3D IMAGING OF THE COLLISION-INDUCED COULOMB FRAGMENTATION OF WATER-MOLECULES

The multiple ionization and fragmentation of H2O by fast H+ and He+ ions was studied using a position- and time-sensitive multiparticle detector. By the coincident measurement of correlated fragment momenta a complete three-dimensional image of the breakup process can be obtained for each individual event. Of special interest is the process H2OH++H++O+ where a simple Coulomb explosion model is insufficient to explain the measured fragmentation energies and angular correlations. Better agreement is achieved with ab initio multiconfiguration self-consistent field calculations of the intermediate H2O3+ parent ion. © 1995 The American Physical Society.