VALENCE AND INNER-SHELL SPECTROSCOPY ON RARE-GAS CLUSTERS

An overview of the present status of valence- and inner-shell spectros copy on rare-gas clusters is given. Fluorescence excitation, time-of-f light ion and photoelectron spectroscopy with synchrotron excitation w as used to study the electronic level structure of rare-gas clusters. Ne and Ar clusters covering the size range from the monomer up to a fe w thousand atoms/cluster are used as examples. Specific advantages and limitations of different methods of the study of electronic level str ucture as well as geometrical structure are discussed. A wealth of inf ormation on the evolution of electronic level structure has already be en obtained. Nevertheless, several interesting questions concerning th e evolution of energy-level shifts remain unresolved. Prospects for fu ture work and experimental developments are given.