Deconvoluting ultrafast structural dynamics: temporal resolution beyond the pulse length of synchrotron radiation

100 picosecond X-ray snapshots visualizing the structural dynamics of macromolecular systems are now routinely available at synchrotron sources. A wealth of fundamental processes in photochemistry, condensed matter physics and biology, however, occur on considerably faster time scales. Standard experimental protocols at synchrotron sources cannot provide structural information with faster temporal resolution as these are limited by the duration of the electron bunch within the synchrotron ring. By walking the timing of femtosecond laser photolysis through a (much longer) X-ray pulse in steps of a few picoseconds, structural information on ultrafast dynamics may be retrieved from a set of X-ray scattering images, initially through deconvolution and subsequently through refinement. This experimental protocol promises immediate improvements in the temporal resolution available at synchrotron sources, facilitating the study of a number of rapid complex photochemical processes. Combined with techniques which reshape the X-ray probe pulse, the accessible temporal domain could further be extended to near-picosecond resolution.