.