Probing free xenon clusters from within

Inner-shell and valence-shell photoionization of van-der-Waals Xe clusters have been measured using both angle-resolved photoelectron spectroscopy and velocity map ion imaging technique. Both techniques have been used to probe the electronic properties and the fragmentation dynamics of clusters as a function of photon energy and cluster size. In particular, the evolution of the photoelectron angular distributions and partial cross sections as a function of photon energy and cluster size has revealed cluster size effects similar to the ones found in solids. Our cluster angular distribution parameters have been compared to the free atoms. In addition, the measurement of the fragmentation dynamic of the clusters seems to be photon energy dependent. (authors)