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.