Ion interactions with pure and mixed water clusters

We report on collisions of highly charged Xe²⁰⁺ ions with weakly bound clusters of water molecules and water/adenine mixtures. Singly and doubly charged water clusters are observed in the size range of n=1 to 65 and n=49 to 61, respectively. In contrast to other comparable systems, the dominant monomer fragment (H₃O⁺) is formed with very low kinetic energy, hence indicating that it is formed by evaporation processes. Larger fragments are produced with larger kinetic energies due to charge-separating processes. Furthermore, water clusters are found to be protonated, only a very small amount of the non protonated dimer (H₂O)₂⁺ is observed. Excited mixed adenine/water clusters fragment by the loss of the surrounding water molecules, thus, adenine fragments are formed without water molecules attached. In addition, the adenine monomer is found to be partly protonated.