FRAGMENTATION OF GOLD CLUSTERS STORED IN A PENNING TRAP

The collision-induced dissociation of positively charged gold clusters (2-23 atoms) stored in a Penning trap has been studied. After collisi ons with rare gases, excited clusters predominantly decay by emission of one or two atoms. The loss of two atoms occurs most probably throug h the emission of a dimer rather than by a sequential evaporation. The minimum kinetic energies of clusters required to induce dissociation exhibit a pronounced odd-even effect. Clusters with an even number of delocalized electrons are more stable than those with an odd number.