Ultra-bright short (<100 fs) pulses of spatially coherent x-ray radiation are expected to produce a variety of results in atomic, molecular, condensed matter and soft-condensed matter science; a partial realization of this promise is already evident from FLASH experiments. Results on ultra-high intensities photoionization of atoms already offer puzzling results  and the same is true for clusters ; novel techniques emerge for diffraction imaging .
The progress towards wavelengths comparable to interatomic distances opens the way to ultrafast structural studies, where atomic motions during photoinduced reactions or phase transformations can be achieved by pump-probe techniques. Early attempts using presently existing sources show the wealth of information and the potential to explore Franck Condon diagrams directly, accessing regions of conical intersections and non-adiabatic regimes [4,5]
(Université Claude Bernard Lyon 1)