PHOTO FRAGMENTATION OF METAL-CLUSTERS STORED IN A PENNING TRAP

Photo fragmentation studies of stored mass selected metal cluster ions of a large size range are reported. The experimental method and the d ata evaluation are described in detail. Gold cluster ions were produce d by laser vaporization and stored in a Penning trap. After size selec tion they were electronically excited by irradiation with a pulsed las er beam. Relaxation by evaporation of neutral atoms and dimers was obs erved as a function of photon energy. From these data upper and lower limits for dissociation energies are determined for Au-n(+) (n = 3 to 23).