SURFACE-INDUCED REACTIONS OF CLUSTER IONS

First results are presented from a new apparatus, consisting of a supe rsonic beam for generating neutral clusters, a variable energy electro n gun for ionizing the clusters, and a tandem mass spectrometer set-up for studying surface induced reactions of mass and energy selected cl uster ions. Rare gas cluster ions, fragment ions from SF6, benzene ion s and benzene cluster ions have been investigated so far. Cluster ion dissociation, intracluster ion molecule reactions and surface reaction s with adsorbed hydrocarbons have been shown to be important reaction channels for these ion-surface collision at energies ranging from a fe w eV to 500 eV. The surface induced fragmentation spectrum is demonstr ated to be a useful tool for probing binding energy and structure of c luster ions.