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

100 picosecond X-ray snapshots visualizing the structural dynamics of macro molecular systems are now routinely available at synchrotron sources. A wea lth of fundamental processes in photochemistry, condensed matter physics an d biology, however, occur on considerably faster time scales. Standard expe rimental protocols at synchrotron sources cannot provide structural informa tion with faster temporal resolution as these are limited by the duration o f the electron bunch within the synchrotron ring. By walking the timing of femtosecond laser photolysis through a (much longer) X-ray pulse in steps o f a few picoseconds, structural information on ultrafast dynamics may be re trieved from a set of X-ray scattering images, initially through deconvolut ion and subsequently through refinement. This experimental protocol promise s immediate improvements in the temporal resolution available at synchrotro n sources, facilitating the study of a number of rapid complex photochemica l processes. Combined with techniques which reshape the X-ray probe pulse, the accessible temporal domain could further be extended to near-picosecond resolution.