Europe’s x-ray laser fires up to help scientists to make molecular movies

Scientists who make movies of molecules in motion have a new high-speed camera to shoot with. The €1.2-billion (US$1.4-billion) European X-ray Free Electron Laser (XFEL) will start running its first experiments in September near Hamburg, Germany.   The European XFEL fires powerful X-rays in bursts of a few hundred femtoseconds: so short that, like strobe lights, they can capture snapshots of jittery molecules frozen in time, and with a wavelength small enough to provide pictures at atomic resolution. The Hamburg machine is one of a few such X-ray lasers worldwide, but boasts a unique rapid-fire feature: it can rattle off 27,000 pulses every second, a firing rate more than 200 times greater than the next-fastest facility, the $420-million Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory in Menlo Park, California. “It’s such a different beast to anything else on the planet that it really feels like going into uncharted territory,” says Arwen Pearson, a biochemist at the Centre for Free-Electron Laser Science in Hamburg.