At the heart of this thesis is the young field of free electron laser science whose
experimental and theoretical basics are described here in a comprehensible manner. Extremely
bright and ultra short pulses from short wavelength free-electron lasers (FELs) have recently
opened the path to new fields of research. The x-ray flashes transform all matter into highly
excited plasma states within femtoseconds while their high spatial and temporal resolution
allows the study of fast processes in very small structures. Even imaging of single molecules
may be within reach if ultrafast radiation damage can be understood and brought under
control.Atomic clusters have proven to be ideal model systems for light-matter interaction
studies in all wavelength regimes being size scalable easy-to-produce gas phase targets with
a simple structure. With FELs single cluster imaging and simultaneous ion spectroscopy makes
possible experiments under extremely well defined initial conditions because the size of the
cluster and the FEL intensity can be extracted from the scattering images. For the first time
large xenon clusters up to micron radius were generated. Their single cluster scattering images
were analyzed for cluster morphology and traces of the ultrafast plasma built-up during the
femtosecond FEL pulse. The simultaneously measured single cluster ion spectra yield
unprecedented insight into the ion dynamics following the interaction. The results will feed
both future experimental effort and theoretical modeling.
