Fluorescence spectroscopy of silver clusters formed in rare gas droplets

The Pick Up technique allows continuous formation of high density metal cluster beams in the otherwise hardly accessible size range Me2 to about Me50. With an apparatus based on the use of cryo-condensation pumps, Ar as inert gas for production of the host clusters by adiabatic expansion and silver as metal we demonstrate how the various source parameters influence the composition and mean size of the resulting cluster distributions. The analysis in the gas phase by means fluorescence spectroscopy allows to conclude that an Ar shell encapsulates the metal clusters.