Site-Specific Excitation in Free Krypton Clusters

Site-specific excitation in Kr clusters is investigated by high resolution inner-shell excitation in combination with model calculations, which are based on a core exciton model. Partial cation and total electron yield spectra of variable size Kr clusters are reported for the Kr3d excitation regime (90--96 eV) using synchrotron radiation. A cluster size-dependent spectral evolution is observed, corresponding to the transition from low lying cluster Rydberg states into surface and bulk exciton states. The results indicate that individual sites in perfectly and imperfectly shaped clusters are clearly distinguished.