The European X-Ray Free-Electron Laser Facility is an X-ray research laser facility commissioned during 2017. The first laser pulses were produced in May 2017 and the facility started user operation in September 2017. From Wikipedia
The experiment leveraged ultrafast X-ray Coulomb Explosion Imaging at the European XFEL to validate quantum predictions of coordinated atomic vibrations, opening the way to electron dynamics studies alongside applications in larger molecular systems.