Measuring and understanding ultrafast phenomena using X-rays

Within the last decade, significant advances in X-ray sources and instrumentation as well as simultaneous developments in analysis methodology has allowed the field of fast- and ultrafast time-resolved X-ray studies of solution-state systems to truly come of age. We here describe some aspects of the physics involved as well as the experimental methodology that have facilitated this development.

Building on this foundation, we discuss how the information-poor, but time-resolved (difference) scattering signals can be analyzed in a quantitative model-comparison framework to provide robust information on sub-Ångstrom structural changes taking place on femtosecond to nanosecond time scales. We illustrate this approach by a presentation of recent results from the Centre for Molecular Movies at the Technical University of Denmark.