Nat. Commun. 9, 4025 (2018)

Serial femtosecond crystallography with ultra-intense X-ray pulses is one of the most promising analytical methods provided by large-scale free-electron lasers. The microsecond interpulse separation afforded by the recently launched European X-ray Free-Electron Laser was anticipated to offer new opportunities by reducing the beamtime and sample volumes required — but its viability was not clear. Now, Anton Barty and colleagues have realized a set-up capable of efficiently collecting high-quality diffraction patterns from small sample volumes.

Barty and colleagues exploited a custom-made version of a rapid full-frame detector and devised a novel high-speed jet to deliver and replenish the irradiated sample volume in the focal spot. They collected diffraction data from two different samples to benchmark their experiment at ångström resolution, demonstrating the ability to amass data from any member of the available megahertz X-ray pulse train. The unique method provides a key step toward future investigations of the temporal evolution of complex molecular structures.